CONTRACT NO. TE14-KLP09Q-0125: PROVISION OF … LINER DDR Report EIA.pdf · 2015-09-17 · a...

Contract No. TE14-KLP09Q-0125: Provision Of Professional Services For The Development Of A New Landfill Site For Transnet Engineering At Koedoespoort Centre

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CONTRACT NO. TE14-KLP09Q-0125: PROVISION OF

PROFFESSIONAL SERVICES FOR THE DEVELOPMENT

OF A NEW LANDFILL SITE FOR TRANSNET

ENGINEERING AT KOEDOESPOORT CENTRE IN

PRETORIA

DETAILED DESIGN REPORT

LANDFILL LINER DESIGNS

SEPTEMBER 2015

Prepared for : Prepared by:

TRANSNET ENGINEERING DIVISION 160 Lynette Street Kilner Park Pretoria 0184 Tel: 012 391 1429

E-SQUARE ENGINEERING (PTY) LTD 95 First Road Farmall 1747 Kya Sands Tel: 011 875 9907 Fax: 011 875 9906

http://www.google.co.za/url?sa=i&source=images&cd=&cad=rja&uact=8&docid=j0sbAwQvSnzbGM&tbnid=9t54QRWkVKHOmM:&ved=0CAgQjRw&url=http://impumelelo.org.za/About Us/transnet-logo-rgb.jpg/view&ei=4u2_U_fmFsKK7Abr-oDgDQ&psig=AFQjCNGcoh6ugS-2fpZN-eTMUVJENuc56g&ust=1405173602459709

http://www.google.co.za/url?sa=i&source=images&cd=&cad=rja&uact=8&docid=j0sbAwQvSnzbGM&tbnid=9t54QRWkVKHOmM:&ved=0CAgQjRw&url=http://impumelelo.org.za/About Us/transnet-logo-rgb.jpg/view&ei=4u2_U_fmFsKK7Abr-oDgDQ&psig=AFQjCNGcoh6ugS-2fpZN-eTMUVJENuc56g&ust=1405173602459709


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Document Control Sheet

PROJECT NAME:

PROVISION OF PROFESSIONAL SERVICES FOR THE DEVELOPMENT OF A NEW

LANDFILL SITE FOR TRANSNET ENGINEERING AT KOEDOESPOORT CENTRE

Project Team:

Project Leader: Hamilton Sithole

Project Manager: Hamilton Sithole

Architect Martin Chinyowa

Architectural Technologist Monametsi Ketlhaetse

Design Engineer: Structural Takudzwa Dodzo

Design Engineer: Civil Alpha Nhambure

Design Engineer: Landfill Andrew Maraura

Design Engineer: Electrical Innocent Matonhodze

Design Engineer: Mechanical Tsunyane Tsotetsi

EIA Professional Gabriel Ngorima

PREPARED CHECKED REVIEWED AUTHORISED

Name

Alpha Nhambure

Takudzwa Dodzo

Hamilton Sithole

Pr Eng 20120515

Hamilton Sithole

Pr Eng 20120515

Signature

Date

10/09/2015

10/09/2015

11/09/2015

11/09/2015


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CHECKIST ON DEPARTMENT REQUIREMENTS

Item

Description Remarks

1.(a)

Design as per National Norms and Standards for

Disposal of Waste to Landfill, Regulation 636, dated 23

August 2013 (Clause 3 (1) and (2).

Yes

(b)

A Classification and Design Report to demonstrate

compliance with Regulation R636 to be submitted by

29 May 2015

Done

(c)

Report signed by the Registered Professional Civil

Engineer, with the name and surname and company,

readable + the ECSA Registration Number

Done

(d) Classification of the waste included Yes

(e)

Drawings signed by a Registered Professional Civil

Engineer, with the name and surname readable + the

Registration Number

Yes

(f) Site geology summarised

Yes

(g) Site geo-hydrology summarised

Yes

(h) All information on all the items in the attached

Regulation R636 section 3 (2) (a) to (i)

Yes


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CONTENTS PAGE

Section Description Page

1.0 INTRODUCTION ................................................................................................................... 6

1.1 Background ........................................................................................................................ 6

1.2 Project Location .................................................................................................................. 6

1.3 Project Team ...................................................................................................................... 7

1.4 Aim of this Report ............................................................................................................... 8

2.0 SCOPE OF WORKS .............................................................................................................. 8

2.1 Waste Disposal ................................................................................................................... 8

2.2 Infrastructure ...................................................................................................................... 8

3.0 INFRASTRUCTURE .............................................................................................................. 9

3.1 Site Status .......................................................................................................................... 9

3.2 Design Aspects ................................................................................................................... 9

3.2.1 Architectural Designs.................................................................................................. 10

Structural .......................................................................................................................... 16

3.2.2 Designs ...................................................................................................................... 16

3.2.3 Civil Designs .............................................................................................................. 16

3.2.4 Electricals Designs ..................................................................................................... 17

3.2.5 Mechanical Designs ................................................................................................... 17

4.0 ENVIRONMENTAL IMPACT ASSESSMENT ....................................................................... 18

4.1 Environmental Impact Assessment ................................................................................... 18

4.1.1 Heritage Impact Assessment ...................................................................................... 18

4.1.2 Ecological Assessment ............................................................................................... 19

4.1.3 Geotechnical Investigation ......................................................................................... 20

4.1.4 Hydrogeological Investigation ..................................................................................... 22

4.1.5 Contaminated Assessment Report ............................................................................. 24

4.1.6 Traffic Impact Study ................................................................................................... 25

5.0 LANDFILL DESIGN ............................................................................................................. 26

5.1 Design Requirements ....................................................................................................... 26

5.2 Design of the Lining System ............................................................................................. 28

5.2.1 Landfill Sizing ............................................................................................................. 28

5.2.2 Detailed Liner Design For The TE Landfill .................................................................. 29

5.3 Landfill Daily Cover ........................................................................................................... 36

5.3.1 Selection for daily cover ............................................................................................. 36


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5.4 Leachate Management ..................................................................................................... 37

5.4.1 Leachate & Contaminated Stormwater Dam ............................................................... 38

5.5 Landfill Operations ............................................................................................................ 39

5.6 Final Cover, Closure & Rehabilitation ............................................................................... 40

6.0 CONCLUSION ..................................................................................................................... 41

Table 1: Landfill Design Guides & Standards ................................................................................. 28

Figure 1: Site Development Plan ................................................................................................... 14

Figure 2: Site Birds Eye View (front of site) .................................................................................... 15

Figure 3: Site Birds Eye View (Back of site) ................................................................................... 15

Figure 4: Main Entrance Gate To Landfill site ................................................................................ 16

Figure 5: Typical Layer Design for Class A Landfill ........................................................................ 27

Figure 9: Typical Final Capping Layer ........................................................................................... 41

ANNEXURES

ANNEXURE 1 Calculations

ANNEXURE 2 Drawings


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1.0 INTRODUCTION

1.1 Background

E- Square Engineering (EE) was appointed by Transnet Engineering (TE) to provide

Professional Services for the Development of a New Landfill Site at Koedoespoort Centre.

