EIA_625SOUTHERN BYPASS

THE REPUBLIC OF KENYA

CHINA ROADS & BRIDGES CORPORATION

ENVIRONMENTAL AND SOCIAL IMPACT ASSESSMENT STUDY REPORT FOR THE PROPOSED NAIROBI SOUTHERN BYPASS PROJECT

AUGUST 2010

ENVIRONMENTAL CONSULTANTS CONTRACTOR Africa W aste and Environment Manage ment

Centre Muthaiga Mini Market Complex

Left wing 3rd Floor P.O. Box 63891-00619 Muthaiga- NAIROBI. Tel: - 020-2012408

Email: [email protected] Website: www.awemac.co.ke

FIRM NEMA Reg. No. 0527

China Road and Bridge Corporation,

P.O. Box 39037, NAIROBI-KENYA Plot 330/265,Hatheru Road-Lavington

Tel: 020-3877955/3870956 Fax: 020-3870334

Email: [email protected] Website http://www.crbc.com

PROPONENT KENYA NATIONAL HIGHWAYS AUTHORITY P.O Box 49712-00100 NAIROBI. Tel: 020-8013842 Telex: 22174; Fax: 720044

PERMANENT SECRETARY MINISTRY OF ROADS P.O BOX 30260-00100, NAIROBI.

AWEMAC

Southern Bypass Project Environmental and Social Impact Assessment Study Report

ii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

PROPOSED CONSTRUCTION OF THE NAIROBI SOUTHERN BYPAS S ENVIRONMENTAL AND SOCIAL IMPACT ASSESSMENT STUDY RE PORT

LIST OF PLANNING AND PARTICIPATING CONSULTANTS

NAME QUALIFICATIONS COMPANY/AFFILIATION

Prof. Jacob K. Kibwage (Lead Expert, Reg. No. 0126)

PhD in Environmental Planning and Management

South Eastern University College &Africa Waste and Environment Management Centre

Mr. Elijah Muthusi ((Associate Expert Reg. No. 0754)

B. Sc Environmental Engineering

Africa Waste and Environment Management Centre

Mr. Theobald Luchidio (Associate Expert Reg. No. 1864)

B. Sc Environmental Science


Mr. Dominic Munyao (Associate Expert Reg. No. 2203)



Mr. Samuel Biringi (Associate Expert Reg No.2342)



Mr.David Andala(Associate Expert, Reg. No. 1927)

B. Sc Environmental Planning


Ms. Hellen Mokaya (Associate Expert, Reg. No. 1798)

B. Sc Environmental Health


Ms. Faith Moses (Associate Expert Reg. No 2605)




iii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

DECLARATION

I, Prof. Jacob K. Kibwage of Africa Waste and Environment Management Centre, submit the following Environmental and Social Impact Assessment Study Report, for the proposed Nairobi Southern Bypass Project. The Environmental Impact Assessment Study has been carried out according to the Environmental Management and Coordination Act, 1999 and Environmental (Impact Assessment and Audit) Regulations, 2003. To my knowledge, all information contained in this report is accurate and a truthful representation of all findings as relating to the project.

Signed at NAIROBI on this 31st Day of August 2010

Signature .

Designation: EIA/AUDIT LEAD EXPERT REG. NO. 0126

DECLARATION

I, ………………………………………………………. on behalf of the China Road and Bridge Corporation (CRBC) and Kenya National Hi ghways Authority (GOK) submit the following Environmental and Social Impact Assessment Study Report, for the proposed Nairobi Southern Bypass Project. To my knowledge all information contained in this report is accurate and a truthful representation of all findings as relating to the project.

Signed at NAIROBI on this ............ day of August 2010.

Signature. ……………………………………………………….

Designation : THE ROAD CONTRACTOR FOR THE PROPONENT


iv ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

ACRONYMS 0C Degrees Celsius asl above sea level BQs Bills of Quantities CBS Central Bureau of Statistics CPP Community Public Participation CRBC China Road and Bridge Corporation EIA Environmental Impact Assessment EMCA Environmental Management Coordination Act ESIA Environmental and Socio Impacts Assessment ESMP Environmental and Social Management Plan GDP Gross domestic Product GoK Government of Kenya GSU General Service Unit HQs Headquarters HWM Household Waste Management IEA Initial Environmental Audit KFS Kenya Forest Sevice KM Kilometers KWS Kenya Wildlife Services KeNHA Kenya National Highways Authority. LPG Liquefied Petroleum Gas NEC National Environment Council NEMA National Environment Management Authority NGOs Non Governmental Organizations NMA Nairobi Metropolitan area NPEP National Poverty Eradication Plan OHSO Occupational Health and Safety Office PCs Private Companies ROW Right of way STIs Sexually transmitted Infections SWM Solid Waste Management TOR Terms of Reference UNEP United Nations Environmental Programme VAT Value Added Tax VCT Voluntary counselling and testing


v ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

TABLE OF CONTENTS

ACRONYMS .............................................................................................................................................. IV

TABLE OF CONTENTS ............................................................................................................................. V

LIST OF TABLES ...................................................................................................................................... IX

LIST OF FIGURES .................................................................................................................................... IX

LIST OF PLATES ...................................................................................................................................... IX

EXECUTIVE SUMMARY .......................................................................................................................... X

1 INTRODUCTION ............................................................................................................................... 1

1.1 BACKGROUND AND RATIONALE FOR AN ENVIRONMENTAL AND SOCIAL IMPACT ASSESSMENT .... 1 1.2 SCOPE OBJECTIVE AND CRITERIA OF THE ENVIRONMENTAL IMPACT ASSESSMENT (EIA) .............. 1

1.2.1 Scope......................................................................................................................................... 1

1.2.2 Terms of Reference (TOR) for the EIA Process ........................................................................ 2

1.2.3 Data collection procedures ....................................................................................................... 3

1.2.4 ESIA organization and structure .............................................................................................. 3

1.2.5 Reporting and documentation ................................................................................................... 4

1.2.6 Responsibilities and undertaking .............................................................................................. 4

1.2.7 Methodology outline ................................................................................................................. 4

1.2.7.1 Environmental screening ........................................................................................................ 4 1.2.7.2 Environmental scoping............................................................................................................ 5 1.2.7.3 Desktop study .......................................................................................................................... 5 1.2.7.4 Site assessment and public participation ............................................................................. 5 1.2.7.5 Reporting .................................................................................................................................. 5

2 DESCRIPTION OF THE PROJECT ................................................................................................ 6

2.1 INTRODUCTION .............................................................................................................................. 6 2.2 SCOPE OF THE WORK ...................................................................................................................... 6 2.3 PROJECT DESIGN ........................................................................................................................... 7

2.3.1 Project design description ........................................................................................................ 7

2.3.2 Technical Standard ................................................................................................................... 7

2.3.2.1 Justification of Design Standard ............................................................................................ 7

2.3.2.2 Major Technical Criteria .......................................................................................................... 8 2.3.2.3 Engineering Scheme ............................................................................................................... 8

2.3.2.3.1 Route Layout ........................................................................................................................... 8 2.3.2.3.2 Sub-grade Design ................................................................................................................... 9 2.3.2.3.3 Design Principle .................................................................................................................... 10 2.3.2.3.4 The pavement structures ..................................................................................................... 11 2.3.2.3.5 Bridge and Culvert Design .................................................................................................. 11

2.3.2.3.6 Major materials ...................................................................................................................... 12 2.3.2.3.7 Bridge works .......................................................................................................................... 14 2.3.2.3.8 Grade separations and culverts .......................................................................................... 24

2.3.2.3.9 Culverts .................................................................................................................................. 25 2.3.2.3.10 Intersections ........................................................................................................................ 26 2.3.2.3.11 Grade-separated Intersection ........................................................................................... 27


vi ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

2.3.2.3.12 Traffic Engineering and road side facilities ..................................................................... 27 2.3.2.3.13 Traffic safety facilities ......................................................................................................... 28 2.3.2.3.14 Bus stations ......................................................................................................................... 30

3 DESCRIPTION OF THE PROJECT ENVIRONMENT................................................................31

3.1 INTRODUCTION .............................................................................................................................31 3.2 NAIROBI IN BRIEF .........................................................................................................................31

3.2 Physical Conditions of Project Area .......................................................................................32 3.2.1 Geographical location ........................................................................................................... 32 3.2.2 Meteorological and Hydrological Condition........................................................................ 33

3.3 CLIMATIC CONDITIONS .................................................................................................................33 3.4 TOPOGRAPHY................................................................................................................................34 3.6 SOILS ............................................................................................................................................35

3.7 HUMIDITY .....................................................................................................................................35

3.8 DRAINAGE ....................................................................................................................................35

3.9 SOCIO-ECONOMIC CHARACTERISTICS ...........................................................................................36

3.9.1 Population ...............................................................................................................................36

3.9.2 ECONOMIC ACTIVITIES .................................................................................................................36 3.9.4 Education .................................................................................................................................37

3.9.5 Gender .....................................................................................................................................38

3.9.6 Poverty Incidence ....................................................................................................................38

3.9.7 TRANSPORT .......................................................................................................................................38

4. RELEVANT POLICY, LEGISLATIVE AND REGULATORY FRAMEWORK .......................39

4.1 INTRODUCTION .............................................................................................................................39 4.2 ENVIRONMENTAL PROBLEMS IN KENYA .......................................................................................39

4.3 ENVIRONMENTAL POLICY .............................................................................................................40 4.4 INTERNATIONAL CONVENTIONS AND TREATIES ...........................................................................40

4.4.1 Ramsar Convention .................................................................................................................40

4.4.2 The Convention on Trade of Endangered Species (CITES), (1973), .......................................41

4.4.3 The Basel Convention ..............................................................................................................41

4.5 NATIONAL LEGISLATION POLICIES ...............................................................................................42

4.5.1 The Traffic Act Cap 403 of the Laws of Kenya- .......................................................................42

4.5.2 The Crop Production and Livestock Development Act, Cap 321 ............................................42

4.5.3 The Water Act Cap 372- ..........................................................................................................43

4.5.4 The Trust Land Act Cap 28 and the Physical Planning Act Cap 286-.....................................43

4.5.5 Physical Planning Act Cap 286 ...............................................................................................43

4.5.6 Agriculture Act Cap 318- .........................................................................................................43

4.5.7 Public Health Act, Cap 242- ....................................................................................................43

4.5.8 The Kenya Roads Board, 1999 ................................................................................................43

4.5.9 Environmental Management and Coordination Act 1999 .......................................................44

4.5.10 National Development strategy ...........................................................................................45

4.6 INSTITUTIONAL FRAMEWORK .......................................................................................................45

4.7 PROJECT IMPLEMENTATION STRATEGY ........................................................................................46

4.8 INSTITUTIONAL FRAMEWORK FOR PASSENGER TRANSPORT OPERATIONS ....................................46

5 PUBLIC PARTICIPATION ..............................................................................................................47

5.1 SOURCES OF INFORMATION ..........................................................................................................47


vii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

5.2 OBJECTIVES OF THE CONSULTATION AND PUBLIC PARTICIPATION ................................................47

5.3 INTERESTED AND AFFECTED PARTIES CONSULTED ........................................................................47 METHODOLOGY USED IN THE CPP .............................................................................................................48 5.4 BACKGROUND ..............................................................................................................................49 5.5 MAJOR ISSUES RAISED ..................................................................................................................50

5.5.1 Positive Social-Economic and Environmental Issues during construction stage ....................50

5.5.1.1 Enhance business Opportunities hence economic growth .............................................. 50

5.5.1.2 Employment............................................................................................................................ 51 5.5.1.3 Resettlement and compensation of the affected parties .................................................. 51

5.5.2 Positive Social-Economic and Environmental Issues during Operation stage ........................51

5.5.2.1 Improved Infrastructure ......................................................................................................... 51 5.5.2.2 Ease of Traffic Jams through Efficient and Effective Transportation ............................. 51

5.5.2.3 Increased Business Opportunity.......................................................................................... 52

5.5.2.4 Improved Security .................................................................................................................. 52 5.5.2.5 Increased Land Value ........................................................................................................... 52 5.5.2.6 A clean Environment ............................................................................................................. 52

5.5.3 Negative Issues ........................................................................................................................53

5.5.3.1 Dust Emissions and poor Health ......................................................................................... 53

5.5.3.2 Noise pollution ........................................................................................................................ 53 5.5.3.3 Vibrations ................................................................................................................................ 54 5.5.3.4 Traffic jams ............................................................................................................................. 54 5.5.3.5 Loss of Land and property .................................................................................................... 54

5.5.3.6 Waste Generation .................................................................................................................. 54 5.5.3.7 Loss of sources of income and increase in social crime .................................................. 55 5.5.3.8 Wetland Disturbance ............................................................................................................. 55 5.5.3.9 Increased water and Electricity demand ............................................................................ 56 5.5.3.10 Increase in Accidents ............................................................................................................ 56 5.5.3.11 Storm water ............................................................................................................................ 56

5.5.4 Community’s general Opinion on the project. .........................................................................56

6 POTENTIAL ENVIRONMENTAL IMPACTS ..............................................................................58

6.1 GENERAL ......................................................................................................................................58

6.2 THE ESIA PROCESS ......................................................................................................................58 6.3 THE PRE-CONSTRUCTION STAGE IMPACTS ...................................................................................58

6.3.1 Social economic Environment .................................................................................................58 6.3.1.1 The Right of Way (ROW) acquisition impacts ................................................................... 58 6.3.1.2 Loss of natural Habitat and reserve areas ......................................................................... 59 6.3.1.3 Loss of assets and land ........................................................................................................ 60 6.3.1.4 Disruption in the learning process ....................................................................................... 60

6.3.1.5 Loss of sources of income and increase in social crime .................................................. 60

6.4 ANTICIPATED IMPACTS DURING CONSTRUCTION STAGE ...............................................................61 6.4.1 Impacts on the Natural environment .......................................................................................61

6.4.1.1 Air quality ................................................................................................................................ 61 6.4.1.2 Loss of playgrounds .............................................................................................................. 61 6.4.1.3 Solid waste accumulation ..................................................................................................... 61 6.4.1.4 Impacts on surface and ground water quality .................................................................... 61 6.4.1.5 Impacts on plant species ...................................................................................................... 62 6.4.1.6 Impacts on animal species ................................................................................................... 62

6.4.2 Impacts on social amenities .....................................................................................................62 6.4.2.1 Water supply .......................................................................................................................... 62


viii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

6.4.2.2 Power usage .......................................................................................................................... 63 6.4.2.3 Housing ................................................................................................................................... 63

6.4.2.4 Land use ................................................................................................................................. 63 6.4.2.5 Transport and traffic .............................................................................................................. 63 6.4.2.6 HIV /AIDS incidences ............................................................................................................ 63 6.4.2.7 Cultural, Historic and Archaeological aspects ................................................................... 64 6.4.2.8 Economic productivity ........................................................................................................... 64

6.4.3 Health and safety impacts ........................................................................................................64 6.4.3.1 Hazardous waste accumulation ........................................................................................... 64

6.4.3.2 Public health ........................................................................................................................... 64 6.4.3.3 Occupational health and safety ........................................................................................... 65

6.4.3.4 Noise and Vibration ............................................................................................................... 65

6.5 PROJECT OPERATION STAGE ..........................................................................................................65 6.5.1 Socio-economic impacts ..........................................................................................................65

6.5.1.1 Transport and traffic flow ...................................................................................................... 65 6.5.1.2 Improved security .................................................................................................................. 65 6.5.1.3 Increased socio-economic benefits ..................................................................................... 66

6.5.1.4 Growth of existing and new towns ...................................................................................... 66

6.5.1.5 Increased revenue collection ............................................................................................... 66

6.5.2 Impact on health and safety .....................................................................................................66 6.5.2.1 Air and noise pollution ........................................................................................................... 66 6.5.2.2 Accidents and related risks .................................................................................................. 66

6.5.2.3 Reduction of water-related diseases................................................................................... 66

6.5.2.4 Health and safety impacts .................................................................................................... 67

6.5.2.5 Identification of Environmental Impacts .............................................................................. 67

7 ENVIRONMENTAL AND SOCIAL IMPACT MITIGATION MEASURES .............................71

7.2 INTRODUCTION .............................................................................................................................71 7.3 M ITIGATION OF THE IMPACTS .......................................................................................................71

7.3.1 Minimization of Hazardous Waste and Materials ...................................................................72

7.3.2 Minimization of Air Quality .....................................................................................................72

7.3.3 Minimization of Noise ..............................................................................................................73

7.3.4 Reduction of Traffic and Circulation .......................................................................................73

7.3.5 Minimization of Public Services, Utilities and Energy ............................................................73

8 ENVIRONMENTAL AND SOCIAL MANAGEMENT PLAN .....................................................75

8.2 GENERAL ......................................................................................................................................75

8.3 MONITORING AND AUDITING ........................................................................................................75 8.4 PROJECT DECOMMISSIONING ........................................................................................................83

9 CONCLUSION AND RECOMMENDATIONS ..............................................................................87

REFERENCES ............................................................................................................................................88

APPENDICES .............................................................................................................................................89


ix ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

LIST OF TABLES

Table 1: Major Technical Parameters ........................................................................................ 8

Table 2: Grade of Concrete used in Bridge Structure ........................................................... 13

Table 3: List of Viaduct Bridges ................................................................................................ 15

Table 4: A list of Grade-separation Bridge .............................................................................. 23

Table 5: Estimated quantities of ROW .................................................................................... 59

Table 6: Impacts of Road Project Construction Activities and Environmental Parameters ....................................................................................................................................................... 68

Table 7: ESMP during the road construction and maintenance phases ............................ 76

Table 8: Environmental and Social Management Plan for the decommissioning and Closure ......................................................................................................................................... 83

Table 9: The Restoration Plan .................................................................................................. 84

LIST OF FIGURES

Figure 1: Institutional Framework for EMCA .......................................................................... 45

LIST OF PLATES

Plate 1: Public Meeting at Kikuyu .................................................................................................. 49

Plate 2: Public Meeting at Mombasa Road, outside Ole-Sereni Hotel .......................................... 49

Plate 3: Public Meeting at Kibera outside COWAFK grounds opposite Raila Centre in Kibera ..... 50

Plate 4: Waste dumped at the road side ....................................................................................... 52

Plate 5: Ole Sereni Hotel and a School Neibouring the Southern Bypass ..................................... 53

Plate 6: Business women and children selling their goodies along the Bypass ............................ 55

Plate 7: Nairobi National Park Bordering the Southern Bypass Road ........................................... 59

Plate 8: Kibera slums at the lower side of Langata area ............................................................... 60

Plate 9: KFS Ngong Forest where the bypass crosses ................................................................... 62


x ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

EXECUTIVE SUMMARY

Introduction The proponent; Kenya National Highways Authority, Government of Kenya and China Road and Bridge Corporation as the contractor are proposing to construct the Nairobi Southern Bypass within Nairobi Road Network Master Plan covering a total of 28.6km. The project road will be funded through raising Chinese Buyer’s Credit and aims at providing Nairobi with an essential corridor for fast transit traffic, hence facilitating quick diversion movement of the urban traffic and improve Nairobi Metropolitan Area’s road network. The Nairobi Southern bypass covers 28.6 Kilometers designed to the Class A – International Trunk Road Standard as pursuant to the ‘Road Design Manual” of Kenya as well as in accordance with their functions in the road network and the need of socio-economic growth in Nairobi and by extension to the outside world. Environmental Impact Assessment is a tool for environmental conservation and has been identified as a key component in new project implementation. According to section 58 of the Environmental Management and Coordination Act (EMCA) No.8 of 1999 second schedule 9 (1), and Environmental (Impact Assessment and Audit) regulation, 2003, new projects must undergo Environmental Impact Assessment. The Report of the same must be submitted to National Environment Management Authority (NEMA) for approval and issuance of relevant certificates. This was necessary as many forms of developmental activities cause damage to the environment and hence the greatest challenge today is to maintain sustainable development through sustainable use of natural resources without interfering with the environment. Scope Objective and Criteria of the Environmental I mpact Assessment (EIA) Africa Waste and Environment Management Centre, a firm of experts, under the lead expertise of Prof. Jacob K. Kibwage, a NEMA registered and licensed Lead Expert in Environmental Impact Assessment and Auditing was appointed as a Consultant to conduct the Environmental and Social Impact Assessment of the proposed Nairobi Southern Bypass project. The scope of the assessment covered impacts directly or indirectly associated with the construction and operation / routine maintenance activities of the proposed project roads; civil work, building of bridges/viaducts/flyovers, execution of drainage structures, road safety devices, bus stop shades, street lights among others. The output of this work was a comprehensive Environmental and Social Impact Assessment Study Report for the purposes of applying for an EIA License. The consultant on behalf of the proponent conducted the EIA by incorporating but not limited to the following terms of reference: • The location of the proposed project road


xi ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

• A concise description of the national environmental legislative and regulatory framework, baseline information, and any other relevant information related to the project

• The technology, procedures and processes to be used, in the implementation of the project

• The materials to be used in the construction and maintenance of the project • The products, by-products and waste to be generated by the project

