REPUBLIC OF MAURITIUS E 20 &

MINISTRY FOR PUBLIC INFRASTRUCTURE

Waste Water Authoritv Public Disclosure Authorized

Montagne Jacquot Environmental Sewerage and Sanitation Project

Environmental Impact Assessment Report

August 1997 Public Disclosure Authorized

-_ --- __ _* Public Disclosure Authorized

= 5~~~~. '-I ~ Public Disclosure Authorized BLACK & VEATCH INTERNATIONAL

Servansingh Jadav and Partners a AkoniagqneJacquot Sewernage and Snittir on Project Environmeital ImpnpactAs4essment

REPORT AUTHORISATION SHEET

Client: V/ Waste Water Authority Ministrv for Public Infrastructure

Project: Montagne Jacquot Environmental Sewerage and Sanitation Project: Environmental Impact Assessment Report

PREPARED BY BLACK & VEATCH INTERNATIONAL ENVIRONMENTAL CONSULTANCY UNIT

Dr. E.A.S. Linlev: Principal Environmental Scientist Dr. S.A.Harris: Environmental Scientist Dr. B. Jerni-an: Environmental Engineer. Project Manager

Date: August 1997

Cover:lop lefti- proposed site fr- new WWTplant at Mlontagne Jacquot.- hottom lefi - marine life ct the proposed outzi/al site at Moniagne Jaccluot: right - present state of the beach at Fort l ictoria 117arks (May 1997j

BlcA & IVeatchinternational a I . 1 .Ilowalgne Jicylaoi Sewerage anuiSanitation Project EnvironmentIalIntpalt .Assessaten:

EXECUTIVE SUMMARY

1.0. Introduction

The Government of Mauritius commissioned the Sewerage Master Plan stud! in 1992. and one of the key recommendations was that the present sewage disposal arrangements for the Port Louis South and Lower Beau Bassin / Coromandel areas should be improved by constructing a waste water treatment plant at Montagne Jacquot. By implementing the Monta-ne Jacquot project. public health and sanitation. the terrestrial and marine environment around Port Louis would be improved and protected: and the project would help to restore sustainable development of economic activities in tile area aftected by the current sewage disposal arrangements. The project also aimed to minimise industrial pollution by recommending pre-treatment options ftor industrial effluents destined for the new waste water treatment plant.

Additional studies carried out in 1994 and 1996 suggested a preliminar' design 'forthe Montagne Jacquot plant based on disposal of treated effluent through an ocean1outfall. and re-use of treated effluent for irrigation of west coast agricultural land.

Subsequently. the Waste Water Authority commissioned three studies. The first was to design the various components of the Montagne Jacquot Sewerage and Sanitation project consisting of pumping stations. transmission mains pipelines and an ocean outfall. and to carry out an environmental impact assessment (EIA). The second was to evaluate the technical and economic feasibility of re-use of treated effluent for irri-ation: and the third. to review the institutional and financial arrangements necessar% ftor implementing the sewerage master plan for Mauritius. The present document reports the results of the EIA carried out bv Black and Veatch Interniational. Environmental Consultancy Unit. and should be read in conjunction with the Montagne Jacquot planning and preliminary design reports, and the reports on the economic feasibility of waste water re-use for irrigation as well as the institutional studies.

BlacA& I eatclhInternational 11 Mlontagne Jclcqulot SeweragLeatd Su,,itatioil Project Entvironmenttal Impact Assesssment

2.0. Brief description of the Montagne Jacquot project

.\ nex\ waste xvater treatmiientplant will be constructed at Montagne Jacquot to treat domestic. commercial and industrial waste water from the Port Louis South. Lower Beau Bassin and Coromandel areas. which together include the main industrial areas and residential areas in southwestern Port Louis. The project includes ne%Npumping stations at Fort Victoria and at Pointe aux Sables to replace the existing works and ocean outfalls. risinul mains to deliver the waste water to the Montagne .lacquot treatment plant. as well as a new outfall at Montagne Jacquot for disposal of treated effluent to the ocean.

3.0. Policy, legal and administrative framewvork.

The Environmental Protection Act (1991) of Mauritius provides the legal framework for implementing the National Environmental Policy. which aims to foster harmonN between qualitv of life. environmental protection and sustainable development for present and future generations of Mauritians. In order to comply with the EPA. all major developments and infrastructure projects now require an Environmental Impact Assessment. The present EIA therefore follows the guidelines issued from the MEQOL for carrvin- out and reporting an EIA. Additional guidelines which apply to coastal developments have also been incorporated into the EIA study.

As the Montagne Jacquot project will be jointly funded by the World Bank. the Oxverseas Economi:c Cooperation Fund (OECF) and the Government of Nlauritius. the environmental impact assessment requirements of all three were incorporated into the EIA programme for the Montagne Jacquot project. The common features ol all three seis of guidelines provide for:

0 a description of the project components and the environment potentially affected b\ the proposed project. 0 idenitification of significant positive and negative environmental impacts of the project and assessment of their significance.

BlacA& IVeiatch Inte'rnatiinal iii WlIon,agIneJacqtuo Sewerage aindSanifiatio,i Proicct EnvironmenralImpact 4 s essnent

O an analysis of alternatives for the project. 0 identification ofn measures to mitigate environmental impacts and proposal for a mitigation plan. C an environmenitalmonitoring plan.

In addition. the World Bank and OECF echo the provisions of the National Environmental Policy of Mauritius in highlighting the need to address particular issues in the EIA. These include biodiversitv protection. coastal and marine resources management. industrial hazards. land settlement and cultural issues. The 'orld Banlik also requires recommendations for environmental management and training to be included in the EIA. Consequently. this EIA report includes all these requiremiienits.to produce a coherent evaluation of the Montagne Jacquot project suitable for decision making bv all the relevant funding organisations.

4.0. The environment affected by the project

T'he environment affected by the project consists of the drainage area to be serviced by the waste water collection svstem. It consists of approximately the southern halt' of the Port Louis Sewerage System. which includes the built up areas of Port Louis South. Cassis. Belle Village and the Plaine Lauzun Industrial Zone: and the lower Beau Bassin reuion includingwthe Coromandel and La Tour Koenig Industrial Estates. the Pointe aux Sables communitv and residential areas to the south. The affected area includes sections of four of the countrv's nine administrative districts, namely the Black River. Plaines Wilhems. Moka and Port Louis.

The coastal waters likely to be affected by the new discharge from the ocean outfall. stretch from the Pointe aux Sables reef to south of Montagne Jacquot. in an area some X)( m to I km ottshore. The area currently affected bv the existing discharge arrangements stretches from Port Louis to the southern end of the Pointe aux Sables reef. with impacts visibly apparent along the shoreline. in shallow lagoon waters and on the sea floor.

Black-& £'enichInter,nationul iv 2lI4ntagne Jac leor Sewerage o'ad Saittation Project E,,vironrneltal imptactAssesSnment

5.0). Principal significant impacts associated with the project

Impacts of the project were evaluated according to their magnitude. duration and extent. and those w hich were found to produce highl' significant impacts were further revxiewed.to determine whether thev were reversible. irreversible or cumnulative.the likelihood of'their occurrence and potential risks also associated with their effects.

It was concluded that the overall effects of the Montagne Jacquot project wvillbe overwvhelminglypositive, since it will result in major improvements in quality of life and environmental quality in the areas affected bv the present discharge arrangements. In turni these improvements are likely to result in a reduction in public health hazards. and revitalised ecoInomy1Nin the tourisin. property. real estate. and services sectors in the currenitlv affected area. The improvements in coastal water quality will also assist in the rehabilitationi of coastal ecosvstems in the long term.

From the results of the environmental impact analysis it was evident that the principal silnificant negative impacts of the project on the community would occur during the construction phase. during laying of the main transmission pipeline if the land-based option was adopted. when congestion of traffic, noise. dust and general disruption will cause considerable irrconvenience. In addition. even although the effluent will meet anticipated standards for water quality. there will be longer term impacts on water quality and benthic communities off Montagne Jacquot in the effluent discharge area which will be significant. but limited in extent to the immediate discharge area. The outfall location off Montagne Jacquot is one of the few breaks in the barrier reef encirclinueMauritius where minimal damage to reefs and lagoon waters from an effluent discharue would be experienced. The potentiallv affected benthic and planktonic communities at the site were evaluated and no conservation-worthy species or unique habitats which could be a particular concern were found. The proposed treatment plant processes. including disinfection. will produce an effluent which should consistentlv maintain water quality in the discharge area suitable for recreational swimming and divino. Thus. the discharge is not expected to have a significant adverse impact on activities whiclh currentlv occur in the area. Because the areas off Fort Victoria and

BlhAc& I eitichInternationl v Mon,)ta,guIeJacqtuof Sewe rage a,tduSm Iljaltion Project Euiviromnenlal Impclthn !,L4'Nessmenl1

Pointe aux Sables currently impacted by effluent discharge are so seriously degraded. and the proposed disposal area off Montagne Jacquot has no significant conservation- wsorthyresources. the project is not expected to adversely affect biodiversit\ protection in Mauritius.

Approximatelh I0 ha ot land will be used for constructing the Monta-ne .Jacquot works. The land is currently undeveloped. unoccupied. and not used for anv beneficial purpose such as agricultural production or recreation. Also. it is immediately adjacent to the Petite Verger prison wlich detracts from its value for alternative purposes. Construction of the treatment plant will not result in displacement of any residential. business or commercial properties. If the land-based option for the transmission mains pipeline is adopted. it will also be necessary to purchase easements across a small number of private properties. No residences. business or commercial properties will need to be relocated. and following construction of the pipeline. the land can be returned to its CLurrenituse.

6.0. Mitigation plan

Based oni the results of' the environmental impact review. mitigation measures were identified to reduce or avoid negative impacts and enhance beneficial impacts. The mitigation plan devised for the Montagne Jacquot project aims to ensure that all project activities are manaoted so as to reduce or avoid negative environmental impacts and enhance positive and beneficial impacts. The plan identifies mitigation activities to be carried OUtin each phase of the project. from planning. to design. through construction. operationi and decommissioninu- stages. The responsibilities for carrying out the mitiuation measures are allocated to individuals or groups involved in the program.

The most important mitigatorv activities identified for the Montagne Jacquot project are directed at: I ) minimisin- the disruption caused bv construction phase activities. particularly along sections of routewavs where land-based sections of the transfer pipelines will be placed:

BlacA& IVeaitc International vi Mnitagnie Jucjuoit Sewt'erageanzd Sanitation PrjLect Env'iro,nmeentalImpacl A.ssessxente

2 minimising deterioration in water quality and disruption and damage to benthic and fish communities during offs]iore pipeline installation. 3 ensUw-inigood and proper management of the WWT plant at Montagne .lacquot to meet required effluent treatment standards and avoid operational failure. 4) recommending appropriate regulator. monitoring. and liaison procedures to assist the WWA in pollution cointroland monitoring of industrial and sew-ageeffluellts. 5) optimising economic benefits for the currently affected communities following improvements in environmental quality.

The main groups ol people identified with responsibilities for mitigatioln *ere: the Waste Water Authoritv. design engineers. the resident engineer during construction. the contractors. the WWT plant manager. plant operators and lAPs. The actions required to meet mitigoationobjectives are summarised in a series of tables for eachi uroup. The costs of implementing the mitigation plan are also discussed.

7.0. Environmental management and training

The environmental management and training requirements of the pro'ject are substantially dependent on the extent to which recommendations in the parallel institutional study for the Waste Water Authority. the preliminary report of which was recently completed by Consulting Engineering Services (India) PVT LTD. The regulatorv control of industrial activity is in its infancv in Mauritius. with nexw wastewater legislation about to be formulated. Once the legislative framekxork has been consolidated. pollution control and a monitoring strateg can be put in place. together vith the necessary capacity building both in government and the private sector. Action plans for developing and implementing appropriate pre-treatment facilities tor industrial vxastes can then also be devised and supported by for example. pricing incentive sclhemes to encourage recvcling and treatment of wastes bv industrv.

Adequate environmental management of the Montagne Jacquot WWT plant. will depend partly on the success of the WWA strategy for re-organisation. capacity building and implementation of environmental management measures. These

BlackA vleayh Isitermtati,al vii .AlItagite Jtcquot Sewerage tonidSanitation Project Envirollmentaf Imnpalc.-Assessinent

developments will also be essential to assist in successful implementation (it' other seweraTe and sanitation projects planned for Mauritius over the next twentN years.

8.1). Monitoring programme

Although framework programmes for monitoring effluent discharges and effluent quality control are in the process of formulation. legislation controllino wastewater discharges has yet to be finalised. Until the legislation is in place and dexelopment of the quality control and pollution control divisions within the WWA is complete. it will be difficult to brinuT existinu industrial wastewater discharges undel control. Nevertheless. the present studv makes recommendations for monitoring which is likely to be necessary to comply with regulations for effluent quality discharged to sexers and coastal waters. as well as for monitoring coastal water quality. This information will also benefit design and location of future wastewater treatment plants in :91auritius.

9.0. Conclusions and recommendations

The analvsis of the current condition of communities and coastal waters in the Port Louis area carried out during the environmental impact assessment indicated that the proposed Montagne Jacquot project will have overwhelming positive and beneficial enxironmental and socio-economic impacts. If improvements are not made in the present sitLatioii. it is clear that the worst affected communities in Bain des Dames and l'ointe aux Sables will remain seriouslv economically disadvantaged and wNillhave to contiinue to tolerate a seriously degraded environment which impacts their qualit%of life on a daily basis. For many vears the communities in the Bain des Dames and Pointe aux Sables areas have witnessed the decline in coastal water quality and disappearance ol' local fisheries resources. and have repeatedly made appeals to government to address the problem of sewage and industrial waste disposal off Fort Victoria and the Pointe aux Sables reef' The proposed Montagne Jacquot project will respond to those appeals and will result in the correction of many of the degraded conditions.

BlatckA I eltt'ci lInter,,ational viii Alonlagtite AJacquatlSewerage anId Sanitation Project Envirtnmenal IntpactiA *ssessmenl

Although a variety of negative impacts associated with the project have been identified. the, are viostnotabl associatedmill with the construction phase. and be particulark acute durietnoathe construction of the land-based transmission mains pipelile if thls

optioin is adopted. These impacts are temporary however. and small in comparison with

the improvements in quality of life which will be experienced by the affected

comml1llunlitiesin the loiin term.

The effluent discharge from the new ocean outfall off Montagne Jacquot w\ill also

negatively impact benthic communities in the immediate discharge zone. Because the main frinuing reef surrounding much of Mauritius is not present offshore tiom the Montagne Jacquot site. it is an ideal location for an ocean outfall. The relatively

exposed nature of the proposed discharge point and impacts already sustained b\ benthic communities from the exposed conditions and discharges from the existing outfalls. have resulted in relativelv low species diversity. with only common and ubiquitous species present. The benthic communities in the proposed discharge zone do not have conservation significance and are not a concern with respect to conservation of' hiodiversitv resources in Mauritius as a whole.

The Montagne Jacquot WWT plant will be located on a I Oha site which is currently not used for agriculture or anv other beneficial purpose. There will be no need to relocate any residences. business or commercial properties. Access to the shore tor recreation w;ill be maintained despite the presence of the plant. and so ensure that current recreational activities along the shoreline need not be disrupted.

The conclusions and recommendations of the Environmental Impact Analysis are

therefore that:

(a) A newv WWT plant should be built at Montagne Jacquot. The plant should consist of' preliminary treatment. primary treatment and disinfection works. The primarx sludge should be dewatered with belt filter presses and stabilized with lime. The facilities should be constructed at Montagne Jacquot because it is an excellent site for such a

BhiciA& I tcaiIlJteruaatio,aIl ix IlIfntagte JgtL'cqut Sewerage al'L'd San,italtion Project Environn talall lIpatLf . NeSSmlle11

facility. and certainly the best available because of its relatively remote nature. and because it avoids the need to relocate any properties. (b) The' construction of the transfer pipelines along the main road between Fort Victoria anid Pointe aux Sables is acceptable. despite traffic congestion and disruptioni during the coinstruction period. The construction of the transfer pipeline across the mtoutl of the (ranad Ris er North W'est would also be acceptable. although the offshore alternative would result in highier construction cost. a number of technical uncertainties. some limited neuative environmental impacts in the lagoon and difficulties of' carryinc out routine maintenance and repairs in future. Once construction is completed. both of the buriedlpipelines would typically function without significant communit) impact. (c) The ocean outfall should be constructed off Montagne Jacquot to a depth of' -',m and distance of 645m from the shore to achieve a 14.000 fold dilution of' effluent at the nearby sensitive target locations. This level of dilution together with primar%treatment and disinfection of effluent will ensure that all components of the discharge from the \A'UT plant are diluted to acceptable levels to achieve the desired water quality- in receiving waters. (d) As institutional capacity building and legislative provisions assist the driN,etowards improved pre-treatment of industrial waste waters at source. and as the %alueof fresh water continues to increase. that wastewater re-use for irrigation ot' west coast auriculture should be considered in conjunction with upgrading the Montagne .lacquot \WA'WTplant to secondary treatment. (e) With the implementation of the Montagne Jacquot project. a comprehensi\e tronitorinu programme along the lines recommended in the EIA will be implemented. with the assistance of Albion Fisheries Research Centre and outside help if necessar\ The intormation collected will be invaluable for future desiun of treatment '\o\rkls and makinu decisions about appropriate treatment options at other sewerage and sanitation projects in Mauritius.

et) That capacity building for environmental management within the W'aste Water Authority will be provided as an integral component of the Montagne Jacquot Sewerage Project.

lack1e& I ecincJu:ternalional X t Ilhiittagne Jacquot SewerageL aud Sanitation Project Entvironnientil Inipact -Issessien,t

ACRONYMS

AFRC .-Albion Fisheries Research Centre CBD Central Business District CEB Central Electricitv Board CHA Central Housin- AuthoritN CW A Central W'ater Authority DBM Development Bank of Mauritius DOE Department of Environment EIA Environmental Impact Assessment EIAR Environmental Impact Assessment Report EPA Environmental Protection Act FC faecal coliforms GOMVGovernment of Mauritius GRNW' Grand River North West IPC integrated pollution control MEPD Ministrv of Planning and Development MEQOL Ministry of Environment and Qualitv of Life MsW Municipal Solid Waste NPDP National Physical Development Plan ODA Official Development Assistance OECF Overseas Econiomic Development Fund TDS total dissolved solids TSS total suspended solids WHO World Health Organisation WID Women in Development WWA Waste Water Authority WU'T Waste water treatment

BItIcA& I eatchl Internantional, Xi a Montaggne Jacquof Sewerage antd Sanritatniol Project Environmenttal ImptcA .4ssessnient

CONTENTS

SECT10.I Pg

EXECUTIVE SUMMARY ... ACRONYMS .. xi

1.0 INTRODUCTION 1.1 Background ...... 1. 1.2 Objectives of the Montagne Jacquot Sewerage and Sanitation Project ... 2.2 1.3 Consulting team ...... 1.3 1.4 Background Information ...... 1.3

2.0 PROJECT DESCRIPTION 2.1 Project purpose . . . 2.1 2.2 Project location . . .2.1 2.3 Project Description. 2 2.3.1 Project overview ...... , 2.3.2 Pumping stations and Transmission Mains ...... 2.3.2.1 Pumpings stations ...... 2.3 2.3.2.2 Transmission Main Routes ...... 2.4 2.3.3 Review of Waste Water Treatment ...... 2.5 2.3.4 Water QualitA and Treatment Standards ...... 2...... 6 2.3.4.1 Water Quality Standards for Ocean and Irrigation Waters ...... 2 .6 2.3.4.2 Microbiological Standards ...... 2.8 2.3.4.3 Waste Water Treatment Plant Effluent Standards 2...... 8 2.3.5 Waste Water Treatment Plant ...... 2 .9 2.3.5.1 Waste Water Flow .. 2 .9 2.3.5.2 Waste Water Characteristics . .2.9 2.3.5.3 Industrial Waste Water ...... 2'.10 2.3.5.4 Waste Water Treatment Alternatives ...... 2.11 2.3.6 Effluent disposal ...... 2 .17 2.3.6.1 Irrigation ...... 2.17 2.3.6.2 Ocean outfall ...... 2.19 2.3.7 Recommended Treatment and Effluent Disposal . . 2.20 2.3.8 Sludge Management and Disposal . 2.20

BlcA & VeatchI Ihuernatioltea Xii Montagie Jacquot Sewerage anid Sanitation: Project Environmental Impacl A.ssessinent

3.0 POLICY, LEGAL AND ADMINISTRATIVE FRAMEWORK 3.1 Environmental Protection in Mauritius ...... 3.1 3.1.1 The Environmental Protection Act, 1991 ...... 1 3.1.2 Administrative Procedures . .3. 3.1.3 Application for an EIA License ...... 3 3.1.4 Coastal water quality standards and effluent standards ...... 5 3.2 Regulations of the Funding Agencies ...... 3.6 3.2.1 World Bank Environmental Requirements ...... 3.6 3.2.2 OECF, Japan, Environmental Requirements . . 3 .7 3.3 Interested and Affected Parties ...... 3.9 3.4 Land Acquisition ...... 3...... 9 3.4.1 Land acquisition procedures .. 3.10 3.4.1.1 Private agreement .. 3.10 3.4.1.2 Compulsorv Land Purchase .3.1 1 3.4.2 Payment of Compensation . . 3.11 3.4.3 Wavleaves ...... 12 3.4.4 Time frame .. 3...... 12 3.4.5 Buffer Zones ...... 3. 12

4.0 DESCRIPTION OF THE AFFECTED ENVIRONMENT 4.1 Physical Environment .. 4.1 4.1.1 Topographv, geology and soils ...... 4.1 4.1.2 Climate ...... 4.2 4.1.3 The Aquatic Environments ...... 4.4 4.1.3.1 River catchments ...... 4...... 44 4.1.3.2 Surface and groundwater supplies ...... 4.4 4.13.3 Irrigation ...... 4.5 4.1.3.4 Water pollution sources ...... 4.6 4.1.3.5 The marine environment ...... 4.6 4.2 Biological Environment ...... 4.7 4.2.1 Terrestrial Environment ...... 4.8 4.2.1.1 Fauna ...... 4.8 4.2.1.2 Vegetation ...... 4.8 4.2.2 Marine Environment ...... 4.9 4.2.2.1 Rocky shore intertidal zone ...... 4.9 4.2.2.2 Coastal waters ...... 4.11 4.3 Socio-Economic Environment ...... 4.16

Black& 'euatciI,ter,a:iomnal xiii MllontagiLe Jf cqiiot Sewerage itnd Saniitation Project Environmental Impact .Assessnment

4.3.1 Affected Population and community structure ...... 4.17 4.3.1.1 Communities affected by curnt arrangements for sewage disposal ...... 4.18 4.3.1.2 Qualiy of life and economic prospects of affected communities .4.20 4.3.2 Land use ...... 4.21 4.3.3 Economic Activities ...... 4.23 4.3.4 Recreation .. 4.25 4.3.5 Cultural and historic sites ...... 4.26

5.0 PREDICTION AND EVALUATION OF ENVIRONMENTAL IMPACTS 5.1 Assessment criteria ...... 1.I 5.2 Potentially significant negative impacts associated with the project ...... 5.8 5.2.1 Land Acquisition and Displacement of Residents or Businesses 5.8 5.2.2 Construction phase impacts ...... 5.8 5.2.3 Impacts of the effluent discharge on water quality in receiving, waters ...... 5 .9 5.2.3.1 Heavy metal and pesticide contamination ...... 5.10 5.2.4 Impacts of effluent discharge on reef communities ...... 5.12 5.2.5 Impacts of the Montagne Jacquot WWT plant ...... 5.15 5.3 Potential positive impacts associated with the project ...... 5 .15 5.3.1 Beneficial impact of rehabilitation of coastal ecosystem .. 5. .16 5.3.2 Beneficial impacts of improved health of affected communities ...... 5.16 5.4. Economic costs and benefits of the Montagne Jacquot project ...... 5.16 5.4.1 Realisation of economic benefits of the project ...... 5.18 5.4.2 Development of service sector and propertv market ...... l91 5.4.3 Development of tourism sector ...... 5.19 5.4.4 Rehabilitation of coastal fishery ...... 5.20 5.4.5 Protection of biodiversity resources ...... 5.20 5.5. Economic costs and risks of the no-project option ...... 5.21 5.6. Potential irreversible and residual negative impacts of the project ..... 5.21 5.7. Irreversible and irretrievable commitments of resources ...... 21

6.0 ANALYSIS OF ALTERNATIVES OF THE PROPOSED PROJECT 6.1 Alternativ es to be considered for the Montagne Jacquot project . 6.1 6.2 Evaluation of alternatives .6.1

Black & I eatcli International xiv Montagpre Jacquot Sewerage and Sanitation, Project Environmental Impact Assessment

6.2.1 Evaluation of the no-project option ...... 6.1 6.2.2 Evaluation of location of project components ...... 6.3 6.2.3 Evaluation of alternative treatment options ...... 6.6 6.3 Recommended combination of options for Montagne Jacquot project .... 6.8

7.0 MITIGATION PLAN 7.1 Introduction . . .7.1 7.2 Persons responsible for implementing the mitigation plan ... 7.2 7.3 Main categories of mitigation measures identified in each project phase ...... 7.3 7.3.1 Design phase ...... t . 7.3 7.3.2 Construction phase ...... 7. 7.3.3 Operational phase ...... 7.5 7.3.4 Decommissioning phase ...... 7.6 7.4 Summarv of mitigation actions necessary to implement the mitigation plan ...... 7.7 7.5 Cost of the mitigation plan .. 7.12

8.0 ENVIRONMENTAL MANAGEMENT AND TRAINING 8.1 Legal and Policy background .. 8.1 8.2 Institutional Framework for Waste Water Management .. 8.1 8.2.1 Waste Water Authority Organization .8.2 8.2.2 Linkages with Other Organizations .8.3 8.3 Industrial Waste Water Management . .8.3 8.4 Environmental Training Requirements . .8.3 8.5 Cost and financing training for environmental management .. 8.5

9.0 ENVIRONMENTAL MONITORING PLAN 9.1 Monitoring proram . . .9.1 9.1.1 Industrial Waste Water Monitoring . .9.1 9.1.2 Domestic Waste Water Monitoring . .9.2 9.1.3 Monitoring of Marine Environment at Montagne Jacquot .. 9. 9.1.3.1 Water quality .9.3 9.1.3.2 Health of benthic communities .9.4 9.1.3.3 Use of monitoring data in environmental management9.5 9.2 Liason Between Montagne Jacquot WWT Plant and Regulatory Agencies .9.6 9.3 Cost of equipment, personnel and training .9.6

Black& lVeatchInternational xv .lMantagneJact qof SewverAgeuad Sanitation Project E,vironmenttaf Inpaci.-ls.sessment

10.0 REFERENCES

11.0 APPENDICES

APPENDIX A: Basic design of the outfall pipeline to be built in the sea at Montagne Jacquot APPENDIX B : Basic design of WWT plant for Scenario 1, Primary and preliminary waste water treatment alternative APPENDIX C: Basic design of WWT plant for Scenario 2, Primary, preliminanr and secondan wvastewater treatment alternative APPENDIX D Work schedule for EIA APPENDIX E: Sludge management methods APPENDIX F: Flow chart of institutional interaction for Environmental Protection APPENDIX G : EIA regulations: Government of Mauritius APPENDIX H: Consultations with lAPs APPENDIX I : Common effluent constituents from dveing industries APPENDIX J : Vegetation on Montagne Jacquot site APPENDIX K: Coral reef communitv key APPENDIX L: State of the environment: media reports APPENDIX M: Assessment criteria for evaluation of impacts APPENDIX N : National Monuments Act 1985, of GOM APPENDIX P :Guidelines for contractors: mitigation during construction

LIST OF TABLES, FIGURES AND PLATES. xvi

Black & eieazchIter,,a:ional xvi Montagine Jaicqluot Sewerage aitd SanitaitiolnProject Environmental ImpactA.ssessment

List of Tables Pg

Table 2.1. Effluent quality standards (irrigation. lagoon and ocean) presented by GIBB(1993) ...... 2.7 Table 2.2. Projected Influent Waste WVaterCharacteristics ...... 2.10 Table 2.3. Projected Influent and Effluent Characteristics. Scenario 1. Primary Treatment . .12 Table 2.4. Projected Influent and Effluent Characteristics, Scenario 2. Secondary Treatment ...... 2.15 Table 3.1. List of IAPs interviewed in the scoping sessions ...... 3.10 Table 4.2. Composition of the rocky intertidal zone between Pointe aux Caves and Montagne Jacquot. 4.10 Table 4.3. Results of divinu survevs based on visual assessments. carried out during April/Mav 1997 at Montagne Jacquot ...... 44.14 Table 4.4. Land use in Mauritius in 1986 ...... I...... 4.21 Table 4.5. Non-EPZ domestic exports in million rupees ...... 4.23 Table 5.1. Potential environmental impacts and assessment of significance ...... 3. Table 5.1 Second step evaluation of highly significant impacts...... 5.7 Table 5.3 Dilution required for typical sewage effluent to meet ambient ocean water quality standards ...... 5.10 Table 5.4. Concentrations of Heavv Metals Measured in Bottom Sediments ...... 5.11 Table 5.5. Estimated Capital Costs for Proposed Facilities...... 5.18 Table 6.1. Key environmental and socio-economic issues for the evaluation of the no-project option...... 6.2 Table 6.2. Evaluation of altematives for transfer pipeline ...... 6.5 Table 6.3. Characteristics of waste water effluent for Scenario I and 2...... 6.7 Tables 7.1 to 7.7.: General responsibilities of parties involved in implementation of the mitigation plan ...... 77

List of Figures (except as noted, figures are grouped at end of each section)

Figure 1.1. Project location showing the existing sewer network and infrastructure. The proposed site for the new WWT plant and two alternative for the transfer pipelines are also shown. Fi-ure 2.1. Location of Stud! Area in relation to Africa and the Island of Mauritius. Figure 4.1. Topography and hydrologv in the Study Area.

Black & I ea:cii Internatitmal xvii Montagne Jztcqlwot Sewerage aniidSanitation Project Eniviron,mental Impact .4ssessmenit

Figure 4.2. Geology and soils in the Study Area. Figure 4.3. Mean monthly rainfall ( 1951-80) at Richelieu and Fort William. and temperature (I 958-75) at Fort William ...... 4.' Figure 4.4. Wind r oses for the Pointe aux Sables area (from SOGETI 1995). Figure 4.5. Bathymetry. ocean currents and barrier reefs on the coast at the proposed nevx outfall site at Montagne Jacquot. The adjacent coastal areas of Pointe au> Caves and Pointe aux Sables are also shown. Figure 4.6. Percentage substrate coverage (I 1 SE) on the reef slope at Montagne Jacquot. Figure 4.7. Land use in the Study Area. Figure 4.8. Aerial photograph (1: 10 000) of the proposed new WWT plant at Montagine Jacquot. Figure 4.9. Main services. historical and cultural sites, and recreational areas in the Stud\ Area.

List of Plates (Plates are grouped at end of Section 4. Note: all photographs in the plates were taken during May/June 1997)

Plate 4.1. Location of the WWT plant site at Montagne Jacquot. Note edue of sugar cane fields to the right and the prison wall to the left of picture. Also note the beach comprised of basalt boulders with sandy patches. and the patches of (. junceu and P.glahru exotic bushes. Plate 4.2. Basalt rocks formin_ the intertidal zone at the Montagne Jacquot proposed WWT site. Note the recreational fisherman on the rocks. Plate 4.3. Secondarised savannah grassland at the proposed site for the WWVTplant. at Montagne Jacquot. Plate 4.4. A creeper. Pussiflorajbetida. belonging to the passionfruit family. Plate 4.5. Occasional ('assia lora (Family: Papilionaceae) at Montagne Jacquot Plate 4.6. Mid-littoral zone with molluscs S ferrugineu and Putelles sp.. barnacles. and some urchins (('olohocentrouts). Plate 4.7. Note the intertidal blennies. A.monochrus (arrow). molluscs. and the presence of algae. Plate 4.8. Note presence of urchins and encrusting coralline algae. Plate 4.9. The impact of raw sewage and solid wastes on the coastline between Fort William and Fort Victoria - note algal mats on the surface of the rocks. Ma\ 1997. Plate 4.1 Oa. The coastline at Pointe aux Sables existing outfall. looking north towards Port Louis.

Black a Veatch linJerni,:iimal xviii Monragne JacqulolSewerage atiil Sanilution Project Environmental Impact A.ssessntenr

Plate 4.1 Ob. The coastline at the Pointe aux Sables existinu outfall. lookin2 south towards Montagne Jacquot. Plate 4.1 Ia. The dark blue plume of surface water at the Pointe aux Sables discharue area - 3rd June 1997. Plate 4.11 b. The sca bottom on the reef seaxvardslope (3 - 7 m deep) in the dischar-e area at Pointe aux Sables. Note the proliferation of black urchins and algal growth indicating high pollution levels. (June 1997). Plate 4.12a. Reef profile at 30 m. note: solitarv coral - Fungia sp.. mushroom-like soft coral - Sarcop4lvon.. and flat sheet-like coral - Lohoph,vtum sp.: butterfly fish - C huelodon lIundlal.coachman - IHeniochussp.; algae. Plate 4. 12b. Reef profile at 30 m. note: leaf-like coral - M1ontipor"'. sheet-like coral - S'aricopilwon sp.. sponges: algal growth: Moorish idol - ZainciisXcanescens. school of two-spot bristle-tooth - Clenochuetus binotatus. Plate 4.12c. Reef profile at 30 m. note: honevcomb coral - Favia sp.. leaf-like coral - /ontipora: algae. Plate 4.12d. Reef profile at 30 m note: Montihpora..Sarcophyton coral. Zcanescens. crosshatch butterflvfish - Chuetodon xnilthus. saddleback hogfish - Bodianuts hilunulatt.s. surgeon - Acain1hihruxsp.: algae. Plate 4.1 3a. Reef profile at 13 m. note: daisy coral - Goniopora. boulder-like coral - Porites:

purple branching soft coral - Vephthea sp. Plate 4.1 3b. Reef profile at 13 m - same as above. Plate 4.14a. Reef profile at 8 m. note: Porites. Favizes corals: two-saddle goatfish - Parapeneus bifasciatus. Z canescens.butterflffish - Chaetodon mehlfnnotius. ( .slnianits. Plate 4.14b. Reef profile at 8 m. note: labvrinthine brain coral - PlatIgvru sp.. porous coral - Porites sp.. Fuviles Plate 4.1 4c. Reef profile at 8 m. note: Porites.longnose butterflyfish - Forcipigen f/lavissutnuis Plate 4.1 4d. Reef profile at 8 m. note: Platygvra sp. Favites and Porites corals: encrustin-z pink coralline ahgae. Plate 4.1 4e. Reef profile at 8 m. note: purple branching soft coral - NVepihetlsp.: urchins colonisin. the rocks. Plate 4.1 4f Reef profile at 8 m. note: brain coral - Plaigtyr sp.: damselfish Chromis sp.: encrustling pinki coralline algae.

BlacA& Veatch Itterinatio,ial xix MontagneJacquor Sewerage and Sanitation Project Environmental Impact A4ssessment

SECTION 1

INTRODUCTION

Blac& & Veatcih International Introduction $ *d c Mt'iontagneJacquot Sewerage and Sanitation Project Environmental Impact .As.essmnenc

1.0 INTRODUCTION

1.1 Background

The Government of Mauritius launched the Sewerage Master Plan Study in 199' with the main objectives being to identify long tern solutions for the safe disposal ot human and industrial waste waters in Mauritius. One of the projects of the SewnerageMaster Plan is the Montagne Jacquot Environmental Sewerage and Sanitation Project which concerns the treatment and disposal of the waste waters from Port Louis South and Lower Beau Bassin/Coromandel (Figure 1.1). The waste water treatment (WWT) plant is to be located at Montagne Jacquot. south of Port Louis and near Pointe aux Sables. This studv was undertaken for the-Waste Water Authority (WWA). Ministry-for Public Infrastructure' . Government of Mauritius (GOM).

Between 1994 and 1996 a number of studies were conducted on the pollution loads from the industrial zones of Coromandel and Plaine Lauzun as well as at the Fort Victoria and Pointe aux Sables treatment works (SETEGUE-ERM-SIGM.A-SAM- SOON 1994-1996). On the basis of these surveys SETEGUE proposed a preliminary design of the WWT plant at Montagne Jacquot based on an ocean outfall to dispose of treated effluent. with a view to re-using the treated effluent for irrigation of the Westem coast agricultural land.

Subsequent to the SETEGUE studies. an environmental assessment of effluent disposal into the lagoonal waters at Pointe aux Sables and of the proposed outfall at Montagne Jacquot was done by SOGETI (1994-1996). This study also highlighted the frauilitv of the Pointe aux Sables lagoon ecosystem and the extent of eutrophication presently occurring there.

In Februarv 1997 a Pre-feasibilitv study on the Montagne Jacquot Environmental Sewerag,e and Sanitation Project was undertaken by Magoarou and Sam-Soon. This investigation resulted in a number of conclusions and recommendations for the project. The main conclusion was that the implementation of the Montagne Jacquot Project is necessary to protect public health. water resources and lagoonar water. particularly at Pointe aux Sables.

formerlythe Ministrvof Energyand WaterResources

Black & J'ea:chtInIerntaional 1.1 Introduction Montagne Jacquiot Sewerage and Sanitation Project Environmental Inmpact4ssessment

The Environmental Impact Assessment of the Montagne Jacquot Project forms the basis of the present document. A separate report on the Detailed Design and Preparation of Tender Documents is also being undertaken and will be submitted at a latter stage. The Baie de Tombeau Project. which is dealing with treatment and disposal of residential and industrial effluents north of Port Louis. also forms part of the Sewerage Master Plan. A Feasibilit' Study for this project was carried out by GIBB (Mauritius) in

December 1993 and was followed by a marine survey of the coastal region north of Port a Louis (CSIR 1996).

1.2 Objectives of the Montagne Jacquot Sewerage and Sanitation Project (Study I)

Studv I of the Montagne Jacquot Environmental Sewerage and Sanitation Project covers the detailed design. preparation of tender documents and environmental impact assessment. whilst Study 2, which is being carried out by a French Consultancy. BRL In-enierie. will address the "Sanitary. Technical and Economic viability of re-use of treated effluent for irrigation purposes":

The Terms of Reference for Study I were as follows:

a) study the available data: b) review the waste water treatment plant alternatives: c) review the treated effluent and sludge disposal options, d) collect the necessary additional data including field and laboratory tests to finalise the design criteria: e) prepare an environmental impact study for the project, f) recommend the most cost effective and environmentally sound alternative: g) update the feasibility report and: h) prepare the detailed design (Phase 1) of the selected waste water treatment plant. related infrastructure and buildings. fencing etc.

The main aims of the Montagne Jacquot Project are to protect and improve public health and sanitation of the population around Port Louis. protect the terrestrial and marine environment. and to maintain sustainable development of economic activities of the country.

In addition. the project aims to minimise industrial pollution by recommending pretreatment of industrial effluents. to reduce the organic and suspended solid loads to the future waste water treatment plant.

Black& I'eagclhInternational 1.2 Introduction A4ontagne Jacquot Sewerage and Sanzitation Project Environmental Impact Aysessnent

1.3. Consulting Team

The team for carrying out the EIA consisted of the following specialists:

Environmental Engineer: Dr E. B. Jemigan Principal Environmental Scientist: Dr E. A. S. Linlev Environmental Scientist: Dr S. A. Harris Botanist: Dr J. Gueho Sociologist: Mr 0. Varma

The work schedule for the EIA is shown in Appendix D.

1.4. Background Information

Lists of data sources, consultations with IAPs. project background reports and studies. relevant publications etc. are all summarised in the appendices.

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SECTION 2

PROJECT DESCRIPTION

Black & lVeatclaInternational Project description a Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

2.0 Montagne Jacquot Sewerage Project

2.1 Project Purpose

Of the three main sources of water pollution in Mauritius, two are from waste water sources. The first causes contamination of domestic water supplies as a result of overflowing of sewage during cyclones and floods. and the second from disposal of industrial waste (e.g. dyes) into natural water bodies (MOQL 1991). This emphasises the need to improve the present state of sewage management in Mauritius. The third source of water pollution is from contamination of underground water by leaching of aorochemicals, pesticides and fertilisers.

The purpose of the Montagne Jacquot Sewerage and Sanitation Project is to provide a long termnsolution for the treatment and disposal of waste water in the Port Louis South and Lower Beau Bassin/Coromandel area. to achieve pollution abatement to a level that allows the disposal of treated effluents in the natural environment and to maintain sustainable development of economic activities of Mauritius. This project is part of the overall Sewerage Master Plan (1992) for Mauritius. the main objectives of which are to provide long term solutions for the safe disposal of human and industrial waste waters.