TE is an operating division of Transnet SOC Ltd and is the backbone of South Africa's railway

industry with nine product-focused businesses, approximately 120 depots, seven factories

and approximately 13,500 employees countrywide. TE operates from seven operating centres

scattered around the country namely, Koedoespoort, Kilner Park, Durban, Germiston,

Bloemfontein, Salt River and Uitenhage. TE is dedicated to in-service maintenance, repair,

upgrade, conversion and manufacture of freight wagons, mainline and suburban coaches,

diesel and electric locomotives as well as wheels, rotating machines, rolling stock equipment,

castings auxiliary equipment and services.

TE generates a lot of waste from its business that comprise of hazardous and non-hazardous

waste. The hazardous waste generated include chemicals, oils, batteries, lead, medical

waste, chemical sludge etc, Non-hazardous or general waste include food waste, metal,

plastic, rubber, paper, PPE, brake blocks etc. There is also remnants of hazardous waste

such as asbestos from previous Transnet operations in the 80-s. This waste needs to be

treated and managed efficiently and this is the reason for the need to develop the

Koedoespoort Landfill Site. This will service Koedoespoort operations, Germiston and

Bloemfontein regions.

The planning and construction of the facility will be financed by TE and the level of service

that can be provided is therefore determined by the amount that is available from the budget

and the minimum level of services guidelines prescribed by TE.

1.2 Project Location

The intended new landfill site will be developed on a site of approximately 13.7 hectares at

Koedoespoort Centre. The Koedoesspoort centre, erected on 100 hectares of land is the

biggest centre of Transnet Engineering situated in Koedoespoort, Pretoria, Gauteng, South

Africa under the City of Tshwane Metropolitan Municipality. It is located about 6.5km from

Pretoria Central.


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The GPS coordinates for all corners of the facility are as follows:

25 42 55.18E 25 43 37.81E 25 43 35.74E 25 42 54.97E

28 17 30.40S 28 17 33.87S 28 16 56.74S 28 16 59.57S

1.3 Project Team

The following role players are involved in the implementation phase of the Project.

TABLE 1: Project Team

Designation Organisation Contact Person

Client Transnet Engineering DUMA MNQUMEVU

160 Lynette Street, Kilner Park

Pretoria

0184

Tel: (012) 391 1429

Fax: 086 773 1322

[email protected]

Landfill Design Engineers E-Square Engineering (Pty)

Ltd

HAMILTON SITHOLE

95 First Road, Farmall

Kya Sands

1747

Tel: (011) 875 9906

Fax: 011 875 9906

[email protected]

EIA Specialist Mawenje Consulting Africa

(Pty) Ltd

GABRIEL NGORIMA

P.O. Box 1453

Lone hill

1062

Tel: (012) 433 6472

[email protected]

Geohydrology Specialist USK Environmental &

Waste Engineering (Pty)

Ltd

DR STEVE K KALULE

P.O. Box 1018

Ruimsig

Rooderpoort 1739

Tel: (043) 748 5567/45

Fax: 043 748 1114

[email protected]

Geotechnical Specialist

USK Environmental &

Waste Engineering (Pty)

Ltd

DR STEVE K KALULE

P.O. Box 1018

Ruimsig

Rooderpoort 1739

Tel: (043) 748 5567/45

Fax: 043 748 1114

[email protected]

mailto:[email protected]


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1.4 Aim of this Report

The report is a detailed design report for submission to Department of Water and Sanitation

(DWS) to obtain a Waste Use Licence.

The report presents the following:

Project Brief

Project Scope

Environmental Impact Assessment Process

Site Geohydrology

Site Geology

Liner Designs

2.0 SCOPE OF WORKS

The overall scope of works for the project is as follows:

2.1 Waste Disposal

Hazardous waste disposal Cell

Leachate dam for contaminated stormwater and landfill leachate dam.

Stormwater management system for clean and contaminated stormwater.

2.2 Infrastructure

For the operation of the landfill, the following facilities will be erected on site;

Recycling facility with an inspection and dispatching office

An administration building

An Operations building

An Access Control Facility with a Weigh bridge and Control room

A Security Office

A Wash bay for trucks connected to contaminated water drainage system

Peripheral gravel ring road within the site

Paved parking area

Monitoring boreholes minimum four (upstream & downstream & 2 others)

Three phase power supply

Perimeter fence

Laboratory


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3.0 INFRASTRUCTURE

3.1 Site Status

The property covers approximately 13.7 hectares most of which are covered with bushy grass

and shrubs. The entire property could be classified into three major zones: i) a rubble

recycling area in the North; ii) concrete manufacturing plant in the Southeast and; iii) an open

undeveloped land. The first two shall be of significance when developing the site. The open

area, which consist of the bulk of the land, has been largely disturbed over several years by

previous activities related to grading, dozing and dumping of mixed waste including: stock

piles of concrete and other construction rubble, paint, tar, scrap metal, tyres, etc. There is

evidence of illegal dumping of material now mostly covered in over grown vegetation. There is

a drainage line that traverses through the site from the southwest towards the eastern portion

of the site. The eastern portion of the site is a low laying area and is characterized by marshy,

swampy and wetland like conditions. This marshy character could have been created by the

impounding of water from the surface water drainage over time, and/or as result of a natural

perched water table i.e. there is an accumulation of groundwater that is above the water table

in the unsaturated zone or marshland in the portion of the site. Ref Hydrogeological Report:

USK 2015.

The site is located around industrial, residential and commercial business areas. There are

gravel roads which are being utilized by the two companies operating there. The site slopes

from the South west to North east. The site is zoned as S.A.R (South African Railway

Services), therefore the site can be developed in any way the Transnet Engineering intends

to, as long as it is in line with T.E core business.

3.2 Design Aspects

Generally, the design criteria follow set guidelines and standards and take cognisance of the

following important aspects;

Use of locally manufactured materials

Unit cost to end-user

Long term maintenance requirements

The design philosophy is that buildings should be functional and provide for adequate natural

ventilation and lighting. Buildings shall be easily accessible by people with disabilities.

Sanitary facilities and water supply shall be provided, all connected to existing municipal

services. Adequate security measures will also be incorporated without compromising the


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safety of people who shall use the facility. The design shall take cognisance of the durability

of the structure and the need to minimise maintenance costs. The design approach shall also

take into consideration the funding limits of the project and the envisaged implementation

modality for the project.

3.2.1 Architectural Designs

a) Design Approach

The Design Approach is based on a smooth operation of contaminated site remediation

and provision new landfill site in line with NEMA and acceptable solid waste management

design, construction and operation. The Approach was also driven by, national

hazardous and general solid waste requirements and municipal regulations that seek to

minimize the environmental impacts associated with landfills.

(i) Site Layout

The landfill and associated facilities are designed to

maximize the site layout

minimize potential environmental impacts

minimize health and safety risks for landfill site operations and the public

encourage recycling in accordance with the waste management hierarchy

make the most efficient use of resources on site

(ii) Access

Main Access to the site will be through Trans road on the South-Eastern part of

the site.

