Environmental Impact Assessment Report · The methodology used complies with section 35 of the...

Environmental Impact Assessment Report For

(Proposed Karimenu Water Scheme)

WATER AND SANITATION SERVICES IMPROVEMENT PROJECT

(WaSSIP)

February 2009

Environmental Impact Assessment Report for Karimenu Water Scheme 1

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Environmental Impact Assessment Report for Karimenu Water Scheme

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CHAPTER 1: INTRODUCTION CHAPTER 1: INTRODUCTION............................................................................2

1.1 GENERAL......................................................................................................5 1.2 PROJECT BACKGROUND ..........................................................................7 1.3 PROJECT JUSTIFICATION .........................................................................8 1.4. STUDY OBJECTIVES..................................................................................9 1.5 ASSESSMENT SCOPE AND TERMS OF REFERENCE ...........................9 1.6 METHODOLOGY .......................................................................................10 1.7 METHODOLOGY STAGES .......................................................................11

Pre-Assessment activities: .............................................................................11 EIA activities: ................................................................................................11 Post-Assessment activities:............................................................................11

CHAPTER 2: PROJECT DESCRIPTION ...........................................................12 2.1 GEOGRAPHICAL LOCATION..................................................................12 2.2 CURRENT STATUS....................................................................................12 2.3 MAIN FACILITY COMPONENT...............................................................13 2.4 IMPLEMENTATION SCHEDULE.............................................................13 2.5 PROJECT COST ..........................................................................................14

CHAPTER 3: BASELINE INFORMATION........................................................15 3.1 TOPOGRAPHY AND PHYSIOLOGY .......................................................15 3.2 DRAINAGE AND HYDROLOGY..............................................................15 3.3 BIODIVERSITY ..........................................................................................15

Vegetation and Animal species......................................................................15 3.4 CLIMATIC CONDITIONS..........................................................................15

Rainfall...........................................................................................................15 Temperatures..................................................................................................16 Humidity and Evaporation.............................................................................16

3.5 GEOLOGY AND SOILS .............................................................................16 3.6 WATER RESOURCES ................................................................................16

Surface Water.................................................................................................16 Ground Water.................................................................................................16

3.7 WATER QUALITY ASPECTS ...................................................................16 Sewage / and other effluents ..........................................................................16 Solid wastes ...................................................................................................17

3.8 SOCIAL SETTING ......................................................................................17 Population and Settlement Patterns ...............................................................17

CHAPTER 4: ENVIRONMENTAL POLICY AND LEGAL FRAMEWORK ...18 4.1 NATIONAL ENVIRONMENTAL ACTION PLAN...................................18 4.2 POLICY PAPER ON ENVIRONMENT AND SUSTAINABLE DEVELOPMENT.............................................................................................................................18 4.3 THE ENVIRONMENT MANAGEMENT AND COORDINATION ACT (EMCA).............................................................................................................................19 4.4 THE WATER ACT 2002. ............................................................................20

Section 18.......................................................................................................20 4.5 WATER RESOURCES MANAGEMENT RULES 2007............................21 4.6 PUBLIC HEALTH ACT. .............................................................................21

Under Section 126..........................................................................................22


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Section 136; ...................................................................................................22 4.8 THE PHYSICAL PLANNING ACT, CAP 286...........................................23 4.9 LAND PLANNING ACT (CAP 303). .........................................................23 4.9.1 AGRICULTURE ACT (CAP 318)............................................................24 4.9.2 THE LAND ACQUISITION ACT CAP 295. ...........................................24

CHAPTER 5: ENVIRONMENTAL IMPACT ASSESSMENT.........................25 5.1 ENVIRONMENTAL AND SOCIO ECONOMIC IMPACTS ....................25

5.2.1 Positive Effects .....................................................................................25 5.2.2 Negative Impacts ..................................................................................26

CHAPTER 6: ENVIRONMENTAL MGT & MONITORING PLAN 6.1 CONSTRUCTION PHASE: ENVIRONMENTAL MGT PLAN................29

CONSTRUCTION ENVIRONMENTAL MANAGEMENT PLAN............31 6.2 OPERATION PHASE: ENVIRONMENTAL MANAGEMENT PLAN ....37

EMP DURING OPERATION .......................................................................38 6.2 DECOMMISSIONING PHASE: ENVIRONMENTAL MANAGEMENT PLAN............................................................................................................................42

EMP DURING DECOMMISSIONING OF THE PLANT...........................43 6.4 MONITORING AND ENVIRONMENTAL AUDITING...........................45

CHAPTER 8: CONCLUSION AND RECOMMENDATION .............................47 PHOTOGRAPHS ..................................................................................................48 LIST OF REFERENCES.......................................................................................53


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ANNEXES

Annex I Water Test Analysis Report Annex II Project Map Location Annex III Public Participation document Annex IV Responses to World Bank Environment specialist Annex V Responses to NEMA comments LIST OF TABLES Table 1 Water Service provider under AWSB Table 2 Access to water by Districts under AWSB Table 3 Diagrammatic Representation of the project


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1.1 GENERAL

The Government of Kenya (GOK), through the Water Act (2002) aims at providing

harmonized and streamlined management of water resources, water supply and sewerage

services through institutional reform. With support of IDA the reforms have been

accelerated in Nairobi and the adjacent four districts of Kiambu East, Kiambu West, Thika

and Gatundu which resulted to strong governance and an institutional and service delivery

framework that has enabled fairly efficient and sustainable delivery of water and sewerage

services to the population. The GOK recognize the need to strengthen the gains achieved

through the reform initiatives by increasing investments in the water supply and sewerage

sector in order to remove the bottlenecks to achieving poverty reduction and economic

growth objectives as stipulated in Vision 2030.

Increasing access to sustainable and affordable water services is a priority of the

Government within the overall policy framework of the Economic Recovery Strategy for

Wealth and Employment Creation. In order to address the problems associated with access

and provision of water services, the Government has embarked on reforms in the water

sector under the framework of the Water Act 2002.

The Act aims at providing for a harmonized and streamlined management of water

resources and water supply. Athi water Services Board (AWSB) and the Ministry of Water

and Irrigation (MWI) are spearheading the implementation process.

These reforms were mainly occasioned by the inability of the existing arrangements for

provision of water services to deliver and maintain basic water supply infrastructure for the

growing population and the need to have structured coordination of the various actors

involved in the water sector.

The institutional framework set out in the Water Act 2002 aims at ensuring that policy

formulation, regulation and service delivery roles are clearly delineated, with each role

being carried out by a separate entity. The Ministry of Water and Irrigation (MWI) will no

longer be involved directly in management of water services. It will mainly undertake

policy formulation, sector strategy development, Research and training, sector


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coordination, planning and financing.

The Water Services Regulatory Board (WSRB) is responsible for the regulation of water

and sewerage services including development and maintenance of quality standards and

issuance of licenses for service provision. Water Services Boards (WSBs) have the legal

responsibility for provision of water and sewerage services within their prescribed areas of

jurisdiction under license from WSRB.

Their responsibilities include holding or leasing and developing water assets, contracting

Water Service Providers (WSPs) who shall be their main agents in provision of water

services, and preparing plans for improvement of services including expanding service

coverage and reviewing tariffs.

WSPs are the entities through which the WSBs will provide water and sewerage services

under appropriate agreements entered into between them with approval of the WSRB. The

WSPs may be community groups, NGOs, private companies including those set up by local

authorities for the specific purpose of operating water services.

Water Services Board formed out of these reforms are Athi, Tana, Tana-Athi, Coast,

Northern, Lake Victoria North, Lake Victoria South and Rift Valley Water Services

Boards.