2.2 Project Location

The Island of Mauritius is located at approximately 20°S and 57°E and covers an area of 1 860 km2 (Figure 2.1). The coastline is only 200 km long and is almost completely surrounded bv fringing coral reefs. except for opposite river mouths. estuaries and a 15.5 km stretch on the south coast. Port Louis is the capital citv of Mauritius and is one of the oldest settlements in the country. Port Louis was first sewered in the early 1880's and the sewerage system extended and reinforced in the 1920's and from the mid-I 960's to the mid- 1970's.

There are four main sewer networks in operation in the country. two of which serve Port Louis and discharge at Fort Victoria and Roche Bois outfalls. In the Port Louis area there are three sewage outfalls discharging sewage into the sea: Fort William. Fort Victoria. and Pointe aux Sables (see Figure 1.1). In the Port Louis system. preliminary treatment (screening and disintegration of solids) is carried out at Roche Bois and Fort Victoria. and includes mainly the following built-up areas (see Figure 1.1):

Black &A'eatch International 2.1 Projectdescription M1'ontagineJacquot Sewerage and Sanitation Project Environmental linpactAssessment

0 Port Louis South: 0 Cassis: 0 Belle Villa2e: 0 Plaine Lauzun Industrial Zone:

Other areas connected to the Port Louis sewerage system are the low Ivingzareas such as part of Tranquebar and the waste waters from these areas are conveyed via the Pouce Valley trunk sewer to Caudan Pumping Station. In the Port Louis area. about 48% of the industries are connected to the sewers.

The southern interceptor sewer leads to the Fort Victoria works and is comprised of:

0 The Caudan Pumping station; 0 Plaine Lauzun Industrial Zone and: 0 Cite Vallijee:

The Fort Victoria works consists only of screening and grit removal with the waste waters being pumped out to sea via a I m diameter asbestos cement outfall.

The Lower Bassin/Coromandel Sewerage System includes the followiniz built areas:

0 North Beau Bassin; 0 Coromandel, 0 Coromandel Industrial Zone and; 0 La Tour Koenig Industrial Zone; 0 Some residential areas (NHDC Housing Estates etc.) of La Tour Koenin.

The Coromandel system was constructed for the industrial effluent of Coromandel Industrial Estate and for the domestic effluent of Beau Bassin North. This s%stem also serves the La Tour Koenig development and the Pointe aux Sables CHA Estate.

The trunk sewer serving the zones flows by gravity from Lower Beau Bassin via Coromandel and La Tour Koenig to the Pointe aux Sables pre-treatment works (coarse screening only). From there it is discharged via a 0.65 m diameter asbestos cement outfall. just beyond the fringing reefs of Pointe aux Sables.

Black A Veatchi International 2.2 Project description MW1ontagne.Jacquot Sewerage and Sanitation Project Environmental Impact .4ssessment

2.3 Project Description

2.3.1 Project Overview

The Montagyne Jacquot Sewerage Project will consist of new sewaae pump stations at the existing Ft Victoria and Pointe aux Sables works. a transmission main to carrv the waste water from the pump stations to the treatment plant. a new waste water treatment plant located at Montagne Jacquot. and a new ocean outfall to discharge the treated effluent to the coastal waters. This section of the report describes alternative facilities that were developed and evaluated for each of the major project components. and recommendations which resulted from the evaluations. In some cases the evaluations have not been completed. so no definite conclusions are presented.

2.3.2 Pumping, stations and Transmission Mains

2.3.2.1 Pumping Stations

The Gibb sewerage master plan proposed constructing a new pumping station near the GRNW. and a second pumping station at the Pointe aux Sables works. In the preliminary design it was concluded that a better alternative would be to eliminate the proposed new St Louis pumping station, and construct a new pumping station at the Ft Victoria works instead. The second pumping station will be constructed at the Pointe aux Sables works.

For the new Ft Victoria pumping station the possibility of modifying the existino structure and installing new mechanical and electrical systems was considered in detail. It was concluded that the cost of modifying the old station would exceed the cost of constructing a new one. and the old one should be retained for possible use in emergencies.

For the two new pumping stations. three options for pump station configurations were considered:

Option 1: a traditional wet well/dry well station similar to the existing pump station at Fort Victoria.

Option 2: a standard submersible pump station configuration using a wet well. with submersible pumps mounted on rails. submerged in the wet well.

Blac A Veatch International 2.3 Project description Mlontagne Jacquot Sewerage and Sanitation Project Environmental Impact .4s.sessmenw

Option 3: a wet well/dry well station which minimizes the wet well volume by-utilizinc variable speed pumps controlled by a flow meter placed on the influent sewer.

2.3.2.2 Transmission MviainRoiutes

Two principal alternative routes for the transmission main to carrv the waste water from Fort Victoria to Montagne Jacquot were developed and evaluated. The routes were as follows (refer to Figure 1.1. Section 1.0):

Alternative Route I This route would pass from the Ft Victoria pumping station. cross the Grand River Northwest (GRNW) in the vicinity of the two bridges. across the area near the La Tour Koenig industrial estate. then along a series of small roads running parallel to the coast road through the Pointe aux Sables community to the Montagne Jacquot site. Other features of this route are:

0 The new pumping station at the Pointe aux Sables works could also discharge directly into the transmission main. thus eliminating the need for a second transmission main from that location to Montagne Jacquot. 0 Waste water from Lower Beau Bassin. Coromandel. La Tour Koenic industrial estates, and future sewerage systems for places such as Richlieu and Petite Riviere would be connected to the existing sewer system leading to the Pointe aux Sables works. From there it would be pumped into the transmission main. 0 The transmission main from the St Louis Pumping Station to the Richlieu header manhole would not be needed. 0 The gravity sewer from the Richlieu mranhole down to the Montagne Jacquot site would not be needed. 0 The cost of pumping would be less. since the elevation of the Montagne .lacquot site is approximately 40m lower in elevation than the treatment works at Richlieu.

The negative impacts of Altemative Route I would be mainly during the construction phase since the building of a pipeline of this nature would pass along a heavilN congested main road.

Alternative Route 2 The second alternative route would be offshore. almost directly from Fort Victoria southwest. across the shallow waters and the mouth of the Grand River Northwest to

Black& Veatc/, International 2.4 Project description Hontagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessmnent

the lagoon at Pointe aux Sables. through the lagoon parallel to the shore. then back inshore and to the Montagne Jacquot site at the southern end of the lagoon. This route would reduce or eliminate all of the problems associated with construction of this transmission main through the developed community and along the most congested roadwavs and through commercial districts.

The advantages of this route are primarilv associated with avoiding the disruption of the community and tratffic congestion during construction. It would also be significantly shorter. Negative impacts would be that it would probably have a significantly higher construction cost than Alternative Route 1. and it would have temporary. adverse impacts on the lagoon environment during construction.

2.3.3 Review of Waste Water Treatment

Waste water treatment processes are grouped into categories according to the level of treatment provided. Treatment levels provide progressively greater health and environmental protection bv removal of greater amounts of impurities. but at a progressively greater cost.

Preliminarv Treatment - consists of removal of large, bulky materials and grit. Bar screens (course or fine) are used to remove large materials such as boards. rags. and plastic items which are not readily biodegradable and which can cause problems with mechanical equipment. Bypasses are usually required so that a screen can be taken out of service for repairs or maintenance. Finer screens collect smaller suspended materials which normally pass through the bar screens. Grit (e.g. sand) can be removed bx. gravity in settling basins or can be separated from the flow with centrifugal devices.

Primarv Treatment - consists of sedimentation basins which remove suspended matter by allowing it to settle to the bottom. From the bonom the settled matter is collected with a raking mechanism and pumped to the sludge processing facilities i.e. primary sludge collection. Floating matter such as oil and grease is skimmed from the surface of the basin and pumped to the sludge processing facilities.

Secondary Treatment - consists of biological processes. using microorganisms. which remove suspended and dissolved organic matter and other impurities from the waste water. It also includes a secondary settling process to separate the microorganism population from the treated flow. The most common types of suspended

BlacA&AVeatch international 2.5 Projectdescription .Iontagne Jacquot Sewerage and Sanitatiaen Project Environmental Impact A.ssessment

microorganism population systems are aerobic lagoons. activated sludge units. and extended aeration units.

Factors which can inhibit or disrupt the biological activity include the presence of toxic substances. large fluctuations in flow and strength of the influent waste water. and large fluctuations in the concentration of total dissolved solids. temperature or pH. Any of these conditions which have an adverse impact on the microbiological population can reduce the treatment efficiency.

Tertiarv treatment - a process that removes nitrogen and phosphorous. and greater removal of suspended solids and dissolved organic matter than secondary treatment.

Disinfection - a process which kills microorganisms and lowers the concentration of bacteria to levels considered safe for public health. and for the health of the ornoanisms present in the receiving waters or disposal sites. Water quality standards typically establish the allowable concentrations of bacteria in the plant effluent. and disinfection processes suitable for achieving those standards can be selected. In the United States disinfection of the treated waste water effluent is almost universallv accomplished by the addition of chlorine. Alternative chemical agents can be used. such as ozone or other halogenated compounds: and other disinfection processes are available. such as exposure to ultraviolet light.

2.3.4 Water Quality and Treatment Standards

It is possible to design waste water treatment processes which will meet virtuallv anv water qualitv standards or effluent standards. In general, as the level of treatment increases. both the capital costs for the facilities and their operating costs increase exponentially. In Mauritius water quality standards have been adopted for rivers and streams used for water supply. for ground water and for lagoons. but not for the ocean water along the coast. No water quality standards have been established for water used for irrigation or for various types of recreation.

2.3.4.1 Water Oualitv Standardsfor Ocean and Irrigation Waters

Following consultation with the WWA. Black & Veatch International concluded that the water quality standards proposed by the Gibb sewerage master plan for ocean waters and for irrigation water should be used as the basis for the design of the Montagne Jacquot works. The water quality standards presented in the Gibb sewerage master plan

BlacJA J"earchlInternational 2.6 Project description AlontagIe Jacquot Sewerage and SanitatiollProject Environmental inpact .4ssessment

for irrigation and ocean waters. as summarized in the Magoarou and Sam-Soon prefeasibility report. are listed in Table 2.1. These standards were based on international guidelines. taking into account the characteristics and sensitivity of the local ecosystems (coral reefs) and natural physical and chemical backsground concentrations of the constituents to be discharged into the ocean. The sea water quality for Mauritius was defined in terms of limits which should not be exceeded in

Table 2.1. Effluent quality standards (irrigation, lagoon and ocean) presented by Gibb (1993) Parameter Irrigation Lagoon Ocean

temperature(OC) - 30 30 50 pH - | 5.0-9.0 5.0-9.0 5.0-9.0 colour(piatinum-cobalt scale) 20o - COD(mg/l)* 90 60 750 BOD(mg/I)* _ 250 TS(mg/I)* 45 15 loo Chloride(mg/I) 250 Sulphate(mg/l) 500 Nitrate-N(mg/1) 5 Ammonia-N(mg/I) 5 ITDS(mg/l) I o000 Cadmium (p2g/I) ao 20 Cliromate-Cr(Ag/I) 50 50 1oo Copper(pg/]) I000 Lead gI)200 2 Mercury(pg/I) 20 20 'O Nickel(pg/l) 200 500 10000 Zinc tp4g!i) s ooo Oil tmg/l) _ none none none Dergents (mg/i)5 5 Pesticides: carbonate(pg/l) 100 _-_ chlorinated(pg/I) 10 10 phosphorous(gg/l) loo 100

*mostimportant variables used in the design of the WWTworks

order to maintain the physical. chemical and biological characteristics of the marine ecosvstem and the fringing reefs. and to ensure that the areas used for direct contact recreation would not impose a health risk to humans. The standards which are normally

Black-& VeatchJIntternational 2.7 Project description Montagne JaicqluolSewerage and Sanitation Project Environmental Impac .Assessment

specified and monitored regularly for waste water treatment plants. and which are used as the basis for design of treatment works are COD. BOD(5). N. P and TSS. The remaining parameters are not normally found in municipal waste w;aters in concentrations which would cause the indicated standards to be violated. or which might interfere with the operation of a typical waste water treatment plant.

2.3.4.2 Microbiological Standards

The recommended microbiological standards presented in the Gibb sewerage master plan were based on EC standards for direct contact recreation. and South African standards for sea water. Standards recommended for recreational waters are: faecal coliform < 100/lOOml (80% of samples): faecal coliform < 2000/lOOml (95% of samples): faecal streptococci < 100/lOOmi(900/o of samples).

Concentrations of faecal coliform in waste water varv widelv. Typical concentrations indicated by previous studies are:

0 either 108/100ml for effluent that received essentially no treatment. or 1Ol/I OOml for effluent that received primary and secondary treatment. but no disinfection. (SOGETI 1995) 0 the faecal coliformnconcentration in raw sewage was typically between lO"'l OOml and 10/ lOOml; industrial waste waters would tend to produce a raw sewage concentration closer-to 106/1OOml:the effect of biological treatment processes was to reduce the concentration by 2 to 3 logarithm units which would result in a concentration of around 104/lOOml or 103/lOOml (Magoarou and Sam-Soon 1997. prefeasibility report)

The concentration of coliform organisms in waste water which receives onlx primary treatment and no disinfection will typically be in the range of IO /I OOml or IO 1OOml. Therefore. the effluent from a primary treatment plant cannot meet the microbiological standards for body contact recreation mentioned above. The concentration of coliform organisms in a waste water which receives secondary treatment and no disinfection will meet the standards at times, but not with any certainty.

2.3.4.3 Waste Water TreatmentPlant EffluentStandards

No standards for the performance of municipal waste water treatment plants in terms of effluent limits have been formally adopted by the Government of Mauritius. Ministry

Blauck Veatchl international 2 8 Project description A'IonutagneJacquol Sewerage and SanitationzProject Environmental Impact .4ssessnienIt

for the Environment. The water quality standards for the receivinu water (ocean) and for irrigation water were therefore used to select the treatment processes for the Montaane Jacquot works.

2.3.5 Waste Water Treatment Plant

Several consultancies have provided planning and development inputs to the oVlontagne Jacquot WWT plant over the last few years. However. the final recommendations for the major components of the project were developed bv Black & Veatch International following detailed review of all of the previous planning and preliminary design reports. The following'descriptions of design criteria and alternative treatment facilities and effluent disposal methods do not include details of much of the preliminar) work carried out in previous studies. The reports containing the details of the previous work- are listed in section 10.

2.3.5.1 WVacxie Water Flow

The first phase of the Montagne Jacquot WWT plant will be designed with capacity to treat the flow projected to occur in 2005. The average daily dry weather flow was projected to consist of 16.000 m3/day of industrial waste water and 32.000 m3/'dav of domestic and commercial waste water in that year. The pumping stations at Fort Victoria and Pointe aux Sables. the transmission main from those pumping stations to the Montagne Jacquot site. and the primary hydraulic structures at the WWT plant will be designed with capacity to deliver the peak wet weather flow projected for the vear 2017. The peak wet weather flow was projected to be 3.9 times the average daily flow. and the total average daily dry weather flow for 2017 was projected to be 6(0.000 m3/day.

2.3.5.2 Waste Water Characteristics

The waste water to be treated by the Montagne Jacquot WWT plant will consist ot' a combination of domestic. commercial and industrial waste water produced in the service area. The fraction of total flow projected to be produced b! industries will decline from 33 percent in 2005 to approximately 25 percent in 2017. The characteristics of the waste water produced by the domestic and commercial sources in the service area are expected to be typical of normal domestic sewage. The characteristics of the industrial waste water will be that of textile industries. since they will produce approximately 90 percent of the total volume of industrial waste water.

Blacl & VeatchiInternational 2.9 Project description Mllontague Jncquor Sewerage and Sanitation Project Environmenial Impact .-.ssessmennt

The projectedinfluent waste water characteristicsused for the design of the Montagne Jacquot WWT plant are summarizedin the following table. The tvpical characteristics shown in the table are projectedmean values. based on a review of all available waste water quality data from the existing Fort Victoria and Pointe aux Sables works. and wastewater survevsof industrialeffluents.

Table 2.2. Projected Influent Waste Water Characteristics

Characterisitc | Typical influent concentration

Conductivity 3000 pH 7.3 COD (m!l) 600 BOD (5) (mgAl) 325 TKN (mg/u 45 Phosphorous (mg/I) 5 Chloride (mg/l) 150 Sulphate (mg/i) unk (a) TDS (mg/l) unk lTSS (mg/[) 400 I Cadmium(gg/l) nil .Cromate (,g!l1)2 Copper(pa/1) nil Lead (gg/l) nil Mercun (ig/lI) nil Nickel (Jig/I) nil Zinc (pg/I) 50 Oil ---- nil Detergents (mg/I) nil Pesticides. total (±g/I) nil Faecal coliform (no./lOOml) 10,000.000

(a) unk = unknown: no sampling data available

2.3.5.3 Induistrial Waste Water

Industriesproduce a significant percentof the total waste water flow in the service area of the Montagne Jacquot facility. The characteristics of the combined industrial. commercialand industrial waste water are shown in the preceding table. The industrial waste water discharges result in relatively high COD. BOD(5). TSS and salinity concentrationswhen comparedto typical domestic sewage. These parameters directlv

BlacAA lPeatctInternational 2.10 Project description mt'ontagne JaLcquot Sewerage and Sanitation Project Environmenltal Impact - s.essmnent

affected the sizing and selection of treatment processes considered in the rev'iew and evaluation of waste water treatment and disposal alternatives.

The detailed study by SETEGUE (1996). on the industrial effluents being discharged into the existing sewer network. recommended a number of actions that should be undertaken by responsible authorities to control the undesirable impacts of the industrial waste waters on the sewerage system and on the receiving waters. SETEGUE made recommendations for several specific industries to have pretreatment works which would remove solids. equalize flow and remove suspended solids and -rease before discharging their effluent. The most recent evaluation of the components of wastes discharged from a selection of industries in Mauritius is shown in Appendix 1. which summarises results from a range of food processing. paint. and textile houses.

The management of industrial waste water from the industries in the study area is an important component of the overall program to control pollution from the waste waters produced in the service areas. The Waste Water Authority recently commissioned an institutional / legislative review to address the problems of updating industrial waste management legislation and capacity building in government to implement pollution control legislation. A review of the sources and characteristics of industrial waste water in the Montagne Jacquot service area is presented in Appendix Q. This review also identifies those industries which will be required to take actions to control their waste water discharges.

2.3.5.4 W;isle Water Treatment Alternatives

Several altemative processes were considered in determining the components for each of two scenarios. Alternative processes were evaluated using factors such as estimated construction and operating costs. reliability, ease of operation. complexity of equipment and required levels of maintenance.

The level of treatment provided by either of the two scenarios can be changed in the future if there are changes in the effluent,quality requirements. The treatment processes proposed for phase I of the two scenarios are considered to be appropriate for both the two altemative effluent disposal methods. The plant will be designed so that the waste water flows through all process units and out through the ocean outfall under the force of gravity. Pumping will only be required for sludge management. a plant industrial water system. and an internal sewer system.

BlucA A Vedttcl International 2.11 Project description AilonrtagneJatcquot Sewerage and Sanitation Project Environmental impctpc.4ssessment

An area will be provided for septic tank hauling trucks to unload. The waste will flow by gravity to the plant influent structure.

Scenario I - Primarv Treatment, Ocean Discharge The level of treatment provided by Scenario I for the WWT works at Montagne Jacquot was determined by the water quality requirements established for dischar-e of the treated effluent through an ocean outfall. The projected influent and effluent waste water characteristics, and the effluent limits which were used to determine the recommended treatment processes for Scenario 1 are listed in the following table. The TSS removal efficiencv of the primary clarification process can be enhanced w%ith liquid poly mer flocculant to achieve the 100 mg/l effluent limit.

Table 2.3. Projected Influent and Effluent Waste Water Characteristics and Effluent Limits for Scenario 1 Primary Treatment Plant

Characterisitc Typicalinfluent Typical effluentconc. Effluentlimits l ______JJ conc. (ocean)

Conductivity 3000 3000 pH 7.3 7.2 5.0-9.0 COD(mg/l) 600 400 750 BOD (5) (m/l) 325 225 50 TKN (mg/l 45 40 Phosphorous(mg/I) 10 9 TSS(mg/l) 400 100 Cadmium(gg/I) nil nil 20 Chromate(Ag/I) . nil nil 10( Mercurv(4/1) nil nil 20 Nickel(pg/1) nil nil0.0( Oil nil nil none Faecalcoliform (no.,'100ml) 10.000,000 2000

The preliminary treatment facilities for Scenario I would consist of bar screen. fine screens and grit removal. The preliminary treatment works would be followvedb! primary sedimentation basins, and a disinfection process. consisting of chemical treatment using chlorine. The effluent would be discharged through an ocean outfall. Sludge management would consist of dewatering with belt filter presses. lime stabilization of the dewatered primary sludge. and disposal of the mass in a sanitan- landfill. A schematic diagram of the processes of Scenario I is included in Appendix B. The configuration of Scenario I was chosen so that secondary treatment processes

BlackA Veatchinternational 2.12 Project description .Montagne Jacqior Sewerage and Sanitation Project Environmental Impact Assessment

could be added at anv time in the future. with minimal change required in the existing works.

Preliminarv Treatment - Flow would enter the plant at a headwork-s structure where screens and grit removal equipment would be located. Since corrosion is often a problem at headworks structures. the components would be constructed of corrosion resistant materials. Hydraulic elements would be designed to minimize turbulence.

Screening - Bar screens would separate large objects from the influent flow-to protect pumps and other rotating equipment. Drum screens would be provided to remove smaller solids to prevent blockages in sludge pipes and protect the belts on the filter presses. The screens would be cleaned with spray nozzles which would deposit the residue in portable containers. The containers would be manually transported. the residue combined with the grit then transported to a sanitary landfill for disposal. A bypass channel would be provided for use when a screen is out of service for repairs or maintenance.

Grit removal - Grit would be removed by equipment using centrifugal forces. The grit collected in the unit would be pumped to a cyclone and washing machine. The cleaned grit would be deposited in portable containers. It would be manually transported to a hopper for holding and eventual discharge into an open truck for transport to the sanitarv landfill for disposal. The underflow from the washed grit would be returned to the plant flow.

Primarv Treatment - From the headworks structure the flow would be divided equally among four primary clarifiers utilizing the principal of geometric symmetry. Provision would be made to allow minor adjustments to the flow to each primary clarifier using manually adjustable gates or similar device. A chemical addition point would be provided upstream of the flow splitter to allow injection of chemicals to aid in settling the solids in the primary clarifiers. The chemical would be thoroughly mixed before the flow splitting operation.

Primary sedimentation - Four circular primary sedimentation basins wvould be constructed in phase 1. Each would include a center feed well. peripheral weirs. rotating sludge collector with rakes to move sludge to a central sump and a surface mounted skimmer arm to move floating solids, oil and grease to a collection sump.

Black & veuich hnternational 2.13 Project description llfon-agneJacquo! Sewerage and Sanitation Project Environmental Impact 4.ssessment

Disinfection - Disinfection would be provided using chlorine solution and an open basin to provide satisfactory contact time. Chlorine gas would be withdrawn from cvlinders of liquid chlorine under vacuum, through chlorinators to chlorine injectors which would form the chlorine solution. The chlorine solution would be injected into the waste water flow at the influent to the chlorine contact basins. Two basins would be constructed to operate in parallel so that either one can be taken out of serxvicefor repairs or maintenance. The chlorine feed rate would be paced by a flow meter placed on the effluent channel of the basins. The feed rate would be adjusted manually in order to maintain a chlorine residual target of about 0.1 mg/I.

Flow measurement - The plant flow would be measured with a venturi flume or weir placed in a channel at the effluent of the chlorine contact basin. The depth of flow would be measured with an ultrasonic instrument which would convert the depth into flow rate. The flow would be recorded and displayed at the instrument. located at the flow meter.

Ocean Outfall - The effluent from the plant would be discharged by gravity to the open sea off the coast of Montagne Jacquot through a pipe line leading to a series of six diffusers at an average depth of -30 m. The outfall would be approximately 645 m out from the shore line. and the diffusers spaced at 10 m intervals at the outer end. to prevent intermixing,before the plumes reach the surface.

Slud-e Processing - Positive displacement primary sludge pumps would deliver the sludge collected from all clarifiers to two holding tanks. The holding tanks would be mixed with recirculating pumps.

The sludge processing equipment would be located in a separate building. divided into a chemical storage and handling area. control room and filter room. From the sludge holding tanks the sludge would be pumped to belt filter presses for dewatering. The belt filter presses would require chemical feed equipment for conditioning the sludge. and a pressurized water system for belt cleaning. The filters would be controlled with a computer based svstem provided as part of the filter package. The filtrate would be collected in the plant sewer system and returned to the headworks. The dewatered sludge would be carried on a conveyor belt to a mixer where it would be stabilized with lime. The facilities would be designed to allow sufficient lime to be added and mixed with the sludge to raise the pH above 11.5 for 30 minutes. This would kill pathogenic bacteria and control odors. From the mixer the sludge would be loaded into trucks which would haul the dewatered. stabilized sludge to a sanitary landfill for disposal.

Black & I eatcl International 2.14 Project description Montagne Jacqliit Sewerage anz/dSanitbitaion Project Environmeiltal Inmpac Assessment

Scenario 2 - Secondanr Treatment, Irrigation and Ocean Discharge The level of treatment provided by Scenario 2 for the Montagne Jacquot works was determined bv the water quality requirements established for COD. BOD(5). and TSS for reuse of the treated effluent for agricultural irrigation. The projected influent and effluent waste water characteristics. and the effluent limits which were used to determine the recommended treatment processes for Scenario 2 are listed in the following table. Schematic diagrams of two alternative treatment process trains considered for Scenario 2 are included in Appendix C.

Table 2.4. Projected Influent and Effluent Waste Water Characteristics and Effluent Limits for Scenario 2 Secondary Treatment Plant

Characterisitc Typical influent [ Typical effluent Effluent limits conc. conc. (Irrigation)

Conductivity 3000 3000 pH1- 7.3 7.2 5.0-9.0 COD (mglI) 600 70 90 BOD (5) (mg/I) 325 35 30 TKN (mg/i 45 30 l Phosphorous (mnz,'l) 5 4 Chloride (mg'l) 150 150 2O Sulphate (mg'l) unk (a) unk 500 TDS (mg/l) unk unk 1000 TSS (mgIl) 400 60 45 Cadmium (;ig/l) nil nil 2O Chromate (gg/l) 2 2 50 Copper (g/I) nil nil 500 Lead (pg/l) nil nil 200 Mercurv (pg/l) nil nil 20 Nickel (ug/l) nil nil 20 Zinc (Ag/l) 50 50 1000 Oil nil nil none Detergents (mg/!) nil nil Pesticides. total (Lg.'l) nil nil 210 Faecal coliform (no.'100ml) 10.000.000 1000 1000 (a) unk = unknown: no sampling data'available

Several of the criteria for irrigation water cannot be met with normal secondarv waste water treatment processes. including the limits for salinity (conductivitv). chloride. sulphate. and color. because secondary treatment processes are not effective in

BlacA& VeutclaInterntionatl 2.15 Project description MontargneJacquot Sewerage and Sanitation Project Environmental Impact 4.ssessmnent

removing these substances. Providing treatment to reduce those substances to meet the standards for irrigation would add significantly to the total cost of treatment. and was considered to be totallv unfeasible. These substances are typically contained in industrial waste waters. and are best controlled at the source. by preventing their discharge into the sewers.

The critical effluent limits which determined the recommended treatment processes were BOD(5) of 30 mg/l. TSS of 45 mg/I. and faecal coliform concentrations of 1000/1 00ml.

For this scenario. the plant would be designed so that the waste water flows through all process units under the force of gravity. Pumping within the plant would only be required for sludge management. a plant industrial water system. and an intemal sewer system. The effluent could flow by gravity out through the ocean outfall. It would have to be pumped through pipelines to agricultural areas for imrgation.

The processes for Scenario 2 would consist of preliminary treatment workls including bar screen and grit removal, followed by primary sedimentation basins. The primarv sedimentation process would be followed by aeration basins for secondary treatment. A final process for disinfection would be provided. probably consisting of chemical treatment using chlorine. When not used for irrigation. the effluent would be discharged through an ocean outfall at a depth of 20 m.

Sludge produced by the primary clarifiers would be dewatered using a belt filter press and stabilized with lime. Secondary sludge would be thickened with a dissolved air flotation unit and dewatered with the primary sludge. Preliminary treatment. primar treatment. primary sludge processing, and disinfection works for Scenario 2 would be essentiallv identical to those described for Scenario I.

Secondarv Treatment - The effluent from the primary treatment units would be carried to two rectangular activated sludge basins. The basins would be configured to provide an anoxic zone to allow for denitrification and aerobic zones for treatment. Oxvgen would be supplied by platform mounted. slow speed rotating surface aerators.

Flow would pass from the aeration basins to circular final clarifiers which would be furnished rotating scrapers with rakes to move the settled sludge to a central hopper. From the secondary clarifiers the flow would pass to the chlorine contact basins which would operate in the same fashion as described for Scenario 1.

Black& IVeatciinternational 2.16 Project descriptionr !t4olntag-le Jacquat Sewerage and Sanitation Project Environmenztal Inipacr .Assessmelf

A portion of the effluent from the aeration basins would be separated and sent to a dissolved air flotation unit for thickening. The thickened waste activated sludge would be combined with the primary sludge and dewatered on belt filter presses. The dewatered sludge would be stabilized with lime. deposited in hoppers. then carried by truck to a sanitary landfill for disposal.

Return activated sludge pumps for all secondary clarifiers would be located in a common pump building. A backup pump would be provided for each pair of sludge pumps. The pumps would be centrifugal pumps. discharging to a common header which would carry the return sludge to the influent to the aeration basins. Pump operation would be controlled with manually adjustable timers.

2.3.6 Effluent Disposal

Two alternative effluent disposal methods were considered in the preliminar\ planning and development of the Montagne Jacquot project. One disposal alternative wvasto use the effluent for irrigation of agricultural lands; the second. to discharge the effluent to the ocean. The level of treatment provided by the Montagne Jacquot WWT plant would be determined by the water quality required for the altemative disposal options. Thus. two waste water treatment scenarios were developed. One was based on water quality standards for ocean waters: the other. for irrigation water.

2.3.6.1 Irrigation

A study was commissioned by the Waste Water Authority in early 1997 bv BRL lngenierie to determine the feasibility of using municipal treatment plant effluent for irrigation in Mauritius. Preliminary findings of the study included a review of the sanitary. technical and economic viability of re-use. It was estimated that the effluent from the initial phase of the Montagne Jacquot WWT plant would provide enough water to irrigate approximately 1300 hectares, and it was determined that there definitelv was a need for this water. The approximate increase in sugar production due to the additional water supply would be approximately 13 000 tonnes per year if all that land were put into cultivation. It was noted. also. that the use of treated effluent for irrigation could also release fresh water for more valuable uses such as potable or industrial water supplies.

BlacA & I eutch International 2.17 Projectdescription 'vlanyagnieJalcquot Sewerage and SanitationtProject EnvironmentalImpact .4ssessment

The preliminary findings of the feasibility study also identified a number of factors that would affect the use of the Montagne Jacquot plant effluent for irrigation. The salinity ot' the water and its sodium content are too high to be used directly for irrigation: the effluent would need to be diluted bv a ratio of approximately I volume of effluent to 4 volumes of natural water. Salts in irrigated water supplies can harm plant growth physically b- limiting the uptake of water. and chemically by metabolic reactions caused by toxic constituents. However, specific limits of permissible salt concentrations for irrigated water cannot be stated because of the wide variations in salinity tolerances among different plants e.g. for groundnuts the tolerance level is 1620 mg,/I TDS. and for potatoes it is 660 mg/I TDS (DWA 1986).

The Montagne Jacquot site is located near the coast at a relativelv low elevation: the effluent would have to be pumped to between 50 and 100 meters higher elevation. Fields currently under irrigation are near the site. but limited in size. The planters in the vicinity are typically small to medium in size.

The feasibilitv study also concluded that the effluent would have to be treated to secondary treatment standards, with disinfection to reduce the concentration of microorganisms in the effluent. It was concluded that water treated to this level could be pumped to the La Ferme water system where it would be adequately diluted. and from there used to irrigate sugar cane fields. However. it was noted that the principal difficulty with implementing this program would be its cost. It appeared that the use of treated effluent from the St Martin waste water treatment facility would provide a larger quantity of irrigation water. and it could be accomplished at a more modest cost since it did not have several of the disadvantages noted for the Montagne Jacquot project.

Based on the preliminary results of the feasibility study it was concluded that the characteristics of the waste water at the Montagne Jacquot project made it unsuitable for irri(gation without dilution, due to high salinity and sodium concentrations caused by industrial waste waters. Also, the cost of pumping the treated effluent from the Montagne Jacquot site to agricultural lands would be significant. Sewage treatment processes are not effective in removing salinity or sodium from waste water. A program to implement controls on industrial waste water which would reduce the salinity and sodium to acceptable levels would require a complex combination of political. institutional. industrial, economic and social factors. It would be impractical to implement such a significant change in the industrial waste water management program before the first phase of the Montagne Jacquot project was implemented. Finally. the cost of providing the higher level of treatment described in Scenario 2 could

Black & VeatchInternational 2.18 Projectdescription MontatgneJacquot Sewerage and Saitiation Project Environmental Inpact .4ssessment

not be recovered from the sale of the waste water for irrigation. For these reasons. it was concluded that it would be unfeasible to rely on agricultural irrigation for disposal of the treatment plant effluent. at least for the immediate future (five to ten years).

2.3.6.2 Ocean Ouiffall

The location for an ocean outfall was studied in detail by two of the preliminary project development documents. The Gibb master plan (1992) collected preliminary data on the characteristics of the coastal waters and conducted mathematical model studies to determine the potential extent and location of the effluent plume resulting from different outfall configurations. The SOGETI report provided a more extensive evaluation of the outfall. with collection of field data on bottom characteristics. currents. winds. and ambient waters. Black & Veatch International used the phvsical data collected by SOGETI to analyze alternative outfall configurations and developed the preliminary design of an outfall.

The Gibb master plan (1992) considered discharging effluent from a facilitx which provided essentially no treatment. via an outfall either to a depth of 30 m or 50 m into the sea. Based on the preliminary analysis using mathematical models of the outfall configurations and receiving water characteristics. the report concluded that an outfall depth of 30 m appeared to be sufficient to provide satisfactory dilution of the effluent from the Montagne Jacquot plant. even if essentiallv no treatment was provided. but it cautioned that a more thorough analysis should be conducted.

The 1995 SOGETI report included a detailed review of the effects of alternative ocean outfall configurations for the Montagne Jacquot plant. Their analysis considered alternative outfall discharge depths of 100 m. 50 m. 30 m and 3 m. The analysis of water qualit, parameters concluded that the bacteriological standard would be the most critical. and the mathematical modeling focused on concentrations of coliform in the receiving waters. Most of the mathematical modeling was performed on an outfall placed at 100 m. SOGETI concluded that an outfall to a depth of 100 m would provide satisfactorv dilution for untreated waste water, but that such an outfall was impractical for technical and financial reasons. For a plant providing secondary treatment with no disinfection. the report concluded that a 645 m long outfall to a depth of 30 m would be. adequate to meet the coliform standard at the adjacent shore and at the Pointe aux Sables lagoon and reef.

Black& IVeatchiInternational 2.19 Project description Montagne JacquotSewerage and Sanitation Project Environmental Impact Assessment

Black & Veatch International prepared an analysis and preliminary design of an ocean outfall using the physical parameters developed by the SOGETI report for the conditions at the Montagne Jacquot site. Based on the results of the mathematical model. it was concluded that a properly designed outfall to a depth of 20 m. with appropriate diffusers. would achieve a dilution factor of approximately 4500 at the Pointe aux Sables reef and lagoon. An outfall to a depth of 30 m would achieve a dilution factor of approximately 14.000 under similar conditions.

2.3.7 Recomnmended Treatment and Effluent Disposal

The preliminary results of the evaluation of using the effluent from the Montaune Jacquot plant for irrigation concluded that it would be unfeasible due to the high salinity of the effluent, because of the cost of providing the required secondary treatment. and because of the cost of transport of the effluent from Montagne Jacquot. Therefore . it was concluded that the treated effluent should be discharged to the ocean. For ocean disposal. the recommended waste water treatment processes and disposal facilities for the Montagne Jacquot plant are those described in Scenario 1. The plant should consist of preliminary treatment works with bar screens. drum screens and grit removal units: primary clarifiers: disinfection: and disposal of the effluent through an outfall. The primary sludge should be dewatered using belt filter presses and stabilized with lime.

An outfall to a depth of 30 m will achieve a dilution factor of approximately 14.000 between a point 645 m offshore and the Pointe aux Sables reef and lagoon. In conjunction with a disinfection process in the treatment works. this outfall will provide assurance that the microbiological standard will be consistently met at the Pointe aux Sables reef and lagoon. All other ocean water qualitv standards will also be met with the proposed treatment plant facilities and this outfall. The recommended outfall should be constructed to 30 m depth. 645 m offshore.

2.3.8 Sludge Management and Disposal

Sludge management and disposal is always one of the most difficult aspects of waste water treatment. Sludge processing is expensive in terms of labour requirements. chemical and energy requirements. For these reasons, almost all waste water treatment plants are engaged in a dynamic and evolving sludge management program. which changes from time to time in response to the practical. economic and regulatory environment in which it must operate.

Black & Veatch International 2.20 Projectdescription Mt/ointagneJacquot Sewerage and Sanitation Project Environmental InpactA Assessnteir

The pianning and review of alternatives for sludge processing and disposal for the Montagne Jacquot plant began with the Gibb sewerage master plan in 1992. and continuedwith the plans and preliminarvdesigns presentedbv SETEGUEet. a] in 1996 and the 1997 prefeasibility report developedby Magoarouand Sam-Soon.The 1997 update to the prefeasibilitvreport. preparedby Black & Veatch Internationalincluded a reviewof the previousstudv results.

The 1992 sewerage master plan provided a general review of advantages and disadvantagesof sludge processing altematives. including sludge thickening using gravitv settling. centrifuges and air flotation operations: sludge stabilization using anaerobic digestion. aerobic digestion. lime stabilization. heat treatment. and composing;and secondaryconsolidation following digestion with sludge conditioning. mechanicaldewatering with plate presses and belt presses. vacuum filters. and drvino beds. A general review of the sludge stabilization alternatives is presented in AppendixE.

Basedprimarilv on considerationof capital costs and complexity of process operations. Black & Veatch Internationalrecommended lime stabilizationfor the primary sludge producedby the MontagneJacquot plant. Lime is producedand is readily availableon Mauritius. The process operationscan be readily adjusted to meet the requirementsof changLingsludge characteristicsand production volumes. Dewateringof the sludge on belt filter presseswill reducethe volume and also assist in handling of sludge.

Once the sludge has been processed.stabilized and dewatered.it is necessaryto dispose of the remaining mass. Although it is common practice to burv it the sludge in a landfill. it is possibleto further reduce the volume by incineration,then dump it into the sea. or spread it on the land. Each disposal alternative has advantages and disadvantages. A general review of sludge disposal alternatives for Mauritius is presented in AppendixR.

The dewatered. lime stabilized sludge will be transported from the Montagne Jacquot WWT plant to the Mare Chicose landfill in trucks, operating generally in tandem with the belt filter press operations. The belt filter presses will typically operate five davs per week. Conservativeestimates were made for the quantities of sludge to be disposed of in the landfill. so the facilities would be able to process and dispose of the total sludge produced. under unfavorable conditions. The average daily primary sludge production (raw. wet. unprocessed) under these circumstances would be about 590

Black & V'eatchInternational 2.21 Project description llontagneJac quo! Sewerageand Sanitation Project EnvironmentalImpacA .4essment

m,/day. The primary sludge will be dewatered on the belt filter presses. and lime will be added to stabilize the dewatered sludge cake. At full plant capacity. the average weekly sludge production delivered to the landfill will amount to 480 m3'wk. or an avera(ge of 95 m3/dav for the five operating days each week. Bv using truck-s with 10 m3 capacitv. 50 trips to the landfill will be required each week. or 10 trips per day for each of the five working davs each week.

