FINAL EIA REPORT - Welcome to...

142 IDA, Phase-II, Cherlapally, Hyderabad–500 051

[email protected], www.vimta.com

(NABET - QCI Accredited, NABL Accredited & ISO 17025 Certified Laboratory,

Recognized by MoEF, New Delhi)

Prepared by :

November, 2016

Sponsor :

M/s. Oil and Natural Gas Corporation Ltd.Assam & Assam Arakan Basin, Cinnamara, Jorhat – 785 704

ENVIRONMENTAL IMPACT ASSESSMENT STUDIES FOR

THE PROPOSED DRILLING OF 3 EXPLORATORY DRILLING WELLS IN

EXISTING NELP BLOCK AA-ONN-2001/2 KOLASIB AND

MAMIT DISTRICT, MIZORAM

FINAL EIA REPORT

M/s. Oil and Natural Gas Corporation Ltd. Assam & Assam Arakan Basin,

Cinnamara, Jorhat – 785 704


THE PROPOSED DRILLING OF 3 EXPLORATORY DRILLING WELLS IN EXISTING NELP

BLOCK AA-ONN-2001/2 KOLASIB AND MAMIT DISTRICT, MIZORAM

For and on behalf of VIMTA Labs Limited

Approved by : M. Janardhan

Signature :

Designation : Head & Vice President (Env)

Date : 30th November, 2016

The report has been prepared inline with the prescribed TOR’s issued vide No.

F.No.J-11011/305/2014-IAII(I) dated 6th January 2016 of Ministry of Environment

and Forests, New Delhi.

This report has been prepared by Vimta Labs Limited with all reasonable skill,

care and diligence within the terms of the contract with the client,

incorporating our General Terms and Conditions of Business and taking

account of the resources devoted to it by agreement with the client.

PREFACE

of 3

DECLARATION

Declaration by Experts Contributing to Environmental Impact Assessment Report for Proposed

Drilling of 3 Exploratory Drilling wells in Existing NELP Block AA-ONN-2001/2, Kolasib & Mamit

District, Mizoram

I, hereby, certify that I was a part of the EIA team in the following capacity that developed

the above EIA.

EIA Coordinator:

Name: Dr. B. Chandra Sekhar

Signature & Date: 2016/11/21

Period of Involvement: January 2016 to March 2016

Contact Information: 040-27264141

Functional Area Experts:

Sr.

No.

Functional

Areas Name of the

Expert/s

Involvement Signature & Date

Period Task

1 AP M. Janardhan Jan 2016 to

Nov 2016

Selected AAQ stations based

on IMD data. Identified the

sources of pollution and

suggested mitigation

measures and management

plan.

2 WP Bh. Durga

Bhavani Jan 2016 to

Nov 2016

Identified the wastewater

streams and effective

treatment measures are

suggested.

3 SHW M. Janardhan Jan 2016 to

Nov 2016

Effective solid waste

management for the entire

project is suggested

4 SE Ch.

Venkatesham

Jan 2016 to

Nov 2016

Social changes arising due to

the project has been

assessed.

5 EB Rajashekar

Tummala

Jan 2016 to

Nov 2016

Conducted primary survey in

the study area

6 HG J Rajendra

Prasad

Jan 2016 to

Nov 2016

Reviewed secondary data

7 NV M. Janardhan Jan 2016 to

Nov 2016

Suggested suitable mitigation

measures for construction

and operation phases

8 AQ Dr. B. Chandra

Sekhar

Jan 2016 to

Nov 2016

Quantified the emissions

using AERMOD. Suggested

Management Plan.

of 3

Sr.

No.

Functional

Areas Name of the

Expert/s


Period Task

9 GEO Dr. V. K.

Bhatnagar Jan 2016 to

Nov 2016

Reviewed the secondary

data

10 LU Dr. Y Rama

Mohan Jan 2016 to

Nov 2016

Present land use pattern as

per satellite imagery has

been studied and presented.

11 RH Rajgopal

Krishnan Jan 2016 to

Nov 2016

Identified the hazards and

recommended the suitable

measures

12 SC B. S. Lole Jan 2016 to

Nov 2016

Identified the impacts and

suggested suitable impacts

Other Associates involved in EIA Report preparation:

Sr.

No

Functional

Areas

Name of the

Expert/s


Period Task

1 AP M Raja Manohar Jan 2016 to

Nov 2016

Involved in Air

quality monitoring

2 AQ

M Raja Manohar Jan 2016 to

Nov 2016

Assisted in

developing

meteorological

data for modeling

3 NV M Raja Manohar Jan 2016 to

Nov 2016

Involved in noise

modeling

4 RH K.S. Vishu Teja Jan 2016 to

Nov 2016 Identified the

hazards

5 SE Narendra C Jan 2016 to

Nov 2016

Prepared the

demographics as

per 2011 census

of 3

DECLARATION BY THE HEAD OF THE

ACCREDITED CONSULTANT ORGANIZATION/AUTHORIZED PERSON

I, M. Janardhan, hereby, confirm that the above mentioned experts prepared the

Environmental Impact Assessment studies for the proposed drilling of 8 exploratory wells in

PML areas of NAS block in Sibsagar district, Assam.

I also confirm that the consultant organization shall be fully accountable for any misleading

information mentioned in this statement.

Signature:

Name : M. Janardhan

Designation : Head & Vice President

Name of the EIA Consultant Organization: Vimta Labs Limited, Hyderabad

NABET Certificate No. & Issue Date: NABET/EIA/1316/RA003

Environmental Impact Assessment Report for Proposed drilling of 3 Exploratory Drilling wells in Existing NELP Block AA-ONN- 2001/2, Kolasib & Mamit District, Mizoram

Table of Contents

VIMTA Labs Limited, Hyderabad TC-1

Table of Contents ________________________________________________________________ Chapter Title Page ________________________________________________________________

Table of Contents TC-1 List of Figures TC-4 List of Tables TC-5 1.0 Introduction 1.1 Purpose of the Report C1-1 1.2 Identification of Project & Project Proponent C1-1 1.3 Brief Description of the Project C1-2 1.4 Scope of the Study C1-13 2.0 Project Description 2.1 Introduction C2-1 2.2 Type of the Project C2-1 2.3 Need for Exploratory Drilling C2-1 2.4 Project Location and Layout Details C2-1 2.5 Size or Magnitude of Operation C2-3 2.6 Proposed Schedule for Project Approval and

Implementation C2-9 2.7 Technology and Drilling Process Description C2-9 2.8 Details of Project Utilities C2-12 2.9 Post Drilling Operations – Abandonment and Restoration C2-17 2.10 Sources of Pollution C2-18 2.11 Qualifications, Skills and Training Practice C2-22 3.0 Baseline Environmental Status

3.1 Introduction C3-1 3.2 Geology and Hydrogeology C3-1 3.3 Landuse Studies C3-7 3.4 Soil Characteristics C3-13 3.5 Meteorology C3-17 3.6 Ambient Air Quality C3-29 3.7 Water Quality C3-35 3.8 Noise Level Survey C3-41 3.9 Ecological Studies C3-44 3.10 Demographic and Socio-economics C3-59

4.0 Impact Assessment and Mitigation Measures 4.1 Impact Assessment C4-1 4.2 Anticipated Impacts from the Project C4-2 4.3 Environment Management Plan C4-23 4.4 Monitoring Environmental Performance C4-30 4.5 Emergency Response and Contingency Planning C4-31


Table of Contents


Table of Contents (Contd.) ________________________________________________________________ Chapter Title Page ________________________________________________________________

4.6 Waste Management Plan C4-37 4.7 Drilling Site Restoration Plan C4-38 5.0 Analysis of Alternatives 5.1 Alternative for Technology C5-1 5.2 Alternatives for Project site C5-1 6.0 Environmental Monitoring Programme 6.1 Introduction C6-1 6.2 Environmental Monitoring and Reporting Procedure C6-1 6.3 Reporting Schedule of the Monitoring Data C6-3 6.4 Infrastructure for Monitoring of Environmental Protection Measures C6-3 6.5 Environmental Costs C6-4 6.6 Audit and Review C6-4

7.0 Additional Studies 7.1 Public Consultation C7-1

7.2 Risk Assessment C7-13 7.3 Recommendations to Mitigate Risk/Hazards C7-23 7.4 Disaster Management Plan C7-24 7.5 Emergency Response Action C7-30 7.6 Emergency Response Procedures C7-31 7.7 End of Emergency C7-48 7.8 Communications C7-49

8.0 Project Benefits 8.1 Improvement in the Physical Infrastructure C8-1 8.2 Improvement in the Social Infrastructure C8-1 8.3 Employment Potential C8-2 9.0 Administrative Aspects

9.1 Operational Philosophy C9-1

9.2 Health Safety and Environment C9-2 9.3 Environmental Organization and Personnel C9-4


Table of Contents


Table of Contents (Contd.) ________________________________________________________________ Chapter Title Page ________________________________________________________________

10.0 Summary and Conclusion

10.1 Location Details of the Project C10-1 10.2 Importance of the Proposed Project C10-1 10.3 Details of Exploration Drilling Operations C10-1 10.4 Baseline Environmental Status C10-2 10.5 Impact Assessment C10-4 10.6 Environment Management Plan C10-6 10.7 Environmental Monitoring Program C10-8 10.8 Risk Assessment and Disaster Management Plan C10-8 10.9 Project Benefits C10-8 10.10 Administrative Aspects C10-9 10.11 Conclusions C10-9

11.0 Disclosure of Consultants

11.1 Introduction C11-1 11.2 Vimta Labs Limited C11-1

List of Annexures

Annexure-I Terms of Reference Letter and Compliance Annexure-II Applicable Environmental Standards Annexure-III Methodology for Sampling and Analysis Annexure-IV Land use Pattern Annexure-V Ambient Air Quality Levels Annexure-VI Demographic Details Annexure-VII Emission Calculations Annexure-VIII Public Hearing Details Annexure-IX Pool Fire Calculations Annexure-X Secondary Data for Risk Analysis Annexure-XI CSR Expenditure Annexure-XII Corporate Environment Policy


Table of Contents


List of Figures ________________________________________________________________ Figure Title Page ________________________________________________________________

1.1 Index Map C1-4 1.2 Topographic Map NAS Block in Kolasib & Mamit District C1-5

1.3 Google Map Showing Well Locations in NELP Block C1-6 1.4 Topographic Map HOAC Well – 10 km radius C1-7 1.5 Topographic Map HOAD Well – 10 km radius C1-8 1.6 Topographic Map BRBAA Well – 10 km radius C1-9 2.1 Typical Layout of Well Site C2-6 2.2 Drilling Rig C2-11 2.3 Drilling Fluid Circulation System at Typical Rig C2-16 2.4 Typical Section View of Drilling Cut and Drill Mud

Collection Pit C2-21

3.2.1 Hydrogeology Map of Kolasib District C3-5 3.2.2 Hydrogeology Map of Mamit District C3-6 3.3.1 Satellite Imagery of the Study Area C3-11 3.3.2 Landuse Pattern Based on Satellite Data C3-12 3.4.1 Soil Sampling Locations C3-14

3.4.2 Soil Sampling Photographs C3-15 3.5.1 IMD Agartala – Pre Monsoon Season C3-22 3.5.2 IMD Agartala – Monsoon Season C3-23

3.5.3 IMD Agartala – Post Monsoon Season C3-24 3.5.4 IMD Agartala – Winter Season C3-25 3.5.5 IMD Agartala- Annual Wind rose C3-26 3.5.6 Site Specific Windrose Winter Season C3-28 3.6.1 Air Quality Sampling Locations C3-32 3.6.2 Air Monitoring Photographs C3-33 3.7.1 Water Sampling Locations C3-36 3.7.2 Water Sampling Photographs C3-37 3.8.1 Noise Monitoring Locations C3-42 3.8.2 Noise Monitoring Photographs C3-43 3.9.1 Ecological Sampling Locations C3-47 4.1 Short Term 24 hourly GLCs of SO2 C4-10 4.2 Short Term 24 hourly GLCs of NOx C4-11 4.3 Noise Level Contours C4-19

7.1a Notice for Public Hearing – Times of India C7-2 7.1b Notice for Postponement of Public Hearing C7-3 7.2 Photographs showing Public Hearing C7-5 7.3 Objectives of Risk Assessment C7-16 7.4 Methodology of MCA Analysis C7-17 7.3 Flow Chart for Evaluation of Consequences of Release of Flammable or Toxic Chemical C7-20 7.4 Emergency Classification C7-26 7.5 Contingency Plan for Onshore Blowout (Drilling Rig) C7-32 7.6 Typical Schematic of BOP Stack C7-35 9.1 Organizational Structure for Environmental Management C9-6


Table of Contents


List of Tables

Tables Title Page

1.1 Block Coordinates C1-3 1.2 Tentative Well Locations C1-3 1.3 Environmental Setting of Well HOAC (10 Km Radius) C1-10 1.4 Environmental Setting of Well HOAD (10Km Radius) C1-11 1.5 Environmental Setting of Well BRBAA (10 Km Radius) C1-12 1.6 Environmental Attributes and Frequency of Monitoring C1-15 2.1 Block Co-ordinates C2-2 2.2 Tentative Well Locations C2-2 2.3 Salient Features of the Proposed Exploratory Drilling in NELP Block of Mizoram C2-4 2.4 Water Requirements per Well Site C2-5 2.5 Details of DG Sets C2-7 2.6 Constituents of Water Based Mud (WBM) C2-7 2.7 Special Additives and Their Functions in Water Based Mud C2-8 2.8 Composition and Parameters of Water Based Drilling Mud C2-8 2.9 Hole Size and Casing Details C2-10 3.2.1 The Dynamic Groundwater Resources as on 31.03.2011 C3-7 3.3.1 Landuse /Land Cover Classification System C3-8 3.3.2 Land Use Break Up of the Study Area C3-10 3.4.1 Details of Soil Sampling Locations C3-13 3.4.2 Soil Analysis Results C3-16 3.4.3 Standard Soil Classification C3-17 3.5.1 Sensitivity of Meteorology Monitoring Equipment C3-18 3.5.2 Climatological Data Station IMD, Agartala C3-19 3.5.3 Summary of the Meteorological Data Generated at Site C3-27 3.6.1 Details of Ambient Air Quality Monitoring C3-30 3.6.2 Summary of Ambient Air Quality Results C3-34 3.7.1 Details of Water Sampling Location C3-35 3.7.2 Surface Water Quality C3-39 3.7.3 Ground Water Quality C3-40 3.8.1 Details of Noise Monitoring Location C3-43 3.8.2 Noise Levels in the Study Area C3-44 3.8.3 Ambient Noise Standards C3-44 3.9.1 Forest Blocks within Study Area C3-46 3.9.2 Details of Proposed Oil Drilling Locations C3-46 3.9.3 Details of Terrestrial Ecological Sampling Locations C3-46 3.9.4 List of Agricultural Crops C3-48 3.9.5 Details of Aquatic Sampling Locations C3-57 3.9.6 List of Phytoplankton Species Identified from Study Area C3-58 3.9.7 List of Zooplankton Species Identified from Study Area C3-58


Table of Contents


List of Tables (Contd…)

Tables Title Page

3.10.1 Distribution of Population in the study area C3-59 3.10.2 Distribution of Population by Social Structure C3-60 3.10.3 Distribution of Literate and Literacy Rates C3-60 3.10.4 Occupational Structure C3-62 4.1 Summary of Impact Assessment: Soil and Landuse C4-4 4.2 Details of DG Sets C4-7 4.3 Emission Characteristics – Model Inputs C4-8 4.4 Predicted 24 Hourly Short Term Incremental Concentration C4-8 4.5 Resultant Concentrations due to Incremental GLC’s C4-9 4.6 Summary of Impact Assessment: Water Resources C4-15 4.7 Input Data for Noise Modeling C4-17 4.8 Predicted Noise Levels C4-18 4.9 Noise Exposure Levels & Its Effects C4-18 4.10 Summary of Impact Assessment: Flora and Fauna C4-21 4.11 Summary of Environmental Management Actions C4-32 6.1 Schedule of Environmental Monitoring C6-2 7.1 Action Plan for Issues raised by Participants during Public Hearing C7-7 7.2 List of Major Hazards C7-14 7.3 Occupational Hazards C7-15 7.4 Damage due to Peak over Pressure C7-18 7.5 Damage due to Incident Radiation Intensities C7-18 7.6 Input Data for Consequence Analysis C7-19 7.7 Summary of Consequence Analysis for Jet Fire Scenario at Well C7-21 7.8 Probability of Ignition for Leaks of Flammable Fluids C7-22 7.9 The Adnoc Individual Risk Assessment Criteria C7-22 7.10 Recommendations to Mitigate Blow out Risk/Hazards C7-23





Prepared by :

November, 2016

Sponsor :

M/s. Oil and Natural Gas Corporation Ltd.Assam & Assam Arakan Basin, Dhansiri Bhavan,

Cinnamara, Jorhat - 785704





EXECUTIVE SUMMARY

Environmental Impact Assessment Report for Proposed Drilling of 3 Exploratory Drilling wells in Existing NELP Block AA-ONN-2001/2, Kolasib & Mamit District, Mizoram

Executive Summary

VIMTA Labs Limited, Hyderabad ES-1

1.0 EXECUTIVE SUMMARY

Oil and Natural Gas Corporation Limited (ONGC) proposes to carryout

exploratory drilling in on-shore Block AA-ONN-2001/2 at Kolasib & Mamit District,

Mizoram.

The NELP block AA-ONN-2001/2 in the state of Mizoram measuring 5340 sqkm

was awarded to ONGC-IOC (80% and 20% PI) consortium with ONGC as

Operator. After fulfillment of MWP in Phase-I & -II, ONGC entered into phase-III

w.e.f 08.04.2013 by relinquishing an area of 1345 sqkm as per PSC norms after

retaining an area of 2660 sqkm. In current exploratory Phase-III, the Operator

ONGC has to drill one well to fulfill MWP commitment. In addition to one MWP

well, ONGC proposes to drill additional exploratory wells to assess hydrocarbon

potentiality of the entire block.

As per the Environment Impact Assessment (EIA) Notification dated 14th

September, 2006, the proposed exploratory drilling project falls under ‘Category

A’ of Activity Type 1(b). The EIA Report is prepared considering the TOR received

from MoEF vide letter. No. J-11011/305/2014-IA II (I) dated 6th January, 2015.

The present project proposal deals with exploratory drilling of 3 wells in AA-ONN-

2001/2 onshore block covering in Kolasib & Mamit District, Mizoram. The

exploratory drilling well locations have been identified in Kolasib & Mamit district

based on the basis of 2-D and 3-D seismic study.

The present EIA report describes the proposed exploratory drilling wells identified

in block AA-ONN-2001/2 and its impacts and mitigation measures for the same.

1.1 Project Description

1.1.1 Location Details of the Project

The block is located in the Kolasib & Mamit District, Mizoram. Out of the proposed

3 exploratory drilling wells, 2 exploratory drilling wells falls in Kolasib district and

1 exploratory drilling wells in Mamit district, Mizoram.

Elevation of the block varies from 400 m to 2000 m. Tentative well coordinates

are given below:

Sr.

No.

Proposed

Location

Latitude Longitude Nearest Village District

1 HOAC 240 12’ 14.24” 920 35’ 53.32” North of Medium Kolasib

2 HOAD 240 09’ 41.42” 920 36’ 13.31” South of Medium Kolasib

3 BRBAA 240 07’ 10.08” 920 31’ 06.77” South of Sauhliap Mamit

The Topo map of the block area, depicting the salient features is shown in

Figure-1. The details of environmental setting of the project block area are given

below.

� There is one reserve forests block (within Inner line forest reserve) and no Wild life sanctuary in the study area.

� The major water bodies in the project block area cover Tlawng river.


Executive Summary


� The project block is connected through National Highways NH-154 and Bairabi Railway station to rest of the region;

� No archaeologically important places are present within project block as per Archaeological Survey of India (ASI) records; and

� The block area falls under Seismic Zone–V as per IS: 1893 (Part-1) 2002.

1.1.2 Importance of the Proposed Project

India is not among the major producers of crude oil, as it doesn’t have much oil

reserves. Therefore, India generally depends on imports of crude oil from other

countries. There is a heavy imbalance between oil production and consumption in

India. The Indian government is encouraging exploration and production of oil

and gas to a great extent. This would primarily allow India to tap its own

resources there by reducing its import bill.

Discovery of viable hydrocarbon reserves in the state can boost the state’s

economic development to a great extent. The proposed exploration project is thus

of immense significance for the state.

1.1.3 Details of Exploration Drilling Operation

It is proposed to drill exploratory and appraisal wells in the delineated area

selected through seismic survey to identify and establish hydrocarbon potential.

The proposed project intends to identify the presence of hydrocarbon prospects

through exploratory drilling and to delineate and quantify hydrocarbon pools in

discovered fields through appraisal drilling. The wells will be drilled upto a target

depth of about 4400 m by using water-based drilling mud only.


Executive Summary


FIGURE-1

TOPO-MAP OF AA-ONN-2001/2 BLOCK


Executive Summary


1.1.4 Infrastructure Requirement

Project Cost: The estimated cost of the proposed exploratory & development

drilling planned to be carried out is Rs. 200 Crores for 3 well.

Land Requirement: Minimum land required at each well site during drilling will be

125 m x 125 m, i.e., 1.56 ha. On an average, the land requirement at each well

site, including site facilities and camp site is considered as 1.5-2.0 ha. The 2.5 ha

land will be acquired on a temporary basis and adequate compensation as per the

guidelines of local administration will be provided.

Power Requirement: The total power requirement at the drilling site will be 2250

KVA. The power requirement in the drilling site will be catered through Diesel

Generator (DG) sets. The power requirement will be met by 3 Nos of 750 KVA DG

sets at drilling site. Stand by DG set arrangement of 750 KVA at drilling site will be

made.

Water Requirement: Water is basically required for preparing drilling mud and for

meeting domestic needs of the campsite. Typically, the water consumption for each

well ranges from 25 m3/day for a period of 4 to 5 months. However, the drilling and

domestic water requirement would depend on the time required to drill the well,

which is primarily dependent on the proposed depth.

Man Power: The drill site construction would be done largely employing local

labour. At each drill site construction, local employment will be generated for

about 25 person/shift of 12 hrs in two shifts.

1.2 Description of the Environment

Environmental baseline data survey has been carried within the entire AA-ONN-

2001/2 block, during 15th January 2016 to 8th April 2016, covering partly winter

and partly pre-monsoon season.

1.2.1 Land Use Studies

The land use pattern of the total AA-ONN-2001/2 block has been studied by

District Census Hand Books and satellite images. It is observed that 4.6 % of the

land falls under crop land. On the other hand, 80.1 % of land falls under

wastelands area. The water bodies contribute about 10.4 % area falls under

Reservoir/River etc.

1.2.2 Soil Quality

The soil samples were tested at 10 locations during winter season covering

various land uses. It has been observed that the pH of the soil ranged from 7.11

– 8.08 indicating that is slightly alkaline to moderately alkaline in nature. The

electrical conductivity was recorded as 118.2 µS/cm to 262.0 µS/cm. The organic

carbon content in the study area observed as 0.31 % to 0.62 %, which the soil

falls under average sufficient to more than sufficient. The potassium values

ranged between 86.6 to 172.0 kg/ha. The phosphorus values ranged between

13.5 to 88.6 kg/ha. The nitrogen values ranged between 31.5 – 69.7 kg/ha.


Executive Summary


1.2.3 Meteorology

On-site monitoring was undertaken for various meteorological variables in order

to generate the site-specific data. The meteorological data generated at the

monitoring site when compared with the data recorded at nearest IMD station

located at Agartala, it is observed that the data generated at the site is broadly in

comparison with regional meteorology, except for minor variations.

1.2.4 Ambient Air Quality

To establish the baseline status of the ambient air quality in the study area, the air

quality was monitored at 10 locations during partly winter and partly pre-monsoon

season of 2016. Out of the ten locations the minimum and maximum concentration

for PM10 and PM2.5 were varied between 37.7 to 46.0 µg/m3 and 11.6 to 15.8 µg/m3

respectively during the study period. The concentrations of SO2 and NOx were

varied between 7.9 to 15.0 µg/m3 and 11.0 to 17.3 µg/m3 respectively. All ambient

air quality locations the PM2.5 levels recorded are within the prescribed standards

for Residential and Industrial areas. The minimum and maximum concentration for

total hydrocarbons, methane hydrocarbons and non-methane hydrocarbons during

the study period were observed as 101 to 166 µg/m3, 50 to 95 mg/m3 and 40 to 96

mg/m3 respectively. The concentrations of VOCs were below the detectable limits in

all the locations during the study period. From the analysis of the monitored data,

it infers that the air quality levels in the study area are of fairly good quality and

comply with the National Ambient Air Quality Standards.

1.2.5 Water Quality

The baseline water quality status in the region is established by analyzing about 6

ground water samples and 4 surface water samples during study period. The

physico-chemical and biological analysis revealed that most of the parameters in

ground and surface water samples are well within the prescribed limits of IS:

10500 limits.

1.2.6 Ambient Noise Levels

The noise monitoring has been conducted at 10 locations, covering residential,

commercial and silence zones in the study area. A review of this data indicates that

at all the locations, the noise level was found within the permissible limits of CPCB.

1.2.7 Ecological Environment

An ecological survey in the study area was conducted particularly with reference to

the listing of species and assessment of the existing baseline ecological (Terrestrial

and Aquatic ecosystem) conditions in the study area. There are no reserved forest

and national park present inside the block area.

Dampa Tiger Reserve – Wildlife Sanctuary is located, near the block of BRBAA at

about distance of 59.5 Km /SSW direction, covering a large part of Mamit district,

in which block study area is covered, is endowed with wide variety of flora and

fauna in the area.


Executive Summary


1.2.8 Socio-Economic Environment

The configuration of male and female indicates that the males constitute about

49.86% and females to 50.14% of the total population as per 2011 census

records. The study area on an average has 1006 females per 1000 males.

In the study area, as per 2011 census, 0.17% of the population belongs to

Scheduled Castes (SC) and 91.54% to Scheduled Tribes(ST).

The percentage of male literates to the total literates of the study area works out

to be 50.13%. The percentage of female literates to the total literates, which is

an important indicator for social change, is observed to be 49.87% in the study

area as per 2011 census records. Total work participation in the project study

areas is 41.78% and the non-workers constitute 58.22% of the total population

respectively.

1.3 Anticipated Environmental Impacts

The identification and assessment of impacts over the various environmental

attributes in the region due to the proposed exploratory drilling activities in the

project block have been discussed followed by mitigative measures and

environmental management plan for the potential impacts due to the proposed

project activities.

The proposed exploratory drilling activities will last for 4 to 5 months and hence

the impact due to the project are temporary and reversible in nature and will be

localised.

1.3.1 Impact on Topography and Land Use

Considering the small foot print area required during the drilling, only marginal

impact due to change in land use is anticipated and there is no topographical

change is envisaged.

1.3.2 Impact on Climate

Impact on the climatic conditions from the drilling will not be significant.

Considering the quantum of exit gas and the short duration of flow, the impact on

the local or global climate will be insignificant.

1.3.3 Impact on Air Quality

The potential sources of air emissions at the well sites will be as follows:

• Dust from earth works (during approach road and site preparation);

• Emissions from DG sets;

• Emissions from possible flaring during well testing; and

• Emissions from vehicles

During the short period of site preparation, mechanical shovels and earthmovers

will be used for vegetation clearance, cut and fill and other site leveling activities.

However, these activities will be only temporary and the impact to ambient air

quality would be within the close proximity of well site.


Executive Summary


The gaseous emissions from the DG set will be controlled by efficient combustion

of fuel in the DG set. The flaring of oil and gas during well testing is a short

duration activity (about 14-21 days). The dimensions of the typical flaring pit

would be approximately 25 m x 10 m x 2 m deep will be used. The setting out of

the flare pit will be done in a manner to direct the flame away from any pockets

of cultivation / existing green cover. Wherever required, special precautions will

be taken to minimize the impact on the local environment and habitat.

1.3.4 Impact on Surface Water and Groundwater Quality

Approximately 15-20 m3/day of wastewater and 4 m3/day of sewage would be

generated from each well site. Water based non-toxic biodegradable fluids with

inhibitive and encapsulative characteristics are proposed to be used as drilling

mud for minimizing any long term impact on groundwater quality. Additionally,

the drilling mud collection and recirculation pond is lined with impervious layer to

prevent seepage and loss of drilling fluid into the subsoil. Further, proper casing

installation and cementing of well will ensure least groundwater contact. The

clarified wastewater will be treated in packaged treatment plant located at the

well sites to meet norms specified by CPCB and MPCB. The sewage will be

discharged into septic tanks and then to subsoil through soak pits.

1.3.5 Impact on Noise Levels

The maximum predicted noise level at about 100 m from the boundary of the drill

site is about 52.0 dB (A). The ambient noise levels at most of the places in the

region are within the CPCB standards. Since, the drilling operations last for only

120-150 days at each location, impact of the noise due to the proposed

exploratory drilling will be insignificant on the community and will be minimized

after 100 m from drilling well site boundary.

1.3.6 Ecological Impacts

Impact on the ecology of the study area will vary with the proximity of the

habitats from the drilling locations. However, the impacts are of temporary

nature, which will last for few days at each drill location during the exploratory

drilling activities and will thus allow subsequent recovery after the activities

stops.

1.3.7 Demography and Socio-Economics

Although the level of existing communications and support services in the area

are considered adequate based on the population density, establishment of the

proposed project would further strengthen the road network and access to some

of the remote areas with all weather roads would be of distinct beneficial impact.

The overall impact is considered to be positive.

Impact on health due to emissions and noise from drilling activity has been

assessed to be minimal. In addition employees working at the drill site would be

provided protective devices like ear plugs/ear muffs for ensuring minimum impact

on human health.


Executive Summary


For most potential drilling sites in the exploration area, it should be possible to

avoid impact on existing arable land. By following the compensation procedures

and by observing common courtesy, impacts on existing use and benefit rights

holders can be minimized.

1.4 Environment Management Plan

1.4.1 Removal of Equipment and Materials

After completion of the drilling activities, the well will be capped with a wellhead

in place, but all other equipment and materials will be removed from the site. The

site would be returned to its original form in most environment friendly manner.

All empty drums, wastes, used and unused drilling fluids, fuel and lubricants will

be removed from the drilling site. Water supply and effluent discharge hoses and

associated equipment will be removed. The access road(s) would be reinstated.

1.4.2 Decommissioning upon Abandonment

In the event that no economic quantities of hydrocarbons are found, a full

abandonment plan will be implemented for the drilling sites in accordance with

the applicable Indian petroleum regulations. The well will be capped and the land

would be handed over back to the owners in the original form.

1.4.3 Atmospheric Emissions

The combustion of diesel for power generation for the drilling and campsite

operation results in atmospheric emissions of SO2, NOx, CO, Particulates and

Hydrocarbons. Flaring during production testing is of 14 to 21 days duration and

atmospheric emissions are marginal.

There will be no sensitive receptors to the emissions of combustion products in

the vicinity of the proposed drilling operations apart from the crew of the drilling

rig. The impacts caused are therefore, considered to be negligible. Measures to

ensure minimal impacts include appropriate management of power generation

source to achieve fuel efficiency and therefore reduce emissions and use of low

sulphur diesel oil. Environmental monitoring is proposed during drilling and well

testing to ensure maximum combustion efficiency. Flaring towards any standing

vegetation will be avoided. In case if it is inevitable, a suitable barrier will be

erected to prevent any vegetation scorching due to direct heat radiation; and

prior to flaring, the critical equipment will be thoroughly tested.

1.4.4 Noise Environment

The modeling results show that the noise levels will attenuate to below

permissible levels within the drilling site boundary. The Generators will be

properly enclosed and the exhausts will be provided with silencers.


Executive Summary


1.4.5 Management of Drilling Wastes

The major waste product of a drilling operation is the generation of rock cuttings

with residual mud adhering to the drill cuttings and spent drilling fluid. About 250-

300 m3 of drill cuttings per well and 15 m3 spent drilling fluid would need to be

disposed off.

ONGC proposes to use internationally followed methodologies while drilling with

Water Based Muds (WBM). The mud will be reused after its separation from the

cuttings. A mud mixing tank will be set up at the drilling site with a collection

system so that any spill of chemicals will be collected.

The spilled oil may be reused in the mud preparation. The residual drilling fluids

will be reused in the drilling campaign to the maximum extent and the drilling

fluid which can not be further used will be discarded as per procedure.

1.4.6 Management of the Solid Wastes

Small amounts of solid wastes will be generated during normal operation at the

drilling rig. The wastes will be disposed on compliance with local and national

legislations. Spent waste oil will be stored in a secure paved area and disposed to

MoEF/ MPCB approved waste oil recyclers. Drill cuttings and sludge from drilling

mud to be buried within the impervious lined pit and covered with soil as part of

the site abandonment plan. Biodegradable waste arising from kitchen and

canteen activities to be scientifically composted and the bio-manure so generated

to be used for green belt development.

1.4.7 Management of Waste Disposal sites within Drill Site

The project proponent is committed to dispose the drill cuttings, drill mud and

wastewater generated during the drilling operations into the lined pits of various

sizes and undertaking plantation within the drill site particularly on the reclaimed

pits will be undertaken.

1.5 Environmental Monitoring Program

A detailed post project monitoring in respect of air, water, soil, landuse,

occupational noise, etc. to assess the changes has been evolved covering various

phases of project advancement. A network of sampling locations around the drill

site will be established. The monitoring will include the compliances to legal and

statutory controls imposed on the operation as well as other corporate

commitment to responsible environment management. Systems for monitoring

resource inputs (energy, chemical use, water, raw materials), equipment and

waste generation will also be set up. A detailed wastes management plan with

monitoring programme will be in place during various phases of activity.

1.6 Risk Assessment and Disaster Management Plan

The hazard potential of oil and gas and estimation of consequences in case of

their accidental release during drilling has been identified and risk assessment

has been carried out to quantify the extent of damage and suggest

recommendations for safety improvement for the proposed facilities. Risk


Executive Summary


mitigation measures based on MCA analysis and engineering judgments are

incorporated in order to improve overall system safety and mitigate the effects of

major accidents.

An effective Disaster Management Plan (DMP) to mitigate the risks involved has

been prepared. This plan defines the responsibilities and resources available to

respond to the different types of emergencies envisaged. Training exercises will

be held to ensure that all personnel are familiar with their responsibilities and

that communication links are functioning effectively.

1.7 Project Benefits

The proposed exploration program will establish hydrocarbons in the block. The

development of the oil field will result in considerable growth of service sector and

will also generate new industrial and business opportunities in the area. Small

and medium scale industries may be developed as consequence.

The major benefits of the project include reduction of the oil import bill of the

nation as well as reduction of the imbalance in oil production and consumption.

The commercial development will also lead to investment in Assam, bringing oil

and gas revenues both to the State and to the Central Government. The presence

of ONGC in the region will substantially improves the socio-economic conditions of

the region.

The proposed exploration drilling programme is expected to generate local

employment in the order of about 25 unskilled and semi- skilled people, for a

period of approximately 4 to 5 months at each drilling site location. While this

benefit is small by most standards, it is a significant employment opportunity in

the block.

1.8 Administrative Aspects

The basis of the operational philosophy is that the activities proposed in oil and

gas processing shall be operated in complete compliance with all applicable Laws,

Regulations, Standards and Permits, the Production Sharing Contract (PSC),

corporate policies, procedures, specifications, rules, standards and guidelines. In

order to achieve this, the proposed drilling sites will be maintained by technically

qualified and experienced people. Detailed procedures and plans will be

developed for each activity prior to operations start up. All persons on board the

drilling rig will be an experienced crew with valid qualifications.

The HSE dept is the nodal agency to coordinate and provide necessary services

on environmental issues during construction and operation of the project.

1.9 Conclusions

The proposed exploratory drilling project has certain level of marginal impacts on

the local environment. However, the proposed project has significant beneficial

impact/effects in terms of providing the employment opportunities and various

CSR practices to be followed by ONGC. Growth and development, in harmony

with the environment, has always been the approach of ONGC.


Executive Summary


The conclusions of EIA are:

• The proposed project meets the compliance requirements of various

environmental regulations;

• Adoption of environmental friendly Best Management Practices results in

minimising the impacts on environment;

• Community impacts of the project will be beneficial, as the project will

generate significant economic benefits for the region;

• The post drilling, commercial developmental activities of ONGC can reduce the

import burdens of crude oil on the nation; and

• With the effective implementation of the Environment Management Plan

(EMP) during the planning, design, construction and operation phases, the

development and production project can proceed without significant negative

impact on the environment.





Prepared by :

April, 2016

Sponsor :

M/s. Oil and Natural Gas Corporation Ltd. Assam & Assam Arakan Basin, Dhansiri Bhavan,

Cinnamara, Jorhat - 785704





RORELNA TLANGPUI KHAIKHAWMNA


Executive Summary


1.0 RORELNA TLANGPUI KHAI KHAWMNA

Oil and Natural Gas Corporation Limited (ONGC) chuan AA-ONN-2001/2 bial,

Kolasib leh Mamit District, Mizoram ah hian ngun taka lei verh a rawt.

NELP bial, AA-ONN-2001/2, Mizoram chhung ami, 5340sqkm hi ONGC-IOC (80%

leh 20% PI) leh ONGC te tang dun chu thu remna pek an ni a; thawh khatna leh

thawh hnihna ah MWP tihhlawhtlin anih hnuah, ONGC hi thawh thumna ah a kai

leh a, 08.04.2013 atanga thawh tan niin, PSC tehkhawng angin helai bial ah hian

1345sqkm chu thlah/bansan a ni a, 2660sqkm chelh a ni thung. Thawh thumna

ngun taka endikna kal mekah hian, ONGC chuan lei verh pakhat a la mamawh/tul

a, heihi MWP nena intiamna a ni. Hemi bakah hian, ONGC chuan heti lai hmun

pumpuiah hian hydrocarbon inphum ru awm theite haichhuah nan lei verh belh a

rawt bawk a ni.

Environment Impact Assessment (EIA) hriattirna, 14th September, 2006-a a lan

angin, he lei verh tumna hna hi ‘Category A’ of Activity Type 1(b) hnuaiah a awm

a ni. EIA thuchhuah buatsaih a ni a, MoEF vide letter. No. J-11011/305/2014-IA

II (I) ni 6th January, 2015 atanga TOR hmuhdan azirin.

Tuna hna rawtna kal mek hi AA-ONN-2001/2, Kolasib leh Mamit District, Mizoram

huam chhunga hmun thum a lei verh chungchang a ni a, 2-D leh 3-D lei lam zirna

atanga enfiah hnuah heng lei verhna hmun tur atan hian Kolasib leh Mamit

District ah te thliar hran ani.

EIA atanga thuchhuak chuan heng lei verh tumna hmun te hi AA-ONN-2001/2 bial

ah a ti a, an insutnat zawng leh tihnep zawng pawh a in ang khat a ni.

1.2 Ruahmanna Sawifiahna.

1.2.1 Hmun chinchang.

Mizoram chhunga Kolasib leh Mamit District ah te an nia a, heng lei verh tumna

pathum zinga pahnih te hi Kolasib district ah niin, pakhat chu Mamit district ah a

ni.

Block hmun san zawng hi 400m atanga 2000m a ni. A hnuaiah hian lei verh

tumna te ruahman dan chinchang tarlan a ni:

Sr.

No.

A Hmun

hming

Latitude Longitude Khaw hnai ber District

1 HOAC 240 12’ 14.24” 920 35’ 53.32” A hmun atanga

hmar lamah

Kolasib

2 HOAD 240 09’ 41.42” 920 36’ 13.31” A hmun atanga chhim lamah

Kolasib

3 BRBAA 240 07’ 10.08” 920 31’ 06.77” Sauhliap atanga chhim lamah

Mamit

Block huam chhunga Topo map hmelhang Figure-1 ah siam a ni. He hna

thawhna tur hian a huam chi chhunga ram chinchang a hnuaiah hian tarlan a ni.

Zirchianna huam chhungah hian Forest hmun pakhat a awm a, Wildlife

Sanctuary erawh a awmlo.


Executive Summary


Hnathawh tumna hian Tlawng lui a huam tel.

Hnathawh tumna hmun te hi National Highway NH-154 leh Bairabi Railway

Station te hmangin a kal pawh theih ani.

Archaeological Survey of India (ASI) ten an chhinchhiah dan atangin

hnathawh tumna hmun huam chinah hian hmasang chanchin zirna hmun

pawimawh a awmlo;

A hmun huam chin hi Seismic Zone–V, IS: 1893 (Part-1) 2002-a tarlan ah a

awm.

1.2.2 A hna pawimawhna

India hian Oil Reserve kan ngah loh avangin oil tak pechhuak tam ram chu kan ni

lo chiang hle. Hemi avang hian oil tak hi ram dang atanga kan lakluh ah kan

innghat tawp a, chuvang chuan oil siam chhuah leh hman danah kan in balance lo

em em phah ta a ni . India sorkar hian oil leh gas zawn chhuah hna leh siam

chhuah hna lamah hian nasa takin hma a la mek zel a, he hmalakna kal mek hian

keimahni ram hausakna te hai chhuakin intodelhna kawngah min hruai thei dawn

a ni.

Hydrocarbon inphum ru te hai chhuah anih chuan a ram neitute inrenchem dan

pawh nasa takin hma a sawntir anga, chuvang chuan he ram tan ngei pawh hian

he hmalak tumna hi thil pawimawh tak a ni.

1.2.3 Lei verh tum dan Chanchin chipchiarin

Heng hnathawh tumna te hi lirnghing tehna survey neih atanga him tura ngaih an

nih bakah rin(line) nena a lem ziak thlapin hydrocarbon imphum ru te laihchhuah

ngei rin a ni a, lei verh dan te pawh hi rin dana verh te a ni hlawm thin a, mahse

engkim duang fel lawk veka tih thin a ni. A lem ziak te pawh nei sa thlapa lei verh

thin a ni a, he hna hian a tum uluk em em chu heng kan lei verh atang te hian

hydrocarbon awm khawm hmuhchhuah a ni. Heng lei verh tumte hi a thuk zawng

atan chuan 4400m a thuka laih tum a ni a, chirh chauh paihchhuakin tui hmang

chunga verh tum a ni.


Executive Summary


FIGURE-1

TOPO-MAP OF AA-ONN-2001/2 BLOCK


Executive Summary


1.1.4 Mamawh hrang hrangte

Sum Hman zat tur relna: He hnathawh nana sum inrelbawlna leh senso atan hian

Rs. 200 Crores vel hman rin a ni a, chu chu hmun thum a verhna atan a ni.

Ram Mamawhna: Lei verhna hmun khat atan zel hian a tlem berah ram hi 125 m

x 125 m, chu chu 1.56 ha mamawh a ni. A average a lak chuan hmun tin atana ram

mamawh chen hi, bungrua te leh camp nan ten nen chuan 1.5-2.0 ha mamawh a

ni. 2.5 ha chin hi chu reilote chhung chauh hman a ni anga, tualchhung emaw

sorkar rorelna ang zelin zangnadawmna/lawman pek a ni bawk ang.

Kawlphetha Mamawhna: Lei verhna hmuna kawlphetha mamawh zat hi 2250 KVA a

ni dawn a, kawlphetha mamawhna te hi min vilpui turin Diesel Generator (DG) te

a ni ang. Heng kan kawlphetha mamawhna te min pui tur hian 750 KVA DG set

thum an awm anga, DG set, 750 KVA hi inring renga dah a ni bawk ang.

Tui Mamawhna: Tui hi a hmuna hnathawk te tan leh khawlin lei a verhna tur atan

mamawh reng a ni dawn a, ni khat ah 25 m3 vel chu thla li emaw thla nga chhung

mamawh a ni ang. Amaherawh chu, heng kan tui mamawhna te hi hna kan thawh

chak leh chakloh in a hril ang.

Mihring Hnathawktu Mamawhna: A hmunhma vel buatsaih nan hian ram chhung

mite rawih an ni anga, hmun tinah hian ram chhung mi 25 in darker 12 chhung

an thawk anga, hnathawh hi tum hnihah in thenin, hemite zawhah hian a dangin

chutiang bawkin anlo thawk veleh zel ang.

1.2 Ram leh a chhehvel sawifiahna

AA-ONN-2001/2 bial in a huam chinah hian ngun taka chhehvel enkualna neih a

ni a, 15th January 2016 atanga 8th April 2016 thleng, khaw vawh deuhlai pawha

en a ni.

1.2.1 Ram/Leilung hman dan zirna

AA-ONN-2001/2 bial chhunga leilung hman dan hi District Census Hand Books leh

satellite thlalak atangte zir a ni a, hmuh dan chuan 4.6 % vel hi chu thlai chin

nana hman ani. Lehlamah chuan 80.1 % vel hi hmanloh a ni a, tui hian 10.4 %

vel huamin tui hi tuikhuah leh luiah te hmuh a ni.

1.2.2 Lei thatna

Lei hi khaw vawh hun laiin, hmun sawm vel atanga lakkhawm a ni a, lei a pH

awm zat hi 7.11 – 8.08 a hmuh a ni a, a pangngai aia al hreta hriat a ni. Electric

a man chak zawng chu 118.2 µS/cm atanga 262.0 µS/cm a ni. Organic carbon hi

0.31 % atanga 0.62 % niin, lei hi a thra tawk viau. Potassium hi 86.6 atanga

172.0 kg/ha a ni a, a hlut zawng chu 13.5 atanga 88.6 kg/ha a ni. Nitrogen erawh

chu 31.5 – 69.7 kg/ha a ni.


Executive Summary


1.2.3 Boruak zirchianna

A hmun ngeiah boruak awm dante hi chiang taka zir a ni a, boruak danglam bik a

awm leh awmloh te enfiah a ni. IMD station hnai ber, Agartala nena khaikhin niin,

boruak hi hmun dang aia a danglamna a tam lem lo a ni.

1.2.4 Borual kal kual vel that leh that loh

Boruak kal kual vel that leh that loh zirnaah hian tun kum 2016 a khaw vawh deuh

lai leh fur tantir lai velin hmun sawm(10) velah en dik a ni a, hemi hmun sawm

zingah hian PM10 leh PM2.5 hiamber lai leh san ber lai chu 37.7 atanga 46.0 g/m3

leh 11.6 atanga 15.8 g/m3 vel ani. SO2 leh NOx inhnawh mukna hi 7.9 atanga

15.0 g/m3 leh 11.0 to 17.3 g/m3 vel a ni bawk a ni. Boruak kal kual vel PM2.5 ina

a chhinchhiah hi mihrnig chenna leh thil siamna hmun bawr vela lak a ni.

Hydrocarbons, methane hydrocarbons leh non-methane hydrocarbons inhnawh

muk chen hi he zirchian naah hian 197 atanga 273 g/m3, 117 atanga 150 g/m3

leh 67 to 125 g/m3 vela hmuh a ni. VOCs ve thung erawh chu hmun tina

zirnaah/enfiahnaah kan chhui phak aia hniam vek a ni. Heng zirchianna atang te

hian a hmuna boruak that zawng hi a tha thawkhat a hriat a ni a, National Ambient

Air Quality Standards nen pawh a inrem thei a ni.

1.2.5 Tui that zawng

Tui zirchian naah hian lei hnaui tui hmun ruk atang leh tui pawnlang hmun li atang

te lakkhawm a ni a, kawng/chi hrang hranga endik a nih hnu in heng lei hnuai tui

leh pawn lam tui te hi a tha thawkhat a, a pangngai tur angin IS: 10500 limit

chinah a awm a ni .

1.2.6 Boruak Bengchhen zawng

Khawchhungah te leh hmun fianrial deuh ah te endikna neih a ni a, a vai hian

hmun sawm ah endikna neih a ni. Heng endikna neih anih hnuah hian CPCB-in a

phal/rem tih chin vek a ni tih sawi ngam a ni.

1.2.7 Nungchate leh an boruak chhehvel

Ngun takin he zirchianna huam chhung bika thil nung hrang hrangte leh a

chhehvelte zichianna neih a ni a, a bik takin lei chung leh tui chhunga awm chi

hrang hrangte enfiah a ni bawk. Heng enfiah a nih hnuah hian a block ina a huam

chinah Forest ram humhalh leh National Park a awmlo a ni.

Dampa Tiger Reserve – Wildlife Sanctuary hi BRBAA bial bulah, 59.5 Km /SSW

lamah a awm a, Mamit District chhungah hian hmun zau tak a awh a ni. Helai

hmunah hian zirchianna kan neih theih chinah chuan thlai, thing, hnim leh ramsa

chi hrang hrang a tam hle a ni .

1.2.8 Khawtlang leh ei leh bar chinchang

Mihring tam zawng hi a lan dan hmelhmangah chuan mipa hi 49.86% niin

hmeichhia hi 50.14% vel an ni a, hei hi 2011 census chhinchhiah dan a ni. Kan

zirchianna huam chhung bikah hian mipa 1000 zelah hmeichhia 1006 awm ang a


Executive Summary


ni. 2011 census-a a lan dan angin, mihring awm zawng zawng zinga 0.17% hi

Scheduled Castes (SC) niin, 91.54% chu Scheduled Tribes(ST) an ni.

Mipa zingah ziak leh chhiar thiam hi kan zirna huam chin bika chhut hian 50.13%

a ni a, vantlang hmasawn nana pawimawh em em hmeichhia ziak leh chhiar

thiam hi 49.87% ani bawk a, hei hi 2011 census chhinchhiah dan ani. Zirchianna

in a huam chinah hian 41.78% hi hnathawk niin, 58.22% chu hna thawklo an ni.

1.3 Chhehvela thil thleng thei thlirlawkna

Lei verh avanga thil awm thei leh thleng thei hrang hrangte thlirlawkna leh

sawihonate neih a ni a, hmun leh ram a tlem thei ang bera he hmalaknaah hian

hman a nih theih dan turte ngaihtuahho a ni bawk.

He hnathawh tumna hian thla li atanga thla nga a huam anga, hnathawhna hmun

leh hma hi hun reilote chhungin a in siamtha leh thei tura ngaih a ni a, a ram

neitu hnena pek let leh a ni bawk ang.

1.3.1 Ram humnhma/leilung nghawng dan leh ram hman dan

Lei verh nana hmun hman hi a zau dawn lova, hmun a heh dawloh avangin

thlirlawkna atang pawhin ram hmunhma/leilung hmelhmang ti danglam khawp

chuan hna hi kalpui anih hmelloh, a huam chin te ah chauh hna hi thawh a ni

dawn a ni.

1.3.2 Sik leh Sa nghawng dan

He hnathawhna atang hian sik leh sa/boruak tidanglam thei khawp chuan

engmah a thlen a rinawm loh. A chhehvel leh ram tan eng harsatna mah a thlen

lovang.

1.3.3 Boruak tha nghawng dan

Hnathawhna hmun te atanga boruak chhuak thei hrang hrang te :

Lei khu (kawng siam lai leh a hmunhma buaipui laiin);

DG set ho atanga khu chhuakte;

Lei verh tur en chhin laia thil hal a ngaih thut chuan;

Motor khu.