• A description of the potentially affected environment

• The environmental effects of the project including the social and cultural effects and the direct, indirect, cumulative, irreversible, short-term and long-term effects anticipated

• To recommend a specific environmentally sound and affordable waste management system

• To provide alternative technologies and processes available and reasons for preferring the chosen technology and processes

• Analysis of alternatives including project site, design and technologies • An environmental management plan proposing the measures for eliminating,

minimizing or mitigating adverse impacts on the environment, including the cost, timeframe and responsibility to implement the measures

• Provide an action plan for the prevention and management of the foreseeable accidents and hazardous activities in the cause of carrying out development activities

• Propose measures to prevent health hazards and to ensure security in the working environment for the employees, area residents, business operators, travelers and for the management in case of emergencies

• An identification of gaps in knowledge and uncertainties which were encountered in compiling the information

• An economic and social analysis of the project Methodology Outline Due to the magnitude of the proposed project, a study report was opted for to ensure comprehensiveness and completeness of the assessment. The general steps followed during the assessment were as follows: • Environment screening, in which the project was identified as among those requiring

environmental impact assessment under schedule 2 of EMCA, 1999 • Environmental scoping that provided the key environmental issues

• Desktop studies and interviews

• Physical inspection of the site and surrounding areas • EIA Public participation via the use of questionnaires and public meetings

• Reporting.


xii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

Project Description Starting from the south eastern Nairobi, the proposed road project, in the form of a bypass, will link up other major road trunks in Nairobi area including Mombasa road, Outer Ring Road, Langata(C58), Ngong(C60), Dagoretti(C63), Thogoto(D411) and then passes through Ondiri River and a Railway ;and finally join Kabete Limuru road(A104) in the town of Kikuyu located south west Nairobi. The project road, once completed, will provide the Nairobi metropolitan area with a vital high speed artery for the traffic hence facilitating prompt diversion of the transit traffic and the urban traffic movement. Located in the confluence of one major international trunk road, i.e. the city of Nairobi has long been suffering from heavy transit traffic congestion which has to cut through the urban centre of Nairobi due to lack of bypass and ring road. According to the traffic survey level of A104, C58, C60, and C63 roads are A, B, C and D level. Furthermore two service roads will be added for the project: one road link Mombasa and Langat a road totaling 6042.471m, the other will link Lang’ata Road and Ngong Forest totaling 2500m.both service roads have the same cross-section of 0.5m soil shoulder +2.0 m hard shoulder +2×3.5carriageway+0.5 soil shoulder, and also have a consistent pavement structure with that of Main road and the same cross section with that of 12m slip road. The Southern bypass has been designed to the class A –International Trunk Road Standard. In terms of cross section layout, dual 4-lane carriage way on 22.5m wide sub grade is adopted in town dotted areas. The design speed is 80km/h and street lighting is for the entire project road. The project will cost approximately One Hundred and Ninety Five Million US Dollars (USS 195,000,000) or estimated at Fifteen Billion Nine Hundred and Twenty Seven Million Four Hundred and Fifty Nine Thousand Four H undred and fifty Kenya Shillings (KShs 15,927,459,450). Impacts and Mitigation Measures There are both positive and negative impacts associated with the proposed road project. These are identified according to two phases namely: Pre-Construction Phase, Construction Phase and Operational Phase. In general the following positive impacts are associated with the proposed development;

• Provision of employment opportunities • Enhance gains in the Local, National and Regional Economy

• Lead to Less time spent on the road due to traffic jam

• Increased business opportunity


xiii ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

• Reduction in environmental pollution; exhaust emission in traffic jams

• Reduced road accidents • Reduction in vehicle maintenance cost

• Among others The negative Impacts associated with the proposed project are:

• Displacement of people from their residences • Encroachment of the Nairobi National park land.

• Loss of physical assets.

• Relocation and interference with public utilities and shared infrastructure e.g. social facilities e.g. St Therese hospital, Alliance High School playground, Kikuyu town bus park among others, access roads, water, sewerage and drainage etc.

• Loss of farming land

• Hydrology and water quality degradation

• Noise pollution • Dust emissions

• Increased insecurity

• Increased water demand • Increased incidences of HIV/AIDS.

• Generation of exhaust emissions

• Construction materials and energy use • Waste management

• Workers accidents and hazards during construction

The Proposed Southern Bypass may encroach the edge of the Nairobi national park

along the existing service road running from Mombasa road through to Langata Road.

Negotiations between the Kenya Wildlife Service (Nairobi National park) and the

proponent (KeNHA) are at an advanced stage and soon they will come to a consensus.

However, the impacts will not be adverse since the bypass follows the boundary of the

National park and thus do not affect movement routes, mating grounds and corridors

followed by the wild animals.

Other concerned parties which may be affected include the Ondiri swamp, the Ngong,

Thogoto, Alliance High School Forest and playground. However necessary mitigation

measures will be implemented as per ESMP.

In order to alleviate the negative impacts associated with the project the proponents

shall take several measures, among these are; dust emissions will be controlled by the

following measures where applicable:

• Watering all active construction areas when necessary.


xiv ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

• Cover all trucks hauling soil, sand and other loose materials or require all trucks

to maintain at least two feet of freeboard.

• Pave, apply water when necessary, or apply (non-toxic) soil stabilizers on all

unpaved access roads, parking areas and staging areas at construction sites.

• Sweep daily (with water sweepers) all paved access roads, parking areas and

bus stops at construction sites.

The following noise-suppression techniques will be employed to minimize the impact of

temporary construction noise at the project site.

• Install portable barriers to shield compressors and other small stationary

equipment where necessary.

• Use quiet equipment (i.e. equipment designed with noise control elements).

• Co-ordinate with relevant agencies regarding all substation construction activities

in the project neighborhoods.

• Limit pickup, trucks and other small equipment to an idling time when necessary,

observe a common-sense approach to vehicle use, and encourage workers to

shut off vehicle engines whenever possible.

In order to control exhaust emissions the following measures shall be implemented

during construction.

• Vehicle idling time shall be minimized

• Alternatively fuelled construction equipment shall be used where feasible

• Equipment shall be properly tuned and maintained.

Several measures shall be put in place to mitigate the impacts that are likely to lead to

Hydrology and water quality degradation. The proponent will prepare a hazardous

substance control and emergency response plan that will include preparations for quick

and safe clean up of accidental spills. It will prescribe hazardous-materials handling

procedures to reduce the potential for a spill during construction, and will include an

emergency response programme to ensure quick and safe cleanup of accidental spills.

The plan will identify areas where refueling and vehicle maintenance activities and

storage of hazardous materials, if any, will be permitted.

Adequate collection and storage of waste on site and safe transportation to the disposal

sites and disposal methods at designated area shall be provided. In addition covers for

refuse containers and appropriate personal protective equipments shall also be provided

by the proponent/contractor.


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Conclusion

It is quite evident that the proposed Southern bypass in the project area will bring

positive impacts including creation of employment, gains in the Local and National

Economy, less time spent on the road, increased business opportunity, reduced road

accidents, reduction in vehicle maintenance cost, improved infrastructure, increase in

revenue among others. However, although the project will come with various positive

impacts, negative impacts will also be experienced hence the need to mitigate them. The

negative impacts of this project include: Increased vehicles into Nairobi city at one

particular time without adequate commensurate parking services and facilities; increased

pressure on infrastructure; air pollution; noise pollution and generation of wastes among

others.

The proponent will ensure that clear negotiations and understanding of the project

impacts is taken care of. Mitigation measures to the directly affected parties like the

KWS, Ngong Forest, Thogoto Forest, Alliance High School and Ondiri Swamp will be

observed to ensure no adverse impact are caused.

On the basis of the above and taking cognizance of the fact that the proponent has

proved financially and environmentally credible, it is our recommendation that the project

be allowed to go on provided the mitigation measures outlined in this report are adhered

to and the Environmental Management Plan (EMP) is implemented to the letter.


1 ©AWEMAC, 2010 CRBC/Kenya National Highways Authority, 2010

1 INTRODUCTION

1.1 Background and Rationale for an Environmental a nd Social Impact Assessment The proponent; Kenya National Highways Authority, Government of Kenya and China Road and Bridge Corporation as the contractor are proposing to construct the Nairobi Southern Bypass within Nairobi Road Network Master Plan covering a total of 28.6km. The project road will be funded through raising Chinese Buyer’s Credit and aims at providing Nairobi with an essential corridor for fast transit traffic, hence facilitating quick diversion movement of the urban traffic and improve Nairobi Metropolitan Area’s road network. The Nairobi Southern bypass covers 28.6 Kilometers designed to the Class A – International Trunk Road Standard as pursuant to the ‘Road Design Manual” of Kenya as well as in accordance with their functions in the road network and the need of socio-economic growth in Nairobi and by extension to the outside world. Environmental Impact Assessment is a tool for environmental conservation and has been identified as a key component in new project implementation. According to section 58 of the Environmental Management and Coordination Act (EMCA) No.8 of 1999 second schedule 9 (1), and Environmental (Impact Assessment and Audit) regulation, 2003, new projects must undergo Environmental Impact Assessment. The Report of the same must be submitted to National Environment Management Authority (NEMA) for approval and issuance of relevant certificates. This was necessary as many forms of developmental activities cause damage to the environment and hence the greatest challenge today is to maintain sustainable development through sustainable use of natural resources without interfering with the environment 1.2 Scope objective and criteria of the Environment al Impact Assessment (EIA) 1.2.1 Scope The Kenya Government policy on all new projects, programmes or activities requires that an environmental impact assessment be carried out at the planning stages of the proposed undertaking to ensure that significant impacts on the environment are taken into consideration during the design, construction, operation and decommissioning of the facility. The scope of this Environmental and Social Impact Assessment, therefore, covered:

• The baseline environmental conditions of the area, • Description of the proposed project,

• Provisions of the relevant environmental laws,

• Identification and discussion of any adverse impacts to the environment anticipated from the proposed project,

• Appropriate mitigation measures, • Provision of an environmental management plan outline.



1.2.2 Terms of Reference (TOR) for the EIA Process Africa Waste and Environment Management Centre under the lead expertise of Prof. Jacob K. Kibwage, a NEMA registered and licensed Lead Expert in Environmental Impact Assessment and Auditing was appointed as a Consultant to conduct the Environmental and Social Impact Assessment of the proposed Nairobi Southern Bypass. The scope of the assessment covered impacts directly or indirectly associated with the construction and operation /routine maintenance activities of the proposed project roads; civil work, building of bridges/viaducts/flyovers, execution of drainage structures, road safety devices, bus stop shades, street lights among others. The output of this work was a comprehensive Environmental and Social Impact Assessment Study Report for the purposes of applying for an EIA License. It was recognised that any form of development such as the road construction project is likely to impact the site and the surrounding environment hence, before any commencement of any work, there is an urgent need to carry out an Environmental and Social Impact Assessment in compliance with the Environmental Management and Coordination Act (EMCA) of 1999 and Environmental Impact Assessment and Audit Regulations, 2003. The Environmental and Social Impact Assessment included the necessary specialist studies to determine the environmental impacts relating to the bio-physical, health and safety and socio-economic aspects and to determine the issues or concerns from the relevant authorities and interested and/or affected parties. The appropriate measures to ensure co-existence of the proposed development with other social and economic activities in the area are provided as part of Environmental Management Action Plan. The main objective of the assignment was to assist the proponent to prepare a study report after carrying out an Environmental and Social Impact Assessment (ESIA) of the Nairobi Southern bypass, ensure the proposed development takes into consideration appropriate measures to mitigate any adverse impacts to the environment. The study identified existing and potential environmental impacts and possible concerns that interested and/or affected parties have with the development, as well as the associated prevention and mitigation measures for the negative impacts as stipulated in the Environmental and Social Management Plan (ESMP) proposed. The consultant on behalf of the proponent conducted the study by incorporating but not limited to the following terms of reference:- • The proposed location of the Nairobi Southern Bypass Road project.

• A concise description of the national environmental legislative and regulatory framework, baseline information, and any other relevant information related to the project

• The objectives of the project.



• The technology, procedures and processes to be used, in the implementation of the project

• The materials to be used in the construction and implementation of the project

• The products, by-products and waste to be generated by the project • A description of the potentially affected environment

• The environmental effects of the project including the social and cultural effects and the direct, indirect, cumulative, irreversible, short-term and long-term effects anticipated

• To recommend a specific environmentally sound and affordable wastewater management system

• Provide alternative technologies and processes available and reasons of preferring the chosen technology and processes

• Analysis of alternatives including project site, design and technologies.

• An environmental management plan proposing the measures for eliminating, minimizing or mitigating adverse impacts on the environment, including the cost, timeframe and responsibility to implement the measures.

• Provide an action plan for the prevention and management of the foreseeable accidents and hazardous activities in the cause of carrying out development activities.

• Propose measures to prevent health hazards and to ensure security in the working environment for the employees, residents in the neighborhoods, business operators, and travelers and for the management in case of emergencies.

• An identification of gaps in knowledge and uncertainties which were encountered in compiling the information

• An economic and social analysis of the project

• Such other matters as the Authority may require. 1.2.3 Data collection procedures First, the Consultant undertook environmental screening and scoping to avoid unnecessary data. The data collection was carried out through questionnaires/standard interview schedules, public meetings, use of checklists, observations and photography, site visits and desktop environmental studies, where necessary in the manner specified in Part V (section 31-41) of the Environmental (Impact Assessment and Audit) Regulations, 2003. 1.2.4 ESIA organization and structure The ESIA was carried out to full completion within a period of fourteen (14) days from the date of undertaking the assignment. The Consultant (Lead Expert) coordinated the day-to-day functions and any related institutional support matters. Otherwise, all formal communications were directed to NEMA through the proponent.



1.2.5 Reporting and documentation The Environmental and Social Impacts Assessment Study Report from the findings was compiled in accordance with the guidelines issued by NEMA for such works and was prepared and submitted by the proponent for consideration and approval. The Consultant ensured constant briefing of the client during the exercise. Description plans/maps and sketches showing various activities are part of the Appendices. 1.2.6 Responsibilities and undertaking The firm of experts undertook to meet all logistical costs relating to the assignment, including those of production of the report and any other relevant material. The consultant arranged for own transport and travels during the exercise. The Proponent provided a contact person on the site of the proposed construction of the Nairobi Southern bypass Project, to provide all the information required by the consultant on behalf of the proponent. The proponent also provided site plan/map(s) showing roads, service lines/layout and other site details, construction material details, proposed process outline and anticipated by-products, project brief, and road history. The output from the consultants includes the following:-

• An Environmental and Social Impact Assessment Study Report comprising of an executive summary, study approach, baseline conditions, anticipated impacts and proposed mitigation measures,

• An Environmental Management Plan outline which also forms part of the report recommendations.

1.2.7 Methodology outline Given the magnitude and the complexity of the proposed project, a full Environmental and Social Impact Assessment Study report was opted for to ensure comprehensiveness and completeness of the assessment. The general steps followed during the assessment were as follows:

• Environment screening, in which the project was identified as among those requiring environmental impact assessment under schedule 2 of EMCA, 1999

• Environmental scoping that provided the key environmental issues • Desktop studies and interviews

• Physical inspection of the site and surrounding areas

• EIA Public participation via the use of questionnaires and public barazas/meetings • Reporting. 1.2.7.1 Environmental screening This step was applied to determine whether an environmental impact assessment was required and what level of assessment was necessary. This was done in reference to requirements of the EMCA, 1999, and specifically the second schedule. Issues



considered included the physical location, sensitive issues and nature of anticipated impacts. 1.2.7.2 Environmental scoping The scoping process helped narrow down onto the most critical issues requiring attention during the assessment. Environmental issues were categorized into physical, natural/ecological, social, economic and cultural aspects. 1.2.7.3 Desktop study This included documentary review on the nature of the proposed activities, project documents, designs policy and legislative framework as well as the environmental setting of the area among others. It also included discussions with the contractor, the resident engineer, and as well as interviews with local residents and investors living along the Road. 1.2.7.4 Site assessment and public participation Field visits were meant for physical inspections of the site characteristics and the environmental status of the surrounding areas to determine the anticipated impacts. To ensure adequate public participation in the ESIA process, questionnaires were administered and public meetings held to the site neighbors and individuals along the proposed road project and the information gathered was subsequently synthesized and incorporated into the ESIA Study Report. 1.2.7.5 Reporting In addition to constant briefing of the client, this Environmental and Social Impact Assessment Study Report was prepared. The contents were presented for submission to NEMA as required by law.



2 DESCRIPTION OF THE PROJECT

2.1 Introduction The proponent; Kenya National Highways Authority, Government of Kenya and China Road and Bridge Corporation as the contractor are proposing to construct the Nairobi Southern Bypass within Nairobi Road Network Master Plan covering a total of 28.6km. The project road will be funded through raising Chinese Buyer’s Credit and aims at providing Nairobi with an essential corridor for fast transit traffic, hence facilitating quick diversion movement of the urban traffic and improve Nairobi Metropolitan Area’s road network. The Nairobi Southern bypass covers 28.6 Kilometers designed to the Class A – International Trunk Road Standard as pursuant to the ‘Road Design Manual” of Kenya as well as in accordance with their functions in the road network and the need of socio-economic growth in Nairobi and by extension to the outside world. . Starting from the southeastern Nairobi, the proposed road project, in the form of a bypass, will link up other major road trunks in Nairobi area including Mombasa road, Outer Ring road,Langata(C58),Ngong (C60),Dagoretti(C63),and Thogoto(D411)and then passes through Ondiri River and a Railway ;and finally join Kabete Limuru road(A104) in the town of Kikuyu located south west Nairobi. The project road, once completed, will provide the Nairobi metropolitan area with a vital high speed artery for the traffic hence facilitating prompt diversion of the transit traffic and the urban traffic movement. Located in the confluence of one major international trunk road, i.e. the city of Nairobi has long been suffering from heavy transit traffic congestion which has to cut through the urban centre of Nairobi due to lack of bypass and ring road. According to the traffic survey level of A104, C58, C60, and C63 roads are A, B, C and D level. Furthermore two service roads will be added for the project: one road link Mombasa and Lang’ata road totaling 6042.471m, the other will link Lang’ata Road and Ngong Forest totaling 2500m.both service roads have the same cross-section of 0.5m soil shoulder +2.0 m hard shoulder +2×3.5carriageway+0.5 soil shoulder, and also have a consistent pavement structure with that of Main road and the same cross section with that of 12m slip road. The Southern bypass has been designed to the class A –International Trunk Road Standard. In terms of cross section layout, dual 4-lane carriage way on 22.5m wide sub grade is adopted in town dotted areas. The design speed is 80km/h and street lighting is for the entire project road. 2.2 Scope of the work Broadly the work will involve; site clearance, earth works, drainage works, construction of bridges and culverts construction of flyovers, viaducts and road over rail, pavement construction, and execution of drainage structures, road safety and bus stop/station



construction among other finer details related to road construction. The Contractor will be Ms China Road and Bridge Corporation (CRBC). 2.3 Project Design The project road consists of the Southern Bypass major trunk road links in the Nairobi Road network, Master Plan: 2.3.1 Project design description Starting from the southeastern Nairobi, the proposed road project, in the form of a bypass, will link up other major road trunks in Nairobi area including Mombasa road, Outer Ring Road, Langata(C58),Ngong (C60), Dagoretti(C63), Thogoto(D411) and then passes through Ondiri River and a Railway ;and finally join Kabete Limuru road(A104) in the town of Kikuyu located south west Nairobi. The project road, once completed, will provide the Nairobi metropolitan area with a vital high speed artery for the traffic hence facilitating prompt diversion of the transit traffic and the urban traffic movement. Located in the confluence of one major international trunk road, i.e. the city Nairobi has long been suffering from heavy transit traffic congestion which has to cut through the urban centre of Nairobi due to lack of bypass and ring road. According to the traffic survey level of A104, C58, C60, and C63 roads are A, B, C and D level. Furthermore two service roads will be added for the project: one road link Mombasa and Langat’a road totaling 6042.471m,the other will link Langata Road and Ngong Forest totaling 2500m.both service roads have the same cross-section of 0.5m soil shoulder +2.0 m hard shoulder +2×3.5carriageway+0.5 soil shoulder, and also have a consistent pavement structure with that of Main road and the same cross section with that of 12m slip road. The southern bypass has been designed to the class A –International Trunk Road Standard. In terms of cross section layout, dual 4-lane carriage way on 22.5m wide sub grade is adopted in town dotted areas. The design speed is 80km/h and street lighting is for the entire project road. 2.3.2 Technical Standard 2.3.2.1 Justification of Design Standard The project is the Southern Bypass Project in Nairobi Road Network Plan. By means of precast to the future traffic volume, the traffic volume of the proposed project will reach 46,522pcu/d by the year of 2033. Based on the Road Design Manual and socio-economic developing demand in Nairobi, the Project is proposed to be a Class A National Trunk Highway with 4 lanes and median strip. The Design Speed is 80km/h and the top of sub grade is 22.5m wide.