Ten trips to the landfill each day will require 20 truck passages on the roadwavs between the WWT plant and the landfill. since each trip requires two passages. It was concluded that 20 truck passages per day was an insignificant increase in the total traffic on the main roadways between the WWT plant and the landfill. but would be a large increase in the total truck traffic on the small residential streets in Pointe aux Sables. Nevertheless. the capacity of even the small residential streets in Pointe aux Sables far exceeds 20 vehicles per day. and there would essentially be negligible impact when the total volume of traffic is considered.

For planning purposes it was assumed that each sludge hauling truck would be able to complete two trips to the landfill each working day. Thus. five trucks would be required. The estimated capital cost for these five trucks was Rs 40 million.

The total cost of sludge management must include the cost of disposal at the Mare Chicose landfill. The estimated operating cost for transportation of the sludge to the landfill was Rs 3.5 million per year. In addition to that. the cost of disposal at the landfill was estimated to amount to Rs 320 per m3. which would amount to Rs 8 million per vear.

Impact on Mare Chicose Landfill The Mare Chicose landfill was designed to receive 650 tonnes/day. or 850 m3/daN of municipal solid waste. Thus. when the waste water flow to the Montagne Jacquot WWT plant reaches its design capacity. the lime stabilized sludge from the plant will amount to an average of 6 to 9 percent of the nominal capacity of the landfill. In other terms. if the sludge disposal continued through the entire life of the landfill. the lime stabilized sludge would occupy 7 to 9 percent of the total volume of the landfill. This would decrease the effective capacity of the landfill to receive municipal solid waste. and consequently. hasten the time when new solid waste disposal facilities will be required.

Black& lieotclhInternational 2.22 Projectdescription iviontagne Jacq"ot Sewerage and Sanitatioln Project Environmental Impact AsNsessient

The disposal of the lime stabilized sludge in the Mare Chicose landfill would not significantlv affect the capability of the leachate treatment svstem to manage leachate produced in the landfill. The sludge would displace an equivalent amount of municipal solid waste (MSW). and the characteristics of the combined sludge/MSW leachate from the co-disposal facility will not be significantly different from the leachate from an ordinary MSW landfill.

The lime stabilized sludge will be processed at the landfill just like ordinary MSW. It can be compacted with the MSW and covered on a daily basis to control odors and nuisance vectors. Its moisture content of less than 70 percent will allow it to be pushed and spread in lavers. much like stiff inud.

BlacA& iVeatchInternational 2.23 Project description Rweft du R.mpart

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A nsin mes Figure2.1. Locabonof StudyArea in relationto Africaand butuparms the Islandof Mauritius

Rw BLACK& VEATCHINTERNATIONAL 0 , dC

Waste Water Authonty Montagne Jacquot Sewerage and Sanitation Project Environmental Impact .4ssessmenl

SECTION 3

POLICY, LEGAL AND ADMINISTRATIVE FRAMEWORK

Black A J'eatchiinternational Policy, legal and administrative frameworL 64; ita MontagneJacquot Sewerageand Sanitation Project Environmental Impact Assessment

3.0 POLICY, LEGAL AND ADMINISTRATIVE FRAMEWORK

3.1 Environmental Protection in Mauritius

The main goal of the National Environmental Policy of Mauritius is to foster harmony between quality of life, environmental protection and sustainable development for present and future generations. Attributes of the policy relevant to the present study include:

0 requiring environmental impact assessment of any major development project. O to complete the National Sewerage Plan. 0 controlling pollution at source and to the extent possible. requiring the polluter to pay. 0 effecting the Master Plan for waste management.

The Montagne Jacquot Environmental Sewerage and Sanitation Project is one of several projects planned as part of the National Sewerage Plan over the next 20 vears. It will result in a substantial improvement in effluent quality in comparison with the present waste water currently being discharged into the sea at Port Louis. and thus greatly improve the quality of life for the communities and the marine life in the affected area around Port Louis. and also eventually result in improvements in the economy of the area.

3.1.1 ThleEnvironmental Protection Act, 1991

The Environmental Protection Act (EPA) Act no. 34 of 1991 establishes the le-al and institutional framework for the management and protection of the environment in Mauritius. and is the mechanism through which environmental policv is implemented (latest edition is October 1996). The Act is divided into several parts. and those particularly relevant to the present study are parts II. which provides for the establishment of the National Environment Council the policy making body in government. and part III. the Environment Coordination Committee which caters for coordination of public departments engaged in environmental protection and pollution control. and Part IV which relates to the requirement for Environmental Impact Assessment (EIA) in relation to new projects. Other pertinent parts of the act cover pollution control in the coastal and maritime zone (part VII), and part X which covers enforcement powers of government, and the enactment of preventitive measures for pollution control.

BlackA&'eatcl, International 3.1 Policy,legal and administrativeframework ilontagne Jac(quot Sewerage and Sanitation Project Environmental Impact Assessment

3.1.2 Administrative Procedures

In 1989 the Government of Mauritius established the Department of Enviroinment to provide the institutional framework to oversee the implementation of conseration and environmental protection legislation in Mauritius. Subsequentlv there was development and clarification of responsibilties in government for different aspects of policy development. setting of national standards and enforcement functions. so that by 1991. the agencies involved in environmental protection in Mauritius and their responsibilities were as shown in Appendix F. To make the environmental decision-makingl process more democratically oriented and consultative the Enviromnental Advisory Council of Mauritius was also established with representatives from ministries. industries. NGO's. educational institutions etc.

According to the Fourth Schedule of the Environmental Protection Act. 1991. government enforcing agencies are responsible for supervising enforcement of National Environmental Standards and notices. orders and directives issued under environmental law. They are responsible for verifying compliance with environmental laws. and for conducting regular monitoring. sampling and analysis so as to ensure compliance.

The enforcing agency with responsibility for inland waters and effluents is the Permanent Secretary to the Ministrv responsible for water resources. This is now the Waste Water Authoritv in the Ministry of Public Infrastructure (see section 8 for details). As the WWA has the responsibility of controlling and monitoring industrial effluent discharges to inland waters. rivers, coastal waters. etc. it has been sug-ested an amendment to the Fourth Schedule of the EPA to make the WWA also the enforcingi agency for control of effluent discharge to sewers (See CES institutional study). In addition to the in-house monitoring and control of discharges by the WWA. the Albion Fisheries Research Centre is responsible for monitoring coastal water quality in discharge zones of wastewater treatment plants and provides water quality information for correlation purposes (R.H. Prayag. DoE. pers. comm).

The enforcing agency with respect to reviewing and managing environmental impact assessments is the DOE. which is also responsible for setting and maintaining national environmental standards for water. noise. odours and solid and liquid wastes.

Black& VeatchInternatiotial 3.2 Policy,legal endadmbiis:rativeframework MontagneJacquot Sewerage and SanitationProject EnvironmentalImpact .lAssessment

3.1.3 Application for an EIA license

Becauseof the potential environmentalimpacts associated with the Montagne.lacquot Project. the Projectmust apply for an EIA License,prior to its implementation.This requiresthat

* a full EnvironmentalImpact Assessment is carriedout. the "ProjectProponent". the Ministrv for Public Infrastructure.will submit the EIA to the Directorof the Departmentof Environmnentof the Ministryof Environment& Quality of Life (MEQOL).for the purpose of complyingwith the legal procedure for EIA licenseapplication. * the EIA must comply with the EnvironmentProtection Act (Act no 34 of 19'91). the EIA must comply with the environmentalrequirements of the funding acencies. which in this case are the World Bankand the OECF.

Accordingto the EPA 1991 the EIA has to cover a range of issues. but as a minimum shouldinclude the following:

a) the locationof the undertakingand its surroundings; b) the principle.concept and purpose of the undertaking: c) the direct or indirect effects that the undertaking is likely to have on the environment: d) the social. economic.and cultural effects that the undertakingis likely to have on people and society: e) anv actions or measures which may avoid, prevent. change. mitigateor remedy the likely effectsof the undertakingon the environment.people and society: f) the inevitableadverse environmental effects that the undertakingis likelx to have on the environmentpeople and society. if it is implementedin the manner proposedby the proponent: g) the irreversibleand irretrievablecommitments of resources which will be involved in the undertaking.if implementedin the manner proposed by the proponent: h) any alternativesto the proposed undertaking; i) such other information as may be necessary to a proper review of the potential environmentalimpact of the undertaking.(See also AppendixG).

The EPA report guidelines from the Departmentof Environment (DOE). indicate that the aim of an EIA is to ensure that potential problems are foreseen and addressedat an early stage in the project'splanning and design (See MEQOL, 1993a). In Mauritiusan

Black & Veutchl International 3.3 Policy, legal and administrativeframework Moiitagne Jacquot Sewerageand Sanitation Project Environmental Impact Assessment

EIA Report (EIAR) has to be prepared at the end of the EIA studv. and this has to be submitted to the DOE (the decision-making authority) as part of a permit application for the project.

The suggested outline of an EIAR (MEQOL 1993a ) is as follows:

0 Title Page: full title. team/consultancy responsible for the EIA. date 0 Non-technical summary: 1-2 pgs. simple language. outline the project and location. focus on key impacts identified in the EIA and measures taken to avoid or mitigate them 0 Project description: project initiator. type of project. need and justification of project. plans and policies with which the project conforms. other related projects and EIA if project is one of a series of development. design. size and scale of project, description of project in terms of raw materials. processes. equipment. work force. products etc.. maps and diagrams/photos. summary of technical economic and environmental features essential to the project. proposed schedule for implementation. need for EIA 0 Method of assessment: baseline data (methodology. information source. limitations. further surveys needed). consultations (statutory bodies. NGOs. local residents. methodology. responses). 0 Alternatives: altematives to project. the "do nothing" option. criteria for rejecting the alternatives, stage at planning process when they were rejected. 0 Local environment: include maps, adjacent centres of population. designated sites of interest. environmentally sensitive areas. other attributes of the area (e.g. amenity. recreational and agricultural value) 0 Site: information on actual site. ownership and access. current land use. findings of specific baseline studies (e.g. vegetation) 0 Predicted environmental impacts: identify key issues identified during scoping stage, direct and indirect impacts, impacts for each stage of project (planning. construction. operation). matrix (long/short terrn. direct/indirect. irreversiblelreversible) 0 Mitigation measures: steps to be taken to avoid or reduce negative impacts. likely success and adequacv of mitigation 0 Residual impacts: EIA must indicate all unavoidable impacts - must be justified in terms of the benefits of the project and enhancements. 0 Monitoring and maintenance: indicate provisions for on-site monitoring of the construction work. further maintenance requirements. any provision for audit during the operation of the scheme

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MWontagneJacqluor Sewerage and Sanitation Project Environmental Impact Assessment

0 Enhancement opportunities: different to mitigation measures - enhancement of work opportunities(e.g. WID) 0 Supporting documentation and references: 0 Appendices: additional plans and maps. species lists. press releases. written responses to the project etc.

Guidelines specifically for coastal developments are also available (MEQOL 1993b) and details relevant to the present study are:

0 measures to conceal facilities such as effluent treatment lagoons. 0 water supply and waste water disposal requirements. in terms of quality. location and volume. 0 the volume. timing. characterisation. and other details of expected water effluents. air pollution. -0 aesthetic features of the project - size. height. setback from HWM. buffer zone etc.. 0 any permanent alteration to natural processes such as river flow and water quality. wave and current movement. ground water characteristics. 0 use of buffer zones to mitigate such effects as noise and odour. 0 change in traffic volume, potential for future expansion on existing proposed site. 0 biological, chemical and physical characteristics of surface. coastal and ground waters in the proposed area of impact. 0 effect of effluent on marine biota, 0 land and resource use - agriculture, marine parks. residential' commercial, industrial/ recreational, zoning laws, land ownership. regional plans for industrial development.

Considering the above environmental guidelines for Mauritius. the proposed WWT plant at Montagne Jacquot and the construction of the associated pipelines will be designed to minimise negative impacts on the environment and to enhance the positive impacts on the local communities.

3.1.4. Coastal water quality standards and effluents standards

Legislation particularly relevant to the present project is that covering wastewater discharges to coastal waters, and the quality of industrial effluents discharged to sewers. Also the water quality standards for coastal ocean water need to be considered since the Montagne Jacquot WWT plant will discharge to these coastal ocean waters.

Black& VeatchInternational 3.5 Policy,legal and administrativeframework Montag,e Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

requires a full EA. Or Category B - may have adverse environmental impacts. but are less siWnificantthan Categorv A. e.g. water supply and sanitation projects.

Potential environmental issues recognised by the World Bank which are relevant to the present studv are:

e Biological diversity: the Bank promotes conservation of endangered plant and animal species, critical habitats. and protected areas. O Coastal and marine resources management: guidelines include planning and management of coastal marine resources. including coral reefs. mangroves. and wetlands. O Cultural sites: protection of archaeological sites. historic monuments. etc. O Industrial hazards: all energy and industrial projects should include a formal plan to prevent and manage industrial hazards O Land settlement: carefully review land settlement in relation to phvsical. biological. socio-economic, and cultural aspects

World Bank requirements for a full EIA report are essentially the same as those required by local Mauritian legislation. but additional sections on policy. legal and administrative background as well as an environmental management plan are also required by the World Bank.

3.2.2 Overseas Economic Cooperation Fund, Japan, Environmental Requirements

The Overseas Economic Development Fund (OECF) is a development finance institution of the Japanese government. providing long-term, low-interest loans to assist the self-help efforts of developing countries. The OECF principallv provides Official Development Assistance (ODA) loans to developing countries. which includes the Republic of Mauritius. The OECF has a cooperative partnership with other funding institutions such as World Bank. the African Development Bank etc. The type of ODA loan given to the Govermnent of Mauritius for the Montagne Jacquot Environmental Sewerage and Sanitation Project is called a "Project Loan" which mainlk covers the procurement of facilities. equipment. machinery, materials, civil engineering works. installment works and consulting services.

The OECF compiled Environmental Guidelines in 1989 (revised 1995: revisions will come into force August 1997) that must be adhered to before finance is approved for any OECF funded project. The guidelines will ensure that each project's impact on the

BacA&eatrc International 3.7 Policy,legal and administrativefranmeworA Montagne Jticqsuot Sewerage and Sanitation Project Environmental Impact .-ssessnient

environment will be taken into account and measures will be devised to counteract negative impacts. if there are any. For large-scale projects. such as those with the risk of significant impacts on the environment. the recipient country must submit an EIA report which must be made available to the public for review.

The OECF is particularly concerned about the role of Women in Development (WID) and endeavors to understand the role of women in the society of the project area. and to monitor how women contribute and participate in the project. The "OECF Guiding Principles on Women in Development" in 1991 can be used to help mitigate negative impacts on women resulting from projects. The OECF consistently emphasises the importance of harmony between development and environmental protection. in the context of sustainable development. and so environmnentalprotection measures must be undertaken throughout the project cycle in accordance with the OECF Environmental Guidelines. The salient features of the guidelines are as follows:

1. Environmental Pollution - air and water pollution, noise. vibration. offensive odours etc. o Where the Borrower's country has regulatory environmental standards. such as emission standards. those standards are to be strictly observed 0 Where the Borrower's country has administrative guidelines. such as environmental standards. the measures adopted must not militate against the attainment or maintenance of those standards. 0 Where the Borrower's country has no such standards. the standards of Japan or other countries or international organisations are to be referred to. In this case. close consultation between the Borrower and OECF is necessary.

2. Natural Environment 0 Legislation and international agreements or conventions to which the Borrower's country is a party must be complied with. 0 A project shall be carried out in such a way that it will not have any considerable adverse effect on the habitat or the principal flora and fauna of the area. 0 Measures must be taken to protect rare and endangered species in the area.

3. Social Environment 0 Impacts on people who will have to be relocated should be assessed. and appropriate measures adopted.

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0 Conservation of the historical or cultural heritage is to be taken into consideration Q Women in development must be taken into account.

4. Others 0 A project shall be carried out in such a way that it will not have any considerable adverse effect on the environment during the construction period. 0 When considerable project environment impacts are expected. adequate environmental monitoring shall be carried out.

3.3 Interested and Affected Parties (IAPs)

IAPs affected. either positively and/or negatively, by the proposed Montagne .lacquot development were identified as follows:

1. Land Owners: Planters/Sugar Cane Owners. Other Land Owners 2. Water Consumers ( industries and agriculturalists in the Study Area etc.) 3. Neighbouring residential communities (Bain des Dames. Pointe aux Sables. Montagne Jacquot) 4. Government agencies (water quality - CWA: waste waters - WW.A: marine resources - AFRI) 5. Government Ministries (MEQOL) 6. Non-Government Organisations (NGOs) (Friends of the Environment. MMCS etc)

During the Scoping Phase of the EIA a number of groups and individuals in the public and private sectors were consulted about the proposed development (Table 3.1 ). A formal record of the Scoping Sessions and the principal issues and concerns raised by each group/individual is provided in Appendix H. Additional scoping sessions were conducted in the communities currently worst affected by the existing waste water discharge arrangements. The issues raised in community meetings are also summarised in appendix H.

3.4 Land Acquisition

Land will be required for construction of the various components of the Montagne Jacquot sewerage project.

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Table 3.1. List of IAPs interviewed in the scoping sessions.

[AP Categorn Person Intervewedt Capacist (tintact Tei ius.

Nlinistrs of Enivironment ant Qualit, of Life Mrs D.S.Lan-Ne Y iii Wine Divisionial Eiiviroitneiital Office 212 K.K.Heeraiitin Eniviroimest Office 2 2 * 311 Nlinistv for Public Infrastructure W isle WatelW,t tAwir, Mr R t guillot Director '4'1(44J Ninstrn of Economic Plantning & Development MrR. Parboieali Econiomisi * 2

Nliinisr, of l (;vernnnentG.i:cat and Puiblic I tilites Dr H R Shainna Heiad Water Rveotiirce1 I lintlt Mfinistrv of Health Mr L Hormaiu Prinal Saitiar, Eieinieer 'It Nliiiistrv ef Agnculture and Natural Resources Matritiis Suigarliidistrv ResearchInstitiute Mr. D Ah-Kooi Head. Impatioti Depatiment Mr 1. Jliotn Head. Lauid Resources Di%isio_ liinistrv of Fisheries Aliitin Fisienes ResearchCenitre Mr V Chiorah Divisioinal Scititific Officer 238 49'9 ______D G xisrah Divstioiial S intrific Officer '3 4485 iminstrsof Housing. Lands and Town Miss K.Y Kioo Lain Tseaii Principal Towsn& Coinirs 25'o28;1 and ( ,itrs- Plannll'.* 1`__latiiiie O)tfice Nliiiistn of Indusirs and Industnal TechnoloM% Liiort Procession Zoic Developinent Atllonts Daitlle WoiiL Director 2 I Exprt i esehopmnentand Investineti Antbontv S. Soondrunt Deputy Directo)2 '5 1 'isdlore GCinadlitir Mananel 2i18'5t Ministrv of Tourism

lmninstrsof Ellucatinn anti Sciences Ihii,,ersits ol rotessorlF:ieeiiiiee Deani FacuitV nt'Scieiice 4t)4'I95

trrieaniinC,ii'tiiriin'uii .sumnorur illicaeasacstoc Dahseesioi, ivestiizattoiitresearlil soecialisi 212.

llauritius Chamber of Agriculture HaiareeJtwalhcer Econontsit-Statisticiaai 2(18V812 La__re:ce Poissoni Assistant Secretars 2081)812 Usater I sers Associftion of the %4estern C'oas Me Si"arSoigi Estate _Mr D'AriEn A^isn:rjsti es Peeheurs _ elioti Jackitt ______A,oiiiflihonil )PV,oisheurs

NlIauri,iius Martnie Cnnsei-satin SoejeyD hiiteI Htye Laionivifere 'inii dro 1

Fortierthe_1 Muistr- of/ EIeti;' anitNWater Resources

Black & Veatch International Policy,legal and administrativeframework AJonragneJacquot Sewerage and Sanitation Project Environmental Impact .lssessment

* The Montagne Jacquot WWT plant will be located on a vacant section of land southwest of the Petite Verger prison. as shown in figures 1.1 and 4.8 at the end of this report. The land is owned by several individuals. and will have to be purchased from those individuals.

* The new pumping stations at Fort Victoria and Pointe aux Sables will be constructed on the grounds of the existing treatment works. No additional propertv will be required at these locations.

* The site access road and the transmission mains route from Fort Victoria to the Point aux Sables works and from there to the Montagne Jacquot site (alternative I see section 2) were located to the maximum extent possible along existing roadways within the rights-of-way, and across property owned by the Government of Mauritius. or controlled by parastatal agencies such as the Development Bank of Mauritius. Although the final alignment of the transmission mains has not been established. the transmission mains will not cross any propertv occupied b% a residence along any of the altemative alignments. so no displacements will be necessary.

* Alon(Tone of the alternative .transmission main alignments and along the access roads to the new WWT plant site.. the new works will affect property owned by either individuals. companies or institutions. The Waste Water Authoritv will purchase way-leaves for construction of the pipeline and access roads across these properties.

3.4.1 Land Acquisition Procedures

Land acquisition by the Government of Mauritius can be carried out in two wavs:

* Private Agreement * Compulsory Land Purchase

3.4.1.1 Private Agreement

The Ministry of Housing and Lands is the agency responsible for land acquisition for the state. The first step in the process of land acquisition is for the agency that needs land to provide a legal description and survey of the property required. The Ministry of

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Housing and Lands then completes a title search to identify the owners of the property. and starts negotiating with landowners after completion of the title search.

3.4.1.2 (ComprulsorvLand Purchase

If necotiations with landowners fail or if the purchase involves long strips of land with numerous individual landowners. the Government may find it expedient to proceed by compulsory purchase under the provision of the Land Acquisition Act. For compulsory acquisition the Government proceeds with the issue of two notices as follows:

* Notice under Section 6 After the owner of the land has been identified. a notice under section 6 of the Act is served on the owner to notifv him of the Government's intention to acquire his land for a public purpose. This notice should be published in two issues of the Government Gazette and two daily local newspapers within seven davs interval between the two publications. This in effect gives the surveyor and engineer entry to the land to complete all survey works as well as site investigations.

* Notice under Section 8 After procedures under Section 6 have been completed. a Notice under Section 8 is published and served on the landowner. This notice is published in two issues of the Government Gazette and two daily local newspapers within seven days interval between the two publications.

A Section 8 Notice can be,served immediately after a Section 6 Notice. In practice. there is always a time lag between the two Notices so as to allow the Land Survevors to complete survey reports and drawings. The Govermnent gets a clear title to the land upon transcription procedures of the Section 8 Notice at the Registrar's General's Office. The transcription procedures take approximatelv one to two months. Government officers and Contractors have entry to the site once govemmeni obtains title to the land.

3.4.2 Pavment of Compensation

Once the notice under Section 8 is served. the dispossessed owners submit a claim for compensation to the Ministry of Housing and Land. Government valuation officers assess the amount of compensation to be paid by the Government. If the negotiations

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between the two parties are successful. the government pays the agreed compensation to the owners after the signing of a deed of acquittance prepared by a notary.

However. if there is no consensus in the negotiations. the matter is referred to a Board of Assessment under the provisions of the Land Acquisition Act. The Board of Assessment consists of a chairman appointed by the Chief Justice and two members appointed bv the Ministrv of Housing. The 4ward of the Board of Assessment is final. However the dispossessed owner can still appeal to the Supreme Court of Mauritius if he believes the compensation awarded is insufficient.

3.4.3 Wayleaves

For wayleaves. the procedures as described previously are applicable.

3.4.4 Time Frame

For the Montagne Jacquot Sewerage Project all surveys (cadastral. etc.) will be completed within two months. Once all the necessary documents have been submitted to the Ministry of Housing and Lands. it takes about 3 months to complete all procedures under the Land Acquisition Act before title is transferred to the Government.

3.4.5 BuifferZones

In order to protect the public from potential exposure to nuisance conditions and to reduce the possibility of complaints regarding the operation of the Monta-ne Jacquot WWT plant. buffer zones of 200 m and 400 m will be established around the perimeter of the WWT plant site. This buffer zones will be identified on maps filed with the Ministrv of Housing and Lands. and activities within the buffer zone will be controlled through the use of zoning restrictions and permits. The kinds of activities that will be prohibited within the 200 m buffer zone include all developments which would result in regular or prolonged activities by individuals or groups. such as residential housing. churches. schools. offices. and certain industries. Activities beyond the 200 m buffer zone. but within the 400 m buffer zone would not be prohibited. but all land owners would be advised of the presence of the WWT plant and the potential for nuisance conditions arising from plant operations. Activities which would be permissible within the buffer zone include developments which require only occasional visits or those *Ihich would employ only a few individuals and require large space. such as

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agriculture. livestock operations, automobile wrecking yards. or warehousing. Other activities would also be permitted in which individuals could choose to participate. such as recreation at the sea shore. picnicing. hiking. or camping.

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7- Monlagne Jacquot Sewerage and Sanitation Project Environmental Impact .4ssessment

SECTION 4

DESCRIPTION OF THE AFFECTED ENVIRONMENT

BlacA& Veatcl International Descriptionof environment i; Montagne Jacquo! Sewerage and Sanitation Project Environmental Inpaca 4ssessmeni

4.0 DESCRIPTION OF THE AFFECTED ENVIRONMENT (Padya 1984; Proag 1995; NPDP 1995: SOGETI 1995)

The Study Area for the environmental impact assessment consists of the drainage area to be serviced bv the waste water collection system i.e. the Port Louis Sewerage Svstem which includes the built-up areas of Port Louis South. Cassis. Belle Village. and the Plaine Lauzun Industrial Zone (see Figures 1.1 and 2.1). The eastern boundary is at Pointe aux Caves on the coast southwards to the road going to Albion (near Canot). the southern border includes Vuillemain. the western border includes the drainage area of Tranquebar. and the northern border is the coastal harbour area of Port Louis. The Study Area includes sections of four of the nine administrative Districts: Black River. Plaines Wilhems. Moka. and Port Louis.

4.1 Physical Environment

4.1.1 Topography, geology and soils

Topography In the Study Area. the western part (west side of the Grand River North-West - GRNW) descends gradually from an altitude of about 230 m. characterised by undulating uplands surrounded by mountain ranges. down to the coastal plain at Montagne Jacquot. The proposed WWT plant at Montagne Jacquot is located 10 to 30 m above sea level (see Plate 4.1 and Figure 4.1). To the east of the GRNVWis the Port Louis CBD. surrounded by mountain peaks. The highest point of these mountains is the peaks Quion Bluff and Speargrass Peak. with a maximum height at Junction Peak of 350 m asl.

GeolSgy Except for the beaches. the coral formation of the reefs and limited extents ot alluvium (e.g. estuary of Black River). Mauritius is entirely volcanic in origin. The western part of the Study Area is comprised of intermediate aged lava (3.5-2.0 mvo) whilst the outcrops and area around Port Louis is old lava (6.2-5 myo) (Figure 4.2). This area forms the Curepipe groundwater basin which is made up of basalt lava flows.

At 5mva a relatively calm period (1.5 my) occurred during which intense erosion took place. after which a younger volcanic series arose. Of this younger series. which consists of early. intermediate and late lavas. only intermediate lavas are found in the Study Area. These consist of grey granular-textured alkali basalts i.e. doleritic

Black & VeatchInteriiatonal 4.1 Descriptionof tIle envirtonment MontagigneJacquor Sewerage and Sanitation Project Environmetital Impact .. ssessment

basalts). The agglomeratesare composedof pebbles of olivine basalt set in a matrix of scoria and ash. There is a smallportion of sandy coast at Pointe aux Sables. which is predominantlybasalt boulderswith pebble areas between the boulders.but with a few small sandy areas (see Plate 4.2).

.Snil.s As the volcanic rock weathered.fertile soil was formed in manv areas of the island which formed agriculturallyimportant soils, and since the Study Area falls into the subhumidclimatic zone of the island. the soils are mainly lowland humic soils. but also shallow stoney soil and dark clay soil inland of Port Louis (Figure 4.2). Low humic latosols(zonal soils)occur in the subhumidand lower rainfall zones - in areas with a distinctdry season. The depth of these soils varies from about 60-100 cm with good internal drainageand low organic content. The beach area at Pointe aux Sables is comprisedof beach sand.

4.1.2 Climate

The Study Area falls into the Northwestclimatic zone. which is within the subhumid part of Mauritius. In general.the wettest months in Mauritius are in Februarv and Marchwith the rainy season ranging from Decemberto April and the dry season from Septemberto November. The high summer rainfallsarise from low pressure troughs. weak depressionsand occasionaltropical cyclones passing over the island. e.g. a total of 812 mm of rain has been recorded in 24 hrs as a result of a tropical cvclone. Localisedfalls of high intensityalso occur during thunderstorms. Droughtconditions do occur occasionally.particularly in the subhumidzone.

Ruin/atll The average annual rainfall in Mauritius varies from 1 300 mm on the east coast to 4 000 mm on the Central Plateau.and is 900 mm on the west coast. The Study Area therefore has an average annual rainfall of less than I 000 mm (the annual rainfall exceeds 1 000 mm only once in 4 years) - the Line Barracks rain gauge near Port Louis has an averageannual rainfall of 946 mm. The coastal section where Pointe aux Sables and Montagne Jacquotare has an averageannual rainfall of 800 mm.

Rain gauges in the StudyArea are at Richelieu (67 m altitude) near Petite Riviereand Fort William (6 m altitude) near the Fort Victoria Sewerage Works (see Figure 4.1) - the monthly rainfall from 1951-1980 is shown in Figure 4.3. The highest rainfall

Black & VeatchInternational 4.2 Descriptionof tlheenvironment Mo,toaguieJacquot Sewerage and Sanitation Project EnvironmnenitalImpacr .4ssessment

occurs during summer and autumn i.e. December to March. and the lowest in winter and spring i.e. May to November

Lon- term rainfall trends (1960 - 1990) are such that abnormally wet periods (1 - 3 years) tend to be balanced by dry periods (up to 10 vears). Maximum daily rainfall is important to consider since it may give rise to local floodin< because drainaiŽeoutlets and sewer systems cannot cope e.g. in the west the max. daily rainfall is 150 mm with a return period of 3 years. The mean annual evaporation in the western coastal areas is more than 1870 mm.

Richelieu _ Fort William _ Fort Wiliiam 200) 30)

-150 20 = 100~~~~~~~~~~~~~~~~~~~~~1 =~~~~~~~~~~~~~~~~~~~ 1250

< &r - month

Figure 4.3. Mean monthly rainfall (1951-80) at Richelieu and Fort William, and temperature (1958-75) at Fort William.

Winds The prevailing winds in Mauritius are the South East Trade winds which blowNin a ESE direction over the island, with speeds of 1-25 knots. Tropical cyclones blowvover Mauritius. particularly between Januarv and March. with wind speeds up to 256 km/h recorded. and average speeds of 166 km/h. Over the last 30 year period. a total of 24 cvclones occurred i.e. one cyclone every 1.3 years. The impact of these cyclones. in terms of rainfall on the island varies at different locations e.g. from the same 30 vear period relevant to the Study Area rainfall recorded was: max in January 1980 Cyclone Hyacintha) was 612 mm at Fort William. min in March 1970 (Cvclone Louise) was 27 mm at Fort William.

The June-Julv 1994 wind rose for Fort William indicates a dominant easterlv/south- easterlv wind of > 1Om/s during winter. but also an occasional north-easterlv wind of < 6 m/s (SOGETI 1995. Figure 4.4). The autumn wind rose (March-April 1995)

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indicates a more dominant easterly wind (8-10 m/s). but still with a relatively dominant south-easterly component. Occasionally the wind blew northerly. north- westerly. and westerly but never more than 6 m/s.

Temnperature The mean annual temperature in Mauritius does not varv much - at Fort William 0 between 1961-70 = 24.8°C. 1971-80 =25.7 C: max temp

4.1.3 ThieAquatic Environments

4.1.3.1 River catchments

Mauritius is divided into 25 main and 22 minor river basins. each corresponding to a main river. The catchment areas relevant to the Study Area vary from 15 to 1 5 kmn and consist of two major and two minor river basins. The largest major basin is the GRNW catchment which covers 114.57 km and consists of the followingTrivers: GRNW. River Moka. River Profonde. River Cascade, River Terre Rouge. River Plaines Wilhems. and River Seche.

In the Study Area. the main river is the GRNW with only the branching off of the River Plaines Wilhems and River Moka being seen (Figure 4.1). East of the GRNW the St Louis basin covers a small area (14.51 km2) and consists only of the St. Louis Stream. The Port Louis area is a combination of the St. Louis and Tombeau basins and covers a total of 52.23 Ikm . The Study Area only includes a small section of this basin. The River Tombeau is the main river in this area with a few smaller streams running into the harbour.

West side of the GRNW is a section of the Belle Eau/GRNW basin with the Belle Eau River beimz the main river (Figure 4.1). Other small streams and canals are also present in this part of the Study Area. The Pointe aux Sables and Montagne .lacquot areas are within both the GRNW and the Belle Eau (18.06 km2) basin and receive water from a number of water tanks in the area which are ultimately fed from La FermneReservoir via the La Ferme Canal i.e. no actual rivers in this area.

4.1.3.1 Surfalce and groundwater supplies

The domestic water supply in the Study Area is from the Port Louis water supply svstem (PLS) which includes the southern suburbs of Pointe aux Sables. Petite Riviere. Pailles etc. Rainfall is the only source of water on the island and provides

Black& Iratcb International 4.4 Descriptionof tie environment Monittagne Jacyuot Sewerage and Sanitation Project Environmental Impact Assessment

water for the PLS in the following forms: surface water (58.29 m3/d) and groundwater (38.50 m3/d). which gives a total of 96.79 m3/d. There has been a piped water system in Port Louis for nearly 200 years which is presently controlled by the Central Water Authority (CWA). The main source of surface water for the PLS is the Grand River Nortlh West at the Municipal Dyke (see Figure 4.1).

Ground water levels fluctuate seasonally due to recharge from rainfall and irrigation and discharge from pumping. Mauritius is divided into four main and three small groundwater basins. The Study Area occurs in the northern section of the Curepipe basin. The Curepipe basin extends from Curepipe Point to meet the coast from the north of the River du Rempart to the mouth of the GRNW. with an overall slope of 3.5%. Surface and groundwater drainage is to the north-west of this basin. The quality of ground water in the Study Area is:

0 predominantly soft water (pH 6.7 - 7.3) but with an area of hard water (pH 7.5) 0 low calcium levels (iso-calcium = 19.2 - 21.2 mg/I) 0 iso-magnesium predominantly below 15 mg/l with a value of 19.7 mg/l inland of the Study Area 0 total hardness i.e. Ca and Mg content, is below 95 mg/l which is in the category of "moderately soft water" by the CWA (hard water is 200 -300 mg/l).

4.1.3.3 Irrigation

Water demand for irrigation is increasing and varies according to weather conditions. The Western coast irrigation system extends over about 4 000 ha of coastal plains. 2 500 ha being served by furrow irrigation and 1 500 ha by overhead and drip irri-ation. Water is distributed via concrete canals and a few earth canals. An annual volume of about 60 Mm3 would be required to satisfy the irrigation needs of the total area. This system is operated and maintained by the CWA but water deliveries are often not necessarily in synchronisation with crop requirements and irrigzation efficiency declines accordingly.

The La Ferme Reservoir has a capacity of 11.9 x 10 m3 and mainly receives water from its own catchment. The La Ferme irrigation system covers the western part of the Studv Area and covers approximately 1 317 ha. The water from this reservoir is distributed to this area via the La Ferme Canal. This system has access to a number of springs (e.g. St. Antoine. Le Bosquet) which supplement the shortfall from La Ferme reservoir. There is a small-scale irrigation project at Pointe aux Caves.

BlacA& Veatcht International 4.5 Descriptionof thjeenvironment Montagne Jatcqluot Sewerage and Sanitation Project Environmental Impact -As.sessmenh

4.1.3.4 Water pollution sources

Water pollution arises from either "point" or "non-point" sources. In the study area waste waters from industry. commercial and domestic sources are discharged to the sewage collection system. transported to the works at Fort Victoria and Pointe aux Sables and discharged to the sea through outfall pipelines which terminate in shallowA water. with no diffusers to aid in dispersion of the effluent. These are the principal sources of water pollution in the study area.

Non-point sources are also major contributors to water pollution in the study area. and include agrichemicals from agricultural land. and storm water runoff from the community. In addition. the water pollution problem in Mauritius is exacerbated during periods of high rainfall. Since the sanitary sewer system does not have the capacity to transport increased volumes of waste water which result from inflow of rain water. sewers can overflow, discharging waste water into open water courses.

The Montagne Jacquot sewerage project will provide relief from point sources of pollution at the Fort Victoria and Pointe aux Sables sewer outfalls. The new treatment plant will remove significant quantities of pollutants from the raw waste water before it is discharged to the sea through the new outfall.

4.1.3.5 T/he marine environment

Coastal currents are mainly dependent on the Great Southern Equatorial current flowing on an east-west axis. so that the currents on the west of the island have a north-south direction during the wet season (Dec to April) and a south-north direction during the drv season (June to October). The drogue studies carried out by SOGETI (1995) in relation to the proposed outfall site confirmed these general trends. with drogues moving offshore in a westerly or southwesterly direction in December. and offshore in a northerly or north easterly direction in June (Figure 4.5).

There are two main tvpes of waves affecting the western coast of Mauritius: those which are generated by storms out in the Indian Ocean. and more locally generated waves. caused by the passage of tropical cyclones. Cyclone-generated waves can reach heights of 13 m and since the west coast of the island is very steeply shelving and deep water is reached quickly. only waves approaching at oblique angles to the coast are likely to be affected by the shoreline.

Black & I4eatchinternational 4.6 Descriptionof thieenvironment MontagneJacquot Sewerage and Sanitation Project Environmental Impact Assessment

The strengzth and direction of currents vary according to wind direction and tides. which are semi-diurnal with a weak amplitude. The tidal regime for Port Louis and environs are characteristic of an open ocean svstem with relatively small amplitude variation e._z.min and max levels recorded for September and November 1995 were - 0.39 m to 0.38 m relative to mean sea level (CSIR 1996).

During the SOGETI study (June to March 1994 - 1995). current measurements were carried out just off Pointe aux Caves. at 30 m depth and varied between 0.1 - 0.15 m/sec with the direction changing according to the tide from north east to south west. Similar and equally feeble current speeds were measured off Port Louis during the CSIR studv ( 1996) and were only greater than 0.25 m/sec for less than 1% of the time and principally from the north. Existing information on current speeds and direction is very limited and insufficient to reflect the annual ranges. or even diurnal variations in the study area. However. measurements carried out by SOGETI off the proposed outfall site suggested that the circum-insular currents do not affect the inshore coastal waters significantly. and so should not be included in the hvdrodynamic model.

Water quality measurements taken in the sea during the SOGETI study (June and December 1994) close to the proposed outfall site indicated ranges for key parameters as follows:

0 conductivity ranges from 3 000 mS/m and 4 1OOmS/m; 0 turbidity from 0.0 to 5:2 NTU depending on currents and presence of effluents: 0 pH in June was 6.5-7.4. and in Dec the pH was 6.3 - 6.8; 0 dissolved oxygen was 65 - 70% saturation; 0 temperature in summer was 270C summer and 25.50C winter: 0 faecal coliform was < 1/lOOml.

These ranges of values were used to carry out the hydrodynamic modeling at the outfall site.

4.2 Biological Environment

The baseline conditions for the terrestrial and marine environments that might be affected by the proposed developmentare described in this section.

Black & VeatcihInternational 4.7 Description of tile environment M/onitagne JacqiowSewerage and SanitationProject Environmental Impact Assessmlent

4.2.1 Terrestrial Environment

The remoteness of the Island of Mauritius, and it's characteristic micro-climates. led to the evolution of plants and animals unique to the island. However. very little of the indigenous vegetation and fauna still exist today and most are concentrated in 16 nature reserves found in the southern part of the Island. green natural areas and the Black River Gorges National Park (NPDP 1995). The closest nature reserve to the Study Area is Le Pouce - which just outside the eastern border of the Study Area.

4.2.1.1 Fwiiinal

The only mammals indigenous to Mauritius are two species of fruit bat (one of which is now extinct and the Mauritius fruit bat). although monkeys, hares. mongoose. and deer exist, thev are introduced and occur mostly in hunting reserves or inland forest. Mongooses were introduced to the Island from India to help control the populations of rats. The only snakes are the Indian wolf snake. and two species of boa constrictor.

There are only nine indigenous bird species left in Mauritius. 16 of which have become extinct (including the dodo). e.g. the Mauritius cardinal (Foudia rubra). the flycatcher (Terpsiphone bourbonnensis). the cuckoo shrike (Orancina fvpicus). and the Mauritius kestrel Falco punctatus. The most common endemic species is the tic-tic Zosterops borbonica. which has adapted well to a man-made environment.