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TABLE 1: WATER SERVICE PROVIDERS UNDER AWSB

Water Company Name Address (P.O. Box)

Town

1 Kiambu Water & Sewerage Company Ltd 176 Kiambu 2 Gatundu South Water & Sanitation Company

Ltd 140 Gatundu

3 Karimenu Community Water & Sanitation Company Ltd

170 Gatukuyu

4 Gatanga Community Water Project 6133 Thika 5 Limuru Water & Sewerage Company Ltd 1286 Limuru 6 Kikuyu Water Company Limited 313 Kikuyu 7 Ruiru Juja Water & Sewerage Company Ltd 1165 -00232 Ruiru 8 Nairobi City Water & Sewerage Company Ltd 30656 - 00100 Nairobi 9 Kitisuru Water Company Ltd 30029 - 00100 Nairobi 10 Runda Water & Sewerage Company Ltd

505 00621 Nairobi

11 Githunguri Water and Sanitation Company Ltd 823 – 00216 Githunguri.

* (Source AWSB Rapid Result Study of 2005)*

1.2 PROJECT BACKGROUND

Karimenu water scheme is only a raw water distribution main constructed in the early

seventies.

During construction there was no habitation upstream of the intake works and therefore

there was no need of the full treatment. However, with time people have continued to

cultivate upstream of the said intake causing pollution through chemicals and eroded soils.

Population served by the project was then small as compared to the present. Population

increase resulted in demand exceeding supply. People sought alternatives sources

elsewhere including Nairobi Water Company mainline, to date, there are eighteen off-takes

serving about 3000 people from the Nairobi mainline.

With the proposed change of intake works an extra head of about 20m shall be created

within the system. The increased head will in return increase flow by about 3000m3 per

day to a total of 9000 cubic meters per day from the current 6000 cubic meters per day. In

addition to above and will construction of proposed full treatment works people currently

served by the 18 off-takes from Nairobi water mains will be connected to the new scheme.

This will allow Nairobi Water Company to supply additional consumers in Nairobi City.


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1.3 PROJECT JUSTIFICATION

Preliminary survey of Karimenu water project revealed that water project falls short of

satisfying target consumer population. With a design capacity of 960m3/d the population is

optimum but serving only 600 connections opposed to the original 2,300. This is a clear

indication of uneven water distribution and unaccountability as the supply is not metered.

Billing is done monthly on a flat rate basis and majority of the consumers particularly in

Karimenu location do not receive water hence they don’t pay.

Infrastructure development of the facility will therefore be necessary for the following

reasons

Revenue generation and collection

Extended water distribution network, accountability, accessibility and streamlined

monitoring capacity.

Improve the water treatment component therefore improving water quality

Clean up the intake to reduce the water purification

Provision of reliable affordable clean water to the consumers

Table 2: Access to water by districts under AWSB area in percentage

District Access to

water 2004

Access to

water

-2006

Access to

water

- 2012

5 year MDG

target increase

Thika 45 % 58% 71% 13%

Larger Kiambu 25% 34% 55% 20%

Nairobi 93% 91% 95% 3%

Average 54% 61% 74%

* (Source AWSB Rapid Result Study of 2005)

** (Source Economic survey of 2006)

From the table it is clear that the current supply of water in the district is not sufficient,

therefore initiating the proposed project will be a mile stone towards handling the problem

of water shortages in the district.


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1.4. STUDY OBJECTIVES

Main objectives of the assessment were to:

Verifying compliance to environmental requirements at both implementation and

operational stage

To identify past, present and potential future impacts on the environment of the

facility and evaluate their magnitude.

Propose appropriate mitigation measures for any identified adverse impacts, and

establish an environmental management plan for the project

Provide information that assures the public and government agencies that the

project is meeting statutory responsibilities in protecting the environment.

1.5 ASSESSMENT SCOPE AND TERMS OF REFERENCE

This report is prepared to meet the requirements of:

The Environment Management and Coordination Act 1999,

Water Act 2002

Water Resources management Rules 2007

Environmental (Impact Assessment and Audit) Regulations, 2003; and

The description of the project

A study of the relevant environmental law and regulatory frameworks on health and

safety, sustainable use of natural resources and acceptable environmental standards

A verification of the level of compliance by the project with the conditions of

environmental regulations and laws

A review of existing project documentation related to all infrastructural facilities

and designs;

An examination of the monitoring programs, parameters, and procedures in line

with control and corrective actions in case of emergencies;

An examination of records of incidences and accidents and the likelihood of future

occurrences of the incidences and accidents.

Preparation of a list of health and environmental concerns of past and on-going

activities.

An examination of the various materials, including non-manufactured goods, final

products, by-products and wastes


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A description of potentially affected environment component both ecological and

socio-economic matters

An identification of all environmental and occupational health and safety concerns

associated with the project

Detailed recommendations for corrective activities, cost, time and mechanism for

implementation.

Identify and establish baseline data (benchmarks) for various environmental and

human aspects relating to the project

1.6 METHODOLOGY

The methodology used complies with section 35 of the Environmental impact assessment

and audit regulations 2003, which states that: an environmental Impact Assessment and

audit shall be carried out through various ways; it is designed to be participatory in order to

capture the views of the proponent and the beneficiaries (both direct and indirect) of the

project. Both reactive and non-reactive research methods were employed in utilizing

various research tools in gathering information.

The following tools were used:

Direct field observation.

Literature review

Checklists.

Questioner’s administration to key informant

Interviews

Photographs.

Area of focus includes: Natural Environment, Human Environment, Physical Environment,

Sustainability, Environmental Monitoring and Protection. Major focus was on

Environmental Conservation, Water Supply, Social Welfare and Human Health and Safety

among others. Personal observations were necessary in order to identify environmental

aspects of the potential impact of the project.

Benchmarks for monitoring environmental aspects were identified. Finally face to face

interviewing of both direct and indirect beneficiaries was done to air out views and feelings

on the project. The tools employed were open-ended questions based on semi-structured

checklist. These were administered to various stakeholders and potential beneficiaries

(chiefly key informers) and individuals likely to be affected by the project.


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1.7 METHODOLOGY STAGES

Pre-Assessment activities:

i. Gathering of background information about the facility

ii. Advance visit to the site

iii. Review of the legal framework

iv. Definition of the objectives and scope of the assessment

v. Preparation of audit questionnaires

EIA activities:

i. An understanding of the management systems through meetings and interviews.

ii. An assessment of strengths and weaknesses inherent risks and internal controls.

iii. Gathering of impact evidence, assessment, documentation, verification, site inspection.

iv. Evaluation of impact evidence, compliance, exceptions, environmental program status

Post-Assessment activities:

i. Preparation of draft report to document findings and prepare recommendations.

ii. Review of the draft report with the client.

iii. Preparation of action plans, proposed actions, responsibilities for corrective action and

timelines.

In addition to documentation of the anticipated impacts and appropriate mitigation

measures, reporting was done by the terms of reference guided by NEMA. The project

report is structured as follows;

Executive summary

Introduction

Project description

Baseline information

Policy, Legal and institutional framework

Environmental impact assessment

Environmental Management plan

Conclusion and recommendation

List of references

Appendices


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CHAPTER 2: PROJECT DESCRIPTION

2.1 GEOGRAPHICAL LOCATION

Karimenu Water Supply is located in Gatundu North district, Gatukuyu division, Karimenu

location Gakoe sub-location

2.2 CURRENT STATUS

Currently, there is no treatment going on at the site as it is a new development where a weir

is being constructed to abstract water upstream in the Aberdare forest. The waters are to be

conveyed to the treatment plant that is designed to be at the peripheral of the forest in the

KFS land.

The current works were constructed in the early seventies and their capacity doubled in

2007 through intervention of AWSB. The scheme comprise of twin 250 cubic meters per

day of raw water.

During construction there was no habitation upstream of the intake works and therefore

there was no need of the full treatment. However, with time people have continued to

cultivate upstream of the said intake causing pollution through chemicals and eroded soils.