Hnathawhna tur hmunhma then fai nan hian khawl chi hrang hrang, thing leh

mau te leh lei thenfai nan te hman tum a ni a, hmun hma siamrem ve a ngaih

vang a ni. Amaherawh chu heng thing leh maul eh lei thenfai hna hian lei verhna

hmunhma bul hnai chauh a huam ang. Ram dang tihchhiat ani loving.

DG set atanga gas chhuak hi ama khawl atang hian a tlem thei ang berin a in

control dawn a ni. Oil leh gas chhem chhung hi hun rei a ni lova, ni sawm leh pali

atanga ni sawmhnih pakhat vel chauh a ni. Heng chhemna atan hian khur 25 m x

10 m x 2 m vela thuk hman a ni ang. He khur atanga thil chhuak reng reng hian

hmun hring emaw, ram tha emaw, lo emaw, thlai chinna leh huan te reng reng

hliau phalo tura siam a ni ang. Mamawh leh remchan dan ang zelin, ram chhehvel

te ti chhelo leh tibuailo thei ang bera hma lak a ni ang.


Executive Summary


1.3.4 Leihnuai tui tha leh tui pawnlang tha te nghawng dan

Hnathawhna hmun tinah hian ni tinin tui chhia 15-20m3 leh tui thli(mihring hman)

4m3 vel hman rin a ni. Lei hnuaia tui awmte hi hun lo kal leh zel tura a

bawlhhlawhloh nan leh thil pawi dang a thlen loh nan kan tui hman te pawh a

thianghlim thei ang ber hman kan tum. Hei mai bakah hian lei verh atanga chirh

lo awmte pawh lei chhungrila a luh loh nan a chhawng hrang hranga khuap a thlit

fim a ni anga, lei hnuaia tui awm nen a inpawlh loh nan cement hmanga char in

khuap thlap tum bawk a ni. CPCB leh MPCB in duh dan an tuk angin heng tui

thlitfim te pawh hi khuap ani ang. Mihring hman tui bawlhhlawh leh thli te pawh

hi septic tank ah luanluh tirin soak pit te nena siam thlap ani ang.

1.3.5 Ri/Thawm bengchheng nghawng dan

Ri/Thawm, hnathawhna hmun atanga chhuak hi, a hmun atanga chhutin 100 m a

hlaah chuan 52.0 dB (A) a ni ang. CPCB in tlinga a ngaih chin chauh heng

hnathawhna hmun atang hian ri/thawm a chhuak dawn a ni. Lei verh hun chhung

hi hmun tinah ni 120 atanga ni 150 ani dawn a, ri/thawm bengchheng em em

khawtlang buaina khawp turin a awm loving. 100 m a hlaah phei chuan ri/thawm

hi a nep viau ang.

1.3.6 Nungchate chunga nghawng dan

He hnathawhna hian thil nung reng reng a nghawng dan turah hian hnathawhna

hmun atanga a inhnaih dana zir a ni ang. He hnathawhna hian harsatna alo thlen

palh anih pawhin hun reilote chhung chauh anih dawn avangin heng a nghawng

buai palh awm theite hi chuan hna zawh fel anih hunah ngai an awh leh theih mai

rin a ni.

1.3.7 Mihring tamzat leh khawtlang inrenchem dan

Mihring tam dan atanga chhut chuan inbiakpawhnate leh inkalpawhnate hi a tha

thawkhat viau a hmuh a ni a, amaherawh chu he hnathawh tumna avang hian

inkalpawh theihna tam tak siam belh ani dawn a, kawng tha chi siam ani dawn

bawk a, heng inkalpawhna siam thar atang te hian tun hmaa la tlawhpawh

theihloh hmun fianrial deuh te pawh kaltlang theih anih phah nual dawn a ni. Hei

hi a ram mi te tan pawh hlawkna tam tak thlen theitu anih zel rin a ni a, a

nawlpui a lakin he hnathawhna hian thil tha tam tak a thlen dawn a ni.

Hriselna lamah chuan he hnathawhna hmun atanga khu chhuak leh ri/thawm

chhuak te hian harsatna a siam lovang. Hei mai bakah hian hnathawktu zawng

zawngten hriselna lama harsatna an tawh loh nan mahni invenhimna turin beng

hnawhna te pek anni dawn bawk a ni.

He hnathawhna hmun hrang hrang leh enkualna ah te hian thlawhhma atana tlak

leilung te leh leilet te khawih telloh hram kan tum. Zangnadawmna intiam dan

ang leh hawihhawmna telin a tlem thei ang bera ram leh leilung hi hman tum a

ni.


Executive Summary


1.4 Chhehvel enkawl dan ruahmanna

1.4.1 Bungrua leh hmanrua dahsawn/lakchhuah

Lei verh hna zawh anih hnuah hian khur hi a chhinna a chhin thlap a ni anga,

bungrua leh hmanrua dang zawng zawngte erawh chu a hmun atang hian lak

sawn/suan chhuah an ni ang. Hmunhma hi a pangngai thei ang bera chhuahsan

tum a ni.

Bungraw ruak te, bawlhhlawh te, lei verh nana hman thil tuiril chi te, thil halna

leh thil hnawih chi te lak chhuah vek a ni anga, tui lakluhna te leh thil

paihchhuahna hmanrua te pawh lak chhuah vek a ni ang. Inkalpawhna te pawh

hmun ngai awhtir leh a ni ang.

1.4.2 Chhuahsan hnua mawhphurhna sut thu.

Heng hnathawhnaah te hian tum anga hydrocarbons hmuhchhuah anih loh chuan,

a hnathawhna hmun pumpui hi Indian Petroleum dan angin chhuahsan a ni ang.

Lei verhna khur hi chhin fel a ni anga, a ram hmun pawh a neitu hnenah a ngaia

pek let leh thlap a ni ang.

1.4.3 Boruak pekchhuah chungchang

Lei verhnan leh a hmun enkawlna a kawlphetha mamawh hi diesel hmanga

pekchhuah anih dawn avangin SO2, NOx, CO, hydrocarbons leh a kaihhnawih

dangte a awm anga, tin, enchhin nana thil hal hi ni sawmleh pali atanga ni

sawnhnih pakhat chhung a ni bawk ang.

Hnathawhna hmunah hian heng thil halna leh khu chhuak te hi hnathawkte tih

bakah chuan a endikna hmanrua a awm hran dawnlo a, hlauhawm emaw pawi

tham a ni lo ang. Kawlphetha mamawh chin tha taka neih anih theih nan

hmalakna tur tha tak duan lawk a ni a, tha taka kawlphetha hi neih theih anih

chuan ‘sulphur diesel oil’ pawh a chhuah tlem phah em em dawn a ni. Lei verh leh

enchhinna neih chhung hian boruak chhehvel te pawh endik/enfiah reng tum a ni.

Thil to na hmun lam hawiin engmah hal/chhem a ni loving a,a tul anih pawhin

daidanna tha tak siam ani ang; tin, hal/chhem anih hma hian hmanrua te endik

phawt zel a ni ang.

1.4.4 Ri/Thawm chungchang

Lemziak atang te a chhut danin ri/thawm bengchheng hi a huam theih chinah

chuan a hniam thei ang bera dah a ni dawn a, generators te pawh tha taka

khuhin a khu chhuahnaah pawh a rik zawihna vuah zel a ni ang.

1.4.5 Lei verh hnawkna enkawl dan

Lei verh atanga ningnawi awm tam ber chu lung them te leh chirh ani tlangpui a,

hmun khat a verhna ah 250 - 300 m3 vel te leh a tuiril ningnawi bikah 15 m3 vel hi

paihchhuah a ngai tlangpui a ni.


Executive Summary


ONGC hian Water Based Muds (WBM) verhna ah hian ram dang tam tak te tih dan

zulzui a tih ve a remti a, chirh laih chhuah te pawh hman tangkai leh theih a siam

ani ang. Chirh chawhkual na tur bawm siam ani anga, he bawm atanga chemical

lo luang chhuak te hi thliar hran zel a ni dawn a ni.

Oil rawn chhuak awm te hi chirh siam lehnaah hian hman leh zel theih a ni dawn

a ni. Lei verhna atana hman tawh sa tuiril te pawh hman nawn zel theih a ni

anga, hman tlakloh anih veleh dan anga paih thlap a ni ang.

1.4.6 Thil ningnawi/bawlhhlawh khal chi enkawl dan

Lei verhna ah hian a pangngai ang chuan thil ningnawi/bawlhhlawh khal chi lam

hi a tlem thin. Heng ningnawi te hi vantlang leh national dan zam anga paihfel ani

ang. Oil hman tawh hnu te erawh chu MoEF/ MPCB-ten an approve thlap ‘waste

oil recyclers’ ah him taka dahthat a ni ang. Lung them te leh chirh hnawk te hi

khurah paih thlap a ni anga, lei a vur in chhilh a ni bawk ang. Choka leh canteen

vel atanga ningnawi/bawlhhlawh te hi tawihral tir a ni anga, heta ‘bio-manure’ hi

‘green belt development’ atana hman a ni ang.

1.4.7 Hnathawhna huam chhuanga ningnawi/bawlhhlawh enkawl dan chungchang

He hnathawhna hian tan a khawh nasat na pakhat chu ningnawi/bawlhhlawh paih

fimkhur hi a ni a, chirh te leh tui paih tur te hi khur laih, size hrang hranga

siamah paih thlap a ni anga, tichuan he hnathawh theihna huam chhungah hian

heng paihfelna hmun te hi thlawhhmaa neih tlaka siam leh thlap tum a ni.

1.5 Chhehvel en thithlaina

Hmun hmelhmang ti danglam thei tur awm - boruak, tui, lei, ram hman dan,

ri/thawm leh a dangte telin - heng hrang hrangte hi en thlithlai reng a ni ang.

Hnathawhna hmun huam chinah pawh hian kalkual/fankual theihna tur siam a ni

ang. Thil en thlithlai dan te hi dan in min phalsak ang leh phalsak chin zel leh

intiamna ang zela kalpui a ni ang. Kan hmanrua te (kawlphetha, chemical te, tui,

raw materials), bungrua te leh ningnawi/bawlhhlawh inenkawlna pawh tha taka

din a ni ang. Hnathawhna hmuna bawlhhlawte leh hnawmhnawk te enkawl dan

chungchangah pawh dan tha tak duan lawk a ni anga, tha taka en thlithlai a ni

bawk ang.

1.6 Chhiat tawh emaw Vanduaina tawh chungchanga inenkawl dan

ruahmanna

Lei verh lai emaw hnathawh laia oil emaw gas hlauhthawn awm lo chhuak thut

thei lakah in venhim dan te leh lo in ven lawk dan te mai bakah heng chhiatna

emaw vanduaina lo thleng thut thei laka in venhimna tha tak ruahman lawk a ni

ang. MCA edikna te leh engineer te lampang rorelna hlawm khawmin kan

kalphungte leh him taka hnathawh theih dan te tha taka siamtha in, chhiatna

emaw vanduaina lian tham lakah pawh a him thei ang ber leh chhiatna thleng

tlem thei ang ber tura in duan lawk a ni.

Disaster Management Plan (DMP) tha tak pawh chhiatna thleng tlem thei ang ber

tura ruahman lawk thlap a ni. He ruahmanna hian mawhphurhna leh emergency a

bungrua mamawh turte thlir lawkin a duang lawk thlap. Hnathawktu zawng


Executive Summary


zawngte hnenah an mawhphurhna hre chiang turin inzirna pek an ni anga, in

kalpawhna leh inbiakpawhna te pawh khaihlak lo turin tha taka vawn a ni ang.

1.7 Hna ruahman hlawkpuina/hamthatna

He hnathawhna hian a block chhungah hian hydrocarbons a din nghet anga, oil

hmun hian nasa takin hna thawhna/inhlawhfakna siam lamah hma a sawn tir hle

ang. Industries leh sumdawnna remchang tha tak a siam phah anga, he

hnathawhna avang hian industries te leh lian te pawh dinna hmun leh hun tha tak

a awm phah thei dawn a ni.

He hnathawh tumna hian a ram pum huapin ram dang atanga kan oil lakluh te

pawh a ti tlahniam thei anga, tin, kan ram chhunga kan oil siam chhuah leh kan

hman dan in rualkhai lo lutuk hi a ti nep sawt dawn a ni.

Sumdawnna lamah hmasawnna tam tak a thlen anga, Assam tan pawh pawisa

peipunna a siam dawn a ni. Heti lai hmuna ONGC awm hrim hrim hian vantlang

inrenchemna pawh hma a sawn tir em em dawn a ni.

He hnathawh tumna hian a ramchhung mite tan hna a inrawihna tha tak a siam

dawn a, mi 25 thiamna nei tha te tan thawhna a awm dawn a ni. He hna hi hna

lian tham tak angin lang lo mahse, a chhehvel a cheng te tan hna pawimawh leh

awmze nei taka thawhna tha tak a siamsak ngei dawn a ni.

1.8 Rorelna hmelhmang

He hnathawh tumna hian a innghahchhan pakhat chu - oil leh gas buaipui hun

chhung hian dan leh phalna a hmuh ang thlap zelin, Production Sharing Contract

(PSC) lamah te, intiamkamna chinah te, in duan lawk danah te, in khaihhruai

danah te leh rorelna bawhzui danahte in vawn dik thlap a ni. Hemi avang hian

heng hnathawhna hmun te hi tha taka enkawl turin mi tling leh tawnhriat nei nei

chauh chhawr an ni ang. Thil tih dan tur leh hna ruahmanna reng reng chu

hnathawh hmain enfiah phawt zel a ni ang. Hnathawk reng reng te hi mi tling leh

tawnhriat nei nei tha an ni ang.

HSE Dept. chuan he hnathawhna kalpui a nih chhung zawng hian a tul apiangah

chhehvel ngaihtuah feltu tur atan mawhphurhna a chang a ni.

1.9 Tawpna/Thu keuh thlukna

He hnathawh tumna hian hnathawhna hmun leh chhehvel chu tlem a zawng

chuan a nghawng ve deuh anga, amaherawh chu hlawkpuina/hamthatna tam tak

a siam tel dawn bawk a ni, chu chu inhlawhfakna a pek hi a ni a, hei bakah hian

CSR tih thin dan anga ONGC ten kan zawm tum inhlawhfakna siam belh te hi a ni.

Chhehvel nena inrem zel chunga hmasawn leh than len zel hi ONGC lo kal tawh

thin dan a ni.

EIA thutawpna/thu keuh tlukna te chu:

He hnathawh tumna hian chhehvel dan zawng zawngte nen inrem thlap a

awm;


Executive Summary


Chhehvel a him thei ang bera enkawl dan, dan tha thei ang ber hmang

chunga hnathawh;

Mipuite nena inkungkaihna tha a hlawkpui khawp anga; a chhan chu

inhlawhfakna tha tak a siamsak dawn vang ani;

Hun kal tawha ONGC-in hma alo lak tawhna te leh a hmalak zelna turah hian

nasa takin a ram pum huapin ram dang atanga oil tak kan lakluhna phurrit hi

min chhawk zangkhai thei dawn a ni;

Environment Management Plan (EMP) nena thawhhona atanga ruahmanna te,

inbuatsaihna te leh induanlawkna tha tak atangte hian he hmalakna hi kan

chhehvel ti hmelhem lo hian tluang takin a kal zel thei dawn a ni.


Chapter-1 Introduction

VIMTA Labs Limited, Hyderabad C1-1

1.0 INTRODUCTION


exploratory drilling in NELP Block AA-ONN-2001/2, Kolasib & Mamit District,

Mizoram. Out of the proposed 3 exploratory drilling wells, 2 exploratory drilling

wells falls in Kolasib district and 1 exploratory drilling wells in Mamit district,

Mizoram.

This chapter describes the purpose of the report, identification of project and

proponent, brief description of nature, size, location of the project and importance

to the region and country. The chapter also describes the scope of the study,

details of regulatory scoping carried out as per Terms of Reference (TOR) issued

by Ministry of Environment Forests (MoEF), New Delhi.

1.1 Purpose of the Report

As per Environmental Impact Assessment EIA Notification dated 14th September,

2006, exploration of oil & gas falls under category ‘A’ of project activity 1(b)

requires prior Environmental Clearance (EC) to be obtained from MoEF before the

commencement of ground activity.

The application for prior EC (Form-1 and Pre-feasibility Report) for the proposed

project has been submitted to MoEF&CC on 17th September 2014 and same was

reviewed by the Expert Appraisal Committee (Industry II) held during 29th -30th

October 2014 in New Delhi to prescribe Terms of Reference (TORs) for the

preparation of EIA/EMP report. TOR has been issued by MoEF vide letter reference

F.No.J-11011/305/2014-IA II (I) dated 6th January 2015. A copy of the ToR

letter, along with its compliance is enclosed as Annexure-I.

This EIA Report is prepared inline with the ToR issued by MoEF&CC and addresses

the anticipated environmental impacts of the proposed project and proposes the

mitigation measures for the same for obtaining Environmental Clearance (EC)

from MoEF&CC, New Delhi. The report covers the primary data collected during

15th January 2016 to 8th April 2016 representing partly winter and partly pre

monsoon season.

Public Hearing for the proposed 3 exploratory drilling wells project has been

conducted on 23rd September, 2016 by Mizoram State Pollution Control (ASPCB)

in accordance with TOR and the public hearing proceedings and action plan have

been included in this final EIA report.

1.2 Identification of Project and Project Proponent

Oil and Natural Gas Corporation Limited (ONGC) is a Public Sector Undertaking

(PSU) of the Government of India, under the administrative control of the Ministry

of Petroleum and Natural Gas. It is India's largest oil and gas exploration and

production company. It produces around 70% of India's crude oil (equivalent to

around 25% of the country's total demand) and around 60% of its natural gas.

With a market capitalization of over INR 2 trillion, it is one of India's most

valuable publicly-traded companies.

ONGC has been ranked 357th in the Fortune Global 500 list of the world's biggest

corporations for the year 2012. It is also among the Top 250 Global Energy




Company by PLATTS. ONGC was founded on 14 August 1956 by the Indian state,

which currently holds a 69.23% equity stake. It is involved in exploring

hydrocarbons in 26 sedimentary basins of India, and owns and operates over

11,000 kilometers of pipelines in the country. Its international subsidiary, ONGC

Videsh currently has projects in 15 countries.

1.3 Brief Description of the Project

1.3.1 Nature of the Project



A’ of Activity Type 1(b).

The proposed project intends to identify the presence of hydrocarbon prospects

through exploratory drilling and to delineate and quantify hydrocarbon pools in

discovered fields through exploratory drilling. The proposed project will basically

involve drilling of three exploratory wells in the block.

1.3.2 Size of the Project

ONGC has identified three well locations HOAC, HOAD and BRBAA are included in

present EIA study. It is proposed to drill three exploratory wells for the fulfillment

of Minimum Work Program (MWP) and also to evaluate potential of the entire

block.

1.3.3 Project Site Details

1.3.3.1 Location of the Block




w.e.f. 08.04.2013 by relinquishing an area of 1345 sqkm as per PSC norms after





Elevation of the block varies from 400 m to 2000 m. Index Map is shown in

Figure-1.1. The block coordinates are given in Table-1.1. Tentative well

coordinates are as given in Table-1.2.




TABLE-1.1

BLOCK COORDINATES

Sr. No ML Name Boundary Points Block Coordinates (WGS-84)

Latitude Longitude

1

NELP Block AA-ONN-2001/2

A 240 17’ 07.88” 930 00’ 22.225”

2 B 240 18’ 46.009” 920 47’ 17.741”

3 C 240 19’ 30.629” 920 39’ 48.847”

4 D 240 14’ 49.215” 920 36’ 37.532”

5 E 240 08’ 01.971” 920 29’ 26.911”

6 F 240 07’ 59.189” 920 27’ 47.016”

7 G 240 14’ 59.891” 920 17’ 39.707”

8 H 230 45’ 58.102” 920 15’ 56.891”

9 I 230 43’ 17.831” 920 19’ 53.406”

10 J 230 40’ 05.799” 920 19’ 53.541”

11 K 230 40’ 07.776” 930 14’ 45.238”

12 L 240 01’ 16.674” 930 14’ 57.824”

F to G interstate boundary between Mizoram & Assam

G to H interstate boundary between Mizoram & Tripura

A to L interstate boundary between Mizoram & Manipur

TABLE-1.2

TENTATIVE WELL LOCATIONS

Sr.

No.

Proposed

Location

Latitude Longitude Nearest Village District

1 HOAC 240 12’ 14.24” 920 35’ 53.32” North of Medium Kolasib

2 HOAD 240 09’ 41.42” 920 36’ 13.31” South of Medium Kolasib

3 BRBAA 240 07’ 10.08” 920 31’ 06.77” South of Sauhliap Mamit

The study area map showing the block location and exploratory drilling well

locations are shown in Figure-1.2. Google map showing block area with well

locations is given in Figure-1.3. The environmental setting of the block area

falling in NELP Block area is given in Table-1.3 to Table-1.5.




FIGURE-1.1

INDEX MAP

HOAC Well Location

HOAD Well Location

BRBAA Well Location




FIGURE-1.2

TOPOGRAPHIC MAP NELP BLOCK IN KOLASIB & MAMIT DISTRICT




FIGURE-1.3

GOOGLE MAP SHOWING WELL LOCATIONS IN NELP BLOCK




FIGURE-1.4

TOPOGRAPHIC MAP HOAC WELL -10 KM RADIUS




FIGURE-1.5

TOPOGRAPHIC MAP HOAD WELL -10 KM RADIUS




FIGURE-1.6

TOPOGRAPHIC MAP BRBAA WELL-10 KM RADIUS




TABLE-1.3

ENVIRONMENTAL SETTING OF WELL HOAC (10 KM RADIUS)

Sr. No. Particulars Details

1 Well HOAC Location

Village North Medium

District Kolasib

State Mizoram

2 Well site Coordinates Latitude- 24°12’ 14.24’’N

Longitude- 92°35’ 53.32’’E

3 Well Site Elevation above MSL 757 m aMSL

4 Geographical location in toposheet 83 D/12

5 Nearest representative IMD station Agartala (139 km, WSW)

6 India Meteorological Dept. (IMD), Data

Annual Mean Max Temp 33.0 oC

Annual Mean Min Temp 10.3 oC

Annual Average Rainfall 176.8 mm

Predominant wind direction

S and SE directions followed by SW direction

Study Period – Site specific

Mean Max Temp 30.7

Mean Min Temp 9.2

Average Rainfall 13.0


S followed by SE. Next predominant are SW & N direction

7 Present land use at the site Single crop rain fed agricultural land

8 Nearest highway NH-154 (0.6 km, SE)

9 Nearest railway station Bairabi R.S (5.8, WSW)

10 Nearest airport Lengpui (Aizwal 39 km, S)

11 Nearest river Tlawng River (6.0 km, WSW)

12 Nearest town Kolasib (8.5 km, NE)

13 Nearest major town with 2,00,000 population

Impal (147 km, NE)

14 Villages within 1 km radius Pangbalkawn (1.0 km, NE)

15 Hills/valleys Nil

16 Nearest tourist place Nil

17 Archaeologically important places Nil

18 Protected areas as per Wildlife Protection Act,1972 (Tiger reserve,

Elephant reserve, Biospheres, National parks, Wildlife sanctuaries, community reserves and conservation reserves)

Nil

19 Reserved / Protected Forests Within Inner line forest reserve

20 Seismicity Zone-V as per IS 1983 (Part-1) 2002

Note: All distances mentioned above in () are aerial distances




TABLE-1.4

ENVIRONMENTAL SETTING OF WELL HOAD (10-KM RADIUS)


1 Well HOAD Location

Village South medium

District Kolasib

State Mizoram

2

Well site Coordinates Latitude – 24o09’41.42’’N

longitude – 92o36’13.31’’E 3 Well Site Elevation above MSL 400 m aMSl

4 Geographical location in toposheet

83 D/12

5 Nearest representative IMD station

Agartala (139 km, WSW)

6 India Meteorological Dept. (IMD), Data






Study Period - Site specific

Mean Max Temp 30.7

Mean Min Temp 9.2



S followed by SE. Next predominant are SW & N direction

7 Present land use at the site Single crop rain fed agricultural land

8 Nearest highway NH-154 (2.7 km, NW)

9 Nearest railway station Bairabi R.S (7.3 km, NW)

10 Nearest airport Lengpuri(Aizwal 34 km, S)

11 Nearest rivers Tuwng River (6.3 km, WSW)

12 Nearest town Kolasib (10.8 km, NNE)

13 Nearest major town with 2,00,000 population

Impal (149 km, NE)

14 Villages within 1 km radius Nil

15 Hills/valleys Nil 16 Nearest tourist place Nil 17 Archaeologically important places Nil 18 Protected areas as per Wildlife

Protection Act,1972 (Tiger reserve, Elephant reserve,

Biospheres, National parks, Wildlife sanctuaries, community reserves and conservation reserves)

Nil

19 Reserved / Protected Forests Within Inner line forest reserve


Note : All distances mentioned above in () are aerial distances




TABLE-1.5

ENVIRONMENTAL SETTING OF WELL BRBAA (10 KM RADIUS)


1 Well BRBAA Location

District Mamit

State Mizoram

2 Well site Coordinates Latitude – 24°07’ 10.08’’N Longitude – 92°31’ 06.77’’E

3 Well Site Elevation above MSL 2000 m aMSL

4 Geographical location in toposheet 83 D/8

5 Nearest representative IMD station Agartala-130 km-WSW

6 India Meteorological Dept. (IMD),

Data






Study Period – Site specific

Mean Max Temp 30.7

Mean Min Temp 9.2



S followed by SE. Next

predominant are SW & N direction

7 Present land use at the site Forest Land

8 Nearest highway NH-154 (6.9 km, NNE)

9 Nearest railway station Bairabi R.S (8.7 km, NNE)

10 Nearest airport Lengpuri(Aizwal 31 km, SSE)

11 Nearest river Tuwng River (2 km, NE)

12 Nearest town Mamit (21 km, SSW)

13 Nearest major town with 2,00,000

population

Impal (159 km, NE)

14 Villages within 1 km radius Nil

15 Hills/valleys Nil 16 Nearest tourist place Nil 17 Archaeologically important places Nil 18 Protected areas as per Wildlife

Protection Act,1972 (Tiger reserve, Elephant reserve, Biospheres, National parks, Wildlife sanctuaries, community reserves and conservation reserves)

Nil

19 Reserved / Protected Forests Inner line forest reserve


Note: All distances mentioned above in () are aerial distances




1.3.4 Importance of the Project

Total crude oil import for FY 2014-15 was 189.43 MMT almost same as the

imports during FY 2013-14 (189.24 MMT; increase of 0.1%). However, import of

petroleum products (20.28 MMT) increased by 21 percent, mainly on account of

increase in import of LPG (26%), MS (58%), HSD (35%), Bitumen (80%), and

other products like - Aviation gas, Pet Coke (33%), etc.

Petroleum products export declined for the first time in last 15 years; registering

a decline of 6.2 percent mainly on account of decline in export of Naphtha, Fuel

oil, Bitumen, etc.

With total import (crude and petroleum products) combined with total products

export of 63.66 MMT translates to net import volume of 146 MMT for FY 2014-15.

Net import bill for crude oil during FY 2014-15 was 6,873.50 billion (US$ 112.75

billion) against 8,648.75 billion (US$ 142.96 billion) during FY 2013-14 – a

decrease of 20.5 per cent in terms of the Indian Rupee and decrease of 21.13 per

cent in dollar value mainly on account of lower crude oil prices in the international

market.

Energy security has become one of the top three goals of the Indian Government.

The Indian Government is encouraging exploration and production of oil and gas

to a great extent. This would primarily allow India to tap its own resources there

by reducing its import bill.


economic development to a great extent. It would also catalyse influx of

industries in the state. The proposed exploration project is thus of immense

significance for the country.

ONGC is engaged in the exploration of oil & gas in the NELP Block. Discovery of

hydrocarbons in this block will substantially improve the socio-economic

conditions of the region. The proposed exploration will also help to discover the

geological past to create the economic future for the region as well as to the

country.

1.4 Scope of the Study

With a view to assess the environmental impacts arising due to the proposed

exploratory drilling in NELP block, ONGC has retained the services of M/s Vimta

Labs Limited, Hyderabad to prepare EIA Report for various environmental

components including air, noise, water, land and biological components along

with parameters of human interest which may be affected and to prepare an

Environmental Management Plan (EMP) for mitigating adverse impacts.

Environmental baseline monitoring has been carried out during 15th January 2016

to 8th April 2016 representing partly winter and pre monsoon season and used to

identify potential significant impacts. The scope of the present study is inline with

the TOR as recommended by MoEF&CC. The scope of study broadly includes:




To conduct literature review and to collect data relevant to the study area;

To undertake environmental monitoring so as to establish the baseline

environmental status of the study area;

To identify various existing pollution activities in the ambient levels;

Establishing the relevant features of the proposed exploratory drilling that are

likely to have an impact on the environment;

Predicting the impacts on the environment due to exploratory drilling;

To evaluate the predicted impacts on the various environmental attributes in

the study area by using scientifically developed and widely accepted

environmental impact assessment methodologies;

To prepare a Disaster Management Plan (DMP) based on Risk Assessment,

studies;

To prepare an Environment Management Plan (EMP) outlining the measures

for improving the environmental quality and scope for future drilling activities

and Occupational Health and Safety for environmentally sustainable

development; and

To identify critical environmental attributes required to be monitored.

The literature review includes identification of relevant articles from various

publications, collection of data from various Government agencies and other

sources.

1.4.1 Administrative and Legislative Background

The principal Environmental Regulatory Agency in India is the Ministry of

Environment and Forests (MoEF&CC), New Delhi. MoEF formulates environmental

policies and accords environmental clearance for the projects.

The applicable environmental standards for the project are given in Annexure-

II.

1.4.2 Study Area for EIA

The study area for the EIA is the entire NELP block. The total block area is

considered as the study area.

1.4.3 Methodology of the Study

Vimta Labs Limited, Hyderabad along with ONGC officials had conducted a

reconnaissance survey and sampling locations were identified on the basis of:

Collection, collation and analysis of baseline data for various environmental

attributes viz Ambient air quality, Water quality, Soil, Noise and Bio diversity etc.

Predominant wind directions in the study area as recorded by India

Meteorological Department (IMD);

Existing topography, location of surface water bodies like ponds, canals and

rivers;

Location of villages/towns/sensitive areas;

Accessibility, power availability and security of monitoring equipment, pollution

pockets in the area;

Areas which represent baseline conditions; and




Field studies have been conducted for a period of three months (15th January

2016 to 8th April 2016 representing partly winter and pre monsoon season to

determine existing conditions of various environmental attributes as outlined in

Table-1.6.

TABLE-1.6

ENVIRONMENTAL ATTRIBUTES AND FREQUENCY OF MONITORING

Sr. No Environmental

Component Sampling Locations

Sampling Parameters

Total Sampling

Period

Sampling Frequency

1 Meteorology One central location

Temperature, Wind Speed, Wind Direction, Relative Humidity, Cloud Cover, Rainfall

one non monsoon season (Three months)

Continuous hourly recording

2 Ambient Air Quality

10 Locations PM2.5, PM10, SO2, NOx, VOC, THC CH4-HC, non CH4-HC, and CO

Two consecutive days per week for one non -monsoon season

24 hourly samples

3 Water Quality 4 Locations of surface water & 6 locations of Ground water

As per IS: 10500 Grab sampling Once during study period

4 Noise Monitoring 10 Locations Sound Pressure Levels

Continuously for 24 hours

Once during study period

5 Soil Analysis 10 Locations in Existing ecological resources within study area

Soil profile, Chemical constituents

Composite sample

Once during study period

6 Ecology 5 Terrestrial Ecological Locations & 3 Aquatic location within Existing ecological resources within study area

Flora and fauna Field observations and secondary sources

Once in study period

7 Demography and Socio-economic aspects

Total block area Demographic profile

Based on District Census Handbook (2011)

8 Land Use Total block area Trend of land use change for different categories

Based on District Census Handbook (2001) and satellite images

9 Geology - Geological history

Data collected from primary sources

10 Hydrology - Drainage area and pattern, nature of streams, aquifer characteristics, recharge and discharge rates.

Based on data collected from secondary sources

Apart from the primary data on the existing baseline quality status of various

environmental components, a summary of physical, natural, social and cultural

environment has also been provided incorporating secondary data collected from

various sources. The methodology of monitoring and analysis is given in

Annexure-III.


Chapter-2 Project Description


2.0 PROJECT DESCRIPTION

2.1 Introduction

This chapter presents the project information including technical details of the

proposed drilling operations, utilities and services, infrastructure facilities and

sources of pollution. The expected quantum of the waste generation and

treatment and safe disposal of the waste are also discussed in the chapter.

2.2 Type of the Project

The exploratory drilling operation involves drilling of holes through various sub-

surface layers (geological formations) to predetermined depth of potential

hydrocarbon reserves that are identified through interpretation of seismic data.

The typical flow of events in planning and executing an exploratory well drilling

activity comprises of the following steps:

Site selection & acquisition;

Site preparation;

Pre-drilling activities like mobilising and commissioning rig;

Drilling activities;

Well testing;

Well site abandonment and suspension phase; and

Well site restoration in case of non-discovery of hydrocarbons.

Exploratory drilling is a temporary activity which lasts for about 4-5 months days

for each well in the block.

2.3 Need for Exploratory Drilling

ONGC proposes to drill 3 nos of exploratory wells at selected area through seismic

survey to identify and establish hydrocarbon potential. As exploration within the

basin is still in its early stages, each new penetration aids in determining the

basins stratigraphic architecture. The objective of exploratory drilling is to more

definitively ascertain the oil reserves in the block, which then can be progressed

to the development phase. The locations will vary, depending on the progressive

exploration drilling results.

ONGC has identified three well locations HOAC, HOAD and BRBAA are included in

present EIA study.

2.4 Project Location and Layout Details

It is proposed to drill 3 nos of exploratory wells in the NELP Block of Mizoram

district. The proposed exploratory well sites has been identified based on the

study and interpretation of the stratigraphy and seismic data. Within the

identified location, the actual well drilling sites will be located based on the

following consideration:




Located at a safe distance from the nearest village habitat;

Located at least the height of the well mast away from public road;

Safe distances from any radio transmitters so that the use of explosives, if

required and detonators may proceed without the danger of external

activation;

Located at least 300 – 500 m away from rivers and natural water bodies;

Ensure natural drainage channels are avoided or drainage channels rerouted

to ensure unhindered flow of rain / flood water. Where necessary adequate

erosion control measures will be provided; and

Located in a manner to avoid mature jungles and reserve forests.

The block coordinates and tentative well locations falling in the NELP on-shore

block in Kolasib and Mamit district, Mizoram are given in Table-2.1 and Table-

2.2.

TABLE-2.1

BLOCK COORDINATES

Sr. No ML Name Boundary Points Block Coordinates (WGS-84)

Latitude Longitude

1

NELP Block AA-ONN-2001/2

A 240 17’ 07.88” 930 00’ 22.225”

2 B 240 18’ 46.009” 920 47’ 17.741”

3 C 240 19’ 30.629” 920 39’ 48.847”

4 D 240 14’ 49.215” 920 36’ 37.532”

5 E 240 08’ 01.971” 920 29’ 26.911”

6 F 240 07’ 59.189” 920 27’ 47.016”

7 G 240 14’ 59.891” 920 17’ 39.707”

8 H 230 45’ 58.102” 920 15’ 56.891”

9 I 230 43’ 17.831” 920 19’ 53.406”

10 J 230 40’ 05.799” 920 19’ 53.541”

11 K 230 40’ 07.776” 930 14’ 45.238”

12 L 240 01’ 16.674” 930 14’ 57.824”

F to G interstate boundary between Mizoram & Assam

G to H interstate boundary between Mizoram & Tripura

A to L interstate boundary between Mizoram & Manipur

TABLE-2.2

TENTATIVE WELL LOCATIONS

Sr.

No

Proposed Location Tentative Well Coordinates (WGS-84)

Latitude Longitude

1 HOAC 240 12’ 14.24” 920 35’ 53.32”

2 HOAD 240 09’ 41.42” 920 36’ 13.31”

3 BRBAA 240 07’ 10.08” 920 31’ 06.77”




All practicable means shall be taken to minimize or avoid detrimental effects on

the surrounding environment by virtue of the construction of the location or the

operation of the drilling rig.

The above locations have been fixed by ONGC so that least possible effect may be

felt by the surrounding environment and habitation due to the proposed

exploratory drilling activities.

The exploratory well drilling is a short duration activity and after the well testing

is completed, the drill site is restored to near original conditions.

2.4.1 Typical Well Site Details

The site will be sized to contain all equipment and buildings, storage, workshops,

etc. using distances between various rig components in line with existing rules

and regulations for the area of operation and the approved standard operating

procedures of the drilling contractor. Within the above constraints, the site shall

be sized to minimize environmental impact. The approximate area of well site is

dependent on the type of drilling equipment deployed which in turn is dictated by

the planned depth of drilling. Minimum land required at each well site during

drilling will be 125 m x 125 m, i.e., 1.56 ha. On an average, the land requirement at

each well site, including site facilities and camp site is considered as 1.5-2.25 ha.

About 2.5 hectare land for each well will be acquired on lease. The typical layout of

the well site with ancillary structures is provided in Figure-2.1.

Each exploratory well drill site will require the following facilities:

Portable office cabins / rest rooms (container type cubicles);

Drilling rig foundation and celler;

Foundation / Pits for ancillary equipments;

Space for drill rig equipment, working area and materials lay down area;

Waste storage pits;

Cutting disposal (impervious lined) pits;

Waste storage pit;

Septic tank with soak away pits;

Paved and contained chemical storage area;

Above ground Diesel storage tanks with paved and bunded area;

Radio room;

Storm water drainage system;

Internal roads and fencing.

The proposed drilling sites will be restricted access area and fenced all round with

round the clock watch and ward facility. Entry of vehicles into the drilling site area

will be prohibited except for material movement. Adequate parking facilities will

be provided outside the drilling location.

2.5 Size or Magnitude of Operation

The proposed exploratory drilling project is subject to drilling of 3 wells in an area

of 2660 km2 to establish the presence of hydrocarbon reserves. The estimated




cost of the proposed exploration well drilling Rs. 200 Crores. The salient features of

the project and magnitude of various resources required for the project is given in

Table-2.3.

TABLE-2.3

SALIENT FEATURES OF THE PROPOSED EXPLORATORY DRILLING IN

NELP BLOCK OF MIZORAM

Sr. No Features Details

1 Total block area in the district

NELP block of 2660 km2 area in Kolasib and Mamit district

2 Project Operator Oil and Natural Gas Corporation Limited (ONGC)

3 Proposed number of wells 3 exploratory drilling wells

4 Depth of wells 4400 m (approximately)

5 Estimated project cost Total of Rs. 200 crores

6 Duration of exploratory drilling at each well site

4-5 months

7 Land requirement at each well site including site

facilities and camp site

The 2.5 hectare land for each well. Total

Average 1.5-2.25 ha

At each well site: about 1.56 ha Base Camp: 0.5 ha

8 Hole size and casing 17 ½” and 13 ⅜”

9 Water requirement at each

drill site during drilling phase and water source

25 m3/day, for a short period of 4-5 months

Source : Local water sources through tankers/ Contactors

10 Drill mud requirement About 700 m3 of water based drill mud for each well

11 Drill cuttings generation About 500 m3/well

12 Drilling Wastewater generation

About 15 m3/day (will be treated before sending for solar evaporation in lined pit at drilling site)

13 Domestic wastewater generation

8 m3/day (treated in septic tank, followed by soak pit)

14 Power requirement 2250 KVA (Drill site: 750 KVA X 3 Nos)

15 Manpower requirement at each well site

25 persons/shift of 12 hrs. in two shifts

Source: Project Report

2.5.1 Resource Requirement for the Project

2.5.1.1 Land Requirement

Three exploratory locations have been identified and tentative well location details

are presented in Table 2.2. Minimum land required at each well site during drilling

will be 125 m x 125 m, i.e., 1.5-2.0 ha. Land requirement for the base camp will be

about 0.5 ha. The land will be acquired on a temporary basis and if commercial

quantity of oil or gas is found, the land will be taken on long lease and if oil and gas

is not found in commercial quantities, the land will be returned to the owner by

bringing back to its original status and adequate compensation as per the guidelines

of local administration will be provided.




2.5.1.2 Water Requirement

Water is basically required for preparing drilling mud, direct washing of drill cuttings,

cooling of gas engines and for meeting domestic needs of the campsite. Typically,

the water consumption for each well will be 25 m3/day. However, the drilling and

domestic water requirement would depend on the time required to drill the well,

which is primarily dependent on the proposed depth. Table-2.4 gives the water

consumption for a typical drill site.

TABLE-2.4

WATER REQUIREMENTS PER WELL SITE

Particulars Water Requirement

Drilling water requirement at drilling site 20 m3/day

Domestic water requirement 5 m3/day

Total Water Consumption (KLD) 25 m3/day




FIGURE-2.1

TYPICAL LAYOUT OF WELL SITE

Fire Pit

Waste Pit

Choke

Mani-foldPipe Rack

Cat WalkGenerator Control Room

Diesel

Tank

Workshop

Water

Tank

Well

Rig Sub-Structure

TripTank

ReserveTank 2

ReserveTank 1

Suction Tank 2Mud Pump 1

Mud Pump 2

Chem/HopperPlatform

Desilter DesanderDegasserShaker

Shale

Water Tank

Tool Bin

Koomey unit

Mud Lab TP Room CM's Room

Canteen

Office TP/Company Man OfficeStore

Rubber

Store

CabinSecurity

125 m

125 m

* Not to Scale




The water requirement will be met from the local sources through water tankers.

Suitable water transport arrangement will be made to transfer water for both

drilling and domestic purposes.

2.5.1.3 Power Requirement

The total power requirement at the drilling site and camp site will be 2250 KVA. The

power requirement in the drilling site and the campsites will be catered through

Diesel Generator (DG) sets. The power requirement will be met by 3 Nos of 750

KVA DG sets. Stand by DG set arrangement of 1 No of 750 KVA at drilling site will

be made. The DG set details and fuel requirements is given in Table-2.5.

TABLE-2.5

DETAILS OF DG SETS

Location DG Capacity Operational Stand by Fuel Requirement

Drilling site 750 KVA 3 1 HSD – 6 KL /day

2.5.1.4 Manpower Requirement

The drill site construction would be done largely employing local labour. At each

drill site construction, local employment will be generated for about 25/shift of 12

hrs in two shifts.

2.5.1.5 Drilling Mud

Only water-based drilling mud will be used for the drilling of all wells. Estimation

of quantity of drilling mud is nearly 700 m3 for each well.

Drilling of wells requires specially formulated muds which basically comprise inert

earth materials like bentonite, barite in water with several additives to give mud

weight, fluidity and filter cake characteristics while drilling. The drilling muds have

several functions like lubrication and cooling of the drill bit, balancing subsurface

formation, bringing out the drill cuttings from the well bore, thixotropic property

to hold cuttings during non-operations, formation of thin cake to prevent liquid

loss along well bore etc. Several additives are mixed into the mud system to give

the required properties. Water based mud will be used in exploratory drilling.

The constituents of water based mud (WBM) are given in Table-2.6. The special

additives and their functions in WBM are shown in Table-2.7.

TABLE-2.6

CONSTITUENTS OF WATER BASED MUD (WBM)

Sr. No Chemicals

1 Barite

2 Bentonite

3 Carboxy Methyl Cellulose

4 Mud Thinner / Conditioner

5 Resinated Lignite

6 Non-Weighted Spotting Fluid

7 Weighted Spotting Fluid

8 EP Lube




Sr. No Chemicals

9 Drilling Detergent

10 Caustic Soda

11 Potassium Chloride

12 Soda Ash

TABLE-2.7

SPECIAL ADDITIVES AND THEIR FUNCTIONS IN WATER BASED MUD

Sr. No. Discharge Category Exploration

1 Sodium bicarbonate Eliminate excess calcium ions due to cement contamination

2 Sodium chloride Minimize borehole washout in salt zone

3 Groundnut shells, mica of cellophane Minimise loss of drilling mud to formation

4 Cellulose polymers or starch Counter thick, sticky filter cake, decrease filter loss to formation

5 Aluminium stearate Minimize foaming

6 Vegetable oil lubricant Reduce torque and drag on drill string

7 Pill of oil based mud spotting fluid Counter differential pressure sticking of string. Placed down hole opposite contact zone to free pipe.

The main components of drilling mud are slurry of inert solids suspended in a

liquid phase. The main constituents of the water-based mud are Bentonite and

Barites and Calcium carbonate, all of which are natural minerals. The role of the

mud in pressure control is especially important. The density of the mud can be

increased by the addition of barite weighting material. Bentonite and Calcium

carbonate are employed to improve the theological properties and enable the drill

cuttings to be transported from the hole while drilling and also be suspended in

the fluid while the drill bit is being changed. The barite used in the drilling mud

would be as per American Petroleum Institute (API) standard specifications.

The composition and other mud parameters for different hole sections are given

in Table-2.8.

TABLE-2.8

COMPOSITION AND PARAMETERS OF WATER BASED DRILLING MUD

Mud Parameters Details for Different Hole Sections

Hole Section 17 ½” 12 ¼” 8 ½”

Depth 350 m to 500 m 900 m to 1500 m 1500 m to 3700 m

Mud Type Spud Mud PHPA – Polymer PHPA – Polymer

Density (ppg) 8.6+/- 9.5 – 10.5 ppg 10.0 – 11.5 ppg

Viscosity (sec /qt) >60 50-60 40-45

PV (cps) Alap Alap Alap

YP (lbs / 100ft2) 30-40 20-25 15-20

6 rpm dial reading 20-25 10-15 5-10

pH 8.8+/- 8.5 – 9.2 8.5-9.2

Ca++ (mg/l) <400 <400 <400

MBT (ppb) 30-35 20-25 <10

Drilled Solids (%) <7 <7 <5

API Fluid Loss (cc) n/c <20 <2

Lower Fluid Loss (cc) <15cc @ casing point <10cc @ casing point <5cc @ casing point

HPHT (cc) n/c <5cc @ 250°F 2cc @ 250°F

Cl– (mg/l) 400-1000 400-1000




If Synthetic Based Drilling mud (SBM) need to be used after certain depth,

synthetic mud will be recycled completely and at the end of the drilling activities,

drilling mud is collected and reused in subsequent drilling operations.

2.6 Proposed Schedule for the Project Approval and Implementation

The proposed exploratory drilling activity of 3 wells in the NELP block area will be

accomplished in phases. To accomplish the exploration, the operator will drill 3

numbers of exploratory wells to a depth of about 4400 m each well.

The duration of various stages of the drilling project is given as under:

The duration of construction works including site excavation, preparation and

well pad construction is expected to last approximately 90-100 days for each

well site.

The duration of drilling will range from 4-5 months, depending on the target

well depth.

Well testing operation will be done over a period of 2-3 days.

Abandonment and restoration of the well site is expected to take about one

month.

Thus, on an average, site preparation and drilling of one well is likely to take

approximately 4-5 months under normal conditions. Working hours during the

drilling operation will be 24 hours per day, seven days per week with 12 hours

per shift.

2.7 Technology and Drilling Process Description

The activity involves drilling of the hole across various ground layers to a

predetermined depth. ONGC proposes to charter a land drilling rig to achieve the

desired above objective. Rig essentially comprises of a mast, a draw work,

rotatory table, Kelly or top drive, mud pump engines and generators. The drilling

rig is presented in Figure-2.2.

2.7.1 Proposed Drilling Sequence

The drilling operation involves simultaneous data logging of the stratigraphy. If

sufficient evidence is found of well location having trapped hydrocarbons, a well

test will be performed to establish the oil & gas flow potential of the various zones

of interest. In case the well test yields encouraging results, further exploratory

wells will be drilled at identified locations within the prospect to delineate the

extent and quantum of the reserve.

The drilling rig will be a “land rig or Mobile Land Rig” of a smaller capacity with a

standard water or synthetic based drilling fluid treatment system. The choice of

the rig would depend on the depth and the geological formations likely to be

encountered. The well site once drilled will be temporarily suspended and the rig

will be moved to next location. The drilling campaign shall continue till adequate

results of the reservoir are collected for estimating the developmental activities.




The details of the exploratory drilling operation are given in the following

sections.

2.7.2 Drilling Phase

Having completed the drill site preparation, drilling rig and associated equipment

will be moved on to the location. This will be followed by a rig building process.

This process involves assembling of various rig parts and equipment to drill a

well. Once the drilling rig is assembled, thorough rig inspection will be carried out

to check equipment working capability and quality standards including compliance

to HSE requirements.

2.7.3 Drilling a Well

Well spudding is the start of drilling activity. Top-hole section will be drilled to a

desired depth based on well design. After drilling top-hole section, it will be cased

with a pipe called “Casing”. “Casing” provides support to hole wall and secures

hole section. Other than that it isolates problematic hole sections such as loss

zones, shale sections, over pressurized formations etc. After running casing,

space between hole wall and “Casing” (annulus) will be cemented. This process of

drilling and casing the hole section continues until the final well depth (target) is

achieved.

Drilling process may encounter various hazards such as well active situation

(kicks), blowouts, H2S situation etc. They are discussed in brief as follows.

Well Kick Situation

While drilling, if the formation pressure exceeds the hydrostatic pressure exerted

by the drilling fluid, formation fluids break out in to the well bore. This is called

kick. Primary means of well control is to have sufficient over-balance, over

formation pressure. For some reason if an unexpected over-pressurized formation

is encountered while drilling and if the well control situation arises, rig is equipped

with equipment to control this situation.

2.7.4 Proposed Hole Size / Casing Programme

The exploratory wells will be of “Slim Hole Design”. The wells will be drilled

vertically to different depths based on the “target” depth. Details of typical hole

size and casing are given in Table-2.9. It is to be noted that the figures given in

the table below are approximate and subject to change as the drilling proceeds.

TABLE-2.9

HOLE SIZE AND CASING DETAILS

Hole Size Casing Size Note

Installed during civil work 24 to 26” 20” Conductor

17 1/2” 13 3/8” Casing

12 1/4 “ 9 5/8 “ Casing

8 ½” 7” Casing

6” 5” Liner (Contingency)




FIGURE-2.2

DRILLING RIG




2.7.5 Surface Testing & Flaring

ONGC will conduct vertical flaring at all the sites, in case the presence of

hydrocarbon is encountered. A flaring stack with burner and adequate stack

height will be provided. Approximately, the duration of the test is around 2-3

days. Temporary test separators with all control facilities for flow metering will be

provided.

2.8 Details of Project Utilities

2.8.1 Site Preparation

On identification of the proposed drilling site, reconnaissance survey will be done

to locate suitable land on temporary lease basis. Land clearance for site

construction at each drilling site will be kept to a minimum practicable in order to

safely accommodate the facilities.