Since the land in the Study Area consists mainly of built-up urban areas and agricultural land (predominantly sugar cane). the likelihood of natural fauna occurring there is minimal and therefore would not be affected by the proposed Montagne Jacquot Project.

4.2.1.2 1egelation (Dr.J Gueho, MSIRI).

Less than I percent of the area of Mauritius is covered by indigenous vegetation which occurs mainlv in the Black River Gorges National Park. The original vegetation in Mauritius consisted of palm savannah along the coast. low altitude Diospyros forests. and Sapotaceae forest on the plateau. In the Study Area. the mountains around Port Louis are the main green area consisting of scattered scrub and a small section of planted forest (see Figure 4.7) but with no natural vegetation.

BlacA & Veatcit International 4.8 Description of lite environment 'IMontagneJacquot Sewerage and Sanitation Project Environmental inpact Assessment

Since the Study Area has no more indigenous vegetation and is mainly land converted for agriculture or built-up areas. the proposed development will have no impact on any natural vegetation resources. The site allocated for the new WWT plant. adjacent to the Prison at Montagne Jacquot is covered by secondarised' savannah grassland dominated by the grass Heteropogon contostrts and scattered swards of Themediadilui with a few isolated trees (e.g. Pithecellobium dilui) (see Plate 4.3). Appendix J summarises the species present on the site. which include occasional weeds and naturalised woody species e.g. Tephorsia perpuria. Waltheria indica. Leucaena leurotphalu,Lantana camara. Setaria. and Trichodesma zeylaica.

Stunted isolated examples of Albizia lebebeck and Flacourtia indica occur. and the presence of the climber. Passiflora foerida. a passion fruit plant was also noted (Plate 4.4). Rare on the site was Ziziphus mauritiana. a low tree 2-3 m high. with the following plants being occasional: Tribulus terristris. PhYllanthzs ul-inariza (a medicinal plant), Melochia pyrmidata. Boerhavia coccinea. Ageratum cornloides Euiphorbia hirta. Cassia tora (Plate 4.5), Wikstroemia indica. Panicum maxinmum (in isolated swards). Amaranthus hvbridus. Dacrvloctenium ctenoides. and a izround creeper Ipomoea obscura.

The area which has been proposed for the new WWT plant at Montagne Jacquot has no conservation value whatsoever. mainly because of the secondarised vegetation present on the site.

4.2.2 Marine Environment

The weathering action of waves. tides. hurricanes. and flooding have created diverse coastal habitats with numerous beaches. lagoons. bays, rocky shores. and scoured river mouths. Several surveys have been taken of these coastal ecosvstems (Hodilkin 1959: Hodgkin and Michel 1963: Fagoonee 1990).

4.2.2.1 Roc4- shore intertidal zone:Pointe-autx-Caves to Montagne Jacquot

The intertidal zone from Pointe aux Caves to Montagne Jacquot is exposed to the full impact of wave action. since this stretch of coast is not protected by a barrier reef - like the beach at Pointe aux Sables. This section of rocky shoreline is significant since the proposed outfall pipeline will be built through this section of coast

establishedafter original vegetationwas removed

Black A Veetc/r International 4.9 Description of tile environment 1ontitgire Jaacuot Sewerage and Stanitation Project Environmental Itnpact .Assessment

The rockv intertidal zone at Pointe aux Sables has been studied 2 and comprises three littoral zones with characteristic fauna and algal zonation pattems (Table 4. 1). The supra-littoral zone is the highest zone on the shore and is never immersed. Gastropods. such as Littorina mauritania are abundant in the cracks of the rocks and since the splashes from the waves still reach this zone. patches of algae. such as Eciocarpus are present.

Table 4.2. Composition of the rocky intertidal zone between Pointe aux Caves and Montagne Jacquot. IntertidalZone || Features Fauna j Algae Supra- highestlevel. never gastropodse.g. Litnorina greenand brown

littoral/splash . submerged mauritiana. algae speciese.g. zone isopodse.g. Geograpsuslividus. Ectocarpits gastropodse.g. Tectarius granularis Mid-littoral MHWto MLW' barnaciese.g. Chthumalus dentatus. molluscse.g. Siphonaria ferruginea, Cellana cernica chitons e.g. Acanthopleura borbonica Sub-littoral MLW-LWS' blenny, Alticus monochrus encrustinmred urchinse.g. Coloboscentrus algaee.g. LithithaiUmionspp. 'MHW- Medium hith water. MHL- Medium low water. LWS- Low water springs

The mid-littoral zone is semi-submerged and is characterised by a covering of small barnacles (Chhtamalus dentiatus) the densities of which decrease with increasing exposure (Plate 4.6). Molluscs (e.g. Siphonariaferruginea. Patelles spp.) and chitons (Acanthopleura borbonica) are also found in this zone.

The sub-littoral zone is usually covered in water. except during spring low tides. High densities of the urchin Colobocentros are found here and mats of encrusting algae (e.g. Lithothamnion) An abundance of the intertidal blennv. Alticus monochri-.s. was also observed on the field visit to Montagne Jacquot (Plates 4.6. 4.7 and 4.8).

- Dr Bikajee. UniversitNof Mauritius

Black A& eatch International 4.10 Descriptionof thleenvironment Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

4.2.2.2 (oastal waters

Most of the coastline of Mauritius is fringed by coral reefs. and consequently the coastal waters in these areas are calm since the sea is enclosed in lagoons. The coral reef in the Studv Area is part of the peripheral fringing reef which is a narrow rim (less than 25 m wide) cut at intervals bv surge channels and narrow breaks or large passes. such as at the harbour entrance and the GRNW river mouth at Port Louis (Figure 4.5) (SaIm. 1976).

The coastline off Pointe aux Sables (± 4 km) forms a sheltered lagoon with a fringing reef approximately 1 km from the coast (Figure 4.5). At the southern part of Pointe aux Sables the fringing reef curves inland and almost closes off the lagoon. South of this point. between Montagne Jacquot and Pointe aux Caves. there is no fringinc reef and the seabed drops off to a depth of 50 m within about 700 m from the shore. The seabed in this area consists of volcanic flagstone with a thin laver of coral. which is a buttress-and-valley zone of volcanic origin (Faure and Montaggioni 1971).

The following is a brief description of the present state of marine life (and sources of information) at different sites in the Study Area: Fort William to Fort Victoria (ERM 1995. pers obs2 ); Pointe aux Sables (SOGETI 1995: ERM 1995: pers obsi. Montagne Jacquot (AFRC survey. pers obs.): Pointe aux Caves (SOGETI 1995).

Fort William to Fort Victoria (ERM 1995. pers obs) From Fort William southwards the fringing reef is still intact although it is covered by a dense algal mat. This reef is comprised predominantly of dead corals and thick sediment deposits and with some fish life (e.g. rockcods). a few sea urchins and calcareous algae (ERM 1995). The diving surveys by ERM in this area noted the presence of raw sewage and solid wastes floating in the water.

The impact of raw sewage effluent on the marine environment in this area is self evident. with sewage sludge and debris deposited on the shoreline between Fort William and Fort Victoria (Plate 4.9).

Pointe aux.Sables (SOGETI 1995: ERM 1995; AFRC survey June 1997: pers obs.) The diving surveys done by ERM (during 1994) in the Pointe aux Sables indicated a gradient in the condition of the barrier reef and the lagoon from north to south. In the

persobs.. personal observations bv BVIEnvironmental Consultants.

Black& J'eatchInternational 4.11 Descriptionof the environment MElontagneJacquof Sewerage and San,itation Project Environmenttal Impact ."sessment

northern section. near Port Louis. live coral cover was poor (0 - 5%) with hard corals and verv few fish. Dead coral rubble covered in brown algae was very evident with nil visibility. The low visibilitv was mainly due to sediment input from the GRN'W. The southern section of the reef was in a better condition with verv good visibilitv and abundant fish life (e.g. damsel fish. goatfish. eels. wrasses etc.). The percentage live coral ranged from 50 to 80% in most places. with no visible signs of pollution. However. the percentage live corals decreased rapidly from the south end to the middle of the reef. where the Pointe aux Sables outfall is present.

The SOGETI diving surveys (during June/July 1994 and March/April 1995) similariy reported the poor state of corals. extensive growth of algae. proliferation of herbivorous urchins. and the disappearance of fish populations. particularlx in the northern section of the lagoon. In addition. the trend towards improvement in the coral reef communities from the Pointe aux Sables outfall southwards is also clear. although the condition of corals on the external slopes of the reef is clearly still quite poor with high percentages of necrosing or already bleached corals.

The nearest site to the proposed outfall surveyed by the SOGETI was transect TRI. some 300m short of the Pointe aux Sables headland. At depths around 7 - 10 m hard corals were relatively uncommon and mainly represented by massive PoriteLs(of the luiea - lobata) group. Pocillopora eydouxi. and some plate forms in the process of necrosing. At higher levels, corals were more abundant (20 - 40% cover) but many of the colonies were moribund or necrosed and sometimes crushed. As well as the Porite.s spp and Pocillopora spp. noted at greater depths there were several species of Acropora. but with onlv the extremities of their branches still livinLi. Alcvonarians (genus Sarcophyton) were dispersed and not particularly rare. whereas the urchins .SIomopneustex variolus and Echinus calamaris were common even abundant in some areas. probably attracted by the algal carpets. which are evidence of the elevated nutrient levels.

The impact of raw sewage effluent on the marine environment at Pointe aux Sables is also evident from the condition of the shoreline where extensive beds of algae (e.g. l;lvu) are exposed at low tide up to Ikm from the entry of the outfall into the sea. There are also dense accumulations of putrefying algae at high water level which add to the unsightly and degraded appearance of the beach (Plates 4.10a. b). The Pointe aux Sables reef and lagoon are currently being monitored by the AFRC. as part of their Marine Pollution Monitoring Programme. Recent photographs taken on 3rd June

Blact A JeatcI hiternational 4.12 Descriptionof theejivironment Uonfagne JacquiotSewerage and Sanitaation Project Environmental Impacr .-4s.essmem

1997 (Plates 4.1 la. b) indicate the degradation of the marine environment at Pointe aux Sables as a result of the sewage discharge from the Pointe aux Sables outfall.

Although the Fort William. Fort Victoria and Pointe aux Sables areas all show evidence of coastal pollution. the Fort William/Fort Victoria area is worse than the beaches further south. because of the accumulation of sewage in embav ments. overbearing malodours and the impact of both on the fishing communities operating there (see Section 4.3).

.Mlonta,gne Jacquot (SOGETI 1995: AFRC survey, pers obs.) The SOGETI study did not include a marine biological survey of the proposed outfall route at Montagne Jacquot. Consequently a diving survey to assess the extent and condition of corals found along the proposed pipeline route was carried out by the Marine Conservation and Pollution Monitoring Division of the Albion Fisheries Research Centre (AFRC) during May 1997, as part of the present EIA study. The main objective of this diving survey was to establish the extent of reef communities at the break in the fringing reef off Montagne Jacquot. and if corals were present. to identifv them and assess their current state of health. This would allow an evaluation of the suitability of the site for the proposed pipeline.

The methods used to assess the nature of the sea bed and the condition of the corals was according to the "line intercept transect" method (English et al. 1994). which is currentlv being used by the AFRC to monitor environmental impacts at various sites on the coast of Mauritius. -This technique assesses the sessile benthic community of coral reefs according to different lifeform characteristics (see Appendix H). which provides a morphological description of the reef communitv. Three dives were undertaken at 30 m. 13 m and at 8 m, and transects completed at both the 13 m site ( Stn 1) and the 8 m site (= Stn 2) and a photographic survey at 30m.

The GPS readings were taken with a Garmin GPS 95 Model. and corresponded to the approximate heading proposed by the SOGETI report and were: S207 10'22.1: E057'25'30.8. corresponding to 650 m offshore and 30 m depth.

In addition to the AFRC diving survey. and underwater video was taken along the whole length of the proposed outfall i.e. from a depth of 28 m up to = 2 m depths.

Black & Veatc* International 4.13 Description of tlheenvironment M1'oiitagneJ acquot Sewerage and Sanitation Project Environmental Impact Assessment

Results of AFRC survev Although the visibilitv of the water was bad (< 10 m) during the AFRC divin( survey. this is not always the case since on a separate occasion (2 weeks previously) the water visibility was considerably clearer (up to 15 - 20 m visibilitv. pers obs.). Based on a Visual assessment. a description of all the diving survevs is summarised in Table 4.3. below and in Figure 4.6.

Table 4.3. Results of diving surveys based on visual assessments, carried out during April/May 1997 at Montagne Jacquot.

Type of dive GPS position' Date and Description

_ _ J tide l

Snorkel 26th April * water visibility: clear 15-20m (Dr.S.Harris near neaps * shallows (1-5 m): mainiv large boulders with & C. Little) patches of live coral and many juvenile fish e.g. goatfish. butterflv fish. moorish idols. wrasses etc. Some indications of pollution - "hazy" water. brown algal mats on sand patches *mid-depths (5-1Sm): flatter reef with grullies of sand in between. A thin layer of corals (live) on the flat reef was observed and a number of juvenile fish species e.g. boxfish. soldier. fusiliers etc.

AFRC dives 8th May

(Dr. Kawazaki . . springs & team & S.Harris Dive I S200 10"22.1 * Max depth 30.5 m 0 E057 25'30.8 * the sea bed consisted of fairh tlat reet (max ht 2 m). with patches of sand (=3-5m in size) in places. * Type of substrata shown in Plates 4.12a-d': Live corals abundant and a number of juvenile fish present e.g. hawkfish. moorish idol, butterfly fish.

lDive 2 S20°10'31.6 * Max depth 13 m 0 E057 25"38.4 * the seabed was similar to the 30 m site: mostly flat reef but with occasional outcrops of reef (1-2 m high) with coral attached. Sand patches relatively dominant

Black A Veatchi International 4.14 Description of tle environment .liontag-ne Jqcziwol Sewerage eiurdSanitation Project Environmental Inmpac .Assessment

(210% of cover). l Macroalgae dominant. mostl\ live corals present (Plates 4.13a-b and Figure 4.6.. Stn I)

Table 4.3 cont. Dive 3 S20° 10'3 1.1 * Max depth 8.6m E057025'39.1 * high reef profile (up to 3 m). mainly fixed boulders * dominated by massive corals (31%). but also encrusting and submassive species. Macroalgae also present but to a lesser extent (5%) (Plates 4.14a-f and Figure 4.6). Underwater S20010"22.1 1ith May * From 28 m to I m depth: 26rn-lowprofile videodive E057025'30.8to 3 days after reef (±lm ht) 80-90% reef cover: 15m- shore springs algae on sand patches. 60-90°oreef cover: 5m-boulders (2-3m ht). 60-900o reef cover * Bad visibility(max 8m) * Substrate initially fairlx flat becoming more boulder-likein the shallows ! Only juvenile fish seen e.g * In shallows (2 m). brown algal mats on sand patches * Along the whole length of the proposed pipeline route. a number of different coral species were observed and were mostl\ live corals.

GPS position was taken with a GarminGPS 95 Model.

From the visual assessments (Plates 4.12a-d and the underwater video) it was evident that the benthic communities at 30 m were basically the same as at 13 m (Station 1). Fish species. such as the halfmoon butterflyfish (Chaetodon lunula) and the coachman (Heniochus acuminalus) were present. and Fungia spp. corals were abundant.

The types of substrata at Station I (13 m depth) and Station 2 (8 m depth) are illustrated in Figure 4.6. At Station I the substrate was covered by less than 6% of rock and 21% sand. Macroalgae accounted for 3 7.5% of the substrata. in the form of algal mats - mainly on the sand patches. Live corals, such as encrusting (e.g. Porites spp.). massive and submassive corals (see Appendix K) were present. A small percentage of dead massive coral (< 2%) was present, whilst soft corals were relatively abundant (7.3% of cover).

Black & eatch International 4.15 Description of ilie environment Mantagne Jacquot Sewerage andSanitation Project Environmental Impact Assessment

At the shallower ± 8 m site. Station 2. the substrate was dominated bv massive corals (31%. Figure 4.6. Plates 14.14a and b). Other live corals present were digitate. encrustingand submassivecoral species. Macroalgalmats were also present but to a lesser extent than at 13 m. Rock and sand covered similar percentages of the substrate. Fish species noted. but not mentionedin plates were: shortspineporcupine fish Diodon litiurosus.whitespotted box fish Ostracion meleagris. a number of damsel fish Abudef:duf spp., freckledhawkfish Paracirrhites forsteri. soldierfish Mvlripristis spp.. neon fusilier Pterocaesio tile, and other fusiliers Caesio sp.. red fire goby .;Vemnaieloetrismagnhfica.

In summary.the combinationof underwatersurveys and video clearly demonstrated the nature of the seabed and the state of the sub-littoral marine environment off MontagneJacquot, the proposedsite of the ocean outfall. Althoughthe fringing reef breaks at this point. and the substratumis characterisedmainly by rock. sand and rubble, there is up to 30% coral cover at depths around 7m. which reduces to around 15-20% with increasing depth. Corals with associated infauna. encrusting sponges and algae. which are the predominanttaxa. are all common. ubiquitous species in Mauritius.with no rare. endangeredor even uncommonspecies identified.Because of the break in the fringing reef. and the exposed nature of the headland at Montagne Jacquot. only the most robust corals appear to survive, and this together with low species diversityis frequentlycharacteristic of impactedenvironments.

4.3 Socio-Economic Env;ironment

This section of the EIAR' describes the socio-economicenvironment in the Studv Area. The human population directly affected by the proposed Montagne Jacquot sewage and sanitation project is described in terms of composition. household structure and householdincome. The affected populationincludes the residentialand artisanalfishing communitieswhich live in close proximity to existing sewageoutfalls at Bain des Dames and Pointe aux Sables. and near the site of the new WWT plant at at MontagneJacquot.

Land use. land ownership.economic activities.industries. historical/cultural sites. and recreationalsites in the affectedarea are also discussed in this section.

Black & Veatct lnternation,al 4.16 Descriptionof thte environment A4'ontagn,e Jacqiow Sewerage and Sanitation Project Environmental Impact Assessment

4.3.1 Affected Populationiand community structure (NPDP 1993)

The population of Mauritius is divided into four types of ethnic groups: general population (includes the descendants of Europeans and the freed slave population). Indians. Indo-Mauritian (Indians born in Mauritius) and the Chinese. The estimated population size in June 1990 was 1 025 448. on a land area of 186 500 ha. with the growth per annum between 1983-1990 being less than I percent. This makes Mauritius one of the most densely populated agricultural islands in the World. with considerable pressures on land resources.

In 1983. the urban population constituted 41.7% of the total population in Mauritius but had declined by 1990 to 40.5%. The majority of this urban population (55.3%) is concentrated in the urban districts of Plaines Wilhems and Port Louis. a large portion of which is in the Studv Area for the proposed project (see Figure 1.1. Section 1.0). The public services and infrastructure in the Plaines Wilhems and Port Louis areas are therefore under considerable pressure.

The average household size in Mauritius decreased from 4.8 persons in 1983 to 4.4 persons in 1990. From the 1990 census, the proportion of the population in the age group 0-14 years was expected to fall from 29.3% to 27.8% in 1994. The working-age group has increased at a faster rate than the rest of the population. so that in the 1990 census 13 000 unemploved people were recorded. which is only a 3.2% unemployment rate. Women have become more active in the labour market with a consequent need for child care services and assistance with management of households.

Since the majoritv of the manufacturing industries in Mauritius are concentrated around Port Louis (see Section 4.3.3) it is significant that 34% of the projected emplovment in 1994 was in the manufacturing industry. and 41% of the working population were emploved in industry-related occupations (e.g. craft and related trade workers. plant and machine operators and assemblers).

These demographic trends have implications over medium and long-term trends e.g. there will be a fall in the school age population. with the result that health and other support services will require corresponding changes.

Black& Veatci,International 4.17 Descriptionof t e environment Montagne Jaccquot Sewerage and Sanitation Project Environmental Impact Assessment

4.3.1.I Communities affected by current arrangementsfor sewage disposval

The investication for the present EIA found that there is a strong awareness among the inhabitants of Bain des Dames and Pointe aux Sables as to the nature and extent of the pollution problem caused bv sewage and industrial discharges. The fishermen of both these communities are particularlv aware of the problem and have been active in voicing their opinion to government in the past few years. which has also often been reported in the local Press.

These media reports highlighted incidents such as the discharge of used fuel. detergents and chemical compounds (e.g. the Mauritian L'Express 30th May 1997 - see Appendix I). During heavy rains, effluent flows out of the Lataniers and Caudan River estuaries. and deposits garbage such as plastic bottles. dead animals. used water from dyeing plants. and rubber pieces into the sea.

Other media reports have documented the following:

0 Air pollution and sewage discharged from the chemical fertilizer factory in Bain des Dames. 0 The impact of untreated sewage effluent. particularly from the Tour Koenig Industrial Zone. is a threat to the marine life at Pointe aux Sables area ( 18th Dec 1994: 5th July 1995). The Society for the Protection & Conservation of the Environment (SPACE) noted that the rivers had been transformed into drains" for discharge of polluted effluents from the industrial estates. O The discharge of waste water from the housing estates of the Mare Gravier area. and the wastes of the Export Processing Zone of Coromandel. are being discharged in the sea hardly a few metres from the Pointe aux Sables lagoon (5th March 1997) 0 The presence of dead fish floating in the area of Bain des Dames and Pointe aux Sables has been reported on various occasions (11th Dec 1994. 25th Feb 1997).

The communities which are most seriously affected by the current sewage discharge arrangements are at Bain des Dames and Pointe aux Sables.

Poinie aur.Sables Community

The Pointe aux Sables area is referred to as the 'Debarcadere' area since a Sunday open market is held here and it is where the fishermen have a work post. There were

Black Veutchinternationui 4.18 Descriptionof tile environment .M1eontagneJaicqtiuo Sewerage andSaitiation Project Environmental Impact Assessment

about 3.800 residents in the Pointe-aux Sables communitv (1990 census). and according to unofficial information from the census office. some 4.000 residents in 1996. Most of the residents in the area fall within the skilled and semi-skilled categJories. with incomes ranging from Rs2000 to RsSOOOmonthly. The issue of obtaining more information on incomes. and more personal information relevant to this studv. is a sensitive issue in Mauritius. Incomes for example are regarded as a completely private atfair.

Community meetings/interviews. using an informal approach. were conducted duringt May 1997 on three different occasions with the fishermen of the Pointe aux Sables area.

0 At the first meeting. one spokesman for the fishermen described the present situation and the problems encountered at Pointe aux Sables. 0 On the second occasion. the area was visited and various people met and interviewed in Pointe aux Sable area so as to obtain the views of residents. 0 The third visit was on a Sunday morning. Sundav being market day. and thus more people would be readily available. It was an opportunity to obtain different points of view from the residents of the Pointe aux Sables beach area. includin- some of the youngsters. They were willing to relate their problems and also offered suggestions as to their expectations for their area.

The issues raised from these interviews and in community meetings are summarised in Appendix H.

Bain des Dames Communities

The Bain des Dames area borders the relatively calm bay near the mouth of the GRNW river mouth (see Figure 1.I). This bav is very sheltered due to the preserice of a strip of rock that was laid ten vears ago to support the existing sewage outfall at Fort Victoria. At the north side of the bay is the Port Louis Harbour and the Mer Rouge area. where a major land fill project has been carried out. In the bay a ship wreck is visible directly opposite Bain des Dames.

The Fort Victoria Treatment Works and a Central Electricity Board (CEB) oil turbine station are found at the south side of Bain des Dames. At the north side of the bav is a fish landing station which is near a sewer canal carrving discharge from inland sites (e.g. Cassis and Caudan).

Black & I'eatrc Internationul 4.19 Descriptionof theenvironment MontagneJo qcurotSewerage andSanitationr Project Environmental impact.4ssessment

There are a number of important public buildings. sites and residential areas at Bain des Dames including a Social Welfare Centre under construction. a football ground. a Green area designated as a recreational centre by MEQOL and a Hindu Temple (refer to Figure 4.8). In addition there is a housing estate (better known as -cite-) w,khichhouses 30 families. and other houses for + 200 families (I 000 individuals). The population at Bain des Dames was estimated at 450 (100 families) in the 1990 census. and according to the census office. may now even be reduced because of the insanitary conditions prevailing in the area. Most of the residents are working class e.g. manual labourers. but there are also about 70 fishermen operating in the area.

The impact of the sewage effluent is very evident in Bain des Dames - extensive eutrophication is occurring in the area indicated by the layer of green algae on the surface of the rocks (see Plate 4.9). accumulation of algae and rubbish (e.g. plastic bottles. material etc.) on the beach. The discharge of waste from the sewage works is exacerbated bv the presence domestic waste from the residential area of Cassis. The road from Cassis to the beach is boarded on both sides by an uncovered drain which is used as a general rubbish dump by the community. There is presently little being done by the Department of Health. Sanitary Dept.. to control domestic waste disposal into the drain. and this. combined with the impacts of sewage have resulted in the aesthetics of the area being completely destroyed.

Noise and air pollution from CEB turbine is another problem in the area. Residents have complained repeatedly to the CEB, and there is presently an active group pressurising the CEB to shift the station. The noise from the turbine is easily detectable in the residential area and causes constant vibrations within the houses.

Community meetings held at Bain des Dames during May 1997 resulted in a number of issues bein, raised. which are reported in Appendix H.

4.3 .1.2 Otfcilitrof life and economicprospects of affected communities

The sociological survey has highlighted the negative impact of sewage effluent on the living standards of communities in both the Pointe aux Sables and Bain des Dames areas. Both communities are suffering from diseases (e.g. skin and gastrointestinal problems) and extremely poor living conditions as a result of untreated sewage accumulating in embayments or being deposited on the beaches near residences.

Black & V"eatch International 4.20 Description of the environment Montagne Jocqitw Sewerage and Sanitation Project Environmental Impact -issessment

The decline in the fisheries in the affected areas is probably partly due to overfishing. but the situation is exacerbated bv environrmental degradation resulting from diverse non-point sources of pollution and decline in the overall productivitN of coastal ecosv stems. The economic prospects of the affected areas are unlikelv to improve until environmental degradation can be halted. and improvements in public health can be achieved. as the first steps towards improved quality of life.

4.3.2. Land use

The land use patterns in Mauritius during 1986 are shown in Table 4.4. It is clear that the dominant land use in the country is agriculture which comprises 48.3% of the total land area. Sugar cane is the main agricultural product (93% of all agriculture). with 35% of the land being occupied by forests. shrubs. grasslands and Lrazini lands. Note that only 1.3% of the land is natural forests. About half of the land in the Study Area is being used for sugar cane (Table 4.4. Figure 4.7) which is concentrated west of the GRNW and on the border of the Pointe aux Sables residential area. A small percentage of other cultivation (e.g tea) also occurs in the Study Area.

Table 4.4. Land use in Mauritius in 1986' Land use category Total Area [| j Studs Area~ (%x.)

.4grc,ulture 90 065 48.29 54 sugarcane 83 289 44.65 51 othercultivation (e.g. tea. tobacco) 6 776 3.62 3 Forests.shrubs, grasslands and grazing 65 330 35.02 20 lands plantedforests 6 774 3.63 3 naturalforests 2 388 1.27 savannah.grasslands. meadows etc. 7 446 4.00 scruband other forest lands 48 772 26.15 16 Buiitp areas v 25 500 13.67 22 Others(reservoirs. roads. rocks) 5 605 3.02 TotalIsland 186500 100 100 MEQOL 1991 approximateestimates

A small area of planted forest (i 3%) occurs in the Pouce Valley and near Guiby Peak (Figure 4.7). Other vegetation in the Study Area is the savannah grassland at Montagne Jacquot (see also Figure 4.8) which covers less than one percent of the

Black & Veatcl,lnternational 4.21 Descriptionof thteenvironment MaontagneJacqiwo Sewerage and SanitationProject Environmental Impaci Assessmenr

whole Stud- Area. and scattered scrub occurrinz on land not occupied by sugar cane or the built-up populated areas around Port Louis.

The residential area at Pointe aux Sables stretches along both sides of the main road travelling2parallel to the coast. The side bordering the sea consists of bungalows built in the 1970s. and the opposite side of the road is mainly occupied by older people. Some fairly neu- apartment blocks were built and were donated to the lower class by the GOM. These apartments are called the Cite housing estates and are behind the old residential area i.e. further from the sea. No new bungalows are being built at Pointe aux Sables since this area does not attract new investors or tourists at present4.

A wetland used to exist opposite the Debarcad&re (the market area at Pointe aux Sables) but has since been filled and buildings built over it.

The proposed spatial pattern of development and distribution of the major land uses are shown in Figure 4.7. Major new developments are concentrated in a limited number of locations, and in the Study Area. the following NPDP Planning Zones are relevant:

(I) Port Louis (2) Pailles (3) Pointe aux Sables (25) Beau Bassin and Rose Hill

A "Green field" development is a term used by the NPDP which is the use of presently undeveloped sites within built-up areas and inside settlement areas. in the Studv Area there is only one area identified as "available" i.e. vacantuncultivated. under utilised. marginal. poorer qualitv agricultural land i.e. Pointe aux Sables/La Tour Koeni. One of the strategic utilities proposals include the new sewage reticulation svstems with the off-site treatment and disposal facilities for Port Louis and Plaines Wilhems towns. which is the Montagne Jacquot Sewerage and Sanitation Project.

Other plan proposals in the Study Area include:

0 three separate 300 ha plots has been allocated as housing land by the Ministry of Housing. Lands and Country Planning. They are situated on a "Green Field" site at the edge of the existing Pointe aux Sables residential area (Figure 4.7 and 4.8).

Om Varma. Sociologist

Black& Veatachnternational 4.22 Description of the environment Montagne Jacquot Sewerage and Sanitation Project Environmential Imnpacr.Assessmene

100 ha of this land is situated behind the prison and mav become the site for net' Montagne Jacquot WWT plant. 0 an office park (15 000-25 000 mt) behind the above mentioned housingTplot Q Ten hectares of industrial land (see section 4.3.3)

Note that there are no proposed marine parks on the coast in the Study Area - the nearest ones occur to the south at Balaclava. and to the north at Trou aux Biches. The main tourist zones are also outside the Study Area some 20 kms awav in the north. east and southwest of island parts of the island.

4.3.3. Economic Activities

A-riculture The agricultural sector plays a vital role in the social and economic development of Mauritius. Sugar cane is the dominant crop in the agricultural industry with sugar and its bv products contributing to 34% of the total foreign exchange earnings in 1989 (MEQOL 1991). Recent figures show that cane sugar and molasses contributed to 930/% of the total non-EPZ domestic exports of agricultural products (Table 4.5). CuT flowers provide a low volume/high value export product which also contributes to the agricultural economy of the Island.

Table 4.5. Non-EPZ domestic exports in million rupees' ~~~~~~~ p Non-EPZ agriculturalproducts 1994 1995 1996- Live animals 26 65 97 Wheatenflour 65 39 105 Cane sugar 5 742 6 326 5 263 Cane molasses 115 136 89 Tea 83 50 22 Cut flowers& foliage 105 126 88 TOTAL 6 136 6 742 5 664 MEPZ 1996 figures for the third quarter (first nine months) of 1996

Fishing The fishernan of the Pointe aux Sables and Bain des Dames areas form part of the artisanal fishery in Mauritius. which consists of coastal operations in lacgoonsand alon- the extemal edge of the barrier reef down to the 200 m isobath. These fishing grounds spread over an area of 1 020 km2 with an annual landing of 1 353 tonnes in the 1980's and 1 612 tonnes in the 1990's (AFRC Annual Report 1995). The NPDP

Black & t eatcl I,sternational 4.23 Descriptionoj tileenvironment 'loliintaagneJacquLW Seweratge and Sanitation Project Environmental Impact Assessment

1993 tforecasted that this level was not likelv to be exceeded in the foreseeable future since the sustainable limit has been reached (See also 4.3.1. 1). The most common fish species captured by the artisanal fisherv frorn the lagoon stocks on the west coast are: capitaine (Lethrinus nebulosus). dame berri (L.mahsena). and cordonnier (Siganus sitlur). Ourite (Octopus vulgaris) are also abundant in the catches of the w\est coast fisherv.

The onlv other fishing industry in Mauritian coastal waters are the Bank Fisheries which consist of deep water shrimp and fish catches on the Rodriguan. Northern and Soudan Banks. and along the Mauritius-Seychelles ridge (includes Save de Malha and Nazareth Banks and the St Brandon group of islands) (Figure 2.1). the industrial fisherv (mainly tunas). and aquaculture. The deep water fishery is not directlx affected by the proposed development although it is indirectlv affected in that the fisherman presently working close inshore. will be forced to start fishing in deeper and deeper waters and impact on these fish populations.

A"Ianuiwtruring-industries Manufacturing industries include: (a) agro-industries (sugar and tobacco processing etc). and (b) export products (such as sugar. tea and textiles and garments etc.). The Export Processing Zone (EPZ) is a dvnamic sector in the manufacturinmzsector and contributed MRs 15 333 to the export market in 1996. Most of these export products were manufactured articles (95%) such as textiles, and miscellaneous articles (MEPZ 1996). emphasising the overall importance of the manufacturing industry.

The textile industry contributes to environmental degradation in two principal ways: a) effluent from dyeing activities and b) textile cuts, wastes and used wrapping materials (includes plastic products and cartons (MEQOL 1991). Appendix I shows the quality of typical waste water effluents from dyeing activities. The Prefeasibility Report Update (Black & Veatch International June 1997) indicated that color and salinitv and some amount of fabric particles (in the form of TSS) from effluents of textile industries will not cause violation of ocean discharge standards. Although color and turbiditv are not normally considered a serious pollution problem. high color presents aesthetic problems and TSS can form sludge deposits if discharged in significant quantities (See also Section 2 and Appendix Q).

Both the Coromandel and Plaine Lauzun Industrial Estates are owned by the Development Bank of Mauritius (DBM). and most major industrial activities in the service area of the Montagne Jacquot WWT plant are located in these estates. The

Black& Veatch International 4.24 Dsacriptionof the environment Miontagne Jatcquot Sewerage and Sanitation Project Environmental ipaclt .4ssessment

proportion of all industries connected to the sewerage systems in the Studv Area are: Port Louis - 47.6%: Upper Plaines Wilhems - 18.3% (MEQOL 1991).

No suLgarfactories or textile stone washing plants are located in the Study Area (Fioure 4.7) and so this source of pollution is not a problem. There is at least one stone crusher near the Study Area - these plants provide construction material and the main problem is dust emissions during the crushing process.

.NPDP(1995) plan proposalsfor economic development The projections to the vear 2010 show that there will be an increase mainly in manufacturing. some construction. retailing. transport and offices. whilst numbers employed in agriculture will decrease. Within the manufacturing sector. the GOM is trving to diversify industry to include value-added export products (e.g. jewelry etc.).

The planning strategy is to provide a better spatial distribution of emplovment areas in relation to places of residence - since the present trend is for industries to move to Port Louis where it is alreadv congested i.e. no new land for large-scale manufacturing is permitted in the Port Louis area. The Pointe aux Sables inland area has been designated as one of the Planning Zones in the country which covers 89 ha of land allocated for large-scale manufacturing. and 5 ha for small-scale (< 10 emplovees) manufacturing (see also Figure 4.8).

Policv No. 1.9 is a plan proposal to allocate land for polluting industries. such as textile factories e.g. a 20ha site at Beau Vallon near the airport and Mahebouria.

4.3.4. Recreation

In addition to the residential properties along the beach. there are two public areas at Pointe aux Sables which can be used for recreation: (a) the place known as -'Debarcadere-where the fishermenoperate, and (b) the public beach area about I km to the south (see Figure 4.9). The beaches are affected by the existing sewage discharge from the Pointe aux Sables works.The area declared as a Public Beach' by the local authoritv does not have a specific name and but is a well manaued and landscaped area. There is.- however. evidence of pollution on the beach (see also secton 4.2.2). Recreationalfishing occurs on the rocks at Montagne Jacquot (pers obs. and see Plate 4.2) and people use the cliff just to the south of Montagne Jacquot as a diving platform(see Figure4.9).

Black & Veutch International 4.25 Description of tie environment Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

At Bain des Dames a football field is present in the allocated "green" area - opposite the Fort Victoria Works.

4.3.5. Cultural and Historical Sites

The cultural and historical sites present in the Studv Area are indicated in Figure 4.9. Historical buildings/structures which are in close proximity to the proposed development are:

a) Transfer mains pipeline. Alternative I (seeFigure 1.1) 0 the abandoned bridge running parallel to the used bridge over the GRNW - status unknown 0 La Tour Koenig Tower - registered as a National Monument 0 Martello Tower (La Preneuse) - registered as a National Monument b) Ocean outfall 0 remnants of mill - status unknown

The final engineering design should take cognisance of these sites. and anv others listed under the National Monuments Act 1985 (Appendix N).

Black & VeatchInternational 4.26 Description of tIle environment ~ ~t~~~:4 *¶>~~~~~~~ ~~~ ~~~KEY rainguages 'jcatchmentslriverbasin boundaries UBA~~~~IN~~barrierN reef ~ 'water ~~/IM~~ eservoirs

on /V rivers/streams~~~~~__

.. ~~~~~~~~~~~~~~~~~~~~~~~~/ cotur m

BLACK & VEATCH MONTAGNEJACQUOT SEWERAGE AND SANITATIONPROJECT INTERNATIONAL ENVIRONMENTALIMPACT ASSESSMENT

Figure4.1. Topographyand hydrology in the StudyArea. Waste Water Authority KEY

//motorway //road:main A //road:main B '/V road:other barrierreef water sandybeach dolerite (younger) dolerite(older) basalts,Trachytes and Pyroclastics darkclay soil shallowstoney soil 1101f11lowland humic soil

0 2km2

MONTAGNEJACQUOT SEWERAGE AND SANITATIONPROJECT BLACK& VEATCH ENVIRONMENTALIMPACT ASSESSMENT INTERNATIONAL

Figure4.2. Geologyand soils in theStudy Area V WasteWater Authority Assessmwent AMontagneJacquot Sewerage and Sanitation Project Environienital Impact

15th June - 13th July

3~~.56

@ 2b- 4 - / - N

2nd March - 6th April

# ,A;~~~~~~~~~~~~

Figure 4.4. Wind roses for Fort William during winter and autumn of 1994 (from SOGETI 199a).

Black & Veagl.iInternational Figures and Plates _~~~~ ! 1015/1

ASS ~~~~~~213 >t

Qr.