2.3.2.2 Major Technical Criteria Table 1: Major Technical Parameters

Item Unit Description

Terrain Category - Flat/Rolling

Class of Highway - Class A National Trunk Highway

Design Speed km/h 80

Design Flood Return Period year 50

Subgrade Width m 22.5

Width of Carriageway m 2-2×3.5

Stopping Sight Distance m 120

Minimum Radius of Horizontal Curve m 350

Maximum Gradient % 5

Design Vehicle Load on - BS5400HA Load, 30 units

Bridges and Culverts HB Load

Bridge Width m Same as the Subgrade Width

2.3.2.3 Engineering Scheme 2.3.2.3.1 Route Layout The route scheme of the project road is determined initially on the geographical map in scale of 1:2500, following the corridor designated by Kenya government. Then field investigation was carried out to rationally avoid existing buildings and infrastructure such as hotels etc. Optimization is made based on actual geological and landform. Totaling 28.6km in design, the Project Road starts from the junction of Mombasa Road where will build an interchange at SK0+397.500 and ends at SK28+600 linking Kabete Limuru Road (A104) at Kikuyu Town. The Road crosses National Park westward then goes through Lang’ata Road (C58), Community Road, Ngong Road (C60), Dagoretti Road (C63), Thogoto Road (D411) then passes through Ondiri River and a railway.



Furthermore, two service roads will be added for the Project: one road will link Mombasa Road and Lang’ata Road totaling 6042.471m, the other will link Lang’ata Road and Ngong Forest totaling 2500m. Both service roads have the same cross section of 0.5m soil shoulder + 2.0m hard shoulder + 2×3.5 carriageway + 2.0m hard shoulder + 0.5m soil shoulder, and also have a consistent pavement structure with that of Main Road and same cross section with that of 12m-slip road. 2.3.2.3.2 Sub-grade Design

(1) General Principle of Sub grade Design

In principle, the regular sub grade shall be designed taking overall account of such physical conditions as the terrain, relief, hydrographic and meteorological features as well as the geological conditions in the Project Corridor, adopting cost-effective defects-control measures, and putting stress on harmoniously merging with local environment.

(2) Cross Section of Subgrade

Dual 2-lane with a 3.0m wide central strip and 20.25m median strip, the width of carriageway is 23.5 + 23.5m, 2.0m hard shoulder and 0.5m soil shoulder, total width of road being 22.5m.

Cross- fall of Crown According to Kenya Road Design Manual, the specific type of the project road, local natural conditions and existing road in the project area, the cross fall of the crown of carriageway shall be 2.5% while the hard shoulder shall be 4%. Side Slope of Sub grade According to Kenya Road Design Manual, side slope of the regular filled sub grade shall be arranged as indicated in the feasibility study report. Topsoil Stripping and Pre-fill Compaction In this project, 30cm of top soil shall be stripped and the thickness of compaction before filling shall be 15cm. Range of the Right-of-Way (ROW) Most of the route shall be within 60m wide corridor provided by Kenya government, only certain local sections need to acquire additional ROW. Total land occupation area is 1,958,656 square meters, among which there is 431,102 square meters are outside of ROW which are used for Interchange at starting point, Community Intersection, Ngong Road Intersection, Dagoretti Intersection and Thogoto Intersection.



Earth Borrowing Soil borrowing for the sub-grade mainly focuses on road sections of

SK9+630～SK10+920 and SK21+240～SK22+590. As land is private property in Kenya,

it is hard to find proper borrow pits along the Project Corridor, hence earth needed for the Southern Bypass shall be purchased from other sources. Special Roadbed Unsuitable Soil, mainly black cotton soil about 100 to 250 cm in layer thickness, has been identified during field geological survey. Sub-grade therein shall be treated by digging and removing the inferior soil and replacing it with 100-250cm-thick sub-grade fillings which is mainly distributed at SK0+000~SK5+600, SK11+000~SK11+280, SK11+420~SK11+640, SK11+800~SK12+200, SK12+760~SK13+050 and SK16+240-SK16+980. To ensure side slope stability, control erosion and achieve an aesthetic design, all filled and cut side slopes shall be protected. Soil slope with fill height more than 4m shall adopt herringbone framework with turfing while stable and weathered rock section with cut height more than 4m shall be protected by mortar rubble grid, and stable soil slope with cut or fill height less than or equal to 4m shall use seeding protection by local grass. Sub-grade Drainage A sound sub-grade drainage system has been designed by taking overall consideration of the road class, terrain, hydrological and meteorological features as well as bridge and culvert layout, and through coordination with the existing local drainage system to protect the local farm land and other water conservancy facilities from being scoured and damaged .In addition, emphasis has been put on environmental protection, erosion control and anti-pollution of the water source. For roads passing through cities and towns, drainage design shall be in coordination with the existing and planned urban drainage system and facilities. 2.3.2.3.3 Design Principle Pavement on the Project Road has been designed in a comprehensive way taking overall account of geological, hydrological, meteorological features and soil characteristics, and making full use of local road-building experience. On the premise of meeting the traffic needs and road function requirements, the pavement design has been carried out in compliance with the principle of proper use of local materials, construction and maintenance convenience as well as fund saving with the pavement structure carefully selected on the basis of advanced road-building technology, cost-effectiveness, safety and reliability considerations, and facilitating mechanized and mass production..



2.3.2.3.4 The pavement structures

• Carriageway Pavement Structure consists of

Asphalt Surface Dressing (10/14): 1cm; Asphalt Concrete Type-I(0-20): 5cm; Dense Bitumen Macadam (0-30): 15cm; Cement Stabilized Graded Crushed Stone (Cement Ratio: 2%-4%): 17.5cm; Sub grade I&II: 30cm Total Pavement Thickness: 68.5cm.

• Pavement Structure of Shoulder Comprises of:

Asphalt Concrete Type-II (0-14): 3.5cm; Cement Stabilized Graded Crushed Stone (Cement Ratio: 2%-4%): 15cm; Cement Stabilized Graded Crushed Stone (Cement Ratio: 2%-4%): 17.5cm; Sub grade I&II: 30cm Total Pavement Thickness: 66cm.

• Pavement Structure of Slip Road and Service Road is composed of

Surface Dressing (10/14): 1cm; Asphalt Concrete Type-I (0-20): 5cm; Dense Bitumen Macadam (0-30): 15cm; Cement Stabilized Graded Crushed Stone (Cement Ratio: 2%-4%): 17.5cm; Sub-grade I&II: 30cm; Total Thickness: 68.5cm. 2.3.2.3.5 Bridge and Culvert Design Basic Documents Referred to in Design

• Road Design Manual of the Republic of Kenya (1987);

• Technical Specifications for Road and Bridge Construction, issued by Ministry of Transport of Kenya, 1986;

• Code of Practice for the Design & Construction of Buildings & other Structures in relation to Earthquakes (1973);

• Steel, Concrete and Composite Bridge, BS 5400, current version;

• Structural use of concrete, BS 8110, 1997, FF1B;

• Design Standard of Groundwork and Foundation, BS 8004, 1986; • Overseas Road Design Manual, BS, 1987;

• AASHTO Standard Specifications for Highway Bridge, 2007

• Specifications for the Design of Reinforced and Prestressed Concrete Bridges and Culverts (JTG D62-2004), PRC；



• General Specifications for the Design of Highway Bridge and Culvert (JTG D60-2004), PRC;

• Technical Specifications for Highway Bridge and Culvert Construction (JTJ041-2000), PRC

• Specifications for Design of Steel Structure (GB50017-2003). 2.3.2.3.6 Major materials

2.3.2.3.6.1 Regular Reinforcement and Structure Ste el

The designed regular reinforcement Grade 460 uses cool-rolled rectangular corrugated steel with characteristic value for tensile strength of 460MPa while Grade 250 Rebar shall use hot-rolled circular steel with characteristic value for tensile strength of 250MPa. When diameter of rebar is more than or equal to 10mm, Grade 460 Rebar is usually used, and when less than 10mm, Grade 250 Rebar is used. The designed steel used for pre-embedding and leveling shall be made of regular carbon steel (Grade S460). Welding steel shall meet the requirements of weld ability. Steel girders shall use Q345D steel plate, and the materials for connection elements of steel girder and stud shall satisfy GB/T 700 Carbon Structural Steels and GB/T 1591 High Strength Low Alloy Structural Steels. The Impact Flexibility of Q345D steel under

the test temperature of 0℃ shall be 34J. The technical specifications of high strength

bolt and washer shall meet with the Chinese standard Specifications of High Strength Bolts with Large Hexagon Head, Large Hexagon Nut, and Plain Washers for Steel Structures. Bridge girder erection machine is assembled by Q345D H shape steel

2.3.2.3.6.2 Pre-stressing

Pre-stressing system proposed in this Design shall be in compliance with the GB/T 5224-2003 Standard, and consists of high strength and low relaxation steel strands φj15.24mm (φj0.6〃) in nominal diameter and 140mm2 in nominal area, with a nominal

tensile strength of fyb = 1,860MPa and an elastic modulus of E = 195,000MPa as well as a 3.5%-relaxation ratio. Anchorage and corresponding linker (all anchorage and linker shall be in set, including anchor ring, anchor backing plate and spiral hooping etc.) shall use metal or plastic corrugated tube, and the plastic corrugated tube shall use vacuum grouting technology and integral tensioning to minimize pre-stressing loss.

2.3.2.3.6.3 Concrete

Strength for structural concrete shall conform to the table below. Quality of sand, stone and water shall be consistent with the Technical Specifications for Road and Bridge Construction.



Table 2: Grade of Concrete used in Bridge Structure Serial No.

Structural Componen t

Grade of Concrete/Masonry

Remarks

1. Upper Voided Slab, Precast T-girder and wet joint

C40 Pre-stressed Concrete

Precast

2. Rabbet of Voided Slab

C40 Pebble concrete

Cast-in-situ

3. Cast-in-situ box girder, cast-in-situ bridge deck of composite girder

C40 Concrete

Cast-in-situ

4. Bridge Deck Paving

C40 Concrete Cast-in-situ

5. Surface Course of Bridge Deck

Asphalt Concrete

Similar to that in road pavement

6. Bent Cap of Pier

C30 Reinforced Concrete

7. Pier Column


8. Spread Footing of Pier


9. Capping of Gravity Abutment


10. Back wall of Gravity Abutment


11. Front Wall and Side Wall of Gravity Abutment

C25 Plain concrete

12. Gravity Abutment Base

C25 Plain concrete

13. Bridge End Transition Slab


14. Crash Barrier


15. Bearing Bed-stone

C40 Pebble concrete

16. Foundation Cushion Layer

C15 Concrete

17. Replacement of Bridge

Foundation

M10 Rubble concrete

2.3.2.3.6.4 Bearing

GJZ/GJZF4 or GYZ/ GYZF4 Plate Rubber Bearing shall be used for prefabricated voided slabs, T-girder bridge and composite girder bridge. Code, type and technical standard of bearing shall conform to Plate Type Elastomeric Pad Bearings for Highway Bridges (JT/T4-2004). Pot rubber bearing shall be used for cast-in-situ box girder bridges.



2.3.2.3.6.5 Other materials

Conical slope and its foundation shall be paved with mortar rubbles, submergible steps with C20 Concrete, whilst sand-gravel cushion shall be provided as the footing of U-shaped abutment. TST elastomers and expansion device shall be provided on both sides of abutment of void-slab bride and steel-concrete composite bridge. Expansion joint shall be used for T-girder and box Girder Bridge with relevant large span. PVC pipes 100mm in diameter shall be used for drainage which is led under the bridge through piers or abutments. FWA-2000 fiber waterproof layer shall be set up under the asphalt concrete of bridge deck. The Impermeability Grade of waterproof concrete shall be more than Grade 8.

2.3.2.3.7 Bridge works

River-crossing Bridges on Main Line Being an essential traffic road, the Project Road has designed a certain quantities of bridges when crossing with other major roads and railways, including the interchange at the project starting point. A list of bridges is shown in the subsequent tables. Determination of bridge type and span layout shall take into considerations of its access roads and net clearance for future plan as well as Kenya National Highways Authority’s comments etc., and can be adjusted during detailed design phase after site investigation and prospecting. Length of bridges and beginning and ending chainage in the design exclude the lengths of side wall and ear wall of abutments. The number of lanes for intersected road in following Table is planned number of lanes (excluding the widened lane of interchange).



Table 3: List of Viaduct Bridges

S/N Central Chainage

Name of bridge

Present Crossed Road Class/Planned Nos. of Lanes

Type of viaduct

Skew Angle (0)

No. of Span -Span Length (No-m)

Bridge width(m)

Bridge Length(m)

1. SK0+397.5

Mombasa Road Bypass

Class A Dual 3-lane

Over cross

87

2-35

2×13.75

70

2. SK3+150.2

Airport Emergency Road Bypass

No Class 2 lane

Over cross

90

1-13

2×10.25

13

3. SK6+697.635

Lang’ata Road(C58) Bypass

Class C Dual 3-lane

Over cross

105

2-25

2×10.25

50

4. SK7+878.2

Community Slip Road Bypass

C Dual 2-lane

Over cross

105

2-25

2×10.25

50

5. SK15+704. 3 Ngong Road(C60) Bypass

C Dual 3-lane + one

lane on each side

of auxiliary road

Over cross

90

20+4×26.4+20

2×13.75

145.6

6. SK21+103 Dagoretti Road(C63) Bypass

Class C Dual 3-lane

Over cross

45

2-35

2×10.25

70

7. SK23+352 Thogoto Road Bypass

Class C Dual 3-lane

Over cross

90 2-25

2×10.25

50

8. SK23+925

Service Road Bypass

2 lane

Over cross

90 1-13

2×10.25

13



Design Parameters

• Design Drive Speed ：80km/h；

• Design Vehicle Load ：BS 5400 HA Load，30 units HB Load

• Bridge Deck Width All viaduct bridges on the main line are split bridges. The cross section of cloverleaf interchange is 0.5m crash barrier + 2m hard shoulder + 3×3.5m carriageway +0.25m curbs +0.5m crash barrier + 2m isolation strip + (0.5m crash barrier + 0.25m curb + 3×3.5m carriageway+2m hard shoulder+0.5m crash barrier). A single separated bridge is 13.75m wide and 29.5m wide for the integral bridge. The cross section of other bridges in the main line is 0.5m crash barrier + 2m hard shoulder + 2×3.5m carriageway +0.25m curbs +0.5m crash barrier + 2m isolation strip + (0.5m crash barrier + 0.25m curb + 2×3.5m carriageway+2m hard shoulder+0.5m crash barrier). A single separated bridge is 10.25m wide and 22.5m wide for the integral bridge. Cross section of grade-separation is (I): 0.5m crash barrier + 1.75m pedestrian way + 0.25 curb + 2×3.5m carriageway +0.25m curb +1.75m pedestrian way + 0.5m crash barrier, totaling 12m. Cross section of grade-separation is (II): 0.5m crash barrier + 1.75m pedestrian way + 0.25 curb + 2×3.5m carriageway +1.0m median strip +2×3.5m carriageway + 0.25m curb +1.75m pedestrian way + 0.5m crash barrier, totaling 20m. Cross section of pedestrian bridge is 0.3m guardrail +3m pedestrian way +0.3m guardrail, totaling 3.6m wide.

• Intersecting Angle: This is the right included angle between the route centerline in advancing direction and the centerline of pier and front wall of abutment cap, etc.;

• Bridge Deck Slope: A one-way cross fall of 2.5%-4% shall be provided;

• Clearance: No less than 5.5m.

• Design Flood Frequency: 1/100.



2.3.2.3.7.1 Bridge structure characteristics Viaduct on Mombasa Road (A104) (SK0+397.5) The viaduct is a component of Mombasa Interchange. The cross section of existing Mombasa Road is dual 3-lane, 2.0m shoulder + 3×3.5m carriageway +23m median strip+3×3.5m carriageway +2.0m shoulder in arrangement. When arrange the layout of viaduct, one widening lane shall be designed on each side of the existing road and preserve a clearance of no less than 5.5m. A bi-directional split steel-concrete composite girder bridge with 2×35m in span layout. The bridge starts from SK0+ 362.500 and ends at SK0+ 432.500, the central chainage being SK0+ 397.500 with an intersecting angle of 87°.The bridge deck is continuous, expansion joints shall be installed at abutments. Each separated bridge is composed of 5 pieces of steel girders with 2,935.75mm spacing between centers of steel girder. The steel girders are 1,800mm in depth and be installed a horizontal linkage at an interval of 4m.the cast-in-situ bridge deck is 280mm in thickness, and the cantilever of concrete deck is 1,050mm long at the place of side girders. Channel steel shear key will be installed at the linking location of bridge deck and steel girder. The bridge deck drainage system will set up a PVC draining pipe every 5m along the bridge and then lead into the rainfall collection tube under the girders and finally drain into the drainage system of the intersected road. For the substructure, the bridge piers are three-columned with spreading foundation. The pier column is 4.5m in spacing with the neighboring column and connects with pile caps. The abutments are thin-walled, 1.2m in thickness with spreading foundation. Bridging slabs are installed on the back wall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377). The steel girders are manufactured in the plant, and transported to the construction site and erected to place. Then cast bridge deck without trestles hence there will be no disturbing to traffic on Mombasa Road. Wilson Airport Interchange (SK3+150.2) The Interchange is a separated bridge for the fire control passageway of Wilson Airport. The existing passageway is earth road, 4m in width. The new Interchange will be designed as a two lane road, one 750mm wide maintaining roadway will be built on each side of carriageway and the traffic clearance will be not less than 5.5m. One 13m-span assembled PC simply supported bridge with voided slabs has been designed for the Interchange. The Bridge starts from SK3+ 143.700 and ends at SK3+



156.700 with the central chainage of SK3+ 150.200, 90°in intersecting angle. Expansion joints will be installed on the abutments. The precast slabs are 70cm in height. Stacking period of the voided slab shall be no more than 30 days to avoid excessive camber. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads. Substructure adopts thin-wall abutments, 1000mm in thickness and spreading foundation. Bridging slabs shall be installed on the back wall of abutment. Abutment back shall be filled up with sand gravel and compacted to the compaction more than 95% M.D.D (BS1377). Viaduct on Lang ’ata Road (C58) (SK6+697.635) The Viaduct is one part of Uhuru Monument Interchange. The existing Lang’ata Road is dual 2-lane with side ditches on both roadside and single pedestrian way, 2.5m side ditch + 2×3.5 carriageway + 7.5m median strip + 2×3.5 carriageway + 2.5m side ditch + 2m pedestrian way in cross section. The new design will be dual 4-lane, adding one carriageway and one widening lane on each side, and will built 2.0m hard shoulder and 0.5m soil shoulder. The traffic clearance will be not less than 5.5m. A PC simply-supported T-girder bridge will be designed for the viaduct. The viaduct will be a two-span structure, 25m in span length. The Bridge starts from SK6+ 672.635 and ends at SK6+ 722.635 with the central chainage of SK6+ 697.635, 105° in intersecting angle. The bridge deck is continuous and expansion joins will be installed on abutments. The single bridge is composed of 5 pieces of T-girders 2177.5mm in spacing between centers of T-girders. The T-girder is 1900mm in depth and 1640mm wide, the side girder being the same with the central girder. An integral cast-in-situ layer will be 100mm thick which casted by C40 waterproof concrete. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads. For the substructure, the bridge piers are rectangular-shaped with spreading foundation. The pier column is 6m in spacing with the neighboring column and connects with pile caps. The abutments are thin-walled, 1.2m in depth, spreading foundation. Bridging slabs are installed on the back wall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377). T-girders are prefabricated at site and post-tensioned. To ensure the precast accuracy, steel formwork shall be used. After cast concrete and reaching 100% of Design Strength,



tension pre-stressing and finally erect. Level the bridge deck and other systems after install finished. No trestles needed hence there is no break to present traffic. Viaduct on Community Slip Road (SK7+878.2) The Bridge is an interchange on the Community Road. The existing Road is 2 lanes with side ditches on both sides which allows for small cars driving. The present cross section is 2.5m side ditch + 2×3.5m carriageway+ 2.5m side ditch. According to comments from Ministry of Works of Kenya, the Road will be built as a dual 2-lane corridor due to increasing traffic volume, hence an interchange is needed. The Bridge will be designed as a dual 3-lane (including widening lane) structure with 2.0m hard shoulder and 0.5m soil shoulder and 7.5m median strip. PC simply-supported T-girder bridge will be designed for the viaduct. The viaduct will be a two-span structure, 25m in span length. The Bridge starts from SK7+853.2 and ends at SK7+ 903.200 with the central chainage of S SK7+ 878.200, 105° in intersecting angle. The bridge deck is continuous and expansion joins will be installed on abutments. The single bridge is composed of 5 pieces of T-girders 2177.5mm in spacing between caners of T-girders. The T-girder is 1900mm in depth and 1640mm wide, the side girder being the same with the central girder. An integral cast-in-situ layer will be 100mm thick which casted by C40 waterproof concrete. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads. For the substructure, the bridge piers are rectangular-shaped with spreading foundation. The pier column is 6m in spacing with the neighboring column and connects with pile caps. The abutments are thin-walled, 1.2m in depth, spreading foundation. Bridging slabs are installed on the back wall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377). T-girders are prefabricated at site and post-tensioned. To ensure the precast accuracy, steel formwork shall be used. After cast concrete and reaching 100% of Design Strength, tension pre-stressing and finally erect. Level the bridge deck and other systems after install finished. No trestles needed hence there is no break to present traffic. Viaduct on Ngong Road (C60) (Crossing Motine River) The Viaduct is one component of Ngong Road Interchange. The existing dual 2-lane Ngong Road has a cross section of 2.0m shoulder +4×3.5m carriageway + 2.0m shoulder. According to the developing program provided by the Client, the Ngong Road



will, in the future, be upgraded to separated dual 3-lane structure with 2 lanes auxiliary road on each side, 2m wide non-vehicle lane and 2.5m wide pedestrian, 2.5m wide median strip, 2.5m wide isolation belt for the main and auxiliary road, 2.5m wide isolation strip for auxiliary road and non-vehicle road. The design will add one widening lane on each side of outer auxiliary road, crossing Ngong Road and Motine River. Based on above mentioned conditions, the Viaduct will be a separated cast-in-situ PC continuous girder structure 20+4×26.4+20m in span layout. The Bridge starts from SK15+631.5 and ends at SK15+ 777.1 with the central chainage of SK15+ 704.3, 100° in intersecting angle. Column pier will be built on the isolation strip between main and auxiliary road and between vehicle and non-vehicle strip. The Bridge deck is continuous and expansion joints will be installed on abutments. The box girder is 13,750mm wide on top and 9,750m on bottom, 1,800mm in depth and 2,000mm for the cantilever. The bridge deck has a 100mm thick cast-in-situ C40 waterproof layer and 50mm thick bituminous paving and 10mm asphalt surfacing treatment. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into Motine River or Ngong Road through piers or abutments. Substructure adopts dual-column pier, 7m spacing between columns. The pier shaft is 1.5×2m rectangular solid pier and connects with pile foundation 1.8m in diameter through pile cap. The abutment is buttressed structure, the abutment body being 1000mm in thickness with spreading foundation. Bridging slabs are installed on the back wall of abutment. Abutment back shall be filled up with sand gravel and compacted to a compaction more than 95% M.D.D (BS1377). Construction of each split bridge is divided into 3 phases. Tensile girder segments and remove trestles, detour the vehicles from the Ngong Road to below of the casted girders, then build next segments. Restore traffic on the crossed road until finish of all bridge sections.