Earth moving equipment typically a bull dozer armed with a grader blade / ripper

teeth and scoop bucket will be used for the leveling / grading and excavating

work. Where possible topsoil will be cleared and stored for later reinstatement

purposes by piling it along the boundary of the site. The natural contours will be

worked on to minimise off-site disposal of excavated earth. The site area (except

the pit areas) will be provided with hard-standing by providing a layered base of

coarse aggregate covered with moorum. This is done to provide sufficient load-

bearing capacity to enable all construction and drilling operations to be executed

safely.

2.8.2 Approach Roads

The approach road to drill sites will need to be constructed/ upgraded to provide

access for the drilling equipment and construction machinery and material, supply

vehicles, passenger vehicles etc. In general, it is intended to make maximum use

of the existing infrastructure by strengthening the roads with the consent of the

local administration and the concerned regulatory authorities. This would result in

an added advantage to the local community. In case new roads are to be made,

compensation for right of way will be provided. The choice to leave these newly

constructed roads or to restore them back to original land use condition will

depend on the requirements of the local authorities.

2.8.2.1 Installation of Facilities

Site construction would include the impermeable layer lined drilling fluid, drill

cuttings, waste and water storage pits, foundations for the drilling rig and

accessories, inter-connecting drains, secure storage provision for chemical, oil

and waste oil, portable-cabins and a sewage treatment system (septic tank and

soak away pits and piping). A ground level flare pit arrangement will be made for

flaring purpose.

The mobilization of the drill site involves transportation of drilling rig in modules

and erected by means of mobile cranes. The drill site equipment’s are designed




as modular / skid mounted type, which facilitates quick demobilization and re-

mobilisation. The installation of the drill site equipment / facilities involves about

50 trailer loads spread over 10 days. Once the site is prepared, drilling

equipment, supplies and drilling personnel will be mobilized and the drilling rig

will be erected.

The salient features of the drill site facilities are detailed below.

Earthwork

The exploratory drill site area will be fenced by high barbed wire. The drilling rig

will be positioned almost in the middle of this area. Typically, a depth of 1.0 or

1.5 m is excavated around the prospecting drilling location. Excavation work shall

be carried out under the permit-to-work system and in such a manner that the

collapse of sidewalls is precluded. The foundations for the drilling rig and

accessories, inter-connecting drains, secure storage provision for chemical, oil

and waste oil, porta-cabins and a sewage treatment system (septic tank and soak

away pits and piping) waste and water storage pits will also be set up.

Appropriate fencing and sign boards will be provided to prevent persons and

livestock from accidentally falling into an excavation pit.

Surface Drainage

Drilling sites and camps will have an adequate drainage and wastewater

conveyance system so that all wastewater are contained and can be disposed as

per the Mizoram Pollution Control Board (MPCB) discharge norms.

The drilling rig location will be connected with paved drains to the lined drilling

fluid collection pits. Surface drains will be adequately graded and maintained and

kept debris free to ensure quick disposal of their contents. Bunds will be sized so

that they can contain surface runoffs for limited period.

Fuel & Chemical Storage Area

The fuel (Diesel) will be received in bulk quantity through road tankers and stored

in above ground steel diesel tanks. The tanks will be constructed, operated and

maintained as per the requirements of the Explosive Rules and all the statutory

licenses will be obtained. The tank farm area will be provided with secondary

containment of adequate capacity to impound any accidental leaks.

Chemicals will be stored on a paved platform with kerb walls and protected

against weather through an impervious covering. Separate storages are

earmarked for liquid and solid chemicals. All the storages are identified with tags

and sign boards. All required safety precautions such as display of the MSDS,

provision of fire extinguishers are followed.

Waste Oil collection, Storage & Disposal System

Waste oil of about 150-200 liters/day from pumps or other machinery will be

trapped and manually collected and stored in a paved dedicated waste oil storage

area. The storage area will be provided with paved flooring, containment bunding




and covered roofing. The storage facility shall be designed based on the CPCB

guidelines for Hazardous waste Storage. The waste oil will be collected and

handed over to MPCB and MoEF&CC authorized waste oil recyclers at the end of

the exploratory drilling campaign.

Spill Containment System

Containment systems and oil traps will be provided to trap any escape of oil

before it can leave the drilling site. All potential sources of spillage will be

equipped with drainage facilities / drip pans / spill collection kits in order to

contain spills. Drains and bunds will be sized to contain surface runoffs for limited

period and any oil detected in the drains will be manually soaked using sorbent

materials.

Water & Drilling Fluid Storage Pit

The water storage pit contains the water used for preparing drilling fluid. The

drilling fluid storage pit will collect all the wastewater, which come from the

drilling operations. The wastewater present in the waste pits will be recycled and

reused during drilling phase. Whereas, the residual wastewater from the drilling

operation will be collected in waste pits for solar drying. The pit will be lined with

polyethylene propylene sheet and the overlaps welded together with the edges

bought over the rim and tucked into the soil. At the end of the drilling phase, the

liquid fraction of the waste drilling fluid will be allowed to evaporate and the pit is

filled with soil and capped with compacted moorum layer.

Drill Cuttings Disposal Pit

Cuttings will be collected and disposed off in an environmentally safe manner.

The cuttings disposal pit will be similar in construction to the wastewater pit.

Typically the pit would be about 30’ x 33’ x 5’ – 2 Nos, 38’ x 33’ x 5’ – 1 Nos, 23’

x 20’ x 5’ – 1 Nos, and oil pit 3’ x 3’ x 4’ – 1 Nos will be lined with polypropylene

liner. The cuttings disposal pit will be placed within the drilling lease area to

prevent the transport of waste mud and cuttings from the drilling site to another

area to prevent any spillage on the other areas.

Domestic Sewage Treatment & Disposal System

The domestic sewage generated from the drill site operations will be disposed off

in a septic tank – soak pit system. The septic tank will conform to the IS design

specification. The overflow from the septic tank will be led into series of soak pits

for sub-surface disposal.

Drilling Fluid Circulation

The drilling fluids circulation system consists of several items of equipment. The

mud pump takes in mud from the mud tanks and sends it out a discharge line to

a standpipe. The standpipe is a steel pipe mounted vertically on one leg of the

derrick. The mud is pumped up the standpipe into a flexible reinforced rubber

hose called the Kelly hose. The Kelly hose is connected to the swivel; goes down

the Kelly, drill pipe and drill collars and exits at the bit. The mud then does a

sharp U-turn and heads back up the hole in the annulus. The annulus is the space

between outside of the drill string and the wall of the hole. Finally, the mud

leaves the hole through a steel pipe called the mud return pipe and falls over a




vibrating screen like device called the shale shaker. The mud containing cuttings

is screened out of the shaker. The mud drains back into the mud tanks and is

recycled back into the well via the mud pump, while the drill cuttings which are

inert materials of shale, sand, and clay fall into the lined waste pits. Once the

mud is cleaned, it is pumped down the drill string again. The drilling fluids left

over at the end of the particular well, which can’t be further reused, will be

discharged into the lined waste pits and dried. The pits will be provided with

HDPE liners to maintain integrity and prevent any leakage. The drill cuttings cut

by the drill bit are removed from the mud by the shale shakers and other solids

removal equipment and transferred to the waste pits. The drilling fluid circulating

system at rig is essentially a self contained, closed system, shown in Figure-2.3.

Role of Drilling Fluids

Drilling fluid serves the following essential functions:

The removal of drilled solids (i.e. cuttings) from the bottom of the hole and

their transport to the surface for separation from the mud;

Lubrication and cooling of the drill bit and string;

Deposition of an impermeable cake on the well bore wall to seal the formation

being drilled;

Suspension of drilling cuttings in the fluid during the interruption of drilling;

and

Countering the natural formation pressures and preventing uncontrolled flow

of fluid from the formations.

The role of the drilling fluids in pressure control is especially important. If the drill

bit penetrates a formation containing oil, gas or water under pressure these fluids

are prevented from flowing into the borehole by ensuring that the drilling mud is

of sufficient density to counter the natural formation pressures. The density of the

mud can be increased by the addition of barite weighting material. Bentonite is

employed to improve the rheological properties and enable the drill cuttings to be

transported from the hole while drilling and also be suspended in the fluid while

the drill bit is being changed. The barite used in the drilling mud would be as per

API standard specifications.

Water based drilling fluids, which are of an environmentally acceptable nature

with regards to current Indian legislation, will be used. The water based drilling

fluid will be non-hazardous in nature.




FIGURE-2.3

DRILLING FLUID CIRCULATION SYSTEM AT TYPICAL RIG




2.9 Post Drilling Operations - Abandonment and Restoration

2.9.1 Demobilization & Decommissioning

Well Capping - Removal of Equipment and Materials

In the event that economic quantities of hydrocarbons are found, the well will be

suspended with a wellhead / X-mass tree in place, but all other equipment and

materials will be removed from the site.



associated equipment will be removed. The access road(s) would be either left

behind or reinstated based on the needs of the local authorities.

Restoration of Cutting Containment Area

At the conclusion of well testing at each drilling site, the spent drilling fluids will

be dewatered by flocculating the contents and allowing the water phase to

evaporate away. All solids & liner will be buried in a secured lined pit and covered

with soil and left onsite. The cutting mud is inert and with appropriate lining of

the pit in place it does not pose any potential for soil or groundwater

contamination. ONGC will follow a well laid site restoration plan. Tree plantation

will be done on the closed pits to restore the original soil conditions. At all the

sites the pits are filled with the black cotton soils or red soils which is available at

shortest distance. Filling and plantations are handed over to the contractors with

close watch of ONGC officials.

2.9.2 Restoration of Well Sites

Decommissioning upon Abandonment

In the event that economic quantities of hydrocarbons are found, the well site will

be closed as detailed above. In the event that no economic quantities of

hydrocarbons are found, a full abandonment plan will be implemented for the

drilling sites.

The actions outlined above would apply to decommissioning upon abandonment

as well, but abandonment would be more permanent. All concrete or steel

installations would be removed to at least 1 m below ground level so as to ensure

that there are no protruding surface structures. In the unlikely event that soil is

found contaminated, measures would be taken to remove or treat appropriately

all contaminated topsoil to promote its remediation.

The overriding principle being that the environment should, with time, be

reinstated to broadly its original condition. Until such time as this is achieved,

ONGC would actively manage the reinstatement process.

2.9.3 Traffic Volumes

During the civil operations earth moving equipment will be working on the access

road and the well location. It is anticipated that there will be an average of 5




truck movements a day to cater the site preparation for an average period of

about 20 days.

Prior to and after the drilling operation, when building the rig or rig move, up to

80 heavy truckloads over a period of 4-5 days are envisaged.

During the drilling operation, supply truck movements are estimated on an

average of Eight to five per day. Small vehicles movements are used mainly for

transport of personnel, visitors etc. which might be as much as 10 per day.

ONGC will engage in constructing compacted approach roads without black

topping to all well locations and camp sites. Though this will not cause any

changes in topography, the dust generation will be less than any other village

roads. The same roads can be used by the villagers after completion of the

drilling activities.

2.10 Sources of Pollution

2.10.1 General

The various types of pollution from the proposed exploratory drilling operations

are:

Wastewater Generation and Disposal;

Air Emissions;

Solid Waste Generation; and

Noise Generation.

Exhaust gases from DG sets, wastewater, drilling wastes and noise from the

drilling operations are the major sources of the pollutants generated during the

proposed drilling operations which is temporary activity lasting for maximum of 4-

5 months at each of the well locations.

2.10.2 Wastewater Generation and Disposal

Water will be required during the exploratory drilling phase for drilling fluid

preparation and for domestic purposes. Thus, wastewater during this phase will

comprise of drilling wastewater and domestic wastewater.

Drilling sites and camps site will have an adequate drainage system so that all

wastewater are contained and disposed as per the PCB Standards. Means will be

provided to trap any escape of oil before it can leave the site. Surface drains will

be adequately graded and kept debris free to ensure quick disposal of their

contents. Minor quantity of wastewater would be generated from cleaning

operations carried out at the rig. About 15 to 20 m3 /day of wastewater is

expected.

All wastewater streams except sewage will be directed to a 1 mm HDPE lined pit.

Wastewater collected in the pit will be clarified and treated in solar evaporation

pond or packaged wastewater treatment plant for removal of oil and suspended

solids to meet the regulatory discharge standards.




Solids generated from the treatment plant will be collected, tested for hazardous

contents and disposed to land once it is ensured that there are no hazardous

contents.

Produced water generation is not envisaged during the exploratory drilling phase.

Domestic Wastewater

Sewage generated from the camps would be discharged and treated in septic

tanks. The supernatant from the septic tanks will be passed through soak pits

into the ground. The quantity of sewage generated at each drill site is expected to

be around 4 m3/day.

2.10.3 Air Emissions

During routine drilling operation, air pollutants are emitted by the diesel engines

that power the drilling equipment. These engines release particulate matter that

can contain heavy metals, volatile organic compounds and polycyclic organic

matter. They also emit Sulphur dioxide, oxides of Nitrogen which contributes to

smog formation. The vehicular movement associated with the drilling activities is

also an important cause for the dust pollution.

The predominant air emissions from the proposed drilling operations are gaseous

emissions, viz., Sulphur dioxide, Oxides of Nitrogen and Hydrocarbons.

Each power generator will have the adequate stack height for easy dispersion of

gaseous emissions. The height of the D.G exhaust stack will be about 7.5 m

(including the height of the trailer from the ground).

Natural gas and traces of crude oil in gas will be flared during the well testing

phase for short period. The test flaring will result in temporary emissions of CO2,

water vapours, NOX and other trace gases in case of natural gas flaring and

additionally particulates in case crude oil is flared. It is assumed that the

occurrence SO2 in the flare gas would be in traces or negligible.

2.10.4 Solid Waste

The drilling operations generate drill cuttings. The minor wastes include sanitary

waste, domestic waste and waste oil from lubricating system.

2.10.4.1 Drilling mud

The drilling mud will be re-circulated and reused to maximum possible extent

through its mud recycling system. Maximum amount of drilling mud attached to

the drill cutting is separated by Solid control System such as Shale Shaker, clay

shaker and will be recycled during the drilling process. However, only a portion of

the non usable mud at the end of the drilling would be discharged. The drilling

mud will be collected in lined pit and solar evaporated.




2.10.4.2 Drill cuttings

Drilling cuttings are worn out rocks from subsurface formations that are

generated during drilling operations. The drill cuttings are conveyed to the

surface, suspended in the drilling fluid (drilling mud). The drill cuttings are

separated in the shale shaker from the drilling mud and are stored in an

impervious 1.5 mm HDPE lined pit. The particle size varies from coarse particles

of less than 1mm diameter to few centimeters. Drill cuttings are encapsulated by

a thin layer of adhering mud.

The drill cuttings will be washed thoroughly and the wastewater generated will be

treated. The clarified drill cuttings would then be dumped in a HDPE lined pit.

Once the drill cuttings are dried it will be further treated and disposed through

land farming by applying oil degrading bacteria, native soil and nutrients.

Bioremediation and land farming are considered as a good treatment options

which are recognised by MoEF as per MoEF guidelines for disposal of Drill Cutting

/ Drilling Mud for onshore drilling activities (G.S.R. 546/E) dated 30-8-05.

2.10.4.3 Waste Pit details

Typical sectional view of the drill cutting and drilling mud collection pit is

presented in Figure-2.4.

The storage pit will be constructed as per the method and specification of

CPCB/MPCB. The pit shall consist of following layers commencing from the

bottom;

Compacted sub-base and side slopes comprising of clay or amended soil layer

of 300 mm compacted thickness;

Synthetic liner (HDPE / geo-membrane) of a minimum of 1.5 mm thick; and

The drill cuttings are dewatered to reduce the amount of liquid fraction carry

over. The liquid fraction of the drilling mud is recycled and excess fluid stored

in the lined pits. The cuttings and mud waste are stored in lined pits and solar

evaporated and covered with layer of local soil. The liner is tucked into the

natural ground to form a continuous layer. All joints are seam welded to

ensure the cover is continuous over the surface of the pit material. The pit is

filled back with natural soil and locally available clay layer is placed at the

upper most layer (top surface). The top surface is cambered with 2–3% slope

to drain away the rain water from the pit location.




FIGURE-2.4

TYPICAL SECTION VIEW OF DRILLING CUT AND DRILL MUD COLLECTION PIT




2.10.4.5 Used / Spent Oil

Used / spent lubricating oil from pumps or other machinery would be trapped and

manually collected and stored in a paved dedicated waste oil storage area.

Approximately 150-200 liters/month of used / spent oil would be generated from

a drilling operation. Stored waste oil would be disposed off to Mizoram State PCB

& MoEF registered used / spent oil recyclers.

2.10.4.6 Summary of Waste Generation Quantities and Treatment and disposal Method

The quantum of wastes that would be generated from each well depends upon its

target depth and duration of testing.

2.10.4.7 Drilling mud and drill Cuttings Analysis

The drill cuttings & the drilling mud at each location will be tested to ensure it

meets the requirement of MoEF&CC guidelines for disposal of drill cuttings and

drilling fluids for onshore operations. The analysis carried out on spent drilling

mud / cuttings during the previous drilling campaigns by ONGC in other parts of

the country have reported LC50 in excess of 30,000 mg/l.

The potential source of heavy metal concentration in the drilling mud is primarily

from the barite used in the mud formulation. Presence of heavy metal in drill

cuttings is attributed to lithological characteristics of subsurface layers. Drill

cuttings and mud would thus also be analyzed for heavy metal concentrations

before disposal.

2.10.5 Noise Levels

The major noise generating sources are DG sets, pumps at drilling rig and other

equipment of drilling rig would contribute to continuous noise. Typically, the noise

generating sources for the drilling activity are provided below (in the immediate

vicinity):

Diesel Generator : 90 to 95 dB(A)

Pumps at the Rig : 85 to 90 dB(A)

Miscellaneous : 80 to 85 dB(A)

Control Room & Quarters : 50 to 60 dB(A)

Noise is not considered to be a potential threat since the drilling sites will be

selected keeping in view that there are no settlements in close proximity to the

drilling site.

2.11 Qualifications, Skills and Training Practice

a) Qualification

Jobs requiring specific qualifications and certificates e.g. welding, driving of

vehicles, electrical work, crane operation, fork lift & bulldozers operation should

be carried out only by persons having the required qualifications and certificates.




The certificates should be properly checked for adequacy and a copy of the same

should be available for verification by ONGC personnel.

b) Skills

Certain jobs e.g. operation of cranes and other mechanical equipment, erection of

scaffolding need required skills and persons deployed should be checked for

possession of adequate skills and experience in carrying out such work.

c) Training

All required HSE related training e.g. safe evacuation during emergencies, permit

to work requirements, proper use of personal protective equipment, should be

provided by the contractor HSE supervisor. The training contents should be

discussed with the ONGC HSE personnel.

d) Personal Protective Equipment (PPE)

No personnel will be allowed into the drill site if the required PPE is not used.

Adequate stock of required PPE will be available and distributed whenever

needed. The PPE requirements are hard hat and safety shoe and those working in

the drilling rig, overalls, gloves, safety glasses, nose masks when needed) and

ear-muffs. Personnel working at height (during maintenance / erection) will need

to use safety belts securely anchored.

e) General HSE Requirements

The general HSE requirements of ONGC which is strictly complied with by all

ONGC and contract employees are enumerated below.

f) Vehicle Movement

The speed limit for vehicles is 10 kms/hr in village area and near to schools and

in construction area. On tar road maximum speed is restricted to 35 km/hr and

on highway speed should not be more then 60 km/hr for heavy vehicles and 80

km/hr for light vehicle.

g) No Smoking Regulations

Smoking is strictly prohibited in all the areas in the site.

h) First Aid Center

A first aid center shall be located at the construction site. The service of a doctor

shall also be available all the time in the first aid center.

i) Permits

Type of permits agreed should be obtained wherever required. Conditions and

precautions mentioned in the permit should be strictly followed.




j) Fire Extinguishers

Temporary fire extinguishers shall be readily available at convenient locations for

use during any fire emergencies.

All persons working in the contract should be above 18 years of age and no child

labour will be engaged in any job at any time.

k) Safety Seat Belts

All the vehicles used for construction purpose should be provided with safety seat

belts. No vehicles are allowed inside the site without safety seat belts.

Environmental Impact Assessment Report for Proposed drilling of 3 Exploratory Drilling wells in Existing NELP Block AA-ONN-2001/2, Kolasib & Mamit District, Mizoram

Chapter-3 Baseline Environmental Status


3.0 BASELINE ENVIRONMENTAL STATUS

3.1 Introduction

This chapter illustrates the description of the existing environmental status of the

study area with reference to the prominent environmental attributes. The study

area covers 3 wells in existing NELP Block AA-ONN- 2001/2, Kolasib & Mamit

District, Mizoram.

The entire block area considered for the study, description of biological

environment and Human environment such as environmental settings,

demography & socio-economics, land-use/land cover, ecology & biodiversity have

been carried out during study period. However, as a universally accepted

methodology of EIA studies, physical environmental attributes such as Ambient

Air Quality, Water Quality, Soil Quality, Noise Levels, Physiography, Hydrology,

Odour, Solid Waste Generation have been studied at selective locations

representing various land uses such as industrial, rural/residential, commercial

and sensitive locations including the densely populated areas, agricultural lands,

forest lands and other ecologically sensitive areas, if any falling within block area.

The existing environmental setting is considered to know the baseline

environmental conditions, which are described with respect to climate, hydro-

geological aspects, atmospheric conditions, water quality, soil quality, ecology,

land use and socio-economic profiles of people. The baseline studies are carried

out in partly winter and partly pre-mosoon season covering 15th January 2016 to

8th April 2016.

This Report incorporates the baseline data monitored for winter season and

secondary data collected from various Government and Semi-Government

organizations.

3.2 Geology and Hydrogeology

3.2.1 Physiography (Kolasib and Mamit Districts)

Physiographically, the terrain is mountainous with prominent relief. Hill ranges

are trending in the north-south direction. Parallel to sub parallel anticlinal hill

ranges, synclinal narrow valleys form deep gorges. Basically these are structural

hills. The process of denudation and weathering is still continuing in response to

various natural forces. One of the dominant forces of formation of such landforms

is exerted by running water. Based upon lithology, relief, drainage, and structural

pattern, the district has been divided into two major units viz denudostructural

hills and valleys.

Denudo-structural Hills

Major portion of the district is occupied by denudostructural hills which are

predominantly argillaceous comprising shale, siltstone and mudstone, fine grained

and compact sandstone with occasional limestone. The processes of denudation

have not yet obliterated the structural features such as dip facets and strike

trend; anticline and syncline. This major form has been further divided as follows:




Low Linear Ridges

These are low elevated hills and occupy outer flank of structural folds. They have

gentle to moderate slopes and possess gully erosion. The main drainage system

is controlled by strike of the formations and shows slight meandering pattern. The

main rock types represent a mixture of arenaceous as well as argillaceous

assemblages, comprising shale and fine to medium grained, friable sandstone.

Moderate Linear Ridge

Moderate linear ridges occupy about 90% of the district. The main constituents

are hard and compact sandstone, shale and siltstone, alterations of Bhuban

Formation. The ridges show serrated top and hogback pattern, which are highly

dissected and separated by intervening ‘V’ shaped narrow valleys.

Valleys in Kolasib District

The valleys have limited aerial extend and occur mostly in the North, Northwest

and a portion of south part of the district adjacent to Hailakandi and Cackar

districts of Assam.

Valleys in Mamit District

The valleys have limited aerial extend trending North-South direction.

Linear rolling valley Kolasib District

These valleys are found in the structural depressions in between low linear ridges

of fine to medium grained, friable sandstone with subordinate shale of Bhuban

group of rocks and siltstone, shale, and mudstone with subordinate sandstone of

Bokabil group of rocks.

Linear rolling valley Mamit District

These valleys are found in the structural depressions in between low linear ridges

of fine to medium grained, friable sandstone with subordinate shale of Bhuban

group of rocks.

3.2.2 Geology of Kolasib District

Geologically, the district is occupied by shale, siltstone, and sandstone of Barail

Formation of Oligocene age and Surma Formation of Miocene age.

Geology of Mamit District

Geologically, the district is occupied by shale, siltstone, and sandstone of Barail

Formation of Oligocene age and Surma and Tipam formation of Miocene age.

Geological setting of the area falling in AA-ONN-2001/2 Block

Geological mapping carried out by ONGC has identified four structures in the

block viz Sentet Anticline, Aizawl Anticline, Teidukhan Anticline & Hachek




Anticline. Gas discovery has been made in well HO-01 from Lower Bhuban play in

Sentet cross faulted plunge area.

3.2.3 Rainfall and Climate (Kolasib and Mamit Districts)

The climate of the district is characterized by tropical humid climate with cool

summers and cold winters. Winter temperatures vary between 11º and 13º C in

general. The winter season is however, without snow. The normal annual rainfall

is 2,216 mm and average annual rainfall is 2,794 mm. the rainfall is due to the

monsoons from early May to late September.

3.2.4 Drainage of Kolasib District

The major drainages include Serlui, Tuichhuahen and Tuirial Rivers. Numbers of

perennial streams flow through the district from north to south.

Drainage of Mamit District

The major drainages include Tuirial River flowing to the South. Numbers of

perennial streams flow through the district from north to south.

3.2.5 Soil types (Kolasib and Mamit Districts)

The soils of the districts, in general, have been derived from parent rock such as

ferruginous sandstone, shale, alluvial and colluvial materials. In general, the soil

formations have been categorized into following groups:

Hills

It includes colluvial soil, formed along the steep sided slopes because of

accumulation of soil forming materials on slope surface.

Valleys

Soils occur as a mixture of colluvial and alluvial materials. It is restricted to the

rolling valleys along the river cources.

Terraces

These are the remnants of deposits of cobbles and pebbles.

3.2.6 Hydrogeology

The hydrogeological studies to understand the local geology, geomorphic

features, drainage network, aquifer characteristics and yield of water.

Accordingly, various components controlling the hydrogeological regime.

Hydrogeology map of Kolasib and Mamit districts is given in Figure-3.2.1 &

3.2.2.




Hydrogeologically, the entire area of Kolasib and Mamit districts is occupied by

semi-consolidated formations of denudostructural hills belonging to Barail

Formation of Oligocene age and Surma and Tipam Formation of Miocene age

with limited aerial extent of linear rolling valleys adjacent to Assam. The low

linear ridges are characterized by low permeability and infiltration capacity. It

acts as run off zone. The moderate linear ridges, which occupy the major portion

of the district, comprise hard and compact sandstone, shale, siltstones and

alternations of Bairal and Surma Group of rocks. This unit is also characterized by

very low permeability and infiltration capacity that acts as run off zone. Ground

water potential is low.

The linear rolling valleys with limited aerial extend are underlain by shale,

sandstone and siltstone alternations. No ground water abstraction structures are

noticed in the valley. However, during earlier field investigation by CGWB,

occurrences of small pond like structures with very shallow water level (2.0 m

bgl) had been reported. As such, shallow ground water structures may be feasible

in suitable locations of the valley portions.

Occurrence of ground water (Kolasib and Mamit Districts)

Ground water systems are a result of the complex combination of different

lithological and structural types within an area that together constitute an aquifer

within which ground water accumulates and moves. Rather than describing

individual lithologies and their tendencies to form aquifers or otherwise, it is

useful to describe the ground water as one continuous across various lithological

types (Kulkarni and Deolankar, 1995).

In general, the terrain is tectonically young and immature. The occurrence of

ground water in such a terrain is mainly restricted to weak zones such as

fractures, lineaments and weathered residuum. These tectonic elements create

seepage conduits, which are sources of springs. These springs are utilized as the

main source of water supply to the populace. The existing water supply for

drinking purposes is mainly from those springs tapped through gravity drainage.

A number of springs were inventoried during earlier field investigations. All the

springs are fractures and joints oriented. A large number of springs are perennial.

In general, discharges of the springs are meager in high altitudes which

progressively increase down slope. Discharges of the spring vary between 3000

and 20,000 litres per day during the period from January to March, which is

generally dry period.




FIGURE-3.2.1

HYDROGEOLOGY MAP OF KOLASIB DISTRICT




FIGURE-3.2.2

HYDROGEOLOGY MAP OF MAMIT DISTRICT




3.2.7 Ground Water Resources

Ground Water Recharge

The main source of ground water recharge is by the rainfall by direct percolation

to the zone of saturation. A significant part of the rainfall is lost as runoff from

area while a limited percentage of rainfall therefore reaches zone of saturation

and becomes the part of ground water storage after meeting the evaporation and

evapo- transpiration losses. There is also ground water recharge from the return

flow of irrigation water from dug wells and tube wells operated by the cultivators

and from canals.

The dynamic groundwater resources of Kolasib and Mamit Districts has been

estimated jointly by CGWB and SWID. Govt of Mizoram, following the norms laid

down by GEC-1997 methodology and projected as on 31.03.2011. The ground

water resources of the districts is given in Table-3.2.1.

TABLE-3.2.1

THE DYNAMIC GROUNDWATER RESOURCES AS ON 31.03.2011

Quantity (Ham)

Sr.No Particulars Kolasib Mamit

1 Total Annual Replenishable Ground Water

Resources

424 325

2 Natural Discharge during Non-Monsoon

Period

42 33

3 Net Annual Ground Water Availability 382 293

4 Total Annual Ground Water Draft 8 7

5 Projected demand for Domestic and

Industrial uses upto 2025

17 21

6 Net Ground Water Availability for Future

Irrigation use

364 272

7 Stage of Ground Water Development (%) 2.07 (“Safe”) 2.41 (“Safe”)

Source: Dynamic Ground Water Resources of India-July 2014

3.3 Land Use Studies

Studies on land use aspects of eco-system play important roles for identifying

sensitive issues, if any, and taking appropriate actions for maintaining the

ecological balance in the development of the region.

3.3.1 Objectives

The objectives of land use studies are:

To determine the present land use pattern;

To analyze the impacts on land use due to drilling activities in the study area;

and

To give recommendations for optimizing the future land use pattern vis-a-vis

growth of drilling activities in the study area and its associated impacts.




3.3.2 Methodology

For the study of land use, literature review of various secondary sources such as

District Census Handbooks, regional maps regarding topography, zoning

settlement, industry, forest etc., were taken. The data was collected from various

sources like District Census Handbook, Revenue records, state and central

government offices and Survey of India (SOI) Topo-sheets and also through

primary field surveys.

3.3.3 Land Use Based on Satellite Imagery

Present land use based on remote sensing satellite imageries were collected and

interpreted for the block area for analyzing the land use pattern of the study

area. Based on the satellite data, land use/ land cover maps have been prepared.

Land use/Land Cover Classification System

The present land use / land cover maps were prepared based on the classification

system of National standards. For explanation for each of the land use category

the details as given in Table-3.3.1 are considered.

TABLE-3.3.1

LAND USE/LAND COVER CLASSIFICATION SYSTEM

Sr. No. Level-1 Level-2

1 Built-up Land Town/cities

Villages

Institution/industry/godown etc

Plotted area/layout

2 Agriculture Land Crop land

Plantations

Fallow

3 Forest Evergreen/semi evergreen

Deciduous

Forest plantation

4 Wastelands Rocky/stony waste

Land with /without shrubs

Saline/sandy & marshy/swampy

5 Water Bodies River/stream

Lake/reservoir/tanks

6 Others Orchard/Other plantation

Shifting cultivation

Salt pans, snow covered/glacial

Barren/vacant land

Data Requirements

IRS Resourcesat-2 of 5m resolution (LISS-IV) FX was acquired for 16th January &

28th February, 2015 and was used for the mapping and interpretation. Besides,

other collateral data as available in the form of maps, charts, census records,




other reports and especially topographical survey of India maps are used. In

addition to this, ground truth survey was also conducted to verify and confirm the

ground features.

Methodology

The methodology adopted for preparation of land use/ land cover thematic map is

monoscopic visual interpretation of geocoded scenes of IRS Resourcesat-2

(LISS3) and field observations are taken. The various steps involved in the study

are preparatory field work, field survey and post field work.

Pre-field Interpretation of Satellite Data

The False Colour Composite (FCC) of IRS Resourcesat-2 satellite data are used for

pre-field interpretation work. Taking the help of topo sheets, geology, geo-

morphology and by using the image elements the features are identified and

delineated the boundaries roughly. Each feature is identified on image by their

image elements like tone, texture, colour, shape, size, pattern and association. A

tentative legend in terms of land cover and land use, physiography and erosion

was formulated. The sample areas for field check are selected covering all the

physiography, land use / land cover feature cum image characteristics.

Software’s used

a) ERDAS Imagine for image processing/rectification/geocoding;

b) AutoCAD for data preparation after visual interpretation of the image; and

c) Arc View for image/landuse presentation.

Ground Truth Collection

Both toposheets and imagery were taken for field verification and a transverse

plan using existing road network was made to cover as many representative

sample areas as possible to observe the broad land use features and to adjust the

sample areas according to field conditions. Detailed field observations and

investigations were carried out and noted the landuse features on the imagery.

Post Field Work

The base maps of the study area were prepared, with the help of survey of india

toposheet. Preliminary interpreted land use and the land cover features

boundaries from IRS false colour composite were modified in light of field

information and the final thematic details were transferred onto the base maps.

The final interpreted and classified thematic map was catrographed. The

cartographic map was coloured with standard colour coding and detailed

description of feature with standard symbols. All the classes noted and marked by

the standard legend on the map.

Final Output

The final output would be the landuse/land cover map and numerals were given

different colour code for each category as shown in map. Area estimation of all




features of land use/land cover categories was noted. The satellite imagery and

land use pattern is shown in Figure-3.3.1 and Figure-3.3.2. The details of the

land use in block area are given in Table-3.3.3. Digital elevation model of the

study area is shown in Figure-3.2.3.

TABLE-3.3.3

LAND USE BREAK UP OF THE STUDY AREA

Sr. No. Landuse Area (Sq. Km) %

1 Built Up Land A. Settlements / Air Port

146.608

4.9

2 Waterbodies A. Reservoir / River etc.

311.168

10.4

3 Crop Land A. Crop land

137.632

4.6

4 Wastelands A. Land with scrub B. Land without scrub C. Mining area

2249.984 77.792 68.816

75.2 2.6 2.3

TOTAL 2992 100

Observations

The land use pattern of the study area indicates built-up land of 4.9%, land under

agriculture is about 4.6 %, waste land is about 80.1% and water bodies

contribute about 10.4% in the study area.




FIGURE-3.3.1

SATELLITE IMAGERY OF THE BLOCK AREA




FIGURE-3.3.2

LAND USE PATTERN BASED ON SATELLITE DATA




3.4 Soil Characteristics

For studying soil profile of the region, sampling locations were selected to assess

the existing soil characteristics in and around the exploratory drilling area

representing various land use conditions. The physical, chemical and heavy metal

concentrations were determined. The samples were collected by ramming a core-

cutter into the soil upto a depth of 90 cm. A total of 10 numbers of samples

within the study area were collected and analyzed. The details of the soil

sampling locations are given in Table-3.4.1 and are shown in Figure-3.4.1. The

soil sampling photographs are shown in Figure-3.4.2. The sampling has been

carried out once in the study period representing partly winter and partly pre-

monsoon season (15th January 2016 to 8th April 2016).

TABLE-3.4.1

DETAILS OF SOIL SAMPLING LOCATIONS

Sampling Station Location Well location

S1 Bilkhawthir -

S2 Kolasib -

S3 Bairabi Near HOAC, HOAD

S4 Suarhlip Near BRBAA

S5 Sethawn -

S6 Zamuang -

S7 Vawngawn -

S8 Mualvum -

S9 Mamit -

S10 Lengpui -

The soil quality at all the locations during the study period is given in Table–

3.4.2. The results are compared with standard classification given in Table -

3.4.3.

3.4.1 Baseline Soil Status

o It has been observed that the texture of soil is mostly clay type in the study

area. The pH of the soil 7.11 – 8.08 indicating that is neutral to moderately

alkaline in nature.

o The Electrical conductivity was recorded as 118.2 µS/cm to 262.0 µS/cm.

Minimum concentration was observed at S3 and maximum concentration at

S7 during the study period.

o The Organic Carbon content in the study area observed as 0.31 % to 0.62 %,

which the soil falls under on average sufficient to more than sufficient

category.

o Available potassium was observed as minimum 86.6 Kg/ha at S6 and

maximum observed as 172.0 Kg/ha at at S7 indicating that the soil falls under

very lees to less.

o Available Nitrogen was observed as 31.5 Kg/ha to 69.7 kg/ha. Minimum

concentration is observed at site S3 and the maximum observed

concentration observed at S8 locations. Based on the above values the soil

falls under very less to less category.

o Available phosphorous was observed as 13.5 kg/ha to 88.6 kg/ha in the study

region. The minimum value observed at S4 location and the maximum was

observed at S7 location. It shows the soil falls under very less to more than

sufficient category.




FIGURE-3.4.1

SOIL SAMPLING LOCATIONS




Soil sampling at Bairabi

Soil sampling at Suarhlip

FIGURE-3.4.2

SOIL SAMPLING PHOTOGRAPHS

Environmental Impact Assessment Report for Proposed 3 Nos of Exploratory Drilling in Existing NELP Block AA-ONN- 2001/2, Kolasib & Mamit District, Mizoram



TBLE 3.4.2

SOIL ANALYSIS RESULTS

Sr.No. Location Unit S1 S2 S3 S4 S5 S6 S7 S8 S9 S10

1 pH (1:5 Aq. Extraction) -- 7.56 7.91 8.08 7.42 7.11 7.36 7.59 7.63 7.78 7.84

2 Conductivity (1:5 Aq. Extraction)

µs/cm 186.0 152.9 118.2 190.0 212.0 164.0 262.0 177.0 225.0 130.0

3 Texture -- Clay Sandy Clay

Clay Loam

Sandy Clay

Clay Clay Clay Sandy Clay

Clay Clay

4 Sand % 19 35 31 38 20 17 15 36 12 14

5 Silt % 21 20 17 20 22 15 19 24 23 16

6 Clay % 60 45 52 42 58 68 66 40 65 70

7 Bulk Density g/cc 0.96 1.18 1.05 1.15 0.98 0.95 1.01 1.16 0.98 1.0

8 Exchangeable Calcium as Ca mg/kg 1395.0 1542 1105.0 1948.0 3432.0 2598.0 3152.0 2173.0 2816.0 1844.0

9 Exchangeable Magnesium as Mg mg/kg 398.0 416 408.0 556.0 679.0 741.0 812.0 480.0 540.0 425.0

10 Exchangeable Sodium as Na mg/kg 42.8 47.2 45.6 63.8 89.5 66.4 71.2 54.5 65.8 49.6

11 Sodium Absorption Ratio -- 0.26 0.28 0.30 0.33 0.37 0.30 0.29 0.28 0.30 0.27

12 Available Nitrogen as N Kg/ha 47.4 52.6 31.5 53.5 52.2 38.9 52.8 69.7 37.0 36.8

13 Available Phosphorous as P Kg/ha 38.5 71.1 56.2 13.5 66.4 47.8 88.6 62.5 28.8 51.6

14 Available Potassium as K Kg/ha 88.1 130.2 146.5 122.6 120.9 86.6 172.0 107.4 131.5 164.9

15 Organic Carbon % 0.51 0.46 0.31 0.48 0.55 0.42 0.54 0.62 0.39 0.38

16 Organic Matter % 0.88 0.79 0.53 0.83 0.95 0.72 0.93 1.02 0.67 0.66

17 Water soluble chloride as Cl mg/kg 141.0 156.4 106.8 178.0 196.0 124.5 267.0 112.6 210.0 89.2

18 Water soluble sulphates as SO4 mg/kg 35.4 45.4 30.7 40.8 51.5 38.6 42.2 54.6 61.2 48.9

19 Aluminium % 2.04 1.7 2.64 0.98 1.88 1.92 2.03 2.65 3.52 1.53

20 Total Iron % 2.53 1.83 2.86 0.92 1.5 2.75 2.32 3.59 3.63 2.01

21 Manganese mg/kg 128.6 109.2 196.6 112.4 124.4 137.6 146.7 209.4 197.5 158.4

22 Boron mg/kg 28.5 31.0 42.1 25.5 19.3 40.8 56.9 30.8 43.4 37.9

23 Zinc mg/kg 51.4 100.3 68.6 41.8 49.7 65.0 87.7 39.4 46.6 75.2




TABLE-3.4.3

STANDARD SOIL CLASSIFICATION

Sr. No. Soil Test Classification

1 pH <4.5 Extremely acidic 4.51- 5.50 Very strongly acidic 5.51-6.00 Moderately acidic

6.01-6.50 Slightly acidic 6.51-7.30 Neutral 7.31-7.80 Slightly alkaline

7.81-8.50 Moderately alkaline 8.51-9.00 Strongly alkaline >9.00 Very strongly alkaline

2 Salinity Electrical Conductivity (ppm) (1 ppm =640mho/cm)

Upto 1.00 Average 1.01-2.00 harmful to germination 2.01-3.00 Harmful to crops (sensitive to salts)

3 Organic Carbon Upto 0.20: Very less 0.21-0.40: Less 0.41-0.50: Medium, 0.51-0.80: On an avg. sufficient 0.81-1.00: Sufficient >1.00 : More than sufficient

4 Nitrogen (Kg/ha) Upto 50 Very less 51-100 Less

101-150 Good 151-300 Better >300 Sufficient

5 Phosphorus (Kg/ha) Upto 15 Very less 16-30 Less 31-50 Medium, 51-65 On an avg. sufficient 66-80 Sufficient >80 More than sufficient

6 Potash (Kg/ha) 0 -120 Very less 120-180 Less 181-240 Medium 241-300 Average 301-360 Better

>360 More than sufficient Source: Hand Book of Agriculture, ICAR, New Delhi

3.5 Meteorology

The meteorological data recorded during the monitoring period is very useful for

proper interpretation of the baseline information as well as for input prediction

models for air quality dispersion. Historical data on meteorological parameters will

also play an important role in identifying the general meteorological regime of the

region.

The year may broadly be divided into four seasons:

Winter season : December to February

Pre-monsoon season : March to May

Monsoon season : June to September

Post-monsoon season : October to November




3.5.1 Methodology

The methodology adopted for monitoring the surface meteorological conditions

observations is as per the standard norms laid down by Bureau of Indian

Standards (IS : 8829) and India Meteorological Department (IMD). On-site

monitoring was undertaken for various meteorological variables in order to

generate the site-specific data. Data was collected every hour continuously from

15th January 2016 to 8th April 2016.

3.5.1.1 Methodology of Data Generation

A Central Monitoring Station (CMS) equipped with continuous monitoring

equipment was installed on top of a building at a height of 6 m above ground

level to record wind speed, direction, relative humidity and temperature. The

meteorological monitoring station was located in such a way that it is free from

any obstructions and as per the guidelines specified under IS: 8829. Cloud cover

was recorded by visual observation. Rainfall was monitored by using rain gauge.

The continuous recording meteorological instrument of Dynalab, Pune (Model

No.WDL 1002) has been used for recording the met data. The sensitivity of the

equipment is as given in Table-3.5.1.

TABLE-3.5.1

SENSITIVITY OF METEOROLOGY MONITORING EQUIPMENT

Sr. No. Sensor Sensitivity

1 Wind speed Sensor ± 0.02 m/s

2 Wind direction Sensor ± 3 degrees

3 Temperature Sensor ± 0.2oC

3.5.1.2 Sources of Information

Secondary information on meteorological conditions has been collected from the

nearest IMD station at Agartala. The available meteorological data of IMD,

Agartala station has been collected for the past 10 years and analyzed.

3.5.2 Presentation of Data

3.5.2.1 Meteorological Data Recorded at IMD, Agartala

The meteorological data is collected from IMD - Agartala, which is the nearest

IMD station to the project site. The data collected from IMD includes wind speed,

wind direction (recorded in sixteen directions), temperature, relative humidity,

atmospheric pressure; rainfall and cloud cover over a period of past 10 years. The

monthly maximum, minimum and average values are collected for all the

parameters except wind speed and direction. All these parameters are recorded

twice a day viz at 0830 and 1730 hours. The collected data is tabulated in Table-

3.5.2.




3.5.2.2 Meteorological Data Generated at site

The meteorological parameters are recorded on hourly basis during the study

period from 15th January 2016 to 8th April 2016 and the parameters recorded at

site include wind speed, wind direction (from 0 to 360 degrees), temperature,

relative humidity, atmospheric pressure, rainfall and cloud cover.

3.5.3 Synthesis of Data on Climatic Conditions

3.5.3.1 Analysis of the Data Recorded at IMD - Agartala

1] Temperature

The winter season starts from December and continues till the end of February.

January is the coolest month with the mean daily maximum temperature at

25.10C and the mean daily minimum temperature at 10.30C. Both the night and

day temperatures increase rapidly during the onset of the pre-monsoon season

from March to May. During pre-monsoon season, the mean maximum

temperature (April) was observed to be 33.00C with the mean minimum

temperature at 18.90C. The mean maximum temperature in the monsoon season

was observed to be 32.40C in the month of June whereas the mean minimum

temperature was observed to be 24.30C in the month of September. By the end

of August, the day temperatures increase slightly, with the mean maximum

temperature at 32.30C and the night temperature decreases with the mean

minimum temperature at 24.70C. The monthly variations of temperature are

presented in Table-3.5.2.

2] Relative Humidity

The air is generally humid in this region during the monsoon season when the

relative humidity was observed to be 83% with a maximum and a minimum of

79%. Generally, the weather during other seasons was observed to be dry. The

monthly variations in the relative humidity are presented in Table-3.5.2.

3] Atmospheric Pressure

The maximum pressure observed was 1014.7 mb occurring during the winter

season, in the month of January. The minimum pressure observed was 997.4 mb

occurring during the month of June in the monsoon season. It can be seen from

the data that not much variations are observed in the average atmospheric

pressure levels. The pressure levels are found to be fairly consistent over the

region. The monthly variations in the pressure levels are presented in Table-

3.5.2.

TABLE-3.5.2

CLIMATOLOGICAL DATA STATION: IMD, AGARTALA

Month Atmospheric Pressure

(mb) Temperature

(0C) Relative Humidity

(%)

Rainfall (mm) Mean

Max Mean Min

Mean Max

Mean Min

Mean Max

Mean Min

January 1014.7 1011.3 25.1 10.3 83 69 8.4

February 1012.7 1009.0 27.9 13.6 74 59 32.7

March 1010.3 1006.1 31.7 18.9 72 56 71.8




Month Atmospheric Pressure (mb)

Temperature (0C)

Relative Humidity (%)

Rainfall (mm) Mean

Max Mean Min

Mean Max

Mean Min

Mean Max

Mean Min

April 1007.6 1003.1 33.0 21.9 74 67 198.5

May 1003.9 1000.1 32.5 23.1 77 74 382.2

June 1000.4 997.4 32.4 24.7 81 79 314.1

July 1000.3 997.4 31.5 24.7 83 80 354.7

August 1001.4 998.2 32.3 24.7 81 81 252.3

September 1004.8 1001.4 31.7 24.3 83 83 252.3

October 1009.5 1006.1 31.3 21.9 82 80 191.1

November 1012.8 1009.5 29.6 17.0 79 78 47.0

December 1014.6 1011.3 26.4 11.8 81 76 16.5

Total Rainfall 2121.6

4] Rainfall

The average annual rainfall based on the 10 year IMD data, was observed to be

2,121.6 mm. The monsoon sets in the month of June and continues till

September and sometime extends upto mid October. The maximum amount of

rainfall (382.2 mm) occurs in the month of May. The maximum number of rainy

days was observed in the month of July. Monthly variations in the rainfall are

given in Table-3.5.2.

5) Wind Speed/Direction

Generally, light to moderate winds prevails throughout the year. Winds were light

and moderate particularly during the morning hours. While during the afternoon

hours the winds were stronger. The season wise discussion of the respective wind

Pattern is given as below:

A) Wind Pattern during Pre-Monsoon Season

0830 Hours:

A review of the wind rose diagram shows that predominant winds are mostly from

S and SE directions followed by SW direction (Figure-3.5.1). Calm conditions

prevailed for 12.7% of the total time.

1730 Hours:


S and SW directions followed by SE direction (Figure-3.5.1). Calm conditions


B) Wind Pattern during Monsoon Season

0830 Hours:


S and SE directions followed by SSE direction (Figure-3.5.2). Calm conditions





1730 Hours:


S and SE directions followed by SSE direction (Figure-3.5.2). Calm conditions


C) Wind Pattern during Post-Monsoon Season

0830 Hours:


NE and N directions followed by S direction (Figure-3.5.3). Calm conditions


1730 Hours:


S and N directions followed by NW direction (Figure-3.5.3). Calm conditions


D) Wind Pattern during Winter Season

0830 Hours:


S and N directions followed by SE direction (Figure-3.5.4). Calm conditions


1730 Hours:


N and SW directions followed by NW direction (Figure-3.5.4). Calm conditions


E) Annual Wind Pattern

0830 Hours:


S and SE directions followed by N direction (Figure-3.5.5). Calm conditions


1730 Hours:


S and SE directions followed by SW direction (Figure-3.5.5). Calm conditions





FIGURE-3.5.1

IMD AGARTALA-PRE MONSOON SEASON

C-12.7%

0% WSW

7.3%

SW

2.2

% S

SW

36.6

% S

SE 14.3%

E 7.0%

ENE 0%

NE 5.6%

NNE 0

%

N 4

.0%0

% N

NW

2.7% N

W

0.3% WNW

2.0% W

SSE 5

.0%

ESE 0.3%

NNE 0

%

N 3

.6%

1.9% N

W

0%

NNW

SSE 2

.6%

2.2

% S

SW

SE 9.5%

10.2%

SW

32.8

% S

E 2.8%ESE 0%

NE 2.0%

ENE 0%

0% WSW

3.3% W C-29.1%

0% WNW

08:30 Hrs

PRE MONSOON

17:30 Hrs

PRE MONSOON

SPEED CALM

1151

SCALE

19 >19 Km/hr

5%




FIGURE-3.5.2

IMD AGARTALA-MONSOON SEASON

0.3

% N

NW

1.5% N

W

NNE 0

.3%

N 2

.7%

SE 11.7%

SSE 5

.0%2

.0%

SSW

4.2%

SW

36.5

% S

E 2.0%ESE 0.3%

ENE 0%NE 1.

5%

0.3% WSW

2.0% W C-29.7%

0% WNW

0.5% WNW

NE 1.