Secondly, the population served by the project was then small as compared to the present.

Population increase resulted in demand exceeding supply. People sought alternatives

sources elsewhere including Nairobi Water Company mainline.

To date, there are eighteen off-takes serving about 3000 people from the Nairobi mainline.

With the proposed change of intake works an extra head of about 20m shall be created

within the system. The increased head will in return increase flow by about 3000m3 per

day to a total of 9000 cubic meters per day from the current 6000 cubic meters per day. In

addition to above and will construction of proposed full treatment works people currently

served by the 18 off-takes from Nairobi water mains will be connected to the new scheme.

This will allow Nairobi Water Company to supply additional consumers in Nairobi City.


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2.3 MAIN FACILITY COMPONENT

The Key investments are for construction of source works, raw water main and 9000 cubic

meters per day treatment plant including;

The construction of the intake weir and the intake chamber along Karimenu River

Construction of 3 km of 300 mm diameter twin raw water gravity main

Construction of aerial crossings

Construction of 2 flocculation tanks

Construction of 4 units of sedimentation basins

Construction of 4 filter units

Construction of Chemical Building

Construction of Utility Building

Construction of 40 cubic meters steel elevated pressed steel backwash tank

Construction of backwash pump house and installation of backwash pumping units

Construction of 150 cubic meters masonry clear water tank

Construction of 1 No staff house

Construction of 500 meters all weather access road

Miscellaneous works including Fencing of treatment site

2.4 IMPLEMENTATION SCHEDULE

The works shall be done in two phases

Phase 1: Immediate measure

Completion of the water treatment works (Flocculants, sand filters, chemicals

dosing units, back washing)

Rehabilitation of existing works

Metering of all the distribution networks

Electricity connections

Construction and equipping of water supply laboratories

Phase II: Mid-term measures

Construction of the distribution system

Rehabilitation of existing distribution systems, storage facilities and replacement of

fittings


14

Completion of staff housing

Support utility (Power generators, a pump house)

2.5 PROJECT COST

The project cost is estimated at Ksh 127,895,824


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CHAPTER 3: BASELINE INFORMATION

3.1 TOPOGRAPHY AND PHYSIOLOGY

Project area is characterized by steep slope and deep valleys. Physiographic of the region is

influenced by Aberdare ranges with topography varying from steep in the western region

and undulating landforms volcanic ranges in the Northern.

3.2 DRAINAGE AND HYDROLOGY

The project area is well drained both horizontally because of the horizontal valleys, vertical

slopes and loamy red volcanic soils which are porous and allow for all infiltration, the

ranges are covered by tea zones. Due to this, cases of flooding are not likely to happen.

Clearing of vegetation on the steep slopes is strictly discouraged as flush surface runoff is

likely to dominate the region. The catchments are constituted by lower Aberdare ranges

feeding to the numerous rivers and streams around.

3.3 BIODIVERSITY

Vegetation and Animal species

Agricultural land is the most important resource in the district. Most of the area lies in the

Agro-Eco-zone III and IV. Agriculture is the main economic activity in this area with tea,

coffee, cabbages and dairy farming being the main activities.

3.4 CLIMATIC CONDITIONS

Rainfall

The region is characteristic by equatorial climatic conditions and rainfall is highly

influenced by altitude and comes in two seasons. Long rains between March to May and

short rains between October and December. The annual mean rainfall varies from 1070mm

to 1750mm per annum.


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Temperatures

Temperature is also influenced by altitude due to the Aberdare ranges. Mean annual

temperature varies from low in higher regions to high in lower region between 17 and 25

degrees Celsius.

Humidity and Evaporation

Main wind direction is easterly and evaporation ranging from 100 to 150mm per month

while the humidity varies between 50% and 90%.

3.5 GEOLOGY AND SOILS

The geology of the area is part of the eastern border zone of the Rift Valley, filled with

kainozonic volcanic and sediments underlying the upper Athi generating good aquifers.

Soils on the other hand develop from weathering activities of the volcanic rocks and are

highly fertile with high levels of perforation.

3.6 WATER RESOURCES

Surface Water

Thika district is generally endowed with numerous springs, streams that constitute one

major Karimenu River that is serves the project area. The river provides the main source of

water to the residents of Karimenu who use the water either directly or through water

schemes such as Karimenu Water Scheme. But due to costs of harnessing water resources

most of the resource is under utilized.

Ground Water

Other sources of water in the region are numerous boreholes in the area with an average

yield of 7m3/hr and pumps set at an average depth of 200 to 300 m deep.

3.7 WATER QUALITY ASPECTS

Water quality monitoring is not done regularly but water is coloured brown and turbid

during the wet seasons. During the time of assessment the water was partly clear.

Sewage / and other effluents

Majority of the people have pit latrines with few having VIP latrine. A few private homes,

institutions and hospitals have septic tanks, but this does not rule out the possibility of


17

contamination. Most alarming wastes are from cattle dips, spraying of pesticides, use of

chemical fertilizers and liquid wastes from agro- processing industries such as coffee, tea

and dairy plants.

Solid wastes

Wastes generated at various levels of the community are generally disposed off into the

natural environment. Most wastes generated include:

• Bio mass from crops and animal wastes

• Agrochemical wrappers, containers, polythene, plastics

• Urban wastes from shopping centers (Gakoe market )

3.8 SOCIAL SETTING

Population and Settlement Patterns

Settlement patterns are influenced by rural - Urban migration, good infrastructure and

proximity to Nairobi. Majority of the population reside around Gakoe shopping center

which is the main market near the project area. The project area is densely populated and

land is subdivided into uneconomic sizes.


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CHAPTER 4: ENVIRONMENTAL POLICY AND LEGAL

FRAMEWORK

This study was conducted within an environmental and policy framework as outlined

below and in particular, the Environmental Management and Coordination Act, 1999 which

has explicit provision for Environmental Impact Assessment (EIA) for projects likely to

have adverse environmental impacts.

The law governing environmental protection and conservation in Kenya are derived from

the constitutional statutes and the ratified international conventions. These laws regulate

the establishment and operation of development projects such as water treatment plants,

boreholes , water abstraction, roads, bridge and associated activities, which may impact

negatively on the environment, human health and socio – economic well being of the

people who interact with such projects. Today, NEMA coordinates all environmental

activities on behalf of the government of Kenya.

4.1 NATIONAL ENVIRONMENTAL ACTION PLAN

The Kenya National Environment Action Plan (NEAP), 1994 advocates for the integration

of environmental concerns into development projects by requiring that new projects

undergo the Environmental Impact Assessment before implementation.

4.2 POLICY PAPER ON ENVIRONMENT AND SUSTAINABLE

DEVELOPMENT.

The objectives of the Policy Paper on Environment and Sustainable Development (1993)

are to ensure that:

• All development programs and projects take environmental considerations into

account.

• An independent environmental impact assessment report is prepared for any

development project before implementation.

• Effluent treatment standards will conform to acceptable standard


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4.3 THE ENVIRONMENT MANAGEMENT AND COORDINATION ACT

(EMCA).

The Environmental Management and Coordination Act, 1999, came into force on 14th

January 2000. Its overall objective is to provide for the establishment of an appropriate

legal and institutional framework for the management of the environment. The act provides

a coordination mechanism for various Sectoral laws dealing with elements of the

environment.

Part II of Environment Management and Coordination Act 1999 states that every person in

Kenya is entitled to a clean and healthy environment and the duty to safeguard and enhance

the environment.

Part V section 42 states that “no person shall, without prior written approval of the

Director-General given after an Environmental Impact Assessment, in relation to a river

lake or wetland erect, reconstruct, place, alter, extend, remove or demolish any structure in,

or under the river, lake or wetland. The Act further states that no one shall excavate, drill,

tunnel or disturb the river lake or wetland.