Secondary access will be through Lynette Street via Koedoespoort Operation

site. This access is a strategic access for use during the site contamination

remediation exercise. TE Kilner Park will also be using this access during the

landfill site operation to bring in the waste from TE Koedoespoort Site.

Solid palisade fencing will be provided to secure the site. Security gates will be

provided at the site entrances so that access to the site can be controlled during

office hours. The gate will be locked outside of normal working hours.

(iii) Gate House at Main entrance

It is the first line of active measures to control any incoming or outgoing movement to

the landfill site. This entrance will be used by vehicles coming from other TE sites

namely Germiston and Bloemfontein. The facility comprises of the guard house and


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covered drive way around the guard house only. The guard house has a security

room, toilet, and kitchenette and security control room.

(iv) Administration & Operations Block

It is situated closer to the entrance and facing the bulk of the site. This building

houses the administration and management functions for the Reverse logistics and

Recycle Facilities. It also provides a support function, administration and operations,

with no internal link between these 2 functions in the building.

The Administration will accommodate 15-20 employees and its section in the

building will accommodate the following; covered entrance, reception, male and

female toilets, kitchen, eating area, boardroom, store room and 2 offices one of

which is for the landfill site manager.

The Operations, within the same building but in a different section, will accommodate

20 employees which includes for the landfill site field workers and it will have the

following accommodation; 2 offices, printing room, storeroom, kitchen with kitchen

yard, eating area, male and female change rooms.

(v) Weigh Bridge and Control Room

The weighbridge and control room has been strategically located to ensure that it will

cater for waste coming into the site through the secondary entrance. In order to

monitor and manage the volumes of waste and cover soils coming into the site, a 40

tonne weighbridge will be installed on site. Records of the waste material will be

submitted to the regional authority annually as per permit requirements. The

equipment used to record volumes of waste will be installed in the landfill Control

Room which will be operated by qualified personnel. The landfill Control Room will

be a double storey structure, with a platform used to inspect the waste before it is

taken to the respective areas.

(vi) Reverse logistics and Recycling Centre

This facility is located between all the facilities around the landfill site and close to the

administration and operations block. The activities in the administration and

operations block support the activities in the reverse logistics and recycling centre.

The reverse logistics and recycling centre are in one building accommodating both

operations, with a warehouse in the middle which will house all the day to day


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operations of the facility. The warehouse has an open plan, with different floor

finishes and colours to demarcate different functions within the building, and a drive

through across the building for the trucks to load and offload materials to be recycled

and for separating the reverse logistics and recycling activities.

The warehouse building is designed with 4 roller shutter doors on either side or a

headroom of 8.5m in order to accommodate 2x 5 ton cranes. The warehouse

accommodates enclosed receiving office, enclosed dispatch office, receiving bay,

dispatch bay, sorting area bay, processing and storage bay for each function. On

both ends, the building has an attached single storey structure accommodating 20

employees per each operation, with the following accommodation schedule, male &

female change rooms, eating area, kitchen, storerooms and supervisor’s shared

offices.

Materials to be utilised for recycling and reverse logistic come from day to day

activities carried out at TE sites. The materials are wood, plastic and cardboard.

(vii) Laboratory

The laboratory is positioned close to the recycling facility and reverse logistics for

testing materials to be recycled. This facility will also be used for environmental lab

testing on landfill sites. Testing analysis includes; ground water, leachate, waste

water and solid waste testing. It is a building housing 3 components, dry laboratory,

wet laboratory and cold storage.

(viii) Wet waste area/Composite area

This facility is for cleaning/washing the skips & bins and it accommodates a hydro

wash areas and it is equipped with proper drainage to take the waste residue from

the skips and bins. This is a slab area having a foot print of 100 msq with bund-walls

and a light roof structure to lighten the storm water. It is positioned close to the

reverse logistics and recycling centre to wash the skips after offloading from the

recycling centre.

(ix) Wash Bay

The Washbay will be used for washing the trucks after they have dumped the waste

material either on the landfill site or reverse logistics and recycle facility. The

washbay will be a semi-automated facility which will allow for the spraying off of


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waste residue and other contaminates from the vehicles with minimal human contact

before leaving the site. The Washbay will have concrete guard walls and covered

top. Water nozzles will be placed at both sides, bottom and top, to ensure maximum

reach and spray to the vehicle. 30000 litre tank (3 x 10 000litres) will be installed to

provide water for the washing process. A water collection chamber will be provided

where all wash water will be collected before being directed to the stormwater dam.

(x) Signage

Signage indicating the class of landfill, site rules, emergency contact details and any

other regulations will be erected. These will be done in line with the Client’s

specifications.

b) Proposed Design

The Architectural Design is presented as follows;

(i) Site Development Plan

(ii) 3D Presentations

Figure 1 below is the Site Development Plan (SDP). 3D Presentations of the site are

shown in Figures 2 to 4.


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Figure 1: Site Development Plan


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Figure 2: Site Birds Eye View (front of site)

Figure 3: Site Birds Eye View (Back of site)


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Figure 4: Main Entrance Gate To Landfill site

3.2.2 Structural Designs

Structural designs were done for all the buildings discussed above.

3.2.3 Civil Designs

The following Civil designs were done;

Stormwater Water Management

Waste Water Design

Water Supply Design

Access and Internal Roads

Civil designs are guided by the following standards;

a) Design for Storm Water Drainage

The storm water design is advised by the rainfall and catchment to the proposed

developed site. As indicated in Section 3.2.1, the site has a North-Easterly slope. The

site has also been subject to drainage system that has been directed to the site. A

number of cut-off drains will be constructed on the site at strategic positions to ensure

that general storm water does not get access into and out of the general site. Storm

water cut-off drains will also be constructed around the landfill area to control storm water


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captured on the waste body and also prevent ingress into the waste body of surface

water runoff.

The base of the landfill will be designed to slope at a minimum 3% gradient to facilitate

drainage of any contaminated storm water away from the waste body to a storm water

dam located on the NE side of the landfill.

A small berm of maximum 1m height with a crest width of 0.5m should be constructed

around the perimeter of the excavation of the landfill. The berm will act as containment

for the waste body that will rise above natural ground levels after the excavation has

been filled. The construction of additional berms will not be required, as long as normal

sanitary land filling practices are adhered to, including proper compaction of the waste,

and the correct amount of soil cover is applied during operation, preventing the

occurrence of litter and odours.

b) Water Supply

Potable water will be tapped from the existing municipal water line.

c) Wastewater / Sanitation Facilities

Waste Water will be discharged in the existing municipal sewer line.

d) Access Road Design

The main access to the site will be through Trans road on the South-East part of the site.

The existing road to the site is a Class 4 surfaced road. The road will be allowed to run

undisturbed. The access to the site will be tapped from this road.

The site will be serviced by Class 5 surfaced road as indicated on the Site Development

Plan. The road around the landfill site will be a Class 5 unsurfaced road.

3.2.4 Electricals Designs

Electrical designs will cater for Power Supply into the facility. The design philosophy is that

the building should be functional and be energy efficient. The building services and general

lighting designs will take into account energy saving installations and operations.