5%

N 1

.7%

NNE 0

.2%

36.1

% S

3.2%

SW

0.5

% S

SW

SSE 9

.0%

ENE 0%

ESE 0.5%

E 8.0%

SE 24.2%

0% WSW

0.5% W C-14.1%

0% N

W

0%

NNW

17:30 Hrs

MONSOON

08:30 Hrs

MONSOON

1151

SCALE

19 >19 Km/hr

5%

SPEED CALM




FIGURE-3.5.3

IMD AGARTALA-POST MONSOON SEASON

0.5

% N

NW

2.0% N

W N

NE 0

.5%

N 4

.0%

SE 1.0%

SSE 0

.5%0

% S

SW

1.0%

SW

4.5

% S

E 1.0%ESE 0%

ENE 0%NE 1.0%

0% WSW

0.5% W C-83.5%

0% WNW

0% WNW

NE 12

.5%N

11.5

%

NNE 1

.5%

11.5

% S

3.0%

SW

1.0

% S

SW

SSE 2

.0%

ENE 0%

ESE 1.0%

E 5.5%

SE 4.5%

0% WSW

2.5% W C-40.5%

3.0% N

W

0%

NNW

08:30 Hrs

POST MONSOON

17:30 Hrs

POST MONSOON

SPEED CALM

1151

SCALE

19 >19 Km/hr

5%




FIGURE-3.5.4

IMD AGARTALA-WINTER SEASON

0.7

% N

NW

3.0% N

W N

NE 0

%N 5

.3%

SE 0.6%

SSE 0

%

0%

SSW

3.3%

SW

2.3

% S

E 0%ESE 0%

ENE 0%NE 1.0%

0.3% WSW

1.9% W C-81.3%

0.3% WNW

0% WNW

NE 3.6%

N 9

.3%

NNE 1

.3%

9.5

% S

4.3%

SW

0.3

% S

SW

SSE 0

.6%

ENE 0.3%

ESE 0.3%

E 2.9%

SE 5.6%

0.3% WSW

2.0% W C-54.4%

4.0% N

W

1.3

% N

NW

08:30 Hrs

WINTER

17:30 Hrs

WINTER

SPEED CALM

1151

SCALE

19 >19 Km/hr

5%




FIGURE-3.5.5

IMD AGARTALA-ANNUAL WINDROSE

0.4

% N

NW

2.1% N

W N

NE 0

.2%

N 3

.9%

SE 5.7%

SSE 2

.0%

1.1

% S

SW

4.8%

SW

19.0

% S

E 1.4%

ESE 0.1%

ENE 0%NE 1.

2%

0.2% WSW

1.9% W C-55.9%

0.1% WNW

0.1% WNW

NE 5.

7%

N 6

.6%

NNE 0

.9%

23.4

% S

4.5%

SW

0.9

% S

SW

SSE 4

.1%

ENE 0.2%

ESE 0.5%

E 5.9%

SE 12.2%

0.1% WSW

1.8% W C-30.6%

2.5% N

W

0%

NNW

08:30 HrsANNUAL

17:30 Hrs

ANNUAL

SPEED CALM

1151

SCALE

19 >19 Km/hr

5%




3.5.3.2 Observations on Primary Data

The site specific data is presented in Table-3.5.3 and discussed below:

TABLE-3.5.3

SUMMARY OF THE METEOROLOGICAL DATA GENERATED AT SITE

Month Temperature (0C) Relative Humidity (%) Rainfall (mm)

Max. Min. Max. Min.

Jan-2016 23.4 9.2 79 67 4.2

Feb-2016 25.6 12.5 72 56 15.3

Mar-2016 29.3 16.7 70 54 10.5

Apr-2016 30.7 18.1 71 63 8.9

1] Temperature

Maximum temperature of 30.7 oC and minimum temperature of 9.2 0C was

recorded during the study period.

2] Relative Humidity

During the period of observation the Relative Humidity recorded ranged from 79

% to 54 %.

3] Rainfall

The 15.3 mm rainfall was observed during the study period.

5] Wind Speed/Direction

The wind rose for the study period representing winter season is shown in

Figure-3.5.6. A review of the wind rose diagram shows that predominant winds

are mostly from N followed by S. Next predominants are NW & SE followed by SW

direction. Calm conditions prevailed for 61.2 % of the total time.




FIGURE-3.5.6

SITE SPECIFIC WINDROSE-WINTER SEASON

C-61.2%

N 8

.3%

NNE 1

.1%

NE 2.

6%

ENE 0.6%

E 1.3%

ESE 0.2%

SE 4.2%

SSE 0

.7%

S 7

.1%

SSW

0.4

%

SW 3.9

%

WSW 0.5%

W 2.4%

WNW 0.9%

NW 4.2%

NNW

0.4

%

SPEED CALM

1151

SCALE

19 >19 Km/hr

5%




3.6 Ambient Air Quality

The ambient air quality with respect to the study zone around the proposed block

forms the baseline information. The prime objective of the baseline air quality

study was to assess the existing air quality of the area. This will also be useful for

assessing the conformity to standards of the ambient air quality during the

operation of proposed drilling project.

This section describes the selection of sampling locations, methodology adopted for

sampling, analytical techniques and frequency of sampling. The ambient air quality

monitoring was conducted from 15th January 2016 to 8th April 2016 representing

partly winter and partly pre-monsoon season.

3.6.1 Methodology Adopted for Air Quality Survey

Selection of Sampling Locations

The baseline status of the ambient air quality has been assessed through a

scientifically designed ambient air quality monitoring network. The design of

monitoring network in the air quality surveillance program has been based on the

following considerations:

Meteorological conditions on synoptic scale;

Topography of the study area;

Representatives of regional background air quality for obtaining baseline status;

and

Representatives of likely impact areas.

Ambient Air Quality Monitoring (AAQM) stations were set up at ten locations with

due consideration to the above mentioned points. Table-3.6.1 gives the details of

environmental setting around each monitoring station. The locations of the selected

stations with reference to the proposed block are given in the same table and

depicted in Figure-3.6.1 and ambient air sampling photographs are shown as

Figure-3.6.2.

Frequency and Parameters for Sampling

Ambient air quality monitoring was carried out at a frequency of two days per

week for three month at each location covering from 15th January 2016 to 8th

April 2016 representing partly winter and partly pre-monsoon season. The

baseline data of air environment was monitored for parameters mentioned below:

Particulate Matter (PM2.5);

Particulate Matter (PM10);

Sulphur dioxide (SO2);

Oxides of Nitrogen (NOx);

Volatile Organic Carbon (VOCs);

Total Hyderocarbon;

Methane Hydrocarbon;and

Non-methane Hydrocarbon




The AAQ sampling is carried out as the present revised standards mentioned in the

latest Gazette notification of the Central Pollution Control Board (CPCB)

(November, 2009).

TABLE-3.6.1

DETAILS OF AMBIENT AIR QUALITY MONITORING

Monitoring Station Name of the Station Well location

AAQ1 Bilkhawthir -

AAQ2 Kolasib -

AAQ3 Bairabi Near HOAC, HOAD

AAQ4 Suarhlip Near BRBAA

AAQ5 Sethawn -

AAQ6 Zamuang -

AAQ7 Vawngawn -

AAQ8 Mualvum -

AAQ9 Mamit -

AAQ10 Lengpui -

3.6.2 Presentation of Primary Data

Various statistical parameters like 98th percentile, average, maximum and

minimum values have been computed from the observed raw data for all the AAQ

monitoring stations. The results of monitoring carried out are presented in

Annexure-V. The summary of these results representing part of winter season are

given in Table-3.6.2. These are compared with the standards prescribed by

Central Pollution Control Board (CPCB).

Summary of Observations – partly winter and partly pre-monsoon

season (2016)

o Out of the ten locations the minimum and maximum concentration for PM10

were varied between 37.7 to 46.0 g/m which are well within the NAAQ

standard i.e 100 g/m3.

o The minimum and maximum concentration PM2.5 were varied between 11.6 to

15.8 g/m3 respectively during the study period which are well within the NAAQ

standard i.e 60 g/m3.

o The concentrations of SO2 were varied between 7.9 to 15.0 g/m 3 which are

well within the NAAQ standard i.e 80 g/m3.

o The concentrations of NOx were varied between 11.0 to 17.3 g/m3

respectively which are well within the NAAQ standard i.e 80 g/m3.

o The minimum and maximum concentration for CO during the study period was

observed as 100 to 239 g/m3 which are well within the NAAQ standard i.e

2000 g/m3.

o The minimum and maximum concentration for total hydrocarbons,methane

hydrocarbons and non-methane hydrocarbons during the study period were

observed as 101 to 166 g/m3, 50 to 95 g/m3 and 40 to 96 g/m3

respectively.

o The concentrations of VOCs were below the detectable limits i.e 0.1 g/m3 in all

the locations during the study period




o Ozone values in all the locations are observed to be less than 2.0 µg/m3.

o Nickel values in all the locations are observed to be less than 0.1 ng/m3.

o Ammonia concentration observed in all the locations is less than 20.0 µg/m3.

o PAH concentration in all the locations was found to be <0.0022 ng/m3.

o BaP values observed in all the locations are <1.0 ng/m3.

o Benzene concentration was observed in all the locations are <1.0 ng/m3.




FIGURE-3.6.1

AIR QUALITY SAMPLING LOCATIONS




Air monitoring at Baiarbi Air monitoring at Mamit

FIGURE-3.6.2

AIR MONITORING PHOTOGRAPHS




TABLE-3.6.2(A) SUMMARY OF AMBIENT AIR QUALITY RESULTS

Monitoring Station

Locations PM10 (µg/m3) PM2.5 (µg/m3) SO2 (µg/m3) NOx (µg/m3)

Max Min Avg 98th %le Max Min Avg 98th

%le Max Min Avg 98th %le Max Min Avg 98th %le

AAQ1 Bilkhawthir 43.7 37.9 41.2 43.3 14.7 12.4 13.5 14.7 10.4 7.9 9.3 10.3 15.3 11.9 13.6 15.1

AAQ2 Kolasib 42.6 38.9 40.5 42.3 15.1 12.4 14.2 15.1 13.7 11.1 12.3 13.7 14.6 11.5 13.3 14.6

AAQ3 Bairabi 43.5 40.9 42.2 43.5 15.3 13.4 13.9 14.8 14.1 9.0 10.5 13.9 15.0 12.0 13.4 14.9

AAQ4 Suarhlip 44.3 37.7 40.1 43.8 15.4 12.1 14.0 15.2 15.0 11.5 13.8 15.0 16.0 12.3 13.9 15.8

AAQ5 Sethawn 41.8 38.4 40.2 41.7 13.1 11.7 12.3 13.1 11.7 9.3 10.4 11.7 13.9 11.0 12.4 13.7

AAQ6 Zamuang 42.4 39.5 40.6 42.0 15.1 13.5 14.2 15.0 12.8 10.0 11.4 12.8 14.6 11.8 12.8 14.1

AAQ7 Vawngawn 45.9 42.4 44.6 45.9 15.8 11.6 14.5 15.8 13.3 11.7 12.4 13.3 17.1 15.0 16.0 17.1

AAQ8 Mualvum 46.0 41.4 44.6 46.0 15.5 12.9 14.2 15.4 12.8 10.3 11.6 12.8 17.3 15.0 16.0 17.2

AAQ9 Mamit 45.6 41.4 44.1 45.6 15.1 13.4 14.1 14.9 12.4 9.4 11.1 12.4 16.8 14.2 15.8 16.8

AAQ10 Lengpui 41.5 37.9 39.6 41.2 13.8 12.6 13.1 13.7 11.9 10.0 10.9 11.8 14.1 11.2 12.6 13.8

Range 37.7-46.0 11.6-15.8 7.9-15.0 11.0-17.3

CPCB Standards 100 60 80 80

TABLE-3.6.2 (B) SUMMARY OF AMBIENT AIR QUALITY RESULTS

Monitoring Station

Locations THC (µg/m3) CH4 HC (µg/m3) Non-CH4 HC (µg/m3) CO (µg/m3) VOC (µg/m3)

Max Min Avg 98th

%le Max Min Avg 98th



%le

AAQ1 Bilkhawthir 157 101 129 157 95 50 69 93 90 40 60 85 176 103 143 175 <0.1

AAQ2 Kolasib 159 114 136 155 76 56 67 76 92 50 68 87 197 100 141 197 <0.1 AAQ3 Bairabi 146 109 135 145 79 60 71 78 77 42 64 77 228 104 176 225 <0.1 AAQ4 Suarhlip 163 119 137 162 89 57 67 86 96 50 70 96 239 140 182 239 <0.1 AAQ5 Sethawn 166 131 140 156 78 70 75 78 89 60 65 79 219 112 168 217 <0.1 AAQ6 Zamuang 154 129 139 154 81 64 74 80 78 60 65 77 211 122 176 210 <0.1 AAQ7 Vawngawn 156 126 140 152 79 63 74 79 84 60 66 80 216 132 181 213 <0.1 AAQ8 Mualvum 172 131 141 166 84 70 74 81 96 60 67 86 203 117 162 202 <0.1 AAQ9 Mamit 147 123 139 146 79 63 74 79 74 60 65 72 224 127 179 223 <0.1 AAQ10 Lengpui 159 132 140 153 79 70 75 79 89 60 65 80 205 104 158 199 <0.1

Range 101-166 50-95 40-96 100-239 <0.1

CPCB Standards 2000




3.7 Water Quality

Selected water quality parameters of ground water and surface water resources

within block area for the study has been carried out for assessing the water

environment and evaluate anticipated impact of present project. Understanding the

water quality is essential in preparation of Environmental Impact Assessment and

to identify critical issues with a view to suggest appropriate mitigation measures for

implementation.

The purpose of this study is to:

Assess the water quality characteristics for critical parameters; and

Predict the impact of water quality due to the proposed block and related

activities.

Two surface water sources and seven ground water sources covering entire block

area were examined for physico-chemical, heavy metals and bacteriological

parameters.

The samples were collected and analysed once during the study period. The

samples were analyzed as per the procedures specified in 'Standard Methods for

the Examination of Water and Wastewater' published by American Public Health

Association (APHA).

3.7.1 Water Sampling Locations

In the study area, two surface and seven ground water samples were collected for

winter season (15th January 2016 to 8th April 2016). These samples were taken as

grab samples and were analyzed for various parameters to compare with the

standards. The water sampling locations are listed below in Table-3.7.1 and are

depicted in Figure-3.7.1 and water sampling photographs are shown as Figure-

3.7.2. The results of monitoring of surface and ground samples carried out for the

study are presented in Table-3.7.2 and Table 3.7.3.

TABLE-3.7.1

DETAILS OF WATER SAMPLING LOCATIONS

Sr. No. Sampling Location Location Well locations

Surface Water

1 SW1 Bulvng Lui Near HOAC

2 SW2 Pakwa Nadi -

3 SW3 Borai Lui -

4 SW4 Gutur River -

Ground Water

1 GW1 Kolasib -

2 GW2 Bairabi Near HOAD

3 GW3 Suarhlip Near BRBAA

4 GW4 Mualvum -

5 GW5 Mamit -

6 GW6 Lengpui -




FIGURE-3.7.1

WATER SAMPLING LOCATIONS




Surface water sampling at Borai Lui Ground water sampling at Lengpui

FIGURE-3.7.2

WATER SAMPLING PHOTOGRAPHS

3.7.2 Presentation of Results

Surface Water Quality

The results for the surface water samples analysed are presented in Table 3.7.2.

The analysis results of surface water samples indicate that the pH value was

observed to be 7.1 - 7.6.

Electrical conductivity of surface water samples was observed to be 115 – 168.

The Total Dissolved solids were observed about 75 - 110 mg/l.

Sulphates were found to be in the range of 3.1 – 7.8 mg/l, and Nitrates were

found to be in the range of 1.1 – 2.1 mg/l which are with in the prescribed

limits only.

Fluoride concentration was found to be 0.2 – 0.6 mg/l the samples.

Ground Water Quality

The results for the ground water samples analysed are presented in

Table 3.7.3.

The analysis results of ground water samples showed the pH in range of 7.12-

7.96. The maximum value was observed at GW6 and the minimum value

observed at GW1 whereas the prescribed limit of is 6.5 to 8.5.




Colour of the samples ranged from 7.12-7.96 Hazen whereas the prescribed

limit is 5 to 15 Hazen.

Turbidity of the samples ranged from 2-4 NTU whereas the prescribed limit is 1

to 5 NTU.

Electrical conductivity of the samples ranged from 198.0 – 780.0 µS/cm.

The Total Hardness of the samples ranged from 130 – 510 mg/l. The

maximum value was observed at GW1 and the minimum value observed at

GW7 whereas the prescribed limit of 200 mg/l.

Calcium concentrations ranged from 13.5– 68.6 mg/l r respectively whereas the

prescribed limit of 75-200 mg/l.

Magnesium concentrations ranged from 4.5 – 28.4 mg/l respectively whereas

the prescribed limit of 30-100mg/l.

The Total Dissolved solids of the samples ranged from 54.0 – 288.0 mg/l. The

maximum TDS was observed at GW1, and where as the minimum value

observed at GW7. The TDS values are well with in the prescribed limit of 500

mg/l

Range of Chlorides concentrations at all the locations 12.8 - 49.6 mg/l whereas

the prescribed limit is 250-1000 mg/l.

Range of Sulphates concentrations at all the locations as 8.0 – 67.8 mg/l

whereas the prescribed limit is 200-400 mg/l.

Similarly, Nitrates are also found to be ranging between 1.2 – 8.5 mg/l whereas

the prescribed limit is 45 mg/l.

Fluoride concentrations are ranging in between 0.2 – 0.8 mg/l and are found to

be within the permissible limits 1.0 – 1.5 mg/l.

Iron concentrations in ground waters varied from 0.01 – 0.21 mg/l whereas the

prescribed limit is 0.3 mg/l.

All other metal concentrations are observed to be below detectable limits.

Based on the above results it is evident that all of the parameters in ground water

fairly meet the desirable standard limits of IS: 10500.




TABLE-3.7.2

SURFACE WATER QUALITY

Sr. No. Parameters UOM SW1 SW2 SW3 SW4

1 pH -- 7.1 7.6 7.5 7.4

2 Color Hazen 5 6 5 5

3 Conductivity µS/cm 146.0 115.0 132.0 168.0

4 Total Dissolved Solids mg/l 95.0 75.0 90.0 110.0

5 Dissolved Oxygen mg/l 5.9 6.0 5.8 6.1

6 Biological Oxygen Demand mg/l <3 <3 <3 <3

7 Chemical Oxygen Demand mg/l <5 <5 <5 <5

8 Total Hardness mg/l 46.0 35.0 33.0 51.0

9 Total Alkalinity mg/l 42.0 39.0 37.0 45.0

10 Calcium as Ca mg/l 9.8 7.4 8.0 11.2

11 Magnesium as Mg mg/l 5.2 4.0 3.2 5.6

12 Chlorides as Cl mg/l 16.2 9.9 15.5 19.6

13 Residual Free Chlorine mg/l <0.2 <0.2 <0.2 <0.2

14 Phosphates as PO4 mg/l <0.1 <0.1 <0.1 <0.1 15 Sulphates as SO4

2- mg/l 5.4 3.1 5.5 7.8

16 Fluorides as F mg/l 0.6 0.5 0.3 0.2

17 Nitrates as NO3 mg/l 1.1 1.8 1.5 2.1

18 Sodium as Na mg/l 11.8 10.1 14.8 14.0

19 Potassium as K mg/l 1.3 1.8 1.2 1.5

20 Total Boron as B mg/l 0.05 0.02 0.06 0.03

21 Phenolic Compounds mg/l <0.001 <0.001 <0.001 <0.001

22 Cyanides mg/l <0.02 <0.02 <0.02 <0.02 23 Oil and Grease mg/l <1.0 <1.0 <1.0 <1.0

24 Cadmium as Cd mg/l <0.003 <0.003 <0.003 <0.003

25 Arsenic as As mg/l <0.01 <0.01 <0.01 <0.01

26 Copper as Cu mg/l <0.01 <0.01 <0.01 <0.01

27 Lead as Pb mg/l <0.01 <0.01 <0.01 <0.01

28 Iron as Fe mg/l 0.09 0.15 0.18 0.11

29 Chromium as Cr +6 mg/l <0.05 <0.05 <0.05 <0.05

30 Selenium as Se mg/l <0.01 <0.01 <0.01 <0.01

31 Zinc as Zn mg/l 0.04 0.03 0.01 0.02

32 Aluminium as Al mg/l <0.01 <0.01 <0.05 <0.05

33 Mercury as Hg mg/l <0.001 <0.001 <0.01 <0.01

34 SAR -- 0.76 0.74 1.2 0.85

35 Insecticides mg/l Absent Absent Absent Absent

36 Anionic Detergents as MBAs mg/l <0.2 <0.2 <0.2 <0.2

37 Total Coliform MPN/100ml

18 14 28 15



7


TABLE-3.7.3 GROUND WATER QUALITY

Sr. No. Parameter Unit Limits as per IS10500 GW1 GW2 GW3 GW4 GW5 GW6 GW7

1 pH - 6.5-8.5 (NR) 7.12 7.55 7.45 7.24 7.61 7.96 7.70

2 Colour Hazen 5(25) 4 5 5 6 4 5 5

3 Taste - Agreeable Ag Ag5 Ag Ag Ag Ag Ag

4 Odour - Agreeable Ag Ag Ag Ag Ag Ag Ag

5 Conductivity µS/cm $ 780.0 216.0 375.0 294.0 310.0 562.0 198.0

6 Turbidity NTU 1(5) 4 2 3 3 2 2 3

7 TDS mg/l 500(2000) 510.0 140.0 250.0 190.0 210.0 370.0 130

8 Total Hardness as CaCO3 mg/l 200(600) 288.0 55.0 137.0 83.0 94.0 192.0 54.0

9 Total Alkalinity mg/l 200(600) 246.0 76.0 130.0 86.0 108.0 165.0 58.0

10 Calcium as Ca mg/l 75(200) 68.6 14.4 28.6 19.6 21.7 42.6 13.5

11 Magnesium as Mg mg/l 30(100) 28.4 4.5 15.8 8.2 9.6 20.7 4.8

12 Residual Chlorine mg/l 0.2(1.0) <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2

13 Boron as B mg/l 0.5(1.0) 0.02 0.01 0.06 0.07 0.05 0.03 0.01

14 Chlorides as Cl mg/l 250(1000) 49.6 12.8 18.2 28.4 22.1 49.6 24.1

15 Sulphates as SO4 mg/l 200(400) 67.8 10.7 20.6 17.0 11.8 39.0 8.0

16 Fluorides as F mg/l 1.0(1.5) 0.8 0.4 0.6 0.5 0.5 0.7 0.2

17 Nitrates as NO3 mg/l 45(NR) 1.2 3.6 8.5 4.2 2.8 5.5 2.1

18 Sodium as Na mg/l $ 45.5 22.1 22.0 28.1 27.2 39.6 19.4

19 Potassium as K mg/l $ 2.8 5.6 1.7 3.9 2.1 3.5 2.5

20 Phenolic Compounds mg/l 0.001(0.002) <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

21 Cyanides mg/l 0.05(NR) <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02

22 Anionic Detergents mg/l 0.2(0.1) <0.2 <0.2 <0.2 <0.2 <0.2 <0.2 <0.2

23 Mineral Oil mg/l 0.5(NR) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

24 Cadmium as Cd mg/l 0.03(NR) <0.003 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003 25 Arsenic as As mg/l 0.01(0.05) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

26 Copper as Cu mg/l 0.05(1.5) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

27 Lead as Pb mg/l 0.01(NR) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

28 Manganese as Mn mg/l 0.1(0.3) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

29 Iron as Fe mg/l 0.3(NR) 0.12 0.18 0.09 0.21 0.15 0.04 0.01

30 Total Chromium as Cr mg/l 0.01(NR) <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

31 Selenium as Se mg/l 0.01(NR) <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

32 Zinc as Zn mg/l 5(15) 0.18 0.22 0.11 0.08 0.05 0.07 0.13

33 Aluminium as Al mg/l 0.03(0.2) <0.01 0.01 0.02 <0.01 <0.01 0.01 <0.01

34 Mercury as Hg mg/l 0.001(NR) <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

35 Pesticides mg/l Absent Absent Absent Absent Absent Absent Absent Absent

36 E.Coli - Absent Absent Absent Absent Absent Absent Absent Absent

37 Total Coliforms MPN/100ml 10 <2 <2 <2 <2 <2 <2 <2 $: Limits not specified as per IS: 10500, UO: Un-Objectionable, Ag-Agreeable, NR-No Relaxation




3.8 Noise Level Survey

The main objective of noise monitoring in the study area is to establish the baseline

noise levels, and assess the impact of the total noise generated by the proposed

drilling operations.

3.8.1 Identification of Sampling Locations

A preliminary reconnaissance survey has been undertaken to identify the major

noise generating sources in the area. Noise at different noise generating sources

has been identified based on the activities in the village area, ambient noise due to

traffic and the noise at sensitive areas like hospitals and schools.

The noise monitoring has been conducted for determination of noise levels at ten

locations in the study area for winter season (15th January 2016 to 8th April 2016).

The noise levels at each location were recorded for 24 hours. The environment

setting of each noise monitoring location is given in Table-3.8.1 and depicted in

Figure-3.8.1 and noise sampling photographs are shown as Figure-3.6.2.




FIGURE-3.8.1

NOISE MONITORING LOCATIONS




Noise monitoring at Lengpui Noise monitoring at Mamit

FIGURE-3.8.2

NOISE MONITORING PHOTOGRAPHS

TABLE-3.8.1

DETAILS OF NOISE MONITORING LOCATIONS

Monitoring Station Name of the Station Well locations

N1 Bilkhawthir -

N2 Kolasib -

N3 Bairabi Near HOAC, HOAD

N4 Suarhlip Near BRBAA

N5 Sethawn -

N6 Zamuang -

N7 Vawngawn -

N8 Mualvum -

N9 Mamit -

N10 Lengpui -

3.8.2 Method of Monitoring

Sound Pressure Level (SPL) measurements were measured at all locations. The

readings were taken for every hour for 24 hours. The day noise levels have been

monitored during 6 am to 10 pm and night levels during 10 pm to 6 am at all the

locations covered in the block area for the study.

3.8.3 Presentation of Results

The statistical analysis is done for measured noise levels at ten locations during

winter season. The parameters are analyzed for Lday, Lnight, and Ldn. These results

are tabulated in Table-3.8.2. Standard noise limits are given in the Table 3.8.3




TABLE-3.8.2

NOISE LEVELS IN THE STUDY AREA

Monitoring

Station Location L10 L50 L90 Leq Lday Lnight Ldn

N1 Bilkhawthir 47.2 43.9 40.2 44.7 45.5 42.0 48.9

N2 Kolasib 45.3 41.0 37.8 42.0 43.9 39.2 46.4

N3 Bairabi 41.6 38.0 34.5 38.9 39.7 36.3 43.0

N4 Suarhlip 49.6 45.9 42.2 46.9 48.0 44.2 51.2

N5 Sethawn 38.4 34.4 30.7 35.4 36.4 32.2 39.2

N6 Zamuang 36.8 32.9 29.1 33.9 35.6 31.2 38.6

N7 Vawngawn 37.7 33.0 29.4 34.2 36.2 31.7 38.3

N8 Mualvum 39.1 35.2 31.4 36.2 37.1 32.6 39.9

N9 Mamit 37.9 34.5 30.8 35.4 36.2 32.5 39.6

N10 Lengpui 40.0 35.7 32.4 36.7 38.6 33.9 41.1

CPCB standards 55 45

TABLE-3.8.3

AMBIENT NOISE STANDARDS

Area Code Category of Area Noise Levels (dB (A) Leq (Limits)

Day time Night time

A Industrial Area 75 70

B Commercial Area 65 55

C Residential Area 55 45

D Silence Zone 50 40 Ambient Noise Standards of CPCB

3.8.4 Observation of Results

The daytime (Lday) noise levels at all the locations are observed to be in the range

of 35.6 dB (A) to 48.0 dB (A) which are well within the prescribed daytime noise

standard for residential zone i.e 55 dB(A).

The night time (Lnight) noise levels at all the locations were observed to be in the

range of 31.2 dB (A) to 44.2 dB (A) which are well within the prescribed night time

noise standard for residential zone i.e 45 dB(A).

It is observed that the noise levels at residential locations are within the prescribed

limit of CPCB ambient noise standard.

3.9 Ecological Studies

3.9.1 Introduction

The primary ecology survey was conducted during study period along with forest

officals. Ecological studies are one of the important aspects of Environmental

Impact Assessment with a view to conserve environmental quality and

biodiversity. Ecological systems show complex inter-relationships between biotic

and abiotic components including dependence, competition and mutualism. Biotic

components comprise of both plant and animal communities, which interact not

only within and between themselves but also with the abiotic components a viz.

physical and chemical components of the environment.




Generally, biological communities are good indicators of climatic and edaphic

factors. Studies on biological aspects of ecosystems are important in

Environmental Impact Assessment for safety of natural flora and fauna. The

biological environment includes terrestrial and aquatic ecosystems.

The animal and plant communities co-exist in a well-organized manner. Their

natural settings can get disturbed by any externally induced anthropological

activities or by naturally occurring calamities or disaster. So, once this setting is

disturbed, it sometimes is either practically impossible or may take a longer time

to come back to its original state. Hence, changes in the status of flora and fauna

are an elementary requirement of Environmental Impact Assessment studies, in

view of the need for conservation of environmental quality and biodiversity.

Information on flora and fauna was collected within the study area. Relevant

details on aquatic life within the study area were collected from related

government offices.

The present report gives the review of published secondary data and the results

of field sampling conducted during winter season January –March, 2016.

3.9.2 Objectives of Ecological Studies

The present study was undertaken with the following objectives:

To assess the nature and distribution of vegetation in and around the block

area;

To assess the distribution of animal life spectra;

To understand the productivity of the water bodies; and

To ascertain migratory routes of fauna and possibility of breeding grounds.

3.9.3 Methodology adopted for the Survey

To achieve the above objectives, a detailed study of the entire Block area was

undertaken. The different methods adopted were as follows:

o Compilation of secondary data with respect to the study area from published

literature and Government agencies;

o Generation of primary data by undertaking systematic ecological studies in

the area;

o Discussion with local people so as to elicit information about local plants,

animals and their uses; and

o Gathering data for ethno-biology.

The list of proposed ONGC wells drilling locations and list of terrestrial ecological

locations as given in Table -3.9.2 and Table-3.9.3.

3.9.4 Forest block with in Mamit district in Mizoram

Dampa Wildlife Sanctuary comprising of Dampa Tiger Reserve which is situated

about 59.5 km / SSW direction from BRBAA well location, in NELP –Block. The

presence of endangered species such as Tigers and others endangered cats,




comprising of larger track of the sanctuary area near the oil drilling blocks in

Mizoram state Table-3.9.1.

TABLE-3.9.1

FOREST BLOCKS WITHIN STUDY AREA

Sr. No Forest Blocks

1 Dampa Tiger Reserve about 59.5 Km/ SSW, comprising of huge area of

Mamit district, in the block area

2 Kolasib Forest Block

3 Mamit Forest Block

4 Innerline Forest Reserve

3.9.5 Terrestrial Ecological Status: Primary Survey

A preliminary survey was made in the study block area. The primary data was

generated through:

1. Preparing a general checklist of all plants encountered in the study area.

This would indicate the biodiversity for wild and cultivated plants.

2. Determining the bird population of migratory and local birds by taking 10

random readings at every location;

3. Observing mammals, amphibians and reptiles, noting their calls, droppings,

burrows, pugmarks and other signs; and

4. Local inhabitants were interviewed for use of plants and animals and to get

ethno biological data.

List of Terrestrial Ecological Locations as given in Table-3.9.3.

TABLE-3.9.2

DETAILS OF PROPOSED DRILLING LOCATIONS

Sr.

No

Proposed Location Tentative Well Coordinates (WGS-84)

Latitude Longitude

1 HOAC 240 12’ 14.24” 920 35’ 53.32”

2 HOAD 240 09’ 41.42” 920 36’ 13.31”

3 BRBAA 240 07’ 10.08” 920 31’ 06.77”

TABLE -3.9.3

DETAILS OF TERRESTRIAL ECOLOGICAL SAMPLING LOCATIONS

Station Code Name of the Station

TE-1 Vegetation near Kolasib

TE-2 Vegetation near North Thingdaw

TE-3 Vegetation near Zawlnuam

TE-4 Vegetation near Mamit

TE-5 Vegetation near Tlangnuam




FIGURE-3.9.1

ECOLOGICAL SAMPLING LOCATIONS




3.9.6 Threatened Plant Species and Agriculture

National threatened species are those found only in small numbers or those very

near to extinction in the country. India has a list of threatened species at the All

India level, published by the Botanical Survey of India entitled ‘Red Data Book‘.

No species observed in the study region comes under the category of threatened

species out of 134 plant species. However, there is intense anthropogenic

pressure on flora, fauna and forest resources, which are observed to be

dwindling.

Agriculture

The staple food of the people in the study region is rice and wheat. Agro-climatic

conditions of the area provide a range of potentialities for growing cash crop like

off seasonal vegetable i.e. onion, chilly, brinjal, bhindi, fruits and flowers, kitchen

gardening is also common because of sufficient available space around house.

Main agricultural crop production in study area is paddy (Oryza sativa),

supplemented by wheat (Triticum aestivum). The common rabbi crops grown in

the study area are wheat, gram, mustard, taramira, potato, carrot, pea etc.

whereas rice, jowar, arhar, tur, moong, til, groundnut, soyabean, chilly, ginger,

etc are kharif crops. Other than cereals fruits like mango, pineapple, orange,

jackfruit, banana, litchi, lemon, papaya, sapota, and guava are also grown in

large quantity. The list of the agricultural crops in the study area is given in

Table-3.9.4.

TABLE-3.9.4

LIST OF AGRICULTURAL CROPS

Sr. No. Scientific Name Common Name

Rabi

Cereals

1 Oryza sativa Rice

2 Zea mays Maize

Pulses

1 Phaseolus Gram

Oil Seeds

Brassica juncea Mustard

Vegetables

1 Coriandrum anum Coriander

2 Allium sativum Garlic

3 Capsicum anum Chilly

4 Solanum tuberosum Potato

5 Daucus carata Carrot

6 Pisum sativum Pea

Kharif

Cereal

1 Oryza sativa Rice

2 Sorghum vulgarum Jowar

3 Cajanus cajan Arhar

4 Phaseolus angularis Urd

5 Phaseolus mungo Moong




Oil Seed

1 Seasamum Til

2 Arachys hypogea Groundnut

3 Glycine max Soya bean

Vegetables

1 Capsicum anum Chilly

2 Zingiber officinale Ginger

Others

1 Potato

2 Saccarum officianalis Sugarcane

Source: Directorate of Agriculture, Aizwal, Mizoram

3.9.5.1 Floristic Composition of FORESTS and FAUNA with Indian Wildlife Schedules

The Forests in Mamit block are generally covered with hills and practically very

rare on moderate slopes due to cultivation. Composition and condition of crops

are affected by nature and depth of soil, the topography and biotic factors, of

which jhuming is the most significant, Forest crop of the tract dealt with is

heterogeneous and most of the tract have lost its original crop character. Trees of

200 to 270 cms girth are still common and upto 300 cms and over is girth are

occasionally met with in the inaccessible area. The top canopy is represented by

tree species like – Michelia champaca, Terminalia myriocarpa, Dipterocarpus

species, Artocarpus chaplasa, Magnifera indica (wild variety), Acrocarpus

fraxinifolius, Castonopsis species, Cedrella toona, Albizia procera, Sapium species,

Morus species, Schima species etc.

The middle canopy is represented by Ficus species, Bauhinia species, Spondia

species, Oroxylum indicum, Syzygium cuminii, Cinnamomum glanduliferum,

Lagerstroemia speciosa, Erythrina species etc. Mesua ferrea, Amoora wallichii etc.

represent the lower canopy. Woody climbers (lianas) and small size shrubs also

add to the varied composition of middle canopy.

In general the crop composition of natural forest of the area shows irregularity in

various parameter. The area out of the tract dealt which has miscellaneous

forests, jhum land and bamboo forests. However, in patches where good forest

exists are available in a scattered manner.

The Forests in Kolasib are composed of miscellaneous species without a single or

two species dominating the forests. Forest covers are usually absent or negligible

where the slope is moderate and convenient for cultivation. Forest covers are also

absent in some low lying areas where wet rice cultivation is being done. The

composition of crop, quantity, health and size are influenced by the depth of the

soil, topography, biotic factors (especially jhumming). Excepting those areas

which are difficult to access, trees of exploitable size are rare due to over

exploitation of the area.

The over woods consist mainly of Michelia champaca, Terminalia

myriocarpa,Artocarpus chaplasa, Cedrella toona etc. underwoods usually

comprise of mesua ferrea, syzygium cuminii, Bauhinia spp. Amoona wallichii,




Derris robusta etc. Undergrowth consists mainly of Clerodendron, solanum spp,

Ageretum conizoyides, Bidens biternata, Begonia dioica, Vermonia cineria etc.

3.9.5.2 List of Wildlife

Sling Mizo Name Common Name Scientific Name Schedule of Indian

Wildlife ( Protection) Act, 1972

1 Bak-sai Indian Flying Fox Pteropus giganteus Sch-V

2 Biang Particoloured Flying Squirrel

Hylopetes alboniger Sch-I

3 Bui-ke-lek Short-tailed Mole Talpa micrura Sch-V

4 Bui-sen Bay Bamboo rat Cannomys Sch-V

5 Bui-pui Red-cheeked Bamboo Rat

Rhizomys erythrogenys

Sch-V

6 Bui-luang-par Hoary Bamboo Rat Rhizomys pruinosus Sch-V

7 Chai-chim Indian Field Mouse Mus booduga Sch-V

8 Che-pa Northern Tree-shrew

Tupaia belangeri Sch-V

9 Chhim-tir Grey Musk Shrew Suncus murinus Sch-V

10 Chinghnia Wild Dog Cuon alpinus Sch-II

12 Dawr Phayres Leaf Monkey

Presbytis phayrei Sch-I

13 Hlei-kap-sen Red-bellied Palla’s Squirrel

Callosciurus erythreaus

Sch-II

14 Hlei-zawng Himalayan Hoary-bellied Squirrel

C.pygerythrus Sch-II

15 Keisen Goden Cat Fells temmincki Sch-II

18 Mang-tir/Sa-mang Malayan Sun Bear Ursus malayanus

19 Ngau Capped Langur Presbytis pileatus Sch-I

20 Ngau Silvered Leaf Monkey

Presbytis cristatus Sch-II

21 Ngau-sen/Ngau-ir-eng

Golden Langur Presbytis geei Sch-II

22 Nghar-thing-awn Spotted Linsang/Tiger Civet

Prionodon pardicolor

Sch-I

23 Ngharbuang Fishing Cat Felis veverrina Sch-I

24 Phivawk Hog Badger Arctonyx collaris Sch-I

25 Ramsial/Sele Indian Bison Bosgaurus Sch-I

26 Safia Yellow throated Marlen

Martes flavigula Sch-II

27 Sahmaitha Chinese ferret badger

Melogale moschata Sch-I

28 Sa-huai Slow Loris Nycticebus coucang Sch-I

29 Sahram Clawless Otter Aonix cinerea Sch-I

30 Sai Indian Elephant Elephan maximus Sch-I

31 Sakhi Barking Deer Muntiacus muntijak Sch-III

32 Sakuh Indian Porcupine Hystrix indica Sch-III

33 Sanghar Leopard Cat Felis Bengalensis Sch-II

34 Saphu Indian Pangolin Manis crassicaudata Sch-I

35 Sa-phai-ruang Crab-eating Mongoose

Herpestes aura Sch-II

36 Sathar Goral Nemorheadus goral Sch-I

37 Sauak Jungle Cat Felis chaus Sch-I

38 Savawm Black Bear U.thibetanus Sch-II

39 Sa-zaw-Zaw-buang)

Himalayan Palm Civet

Paguma larvata Sch-II

40 Sa-zaw(Zaw-hang)

Toddy Cat/Common Palm Civet

Paradoxurus hermahroditus

Sch-II




Sling Mizo Name Common Name Scientific Name Schedule of Indian Wildlife ( Protection)

Act, 1972

41 Sazu Common Mouse Rat

Rattus rattus Sch-II

42 Sazuk Sambar Cervus unicolor Sch-III

43 Sihal Bengal Fox Vulpes bengalensis Sch-II

44 Tlum-therte Small Indian Civet Viverricular indica Sch-II

45 Vahluk Common Flying Squirrel

Petaurista petaurista

Sch-I

46 Zamphu Binturong/Bear-cat Arctictis binturong Sch-I

47 Zawng Rhesus Macaque Macaca mulatta Sch-II

48 Zawng-mawt Stump-tailed Macaque

Macaca arctoides Sch-II

49 Zawng-hmeltha Pig-tailed Macaque Macaca leonine Sch-II

50 Zohang Small Indian Mongoose

Herpestes favanicus Sch-II

51 Zutam Bandicoot Rat Bandicota indica Sch-V

52 Zuthel White-tailed Wood Rat

Rattus blanfordi Sch-II

53 Sa-zaw(Zaw-hang)

Toddy Cat/Common Palm Civet

Paradoxurus hermahroditus

Sch-II

54 Sazuk Sambar Cervus unicolor Sch-III

55 Sihal Jackal Vulpes bengalensis Sch-II

56 Tlum-pui

Large Indian Palm Civet Viverra zibetha

Sch-II

57 Zawng-hmeltha Pig-tailed Macaque Macaca nemestrina Sch-II

58 Zuthel

White-tailed Wood Rat Rattus blanfordi

Sch-II

59 Keipui Tiger Panthera tigris Sch-I

61 Keisen Golden Cat Fells temmincki Sch-II

62 Keite Leopard Panthera pardus Sch-I

63 Kelral Clouded Leopard Neofelis nebulosa Sch-I

69 Mang-tir/Sa-mang Malayan Sun Bear Ursus malayanus Sch-I

70 Ngau Capped Langur

Trachypithecus pileatus

Sch-I

72 Nghar-thing-awn

Spotted Linsang/Tiger Civet

Prionodon perdicolor

Sch-II

Aves ( BIRDS)

Sl.No Mizo Name Common Name Scientific Name Schedule of Indian Wildlife ( Protection)

Act, 1972

1 Bawng Scarlet Minivet Pericrocotus flammeus

Sch-IV

2 Bawng irpaw Grey-chinned Minivet

P.Solaris Sch-IV

3 Bawngmeisei Long tailed Minivet P.mariae ethologus Sch-IV

4 Bawngte Short tailed Minivet P.brevirostris Sch-IV

5

Bemkawng Grey Tree pie Dendrocitta formosae

Sch-IV

6 Buarchawm Blue-napped Pitta Pitta nipalensis Sch-IV

7 Buarchawm lu-uk Hooded Pitta Pitta sordida Sch-IV

8 Bullut Mountain Imperial pigeon

Ducula badia Sch-IV

9 Bullutte Green Imperial Pigeon

Ducula aenea Sch-IV

10 Changkak Black Drongo Dicrurus adsimilis Sch-IV

11 Changkakte Bronzed Drongo Dicrurus aeneus Sch-IV

12 Changsen Maroon Oriole Oriolus traillii Sch-IV

13 Chang-hlawi Lesser Racket- Dicrurus remifer Sch-IV





Act, 1972

tailed Drongo

14 Changrual Blue-winged Siva Minla cyanouroptera

Sch-IV

15 Chawngzawng House Sparrow Passer domesticus Sch-IV

16 Cheih Chin Hills Green shrike-babbler

Pteruthius xanthochlorus hybridus

Sch-IV

17 Chhawlhring-lu-eng

Orange-bellied Leaf-bird

Chloropsis hardwickii

Sch-IV

18 Chhawlhring-thla-paw

Blue-winged Leaf bird

Chloropsis cochinchinensis

Sch-IV

19 Chhawlhringlu-eng Gold- fronted Leaf bird

Chloropsis aurifrons Sch-IV

20 Chhemhur-uk Brown Shrike Lanius cristatus Sch-IV

21 Chhemhur Black-headed Shrike

Lanius shack tricolor

Sch-IV

22 Chhemhur Grey-backed Shrike Lanius tephronotus Sch-IV

23 Chhenhurpaw Long-tailed Shrike L.schach tricolor Sch-IV

24 Chhimbuk Spot-bellied Eangle Owl

Bubo nipalensis Sch-IV

25 Chhimbuk Burmese Collared Scops Owl

Otus bakkamoena lettia

Sch-IV

26 Chhimbuk Common Scops- Owl

Otus Scops Sch-IV

27 Chhimbuk Spotted Scops-Owl Otus spilocephalus Sch-IV

28 Chhimbuk( Va-uk) Brown Hawk Owl Ninox scutulata Sch-IV

29 Chhimbukte Barred Jungle Owlet

Glaucidium radiatum

Sch-IV

30 Chhuangtuar/Va-se-ek

Hoopoe Upupa epops Sch-IV

31 Chi-ling Yellow-throated Fulvetta

Alcippe cinerea Sch-IV

32 Chinrang Black backed forktail

Enicurus inemaculatus

Sch-IV

33 Chirh-dawt Fantail Snipe Gallinago gallinago Sch-IV

34 Chirh-dawt Pintail Snipe Gallinago stenura Sch-IV

35 Chirh-dawt-lian-chi

Woodcock Scolopax Sch-IV

36 Chikkut Mountain Bulbul Hypsipetes viridescens

Sch-IV

37 Chingpirinu Brown-wood-Owl Strix leptogrammica

Sch-IV

38 Chingpirinu Himalaya Wood

Owl

Strix aluco nivicola Sch-IV

39 Chip Olive-backed Tree Pipit

Anthus novaeseelandiae

Sch-IV

40 Choak Jungle Crow Corvus macrorhynchos

Sch-IV

41 Daikat Golden headed tailor bird

Orthotamus Cucullatus

Sch-IV

42 Dawithiama arpa Mrs. Gould’s Sunbird

Aethopyga gouldiae Sch-IV

43 Dawithiama arpa Dulsen

Crimson Sunbird Aethopyga siparaja Sch-IV

44 Dawithiama arpa Meisen

Fire-tailed Sunbird Aethopyga ignicauda

Sch-IV

45 Dawkek White-throated Bulbul

Cringer flaveolus Sch-IV

46 Dawntliang Green Magpie Cissa chinensis Sch-IV





Act, 1972

49 Dil Arte Little Grebe Podiceps ruficollis Sch-IV

50 Dumar Purple Swamp-hen Porphyrio porphyrio Sch-IV

51 Fanghmir thloh Pale-headed Woodpecker

Gecinulus grantia Sch-IV

52 Fanghmir thloh Rufous Woodpecker Micropternus brachyurus

Sch-IV

53 Fuanhawr Asian House-martin Delichon dasypus Sch-IV

54 Fuanhawr Nepal House-martin

Delichon nipalensis Sch-IV

55 Hmarvaiva Pied Myna Sturnus contra Sch-IV

56 Hmunchhe arpui Pygmy Wren-babbler

Pnoepyga pusilla Sch-IV

57 Hrangkir Asian Barred Owlet Glauacidium cuculoides

Sch-IV

58 Hrangkir/ Collared Pigmy Owlet

Glaucidiulbrodiei Sch-IV

59 Huipui Thick-billed Green Pigeon

Treron curvirostra Sch-IV

60 Irliak Large Cuckoo Shrike

Coracina novaehollandiae

Sch-IV

61 Irliakte Dark-winged Cuckoo Shrike

C.melachistos Sch-IV

62 Kawr vaiva Collared Myna Acridotheres albocinctus

Sch-IV

63 Kaikuangral Blyth’s Kingfisher Alcedo Hercules Sch-IV

64 Kaikuangral Stork-billed Kingfisher

Pelargopsis capensis capensis

Sch-IV

65 Kaikuangral Crested Kingfisher Ceryle lugubris Sch-IV

66 Kaikuangral Pied Kingfisher Ceryle rudis Sch-IV

68 Kaikuangral te chi Black-backed Kingfisher

Ceyx erithacus Sch-IV

69 Kaikuangral Awrvar

White-throated Kingfisher

Halcyon smyrnensis Sch-IV

70 Kaikuangral-ludum

Back-capped Kingfisher

Halcyon pileata Sch-IV

71 Kaikuangralte Common Kingfisher Alcedo atthis Sch-IV

72 Kaikuangraluk Ruddy Kingfisher Halcyon coromanda Sch-IV

73 Kanghlai Lesser Adjutant Leptoptilos Javanicus

Sch-IV

74 Kawlhawk Wreathed Hornbill Rhyticeros undulates

Sch-IV

75 Kawl-rit/Pi-kawl-rit

Brown-eared Bulbul Hypsip[etes flavalus

Sch-IV

76 Kawl va sir Red winged shrike-babbler

Pteruthius flaviscapis

Sch-IV

77 Khawimu-chinrang White Wagtail Motacilla alba Sch-IV

78 Kham- va-mur Dark-backed Swift Apus acuticauda Sch-IV

79 Kitheihrawk Common Hawk cuckoo

Cuculus varius Sch-IV

80 Kitheihrawk Large Hawk-cuckoo Cuculus sparverioides

Sch-IV

81 Kireuh Streaked Spider Hunter

Archnothera magna Sch-IV

82 Klawt Slatey-headed Parakeet

Pstillacula himalayana

Sch-IV

83 Ko-ro/Koro-lu-par White-rested Laughing thrust

Garrulax leucolophus

Sch-IV

84 Kulherh nu Crow-billed Drongo Dicrurus annectans Sch-IV

85 Kul herh Hair-crested Dicrurusll Sch-IV





Act, 1972

Drongo hottentottus

86 Lailen Grey Wagtail Motacilla cinerea Sch-IV

87 Lalruanga Sehnawt

Crow Pheasant Centropus sinensis Sch-IV

88 Lawizit Ruby-cheeked Sunbird

Anthreptes singalensis

Sch-IV

89 Lengder Ashy Wood Swallow

Artamus fuscus Sch-IV

90 Liandorit Black Bulbul Hypsipetes madagasdariensis

Sch-IV

91 Limchho Brawn-throated Tree Creeper

Certhia discolor Sch-IV

92 Lungdup Black Eagle Ictinaetus malayensis

Sch-IV

93 Luang tu-bek/Mau Thloh

Rufous Piculet Sasia ochracea reichenowi

Sch-IV

94 Mangkhai-a-ral-veng

Red-wattled Lapwing

Vanellus indicus Sch-IV


Grey-headed Lapwing

Vanellus cinereus Sch-IV


Spur-winged or River Lapwing

Vanellus duvaucelli Sch-IV


White-tailed Lapwing

Vanellus leucurus Sch-IV

98 Mawntaipirtliak Plaintive Cuckoo Cacomantis merulinus

Sch-IV

99 Mawntaipirtliak Lesser Cuckoo Cuculus Poliocephalus

Sch-IV

100 Mimsirkut Bar-tailed Cuckoo-Dove

Macropygia unchall Sch-IV

101 Mitval Nepal Fulvetta Alcippe nipalensis Sch-IV

102 Muarla Crested Honey Buzzard

Pernis Ptilorhyncus Sch-IV

103 Muawmsen Oriental Hobby Falco severus Sch-IV

104 Mungek Peregrine Falcon Falco perefrinus Sch-IV

105 Muarla Rufous-bellied Hieraaetus badius Sch-IV

106 Mu-te Shikra Accipiter badius Sch-I

107 Mu-ni-ngal-dang Crested Goshawk Accipitertrivirgatus Sch-I

108 Mu-te Besra Accipiter virgatus Sch-I

109 Mu-kel-rang Black Baza Aviceda leuphotes Sch-I

110 Mu Common Buzzard Buteo buteo Sch-I

111 Mu-te Eurasian Kestrel Falco tinnunculus Sch-I

112 Muvanlai Crested Serpent Eagle

Spilornis cheela Sch-I

113 Ngal Vapual Spot-breasted Scimitar-

Pomatorhinus Sch-IV

Babbler Erythrocnemis Sch-IV

114 Ngal Vapual Coral-billed Scimitar-

Pomatorhinus Sch-IV

babbler Ferruginosus phayrei

115 Ngal Vapual Large Scimitar-babbler

Pomatorhinus hypoleucos

Sch-IV

116 Ngal Vapual Rufous-necked Scimitar

Pomatorhinus ruficollis bakeri

Sch-IV

117 Ngal Vapual Slaty-headed Scimitar-babbler

Pomatorhinus schisticeps

Sch-IV

118 Ngawihup/Kawlpui

saruhhak

White-bellied Heron Ardea insignis Sch-IV





Act, 1972

119 Ngaw Lailen Forest Wagtail Motacilla indica Sch-IV

120 Pengleng House Swift Apus affinis Sch-IV

121 Va te chikhat Yellow-breasted Babbler

Macronous gularis Sch-IV

122 Vathu Oriental Turtle Dove

Streptopelia orientalis

Sch-IV

123 Vavu Mrs. Hume’s Pheasant

Syrmaticus humiae Sch-I

124 Va-zar(Zar-fek) Yellow-throated Garrulax galbanus galbanus

Sch-IV

125 Va-zar(Zar-fek) Necklaced Laughing thrush

Garrulax moniligerus

Sch-IV

126 Va-zar(Zarpui-thi-awrh)

Black-gorgeted Laughing thrush

Garrulax pectoralis Sch-IV

127 Vazum Green-billed Malkoha

Phaeni cophaeustritis

Sch-IV

128 Zairumva Common Lora Aegithina tiphia Sch-IV

129 Zetzet Little Spider Hunter Arachonothera Sch-IV

130 Zotuklo Golden-throated Barbet

Megalaima frankinii Sch-IV

131 Zo-bul-lut/Bul-lut-tial

Speckled Wood Pigeon

Columba hodgsonii Sch-IV

Reptiles

Sl.No Mizo Name Common Name Scientific Name Schedule of Indian Wildlife (Protection) Act, 1972

1 Chawngkawr Mono-cellate Cobra Naja kaouthia Sch-II

2 Daidep Garnot’s Gecko Hemidactylus gamoti

Sch-IV

3 Laiking Common Calotes Calotes versicolor Sch-IV

4 Laitel Spiny-headed Forest Calotes

Calotes emma Sch-IV

5 Rulngan King Cobra Ophiophagus Hannah

S ch-II

6 Rultuha White-lipped pit viper

Trimeresurus alborabris

Sch-II

7 Rulsakhi Cat snake Boiga ochrecea Sch-II

8 Saphai Eastern Indian/Burmese Python

Python molurus Sch-I

9 Satel Yellow Tortoise Indotestudo elongate

Sch-II

10 Tangkawng Saw Fish Xenantodon cancella

Sch-II

11 U-leuh Spotted Gliding Lizard

Draco maculates Sch-II

Fishes

Sl.No Mizo Name Common Name Scientific Name Schedule of Indian Wildlife (Protection)

Act, 1972

1 Nghatun (Tunzem) Rohu Laebo rohita -

2 Nghatun (Tunhang)

Rohu Laebo calbasu -

3 Zawngdulinu Gangetic Dolphin Platanista gangetica Sch-I

4 Thaichhawninu Cat Fish Bagarius yurrellii -

5 Nghafunglawr Saw Fish Xenantodon cancella

-

6 - Tilapia Tilapia mosambica -

7 Nghadawl Amblifiring godon mola

-





Act, 1972

8 Nghatun Puntius Puntius ticto -

9 Nghameidum Puntius Puntius sarara -

11 Nghavawk Sport Fish Chana striatus -

12 Ngharul Eel Muraena thyroidea -

13 Nghathinghar Flat Fish Chanda nanaraya -

14 Sport Fish Copper Mahaseer(Sport Fish)

Acrossochilous hexagonalopis

-

15 Catla Bau (Catla) Catla catla -

16 Mrigal Mrigal Cirrhinus mrigala -

17 Silver carp Silver carp Hypothalmichthys molitric

-

18 Grass carp Grass carp Ctenophayngodon idella

-

19 Common carp Common carp (Scale carp)

Ciprinus corpio -

20 Nghahrah Tor (Sport Fish) Tor pituitora -

21 Nghalim Sport Fish Channa orientalis -

Amphibians

Sl.No Mizo Name Common Name Scientific Name Schedule-I of the Indian Wildlife (Protection),

Act, 1972

1 Utawk Common Asian Toad

Bufo mela Sch-IV

3.9.6 Aquatic Ecological Status: Primary Survey

3.9.6.1 Introduction

The impact of pollution on aquatic ecosystem manifests itself first on the biotic

aquatic communities. The species composition of aquatic organisms in natural

communities is directly influenced by ambient water quality. The responses of plants

to pollutants, when measured quantitatively give an insight about the conditions of

existing aquatic ecosystem.