Section 58 of the Act provides for an environmental impact assessment for all projects

likely to have adverse environmental impacts. The projects must undergo a mandatory EIA

as given in the second schedule of the Act. The operator must have self-audit through

which he/she can monitor effects of the operations on the environment and take initiatives

that are necessary for compliance with the provisions of the Act.

EMCA 1999 also has provision for Environmental Quality Standards, which includes

Water, Air, and Wastes, Pesticides Management, among others. The Act provides

legislation control over soil conservation and land management. Abstraction of water,

clearing of vegetation and any other land use activity on steep slopes, which are likely to

cause an environmental degradation are not recommended.

Environmental Impact Assessment and Audit Regulations, 2003, provides guidelines that

should be followed in carrying out an EIA which include qualification of experts and

aspects such as ecological, social, landscape, land use and effects of projects on water and

general drainage pattern.


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Under EMCA, 1999 a project proponent shall not implement a project likely to have

negative environmental impact, or for which an EIA is required, unless an EIA has been

concluded and approved in accordance with the law.

4.4 THE WATER ACT 2002.

The water Act 2002 is concerned with sustainable management of water resources. It

prohibits activities that may cause pollution of water sources for domestic, industrial,

agricultural or recreational use.

Section 25 of the Act requires a permit to be obtained for among other uses of water from a

water resource, discharge pollutant in a water resource. Section 75 and sub section 1 allows

a licensee for water supply to construct and maintain drains, sewers and other works for

foul water arising or flowing upon land for preventing water belonging to the licensee or

which he is authorized to take from being polluted. However, if the proposed works not

affect or is likely to affect any body of water in the catchments, the licensee shall obtain

consent from the water resources management Authority.

Section 76 states that no person shall discharge any trade effluent from any trade premise

into sewers of a licensee without the consent of the licensee upon application indicating the

nature and composition of the effluent, maximum quantity anticipated, flow rate of the

effluent and any other information deemed necessary. Underground water sources are

likely to be polluted by seepage of construction waste contaminants and drains-water from

the building. Construction work also uses a lot of water.

Section 18 of the Act provides for the National Monitoring and Information Systems on

water sources. Sub-section 3 allows the Water Resources Management Authority (WRMA)

to demand from any person or institution specified information, document, samples or

materials on water resources. Specific records are required to be kept by the site operator

and the information is furnished to the Authority. The Act allows the person with the

license to supply water and make regulations for the purpose of protecting it against

degradation of water sources.


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The Act makes it an offence to throw rubbish, dirt, refuse, effluent, trade waste or other

offensive matter into or near water sources in such a manner as to cause or likely to cause

pollution of the water resources.

4.5 WATER RESOURCES MANAGEMENT RULES 2007

According to the third schedule of the Water Resource Management Rules 2007, any water

activity that involves the under listed activities requires a water use permit.

Temporary abstraction of water for construction

Diversion of water from a water course

Abstraction from surface water

Diversion of a water course

Abstraction from ground water, either by borehole or a shallow well

Ground water recharge augmentation

Water storage in dams and pans

Effluent discharge being the disposal of wastes into a water resource

Swamp marsh or wetland drainage

In stream works

Mixing of water from different water resources

Hydro power generation

4.6 PUBLIC HEALTH ACT.

The Public Health Act (Cap 242) the main purpose of this Act is to secure and maintain

public health. Some of its provisions relevant to this project include prohibition of nuisance

activities such as spillage, discharge of untreated effluents or noise or other condition

deemed to be injurious or dangerous to human health.

According to Part IX Section 115 no person will be allowed to cause nuisance or condition

liable to be injurious or dangerous to human health .Section 116 requires local Authorities

to take all lawful, necessary and reasonably practicable measures to maintain their

jurisdiction clean and sanitary to prevent occurrence of nuisance on conditional liable for

injurious or dangerous to human health.


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The Act further states that nuisance conditions are defined according to the opinion of

Medical Officer of Health. Any noxious matter or waste water flowing or discharged from

any premises or project into a public street or into the gutter or site channel or water course,

irrigation channel not approved for discharge is also deemed as a nuisance.

Part XI Section 129 of the Act states that it is the duty of every local authority to take all

lawful, necessary and reasonably practicable measures for preventing any pollution

dangerous to health of any supply of water which the public within its districts has a right

to use for drinking or domestic purposes. It’s also charged with purification of water so

polluted.

Part XII Section 136 states that all collections of water, sewage, rubbish refuse and other

fluids which permits or facilitate the breeding or multiplication of animals or vegetable

parasite of men or domestic animals or insects or other agents which are known to carry

parasite shall be deemed nuisance and are liable to be dealt with as provided for in the Act.

Under Section 126 the Public Health Act gives the rules on drainage and latrines in

buildings. Under this section the local authority is the enforcer of such regulations. The

section refers to the local authority enforcing drainage of un-drained buildings, sinks and

drains to be provided in buildings and the examination of the drainage. It also prohibits

injurious substances being passed into sewers. Generally the section covers wastes disposal

in buildings and the role the local authority plays in wastes disposal management.

Under section 11 B of the Act provides rules that wastes pipes, sewer, drains or refuse pits

should be constructed in a state that would not be injurious or offensive to health. Any

noxious matter or wastewater flowing or discharge from any premises into a public street

or into the gutter or side channel be avoided. Other nuisances are accumulation of materials

or refuse which in the opinion of the medical officer of health is likely to harbor rats or

other vermin.

Section 136; states that all collectors of water, sewage, rubbish and others fluids which

permit or facilitate the breeding or multiplication of pests shall be deemed a nuisance and

are liable to be dealt with in the manner provided by the Act.


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4.8 THE PHYSICAL PLANNING ACT, CAP 286

The local authorities are empowered under section 29 to receive and maintain all land

planned for open spaces, parks, urban forests and green belts. t provides for the preparation

of a physical development plan for the purpose of improving the land and providing for the

proper physical development of such land, and securing suitable provision for

transportation, public purposes, utilities and services, commercial, industrial, residential

and recreational areas, including parks, open spaces and reserves and also the making of

suitable provision for the use of land for building or any other purposes.

The Physical planning act provides for the control of development and use of land in

particular areas, especially where a project may involve sub divisions or amalgamations of

land parcels or located in an area otherwise reserved for other use.

The objective of this Act is to promote harmony, convenience, comfort and beauty in land

use. Section 29 of the Act empowers local authorities to control all development activities

so as to ensure conformity to approved planning standards.

Section 30 states that any person who carry out development without permission will be

required to restore the land to its original conditions.

The Act also provides an environmental impact assessment for a project which is likely to

have injurious impact on the environment. Such an EIA should be approved by the

National Environment Management Authority (NEMA).

4.9 LAND PLANNING ACT (CAP 303).

This Act is the overall planning law for land for both agricultural and constructed

environments.

Under this Act, all developments or changes to land use must be approved by a planning

authority.

Section 9 of the subsidiary legislation (the development and use of land legislation 1961)

stipulates that before any plans are submitted to the Minister for approval steps should be

taken as may be necessary to acquaint the owners of any land affected such plans

particulars of comments and objects made by land owners should also be submitted. This is

meant to reduce conflicts with other interests such as residential and commercial land uses.

The Act ensures that all development plans within local authorities to be submitted to the

Ministry for approval, this is intended to reduce potential conflicts between the interests of


24

the authorities and those of landowners in respect of settlement, social and economic

activities.

The project area covers land legally granted under the Registrar of Tittles Act (Cap281).