3.2.5 Mechanical Designs

The following mechanical systems will be in cooperated in the buildings;


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Heat recovery, ventilation and air-conditioning system (HVAC)

Hot Water Generation

Fire Protection

Fire Detection

Smoke ventilation louvres at roof level.

4.0 ENVIRONMENTAL IMPACT ASSESSMENT

4.1 Environmental Impact Assessment

As per requirements from national landfill standards, an Environmental Impact Assessment

(EIA) study has been conducted to get a Waste Use Licence. Specialist studies were also

carried out to input into the EIA study and the Landfill Cell Design.

The various Specialist studies that were carried out are as follows:

a) Heritage Impact Assessment,

b) Ecological Assessment,

c) Geotechnical Investigations,

d) Hydro geological Investigations covering the following;

i. Geophysical Investigations,

ii. Borehole drilling, rehabilitation and groundwater monitoring

The Specialist studies as extracted from the respective reports carried out are outlined below;

4.1.1 Heritage Impact Assessment

Heritage Impact Assessment was intended to determine the presence of cultural heritage

sites and the impact of the proposed project on these resources within the area demarcated

for the proposed landfill site development.

4.1.1.1 Summary of Findings

The surveyed area has no identifiable heritage resources on the surface but sub-surface

chance finds are still possible.

4.1.1.2 Recommendations

If during the construction, operations or closure phases of this project, any person employed

by the developer, one of its subsidiaries, contractors and subcontractors, or service provider,

finds any artefact of cultural significance, work must cease at the site of the find and this


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person must report this find to their immediate supervisor, and through their supervisor to the

senior on-site manager.

4.1.2 Ecological Assessment

The aim of the study was;

To undertake a study of the vegetation on site and provide species list

To identify red data floral species and important habitat that may occur within the

proposed site

To provide a desktop faunal survey of the site

To assess the impact of the proposed site on the ecological integrity of the area

To provide recommendation on ecological mitigation measures for the proposed

development

To provide an indication of the relative conservation importance and ecological function

of the study area in terms of flora and fauna

4.1.2.1 Findings

Marikana Thornveld (SVcb6) – this is the most widespread vegetation within the project area

and it is endangered vegetation.

4.1.2.2 Findings and Recommendations

It was found that the study area seems to have a general trend of low sensitivity and a

decrease sensitive feature to the north-eastern side, where historic farming and sand

mining and seem to have taken place with higher intensities.

The proposed landfill and associated developments must take special cognisance of the

drainage lines which poses a threat to the integrity of habitats and fresh water resources

if erosion processes continue or are worsened.

There were no protected animal and plant species identified on site, the site warrants a

careful approach to development through keeping the lay-out and construction footprint

to a minimum

There shall be rehabilitation provision for the weed infested previously cultivated potions

of the study site using erosion rehabilitation structures for the river banks and veld

restoration techniques

The majority of the site is suitable for development but the remaining unsuitable potions

should be afforded formal protection. Therefore a development with its associated

footprint and impacts can only be possible under strict environmental protection

guidelines to ensure prevention of further habitat loss for present flora and fauna as it


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causes irreversible damage to biodiversity ecosystems within the Marikana Thornveld

vegetation type in the Savannah biome.

4.1.3 Geotechnical Investigation

The main objective of the study was to assess, evaluate and analyse the present soil material

properties of the site and provide recommendations based on the results.

4.1.3.1 Analysis Of Field And Laboratory Results

a) Site Geology

The site is underlain by shallow shale of the Silverton Formation on the South and the

diabase in the northern third of the site. Whilst the shale is relatively resistant to

weathering and thus the soil cover in the south is relatively thin, the diabase is resistant

too and forms quite a prominent ridge. The hard rock geology is covered by varying

thicknesses of an overburden that typically grades from mature residual soil through

completely decomposed and weathered rock to fresh bedrock. The evidence of the shale

and diabase was intersected in all test pits with the decomposed rock retaining the

original rock structure.

b) Site Hydrogeology

At the time of the investigation, there were no indications of presence of groundwater

within the top 4m from the surface as no water table was encountered in all boreholes

and trial pit locations. However, there was seepage of water from sides of two trial pits at

2.8 m and 3.2 m respectively. This was attributed to a possible localized patched water

table. As discussed previously, an open channel drainage line traverses eastwards

through the site to a marshy ground on the lowest areas of the property.

c) Description of the soils

The site is characterized by the residual soils comprising clayey sand or sandy clay with

pockets of silty clay. Due to the weathering of the shale and diabase, there are variations

to the soil profile across the site. Generally, the soil profile tends to be more deeply

weathered in the northern than in the southern portions.

d) Bedrock

According to borehole and trial pit logs, the depth to hard rock is concluded to be in

excess of about 4.0 and 2.5 m in the northern and southern portions respectively – with


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soft rock being probably between depths of 2 m and 3 m. Tests were terminated between

these depths.

e) Compaction Characteristics

The maximum dry density (MDD) and optimum moisture content (OMC) values ranged

between 1569 kg/m3 and 1996 kg/m3, and 11.6 % and 23.1 % respectively. Usually soils

with MDD greater than 2000 kg/m3 and OMC less than 15% are easier to compact and

recommended for road construction. The MDD is also directly proportional to the strength

characteristics of a soil.

f) Excavation

The boreholes were auger drilled to depths of 1, 0 m to 3.6 m below the surface. The trial

pits were excavated with depths varying between 2.9 m and 4.0 m. The shale and

diabase rocks caused the drilling machine and TLB refusal at those respective depths.

On this evidence the use of a TLB could be utilized to excavate to a depth of about 1.4 m

to 4.0 m below the surface. (The observations regarding depth of excavation refer to

depths measured from existing natural ground level). Hard residual soils and rocks at

deeper depth may result in difficult excavation conditions. The use of a large excavator

(18-20 ton) would probably be required to allow deeper excavations in excess of 4.0 m

over most of the site.

g) Contamination Barrier and Cover

Although the highly weathered to completely weathered residual soil in majority of the

site can be regarded as suitable construction material, much of the clayey or fine material

found was highly variable with considerable portions of silt, sand, etc. that were non

plastic. Laboratory results confirmed it to be of low to medium plasticity. Therefore,

because of its quality and contamination in several places (refer to previous USK

Consulting reports of the site), it cannot form an effective seal between the surface and

the underlying rocks (and any associated aquifer). Neither can it be suitable as one of

the layers for the capping design.


Dumped substances into the area should be considered before and during the

construction.

The in-situ clayey or fine material cannot be used as one of the layers for the liner or

capping system due to its quality and contamination


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Ground water expectations should always be considered especially during wetter months

Proposed landfill cell basin floor levels could be extended between 3.0 – 4.0 m below

ground. Sub-surface drainage shall be considered for the floor liner protection

The rock sequence of shale and diabase has undergone weathering thus it is likely not to

withstand pressure of more than 300 kPa

The in-situ clayey sands and sandy clay soils compacted to 98% Standard proctor

density are capable of forming the basin floor

The ground can sustain slopes of up to 450 without posing any slope instability issues

TLB will be required for 1.0 m to 4.0 m deep excavations unless diabase and shale rocks

are encountered. For deeper layers, a 20 ton excavator should be capable of excavating

with little difficulty.