3.9.6.2 Plankton Study

Protecting the environment and making efficient use of natural resources are two of

the most pressing demands in the present stage of social development. The task of

preserving the purity of the atmosphere and water basins is of both national and

global significance since there are no boundaries to the propagation of

anthropogenic contaminants in the water. An essential pre requisite for the

successful solution to these problems is to evaluate ecological impacts from the

baseline information and undertake effective management plan. So the objective of

aquatic ecological study may be outlined as follows:

To characterize water bodies like fresh waters;

To understand their present biological status;

To characterize water bodies with the help of biota;

To understand the impact of industrial and urbanization activities; and

To suggest recommendations to counter adverse impacts, if any on the

ecosystem.




To meet these objectives following methods were followed:

Generating data by actual field sampling and analysis in these areas through

field visits during study period; and

Discussion with local people to get the information for aquatic plants and aquatic

animals.

To fulfill these objectives and to understand the present status of aquatic

ecosystem, samples were collected from different fresh water system (river) under

investigation. In order to get a clear picture and to assess the various parameters of

water, threesampling locations were identified for sampling. Samples were collected

during study period. The sampling locations are presented in Table-3.9.5 and

shown in Figure-3.9.1.

TABLE-3.9.5

DETAILS OF AQUATIC SAMPLING LOCATIONS

Sr. No. Code Locations Remarks

1 AE-1 Bulang tat river near Bairabi Fresh water

2 AE-2 Vaak Lui, river near Mamit Fresh water

3 AE-3 Sakhi Lui, river Belkhai Tlang Fresh water

3.9.6.3 Methodology Adopted for Aquatic Studies

The biological species specific for a particular environmental conditions are the

best indicators of environmental quality. This includes different biological species

such as phytoplankton, zooplankton and bacteria.

Diatoms, desmids and dinophyceaen members are indicative of clean water

conditions. Increasing dominance of diatoms, ciliates, flagellates, chlorophycean

and cyanophycean species indicates progressively increasing trophic conditions.

Presence of Euglenophyceae indicates high eutrophic conditions. Planktonic

rotifers are usually more abundant in fresh water than estuarine waters. It is

believed that when crustacean and insect out number other groups the situation

reflects the enriched organic conditions of water. Thus, of certain organisms help

in classifying water body in trophic levels on knowing its physico chemical

characteristics.

The plankton samples were collected by using plankton net. The filamentous

algae and debris were avoided by filtering through the plankton net. The collected

sample was condensed to 100 ml by filtration and the samples were preserved

using pinch of Rose Bengal and 10 ml of 4% formaldehyde solution.

For the measurement of frequencies of various forms of Phytoplankton and

Zooplankton, one drop of the sedimented plankton was mounted on a micro-slide,

as many as 20 different microscopic fields situated at more or less even distances

from each other were examined, and numbers of individual organisms are

counted.




3.9.6.4 Phytoplankton

Phytoplankton group reported from three locations, 8 species of phytoplanktons

were reported.

3.9.6.5 Zooplankton

About 6 zooplankton species are recorded from all the three the sampling locations.

The list of plankton recorded in fresh water bodies in study area during study period

are presented in Table-3.9.6 and Table-3.9.7.

TABLE-3.9.6

LIST OF PHYTOPLANKTON SPECIES IDENTIFIED FROM STUDY AREA

Sr. No Family Species

1. Bacillariophyceae Navicula sp Diatoma sp Synedra sp

2. Cyanophyceae Chlorella sp

Scenedesmus sp

Ankistodesmus sp

3. Chlorophyceae Merismopidia sp

4. Euglenophyceae Euglena sp

TABLE-3.9.7

LIST OF ZOOPLANKTON SPECIES IDENTIFIED FROM STUDY AREA

Family Zooplankton Species

Rotifera Brachinous sp.

Arthropoda Nauplius sp.

Acroperus sp.

Macrothrix sp.

Ceriodaphnia sp.

Simocephalus sp.

3.9.8 Conclusion

As per primary survey and secondary data referred, it was concluded that the

study areas flora and fauna is ecologically rich and it is also fragmented owing to

anthropogenic pressures.

The endangered fauna are only present in the core of the forest areas, and there

is impact of fragmentation owing to the road construction and extraction of the

forest material on non timber forest produce like bamboo in the forests.

Instance of Hunting and Poaching are also reported in the forest fringe villages.

Thus many of the rare and threatned species were found in the villages.




3.10 Demography and Socio-Economics

The demographic and socio- economic conditions prevailing in the block of the

proposed drilling of exploratory wells area Meidum, Taitow, Zanlawn Villages in

kolasib district, Sauhliap village in Mamit district, Tlangnuam rural development

block in Aizawl district of Mizoram” is analyzed. The socio-economic data forms

the basis for developing a suitable enterprise social responsibility plan to address

the needs of the population.

The project proponent is committed to take up the socio-economic development

initiatives not only to minimize the negative impact on the population and also

improve the socio-economic status of population living in block of the wells as its

sustained effort as part of corporate social responsibility.

3.10.1 Methodology Adopted for the Study

The methodology adopted for the study mainly includes primary survey and

review of published secondary data (District Census Statistical Handbooks- 2011

and Primary Census Abstract of Census-2011) with respect to population,

household size, sex ratio, social stratification, literacy rate and occupational

structure for block area.

3.10.2 Review of Demographic and Socio-Economic Profile-2011

The village wise demographic data of 72 villages and 04 notified towns are falling

within the block of the project site as per the 2011 census is given in Annexure-

VI. The salient features of the demographic and socio-economic conditions are

analyzed and described in the following sections.

3.10.3 Demography

Distribution of Population

As per 2011 census the study area consisted of 399283 persons inhabited in

study area. The distribution of population in the study area is shown in Table-

3.10.1.

TABLE-3.10.1

DISTRIBUTION OF POPULATION

Particulars NELP Block Area

No. of Households 82590

Male Population 199084

Female Population 200199

Total Population 399283

Male Population (0-6 years) 27452

Female Population (0-6 years) 26863

Total Population (0-6 years) 54315

% of 0-6 years population 13.60

Average Household Size 4.83

% of males to the total population 49.86

% of females to the total population 50.14

Sex Ratio (no of females per 1000 males) 1006

Source: District Census Hand Book –2011




Average Household Size

The study area has a household size of 4.83 as per 2011 census.

Sex Ratio

The configuration of male and female indicates that the males constitute to about


records. The study area on an average has 1006 females per 1000 males as per

2011 census reports. In comparison to the state sex ratio (Mizoram 976) the

study area has recorded more sex ratio. The sex ratio in the study area indirectly

reveals certain sociological and cultural aspects in relation with female births.

3.10.4 Social Structure


Scheduled Castes(SC) and 91.54% to Scheduled Tribes(ST). Overall the data of

social stratification reveals that the SC and ST % to population is more than

91.7%, The SC and ST community are marginalized and they are at considered at

low level of social strata and calls for a special attention in Social Impact

Management Plan for improving their socio-economic status apart from

preservation and protection of their art, culture and traditional rights of livelihood.

The distribution of population by social structure is shown in Table-3.10.2.

TABLE-3.10.2

DISTRIBUTION OF POPULATION BY SOCIAL STRUCTURE

Particulars NELP Block area

Schedule caste 660

% To the total population 0.17

Schedule Tribes 365488

% To the total population 91.54

Total SC and ST population 366148

% To total population 91.70

Total population 399283


3.10.5 Literacy Levels

The data of study area reveals that literacy rate of 95.85% as per 2011 census,

which is found to be more than state rate of literacy (Mizoram 89.3%). The

distribution of literate and literacy rate in the study area is given in Table-

3.10.3.

TABLE-3.10.3

DISTRIBUTION OF LITERATE AND LITERACY RATES


Male Population 199084

Female Population 200199


Male Population (0-6 years) 27452





Female Population (0-6 years) 26863

Total Population (0-6 years) 54315

Total Population above 7 years 344968

Male literates (7+ years) 165743

Female literates (7+ Years) 164908

Total literates (7+ Years) 330651

Male literacy rate (%) to the total literates 50.13

Female literacy rate (%) to the total literates 49.87

Average Male Literacy to the total population (%) 48.05

Average female Literacy to the total population (%) 47.80

Total Literacy rate (%) to the total population 95.85





area as per 2011 census records.

3.10.6 Occupational Structure

The occupational structure of residents of work participation rate in the study

area is studied with reference to main workers, marginal workers and non-

workers. The main workers include 10 categories of workers defined by the

Census Department consisting of cultivators, agricultural laborers, those engaged

in live-stock, forestry, fishing, mining and quarrying; manufacturing, processing

and repairs in household industry; and other than household industry,

construction, trade and commerce, transport and communication and other

services.

The marginal workers are those workers engaged in some work for a period of

less than six months during the reference year prior to the census survey. The

non-workers include those engaged in unpaid household duties, students, retired

persons, dependents, beggars, vagrants etc.; institutional inmates or all other

non-workers who do not fall under the above categories.

Total work participation in the project study areas is 41.78% and the non-workers

constitute 58.22% of the total population respectively. The distribution of workers

by occupation indicates that the non-workers are the predominant population.

The main workers to the total workers are 84.67% and the marginal workers

constitute to 15.33% to the total workers. The occupational structure of the study

area is shown in Table-3.10.4.




TABLE-3.10.4

OCCUPATIONAL STRUCTURE

Particulars NELP Block Area


Total workers 166828

Work participation rate (%) 41.78

Total main workers 141248

% of main workers to total workers 84.67

Marginal workers 25580

% of marginal workers to total workers 15.33

Non-workers 232455

% of non-workers to total population 58.22

Source: District Census Hand Book-2011


Chapter-4 Impact Assessment and Mitigation Measures


4.0 IMPACT ASSESSMENT AND MITIGATION MEASURES

This chapter presents the identified environmental impacts due to the proposed exploratory drilling and proposed mitigation measures for minimizing or avoiding adverse impacts as well as other best practices. The proposed mitigation measures will be implemented during exploratory activities.

4.1 Impact Assessment

Generally, the environmental impacts can be categorized as either primary or secondary. Primary impacts are those, which are attributed directly by the project and secondary impacts are those, which are indirectly induced and typically include the associated investment and changed patterns of social and economic activities by the proposed action.

The drilling programme can be considered as a temporary activity which lasts for about 4-5 months at each well location. No above ground permanent structure, except the well head will be built at the well locations during the exploratory drilling phase of the project. The well site once drilled will be temporarily suspended / permanently abandoned based on the success and the rig will be moved to next location. Anticipated impacts from the proposed project can be classified into the following phases:

a) Well site and Access Road construction

• Impacts from location of drill sites on land-use, aesthetics, vegetation and drainage pattern;

• Impacts on vegetation and soil from site clearance; • Impact on ambient air from fugitive dust and vehicular exhaust emissions; • Impact on soil from construction activities; • Impact on socio-economics from local employment and use of local resources;

and • Impact on local community from temporary land acquisition, noise and

disturbance.

b) Drilling Operation

• Impacts from handling and disposal of drill cuttings and waste drilling mud; • Impact on ambient air from DG set and vehicular emissions; • Impacts from wastewater generation during drilling and camp site operations; • Impacts from noise generating equipments e.g. DG sets, land rig and vehicles; • Impact from transportation of material; • Impact on local water resources due to use of water for drilling operations; and • Impact from well testing on local environment.

c) Decommissioning and Site Restoration

• Impacts from waste handling and management; • Impacts on local drainage pattern; • Potential impacts from migration of fluids in well bore; and • Impact on local community (farm owner).




4.1.1 Method of Impact Identification

Both beneficial as well as potential adverse impacts may be expected on the environment from the proposed drilling activities. The impacts may be direct or indirect, short or long term and reversible or irreversible. The present environmental quality has been taken into consideration while assessing the magnitude and importance of specific impacts.

The techniques used for assessment of impacts are both qualitative and quantitative. Qualitative assessment is based on historical evidence and available literature. Quantitative assessment has been carried out for potential air and noise pollution impacts, the results of which will be used for siting of well sites, i.e., by maintaining safe distances from sensitive receptors.

4.2 Anticipated Impacts from the Project The potential environmental impacts from the project are discussed in the following sections.

4.2.1 Land use and Aesthetics

Impact on land use and aesthetics is expected to be from vegetation clearance, excavation, leveling and grading of the site. Thus there might be need for clearing crops and trees. As the land requirement for each drill site is quite small (1.5-2.0 ha) compared to the large stretches of agricultural land there would be insignificant change to land use. Movement of heavy vehicles, earth moving equipments, piling of removed soil at the site periphery during construction would have aesthetic impacts.

4.2.2 Land Required for Drilling Activity Though exploratory / appraisal drilling is a temporary activity yet the period for which the land is required would depend on discovery of hydrocarbons. Approximately, 15,600 m2 of land for drilling rig facilities would be impacted for each drill site. The actual drilling platform area would be approximately 5,200 m2. The parcel of land would be temporarily acquired as per the applicable laws and in consultation with the land owners. Adequate compensation for loss of income from that piece of land, including crop loss, tree loss and any other direct or indirect loss as determined by the local revenue officials would be paid to the landowner. Drilling rig activities will result in disturbance and compaction of soils within a 1.0 ha zone around the drilling rig due to equipment, vehicles. Access roads to the drilling sites will also impact top soils. The total loss of soils as a result of exploration drilling with probably be in the order of 3-5 ha per well, depending on the length of access road required to access each site.

4.2.3 Topography & Drainage

There would be slight change in topography at the drill site as it will be elevated from ground level to avoid storm water accumulation. The study area has hilly terrain and is almost devoid of approach roads with elevations varies from MSL 400 m to 2000 m. There would be minor changes in the natural drainage pattern at




immediate vicinity of the well site. This impact would be substantially further reduced as the identification of wells sites would consider local drainage patterns in the area. Additionally the grading of the drilling site will be done keeping in mind that the existing aerial drainage flow pattern of the well site location. As drilling is a single point activity at each well location there will not be any change in subsoil drainage patterns.

4.2.4 Impacts on Soil Quality

During construction the major impacts on soil would occur due to excavation, compaction due to movement of heavy equipment and levelling as well as pollution due to addition of moorum. Site preparation will entail stripping and removal of the topsoil which contains most of the nutrients and organisms that give soil a living character and productivity. This will in turn result in minor changes in soil hydrology and small changes in the topsoil structure. However, as the project design takes into account the preservation of the top soil and its subsequently use for topping up of the rehabilitated land. The impact on soil quality will be insignificant considering the mitigation measures implemented. The hazardous wastes generated from the exploratory drilling operations include drill cuttings, drilling mud, spent lube oil and waste oil (Category 2.2, 2.3, 5.1 and 5.2). Apart from the above, packaging wastes, used containers and any contaminated soil arising out of any accidental oil spillages during the Drill Rig movements and operations etc. are also expected to be generated from proposed drilling activities.

4.2.4.1 Soil Contamination Drilling wastes are generated during drilling operation through various geological formations to reach the reservoir that might hold the hydrocarbons. The mud used brings the rock cuttings (generated from drilling) to the surface, which along with the mud are called drilling wastes. Drilling operations are typically associated with a range of wastes such as drilling mud, used oils, hydraulic fluids and various discarded chemical products, empty drums and sacks, acids, surfactants, cement, biocides, solvents, and camp wastes.

The chances of soil contamination are from the storage and handling practices of chemicals and fuels, surface runoff carrying contaminated substances. The drilling mud and the cuttings could also add to the sub surface contamination if not handled appropriately. ONGC has considered all the above aspects and have incorporated all these aspects in the well sites design.

4.2.4.2 Alteration of Soil Quality by Loss of Topsoil

Loss of topsoil in these areas, either by mechanical removal or by erosion would alter the soil structure with resultant implications for revegetation.

Measures inherent in the design of the project to minimize loss of topsoil and overburden are as follows:

• Topsoil suitable for supporting agriculture, removed during site clearance will be retained, stored as a berm on the edge of the well site, protected from erosion by plastic sheeting;




• Native vegetation, wherever appropriate will be kept at the edge of the well site as a seed bank, or replanted at an alternate location or will be used to protect/stabilize soil surfaces on slopes;

• On demobilization, adequate measures would be provided to facilitate re-growth and hence retention of topsoils; and

• Planned and systematic tree replanting program will be put in place.

On consideration of the poor vegetation cover, the physical features of the proposed exploration block, the impact of drilling operations on soil quality will be insignificant. It is, however, important that mitigation measures are monitored to ensure that they are effective.

Summary of impacts on soil and land use are given in Table-4.1.

TABLE-4.1 SUMMARY OF IMPACT ASSESSMENT: SOIL AND LAND-USE

Impact Area Nature of Impact 1 Targets/Interests2 Magnitude and

extent3 Overall

Magnitude4

Land Use Change in original land use, land degradation, reversible (partially)

Original land use Well sites and access roads only, small scale; beneficial effect for afforestation and all weather access roads.

�� Minor

Derogation of Soil Quality

Cumulative contamination with dust, surface run-off; reversible

Soil quality, flora and fauna, including grazing livestock

Localised near sources; small contribution to existing background levels;

�� Minor

Physical effects on soils due to topsoil removal, nutrient loss; reversible

Soil quality, flora Around the well location small scale degradation of soil quality

�� Minor

Soil Contamination

Subsurface contamination due to spillage and handling of the chemicals and other waste materials, reversible(partial)

Soil quality, groundwater flora and fauna and the grazing livestock

Localised near the source of operation and could be nullified with proper house-keeping & waste management

�� Minor

1 Description; short or long term; reversible or permanent; associated with construction, operation, decommissioning; cumulative, accidental, etc

2 Targets and interests potentially affected. 3 Adverse or beneficial; small, large, etc; very localised (sites only), local, regional national. 4 Overall significance against criteria (� minor; •moderate, some significance; ••major)

The mitigation measures inherent in the design of the well site, together with rigorous implementation of the waste management plan will ensure that significant impacts in relation to soil quality are not anticipated at the well site.




4.2.5 Impact on Topography and Climate

4.2.5.1 Impact on Topography The envisaged topographical changes would be due to the manmade structures like drilling rig and other associated structures. As mentioned previously drilling exploratory well is a short duration activity at each drilling location, typically encompassing a period of 3-4 months from land acquisition to site abandonment. The impact would therefore be localised, temporary and minimal.

4.2.5.2 Impact on Climate

Impact on the climatic conditions from the drilling will not be significant. The maximum temperatures of the exit gas from the DG stack and flare stack will be around 300°C and 400°C respectively. In terms of total emission of green house gases and consequent impact on global warming or on potential for local increase of ambient temperature, considering the quantum of exit gas and the total duration of flow, the impact on the local or global climate will be insignificant.


The potential sources of air emissions at the well sites will be as follows: • Dust from earth works (during approach road and site preparation); • Emissions from DG sets; • Emissions from possible flaring during well testing; and • Emissions from vehicles.

During the short period of site preparation mechanical shovels and earthmovers will be used for vegetation clearance, cut and fill and other site leveling activities. These activities could generate dust particles which will be mobilized by wind, and deteriorate the ambient air conditions. However, these activities will be only temporary and with the clay nature of the soil, the impact to ambient air quality would be within the close proximity of well site. All the anticipated air emissions other than dust arise from combustion of hydrocarbons. The pollutants of concerns are NOx, SO2, CO, Particulate, and un-burnt hydrocarbons.

4.2.6.1 Potential Impacts Ambient air quality effects are normally assessed in relation to their potential to cause: • Health deterioration and nuisance in local communities; • Health deterioration amongst on site workers; and • Damage to vegetation. The gaseous emissions from the DG set will be controlled by efficient combustion of fuel in the DG set. The flaring of oil and gas during well testing is a short duration activity (about 14 - 21 days) and will be done within a ground level enclosed pit. Wherever, required special precautions will be taken to minimize the impact on the local environment and habitat.




The impact on ambient air quality is assessed hereunder considering the following:

• The air quality impacts have been predicted for the proposed drilling; and • Site-specific meteorological parameters have been recorded. Short-term 24

hourly GLC's incremental values were estimated using the site-specific meteorological data.

4.2.6.2 Fugitive Emissions

Air pollution during construction would be primarily due to fugitive emissions from vehicular movement, site preparation activities and material handling. Weathering of soil would take place as a result of clearing of vegetation, excavation and movement of heavy vehicles. The weathered soil generates dust due to re-entrainment during vehicular movement and equipment mobilization. Such dust emissions as experienced in other similar construction activities are of larger that 10µ (more than respirable range) and propagates to short distances. These emissions only have nuisance factor affecting workers at site. Use of dust masks would be adequate to mitigate impacts on workers. Fugitive emissions of VOC may result from the vents from the venting of un-burnt methane from well testing. However, the testing phase will be short duration of 14 - 21 days. Fugitive emissions in the form of material dust is expected during drilling operations (loading, unloading, handling of drilling fluid, chemical additives, cement and cement additives). Some fugitive emissions are also anticipated from storages of volatile chemicals and fuel at the site if the storages are not properly capped or are handled without due care. However, such emissions will not disperse widely and can only affect workers and people at site. Fugitive emissions during drilling operations are however not as significant as during site preparation. Fugitive emissions during drilling are not expected to travel beyond project boundaries. Workers working near fugitive emission sources are only susceptible which would be mitigated through use of PPEs in these areas.

4.2.6.3 Air Pollution Modeling

Prediction of impacts on air environment has been carried out employing mathematical model based on a steady state Gaussian plume dispersion model designed for multiple point sources for short term. In the present case, AERMOD dispersion model based on steady state gaussian plume dispersion, designed for multiple point sources for short term and developed by United States Environmental Protection Agency [USEPA] has been used for simulations from point sources.

4.2.6.4 Pollutants/Model Options Considered For Computations

The model simulations deal with two major pollutants viz., Sulphur dioxide (SO2) and Oxides of Nitrogen (NOx) emitted from the DG sets.




Model Options Used For Computations

The options used for short-term computations are:

• The plume rise is estimated by Briggs formulae, but the final rise is always limited to that of the mixing layer;

• Stack tip down-wash is not considered; • Buoyancy Induced Dispersion is used to describe the increase in plume

dispersion during the ascension phase; • Calms processing routine is used by default; • Wind profile exponents is used by default, 'Irwin'; • Flat terrain is used for computations; • It is assumed that the pollutants do not undergo any physico-chemical

transformation and that there is no pollutant removal by dry deposition; • Washout by rain is not considered; • Cartesian co-ordinate system has been used for computations; and • The model computations have been done for 10 km with 1000-m interval.

4.2.6.5 Model Input Data

• Emissions from DG Stacks

Air pollution from point sources at the drill site will be primarily contributed by the DG sets. Drilling requires a considerable amount of electric power and as a result will need the installation of DG sets which can supply around 2250 KVA of power at peak periods. The primary pollutants emitted by DG Sets consist of Oxides of Sulphur and Nitrogen, Carbon monoxide, Carbon dioxide and Hydrocarbons. Combustion of fuel in a DG set typically happens at high temperatures resulting in generation of considerable amounts of NOx. The SO2 concentration in emissions is dependant on the Sulphur content in fuel burnt and particulate matter consists of unburnt Carbon particles. The emission from each of the power generator sets in the drilling rig will be due to combustion of diesel. For a particular drilling site during drilling operation, there will be 3 operating DG sets, as detailed in Table-4.2.

TABLE-4.2

DETAILS OF DG SETS

Location DG Capacity Operational Stand by Fuel Requirement

Drilling Site 750 KVA 3 1 HSD – 6KL/day

The operational DG sources are considered as source for the modeling. The emission from each of these diesel generators will be due to combustion of diesel.

• Emissions from Flare Stack Another major source of emission from a single point is flaring pit. Flaring will be conducted only in the event of a hydrocarbon discovery. Flaring will be avoided as far as practicable for liquid hydrocarbons as these would be collected for surface testing and transported to legally approved entities. There is maximum




probability of only gas being flared from a specially designed pit. Though flaring is a point source yet the dispersion of emission starts at the ground level as it would be carried out in a pit. Flaring of gases is a high combustion process which generates nitrogen oxides as pollutant. There are negligible quantities of particulates, Sulphur dioxide or other pollutant. Improper flaring may however lead to escape of unburnt hydrocarbons (primarily) CH4.

• Modelling Scenarios

Emissions from diesel generator sets will be continuous throughout the drilling operations. The main pollutants from diesel generator sets include NOx and SO2 while NOx is the main pollutant expected to emit from test flare. As the fuel used is low sulphur HSD, insignificant amount of particulate emissions and gaseous emissions are envisaged. Similarly, during flaring also, particulate emissions are negligible.

The emission characteristics considered for the modeling exercise from DG generator sets and test flaring are given in the Table–4.3. The emission rate calculations for air dispersion modeling are given in Annexure-VII.

TABLE-4.3 EMISSION CHARACTERISTICS-MODEL INPUTS

Sr. No

Particulars DG Set (3 x 750 KVA)

1 No of engines and stacks 3

2 Height above ground level (m) 7.5

3 Diameter (m) 0.5

4 Gas temperature (0C) 300

5 Gas velocity (m/s) 15

6 Emission rate (g/s) - Sulphur dioxide - Oxides of Nitrogen

0.84 1.38

4.2.6.6 Presentation of Results

Model stimulation was carried out for pollution SO2 and NOx. The results for SO2 and NOx [1st maximum] are presented in Table-4.4. The isopleths for SO2 and NOx concentrations are depicted in Figure-4.1 and Figure-4.2.

TABLE-4.4 PREDICTED 24-HOURLY SHORT TERM INCREMENTAL CONCENTRATIONS

Season

SO2 NOx

Maximum Incremental

Conc. (µg/m3)

Distance (km)/

Direction

Maximum Incremental

Conc. (µg/m3)

Distance (km)/

Direction

Winter & pre-monsoon

3.1 1.0, NW 4.6 1.0, N

• Comments on Predicted Concentrations

A perusal of Table-4.4 reveals that the maximum incremental short term 24 hourly ground level concentrations for SO2 and NOx likely to be encountered due to DG




sets are 3.1 µg/m3 and 4.6 µg/m3 occurring at a distance of 1.0 km in northwest direction.

The predictions indicate that the SO2 and NOx concentrations are likely to be well within the prescribed limit for residential and rural zone. Based on the above it can be inferred that the ambient air quality in the study area is unlikely to be affected due to the proposed drilling.

• Resultant Concentrations After Implementation of the Project

The maximum incremental GLCs due to the proposed project for SO2 and NOx are superimposed on the maximum baseline SO2 and NOx concentrations recorded during the study to arrive at the likely resultant concentrations during winter season after commissioning of the proposed drilling. The cumulative concentrations (baseline + incremental) after implementation of the project are tabulated below in Table-4.5.

TABLE-4.5 RESULTANT CONCENTRATIONS DUE TO INCREMENTAL GLC's

Pollutant Maximum AAQ Concentration Recorded

During the Study

Incremental Concentration due to

drilling

Resultant Concentration

SO2 12.7 3.1 15.8

NOx 13.8 4.6 18.4

All values are in µg/m3

The maximum GLCs for SO2 and NOx after implementation of the proposed project are likely to be within the prescribed standards for rural and residential areas. However, the maximum GLCs are occurring during test flaring which is for a period of 14-21 days at each location. Further considering that the maximum GLCs occur at about 1.0 km, which is in the vicinity of the site boundary, no impact on outside environment is envisaged. Based on the above details, it can be inferred that the ambient air quality in the study area is unlikely to be affected due to the proposed activity.




FIGURE-4.1 SHORT TERM 24 HOURLY GLCs OF SO2




FIGURE-4.2 SHORT TERM 24 HOURLY GLCs OF NOx





The study area is having small tributaries river system. The block area is drained by some small tributaries. Location of well sites near to the rivers and major water bodies is however ruled out and thus any direct impact on water bodies is not anticipated. Therefore considering the water availability and abundant sources, there would be insignificant impacts on water resources due to usage in the project. Surface water quality in the region has been found to be of good quality and is being used by villagers for irrigation and other domestic purposes. Ground water in the region is potable in nature.

4.2.7.1 Sources of Pollution

In general circumstances, the surface water impacts that could be potentially caused from the drilling activities are as follows: • Withdrawal of groundwater; • Accumulation of the wastewater in the drilling site; • Potential wastewater discharges may arise from the following sources:

o Treated domestic effluent (sewage and kitchen waste); o Spent drilling muds, cuttings and completion fluids disposal; o (Potentially) contaminated storm water drainage from the derrick floor and

other systems; o Seepage of drilling mud fluid into subsoil from mud collection &

recirculation pond; o (Potentially) high sediment loads in runoff from unpaved well site areas

during heavy shower; and o Any produced water and liquid hydrocarbon fractions collected in the test

separator during well testing.

• Potential accidental spills of fuel, lubricants or chemicals and leaks from engines (i.e. power generators, vehicles) and liquid hydrocarbons during testing; and

• Waste handling particularly spent lubricants and chemicals during disposal may give rise to accidental releases.

4.2.7.2 Potential Surface and Groundwater Impacts

Based on the above-mentioned activities, the following potential impacts have been identified:

• Potential for water logging during monsoon in the site; • Potential for adverse impact on the surface water quality; • Potential for adverse impact on the groundwater quality; and • Likely change in the aquifer potential within the study area.




4.2.7.3 Water Pollution

• Process Wastewater Approximately 15-20 m3/day of wastewater would be generated from the drilling operation including minor quantities from washing and cleaning of rig floor and other equipments. Water based drilling mud is non-hazardous in nature. The primary pollutants in the wastewater would thus be suspended solids, dissolved solids and traces of floating oil from washing of rig floor and other equipments.

Effluents can cause significant pollution to water bodies especially ponds and lakes if disposed untreated. However, the wastewater will be collected in lined pits and clarified wastewater will be treated in packaged treatment plant located at the well sites to meet norms specified by CPCB and MPCB for discharge to land and surface water bodies.

• Sewage

It is estimated that approximately 8 m3/day of sewage will be generated from each well site. The sewage will be discharged into septic tanks and then to subsoil through soak pits. The subsoil in the area is found to be rich in organic content and micro-organisms. No impacts are thus envisaged from sewage disposal from site.

• Pollution Potential from Surface Runoffs

As the area experiences high rainfall, the site will generate considerable volume of runoffs during such rainy periods. The storm water generally contains high concentration of suspended matter eroded from the soil by the runoff. There is also a potential for contamination of the storm-water if the runoff picks up contaminants in the form of chemicals, oil and lubricants, etc. that could have been spilled or if material is stored in open areas (uncovered) in any particular area like the fuel storage or the non-hazardous chemical storage areas. This may result in a potential impact to the receiving water body. • Potential Impacts on Ground Water and Hydrogeology

There is a probability that during excavations, especially if conducted immediately after monsoon may lead to development of springs which may have to be dewatered. • Reduced Infiltration

The compaction of the working areas for setting up heavy machineries and equipments like the rig may lead to increased runoff and reduced infiltration, thereby affecting localised subsurface groundwater recharge. However, given that the occupation of the area is temporary and the area experiences high rainfall and thereby high recharge potential, the effect on the groundwater regime of the area will not affect water availability in neighbouring wells and tube wells and any resulting conflict with other users of groundwater in the area.




4.2.7.4 Impact to Surface Water Quality The probability of contamination of surface water bodies and sub-surface water bodies was discussed above. The impact to the surface water bodies could arise from discharge from the site, disposal practice of spent drilling mud, cuttings, completion fluids, handling of liquid hydrocarbons, fuels etc. With the proposed concrete pavement and secondary containment provisions, the surface water quality contamination will be negligible. Noticeable impacts to water quality in nearby watercourses are more likely to occur as a result of increased suspended particle load. During the well site preparation the extent of impact to nearby watercourses will be function of: • Area cleared; • Amount of rainfall from the period between site construction and drilling; • Distance of the watercourse from the well site; and • Mitigation measures to prevent any soil erosion within well site. However, if the site preparation activities were conducted in dry season, the above impact would be negligible or insignificant. Overall, with the appropriate measures to protect the well site and prevent discharges, installation of soil erosion control measures, prevention of spillages while handling and management of chemicals, the likely chances of impact on surface water will be minor.

4.2.7.5 Impact on Groundwater Regime

The water is used for preparing drilling mud and for domestic needs of the campsite. The water requirement is primarily depended upon the depth of the proposed well and time required for the drilling the well. The drilling fluid will be recycled and fresh water will be used as makeup water and for general washing and daily maintenance. The water requirement is proposed to be met from the local sources through water tankers. Since the drilling activity being temporary and water requirement is meager, no adverse impact on ground water resources is envisaged.

ONGC is using water based non-toxic biodegradable fluids with inhibitive and encapsulative characteristics as drilling mud. Additionally, the drilling mud collection and recirculation pond is lined with impervious layer to prevent seepage and loss of drilling fluid into the subsoil. Further, proper casing installation and cementing will ensure least groundwater contact.

Apart from the mud characteristics, the waste and spent mud would be disposed in polyethylene propylene lined pits for all the storage areas as per the EHS Management Plan – Civil works. The mud components during the storage form a bentonite (clay) lining along the pit wall preventing the seepage of water to the underground strata. Any hydrocarbons contamination will be skimmed off from site before proceeding to the next site so as to ensure that no leaching or subsurface contamination finally reaches the groundwater table. The waste oils and the skimmed oils collected from the drill site will be sent to the MPCB authorized recyclers.




Overall, with the appropriate management practices in place impacts on groundwater quality at the site is likely to be insignificant. The summary of impacts on water resources is given in Table-4.6.

TABLE-4.6

SUMMARY OF IMPACT ASSESSMENT: WATER RESOURCES

Impact Area Nature of Impact1 Targets/Interests affected2

Magnitude and extent3

Overall significance4

Surface Water

Physical Impact

Long term modification to the distribution of rain water catchment, if located near it

Local inhabitants depending on the water harvesting for water

Local, could be mitigated by avoiding water harvesting areas

• Minor

Short term due to increase in siltation load of the water bodies in rainy season

Localized impact to surrounding Rivers and adjoining the water bodies in monsoon

Regional, and for short term

• Moderate

Chemical Impact

Short term contamination of surface water flows due to untreated effluent, run-off, seepage from water holding tanks etc.,

Localised impact to surrounding nallahs and the river bodies in monsoon

Local, small scale mitigated by well site design and operations

• Minor

Long term contamination in the region due to surface runoffs from well sites during flash floods

Could also result in sub surface contamination around the region

Regional, dependent on occurrence of flood. Good engineering. practices will reduce risk of flooding and overflow

• Moderate

Ground Water

Groundwater quantity

Long & medium term, reduction due to percolation of subsurface contamination

Shallow aquifers surrounding the well sites

Local/Regional possibility remote with mitigation measures

• Minor

Resource Management

Resource Management

Long term, medium reduction

Judicious abstraction of water for usage

Regional, Can be mitigated by sourcing water from water surplus catchment areas. Drill site borewell can be used by locals after drilling, if water quality is acceptable

• Minor

1 Description; short or long term; reversible or permanent; associated with construction, operation, decommissioning; cumulative, accidental, etc 2 Targets and interests potentially affected. 3 Adverse or beneficial; small, large, etc; very localised (sites only), local, regional national. 4 Overall significance against criteria (� minor; • moderate, some significance; •• major)





4.2.8.1 Sources

During the drilling operation at the well sites, there would be various sources of noise in the area. These sources would be:

• Drilling draw works/rotors; • Mud Pumps; • Power generators; • Vehicular Movement; and • Cranes and material handling equipment.

4.2.8.2 Potential Impacts

Ambient noise quality is normally assessed in relation to its potential to cause:

• Health deterioration and nuisance in local community; • Health deterioration amongst on site workers; and • Disturbances and fragmentation to local habitats.

4.2.8.3 Assessment of Noise Impacts due to Site Activities

Driller rotors and the power generators and pumps would be the main sources of noise pollution during the drilling activity. Noise due to vehicular movement will be intermittent, but will also add to the background noise levels. The well site during excavation phase of the site preparation where heavy earth moving machinery will be in operation, noise level of the vehicle should not be more than the 90 dB (A). Typically, the noise generating sources for the onshore drilling activity are provided below (in the immediate vicinity) • Diesel Generator : 90 to 95 dB(A) • Pumps at the Rig : 85 to 90 dB(A) • Miscellaneous : 80 to 85 dB(A) • Control Room & Quarters : 50 to 60 dB(A) In order to predict ambient noise levels due to the proposed drilling the preparative modeling has been done. For computing the noise levels at various distances with respect to the plant site, noise levels are predicted using an user friendly model the details of which is elaborated below.

4.2.8.4 Details of Noise model

• Mathematical Model for Sound Wave Propagation During Operation

For an approximate estimation of dispersion of noise in the ambient from the source point, a standard mathematical model for sound wave propagation is used. The sound pressure level generated by noise sources decreases with increasing distance from the source due to wave divergence. An additional decrease in sound pressure level with distance from the source is expected due to atmospheric effect or its interaction with objects in the transmission path.




For hemispherical sound wave propagation through homogenous loss free medium, one can estimate noise levels at various locations, due to different sources using model based on first principles, as per the following equation:

)1r/2rlog(201p2p LL −= (1)

Where Lp2 and Lp1 are Sound Pressure Levels (SPLs) at points located at distances r2 and r1 from the source. The combined effect of all the sources then can be determined at various locations by the following equation.

....)101010(Log10L)10/3pL()10/2pL()10/1pL(

)total(p ++= (2)

Where, Lp1, Lp2, Lp3 are noise pressure levels at a point due to different sources.

Based on the above equations an user friendly model has been developed. The details of the model are as follows: ∗ Maximum number of sources is limited to 200; ∗ Noise levels can be predicted at any distance specified from the source; ∗ Model is designed to take topography or flat terrain; ∗ Coordinates of the sources in meters; ∗ Maximum and Minimum levels are calculated by the model; ∗ Output of the model in the form of isopleths; and ∗ Environmental attenuation factors and machine corrections have not been

incorporated in the model but corrections are made for the measured Leq levels.

4.2.8.5 Input for the Model

The incremental increase in noise levels due to the operation phase of the exploratory drilling has been done. Noise levels are mainly generated from DG sets, air compressors, pumps and transformers. The noise sources have been defined with respect to center of drill site. The input data pertaining to corresponding noise level are tabulated below in Table-4.7.

TABLE-4.7 INPUT DATA FOR NOISE MODELING

Sr. No. Location Noise Levels dB(A)

1 Diesel Generator sets 90 to 95

2 Pumps and the rig 85 to 90

3 Miscellaneous 80 to 85

4 Control Room and Quarters 50 to 60

4.2.8.6 Presentation of Results

The model results are discussed below and are represented through contours in Figure-4.3. The predicted noise level at 100 m distance from the boundary of well site is 52.0 dB (A) and are tabulated in Table-4.8.




TABLE-4.8 PREDICTED NOISE LEVELS

Sr. No. Distance from well site boundary Noise Level, dB(A)

1 25 m 58.0

2 50 m 55.0

3 75 m 54.0

4 100 m 52.0

4.2.8.7 Observation

Occupational Health Hazards from Noise Pollution

Exposure to noise levels, above Threshold Limit Value (TLV), has been reported to have detrimental effect on the workers' health. Personnel’s working for more than 4 to 4.5 hours per shift near the sound pressure level of 90 dB(A) will be greatly affected, unless suitable mitigatory measures are taken. The adverse effects of high noise levels on exposed workers may result in:

• Annoyance; • Fatigue; • Temporary shift of threshold limit of hearing; • Permanent loss of hearing; and • Hypertension and high blood cholesterol, etc.

Noise pollution poses a major health risk to the workers near high noise source. If the magnitude of noise exceeds the tolerance limits, it is manifested in the form of discomfort leading to annoyance and in extreme cases to loss of hearing. Detrimental effects of noise pollution are not only related to sound pressure level and frequency, but also on the total duration of exposure and the age of the person. Table-4.9 below gives noise levels and associated mental and physical response of humans.

TABLE-4.9 NOISE EXPOSURE LEVELS & ITS EFFECTS

Noise Levels (dB(A)) Exposure Time Effects

85 Continuous Safe

85-90 Continuous Annoyance and irritation

90-100 Short term Temporary shift in hearing threshold, generally with complete recovery

Above 100 Continuous Permanent loss of hearing

Short term Permanent hearing loss can be avoided

100-110 Several years Permanent deafness

110-120 Few months Permanent deafness

120 Short term Extreme discomfort

140 Short term Discomfort with actual pain

150 and above Single exposure Mechanical damage to the ear

Source: OSHA

During drilling operation, the personnel required to continually present in high noise source like DG is remote. All personnel working on rig are given noise abatement personnel protective equipments like earmuffs etc.




FIGURE-4.3 NOISE LEVEL CONTOURS

-1000.00 -800.00 -600.00 -400.00 -200.00 0.00 200.00 400.00 600.00 800.00 1000.00

-1000.00 -800.00 -600.00 -400.00 -200.00 0.00 200.00 400.00 600.00 800.00 1000.00

-1000.00

-800.00

-600.00

-400.00

-200.00

0.00

200.00

400.00

600.00

800.00

1000.00

-1000.00

-800.00

-600.00

-400.00

-200.00

0.00

200.00

400.00

600.00

800.00

1000.00




• Community Noise Level The maximum predicted noise level at about 100 m from the boundary of the drill site is about 52.0 dB(A). The ambient noise levels at most of the places in the region are within the CPCB standards. Since, the drilling operations last for only 3-4 months at each location, impact of the noise pollution due to the proposed exploratory drilling will be insignificant on the community. It can be concluded that the impact due to elevated noise is confined only up to a distance of 100 m from the drilling point and in areas beyond this distance, the ambient noise levels are within the stipulated ambient noise quality norms.


Impact on the ecology of the study area will vary with the proximity of the habitats from the drilling locations. However, the impacts are of temporary nature, which will last only for few months at each drill location during the exploratory drilling activities and will thus allow subsequent recovery after the activities stops. The block area is Golaghat district is mostly confined in amidst agrarian habitations comprising of paddy fields dotted with few betel nut trees and cash crop of tea gardens in the homesteads.

Considering the above aspects the chance of irreversible ecological impact at the exploration stage is minor. The primary form of impact could be in form of habitat disturbances, which would normalize after completion of the drilling activity. During the site preparation activities vegetation clearance would be nominal or minor. Efforts will be made to avoid areas of comparatively dense vegetation cover, unless absolutely essential. The land use in the block area is predominantly devoid and forest area. Efforts will be made to avoid areas of comparatively dense vegetation cover, unless absolutely essential. The impact predictions based on the air dispersion modelling found to be well within the prescribed standards. Hence, the impact on ecology will be negligible. The flora and faunal habitats in the study area may be affected by erosion, siltation and water stagnation arising from run-on and runoff at the well site, if suitable mitigative measures are not implemented. The mitigative measures pertain to surface run-off from well site, wastewater discharges, solid waste disposal, erosion abatement measures, etc; As long as strict environmental management measures are put in place, including adequate measures for supervision of contractors and staff, negative effects on fauna will be minimised. There are, however, likely to be some residual, unavoidable, impacts, linked to the requirement of optimal clearing the vegetation to facilitate drilling activities. The summary of impact on flora and fauna are given in Table-4.10.




TABLE-4.10 SUMMARY OF IMPACT ASSESSMENT: FLORA AND FAUNA

Aspect Nature1 Targets/Interests

2 Magnitude3 and extent

Overall Significance4

Loss of habitat Loss of vegetation land

Flora and fauna, flora typically type vegetation, faunal comprise grazing animals and dependent mammals and reptiles.

Small & localised. . Beneficial, Medium,

�� Minor

Disturbance Light, noise. Surface run-off. Project duration only

Local community, Breeding birds, and flora and other fauna.

Small, localized. Mitigative measures in-built in equipment /well site design to meet ambient limits. Flaring would cause disturbance of transient nature for a very short duration

• Moderate

Invading species

Colonisation by species associated with human activity

Avifauna and fauna Small, Localised. No migration route / paths reported in the block.

�� Minor

Waste disposal/ run-off

Contaminated water/rain water,

Fauna, especially birds and reptiles

Small, Localised. No off-site disposal is likely to occur from the exploratory drilling operation. Area fenced and maintained even after drilling operation completed

�� Minor

1 Description; short or long term; reversible or permanent; associated with construction, operation, decommissioning; cumulative, accidental, etc

2 Targets and interests potentially affected. 3 Adverse or beneficial; small, large, etc; very localised (sites only), local, regional national. 4 Overall significance against criteria (� minor; •moderate, some significance; ••major)

4.2.10 Impact on Socio-Economic Aspects

Although the well site would be selected to avoid any major social impacts, there will, nevertheless, be some issues that need to be addressed in the region. The drilling programme would involve setting up the actual drilling rig, construction of campsite for accommodation and operational crew. An approach road from the road head to the drilling rig will also be developed and also to facilitate regular transport from campsite. It is anticipated that the drilling activity would involve direct and indirect impacts on socio-economic environment. These impacts are short term in nature.




ONGC proposes to avoid any settlements, there is expected to be no displacement of people for the proposed drilling campaign. The well sites are expected to be in non-residential lands/ human settlement zones. The types of impacts due to drilling activities have been summarized below: • Land required for drilling activity • Partial loss of productivity of land due to the project • Temporary losses during the drilling activity • Common Property Resources

4.2.11 Demography and Socio-Economics 4.2.11.1 Impact on Civic Amenities

The area has limited network of roads and communication in the village areas. Many villages have been electrified during the last decade. There are few business centers and industrialized zones in the project block area, covered in both the districts. Although, the level of existing communications and support services in the area are considered adequate based on the population density, establishment of the proposed project would be a distinct beneficial impact. The overall impact is considered to be positive.

4.2.11.2 Impact on Health

Impact on health due to emissions and noise from drilling activity has been assessed to be minimal. In addition employees working at the drill site would be provided protective devices like ear plugs/ear muffs for ensuring minimum impact on human health.