4.9.1 AGRICULTURE ACT (CAP 318).

The Agriculture Act requires a person carrying out a land use activity that may lead to soil

land

degradation to take such measures to conserve the soil. Such activities may be abstraction

of water to a treatment plant, cultivation road construction, building and human settlement

Conservation measures must be implemented. It also restricts

4.9.2 THE LAND ACQUISITION ACT CAP 295.

This Act empowers the government and the local authority to acquire private landing in

accordance with section 117 and 118 of the constitution of Kenya for development that are

at the interest of the public. Acquired land is compensated at a market rate plus 15%

disturbance allowance. This Act has been very useful especially where land needs to be

acquired for public use. Similarly, the Government has often found it more convenient to

acquire land for urban development, which in turn gives it a greater influence in terms of

planning, and development control.


25

CHAPTER 5: ENVIRONMENTAL IMPACT ASSESSMENT

Reliable water availability is considered to be critical to economic growth and poverty

reduction especially in agricultural zones that support urban and industrial activities

through provision of raw materials and food supply. With increasing pressure on land for

agriculture and settlement, water resources come under serious threat of degradation. Use

of chemical fertilizers and pesticides near drinking water sources exposes consumers to the

risk of water borne diseases, water pollution and sometimes conflict over use of resources.

Socio – economic needs of a particular community entirely require water, over abstraction

from sources, infrastructure maintenance, management of related wastewater and

ecological balance and sustenance is among the problems associated with public water

supplies.

From the foregoing, public water supplies such as Karimenu Project have far reaching

social and economic implications that need to be addressed throughout the project cycle.

The effects are mainly positive calling for enhancement and the negative ones calling for

mitigation

5.1 ENVIRONMENTAL AND SOCIO ECONOMIC IMPACTS

Environmental and socio economic impacts associated with the development of the

Karimenu Water Scheme are outlined below.

5.2.1 Positive Effects

Improved Water Quality and accessibility to clean water

Improved water quality will in turn reduce exposure to water borne diseases to the

consumers. General hygiene in the served area will improve through use of acceptable

water quality.

Majority of the population around Gakoe Township and entire Thika will have access to

clean water. Extension of the distribution networks will make more people access clean

water as compared to the number that is currently accessing. Adequate supply of water

from Karimenu Water Scheme will make it possible to disconnect them from the main lines

of Sasumua hence help release more water to Nairobi.

Improved living standards in Karimenu area


26

Access to water will in the long term result in improved income levels and health of the

people, this consequently leads to poverty reduction. Reduced distances traveled and time

used to collect water is then put to economic activities.

Reduced Exposure to Health Risks

Improved water quality for domestic consumption reduces the risk to the health of the

consumers and dependants of water resources that could translate into financial saving

through less related expenditures

Improved Food Security and Nutrition

It will result from saving on health and incomes an diversification of farming activities of

high yield using irrigation, expansion of farming can bring back abandoned farm in

farming.

Stimulation of the Local Economy

Construction phase will stimulate local economy through procurement of construction

material and provision of labour by the locals. This will lead into increased capital flow and

demand for goods and services will increase. Water availability will also stimulate growth

of economic activities at local level

Sustainability of Karimenu Water and Sewerage Company

Increased revenue collection will help the company to be sustainable in terms of meeting

their own operational cost which are currently being met by Ministry of Water and

Irrigation

Enhanced Gender and Participation in Development

Female form a high percentage of the areas population but are in adequately participating

in development activities due burden of fetching water. Increased availability of water will

relieve them and thereby give them an opportunity to engage in development activities

5.2.2 Negative Impacts

Impacts on biodiversity

Destruction of vegetation around the intake and distribution areas

Interaction with wild animals within Aberdare forest e.g. elephants

Destruction of habitat

Water pollution


27

Impacts on water resources

Possibility of over abstraction of water from river Karimenu River

Reduced flow of water in river Karimenu with effects of water shortage for users

and capacity of the river to assimilate and dilute wastes downstream

Supply of water to the consumer will consequently generate waste water. However

it is not easy to quantify how much of the waste water will reach the water bodies.

Due to large scale tea farming and heavy rainfall, possibility of non point pollution

is inevitable.

Impacts on Drainage and Hydrology

Abstraction of more water from the river Karimenu might reduce flow level down

stream due to ineffective compensation

Specific consumption points will require discharge point for the waste water,

improper drainage will lead to pools and channels with stagnant water harboring

vector diseases.

Impacts on public health

Temporal interference with water quality and distribution during construction

impacts negatively into people’s health.

During construction, network improvement, metering and treatment enhancement

will disrupt the hygiene and availability of clean water and hence potential water

borne infection.

There is a likely hood that with increased water availability probability of water

borne diseases will increase.

Impact on soil

Possibility of erosion at burst pipes along the steep slopes during construction

Siltation of springs and rivers as well as pollution of water at the valley bottoms

Disruption of soil structure during construction of treatment plant

Impacts on water cost


28

Added water cost will be received negatively by the consumers especially the poor,

this may lead them to go for cheap available water sources hence cases water borne

diseases might increase

Metering of water distribution may also be associated to an increase of cost of

living which has a negative impact especially on the poor. Meter rent and delay in

installation meters may lead to the consumers buying their own which is also an

added cost

Impacts on Community Based Organization

With the taking over water management by the WSP, community based groups that

initially provided the same may collapse

Local water vendors who had also ventured in the same business will loss market


29

CHAPTER 6: ENVIRONMENTAL MANAGEMENT AND

MONITORING PLAN

Environmental Management Plan (EMP) has been developed to assist in prioritizing the

key findings of the EIA, and to suggest necessary mitigation actions. From the EMP, a

schedule for the operations implementation could also be drawn that takes into

consideration all issues that could develop into serious risks to environment, health and

safety at all times.

Environmental management plan is based on the ISO 14001 which states management

principles for environmental management. Finally, management reviews and continuous

improvement determines which of the activities require to be re-visited and at what

schedules.

On the basis of the policy guidelines and development of the EMP, among other actions

recommended to be undertaken by the management in the implementation of the latter are;

• Develop a training plan and schedule,

• Develop an in-house environmental audit protocol and schedule,

• Establish a suitable and comprehensive database in environmental issues

• Put in place an emergency preparedness system

• Establish an EMP implementation schedule

• Establish an incident log book to manage environmental incidents

• Establish an environmental management committee to oversee and assist in the

implementation of the EMP.

The recommended mitigation measures and the targeted achievements have been tabulated

below. A timeframe has also been presented.

6.1 CONSTRUCTION PHASE: ENVIRONMENTAL MANAGEMENT PLAN

The following were key environmental concerns that need to be addressed during the

construction phase of the project. They include:


30

• Effects on biodiversity

• Solid waste management issues

• Noise and vibrations from construction machineries

• Effluents from construction machineries to the quality of water

• Impacts of the construction activities on water quality

CONSTRUCTION ENVIRONMENTAL MANAGEMENT PLAN

Activity Source of

Impact

Impact Mitigation Measure Actors Cost

(KSH)

Clearing

vegetation

Bush clearing Loss of habitat Limit vegetation clearance to a minimum Contractor

Loss of fertile soil Pile the top soil where it can be reused

Contractor Stripping the

soil

Top Soil

removal

Loss of habitat Restrict disturbance to soil structure within

project site

Contractor

Soil Erosion Put measures for protection of soil erosion Contractor

Water contamination Control oil spillage by machinery Contractor

Earth Works Cuts and fills,

Graveling

Mud generation Installing necessary temporary and

permanent drainage works

Contractor

50,000

Hindrance to movement Provision of access routes to locals Contractor

Air Pollution

Ensure use of machine with low Carbon

emission

Ensure the use of dust suppressants

Conduct Regular Air Quality Test

Contractor

Mud Generation Provision of Drainages

Gravelling of Access Routes

Contractor

Water Contamination Control Oil Spillage Contractor

Construction Track

circulation

Accidents Ensure Proper Road Safety Measures Contractor

150,000


31

Safety Gear for Workers & Site Visitors

Insurance Cover for Workers

Provision of First Aid & Medic’ Assistance

Impact on quality of

water and soil

Use of cleaner technologies / productions

Contractor


water and soil

Waste minimization, by recycling and reuse

of wastes generated

Contractor


water and soil

Green procurement where by all goods and

services procured should be eco friendly

Contractor

Solid waste

management

Soil and water

contamination

Careful disposal of non recycled wastes into

a landfill

Contractor

80,000

Impact on quality of air Maintaining machineries at manufacturers

specifications

Contractor

Impact on quality of air Site roads should be dampened every 4-6

hours or within reason to prevent a dust

nuisance and on hotter days, this frequency

should be increased.