4.1.4 Hydrogeological Investigation

The aim of the study was to;

Conduct a hydro census on site as well as the surrounding area – at least a 250 m

radius;

Conduct a geophysical survey on site by means of magnetic and resistivity methods;

Perform Electrical Conductivity profiling surveys on site;

Collect groundwater samples during the hydro census as well as after drilling of

monitoring boreholes;

Construct a preliminary, robust numerical groundwater model in order to simulate

possible plume extent and migration direction along the natural gradient at the proposed

site; and

To evaluate field generated data as well as information from literature in the public

domain and compile a report.

Assess and evaluate the hydrogeological aspects and requirements, and risk to

groundwater resources for the landfill.

Assess and evaluate the requirements for the landfill containment barrier system

(geomembrane lining) in accordance with the current legal framework and make key

recommendations in relation to the above site investigations.

Develop a suit of site-specific recommendations for consideration during the engineering

design of the proposed landfill site and associated infrastructure.


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4.1.4.1 Findings

Ten private boreholes were identified in the residential area directly to the south of the

proposed site

Residential borehole depth information was sparse as most of the residents were not

present during the time when the borehole was drilled. The maximum recorded depth is

54 mbgl;

Recorded groundwater level information is sparse due to no access for measuring

equipment. Most boreholes were closed up to prevent theft and vandalism

Static groundwater levels could also not be measured due to reasons mentioned above

and some approximations were made. The deepest groundwater level recorded was

10.89 mbgl, which is the exception. All other groundwater levels measured were less

than 6 mbgl. If one compares this with drilling records of the four boreholes that was

drilled on site, most static water levels are above the main water strike zones, which is

indicative of a piezometric level and confined conditions

Two sumps were encountered that was collecting either groundwater seepage or storm

water runoff. If one compares the chemical characteristics of the samples obtained from

the two sumps, they are very similar to groundwater samples from the boreholes in the

residential area


The option of engineering a landfill site must be viewed as a mitigation measure to an

existing threat and risk to water resources.

The aquifer at the proposed site is classed as a minor aquifer and can be described as a

low to moderately yielding aquifer system of variable water quality.

Initial studies and existing geological maps suggest that there is a contact zone on the

site.

Geophysical surveys conducted at the site remained non-conclusive about the presence

of the contact zone.

Engineering designs must diligently consider and mitigate the risk imposed by the

probable presence of the contact zone

The aquifer is rated to have a Medium susceptibility.

Due to the clay presence on site, the landfill site poses a low – medium risk to

groundwater contamination risk.

The 4 new drilled monitoring boreholes should be maintained as part of a water quality

monitoring programme.


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Monthly monitoring of water levels, rainfall figures and water quality is strongly

recommended and should strictly be adhered to. This data will form the basis from which

any changes in the groundwater regime are recognized.

A Groundwater Management Plan with relevant Groundwater Monitoring and Reporting

Protocol should be established and calibrated annually

4.1.5 Contaminated Assessment Report

The aim of the assessment was to evaluate the magnitude and severity of pollution of the five

identified sites at Koedoespoort centre.

The five sites are supposedly contaminated with asbestos which must be removed and

dumped in the landfill site under consideration. The landfill site proposed position is Site 5

which is this landfill under consideration.

4.1.5.1 Findings

Sites 1 – 4 are mainly contaminated with asbestos with low levels of heavy metals.

The contamination sources at the sites 1 – 4 can be classified as historical as there is no

on-going activity that is continuing to emit pollutants into the environmental space.

Site 5 was extremely littered with exposed observable asbestos sheets on the surface.

The direct probe drilling undertaken also exposed blue asbestos on sites 1, 4 and 5.

Besides asbestos, it was found that site 5 has been contaminated with the following

substances; Heavy Hydrocarbons (Tar), Coal waste, Oily Wastes and other mixed

wastes.

The contamination at site 5 has both a historical and current context to it, mainly because

the site continues to be used as an illegal dumping site.

The groundwater chemistry results from the samples drawn from the 4 new monitoring

wells at site 5 suggested that there is some level of impact on the groundwater from

contamination at the site.

Underground water was found to be endangered due to the on – going illegal dumping.


Given the above findings it is recommended that steps are taken to remediate all 5

impacted sites.

Given the type of contaminants and the wide spread nature contamination especially at

site 5, it is recommended that an onsite remedial option i.e. engineering the site to

contain the pollution be in form of a lined site be considered. The advantage that this


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option offers is that contaminated soil from sites 1 – 4 can be disposed of at the ‘new

engineered and lined site 5, which eliminates risk of transporting contamination far off

site.

4.1.6 Traffic Impact Study

The aim of the study was to evaluate the impact of the development of the site on the

surrounding roads network from a traffic impact point of view

4.1.6.1 Findings

Taking cognizance of the small amount of trips that are expected to be generated by the

development, it is not expected that the additional traffic would have a significant impact

on the surrounding road network.

The addition of the expected trips to be generated is not seen as to contribute to any

significant changes to the current levels of service and congestion along the route.

It is not expected that any traffic from this development will move along the local road

network in the surrounding neighbourhoods affecting the residential region close to the

site. This region is primarily located south of the site (south of the existing railway lines

and Moreleta Street.

The site access will be provided along an existing access route and is not expected to

have an impact on access by the community. The current access route serves other

developments but the current traffic volumes generated by these developments are low

as shown on the applicable figures.

The access to the site is proposed off an existing access road that is well-defined and

constructed as paved route. It intersects with Dykor Street and curves at this intersection

is such that heavy vehicles can turn without difficulty to and from the access route


Limited mitigating measures are proposed for the development to ensure safe and

efficient traffic movements and the applicant is to be responsible for the costs associated

with these

It is further recommended that the application is to be supported from a traffic

engineering point of view.

That “Box marking” is provided within the intersections of the access road and Silwereike

Street to prevent blockage of the intersections by queuing vehicles from Moreleta Street

A properly constructed access road is to be provided from the existing access road from

Dykor Street to ensure safe vehicular movements to/from the main access road


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5.0 LANDFILL DESIGN

5.1 Design Requirements

The type of waste to be dumped at the landfill comprise of hazardous and non-hazardous

waste. The hazardous waste generated include asbestos, chemicals, oils, batteries, lead,

medical waste, chemical sludge etc. Non-hazardous or general waste include food waste,

metal, plastic, rubber, paper, PPE, brake blocks etc.

Disposal for this kind of material is only allowed at a Class A landfill. This should be

designed in accordance with section 3(1) and (2) of the Norms and Standards.

In accordance with section 3(1) requirements, the typical layers are as indicated below.

Figure 8 below shows typical liner designs for Class A Landfill.