Viaduct on Dagoretti Road (C63) The Viaduct is one component of Dagoretti Road Interchange. The existing Dagoretti Road is a dual 2-lane structure which has a cross section of 2.0m shoulder + 2×3.5m 85 carriageway + 2.0m shoulder with a 45 degree intersecting angle with the Southern Bypass Road. Based on site conditions and developing plan, a separated steel-concrete composite girder bridge with 2×35m in span layout. The bridge starts from SK21+ 068 and ends at SK21+ 138, the central chainage being SK21+ 103 with an intersecting angle of 45°.The bridge deck is continuous, expansion joints shall be installed at abutments. Each



separated bridge is composed of 5 pieces of steel girders with a 2,937.35mm spacing between centers of steel girder. The steel girders are 1,800mm in depth and be installed a horizontal linkage at an interval of 4m.the cast-in-situ bridge deck is 280mm in thickness, and the cantilever of concrete deck is 1,050mm long at the place of side girders. Channel steel shear key will be installed at the linking location of bridge deck and steel girder. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads. For the substructure, the bridge piers are rectangular-shaped with 1.5m×1.2m pier shaft and spreading foundation. The pier column is 4.5m in spacing with the neighbouring column and connects with pile caps. The abutments are thin-walled, 1.2m in depth, spreading foundation. Bridging slabs are installed on the backwall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377). The steel girders are manufactured in the plant, and transported to the construction site and erected to place. Then cast bridge deck without trestles hence there will be no disturbing to traffic. Viaduct on Thogoto Road (D411) (SK23+352.000) The Viaduct is one part of Thogoto Interchange of South Bypass Road. The existing Thogoto Road is dual 2-lane with ditches on sides, 2.0m shoulder + 2×3.5m carriageway + 2.0m shoulder in cross section. The design shall widen the present road and add widening lane for the interchange, totaling 6 lanes, and preserve 2.0m hard shoulder and 0.5m soil shoulder on each side of the road. Based on site investigation and development plan, a separated PC simply-supported T-girder bridge will be designed for the viaduct. The viaduct will be a two-span structure, 25m in span length. The Bridge starts from SK23+ 327 and ends at SK23+ 377 with the central chainage of SK23+ 352, 105°in intersecting angle. The bridge deck is continuous and expansion joins will be installed on abutments. The single bridge is composed of 5 pieces of T-girders 2177.5mm in spacing between caners of T-girders. The T-girder is 1900mm in depth and 1640mm wide, the side girder being the same with the central girder. An integral cast-in-situ layer will be 100-mm thick which casted by C40 waterproof concrete. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads.



For the substructure, the bridge piers are rectangular-shaped with spreading foundation. The pier column is 6m in spacing with the neighboring column and connects with pile caps. The abutments are thin-walled, 1.2m in depth, spreading foundation. Bridging slabs are installed on the back wall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377). Bridge on Service Road (SK23+925.000) The Bridge is viaduct on Service Road. The existing dual lane Service Road has a cross section of 2 ×3.5m carriageway with side ditches. The Bridge is designed as a 1*13m assembled PC simply-supported structure with voided slabs. The Bridge starts from SK23+918.500 and ends at SK23+ 931.5 with the central chainage of SK23+ 925, 90°in intersecting angle. Ex pansion joints will be installed on abutment. The precast slabs are 70cm in height. Stacking period of the voided slab shall be no more than 30 days to avoid excessive camber. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the crossed roads. For the substructure, the abutment is thin-wall shaft, 800mm wide along the bridge direction with spreading foundation. Bridging slabs are installed on the back wall of abutment. Sandy gravel shall be filled in behind the abutment and compacted with a compaction of more than 95% M.D.D (BS1377).



Table 4: A list of Grade-separation Bridge

S/N Central Chainage

Bridge type

Nos. of lanes

Crossing type

Skew Angle ( 0)

No. of Span -Span Length (No-m)

Bridge width(m)

Bridge Length(m)

1. SK1+197.2

Pedestrian Bridge

3m net width

Under pass

90

(5.5+6+5.5)+2*16.25m+(5.5+6+5.5)

3.6

100.5

2. SK9+400

Grade separation

2 lanes

Under pass

90

2-16

12

32

3. SK16+050

Grade separation

2 lanes

Under pass

90

2-16

12

32

4. SK26+300

Pedestrian Bridge

3m net width

Under pass

90

(5.5+6+5.5)+2*16.25m+(5.5+6+5.5)

2×10.25

100.5

5. SK27+114.941

Box culvert

4 lanes for main road, 2 lanes for auxiliary road

Under pass

90

2×11×6.4 10×6.4

6. SK27+390

Pedestrian Bridge

3m net width

Under pass

90

(5.5+6+5.5)+2*16.25m+(5.5+6+5.5)

2×10.25

100.5

7. SK28+100

Grade separation

Dual 2-lane

Under pass

90

2-16

2×10.25

32



2.3.2.3.8 Grade separations and culverts

Grade-separations, 12m Wide (SK9+400, SK16+050) To satisfy the traffic demand for residents on both sides of road, 2-span 16m voided-slab bridge are used for the grade-separation with a 90°intersection angle. 2 lanes, 1.75m pedestrian way and 0.5m crash barriers shall be built on both sides. Expansion joints shall be built on abutment. Prefabricated slabs are 800mm high and 990mm wide. Stacking period of the voided slab shall be no more than 30 days to avoid excessive camber. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the main line. The piers use twin column 1.2m in diameter and 6.5m in spacing which connects pile caps with spreading foundation. Substructure adopts thin-wall abutments, 1000mm in thickness and spreading foundation. Bridging slabs shall be installed on the back wall of abutment. Abutment back shall be filled up with sand gravel and compacted to the compaction more than 95% M.D.D (BS1377).

Installation of void slabs shall be finished before construction of main line.

Grade-separations, 20m Wide (SK28+100) A dual 2-lane grade-separation structure will be built at SK28+100 on the main line. The bridge will be a 2-span void slab structure 16m in span length and 90° in crossing angle. Totaling 20m wide and being separated by 0.5m double yellow lines, 1.75m pedestrian way and 0.5m crash barriers shall be built on both sides. Expansion joins shall be built on abutment. Prefabricated slabs are 800mm high and 990mm wide. Stacking period of the voided slab shall be no more than 30 days to avoid excessive camber. PVC weep pipes shall be installed for deck drainage at an interval of 5m, and through the rainfall collection pipes finally lead the rain water into the drainage system of the main line. The piers use twin column 1.2m in diameter and 6.1m in spacing which connects pile caps with spreading foundation. Substructure adopts thin-wall abutments, 1000mm in thickness and spreading foundation. Bridging slabs shall be installed on the back wall of abutment. Abutment back shall be filled up with sand gravel and compacted to the compaction more than 95% M.D.D (BS1377). Installation of void slabs shall be finished before construction of main line.



Pedestrian Bridge (SK1+197.2, SK26+300, SK27+390) Steel structured pedestrian bridge will be built at SK1+197.2, SK26+300 and SK27+390. The pedestrian way is 3m in net width with 300mm wide guardrails. Twin-column steel structure piers shall be built on both ends of bridge whilst single-column pier shall be built on median strip with pile foundation. The walking stairs use single-column type with spreading foundation. All elements shall be manufactured in plant and assembled at site. Box Culvert underpass the Railway The railway is single track, 1m in spacing. The railway has a 6m wide sub-grade and 250mm in height. It is 7.8m from top of the rail to surface of the road under the railway. The present railway bridge crosses over the right auxiliary road of the main line. The auxiliary road has a 1.5m wide pedestrian way on both sides and 6m wide road surface. The present railway is a steel-concrete composite bridge which is composed of 2 pieces of I-shaped girders. Main line of U-shaped abutment has a 60 degree skew angle with railway. Based on site investigation and fill height of sub-grade, 3 continuous holes box culverts under passing the railway are proposed.

2.3.2.3.9 Culverts

Culverts shall be designed based on geological, landform, meteorological and hydrological conditions. There are 100 culverts for the main line, 36 for slip road of interchanges, 30 for service roads, and there will be 42 side culverts and 14 box culverts among which there are 4 box culverts for drainage, 4 for pedestrian way and 6 for vehicles passage. There are 2 arch culverts nearby Ondiri River. Detailed culverts arrangement is shown in List of Culverts. Structural design shall take following live loads: BS 5400-2:2006 Most Unfavorable Effect Loading: HA for Carriageway Loading and 30kN/m for HB.

Concrete and Rebar

• All Design Concrete Strength shall satisfy pertinent requirements for Portland cement in BS 12 and BS 146;

• Quality of sand and stone shall conform to Clause 3.2.2 of BS 5400, 1978 edition;

• Strength design of concrete mixture ratio shall reach 28-day curing period;

• The maximum diameter of concrete aggregate shall not exceed 20mm;

• Reinforcement ratio for high strength corrugated steel (Grade 460) and hot-rolled mild steel (Grade 250) shall satisfy specifications in BS 4449;

• The minimum net protection layer to rebar in RC shall be 40mm; and



• Welding rebar is not allowed to be used for enhancement of rebar strength. Construction Highlights of Box Culverts

• Thickness of fill on top of box culverts (including pavement structure layer) shall not be less than 0.5m;

• Backfill at retaining back wall cannot be carried out until concrete strength reaching 50% of standard value. The backfilling shall be compacted symmetrically by sand, stone or sandy soil which meet with specifications and reach 100% dense. Vibrating roller is prohibited to be used for one-off compacting.

• When the fill-up thickness for the first layer is only 20-30cm on top slab, Vibrating roller is not allowed for compaction;

• Inlet and outlet of box culvert which connects natural draining ditches on road side shall be cleared to ensure smooth flow of water

Construction Highlights of Pipe Culverts • Fillings for top culvert and for the scope within twice diameter of tube on both

sides shall be compacted symmetrically, and the compaction shall not be less than 95% MDD;

• Filling thickness on top of culvert (including pavement structure thickness) shall be not less than 0.5m. Any vehicles and equipments are prohibited to pass by during construction. And

• Inlet for connecting ditches shall be cleared to ensure smooth flow of water.

2.3.2.3.10 Intersections

Interchange There will be 6 interchanges on the Southern Bypass, and two types of cross section for the slip road and service road: 2 lanes, one-way: 0.5m soil shoulder + 1.0m hard shoulder + 2×3.5m carriageway+ 2.0m hard shoulder + 0.5m soil shoulder, totaling 11m; Dual lane: 0 Dual lane: 0.5m soil shoulder + 2.0m hard shoulder 2×3.5m carriageway+2.0m hard shoulder + 0.5m soil shoulder, totaling 12m, which also applies for service roads; Mombasa Road Interchange Mombasa Road Interchange is designed at SK0+397.500, reaching Nairobi to the northwest, Industrial Area to the Northeast, Kikuyu to the Southwest and Mombasa to the southeast, and is a traffic hub for the main line and A104.



Lang’ata Road Interchange Lang’ata Road Interchange crosses Lang’ata Road at SK6+697.635, connecting Kikuyu to the direction of northwest, and linking Nairobi to northeast and reaching Karen to Southeast. Community Interchange Community Interchange is designed at SK7+878.2, linking Kikuyu to the west, Community to southwest and Mombasa to east. Ngong Road Interchange Ngong Road Interchange is designed at SK15＋704.3, connecting Kikuyu to northwest,

Nairobi to northeast, Karen to southwest and Mombasa to southeast. Dagoretti Road Interchange Dagoretti Road Interchange is designed at SK21+103, reaching Kikuyu to the west, Community to the southwest and Mombasa to the East. Thogoto Road Interchange Thogoto Road Interchange is designed at SK23+352, arriving Kikuyu to northwest, Dagoretti to northeast and Mombasa to the Southeast.

2.3.2.3.11 Grade-separated Intersection

Based on design principles of in favor of smooth traffic for the crossed road, easy construction and aesthetic view, the Project has 5 grade-separated intersections among them there are 4 crossing highway and 1 crossing railway. The 4 grade separations are respectively at SK3+150.2 (main line over cross), SK9+400 (main line under cross), SK16+050 (main line under cross), SK23+925 (main line over cross) and SK28+100 (main line under cross). The grade-separation across railway is at SK 27+121.994 (main

line under cross)

2.3.2.3.12 Traffic Engineering and road side facili ties

Traffic engineering system shall be designed in accordance with the general principle of “Ensuring Safety, Providing Service, and Facilitating Management” with an overall goal of delivering a safe, cosy and environmental-friendly design centered on “Safety and Service”. Traffic engineering and roadside facilities consists of safety service and management setups and facilities which are most important parts for the Project Road and indispensable for improving socio-economic benefit and enhancing traffic safety.



2.3.2.3.13 Traffic safety facilities

Traffic safety facilities include traffic signs, road markings, guard post/guard rails, sight-line induction signs, boundary stone, kilometer post, lighting/illumination facilities, as well as variable speed-limit signs, and etc. Speed limit signs Speed-limit signs, place name and distance signs, prohibitory signs, and auxiliary signs are

erected along the regular road segments whereas exit signs are furnished on interchanges..

Road markings Road Markings are divided into pavement centerline marking, lane-dividing marking, carriageway edge marking, entrance/exit marking, direction arrow, etc. To satisfy the vision and safety for driving at night, all markings shall use hot-melt reflecting markings. The thickness of marking of edging line of carriageway and central line of road is 1.8±0.2mm. Guard posts and Guard rails Guard posts are provided along bridge approaches, steep gradient segments (grade > 4%), and sections with culverts, at 2.5m intervals. Guard rails constitute an essential measure to ensure fast and safe driving, and are, on the segments where embankment fill height is more than 3m of the Project Road, installed with corrugated steel-beam railings. Sight-line Induction Signs Traffic diversion and merging signs shall be erected at and in advance of entrance and exit ramps on interchanges to alert drivers to leave or merging into the traffic flow for safety purpose. Lighting/Illumination Facilities Illumination facilities are arranged along the whole Project Road only for traffic purpose instead of landscape view

� Illumination and Power Distribution Design Lights shall be installed for the central strip of the whole line, and each quadrant of cloverleaf interchange shall set up one lamp with high column. According to places and conditions of illumination, ground power distribution box shall be installed. The power shall come from the Transformer Box which is set up by the Client. Power distribution box uses SCHNEIDER electrical device and SIEMENS controlling system which can also use distributing system of other same types. Switching system shall be controlled at will or can be controlled by hand, based on future’s plan, and will connect with monitoring and management system of the city. Wireless communication system can be used on the power distribution system. Power of the box shall be the



responsibility of the Client, the cable using YJV type, the codes is shown in Pipelines Illumination Distribution System. The Project uses 380/220V, 50HZ and 3D/5wires

(L1，L2，L3，N，PE) distribution system. Under the normal operation of power

leading-in end, allowable value of voltage of powered device (expressed by percent of nominal voltage) shall be as following:

（1）Electromotor shall be ±5%;

（2）Illumination； under general work place shall be ±5%; and ＋5%、－10% for small

work place where is far from substation and hard to satisfy above requirement; and it

should be ＋5%、－10% for emergent lighting, road lighting and security lighting.

（3）when there is no other special stipulations for powered device, it should be ±5%.

� Electricity Safety • TN-S grounding type will be used, all metal tube coating, metal coating of lamps,

coating of trestles for installation, shell of power distribution box shall be connected on PE wire and linked with general earthed system. Artificial grounding device shall be set up besides the power distribution box and connects with general earthed system to ensure the Resistance less than 4 Ohm.

• For passing voltage, lightning switch is installed in the distribution box. • All metal shell and steel tubes for threading of electric equipment shall be

connected with PE protection wire.

• Electric cable shall be repeated earthed at entrance of each building. Each building shall use Main Potentiostat Box through which be earthed repeatedly. Grounding resistance shall no more than 10 Ohm.

• Lightning rod shall be installed on the top for lamp posts with height more than 15m, and connects with earthing through metal rods. The Earthing Resistance shall be not more than 30 Ohm.

• Flat steel for connection shall be linked with PE bus bar, channel trestle and coating of the box.

• Earth electrode shall be in the greening ground which can be adjusted based on actual situation; however earth electrode and connection flat steel shall be on the same elevation.

� Wires Layout � Each branch loop from the power distribution box shall use YJV cables and be

laid by threading. � All loops shall be protected by DN110 galvanized steel pipe when passing roads,

and shall keep one reserved. � Each loop shall be treated individually when passing expansion joints and

settlements. � Exposed part of local wire duct or of protection pipes shall be painted with same

colour with that of decoration.



� Cables length and numbers can be properly reduced based on its power of each loop.

� Cables transition shall be set up based on actual situation, and can refer the size of 100 × 100 × 80 cm.

2.3.2.3.14 Bus stations

Being a city bypass, the Project Road should be provided with bus stops or bus station along road sections passing by towns and major villages.



3 DESCRIPTION OF THE PROJECT ENVIRONMENT

3.1 Introduction The name "Nairobi" comes from the Masai phrase Enkare Nyirobi, which translates to "the place of cool waters". It is popularly known as the "Green City in the Sun" and is surrounded by several expanding villa suburbs. Nairobi was founded in the late 1890’s as a simple rail depot on the railway linking Mombasa to Uganda. The town quickly grew to become the capital of British East Africa in 1907 and eventually the capital of a free Kenyan republic in 1963. Nairobi is also the capital of the Nairobi Province and Nairobi District. Nairobi is strategically located within two major international trunk roads, i.e. A104 and A2 and therefore has long been suffering from heavy transit traffic cutting through the centre of the city due to lack of bypasses and ring roads. The primary influence areas of study include Nairobi City and part of Central Province where the project is located.

3.2 Nairobi in Brief

Nairobi is the most populous city in Kenya, with a current estimated population of about 3.13 million (Central Bureau of Statistics (CBS) 2009) According to the 1999 Census, in the administrative area of Nairobi, 2,143,254 inhabitants lived within 696 km2 . The city is located on the plateau which is averagely 1680 m above sea level and lies on the Nairobi River, in the south central of the nation. The Port of Mombasa in the Indian Ocean is 480 km to the south east of Nairobi. The Ngong Hills, located to the west of the city, is the most prominent geographical feature of the Nairobi Area. There are various conservation areas in Nairobi City including a national park, forest areas, and city parks. The Nairobi National Park in the south of Nairobi City is the largest conservation area in Nairobi City with a land area of 117 sq km and is within the project area. Its land usage is prohibited and is preservation for the natural environment fostered as an important tourism resource.