Contractor

Gaseous

emissions

Excavations

Truck

movements

Impact on quality of air Minimize cleared areas to those that are Contractor


32

needed to be used.

Cover or wet construction materials such as

marl to prevent a dust nuisance.

Impact on quality of air Where unavoidable, construction workers

working in dusty areas should be provided

and fitted with N95 respirators.

Contractor

Impact on quality of air Wetting of unpaved areas and the entire

work place

Contractor

Impact on quality of air Limit removal of vegetation and a

rehabilitation programme on site and

associated infrastructure following

construction

Contractor

50,000

Impact on health of the

workers & neighbors

Use equipment that have low noise

emissions as stated by the manufacturers.

Contractor


workers & neighbors

Use equipment that is properly fitted with

noise reduction devices such as mufflers.

Contractor


workers & neighbors

Workers should be provided by PPE Contractor

Noise pollution

and vibrations

Nuisance to the

ambient cool

Constructions should be limited between

50,000


33

7.00 am to 6.00 pm

Impact on Ecology,

water and soil quality

Skips and bins should be strategically

placed within the campsite and construction

site, they should also be adequately

designed and covered to prevent access by

vermin and minimize odour.

Contractor Construction

activities

Impact on Ecology,


The skips and bins at both the construction

campsite and construction site should be

emptied regularly to prevent overfilling.

Contractor

Solid Waste

Generation

Construction

activities

Impact on Ecology,


Disposal of the contents of the skips and

bins should be done at an approved disposal

site. Contractor should comply with the

solid waste management regulations.

Contractor

100,000

Wastewater

Generation and

Disposal

Construction

activities

Impact on Ecology,


Provide portable sanitary conveniences for

the construction workers for control of

sewage waste. A ratio of approximately 25

workers per chemical toilet should be used

Contractor

50,000

Impact on water and

soil quality

Raw materials that generate dust should be

covered or wetted frequently to prevent

them from becoming air or waterborne.

Contactor Storage of Raw

Material and

Equipment

-

Impact on water and Equipment should be stored on Contactor


34

soil quality impermeable hard stands surrounded by

berms to contain any accidental surface

runoff.

Impact on water and

soil quality

Bulk storage of fuels and oils should be in

clearly marked containers (tanks/drums etc.)

indicating the type and quantity being

stored. In addition, these containers should

be surrounded by berms to contain the

volume being stored in case of accidental

spillage.

Contactor

40,000

Accidents impact on

humans and livestock

Adequate and appropriate road signs should

be erected to warn road users of the

construction activities. For example,

reduced speed near the entrance roads. This

should be done in conjunction with the

Ministry of Transport and Works.

Contactor

Impact on air quality

Impact on health

Raw materials such as marl and sand should

be adequately covered within the trucks to

prevent any escaping into the air and along

the roadway.

Contactor

Transportation

of Raw

Material and

Equipment

Impact on ambient cool The movement of equipment (trucks) during Contactor

20,000


35


36

the construction of the plant should be

limited to the working hours, 8:00 am - 4:30

pm per day.

Impact on ambient cool Heavy equipment should be transported

early morning (12 am – 5 am) with proper

pilotage.

Contactor

Impact on health of

workers

Ensures workers health and safety through

awareness campaign and provision of

appropriate PPE

Contractor

Impact on health of

workers

Rehabilitate excavated sites as soon as

construction is complete

Contractor

Impact on health of

workers

provision of adequate sanitary facilities Contractor

Occupational

health and

safety

Accidents, fire

outbreaks

Training of all workers in Safety Health and

Environment (SHE)

Contractor

75,000

Monitoring /

inspections

Routine monitoring of the proposed actions

to ensure compliance of their effectiveness

KCWSC

AWSB

100,000

Sub Total 1 765,000


37

6.2 OPERATION PHASE: ENVIRONMENTAL MANAGEMENT PLAN

Operation phase is the most critical stage as it will have long term direct reflection on quality

of environment once the project is commissioned. Main concerns during operation phase

include.

• Sludge management

• Backwash water management

• Solid waste management

• Chemical handling (Aluminum sulphate and chlorine)

• Operations and maintenance

• Emergency preparedness and response

EMP DURING OPERATION

Activity Source of Impact Anticipated

impact

Management and Mitigation Actors Cost KSH

Impact on water

quality.

Provision of solid waste storage bins and

skips.

KCWSC

Impact on water

quality.

Monitor skips so that they do not become

overfilled.

KCWSC

Solid Waste

Generation and

Disposal (wastes from

the plant screens)

general operation

of the plant

Impact on water

quality.

Ensure that the solid waste collected is

disposed of in an approved dumpsite

KCWSC

20,000

Impact on water

quality.

Alternative 1

Apply quicklime treatment to dewatered

sludge in order to create a pathogen and

odor free product.

KCWSC

Impact on health

of people around

the plant

Alternative 2 recommended

Dry sludge on the drying beds before

disposing off in a predetermined landfill

KCWSC

Impact on habitat land filling in a dedicated disposal site /

clearly designated landfill N/B the land fill

shall only be for disposing dry odourless

sludge.

KCWSC

Sludge Management De-sludging

exercise

Impact to aquatic

life

Preparation and enforcement of operational

guidelines for sludge treatment /

AWSB

100,000


38

management

Impact on water

quality

Drain the waste water into an oxidation

pond / tank to allow for stabilization and

neutralization

KCWSC

Impact to aquatic

life

Alternative1

Pass the stabilized backwash water into a

soak pit or a controlled wetland before the

water diffuses underground with sand

filtration

KCWSC

Alternative 2 Recommended KWSCO

Back Wash water Filtering of the

water from the

flocculation tanks

Recycle the treated backwash water to the

channel leading to the filters

80,000

Impact on water

quality

Carrying out water sampling tests for both

bacteriological and physical element

AWSB

Improve chemical handling, avoid leakages

and spillages

KWSCO

Appropriate record keeping of data on

chemicals and material safety data sheets

Chemical Handling Chlorination

exercise and use

of Aluminum

sulphate used in

the flocculation

tanks

Impact on water

and soil quality

Awareness creation amongst workers on

proper handing of chemicals through

training.

10,000


39

Impact on safety

and health of the

people

Design and implement an emergency

response plan.

KCWSC

AWBS

Impact on safety

and health of the

people

Coordinate with mutual aid

organizations/agencies such as with the

local fire brigade.

KCWSC

AWSB

Impact on safety

and health of the

people

Install fire hydrants within the proposed

development

KCWSC

AWSB

Emergency

preparedness and

response

Plant operations

Install a fire extinguisher at the plant and

train workers on how use

AWSB

30,000

Plant operations Impact on the

quality of the

environment

Motivating workers with an aim of

enhancing their contribution towards

environmental management practices

KCWSC


quality of the

environment

Ensure equipment spares and protective

personal equipments are available to

workers

KWSCO

50,000


quality of the

environment

Develop a database and relevant records on

environmental performance and other

monitorable parameters

AWSB

Operations and

Monitoring

Impact on the

quality of the

Activate the monitoring points as designed

in the project premises and the

KCWSC

30,000


40


41

environment surroundings


quality of the

environment

Develop a database and relevant records on

environmental performance and other

monitorable parameters

KCWSC

Capacity Building Workshops /

seminars

Human resources

development.