40 ~~~~~~~~~~~~GrandRiverUI /~~' e PORTLOUI

, c q uot Jacquo pa / 4n,f' pe ew-1l

Points auxCaves

KEY MONTAGNEJACQUOT SEWERAGE

barrierroef AND SANITATION PROJECT A/roads / wintercurrents ENVIRONMENTALIMPACT ASSESSMENT 4 , summer cu rrnts depth (m) depthcon ( Fursigure 4.5. Bathymetry and barrier reefs on the coast at Pointe aux Sables and Montagne Jacquot. 0 1 km Summer(7Dec94)andwinter(12June94) curents (from SOGETI 1995) at the proposed outfall site are also shown. N

-q i BLACK& VEATCHINTERNATIONAL

S Waste Water Authority 45300 1j t1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I Sin 1: 12.3,u: -'1

40.00 *Stn 2: 7.rm; nn'3

35.00 4-I

30.00

25,00 M

1V.0

10.00

5,00 T1

Z-I-- 0,00 -t.-- 4-1 4 --- * --1 I -~--

uuUi uOfUfl, typesof substrata '4 r

Figure 4.6. Percentagesubstrata coverage (+ I SE)on reef slope at MontangeJacquot. This surveywas undertaken during May 1997.Percentage of cover wascalculated by meansof 25 m line transectwithin a 50x 100m areaon the reefslope. Three to sixreplicate transects were laid on the substrataat each 4 site. Theclassification of substratawas according to theAIMS surveymanual (English et al., 1990;see Appendix x): ACB=Acropora sp. branchitigcoral, a ACD=Acroporasp. digitatecoral, ACE= Acropora sp. encrustingcoral, ACS-Acropora sp. submassivecoral, ACT--Acropora sp. tabulatecoral; CB=Non Acropora sp. branchingcoral; CE=Encrusting coral; CF=foliose, CM=Massive coral, CME=flre coral, CMR, mushroomcoral, CS=Submassive coral, DCB=Deadbranching coral, DCD= Dead digitate coral, DCM=Dead massive coral, DCS=Dead submassive, DCT=Dead tabulate, HA=Halimneda algae, MA=Macroalgae,OT=Others, R=Rubble, RCK=Rock, S=Sand, SC=Soft coral, SP=sponges, TA=turf algae. KEY

.A proposedIndustrial land (ea loha-tol,'ha) IV2 proposedoffice park (gOOha) *proposed housingdevelopment (25hael Lproposedhousing development (IlDOha) stonecrusher / tost Koenig pSTFICT a dye houses ! /::l t } 8 * t f t Industrialestates (DBM) .,II I ...... -b ;p .llit, d t * t tDstrbdry.shp . other cultivation marsh or swamp area Tranquebar I scrub

oAbarrier reef

aa ~~~~~~~~~~sugar plantations Figurea.7. Ld enet AeP od wpopulatedareas

BLACKRIVER I0~~~~~~~~~~~~~~~ 2km

DISTRICT ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ a ~ OK ISRC

Beft E aile': P

PLAINESWILEJrS DISTRICT Auroit

MONTAGNEJACQUOT SEWERAGE AND SANITATION PROJECT BLACK & VEATCH ENVIRONMENTALIMPACT ASSESSMENT INTERNATIONAL FigUre4.7. Landuse in theStudy Area. Proposed new developments (NPDP 1995) are also shown. ~K / > Circle- seeFigure 4.8 which shows this area in moredetail. Waste Water Authorit

C~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ . ~~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~t

...... _ .~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MONTAGNEJACQUOT SEWERAGE AND SANITATIONPROJECT ENVIRONMENTALIMPACT ASSESSMENT N BLACK& VEATCH Figure4.8. An aerialphotograph of Ihe proposedsite for the new wwr plantat MontagneJacquot, and the adjacent areas of land: pe tl - thewestern edge of thePointe aux Sablesresidential area V\ ; . thePonlne aux Sablesprison (Petite Verger) T N - theproposed housing development site behind the prison "°20500 m - othersites with private land owners|| WaSteWater Authority KEY

greenareas market VI iv) 4! 14~~~~~~~~~~~~~~~~~~~~~~~~~'historical sites + hospital ai cemetery am hotel OISTRICT mi1ls + dispensary PatileVofger A4~~~~~~~~~~~~~~~~~~~~~~. policePOstOffice communitycentre ...... ~~~~~~~~~~church/temple A,~~~ITRCIS11 Cotins PORLOI , Imirod:ohe school /V/drainagearea boundary //barrierreef motorway \/road:main A //road;main 8 9LACKRIVER ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~road:other Figure4.9. Districtboundaries (~~existingtrunk sewers Waterw sugarplantations

PLAINE4ILHEMS Montabal ~ ~~~~~~01 2km

DISTRICTMNTA IMPCTASESMET

BLACK& VEATCH MONTAGNEJACQUOT SEWERAGE AND SANITATIONPROJECT INTERNATIONAL ENVIRONMENTALIMPACT ASSESSMENT

Figure4.9. Mainservices, historical/cultural sites, and recreational areas In the Study Area, v I WasteWater Authority liontagnc Jacquot Sewerage asid Saniiatiorr Projecl Environmental Imlpact Assessmene

.5~~~~~~~ .

-~~~~~~~~~~~-~ ~ ~ i

4:-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-

b_ - l_- .__ ,= , ,

Plate 4.1. Location of the WWT plant site at Montagne Jacquot. Note edge of sugar cane fields to the right and the prison wall to the left of picture. Also note the beach comprised of basalt boulders with sandy patches, and the patches of Cjuncea and P.glabra exotic bushes.

0~~~~

-- -. . ., .

j,7,- ',, K;.-

Plate 4.2 Basalt rocks forming the intertidal zone at the Montagne Jacquot proposed WVWTsite. Note the recreational fisherman on the rocks

Black & Veatch International Figures and Plates 4tollwagne Jacquot Sewerage and Sanitatio,i Project E nvironnien tal Impact 4ssessmtent

Plate 4.3. Secondarised savannah grassland at the proposed site for the VVWTplant, at Montagne Jacquot.

W1~ ~ ~ ~ 18

Plate 4.4. A creeper, Passiflorafoetida, belonging to the passionfruit family. A localised patch of mont aux ciel (Labiatae) was also noted. At edge of site, near the beach are isolated small trees (Crotalariajuncea and Ponjamia glabra).

Black & Veatch International Figures and Plates Mtontague Jacquot Sewerage and Saniitatiol Project EnIviro,,,emetal IInpactA ssess,neii

:W

Plate 4.5. Occasional Cassia tora (Family: Papilionaceae) at Montagne Jacquot

"Si-. . . ,

.. * ,< - '

. .~~~~~~~~~~~~~.~

Plate 4.6. Mid-littoral zone with molluscs S.ferruginea and Patelles sp., barnacles, and some urchins (Colobocentrotus).

Black & Veatc* International Figures and Plates .Jlontagne Jacquot Sewerage and Sanitationl Project Env ironnental Impact .Assessment

Plate 4.7. Note the intertidal blennies, A.monochrus (arrow), molluscs, and the presence of algae.

Plate 4.8. Note presence of urchins and encrusting coralline algae.

Black & V"eatclhInternational Figures and Plates llontagne Jacquot Sewerage and Sa,irtatio,m Project Environmental Impact.4ssessmnent

Plate 4.9. The impact of raw sewage and solid wastes on the coastline between Fort W,Vlliamand Fort Victoria - note algal mats on the surface of the rocks. May 1997.

Black A Vearc/i international Figures and Plates .olhmnagneJacquor Sewerage antI San itation Project Enviro,,mental ImpacA .4ssessment

Plate 4.10a. The coastline at Pointe aux Sables existing outfall, looking north towards Port Louis.

F |~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~7

Plate 4.10b. The coastline at the Pointe aux Sables existing outfall, looking south towards Montagne Jacquot.

Black & Veatclh international Figures and Plates Alonlagne Jacquo! Sewerageanal Sanitation Project Environmental Impact .4ssessmenl

Plate 4.11a. The dark blue plume of surface water at the Pointe aux Sables discharge area - 3rd June 1997.

_ ' ~~~~~~~~...

Plate 4.1 b. The sea bottom on the reef seaward slope (3 - 7 m deep) in the discharge area at Pointe aux Sables. Note the proliferation of black urchins and algal growth indicating poor health of reef. (June 1997)

Black & Veatc/aInternational Figures and Plates MloIntagne Jacquor Sewerage and Sanitation Project En tironmental Impact Assessment

Plate 4.12a. Reef profile at 30 m, note: solitary coral - Fungia sp., mushroom-like soft coral - Sarcophyton., and flat sheet-like coral - Lobophytum sp.; butterfly fish Chaetodonlunula, coachman - Heniochus sp.; algae.

Plate 4.12b. Reef profile at 30 m, note: leaf-like coral - Montipora, sheet-like coral - Sarcophyton sp., sponges; algal growth; Moorish idol - Zanclus canescens, school of two-spot bristle-tooth - Ctenochaetusbinotatus.

Black & Veatch International Figures and Plates .lIt)1agne Jaicquiot Sewerage and Sanitation Project Environmental Imnpact .4ssessinent

*~~~~~~~~~~ .

.~~~~~h ,

Plate 4.12c. Reef profile at 30 m, note: honeycomb coral - Favia sp., leaf-like coral - Montipora; algae.

Plate 4.12d. Reef profile at 30 in note: Montipora, Sarcopihyton coral; Z canescens, crosshatch butterflyfish- Chiaetodon xanthtus, saddleback hogfzsh - Bodianus bilunuatus-surgeon -Acant;urus sp.; algae.

Black A VecatchiInternational Figures and Palaes Mlontagnc Jacquot Sewerage anzdSanitatioa, Project Env'ironmnentalImpactA ssessiene

Plate 4.13a. Reef profile at 13 m, note: daisy coral - Goniopora, boulder-like coral - Porites; purple branching soft coral - Nephthea sp.

Plate 4.13b. Reef profile at 13 m - same as above.

Black & Veatc/rInternational Figures and Plates lIontagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessmnent

yI-iMe ,i'

-~~~~~~~~-

Plate 4.14a. Reef profile at 8 m, note: Porites, Favites corals; two-saddle goatfish - Parapeneus bifasciatus, Z.canescens,butterflyfish - Chaetodon melannotus, C.striatus.

.. , F e an Bai Veat. Intrn . a

. coral~~~~~~~- Porite sp. Fa'vi'tes7

-~~- -

Plate 4.14b. Reef profile at 8 in, nOte: labyrinthine brain coral - Platyyran sp., porous

coral - Porites sp., Fovites.

BlJack& V'eatchInternational Figuresand Plates .lontag,ic Juic,uiot Sew erage an(dSaiiizalitji) Project Environimental Itict .-lc Lssessnieli

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-7-

Plate 4.14c. Reef profile at 8 m, note: Porites, longnose butterflyfish - Forcipiger flavissumus.

Plate 4.14d. Reef profile at 8 m, note: Platygyra sp. Favites and Porites corals; encrusting pink coralline algae.

Black & VeoichInternational Figures and Plates Mlomlagne Jacquot Sewerageand Saniration Project Environmental Impact Assessment

7

Lg.

Plate 4.14e. Reef profile at 8 m, note: purple branching soft coral - Neptlhea sp.; urchins colonisingthe rocks.

VV

-- 7"-' ' '

Plate 4.14£ Reef profile at 8 m, note: brain coral - Platygyra sp.; damselfish Chromis sp.; encrusting pink coralline algae.

Black & VeatchiInternational Figures and Plates -1 Montagne Jacquot Sewerage aotdSanitation Project Environmental Impact .-ssessment

SECTION 5

ENVIRONMENTAL IMPACTS

BlacA & Vearcli International Environmental impacts

MontagneJacquot Sewerageand Sanitation Project EnvironmentalInmpacr .4ssessmenlt

5.0 PREDICTION AND EVALUATION OF ENVIRONMENTAL IMPACTS

The overall environmental impacts of waste water projects are positive since they prevent or alleviate the effects of pollutants on the human and natural environments (World Bank 1991). In addition. installation of a waste water collection and treatment works provides an opportunity for more effective control of industrial wastewater through pretreatment and connection to public sewers. and offers the potential for beneficial reuse of treated waste water.

Some of the observed environmental impacts which result from discharging untreated sewerage effluent into the sea at Pointe aux Sables and Fort Victoria have alreadx been highlighted in Section 4 (see Plates 4.9 and 4.10. Press Release in Appendix M). However, a more detailed evaluation of both the positive and negative environmental and socio-economic impacts. which might be expected as a result of the Montagne Jacquot project. is provided in this section of the EIAR.

5.1 Assessment Criteria

The approach used to assess the significance of the potential impacts is to apply "significance ratings" to each impact using objective criteria. such as magnitude. extent and duration of that impact to yield a final evaluation of the significance of impacts. The use of significance ratings reduces the number of variables which need to be considered bv the decision-maker. whilst providing pertinent information about the implications of the proposed project. -Appendix N summarises the assessment criteria used in this study.

There are four main parts of the Study Area which will be affected by the proposed project:

I. The proposed site at Montagne Jacquot allocated for the new WWT plant 2. The proposed site of the new outfall into the ocean at Montagne Jacquot 3. The new pipeline route transferring waste water from the Fort Victoria and Pointe aux Sables works to the new WWT plant at Montagne Jacquot. 4. The existing works and ocean outfalls at Pointe aux Sables and Fort Victoria.

As the possibility of waste water re-use for irrigation does not appear to be a viable alternative in the short term (see 2.3.6.1) and at least until further studies are

Black& VeatchiInternational 5.1 Environmentalimpacts Montagne Jacquo1 Sewerage and SanitationrProject Environmental Impac .4ssessment

commissioned. the potentially significant impacts of this aspect of the project have not

been included in the evaluation.

The principal potential negative and positive environmental impacts (environmental

and socio-economic) arising as a result of the project are summarised in the followine

Table 5.1 which shows potential impacts during the construction and operational phases

of the project. together with their significance ratings. suggested mitigation measures.

and the significance of the impact before and after mitigation.

BlackA Vieautc*aInternational 5.2 Environmentalimpacts 'lathht*5.1. l' l'l:N'll Vt. t:N\'lH0)N%ll:Nr s1 Il',\IP IS %Nl).SSESSMII:Nl '(1Sl(.Nll IH ' N( l tSI I ,il'PI .NI)IX N tfio detilsiii1>'deud a;, (Y 1,V.V7R1(TCIONI'/I4 XE

l:llsEllwllll~~lelllllillcis ' 11e111gliagltiolll Rsii-i/D lifier giligtgltioll ~I 5/: |______! - Slal e c _ Sigttificaancc A) Nei$ "A'W'I pPlAnt'it lIonlRgne .lcqsunt vm1ise.dust anidall tcinporars nitistilcC associated %sith Imn I l(cal /S'I' ' nslag.e site to mitlimise allemipofsir ouisaice eg imptllesrant his cI S' colinstrlclio l til %sorksat iontriagueJacalltU0 I 1)W dustcimtriol neasuires:liaise prisonilpersolilrel rc likel) impacts 1 SW .., .....,, ...... , .... , ...... , ...., ..... I...... I...... I...... I...... I...... *.oise, dist, materialsdeliher\ etc restittisg 1ini loss/ local/ST asahlove lm% flocal IS'I' yrading / improvilg accessroad to site I (W ...... I ()W iincreased ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~m,,loa , I asaoe idiiaag dlkcrstoa, oi oiet iec...... trallic aloig thicaccessriad delisering materials loss/Ilcal/ /S as aboveand maniagedeliIeries to asoid congestionetc Isis / local / S'l ltor coiistrtiction on site. engineeringpersonhel ItW (secdetailed trallic conitrolpsos isions. Appetdix P) (Aw |I)Transfer imiliis pitieliuue *disruption ol'trallic pedestrials etc high/ local / S'I' I managetral'ic diversions hiase isith transportplaiures s Isgil / lical / S I' AtlernauthseI |along alreadi coingested routte I IGil I opsimisesnse oi access/fcederroads I l1il l land-basedpipeline darmage to roadsersitaides. pavements oredistun/ locai I I " ussticirctrnIsoll nain paerent vshere possible,t / existihg irrigaliill chaninlels eta! as a resull ol' NM DllIIM especiall ihere otler iiltrastrticitirc exists. limit extlento/t open I digging a Irelnclh lii pipeline. ditclh, e!poRrarypa rn a, le required(see Appx i'I W l coslsig"l or'la -ingpipel" e alonigalrea congestedsd hig.. / local / Sl ' design-atemeo-aser of cmosdstictisinlleantos keep a record iusedtais/ hnscal roule. potential for claims lIr damageto persouial MlElDlIUM ol'comiplainsisaind as far as possibledeal ssith thetisdirecil) S I and public propert5 in thleesint ol claims etisatreaccurate record of evesnts MNI)II Ml potential damageto other kes infiastructural higll / regional ensurcthat oitler iaitastruictitremapped o0t1o plains befire riedisioI componientse g telephlonelines, watersuppl S I constructionphiase begiis. Rl toialert colistrtctioi teamii regiolal I S I electricit).etc. MIME)IUM esptrrchi digger M l)l1lNl vsorkeraccideits ailoig constrtictini rottle as resilt highi;iregiolsal isstdirnr/o-isioiisforilii andsaiei oieons ir ofrcotigestion atid uaniagetmclitof tral1ic utider SI' sorkers iapleaseaitedand ssilft dispatel to isedical I egillala / Sl difficl1t Conditions M DI)llJM ...... ,,,, ,,...... ,, ,... I...... I...... racilit5 if retatiired I , ,,,...... I...... WsIM) ...... iM . ... negatise impressionon toirists resulting1romt aneditatii/ national leassare tiptianal tmnaisageaiieaitsl'trallic alotig cotistrasetitsl rassate ,iscdiaiaa/ disription causedh! consirtctionaphase ol'project S I (seeAppeadis I' for details) aittiollill I SI alo(ig principal rotite around islatid MED)IN Iii M 1I)D *\sste soil atid sediassentstashed itito stormdrains loss/ loCal/ S'I' "easIUrescreess over drains %shichare partiCularlyvslnerable. los / I scal/ S lI vsitlapotenitial br causingbloickages ol'existing MEI)IIIM dhiert haosonitos agrictaltutral land %s%ereposs I.51w

ii( is an d Itisi *causedc asoiseatise aisd'h\hi sluistdiegigmy!digging Ircn'illtreaseli ~~~itdand''''"'"'''" la~II.%il'' hg . higilash I lascaloaiS IST *risaisageml trench ric diggiasg!i iici/i;t;itielficienth t)la siaiaisitisems timie rellitired liseiua/ I aicaL pctIselitiealiiig roalsts Nll:)I UM liaise stith alfected locals re- tine scaleanid activitics S I lfor detailedguidanice oit caiastitictiotlsee Appenidix I' NKll:lIIDIM _ I'ras sfer saltainspIliselue dalifri otall It' laattilloseslitsrls III k llanis higli / liocall I 1 I lise silt calltisas arosuindsarase ta pi escilatdiill osf'seditisit I'lls / lIcall / S I Aiterinilhs e 2 Ilics,tcse lit plallsi,iulati Imamlt ina1lslilonslils asid NIl 1)D1NI restsict diggisig toi pi tsodsst' slack s ater I ( W titlisiole-Iasedclsiseliaie dilllSqtllwchsdi Isisdeps. tIlsl/lsaslon elsosslere ia hliaise lfocal lislieraiscas te aclis sties mnssaitoarreel';saad statcr st1s;silts th.i; iliellol satIseithie InaiialCo',aai lifi.s asiessaOt Isiedliton ilt is lestsre spsils depsasited ill csii icted arca almiasasidetIse sci iresislt i foc l / I al alaggigiiencat tarls tspilpe c S I Pse spoils toahins pipelialeas tar as poussilste I oW Ipls ,nl lal filiiial 'lid iLiseslst bleachiio, h1iii;,/ local/ I i a aloisec i,id utsesill ciamil's 11 iiuhliout treIrcli diLLIlIc Cowatlreel com,llilililtles %lhicl lofil ii inging rec lioill MIlMI local NI properlI deplised: liaise lislierigoei.die at slack tide oils1 ol lS;ri.atis-Sjlles. itlh sedimentsin stiperl .101 S I 481~~~~~~~~~~~~~~~~~.la.-!.X.-.I:.....;...... le^! mlonlitoirdri-if oC 'sediuten - impimi mloaagemolt z!s.f...... s...... 0litr...l)W\ : r ! ! ..!tsdle| ...... it ecCeSsai I.M \\ degr.laLdltionmi oci'lhlioms n\aie tI lalit\ dootisil eagi) OWrtlitll / local as5alios\ C and hlilrmiilocals ill ltime scale mtu niuare of lagooll bel.alse olfi ii tit s l / lcal I S'l Ol ilclrealsein sedinitelitin stispelnsiolil. SIl that sediments in suislpenlsioinout\ a tempilorar\ plipenmemoll H A * poiciltOIl di\lirliji . riMW )' eeartional swinmiulg still plossible 1'rel' 7islera as restilt lii medium/ local ' asalimo e plis dip treinchiin leasi sensithieperiod tlo\ local / I t redepositionol'sediment ih spanilg / mirsernareas SI I MW , ,~~~~~~~~~~~~~~~~~~~~~~~~ ..... 1(1W ...... ,,, ...... ,,,,,,..,,...... possibledislturbnce ot reel lislerv is ilthadult liso, nosing , ...... I...... iteditm / local 'as above plus liaise rislierieni reic miig anidactivities ont olrnrea tn plaiined tnos/ lcal / S I escapepoor \aler qualiit, SI' to minimise disrtptiui I tW

OceasnOnliIll Idisrnption ol'theituic communitiesand especiall\ sessile' editi,n / i I lse floaillng bargeto It' piplielic enttOc that speciesalong til areadilnd agcdtt 0' lss I cl lSI thleproposed pipelinie r(tte SIl disrupted is assmall as possihie nsespoils ftron trenciicnIo i(1W LOW cover pipeline idistuithaceof rel';lsh C iit lishi n1;;ing otli oi itie area ios\/ local / SI 'plai conistructioi phaseactis it% tn in iinise distIrbartce oppornities for recreationialr7slhermne in itelarea ae los\ / local I SI LW to reel and reel'lislier) isork ai slack tide. ensineelficicit uise temporarilysuspended ot 1I(\V lime throtiil,oti the pipeline placemeintoperation potential hlaitkettii,g and sttilseqtie;,tbleaching and meditnii,/ local sherc there are soil sedimentsensuire that sill etilinis are in place lo\ss/ local / sr eathol' corals in the s icinit, og the digging operation 1'1 miiiinise el1icctsby uisi,e currei,t flovi optimally mnonitor to eils,ire I (1W ...... I.(NW impacts , ...... ,,,...... aremnioimal. , , , L , n c __ _ ...... cOncer,,sof regarditig .. ,...... Aishermnen managementof inedinini/ local / Iliaise sit, ...... locals about planied s\OFLS.activities. timing sstl respectit hIss/ local / Si mechdigging. potentialios slamrsctionl b\ pipicle ec Sl' local fisler. disrtption reslt(ing Iruii presenceof coi,srtiction barge asnavigation lhazard MtW MFlD1 IM biargeaid any other equipinelt

A, E)PER.1T/10Y-41 lQisE E . |' _ l c iithlttli -J :/I) .4 rm mft4-itigatiu)lAn ul//D [ -- ______=_____---=______--_____--__ Siglfi.amiceI ] Siguiiicance

il) Nessli1 II' l nl tit all te e OsisidOiff 111 iiccalsio"ills he exlperieniced iiieditill lcIlal / "'if odorprohtlems persisi imilemeit an odii, conitrols> steln iss)1 n l /1 1 Mlontaigne Jlacquol at pI isnioss len illte ri ilranagemeintproblems ;:1 I t )W Ir thc plant. maintaingooid blosekcepilig pi acticcs (ii site I ( )W Iicalelinei omiksi I(olhlersiseno (ithel residenices eisuireprocesses causing m11ost signiticait (idotirs contained is this sipprox I kini I is thitt Ibuildinigs,maintain relationiship is lith locals a.d d"!!i't.'i!"ia !'r0.'t...... !.' ...... I...... I\ .tll.oie+ios ...... additional tralilic along accessroads to works medilim/ local /1. ' designanid maintain access roads to causeminimal loss / local /Lr associatedms itli suppl%ol' goodsand maintenance I ()W disruption.efficient ;nd cleatislidge renss al operation. I OW and rerss al il' sludge from treaitigicintnorks to enstirecon uintuicationilihes open. deal %sith complaints, keep municipal lauidlr-illsite record of incidents involving genseralpublic etnissioutsiil' olatile organic or otiler cumipoutttds meditim/ local I '.* isoisitor anidevaluLate sigiiificance - itistall appropriate loss / local / IT fromnthle treatilelt process%%ith healthi ictiplications I OW technology if necessar) ...... 1()W ...... I...... , .... I.. ,,:...... nestlietic/ (doulr iitttsioti of works it antarea mediumit local I * screensite ss ith trees mainitainianid manlage site using lo%sI local / 1I' curretitll usedoccasionIall) lor sinumitig LoW hestpractice to uinitiuise aestheticand oilier iipacts I .(W becaclhcouinbiisig/lislitsg/picnikinlgb,)locals ,,, surroundingarea Impactsof tuisanceconditii ns associatedwith normal low / local/ L.r eussureplanit maniaged accordinig to operationalmanuals: loss/ local I/ I of WWTplant and ptsinpstatiois LoW inaintaiti good relatiotisisith communitiesiii the area I .)'W reduction it propert) valtuesit adjacenil areas. atid los%/ local /LIT 'euuStreiniformationi about progressof project circulated freel) in loss/regioal/S r conceriisof allected locals wvitlilatid as yet tndeveloped o.OW pressarid to local residet's assoiciations. L SW g(

, esueopportun!aitiesprovided for ptiblic ineetitigs etc. ~~~~~~~~~~~~~~~~~~~~~~~~~~...... ,...... I...... C !Sl!r ...... poor managemetitofl orks restiliig in performance ineditim / regiottal 'enisureinauiagemenit tfs%norksis efficiegit.sell trained anidhighly loss/ locil / I r ielos desigtnedstaidards. efiluteit iinproperly treated IA motivated.monitor perloruiiaticeirutrodimce qutality cotitrol system, 1.)w 1poor%vater qtialit) in dischargearea etc MlEDIUM moiitor oceanouti'all to ascertain sshetherit spec potentialbenerits of tsing wastetatierpansitng itiroutgli inedium / local 'refer to study 2 regardingrecotmendationis for frurthersttdies for irrigation on neatb)sugar estates LIF LOW ol' wastewaterre-use B)Tratnsfer attainspipeline 'hlockage of sesers or malfunction at pumpingstation medittm/ local 'etisuire local commiunitiesknoss hosw to alert autthorities loss/ local/ ST AlternstiveI maycause ras efliuenitto spill onto the road 1.1 WWA to deviseaction plait to deal with leaks/blockages:ensure I )W land - basedpipeliine ssithrestiltatit odours. itnplicatiotts fibrptiblic hIealtlsetc Lo(W appropriatespares are asailable disrttption it local trallic. h;tsiitessesetc resutliingfroin nediutn / local/i sie trallic mantagementscitne adopteddtritig los / local I SI imuise.odors, etc associatedisith pipeliie repair s I LOW coaistrtictiotipase: ilirm locals: eftlicietitdiagiosis and rened L W.0W itiereasedcoitgestiott of iimfrastrticltitecorridor loss/ regional ' liaise wsith iiutticipal plaiiitersregarditg loog-terin low/regionial/l r (road rotne)as resultof nesspipeline Mtilitim I 1 developmentsin areaatid resolve contlicts, ensure I (W diameter ia) conistrainluttre deselopments I O(W plannitig guidelineslbllossed "shere tlhe) excist! ...... 'couscergmsofl'ocal coimiunitlitiesregarding hcalthi lows/ local / SI' 'ensiurel(Icals kept iiiloriuuedtlirisighl mediaor local loss/ lcal / st impacts potenti:tl fiorcontatination ictditcedtpiailits It OW iesideii's ongaitisatiois. icludinigadvice abouit I SW ut sc eragetreutillelit etc 'iiiittinsisilig lhcaltlhimpacts .lllerntglls'c 2 'b,lock ac oi sesscrsir irmalfuittiounat puimirpillstaioin high / local / S. *etstire locallcotilmlnitics aiVeniiC ti il the tit mitiCident ssediii/local lgioon-ihsed uiMMresuilt l massclllmmeit spliliLn itntolIgoi(ill IDlltll I ceiistirepromipt diagnosis and iemedial acfion. iinipleincii WWA I I enircgeocitPlan it' necessilll c11 tiM ii mipislmlocatseud hIs imsainielianicc all lcpair ut1lipeflmc iiiediiiiim/ local 'ensure coir.aclotrstnatgi;ed to saamestaoidaid as duiriiL los lcl SI dio iuiutilhpleseice sit'blree mss\igalionli h:ard . ioi local S I coistructioin phNs,CLusC sili cUItaIIISoa herepipel ic halsto lie I (tW cosastllvessels I ()W duigtip. monitor aci\ ities, is dminig lights oinbarge etc 4d iiurham 1c.-o i .1llsli*er aliil iecru;l2ioll I iliille Its / loc1ll / S I * n,iaageurepails etlicienlt (see2\ppesidi PM for dctails\ 1,, ! loali: / SI m\ ihillolle 1112211Iiili12liiiid)l1t1 "Ii jilug'ep'ails I ( Ai ise all preca j liona\ ! irc s adopll d ill conisii2ictioll l1las1 I 1A aliditlolintic olailieilalice iopertliois ...... ,, ,, to miioiosise sedisenit dill. maiiitaill coltlac \\ils locals ....., ...... ,...... I...... -...... ,.....I ... ..,.,,,,,,,,,,,,,,,,,,,,,,,,,..,,...... piiteiiiia liballtl Iul;p is Moriecliati(iill s%5 il5 inlters ' mediulit I local dcispla licalli s%lirling sitis piiiiptls i . Ii .i s iliil11 tMs /1 a / SlI tislicil5>10121 1 I:lellhuii l*u \\lluss !0511211/ ill plipelinle SIlIcrusllis locals.enlsure lr altensiotiipi to imalhictiuon ad ressi litluill o1 I I AV ...... I h ate q u ......

Oceirt Otitritil 'p05Sith impalct2 Itranslerillg point of dischairgcfirol ser liig±hI / jinlorm coiinmiiiities regarding iik l\ ti1e-scales h1l're \ \ Iil/ (linked to Nlionltgne lactolo 1\ istililt Is lo oinlhagiie Jillol - imprsro ments is regiiiial/ imptoSements experienced, assist conmiiuiiities in developiunet IegiIlI iii 's 'sl1 pli nI j ater qluali\ heallltlot ilriine/fieshater ecos%steiss I .1 strategiesto assist il optiliisilig opportunities in tolirisl;. itMa l/ lotentiil lfo longlterin rehahil itation of reef and reerlisher. PIliI I pros ii5o5 ol serv ices. accmmnadatidtio etc %%hichare p0t11 ii at I I cessati 1oofl toxic alyals bloomlsimproved leialtll and meansoto einhanicinegicomes and providilig employilent ill th I lI(l I citi1 ith *of lire fIr coiiiiiiiiniiieS in naides Valuies and area. implemeii rehabilitaltioinmezslures in collaboration l it h l'uiiite-atux.Sablbs priupects fisr lourism des eliupmenil IolU and uisherN(i()s seek assistance froms gosernlmet illn icilli l prl adlid acent beaches and ililiges agencies tio optimnise econilmiiic and social opportunities Ii lmpacite'lliuail discharge on;recreational iigh / local Il 1 design ontall 1t achievedispeision ol'cil ii to ine1t 112111iircl iiiediiimn local shinners. dheis lislierileninear poiit( oldischarge IlI(ill %%aterqualil standards. disinlect x%aste%%aterto avoid uiea\c 1:1 potential fIr IN I. hepatitis. gastro enteritis etc healtilimpalctS. monitor discharge to enstire wwTrplant MlDI AIM ...... ,, .,, ...... , peC lbrmini correctly...... I...... I...... - ...... the impact of diselarging a cocktail of sesageanid bigls/ cnsire ouitfalllocated at breakin reef and as far from cotal teel mediulilo/ local industrial%taste on mn trilelentilihie /coral reef iegiollill/ coim iniities as poss.ensure iidtistrial svastesare invelitotiisd il communitiesclose to clt7icentdischarge poiit I 1 regularIhchecked: moniili pre- and post dischargehealih ol MEDlIIIM Ileacuhing/ death ofcorals, reduction ithenith ol reel I IIGI I benthiiecomisunities and %saterqcialit) in dischargearea encourage/ legislate l;r pre-treatimienititidustrial waste the impact of diselarging efiluent into area not inedium/ 'silsttre recreatiotialsvimmers. divers. etc are warned notices medlitm/local impactedpreviotish) direcil) impactedhb sesage local/I I' n beaci etc Monitor changesini water qiality; take action it' I. I and resultaistredtictioti in %salerqttalit) MF.)lD IM autlhlli notperf'orming to designstandard. It W illipaietol discihargingstasteivater on nmarilte planitonici ncditin/ etisiireWW' I' plait perforiniig to designstandord: cieck iipits iedilio / commisiitiesssitfh resultant redticttimin in priinar regional/ .1 from iiduistrial dischargersregmilarls keep up to date inventor) ol regional / LA productimn.biomass and death ofr ulerable species MlI) l)lPM t)pe/ concentration ol'indiustrial discharges: implement legal / Mll)lt iM pricing incentives to get industry to pre-treat uastes. progressi e dlcteri tlion il oil the corali reel' tiid local hIiell/regiial *mrailage WW I plati ell7icientlI install secondary treatmtnit s mein hiss/ regionial lishleriestip tl ill floiorthe dlischalrge poilt in th,ellig ter' as I I possible mni itor wIlIer qulialts thioughliot: comsibines itli bentlic I T Ia tesull iief tlriphiclit olll ' colastal ...... ,, , wilters il I mnitlrirng oIn to evaluatte ...... I...... , ...... ellects of pr bnar treatment and disitfectioti I ( )W ...... plutetiall flo itnsersible tlaliaec ...... resutilluirg1rol o sto Al hiehi/ilgioilal 'ensuirc industries dischar6ing ih sesiet sltictl cotsuolledlilcslbmcuml 1 .*asille ilguls tIuic iiliistt l Cihel icl al iito 11iliuticliil I I ills ciaii u. ilspls a1ndultutglillp1s lo all ili;lilts illirildice heals cgiial ucisei I lI(ull plenlltics lii delibevwralte dlisclllllpscha ll lolfitlorised substiances I slilet a stelsiliCsOil site to n ii id lrilile isis. iuncenltives ltoi catie Nil 1111tNI * . hsuuteiltililii ii ucs civ%silsle t slmage caused Is iszs. I itciuea *is laisve. mmisinur dischaeige incliidumsgscein;ing checks liun

S I' bt IscIisitIjt;' IllCtsch,gc's4)1 Il:itititlttiSt 'c tItttIIIl)l)ttt'ts 1.1 zitttattltotisedtIttp)44?fle44t5 ICL'jeill I I inot iticltided II inmcllit ics...... Ill)t inoltitoled 111(1 . .. .. , ...... ,...... -...... I...... I. . ... I ow polteitiatlinr mttatrat)ect,ettprobllems :t *WW IUplant I;edrls l/ocalj Ils:i o%e rointinec hc Ks ot il celit qitlitsIN ll inOgiat l);ait utednuttI resltittit Imml not-compatiihilt,s ol imtdostriaiand I I l i, tecordso(f lprbleitts and hlo%remredied identil\ s-IttIces letionzO l 'I' domtiestic 'e 11At)V %%hichare problemiatic alld prin itise canididates for pitre eira iti( I Nu-gto1jc onion continuattosi 4 m Itnaccecptableimpacts on beachiat \ltigit itttplettteti*Klontene aq M \,er and sanilation project ic 1it,11 ilag .eJa.lctiot project loititc-auvSahics and llaini des l)ames especiall\ tatiottIal/ monitorel1iects closel and identili measuires1ti assist \ith cancelled1lteinsihe odours. scttlatuio)nol pntrcl itig alegae. 1.1 rehtabilitation ol comititnifies antdecos) stemis ilappropriate o aicr qutalilqs,lhichs poses at dangeI.to P!Iillic hlealthi I l( ill ...... ! p..... s .s.- d. " I'll" ''I' l I...... |' '.!.!I...... Npoorhltcllh ol c01mtiMitIlilies ait Pl'oitleamii-Sables and hiighi local I i.1 asahove Itaiit des I)ames h resmiltinie 4t4laih borne spteadof I ll(ill assistcommunit\ itlhhealth edtcatiosl anldresoTceS tO l ittigatc infrectiotist qci. |rot...... iewv diseases .e..a.c...... frtomi ...... dried sess age oni beachles cuirrenitealtlb eilectS *z...... - ...... eta!e!...... !...I s ...... i*longterm filiture ofcoiolninities to realiseeconomic highi local I 1 acah0 c postetial as tesult Or ilicipielt ttitections and general I Ill 1 tinidetiniitiiig el licctor diseaseantd p4)441 hcalith ndI...... ilil c c.... . e...... I ...... " ...... siudge 4it) ntrcatedefliltint accttttitilatnig in disciharge sigh/ local I .T asablotve osone.sinotheritig all exitultic organtislms testiltiieg it I l( ill . xtenSsieaiso.. z ic one-...... atids.c....Ii -...... *tIshernsetsltViced to travel to ishlinggtositds long nisediuumsl asaho c dlistances fronti lIoite. ssitll conseqtences lior efficiencc regional/l.1I ol.rsta litel. pressu!res Onl resotirces else"hl.ere MIDI)LJ.M huiipactsol p)o(r naterpmlsiit on healthimtid v italy o hliieli/ asabove isarilselxniuthic and platiltoitie comtssiities in Iloiite- regitsal/l.1l atgs-Sables...... lt...... lai!* aitd Riaindes l)atnes area LOW ...... ).t ...... - ...... itnpactof exceptionall) poorensironmental qttalit\ oni high / regiotnal/ 1. as abose ll'ortsto realise the tourismpotential ol'curretutl5 i Iill a1Tectedareas. ichiel!are lideally locatedfIr locals iimpactof'degraded cimirotutneit on attittudesof cdhiin/ as ahove o) erseas visitors to Matiritius national/LT

...... I ...... I...... I0z...... ul...... MEDIUtM...... ,4ontagire Jacquot Sewerage and Sanitation Project Environmental Impact A1ssessment

After the impact analysis shown in table 5.1 had been completed. impacts which were rated as highlv significant were evaluated to assess their potential for reversibility or irreversibilitv, cumulative effects. their probability of occurrence and the risks associated with them. This evaluation is shown in Table 5.2. below.

Table 5.'. Second step evaluation of highlysignificant impacts (see also AppendixN).

negative impactsof project reversible no probableto low% constructionphase ____ definite negative impactof loss of lOhaland irreversible no definite low for VvWTplant negativeimpact of effluentdischarge irreversible maybe probable lou on benthosand water quality in dischargearea off MontagneJacquot positiveimpact of projecton irreversible cumulative definite lo" environmentalquality in Baindes Damesand Pointe aux Sables areas positiveimpact on publichealth and irreversible cumulative definite loss sanitation positiveimpact on economic irreversible cumulative definite lo%% potentialof Baindes Dames and Pointeaux Sables communities. especiallyin the tourism.service. propertvand real estate sectors positiveimpact on coastalwater irreversible cumulative definite lou qualityfrom PortLouis to Pointeaux Sables positiveimpact on the coastal irreversible cumulative definite lou ecosystemsand coastal fisheries from PortLouis to Pointeaux Sables

The table shows that the risksassociated with all the highly significant positive and negative impacts were considered to be low. Irreversible negative impacts included the loss of I Oha of land for the proposed WWT plant site. and the impact of the wastewater discharge on benthic communities in the discharge area. The project is expected to result in cumulative and positive impacts on coastal water quality and coastal ecosvstems. as well as public health and sanitation. with downstream beneficial effects for realisation of economic potential of the Bain des Dames and Pointe aux Sables areas.

Slack A J'eatchInternational 5-7 Environmental impacts Montagne Jacquot Sewerage and Sanitation Project Environmental Impact .4ssessment

5.2 Potential significant negative impacts associated with the project

5.2.1 Land Acquisition and Displacement of Residents or Businesses

Land must be acquired for different components of the project. The largest area will be the approximately 10 ha Montagne Jacquot WWT plant site. It is located in an open. undeveloped area southwest of the Pointe aux Sables community The site is unoccupied. It is unused for any beneficial purposes. The ground is generally too steep. too rockv and too dry for agricultural use. The nearest residents are the prisoners in the Petite Verger Prison located immediately northwest of the site.

In addition to the Montagne Jacquot WWT plant site. it will be necessary to purchase easements or rights-of-way for placement of the transmission pipe line across private property. if alternative I is adopted for the transfer pipeline. The alignment of the pipe line mostly follows existing public roadways. but there are sections which will apparently cross private lands. Since the property surveys for the pipe line route have not been completed. it is not possible to identify the property owners. or to establish exactlv how much land will be required. However. the alignment was chosen to avoid crossing any residential property or any property occupied by business or commerce which would have to be relocated (see also section 3). The longest sections of easement acquisition will be across land under cultivation just inland from Pointe aux Sables. Following construction the land can be returned to its current beneficial use. and no residents will be displaced as a result of implementing the Montagne Jacquot project.

5.2.2 Construction phase impacts

The principal significant negative impacts associated with the Montagne Jacquot project will be experienced during the construction phase. If alternative I is adopted. this will be mainly during trench digging to lay the main transfer pipeline from Fort Victoria via Pointe aux Sables works to Montagne Jacquot. Whether the route chosen is along the main road (alternative I) or across the mouth of the GRNW and through the lagoon off Pointe aux Sables (alternative 2). mitigation of the negative impacts is not a straightforward matter. As shown in Table 5. 1.. the disruption to traffic. congestion and inconvenience during construction along the main road cannot be avoided if the land- based route is adopted. as there are no other potential routes further inland. The offshore-based option avoids the disruption along the road. but has cost implications. both during the construction phase. and later as a result of routine maintenance and repairs. Whichever option is chosen. the contractors will need to be closely supervised.

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to ensure implementation of the recommended mitigation measures. as well as efficient and competent management of the construction activities.

5.2.3 Impacts of the effluent discharge on water qualit, in receiving waters

The tvpical characteristics of the effluent to be discharged from the first phase of the Montagne Jacquot WWT plant were presented in Section 2.3.5 which described the treatment processes to be provided. A comparison of the typical effluent qualitv with the water quality standards for the ocean indicates that there are no pollutants expected in the waste water which would cause a violation of the standards. even without considering the effects of a reasonable mixing zone in the vicinitv of the outfall. or the further dilution effects of the effluent as it is carried away from the point of discharge.