3.1.1 Description and Map of Project Location

The project is located on the Southwest of Nairobi City. The project has a length of 28.6 km with slip road around 12 km, and two more service roads: one road will link Mombasa Road and Lang’ata Road totaling 6.042km, the other will link Lang’ata Road and Ngong Forest totaling 2.5km. This Project will, upon completion, also enhance and improve the structure of local road network, increase the integrated transportation capability in this area significantly promote the regional socio-economic growth.



Planned route of the southern bypass in Blue from Mombasa Road to Kikuyu

3.2 Physical Conditions of Project Area

3.2.1 Geographical location

The Project Road is located in Nairobi, the capital of The Republic of Kenya. Its geographical coordinates are 10 09’ 11” to 10 19’ 55” North and 360 46’ 57” to 360 55’ 14”East which is in a plateau area in the central south of Kenya. The project is located on the Southwest of Nairobi City and will link up major trunk roads in Nairobi Area.

The Project Road starts from the junction of Mombasa linking Kabete Limuru Road (A104) at Kikuyu Town. The Road crosses the National Park westward then goes through Lang’ata Road (C58), Community Road, Ngong Road (C60), Dagoretti Road (C63), Thogoto Road (D411) then passes through Ondiri River and a railway. The project has a length of 28.6 km with slip road around 12 km, and two more service roads: one road will link Mombasa Road and Lang’ata Road totaling 6.042km, the other will link Lang’ata Road and Ngong Forest totaling 2.5km.

There are various conservation areas within the proposed project road that may be affected including the national park and forest areas. The locations of these areas are shown below.



Table 1 Conservation areas that might be affected Conservation area Effect

Ngong forest It will be partly affected

Dagoretti forest It will be partly affected

Nairobi National park It will be partly affected

Alliance High School forest It will be partly affected

Thogotho forest It will be partly affected

Ondiri Swamp It might be partly affected

Land acquisition for sections of the road has been in progress with much of the route tracing on the existing road. However since the width of the road will be 60m, major land acquisition on the agricultural areas together with a large number of resettlement of the local population is involved. The section between Mombasa Road and Kikuyu Road was acquired and designed in the 1970s. However a section within the National Park shall be realignment which should lead to acquiring of new land. This action will cause a loss of the indigenous trees that are planted along the current road adjacent to the park. Although some owners of the structures built on the road reserves have demolished their structures, there are still areas with illegal structures along the corridor.

3.2.2 Meteorological and Hydrological Condition

Due to the effect of high altitude, the temperature in Nairobi is rarely higher than 270C and the average rainfall is about 760-1270mm making it enjoy distinct seasons.

The weather from December to March is clear and warm when northeast wind prevails. There are two rainy seasons, March to May and October to December with dry spells in between but rainfall can be moderate. As Nairobi is situated close to the equator, the differences between the seasons are minimal. The timing of sunrise and sunset varies little throughout the year, due to Nairobi's close proximity to the equator.

3.3 Climatic Conditions

Nairobi City lies so close to the Equator but being 1680m above the sea-level, it enjoys moderate climate with altitude modified temperatures. The altitude makes for some chilly evenings, especially in the June/July season when temperature can drop to 10ºC. The period between December and March is the sunniest and warmest with temperatures averaging the mid twenties during the day. The mean annual Temperature is 17˚C and



the mean daily maximum and minimum are 230C and 120C respectively, (Chandler, 1971). The mean annual rainfall in Nairobi ranges between 800 mm and 1,300 mm per annum falls in two distinct seasons: The short rains fall between October and December while the long rains fall between March and May. Annual rainfall is influenced by altitude. The highest area, especially on the Northern and the Western Areas receive high amounts of rainfall, while the low lying Areas on the Eastern and the southern parts receive low amounts of rainfall influenced by altitude.

Table 2 Climate data for Nairobi Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year

Average high °C (°F)

24.5 (76.1)

25.6 (78.1)

25.6 (78.1)

24.1 (75.4)

22.6 (72.7)

21.5 (70.7)

20.6 (69.1)

21.4 (70.5)

23.7 (74.7)

24.7 (76.5)

23.1 (73.6)

23.4 (74.1)

23.4 (74.1)

Average low °C (°F) 11.5

(52.7) 11.6

(52.9) 13.1

(55.6) 14.0

(57.2) 13.2

(55.8) 11.0

(51.8) 10.1

(50.2) 10.2

(50.4) 10.5

(50.9) 12.5

(54.5) 13.1

(55.6) 12.6

(54.7) 12.0

(53.6)

Precipitation mm (inches)

64.1 (2.52)

56.5 (2.22)

92.8 (3.65)

219.4 (8.63)

176.6 (6.95)

35 (1.38)

17.5 (0.689)

23.5 (0.925)

28.3 (1.114)

55.3 (2.177)

154.2 (6.07)

101 (3.98)

1,024.2 (40.33)

Avg. rainy days 4 5 9 16 13 5 3 4 4 7 15 8 93

Sunshine hours 288.3 268.4 266.6 204 189.1 159 130.2 127.1 180 226.3 198 257.3 2,494.3

Source : World Meteorological Organisation Source, Hong Kong Observatory

3.4 Topography

The project land is high in the west extending from the eastern edge of the Rift valley at an elevation of 2,300m, gradually sloping down towards the east and the south to an altitude of 1,400m.The western part above the,1,700m altitude has rugged topography ,while the eastern part slopes gently to flat land. The ground vegetation is grassland and scrub forest as shown on the figures below. The road passes through Ngong forest, Dagoretti forest, Alliance High School forest and finally Thogoto forest.

3.5 Geology

The rocks in the Nairobi area mainly comprise a succession of lavas and pyroclastic of Cenozoic age, overlying the foundation of folded Precambrian schist and gneisses of the Mozambique belt. Pegmatite is seldom found though some fragments could be found as agglomerates derived from former Ngong volcano. The west part of the Project Area is lava and the east part is metamorphic rock (such as mica, marble, quartzite, gneiss and shale). Unfavourable geological conditions for the Project is focused on black cotton soil with an average thickness of 100~250cm which is distributed at SK0+000~SK5+600, SK11+000~SK11+280, SK11+420~SK11+640, SK11+800~SK12+200, SK12+760~SK13+050 and SK16+240-SK16+980.



As Nairobi is adjacent to the eastern edge of the Rift Valley, minor earthquakes and tremors occasionally occur.

3.6 Soils

Soil is composed mainly of shallow red –brown sandy loam in the east, fertile highland clay loams in the north, fertile low-lying black clays in the central area. The soils of the Nairobi area are mostly products of weathering of mainly volcanic rocks. Weathering has produced red soils more than 15m thick. A number of soil subdivisions are recognized in the Nairobi area according to drainage, climatic regions and slopes. The principle soil overlying the trachytic rocks of the north-western part of Nairobi includes strong brown to yellow-red friable clays (latosolic soils) with high humus layer overlying clay. These are developed from lava, volcanic tuff and ash in humid region with rainfall of more than 1,000mm per year. In the area to the south and the southeast, red friable clays (latosolic soil) are developed over similar rock types in areas where the annual rainfall is 760-1,000mm.

3.7 Humidity Because of the Nairobi location just south of the equator in combination with humid air pumped in from the Indian Ocean, the humidity values for each day are generally on the higher end. This is not to say that values are always high, since the easterly winds coming off the Indian Ocean tend to keep the temperatures standard throughout the country; therefore the “warm sticky” feeling is usually not associated with Nairobi and Central provinces as much as one would think. In the summer to autumn months of January to April, relative humidity values have been known to plummet to anywhere from 10% to 20%. The typical day, humidity-wise, starts off with nearly saturated in the morning hours, and steadily decreases throughout the remainder of the day.

3.8 Drainage The NMA falls largely in the drainage basin of the Athi River and its tributaries. The Nairobi River, a major tributary, flows from the southwest to the northeast through Nairobi City, and is joined by the Kamiti, Thiririka and Nalaruru Rivers in the eastern part of the Nairobi before draining into the Athi River. The Ruiru River, another major tributary, originates from mountainous areas to the northwest of Nairobi. The main stream of the Athi River itself flows generally from the southwest to northeast in the eastern part of the NMA. There are few river flows in the Southwest area. The major rivers affecting this project are Ruora River, Motoine River and Ondiri River. The bypass also cuts through the Ondiri swamp a major concern of the local residents.



3.9 Socio-economic characteristics

3.9.1 Population

Nairobi has experienced one of the highest growth rates of any city in Africa since its foundation in the late 1890s.The population of Nairobi has increased dramatically, from 343,500 in 1962, 1,324,570 in 1989, to 2,751,860 in 2005 with 4.95% average year on year growth rate during 1962-2005 and current population of 3.13 million (CBS 2009). The average annual growth rate registers 4.26% during 1999-2005, lower than the average annual growth rate of 4.90% during 1989-99. The growth rate is currently 4.1 with an estimation of a population of 5 million in 2015

The Kibera slum, with an estimated population of 0.5 million people is located near the bypass. The Kenya Government is attempting to solve the problem, having initiated a program to replace the slum with a residential district consisting of high rise apartments, and relocating the residents to these new buildings upon completion. The apartments are being built in phases in line with the Government's budgetary allocations, and a few apartments in phase 1 of the project have already been occupied. The new houses are.

3.9.2 Economic Activities

Nairobi is one of the most prominent cities in Africa politically and financially. (Bauck 2009) It is home to many companies and organizations, including the United Nations Environment Program, UN-Habitat and the UN Office in Africa. It has established as a political, economic and cultural hub. Nairobi has an international airport connecting many countries and cities with a railway network connecting Uganda and Tanzania through Nairobi

Nairobi is home to the Nairobi Stock Exchange (NSE), one of Africa's largest. The NSE was officially recognized as an overseas stock exchange by the London Stock Exchange in 1953. The exchange is Africa's 4th largest (in terms of trading volumes) and 5th (in terms of Market Capitalization as a percentage of GDP), (Millennium IT 2009). Goods manufactured in Nairobi include clothing, textiles, building materials, processed foods, beverages and cigarettes. Several foreign companies have factories based in and around the city. These include General Motors, Toyota Motors, and Coca Cola, etc. The city also has a large tourist industry, being both a tourist destination and a transport hub. This makes the city to be considered the commercial centre of Kenya and Eastern Africa.

The main economic activities and features along the route are human settlement structures with some farming activities but with significant urban characteristics. There are well over 50,000 primary sub-plots along the project road. The area is characterized with mixed land use patterns which include residential plots and business premises such as petrol stations, commercial premises, shops, catering, stores and educational



institutions. Due to its geology and rich soil texture along the route, there is also much livestock and crop farming.

The city has several tourist attractions the most famous being the Nairobi National Park. The national park is unique by bordering a capital city and contains many animals’ including lions, giraffes, and black rhinos. However, the impacts will not be adverse since the bypass follows the boundary of the National park and thus do not affect movement routes, mating grounds and corridors followed by the wild animals

3.9.3 Society and culture

Nairobi has two informal nicknames. The first is "The Green City in the Sun", which is derived from the city's foliage and warm climate (United Nations Office in Nairobi 2007). The second is the "Safari Capital of the World", which is used due to Nairobi's prominence as a hub for safari tourism (Serena hotels 2008)

It is a cosmopolitan and multicultural city which has maintained a strong British presence since its foundation, and a lasting legacy from colonial rule. Many foreigners settled in Nairobi from other British colonies, notably those workers who arrived to construct the Kenya-Uganda railway, settling after its completion, and merchants from India. Nairobi also has established communities from Somalia and Sudan. Therefore, since Nairobi has a diverse and multicultural composition, there are a number of churches, mosques, and temples within the city. There are a number of modern malls in Nairobi as well.

A number of institutions have developed along the route e.g. churches like the Redeemed Gospel Church, Jehovah’s Witness in Langata, and PCEA Thirime in Thogoto among others. Estates along the route include NHC Scheme near Langata road, Uhuru A and B, Kibera upgrading scheme, and the housing estates in Kikuyu. There are also hospitals like St. Theresa Hospital Kikuyu and PCEA Kikuyu Hospital along the route.

3.9.4 Education

The primary school enrolment in Kenya increased gradually in the last three years with the trend of enrolment getting higher and higher. In 2005 there were 3.6 million children in primary and 0.9 million children in secondary schools in Kenya, giving cross enrolment ratios of 89.1% and 30.7% respectively.

The Majority of schools follow either the Kenyan Curriculum or the British Curriculum with attendance of primary and secondary schools on the steady increase. Nairobi is home to several tertiary institutions including universities. Many Institutions have developed in along the Southern bypass, including a Christian university (Presbyterian University of East Africa) which will be directly affected, and the College of Insurance, many primary and secondary schools have been developed along the route e.g. Life spring Academy near Kibera, Malezi School, Kikuyu Township Academy, Alliance Boys High School which will be directly affected, and Star Sheikh Academy.



3.9.5 Gender

Male headed and female headed households are almost equally distributed. The number of household members ranges from 3 - 6 persons for both male and female headed households with the population depicting a youthful population leading to a high dependence ratio. Males and females rent their living places almost equally, but their cooking fuel consumption distinctly differs. Male headed households spend more paraffin and charcoal than female headed households. This indicates that female headed households are generally poorer in terms of household expenditure.

3.9.6 Poverty Incidence

Based on the survey CBS and World Bank, it was estimated that in 1997, about 53% of the rural and some 50% of the urban population in Kenya could be deemed poor (GoK 2000). Comparably, the Nairobi Province average urban poverty rate is 44% urban poverty incidence. The average Gini Index for constituencies in the urban Nairobi Province is 38. Due to high levels of poverty incidences along the route, there are incidences of forest destruction in search of firewood.

3.9.7 Transport

Nairobi is currently undergoing major road constructions in order to update its infrastructure network. The constructions include the Eastern and Northern Bypasses, Thika Road and other roads, flyovers and bridges. The new systems of roads, flyovers, bridges and the proposed Southern bypass will cut outrageous traffic levels caused by the inability of the current infrastructure to cope with the soaring economic growth in the past few years. Starting from south-eastern part of Nairobi, the proposed road project, in form of a bypass, will link up other major trunk roads in Nairobi Area. It is major component of Kenya's Vision 2030 and Nairobi Metropolis plans.

Wilson airport, a small but busy airport to the south of Nairobi is located a short distance from the bypass route. It handles small aircrafts that generally operate within Kenya, although some offer services to other East African destinations.

3.9.8 Crime

Nairobi is struggling with rising crime as a result of unplanned urbanization, minimal number of police stations and a proper security infrastructure. However, many claim that the biggest factor for the city's alarming crime rate is police corruption, which leaves many criminals unpunished. As a security precaution, most large houses and estates along the project route have a watch guard, burglar grills, and dogs to patrol their grounds during the night. Most crimes, however, occur around the poor neighborhoods such as Kibera where it gets dangerous during night hours.



4. RELEVANT POLICY, LEGISLATIVE AND REGULATORY FRAM EWORK

4.1 Introduction

Many forms of development activities cause damage to the environment because they have a potential of damaging the natural resources upon which the economies are based. Because of this, Environmental Impact Assessments (EIAs) are useful tools for protection of the environment from the negative effects of these developmental activities. It is now accepted that development projects must be economically viable, socially acceptable and environmentally sound for sustainable development. Sections 58 and 138 of the Environmental Management and Coordination Act (EMCA) No. 8 of 1999 and Section 3 of the Environmental (Impact Assessment and Audit) Regulations 2003 (Legal No. 101), requires an Environmental Impact Assessment project/study report prepared and submitted to the National Environment Management Authority (NEMA) for review and eventual Licensing before any development can commence. This is necessary as many forms of developmental activities cause damage to the environment and hence the greatest challenge today is to maintain sustainable development through sustainable use of natural resources without interfering with the environment.

4.2 Environmental Problems in Kenya There are many environmental problems and challenges in Kenya today many of them associated with biodiversity and habitat loss, land degradation, land use conflicts, human animal conflicts, water management and environmental pollution. Lack of awareness and inadequate sensitization among the public on the consequences of their actions on the environment has aggravated the situation. Some of the environmental problems associated with this project include but are not limited to:

a) Sourcing of Road-building Materials along the project road and transport condition e.g. Sands, Stones and sub grade filling materials

b) Water source for construction and other uses can also affect water quality and drainage

c) Source and Supply of major materials, e.g. cement, timber etc and fuel. d) Local change in existing land use practices. e) Erosion and vegetation deteriorating due to road excavation works f) Construction noises to residents living close to the road construction site g) Movement of construction equipment will also increase the emission of

pollutants. h) Noise and vibration resulted from construction activities.



4.3 Environmental policy In order to achieve sustainable economic and social development goals while safeguarding environmental integrity, the Kenya Government put in place the EMCA, 1999 to coordinate environmental activities in the country. This is done through carrying out Environmental Impact Assessments (EIA) which critically examines the effects of a project on the environment. It identifies both negative and positive impacts of any development activity or project, how it affects people, their property and the environment. EIA also identifies measures to mitigate the negative impacts, while maximizing on the positive ones i.e. it is basically a preventive process that seeks to minimize adverse impacts on the environment and reduces risks. If a proper EIA is carried out, then the safety of the environment can be properly managed at all stages of a project-planning, design, construction, operation, monitoring and evaluation as well as decommissioning. The assessment is required at all stages of project development with a view to ensuring environmentally sustainable development for both existing and proposed public and private sector development ventures. The broad objectives of the national environmental policy include:-

• Optimal use of natural resources while improving environmental quality;

• Conserving resources such that the resources meet the needs of the present without jeopardizing future generations in enjoying the same

• Developing awareness that uncalculated environmental stewardship among the citizenship of the country;

• Integrating environmental conservation and economic activities in the development process;

• Ensuring that national environmental goals contribute to international obligations on environmental management.

To achieve this, it is a policy direction that appropriate reviews and evaluations of developmental plans and operations are checked to ensure compliance with the environmental policy.

4.4 International Conventions and Treaties The applicable international conventions and treaties that may affect the proposed project are as stated below:

4.4.1 Ramsar Convention

The Convention on Wetlands of International Importance (1971), called the Ramsar Convention, is an intergovernmental treaty that provides the framework for national action and international cooperation for the conservation and wise use of wetlands and their resources. The Ramsar Convention is the only global environmental treaty that



deals with a particular ecosystem, and the Convention's member countries cover all geographic regions of the planet.

The Ramsar Convention is significant in this project as the road network traverses through a wetland (Ondiri swamp) within the study area. It is emphasized that storm water drainages at stream crossings should be well planned to reduce frequency of flooding and to enhance surface flow and groundwater recharges.

4.4.2 The Convention on Trade of Endangered Species (CITES), (1973),

Because wild fauna and flora in their varied forms are an irreplaceable part of the natural systems of the earth which must be protected for this future generations and the ever-growing value of wild fauna and flora from aesthetic, scientific, cultural, recreational and economic points of view, peoples and States are and should be the best protectors of their own wild fauna and flora. Therefore international co-operation is essential for the protection of certain species of wild fauna and flora against over-exploitation through international trade.

The Convention is important because the roads sector affects the movement of the animals and plants species or their product prohibited under this convention. The proposed road cuts through protected areas harboring a variety of fauna and flora thus Nairobi National Park, Ngong Forest, Dagoretti Forest, and Thogoto forest etc on top of providing an avenue for movement of the same.

4.4.3 The Basel Convention

The Basel Convention on the Control of Transboundary Movement of Hazardous Wastes and their Disposal was adopted by the Conference of Plenipotentiaries in Basel in 1989 and defines the global means to reduce and strictly control the movements of hazardous wastes and to ensure that these wastes are disposed of in an environmentally friendly manner. It aims to protect human health and the environment against the adverse effects resulting from the generation, management, transboundary movements and disposal of hazardous and other wastes. The Basel Convention came into force in 1992.

Since the proposed Southern Bypass project is an international trunk road, it is likely to facilitate the transportation and handling of such wastes.

4.4.4 The Convention on Biological Diversity (1992)

The Convention on Biological Diversity (1992) is important because the project activities impact on flora and fauna. The road passes through Ngong forest, Nairobi National Park etc both of which are a reserve for genetic biodiversity. It mandated that routing of roads be done in accordance with Physical Planning Act Cap 286 that had been prepared taking into account the uniqueness of various ecological zones while avoiding the environmentally sensitive and geologically unstable areas.



4.4.5 The 1988 United Nations Convention Against Il licit Traffic in Narcotic Drugs

and Psychotropic Substances The Convention represents an escalation in the War on Drugs. The Preamble notes that previous enforcement efforts have not stopped drug use, warning of "steadily increasing inroads into various social groups made by illicit traffic in narcotic drugs and psychotropic substances." It cautions that the drug trade and related activities "undermine the legitimate economies and threaten the stability, security and sovereignty of States." This convention is significant because the proposed project road will be an international highway. 4.4.6 United Nations Convention against Transnation al Organised Crime. Human trafficking is the illegal trade in human beings for the purposes of commercial sexual exploitation, forced labor and a modern-day form of slavery. It is also a lucrative industry being one of the fastest growing criminal industries in the world. The protocol to prevent, suppress and punish trafficking of persons was adopted in Palermo, Italy in 2000 and it is an international set of diplomatic guidelines established by the United Nations Convention against Transnational Organized Crime. The Trafficking Protocol is one of three Protocols adopted to supplement the Convention and since the proposed project road is an international highway, it is of significance. 4.5 National Legislation Policies

The transport sector in Kenya is governed by numerous statutes that fall under two broad categories, namely statutes affecting all sectors of the economy and sector-specific legislation. Transport parastatals operate under their specific statutes and are also subject to the State Corporations Act. They therefore experience lack of managerial autonomy and depend on decision-making by their respective Ministries thus they are burdened with bureaucracy.