4.2.11.3 Social well being At the camp sites, while communication between locals and outside workers may sometimes be good (exchange of information about places and lifestyle) there is a risk that an influx of migrant population from outside areas could well lead to social tensions. As a general rules, base campsites would be located away from centers of population in order to minimize these risks. Development and exploration drilling programme is expected to generate local employment in the order of 50 to 80 unskilled and semi- skilled people, for a period of approximately 3 – 4 months at each drilling site location. While this benefit is small by most standards, it is a significant employment opportunity in the block.

4.2.12 Impact due to Vehicular Movement

The anticipated traffic volume during the construction phase of about 30 days, would approximately be 30 truck loads per day of material movement. The installation of the drill site equipment / facilities involves about 80 trailer loads spread over 10 days and during regular drilling operations on an average 5 truck




movements per day with 10 small vehicles for the visitors and the drilling team would take place. Considering the sparse vehicular movement in the block as a whole, the above anticipated traffic volume and the resulting emissions will be well within the stipulated ambient air quality norms.

4.2.13 Other Impacts on Resources and Infrastructure

As highlighted earlier, infrastructure is very scarce in the study area, especially in the vicinity of the proposed well sites. Preparation and drilling operations could conceivably affect the following infrastructure.

4.2.13.1 Glare from Flaring

During well testing, flaring will take place continuously for 14 - 21 days period. This activity will cause a significant change in the background levels of light due to glare in the local vicinity of the site, especially during the night, during the period of flaring. There will be some impact on the surrounding fauna and habitat whose living patterns will be disturbed significantly, due to the glare during the flare testing. Given that the duration of the flare testing will be relatively short, it is anticipated that the impact will be of temporary nature with no residual impacts after the well testing has been completed. Nevertheless, ONGC will fore warn the communities in advance of well testing. Exploratory drilling is a temporary activity which lasts for about 3-4 months at each location. Thus, the environmental impacts are transient in nature and there will not be any residual impact on the environment.


The objective of the Environmental Management Plan (EMP) is to identify project specific actions that will be undertaken to mitigate and manage impacts associated with the proposed drilling programme. In view of the proposed exploratory drilling project, the adequacy of the proposed pollution control measures has been analysed to meet the standards and norms of concerned authorities. The EMP reflects statutory requirements, ONGC’s own corporate operational guidelines for onshore hydrocarbon exploration and development projects. Cognizance has been taken of all the applicable standards and guidelines (amongst others) in the preparation of the EMP. The following sections discuss the mitigation measures for each potential effect. Actions and monitoring requirements are summarized Table-4.11. The Environmental Management Plan (EMP) describes both generic good practice measures and site specific measures, the implementation of which is aimed at mitigating potential impacts associated with the exploratory drilling in the “AA-ONN-2009/3” block.




4.3.1 Environmental measures during well construction

i. As a preventive measure to avoid impacts the well site will be located based on the following consideration:

• Located at least 300 - 500 m away from the nearest village habitat /

sensitive receptors; • Located at least the height of the well mast away from public road; • Located at least 300 - 500 m away from existing water bodies; • Ensure natural drainage channels are avoided or drainage channels

rerouted to ensure unhindered flow of rain / flood water. Where necessary adequate erosion control measures will be provided;

• Located in a manner to avoid plantations of timber yielding trees

ii. Construction activities will be coordinated in consultation with landowners and local authorities to reduce interference with agricultural activities.

iii. In dry weather conditions, water sprinkling during excavation, levelling

and transportation will be implemented.

iv. Topsoil will be stripped below plough depth from the well site and stored on the site. The depth of stripping will be on the basis of site specific soil survey. Topsoil will also be stripped from and stored adjacent to the site.

v. The well site ground level will be raised and hard standing provided.

Drainage channels around the site area will be constructed to ensure no obstruction to flow pattern.

vi. The approach roads will be routed in a manner so that disturbance to

existing activity and to the local community is minimized. Routing through village habitat areas will be avoided, as far as practical. The road surface will be maintained to minimize generation of vehicular movement dust in the local area.

vii. The drill site would be provided with sufficient and suitable sanitary

facilities and these will be connected to well designed and maintained septic tanks.

viii. Hazardous materials such as diesel, lubrication oil and paint materials

required at the site during construction activities would be stored and disposed as per hazardous waste authorisation conditions.

ix. To ensure that the local inhabitants are not exposed to the hazards of

construction the site would be secured by fencing and manned entry posts.

x. The chemical and diesel storage area will be paved and provided with spill containment walls. Pits for storage of water, drilling mud and drill cuttings will be provided with impervious liner. Sufficient free-board will be provided to prevent overflow.




xi. It would be ensured that diesel powered construction vehicles are properly maintained. Vehicle maintenance would be carried out authorised service centres. Service centres will be so selected to ensure that these conform to statutory regulations.

4.3.3.1 Soil Erosion

Well site design and planning incorporates certain best practices principles such as grading and levelling of ground and ensuring the local drainage patterns are disturbed to the minimum, minimum clearance of vegetation, restoration of topsoil and drainage system to minimize the soil erosion. Efforts will be taken up to reduce long-term soil erosion and loosening of the soil in the site preparation activities. With the adequate management plan for restoration of the soil cover and proper management plan the impact on soil erosion will be minimized.

Soil Contamination

ONGC also has a detailed waste management plan to ensure safe disposal practices and minimize potentiality of soil or sub surface contamination. Some of the specific measures included in the management plan are:

• Only effluent from treated sewage (septic tank system) will be discharged to the local environment;

• The clarified waste water will be collected in lined pits and treated through packaged treatment plant for oil and suspended solids removal to ensure that it meets land or water discharge standards depending on discharge point;

• Spent lubricants and other waste or unused materials will be removed from site as soon as is practicable (and certainly prior to leaving the site) for appropriate off-site disposal or use elsewhere;

• An inventory will be maintained of all fuel, lubricants and chemicals stored on the site. Oil and chemicals, will be stored in dedicated paved and contained areas;

• Waste oil resulting from equipment lubrication will be stored and handled as per the provisions of the Hazardous Waste (Management, Handling & Transboundary Movement) Rules, 2008; and

• Implementation of the waste management plan actions as described in the earlier points are subjected to regular audits to ensure effectiveness All oil handling and storage areas will be provided with concert paving and secondary containment. The impact on surrounding soils from any accidental fuel spills will depend upon the season and the nature of the spillage. During the dry season, small spills are likely to cause only localized impact on soil. During the monsoon season, however, when surface soils are likely to be water saturated, pollutants are more likely to travel along the surface as runoff. Oil spill response plan will be put in place including the provision of absorbents and in case of unlikely event of a significant spill, soil remediation measures will be taken to clean up the contaminated area.




4.3.2 Removal of Equipment and Materials In the event that economic quantities of hydrocarbons are found, the well will be suspended with a wellhead in place, but all other equipment and materials will be removed from the site. All empty drums, wastes, used and unused drilling fluids, fuel and lubricants will be removed from the drilling site. Water supply and effluent discharge hoses and associated equipment will be removed. The access road(s) would be reinstated.

4.3.2.1 Restoration of Cutting Containment Area At the conclusion of well testing at each drilling site, the lined pits of drilling wastes will be covered with soil and left onsite. All these sites will be fenced as per the HSE Management. With appropriate lining of the pit in place, it therefore does not pose any environmental hazard.

4.3.2.2 Restoration of Well Sites

Grading will take place to ensure natural runoff. Any remaining topsoil that has been stocked during site clearance will be re-spread over appropriate portions of the site. All efforts will be taken to restore the land suitable for pre-project land use condition.


In the event that no economic quantities of hydrocarbons are found, a full abandonment plan will be implemented for the drilling sites in accordance with the applicable Indian petroleum regulations. The overriding principle being that the environment should is reinstated to broadly to its original condition. Until such time as this is achieved, ONGC would actively manage the reinstatement process. All concrete or steel installations would be removed to atleast 1 m below ground level so as to ensure that there are no protruding surface structures. In the unlikely event that soil is found to be contaminated, measures would be taken to remove or treat appropriately all contaminated topsoil to promote its remediation.


Other potential sources of emissions which can cause impacts on environmental components are gaseous emissions and noise pressure levels at the rig. The gaseous emissions would routinely be contributed by D.G. sets deployed for power generation. But in this project, diesel with low sulphur content will only be used. The incremental concentrations of SO2 and Oxides of Nitrogen due to the operation of DG sets and flaring will be negligible. There will be no sensitive receptors to the emissions of combustion products in the vicinity of the proposed drilling operations apart from the crew of the drilling rig. The impacts caused are therefore, considered to be negligible. Measures to ensure minimal impacts include:




• Appropriate management of DG sets to achieve fuel efficiency and therefore reduce emissions;

• Use of low sulphur diesel oil (<0.05% sulphur content) if available; • Environmental monitoring during drilling and well testing to ensure compliance

to the standards ; • Flaring towards any standing vegetation will be avoided. In case if it is

inevitable, a suitable barrier will be erected to prevent any vegetation scorching due to direct heat radiation; and

• Prior to flaring, the critical equipment such as burners, anti glare accessories will be thoroughly tested.


The modeling results show that the noise levels will attenuate to below permissible levels within the drilling site boundary. However, the following measures that already exist on the drilling rig will be followed. • Generators will be properly enclosed; • The exhausts will be provided with silencers; and • Operators/personnel working near the noise sources at the DG sets of drilling

rig will be provided with earmuffs and earplugs.


The major waste product of a drilling operation is the generation of rock cuttings with residual mud adhering to the drill cuttings and spent drilling fluid. About 250-300 m3 drill cuttings per well and 40 m3/day spent drilling fluid would need to be disposed off. Following measures to be adopted for disposal of drill cutting and residual drilling fluids: • Drill cuttings separated from WBM should be properly washed and unusable /

residual drilling fluids WBM should be disposed off in a well designed pit lined with impervious liner located offsite or on sit.

• The chemical additives used for preparation of DF should have low toxicity i.e

96 hr LC50 > 30,000 mg/l as per mysid toxicity or toxicity test conducted on locally available sensitive species. The chemicals used (mainly organic constituents) should be biodegradable.

• The waste pit after it is filled up shall be covered with impervious liner, over

which, a thick layer of native soil with proper top slope is provided. • Drilling wastewater including DC wash water should be collected in the

disposal pit evaporated or treated and should comply with the MPCB discharge standards.

• Barite used in preparation of DF shall not contain Hg > 1 mg/kg & Cd > 3

mg/kg.




• Total material acquired for preparation of drill site must be restored after completion of drilling operation leaving no waste material at site. MPCB should be informed about the restoration work.

The proposed control measures include: • Use of water based drilling mud; Only in case of problem due to geological

formation Synthetic Based Mud would be used. Proper washing and disposal as per MOEF guidelines vide GSR 546 (E) would be adhered to in case of use of SBM.

• Mud recovery from cutting during drilling and recycling of drilling fluid; • Management of drill fluid losses as part of the standard operational procedures

of the drilling rig;

• Impervious layer lined storage pond for the storage and recycling of drilling mud;

• Drill cuttings to be stored in impervious lined drill cutting pits; and

• Drill cutting and spent drilling fluid to be treated with flocculant and liquid

fraction solar evaporated. The solids to be solar dried and covered with an impervious lining and buried in a lined secure pit and the disposal pit covered with soil and closed. The disposal pit location to be fenced to prevent any stray animal / unauthorised man entry.

Most of the hired drill rigs are provided with facility for maximum recycle of drilling fluids. The site during construction phase is provided with waste pit to hold treated/settled liquid wastes. The cuttings are segregated and stored in confined area and used later on being inorganic in nature for reclaiming the site or for preparation of approach road. Waste pits are provided with adequate holding capacity to store the wastewater generated during entire drilling phase of the rig. The waste pits are lined with impervious material to prevent leachate and percolation into groundwater.


Small amounts of solid wastes will be generated during normal operation at the drilling rig. Measures for effective waste management include:

• Solid wastes generated on the Drilling Rig will be properly segregated;

• The wastes will be disposed on compliance with local and national legislations;

• Spent waste oil to be stored in a secure paved area and disposed to MoEF/

MPCB approved waste oil recyclers;

• Ensure that a waste management programme is implemented to minimize the amounts generated. ONGC has a well established waste management plan which is strictly implemented at all well sites;




• Ensure all waste packaging material are suitably stored and kept to prevent unintended use;

• Drill cuttings and sludge from drilling mud to be buried within the impervious

lined pit and covered with soil as part of the site abandonment plan;

• Biodegradable waste arising from kitchen and canteen activities to be scientifically composted and the bio-manure so generated to be used for green belt development. Alternatively, the food wastes to be disposed as domesticated animal feed;

• Proper training and information on regulatory requirements shall be provided

to the staff responsible for waste disposal to ensure proper disposal of the waste; and

• Inventory of solid waste generation and type shall be prepared and disposal

facilities should be audited for suitability prior to the commissioning of drilling programme.

The drill cuttings are washed on the screen and separated. Quantity of cutting vary from well to well depending on well drill programme, casing policy and depth of well. About 250-300 m3/well of drill cuttings - are envisaged per well. These cuttings are inorganic in nature and stored at the corner of a drill site and later removed from the site when site is reclaimed.

4.3.8 Management of Discharge of Aqueous Effluents

Wastewater generated from drilling rig wash down possibly contains mud, lubricants and residual chemicals in traces resulting from small leaks or spills. Though, these are all relatively low volume discharges containing small residual quantities, measures shall be taken to ensure no waste is discharged directly onto the land or in a manner to impact any water body. Potential control measures include:

• The drilling rig should be equipped with suitable containment and treatment

systems as part of the contract specifications;

• ONGC shall also ensure that good housekeeping standards are maintained to prevent hydrocarbons and other containments entering the storm water drainage systems;

• Careful consideration should be given and necessary controls exercised to

minimize the amount of waste generated;

• The spent drilling fluid to be stored in impervious lined pit with sufficient free board to prevent any overflows. On completion of the drilling operation the waste drilling fluid to be solar evaporated; and

• The sanitary effluents should be treated in a septic tank system designed for

the anticipated person equivalent loading and the treated sewage to be let out into soak away pits.




4.3.9 Soil Erosion

The following mitigative measures shall be taken to reduce the impact of soil erosion:

• Minimize area extent of site clearance, by staying within the defined

boundaries;

• Stockpile of topsoil wherever possible and applicable at the edge of site; • Install and maintain effective run-off controls, including siltation ponds, traps

and diffusion methods so as to minimize erosion; and

• Avoid uprooting trees or removing undergrowth where possible so as to retain land stability;

4.3.10 Management of waste disposal sites within Drill site

ONGC will dispose the drill cuttings, drill mud and waste water generated during the drilling operations into the lined pits of various sizes and undertaking plantation within the drill site particularly on the reclaimed pits.

4.3.11 Drilling Program Safety Guidelines

All API, Indian Petroleum Act and Indian Mines Act shall be strictly adhered to. Drilling Contractor’s safety guidelines shall be strictly adhered to along with all Personnel Safety Guidelines. The well site supervisor shall carry out regular safety checks. All crew members would be reminded frequently of working safety aspects as part of work procedure. Should unsafe equipment or procedures be observed, operations would cease immediately and the hazard duly corrected. The well site supervisor would ensure that the Driller and above should have a valid “Well Control Certification”. Driller and above would have sound knowledge of the API specification relevant to Well Control Practices (API RP53 and those prescribed in it) and practice the same in all aspects of the job. The well site supervisor would maintain a separate mud material inventory and would ensure that accurate amounts of material used are entered in the Contractor’s daily drilling reports. Contractor would ensure that a document is posted in the doghouse showing “maximum back pressure held on casing" vs. “various mud densities” and would supply daily and weekly rig inspections by the company representative and the tool pusher. A detailed inspection would be carried out prior to drilling out the surface casing it would be ensured that all inspections are recorded in the tour book.

4.4 Monitoring Environmental Performance

Environmental performance should be monitored throughout the drilling programme. ONGC should develop specific environmental inspection / monitoring plans and environmental audits. The environmental inspection / monitoring program shall include all the phases of the proposed activity (namely pre-drilling,




drilling, testing and post drilling project activity). The wastewater from the drilling mud collection and recirculation pond should be tested.

The detailed monitoring plans / inspection and environmental audit should become a part of the operating procedures for the work programme.

4.5 Emergency Response and Contingency Planning

An emergency response plan will be in place for the drilling operations. These plans will define the responsibilities and resources available to respond to the different types of emergency envisaged. Training exercises will be held to ensure that all personnel are familiar with their responsibilities and that communication links are functioning effectively. The Disaster Management Plan (DMP) details the emergency response and preparedness plan to be implemented.




TABLE-4.11 SUMMARY OF ENVIRONMENTAL MANAGEMENT ACTIONS

Potential Impact Action Responsibility Parameters for Monitoring Timing

1. Land take 1.1 Ensure that all necessary protocols are followed and legal requirements implemented:

a) Ensure that appropriate legal requirements have been met with regard to land occupancy, land ownership or usage rights, notice and compensation etc;

b) Establish and clearly document land take agreements with owners, users and state authorities.

ONGC, Land Acquisition coordinators Land Acquisition coordinators

Check list of action items Pre-deployment of topographic survey team or site clearance crew.

1.2 Mark out site boundaries. Ensure that land take during drilling site construction is restricted

to pre-agreed area

ONGC/Contractors Site boundaries marked After selection of precise site location and orientation. Prior to onset of site clearance.

2. Soil Erosion 2.1 Minimize area extent of site clearance, by staying within defined boundaries.

Contractor Supervisor Site boundaries marked Prior to onset of site clearance.

2.2 Stockpile of topsoil wherever possible and applicable at the edge of site.

Contractor supervisor Topsoil stockpile in place on site edge.

Site Construction. Duration of program up until demobilization.

2.3 Install and maintain effective run-off controls, including siltation ponds, traps and diffusion methods so as to minimize erosion.

Drilling Site manager Condition of siltation ponds. Rill or gully development in immediate off-site surroundings.

Site construction. Duration of program and beyond.

2.4 Avoid uprooting trees or removing undergrowth where possible, so as to retain land stability.

Contractor supervisor Trees to be preserved identified Site clearance.

3. Habitat disturbance 3.1 Mark out site boundaries Drilling Site manager Clear boundary markers in place. Prior to commencement of site clearance.

3.2 Avoid uprooting trees and other plants where possible so as to

Contractor Supervisor Trees to be preserved identified Entire drilling campaign





facilitate subsequent re-growth.

3.3 For cleared areas, retain top soil in stockpile where possible on perimeter of site for subsequent re-spreading onsite during restoration

Contractor Supervisor Topsoil stockpile in place on site edge.

Duration of programme until Demobilization or prior opportunity for revegetation of verges.

3.4 All bulldozer operators involved in site preparation shall be trained to observe the defined site boundaries.

Contractor Supervisor Maintenance of integrity of boundary markers.

Duration of site preparation.

3.5 Hunting, fishing and wildlife trapping is forbidden. Removal or disturbance to nesting or breeding birds and animals, their eggs or young is strictly prohibited.

Contractor Supervisor Awareness training Entire drilling campaign

4. Fuels, Lubricants and Chemicals Management

4.1 Maintain strict inventory of all fuel, lubricants and chemicals brought to the drilling site.

Drilling Site manager Up-to-date inventory in place. -do-

4.2 All fuels, lubricants and chemicals placed in controlled storage.

Contractor Supervisor Periodic checking of Integrity of storage area, impervious liner; All drums and containers located within footprint of storage area.

-do-

4.3 All used and unused lubricants and chemicals no longer required, to be stored in a secure paved area and disposed to authorized recyclers

Drilling Site Manager Validity of authorization of the approved recyclers; Manifest and records to be maintained;

-do-

4.4 Refueling operations to be undertaken over area with impervious flooring and surface drainage with oil traps.

Drilling Site Manager.

Paved facilities to be installed and training to concerned to be provided.

-do-

4.5 Delivery of fuel to drilling site to be supervised.

Drilling Site Manager. Detailed procedure in place and training to concerned provided.

-do-

4.7 Adequate oil spill containment and clean-up equipment and materials on-hand and available to contain foreseeable oil spill.

Construction Supervisor/ Drilling Site manager

Facilities and inventories readily available and in good working order.

Entire drilling campaign

5. Waste and Effluent Management

5.1 Implement Drilling Waste Management Plan

Drilling site Manager. Comprehensive Waste Management Plan in place and available at site.

Prior to site clearance.





6. Soil Contamination 6.1 Impervious liners in place for

a. Fuel, lubricants and chemicals storage area.

b) cuttings pit;

$ streamside pump set station.

Contractor Supervisor Evidence of protective measures in place. No visual sign of oil spills.

Daily throughout duration of programme.

6.2 Effective bunds capable of containing 110% of the volume of the largest container within and enclosing all potentially contaminating materials. To be used for fuel lubricants and chemicals storage area.

Contractor Supervisor Evidence of protective measures in place. Absence of visual evidence of contamination.

Daily throughout duration of programme.

6.3 Non - contaminated and potentially contaminated run-off will be kept separate. Non-contaminated run-off will be routed to off-site areas via silt traps. Potentially contaminated surface run-off will be routed through oil traps

Drilling Site manager Evidence of separate routes and effectively working silt traps. Oily water separation in good working order.

Duration of entire drill programme.

6.4 Oil drip pans shall be used wherever there is significant potential for leakage including, but not limited to;

• drill rig engine; • electric generator engine; • compressors, pumps or other

motors; • maintenance areas; • fuel transfer areas.

Contractor Supervisor Drip pans in place. Absence of visible signs of soil contamination.


6.4 All spills/leaks contained, reported and cleaned up immediately: • oil absorbent /spill containment

material deployed to contain large spills;

• contaminated soil dug up, placed in drums and subsequently removed from site.

Contractor Supervisor Written spill procedure in place. Oil spills containment materials on-site (and always ready for deployment). Spill reporting procedure in place






7. Water quality and other aquatic impacts.

7.1 No untreated discharge to be made to watercourses.

Drilling Site manager Ensure no untreated effluent discharged on land or watercourse from the drilling site / campsite.

Duration of programme with particular emphasis during site layout design and site construction.

7.2 Minimize suspended solids loads to watercourses by installing appropriate surface run-off drainage systems (eg silt traps)

Contractor Supervisor Surface drainage systems in good working order. Absence of visible erosion and gullies. Absence of visible suspended solids loads in streams. Results from water monitoring programme.

Duration of programme.

8. Noise and Vibration (Applies to Site preparation as well as drilling)

8.1 List of all potential noise / vibration generating machinery on-site identifying age of plant.

Drilling Site manager Ensure that the drilling rig DG sets have acoustic hoods and noise dampers in place; Mapping of noise generating equipments noise levels before commencement of drilling and once during the drilling operation; Check the anti-vibration pads / other measures in place to attenuate transmission of machinery vibration

Prior to commencement of work by contractors at each drilling site. During drilling operation

8.2 Equipment maintained in good working order. Workers near noise source provided with noise protection equipment (ear muffs)

Contractor Supervisor Written record of maintenance for all equipment. Monitor effective use of personnel protective equipments

Prior to commencement of work by contractors at each drilling site.

8.3 Implement good working practices to minimize noise.

Contractor Supervisor No machinery running when not required.


8.4 Acoustic mufflers in large engines (where practicable)

Contractor Supervisor Mufflers in place. Duration of entire drill programme.

9. Air Emissions 9.1 All equipment operated within Drilling Site manager N/A Duration of entire drill





specified design parameters (site preparation and drilling phases)

programme.

9.2 Any dry, dusty materials (chemicals, mud etc) shall be stored in original packings and loose storage avoided (wherever possible).

Contractor Supervisor Absence of stockpiles or open containers of dusty material.


9.3 Well testing (flaring) to be undertaken so as to minimize impacts of emissions:

• Duration of testing minimized by careful planning;

• High combustion efficiency, smokeless flare/burner to be used.

Drilling site Manager / Contractors supervisor

Check flare controls before flaring; Physical Inspection during flaring; Maintenance checklist of flaring equipment; Check firewall in place, where required and flare direction

Well testing.

10 Socio-Economic impacts

10.1 Well site to be developed to avoid any habitat and cultural / archaeological centers

10.2 Adequate dialogue with the local

population and the authority while designing compensation packages, close monitoring on the type of land loss:

• Permanent • Temporary

ONGC Land Acquisition Supervisor

Checklist of action items. Continued dialogue with the local villagers and other stake holders

At the initial stage of well site planning

Protection of traditional water structures provision of health and education services. Loss of land and crop loss to be compensated Provide temporary employment generation opportunities, where feasible

ONGC Land acquisition supervisor

Project management plan should incorporate these aspects at the initial planning stage

All through drilling and post drilling operation During site acquisition phase During the site preparatory works




4.6 Waste Management Plan

The Waste Management Plan (WMP) covers disposal of all wastes with further reference to off-site disposal of those wastes, which cannot be dealt with on-site. The objectives of the WMP are: • To provide the drilling contractor with the necessary guidance for the

reduction and appropriate management of wastes generated on the drilling site;

• To comply with all current Indian environmental regulations and ONGC

requirements; • To meet industry standards on waste management and control; and • To prevent occurrence of any environmental degradation within the vicinity of

the well site due to waste handling.

4.6.1 Classification of Waste In general, wastes generated during the drilling activities can be categorized as follows: • Paper - any paper waste generated as a result of drilling activities, inclusive of

uncontaminated fluid, sacks, cement and food containers, office wastes, newspapers, packaging material, etc;

• Wood - waste pallets used for carriage of fluid and cement or packing crates;

• Plastic - shrink wrapping on fluid/cement, protective material, kitchen and domestic container wastes;

• Inert Waste - metal cans, glass jars, various containers, etc. which are not combustible and do not contain toxic or hazardous substances and are not under pressure;

• Liquid Wastes - any liquid wastes, chemicals or receptacles. This also includes small volumes of paints, solvents, lubricating oil, antifreeze, etc.;

• Solid Wastes - fluid, cement, or testing chemicals, containers holding or previously holding volumes of chemicals;

• Waste Lead Acid batteries: Spent batteries from equipment and DG set operations;

• Contaminated Soils - Soils contaminated by chemicals and oil;

• Hydrocarbon Wastes - waste oils, eg from oil changes or leakage from equipment or storage tanks;

• Produced Hydrocarbons - gas, condensate or oil produced during well testing;

• Drill Cuttings - drilled formation cuttings, consisting of shale, sands and carbonate ideologies; and




• Drilling Fluids - fluids used in the drilling or completion of the wells.

4.6.2 Disposal Options The following disposal options will be available on site. However, ONGC will evaluate the suitability of various waste specific technologies for the site and select an option that will cause minimum environmental impact on the surrounding: • Landfill – ONGC will dispose off non-hazardous inert solid waste by

compacting the waste to the smallest practical volume and final disposal at the designated site of MPCB;

• Offsite Disposal –Wastes which cannot be handled at the drilling site will be removed by ONGC to and designated authorized sites of MPCB;

• Produced Hydrocarbon Flaring - Hydrocarbons produced during well testing will be flared via a high efficiency burner system;

• Cuttings – All the Drilled cuttings generated will be disposed off into lined pits within the drill sites;

• Sewage Treatment and Disposal - A septic tank system with soak away pits will be constructed on the drilling site / camp site. Digested sludge, will be used as manure for green belt programme under restoration plan.

4.6.3 Labelling of Waste

Any wastes, which cannot be dealt with on site, will be removed to a suitable location for further handling and/or disposal. All off-site transportation and disposal of hazardous waste (as per the Hazardous Waste Rules, 2000 Schedule I & II) shall be done after obtaining necessary authorization from MPCB.

Wastes will be clearly labelled according to:

• Non-hazardous wastes mentioning type of waste; • Hazardous wastes as per Hazardous Waste Management & Handling Rules

Form-8.

4.7 Drilling Site Restoration Plan

Upon completion of drilling the drilling rig and crew will demobilize from the site. All equipment and debris will be removed and the site will be returned to an acceptable condition including revegetation (re-forestation) as required.

Special care will be taken in sealing of the cuttings pit to ensure that there is no leaching of contaminants into the surrounding soils and that the fluid pit is buried to sufficient depth as not to interfere with existing land-use. If a commercial discovery is made, the site will be restored to a standard acceptable depending on the requirements of the local authorities and consistent with future land-use.

Residual slurries in the waste and water pits will be buried in the PPE lined pits. This will constitute a secured landfill site. The residue in the pits will be covered with soil and impervious layer spread over this. One metre of topsoil cover will be placed the surface profiled to enhance the runoff of rain watered.


Chapter-5 Analysis of Alternatives


5.0 ANALYSIS OF ALTERNATIVES

5.1 Alternatives for Technology

The technology to be used in the proposed project has been explained extensively in

Chapter-2. The exploratory drilling facilities involved in the project are very simple

technologies and very much tested and being used world-wide in Oil and Gas

industry.

No technology alternatives were considered as the project involves only exploratory

drilling facilities.

5.2 Alternatives for Project Site

Consideration of the alternate project sites is not applicable as the exploratory

drilling wells in NELP Block has received Mining Lease of these areas from

MOPNG, Govt of India for exploring and producing hydrocarbons.


Chapter-6 Environmental Monitoring Programme


6.0 ENVIRONMENTAL MONITORING PROGRAMME

6.1 Introduction

Regular monitoring of environmental parameters is of immense importance to

assess the status of environment during project operation. With the knowledge of

baseline conditions, the monitoring programme will serve as an indicator for any

deterioration in environmental conditions due to operation of the project, to enable

taking up suitable mitigatory steps in time to safeguard the environment.

Monitoring is as important as that of control of pollution since the efficiency of

control measures can only be determined by monitoring.

Usually, as in the case of the study, an Impact Assessment study is carried over

short period of time and the data cannot bring out all variations induced by the

natural or human activities. Therefore, regular monitoring programme of the

environmental parameters is essential to take into account the changes in the

environmental quality.

6.2 Environmental Monitoring and Reporting Procedure

Development of the programmes during the planning process shall be conducted

or supported by environmental specialists. However, the implementation

responsibility rests with line managers, who should, therefore, ensure they fully

understand and subscribe to the commitments being made. These commitments

will include the legal and statutory controls imposed on the operation as well as

other corporate commitment to responsible environment management.

The key aims of monitoring are: first to ensure that results/conditions are as

forecast during the planning stage, and where they are not, to pinpoint the cause

and implement action to remedy the situation. A second objective is to verify the

evaluations made during the planning process, in particular in risk and impact

assessments and standard and target setting and to measure operational and

process efficiency. Monitoring will also be required to meet compliance with

statutory and corporate requirements. Finally, monitoring results provide the

basis for auditing. A more detailed approach to monitoring and performance

measurement is provided in various publications.

6.2.1 Objectives of Monitoring

The objectives of monitoring are to:

• Verify effectiveness of planning decisions;

• Measure effectiveness of operational procedures;

• Confirm statutory and corporate compliance; and

• Identify unexpected changes.

6.2.2 Monitoring Schedule

Periodic environmental monitoring schedules are prepared covering various phases

of project advancement. This comprises the duration of proposed exploratory

drilling as well as post-project phase, when the hydrocarbon is established in the




wells and production program is undertaken as well as the

Decommissioning/Closure Phase for minimum 10 years.

In order to assess the extent and nature of impacts on environment due to

drilling operations, the monitoring on various attributes of environment will be

carried out during various phases of drilling as under:

Pre-Drilling Phase: Prior to the start of drilling activities, the environmental

status around the proposed drilling locations shall be monitored. These results will

represent the baseline environment status, against which the monitoring results

from the other phases are compared.

Drilling Phase: Monitoring during drilling phase serves as a measure of the

impact on the environment due to drilling operations. Besides, the analysis of drill

cuttings and drilling mud at various depths shall be carried out as per MoEF&CC

guidelines on disposal of drilling wastes.

Testing Phase: Well testing is a short term activity spread over a period of 2 to

3 days. Testing operations are carried out to determine the presence of

hydrocarbons and to understand the reservoir characteristics. Monitoring during

this phase will serves as a measure of the impact on the environment due to

testing operations.

Post-Drilling Phase: Monitoring shall be carried out after completion of drilling

and testing operations to determine if there has been any residual impact on the

environment due to drilling and testing operations.

The detailed monitoring program covering development drilling phase is given in

Table-6.1.

TABLE-6.1

SCHEDULE OF ENVIRONMENTAL MONITORING

Sr.

No. Aspect Parameter Frequency

No. of

Locations

I. Pre-drilling Phase

1 Ambient air quality

PM10, PM2.5, SO2, NOx , CO

and Hydrocarbons as CH4

Two days in

week 4 locations

2 Noise monitoring Leq(n), Leq(d), Leq(dn) Once 4 locations

3 Water quality

As per IS: 10500 including

heavy metals Once Min 5 locations

4 Soil quality

Texture, conductivity,

organic carbon, P2O5, K2O,

pH, Cl, O & G, Heavy

metals viz. Cr, Ni, Cu, Zn,

Cd, Hg and Pb Once 8 locations

II. Drilling Phase




Two days in

week for

two weeks 4 locations

2 Noise monitoring Leq (n), Leq(d), Leq(dn) Once 4 locations

3

Source emissions

monitoring

Flue gas temp., velocity,

flow, dust conc., SO2, NOx Once 4 samples




Sr.

No. Aspect Parameter Frequency

No. of

Locations

I. Pre-drilling Phase

4 Water quality

pH, TDS, Alkalinity, F,

Sulphates, Cl, Cr, Ni, Cu,

Zn, Cd, Pb Once Min. 5 locations

III. Testing Phase




Two day in

week for

two weeks 4 locations

2 Noise monitoring Leq(n), Leq(d), Leq(dn) Once 4 locations

IV. Post Drilling Phase




Two days in

week 4 locations

2 Water quality

As per IS: 10500 including

heavy metals Once Min. 5 locations

3 Soil quality

Texture, conductivity,

organic carbon, P2O5, K2O,

pH, Cl, O & G, Heavy

metals viz. Cr, Ni, Cu, Zn,

Cd, Hg and Pb. Once 8 locations

6.3 Reporting Schedules of the Monitoring Data

It is proposed that voluntary reporting of environmental performance with

reference to the EMP should be undertaken.

The environmental monitoring cell shall co-ordinate all monitoring programmes at

site and data thus generated shall be regularly furnished to the State regulatory

agencies.

The compliance reporting shall be on six monthly basis to the local State PCB

officials and to Regional Office of MoEF. The Environmental Audit reports shall be

prepared for the entire year of operations and shall be regularly submitted to

regulatory authorities. 6.4 Infrastructure for Monitoring of Environmental Protection Measures

A well-equipped laboratory with consumable items shall be provided for monitoring

of environmental parameters in the site. Alternatively, monitoring can be

outsourced to a recognized reputed laboratory.

The following equipment and consumable items shall be made available in the site

for environmental monitoring.

Air Quality and Meteorology

High volume samplers, Stack monitoring kit, Personal Dust sampler, Central

Weather Monitoring Station, Spectrophotometer (visible range), Single pan

balance, Flame photometer, Relevant Chemicals as per IS:5182.




Water and Wastewater Quality

The sampling shall be done as per the standard procedures laid down by IS: 2488.

The equipments and consumables required are:

BOD incubator, COD reflex set-up, Refrigerator, Oven, Stop watch, Thermometer,

pH meter, Distilled water plant, Pipette box, Titration set, Dissolved oxygen

analyser, Relevant chemicals.

Noise Levels

Noise monitoring shall be done utilising an integrating sound level meter to record

noise levels in different scales like A-weighting with slow and fast response options.

6.5 Environmental Costs

All costs involved in environmental mitigating measures and management are

included in the project cost.

6.6 Audit and Review

Review and audit is essentially a management tool. However, its application is

crucial at the operational level for verification and feedback on the effectiveness

of organization system and environmental performance. Basically, Auditing

involves in the following items:

• Line management system;

• Awareness and training;

• Procedures, standards, targets;

• Plans: waste, contingency, pollution control compliance;

• Monitoring programmes;

• Verify Environmental Impact Assessment;

• Verify mitigation;

• Reporting and communication;

• Documentation; and

• Feedback.

Audit serves to substantiate and verify monitoring programmes and compliance,

and to ensure that site environmental plans, procedures and standards are both

effective and fit for purpose. Other benefits of auditing include increased internal

and external awareness, communication and credibility of company

environmental activities by demonstrating commitment to and achievement of

responsible environmental management.

In addition to management and compliance audits, a number of technical or

process audits, sometimes termed assessments or valuations, may be conducted.

Thus, waste and emissions audits, energy audits, site (contamination) audits,

emergency counter measure audits, worker health and safety audits, may be

instigated independently or as part of a broader management audit.

Reports on environmental performance shall be made available for a wide public

readership including shareholders and financing bodies. An important audience is

also the company employees, who benefit from having the company's




environmental position and activities described in a way that allows him or her to

be an ambassador in a general sense for the company. Reporting is becoming

increasingly sophisticated, and more closely linked with the total environmental

programme of companies.

The contents of these reports still vary greatly, with a gradual but noticeable

tendency to quantify environmental performance, and include mention of a range

of environmental and sustainability indicators such as pollution and safety

incidents, greenhouse gas emissions, and even non-compliance statistics.


Chapter-7 Additional Studies


7.0 ADDITIONAL STUDIES

This chapter describes the public consultation for the proposed project, Risk Assessment and Disaster Management Plan, occupational health and safety issues.

7.1 Public Consultation

As per the Environmental Impact Assessment (EIA) notification dated 14th September 2006, the proposed exploratory drilling project falls under ‘Category A’ of Activity type 1(b). The proposed project intends to identify the presence of hydrocarbon prospects through exploratory drilling. The proposed project will basically involve drilling of three (3) exploratory wells in NELP Block of AA-ONN- 2001/2, Kolasib & Mamit District, Mizoram by M/s. Oil & Natural Gas Corporation Ltd. The press notification indicating date and venue of the public hearing was issued by member Secretary, Mizoram Pollution Control Board on 18th August, 2016 in prominent newspapers viz. Vanglaini (a leading local newspaper in Mizo language) and the Times of Indian that the public hearing is scheduled on 23rd September, 2016 at BNRGSK hall, Suarhliap, Mamit district, Mizoram with project details inviting suggestions, views, comments and objections from the public regarding establishment of proposed exploratory drilling project. The notice of postponement of public hearing was issued by the Mizoram state pollution control board on 20th September, 2016, due to unavoidable circumstances and it was rescheduled on 21st October, 2016 at the same venue and time. The copies of the notification issued in newspapers for public hearing are shown in Figure-7.1.

Interested persons of the locality including bonafide residents, environmental activities groups, NGOs within the neighborhood of the proposed project were requested to attend the public hearing on date, time and venue as stated above for getting their statements, suggestions, comments, views recorded regarding likely environment impact and mitigation measures if any. Also, they may send their views and opinion within one month from the date of publication of this public hearing notice to the office of the Board.

The EIA reports along with Executive Summary in English and Mizo languages were made available at the following offices and at the websites: www.mizenvis.nic.in. • The Deputy Commissioner, Mamit District, Mamit, Mizoram; • District Industry Centre, Mamit District, Mamit, Mizoram; • Regional Office of the Ministry of Environment & Forests, Shillong, Meghalaya; • Director, Geology & Mineral Resources department, Government of Mizoram. • Mizoram State Pollution Control Board, Tuikhuahtlang, Aizwal.




FIGURE-7.1(A)

NOTICE FOR PUBLIC HEARING – TIMES OF INDIA




FIGURE-7.1(B)

NOTICE FOR POSTPONEMENT OF PUBLIC HEARING




The public hearing was presided over by smt. H Lalchhandami, (SDO), Mamit district, Mamit, Mizoram at the scheduled date and time. The participants included all sections of life. At the outset, the chairperson after welcoming all the participants briefly explained the reason for the public hearing. She said that oil exploratory drilling in Mizoram is the central government initiative and the ONGC is assigned to undertake the work in this area. she then requested for self introduction of all stake holders present. The chairperson then invited Smt P C Lalmuanpuii, AEE, Mizoram pollution control board for introductory remark. The AEE mentioned that public hearing is held as per the EIA notification as amended in 2006. She explained the need and objectivities of holding public hearing saying that some development projects require Environmental clearance from the Ministry of Environmental, Forests & Climate Change, Government of India for which Public hearing is mandatory. She added that the hearing was notified in Vanglaini (a leading local news paper in Mizo language) and the Times of India for 30 days prior to public hearing, during which the draft EIA report prepared by the company was kept for suggestion and comments as per the aforesaid rule. She also reported that no suggestions or comments were received from the public during this period. She requested the public to speak out their views, comments and suggestions regarding environmental impact of the proposed project so that the company could make changes in the draft and make final report accordingly. About 106 people attended the public hearing. The list of people attended public hearing and the minutes of the public hearing are enclosed as Annexure-VIII. The photographs of the public hearing are shown in Figure-7.2. The response for issues raised by participants during public hearing with action plan and budgetary allocation is given in Table-7.1.




FIGURE-7.2 (A) PHOTOGRAPHS SHOWING PUBLIC HEARING

Environmental Impact Assessment Report for Proposed Drilling of 8 Exploratory Wells in PML Areas of NAS Block in Sibsagar District, Assam



FIGURE-7.2 (B) PHOTOGRAPHS SHOWING PUBLIC HEARING




TABLE-7.1 ACTION PLAN FOR ISSUES RAISED BY PARTICIPANTS DURING PUBLIC HEARING

Sr. No.

Issue raised by Issue Action Plan Financial Allocation

Timeline

1 J.Lalchungnunga Suarhliap

It is stated in the Executive Summary No.1.1.4 that the area of land required for the project is 1.56 and about 1.5-2.0 ha would be required on average. The last two lines of the para stated the requirement of land to be 2.5 ha The Executive summary also stated that adequate compensation will be given for the land that will be acquired on temporary basis as per the guidelines of the local administration/state government. In this regard could you clarify the amount of compensation (in figures) to be granted for these lands? I guess compensation would be given only to the land where the drilling site is to be located at ‘Tlangslang’, wide approach is to be constructed through Suarhliap leading to destruction of locally owned agricultural lands. If so, how much area would be destructed for the purpose. Hence it is of utmost importance tha the villagers know the exact drilling site location or is it that the company has knowledge of the location of the site which is later to be notified to the villagers. How would these acquired lands be awarded, would it be compensated or would it be in the form of remittance to the villagers> Further, as the DC Mamit & SDO (Sadar) are witness of the hardship and poverty of the village and if such a huge development works are to be executed in the village, would compensation and benefits be given to the contentment of the local people?

ONGC : Drilling site: The co-ordinates of the drilling site is cited in the map, which is 5-10 km from Surhliap village. However, the exact location is yet unknown. After obtaining environmental clearance from the concerned authority, physical verification of the exact location of drilling site would be surveyed with the help of GPS & co-ordinates given in the map. Hence exact location of the site cannot be disclosed as of now. “As clarified by chairperson of the meeting” “As well are aware, all matters regarding land acquisition and rentals are to be dealt with through the office of the respective Deputy Commissioner Office. Their work involves exploration of hydrocarbons and if unsuccessful, the land might have to be abandoned. As such, the acquisition of land might be on temporary or rental basis. To sum up, the office of the Deputy Commissioner would initiate the process as per relevant acts and rules and clarification may be given to you if required”.

Compensation: Compensation would be done as per the guidance of the state government. As for now, details cannot be chalked out. Further, after this public hearing, Environmental clearance for the project will be applied, only after which compensation would be discussed.

Before site preparation for drilling




Sr. No.


Timeline

2 C. Lalchunglura,

Teacher Suarhliap H/S

“My questions concerning the water requirement of the project. As stated in page 4 of the summery, the drilling process would require 20 m3 and domestic water requirement is 5 m3 which would be locally provided. However, as Suarhliap village faces severe scarcity of water, water scarcity problem in the village would be more intense if we are added with 100 more people. Is there many plant to resolve such issues? Also, as stated in page 10 (1.7), 25 local people would be employed. Meanwhile, it is stated in the last para that ’25 qualified people would be employed”. Does this extend to the whole of Mizoram or this village only? If local people are to be employed what is the qualification required and what would be the duration of the employment? Would they be employed throughout the drilling process?

ONGC: Employment: ”No qualification is required for employment”. “Water requirement: the water requirement will be met by transportation of water from streams and rivers, using water tankers. We would purchase water”.

3. Lairothangi, VCP+MHIP President

“It is a remarkable day indeed for the village with such a huge development works to be commenced in the village. We feel that this project would benefit the society. As discussed earlier, the drilling site would occupy many private lands as Suarhliap Village is mostly privately owned. I would like to mention that there is one Community Reserve Forest at ‘Kananthar Ram’” “We have also enquired from the office of the Deputy Commissioner, regarding the drilling site. According to the co-ordinates in the map. ‘Kananthar’is sjhown in two places while there is only one ‘Kananthar’. The directions i.e.

ONGC : Äs per the corporate social responsibility (CSR), the ONGC would take up socially initiative projects such as construction of school toilets, streets lights, internal road and creation of employment to some extent”. Chairman of the Meeting: “The ONGC has provided a list of social initiatives taken up by them where the projects have been undertaken. These are donations for organisation medical campus at Medium, Moriah Station for the blind, Aizawl, Chawlhhmun High School, Yound Mizo Association (YMA) Conference, Kolasib District Hospitial, Hortoki-water supply

-




Sr. No.


Timeline

north, east, west, or south are also not depicted properly in the map. So we could not make out the exact location of the proposed drilling. We had tried to contact office of the Deputy Commissioner, Mamit also. Even they could not tell us the proposed drilling area. Had we been aware of the exact location of the drilling site, the village council could be of much help in locating owners of the affected land. Further, regarding social benefit of the village, I would like to bring to your notice, the problem of unemployment in the village. The village council and the YMA had recorded the needs of the Suarhliap and some the m are as follows:

1. Construction of Internal road 2. Construction of road for extension of

village 3. Setting up of street lights 4. Employment generation for villagers 5. Construction of playground 6. Construction of public lavatory 7. Afforestation 8. Water pumps

scheme, women employment, for inmates of Kolasib Jail, Bethany Rehabilitation etc. These social initiatives should be led by the village council; the District Administration will also assist the village council in this matter if required”.

4. H. Laldingluaia, Teacher, Middle School, Suarhliap

“My question is in regard to page 9(1.6) of the summary regarding Risk Assessment and Disaster Management plans. It is stated that various safety provisions in the proposed facility are to be provided and training to ensure effective communication and functioning. However, it does not state the provision to be provided to the workers in case of accidental death or disability during the execution of the project. What are the provision regarding this

ONGC: Accidents etc will be compensated as per the Mines Act, 1952. As per Govt. directive each and every people who is working in the site, who has met such accidents would be entitled to whatever compensation available as per Government Acts”. Chairman of the Meeting (on repeating the second query asked by the School




Sr. No.


Timeline

matter?

teacher which remains unattended): If accidental death occurs in any case, can you tell the amount to be received in the form of compensation?” ONGC: “The amount to be compensated cannot be said as for now. However, compensation or remittance will be provided as per the Mines Act, 1952. Further, the ONGC has taken up necessary precautionary measures to prevent occurrence of such accidents. Since, the past 5 years, only 1 accident has been reported from 100 wells. The employees are provided with safety gcars such as hard hat etc., and only trained workers, provided with safety gears etc will be permitted to work in the danger zone whereas local people will be working within the safety area”.

5. Pu Lalzarthanga, Suarhliap

We had just seen from the presentation that there was something about ‘Safe Zone’, which makes me conclude that there will be an unsafe or danger zone. Many of us present here are parent and I would like to say that school going children and the younger youths used to go in the wild forest. In this regard, could you please specify the exact distance between the danger zone and residential area? How far is the safe zone from the residential area? I want to ask for the safety of the community whether it would be dangerous for children playing nearby the site.

ONGC: “The drilling site will be fenced. Zone zero where actual work/drilling will be done is located quite at the centre fo the site and nobody will be allowed to enter within 200 m of zone zero. Only one zone i.e. Zone zero is a dangerous zone and fencing will be made within 200 m of this zone and tight security will be placed. So, there will be no danger in this regard”. Chairman of the Meeting: “This area will be restricted for entry by making demarcation. The danger zone will be far from the residential area an d it will be fenced so as to prevent unauthorized entry. So, let’s hope that it will be dangerous as they had informed us and they too will do




Sr. No.


Timeline

their part in maintain the safety of the public. But, I would like to request the local people to explain these things to the children. As we all know children are playful and tend to roam about out of the watchful eye of parents and grandparents. So we need to carefully inform them about this drilling place”.

6 Pu B. Sangzuala, Suarhliap

“If hydrocarbons is found, various equipment would be installed which might create air pollution. We the villagers, if exposed to such kinds of pollution would be affected immensely. I would therefore like to ask if there is any plan to save us from such pollution.

ONGC: “Regarding pollution from the project, Mizoram Pollution Control Board is keeping strict vigilance on our activities. We are working with some 2-3 contracts which would be monitoring air, noise, and water pollution and whatever residue including water would be recycled. So there will be no problem regarding this matter”.

7. Thangbika, Suarhliap

“In reference to 1st page of the executive summary report under the head ‘Location details of the project’, it is reported that there is one Forect within the project area. As officials of ONGC reported that they had not yet visited, there is uncertainty on the details of the said forest. It is still unknown wheather the said Forest is in Tlangasang or Bawk Tlang. Tehre is a forest in Bawk Tlang and let us assume that it is the one which is reported in the Executive Summary. Meanwhile, 4the page of the report says that the land requirement shall be around 200 m which may be around 7 – 7.5 Ha. With all the span of the area required and a depth of about 4000 meter to be drilled, it could be presumed that massive drilling equipment would be required and an approach road shall also be required. Would owners of affected private land en route to the drilling site be

ONGC: “Drilling site may probably fall within a forest land and one or two privzte land may be included. If we are to acquire private lands, compensation shall be giben and processed through office of the Deputy Commissioner. Wer are not permitted to make any agreement directly with any party or an individual. Joint service would also be required to locate the drilling area and compensation would be granted to any acquired land as per relevant rules under the guidance of the Deputy Commissioner. Chairman: There are certain procedural steps to follow for acquisition of land. It has to be processed through office of the Deputy Commissioner and the ONGC officials are also well aware of the process. The company shall submit application and joint




Sr. No.


Timeline

entitled to get compensation? Is compensation to be processed by the company directly through their own rules or through office of the Deputy Commissioner? What kind of policy would be in place for the process of compensation?”

survey shall be conducted by officials of ONGC, Revenue Department and office of Deputy Commissioner. Though the company officials could not yet inform the exact drilling site and the land which might be affected at the moment, everything shall be processed and carried out as per the relevant rules”.




7.2 Risk Assessment

Environmental Risk Assessment is a scientific analysis for identification of credible risk and thereafter estimating the safe distances from any hazardous installations/processes in the eventuality of an accident. Estimation of near-accurate safe distances is absolutely necessary to protect the public, property and environment.

‘Risk Assessment’ also known as ‘Hazard Analysis’ and ‘Vulnerability Assessment’ is a procedure for identifying hazards and determining their possible effects on a community and environment. Risk or hazard by itself is not an event - it is the potential for an event.

7.2.1 Approach to the Study

Risk involves the occurrence or potential occurrence of various type accidents consisting of an event or sequence of events. The main objectives of the risk assessment of the proposed onshore exploratory drilling are illustrated schematically in Figure-7.3.