Provide a forum for human resources

development on environmental

conservation

AWSB

KCWSC

Workshops /

seminars

Human resources

development.

Establish a schedule for continuous

improvement of human capacity on

environmental management,

AWSB

KCWSC

Workshops /

seminars

Human resources

development.

Develop in-house guidelines on

environment, health and safety

management

AWSB

KCWSC

80,000

Subtotal 2 400,000

Total

1,115,000


42

6.2 DECOMMISSIONING PHASE: ENVIRONMENTAL MANAGEMENT PLAN

Decommissioning phase the stage the project has to be removed or dismantled after its

has outlived its lifespan. Before the decommissioning exercise a comprehensive

decommissioning plan has to be developed by all the stakeholders. The

decommissioning action plan has to capture all the issues that need to be handled

during the dismantling exercise.

The management has to notify responsible authorities in this case NEMA on the

intentions to decommission the facility within 1 year in order for the authority to

carryout assessment and determine potential negative impacts on environment and

therefore giving recommended mitigation measures.

EMP DURING DECOMMISSIONING OF THE PLANT

Activity Management and Mitigation Actors Cost (KSH)

Provide justification data for the decommissioning including

technical and socio-economic studies KCWSC

AWSB

Stakeholder engagement ( Liaise with the stakeholders in

identifying the need for decommissioning.

KCWSC

AWSB

Develop decommissioning Action Plan

KCWSC

AWSB

Management strategy

Obtain certificate of decommissioning from appropriate

authorities.

AWSB

To be determined then

Carryout benching and land scaping after demolition as

recommended in the audit report

KCWSC

Allow adequate base flow into the natural stream at the

abstraction units by opening up the units.

KCWSC

Conduct a comprehensive

environmental Audit

Improve on the catchments protection through planting

vegetation cover

AWSB

To be determined


43


44

Recycling and reuse of all wastes generated

KCWSC


45

6.4 MONITORING AND ENVIRONMENTAL AUDITING

There is need for an effective monitoring and maintenance schedule, which can be done

bi annually after the commissioning of the facility. The process includes continuous

improvement of the technologies aimed at improving efficiency and reducing waste.

For effective monitoring, the following must be taken into consideration

• There should be regular maintenance of all the equipment within the facility

according to operational manuals and manufacturers specifications.

• Drains at all sections of the treatment plant should be kept free of solids and

blockages for ease of wastewater flow,

• Accurate and up-to-date records on system performance should be maintained.

• Documentation plant Maintenance records should be established as forms,

system performance briefs or reports, repair expenses among others. The Plant

Manager should keep such documentation materials for reference during

monitoring activities.

It will be the responsibility of the KCWSC Management to undertake environmental

self audits as required by the law and to submit annual report to the authorities. Such

audits form the basis for monitoring the environmental performance of the plant as part

of the operation and maintenance.

Monitoring should include the following aspects;

• Maintain appropriate monitoring points in the premises to be provided for in the

plant,

• Identify the most critical parameters to monitor including among others the raw

water consumption verses output levels, waste generation trends, equipment

performance, energy consumption trends, backwash water re-use patterns,

sludge management and changes in social perception.

• Identify one or two credible laboratories for analysis of wastes at least once

every three months.


46

• Carry out self-audit exercise at least once every 6 months and an annual

independent environmental audit to ensure continued compliance with

environmental regulations under the national laws. A data base would be ideal

for this purpose,

• Monitoring and audit reports should always be studied with inputs from experts

to establish performance gaps and identify suitable corrective measures


47

CHAPTER 8: CONCLUSION AND RECOMMENDATION

From the assessment it is concluded that:

Completion of the project will have social and economic benefit not only to

Karimenu residents but also Nairobi residents as well. This will happen when

current water consumed in Karimenu is released to Nairobi

The project is appreciated by the community and other water sector players in

the project area.

From the assessment of impacts, there are more benefits to be derived from the

project implementation. Any significant negative impacts can be mitigated.

Recommendations

It will be necessary to enlist sustainable community participation by utilizing

carefully selected tools and methods to enhance local resident’s support as well

as intensifying community awareness creation and sensitization on hygiene and

sanitation

There is need to improve on the integrity of existing water distribution system

so as to minimize loss of treated water once the project is commissioned.

PHOTOGRAPHS

Plate. Description Photographs

Plate 1.

Photo showing Karimenu

River, proposed source of

water for the treatment

works

Plate 2.

Plate showing proposed

site of the treatment works

next to Aberdare forest


48

Plate 3

Public participation

session

Plate 4

Electric fence around the

Aberdare forest. The fence

was put up to minimized

human wildlife

(elephants) conflict and

illegal logging.


49

Plate 5

Plate showing numerous

tea plantations under the

Nyayo tea zones. Use of

Agro - chemical and poor

farming practices are

responsible for siltation

and pollution down

stream


50

Plate 6


51

Shows subsistence

farming being practiced in

the region. Residents

mainly grow cabbages

under furrow irrigation


52


53

LIST OF REFERENCES

1) Britha Mikkelsen. “Methods for Development Work and Research: A Guide for Practioners” Sage Publications London. 1995

2) Department of Environment, the World Bank, Washington DC.

“Environmental Assessment Source Book, Volume I – Policies, Procedures and Cross – Sectral Issues” June 1998.

3) Environment Management and Coordination Act (EMCA) 1999. 4) Gerald k. Rukunga editor, “Environmental Health for East Africa. African

Medical and Research Foundation” (AMREF). Nairobi, Kenya. 5) G.M. Wamukoya and F.D.P. Situma. “Environment Management in Kenya.”

A Guide to the Environment Management and Coordination Act (EMCA) 1999”.

6) Hussein Abaza, - DTIE-ETB, UNEP: Iron Biset-BTM Cordah Limited. Bastry

Sadler – UNEP Adviser, “Environmental Impact Assessment and Strategic Environmental Assessment: Towards an Intergrating Approach.”

7) Kenya Institute of Administration, “Lecture and Tutorial Notes: Environmental

Impact Assessment and Environmental Audit Course No. 12/2004 from 16th – 26th November 2004”

8) R.E. Munn, editor, Environmental Impact Assessment (EIA), Principles and

Procedures.” Published on behalf of the scientific committee on problems of the environment (SCOPE) of the International Council of Scientific Union (ICSU) by John Wiley & Sons. Chichester. New York. Brisbane. Toronto.

9) Republic of Kenya “Environmental Impact Assessment (EIA) Guidelines

and Administrative Procedure.” National Environment Management Authority (NEMA). Nairobi, Kenya, November 2004.

10) Republic of Kenya “Community Guide to Environmental Issues and EMCA,

1999 Western Province.” Environment law project: Environmental Liaison Center International (ELCI) Nairobi Kenya, March 2005.

11) Republic of Kenya “Water and Beyond: Water Beyond the Taps.” Water

Service Boards Lake Victoria North. Newsletter issues No.2

ANNEX I Water test Analysis Report


54

ANNEX II: Project Map Location


55

ANNEX III


56

Environmental Impact Assessment Report for Karimenu Water Scheme 57


58


59

ANNEX IV

A RESPONSE TO COMMENTS ON EIA FOR KARIMENU BY WB ENVIRONMENT CONSULTANT The proposed Karimenu Water Supply Scheme is to be located on the slopes of the

Aberdare ranges. The source of the water supply is Karimenu River which originates

from the Aberdare ranges. The intake works will comprise of a 20m long wier across

the river and a height of 2m. the wier is located within the forest but the treatment plant

is outside the protected forest. The location of both intake and treatment works was

arrived at after consultations with the Kenya Forest Service (KFS) – Government

Department responsible for management of gazette (protected) forests. A permit to

construct the weir was obtained from KFS on the same.