4.5.1 The Traffic Act Cap 403 of the Laws of Kenya-

Section 91 of this Act declares it illegal to erect any structure of interference within the road reserves. Although many residents have demolished structures on the road reserve, there are a few structures within the road reserve which shall be demolished after notification to the owners without any subsequent compensation.

4.5.2 The Crop Production and Livestock Development Act, Cap 321

The construction of the bypass may endanger livestock crossing the road and also destroy crops within the road reserve. Notwithstanding the economic value of the crops to their owners, the resultant vegetation cover serves as an erosion deterrent in the road environment. Provision of animal crossing areas, installation of



appropriate road signs and relevant awareness campaigns shall be incorporated in the project.

4.5.3 The Water Act Cap 372-

The said Act states that the off-road drainage system shall be so channeled to blend with the natural watercourses and not interfere with the private water reservoirs.

4.5.4 The Trust Land Act Cap 28 and the Physical Pl anning Act Cap 286-

The said Acts states that while giving due considerations to the rights and obligations of landowners, there shall be compensation wherever a materials site, diversion or realignment results into relocation of settlement or any change of user whatsoever of privately owned land parcels.

4.5.5 Physical Planning Act Cap 286

The land use planning of human settlements along the road reserves requires enforcement or road reserve standards especially the width, and provision of facilities such as Bus parks, open air market among others, building encroachment, design on the road reserves

4.5.6 Agriculture Act Cap 318-

The road sector once improved will enhance accessibility and marketing of Agricultural produce. Any crops damaged during the construction will be compensated using rates compiled in liaison with the local agricultural officers as provided for in this act.

4.5.7 Public Health Act, Cap 242-

Although the road works are likely to pollute the drinking water sources resulting from any oil spillages, the improved network will facilitate speedy movement to health facilities.

4.5.8 The Kenya Roads Board, 1999

This Act encourages participation of all stakeholders in the road sector during the planning, design, construction and maintenance. The establishment of the Kenya Roads Board in 2000 and the enactment of the Kenya Roads Act in 2007 will go a long way in improving the legal and institutional framework for road development and maintenance in the country. 4.5.9 Kenya Roads Act 2007

The passing of the Kenya Roads Act 2007 brought wide ranging institutional reforms in the management of the roads sub-sector. The Kenya National Highways Authority will provide oversight of three Road Authorities which will operate under the State Corporation Advisory Board regulations. According to the Roads Act 2007 enacted by



Parliament in July 2007, all roads in the country including those controlled by Local Authorities will now fall directly under the new Authorities. The Minister for Roads will be responsible for all issues pertaining to roads in the country. The Authorities are:

a) The Kenya Highways Authority (KENHA)

KENHA is the implementing agency that manages and maintains all road works on Class A, B and C roads. In addition to implementation of works, KENHA advises the Kenya National Highways Authority on technical issues such as standards, axle loads, research and development. KEHNA also creates regions and then reports to the Kenya National Highways Authority that approves its development budgets while the Kenya Roads Board approves the maintenance budget.

b) Kenya Rural Roads Authority (KERRA)

KERRA is responsible for all rural and small town roads, Class D and below including special purpose roads and unclassified roads. It is also responsible for Forest Department Roads and County Council Game Reserve Roads.

c) Kenya Urban Roads Authority (KURA)

KURA manages and maintains all road works on urban roads in cities and major municipalities. It falls under the Kenya National Highways Authority where the Ministry approves its Roads Development budgets. Kenya Roads Board approves KURA’s road maintenance budget.

Local Authorities Transfer Fund” has the meaning assigned to it under the Local Authorities Transfer Fund Act, 1998;

The Kenya Wildlife Service (KWS) remains a roads agency responsible for roads under their jurisdiction as well as access roads allocated to KWS by the Kenya National Highways Authority. KWS reports to the Kenya National Highways Authority and Public Works on development projects while Kenya Roads Board approves its maintenance works.

The implementation of the Kenya Roads Act 2007 acts as a catalyst for mobilizing more resources for roads development and maintenance.

4.5.9 Environmental Management and Coordination Act 1999

This Act empowers stakeholders in participation to sustainable management of the natural resources. It calls for Environmental Impact Assessment (EIA) (under section 58) to guide the implementation of environmentally sound decisions. It is under this precision that the current study is being undertaken.



Enforcement of the Environmental Management and Coordination Act of 1999 and the Physical Planning Act, Cap 368 shall be observed to ensure that environmental issues are explicitly part of multiple criteria decision-making systems.

4.5.10 National Development strategy

The National Development Strategy was formulated on realization that Development was taking place in Urban Centers alone leading to rural-Urban migration. This led to a situation where the old and sickly people were left in the villages while the young people went to Urban Centers to search for employment, better status and facilities. The urban transport, and infrastructure, strategy plays a bigger role in socio-economic development. To reverse the, district Focus for Rural Development Strategy was formulated so as to take development closer to the rural areas and enable people at the grass roots make decisions to govern their livelihood and also participate in decision-making. 4.6 Institutional Framework At present there are over twenty (20) institutions and departments which deal with environmental issues in Kenya. Some of the key institutions include the National Environmental Council (NEC), National Environmental Management Authority (NEMA), the Forestry Department, Kenya Wildlife Services (KWS) and others. There are also local and international NGOs involved in environmental issues in the country. From the above institutions, NEMA plays the regulatory role in the management of environment in Kenya.

Figure 1: Institutional Framework for EMCA



In regard to the project under study, the KENHA is responsible for the maintenance of the road (that is A, B, and C roads) while the Kenya Wildlife services (KWS) is responsible for the maintenance of the roads within the National Parks and Game Reserves. KERRA is responsible for the maintenance of secondary, minor, special purpose, adopted streets and all unclassified roads in the districts. 4.7 Project Implementation Strategy The establishment of KENHA whose purpose is to manage and maintain all Class A, B and C roads will oversee and coordinate the development and maintenance of this road. It will also be the principal advisor to the Government on all matters related thereto. The Roads Board Act provides for the participation of all stakeholders. 4.8 Institutional Framework for Passenger Transport Operations The current regulating framework (Cap 404) shall be reviewed with a view to enactment of a service and operation management legislation to ensure the road passenger transport services are carried out in a legally organized environment. The institutional framework will distribute functions between the licensing and service authorities in both local and central governments in accordance with capacity and institutional responsibilities to provide a climate that is conducive to private sector investment. In accordance with Vision 2030, the Metropolitan Transport Authority (MTA) is to be established for Nairobi City followed by other cities, as appropriate, to manage urban transport issues in the urban areas. A Metropolitan Police Department (MPD) will be set up to manage urban traffic and inculcate order and discipline in urban traffic countrywide. Both institutions will be staffed and managed by transport experts.



5 PUBLIC PARTICIPATION

5.1 Sources of Information

One of the key information sources used during the Environmental Impact Assessment Study exercise was public participation carried out via interviews and discussions under the guidance of standard questionnaires developed to capture the concerns, comments and issues from the neighbours and the key stakeholders surrounding the proposed project site whereby positive and negative views were sought. Three public meetings were also held in different venues, Kikuyu town(at Kikuyu Township Primary School), Kibera (at the open grounds at Catholic Women Fighting HIV-Aids in Kenya(CAWOFAK) near Raila centre and Mombasa road Junction (outside Ole Sereni Hotel) in order to capture more information. The exercise was conducted by a team of experienced registered environmental experts. Main issues raised are as summarized below:

5.2 Objectives of the consultation and public parti cipation The main objective of the consultation and public participation was to:

1) Disseminate and inform the key stakeholders about the Southern By-Pass project with Special reference to its key components and location in order to avoid conflicts

2) Gather comments, suggestions and concerns of the neighbours and stakeholders to the project

3) Incorporate the information collected in the EIA study report In addition, the process enabled;

1) The establishment of a communication channel between the general public and the team of consultants, the project proponents and the Government.

2) the concerns of the stakeholders be noted and considered by the decision-making bodies at an early phase of project development

5.3 Interested and affected parties consulted The following list outlines the parties that are affected and interested in the proposed Southern Bypass (see full list of the people/Stakeholders consulted in the appendix)

1. Business Premises near the project site 2. Government institution/ officials 3. NGOs 4. Ordinary citizens 5. Local Authority leaders 6. Local community representatives (Local chairmen, Residential Association and

peasant farmers)



Methodology used in the CPP The Consultation and Public Participation (CPP) Process is a policy requirement by the Government of Kenya and a mandatory procedure as stipulated by EMCA 1999 section 58, on Environmental Impact Assessment for the purpose of achieving the fundamental principles of sustainable development. It is an environmental and social assessment exercise which was conducted on the 18th-26th August 2010. The exercise was conducted by a team of experienced registered environmental experts in three ways, namely, (i) focus group and Key informant interviews and discussion, (ii) field surveys and observations and (iii) Public Barazas. A series of public Barazas held at various points along the Bypass corridor with attendance of over 60 people at every point and questionnaires were developed in order to capture all concerns, comments and issues that the local communities and key interest groups had on the proposed Southern Bypass. The completion of such questionnaires and the issues raised during the public Barazas subsequently allowed for identification of the specific issues from the stakeholders’ response which provided the basis upon which the aspects of the Environmental and Social Impact Assessment was undertaken. The purpose for such interviews was to identify the positive and negative impacts and subsequently promote proposals on the best practices to be adopted and mitigate the negative impacts respectively. It also helped in identifying any other miscellaneous issues which may bring conflicts in case project implementation proceeds as planned. In general, the following Steps were followed in carrying out the entire CPP process:-

I. Identification of institutions and individuals interested in the process- database of the interested and affected parties

II. Administration of questionnaires to the different target groups and local community members along the Bypass corridor Meetings at various levels and with different target groups

Below indicated are the meetings held and the respective target groups.

I. Meetings with the District Officer1 (D.O1), local area chiefs and assistant chiefs in Kikuyu town, local chiefs in Gitaru, Thogoto, Wilson Airport, and Mugumoini.

II. Meetings with the local leaders and members of the community at Kikuyu Thogoto, Dagoretti and Kibera during the interviews and administration of questionnaires, open ground outside Olesereni Hotel

III. Meetings with the various heads of institutions or their representatives to be affected by the project such as the Industries (Optimum Lubricants in Kikuyu town), Kikuyu town council chairman and engineer at their offices, Alliance High School, Presbyterian University of East Africa School, Total Petrol station in Kikuyu, and St.Therese Nursing Hospital in Kikuyu, Carnivore restaurant, Ole Sereni hotel, Nairobi National Park College of Insurance including home owners and property developers along the length of the bypass.



5.4 Background Data collected from the field work revealed that majority of the neighbours, stakeholders and the local community members were aware of the proposed Southern Bypass project. The engaged parties had different opinions, citing positive and negative impacts towards construction and implementation of the Bypass. The local communities and major stakeholders independently gave their views, opinions, and suggestions as in the best of their interest and in the interest of the factors that affected the circumstances, influences, and conditions under which their organizations exist in. See appendix for the list of participants in the Consultation and Public Participation by interviews through questionnaires, discussions, and public Barazas. Public Barazas were held on August 25th (2 p.m), 26th (9.30a.m), and 26th (2pm) at Kikuyu Township Primary School(Kikuyu Town),at the open ground in front of the Ole Sereni Hotel off Mombasa road and at the open ground near Raila centre in Kibera respectively. (See appendix for the attendance list).

Plate 1: Public Meeting at Kikuyu

Plate 2: Public Meeting at Mombasa Road, outside Ole-Sereni Hotel



Plate 3: Public Meeting at Kibera outside COWAFK grounds opposite Raila Centre in Kibera

5.5 Major Issues raised Information collected through oral interviews, administering of questionnaires and through charring of public barazas highlights both positive and negative socio-economic and environmental impacts, anticipated during the construction and operational phases of the project by key stakeholders (local leaders, surrounding, institutions/organizations, interested persons or groups). The community also suggested some mitigative measures that the contactor should put into consideration during construction and operation phases of the project in order to minimize environmental degradation and promote sustainable development. General opinions and expectations of the neighbours, local community and those given by the key stakeholders to the proposed project are also highlighted.

5.5.1 Positive Social-Economic and Environmental Is sues during construction stage

5.5.1.1 Enhance business Opportunities hence econom ic growth

Majority of the respondents revealed that the Southern bypass project will open up chances of more business opportunities through interaction with businesses near the project site and also through the use of locally available materials during the construction phase, such as cement, concrete and ceramic tiles, timber, sand, ballast electrical cables etc, the project will contribute towards growth of the economy by contributing to the gross domestic product. The consumption of these materials, fuel oil and others will attract taxes including VAT which will be payable to the government hence increasing government revenue while the cost of these raw materials will be payable directly to the producers, the hotel owners near the bypass also acknowledged that the project would



increase the efficiency of customers to their business, this in turn will boost the Kenyan economic status at a greater rate.

5.5.1.2 Employment According to the data collected from field work, it was clear that majority of the interviewed people acknowledged that the proposed project will create employment opportunities either direct or indirect as soon as construction begins. The project will have many chances of casual laborious so many people are likely to be employed to assist in construction work, However, they wanted assurance that the locals will be given the first priority for employment once the construction of the Bypass begins, also food kiosks may be opened up along the bypass, which are to supply food to the workers and also transportation vehicles are likely to benefit from the construction workers. This will be a source of income for over 2000 households and hence is expected o boost the GDP and improve the living standards of the local people involved in the Southern bypass project.

5.5.1.3 Resettlement and compensation of the affect ed parties The Residents near the road who were affected, especially those at Kihumburi – Thogoto area were grateful that they had been compensated their property and been able to move to other places. The respondents also felt that the project had promoted subdivision of a land which has been on a free lease hold for many years, hence enabling them to live on their own land.

5.5.2 Positive Social-Economic and Environmental Is sues during Operation stage

5.5.2.1 Improved Infrastructure

All the respondents interviewed were positive on the fact that the construction of the Southern bypass Road would lead to improved infrastructure within Nairobi city, hence development and improvement of the living standards. They said that the Road will create a new and improved way for transport. Majority of the respondents were optimistic that the Road would lead to development of other social amenities which did not exist before like electricity power supply, water supply, schools and hospitals. Some more businesses may also develop due to accessibility and efficiency of the new Road.

5.5.2.2 Ease of Traffic Jams through Efficient and Effective Transportation Data collected from the interviewed respondents revealed that, by developing the Southern bypass Road, the problem of intense traffic congestion being experienced today within the currently existing roads, i.e. Mombasa Road, Lang’ata Road, Ngong Road and Dagoretti Road will be solved. This is due to the fact that the bypass road joins the existing main roads within the southern part of Nairobi; hence movement will be made easier and more efficient compared to the current state.



5.5.2.3 Increased Business Opportunity

According to the interviewed respondents who own businesses which are near or along the Proposed Southern bypass, they were so positive that after the development of this new road their business will also improve, due to the fact that they will have increases number of customers, since access to their premises will be made easier. Owners of residential houses were happy too, since they will be able to get more tenants. Institutions such as schools and colleges along the bypass also appreciated that they will be able to attract and enroll many students due to improved means of transport. Some new businesses and estates will also be developed after the construction of the bypass road.

5.5.2.4 Improved Security The construction of the Southern bypass will be a great achievement towards improved security, especially for the areas between Langata and Ngong, Ngong and Dagoretti areas which most part of the proposed road pass through the Ngong Forest. Respondents revealed that the security of those areas have been threatened for some time, reporting a lot of robbery cases along the route or even murder. With the Southern bypass project, which after construction there will be full time security light all the way from Mombasa Road where it starts up to Kikuyu junction where it ends, security along the route will good both during day and night times. The police officers patrol group and other security firms will also have an easy time to maneuver along the new road.

5.5.2.5 Increased Land Value Land value along the bypass will definitely increase due to the development of the new road. The demand for the land near the road will be high due to accessibility of the means of transport; in turn the land owners will have to increase the price of the land in the areas along the bypass.

5.5.2.6 A clean Environment The residents were optimistic that after the development of the proposed project, the status of the environment will change in terms of cleanliness. Some of the along the road places currently being used as waste dumping site will disappear, hence reduce the cases of health hazards.

Plate 4: Waste dumped at the road side



5.5.3 Negative Issues 5.5.3.1 Dust Emissions and poor Health

During the time of the Road construction there will be a lot of dust emissions. People along the bypass already had many complains concerning the air dust pollution, residents said that the road was emitting a lot of dust thus they have a hard time in maintaining cleanness at their houses. Schools and institutions neighboring the road also had the same complain. Business people along the road expressed great fear in that during the period of construction, the rate of customers turn up will be very low, hence a disadvantage since low profits will made. Some residents complained that they had health complications such as common cold and coughing arising from dust being emitted from the road site. The proponent shall ensure that dust levels at the site are minimized through sprinkling water in areas being excavated and along the tracks used by the transport trucks and diversions within the site. Additional mitigation measures presented within the EMP will be fully implemented to minimize the impacts of dust generation.

Plate 5: Ole Sereni Hotel and a School Neibouring the Southern Bypass

5.5.3.2 Noise pollution

Noise coming from the machinery which will be utilized during the road project construction period was evident from all the respondents at the roads vicinity. The noise shall emanate from the compacting vehicles, workers, vehicular movement and running of engines. The neighbours to the project therefore requested that appropriate noise suppression measures be put in place e.g. avoid unnecessary hooting, gunning of engines, shouting to each other and ensure a common sense attitude at the work place, this was especially from the near learning institutions, churches, offices and major



businesses. They requested the proponent to use minimum noise producing machines and to reduce the duration of idling of vehicles making deliveries.

5.5.3.3 Vibrations The residents expressed fear over vibration produced by the construction machines and dynamites used for blasting at the construction sites and its likely effects on the structure of the buildings along the Bypass.

5.5.3.4 Traffic jams

The interviewed respondents expressed their fears that the likelihood of having traffic jams during the road construction period was very high, though it should be noted that the Southern bypass project has a provision of two servicing roads, one joining Mombasa and Lang’ata Roads and another one connecting Lang’ata and Ngong roads. This will be purposely implemented to reduce the rates of traffic jam along the proposed bypass road. Suggestions from the respondents were that the contractor should have staff on site and road signs to direct traffic appropriately, hence reduce traffic jam.

After construction road users should drive safely to avoid accidents caused by over speeding because of the smooth road. Road bumps and other speed control structures should be erected appropriately for the safety of all road users

5.5.3.5 Loss of Land and property

It was so obvious that some people were going to lose their land and properties due to the construction of the proposed road project. Most of the affected parties, especially from the Kikuyu side revealed that they had been compensated and some had already resettled at new places. Some declared that they even got new settlement places after a land which was at a free lease for long time was subdivided and given to them officially. Only few complaints were reported about the inventory of the project into individuals land especially for the people who reside at junctions where the interchange and intersections such as overpasses may cut.

5.5.3.6 Waste Generation Large amounts of solid waste will be generated during construction of the project. These will include metal cuttings, rejected materials, surplus materials, surplus spoil, excavated materials, paper bags, empty cartons, empty paints and solvent containers, broken glass among others. Solid wastes if not well managed have a potential of causing accidents and disease outbreaks due to suitable breeding conditions for vectors of cholera and typhoid. Malaria outbreak could also be exacerbated by the presence of open water ditches for breeding of anopheles mosquitoes. The major vulnerable groups are children who could be exposed to these conditions.



Some of the excavation material will be rendered unusable and thus will have to be disposed off. This also applies to some of the soil/rocks which may not be reusable after excavation processes are complete. All these materials needs to be collected, transported and disposed off appropriately in approved designated areas. It is encouraged that other alternative uses of these materials should be found e.g. filling pot holes along the feeder roads.

5.5.3.7 Loss of sources of income and increase in social crime

Some of the local community persons who had small businesses operation at the road side were greatly worried that after the commencement of the Southern bypass road project they will be automatically be misplaced. Some existing structures along the road will have to be demolished. This will obviously interpreted to the fact that their sources of income is closed and that they will be forced to seek other means of survival, for they initially depended fully on this businesses. Most of the respondents also expressed their fear that there would be increase in social crime along the road, with a lot of youths being not employed initially; there is a tendency that they will be attracted to the project site, especially during the time of its construction. Thus social crime and great insecurity is opted to arise during the project construction period.