The 1992 Gibb sewerage master plan provided a preliminary analvsis of the level of dilution that might be required for a typical waste water effluent to meet international ouidelines for coastal water quality standards. The analysis considered conservative parameters such as temperature. salinity, turbidity. suspended solids. and dissolved oxygen: nutrients in the form of common nitrogen and phosphorus compounds: toxic inorganic substances consisting primarily of the heavy metals: and microbiological organisms. It was assumed that toxic organic substances such as pesticides would be controlled at the source, before entry into the public sewers. The required dilutions for each of the water quality parameters were calculated. and found to range from negligible dilution. required to achieve temperature standards. to 100.000. to meet the standard for fecal coliforms for direct contact recreation. The dilutions required for the parameters considered by Gibb (1992) are summarized in Table 5.3.

The mathematical model of the ocean outfall constructed to a depth of 30 meters predicted that the typical dilution that would be achieved between the location of the outfall and the sensitive receptors at the Pointe aux Sables reef and lagoon was 14.000.

Applying this dilution factor to concentrations of any reported pollutants reduces their concentration to below the maximum acceptable levels set for lagoon water quality. without considering any possible attenuation in the concentration of substances due to biological or physical processes. For example, if the concentration of ammonia in the effluent discharged from the ocean outfall is the highest value measured at the Pointe aux Sables works. 85 mg/I. and if no attenuationwas achieved in the ocean as the waste water moved down to the lagoon. the concentration in the lagoon would be 0.006 mg/I. which is well below the acceptable standard of Smg/l.

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Table 5.3. Dilution required for typical sewage effluent to meet ambient ocean water qualitv standards (GIBB 1992). Parameter Dilution required aesthetics >100 pH none temperature nil dissolvedoxygen 166 (worst condition) salinity 12 suspendedsolids 240 nutrients 166 (worst condition) arsenic 10 cadmium 8.3I chromium 12 copper 166 lead 50 nickel I silver zinc 45 faecalcoliform 100 000 (worst condition)

With a dilution factor of 14,000 and no die-off of bacteria between the outfall and the lacoon. the concentration of fecal coliforms in the effluent could be as high as 106 '100 ml and still meet the standard of 100/100 ml. However. disinfection of the effluent will provide assurance that the coliform concentration is consistently below the required standard. so that the discharge for the proposed WWT plant at MontagTe Jacquot will consistently achieve the microbiological standard.

5.2.3.1 Heavy metal and pesticide contamination These pollutants are mentioned because they have been associated with serious environmental pollution incidents at various locations around the world. The best data on the occurrence of heavy metal in the coastal environment of Mauritius was published by SOGETI in its 1995 report on the inspection and analvsis of the effects of the waste water discharge at Pointe aux Sables. Samples of bottom sediment were collected at about 20 locations along four transects across the Pointe aux Sables lagoon. from the beach to the reef. The results of the analyses are shown in the following Table 5.4:

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Table 5.4 Concentrations of Heaw Metals Measured in Bottom Sediments from Pointe aux Sables Lagoon, and U.S. EPA Allowable Concentration in Sludge

_ 1 I EPA Parameter No. samples Range(gg/g) | Mean(i.g'g) Allowed (ig'g) Copper 19 19.8-34.8 25.8 4300 Zinc 19 125-736 365 7500 Nickel 19 2-23.5 9.4 420 Lead 19 16.9-47.8 28.2 840 Chromium 4 26.7-34.7 30.0 (a) Manganese 18 73-136 97 (a) (a) No limit imposedon this parameter

The sediment samples were analysed for copper. zinc. nickel. lead. chromium and manganese. Unfortunatel,.no bottomsediments were collectedand tested from along the coast away from developed areas, to provide an indication of the typical concentrationof these substancesin the ambient, unaffectedsediments. The results of the SOGETI samplingprogram indicatedthat the concentrationsof these metals were higher in the sediments in the vicinitv of the drainage ditches. near the Grand River North West end of the lagoon, and in the vicinity of the Pointe aux Sables works outfall. A previous study had also shown that the concentrationof manganesewas significantlyhigher in sedimentsfrom the GRNW than in sediments elsewhere alona the coast. No other conclusionscould be drawn as-tothe probable source of the metals.

A measure of the significanceof the concentrationsof heavy metals shownin the table can obtained bv comparing the concentrations found in the sediments with the concentrationsof the parameters considered to be acceptable in sewage sludge. The U.S. EPA has establishedmaximum limits for heavy metals that should not be exceeded in sludge that is sold or given away, for use by the general public or others for any purpose. The sludge is consideredsafe for any use if the concentrationsare below the values shown in the table. The 'safe' concentrations of these substances in sludge ranged from 20 to 165 times the mean concentrationsfound in the sedimentsamples. It was concluded that the concentrationsfound in the sediments were not a significant problem. Also. even if the heavy metals found in the sediment samples were caused wholly by the existing sewage outfall. the fact that the concentrationswere generally lo%Ais a good indication that the discharge of heavy metals in concentrationsfound in the Pointe aux Sables sewageeffluent is not a significantthreat to the environment.

No data are availableon the concentrationsof pesticides in the marine environmentnear Pointe aux Sables or Montagne Jacquot. nor are any data available on the

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concentrations of these substances in the waste water. However. most pesticide contamination is due to contaminated storm water runoff from agricultural lands. rather than from point source waste water discharges. Based on a review of the industries in the Montagne Jacquot project service area. there is no reason to suspect that significant quantities of pesticides would be present in the industrial waste waters discharged to the seu-eragyesystem.

5.2.4 Impacts of effluent discharge on reef communities

Althou-h the wastewater discharge at Montagne Jacquot is expected to fall well within the required effluent standard and to achieve the desired water quality standards in the receiving environment, the actual environmental impacts of the discharge on reef communities cannot be accurately predicted on the basis of the available information. Experience from elsewhere suggests that the performance of individual outfalls and environmental impacts on living communities. depends so much on the physical dispersion characteristics of the receiving environment. that generalisations can be misleading.

The most vulnerable organisms in the discharge area are the sessile benthic fauna. as thev have no possibility of moving. Typically, corals are among the first organisms to be affected by elevated nutrients and increased DOM in a wastewater dischar-e. as they are adapted to micromolar concentrations of nutrients and rapidly become necrosed and die-off. The situation may be exacerbated by the presence of bacteria and viruses. some of which may survive'disinfection at the WWT plant. to attack necrosing coral tissues. Other sessile organisms such as sponges and encrusting algae are also likelv to be adversely affected in the inrimediate discharge area. although some algal species will benefit from the elevated nutrient levels and grow more prolifically. providing light is not attenuated by increased concentrations of suspended solids.

Although some baseline research has been carried out into water quality in local reef ecosystems by the Albion Research Centre. impacts of existing wastewater discharges have not been monitored over time or in sufficient detail to allow extrapolation to the proposed discharge and prediction of potential impacts. Also. there is insufficient species specific information to allow prediction of environmental impacts of the proposed discharge on individual species.

The extent to which both corals (which tend to illicit most concern) and non-coral species are impacted bv sewage discharges, is in fact very poorly substantiated for

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tropical reef ecosystems. Results of a review of nutrient levels which can cause eutrophicationin coral reef systemswere reported by Bell in 1991.following analvses conductedat KaneoheBay. Hawaii and Barbados.It was concludedthat eutrophication can occur at inorganicnitrogen concentrationsof about 0.014 mg/l and phosphate (as phosphorus)concentrations of 0.003 to 0.006 mg/l. The report further considered it likely that the addition of nutrients would lead to eutrophicationwhich would cause significant changes in the coral reef community bv promoting the growth of phvtoplankton and benthic algae. Phytoplankton compete with the photosvnthetic zooxanthellaein corals for light, and thus interfere with coral growth. Benthic algae also interfere with the life processes that ordinarily occur at the coral surface. and to-ether with filter feeders directly compete with corals for space. It is worth noting that the highest concentrationsof N and P in untreated waste water discharged from Fort Victoria and Point aux Sables were 101.6mg/I and 49.5 mg/I respectively.After primary treatrnent the expected reduction in N and P will be around 20% and 15% respectively.Consequently as the treated effluent is discharged from the ocean outfall and diluted approximately 14000 times. it seems unlikely that the N and P concentrationswill be sufficientlyhigh after primary treatmentto cause eutrophicating conditions.except in the immediatedischarge zone.

The effects of sewageeffluent on coral reef communitieswere also reviewed in '-Effects of Sewage Pollutionon Coral Reef Communities"(Pastorak and Bilyard. 1985). The report concluded that although a wide range of impacts from sewage on coral reef communitieshave been reported. little or no impact has been observed in well flushed waters. Dischargesinto poorlyflushed lagoonsare the most damagingand have caused major changesin speciescomposition and abundance. The three componentsof sewage consideredmost detrimentalto coral communitieswere nutrients. sediments.and toxic substances. Nutrient enrichmentmainly from terrestrial sources has caused significant impacts over substantialareas of the Great Barrier Reef. and so reduction in nutrient concentrationsfrom both point and diffuse sources is now a pivotal strategy in the Great Barrier Reef Marine Park Authoritywater quality improvementprogramme. As settled solids will be removed from the discharged effluent during primary treatment at Montagne Jacquot. heavy sediment loads which may be lethal to corals. and lesser quantities which may inhibit the growth or alter species composition.are not expected to cause problems in the dischargearea off MontagneJacquot.

Rogers (1990) described the variety of mechanisms used by corals in coping with sediments. Where currentsand wave action are strong, water movement will help keep sediment particles from settling on corals. and corals will exert less energy in sediment

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rejection. A common problem in working with corals is that field studies frequentli vield contradictory results. which may also differ from laboratory results. which means that site specific and species specific information is necessary to predict impacts of effluent discharges accurately. In the present case. the lack of species specific information. in particular means that the implications of the proposed wastewater discharge for individual species cannot be predicted

Despite the system of diffusers and expected dispersion and dilution performance of the outfall. the relatively slow bottom currents in the discharge area at some periods of year. mav militate against steady removal of effluent out of the main discharge area. leading to eutrophication of coastal waters off Montagne Jacquot in comparison with areas not affected by wastewater discharges. The extent of this effect will onlh be established during follow-up monitoring water qualitv surveys. The target water quality standards which the discharge will be required to meet to allow recreational activities in the waters off Montagne Jacquot. and the introduction of a disinfection stage into the effluent treatment process. means that the potential health hazards for swimmers. divers etc. in the vicinity of the outfall will be negligible.

As mentioned above, because of the extreme sensitivity of corals to elevated nutrient concentrations, it is highly likely that some bleaching and death will be observed in communities near to the discharge and some damage can be expected to extend as far as Pointe aux Sables reef. However. the extent of the area impacted by the discharge cannot be predicted accurately at present. and it would only be possible to reduce this area if hieher levels of treatment were installed at the WWT plant.

Inevitably loss of corals leads io progressive deterioration of the reef ecosvstem. since it is dependent on coral productivity to drive the system. so that the greater resilience of associated species becomes more or less irrelevant. Whilst it is obviously preferable to avoid anv deterioration in coastal marine communities and reef ecosvstems in particular because of the manv important resource generation and protection functions the! serve. there are verv few locations around the coast of Mauritius where it is possible to avoid coral reefs. The site adopted for the Montagne Jacquot outfall is one of the fesx breaks in the reef on the west coast of Mauritius suitable for an outfall. where the consequences of some deterioration in reef communities (not of exceptional quality or diversitv) are acceptable. on grounds of making possible the urgent and very necessarv improvements in environmental qualitv further north.

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5.2.5 Impacts of tize Montagne Jacquot WWT plant

The impacts resulting from normal operation of the new WWT plant at Montagne Jacquot will depend to a large extent on whether the plant is efficiently and properly managed. The potentially significant impacts can be mitigated in the course of normal operations at the site and/or through supervision and monitoring of staff activity A plant of this type can produce offensive odors. and if they prove to be unacceptable to the local residents. as a result of their frequency. duration or magnitude. new odor control facilities can be constructed. Additionally if the sludge disposal operation is not managed cleanly and efficiently. it is likely to result in complaints from the general public. The technology on site will be relatively straightforward to manage. and so the most important element in maintaining future trouble free operations is to ensure that the plant staff are conscientious and committed to running a well managed operation.

But no matter how efficientlv the WWT plant and associated operations are managed. it seems unlikelv that it will be possible to avoid some localised impact on property values in the vicinity of the plant. However. the inclusion of the 400m buffer zone. planted up with trees will do much to mitigate the negative impact on property values. which may recover once local residents realise that a modem-day WWT plant which is properly managed need not have the same offensive environmental impacts as many of it's predecessors.

5.3. Potential positive impacts associated with the project

The environmental and socio-economic impacts of the Montagne Jacquot Sewerage and Sanitation Project are expected to be overwhelmingly positive. The present discharge arrangements in the Port Louis area and south beyond Pointe aux Sables are resulting in extremelv poor environmental quality. unacceptable impacts on human health and well-being. The degradation of the marine enviromnent is so serious that only a few species can survive in the areas affected bv waste water discharges. Removal of the discharge point to the proposed location off Montagne Jacquot. combined with treatment and disinfection. is expected to result in major improvements in environmental quality in coastal waters. along the shoreline and in the coastal v illages from Port Louis to Montagne Jacquot.

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5.3.1 Benieficial impact of rehabilitation of coastal ecosystems

The implementation of the Montagne Jacquot Project. and in particular the decommissionin- of several outfalls and their replacement with a single ocean outfall off Montagne Jacquot. is expected to have some immediate beneficial effects. but because of the exceptionally serious degraded state of the local marine environment. natural rehabilitation of the currently affected areas will take some time. It is possible however, that as a result of a single cyclonic event. the coastal embayments will be flushed out and residual settled sewage sludge will be carried offshore - but cvclonic events cannot be depended upon to have this effect. It is more likely that normal seaside activities such as swimming. fishing, various activities in boats and beachcombiny will only be resumed in the Bain des Dames and at Pointe aux Sables after several vears. as locals overcome their concerns about health risks and realise that these activities can become a part of their normal lives. As the contributions from the port and the GRNW to coastal pollution have not been evaluated and will not be diminished by the proposed project. it could take many years before improvements are recognised. Natural rehabilitation mav be assisted nevertheless. by communitv efforts at beach cleaning. removal of waste garbage from the shoreline. In the longer term. rehabilitation of coastal ecosystems should include recovery of the coastal fishery to some extent. providing there are no other adverse impacts which halt the rehabilitation process.

5.3.2 Beneficial impacts of improved healtih of affected communities

The undermining effect of poor health resulting from frequent ear. nose and throat infections. and respiratory disease as well as debilitating skin infections such as those frequently experienced by fishermen in the area, has a serious undermining effect on the energy and industry of any community. Restoration of better health and morale to those currently affected communities in the Bain des Dames and Pointe aux Sables areas. is likely to result in initiatives for self-improvement and developing economic actixits.

5.4. Economiccosts and benefits of the MontagneJacquot project

The economic costs of the project can be divided into the capital cost of financingthe constructionof the facilities.the annual costs of operatingand maintainingthem. and a variety of other costs to the community as a whole. The most readily apparent costs are the values of goods and services and altemnativeinvestments that have to be foregone because the money is expended for the sewerage project instead of something else. This can be approximatedby the initial capital costs of construction and the ongoing

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monetary costs of operation and maintenance. The economic costs associated with the project include all costs to the people of Mauritius (and visitors- and foreicn monies). not just those directly incurred by the Waste Water Authority. Examples of these external costs are the lost time and added expense of travel and inconvenience due to traffic congestion during construction. and the intangible costs due to nuisances such as odors from sludge hauling trucks. or noise from the pump stations. or unsightly industrial facilities. The cost of damage to the ocean and the local environment is another type of cost that cannot be quantified.

Economic benefits can be as difficult to quantifv as some economic costs. It can be argued that the value of the benefit of having better sewerage facilities is at least equal to the cost of providing the facilities - otherwise the community would elect not to build them. The economic benefit of cleaner water at Bain des Dames and at Pointe aux Sables will be certain. but providing accurate estimates of the value is not possible. Rational approaches have been developed to estimate the value of recreation. for example. but these estimates typically only consider verv limited aspects of the total experience. One method considered appropriate is to measure how much individuals would be willing to pay for the benefit (or to avoid the cost), but this measure also has many drawbacks since the willingness to pay varies with countless parameters among the countless individuals participating in the recreation. Also. the value of better health among the local population cannot be accurately estimated. For example. there are no data or statistics on the incidence of illnesses (of all kinds) which can be attributed to exposure to the unsanitary conditions. nor any data which can be used to determine the extent to which the unsanitarv conditions can be attributed to the sewerage svstem. nor anv data on the costs incurred by the population due to ill health from these causes.

The costs which can be fairly accurately estimated (as compared to those mentioned in the preceding paragraphs) are the capital costs, finance costs. and annual operation and maintenance costs. As part of the project planning process. capital and operating costs were estimated for the proposed treatment planL for the transmission pipe lines. and for the two new pump stations at Fort Victoria and Pointe aux Sables. as shown in Table 5.5 below.

Operating costs for waste water systems are primarily due to the cost of labor to operate and maintain the system. the cost of chemicals required for process operations. the cost of supplies and spare parts to maintain the facilities. and the cost of electricity to operate the processes. These costs typically increase as flows increase. The preliminarv estimate of probable annual operating cost in 2005 and beyond. for the proposed waste

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Table 5.5. Estimated Capital Costs for Proposed Facilities

Facility Cost

Transferpipelines 300 Transferpumping stations 140 Wastewater treatmentplant 420 Oceanoutfall 200 TOTAL I Rs 1,060 million

water treatment facilities at Montagne Jacquot was Rs 30.5 million per vear. The annual cost of operating and maintaining the proposed pump stations and transmission mains was estimated to be Rs 5 million per year.

The cost of financino the construction of the proposed facilities must also be considered as part of the total project cost. The financing cost will depend primarily on the source of the money borrowed to pav for the construction and the terms of the loans. Several alternative financial packages are being considered. The estimated effective interest rate over the life of the loans will be between 6.5 and 7.0 percent. based on constant valued Rupees. On this basis. the equivalent annual cost of the loans will be between Rs 95 million and Rs 100 million per year.

5.4.1 Realisation of economic benefits of tlhe project

The realisation of manv of the potential economic benefits of the Monta(gne Jacquot project will depend on a multitude of factors, including macro-economic conditions prevailing in the next few vears. the capacity and will of government to assist communities with development of skills and business opportunities. the time scale of rehabilitation of coastal water quality and natural ecosystems as well as motivation and initiatives by local communities themselves.

There is little doubt that development of strategic plans with the relevant gtovernment agencies for regeneratin- and enhancing economic opportunities of the worst affected communities. will help them to realise the economic potential of the area. Because of the proximity of the Bain des Dames and Pointe aux Sables communities to the main commercial centre of Mauritius. and the recognition they have already received as potential recreational zones in the city, it is likely that development of the services and propertv sectors and development of tourism. may well assist in the diversification of economic activity and expansion of employment opportunities in the area.

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5.4.2 Development of service sector and propertv market

Improvements in environmental quality in the Bain des Dames and Pointe aux Sables area. and especially the removal of offensive odors and negative aesthetic impact of raw sewagyeand miscellaneous debris on the shoreline. will almost inevitably result in these areas becoming more sought after, both for residential and business / commercial premises. with consequent direct impact on real estate prices. A port-side location is advantageous for a whole range of businesses and, commercial activities servicing the port itself and international and local trade through the port. so that marine equipment and service providers. small boat and yacht building. cartographic and marine suppliers and many others types of business are likely to show renewed interest in the area as a direct consequence of improvements in environmental quality The pressure for space is already being felt in the central port zone. and in the long term. if plans to expand the economic free trade zone are realised. there will almost certainlv be renewed interest from the property and investment sectors in the Bain des Dames area in particular. The associated drive for improved infrastructure. especially in relation to water. sewage and communications and roads. will drive up property prices still further. and stimulate the building sector to improve / adapt and renovate existing properties or build new ones.

Similarly, development of businesses which depend on raw materials or products landed at the port - will also look on the area with renewed interest. These might range from fish restaurants to software houses. but property close to the port and main island infrastructure is likely to be a prime consideration. Despite the new developments which have occurred'in the main port area. Bain des Dames. with it's remaining traditional homes. mix of cultures and colonial properties. will be highly sought after to develop restaurants. wine bars and jazz clubs etc.

5.4.3 Development of tourism sector

Although the time scale of rehabilitation of coastal ecosystems is difficult to predict. the potentiallv positive economic benefits resulting directly from improvements in water quality in the Fort Victoria and Pointe aux Sables areas. will immediately- make it feasible to conduct a range of recreational activities in coastal waters which have previously been avoided by locals and tourists The traditional / fishing communities Bain des Dames and Pointe aux Sables are ideally located for developing water based activities. Sightseeing. fishing and diving from shore-based boating enterprises. as well as visiting the port or reefs accessible from the port base. may well become potential business development areas. Sailing, wind-surfing. canoeing. water skiing and other

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wind or motor-driven activities all become possible near Fort Victoria and in the Pointe aux Sables lagoon with improved water quality. with associated potential for expansion of hire companies to service tourists along this stretch of coast. Bird wvatchingand photographic tours. boat trips to attractive localities along the coast. may all find a market close to the port and contribute to the incomes of local communities.

5.4.4 Rehabilitatioin of coastal fishery

The prospects for rehabilitation of the coastal fishery are difficult to predict - much depends on the rate at which natural functions are restored to the coastal ecosystems. and the extent to which spawning areas for the main coastal fish species have been irreversiblv damaged. There is insufficient information available at present to provide a realistic evaluation of the prospects. but clearly. for those traditional fishinu communities in the area who currently have to travel long distances to fishing grounds further south. incurring time and additional costs. the gradual rehabilitation of coastal fisheries closer to home is a very important issue. There is little doubt that a return to sustainable exploitation of fisheries in easy access of their home port. would be widelx supported bv the local traditional fishing communities.

5.4.5 Protection of biodiversity resources

The extent to which coastal marine and estuarine biodiversity resources have been irreversibly damaagedby the current disposal arrangements is impossible to predict. To our certain knowledge there were no detailed evaluations of the coastal marine resources prior to the present degraded situation developing in the Port Louis area. and there is really only anecdotal'evidence to testify to the gradual decline in fishery and coral reef ecosystems off Port Louis and Pointe aux Sables. Although it is very unlikely that the natural resources base in coastal waters close to Port Louis will ever fully rehabilitate, the partial restoration of normal ecosystem functions will assist to some extent in the rehabilitation of west coast waters, by reducing inputs of' untreated effluents. Because of the gross deterioration in water and sediment quality. it is highly unlikely that any exceptionally protection-worthy species have survived. although confirmation of this presumption will have to await more detailed studies. At this stage. the most we can say is that the improvements that the Montagne Jacquot project will bring to the area. can only benefit protection of biodiversity. by reversing the trend towards increased degradation of the directly impacted and adjacent ecosystems.

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Field studies carried out during this environmental impact assessment indicate that there are no conservation-worthy biodiversity resources in the area which will potentially be impacted by the new discharge off Montagne Jacquot. Although common species of coral are present in the area, there is relatively low species diversity. with maximum of 30% coral cover at 7m depth in the discharge area. It appears that these communities are already impacted to some extent from the combined effects of phvsical storm damage to the reef and eutrophication originating at the existing discharges.

5.5. Economic costs and risks of the no-project option

For the communities which are currently tolerating the gross irnpacts of the present lamentable situation. the costs of not implementing the Montagne Jacquot project are incalculable. All the potential improvements mentioned above in quality of life. health and transformation of the economic prospects in the affected communities will simply not materialise. Whilst it is often helpful to provide estimates of economic costs and benefits in hard currency. in the present case. there are many unknowns which make such a calculation meaningless. Realisation of potential economic benefits depends on many factors which are outside the scope of this study to determine such as long term macro-economic trends and motivation from within the communities themselves to diversify economic activity. Equally an assessment of the costs incurred through the present situation depend partly on information which it is impossible to establish correctlv - such as the costs of medication to treat illness resulting from the existing discharge arrangements in the worst affected communities and the indirect costs of poor health in terms of unrealised human potential and social capital. Because of the hypothetical nature of the quantitative economic evaluation, it has been excluded from this EIA.

5.6. Potential irreversible and residual negative impacts of the project

The irreversible and residual negative impacts of the Montagne Jacquot project are those negative impacts for which no mitigation measures have been identified and which are irreversible once they have occurred (see table 5.2.) Taking the main components of the project in turn, these impacts may be summarised as follows:

0 direct loss of land as a result of locating WWT plant at Montagne Jacquot. 0 associated loss of recreational opportunities along shoreline boundary of site. 0 decrease in value of real estate adjacent to WWT plant site. 0 limitations on the use of land adjacent to the plant for residential developments.

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These residual negative impacts in relation to the site are inevitable. and as far as we can discern. there are no mitigrating measures which can be taken at that location to offset the impacts. Information which emerged in scoping sessions (see Appendix H) should be verified regarding granting of planning permission for new- residential developments. since these may be fundamentally affected bv the need for a buffer zone around the Montagne Jacquot plant.

With respect to the location and functions of the ocean outfall. residual negative impacts will result from O the placement of the outfall structure at the proposed location with inevitable loss of benthic communities along the pipeline route. O the discharge of treated effluent from the outfall. with inevitable impacts on benthic and planktonic biota.

With care on the part of the contractors to minimise disturbance during the pipeline emplacement operations. the direct losses of benthic organisms and general disruption of the communities can be kept to a minimum. Certainly the benthic infauna are very resilient and normally recover rapidly. but damage to corals cannot be reversed - once the calcareous structural components have been damaged there is no possibility of restoration except in the long term. It is inevitable that communities in close proximity to the discharge which are subjected to elevated nutrient levels. will deteriorate. but the full extent of permanent damage to the marine communities in the outfall area will onl- be understood following intensive monitoring of the area over a number of vears.

If the transfer pipeline between Fort Victoria and Montagne Jacquot follows the land- based route. the main concern in the long term is the increasing pressure on an infrastructure corridor which is already congested. If electric cables. telephone lines. potable water mains. sewers. storm drains or other infrastructure need to be laid or repaired along the same route. the problems of interference become increasingly acute. The offshore-based route on the other hand has no such constraints. and once the pipeline is laid it is very unlikely that there will be interference from other infrastructure. However. it will be essential for the offshore trench digging operations to be managed efficiently with implementation of all recommended mitigation measures. if further environmental degradation in the marine environment is to be avoided.

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SECTION 6

ANALYSIS OF ALTERNATIVES OF THE PROPOSED MONTAGNE JACQUOT PROJECT

Black & Veatcl, International Analysis of project alternatives A 4,is Pt Montagne Jacquot Sewerage and Sanitation Project Environmental Impact .4ssessment

6.0 ANALYSIS OF ALTERNATIVES OF THE PROPOSED PROJECT

6.1. Alternatives to be considered for the Montagne Jacquot project

The main options which will need to be considered before final decisions are made regarding the components of Montagne Jacquot to be implemented are as follows:

0 Firstly whether the project should go ahead at all; do the socio-economic and environmental benefits outweigh the costs. and are the necessary financial resources available to meet capital. operation and maintenance costs? The consequences of the 'no-project' option will therefore be evaluated. 0 Secondlv. the location of project components must be reviewed. includint the preliminarv decisions which fixed the Montagne Jacquot site for the WAWTplant together with the location of the outfall (see Figure 1.1). and the final route of the transmission pipe lines. There are two general options regarding the route of the transfer pipeline from Fort Victoria to Pointe aux Sables. The land-based option follows communitv roads for most of the route. whereas the offshore-based route avoids particularly congested stretch of road in the vicinity of the GRNW and passes across the mount of the river and through the shallow lagoon just off the Pointe aux Sables beach. 0 The final choice which will need to be made concerns the level of treatment to be installed at the WWT plant. The two options being considered are firstly. primary treatment with disinfection. and the effluent discharged through the ocean outfall. or alternatively, secondary treatment with ocean discharge of effluent.

6.2 Evaluation of alternatives

The project altematives shall be compared in terms of their potentially significant environmental and socio-economic impacts. including capital. operational and maintenance/repair costs. The weighting system used to evaluate each pair of options simplv used a negative (-) and positive (+) weighting to evaluate the consequences of one or the other option for the key environrmental and socio-economic issues considered.

6.2.1 Evaluation of the no-project option

The following Table 6.1 summarises the key environmental and socio-economic issues identified in the EIA and evaluates the consequences of the Montagne Jacquot project being abandonned (ie. the no-project option) or being implemented.

Black& VeatclImternational 6.1 Analysis of project alternatives MontagneJacquot Sewerage arndSanitation Project Environmental Impact Assessment

Table 6.1. Kev environmental and socio-economic issues for the evaluation of the no-project option.

biophysicalII wvaterqualitv off existing outfallsI_ water quality off Montagne Jacquot contaminationisediments : existin2 outfalls I_I contamination sediments: new outfall ecological health of benthic infauna - health of coral reef communities ._ _ coastal fisheries I nurseries and spawning areas _ land-use wastewater re-use for irrigation (potential) l _ social

improvement in quality of life ______health risks - air quality risks from eating contaminated fish recreational health risks _ occupational health risks economic potential recreational potential _ _ infrastructure conflict with existing infrastructure tourism development of tourism development of services employment opponunities _ costs capital costs operational costs maintenance costs environmental management

mitigation -. Ratio positive to negative 0.39 2.57

The analysis is simplistic. It implicitlyassumes all listed issues have the same relative value: it only provides a single response (positive / negative) for infinitelycomplex and interrelated issues; it groups complex issues into single items: it relies exclusivelvon qualitative evaluation. Nevertheless.its value is that it distills the complex questions and issues into specific conclusions. The result is that the analysis demonstratesthe overwhelminglypositive benefits which are likely to flow from the implementationof the Montagne Jacquot project where enviromnental and socio-economic issues are considered.in comparisonwith the no-projectoption.

Black& JeatclInternational 6.2 Analysisof projectalternatives .MonItagnleJ'icqiiot Sewerage and SaunitationProject Environmental Impacta4ssessiment

The financial implications associated with capital. operation and maintenance costs are the most important negative consequences of implementing the project. However. most of the favorable financial implications could only by described qualitativelN due to the difficulty of assigning monetary value to many of the environmental and socio- economic costs of allowing the present situation to continue. There are inevitably costs resulting from health impacts. from direct loss and degradation of marine resources. losses from unrealised economic potential. reduction in social capital through loss of well-being and quality of life in the affected communities and so on. These costs are extremely difficult to quantify in conventional economic terms. However. it is generallv recognised that natural systems which have lost the ability to sustain theilselves or the communities which were in the past dependent on them. result in serious direct and indirect costs with ramifications far bevond the visible pollution effects which constitute most people's evervday experience of ecosvstem deterioration.

6.2.2 Evaluation of location of project components

MontagneJacquot Project Site. The site of the proposed waste water treatment plant was first recommended in the 1992 sewerage master plan prepared bv Gibb (Mauritius) for the islands of Mauritius and Rodrigues. The principal advantages of the location are:

O There is sufficient open land to provide a site large enough for initial facilities and future plant expansions. O It is remote from densely populated or residential areas. yet close enough to the community to avoid the cost of excessive transmission pipe line costs. O The plant will not displace any residential properties. 0 It is in a location alreadv served by water and electric utilities. 0 The shore line at that location is not protected by offshore reefs and lagoons. so those valuable ecosvstems will not be directly damaged: deeper ocean waters are closer so the ocean outfall can be shorter: and ocean currents and tidal movements provide better dispersion of the effluent. O The site is near to active agricultural areas which could benefit from reuse of the effluent if it is determined to be economically feasible: the location aids the potential for this reuse because of its proximity to potential reuse areas. 0 The plant will not takLeexisting agriculturallv productive land out of production. 0 The site is lower in elevation than other potential sites further inland. which makes the cost of transmission of the waste water lower.

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O The site is currently undeveloped and is designated as beyond the approved residential zone in the NPDP (deferred zone). The site is rockv and dry. with poor soil and has Iow value for agricultural use. 0 The nearest occupied property is a prison. which generally detracts from the value of the property for alternative uses. 0Although there have been preliminary plans made by property owners in the vicinity of the site to construct residential units. no residences or businesses exist within about 600m of the site. 0 Although there is a small amount of activity along the shoreline (fishing etc.) access througththe buffer zone will allow these activities to continue.

The unfavorable characteristics of the site are that it has a relatively steep slope and is underlain by basalt rock at shallow depths which will make excavation expensive. and the placement of the structures on the site may be dictated by the ground surface elevation rather than preferred geometric arrangements. Finally. the site is adjacent to the coast which despite the presence of the Petite Verger prison. may have potential value for recreation. scenic and aesthetic opportunities. and construction of the treatment plant will conflict with these alternative uses.

It was concluded that the favorable characteristics of the site far outweighed the unfavorable characteristics. No other location was identified which possessed all of the favorable characteristics of the Montagne Jacquot site. although several were observed which were more level and which had more soil over the subsurface basalt rock. The site review was carried out by examining maps and by visual inspection of open lands between Fort Victoria and Montagne Jacquot.

Transmission Pipeline Route. The main impacts associated with both the offshore and the land-based option for the transfer pipeline occur during the construction phase of the project. Once the pipeline is in place. it serves it's vital transfer function wxithout interfering with the lives of people living or working near it. The pipeline might only become problematic during routine maintenance or if leaks develop and repairs become necessarv. However. it was primarily to avoid the construction phase impacts of laying the transfer pipeline along the main road. that the offshore based option has been considered at all. The offshore-based option clearly has essentialIh the same characteristics as the land-based option. in that if it fimctions without developing leaks. or is damaged in any way. there are unlikely to be problems associated with it. except during routine maintenance or repairs. when many of the impacts experienced during the construction phase will again occur. However. the offshore based option is more

Blac & I-eatchInternational 6.4 Analystsof project alternatives MontagneJacquot Sewerageand Sanitation Project Environmental Impact .4ssessment

susceptible to severe corrosion conditions and therefore has a shortened life span. Table 6.2 below shows that the two options emerge as being very similar in this simple analvsis. On the one hand the land-based option is the preferred option if cost. technical requirements and availability of construction equipment are considered whereas the offshore based option is preferred when the construction phase impacts are considered .

Table 6.2. Evaluation of alternatives for transfer pipeline

Construction phasel InfrastructureI conflict with existing infra-structure e.g-. telephone._l |electricity, water, etc. disruption caused by trench digging and resultant one way traffic along already congested routeway noise. dust, general disturbance to residents alongo road associated with digging trench l damage to road servitude. premature requirements for maintenance. road repair, etc. I lack of space for future infrastructure as result of large transmission pipeline along right-of-way l requires imported construction techniques. expertise + and equipment which may not be available locally uses risky construction techniques which can cause unanticipated costs or delays l | worker accidents along route. traffic management under difficult conditions. vehicle accidents lBio-p lysical temporary lowering of water quality offshore - temporary increase in sediment offshore deterioration in downstream water qualityv +_| run-off and sediment into storm drains Ecological disruption benthic infauna offshore + blanketing of corals from sediment drift r disruption of reef fish populations. _ Socio-economic quality of life for residents along road noise, dust, disturbance from heavy machinery disruption of fishing vessel movements disruption of recreation in vicinity of construction Costs Capital -_ t_____ Mitigation + Maintenance and repairs + Total 13/9 91 3

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6.2.3 Evalulation of alternative treatment options

The treatment options were evaluated on the basis of the following: * environmental impacts of wastes discharged after treatment using different alternatives, * relative costs of alternative treatment options - (ie. capital. maintenance. operating). * resources and skills required to operate and maintain plant based on different alternative treatment options, * legal implications - to what extent could effluent discharged from alternative treatment plants meet water quality standards in receiving waters.

- - The deficiencies in background scientific data on marine organisms from Mauritius. mean that the impacts of different levels of treatment at the WWT plant. cannot be meaningfully compared at present. The level of treatment selected for a new- plant is usually based on the water quality standards of the receiving waters. typically classified according to their beneficial uses - as general, bathing waters or for protection of conservation-worthy habitats or species. or the minimum treatment requirements established by the appropriate regulatory authority. The standards are therefore set after taking into consideration as many of the relevant factors that are known. and the standards can be adjusted as conditions or requirements change.

Nevertheless. Table 6.3 below summarises the predicted characteristics of waste water effluent following primary or secondary treatment at the WWT plant. and the likely water quality in the receiving environment off Montagne Jacquot and impacts on coastal marine communities in comparison with the present situation.

There is no doubt that installing secondary treatment at Montagne Jacquot WWT plant will result in a higher quality effluent being discharged with removal of a larger percentage of all the main components with potential for causing impacts. Notably the reduction in BOD. COD. TSS. total coliformns.N and P. result in higher standards of water quality being acheived in the receiving waters, with consequent higher standard of protection for marine communities in the discharge area.. As has already been discussed in section 2. the recommended alternative treatment option of primary treatment plus disinfection with chlorine is based on the need to meet proposed national water quality standards in the receiving waters (Gibb. 1993). Experience from elsewhere has shown that it is not possible to predict the exact nature and extent of the environmental impacts at a particular location, as they are dependent especially on local dispersion characteristics of the receiving waters. The comrnunities in the proposed

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discharge zone are not considered to be particularly conservation-worthy. because of the break in the fringing reef. poor phvsical state of the reef off Montagne Jacquot and limited species diversity in comparison with other sites in Mauritius. There is alwavs a drive for higher standards of treatment. but the gains in environmental protection have to be realistically balanced against the willingness of society to pay for improvements.

Table6.3. Characteristics of waste water effluent for Scenario I and 2.

Characteristicsof waste watereffluent ScenarioI Scenario2 Primary plus Secondarytreatment disinfection Effluentquality Suspendedsolids 50-65%removed 85-90%removed BOD 30-40 80-90 COD 30-40 80-90 Totalnitrogen 10-20 25-45 Total Phosphorus 5-15 20-40 Totalcoliforn 30-60 90-99 Heavymetals (bar Ni) 30-50 50-70 Organicpesticides 20-50 70-100

Waterquality (cL present) BODand COD =_I nutrients (N,P,K) l turbidity i faecal coliform= risk of toxic chemicals l

Waterquality standard achieved general coastal waters yes ves recreationalbathing waters yes yes conservation-worthyecosystems - special no maybe |protectionstatus (immediate vicinity) ll

|Ecosystemhealth (cf. present)l Benthicinfauna Phytoplankton production = Zooplankton production l _l Fisheries l_l_=_l Spawning and nursery areas Coral reef communities Flora and fauna associatedwith reef

Black A V"eatchtInternational 6.7 Analysisof proijectalternatives Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

6.3 Recommended combination of options for Montagne Jacquot project

The evaluation of alternatives which have been considered for the Montagne Jacquot project suggests that the following conclusions and combination of options should be adopted on environmental and socio-economic grounds:

O All the evidence gathered in the environmental impact assessment suggests that the Montagne Jacquot project is urgently required to address a situation which has long been unacceptable for the affected communities, particularly in the Pointe aux Sables and Bain des Dames area. If the no-project' option is adopted. the prospects for improvement to local pollution which adversely affects both human communities and marine ecosystems in the Port Louis area will be very bleak indeed. with no possibility of restoration of natural functions in ecosystems or rehabilitation of communities with associated economic and social revival. It is strongly recommended that the 'no- project' option be rejected. O The Montagne Jacquot site possesses many significant advantages which outweigh the disadvantages of the site. notably the fact that there will be no need to relocate or disrupt in any way residences, businesses or existing commercial operations. No other location offers better advantages. The Montagne Jacquot site should be chosen for the proposed waste water treatment plant. , OThe analysis of alternative transmission pipeline routes indicates that the land-based option will result in significant negative impacts during construction of the transfer pipeline. However. when construction costs are considered. the potential for use of local labor and technology for construction. the lower risk of unanticipated costs and delays. and the lower risk of pipeline corrosion are all considered. the land-based route is the preferred option. There are many impacts which humans are prepared to tolerate for a better life. and although it is evident that local communities would prefer to avoid the disruption and inconvenience during construction along the land-based route. concems regarding additional damage which may be sustained by the reef communities if the offshore option were recommended, will need to be discussed with the community. It appears that technical and financial considerations will anvwav drive the final decision with respect to these two options for the transmission mains pipeline. O The decision regarding the level of treatment to be provided by the proposed Montagne Jacquot WWT plant was determined by the effluent water quality standards proposed for ocean discharges and potential environmental impacts of effluent on benthic communities. It was also supported by considerations of capital. operation and maintenance costs. The level of treatment can be upgraded in the future if water

Black& 'eautchInternationul 6.8 - An,alysisof projectulternatives Montagne Jacquot Sewerage and Sanitation Project Environmental Impact A.ssessment

quality standards change, or other factors indicate that the quality of the effluent should be improved.