A survey was conducted during the EIA preparation during which the views of the

communities along the river were solicited. Structured questionnaires were used and are

available if needed. The findings showed support of the project by the community that

hitherto is supplied with raw water from Karimenu River. It is for this reason that the

project will now introduce treated water to its consumers and hence reduce cases of

water borne diseases in the project area.

Karimenu water supply is an old Government operated scheme where raw water from

Karimenu River is supplied to the consumers. Recent growth in population and

increased Agricultural activities in the project area has necessitated treatment of the

water supplied to consumers. This is the main reason of locating the intake within

protected forest area where pollution from human activities is and will remain minimal

in the future.

Karimenu water project has no direct link to Thiririka and Ndarugu as the three sub-

projects have different water sources.Each of the sub-projects derives its name from the

respective name of the River. The purpose of clustering them as one project under the

name: Independent Mataara Production Mains was informed by two main reasons

namely;


60

• Ease of contract administration of these sub-projects under one supervision

contract and one construction contract.

• The sub-projects have one common objective of having independent water

sources so that more water can be released to Nairobi city. Hitherto, water

transmission pipelines to Nairobi traverse these areas and some of the water

targeting Nairobi city has to be distributed in these localities thus reducing

available water to Nairobi city.

International Water ways

The proposed Karimenu water project does not trigger the international water ways

operationa policy in anyway and has no correlation with Lake Victoria that is an

international water source. Karimenu River joins Chania River which eventually joins

Thika River and drains into Athi River and eventually Indian Ocean.

B RESPONSE TO COMMENTS ON EIA FOR KARIMENU BY WB ENVIRONMENT CONSULTANT

Karimenu Water Supply Scheme is an old government project that was constructed in

the early seventees to supply water to residents of larger Gatundu district. The project

supplied raw water to residents as water then was free from contamination. Up to now,

the project still supplies 9000m3 of untreated water per day to consumers.

It is for the above reason that the proposed plant is being set up to treat the authorized

9000m3 of water which is currently being abstracted and distributed raw. No additional

abstraction from the river will be done and therefore river flow downstream will be

maintained. Nevertheless, normal river flow measurement is periodically done by

Water Resources Management Authority and this information will be in cooperated in

the project progress reports.


61

ANNEX V

KARIMENU WATER SCHEME GATUNDU NORTH DISTRICT

RESPONSE TO NEMA REMARKS ON ENVIRONMENTAL IMPACT ASSESSMENT PROJECT REPORT: NEMA REF NO: 0282

ISSUE TO BE ADDRESSED: WATER TREATMENT METHOD

Introduction Karimenu Water Treatment Scheme is designed to abstract water from Karimenu River which is a tributary of Thika River. The plant is divided into two sub plants one of which is expected to produce 9000 m3/day and another smaller plant to produce 2000m3/day.

Originally, water from Karimenu River was fresh and clean, but due to human settlement in recent years and wildlife grazing upstream, contamination is evident as indicated in the water analysis conducted by Central Water Testing Laboratory which shows presence of general coliforms.

It is for this reason that Athi Water Services Board is planning to set up a water treatment scheme to ensure water supplied to consumers is safe for human consumption. The method of treatment is the conventional water treatment procedure as outlined from the steps below: (See schematic diagram)

Intake Weir (Karimenu River)

Water flows by Gravity to consumers

• Intake weir • coagulation/flocculation • Sedimentation, • Filtration, • Stabilization, • Fluoridation and Chlorination.

Intake weir Water is abstracted through intake weir raised 2 inches above water level, water then flows through the intake mains by gravity to the flash mixer where Alum is added before flowing to the flocculation basins.

Coagulation / Floculation


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In the coagulation/flocculation process, very fine suspended particles are caused to come together to form larger particles that can be settled and filtered out of the water. These include fine silts, bacteria, color causing particles and viruses that might not settle for days, months or even years. Although individual particles cannot be seen with the naked eye, their combined effect is often seen as cloudiness, or turbidity, in the

water. These particles are small enough to pass through later treatment processes if not properly coagulated and flocculated. This could adversely affect not only the clarity of the water, but its taste and odor, as well as the effectiveness of chlorine disinfection.

During coagulation, the chemical Aluminum Sulfate, or filter alum, is added to the incoming raw water (untreated water from the river). The water is stirred vigorously in a flash mixer to assure quick, uniform dispersion of the alum. The alum reacts rapidly with compounds in the water that contain carbonates, bicarbonates and hydroxides to produce a jelly-like substance that absorbs impurities. At the same time, alum, with a positive charge, neutralizes the negative charge common to natural particles, which draws them together. Small particles called microfloc are formed. The following equation shows the reaction of alum with alkalinity:

Al2(SO4)3 . 14H2O + 3Ca(HCO3)2 2Al(OH)3 + 3CaSO4 + 6CO2 + 14H2O

Aluminum Sulfate Calcium Bicarbonate Aluminum

Hydroxide Calcium

Sulfate Carbon Dioxide Water

The water moves from the flash mixer to the flocculation basins which contain horizontal paddle systems. The basins provide a gentle, constant mixing of the microfloc formed during coagulation. This stirring promotes formation of larger and heavier floc. After 20 to 30 minutes, the floc particles are usually visible and will look like tiny tufts of cotton or wool, separated by clear water. Once the flow is of sufficient size and density to be settled, the water moves into the sedimentation or settling basins.

Sedimentation Sedimentation is the removal of solids from water by gravity settling. Basins are designed to hold large volumes of water for several hours and to give a smooth, even flow. This design allows the velocity and turbulence of the water to be decreased to the point that the water will no longer transport the flocculated solids and they will settle to the bottom of the basin.

At the end of the settling basin, hydrated lime, Ca (OH) 2, is added to the water to increase its pH. This is necessary because the alum that is added during the coagulation/flocculation process is acidic.

Filtration The water flows from the sedimentation basins into the filter beds. Filters contain material of graduated size in layers that remove solids from the water. The first layer of filter is gravel and the second layer is filter sand. Under the sand is a layer of stone or plastic composite. At the bottom of the filter is an underdrain system that supports the filter.

Water gravitates onto the filters, leaving behind suspended matter as it passes downward through the filter. Solids that are larger than the pores or holes between the grains are captured by the filter. Also, some suspended matter adsorbs, or sticks to the surface of the filter or the previously deposited material.

After a period of time, the accumulated solids begin to clog the filter, so the filter is backwashed. Backwashing is the reversal of the direction of the water flow through the


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http://www.greensboro-nc.gov/departments/Water/watersystem/chemicals.htm#alum

http://www.greensboro-nc.gov/departments/Water/watersystem/chemicals.htm#alum

http://www.greensboro-nc.gov/departments/Water/watersystem/chemicals.htm#lime


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filter. A rapid upward flow lifts the particles and keeps them in suspension until they can be washed out.

Following filtration, the water flows underground into a storage tank called a clearwell. Water leaving the clearwell is stabilized, fluoridated and chlorinated in-line on the way to the distribution pumps.

Chlorination Chlorination of public water supplies is the most important process used to produce safe drinking water. A sufficient amount of Sodium Hypochlorite, essentially strong bleach, is added to the finished water so that a minimum amount of chlorine remains in the water until it reaches the customer's tap. Chlorine is necessary for disinfection of water before it is release to the consumers, chlorine will be responsible for killing all the general coliforms and E – coli identified in the water by the Central Water Testing Laboratory sampling reports. Distribution After the final addition of chlorine, the water is released by gravity to the pipes that lead to the customer's tap. Chlorine is re-injected into the system to address issues of re contamination for system running for long distances.

http://www.greensboro-nc.gov/departments/Water/watersystem/chemicals.htm#chlorine

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