Plate 6: Business women and children selling their goodies along the Bypass

5.5.3.8 Wetland Disturbance The proposed Southern bypass project is marked to cross cut one major wetland near Kikuyu Town popularly referred to as the Ondiri Swamp. Residents near the swamp expressed their fear over the destruction of the Ondiri swamp that would be destroyed by the construction of the bypass. Interference with the Ondiri swamp on the lower edge could lead to disappearance of some spring sources in that area, also interference with the water reticulation systems along construction route could lead to loss of investment and water. Pollution of rivers (surface) water sources due to massive movement of soils and debris and increased rates of soil erosion will be experienced. Peoples’ suggestion



was that the contractor should have flyovers/ bridges or culverts at all wetlands to avoid any major disturbance. The proposed project also goes through the Ngong Forest, Thogoto forest and Alliance High School forest which are major catchment areas; and due to the road development, some tree species and vegetation will be lost. This may lead to other ecosystem effects. Waste from machinery such as oils and lubricants are likely to be washed into the surface water sources, hence contamination/pollution.

5.5.3.9 Increased water and Electricity demand It is expected that both the workers and the construction works will create an increased demand for water and electricity in addition to the existing demand. Water will be mostly used in the creation of aggregates for construction works and for wetting surfaces for softening or hardening after creating the formworks, watering dusty diversions and active construction sites.

5.5.3.10 Increase in Accidents

Respondents expressed great fear over the likelihood of increase in the number of accidents that might result after the completion of the Bypass. At the operation stage, it is opted that the road uses, especially the vehicle operators will be driving at higher speed since the road will be quite comfortable and smooth to run at. They feared that many lives could be lost due to reckless driving. Parents and teachers expressed their fear that it will be difficult for children to cross the bypass road alone, and that lives of students and pupils may be claimed by this road, if some strict speeding measures will not be taken. However they were assured that this will be highway where design speeds are 80km/h but there will be service roads, fly over’s and tunnels that will be considered in such areas during the construction.

5.5.3.11 Storm water Storm water runoff from the constructed parts of the Bypass which will be rendered impermeable may run into the neighboring sites thereby flooding and causing interference to the equipments, property or other people’s use of their own property, leisure and pleasure. At the Kikuyu meeting, some were of the opinion that the storm water could be directed to channels that would drain into water pans and used for irrigation. 5.5.4 Community’s general Opinion on the project. The community gave its general opinions towards the proposed Southern bypass project, these was presented as listed below:

• Majority were for and said the project will be beneficial to all once it will start operating and so it should go on as scheduled.

• There will be employment opportunities for the locals and training during the project construction.



• There will be improved infrastructure

• There will be improved security • Community will be allowed to participate in environmental and socioeconomic

matters related to or associated with the project. • The associated negative environmental Impacts and health hazards will be

addressed • Environmental auditing and monitoring to minimize negative impacts associated

with the plant. • Proper waste management and disposal procedures and standards be

employed • The project will enhance development • The project will enhance access to resources like water, electricity e.t.c • Roads are the blood vein for the movement of goods and services



6 POTENTIAL ENVIRONMENTAL IMPACTS

6.1 General The construction of the proposed Nairobi Southern Bypass Road is envisaged to generate undesirable environmental impacts hence the need to subject this project to Environmental and Social Impact Assessment (ESIA). EIA is a tool used to guide environmentally sustainable decisions especially through the identification of potential impacts of the proposed Nairobi Southern Bypass Road. This chapter describes the potential Impacts derived from the proposed project activities discussed earlier in this report.

6.2 The ESIA Process A participatory ESIA process was undertaken through observation, key interviews and public meetings involving various stakeholders including amongst others:-

• Respective District Roads Engineers and Roads Officers • Institutions along the bypass

• Road users of the project road

• Business people along the road • Nairobi National park and other protected areas

• Residential building owners

• Provincial administration officers • Road Engineers

• Other relevant institutions and individuals 6.3 The Pre-construction Stage Impacts 6.3.1 Social economic Environment

6.3.1.1 The Right of Way (ROW) acquisition impacts

The proposed Nairobi Southern Bypass road totaling 28.6km in design starts from the junction of Mombasa Road where will build an interchange at SK0+397.500 and ends at SK28+600 linking Kabete Limuru Road (A104) at Kikuyu Town. The Road crosses Nairobi National Park westward then goes through Lang’ata Road (C58), Community Road, Ngong Road (C60), Dagoretti Road (C63), Thogoto Road (D411) then passes through Ondiri River and under a railway.

Furthermore, two service roads will be added for the Project: one road will link Mombasa Road and Lang’ata Road totaling 6042.471m, the other will link Lang’ata Road and Ngong Forest totaling 2500m. Both service roads have the same cross section of 0.5m soil shoulder + 2.0m hard shoulder + 2×3.5 carriageway + 2.0m hard shoulder + 0.5m soil shoulder, and also have a consistent pavement structure with that of Main Road and same cross section with that of 12m-slip road. Land acquisition for some sections of the



right of way will affect the built environment of near Lang’ata and Kikuyu Township, agricultural lands especially in Thogoto area, forested areas of Ngong forest and Alliance forest, protected areas as the Nairobi National Park among others. Most of the structures built on the road reserve have been demolished especially near kikuyu town while the extra land required has been acquired and the owners adequately compensated. There is no significant natural environment to be affected by the project since it touches the national park at the periphery and follows on an existing road at Ngong forest which will only be expanded. The section between Mombasa Road and Kikuyu Road was acquired and designed in 1970. And section between 0km to 5+600 km within Nairobi National Park shall be realignment which should acquire new land. Table 5: Estimated quantities of ROW Item Land

acquisition Building demolishment

Removal of culvert

Removal of trees

Removal of power cable

Unit Ha M2 M3 /No No km Southern Bypass

195866 86106 83 7377 86.61

Source: Field work and Feasibility study report

6.3.1.2 Loss of natural Habitat and reserve areas

Nairobi National park is likely to be affected by the bypass. This protected area is likely to lose a sixty-meter track of land right from the former US Embassy to the Carnivore near Lang’ata junction. This is likely to affect the natural habitat for wildlife within the park. Other areas likely to be affected include the Ngong forest natural habitat, the Dagoretti natural habitat, Thogoto and Alliance forest natural habitats and the swamp on Ondiri River near Alliance High School.

Plate 7: Nairobi National Park bordering the proposed Southern Bypass Road



6.3.1.3 Loss of assets and land The project is likely to affect households in Kikuyu, Thogoto, Dagoretti and Lang’ata, businesses including the Total filling station and the Optimum Lubricants Industry in Kikuyu town, firms and institutions including the Kikuyu town bus park, St. Theresa Nursing Home, Alliance Boys High School and the Presbyterian University stand to lose all or part of their land, housing, public utilities and other assets including forested areas. Moreover there is possibility of adverse effects on the quality of life of affected households and community members.

6.3.1.4 Disruption in the learning process

A number of schools are located close to the bypass. The principal of the Star Sheikh H Academy expressed his fear over the likelihood of disruption of smooth learning in the school owing to its closeness to the Kikuyu Junction interchange. Alliance Boys will also face a similar problem. Although no school near the bypass have been marked for demolition, their closeness to it makes it prone to noise and vibrations associated with the construction activities.

6.3.1.5 Loss of sources of income and increase in s ocial crime

Residents of Gitaru junction, Kikuyu town centre, Thogoto, Dagoretti, Lang’ata and other small business centres along the bypass expressed their concerns over the demolition of their mini kiosks and shades build on the road reserve along the bypass. This they reiterated would disrupt their sources of income and livelihood per se. As a result, social crime rate in the area is expected to rise with the beginning of the construction as people left without jobs might resolve to go into crime to earn their daily livelihood. security of the residents is threatened especially at Langata area neigbouring Kibera slums. The community at Kikuyu,Thogoto and Lang’ata suggested that the people affected should be employed to work as casuals during the construction stages of the Bypass in order to minimize crime rates.

Plate 8: Kibera slums at the lower side of Langata area



6.4 Anticipated impacts during Construction Stage It is at the construction stage that major changes in the physical environment will occur. These changes in the environment are likely to cause both positive and negative impacts which must be carefully identified and respective enhancing and mitigating measures developed. These impacts can be subdivided into smaller categories for easier understanding as discussed below. 6.4.1 Impacts on the Natural environment

6.4.1.1 Air quality The air quality of the area will be directly affected through dust emissions and made worse by dry, windy and dusty weather especially during road construction and movement of building materials to and from the site. Heavy machinery involved during the movement of construction equipment will also increase the emission of pollutants to the air and thus lower its quality. Low quality air full of dust particles, nitrogen dioxide, vaporized lead and sulfur dioxide and exhaust fumes containing CO and CO2 will have adverse effects on people in the immediate project vicinity as well as commuters in open vehicles. Build-up of traffic especially in junctions of Kikuyu, Dagoretti, Ngong and Lang’ata during peak hours will be exacerbated by the presence of construction equipment and earthworks causing the rise in the level of air pollutants emitted.

6.4.1.2 Loss of playgrounds

Most of the fallow land proposed for the construction of the Nairobi Southern Bypass in 1970 is currently being used by children from the neighboring villages as playgrounds. This was witnessed near Kibera and Dagoretti junction during field work; as well as Alliance High School playing field. The construction stages will deprive these children of recreational space.

6.4.1.3 Solid waste accumulation Earth movements and demolition works associated with construction activities are likely to generate large volumes of solid wastes. The building materials used including cement and bitumen will also generate a sizeable amount of solid wastes. Other wastes in smaller quantities include waste papers, organic wastes and metals. Such wastes are unsightly and may obstruct passage ways. They can also harbor vectors that spread diseases.

6.4.1.4 Impacts on surface and ground water quality The Nairobi Southern Bypass Road does not pass through many significant river or water body. Only the Ondiri River near Alliance high school is likely to be affected by the construction works. Used oil and lubricants from heavy equipment and of the construction vehicles may find their way in the water bodies. Run-off experienced during rainy season of the construction phase is likely to affect the turbidity of water in the neighboring shallow streams and wells though for a short period of time.



6.4.1.5 Impacts on plant species

The project passes through Nairobi National Park and major forested area including the Ngong, Thogoto, Dagoretti and Alliance forests. This therefore means that a good number of tree species will be cleared to pave way for its construction. The exotic tree species include: Spathodea companulata, Cypress spp., Eucalyptus spp.; among others. The indigenous tree species include: Ficus spp (Mugumo), Cordia Abyssinica, and food crops including maize and beans. However, no endangered tree species will be affected by the project. Trees will be re-planted at the entire length of the project after completion.

Plate 9: KFS Ngong Forest where the bypass crosses

6.4.1.6 Impacts on animal species Both macro and micro fauna species exist in the proposed project area and are likely to be affected by its construction. The macro-fauna species include: antelopes, lions, zebras, buffaloes, wild birds, wild rabbits, among others found in Nairobi National Park and the Micro faunal species including insects, aphids and earthworms. The tamed animal species include: doves, cats, dogs, cows, goats, and sheep, among others. However, the impacts will not be adverse since the bypass follows the boundary of the National park and thus do not affect movement routes, mating grounds and corridors followed by the wild animals 6.4.2 Impacts on social amenities

6.4.2.1 Water supply The construction of the project requires large quantities of water for concrete mixing, domestic water requirements of the construction workers and staff and watering the road to control suspended dust. These uses are likely to exert undue pressure on the existing water supply which was not designed for such works. However, owing to the existence



of natural water pools and rivers like the Ondiri River near the proposed road, no main shortages are anticipated during the construction phases.

6.4.2.2 Power usage Local consumption of electricity is likely to rise with the commencement of the project. This however will not be significant as it will be used for lighting of warning signs of the construction area, bunkhouses, office equipment and appliances in the engineers and contractors’ offices and in the field laboratory.

6.4.2.3 Housing There will be need for secure and well served houses for the construction staff. However to the extent possible, local labor will be hired to minimize the need to provide housing for the construction crew. Temporary bunkhouses may be provided for those workers that will be hired off-site.

6.4.2.4 Land use Diverse land uses exist within the entire length of the Nairobi Southern Bypass road. The Mombasa road junction through to the Lang’ata road contains offices and residential apartments including the former US embassy, the College of Insurance, the Wilson Airport, Carnivore Restaurant, Kingdom Hall of Jehovah witness and the Lang’ata Barracks. To the left side is the famous Nairobi National Park. Forest ecosystem is predominant l the project area from the Ngong forest to Dagoretti forest junction and some parts of Thogoto. The area from Thogoto Junction to Kikuyu Township Junction is private land used for residential, agricultural and commercial purposes. The existing land use patterns in the project area will not significantly change except for areas beyond the corridors of the project. The land needed for this project shall be bought by the GOK and be changed into land for infrastructure and public use.

6.4.2.5 Transport and traffic The flow of the current traffic is likely to be affected during the construction stage especially in the main junctions such as Mombasa road junction, Lang’ata road junction, Ngong road junction, Dagoretti road junction, Thogoto road junction and the Kikuyu Junction among other areas. Thus, necessary coordination and control is needed to direct the anticipated traffic delays. Traffic management will be coordinated with the concerned local government units and national government agencies. As endeavored however, traffic is going to ease up with project completion.

6.4.2.6 HIV /AIDS incidences During the construction of the project there is likelihood of the incidences of HIV /AIDS increasing due to influx of new communities related to or influenced by the proposed project



6.4.2.7 Cultural, Historic and Archaeological aspec ts Construction of the Nairobi Southern by pass is not expected to affect any site or structure of cultural and historic importance nor any known archaeological or paleonological site. During construction, stockpiles of materials and wastes in the project site will be unsightly but will be removed as the project nears completion. Natural landscaping and planting of trees will also be done after project completion to improve the aesthetic value of the project site. Recreational grounds and temporary playgrounds currently existing within or near the construction site as witnessed in near Kibera and in Dagoretti areas. A good number of primary school going children will have to seek alternative playground since the current one is on the road reserve. Local and foreign tourists using the nearby roads to Nairobi National Park and the neighboring conservation areas may be adversely affected if caught in the slowed traffic near the site. However, this will only be limited to the construction period.

6.4.2.8 Economic productivity The Nairobi Southern project will generate employment opportunities to hundreds of women, youth and other members of the community mostly during the construction period and will reduce as the project nears completion. Income of people hired from the locality may increase the demand for goods and services. Small scale businesses mainly dealing with food may thrive with increased number of people to feed. Skilled and administrative support personnel may also be required. The land and assets neighboring the project are likely to appreciate in value due to improvement in road infrastructure. 6.4.3 Health and safety impacts

6.4.3.1 Hazardous waste accumulation The project is likely to result in unexpected contamination of soil or groundwater from machinery maintenance, storage, and washing/cleaning activities which through run-off may affect the aquatic habitats, water resources, or agricultural lands in the project vicinity. Vehicles and equipment used during construction may have the potential for mechanical breakdowns leading to site spillage.

6.4.3.2 Public health There increase in influx of construction workers is likely to result in the spread of communicable diseases in the project vicinity. Sexually transmitted diseases e.g. HIV/AIDS, water-borne, air-borne are likely to increase in incidence levels within the project area. Different forms of diseases will have a probability of being contacted by



workers and staff of the project as well as by the people living near the project site. The affected population can continue to seek treatment from public and private health care services in the locality.

6.4.3.3 Occupational health and safety Any construction activity comes with its own set of occupational health and safety issues and this project will not be an exception. There is likely to be accidents experienced by the construction staff and road users during the construction phase. Clear markings including warnings will be mounted by the project management to minimize accidents. Fire extinguishers and protective clothing including helmets, face masks, gloves and overall coats will be use by the construction crew to minimize exposure to unforeseen risks. Project management will provide first aid and possibly primary health care services to staff and crew. Due to the proximity of the project to the city, emergency and serious cases can be sent to the most accessible clinics and hospitals.

6.4.3.4 Noise and Vibration Since heavy construction machinery and earth movers will be used during the construction phase, there will be likelihood of noise pollution and vibration in the surrounding environment. This may act as a potential source of disturbance to the surrounding neighbors and a health hazard to the workers themselves. However, this pollution may be short-lived owing to the short period of time which these machines are used. Appropriate time of the day will also be determined when the machines which generate a lot of noise can be used. Such noise emissions should be minimized as much as possible from the source point while workers should be provided with appropriate personal protective wear wherever necessary. 6.5 Project operation stage 6.5.1 Socio-economic impacts

6.5.1.1 Transport and traffic flow The rates of traffic jams along the existing roads will be reduced after completion of the proposed project since it aims to offer alternative passageway to motorists passing through Nairobi City. The Initial Environmental Examination (IEE) is conducted as alternative bypass and connecting A104, C58, C60 and C63 etc. with a distance of 28.6 km. It is a dual carriage way that is expected to ease traffic in the city of Nairobi by providing alternative passage way to motorists who do not wish to enter the City from either Mombasa or Naivasha.

6.5.1.2 Improved security

The Nairobi Nairobi Southern Bypass project will be installed with security lighting for its entire 28.6 km length and thus improve security of the road users. The areas of Kikuyu,



Thogoto and Ngong forest will be patrolled to minimize cases off thugs and carjacking in the highway.

6.5.1.3 Increased socio-economic benefits There will be increased efficiency in commercial activities especially between the port of Mombasa and other towns including Naivasha, Nakuru, Kisumu and Eldoret with better transport conditions for goods and services. The population within Nairobi city will have more time to engage in productive activities which are lost during slow moving traffic since vehicles which have no business in the city centre will be diverted.

6.5.1.4 Growth of existing and new towns

Due to the influx of people owing to improved road network, there is a possibility of growth of towns especially on or near the Mombasa road junction, Lang’ata, Ngong, Dagoretti, Thogoto and Kikuyu. New amenities including high class commercial and residential areas are likely to thrive next to the bypass.

6.5.1.5 Increased revenue collection The project is anticipated to generate revenue since motorists will continue to contribute to revenue collection by paying relevant taxes and fees. In some cases, the cost of transportation may reduce due to reduced wear and tear of vehicles. 6.5.2 Impact on health and safety

6.5.2.1 Air and noise pollution Air pollution from exhaust fumes and noise pollution due to increased traffic will increase along the project area, however for the Nairobi city centre, air and noise pollution from motor vehicles will reduce due to less vehicles, increased mobility and faster traffic.

6.5.2.2 Accidents and related risks It goes without saying that there are risks and problems that may face the members of the community and workers involved in operating and utilizing the road. Health and safety impacts are likely to be experienced such as accidents which are associated with vehicular traffic on the main highway due to speeding, coupled with the fact that the road leads to the central province hence there is a high traffic during the peak hours that may result in spills of toxic materials injuries or loss of life.

6.5.2.3 Reduction of water-related diseases The removal of trenches and ditches along the road by construction of the culverts will remove the fertile ground for the breeding of anopheles mosquitoes which will reduce the spread of water-related diseases such as malaria.



6.5.2.4 Health and safety impacts

It goes without saying that there are risks and problems that may face the members of the community and workers involved in operating and utilizing the road. Health and safety impacts are likely to be experienced such as accidents which are associated with vehicular traffic on the main highway due to speeding, coupled with the fact that the road leads to the central province hence there is a high traffic during the peak hours that may result in spills of toxic materials injuries or loss of life.

6.5.2.5 Identification of Environmental Impacts In order to identify the potential impacts, the study team ensured that many stakeholders were involved in the exercise. Scoping discussions were held with various interested and affected parties within the roads’ environs during the fieldwork. In these discussions held at the resident Engineer’s site office, key environmental issues relating to road construction activities were identified.

The study team used both structured and non-structured questions to solicit for information. The potential impacts of the Nairobi Southern Bypass Project fall under two broad categories of Bio-Physical (Natural) and Socio-Economic environments. The experts used the matrix in the below to analyze these impacts. Project activities are listed in the columns while the environmental parameters are reflected in the rows. Through brainstorming sessions and use of the road sector checklist contained in the Kenyan EIA draft guidelines and administrative procedures, potential impacts were identified.

The identified potential impacts were rated as positive or negative. These were further subjectively quantified as low (*), medium (**) and high (***) respectively.

Table 6: Impacts of Road Project Construction Activ ities and Environmental Parameters

PROJECT ACTIVITY ENVIRONMENTAL PARAMETERS

BIO-PHYSICAL SOCIO-ECONOMIC

Soil Water Flora Fauna Economy Employment Tourism Health

CONSTRUCTION PHASE

1. Site Clearance within the Road Reserve

l

l

h+

h-

h+

h-

h+

m-

h+

h+

h-

h+

2. Reshaping and stabilization of shoulders m- l m- m- h+ m+ h+ m+

3. Culverting according to Specifications h+

m-

H+

l

l

h+

m+

h+

m+

4. Excavation of Material Sites h- h- h- h+ h+ h+ h- h-

5. Bridges, Box Culverts and Drifts. h+ l l l h+ h+ h+ None

6. Drains or Ditches l+ l+ l+ l m+ h+ h+ h+

7. Protection Works, Gabions, Stone Pitching, Scour Checks

h+

h+

h+

m-

h-

h+

h+

h+

h+



PROJECT ACTIVITY ENVIRONMENTAL PARAMETERS

BIO-PHYSICAL SOCIO-ECONOMIC

Soil Water Flora Fauna Economy Employment Tourism Health

8. Surfacing (Spot Patching Resealing or Re-carpeting) None l None l l l h+ m+

ROUTINE MAINTENANCE (After Construction)

1. Bush clearing l l h- l h+ h+ h+ h+

2. Culvert Cleaning and Headwall Repair

m+

l+

l

l

h+

h-

l

l+

3. Drainage or Ditch De-Siltation

m+

m+

l

l

m+

l

h+

m+

4. Installation of Access Culverts

m+

m+

l

l

m+

l

h+

m+

5. Pothole patching l l None None h+ l h+ h+

6. Encroachment Control h+ l+ m+ None None l h+ M+

7. Fast driving l l l h+ h+ m+ h-



The identified potential impacts were rated in table above as positive or negative (+/-) depending on the eminent benefit or loss. These were further subjectively quantified as low (l), medium (m) and high (h) respectively.