The recommended combination of treatment processes for the Montagne Jacquot treatment works is therefore preliminarv treatment with screening and grit removal, primary treatment and disinfection. The recommended sludge management system is dewatering with belt filter presses, stabilization with lime, and disposal by hauling the sludge to the Mare Chicose landfill. The recommended effluent disposal method is to discharge the effluent to the sea through an outfall 645 m long, at a depth of 30 m.

It is worth mentioning that no matter which level of waste water treatment is provided at the Montagne Jacquot WWT plant, the project will acheive major environmental and social benefits simply by transferring the point of discharge to a less sensitive site at a break in the fringing reef. with better dispersion characteristics which is more distant from human communities and their associated fishing and recreational activities. Although there will be environmental impacts on the benthic communities in the new discharge area. by implementing a comprehensive environmental monitoring program (see section 9). and taking action to control components of the discharge if necessarv. it will be possible to restrict impacts on marine communities to a limited area around the point of discharge.

BlackA V"eatchInternational 6.9 Analysis of project alternatives I Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

SECTION 7

MITIGATION PLAN

Black Veatclh International Mitigation plan 4 (: Montagne Jucquot Sewerage and Sanitation Project Environmental Impact Assessment

7.0. MITIGATION PLAN

7.1. Introduction

The main purpose of the mitigation plan is to provide a strategy for environmental protection whereby all the activities associated with the Montagne Jacquot project through design, construction and comnissioning of the plant. to operation are controlled and monitored to ensure that time and national resources are not wasted through lack of ongoing care, and that problems occurring during the project are identified and rectified to prevent damage to the environment.The mitigation plan addresses specificimpacts identified in the EIA. If some issues have been overlooked. the mitigationplan shouldbe amendedin consultationwith the regulatoryauthorities to ensureeffective mitigation is implemented.

The mitigationplan thereforeaims to ensurethat:

I project activitiesare managedso as to reduce or avoid negative environmentaland social impactsand enhancepositive impacts, 2. the currentlyaffected communitiesare better off after the project is implemented. 3 precautionsare taken against damage, and claims arising from damageare handled in a timely manner, 4. informationflow betweenthe client. the consultants.contractors and affectedparties is optimisedto ensureall role playersare awareof their particular responsibilities. 5. the commissioningof the WWT plant is not delayed due to problemsresulting from addressingIAP or other concernsarising in the courseof constructingthe plant. 6. affectedstructures, roads and natural featuresare protectedduring constructionthen rehabilitatedaccording to the guidelinesin the mitigationplan. 7. local labour and entrepreneursfrom the affected communitiesare used throughout the project and for projectrelated activitieswherever possible, 8. accurate records of the progress of the project are kept. including objections.so that responsibilitiescan be allocatedin the event of claims against the client. 9. monitoringreports are produced for regulatorybodies. their frequenc) and content to be agreed in advanceof work commencingon the constructionphase. 1Omechanisms are in place for reviewing the efficacy of the mitigation plan. and any improvementsmade in the course of the project, so that other similar projects may benefit from the experiencegained on the MontagneJacquot project.

Black & Veatch International 7.1 Mitigation plan Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

In order that the mitigation plan can be effectively implemented. it identifies:

0 mitigation measures to be implemented at each stage of the project. 0 individuals. groups, government agencies and NGOs with responsibilities or potential skills for carrying out mitigation actions identified in the impact assessment. 0 guidelines for communication between all parties with responsibilities for implementing the mitigation plan. 0 costs of implementing mitigation measures. 0 institutional and training requirements for implementing mitigation measures. 0 a monitoring programme to track project related events and progress in implementing mitigation measures. 0 community liaison procedures. 0 mechanisms for improving the mitigation plan.

7.2 Persons responsible for implementing the mitigation plan

The main individuals groups. government agencies, NGOs etc. identified with responsibilities for implementing the mitigation plan are as follows:

I. The Waste Water Authority, 2. Design engineers, . 3. The Resident Engineer. 4. Contractors, ,. The WWT Plant Manager. 6. Plant operators. 7. IAPs.

The individual and group responsibilities of these persons for mitigation actions are summarised later in tables I to 7, whilst the following section provides a brief overviewk of the mitigatorv actions to be undertaken at each stage of the project.

Black& VeatciIniernatonal 72 Mitigationplan Montagne Jatcquot Sewerage and Sanitation Project Environmental Impact Assessment

7.3. Main categories of mitigation measures identified in each project phase

7.3.1 Design phase

Many of the most significant environmental impacts of the project can be addressed in the design phase. and are therefore mainly the responsibility of the design engineers. In particular. the location and design of the ocean outfall potentially has a critically significant mitigatory effect on the efficient dispersion of effluent.

The nature and level of treatment adopted will, together with outfall design. determine whether the desired dilution/dispersion of effluent to ensure water quality standards off Montagne Jacquot and in the vicinity of the nearby Pointe aux Sables reef and lagoon are actually achieved. Despite having carried out hydrodynamic modeling. the idiosyncrasies of currents at individual discharge points often cannot be predicted. and so the efficacv of the design will only finally be tested when the results of follow up water quality monitoring become available.

The proposed site of WWT plant at Montagne Jacquot also achieves important mitigatory effects by virtue of its location. The site was chosen partly because it was available, but also because the environmental and socio-economic impacts would be minimal as a result of its location. The plant itself will not be noisy and is not expected to create offensive odors. Nevertheless. it is prudent to include a buffer zone around the perimeter of the WWT plant site to assist in minimising these potential impacts still further. Disturbance caused by traffic along routes to the plant as a result of deliveries of personnel. supplies for maintenance. removal of sludge to landfill etc. should also cause minimal disruption to nearby communities. The nearest population to the site that will be affected by these impacts is those individuals living at the prison. If trees are planted in the 400m buffer zone around the works, the potential visual impact of the site. and odors carried inland by sporadic onshore breezes will also be further diminished.

7.3.2 Construction phase

The main responsibilities for mitigation during the construction phase of the Montagne Jacquot project rest with the Contractors appointed to construct the WWT plant. outfall and transfer pipeline. The Resident Engineer will however, have responsibility for monitoring the implementation of mitigatory actions by contractors. and will need to implement his own system of internal checks to ensure that mitigatory actions are

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carriedout satisfactorily.In exceptionalcircumstances. the Waste Water Authoritymay need to use its authorityto call a halt to constructionactivityv if the contractorsrefuse to adhere to the requirementsof the mitigationplan containedin the contractdocuments.

In order that there can be no misunderstandingsregarding who is responsible for particular mitigatoryactivities recommended for the constructionphase. the mitigation plan shouldbe appendedto tender documents. This will ensurethat contractorsinclude the cost of mitigatoryactions into their bids, and will provide a reliable mechanismfor enforcement. In fact, most of the recommendedactions involve no capital cost, but depend on the contractor managers adopting a responsible attitude to environmental protection, ensuring construction activity is properly planned. then using their managerialskills to ensuremitigatorv actions are correctlyimplemented.

The mitigatoryactions recommendedduring the constructionphase have the following principalobjectives:

1. to maximise safety. security and environmentalprotection measures accordingto the requirementsof local industrystandards, 2. to minimise disturbance to residents caused by noise. dust, polluted runoff. and sediment etc, and to minimise inconvenience / congestion caused by restricted traffic lanes and single file traffic along routes between Fort Victoriaand Montagne Jacquot during trench digging and laying of transmission pipeline if land-based route adopted, 3. to minimise disturbance to marine! estuarine benthic and fish communities.and minimise deteriorationin water quality during pipeline laying operation if offshore based route adopted. 4. to minimise disturbanceof benthic infaunal, coral reef and fish communitiesoff Montagne Jacquot and to avoid collisions and inconvenienceto offshore vessels during constructionof the ocean outfall, 5. to minimise disturbancethrough increasedheavy traffic. noise. dust. activity at the Montagne Jacquot site and along access roads during site preparation and plant construction.

The detailed mitigatory actions to achieve these objectives are summarised in Tables I to 7. but with regard to the constructionof the land-based transfer pipeline. which is potentially the most disruptive component of the projects they particularly concern:

Black& l'eatchlInternational 7.4 Mifitigationplan- Monhagne Jalcquot Sewerage atd Sanitation Project Environmental Impact Assessment

O detailed planning of construction activities to ensure contractors are aware of other infrastructure. to minimise accidental damage to buried telephone lines. electric cables. water mains. sewers etc.. 0 planning of construction schedule to ensure appropriate management of traffic along routes from Fort Victoria to Montagne Jacquot with safety/warning features in place. 0 liaison with affected communities to allow them to plan for the construction phase and make necessarv adjustments in their work / domestic schedules.

During construction of the WWT plant at Montagne Jacquot. the mitigatorn actions mainlv involve efficient planning and management of contractors on site to minimise the potential disruption caused by heavy machinery. noise etc. at the site and along access roads to the site. to prevent unauthorised dumping of waste materials around the WWT plant site or along access roads. to manage traffic efficientlv to minimise congestion and to deal with complaints from communities affected by construction activity.

Similarly. during construction of the ocean outfall, efficient planning and management of the operation is essential. Contractors should endeavour to cause minimal disturbance to the sea floor: for example. by deploying silt curtains where disturbance of sediments is anticipated. locating and placing anchors to avoid damage to the reef and massive corals, containing waste fuel oil and retaining garbage on board until it can be properly disposed of on shore. In addition. the construction vessels should be marked with lights to ensure there is no risk of collision with vessels using the coastal waters. The detailed requirements for safety. security and environmental protection to meet industry standards in Mauritius, are summarised in Appendix P together with the guidelines for mitigatory action for contractors commissioned to construct the transmission mains pipeline.

7.3.3 Operationalphase

Once the pipe laying operations are complete the general public should be blissfully unaware of the new infrastructure linked to the new WWT plant at the Montagne Jacquot site. Therefore mitigatory activity will primarily be the responsibility of the Plant Manager (PM) and it will mainly be a matter of exercising good and proper management of the WWT plant. Most of this activity should be covered by the management manuals devised for operation of the WWT plant. which will outline procedures for managing or otherwise responding to:

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1. operational failure resulting from obstructions in pipelines. screens. etc.: 2. pump failures, equipment malfunctions and treatment process failures. etc. of any kind in the plant: 3. operational failure resulting from fuel. oil. volatile chemicals arriving at plant: 4. plant emergencies such as general power failures. storms. etc.: 5. safetv measures. including fire protection equipment, procedures for access to confined spaces, limiting hazardous and toxic gas exposure, training in proper and safe operation of all equipmenL training to avoid exposure to hazardous situations such as high voltage electrical gear. safe driving training. and general safety procedures to avoid personal injury such as muscle strains or damage to eves. ears. hands. feet. head. etc., 6. dealing with noxious conditions such as odors from inlet structure and related equipment. sludge management facilities, or septic tank dumping station: 7. handling dangerous or corrosive chemicals such as chlorine gas and quick lime: 8. handling other special chemicals such as polymers: 9. cleaning sludge trucks to avoid accumulation of offensive deposits: 10. maintaining plant grounds in a suitable manner: 11. maintaining secure plant site to prevent injury to public or damage to plant facilities: 12. handling operational problems such as spills. or overflows of chemicals. sludge. pump stations. etc.

In addition. it will be essential for the PM to be appropriately motivated and trained to manage the plant and its operators to achieve a high quality performing plant. This will entail keeping equipment working properly by regular maintenance and repair. regular monitoring of effluent quality. monitoring of influent for general water quality parameters as well as hazardous wastes and special industrial waste water arriving at the plant. The PM will also need to take responsibility for liaison with the general public. and deal with complaints to community satisfaction by provision of monitoring or other information.

7.3.4 Decommissioning phase

The life of the plant is likely to be at least 50 years. providing regular maintenance and repairs are carried out. Whether the proposed waste water treatment and solids handling facilities at the plant will be supplemented by more advanced treatment works in a shorter time frame cannot be accurately predicted, but there is no reason to suppose the

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planned transmission pipelines and pumping stations delivering waste water to the Montagne Jacquot site. or any of the proposed treatment works will need be decommissioned because of equipment failure in the foreseeable future. In the event that the Montagne Jacquot site is required for an alternative use in future. it is a relativelv straightforward process to dismantle the plant. demolish concrete structures. backfill excavations and remove and dispose of mechanical and control equipment. There should be no accumulation of hazardous or toxic materials at the site which would require extensive remediation measures if the site is abandoned. The sludges will be removed to a landfill site during the normal course of operation.

7.4. Summarv of mitigation actions necessary to implement the mitigation plan

The following tables summnarise the mitigatory responsibilities of parties involved in implementation of the mitigation plan. These tables should not be regarded as comprehensive. but a guide only. Additional mitigatorv actions may be agreed with the regulatory authority or resident engineer to achieve more effective mitigation.

TABLE r. WASTEWATERAUTHORITY Objectives Mitigatory actions To improve regulatory control of 1. motivate for stricter legislative control of industrial waste industry to prevent damage to disposal. sewerage system. help reduce the 2. set up wastewater inspectorate and implement active program occurrence- of operational to monitor industrial inputs to wastewater collection system. problems. and to prevent the 3. ensure all new industry appropriately sited on existing estates. release of hazardous. toxic. or 4. ensure new industry does not import outdated technology, but otherwise harmful . waste addresses environmental impacts at design stage. materials into the environment 5. train inspectorate staff to liaise with industry. monitor effluent through the sewerage system discharges and implement new legislation. To provide incentives for 6. Devise system of tariffs for treatment of wastes. setting industry to pre-treat waste waters charges according to impacts and direct cost of treatment. 7. Provide incentives for industries to progressivel) implement their own pre-treatment systems. To provide capacity and expertise 8. set up forum for industrialists to discuss waste management to assist industrv to develop and problems. provide technology for waste 9. act as facilitator by assisting with solutions to waste treatment management problems.

TABLE 2. DESIGN ENGINEERS Objectives Mitigatory actions To coordinate and provide for 1. ensure mitigation requirements appended to tender documents so mitigation program during costs will be included by contractors preparing bids. construction 2. ensure that the mitigation requirements included in tender documents and construction contract are enforceable. To design an efficient outfall 3. locate away from main commercial area of Port Louis. with appropriate balance 4. avoid circum-insular fringing reef, between construction cost and 5. avoid conservation-worthy benthic communities. environmental impacts 6. avoid potentially important recreational areas. 7. avoid existing tourist beaches. 8. avoid entering the sea where there are beach front homes.

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9. avoidcoast where particularlyattractive natural featuresexist. 10.discharge effluent into waterof sufficient depth and with natural currentsto ensureadequate dispersion. I1. incorporatesdiffusers to further enhancedispersion diffusionof effluent. To designa wastewater 12.avoid all high density residentialareas. treatment plant with minimal 13.avoid areas targetedfor developmentof coastal tourism. environmentaland socio- 14.avoid shorelineswith sandy beacheswhich are particularlk economic impacts sought after for recreationalswimmine etc. 15.avoid land with potentiallyhigh real estate value. 16.avoid land suitablefor agriculturaldevelopment. 17.adopt site which is easily accessibleusing existing accessroads and where water and electricityare available 18.provide features for public and operatorsafety. 19.design facilities which can be readilyoperated and maintained properly, 20. incorporatefeatures to minimizeproduction of odors. 2I .enclose areas with higher potential,for odor production. 22. provide featuresfor security. 23. provideappropriate landscaping for visual effect. noise suppression. 24. enclose noisy equipment. 25. provideemergency generators so the facilitiescan operateduring power failures. To design transferpumping 26. identifvroute whichcauses as little disruptionas possible stations and transmission between Fort Victoriaand MontagneJacquot. pipelinewith minimalimpacts 27. ensure existing infrastructurelocated and consideredin routing new pipeline. 28. replace and reconstructfacilities disturbed during construction to return to originalcondition. 29. requirecontractor to plan and implementtraffic controlsystem for safety of public and workers, and to minimize inconvenience to public if land-basedoption chosen(seeAppendix P for details) 30. requirecontractor to devise plan for laying pipelineoffshore which minimisesimpacts on water quality and marine estuarine benthic and fish communitiesif offshorebased route adopted. 31. design pumpingstations for ease of maintenanceand operation. 32. enclose areas with higher potential for odor produciionor noise generation. 33. providefeatures for security. 34. provideappropriate landscapingfor visual effect. noise suppression. 35. provide featuresfor public and operatorsafetN. 36. provideemergency generators so the facilitvcan operate durino

I power failures.

TABLE 3. RESIDENT ENGINEER Objective Mitigatoryaction To ensure construction of 1. ensure contractors understand mitigation requirements and their WWT plant carried out with . responsibilitiesfor implementingthe mitigationplan. minimal environmental and 2. monitor contractor's actions and enforce contract requirements. socio-economic impacts and that the mitigation plan is implemented effectively. Enforce provisions contained 3. ensure trench digging along land-based pipeline route adequately in the construction contract controlledto avoid interferencewith other infrastructure documents to ensure transfer 4. ensure trench off main pavement where-ever possible to minimise

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pipeline (whether land-based damage to new roads. or offshore) constructed with 5. plan construction schedule with contractors to ensure efficient minimal environmental and management of traffic along routes between Fort Victoria and socio-economic impact -- MontagneJacquot. (see Appendix P for details). Note that full responsibility 6. ensure contractors deploy adequate resources for traffic for these actions remains with management along route. (see Appendix P for details). the Contractor. The Resident 7. iiaise with traffic planners to identify alternatives routes around Engineer onlx monitors the works where possible, compliance and has no power. 8. ensure contractors have developed schedule which optimises time authoritN or responsibilitr to and tide to minimise impacts of laying offshore pipeline. direct Contractor's actions. 9. ensure contractors have appropriate equipment (including silt curtains where necessary) for digging trench and laying pipeline. 10. liaise port authority regarding disposal of spoils. I I. minimise disturbance to benthic and fish populations. 12. ensure provisions for health and safety of construction workers in place. including swift dispatch to medical facilities in the event of accidents. 13. liaise with affected communities so that they have time to make necessary adjustments in their work and domestic schedules. To ensure ocean outfall is 14.plan operation with contractors to ensure construction is as quick constructed with minimal and efficient as possible. environmental and socio- 15. plan construction work to minimise disturbance to reef and reef economic impact fishery. 16.deploy silt curtains where disturbance of soft sediments is anticipated, 17.restrict digging to periods of low current speeds or slack water 18.ensure anchors are dropped on soft bottoms not coral outcrops. 19.waste fuel and garbage should be stored on board and disposed of on land in appropriate waste disposal facilities. 20.barges for construction work should be appropriately marked to avoid collisions with coastal vessels. 21. liaise with locals regarding planned works.

TABLE 4. THE CONTRACTORS Objectives Mitigatory actions To minimise impact of I. ensure site managed efficiently for storage of equipment. stockpiling constructing Montagne . materials etc. Jacquot WWT plant (see 2. ensure construction plan devised and agreed with RE. Appendix P for details) 3. recruit labour from local affected communities first. 4. if construction camp necessary on site, ensure appropriate sanitary arrangements, accommodation and drinking water available. 5. liaise with local communities regarding services and goods supply to contractors and staff. 6. liaise with local communities regarding construction activit., time span, likely nuisances such as noise. dust and disturbance. To minimise impact of 7. plan construction programme to take account of season. tides. laying the ocean outfall currents etc. (see Appendix P for 8. ensure barge 'platform adequately secured before commencing details) underwater activity. 9. ensure barge i platformnappropriately marked to avoid niuht-time collisions with sea-going vessels. 10. retain waste materials on barge / platform and provide for proper disposal, 11. prevent and control discharges from vessels, 12.provide emergency spill containment facilities where appropriate.

-ro minimise impact of 13. plan manage and execute construction programme as efficiently as laying the transfer pipeline possible whether land or offshore based,

Black & VeatchlInternational 7.9 Mitigation plan Montagne Jacquot Sewerage anadSanitationi Project Environmental Impact Assessment

from Fort Victoria to 14.ensure adequate resources for traffic management during pipe laying Montagne Jacquot whether operation along road route. land or offshore based (see 15. ensure appropriate night lights.' markers on barges or other vessels detailed -uidelines in carrying out work offshore, Appendix P) 16. ensure trench diggers aware of other infrastructure such as telephone. electricity to avoid damaging lines etc. 17. plan working hours to provide minimum disturbance to communin' - - balance inconvenience to traffic with nuisances to local residents. 18.plan trench digging to coincide with slack tide - or conditions which minimise deterioration in water quality on site. 19. select storage locations for pipe and construction equipment to minimize disturbance to community; restore after use. 20. ensure active trench site is set up properly and safe to leave unsupervised overnight. 21. liaisewith affected parties along route to ensure they are aware of construction schedule. 22. liaisewith port authority to ensure they are aware of presence of barge and/or other vessels if in or near shipping lanes.

TABLE 5. THE WWT PLANT MANAGER Objectives Mitigatory actions To manage the plant I. manage plant efficiently at all times. efficiently for safe and 2. maintain cleanliness of site and facilities. effective disposal of 3. recruit highly motivated and well trained staff to run the plant. industrial and domestic 4. ensure staff aware of content of operational manuals. especially with waste waters regard to safety procedures. emergency. shut-down or accidental injury on site. 5. ensure all equipment regularly maintained and repaired. 6. keep stocks of spares in case of equipment failure, 7. ensure effluent quality monitored daily and problems remedied as soon as possible, 8. if problems with unauthorised waste received at works. coordinate with inspectorate to identify source of problem and take remedial action. 9. ensure sludges regularly removed from the site to landfill. 10.ensure rapid diagnosis and of repair leaks. spills. blockages - alert . communities if health hazard anticipated in discharge area. To maintain transparent Ir. liaise with community organisations regarding nature. functions. relationship with operation of plant. communities in 12.provide timely responses to complaints about the plant. and provide surrounding areas information to satisfy concerns. 13.keep record of complaints receivedand actions taken. 14. respond to requests for school visits etc. positively to enhance relations with locals. To ensure correct 15. if monitoring shows effluent treatment not adequate to meet water application of technology quality standards. take action to install treatment which is adequate. for safe and 16. if necessary, seek advice on how to improve the situation. especiall% environmentally sound if equipment not performing to spec. disposal of waste in the 17.ensure sludge dewatering and removal carried out efficiently and environment cleanly. 18. devise odour control system if problems develop and persist.

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TABLE 6. WWT PLANT OPERATORS Objectives Mitigation actions To ensure safe and 1. read and inwardly digest operational manuais: efficient operation of 2. ensure safety and fire fighting equipment in place and accessible WU'T plant at all times 3. ensure works equipment maintained regularly and timeh repaired. 4. report malfunctions. equipment failure to PM, 5. ensure responsible and conscientious attitude to execution of duties at l ______all tim es.

TABLE 7. INTERESTED AND AFFECTED PARTIES Objectives Mitigation actions To be kept informed about I. iiaise with RE regarding schedule of construction activities. progress of Montagne Jacquot 2. alter personal and work routines to avoid construction routes. project to minimise disruption during construction To avoid health problems during 3. take note of health wamings if they occur. recreational activity in discharge 4. liaise with PM regarding source and likely duration of area problem. To provide feedback on public 5. if plant creates nuisance odors or excessive noise. contact PM perception of project with information on time place. wind direction. etc. 6. if sludge removal operation not carried out efficienthl and cleanly, phone PM and complain. 7. if Montagne Jacquot plant or activities associated with it in any way jeopardise health of nearby communities. ensure PM and Ministry of Health are alerted. To ensure communities in Pointe 8. community organisations to take the lead in distributing aux Sables and Bain des Dames information, networking to facilitate the process of optimise potential benefits flowing developing economic potential. with assistance of government from implementation of the organisations / departments Montagne Jacquot project 9. organise regular beach cleaning operations and seek assistance with rehabilitating shoreline and general environmental quality of area. 10. liaise with government agencies regarding assistance to develop recreational facilities. I1. liaise government agencies regarding upgrading of other infrastructure in the area. 12. as area rehabilitates, becomes safer and cleaner. ensure communities are aware that normal coastal recreational activities such as fishing, swimming. etc. possible 13.community / public awareness campaign should be implemented with WWA support to provide information on progress of construction. and opportunities and assistance offered by government to affected communities. 14. use community networks to alert property market to potential opportunities in area. I5. assess market potential for development of tourism. seek assistance from Ministry of Tourism, 16. use community networks to assist with information distribution for people wanting to set up business in service sector. food. accommodation, boat hire, sports. diving. fishing etc.

BlacA& Veatch International 7.111itigadon plan MonhagneJacquot Sewerage andSanitation Project Environmental Impact Assessment

7.5. Cost of the mitigation plan

The direct costs of implementing the mitigation plan will be very modest. as nearly all the recommendations depend on good and proper management of construction activities, then on high standards of operation at the plant itself. Consequently these costs are already included in the cost of the project. However. the following are suggestions for activities which could help to minimise environmental impacts and enhance beneficial impacts of the project. which do have cost implications:

0 appoint a multi-disciplinarv task team (MEQOL. MEPD etc.) to assist communities in Pointe aux Sables and Bain des Dames to rehabilitate the area. by improving (eneral environmental quality. upgrading infrastructure etc. to assist the communities in realising the economic and recreational potential associated with improved environmental quality. through development of tourism. accommodation. services etc.. to cater for the nearby port area and commercial centre. 0 the site at Montagne Jacquot will be surrounded by a 400m buffer zone. The whole site could benefit from a tree planting scheme in the buffer zone to screen the plant completely. This would not only minimise the visual impacts, but also provide a buffer against odors penetrating inland when sea breezes are onshore. The plant perimeter should be situated so that the public continues to have access to the shoreline. so that even if divers and swimmers become less numerous than at present. walking and fishing from the shore need not be prohibited. 0 Construction of this new WWT plant and its ocean outfall provides an extremely valuable opportunity for monitoring the impact of a discharge from a new ocean outfall into an area not previously impacted by waste water effluent. Local research institutions should be encouraged to develop a monitoring program. which expands on the statutory requirements of monitoring water quality. Also, provision for environmental monitoring should be incorporated into the operational budget of the WWhTplant, since this could provide invaluable information for managing the new plant efficiently and the design of future WWT plants and outfalls. No such information is available at present from Mauritian waters. and only scant information is available from other sub-tropical I tropical ecosystems.

BlackA& Veatci lInternational 7.12 Mitigationplan Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

SECTION 8

ENVIRONMENTAL MANAGEMENT AND TRAINING

BlacA & VeatchiInternational Environmental management and training a MontagneJacquo: Sewerageand SanitationProject EnvironmentalImpact Assessment

8.0 ENVIRONMENTAL MANAGEMENT AND TRAINING

8.1 Legal and Policy background

One of the key recommendationsof the National SewerageMaster Plan for Mauritius was that a Waste Water Authorit) should be set up. Subsequently.the WWA Act was passed by the National Assembly in June 1991 and promulgated in late 1996. The development of a comprehensivewaste water management policy is still underwav however, and until this task is complete and new legislationhas been promulgated. there is lack of tools to enable the WWA to provide incentives and put pressure on industrv to manage its waste more safely. economically and efficiently. The preliminarvreport of the institutionalstudy for the Waste Water Authoritvcarried out bv Consulting EngineeringServices (India) PVT LTD (CES; 1997). suggested that comprehensivenew legislation is required to respond to the multiplicity of factors involved in controllingindustrial pollution, and that this would be more effectivethan making amendmentsto the existinglegislation.

In the mean time, the EnvironmentalProtection Act (1991) has given the WWA the responsibilityfor control and monitoringof wastewaterdischarges to ensure that the water environmentis not polluted. for ensuring that industry undertakes to treat its wastes-beforedischarge and ensuring that effluent quality from industrial and WWT facilities is regularlychecked. The MontagneJacquot project is one of several priority projects recommendedin the master plan currently being managed by the WWA. and the environmtentalmanagement and monitoringby the WWAwill be centralto ensuring successfulimplementation of the project. Experiencegained in the MontagneJacquot projectwill also be valuablefor other projects planned over the next twenty year period.

8.2. Institutional Framework for Waste Water Management

Following the initial review of the preliminary report of the institutionalstudy (CES. 1997) the WWA concluded that the proposed reorganizationof the WWA should be modifiedto include a substantialinvolvement of private contractors.The WWAwould then graduallybe transformed into an organization which would rely on private firms who would assume responsibility for construction, operation and maintenance of all new works, as well as increasingresponsibility for the operationand maintenanceof the existing sewerage system. To implement the first stages of this shift to contract operations the WWA will issue contracts for at least three years of operation and maintenance by a private contractor following completion of construction of major

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waste water treatment facilities and pump stations. including the Montagne Jacquot WWT plant. and the Fort Victoria and Pointe aux Sables pumping stations.

8.2.1 Waste WaterA uthority Organization

In order to respond effectively to the new order. the WWA will need to modify its organizational structure. The institutional study (CES, 1997) suggested that the WWA should be separated into three principal units, reflecting the basic concepts contained in the preliminary report, but also reflecting the shift toward more involvement by private contractors and private consultants for operation and maintenance functions. The new organization will enable it to effectively manage the contractors responsible for the major capital improvements program and new responsibilities related to operation and maintenance of the new facilities.

The proposed new Project Management Unit -- or an equivalent unit. as established by the final institutional analysis report -- will have the primary responsibility for qualitv control in the WWA. which will include monitoring of treatment plant effluent. collection and analyses of samples. monitoring discharges of industries entering sewers. and performance evaluations of treatment plants. An organization chart for the Quality Control Wing of the PMU is shown in Appendix 0. Although some of the staff proposed in Appendix 0 will be provided through consultants or through private contractors. the responsibilities assigned to the wing will be carried out by a staff of approximately 15, with qualifications in engineering, biochemistry. and laboratory services. A summary of the qualifications that will be required for the key personnel in this wing is presented in Annex 3.3.2(B) in Appendix 0.

Based on a review of the scope of its responsibilities and the activities of the Pollution Control Unit in 1996. the institutional study (CES. 1997) concluded that this unit needs to be expanded as a matter of urgency. The inauguration of the new National Laboratories Complex in Reduit on June 18. 1997 provides strong evidence that the monitoring of the environment and natural resources will be given significantly higher priority in the coming years.

It was also concluded by the institutional study that the operation and maintenance of the new treatment works and pump stations should be performed by private contractors. and this transition to facilities management by the private sector has been recognized as a goal of the WWA. Privatisation will provide the skilled personnel and expertise necessary for proper function of these facilities. It will also provide separation between

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the operation and maintenance function of the WWA and the monitoring of compliance functions of the WWA. which will allow the new qualitv control wing to exercise greater control over and enforcement of effluent standards.

8.2.2 Linkages Withi Otlher Organizations

One of the institutional considerations reviewed by the CES study (1997) was the relationship between the WWA and other parastatal and government departments. Appendix 0 shows the linkages between the WWA and other organizations. and the institutional report describes the responsibilities of the various agencies. the requirements for legal understandings on the division of responsibility. and how they will have to interact at the operational level.

8.3 Industrial Wastewater Management

The management of industrial waste waters is a complex problem which involves competing interests associated with technical problems. legal issues. institutional responsibilities and public interests. Comprehensive industrial waste water management must involve several government ministries, quasi-government agencies which promote and manage the industrial estates, the industries themselves. the public. the economy of Mauritius and the environment. It will require changes in many institutional arrangements. which will only evolve over several years.

A detailed review of the industrial waste water generated in the Montagne Jacquot service area is presented in Appendix Q. The appendix includes a review of recommended effluent standards, which will be implemented into regulations by the Ministry of Environment and the Waste Water Authority. Pre-treatment systems will be required at many industries to meet the new effluent standards. The expected pre- treatment facilities for the major industrial waste dischargers and their estimated construction cost are also presented in Appendix Q. As the primary agency responsible for the sewage collection system and the quality of the effluent from the Montagne Jacquot WWT plant, the WWA will develop a program for monitoring the effluents from industries. The monitoring program is described in Section 9 of this EIA report.

8.4 Environmental Training Requirements

Once effective legislation has been passed. the training requirements for implementing the pollution control and monitoring programs. and to allow the WWA to discharge its

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duties effectively. are considerable. The institutional study will be responsible for defining in detail exactly what the training and staff requirements will be for monitoring. laboratorv and engineering support. but as there are strono moves afoot to privatise many operations including management of wastewater treatment facilities. the requirements will change depending on the pace of the privatisation program and depending on which operations are targeted first.

There are awareness building requirements and training needs at every institutional level in government and throughout industry. The situation in Mauritius is similar to the situation which was common throughout Europe and the United States several vears aggo.and which is still evident in some non-transformed industries. In order to build a sustainable economy. and to protect Mauritius' natural resource base. environmental protection has to be taken seriously. Increased pressure for regulation and effective enforcement of waste water legislation and pollution control in general will then come from within the country. as well as from consumer markets outside the countrv.

As in other countries throughout the world, Mauritius has been involved in a mass environmental education programmnewhich should heip to improve public awareness of the problems. Several NGO's have played a central role in these programmes. but the WWA could do much to assist the process. There have also recently been short courses in environmental and coastal zone management at the University of Mauritius. which were attended by a wide spectrum of interested individuals from government. NGOs. business and industry: This all helps the general understanding of the issues. and why environmental protection needs to be a priority in national planning and economic development initiatives.

The specific training needs which will be required to ensure successful implementation. management and monitoring of the individual water and sanitation projects. will only be identified when the final provisions of the WWA Act are known. However. the present situation suggests the following individuals will be required as a minimum for management and operation of the new WWT facility at Montagne Jacquot and implementation of the WWA monitoring functions:

O well educated individuals with good basic skills will need to be recruited as managers for the WWT plants. who can be trained through both course work and intensive on the job training. The prospective plant managers will need to be conscientious individuals. committed to high standards of management and operational performance at the plants.

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In addition, plant operators with similar personal attributes of being conscientious and committed. but with technical rather than managerial abilities will also be required. O The programs at the National Laboratories Complex will require individuals with a scientific background to university level. who are trained to oversee the pollution control monitoring programme. Depending on the final provisions of the neA WWA Act. basic programmes will have to be devised for screening of industrial discharges and water quality monitoring in freshwater and coastal waters. The staff should also be sufficiently experienced to be able to liaise with independent scientists regarding specialist monitoring required in relation to particularly toxic wastes or discharges with multiple inputs. 0 additional laboratory staff with suitable qualifications in chemistrv will need to be trained for the Quality Control division of the WWA. to analyse samples of industrial or wastewater effluent

Other specialists who may potentially be in demand once the WWA policies begin to take effect are those who would seek ways to optimize the management of industrial wastes through reuse programs, internal recycle. partnering with other industries with similar or complementary waste problems. or finding economic or alternative applications for waste disposal. The incentives of the economy and economic competition will ensure optimal solutions are devised for waste management programns. In aeneral. it has been demonstrated in many situations that effective pollution control makes good economic sense.

8.5. Costs and financingtraining -for environmental management

The costs of environmental training related to the Montagne Jacquot project should not be considered in isolation. since many of the capacity building requirements concern the WWA as a whole and are not project specific. The CES study will be addressing the precise capacity needs of the WWA. as well as training and resource requirements. Nevertheless. it is pertinent to draw attention to the fact that although suitable graduates with tertiary level education in appropriate disciplines will almost certainly be available in Mauritius to fill technical positions at the National Laboratories complex, and to carry out routine monitoring functions. individuals with the skills and experience suitable for coordinating, managing and implementing the national wastewater management and monitoring program may not be available locally or at least benefit from some experience outside the country. Consequently. provision should be made for post-graduate work experience / study overseas within a waste

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water authority or regulatory body with similar functions for selected personnel. A program of higher level contact and discussions for potential senior personnel with their analogs. mav also be extremely beneficial. and may help the waste water authority to axoid some of the pitfalls and setbacks which have slowed the progress and delaved implementation of control and monitoring of industrial wastewaters b! similar orcyanizationsworldwide.

BlacA:& Veatcl International 8.6. Environmentalmanagement and training Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

SECTION 9

ENVIRONMENTAL MONITORING PLAN

Black & VeatchiInternational Environnwntal monitoring plan i

4s c PI Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

9.0 ENVIRONMENTAL MONITORING PLAN

The environmental monitoring responsibilities in the WWA will be performed by the Quality Control Wing of the Project Management Unit. as described in Section 8. The monitoring will be performed by the scientific unit of the wing which will employ a staff of four laboratory technicians. two biochemists, and one senior biochemist. under the direction of the manager of the wing who will also be the principal biochemist.

The Quality Control Wing will collect and analyze samples of industrial discharges to sewers. of the effluents from waste water treatment plants, and within the waste water treatment plants to evaluate their performance. The dav to day performance of the waste water treatment plants and the testing associated with plant operations will be performed by the plant operating staff.

9.1 Monitoring Program

Tlhe monitoring program of the Quality Control Wing will be divided into the industrial sector and the domestic sector.

9.1.1 Industrial Waste Water Monitoring

There are approximatelv 175 industries in the service area of the Montagne Jacquot WWT plant. All but, about 20 discharge to the sewage collection svstem. Industrial waste water monitoring will be carried out at two levels. The first level will be the routine screening level. and the second. the detailed evaluation level. A different sampling and analysis program will be developed for each individual industry. depending on the typical characteristics of the waste water produced by that industry. and the amount of waste water it produces. Those industries which produce only domestic waste water, or which produce waste water which is equivalent to domestic waste water in terms of specific contaminants and concentrations of those contaminants. will not be monitored on a regular basis.

Routine screening will be perforrned on those industries which produce large quantities of pollutants either in terms of high volume and high or low concentration or low volume and high concentrations. but which do not discharge priority pollutants such as those which are potentially toxic or hazardous. The specific parameters to be measured will be determined by the effluent discharge standards established by the WWA and Ministnr of Environment. as well as the type of contaminants expected to be contained

Black- & VeatcihInternational 9.1 Environmental monitoring plan Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

in the waste water from an individual industry. and by the waste water characteristics used to calculate sewage disposal tariffs. The specific parameters to be monitored by the existing industries in the Montagne Jacquot service area are described in Appendix Q.

Normal effluent monitoring will consist of a composite sample compiled over one operating day from each industry twice each year. The industry will be requested to provide records of water consumption (including all sources of water) which will be used to estimate average daily flow. The water consumption and the waste water characteristics will be used to determine the waste water disposal tariff. and to verify that the industrv is meeting the effluent limits imposed by regulations.

Those industries which have the potential to discharge significant quantities of priority pollutants will be subject to both the routine screening and detailed evaluations. The detailed evaluations will be conducted once each year. The detailed evaluation will consist of requirements for the industry to report on its operations. and will include sampling and analysis of the effluent. The report on operations will include a tabulation of average daily quantities and specific types of chemicals used in processes which contribute to the waste water effluent. and records of water consumption (all sources). The detailed evaluation sampling will consist of a composite sample compiled over one operating day. The samples must be collected on a day which is representative of the normnalfacility operations. The samples will be tested for the same parameters as in the routine screening, plus those pollutants either known to be associated with that industrial activity or those chemicals used in the processes.

9.1.2 Domestic Waste Water Monitoring

The domestic waste water monitoring will be conducted at the influent to and effluent from the Montagne Jacquot WWT plant. Weekly samples will be collected for the plant influent and effluent. The samples will be flow proportioned. composite samples. assembled by the WWT plant staff on a routine basis. The weeklv samples will be analyzed for the routine pollutants included in the effluent water quality standards for an ocean discharge: i.e. pH. COD. BOD(S), TSS. In addition. once each year a composite sample will be collected at the influent and the effluent and analyzed for the special parameters contained in the water quality standards for ocean discharge: cadmium. chromate. mercury. and nickel. In addition. a weekly grab sample will be collected at the influent to the chlorine contact basin. and this as well as the plant

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influentand effluentweekly samples will be tested for total coliform. A grab sampleof plant effluentwill also be tested for residualchlorine concentration once each week.

9.1.3 Monitoring of Marine Environment at Montagne Jacquot

Monitoring of the environmentalimpact of the effluent from the Montagne Jacquot WWT plant will not be carried out by the WWA on a regular basis. The WWA will have neitherthe equipmentnor the qualifiedpersonnel required for collectingsamples in the ocean near the outfall,or for conductingsurveys of the areas on the sea floor at that location.

The AlbionFisheries Research Centre (AFRC)of the Ministry of Fisheriesand Marine Resources have expressed an interest and willingness to be involved in an environmentalmonitoring programme for the new WWT plant. and the DOE have indicated that data generated in the AFRC monitoring programme will be used for correlationpurposes in enforcingwater quality standards.Extensive water quality and coral community monitoring is already underway in Mauritian coastal waters and adding sites in the discharge area off Montagne Jacquot would simply represent an extension of this programme.The commissioningof a new ocean outfall discharging treated effluent should yield invaluable data to allow the prediction of impacts from similar discharges into coastal waters elsewhere in Mauritius. Information on the quality of effluent dischargedfrom the WWT plant. would then also provide important backgrounddata against whichenvironmental monitoring results could be interpreted.