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Figure 5: Typical Layer Design for Class A Landfill


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The following standard layers have been designed for the landfill site;

a) Layer 1 (top) – Geotextile Filter

b) Layer 2 – 200mm Stone Leachate collection system

c) Layer 3– 100mm protection layer of silty sand or Geotextile protection layer

d) Layer 4 – Composite layer of 2mm HDPE Geomembrane and Geosynthetic Clay Liner

(GCL) or 2mm HDPE Geomembrane and 600mm Compacted Clay Liner (CCL)

e) Layer 5 – Geotextile Filter Layer followed by 150mm Leakage detection system of

granular material or geosynthetic equivalent

f) Layer 6 – 100mm protection layer of silty sand or Geotextile protection layer

g) Layer 7 – Composite layer of 1.5mm HDPE Geomembrane and Geosynthetic Clay Liner

(GCL) or 2mm HDPE Geomembrane and 200mm Compacted Clay Liner (CCL)

h) Layer 8 (bottom) –150mm base preparation layer

Landfill layers are designed in accordance with design guidelines below;

Table 1: Landfill Design Guides & Standards

GUIDELINE

REFERENCE

TITLE

Statute National Environmental Management Act (NEMA) (No. 107 of 1198) &

National Environmental Management Regulations

Statute National Environmental Management Waste Act (NEMWA) (No 59 of

2008)

Guide Minimum Requirements for Waste Disposal By landfill, DWA Second

Edition, 1998

Government

Gazette

Regulation 636 of the Government Gazzette 23 August 2013

5.2 Design of the Lining System

5.2.1 Landfill Sizing

The major purpose of the landfill is to remediate asbestos containing material from Sites 1-5

within the Transnet Koedoespoort area as discussed under the Alternatives Assessment

Report section. After disposing of all this material, waste from TE’s three sites namely

Germiston, Koedospoort and Bloemfontein will be disposed on the remaining space of the

landfill.


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A summary of the Landfill sizing is indicated below. Refer to Annexure 1 for detailed

calculations

(a) The expected waste for disposal from the three sites is

2633.26 tonnes/year.

(b) The amount of Waste to be remediated = 290 110 m3

(c) Maximum cell excavation depth = 4 m

(d) Maximum Available Landfill Area on Site = 31 766 m2

(e) Maximum recommended Side slopes going up and down = 1:4

(f) Maximum height above ground = 15 m

(g) Calculated Maximum Excavated Volume = 106 670.00m3

(h) Calculated Maximum Airspace = 241 117.50 m3

(i) Maximum Total Volume Available on Site is ( (g) + (h)) = 347 787.50 m3

It is therefore concluded that the Landfill is adequate for waste

remediation

(j) Therefore Volume Available after remediation i.e ((i) – (j))

= 57 677.50 m3

(k) From (k) above, the calculated site life after remediation is 20 years (this

is assuming that TE is dumping 2633.26 tonnes per year. An increase in

this quantity results in a reduced landfill life and a decrease in the

quantities disposed will increase the Landfill Life.

In 20ys, the amount of waste that can be dumped on the landfill is

289 822.91 tonnes

5.2.2 Detailed Liner Design For The TE Landfill

The quantity of leachate produced is affected to some extent by decomposition

reactions and initial moisture content. However, it is largely governed by the

amount of external and initial moisture content. Thus, a key first step in controlling

leachate migration is to limit production by preventing, to the extent feasible, the

entry of external water into the waste layers. A second step is to collect any

leachate that is produced for subsequent treatment and disposal to limit the


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amount of leachate that migrates into adjoining areas to a virtually immeasurable

volume. The integrity of the landfill structure and leachate control system should

be maintained.

Discussion on each layer is presented below;

5.2.2.1 Layer 1 – Geotextile Filter

Geotextiles are permeable fabrics which have the ability to separate, filter, reinforce, protect

and drain. Landfill designs consist of many layers to ensure that a durable system is created.

Mixing drainage materials with soils and liquids causes failures to the system. Using

geotextiles to separate these layers ensures long-term durability of the system; they

strengthen and stabilize by providing a permeable separation layer. Geotextiles are available

in different styles having various opening sizes which allows the designer to select the

appropriate filter opening size for specific soil conditions.

On this layer, the geotextile will serve the following purpose;

(i) Protection layer to prevent intrusion of soil and other waste into the layers underneath

(ii) Permeable filtration layer to separate liquid waste from solid waste.

General considerations for this layer are as follows;

(i) An A6 geotextile which provides the top end performance for available geotextiles. This

is a non-woven, continuous filament needle punched geotextile with the following

advantages;

High through flow and excellent filtration

High isotropic strength

High elongation

Superior chemical resistance

(ii) The selected filter has to last for the operational life of the landfill and the time it takes to

fill it, i. e. 20yrs (as per landfill site calculations).

(iii) The geo-textile should have 6 months life in the sun

5.2.2.2 Layer 2 – Leachate Collection System

Three different options have been considered on this layer as follows;

(i) Granular soils i.e 19mm stone and silty sand

(ii) Geosynthetics e.g geonets and geocomposites

(iii) Alternative materials such as recycled materials like tyres and glass cullet


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The following considerations have been evaluated;

The material should be permeable enough to collect and transport leachate.

In case of soils and alternative materials, permeability tests are performed using standard

test methods

In case of geosynthetics, the equivalency in the hydraulic conductivity is considered.

The material should avoid accumulation of leachate head greater than 150mm

The material should be chemically compatible with the waste. For soils and alternative

materials, chemical compatibility is checked by immersing the test sample in a

representative leachate for two to three months and then a grain size analysis is

performed. If there is a difference in the grain size distribution between the original and

tested samples, it means its not compatible.

The material should not damage the liner. In the case of soil particles, sharp particles

have a potential of damaging the liner.

The material should be stable on slopes. The stability on slopes must be evaluated

The material should not get clogged easily. Clogging potential should be checked

In this design, a geosynthetic layer has been selected for the side slopes because of the

following;

Geosynthetics are already tested and have known properties. This gives us better quality

assurance (a requirement as per Regulation 636, Clause 3(2) (g)) as human error is

reduced during construction which would not be the case if using granular and alternative

materials.

Geosynthetics ensure a high degree of consistency within the layer

A geosynthetic collection layer eliminates the need for a protection layer.

Geomembranes in the liner system are only able to perform their function if they are

reliably protected against damage during installation and landfill operation. This makes

the use of geosynthetic suitable.

Geonets are a lot more stable on slopes than sand.

However, the base of the leachate collection will comprise of a 200mm stone leachate

collection layer for the following reasons

The stone layer will provide support for the leachate collection pipes

The extra depth i.e. 200mm + 100mm will reduce the leachate head that will extend into

the waste body


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The drainage layer must contain drainage pipes of adequate size, spacing and strength to

ensure atmospheric pressure within the drainage application for the service life of the landfill.

To ensure that no leachate accumulates, the leachate should gravitate to leachate collector

pipes that drain to a leachate drainage network which lead to a leachate dam via a sump.

110mm diameter perforated HDPE pipes at 25m centres are recommended for the drainage.

The leachate should gravitate into 200mm diameter perforated HDPE pipes.

5.2.2.3 Layer 3 – Geotextile Protection Layer

On this layer, another geotextile is encooperated to protect the geomembrane underneath. It

has been found out that with a landfill liner at temperatures of 350C, the oxidant depletion time

for the geomembrane if it is in a composite liner with a geotextile protection layer is 40 years.

For the required life of 20years, this combination will be suitable.