7 ENVIRONMENTAL AND SOCIAL IMPACT MITIGATION MEASUR ES

7.2 Introduction This chapter highlights the necessary mitigation measures that will be adopted to prevent or minimize significant negative environmental, health and safety impacts associated with the activities of the project life time. 7.3 Mitigation of the impacts The Kenya National Highways Authority will prepare prior to commencement of construction activities measures to be implemented by the project contractor to mitigate project-related impacts and point source pollution at project site. It will also identify all hazardous materials used or stored on site and all wastes that may be generated during construction phase. For management of unexpected spills during construction activities, there will be an Emergency Spill Containment Plan. That will contain, at minimum the following:

• A description of all hazardous materials used on site

• Methods of managing each hazardous material • Soil and water testing methods, if required

• Methods of transportation, storage, handling, and disposal of hazardous materials

• Disposal requirements and sites

• Recycling and waste minimization/reduction plans

• Emergency Spill Containment Plan

All in-stream work will be conducted from the top of bank or existing road surface where feasible. In-stream work will require the preparation of a dewatering plan. Avoid all unnecessary removal of vegetation. Limit vegetation removal to only those areas where such removal is necessary for project completion. The following measures will be implemented to prevent this:-

• Concrete effluent or slurry will be isolated from flowing water by coffer dams or stream diversions. Waste (used) drilling fluids will be pumped to holding tanks for storage or disposal at an approved facility. Settling basins or similar concrete washout areas will be constructed for the purpose of isolating and stabilizing wet concrete slurry or effluent. Minimal amounts of water will be used to avoid unnecessary run-offs.

• Batch plants will be located a minimum of 100 feet from aquatic habitats or water resources of the Project Vicinity. When not in use, all fine grain concrete and asphalt batch plant materials (cement, sands) will be covered or contained to reduce air contamination and rain runoff.



7.3.1 Minimization of Hazardous Waste and Materials

A Contingency Plan will be prepared to address the actions that will be taken during the construction of the road should unexpected contaminated soil or groundwater be discovered. The Plan will contain at least minimal health and safety considerations, handling and disposal of wastes, reporting requirements, and emergency procedures. Accidentally contaminated soil will be removed from the site and conveyed to an appropriate disposal facility as soon as it is realized. The Contingency Plan will serve as the Emergency Spill Containment to be prepared, and/or part of the Waste and Storm Water Management Element of the Construction Mitigation Plan to be developed by the contractor before starting the work.

Equipment parking areas will be provided for all maintenance, storage, and washing/cleaning activities. Parking areas will be located at least 7.5 metres (25 ft) distance from aquatic habitats, water resources, or wetlands in the project vicinity. Vehicles and equipment used during construction will receive proper and timely maintenance to reduce the potential for mechanical breakdowns leading to site spillage.

The contractor will have employees trained in spill response on site during all construction activities Emergency response actions/protocol will be identified and implemented by the construction contractors. Contractor will be required to conform to Health and Safety Codes provided on approved Material Safety Data sheets.

7.3.2 Minimization of Air Quality The Proposed Project will comply with all applicable rules and regulations and not limited to the following:-

• Cover all trucks hauling loose materials or maintain at least 6 inches of freeboard.

• Apply water or other dust suppressants as warranted on dirt roads, material stockpiles, and other surfaces which can give rise to airborne dust during construction operations, grading of roads, or the clearing of land.

• Promptly remove earth or other unused material from pavements during and after construction.

• Restrict speeds of vehicles within and around construction activities. • Construction vehicles will be kept in proper running condition and in proper tune

per manufacturer’s specifications. Equipment will be operated to minimize idle time.



7.3.3 Minimization of Noise

Adhere to the required standard specifications with respect to construction noise. These standard specifications include the following provisions.

• The Contractor shall comply with all local sound control and noise level rules, regulations, and ordinances which apply to any work performed pursuant to the contract.

• Each internal combustion engine, used for any purpose on the job or related to the job, shall be equipped with a muffler of a type recommended by the manufacturer. No internal combustion engine shall be operated on the project without the muffler.

• Notify local residents of percussive activities that are expected, such as pile driving and rock drills. No percussive activities (e.g. blasting, pile driving) will be allowed at night.

7.3.4 Reduction of Traffic and Circulation

During the construction phase the contractor will prepare public information Plan addressing information distribution to local and foreign communities. The plan will include a web site, web link connections from tourist web sites, telephone hotlines, roadside signs, construction schedule fact sheets and particular outreach to businesses, delivery services, local residences, and emergency service providers. Signage will be developed to provide general road closure times and locations. Temporary construction signs will be placed in the Project Vicinity at least ½ mile before the beginning of construction zones.

7.3.5 Minimization of Public Services, Utilities an d Energy An Emergency Preparedness Plan will be developed between the Contractor, Kenya National Highways Authority Fire Fighting Department and Community Services. The plan will establish lines of communication so that the construction crew receives notification of an emergency need to open the road prior to the arrival of emergency vehicles at the site. Procedures will also be established to keep emergency service providers advised of the location of construction crews, the activities going on at the time and the estimated time to clear the road for each activity. Communication will also include current information on the status and possibility of alternate routes. The emergency service providers will use this information to determine the fastest way to reach the emergency site under the present circumstances.

The Plan will at minimum require that the Contractor make use of serviceable telephone, radiotelephone or radio system connecting each construction operation with the



Contractor’s headquarters. The communication system will provide prompt and reliable communications between the Contractor’s headquarters. The communication system will be functional during Contractor’s operation in the fire precautionary period. The Contractor will be required to coordinate the Emergency Preparedness Plan throughout the project and ensure that all construction workers are trained on Emergency Preparedness Plan.



8 ENVIRONMENTAL AND SOCIAL MANAGEMENT PLAN

8.2 General

An Environmental and Social Management Plan (ESMP) is the incorporation of all proposed mitigation and monitoring actions set to a time-line with specific responsibilities assigned and follow up actions defined. The ESMP in the roads sector is one of the most important outputs of the Environmental and Social Impact Assessment, which ensures that the implemented mitigation measures are sustainable. It outlines the monitoring frequency, cost measurable and verifiable indicators as well as individuals/institutions to undertake the required actions. The assumption here is that the proposed mitigation measure will be implemented under the contractual arrangement during construction and maintenance works.

The ESMP outlined in table 4 below is in respect of the environmental issues, which have been derived from the potential impacts whose mitigation measures are tabulated in chapter 7. It recognizes similarities in environmental impacts of the road construction and maintenance activities within the proposed road site.

8.3 Monitoring and Auditing

Environmental monitoring establishes benchmarks to judge the nature and magnitude of potential environmental and social impacts. Monitoring and auditing are conducted to ensure that negative impacts are minimized through adequate implementation of mitigation measures. Some of the key parameters for monitoring and auditing of the Road Project maintenance programme include the following: -

• Soil erosion and siltation.

• Oil spillages

• Dust and gaseous emissions.

• Water quality

• Bush encroachment

• Traffic accidents

• Traffic flow

• Noise and vibration

• Change in biodiversity

• Socio-economic change

• Land use changes.

Table 7: ESMP during the road construction and main tenance phases

EXPECTED NEGATIVE IMPACT RECOMMENDED MITIGATION MEASURES

RESPONSIBLE PERSON/ UNIT

TIME FRAME MONITORING FREQUENCY COST ESTIMATE (Kshs)

Curb Right of Way Conflicts

1. Planned project alignment affects existing settlements in the project area and leading to displacement of people, property and assets.

Avoid or minimization of involuntary resettlement and relocation of public utilities to the extent possible

Contractor and the Government of Kenya

During the Project Pre-Construction Phase; site inspection, reconnaissance, land survey, site acquisition and Environmental Impact Assessment period

During and after field work/site visit

10,000,000

Resettlement of displaced people as per the resettlement plan

Draft, finalize, and implement land acquisition, compensation and resettlement plan for affected households, businesses, public utilities, and other groupings using participatory approach

Weekly until compensation and resettlement is completed

15,000,000

Restrict project within the corridor set by the GoK as much as possible

Contractor During actual clearing operation

5,000,000

2. Entry of inspectors and surveyors in the project area may incur adverse reaction from local officials and residents

Secure official permission from concerned Local Government Units (LGU) regarding entry in project for research purposes

Contractor During pre-construction operations site visits

5,000,000

Bio-Diversity Conservation (Vegetation)

3. Bio-diversity degradation (vegetation) Create awareness on importance

of bio-diversity amongst the road construction crew

Project Engineer, Supervision Consultant, Contractor, Environment.

Construction Phase Daily 4,000,000






Discourage site clearance beyond the road reserve

Unit

in the Kenya National Highways Authority, Provincial Environmental Officer,

Construction Phase During actual clearing operation

4. Increased turbidity an annihilation of aquatic organisms in surface water

Protect any surface water body encountered on the way from any kind of pollution

Through out the project cycle

Weekly

Minimize spillage of concrete and other loose construction materials

Construction Phase Daily

Management of storm-water

5. Soil Erosion Adopt an appropriate landscaping programme to curb soil erosion within the project area

Project Engineer, Supervision Consultant, Contractor, Environment. Unit

in the Kenya National Highways Authority, Provincial Environmental Officer,

Construction Phase Daily, weekly or monthly through progress reports

1,000,000

6. Alteration of natural drainage can lead to localized flooding Ensure well engineered site

leveling and ground grading to minimize flooding

Construction Phase 2, 000,000

Utilize spoil earth materials as filling for low lying flood prone areas

Construction Phase Daily, weekly or monthly through progress reports

500,000

7. Works coinciding with rain may adversely affect drainage Schedule works during dry

season to the extent possible Contractor Construction Phase Through monthly progress

reports 1,000,000

8. Impeded drainage and or inefficiency of drainage structures Adequate drainage structures

should be provided for the road Construction Phase






Any area beyond project boundaries compacted as a result of project activities should be ripped to enhance ground water infiltration

Construction Phase

Desiltation, Repair of drainage structures

Kenya National Highways Authority of the Gok

During Construction and Maintenance

Monthly 2,000,000

Reduce air pollution within the project site

9. Air pollution by dust Ensure well engineered site leveling and ground grading to minimize loose soil and dust suspension


in the Kenya National Highways Authority, Provincial Environmental Officer

Construction Phase Monthly 1,000,000

Regular watering of the diversion road


Encourage use of dust masks Construction Phase Daily

Optimal Choices of quarry locations minimizing haulage distance

Construction Phase Monthly

Enforcement of air quality standards accepted locally and internationally

Construction Phase Daily or weekly through progress reports

Curb noise pollution and vibrations






10. Noise pollution and vibrations from site activities Schedule drilling during day time

in high populated area when most of the adults are at work and children in school


In the Ministry of Roads, Provincial Environmental Officer

Construction Phase Daily when applicable 500,000

Inform residents in the vicinity of schedule of drilling and other noisy operations

Construction Phase Daily when applicable

Enforcement of standards accepted locally and internationally


Strictly use appropriately tuned/ maintained equipment

Construction Phase, Operation and Maintenance Phase

Daily

Roadside tree planting After construction and maintenance activities

Quarrying sites management

11. Land degradation, pollution and workplace accidents within quarrying sites

Site quarries appropriately Contractor Pre-Construction Phase, Construction Phase and During Road Maintenance/ Rehabilitation period

Monthly 1,000,000

Water access roads to quarries to avoid dust pollution

Contractor Daily

Adopt proper quarrying techniques

Contractor Monthly

Uniform training of supervisory personnel

Contractor






Rehabilitation of the Quarries to the satisfaction of the owner by creation of water points, earth dams and farms and controlled fencing and tree planting


in the Kenya National Highways Authority, Occupational Safety and Health Dept. in the Ministry of Public Works, Provincial Environmental Officer

Observe the requirements of Occupational Safety and Health Act, 2007 regarding workplaces

Improved health and sanitation throughout project c ycle

12. Poor health and sanitation as a result of the project activities

Provide adequately located and maintained latrines for site workers

The Project Contractor in corroboration with the Ministry of Health (Basic Health Care, Public Health and Sanitation), Local NGOs and the Provincial Administration of the Government of Kenya

Construction Phase and During Road Maintenance/ Rehabilitation period

Through the monthly progress reports

2,000,000

Create awareness prevention on HIV/AIDS and other related diseases

Avail health care services to working crew

Provide adequate drinking water to working crew

Control of Malaria and Schistomiasis

Where possible avoid materials’






extraction in human settlement areas

Create awareness on the dangers posed by stagnant water

Road safety

13. Traffic Accidents Driver sensitization on road safety. Project Engineer,

Contractor,

Road Safety unit,

Traffic Police Department

Construction Phase and During Road Operation, Maintenance/ Rehabilitation period

Monthly 200,000

Provision of proper road safety elements such as adequate shoulders, road signs and furniture

Monthly 200,000

14. Increased vehicular traffic Encourage use of public transport. Traffic Police

Department, the Media, Project Engineer, Supervision Consultant, Contractor,

Construction Period Daily 300,000

Driver sensitization on road safety Construction, Operation and Maintenance Phases

Daily

Erection of adequate and visible diversion signs

Daily when necessary

15. Characteristic edge failure along the existing road Use Engineering Design and

Materials Quality Control to ensure homogeneity and curb road failure

Monthly progress report 100,000

Waste management at the project site

16. Litter along the Roadside Create awareness on the importance of a clean

Project Engineer, Supervision Consultant,

Construction Phase, Operation and







environment Contractor, Environment. Unit

In the Ministry of Roads,

Maintenance/ Rehabilitation Phase

Install permanent litterbins (Concrete) as part of the road furniture at preset intervals to be emptied regularly

Monthly progress report

17. Soil and water contamination through accidental spillage of oil, grease and fuel in the mechanical plant workshop and along the road

Collect, recycle and re-use oils for treating wood e.g. Fencing posts.

Construction Phase, Operation and Maintenance/ Rehabilitation Phase


Avoid accidental spillage through good mechanical practices and proper storage.


Proper training and sensitization of mechanical staff.




8.4 Project Decommissioning

The main purpose of decommissioning is to restore/rehabilitate the site to acceptable standards

and all efforts which should be geared towards making the site as close as possible to its original

state before the start of the project. The decommissioning will in brief involve;

• Filling the quarry sites where the materials will be excavated, removal of debris and

landscaping to have aesthetic value.

• Planting of fast growing indigenous trees which exist within and around the project site

to compensate for the lost fauna and flora during site preparation.

• Applying the most appropriate controls and procedures in place throughout project

implementation/construction phase, to control environmental degradation by dividing

the site into a number of portions and quarrying in turn. The debris from one quarry pit

will be used to fill the pit previously quarried

Moreover, to rehabilitate the site as close as possible to its original state, the following

rehabilitation measures as discussed in the table below should be practiced by the proponent;

Table 8: Environmental and Social Management Plan f or the decommissioning and Closure

Objective: To make the place after operation equivalent or better than its original condition

Action required Responsible

party

Time

frame

� All stone wastes should be used in landscaping and covered with soil

which can support vegetation. Operator Once

� All pits and depressions should be filled as much as possible and

landscaping involving covering the surface with suitable soils for plant

growth

� Improve soil fertility where needed.

Operator Once

� Once operations cease, areas under modification /rehabilitation must

be demarcated with danger tapes or barbed wire to prevent access by

animals and human beings as rehabilitation continues. Operator

Continu

ous

� A security fence should be constructed to completely limit access from

higher areas. Operator once

� Transport all equipment and dispose wastes appropriately. Operator Once

Southern Bypass Environmental Impact Assessment Study Report

84 ©AWEMAC CRBC/Kenya National Highways Authority, 2010

Table 9: The Restoration Plan

Environmental

Social Impact

Aspect

Mitigation Action Responsibility Time frame

Material Site -Exhaust and rehabilitate the material site

before opening another section.

-Exhausted quarries and borrow pits be

backfilled

-Hold top soils by planting vegetation on the pit

backfilled.

-Ensure reduced stagnation of water in borrow

pits

-Develop appropriate agreement with land

owners on conditions and terms of quarrying

Proponent/ site manager Throughout the project

cycle

Destruction of

physical

environment,

soil erosion and

-Protective structures should be used to avoid

small scale landslides

-Topsoil should be stockpiled , backfilled and

Proponent/ site manager Throughout and once

after completion work



loss of

biodiversity

compacted separately from subsurface and

after completion works be restored in order to

facilitate natural regeneration around the area

of quarrying site

-Planting of trees

Sediment run-

off

-Install sedimentation traps

-Silt fence should be established where erosion

is predetermined

-Design drainage ditches to avoid affecting

nearby land

-Divert run-off around working area

Proponent/ site manager Throughout the project

cycle

Storm water run

off

Creation of diversion channel to ensure no

water flows across rehabilitated areas until it is

stable

Proponent/ site manager Once off

Flora and Fauna -Minimize area of clearance

-Re-vegetate disturbed area within the site

with fast growing plant that are existing within

and around the quarry site

Proponent/ site manager Throughout and once

after completion work

Surface and -Preserve vegetation along drainage channel Proponent/ site manager Throughout the project



ground water

drainage

obstruction

-create run-off barriers cycle

Loss of land Soiling and grassing of all the borrowed pit

-Compensation

Proponent Once –off

Total Cost



9 CONCLUSION AND RECOMMENDATIONS

The Environmental and Social Impact Assessment Study has established that the proposed construction of the Nairobi Southern Bypasses is of paramount importance in terms of facilitating a fast traffic diversion, enhancing service level, alleviating traffic pressure, mitigating vehicle emission, improving urban environment, and above it all, the use of the available limited environmental resources to achieve sustainable socio-economic development in Nairobi and its environs.

Numerous positive impacts which come along with the proposed project have also been identified which will not only enhance economic growth at local level but also contribute to the national, regional and international economy. Just like any other project, both direct and indirect negative environmental impacts will result from the project activities as discussed before which include; displacement of people and public utilities, soil erosion, waste generation, noise pollution, dust and exhaust emissions, oil spills, increased water demand and workers accidents and hazards during construction among others which can be adequately mitigated as prior outlined in this report.

The proponent of the proposed project shall be committed to putting in place several measures to mitigate the negative environmental, safety, health and social impacts associated with the life cycle of the project. It is recommended that in addition to this commitment, the proponent shall focus on implementing the measures outlined in the ESIA as well as adhering to all relevant national and international environmental, health and safety standards, policies and regulations that govern establishment and operation of such projects.

On the basis of the above and taking cognizance of the prevailing transport crises within Nairobi Metropolitan Area’s road networks which has actual far reaching negative impacts to the outside world, it is highly recommended to construct the Nairobi Southern Bypasses as a matter of urgency provided the mitigation measures outlined in

this report are adhered to and the Environmental and Social Management Plan is implemented to the letter.



REFERENCES

Kenya gazette supplement Acts 2000, Environmental Management and

Coordination Act Number 8 of 1999. Government printer, Nairobi

Kenya gazette supplement Acts Land Planning Act (Cap. 303) government printer,

Nairobi

Kenya gazette supplement Acts Local Authority Act (Cap. 265) government printer,

Nairobi

Kenya gazette supplement Acts Penal Code Act (Cap.63) government printer,

Nairobi

Kenya gazette supplement Acts Public Health Act (Cap. 242) government printer,

Nairobi

Kenya gazette supplement Acts Water Act, 2002 government printer, Nairobi

The Nairobi Southern Bypass Project preliminary Engineering Scheme, July 2010 Kenya National Highways Authority (KeNHA) and China Road and Bridges Corporation (CRBC)

Feasibility Study Report of the Nairobi Southern Bypass Project preliminary Engineering Scheme, July 2010 Kenya National Highways Authority (KeNHA) and China Road and Bridges Corporation (CRBC)

The Petroleum Act (Cap 116), Government Printers, Nairobi

The Traffic Act (Cap 403), Government Printers, Nairobi

The Crop Production and Livestock Development Act (Cap 321), Government

Printers, Nairobi

The Trust Land Act (Cap 28), Government Printers, Nairobi

The Physical Planning Act (Cap 286), Government Printers, Nairobi

The Agriculture Act (Cap 318), Government Printers, Nairobi

The Kenya Board Act, 1999, Government Printers, Nairobi



APPENDICES

• Licences, permits and incorporation documents/certificates • Site Maps

• Sample Public Participation Questionnaires

• Organizational Chart-Road Case • Minutes of public Barazas and attendance lists

• List of public participation and consultation interviewees

• Site designs and drawings