Standard industry practices of risk assessment are considered in the project. Maximum Credible Accident analysis is carried out to arrive at the hazard distance for the worst case scenario.

7.2.2 Maximum Credible Accident Analysis (MCAA)

Maximum Credible Accident (MCA) is a probable accident with maximum damage distance. In practice, the selection of accident scenarios for MCAA is carried out on the basis of engineering judgement and past accident analysis. MCAA does not include quantification of the probability of occurrence of an accident.

Risk involves the potential occurrence of some accident consisting of an event or sequence of events. Accidental release of oil and gas to the atmosphere from well or processing equipment is studied by visualising scenarios on the basis of their properties and the impacts are computed in terms of damage distances. A disastrous situation is the outcome of fire or explosion of the released gas in addition to other natural causes, which eventually leads to loss of life, damage to property and/or ecological imbalance.

Depending on the effective hazardous attributes and their impacts, the maximum effect to the surroundings could be assessed.

The steps of MCA analysis along with data requirement are shown in Figure-7.4.

• Past Accident Data Analysis

The data required for MCA analysis has either to be generated by monitoring and/or collected from the records of the past occurrences. This data, when analysed, helps in formulation of the steps towards mitigation of hazards faced commonly. Trends in safety of various activities can be evaluated and actions can be planned accordingly, to improve the safety.

Data analysis helps in correlating the causal factors and the corrective steps to be taken for controlling the accidents. It is, therefore, of vital importance to collect the data methodically, based on potential incidents, sections involved, causes of failure and the preventive measures taken. This helps to face future eventualities with more preparedness.




• Hazard Identification

A major hazard is defined as an event, which may have the potential to cause one or more fatalities and also the potential to affect the integrity of the facility as a whole. The aim of this step is to create a complete tabulation of identified hazards.

Hazards are identified in terms of safety and/or environmental impact. The hazard in terms of blowout has been identified from well pad in the present exploratory drilling project. It is noted that some hazards are incorporated within other hazards.

Identification of hazards in the proposed drilling campaign is of primary significance in the analysis, quantification and cost effective control of accidents involving chemicals and process. Hence, all the components of a system /process need to be thoroughly examined to assess their potential for initiating or propagating an unplanned event/sequence of events, which can be termed as an accident.

Typical schemes of predictive hazard evaluation and quantitative risk analysis suggest that hazard identification step plays a key role. The hazard in terms of blowout has been identified from well pad in the present exploratory drilling project. Major accident hazards considered are:

• Hydrocarbon escapes due to high geological pressures lead to possibility of fire, explosion, gas ingress to sensitive areas, contamination or toxic hazards arising from wells, test equipment fuel supply systems, storage, pipe work systems, etc.;

• Structural or foundation failure, including effects of corrosion, fatigue, extreme weather, overloading, seismic effects, abuse or accidental loading;

• Possibility of H2S release while drilling; and

• Fire, including fires in accommodation, electrical fires, hot work, oxygen enrichment

The complete list of hazards and Occupational Hazards applicable to onshore drilling are presented in Table-7.2 and Table-7.3.

TABLE-7.2

LIST OF MAJOR HAZARDS

Sr. No.

Hazard Source/Reason

Description Impacts

1 Fire and Explosion Occurrence of Blow Out Topsides blow out Non hydrocarbon fires Electrical fire in control room

Fire in accommodation 2 Impacts and Collisions Objects dropped from a

crane/ derrick Fatal accidents Loss of materials and equipment

3 Loss of station/ stability

Loss of stability Structural failure Tug failure (during towing)

4 Extreme Weather Conditions Extreme winds

Loss of lives and material Temporary withdrawal of well operations

5 Earthquakes Sudden ground movement Strong vibrations, failure 6 War, Crisis Crisis situation -




TABLE-7.3

OCCUPATIONAL HAZARDS

Sr. No. Hazard Description Specific Hazard

1 Working at heights Fall Fall

Man overboard 2 Disease/ Illness Illness Medical evacuation 3 Storage of chemicals Release of

chemicals Exposure to chemicals, inhalation, ingestion, body contact etc

• Consequence Analysis

Quantification of the damage can be done by means of various models, which can then be translated in terms of injuries and damage to the exposed population and buildings. Oil and gas may be released and result into jet fire & less likely unconfined vapour cloud explosion causing possible damage to the surrounding areas. Extent of the damage depends upon the nature of release. The release of flammable material and subsequent ignition results in heat radiation, pressure wave or vapour cloud depending upon the flammability and its physical state.




FIGURE-7.3

OBJECTIVES OF RISK ASSESSMENT

� Identification of potential

hazard zones � Scenario Identification

Hazard Identification

� Identification of

representative failure cases

� Failure Frequency Analysis � Consequent Analysis

Assessment of Risk

(via MCA Analysis)

� Disaster Management Plan

o Emergency Classification

o Roles & Responsibilities

Risk Mitigation Measures




FIGURE-7.4

METHODOLOGY OF MCA ANALYSIS

Steps in MCA Analysis

� Past accident database

generation

� Analysis of created

database

Past Accident Data Analysis

DATA REQUIREMENT

• Operation Procedures • Detailed design parameters • Physical & chemical properties data • Detailed information about facility • Past accident data

Probable accident with maximum damage distance MAXIMUM CREDIBLE

ACCIDENT (MCA) ANALYSIS

� Hazard identification in

terms of safety and

environmental impact

� Identification of

representative failure cases

for the wells and various

equipments

Hazard Identification

� Damage distance

computations for the

released cases

� Identification of release

scenario

� Calculation of damage

distances for various Heat

Loads

Consequence Analysis

Emergency Planning




An insight into physical effects resulting from the release of hazardous substances can be had by means of various models. The results of consequence analysis are useful for getting information about all known and unknown effects that are of importance when some failure scenario occurs and also to get information as how to deal with the possible catastrophic events.

7.2.3 Damage Effects of Various Heat Loads

Damage effects of various peak over pressures and incident radiation intensities are detailed in Table-7.4 and Table-7.5 respectively.

TABLE-7.4

DAMAGE DUE TO PEAK OVER PRESSURE

Human Injury Structural Damage

Peak Over Pressure - bar

Type of Damage Peak Over Pressure- bar

Type of Damage

5 - 8 100% lethality 0.3 Heavy (90% damage) 3.5 - 5 50% lethality 0.1 Repairable (10% damage) 2 - 3 Threshold lethality 0.03 Damage of Glass

1.33 - 2 Severe lung damage 0.01 Crack of Windows 1 - 11/3 50% Eardrum rupture - -

Source: Marshall, V.C. (1977) 'How lethal are explosives and toxic escapes'

TABLE-7.5

DAMAGE DUE TO INCIDENT RADIATION INTENSITIES

Sr. No.

Incident Radiation (kW/m2)

Type of Damage Intensity Damage to Equipment Damage to People

1 37.5 Damage to process equipment 100% lethality in 1 min. 1% lethality in 10 sec.

2 25.0 Minimum energy required to ignite wood at indefinitely long exposure without a flame

50% Lethality in 1 min. Significant injury in 10 sec.

3 19.0 Maximum thermal radiation intensity allowed on thermally unprotected adjoining equipment

--

4 12.5 Minimum energy to ignite with a flame; melts plastic tubing

1% lethality in 1 min.

5 4.5 --

Causes pain if duration is longer than 20 sec, however blistering is un-likely (First degree burns)

6 1.6 --

Causes no discomfort on long exposures

Source: Techniques for Assessing Industrial Hazards by World Bank

7.2.4 Scenario Identification

Emergency scenario is identified based on past experiences and historical evidences. A flowchart that can be followed to evaluate the consequences of the release of a flammable or toxic chemical is given in Figure-7.5.




Historical evidence demonstrates that although unlikely, the most significant hazard arises from the thermal radiation produced by an ignited liquid or gas release. Releases from the wells could arise in the form of blowouts. This may lead to release of gas into the atmosphere. An availability of ignition source can lead to jet fire.

• Model for the Calculation of Heat Loads and Shock Waves

If a flammable gas or liquid is released, damage resulting from heat radiation or explosion may occur on ignition. Humidity of the air (water vapour) has a relatively high heat-absorbing capacity. The orientation (horizontal / vertical) of the object irradiated with respect to the fire is an important factor to be considered. If a jetted release of the oil & gas mixture is ignited, a stable diffusion torch or jet fire may be produced. For the flammable gas, in this model, an ellipse is assumed for the shape of a torch. The volume of the (torch) flare in this model is related to the outflow. In order to calculate the thermal load, the centre of the flare is regarded as a point source. This centre is taken as being half a flare-length from the point of outflow.

A flash fire is the non-explosive combustion of vapour cloud resulting from release of a flammable material in the atmosphere, which after mixing with air, ignites. A flash fire results from the ignition of a released flammable cloud, in which there is essentially no increase in combustion rate. The ignition source could be electric spark, a hot surface, and friction between moving parts of a machine or an open fire. Part of the reason for flash fire is that flammable fuels have a vapour temperature less than ambient temperature. Hence as a result of spill, they are dispersed initially by the negative buoyancy of the cold vapours and subsequently by atmospheric turbulence. After the release and dispersion of a flammable fuel, the resulting vapour cloud is ignited and when the fuel vapour is not mixed with sufficient air prior to ignition, it results in the diffusion fire burning. Therefore, the rate at which the fuel vapour and air are mixed together during combustion determines the rate of burning in the flash fire. The main dangers of flash fires are radiation and direct flame contact. The size of the flammable cloud determines the area of possible direct flame contact effects. Radiation effects on a target depend on several factors including its distance from the flames, flame height, flame emissive power, local atmospheric transitivity and cloud size. Most of the time, flash combustion of a flash lasts for no more than a few seconds.

7.2.5 Input Data for Consequence Analysis

The data used for the consequence analysis is depicted in Table-7.6.

TABLE-7.6 INPUT DATA FOR CONSEQUENCE ANALYSIS

Parameter Case

Ambient Temperature 350C Atmospheric stability A & D Relative humidity 70% Wind speed 2 m/s for stability class A

5 m/s for stability class D




Release of Chemical

Instantaneous Continuous

BottomTop

Two Phase Outflow

Liquid

IgnitionVapours

Ignition ?

Pool Formation

Ignition ?

FlarePool Fire

Evaporation

Dispersion

Vapour Cloud Formation

Ignition ?

BLEVE

Toxicity

Vapour Cloud Explosion

Pressure Wave

CONSEQUENCE MODELLING

Heat Radiation

No

Yes

No

Yes

No

No

Yes

Yes

TOXICITY COMPUTATION

Flash Fire

FIGURE-7.5

FLOWCHART FOR EVALUATION OF

CONSEQUENCES OF RELEASE OF FLAMMABLE OR TOXIC CHEMICAL




7.2.6 Results and Discussions Jet Fire from Well (Oil) Blowout is visualised for carrying out the consequence analysis. A well blow out can lead to uncontrolled release of oil into the atmosphere. A subsequent jet fire could result on availability of an immediate ignition source. Heat load generated by the flame depends upon the mass flow rate of the released material. Damage distances are computed for the operating pressure of 290 psi and temperature of 70°C. Weather conditions 2A and 5D are considered while computing the damage distances. The damage distance of 95.7m is obtained for the heat load of 4 kW/m2 in case of well blow out for 5D conditions. Results are shown in Table-7.7. The calculations of Pool Fire is given in Annexure-IX.

TABLE-7.7

SUMMARY OF CONSEQUENCE ANALYSIS FOR JET FIRE SCENARIO AT WELL

Pressure (psi) /

Temp (°C) Scenario Mass Flow

Rate (kg/s) Weather Damage Distance (m) for

various Heat loads

4.0 kW/m2

12.5 kW/m2

37.5 kW/m2

290 / 70 Blow out 16 2A 82.5 - - 5D 95.7 - -

7.2.7 Failure Frequency Analysis

A blowout is defined as an uncontrolled release of fluid, viz., hydrocarbon (oil and/or gas), but drilling mud, completion fluid or water from a well. It is most hazardous when the fluid is hydrocarbon. Blowouts are important because they have the potential to release large amounts of hydrocarbons and are very difficult to control. A well control incident is one in which a high potential release which may result in blowouts either does not occur or is quickly stopped. They typically involve formation fluid accidentally entering the wellbore, but controlled by the available barriers such as the blowout preventer (BOP). These incidents usually have relatively minor consequences, and are not well reported.

For some events, it is unclear whether they should be counted as a full blowout or as a well control incident. Different databases categorise events in different ways, and some analyses use the term "blowout" to refer to all well control incidents.

7.2.8 Historical Data Sources

The main compilations of secondary data on blowouts are:

• SINTEF blowout database - An internal SINTEF compilation sponsored by 6 operators and 2 consultants (Holand 1995), including 319 blowouts for the period 1970-94, of which 128 occurred in the US GoM OCS or North Sea during 1980-94. It is an update of the Marintek blowout database, for which the full list (SINTEF 1983) and an analysis (NSFI 1985) were published. Detailed analyses have been published for the period 1980-93 (Holand 1996, 1997). Scandpower (1995) analysed the data for the period 1980-92, and included a full list of the events.




• E&P Forum database - Frequencies from BLOWOUT for the period 1970-85 were published by OCB / Technica (1988) and E&P Forum (1992).

The secondary data on Failure Rate Frequency is given in Annexure-X.

7.2.9 Probability of Immediate Ignition and Individual Risk Assessment Criteria The information available on probability of ignition is mostly in the form of expert estimates. The details of immediate ignition probabilities used in this analysis are given in Table-7.8. This data has been obtained from E&P Forum. Similarly, the ADNOC individual risk assessment criteria are given in Table-7.9.

TABLE-7.8

PROBABILITY OF IGNITION FOR LEAKS OF FLAMMABLE FLUIDS

Leak Rate Probability of Ignition

Gas Liquid

Minor (< 1kg/s) 0.01 0.01 Major (1 to 50 kg/s) 0.07 0.03 Massive (>50 kg/s) 0.30 0.08

Source: E&P Forum

TABLE-7.9

THE ADNOC INDIVIDUAL RISK ASSESSMENT CRITERIA

ADNOC Acceptability Criteria

Maximum Individual Risk Criteria for Workers

Maximum Individual Risk Criteria for

Public Existing Installation

New Installation

Benchmark IR < 2 x 10-4 IR < 2 x 10-5 IR < 1 x 10-5 Unacceptable IR > 1 x 10-3 IR > 1 x 10-3 IR > 1 x 10-4 Acceptable IR < 1 x 10-5 IR < 1 x 10-5 IR < 1 x 10-6

Source: E&P Forum

7.2.10 Individual Risk Assessment

The Individual risk due to well blowout is calculated with the help of SAFETI Software. 20 persons were considered as a population present within the well pad in a shift and frequency of well blowout is taken from Annexure-X. The individual risk due to well blowout varies from 1E-06 to 1E-09 and it is concluded that the risk due to well blowout is acceptable for workers as well as for the public as per Table-7.9.

7.2.11 Geo-hazards

Geo-hazards include land slides, flooding, land subsidence and earth quakes. The major geo-hazard associated with oil production is land subsidence. Land subsidence is termed as the sudden sinking or gradual downward settling of land with little or no horizontal motion, caused by a loss of subsurface support which may result from a number of natural and human caused occurrences including subsurface mining or the pumping of oil or ground water. Land subsidence events, depending on where they occur, can pose significant risks to health and safety or interruption to transportation and other services. Land subsidence is effected by characteristic of the reservoir rocks, pressure of overburden, relationship between compaction and pressure gradient in the reservoir, pressure decline dynamic and its influence on the compaction rate and the surface subsidence.




Drilling activities do not involve any extraction of hydrocarbon and thus in this case, any possibility of subsidence is ruled out. In the event of a successful discovery leading to production activities, geo-technical investigations, geological impacts assessment will be carried out and appropriate measures will be undertaken.

7.3 Recommendations to Mitigate Risk/Hazards

The recommendations to mitigate risk at the well site during the drilling operation are given in Table-7.10.

TABLE-7.10

RECOMMENDATIONS TO MITIGATE BLOW OUT RISK/HAZARDS

Sr. No. Mitigative Measures Remarks

1 Maintenance of mud weight

• Drilling Mud Engineer should check the ingoing & outcoming mud weight at the drilling well, at regular intervals;

• If mud weight is found to be less, barytes should be added to the circulating mud, to raise it to the desired level;

• Failure to detect this decrease in level may lead to well kick & furthermore, a well blow out.

2 Monitoring of active mud

tank level

• Increase in active tank level indicates partial or total loss of fluid to the well bore, which can lead to well kick;

• If any increase or decrease in tank level is detected, shift

personnel should immediately inform the Shift Drilling Engineer & take necessary actions as directed by him.

3 Monitoring of Hole Fill-up / return mud volume during tripping

• During swabbing or pulling out of string from the well bore, the hole is filled with mud for metallic displacement which returns back to the pit when the string runs back;

• Both the hole fill up & return mud volumes should be

monitored, as they indicate any mud loss or inflow from well bore, which may lead to well kick.

4 Monitoring of inflow

• The flow nipple during tripping or connection time should be monitored for any inflow from the well bore

5 Monitoring of Background / trip gas

• Increase in background gas or trip gas indicates insufficient mud weight against drilled formation. Such indications should be immediately brought to the notice of the Shift Drilling Engineer.

6 Team Coordination • Each team member must religiously follow the safety aspects pertaining to respective operational area.

• Drilling operation is a team effort and success of such an operation depends upon the sincerity, efficiency & motivation of all team members.

• Safety in such operations is not the duty of a single person, but it is everyone's job.

• The use of protective fireproof clothing and escape respirators will reduce the risk of being seriously burnt.

• Adequate fire fighting facilities and first aid facilities should be provided, in case of any emergency.

• Risk reducing measures include kick simulation training for personnel, presence of well trained drillers and mud engineers, and strict adherence to safety management procedures and good well control procedures.




7.4 Disaster Management Plan A generally accepted definition endorsed by ONGC is a critical condition that may endanger life, the environment, or Company assets. This Emergency Management Plan (DMP) addresses two levels of Emergencies: •••• Minor (Tier I); and •••• Major (Tier II & III).

Minor Emergency An Emergency requiring local support that can be handled by members of Incident Response Team (IRT) such as:

•••• Light bodily injury requiring the assistance of the doctor or a local nurse; and •••• Minor environmental or property damage.

Major Emergency

An Emergency that may require the assistance and support of the Emergency Response Group (ERG) at Regional Office in case of Tire-II emergencies and Crises Response Team (CRT) at Head Office for the Tire-III emergencies and external agencies. e.g.: •••• Serious incidents of spills, blow outs, release of hazardous / toxic substances,

structural failure / collapse; •••• Medical evacuation in the event of life threatening bodily injury or severe

electric shock, life threatening illness; •••• Major environmental or property damage; •••• Man lost situation; •••• Major fire, explosion, radiation; and •••• Unplanned evacuations such as natural calamity, war crisis, security breach.

7.4.1 Overall Philosophy of Emergency Response

Initial response to any incident will be managed at the incident location; in this case, it would be the site of infill well drilling. The overall level of response will depend on the nature and scale of the emergency. The overall philosophy of emergency response is to: • Ensure safety of people, protect the environment and safeguard commercial

considerations; • Immediate response to emergency scene with effective communication

network and organized procedures; • Obtain early warning of emergency conditions so as to prevent impact on

personnel, assets and environment; • Safeguard personnel to prevent injuries or loss of life by protecting personnel

from the hazard; and • Evacuating personnel from an installation when necessary and minimize the

impact of the event on the installation and the environment by:




• Minimizing the hazard as far as possible; • Minimizing the potential for escalation; and • Containing any release.

7.4.2 Auditing

Audits should be carried out on a regular basis to verify and update the Emergency Response Plan and the corresponding procedures. The audit will review: • The roles and responsibilities of the ERG and support organization; • The requirements of legislation and regulatory bodies; and • Resource requirements and availability.

7.4.3 Emergency Priorities

In the event of an Emergency occurring, the ONGC Policy lists, in order, the following priorities: • Safeguard Life; • Protect the Environment; • Protect the Company / Third Party assets; • Maintain the Company image and reputation; and • Resume normal operations as soon as possible.

7.4.4 Emergency Response Management Group Interfaces

The relationship between the Remote Location “Incident Response Team” (IRT), “Emergency Response Group” (ERG), “Crisis Response Team” (CRT) and classification of emergencies is illustrated in the Figure-7.6.




TIER I INCIDENTA MINOR INCIDENT WHERE LOCATION REQUIRES NOEXTERNAL ASSISTANCE & CAN CONTROL THE INCIDENTWITH LOCATION RESOURCES. LOCATION MANAGER (E.G.IM/OIM) MUST NOTIFY EMERGENCY RESPONSE GROUPDUTY LEADER.TYPICAL INCIDENT TYPES:- MINOR OIL SPILLS SHOULD BE UPTO TEIR 1 - 100TONNES- MINOR MEDICAL OR INJURY CASE- EQUIPMENT DAMAGE WITHOUT LOSS OF PRODUCT- MINOR FIRE WITHOUT INJURY OR PLANT DAMAGE-NOTIFICATION OF CYCLONE WITHIN 72 HRS

TIER 2 INCIDENTSUBSTANTIAL INCIDENT. EMERGENCY RESPONSEGROUP DUTY MANAGER'S DECISION TO CALL OUTEMERGENCY RESPONSE GROUP MEMBERS. ERG DUTYMANAGER MUST NOTIFY CRISIS RESPONSE TEAM DUTYLEADER.TYPICAL INCIDENT TYPES:- OIL SPILLS ABOVE TEIR 1- CIVIL UNREST OR SECURITY BREACH- FIRE &/OR EXPLOSION- INJURY OR ILLNESS REQUIRING EVACUATION- CYCLONE WARNING-BLUE ALERT WITHIN 48 HRS- KIDNAP

TIER 3 INCIDENTCRISIS SITUATION APPEARS LIKELY. CRISIS RESPONSETEAM DUTY LEADER'S DECISION TO CALL OUT CRISISRESPONSE TEAM. CRISIS RESPONSE TEAM DUTY LEADERMUST NOTIFY THE CHIEF EXECUTIVE OFFICER.TYPICAL INCIDENT TYPES:- MAJOR POLLUTION - OIL SPILL >1000 TONNES- INCIDENT LEADING TO LOSS OF A FACILITY- INCIDENT LEADING TO SIGNIFICANT FINANCIAL LOSS- KIDNAP OR EXTORTION / THREAT- INCIDENT LEADING TO MULTIPLE INJURIES OR AFATALITY- INCIDENT WHICH COULD LEAD TO INTERNATIONALMEDIA INTEREST-CYCLONE WARNING - YELLOW ALERT WITHIN 12 HRS

INCIDENT

REMOTELOCATIONINCIDENT

RESPONSETEAM

COUNTRYEMERGENCYRESPONSE

GROUP

CRISISRESPONSE

TEAM

RESPONSIBLE FOR:

- DEALING WITH ALL LOCATION INCIDENTSAND EMERGENCIES

- NOTIFYING & LIASING WITH COUNTRYEMERGENCY RESPONSE GROUP DUTYMANAGER

RESPONSIBLE FOR:

- PROVIDING SUPPORT, ADVICE & OFF-LOCATION ASSISTANCE TO LOCATIONWHERE INCIDENT IN PROGRESS

- NOTIFYING OPERATING COUNTRY NEXTOF KIN, AUTHORITIES, EMPLOYEES,CONTRACTING COMPANIES, DISPOSAL OFFATALITIES

- NOTIFYING & LIASING WITH CRISISRESPONSE TEAM DUTY LEADER

- PROVIDING & CO-ORDINATING SPECIALISTSUPPORT

- CO-ORDINATING RECOVERY FROMINCIDENT.

- OBTAINING CLEARANCES FOR & ISSUINGRELEASE TO NATIONAL MEDIA

RESPONSIBLE FOR:

- PROVIDING STRATEGIC RESPONSEASSISTANCE, SUPPORT & ADVICE TO THEEMERGENCY RESPONSE GROUP IN THECOUNTRY WHERE THE INCIDENT TAKINGPLACE

- NOTIFYING EXPATRIATE NEXT OF KIN,INTERNATIONAL AUTHORITIES SHAREHOLDERS, JOINT VENTURE PARTNERS &FINANCIAL INSTITUTIONS

- CO-ORDINATING & APPROVING ALL MEDIARELEASES, ISSUING INTERNATIONAL MEDIARELEASE(S)

- AUTHORISING EXTRAORDINARYEXPENDITURE

- DECIDING ON COURSE OF ACTION & CO-ORDINATING REPATRIATION OFEXPATRIATE & FAMILIES IN THE EVENT OFCIVIL UNREST OR WAR

- CO-ORDINATING RESPONSE TO KIDNAP &EXTORTION DEMANDS

- PROVIDING LEGAL ADVICE & RESPONSE

FIGURE-7.6

EMERGENCY CLASSIFICATION




7.4.5 Emergency Response Procedures

7.4.5.1 Minor Emergency

To enable the appropriate level of response to be implemented, emergency incidents are to be categorized according to three levels as follows: Tier-1 (Minor Emergency) – an event with no escalation potential, which can be controlled and contained by the action of personnel of Incident Response Team (IRT) at the incident site. In such cases of local alert, the ‘ERG leader’ will be notified but the ERG is not called out. Some typical incidents are: • Minor accident; • Equipment damage; • Medical evacuation (not very serious cases); and • Minor fires.

7.4.5.2 Major Emergency

Tier-II Emergency

Events with escalation potential, depending on the effectiveness of the local response. These incidents may impact the entire site. For such type of incidents the installation manager assumes the charge of Incident Response Controller (IRC) and activates ERG who aide/guide the IRC in controlling the emergency situation. The country manager is notified on the same.

Some typical incidents are: • Substantial security incident; • Multiple casualties; • Cyclone flooding; • Serious damage to man/machinery; • Substantial fire; • Cultural conflict, and • Serious incident.

Tier- III Emergency A crisis that requires assistance from external resources in order to save lives, minimize damage and to bring the abnormal situation back under control. These incidents have the potential to impact beyond ONGC site limit. In such cases, IRC activates the ERG who notify the country manager and Crises Response Team (CRT) in Head Office will be activated. The CRT would guide / aide the ERG in controlling the emergency situation.




Some typical Tier-3 incidents are: • Major fire/explosion; • Evacuation of the rig/platform; • Loss of the rig/platform; • Fatality; and • Terrorist attacks. For a major emergency, the ERG team will use the Emergency Control Centers (ECCs) to enable constant guidance / aide during emergency situation between the incident site, ERG and CRT.

7.4.5.3 Emergency Response Strategies

Whenever there is an emergency, the response team is required to swing into action without losing time. Time is the essence of the immediate relief and rescue operations to save human life, to mitigate the impact on the environment and to safeguard commercial consideration. This DMP has been prepared keeping in mind the above fact and it is conceptually based on the Trigger Mechanism. The Trigger Mechanism envisages that on receiving signals of a disaster happening or likely to happen, all activities required for the mitigation process are energized and activated simultaneously without loss of any time. The primary objective of this mechanism is to undertake immediate rescue and relief operations and stabilize the mitigation process as quickly as possible.

The main parameters of such a response plan include:

• Signal / Warning Mechanism; • Activities and their Levels; • Sub-activities; • Command and Control Structure; • Individual Roles and Responsibilities of each specified authority to achieve the

activation as per response time; • Response teams for each specified authority; • Emergency Procedures; and • Alternate Plans & Contingency measures.

7.4.6 Alert Phase

It will be the duty of all site personnel at the site to remain alert at all times for hazardous situations that have the potential to escalate into an emergency incident. The ERG members would be activated as required. Emergencies on site can be initiated in a number of ways depending upon the severity of the incident i.e., by the site fire alarm siren, which any personnel on the incident site can activate. The site siren will sound in an intermittent mode. Also, the individual fire alarms will sound in the area of the incident.




This procedure initiates the site fire and Rescue Department and Site Security into their standard procedures to attend the incident. This has the advantage of permitting the earliest possible action to be taken to control the immediate situation, which may avoid the development of a major emergency. The ‘Incident Controller’ will attend the scene of the incident and the ‘ERG Leader’ will be notified. Depending upon the severity of the emergency (Tier-2) the ERG Leader will activate the ERG and notify the ‘Country Manager’ as appropriate. The incident controller will assess the situation from the edge of the incident scene to reduce the probability of personal injury. The ERG members will be on standby to go to the Emergency Control Centre (ECC). Evacuation of employees to the nearest assembly point or refuge may be required, if not hindered by fire or toxic cloud (all personnel present on the incident site would make it a point to always move upwind in case of fire).

7.4.7 Preparedness for Emergencies

• Command by Competent Persons

Effective command and control starts with a clear definition of the overall command and control structure and description of the duties of key personnel with specific responsibilities for emergency response.

• Number of Persons for Emergency Duties

The command/control of emergencies must identify the minimum number of persons required to provide an adequate response to emergencies. This includes having staff trained and competent to fulfill the roles of other members of staff if they are not available.

• List of Persons for Emergency Duties

A list of those staff that has emergency duties is displayed in the Control room. It is the responsibility of the ONGC Radio Officer would ensure that these lists are kept up to date.

7.4.8 Control of Emergencies The major systems for controlling emergencies and preventing escalation are detailed in subsequent sections of the DMP, which gives the emergency procedures to be followed in case of an impending/occurring disaster.

It is absolutely necessary for the ERG leader to review the incident response and provide his inputs for improvements / modifications to the DMP and update accordingly. ERG leader would debrief all personnel involved in the emergency response action. It will be the responsibility of the ERG leader to develop a Post Emergency Action Plan with the assistance of Incident Controller. It will be the responsibility of the designated HSE personnel to prepare a complete incident report collating incident reports/ logs from the respondents and forward the same to higher authorities as appropriate.




7.5 Emergency Response Action

Incident Control Centres (ICC)

The Incident Controller will be responsible for co-ordinating the site response to any emergency and direct emergency response personnel as appropriate to the emergency. The installation manager’s office shall be the designed ICC: At the drilling rig, it is suggested that the best location for control centre will be main control room and alternately it may be shifted to Temporary Refuge (TR) in case of major emergency. There will be radio, telephone or messenger contact with the ICC. The incident area will be tapped off and warning notices posted. The in-house Fire Team cordon off the incident area (Inner Cordon). Route markings from ICC to the incident to aid the emergency services will be arranged; Various personnel will wear fluorescent jackets with a description of their role. This will include the Incident Controller and medics.

Emergency Control Centres (ECC)

The Emergency Control Centre is to be set up by a person designated by the ERG office. The ONGC’s Guesthouse (if available) could be the alternate ECC. It is place from where the operations to handle the emergencies are directed and co-ordinated. The centre is equipped to receive and transmit information and direction from and to the Incident Controller as well as from outside. ECC shall contain equipment for logging the development of the incident to assist the controllers determine any necessary action:

The ICC and ECC should contain:

An adequate number of external telephones. At least one will be ex-directory or capable of use for outgoing calls only. This will avoid the telephone switchboard being overloaded with calls from anxious relatives, the press etc;

An adequate number of internal telephones; Radio equipment;

A plan or plans of the works to show

� Areas where there are large inventories of materials, including oil storage,

drilling materials;

� Sources of safety equipment;

� The fire water system and additional sources of water;

� Stocks of other fire extinguishing materials;




� Assembly points, casually treatment centres;

� Location of the works in relation to the surrounding community; and

� Lorry/truck parks. Additional plans which may be marked up during the emergency to show

i Areas affected or endangered; ii Deployment of emergency vehicles and personnel; iii Areas where particular problems arise; iv Area evacuated; and v Other relevant information

• HAZCHEM sheets for the various hazardous materials used on-site; • Note pads, pens, pencils to record all messages received and sent by whatever

means; • Nominal roll of employees or access to this information; • List of key personnel, addresses and telephone numbers.

Emergency Control Centre is located, designed and equipped to remain operational in an emergency.

7.6 Emergency Response Procedures

7.6.1 Blowout

During a blowout, the Rig (specific) emergency Response Plan would be referred. The contingency plan for onshore blowout (drilling rig) is given in Figure-7.7. Common steps required during blowout are discussed as below: Driller/person on the spot In case, the kick is timely detected In case of string at the bottom of hole

1 Lift and clear tool joint out of rotary and stop pumps; 2 Close BOP and choke; 3 Record Shut In Drill Pipe pressure (SIDP) and Shut In Casing Pressure (SICP);

and 4 Prepare kill sheet and make calculations for standard well killing procedures;

In case of while making trip:

1 Stop tripping operations; 2 Position tool joint at rotary table and set slips; 3 Install safety valve and close safety valve; 4 Open choke line; 5 Close BOP and choke; 6 Make up Kelly;




7 Record shut in SIDP and SICP; and 8 Prepare the kill sheet and make calculations for standard well killing procedure.

In case of string out of the well:

1. If well condition permits attempt run in hole and whenever situation is critical

shut the well by following steps as mentioned in case of while making trip; and 2. If the trip in is not possible then use volumetric method off well control.

FIGURE-7.7

CONTINGENCY PLAN FOR ONSHORE BLOWOUT (DRILLING RIG)




In case of sudden kick:

1 Close the BOP; 2 Record SIDC & SICP; and 3 Prepare kill sheet and make calculations for standard well killing procedure.

On detection of a kick the Senior Tool pusher/Drilling supervisor is to be informed immediately; and Person discovering the blowout should notify radio room of the incident. Radio Room Alert to the fire team; Notify Incident Controller of the incident to clear non-essential traffic; and Send radio and other communications on instructions from Incident Controller Drilling Supervisor/PIC Minimize ignition sources; Assess the situation along with Senior Tool pusher and declare the incident to be: • Minor event, which can be brought under control using in situ equipment • Serious event, which may not be brought under control; and • Major event, in which the well is unlikely to be brought under control • Incident controller to be informed immediately if the event is classified as

serious or major event; and • Instruct control room to suspend drilling operations Incident Controller • Inform to the ERG Leader, provide full details and likely requirements and

maintain contact; • Activate site response personnel as appropriate, provide full incident briefing

and likely requirements and maintain liaison; • Ensure that Fire team is on standby; • Instruct to all non-essential personnel to prepare for evacuation. In a major

emergency, an order for total evacuation must be given; • After situation has returned to normal, inspect incident site to determine

whether further corrective action is required to make situation safe. ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller

and maintain liaison; • Active ERG appropriate contact Directory; • Notify EMT Leader and provide full incident briefing and likely requirements; • Co-ordinate support activities as required;




• Determine need for external assistance for safety of personnel, well control and pollution prevention;

7.6.2 Well Control

The following preventers are stacked in a sequence and this assembly of preventers is termed as “BOP Stack” as shown in the Figure–7.8. Blowout Preventers: Blow out Preventer consists of Annular Preventer, which can generally close on any size or shape of tubular in the well bore which closes the annular space between drill string and casing.

Ram Preventer: Ram preventers are of two types i.e. Pipe Rams and Shear Rams. Pipe rams also close the annulus between drill string and casing, but they have a fixed size. As such a specific pipe rams can be closed on a specific size of pipe. Shear rams are generally the last choice of preventer to be operated as they shear drill string and shut off the well bore.

Blowout prevention equipment shall be installed, tested and operated according to the Well Control Manual for Drilling Operations. Certain key personnel on the drilling unit shall hold a valid certificate of examination from a recognized pressure control course.

The BOP stack in use shall be pressure tested initially before drilling out of the casing shoe and thereafter weekly. A sequence of successful tests indicate that greater confidence could be placed in the stack and control equipment, then the testing interval can be extended up to a maximum of two weeks.

All pipe fittings, valves and unions placed on or connected to blow-out prevention equipment, well casings, casing head housing, drill pipe or tubing shall have a working pressure rating at least equivalent to that of the component to which it is fitted.

Drilling operations shall not proceed until blowout prevention equipment is found to be serviceable by visual inspection and appropriate pressure testing.

BOP control systems are installed, tested and operated according to the Well Control Manual for Drilling Operations. In addition to the instrumentation to indicate the availability of air pressure and fluid pressure, the following safety features will be considered for the control systems: A relief valve installed; accumulator low-pressure alarm; air-driven hydraulic fluid charge pumps; electric-driven hydraulic pump to be connected to the emergency generator; fail safe regulators; manifold pressure is consistent with ram closing force requirements at anticipated maximum surface pressure (high pressure wells); accumulator capacity at elevated manifold pressures still meets requirements; fire resistant hydraulic control hoses and control fluid; appropriate location of remote operating panels; redundant functions plugged off; hydraulic control hose are tested to the rated pressure of the unit.




7.6.3 Hydrogen Sulphide (H2S)

Natural gas leaks are expected regardless of the location. Natural gas is an extraneous material. As such all natural gas leak carry the risk of fire and explosion until the leak is contained. Hydrogen sulfide is a toxic chemical gas frequently found in natural gas deposits. During drilling operations, the consequences of leaks or kicks with sour gas or crude can be very serious. Personnel can be incapacitated by relatively low concentrations of H2S in a very short time and equipment can suffer catastrophic failure due to H2S embrittlement. A contingency plan will be drawn up when H2S may be expected during well operations. A study will be made of the geological and geographical features of the area, in order to predict the expected areas where H2S may be encountered or may accumulate. Information about the area and known field conditions, including temperatures, pressures, proposed well depth and H2S concentrations will be obtained and taken into consideration. The drilling program will highlight this hazard and give details of controls and recovery measures in place. Once the cellar has been excavated, the drill pad constructed and equipment set in place, drilling can commence. Typically, at the time of site construction, a false conductor of large diameter will be grouted upto 3.5 m from surface. Initially, the drilling fluid used is quite often water alone. Drilling will then continue for several hundreds of meters. At this depth smaller diameter casing is usually cemented into the hole. This intermediate casing protects the well by sealing potentially weak zones. At this stage low density drilling muds will be used and although it is unlikely that gases or fluids under pressure might be encountered, a blowout preventer is typically installed to prevent fluid from the formation gushing to the surface. Drilling continues using progressively smaller bits and incrementally decreasing casing diameters. Changes in mud composition, and drill bit, are likely to occur according to the different strata encountered.

FIGURE-7.8

TYPICAL SCHEMATIC OF BOP STACK

Annular

BOP

Pipe Ram

Shear Ram

KILL LineCoeflexip Hose to

Choke Moni-Fold




7.6.4 Abandonment of Rig/Well

In case of major incident, which necessitates the abandonment of the rig/well, the following actions will be taken;

Emergency Siren Modes

Fire High/Low tone Proceed to muster point(s)

Evacuation On/off monotone Evacuate as directed All clear Continuous monotone Emergency ended Control room will activate Emergency Siren upon fire Call Point or ESD being activated. Personnel can also alert Control Room by radio or phone

Rig/well PIC

• Notify Radio Room of intention to abandon the rig • Ensure that rig facilities are cleared for evacuation (e.g. clear equipment from

heli-deck etc); • Determine appropriate safe method of abandonment and notify all personnel to

assemble at appropriate Muster Point; • Contact Incident Controller to provide full incident briefing and likely

requirements and maintain liaison; and • Instruct all personnel to evacuate the rig.

All Other Personnel of Rig

• On hearing alarm, put on life jacket and proceed to Muster Point nominated by

Rig–PIC, remain calm and await instructions; and • If evacuating by jumping into “buddy up” and tie off if possible any try to stay

together with as many people as possible.

Radio Room

• On receiving emergency call, nominate a dedicated frequency for the emergency calls;

• Notify Incident Controller and advise of emergency frequency and update frequently;

• Inform all ONGC radio stations of incident and ask to clear non-essential traffic; and

• Send radio and other communications on instructions of Incident Controller.

HSE Support

• Conduct headcount of personnel assembled at Muster Point; • Notify Incident Controller of headcount/token results and emphasize on any

discrepancy; • Ensure that headcount is updated if people are allocated tasks that remove

them from Muster Point (e.g. fire team etc); and




• For any discrepancy in headcount, reconcile daily record of persons on site with lists of persons assembled at Muster Points and notify Incident Controller of identify of missing person(s).

Incident Controller

• Obtain full incident briefing and likely requirements from RIG PIC and maintain liaison;

• Ensure that all production is shut in and that all machinery is rendered safe; • Ensure that all personnel are accounted for via headcount as SAR is conduct for

any missing persons; • Obtain a personnel list on the affected rig; and • Notify ERG Leader of rig evacuation and any likely requirements

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller an

maintain liaison; • Activate ERG with appropriate Contact Directory • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Co-ordinate support activities as required.

7.6.5 Structural Damage/Failure of the Rig

The actions to be taken during a structural damage/failure of the rig/well are as follows: Drilling Supervisor/PIC

• Notify Radio Room of incident; • Instruct Site Control Room to shut the drilling operation if required; • Inspect any damage/failure sustained by rig, if safe to do so, assess actions

required to make rig safe; • Ensure that all personnel are accounted for and consider need for evacuation;

and • Contact Incident Controller to provide full incident briefing and likely

requirements and maintain liaison.

Radio Room

• Call support vessel to affected rig if required; • Notify Incident Controller of incident and update as further communications

received; • Inform all ONGC radio stations of incident and ask to clear non-essential traffic;

and • Send radio and other communications on instructions from Incident Controller.




Incident Controller

• Obtain full incident briefing, and likely requirements from Drilling Supervisor/PIC and maintain liaison;

• Ensure that all personnel have been accounted for; • Ensure that drilling activity has been stopped if appropriate; • Notify ERG Leader, provide full incident briefing and likely requirements; • Proceed to affected part of the rig for damage assessment and depending on

severity of damage, suspend drilling operations, make all equipment secure and restrict access until repairs can be undertaken;

• To assess and declare the incident to be a minor, serious or major event; and • To consider evacuation of non-essential personnel and depending on the

severity of the incident, the evacuation of all personnel.

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller and maintain liaison;

• Activate ERG with appropriate Contact Directory; • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Activate technical support as appropriate for evaluation and control of situation.

All response Members Maintain log of events for collection at end of incident

7.6.6 Well Control Emergencies

Person first on scene

• Notify radio Room of incident; • Follow appropriate well control procedure; • Instruct all non-essential personnel if any to proceed to Muster Point(s);

conduct headcount(s) as required; • Ensure that all possible ignition sources on affected platform are turned off; • Determine source of the problem and safest & most effective way to prevent

incident from escalating; • Ensure that wire line crew are advised/aware of any incident and likely

requirements; • Contract Incident Controller to provide full incident briefing and likely

requirements, Maintain liaison.

Radio Room

• Notify Incident Controller, Production Supervisor and Petroleum engineer of incident; update as further communications received;

• Inform all ONGC radio stations of incident and ask to clear non essential traffic; • Send radio and other communications on instructions from Incident Controller.




Incident Controller

• Obtain full incident briefing and likely requirements from Wire line and/or site Supervisor, Maintain liaison;

• For wire line incident, ensure that drilling supervisor and petroleum engineer is notified;

• Consider need to evacuate platform, if any, request results of any headcount and ensure that all personnel are accounted for conduct SAR for any missing personnel; and

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller. Maintain liaison

• Activate ERG with Contact Directory as required; • Notify wire line contactor management and maintain liaison; • Determine need for external assistance for safety of personnel, well control and

pollution prevention; • Activate pollution control procedures as required; • Liaise with support co-ordinator to activate well control specialties and

equipment to incident site as required; • Consult with Incident Controller and Wire line Supervisor regarding safest, most

effective way to resolve incident.

All Response Member

As time permits, maintain log of events for collection at end of incident 7.6.7 Fire On Rig

Person first on scene

• Shut down production by activating ESD; • Close down any manual feed valve that may be feeding the fire, if safe to do so, • Notify Radio Room on incident; • Attempt to extinguish the fire with portable equipment, if safe to do so; and • Contact Incident Controller to provide incident briefing and any likely

requirements.

Radio Room

• Alert Fire Team of incident, • Notify Incident Controller of incident and update as further communications

received; • Inform all radio stations of incident and ask to clear non-essential traffic; and • Send radio and other communications on instructions from Incident Controller.

Rig PIC (if any maintenance/survey team is on the platform)

• Instruct Control room to shutdown activities from affected rig;




• Instruct all non-essential personnel, if any to proceed to Muster Point and conduct headcount as required; and

• If fire cannot be extinguished safely, consider need for evacuation (if any) of rig.

Incident Controller

• Activate site response personnel as appropriate and provide full incident

briefing and likely requirements. Maintain liaison; • If fire extinguished, ensure that there is no gas leak. If gas leak detected, and if

safe to do so, shut off all ignition sources, close all relevant shut-off valves and evacuate rig;

• Notify ERG Leader, provide full incident briefing and likely requirements; • After situation has returned to normal, inspect incident site to determine

whether further corrective action is required to make situation safe.

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller. Maintain liaison;



All Response Members

As time permits, maintain log of events for collection at end of incident.

7.6.8 Rig Evacuation

Person on Rig

• Notify Radio Room of intention to abandon the rig • Ensure that platform/rig facilities are cleared for evacuation; • Determine appropriate safe method of abandonment and notify all personnel to

assemble at appropriate Muster Point’ • Contact Incident Controller to provide full incident briefing and likely

requirements. Maintain liaison; • Instruct all personnel to evacuate the platform / rig; • Put on a lifejacket and proceed to Muster Point nominated by rig PIC. Remain

calm and await instructions; and • If evacuating by jumping into the water, “buddy up” and tie off, if possible, try

to stay together with as many people as possible.

Radio Room

• On receiving emergency call, nominate a dedicated frequency for the emergency calls;

• Notify Incident Controller and advise of emergency frequency and update frequently;




• Inform all radio stations of incident and ask to clear non-essential traffic; and • Send radio and other communications on instructions from Incident Controller.

Incident Controller

• Obtain full incident briefing and likely requirements from rig PIC and maintain

liaison; • Ensure that all activity is shut in and that all machinery is rendered safe; • Ensure that all personnel are accounted for via headcount and SAR is conducted

for any missing persons; • Obtain a personnel list for the affected rig; and • Notify ERG Leader of platform evacuation and any likely requirements.

ERG Leader

• Obtain full incident briefing and likely requirements from ERG Leader and

maintain liaison; • Activate ERG with appropriate contact directory; • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Co-ordinate support activities as required;


As time permits, maintain log off events for collection at end of incident

7.6.9 Gas Release on Rig

Person Discovering Release

• Avoid creating any source of ignition; • Shutdown platform/rig by activating ESD; • If the location of the leak is known, and if safe to do so, shut any relevant

manual valves; • Notify Radio Room of incident; and • Inform radio room of incident

Rig PIC

• Stop all hot work and shutdown all other sources of ignition; • If safe to do so, attempt to locate and shut off the source of the leak; and • Contact Radio Room/Incident Controller to provide full incident briefing and

likely requirements. Maintain liaison.

Radio Room • Notify Incident Controller of incident and update as further communications

received; • Notify Drilling Supervisor, if appropriate; • Inform all radio stations of incident and ask to clear non-essential traffic; and • Send radio and other communications on instructions from Incident Controller;




Incident Controller

• Obtain full incident briefing and likely requirements from radio room and maintain liaison;

• Instruct Site Control Room to shut in production, if required; • Ensure that all personnel are accounted for and consider need to evacuate that

all personnel are accounted for and consider need to evacuate non-essential personnel (in case team is present on the platform). Evacuate all personnel if gas concentration reaches danger level;

• Notify ERG Leader and provide full incident briefing and likely requirements.

ERG Leader





As time permits, maintain log of events for collection at end of incident

7.6.10 Structural Damage

Rig PIC

In case of any maintenance/survey team is present on the rig.

• Notify Site Radio Room of Incident; • Instruct site controller room to shut in production if required; • Inspect any damage sustained by rig, if safe to do so and assess actions

required to make rig/platform safe; • Ensure that all personnel are accounted for and consider need for evacuation, if

any, and • Contact Incident Controller to provide full incident briefing and likely

requirements, Maintain liaison.

Site Radio Room

• Notify Incident Controller of incident and update as further communications received;

• Inform all radio stations of incident and ask to clear non essential traffic; and • Send radio and other communications on instructions from Incident Controller.

Incident Controller

• Obtain full incident briefing including status of any instrument, which may have

collided with the rig/platform, and likely requirements from site radio room. Maintain liaison;




• Ensure that support vessel proceeds to affected platform if required; • Ensure that production on the affected rig/platform has been shut in; • Notify ERG Leader and provide full incident briefing and likely requirements;

and • Proceed to affected platform for damage assessment and depending on severity

of damage, keep production shut in, make all equipment secure and restrict access until repairs can be undertaken.

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller and

maintain liaison; • Activate ERG with appropriate Contact directory. • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Activate technical support as appropriate for evaluation and control of situation;

All response Members


7.6.11 Ground Movement

Any Person

• Establish the severity of the movement; • Drilling/production Supervisor/PIC is to be alerted as the movement is

detected; and • Contact Site Radio Room and notify the incident

Site Radio Room

• Inform the Incident Controller • Inform all radio stations of incident to clear non essential traffic; and • Send radio and other communications on instructions from Incident Controller;

Drilling/Production

• Assess the situation; • Drilling/production to be suspended; and • Inform the Incident Controller and to be informed immediately if the event is

classified as serious or major.

Incident Controller

• Obtain full status briefing from the Drilling/production supervisor/PIC and maintain continuous contact;

• Ensure that support are proceeded to the rig/platform if required; • Ensure the safety of all personnel; • Consider evacuation if it is required depending upon the severity of the

situation;




• Contact ERG leader and provide details of the situation; and • Proceed to carry out damage (if any) assessment and take control measures as

required;

ERG Leader


• Activate ERG with appropriate Contact directory; • Notify EMT Leader if required and provide full incident briefing and likely

requirements All Response Members

Maintain log of events for collection at end of incident

7.6.12 Un-ignited Gas Release

Person discovering Fires

• Avoid creating any source of ignition; • Shutdown drilling by activating ESD; • If location of the leak is known, and if safe to do so, shut any relevant manual

valves; • Notify Site Radio Room of incident; and • Contact Incident Controller to provide incident briefing and any likely

requirements.

Site Radio Room

• Alert Fire Team of incident; • Notify Incident Controller of incident and update as further communications

received; • Inform all radio stations of incident and ask to clear non-essential traffic; • Send radio and other communications on instruction from Incident Controller.

Incident Controller

• Stop all hot work and shutdown all other sources of ignition; • Instruct Site Control Room to shut in production, if appropriate; • Evacuate all non essential personnel and ensure that alternate Muster Point

advice is given if a gas release threatens Primary Muster Point; • Evacuate all personnel, if gas concentration reaches danger level; • If safe to do so, organize for location and shut off of leak source; • Ensure that system is depressurized to flare/atmosphere as appropriate; • Notify ERG Leader, provide full incident briefing and likely requirements and

maintain liaison; • Ensure that all personnel have been accounted for and ensure that non-

essential personnel stay clear of incident site and initiate SAR for any missing persons;

• Notify ERT Leader provide full incident briefing and likely requirements




ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller and maintain liaison

• Activate part or all of ERG as appropriate; • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Co-ordinate support activities as required;

All Response Member


7.6.13 Hydrocarbon Spill

Equipment and Training

• Assure emergency dispersant and spray equipment for dealing with spills is readily available; and

• Assure personnel are trained in use of emergency dispersant and spray equipment, and with the provision of this procedure.