The geotextile used should be minimum 1000g/m2 A10 bidim.

5.2.2.4 Layer 4 – Composite Liner

A composite liner is used for this layer consisting of a combination of either;

(i) Geomembrane (GM) and Compacted Clay Liner (CCL)

(ii) Geomembrane (GM) and Geosynthetic Clay Liner (GCL)

The following considerations have been evaluated;

Composite liners involving either a GM over a GCL or a GM over a CCL result in

leakages many orders of magnitude less than that expected for single liners. (Rowe,

2005). Thus using a composite liner in this design.

Geomembranes prevent contamination of soil and groundwater by leachate seepage.

This layer requires a material which is impermeable and heat resistant.

The required CCL, if used should have a high potential of expansion, with plasticity index

more than 20.

Factors determining the selection of GCL and CCL;

a) CCL Properties

Materials - Are obtained from native soils or blends of native soils and bentonites

Thickness - The layer thickness should be minimum 600mm

Permeability - should be less than or equal to 1 x 10-10 m/s

Constructability – slow speed and complicated


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Manufacturing Quality Assurance & Manufacturing Quality Control - These are

naturally found materials or mineral layers generally requiring little inspection

Construction quality assurance & Construction Quality Control – complex procedures

requiring highly skilled and knowledgeable people.

Field desiccation Sensitivity – CCLs are nearly saturated; they can desiccate during

construction

Availability of materials – Varies widely from readily available to not available at all

Experience – CCLs have been used for many decades with great confidence as a

linear material.

b) GCL Properties

Materials – made of bentonites, adhesives, geotextiles and geomembranes

Thickness - The layer thickness should be 7 – 10mm @ minimum 3.8kg/m2 which is

equivalent to 600mm of compacted clay.

Permeability - should be less than or equal to (1 -5 )x 10-11 m/s

Constructability – rapid, simple installation

Manufacturing Quality Assurance & Manufacturing Quality Control - These are

naturally found materials or mineral layers generally requiring little inspection

Construction quality assurance & Construction Quality Control – factory

manufactured material requiring constant inspection

Field desiccation Sensitivity – GCLs cannot desiccate during construction unless

prematurely hydrated.

Availability of materials – Materials are available at different suppliers and readily

transported to any site

Experience – There is limited use due to newness and non-familiarity

The factors highlighted above indicate that a GCL would be more ideal for use than a

CCL. To add on, the type of clay on site has medium to low potential of expansion with PI

less than 20 thereby not suitable for use. All material will have to be imported. It has also

been found out that composite liners involving a GM over a GCL gives rise to

substantially less leakage than those involving a GM over a CCL. (Rowe, 2005).

Precautions must be taken when placng a GCL. The moiture content of the soil below

should be as close to the optimum moisture content as possible (OMC). The GCL should

be covered as quickly as possible after placement.


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To add on, based on the fact that this is a Class A site which is a high risk, quality takes

priority over all other factors like cost etc. As such a GCL is the best option.

Selection for an HDPE

The selection for an HDPE is based on

Impermeability

This layer requires a material which is impermeable and heat resistant. This necessitates

the use of an HDPE geomembrane.

Service life

Service life is dependent on the polyethylene resin, the carbon black and the anti-oxidant

package. The anti-oxidants are depleted over time especially when immersed in water at

elevated temperatures. A 2mm HDPE will be utilised in this layer as recommended in the

regulations. A 2mm HDPE offers a long term time to anti-oxidant depletion.

Selection for a GCL

Three data sheets were obtained from AQUATAN. The Bentomat CL has been selected

because of its low conductivity which ensures a low passage for leachate. ASTM 5887 testing

is performed only on a periodic basis because the membrane is essentially impermeable.

5.2.2.5 Layer 5 – Leakage detection system (Underdrainge Monitoring System)

A geotextile filter is encooperated to filter any leachate from the liner, separate the liner and

the layer beneath (150mm leakage detection system) and to protect the liner. A6 bidim is

recommended. On the sides however, a geonet is used in place of 150mm stone, thus a

geotextile filter will not be required.

The leakage detection system follows. This system ensures that any leachate from the

system is collected in a sump. Samples for monitoring leachate will be taken from this sump

at regular basis during the operational phase of the landfill.

To ensure that no leachate accumulates, the leachate should gravitate to leachate collector

pipes that drain to a leachate drainage network which lead to a leachate dam via a sump. 100

by 100mm finger drain filled with 19mm stone wrapped in bidim at 25m centres are

recommended for the drainage.


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5.2.2.6 Layer 6 – Geotextile Protection Layer

For Class A Landfills, extra precautions should be taken to ensure that no leachate escapes

into the ground water beneath. A geotextile protection layer, A10 bidim as described above is

installed.

5.2.2.7 Layer 7 – Composite Liner

Another composite liner as described in Layer 4 above is put on this layer. The differences

are

(i) the use of 1.5mm HDPE pipe in place of 2mmm pipe

(ii) use of a CCL in place of a GCL

(iii) thickness on the CCL which should be 200mm as opposed to the 600mm for Layer 4 in a

case whereby a CCL would have been used.

Lighter layers are used since this is serving only as a precautionary measure; we are not

expecting critical situations as in Layer 4.

5.2.2.8 Layer 8 (Bottom) 150mm Base Preparation Layer

The 150mm base preparation layer is a preparatory base for the cell. It is to be compacted to

95% MOD AASTHO and acts as a foundation for the liner. It should slope at a minimum 3%

gradient towards the lowest corner of the landfill cell.

5.2.2.9 Summary of Recommended Layers

Table 2: Summary Of Recommended Layers And Prospective Suppliers

Layer Material Specification Supplier

Contacts Quantity

required

1 Geotextile A6 Bidim or

similar

Kaytech 031 717 2300

2 (i) Geosynthetic

(slopes)

1. Flownet™ Kaytech 031 717 2300

2. Geonet GN

1250

Aquatan 011 974 5271

(ii)200mm

leachate

collection

layer(Base)

3. 19mm stone Commercial

Sources

4. 110mm

Perforated

Kaytech,

Geotextile

031 717 2300,

011 965 0205


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HDPE Pipe Africa

3 Geotextile A10 Bidim Kaytech 031 717 2300

4

2mm HDPE

Geomembrane

Hi-DRILINE®

Textured

(HDPE)

Aquatan 011 974 5271

Geosynthetic

Clay Liner

X800

(4010g/m2)

Kaytech 031 717 2300

Bento 6 NFP

4000

(3670g/m2)

Geotextile

Africa

011 965 0205

5 (i) Geosynthetic

(slopes)


6. Geonet GN

1250

Aquatan 011 974 5271

(ii)200mm

leachate

collection

layer(Base)

Geotextile A10

Bidim

Kaytech 031 717 2300

19mm stone Commercial

Sources

110mm

Perforated

HDPE Pipe

Kaytech,

Geotextile

Africa

031 717 2300,

011 965 0205

6 2mm HDPE

Geomembrane

Hi-DRILINE®

Textured

(HDPE)

Aquatan 011 974 5271

CCL 200mm Commercial

Sources

7 Base Preparation 150mm In situ

Material

5.3 Landfill Daily Cover

A landfill daily cover helps control and prevents disease, fire, odour, blowing litter and

scavenging in landfills. It is also expected to control dust, improve general site aesthetics and

act as a moisture barrier to limit excess precipitation from entering waste.