Oil Spill Detection

• Be alert during operations such as fuel oil transfer and critical drilling operations that could result in oil spills;

• Keep watch on the transfer pump, manifolds, transfer hoses, and all other connections;

• During critical drilling operations, keep watch on the drilling equipment instrumentation and stop drilling when unsafe conditions arise; and

Shut Down the Source

• Review site for safety hazards; • Stop the spill at the source as quickly as possible; • Assure that transfer pumps are immediately stopped if spill occurs during fuel

oil transfer; and • If the spill occurs from any equipment on either vessel, shut down the

operating equipment and close any valves between the leak source and the equipment.

Oil Spill Reporting

Spills should be reported using the Pollution Report Form. Oil Spill Contingency Plan

Detailed oil spill response actions are included in Oil Spill Contingency Plan (OSCP).




7.6.14 Medical Evacuation

The incidents that may require medical evacuation are mainly severe casualties. The actions to be taken during medical evacuation are as following:

Incident Controller

• Determine need for Medevac and type and special conditions of transport

required. Consult with Site doctor regarding appropriate action and maintain liaison;

• Consult with Site doctor on appropriate destination for serious Medevac; • If patient is a contractor, contact contractor manager and provide full Medevac

details; and • Notify ERG Leader and provide full incident briefing and likely requirements. • Name of ill/injured person(s) to be communicated secure communications.

ERG Leader

• Obtain full incident briefing and likely requirement from Incident Controller and

maintain liaison; • Activate ERG as appropriate; • Liaise with aircraft operator and airport authorities to facilitate medevac and

ensure that site representative is at airport to accompany patient to hospital; • If required, obtain permission for hospital ambulance to access airport security

zone. If access denied, ensure that airport ambulance should be available for transfer to hospital ambulance;

• Notify next of kin; • If patient is a contractor, ensure that contractor manager is informed with full

Medevac details; and • Maintain liaison with patient and patient’s family until discharged and consider

arranging for relatives of injured person to be brought to hospital.


Maintain log of events for collection at end of incident 7.6.15 Criminal Acts

Incident Controller

• Take actions to detain offender(s) if, appropriate; • Notify ERG Leader and provide full incident briefing for the following: • Nature of crime; • Identify of person(s) involved; • Extent of any injury to personnel and if Medevac required • Any assistance required; and • Action taken to date • If person(s) have been taken into custody, determine with ERG Leader the need

to involve Police and contact Police as appropriate: • Secure evidence, close off incident site, prepare sketches and photographs,

identify witnesses and take statements;




• Consider need for suspension of any impending crew change; • Consider restriction of information to “need-to-know” basis; and • Assist Police with their inquires.

ERG Leader

• Obtain full incident briefing and likely requirements from Incident Controller and

maintain liaison; • Activate ERG as appropriate; • Notify EMT Leader and provide full incident briefing and likely requirements;

and • Submit reports to relevant authorities


Maintain log of events for collection at end of incident.

7.6.16 Bomb Threat/Extortion

• If there is a contingency like bomb threat/extortion attempt then the following procedures would be followed:

Person Receiving Threat

• For written threat, keep all paper, envelopes etc. to preserve as evidence; • For verbal threat, use bomb threat checklist while talking to the person making

threat and write details notes checklist not available; • Do not use radio to raise alarm–radio signals may trigger an explosive device • For verbal contact, be calm and respectful and DON’T PANIC; • Take threat seriously; • Signal for assistance if in a position to do so; • Pay attention to what is being said and to any background noise; • Accurately write all that is being demanded and ask calmly for confirmation if

unclear; • Do not agree or concede to any demands without prior approval; • Try to keep caller talking as long as possible and DON’T HANG UP; • If caller “hangs up, do not hang up your phone (it may be possible to trace

call); and • At the conclusion of the call, check all notes taken to ensure accuracy.

Incident Controller

• Immediately shut in all drilling/production activities if appropriate; • Notify ERG Leader and provide full incident briefing and likely requirements; • Evacuate all non-essential personnel to a safe area and consider total

evacuation as required; • Ensure that all relevant authorities (e.g. Police etc) are notified immediately; • Ensure that bomb threat checklist is completed by person receiving a verbal

threat; • Make every effort to calm all involved and don’t aggravate situation by personal

attempts to resolve situation hastily;




• Ensure that someone is continually standing by a phone to receive next communication from extortionist or ensure that alternative number is provided to caller; and

• Await assistance from appropriate authorities.

ERG Leader

• Obtain full incident briefing and likely requirement from Incident Controller and maintain liaison;

• Activate ERG as appropriate; • Ensure that all relevant authorities (e.g. Police etc.) are notified immediately; • Liaise with relevant Government agencies to obtain assistance (e.g. Indian

Armed forces etc) as required; and • Notify EMT Leader and provide full incident briefing and likely requirement. All Response Members

Maintain log of events for collection at end of incident

7.7 End of Emergency

• Prior to termination of an emergency, the following issues would be considered

and necessary action taken: • Confirm that the emergency is concluded; • List of resources that are required for on going incident control (if appropriate); • Final information release and/or notification to

o Site incident response personnel, ERG, EMT and Chairman; o Consultants; o Contractors; o Customers; o Emergency services; o Employees o State Regulatory Authorities; o National Regulatory Authorities o Environmental Agencies o Joint Ventures; o Local Communities; o Neighbour / third parties o Pressure groups o Suppliers o Trade unions; and o Media

• De-briefing of all personnel (including people currently relieved or stood down); • Close down additional security arrangements; • Finalize additional catering and other services; • Continuing counselling for those involved in the incident; • Compile and file all documents relating to the response; • Arrange for full incident investigation and analysis; • Carry out follow up review to ascertain effectiveness of




• Callout; • Site incident Response, ERG and EMT Functions; • Operational emergency response; • Approve / comment on incident debriefing reports and recommended actions;

and • Recommended revision of Emergency Plans as required.

7.8 Communications

All nominated and dedicated emergency response stall will carry VHF radios programmed with the relevant Watch Keeping / Emergency Frequency.

7.8.1 Communication Network

It is essential that all emergency communications will be relayed to the Incident Controller (or Alternate) and/or the ERG leader (or alternate as soon as possible in case of an emergency situation. As far as possible all Emergency Calls from site, helicopter and base station would be passed on through the site Radio Room. The Radio Operator will allocate a dedicated emergency frequency and will advise the Incident Controller of the emergency situation and frequency. Upon the commencement of an emergency, the Radio Operator will inform radio stations that there is an emergency and ask to clear all non essential radio traffic on the designated emergency radio channel/frequency for communications. If an incident occurs after normal business hours, the Site Radio Room will make contact with all Radio rooms, which will in turn activate the ERG Leader and other personnel as advised.




REFERENCES

1. “Offshore Blowouts, Causes and Control” Per Holand, 1997. gulf Publishing Company

2. “Comparative Safety Evaluation of Arrangements for Accommodating Personnel Offshore” Report ref. OTN-88-175 December 1998, OCB/Technical

3. “A 100 well study of offshore blowout causes “ E.Dahl and T.I.Beru, 1983

4. “Hydrocarbon Leak and Ignition Database” 1992, E and P Forum

5. “Techniques for Assessing Industrial Hazards, A Manual”, World Bank, Technical Paper number 55, Technica Ltd, 1998

6. “Study on Offshore Installations Protection against Impact”, J.P.Kenny, 1987

7. “Risk Assessment of Buoyancy Loss, Case Study I” Report 6 of RABL Project, Siktech, 1987

8. OREDA-92 Offshore Reliability Data Handbook 2nd Edition

9. The Offshore Installations (Safety Case) Regulations 1992

10. “Analysis Methods and Inservice Experience-submersible Platforms” C.A.Carlsen and S.Knudsen, 1986

11. “Mobile Platform Stability. Sub-project 0.6, Estimation of Damage Conditions”. Det

Norske Veritas, 1982 12. Worldwide Offshore Accident Databank Statistical Report 1996, Det Norske Veritas 13. “Assessment Principle for Offshore Safety Cases” HSG 181, HSE Books, 1998. 14. International Association of Drilling Contractors, Accident Statistics Program, 1989-94 15. E&P Forum, Accident data, 1985-1994 16. UK Department of the Oil and Gas Reserves of the United Kingdom (The Brown Book),

1990; 17. Norwegian Petroleum Directorate, Annual Report, 1987 18. Health and Safety Executive, “Parloc 92. The update of Loss of Containment Data for

Offshore Pipelines; prepared by Advanced Mechanics and Engineering Limited for the Health and Safety Executive, 1994

19. Results taken from BP CIRRUS Consequence Modeling Software Package 20. SINTEF Offshore Blowout Database 1994 21. E&P Forum, Risk Assessment Data Directory, 1996 22. J.P.Kenny – Protection of Offshore Installation against Impact – Report OTI 88535,

1988 23. Scand Power Model for Blowout Prediction Feb, 1995


Chapter-8 Project Benefits


8.0 PROJECT BENEFITS







The commercial development will also lead to investment in Mizoram, bringing oil


of ONGC in the region will substantially improve the socio-economic conditions of

the region.

In Operation phase, ONGC will require significant work force of non-technical and

technical persons. Migration of persons with better education and professional

experience will result in increase of population and literacy in the surrounding

villages. The expenditure towards CSR activities by ONGC is enclosed as

Annexure-XI.

8.1 Improvements in the Physical Infrastructure

The beneficial impact of hydrocarbon development on the civic amenities will be

substantial after the commencement of project activities. The basic requirement

of the community needs will be strengthened by extending health care,

educational facilities to the community, building/strengthening of existing roads in

the area. ONGC will initiate the above amenities either by providing or by

improving the facilities in the area, which will help in uplifting the living standards

of local communities.

The construction of new roads in the project area will enhance the transportation

facilities. With improved transportation facilities there is always a scope for

development.

8.2 Improvement in the Social Infrastructure

• Generation of employment: The project will create opportunities for direct and

indirect employment;

• Increase in purchasing power and improved standard of living of the area;

• Establishment of small and medium scale industries may be developed as

consequence;

• Increased revenue to the state by way of royalty, taxes and duties;

• Regular Fund flow to local market;

• Overall Growth of the neighboring Area viz.:

° Agriculture and Animal husbandry;

° Health and family welfare;

° Watershed development;

° Sustainable livelihood and strengthening of village Self Help Groups; and

° Infrastructure development.

In addition to above, due to increase in purchasing power of local habitants:


Chapter-8 Project Benefits


• There shall be significant change in the socio-economic scenario of the area;

• The proposed project shall enhance the prospects of employment;

• Recruitment for the unskilled and semiskilled workers for the proposed project

will be from the nearby villages;

• The basic amenities viz., roads, transportation, electricity, proper sanitation,

educational institutions, medical facilities, entertainment, etc. will be

developed as far as possible; and

• Overall the proposed project will change living standards of the people and

improve the socio-economic conditions of the area.

8.3 Employment Potential

The impact of the project on the economic aspects can be clearly observed. The

proposed project activities will provide employment to persons of different skills

and trades. The local population will be given preference to employment. The

employment potential will ameliorate economic conditions of these families

directly and provide employment to many other families indirectly who are

involved in business and service oriented activities.

The employment of local people in primary and secondary sectors of project shall

upgrade the prosperity of the region. This in-turn will improve the socio-economic

conditions of the area.

• During construction phase of the project, this project will provide temporary

employment to many unskilled and semi-skilled laborers in nearby villages;

• This project will also help in generation of indirect employment to those

people who render their services for the personnel directly working in the

project; and

• In case the hydrocarbon is established in the block, considerable number of

people will be benefited by provision of services to the residents in for of

employment opportunities. Thus, the direct and indirect employment

generation by this project.

The present trend of out migration for employment is likely to reduce due to

better economic opportunities available in the area.

During the construction phase about 500-600 people on average per day will be

employed for a period of one year.

The ONGC Corporate EHS policy is given in Annexure-XII.


Chapter-9 Administrative Aspects


9.0 ADMINISTRATIVE ASPECTS 9.1 Operational Philosophy

The activities proposed for the proposed exploratory drilling programme shall be in complete compliance with all applicable Laws, Regulations, Standards and Permits, the Production Sharing Contract (PSC), procedures, specifications, rules, standards and guidelines. In order to achieve this, the drilling operations will be maintained by technically qualified and experienced people. Detailed procedures and plans will be developed for each activity prior to operations start up. All persons on board for the drilling rig will be experienced crew with valid qualifications. Besides compliance to regulatory framework, the primary operational objectives are that all operations shall be consistently operated in a manner that causes neither threat nor harm to people or the environment. The methods used to operate and maintain the assets shall not cause damage to either the installed facilities or the local infrastructure, whilst at the same time consistently providing a production availability level that meets the target demand. Operational requirements are primarily based on global best practice, lessons learned and experiences transferred from ongoing operations and provide the criteria for operation verification in both design and fabrication. Verification of design and fabrication will be a significant feature of the development to ensure operation requirements are appropriately incorporated; these should include but are not limited to: • Operating HSE performance will be duly considered and consistently

incorporated into design; • Maximum life-of-asset value will be sought through design selections that

optimally integrate capital and operating costs; and

• Operations staff will become highly competent and knowledgeable of the design and operations details in advance of start-up, in order to more safely and efficiently support commissioning and better prepare themselves for the initial and longer term operations.

The HSE Management System Process which will be developed for use as part of the implementation of the Operations Philosophy will be followed, together with the commitments. Continuous Improvement (CI) is a key consideration of the Philosophy and will be achieved by measures that will include bench-marking, use of key performance indicators, the application of structured competency assessment and competency improvement training programs for personnel involved in operations activities, the progressive introduction of Improvement Teams, as well as enhancement of the breadth, level and quality of local support through a Local Content Development Plan.




9.2 Health Safety and Environment 9.2.1 HSE Management System

The Group HSE Management System describes how ONGC manages health, safety, environment, security and corporate social responsibility risks within business activities, in order to meet the commitments in the Group HSE, Security and CSR policies. The aims and objectives of the Group HSE Management System are to: • Enable risk identification and management; • Provide clear definition of roles and responsibilities; • Stimulate high levels of ‘ownership’ throughout the organization; • Promote ‘empowerment’ and not discourage innovation; and • Identify mandatory control processes both at Group level and within the

operating subsidiaries. The goal being for ONGC to assure itself and other stakeholders that all operations are reflective of good industry HSE practice and is able to comply with Company Policy and legislation through a process of self regulation and control. The emphasis is placed on an approach which is: • Objective setting (establishing what to do and then doing it); • Proactive (taking action before and not after the event); and • Risk-based (measures taken are necessary and cost effective to reduce risk to

acceptable levels, at which the cost of further risk reduction is disproportionate to the benefit gained).

9.2.2 Key Elements of Safety Plan

An area plan will be devised by the HSE team in the region to make the system much more specific and appropriate for the asset and the types of activities being carried out. This will be communicated to all members of staff via training, inductions and regular safety meetings. All visitors to site will be inducted and told what part they play in maintaining safety whilst they are on site. The following topics are included in the HSE Management System: • Leadership & Commitment; • Policy & Strategic Objectives; • Organisation, Resources and Documentation; • HSE Risk Management; • Planning & Procedures; • Compliance & Regulations; • Emergency Preparedness; • Implementation & Monitoring; and • Auditing & Review.




9.2.3 Emergency Response Emergency response teams will be made up from operations personnel, who can be called upon 24 hours a day, supported by an Incident Management Centre (IMC) manned by operations senior management field personnel as and when required. There will also be a dedicated fire and emergency team out with the routine operations personnel. The fire and emergency response teams will receive specific training for their roles and will be drilled and exercised on a regular basis, as described in the Site Emergency Response Plan.

9.2.4 Safety Case

The details of how HSE will be managed on site are contained within the stand alone HSE plan that will be developed by the HSE team in conjunction with the operations team management. In summary the following key points are the core of the HSE philosophy. The Safety Report will be a document prepared by ONGC Ltd. and will provide information that will demonstrate that all measures necessary for the prevention and mitigation of major accidents have been taken.

The Safety Report will include: • A policy on how to prevent and mitigate major accidents; • A management system for implementing that policy; • An effective method for identifying any major accidents that may occur; • Measures (such as safe plant and safe operating procedures) to prevent and

mitigate major accidents; • Information on the safety precautions built into the plant and equipment when

it was designed and constructed; • Details of measures (such as fire-fighting, relief systems and filters) to limit

the consequences of any major accident that might occur; and • Information about the emergency plan for the site, which can also be used by

the local authority in drawing up an off-site emergency plan. Hazard management will identify hazard and consequences, assess and optimize risks and provide tools for managing each risk. There will be hazard reviews including Hazard and Environmental Identification (“HAZID” and “ENVID”), Project Safety Reviews (PSR’s), Hazard and Operability (“HAZOP”), PHSER (Project Health Safety Environmental Review) and other project safety and environmental processes during the project stages. All personnel working at sites will be expected to fully conform at all times to the appropriate ONGC requirements for PPE (Personal Protective Equipment) for the area in which they work Safety rules will be developed and adhered to by all employees and contractors whilst involved in ONGC Ltd. activities. Key areas such as Permit to Work (PTW), energy isolation and hazard identification / risk assessment shall be fundamental to the development of these rules. These rules shall also be in compliance with relevant laws, company policy and established international practices.




9.2.5 Health Systems, equipment and layout should be designed to ergonomic principles to help facilitate both operation and maintenance of the equipment. Health and Safety of all personnel will be a consideration in design to ensure that the risks to those personnel are minimised. This should include a human factor study of the design which will address issues such as exposure to noise, heat, cold, stress, lighting, control room design, control desk VDU layout, field accommodation and recreation facilities, transportation etc.

A pre-mobilisation, company approved minimum level of medical fitness including all applicable regional vaccinations will be required for all persons working at the drilling well site. This will apply to all company and contract employees and will continue throughout the life of the project and into the operations phase.

An approved exposure monitoring and health surveillance programme will be in place throughout the project phases.

9.2.6 Environment

The exploratory drilling operations will be strictly avoided in sensitive ecological locations within the block area. The EIA will provide guidance on what particular areas should be monitored; these will typically include flaring, chemical consumption, emissions to air, liquid discharges and waste disposal. Waste management will be designed into the facilities to allow and encourage safe and efficient waste reduction, recycling, segregation and disposal. The drilling operation will be designed to first minimise waste and then effectively deal with that waste which is generated. The detailed design needs to ensure waste disposal is consistent with local and or statutory regulations and requirements. Any implications on wildlife need to be understood and any impacts avoided or minimised.

9.3 Environmental Organisation and Personnel

To facilitate the implementation of the Environmental Management systems, one of the most important aspects related to are, the organization and personnel. ONGC is committed to extend the EMS to its proposed facilities in Kolasib town, Kolasib District, Mizoram. All individual departments will be accountable for the environment in and around them and individual departments take prompt action in dealing with environmental issues. The HSE dept is the nodal agency to coordinate and provide necessary services on environmental issues during construction and operation of the exploratory drilling project. The department consists of officers from various disciplines to co-ordinate the activities concerned with the management and implementation of the environmental control measures. Basically, this department will supervise the monitoring of environmental pollution levels viz. ambient air quality, water and effluent quality, noise level either departmentally or by appointing external agencies wherever necessary.




In case the monitored results of environmental pollution found to exceed the allowable limits, the Environmental Management Cell will suggest remedial action and get these suggestions implemented through the concerned authorities. The Environmental Management Cell will also co-ordinate all the related activities such as collection of statistics of health of workers and population of the region, afforestation and green belt development. A dedicated HSE set-up in the corporate level will oversee the environmental management and pollution control aspects and headed by Director (Business Services) and constituted by Deputy General Manager (Environment and CSR), Environmental Manager, Environmental Engineers and Social Scientists. The Organizational Structure of Environmental Management is presented in Figure-9.1. This environmental group is responsible for implementation of environmental management plan at asset level, interaction with the environmental regulatory agencies, reviewing draft policy and planning, etc. This department interacts with MoEF&CC, Central Pollution Control Board (CPCB) and other environment regulatory agencies. The department shall also interact with operational and local people to understand their problems and to formulate appropriate plans.




FIGURE-9.1 ORGANIZATIONAL STRUCTURE FOR ENVIRONMENTAL MANAGEMENT

Organizational Setup – Environment

I/C HSE, A & AA basin, Jorhat

I/C HR/ER - CSR

Basin manager, A & AA basin, Jorhat

Head Drilling

Services(HDS)

Field Environmental Engineer

Drilling HSE

Engineer

HSE Engineer


Chapter-10

Summary and Conclusions


10.0 SUMMARY AND CONCLUSIONS


exploratory drilling in on-shore Block AA-ONN-2001/2. The block is located in the

NELP Block area of Kolasib & Mamit District, Mizoram.




w.e.f 08.04.2013 by relinquishing an area of 1345sqkm as per PSC norms after







A’ of Activity Type 1(b).

10.1 Location Details of the Project

The block under study falls in district of Kolasib and Mamit, Mizoram. The Block

area lies between latitude 23°40‘00” & 24°19’30”and longitude 92°16’03.00” &

93°11’19.40“. The area has undulating terrain, dense jungles and is almost

devoid of approach roads. The three well coordinates are given below:

Sr. No.

Proposed Well Location

Latitude Longitude

1 HOAC 240 12’ 14.24” 920 35’ 53.32” 2 HOAD 240 09’ 41.42” 920 36’ 13.31” 3 BRBAA 240 07’ 10.08” 920 31’ 06.77”

10.2 Importance of the Proposed Project

India is not among the major producers of crude oil, as it doesn’t have much oil

reserves. Therefore, India generally depends on imports of crude oil from other

countries. There is a heavy imbalance between oil production and consumption in

India. The Indian government is encouraging exploration and production of oil

and gas to a great extent. This would primarily allow India to tap its own

resources there by reducing its import bill.


economic development to a great extent. The proposed exploration project is thus

of immense significance for the state.

10.3 Details of Exploration Drilling Operation

It is proposed to drill exploratory and appraisal wells in the delineated area

selected through seismic survey to identify and establish hydrocarbon potential.


Chapter-10



The site will be sized to contain all equipment and buildings, storage, workshops,

etc. using distances between various rig components in line with existing rules

and regulations for the area of operation and the approved standard operating

procedures of the drilling contractor. Within the above constraints, the site shall

be sized to minimize environmental impact. The approximate area of well site is

dependent on the type of drilling equipment deployed which in turn is dictated by

the planned depth of drilling.

10.3.1 Infrastructure Requirement

Land Requirement: Minimum land required at each well site during drilling will be

125 m x 125 m, i.e., 1.56 ha (2.5 ha will be acquired). On an average, the land

requirement at each well site, including site facilities and camp site is considered as

1.5-2.0 ha. The land will be acquired on a temporary basis and adequate

compensation as per the guidelines of local administration will be provided.

Power Requirement: The total power requirement at the drilling site will be 2250

KVA. The power requirement in the drilling site will be catered through Diesel

Generator (DG) sets. The power requirement will be met by 3 Nos of 750 KVA DG

sets at drilling site. Stand by DG set arrangement of 750 KVA at drilling site will be

made.

Water Requirement: Water is basically required for preparing drilling mud and for

meeting domestic needs of the campsite. Typically, the water consumption for each

well ranges from 25 m3/day for a short period of 4–5 months. However, the drilling

and domestic water requirement would depend on the time required to drill the

well, which is primarily dependent on the proposed depth.

Man Power: The drill site construction would be done largely employing local

labour. At each drill site construction, local employment will be generated for

about 25 person/shift of 12 hrs in two shifts.

10.4 Baseline Environmental Status

Environmental monitoring has been carried within the entire AA-ONN-2001/2

block, during partly winter and partly pre-monsoon season of the year 2016.

10.4.1 Land Use Studies

The land use pattern of the total AA-ONN-2001/2 block has been studied by

District Census Hand Books and satellite images. It is observed that 4.6 % of the

land falls under crop land. On the other hand, 80.1 % of land falls under

wastelands area. The water bodies contribute about 10.4 % area falls under

Reservoir/River etc.

10.4.2 Soil Quality

The soil samples were tested at 10 locations during winter season covering

various land uses. It has been observed that the pH of the soil ranged from 7.11

– 8.08 indicating that is slightly alkaline to moderately alkaline in nature. The

electrical conductivity was recorded as 118.2 µS/cm to 262.0 µS/cm. The organic


Chapter-10



carbon content in the study area observed as 0.53 % to 1.02 %, which the soil

falls under average sufficient to more than sufficient. The potassium values

ranged between 86.6 to 172.0 kg/ha. The phosphorus values ranged between

13.5 to 88.6 kg/ha. The nitrogen values ranged between 31.5 – 69.7 kg/ha.

10.4.3 Meteorology

On-site monitoring was undertaken for various meteorological variables in order

to generate the site-specific data. The data generated is then compared with the

meteorological data generated by nearest India Meteorological Department (IMD)

stations located at Agartala. The meteorological data generated at the monitoring

site when compared with the data recorded at nearest IMD station, it is observed

that the data generated at the site is broadly in comparison with regional

meteorology, except for minor variations.

10.4.4 Ambient Air Quality

To establish the baseline status of the ambient air quality in the study area, the

air quality was monitored at 10 locations during partly winter and partly pre-

monsoon season of 2016. Out of the ten locations the minimum and maximum

concentration for PM10 were varied between 37.7 to 46.0 µg/m which are well

within the NAAQ standard i.e 100 µg/m3. The minimum and maximum

concentration PM2.5 were varied between 11.6 to 15.8 µg/m3 respectively during

the study period which are well within the NAAQ standard i.e 60 µg/m3.

The concentrations of SO2 were varied between 7.9 to 15.0 µg/m 3 which are well

within the NAAQ standard i.e 80 µg/m3.The concentrations of NOx were varied

between 11.0 to 17.3 µg/m3 respectively which are well within the NAAQ standard

i.e 80 µg/m3.The minimum and maximum concentration for CO during the study

period was observed as 100 to 239 µg/m3 which are well within the NAAQ standard

i.e 2000 µg/m3.The minimum and maximum concentration for total hydrocarbons,

methane hydrocarbons and non-methane hydrocarbons during the study period

were observed as 101 to 166 µg/m3, 50 to 95 µg/m3 and 40 to 96 µg/m3

respectively.

The concentrations of VOCs were below the detectable limits in all the locations

during the study period. From the analysis of the monitored data, it infers that the

air quality levels in the study area are of fairly good quality and comply with the

National Ambient Air Quality Standards.

10.4.5 Water Quality

The baseline water quality status in the region is established by analyzing about 6

ground water samples and 4 surface water samples during study period.

The physico-chemical and biological analysis revealed that most of the parameters

in ground water samples are well within the permissible limits when there is no

alternative choice as per IS: 10500. The physico-chemical and biological analysis

revealed that all the parameters in surface water samples are well within the

prescribed limits of IS: 10500 limits.


Chapter-10



10.4.6 Ambient Noise Levels

The noise monitoring has been conducted at 10 locations, covering residential,

commercial and silence zones in the study area. A review of this data indicates that

at all the locations, the noise level was found within the permissible limits of CPCB.

10.4.7 Ecological Environment

An ecological survey in the study area was conducted particularly with reference to

the listing of species and assessment of the existing baseline ecological (Terrestrial

and Aquatic ecosystem) conditions in the study area. There are no reserved forest

and national park present inside the block area.

Dampa Tiger Reserve – Wildlife Sanctuary is located, near the block of BRBAA at

about distance of 59.5 Km/SSW direction, covering a large part of Mamit district,

in which block study area is covered, is endowed with wide variety of flora and

fauna in the area.

10.4.8 Socio-Economic Environment

The configuration of male and female indicates that the males constitute about


records. The study area on an average has 1006 females per 1000 males.


Scheduled Castes (SC) and 91.54% to Scheduled Tribes (ST).




area as per 2011 census records. Total work participation in the project study

areas is 41.78% and the non-workers constitute 58.22% of the total population

respectively.

10.5 Impact Assessment

The identification and assessment of impacts over the various environmental

attributes in the region due to the proposed exploratory drilling activities in the

proposed AA-ONN-2001/2 block are discussed and mitigative measures and

environmental management plan for the potential impacts have also been

presented.

The duration of construction works including site excavation, preparation and well

pad construction is expected to last approximately 4-5 months for each well site.

10.5.1 Impact on Topography and Land Use

Drilling exploratory well is a short duration activity at each drilling location,

typically encompassing a period of 4 to 5 months from land acquisition to site

abandonment. The impact would therefore be localised, temporary and minimal.

Because of the above activities, the topographical structure may change locally.


Chapter-10



However, considering the small foot print area required during the drilling, only

marginal impact due to change in land use is anticipated.

10.5.2 Impact on Climate

Impact on the climatic conditions from the drilling will not be significant. The

maximum temperatures of the exit gas from the DG stack and flare stack will be

around 300°C and 400°C respectively. In terms of total emission of green house

gases and consequent impact on global warming or on potential for local increase

of ambient temperature, considering the quantum of exit gas and the total

duration of flow, the impact on the local or global climate will be insignificant.


The potential sources of air emissions at the well sites will be as follows:

• Dust from earth works (during approach road and site preparation);

• Emissions from DG sets (including noise emission);

• Emissions from possible flaring during well testing; and

• Emissions from vehicles

During the short period of site preparation mechanical shovels and earthmovers

will be used for vegetation clearance, cut and fill and other site leveling activities.

These activities could generate dust particles which will be mobilized by wind, and

deteriorate the ambient air conditions. However, these activities will be only

temporary and the impact to ambient air quality would be within the close

proximity of well site.

The gaseous emissions from the DG set will be controlled by efficient combustion

of fuel in the DG set. The flaring of oil and gas during well testing is a short

duration activity (about 14 - 21 days) and will be done within a ground level

enclosed pit. Wherever, required special precautions will be taken to minimize the

impact on the local environment and habitat.


Approximately 15-20 m3/day of wastewater and 4 m3/day of sewage would be

generated from each well site. Water based non-toxic biodegradable fluids with

inhibitive and encapsulative characteristics are proposed to be used as drilling

mud for minimizing any long term impact on groundwater quality. Additionally,

the drilling mud collection and recirculation pond is lined with impervious layer to

prevent seepage and loss of drilling fluid into the subsoil. Further, proper casing

installation and cementing of well will ensure least groundwater contact. The

clarified wastewater will be treated in packaged treatment plant located at the

well sites to meet norms specified by CPCB and MPCB. The sewage will be

discharged into septic tanks and then to subsoil through soak pits.


During the drilling operation at the well sites, there would be various sources of

noise in the area, viz., drilling draw works/rotors, Mud Pumps, Power generators,

Vehicular Movement and Cranes and material handling equipment.


Chapter-10



The maximum predicted noise level at about 100 m from the boundary of the drill

site is about 52.0 dB (A). The ambient noise levels at most of the places in the

region are within the CPCB standards. Since, the drilling operations last for only 3

to 4 months at each location, impact of the noise pollution due to the proposed

exploratory drilling will be insignificant on the community.


Impact on the ecology of the study area will vary with the proximity of the

habitats from the drilling locations. However, the impacts are of temporary

nature, which will last only for few months at each drill location during the

exploratory drilling activities and will thus allow subsequent recovery after the

activities stops.

10.5.7 Demography and Socio-Economics

Although the level of existing communications and support services in the area

are considered adequate based on the population density, establishment of the

proposed project would further strengthen the road network and access to some

of the remote areas with all weather roads would be a distinct beneficial impact.

The overall impact is considered to be positive.

Impact on health due to emissions and noise from drilling activity has been

assessed to be minimal. In addition employees working at the drill site would be

provided protective devices like ear plugs/ear muffs for ensuring minimum impact

on human health.

For most potential drilling sites in the Exploration Area, it should be possible to

avoid impact on existing arable land. By following the compensation procedures

and by observing common courtesy, impacts on existing use and benefit rights

holders can be minimized.

The proposed exploration drilling programme is expected to generate local

employment in the order of about 25/shift 12 hrs. Unskilled and semi-skilled

people, for a period of approximately 3 to 4 months at each drilling site location.

While this benefit is small by most standards, it is a significant employment

opportunity in the block.


10.6.1 Removal of Equipment and Materials

In the event if economic quantities of hydrocarbons are found, the well will be

suspended with a wellhead in place, but all other equipment and materials will be

removed from the site.



associated equipment will be removed. The access road(s) would be reinstated.


Chapter-10




In the event that no economic quantities of hydrocarbons are found, a full

abandonment plan will be implemented for the drilling sites in accordance with

the applicable Indian petroleum regulations.


The combustion of diesel for power generation for the drilling and campsite

operation results in atmospheric emissions of SO2, NOx, CO, Particulates and

Hydrocarbons. Flaring during production testing is of 14-21 days duration and

atmospheric emissions are marginal.

There will be no sensitive receptors to the emissions of combustion products in

the vicinity of the proposed drilling operations apart from the crew of the drilling

rig. The impacts caused are therefore, considered to be negligible. Measures to

ensure minimal impacts include appropriate management of power generation

source to achieve fuel efficiency and therefore reduce emissions and use of low

sulphur diesel oil if available. Environmental monitoring is proposed during drilling

and well testing to ensure maximum combustion efficiency. Flaring towards any

standing vegetation will be avoided. In case if it is inevitable, a suitable barrier

will be erected to prevent any vegetation scorching due to direct heat radiation;

and prior to flaring, the critical equipment will be thoroughly tested.


The modeling results show that the noise levels will attenuate to below

permissible levels within the drilling site boundary. The Generators will be

properly enclosed and the exhausts will be provided with silencers.


The major waste product of a drilling operation is the generation of rock cuttings

with residual mud adhering to the drill cuttings and spent drilling fluid. About 250-

300 m3 of drill cuttings per well and 15 m3 spent drilling fluid would need to be

disposed off.

ONGC proposes to use internationally followed methodologies while drilling either

with Water Based Muds (WBM). The volume of drilling fluids used will be

optimizing at the design stage by selecting modern drilling engineering

technology.

The mud will be reused after its separation from the cuttings. A mud mixing tank

will be set up at the drilling site with a collection system so that any spill of

chemicals will be collected.

The platform all around the tank on the pedestrial shall be of metal gratings to

facilitate walkway as well as to permit the fluid to pass through so that it can be

collected in the collection for further reuse / disposal.

The spilled oil may be reused in the mud preparation. At the extent possible reuse

the residual drilling fluids in the drilling campaign only the drilling fluid which is

not further used can be discarded.


Chapter-10




Small amounts of solid wastes will be generated during normal operation at the

drilling rig. The wastes will be disposed on compliance with local and national

legislations. Spent waste oil to be stored in a secure paved area and disposed to

MoEF/ MPCB approved waste oil recyclers. Drill cuttings and sludge from drilling

mud to be buried within the impervious lined pit and covered with soil as part of

the site abandonment plan. Biodegradable waste arising from kitchen and

canteen activities to be scientifically composted and the bio-manure so generated

to be used for green belt development.

10.6.7 Management of Waste Disposal sites within Drill Site

The project proponent will dispose the drill cuttings, drill mud and wastewater

generated during the drilling operations into the lined pits of various sizes and

undertaking plantation within the drill site particularly on the reclaimed pits.

10.7 Environmental Monitoring Program

A detailed post project monitoring in respect of air, water, soil, landuse,

occupational noise, etc. to assess the changes has been evolved covering various

phases of project advancement. A network of sampling locations around the

operational facilities will be established. The monitoring shall include the

compliances to legal and statutory controls imposed on the operation as well as

other corporate commitment to responsible environment management. Systems

for monitoring resources inputs (energy, chemical use, water, raw materials),

equipment and plant performance and waste generations will also be set up. A

detailed wastes management plan with monitoring programme will be in place

during various phases of activity.

10.8 Risk Assessment and Disaster Management Plan

The hazard potential of oil and gas and estimation of consequences in case of

their accidental release during drilling has been identified and risk assessment

has been carried out to quantify the extent of damage and suggest

recommendations for safety improvement for the proposed facilities. Risk

mitigation measures based on MCA analysis and engineering judgments are

incorporated in order to improve overall system safety and mitigate the effects of

major accidents.

An effective Disaster Management Plan (DMP) to mitigate the risks involved has

been prepared. This plan defines the responsibilities and resources available to

respond to the different types of emergencies envisaged. Training exercises will

be held to ensure that all personnel are familiar with their responsibilities and

that communication links are functioning effectively.

10.9 Project Benefits




Chapter-10







The commercial development will also lead to investment in Mizoram, bringing oil


of ONGC in the region will substantially improves the socio-economic conditions of

the region.

In Operation phase ONGC require significant work force of non-technical and

technical persons. Migration of persons with better education and professional

experience will result in increase of population and literacy in the surrounding

villages.

10.10 Administrative Aspects

The basis of the operational philosophy is that the activities proposed in oil and

gas processing shall be operated in complete compliance with all applicable Laws,

Regulations, Standards and Permits, the Production Sharing Contract (PSC),

ONGC corporate policies, procedures, specifications, rules, standards and

guidelines. In order to achieve this, the proposed drilling sites will be maintained

by technically qualified and experienced people. Detailed procedures and plans

will be developed for each activity prior to operations start up. All persons on

board the drilling rig will be an experienced crew with valid qualifications.

ONGC has a well defined Organization for Environment Management System.

ONGC is committed to extend the EMS to its proposed facilities in Mizoram. The

Director (Operations) of the project oversees the total environmental activity on a

day-to-day basis. All individual departments are accountable for the environment

in and around them and individual departments take prompt action in dealing

with environmental issues. The HSE dept is the nodal agency to coordinate and

provide necessary services on environmental issues during construction and

operation of the project.

10.11 Conclusions

The proposed exploratory drilling project has certain level of marginal impacts on

the local environment. However, the proposed project has significant beneficial

impact/effects in terms of providing the employment opportunities and various

CSR practices to be followed by ONGC. Growth and development, in harmony

with the environment, has always been the approach of ONGC.

The conclusions of EIA are:

• The proposed project meets the compliance requirements of various

environmental regulations;

• Adoption of environmental friendly Best Management Practices results in

minimising the impacts on environment;


Chapter-10



• Community impacts of the project will be beneficial, as the project will

generate significant economic benefits for the region;

• The post drilling, commercial developmental activities of ONGC can reduce the

import burdens of crude oil to the nation; and

• With the effective implementation of the Environment Management Plan

(EMP) during the planning, design, construction and operation phases, the

development and production project can proceed without significant negative

impact on the environment.


Chapter-11 Disclosure of Consultants


11.0 DISCLOSURE OF CONSULTANTS

11.1 Introduction

The Environmental Impact Assessment (EIA) and Environment Management Plan

(EMP) report has been prepared by carrying out various scientific studies. Studies

have been carried out by engaging scientists/engineers/experts of Vimta Labs

Limited, India and its associates.

11.2 Vimta Labs Limited - Environment Consultant

Vimta Labs Limited is a leading multi-disciplinary testing and research

laboratory in India. VIMTA provides contract research and testing services in the

areas of environmental assessment, analytical testing, clinical research, pre-

clinical (animal) studies, clinical reference lab services, advanced molecular

biology services and research & development studies.

The Environment Division has been in the forefront of its vision to provide

better environment through guiding and assisting the industry for sustainable

development. A stalwart in the mission to protect and preserve the natural

resources on earth for future generations, it offers extensive research and

consultancy services in the field of environment. With its rich experience, multi-

disciplinary expertise and with the support of its state-of the-art analytical

equipment, the services offered by the division are wide ranging and

encompasses entire gamut of environment management and monitoring services.

With its emphasis on quality services over the years, it has evolved itself into a

single reference point in India for comprehensive environmental services.

11.2.1 The Quality Policy

• VIMTA is committed to good professional practices and quality of operations in

its testing, validation and research services;

• VIMTA shall ensure customer satisfaction by maintaining independence,

impartiality and integrity in its operations;

• VIMTA shall provide the services in accordance with national and international

norms;

• VIMTA shall implement quality systems as per ISO/IEC 17025 and applicable

Good Laboratory Practices (GLPs) & Good Clinical Practices (GCPs), to

generate technically valid results/data; and

• VIMTA shall ensure that all its personnel familiarize with the policies and

procedures of the quality system and implement the same in their work.

11.2.2 Major Milestones and Accreditations

• 1984 - Registered with an initial investment of Rs.200,000=00

• 1985 - Recognized by ISI (now known as Bureau of Indian Standards)




• 1987 - Qualified by the criteria of Ministry of Environment and Forests, India

and was notified as one of the first 14 Standard Environmental Laboratories

published in the Gazette of India

• 1988 - Licensed for carrying out tests on Drugs and Pharmaceuticals

• 1991 - Accredited by NCTCF, DST, Government of India (the forerunner of

NABL)

• 1995 - Accredited by NABL, India under its revised scheme, certified by

Standards Australia, Quality Assurance Services as per ISO/IEC Guide 25 and

ISO 9002

• 1996 - GLP Compliance

• 1998 - Accreditation by GOSSTANDART and joint venture for certification of

Food Exports with ROSTEST, Russia

• 1998 - World Bank Recognition

• 2002 - ANVISA Brazil Certification

• 2003 - USFDA accepts Vimta Bioequivalence study report. Showcased Vimta

at AAPS (USA) and ICSE-CPHI (Germany)

• 2003 – Recognized by Saudi Arabian Standards Organization

• 2004- Enters Gulf market - Executes a contract for environmental consultancy

in Kuwait

• 2006 –Expands its overseas activities. Undertakes environmental assignment

in Saudi Arabia

• 2006 – Undertakes environmental impact assignment in Tanzania, Africa

• 2008 – Has been Pre-Qualified by World Health Organization (WHO)

• 2009 – Undertaken environment impact Assignment in Cameroon, Africa.

11.2.3 Services Offered

Spread over 70,000 sq.ft lush green garden premises at Cherlapally, Hyderabad

(India), the scientifically designed and meticulously groomed infrastructural

facility of the Central Laboratory of VIMTA has the most sophisticated

instruments backed by an excellent team of professionals.

Over 150,000 sq. ft. of world class research laboratory is also under operation at

Biotech Park-Genome Valley, Hyderabad (India). Having all the facilities under

one roof is perhaps the only one of its kind in South Asia in the contract testing

and research sector.




VIMTA Central Laboratory, Cherlapally, Hyderabad VIMTA Life Sciences, Genome Valley, Hyderabad

Vimta offers services under the following specializations:

• Environment;

• Analytical;

• Clinical Reference Lab;

• Clinical Research;

• Preclinical;

• Molecular Biology; and

• Research and Development.

The environment division of VIMTA Labs Limited (VLL) has its presence all over

India and other countries including a strong association with international

consultants like Japan Bank for International Cooperation (JBIC), Kennametal Inc.

- USA, Rudal Blanchard – UK, E&E Solutions – Japan, NAPESCO & Kuwait National

Petroleum Corporation – Kuwait, Marafiq and Haif Consultants – Saudi Arabia and

others. Vimta Labs Limited has the following credentials:

• Recognition by BIS, India;

• Recognition by Ministry of Environment and Forests, Govt. of India and

various State Pollution Control Boards (wherever applicable);

• Recognition by Department of Science & Technology, Govt. of India (NABL);

• Recognition by Ministry of Defence, Govt. of India;

• Recognition by APEDA, Ministry of Commerce, Govt. of India;

• Recognition by Saudi Arabia Standard Organization (SASO), Saudi Arabia;

• Recognition from NEMC, Tanzania;

• Accreditation by NCTCF;

• Certification from Standard Australia;

• Recognition from ANVISA Brazil;

• Recognition from USFDA;

• Quality Assurance Services as per ISO/IEC 17025;

• Quality Assurance Services as per ICH Guidelines; and

• Recognition by World Health Organization (WHO).




11.2.4 Services of Environment Division

Environment essentially being a multi-disciplinary science, the range of services

offered by the division are also comprehensive and caters to the needs of

industry, pollution control agencies, regulatory authorities and in a larger pursuit

of a green globe. The services under environment include:

• Site selection and liability studies;

• Environmental impact assessments;

• Environment management plans;

• Carrying capacity based regional studies;

• Environmental audits;

• Solid and hazardous waste management;

• Risk assessment (MCA,HAZON,HAZOP) & disaster management plans;

• Occupational health and safety, industrial hygiene;

• Environmental monitoring for air, meteorology, water, soil, noise, ecology and

socio-economics;

• Industrial emission source monitoring;

• Offshore sampling and analysis of marine water and sediments;

• Marine ecological studies;

• Marine impact assessment;

• Rehabilitation and resettlement studies;

• Forestry and ecological studies;

• Geological and hydro-geological studies;

• Land use /land cover studies based on remote sensing;

• Socio-economic studies;

• Due diligence studies;

• Industrial epidemiological studies;

• Wasteland management studies; and

• Study on bio-indicators.

The services under Environmental Chemistry include:

� Analysis of water, wastewater, soil, solid waste, hazardous waste as per

international codes;

� Source emissions and work zone air/noise quality monitoring;

� Analysis of SVOCs, VOCs, PAH, BTEX, AOX, PCB’s, TCLP metals, TOC etc.;

� Categorization of hazardous waste; and

� Pesticide residue analysis.

11.2.5 Facilities of Environment Division

Vimta-Environment Division is located in scientifically designed Central Laboratory

with the state-of the-art modern facilities to offer vide range of services in indoor

and outdoor monitoring and analytical characterization in the field of

Environment. Further, it is ably supported by highly skilled and experienced team

of professionals in the fields of science, engineering, ecology, meteorology, social

planning, geology & hydro-geology and environmental planning.




Besides the regular monitoring equipment such as PM10 & PM2.5 Samplers,

automatic weather monitoring stations, stack monitoring kits, personal samplers,

noise meters, portable water kits etc, the other major specialized equipment

include:

• Monostatic Sodar–Designed by National Physical Laboratory, GOI;

• Integrated Noise Level Meters–Quest, U.S.A;

• Flue Gas Analyzers–Testo, Germany;

• 113-A Gravimetric Dust Sampler-Casella, London;

• ICP AES– Varian, USA;

• Gas Liquid Chromatographs with FID, ECD & pFPD–Varian, USA;

• Gas Chromatograph with Mass Detector–Varian, USA;

• Atomic Absorption Spectrometer [AAS]–Varian, USA;

• PAS-AFC-123 instrument;

• High Performance Liquid Chromatograph (HPLC);

• Laser Particle Size Analyzer;

• Bomb Calorimeter;

• Polarographs;

• X-ray Fluorescent Spectrometer;

• Flame Photometer;

• Carbon Sulphur Analyzer;

• Computerized Fatigue Testing Machine;

• Electronic Universal Testing Machine;

• Fourier Transmission Infrared Spectroscope; and

• Water Flow Current Meter – make Lawrence & Mayo.

HIGH RESOLUTION GAS CHROMATOGRAPHS




11.2.6 Quality Systems

The basic fact that environment division and its supporting site laboratories are

accredited by NABL (IS0-17025) and Ministry of Environment and Forests, India

and by other international bodies stand testimony to its emphasis on Quality

Systems.

The detail of the persons involved in the preparation of present EIA/EMP report is

presented below:




DETAILS OF PERSONNEL INVOLVED IN CURRENT EIA/EMP STUDY – VIMTA LABS LTD

Sr. No. Name Qualification Position Contribution Expertise/Functional

Area Experience

1 Mr. M. Janardhan M.Tech (Env. Engg)

Vice President & Head (Env)

Co-ordination EIA Co-ordinator and FAE for AP, AQ, NV &

SHW

About 24 years of experience in the field of Environmental Management and Environmental Engineering

2 Dr. B. Chandra Sekhar M.Sc., Ph.D Sr. Manager Co-ordination EIA Co-ordinator About 15 years of experience in the field of Environmental Management and Modeling

3 Mr. G. V. Raghava Rao M.Tech (Env) Manager Expert FAE-AP, ISW & MSW About 12 years of experience in the field of Environmental Management and Environmental Engineering

4 Ms. Durga Bhavani M. Sc (Env Science), M.Tech

Group Leader Expert FAE – WP, AQ, Team Member SHW

About 11 years of experience in the field of Environmental Management and Environmental Chemistry

5 Mr. S. Kishore Kumar M.Tech (Env) Group Leader Expert FAE – AP, NV About 5 years of experience in the field of Environment Management and Engineering

6 Mr. M. Raja Manohar M.Tech (Env ) Env Engineer Expert Team Member About 5 years of experience in the field of Environment Management and Engineering

7 Mr. Rajashekar T M.Sc., Ph.D Sr. Scientist Expert FAE-EB About 10 years of experience in the field of Terrestrial and Aquatic Ecology

8 Mr. S. Srinivas Goud M.S.W Group Leader Expert FAE-SE About 12 years of experience in the field of social Impact Assessment Studies

9 Mr. Ramakrishna Pullipaka

M.Tech Env Engineer Expert Team Member About 4 years of experience in the field of Environment Management and Engineering

10 Mr. M. Praveen Kumar M.E Env Engineer Expert Team Member About 2 year experience in the field of Environment Management and Engineering

11 Mr. J. Sunil Kumar M.Tech Env Engineer Expert Team Member About 2 year experience in the field of Environment Management and Engineering

12 Mr. Sanjay Chavan M.Sc (Env) Env Scientist Expert Team Member About 3 years of experience in the field of Environmental monitoring and management

13 Mr. K.S.Vishnu Teja M.Tech Env. Engineer Expert Team Member About 3 year experience in the field of Environment Management and Engineering

14 Mr. Ch. Narendra M.S.W Scientist Expert AFAE-SE About 3 years of experience in the field of Social Impact Assessment Studies

15 Mr. Rajeshwar MSc. Geology & Hydrogeology

Scientist Trainee Team Member

Team Member-HG About 5 years of experience in the field of geology and Hydrogeology




Sr. No. Name Qualification Position Contribution Expertise/Functional Area

Experience

16 Mr. P. Niranjan Babu B.Com Dy. Manager Secretarial Support

-- About 25 years of experience in the field of environmental monitoring and secretarial support

17 Mr. P. Krishna I.T.I (Civil) Jr.Engineer Cartography -- About 15 years of experience in the field of environmental management and civil drawings

18 Mr. J. Rama Krishna I.T.I (Civil) Jr.Engineer Cartography -- About 14 years of experience in the field of environmental management and civil drawings

Empanelled Experts

1 Dr. Y. Rama Mohan Rao M.Sc. Consultant Expert FAE-HG, LU/LC About 15 years of experience in the field of Land use studies, Remote Sensing and Hydrogeology

2 Mr. Rajgopal Krishnan M. Tech (Chemical Engg)

Consultant Expert FAE for RH About 40 years of experience in the field of Risk and Hazard assessment

3 Mr. Balakrishna Shankarrao Lole

M.Sc. (Ag) Consultant Expert FAE for SE About 38 years of experience in the field of Soil Conservation

FINAL EIA REPORT - Welcome to...

Documents

Transcript of FINAL EIA REPORT - Welcome to...