5.3.1 Selection for daily cover

The following considerations were made during the selection;

a) Soil


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Soil is one of the cover materials that can be used.

It however consumes landfill space, 150mm thickness every day that could be used

for waste disposal. The size of each lift will vary depending on the quantity of waste

that is received each day. The use of cover material should be very carefully

managed so that no more than 15% of the total waste-fill in place comprises cover

material (i.e 150mm for every 1m of waste in place). If excessive cover material is

used, additional materials will have to be imported during the later operation of the

site.

Wet weather conditions can complicate the application of the cover.

Compactions must be proper to ensure the landfill reaches the design life

Plant will be required for compactions. The municipality may however run short of

plant or experience breakdowns thus affecting the landfill operation.

b) Geotextiles

is an ideal reusable daily cover material to provide overnight surface confinement

Ease of handling allows Geotextile to be quickly installed and removed on a daily

basis thus consuming no landfill space

It can be easily installed even in cold, wet weather. Its smooth surface makes it slide

easily over compacted refuse, and its tight fiber structure sheds excess precipitation.

Geotextile can be used over and over again.

For this design, an A10 Bidim geotextile is recommended for daily cover because of

reasons given above.

5.4 Leachate Management

Further to the considerations taken under the leachate collection layer, a sump will be

provided in the cell. This sump will have a 2.5mm thick HDPE liner over the 1.5mm HDPE

liner. An HDPE riser pipe will be inserted into the sump which will be perforated for the depth

of the sump. The HDPE pipe will be anchored to the side slope. A well sized submersible

pump will then be inserted into the HDPE pipe with an automatic level switch that will

automatically pump leachate once the sump is full to minimise start and stops in a timeous

manner.

The leachate collected from the landfill cell will be discharged in a leachate dam. This

leachate dam will also receive water from the stormwater dam. The mixture will be treated

and discharged into the municipal line.


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5.4.1 Leachate & Contaminated Stormwater Dam

The dam will be constructed in a similar manner as the landfill cell. Below is a summary of the

layers.

Table 2: Summary Of Recommended Layers And Prospective Suppliers

Layer Material Specification Supplier

Contacts Quantity

required

1 Geotextile A6 Bidim or

similar

Kaytech 031 717 2300

2 (i) Geosynthetic

(slopes)

1. Flownet

™

Kaytech 031 717 2300

2. Geonet GN

1250

Aquatan 011 974 5271

(ii)200mm

leachate

collection

layer(Base)

3. 19mm stone Commercial

Sources

4. 110mm

Perforated

HDPE Pipe

Kaytech,

Geotextile

Africa

031 717 2300,

011 965 0205

3 Geotextile A10 Bidim Kaytech 031 717 2300

4

2mm HDPE

Geomembrane

Hi-DRILINE®

Textured

(HDPE)

Aquatan 011 974 5271

Geosynthetic

Clay Liner

X800

(4010g/m2)

Kaytech 031 717 2300

Bento 6 NFP

4000

(3670g/m2)

Geotextile

Africa

011 965 0205

5 (i) Geosynthetic

(slopes)


6. Geonet GN

1250

Aquatan 011 974 5271

(ii)200mm

leachate

collection

layer(Base)

Geotextile A10

Bidim

Kaytech 031 717 2300

19mm stone Commercial

Sources


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110mm

Perforated

HDPE Pipe

Kaytech,

Geotextile

Africa

031 717 2300,

011 965 0205

6 2mm HDPE

Geomembrane

Hi-DRILINE®

Textured

(HDPE)

Aquatan 011 974 5271

CCL 200mm Commercial

Sources

7 Base Preparation 150mm In situ

Material

5.5 Landfill Operations

It is recommended that landfill operations commence in the lower side of the cell and that the

waste is deposited in lifts of no more than 500mm in height and compacted, with the overall

waste body being covered by 150mm compacted cover material on a daily basis in

accordance with the specifications of the permit.

The Landfill slopes above ground level should not exceed 1:4 for stability purposes and for

equipment access.

It is further recommended as follows;

At the end of every working day, a geotextile fabric must be spread on top of the

compacted waste. A time personnel should be appointed for this task.

Monitoring of water quality from all drilled boreholes to be undertaken annually – TE to

appoint a service provider for this service if it does not have capacity

Monitoring of contaminated storm water from the site to be undertaken annually– TE to

appoint a service provider for this service if it does not have capacity

A waste management system including the use of a transfer station and recycling

systems to be implemented.

All the mitigation measures for the operational phase as per EMP report to be

implemented.

A professional landfill operator must be appointed. – TE to appoint a service provider for

this service if it does not have capacity. The operator must work in accordance with the

permit, approved Environmental management plan, the minimum DWA regulations and

the local municipality regulations.


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Surveys should be undertaken annually to check the heights and slopes for compliance

with the permit.

5.6 Final Cover, Closure & Rehabilitation

Final cover is a requirement on all landfills as per Minimum Requirements. Cover is designed

for with the aim of achieving the following:

Separating the waste body from the environment for example wind and water erosion,

burrowing animals etc

Limit and control the amount of precipitation that infiltrate the waste body.

To promote stability of the waste body

Prevent ponding of water on the surface of the landfill and encourage vegetation growth.

When the capacity of the landfill is reached, the waste cells may be covered with a cap or

final cover. The landfill profile should comprise of gentle slopes and for this case a slope of

1:4 is recommended. A final 200mm thick top soil layer as shown below will be capable of

supporting vegetation in order to protect the landfill surface from wind and water erosion. The

topsoil should be grassed as soon as possible after formation to limit erosion.

The cover system consists of 150mm foundation and gas drainage layer, GCL, 200mm

compacted soil and 200mm top soil. The figure below illustrates the typical final cover layer

working in the following manner:

200mm thick top soil layer capable of supporting vegetation in order to protect the landfill

surface from wind and water erosion.

200mm thick layer of compacted soil of low permeability to limit and control the amount of

precipitation that enters the waste.

A Geosynthetic Clay Liner (GCL) to maximise runoff of precipitation while minimising

infiltration and preventing ponding of water on the landfill.

150mm thick foundation and gas drainage layer


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Figure 6: Typical Final Capping Layer

Upon closure, the site can be used for recreational activities such as a soccer field or Public

Park and this can contribute to improved social conditions in the years to come

6.0 CONCLUSION

The report addressed all requirements from Regulation 636 3(1) and 3(2). Approval of design

report by DWA will enable movement to the construction phase.


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ANNEXURES


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ANNEXURE 1 Calculations


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ANNEXURE 2 Drawings

CONTRACT NO. TE14-KLP09Q-0125: PROVISION OF … LINER DDR Report EIA.pdf · 2015-09-17 · a...

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Transcript of CONTRACT NO. TE14-KLP09Q-0125: PROVISION OF … LINER DDR Report EIA.pdf · 2015-09-17 · a...