9.1.3.1 Water qualit

The coastal waters monitoringprogramme should commencebefore constructionwork begins in the proposed outfall location.to provide backgroundinformation on ambient conditions in the discharge area and monitoring should continue through the commissioningperiod of the new ocean outfall. The precise content and frequencyof sampling for the monitoringprogramme will depend to some extent on the resources and staff available at the AFRC, but should finally be agreed between the AFRC and the regulatory body. Bearing in mind the likely characteristics of the discharged effluent. the following key water quality parameters should initially be monitoredas a minimum: pH. temperature.TSS. conductivity, nutrients (N. P) and faecal coliforms. Ideally, water quality surveys taking in these parameters should be carried out using automatedequipment as far as possible.

Black & VeutchiInternational 9.3 Environmentalmonitoring plan Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

Once the new WWT plant has been commissioned.it will be necessary at first to carry out monitoring surveys regularly along the axis of the effluent plume. at different conditionsof tide, current and season. to evaluate the effect the discharge has on local water quality. After the main area impacted by the discharge has been delimited in terms of the aboveparameters, it will be possible to refine the water qualitymonitoring programme.and carry out survevs four times per year (current frequency of AFRC program at other sites). or followingany major changes in treatmentprocess. intluent or effluentcomposition. Some of the analyses are time-consumingand will have to be critically evaluated in terms of the information they yield. As the main concern at present in terms of local ecosystemsis the potentialfor elevatednutrient concentrations in the dischargezone, it may be appropriateto reduce parametersmeasured to pH and conductivity, which are very easily determined, and nutrients (nitrogen and phosphorus). which together with BOD determinations would provide the most importantinformation.

Monitoringwill provide checks on the water quality in the discharge area and adjacent coastal waters,particularly in respect of nutrient levels, which are the principal concern in the long term. However.until the coastalwater quality standardshave been finalised by the DOE, the precise requirementsof the water quality monitoring programme cannot be finalised, but should be agreed with the DOE on an interim basis until legislationis promulgated.

9.1.3.2 Healtl of bentlhic communities

The diving survey carried out at the proposed outfall location showed that the area likely to be impacted by the discharge at the break in the fringing reef is characterised bv mixed character substratum. with areas of flat reef, often with encrusting coral species.giving way to patches of sand, with scattered massive and sub-massivecorals. The corals in the proposed discharge area were live and appeared to be in good condition. although as the proposed discharge site is very exposed. corals appear to have been subject to storm damage.

The mixed characterof the sea floor suggeststhat an approach which evaluatesnot only the health of corals. but also the benthic infauna is appropriate. As the corals do not form a continuous reef flat, it may be appropriateto map individual massive corals in the discharge area, and regularly monitor the degree of bleaching and dead/moribund. infection with bacterial disease etc. Alternatively, an approach such as that already described in section 4 (see English et al. ) using permanent quadrats along a fixed

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transect parallel to the axis of the effluent plume (should change direction with season) would also be appropriate. since it also builds on that already being carried out by the AFRC at other sites around Mauritius.

One problem with carrying out this type of survey in an area impacted by waste water is the potential health impacts for the divers carrying out direct observations on corals. Although there is obviously the possibility of doing this work remotely. the costs involved are usually prohibitive. Consequently, as an alternative (or in addition) to the above. soft sediments could be sarnpled for meiofaunal analysis. The dominant meiofaunal populations in soft marine sediments are nematodes. which as a taxon, are good indicators of sewage and industrial waste contamination. with some species flourishing and others being eliminated. Because of the rapid turnover of meiofaunal populations, and the community structures which evolve in response to particular wastes discharge. the extent of the impact of a discharge area can be much more precisely defined with meiofaunal analysis than with larger benthic infaunal organisms.

The skills necessary for carrying out this type of analysis are probably not vet available in Mauritius, but increasingly, meiofaunal analysis is being used as an indicator of marine ecosystem health, which is generally expressed in the changing diversitv. species composition and density of meiofaunal organisms.

9.1.3.3. Use of monitoring data in environmental management

The main objectives of carrying out water quality and benthic community monitoring in the discharge zone offshore from Montagne Jacquot, is to provide assurance that the recommended treatment process at the Montagne Jacquot WWT plant achieves the required levels of concentration of TSS, faecal coliforms, nutrients etc. to meet water qualitv standards in the receiving waters. The main unknown is that hvdrodvnamic modeling is invariably carried out using limited data sets (see sections 2 and 4). and the theoretical dilution / dispersion characteristics of effluents need to be verified once the local conditions of tide. currents and wave action are interacting on a daily basis.

The results of water quality monitoring will need to be scrutinised on a regular basis. and if as predicted the impacts of the discharge are negligible on the receiving waters. the water quality monitoring can be reduced to screening checks. On the other hand. there may be instances which lead to water quality in the discharge zone not meeting the required standard. in which case the nature of the problem will need to be diagnosed and action taken to remedy the situation. There may have been operational problems at

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the plant of a temporarv nature leading to discharge of effluent below standard. there may have been a new industrial discharge to the WWT plant with unanticipated impacts. These tvpes of problem can then be addressed by the WWA and tackled at source to prevent any further deterioration in water quality.

Monitoring water quality alone is not alwavs sufficient to guarantee the health of marine benthic communities in a discharge zone - occasionally parameters which either cannot be measured for technical reasons, or parameters not known to affect the health of local species are identified. Consequently. checking the health of benthic communities in the context of the monitoring program will provide additional assurance that the discharge is only having a limited effect on benthic communities. and one is acceptable given the predicted performance of the treatment plant. quality of final effluent and the predicted impact of the discharge.

9.2 LiaisonBetween Montagne Jacquot WWT Plantand RegulatorvAgencies

For at least the first three yearsthe MontagneJacquot WWT plant will be operatedby a qualified firm under contract to the WWA. The firm will have full responsibilityfor operatingthe plant in accordancewith all regulations.and will be required to monitor treatment processes as part of its norrnal duties. It will operate as an independent contractor.in the same way that an industryoperates its waste water facilities. and the contract operatorwill be subjectto the rules of all regulatoryagencies.

9.3 Costs of equipment, personnel and training

The industrialand domesticwastewater monitoring programs linked to the Montagne Jacquot project will be carried out by the Quality Control Wing of the Project ManagementUnit. The staffing requirementsof the unit have alreadv been considered. and the equipment and capital cost involved in setting up this unit will be covered further by the institutional study. Clearly a substantial amount of the monitoring workload of the unit will be linked to industries in the service area of the Montagne Jacquot project.

The costs and equipment required to carry out water quality and benthic community monitoring will be modest providing the program can be developedas an extension of that already in place and implementedby the Albion Fisheries Research Centre using equipment possessed by the Centre. There will be the additional costs of materials. fuel and time involved in monitoring the Montagne Jacquot discharge area. but until the

BlacA & Veatcih international 9.6 Environmental monitoring plan Montagne Jacquot Sewerage anid Sanitation Project Environmental Impact Assessment

requirements of the program have been discussed with the AFRC and the DOE. and the restrictions the AFRC mav need to impose with respect to time. staff and analytical capacity. it is not particularly helpful to discuss cost in detail.

Black & Veatc/lnternatuional 9.7 Environmentalmonitoring pJan ic Montagne Jacquot Sewerage and Sanitation Project Environmental Impacl Assessment

SECTION 10

REFERENCES

Black & Veatch International References p. p ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A Montagne Jacquot Sewerage and Sanitation Project Environmental impact Assessment

10.0 REFERENCES

Albion Fisheries Research Centre (AFRC). 1995. Annual Report 1995. Ministry of Fisheries and Marine Resources.

Bell. F. 1991. Status of Eutrophication in the Great Barrier Reef Lagoon. Marine Pollution Bulletin. 23:89-93

BRL Ingenierie. July 1997. "Inception Report, Montagne Jacquot Study on sanitary technical and economic viability of re-use of treated effluent for irrigation purposes.

Central Water Authority. 1991. Master Plan on Water Resources of Mautritiuii. French Coopoeration Fonds d'aide et de coopoertation. Government of Mauritius. Ministrx of Energy, Water Resources and Postal Services.

CES. 1997. Consulting Engineering Services (India) PVT LTD. Institutional Study for the Waste Water Authority: Preliminary Report submitted June !997.

Coates Paigrave. K. 1983. Trees of Southern Africa. Struik Publ.. Cape Town.

Cooper. S. 1994. Environmental Impact Assessment: Runway extension project SSR International Airport. Binnie & Partners in association with Servansingh Jadav & Partners. Mauritius.

CSIR. 1996. Marine survey at Baie du Tombeau. Stellenbosch. South Africa.

Department of Water Affairs (DWA). 1986. Management of water resources of the Republic of South Africa. DWA, Pretoria, SA.

English. S.. Wilkinson, C. and Baker. V. 1994. Survey Manualfor Tropical Mlarine Resources. Australian Institute of Marine Science, Townsville.

ERM-SIGMA-SAMSOON. 1994-1996. Audit de l'utilisation des eaux et definition des amengements necessaires dans 8 usines.

ERM. 1995. Port Extension and Free Port Development Project: Environmental Impact Assessment and Risk Analysis Study.

Black & Veatch International 10.1 References Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

Fagoonee. l. 1990. Coastal marine ecosystems of Mauritius. Hydrobiologia. 208:55-62.

Faure. G. and L. Montaggioni. 1971. Les recifs coralliens Sous-le-Vent de l'ile Maurice (Archipel des Mascareignes. Ocean Indien): morphologie et bionomie de la pente externe. C.R.Acad.Sc.Paris.ser.D: 273:1914-1916.

Fransois. C. P. 1987. Boulders in sugar cane fields and their potential uses. Mauritius 2000 studies. Physical Resources Planning. University of Mauritius Journal.

GIBB (Mauritius). 1993. Feasibility study - Baie du Tombeau Sewerage Plan Project.

Hodgkin. E.P. 1959. Patterns of life on rocky shores. J.Soc.West Aust. 35-45.

Hodgkin, E.P. and C.Michel. 1963. Zonation of plants and animals on the rocky shores of Mauritius. Proc.Soc.Arts & Sci. Mauritius. 2:121-145.

MAGOAROU/SAMSOON. 1997. The Environmental Sewerage and Sanitation Project Montagne Jacquot Pre-Feasibility Study.

Maurel, M. 1995. Mauritius. New Holland Publ., London

Ministry of Environment and Quality of Life (MEQF). 1991. State of the Environment in Mauritius. Department of Environrment, Port Louis. Mauritius. pp. 403.

Ministry of Environment and Quality of Life (MEQF). 1993a. Guidelines on the content of an Environmental Impact Assessment. Port Louis, Mauritius. pp. 19.

Ministry of Environment and Quality of Life (MEQF). 1993b. Environmental Impact Assessment. Protocol for coastal development. Department of Environment. Port Loius. Mauritius.

Mauritius Sugar Industry Research Institute (MSIRI). 1995. Annual Report. MSIRI. Reduit. Mauritius.

National Physical Development Plan (NPDP). 1992-1994. Vol 1: Programmes and Policies. MEPD. GOM.

BlacA & Veatclh International 10.2 References Montagne Jacquof Sewerage and Sanitation Project Environmental Impact Assessment

National Physical Development Plan (NPDP). 1992-1994. Vol II: Public Sector Investment Programme. MEPD. GOM.

National Physical Development Plan (NPDP). 1995. Vol 1. Strategy and Policies. Planning Division. Ministry of Housing. Lands and Town & Country Planning. Mauritius.

Overseas Economic Cooperation Fund (OECF). Japan. 1997. Environmental Guidelines. Public Relations Division, Tokyo, Japan. 25pp.

Overseas Economic Cooperation Fund (OF), Japan. 1997. Operational Guidelines on OF Loans. Public Relations Division. Tokyo, Japan. 25pp.

Overseas Economic Cooperation Fund (OECF), Japan. 1997. What is OECF ? Roles and Functions. Public Relations Division, Tokyo, Japan. 25pp.

Padya. B. M. 1984. The Climate of Mauritius. Second Edition. Meteorological Office. Mauritius.

Pastorak. R.D. and G.R. Bilyard. 1985. Effects of Sewage Pollution on Coral-Reef Communities. Marine Ecology Progress Series. 21: 175-189.

Proag. V. 1995. The Geology and Water Resources of Mauritius. Geography of Mauritius SeriesVol II. MahatmaGandhi InstitutePress. Moka. Republicof Mauritius.

Rogers. C.S.. "Responses of Coral Reefs and Reef Organisms to Sedimentation. Mlarine Ecolog Progress Series, Vol. 62: 185-202, 1990.

SaIm. R.V. 1976. The structure and successional status of three coral reefs at Mauritius. Proc.Soc.Arts & Sci. Mauritius. 3:227-240.

SETEGUE-ERM-SIGMA-SAMSOON.1994-1996. Etude et definition des Reseaux des zones industrielles,de stations de pretraitementd'effluents et d'une stationd'epuration mixte.

Severn Trent Water International/GIBB(Mauritius). 1993. The Sewerage Master Plan for the Islands of Mauritiusand Rodrigues.

SOGETI. B.E.T. 1995. Inspection et analyse du fonctionne d'un rejet mer d'aux usees. B.P. No. 9, 76231 Bois-Guillaume,France

Black & VeatchInternational 10.3 References Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

World Bank Appraisal Mission. 1990. Preparation of a Marine Environmental Management Plan.

World Bank. 1991. Environmental Assessment Sourcebook. Vol II. Sectoral Guidelines. Chapter 9: Population, health and nutrition; urban development: transportation: water supplv and sewerage. Environment Department. Washington. USA. pp. 145-261.

Black& VeatchInternational 10.4 References Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

SECTION 11

APPENDICES

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APPENDIX A: Basic design of the outfall pipeline to be built in the sea at. Montagne Jacquot ...... ii APPENDIX B: Basic design of WWT plant for Scenario 1, Primary and preliminary. waste water treatment alternative ...... vii APPENDIX C: Basic design of WWT plant for Scenario 2, Primary, preliminary and secondary waste water treatment alternative .viii APPENDIX D: Work schedule for the EIA. x APPENDIX E: Sludge management methods.xi APPENDIX F Flow chart of institutional interaction for Environmental Protection . in Mauritius. xiii APPENDIX G: EIA regulations: Government of Mauritius .xiv APPENDIX H: Consultations with LAPsand minutes of public meetings.xxi APPENDIX I: Waste water characteristics from a representative selection of key industries (pers.commSam-Soon 1997)...... xxxiii APPENDIX J: Vegetation types at the Montagne Jacquot proposed site for the WWT plant. xxxiv APPENDIX K: Coral reef community key (English el aL 1994).xxxv APPENDIX L: The National Monuments Act 1985, Government of Mauritius xxxvi APPENDIX M: State of the environment media reports e.g. 30th May 1997, L'Express.xi x APPENDIX N: Assessmentcriteria for evaluation of impacts .xli APPENDIX 0: Extract from CES Institutional Study showing WWA linkages with other . organisations...... xliii APPENDIX P: General requirement for safety, security and environmental protection and more specificmitigatory actions for contractors to be carried out during . construction of transmission pipelines.xliv APPENDIX Q: Industrial Waste Water Management .xlix APPENDIX R: Sludge Disposal.lviii

Black & Veatch International Appendices Montagne Jacquot Sewage and Sanitation Project Environmental ImpactAssessment

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APPENDIX E: Sludge Management Methods

The amount or degree of stabilizationof the organic matter required for disposal is one of the primary variables which determinesthe sludgeprocesses to be used. The second variable is the amount of dewateringprovided to reduce the volume of the sludge.

The most frequently used stabilization processesare lime addition, aerobic digestion and anaerobic digestion. Ocean disposal is also an option for sludge produced on Mauritius. The most frequentlv used dewatering processes are sand drying beds, centrifuges, and belt filter presses. Composting is also used for further stabilizationand dewateringof digested sludge.

Anaerobic Stabilization The anaerobic stabilizationprocess was describedin the both the Gibb sewerage master plan and the SETEGUE report. Anaerobic digestion is an efficient means of stabilizing sludge and results in a product which can be disposed of withoutcausing nuisanceconditions. However,it requires a high capital cost for the processunits and equipment, and can be difficult to operate effectively. It has a relatively low operating cost, associatedwith mixing the contentsof the digesters.

Aerobic Stabilization Aerobic digestion of sludge is essentiallyan extensionof the activatedsludge or extended aerationprocess. The TSS concentration in the aerobic digester is maintainedat a higher level than in the activated sludge process basins, and the detention time is longer. It is well suited to stabilization of waste activated sludge, but not for primary sludge because of the high oxygen demand of the raw sludge and potential for initial release of odors. Aerobic stabilization process units have lower capital cost than equivalent anaerobic process units, but their operating costs are significantlyhigher due to the power requirementsof the aeration system.

Lime Stabilization Lime stabilization of sludge can be used to control odors, prevent contaminationby pathogenic organisms,and reduce the attraction of vectors. It is not a biological stabilizationprocess. Lime stabilizationconsists of adding sufficient lime to the sludge to raise the pH to above 11.4 for a period of at least 30 minutes. The lime kills bacteria and prevents the productionof odors. This process has low initial cost, but requires continuing use of lime which results in relatively high operating costs. The addition of lime to the sludge increases the mass of sludge that must be delivered to the disposal site. Primary sludge requires between 100 and 150 g of hydrated lime per kilogram of solids. Secondarysludge from biological processes is more difficult to stabilize using lime, and requires between300 and 500 g/kg. Black& VeatchInternational concluded that the most appropriatesludge stabilization process for the Montagne Jacquots works would be to use lime stabilization. This was based primarily on the simplicity of the process and its low capital cost The mechanical equipment requires no sophisticatedmonitoring and control instrumentation.The process can be easily adjusted to changing conditions of sludge quality and quantity. It can be started and stopped to match the operation of the sludge dewatering equipment. The chemical handling can be done manually or with automated equipment. The proper chemical dosage can be determined using testing proceduresthat are within the capability of most treatment plant operators. Since capital costs are relatively low, changing to alternative or more comprehensive sludge stabilization processes in the future will not require abandonmentof large investments.

Black & Veatch International xi Appendices Montagne Jacquot Sewage and Sanitation Project Environmental Impact Assessment

Sludge Composting Sludge compostingis a method of stabilizingsludge which relies on low temperatureoxidation in open piles. The process relies on a proper mixture of the sludge with a dry, organic material such as wood chips to achieve a correct moisture and porosity and a forced draft of air to provide oxygen for oxidation and air for drying. It has been found to be effective and low in cost, but odor control is often a serious problem. It also requires an informed operatorto adjust air rates, monitortemperature and moisture, and mix the piles at proper intervals. The compostedproduct can be suitable for sale as gardensoil amendmentor simply spread on open land for disposal. The primary problem experiencedwith sludge compostingoperations is that they routinely produce significant foul odors which can be distractingto plant staff and offensiveto neighbors.

Sludge Dewatering Sludge is a mixture of organic matter and water. The percent moisture in raw sludge varies from more than 99 percent for dilute secondary sludge, to 96 percent for well settled primary sludge. At this moisture content, the sludgebehaves just like water. For disposal,it must be thickened or dewateredin order to reduce the total volume that must be transported,and to prevent problemscaused by excess water such as runoff from landfills. Sludge can be dewateredby gravity draining on sand beds or air drying. The most common mechanical dewatering processes are centrifuges and belt presses. All of these dewatering alternatives were reviewed by the Gibb seweragemaster plan and the SETEGUEpreliminary design report.

The most appropriatedewatering process for the MontagneJacquots works is to use belt filter presses. Although the capital cost is relatively high, they are generallyrobust units, and when properly operated produce a sludge cake suitablefor hauling in open trucks and for disposal in sanitary landfills. They do require trained operatorsto monitor and adjust the machine and chemicalrequirements to suit the changing characteristicsof the raw sludge, and to maintainthe various componentsof the machinery.

Black Veatch International xii . Appendices Black*& VeuJe ilnternational Xil . open dices Monlagne Jacquot Sewage and Sanitation Project Environmental Impact Assessment

APPENDIX F: Flow chart of institutional interaction for environmental protection in Mauritius

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APPENDIX G: E1A regulations: Government of Mauritius

Part IV

13. APPLICATION FOR EIA LICENCE (1) Notwithstanding any licence, permit, or approval granted under any other enactment, any person being a proponent who commences, proceeds with, carries out, executes or conducts, or causes to conmence, proceed with, carry out, execute or conduct, an undertaking (a) without an EIA licence; or (b) in breach of any condition of the licence, shall commit an offence. (2) Notwithstanding subsection (1) a proponent (a) may for the purpose of an understaking prepare a feasibility study or do any research or any act in furtherance of an application for an EIA licence, or for an approval, perm;ission or licence reouired under any other enactment in respect of the undertaking; (b) shall inform the Director of any.act done under paragraph (a).

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Black & Veatch international xiv Aopen dices MVontagneJacquot Sewage and Sanitation Project Environmental Impact Assessment

(3) A proponent apvlying for an EIA li'ice.ncejlp on to this undertaking shall submit to the Director an environment impact assessment. u - (4) Where owners.hip, control or management or an undertaking is transferred before an ELA iS approved to any person, the proponent and that persbinshall jointly notiry the Director of the transfer and co.

14. CONTENTS OF EIA An EIA shall contain a true statement and desc.pition of (a) the location of the undertaking and its surroundings; (b) the principle, concept and purpose of the undertaking; (c) the direct or indirect effects that the undertakinz is likely to have on the environment; (d) the social, economic and cultural effects that undertaking is likely to have on people and socier-; (e) any actions or measures which may avoid, prevent, change, mitigate or remedy the likely effects of the undertaking on the environment, people and society; (f) the inevitable adverse environmental effects that the undertaking is likely to have on the environ- ment, people and society, if it is implemented in the manner proposed by the proponent; (g) the irreversible and irretrievable commitments of resources which will be involved by the under- taking, if implemented in the matter proposed by the proponent; (h) any alternatives to the proposed undertaking; (i) such other information as may be necessary to a proper review of the potential environmental impact of the undertaking.

15. PUBLIC COMMENT (1) An EIA submitted under section 13 (3) shall be open at all reasonable hours for public inspection. (2) The Director shall give notice to that effect in two issues of the Gazette and in two issues of two daily newspapers, there being in each case an interval of at least 7 days between the first and second publi- cations. (3) A notice published under subsection (2) shall state (a) a summary description of the undertaldng; (b) the address where the undertaking is to be carried out; (c) the place where the EIA may be inspected; (d) the tine limit for the submission of public comments in writing. (4) The Director may on application extend the time limit to afford reasonable opportunity for any person to submit public comments on the EBA.

16. REVIEW OF EIA (1) The Director shall (a) review an EIA submnitted by a proponent and determine its scope and contents; and

Black& VeatchInternational xv Anrvendices Montagne Jacquot Sewage and SanitationProject Environmental lmpact Assessment

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(b) refer the EIA totanexemt undertaking with such conmmentsand obser- vations as he thinks ap- public comments submitted, to the ELACommittee for examination (Amended 4/93),' (2) The Director may for the purpose ot-th?erevew unde subection (1) (a) (a) request anv public department, an en-forcing agency, any non-governmental organisation or any other person to submit their observation in writing on the ELA;

| - (b) set up a technical advisory committee to advise him on the EIA or on any aspects of the undertaldn; (c) require the proponent to carry out fiu*her'study or-to submit additional information for the purpose of ensuring that the ETAis as accurate and exhaustive as possible.

17. EIA COMMITTEE I.- (1) There is established for the purposes of this Act an EIA Committee which shall consist of (a) the Permanent Secretarv, Ministrv of Environment and Qualitv of Life, as Chairman; 3 (b) the Director; (c) a representative of the Ministry of Health; (d) a representative of the Ministry of Agriculture, Fisheries & Natural Resources; (e) a representative of the Mvfinistryof Industry and Industrial Technology; (f) a representative of the Ministry of Housing, Land & Town & Country Planning; and (g) a representative of the Ministry of Energy, Water Resources & Postal Services. (2) The EIA Comrnmitteeshall examine applications for ETAlicence referred to it after review bv the Director and shall make such recommendations to the Minister as it thinks fit. (3) Four members of the EIA Committee shall constitute a quorum. (4) The EIA Committee may (a) establish any sub-committee J (b) with the approval of the Minister, co-opt any person as member. (5) No co-opted member shall (a) be deemed to hold a public office solely by virtue of his designation as member of the EIA i Committee; (b) have any voting right. (6) Subject to the other provisions of this section, the EIA Comnmitteeshall regulate its meetings and pro- ceedings in such manner as it thinks fit. (Amended 4/93)

18. DECISION ON EIA (1) The Minister shall after taking into account recommendations of the EIA Comnittee make his findings; (Amended 4t93) (a) refer it back to the Director with a direction to set up a technical advisory committee for further con- sideration of the ETA; (b) require the proponent to furnish any additional information as may be needed to determninethe environmental impact of the undertaldng; (c) where an ETAprovides insufficient information to determiine the scope or the impact of the under- taking on the environment, people or society, disapprove the EIA; (d) subject to section 19, approve the EIA with a direction to issue an ETAlicence on such terms and con- ditions as it considers appropriate.

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Black& VeatchInternational xvi - Appendices Montagne Jacquot Sewage and SanitationProject EnvironmentalImpact ASSeSSMent

(2) subject to an aDpeal undersfe Ministershall be final and binding. (3) DneDirector shall comv e ans h of the Minister under subsect.on (). (4) where an ELAis approved by the Ministlhe-Director shall issue an EIA lice-nceon the te.ms and co ditiors contained in a direction under subsectibn (1).

I19.ELT APPROVAL (1) In considering approval of an EIA, account shall be taken of (a) the mirnimumrequirements of an EIA as prescribed in regulations; (b) the environmental factors considered in the EIA; (c) the measures proposed to avoid or minimise adverse effects on the environment, peopie or society; (d) the alternatives proposed in the EIA; (e) such other matters that may be relevant in weighing the significance or insiriitncance ci the p.oter tial environmental imnact of the undertaking. (2) Where an ETAis approved or a direction is given by the Molinisterunder subsection 3(b) , the ETAand tht directions shaLlbe deemed to be conditions of the EIA licence issued under section 1S (4). (3)The Mfinistermay at any time notwithstanding an approved EIA (a) revoke an EIA licence, or amend the conditions of an EIA licence; (b) give the proponent such directions as he considers necessarv in relation to (i) the methods of execution and the phasing of the undertaking; (ii) works or actions required to prevent, reduce or eliminate the adverse effects of the under- taking on the environment, people and society; (iii) research, investigation, and monitoring programmes related to the undertaking; (iv) any other aspect of the undertaking or of the execution of the undertaking which is reason- ably expected to have adverse environmental effects; (c) require the proponent to submit at such interval as he may detemiine, reports on the impacts of the undertaking on the environment, people and society. (4) Any person who fails to comply with a requirement under subsection 3(c), shkl commit an offence.

20. SUBMISSION OF FRESH EIA' (1) The Director may at any time after the issue of an EIA licence order a holder to submit a fresh EKAin respect of his undertaking within such time as may be specified. (2) An order under subsection (1) may be issued where in the opinion of the Director (a) the undertaking is or is likely to be a source of pollution to the environment; (b) there is a substantial change or modification in the undertaking, or in the manner in which the undertaking is being operated; (c) the undertaking poses a threat to the environmeht; or (d) the circumstances of the undertaking with regard to its surrounding environment so require. (3) Where a person being a holder fails to comply with an order issued under subsection (1) (a) he shall commit an offence; (b) his EIA licence shall be cancelled.

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21. TRANSFEROF EIA LICEN4CE U'-"--:.. (1) An EIA licence may be transferred by the holder to a person who purports to own, or to have charge. or management, or controi of the undertaking to whi'ch the licence relates. = - (2) Where an EJAlicence is -ransferred un t section, the person to whom it is transferred and t1hehold- er shall jointly notify the Director in writing or the transfer not later than thirrv days of the transfer, and cormmunicatethe document witnessing the transfer (3) vhere no joint notification of transfer is given in accordance with subsection (2), the hoider shall be deemed for the purposes of this Act to be the owner, or the person having charge, or management or control of the undertaking, as the case may be. (4) An EIA licer.ce which is transferred to a person under this section shall have effect on the date the Director is notified as if it has been issued to that person and be subject to the same conditions as were attached to it immediately before that date. (5) Any person who contravenes subsection (2) shall comnit an offence.

22. FFECT OF EIA LICENCE (1) No civil or criminal liability in respect of an undertaking or consequence resulting from an undertakine shall be incurred by the Government of Mauritius, the M'linister,or any public officer by reason of the approval oi an EIA or the grant of an EIA licence, or by reason of any conditions attached to an TLA licence. (2) The fact that an ETAlicence is issued in respect of an undertaking shall afford no defence to any civil action or to a prosecution under any enactment other than section 13(1) concerning that under-aking or the manner it is operated or managed.

23. EXEMPNON (1) The Minister may declare an undertaking by a public department, which in his opinion is urgently nee- ded in the national interest or for the economic development of Mauritius, to be an exempt undertaking (2) Sections 13 and 16 (b) shall not apply in respect of an exempt undertaking. (3) The Director shall refer an EIA in respect of an exempt undertaking together with his comments and observations and with any public comments submitted to the Minister for his decision. (4) The Minister may approve the EIA on such conditions as he thinks fit, having regard to section 19. (5) On approving an EtA under subsection (4), the -Minister shall cause a notice to be published in the Gazettestating - (a) a summary description of the undertaking and its location; (b) the proponent of the undertaking; (c) a declaration that the undertaking is an exempt undertaking; (d) the approval of the EIA and the conditions attached to the approval.

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(2) For the purpose of subsection (1), .-aw agnc:tural comnmodities (a) include fresh or frozen hfuits and vege.tablesin their raw state, grans, nuts, eggs, raw milk, meat and other agricultural produce, :. (b) but do not include any agricultural produce or food which is processed, fabricated or manufactured by cooking, dehydrating, milling or by anv others means.

40. STANDARDS FOR ODOURS The Minister shall prescribe such standards for odours as are required to preserve and maintain public health and the environment.

41. QUALITY CONTROL OF LABORATORIES (1) For the purpose of assessing analytical performance and ensuring the validitv and comparabilitv or envi- ronmental data, the Minister shall, in relation to accredited laboratories (a) prescribe standards of procedure for quality-assuranceand quality control; (b) establish analytical quality control programmes; (c) prescribe calibration procedures for analytical instruments used in accredited laboratories. (2) The Minister may on application accredit a public or private. laboratory conducting or intending to con- duct laboratory analyses of environmental samples or providing environrmental data. (3) An analysis of environmental sample conducted by or environmental data provided by a laboratorv other than an accredited laboratory shall not be admissible evidence in any proceeding before a Court of law or before the Tribunal.

Part VII

COASTALAND MARIMEZONEMANAGEMENT

42. INTERPRETATION UNDER THIS PART In this Part - 'baseline' has the meaning assigned to it in the Territorial Sea Act; "coastalzone' (a) means (i) any area of seawater including any low-tide elevation, land, beach, islet, reefs, rocks, lying between the baseline and the highwater mark; (ii) any land which is situated wholly or partly within 81.21metres from the highwater mark; tb) includes any estuary or mouth of a river, stream or canal which lies within 8171 metres from the outermost point of its bank on the sea at high tide; "dumping" means

(i) any deliberate disposal of wastes or other matter from vessels, aircraft, platforms or other l man-made structures at sea; (ii) any deliberate disposal of vessels, aircraft, or other man-made structures at sea;

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"maittimezone means the man s dithon of the State of Mautius, and indudes the territorial sea, the exclusive econo 5if7o-na nitinental shelf, as defined in the' Maritime Zones Act; "zone" means the coastal aindm-ai-timez'one a

-. ;. ; ' . 43. PROTECTION OF THE ZONE. (1) The Minister may make such regulations as he thinks fit to prevent, reduce and control pollution in the zone. (2) Notwithstancding the generality of subsection (l), the regulations may provide for - | (a) such measures as are necessary to ensure that actvities in the zone are so conducted as not to cause damnageby pollution to the natural environment; (b) the control and prevention of pollution from vesseis, crafts, and other engines used in the zone; (c) the control and prevention of pollution from installations and devices used in the exploration or exploitation of the natural resources of the sea-bed and subsoil of the maritime zone; (d) the control and prevention of pollution of the marine environment from land-based sources, inldud- ing rivers, estuaries, pipelines, and outfall structures; (e) the control and prevention of pollution of the marine environment arising from or in connection I - with seabed activities and from artificialislands, installations and structures in the maritime zone; (f) such other matters relating to the preservation and conservation of the environment of the zone.

44. DUMPING IN THE ZONE

- (1) Subject to subsection (2), no person shall release or cause to release into the zone such toxic, harmful or noxious substances from or through the atmosphere or by dumping. (2) It shall be a defence to a prosecution under subsection (1) to prove that the release or the dumping was | due to or was rendered necessary by "force majeure", or for the protection of human life. (3)Any person who contravenes subsection (1)shall commit an offence.

Part VIlI

1~~~~~~~~

I _ - .= - -~~I

45. THE ENVIRONMEINT APPEALTRIBUNAL (1) There is established for the purposes of this Act an Environment Appeal Tribunal which shall consist of (a) a Chairman, who shall be a barrister-at-law of not less than ten years standing, appointed bv the Public Service Commnission,and (b) such other members as may be appointed by the Minister. (2) The Minister may - (a) appoint such members on an ad hoc basis and for such period as he considers necessary to serve on the Tribunal; (b) designate such public officers as he thinks fit to assist in conducting the business of the Tribunal; (c) approve such fees as may be paid to the members of the Tribunal.

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APPENDIX H: Consultations with lAPs and minutes of public meetings

CONSULTATIONS WITH PS

1.0. Medine Sugar Estate: Mr. D'Arifat

0 noted extent of property - to the west coast as far as crown lands, in the south to the Grande Riviere Noire and in the north, patches of cultivation up to area of project, 0 is wastewater effluent suitable for irrigation ? - they currently use raw sewage in open channel irrigation system with no apparent adverse consequences so no objections in principle, main problem is distance from Montagne Jacquot treatment works which would normally be prohibitive; estate were interested in treated effluent from St Martin works which is much closer, 0 health implications of using treated effluent discussed - can be managed in a commercial operation more easily than for eg. small scale vegetable growing, by introduction of apprdpriate management practices eg. cessation of irrigation one month before harvesting, using rubber boots to reduce exposure, 0 irrigation channels used for washing and cleaning by a few individuals in local communities even in locations where sewage is in evidence- implications of introducing wastewater effluent need to be investigated if it is to be introduced in areas where exposure is not already occurring, 0 planters in north of area use gravity fed open channels to irrigate crops - need to discuss with them the implications. 0 Medine have recently commissioned a study by STAME (a subsidiary of Unite des Eaux) to investigate their solid wastes disposal options - could be extended to include liquid wastes / water utilisation options, including use of treated effluent. 0 Aesthetic considerations and potential practical problems of using wastewater effluent suggest on-site screening would be advisable, tho none of Medine irrigation is by drip-fed systems (would be more problematic in terms of blocked nozzles etc). 0 Because of emotive aspects of co-discharging dyes from industrial plants with sewage from municipal sources in sensitive coastal areas, some thought regarding pre-treatment of industrial wastes would be necessary; but if it was to be subsequently used for irrigation there would not really be a problem. 0 discussed 'polluter pays principle' in context of Medine as recipient of treated effluents. Irrigation with municipal-wastes could potentially reduce capital treatment requirement at STW which would benefit the public. Also why should irrigators pay for treatment of the public's wastewater - especially if treatment not required for irrigation use ? 0 in general, any arrangement which improves the current situation must be good, but who will pay for water treated to a higher standard ?

2.0. Albion Research Station : Dr. V. Chineah, M. Nallee, Mme. R. Pillay, M. Chooramum.

Discussed diverse research activities carried out by research station, but none of these specific enough to cover the area of the project in anything but general terms. The particular disciplines covered by individuals at the centre L include:

0 water quality studies and pollution monitoring at selected sites around Mauritius, especially at sites regarded as sensitive for tourism and protection of existing resources, 0 ecosystems studies (quantitative and qualitative), focussed on representative ecosystems around Mauritius and especially on coral reef systems; in the process of introducing rec-diver surveys to augment data base,

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0 hydro-dynamic studies - measurements of currents and tidal flows to characterise more precisely the hydro- dynamic characteristics of Mauritian coastal waters, O fisheries evaluation in collaboration with the ministry personnel, collecting data at fish landings around the island eg.rBain des Dames.

(NB. Geophysical studies may have been carried out at the university - Dr. Jutang ?)

O contact Port Authority regarding up-to-date charts, and bathymetric surveys / bottom profiles which may have been carried out of immediate coastal zone - but no known new reef areas identified in recent past which do not appear on charts, 0 no formal assessments of coastal fisheries had been carried out in the potential discharge area (but see catch statistics for west coast fishing communities), 0 there are no assessments of the juvenile fish populations or nurseries in the estuarine areas to the north of the project area, but these areas are assumed to be important for the species which can tolerate the pollution concentrations present, O there are no Fish Aggregation Devices (FADs) or artificial reefs in the immediate project area - to their knowledge these occur further south, 0 there is no formal industry exploiting shellfish in the vicinity of the project area, although clams and oysters are collected recreationally along parts of the coast, 0 the reef offshore in the project area is heavily eutrophicated as a result of sewage discharges from the existing ocean outfalls which discharge untreated sewage, and although no recent assessment of the health of the reef has been conducted, they suspect it is in poor condition, O they would be concerned about the construction of a pipeline through the lagoon - would it cause even more damage ? (ie. offshore of Pointe des Sables parallel to the coast) but recommended consulting with the fishermen at Pointe des Sables who would be more affected than anyone (contact: Mr. Dennis Jackson), O they know of no notably significant or valuable marine resources in the vicinity of the proposed outfall site which might be impacted by the development

3.0. Marine Conservation Society: M. Phillippe Lahausse (Tel: 686 3094)

0 Discussed general importance of expansion of diving tourism to Mauritian economy especially in rural locations, 0 main sites on the west coast are Flic-en-Flac, where there are at least 5 diving centres of a total of 30 on the island, 0 complaints regarding St. Martin sewage works have been sporadic, but sufficient to indicate there is a serious problem with the functioning of the works, O Pointe aux Sables fishing community exploit the reefs at Fli-en-Flac, offshore FADs and set traps on the reef, but are always complaining about sewage pollution from the port and Pointe-aux-Sables outfall, 0 concerns regarding impact of sinking the pipeline along the lagoon inshore of the fringing reef, mainly because of the potential for current-driven sediment to smother such coral communities as still survive along the reef rim, O will confirm whether sensitive dive sites exist between Pointe aux Caves and Pointe aux Sables, and offerred to conduct or participate in dives to ascertain whether there are sensitive coral communities or habitats of particular value in the vicinity of the proposed outfall, and especially along the fringing reef which may be vulnerable during the construction phase of the project.. O diving sites at caves are probably the closest notable conservation-worthy resources,

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O in general indicated that anything which improves the present situation has to be welcomed, but signalled desirability of involving affected parties more extensively at an early stage to avoid adverse public perception of the project and dissemination of misinformation.

4.0. Development Bank of Mauritius Ltd.: Mr. Aubeeluck

0 Situation at La Tour Koenig industrial site discussed - road infrastructure in dire need of upgrading, and allocation of sites almost complete with rapid development of new industries occurring - some of which will be heavy water users with net total water utilisation of up to 800,000 gallons/day, 0 CWA getting a loan from Development Bank for provision of water supply, O SIGMA study of Coramandel industrial estates should be able to provide information on quality/quantity of effluents from individual industries, 0 all industrial plants on site recommended to integrate sedimentation tanks and rudimentary treatment into their systems prior to discharge into the common sewer, but the few of them that apparently have adopted this advice, do not properly maintain their systems so they are ineffective, O current overflow problems on site suggest that some sections of piping need to be increased in diameter and/or replaced - the situation being addressed as a matter of urgency, 0 water is an increasing problem - water supply will be developed for the estate using a Development Bank loan exclusively for industrial users, 0 the concept of a joint pre-treatrnent works for the industrial estate has not seriously been considered because of the lack of a site and costs involved, which are perceived to be prohibitive.

5.0. Friends of the Environment: Dr. Monique Koenig

0 they have received many complaints about the sewage discharges around the port and off Pointe-aux-Sables, and reports of algal blooms, 9 normally the MMCS deal with issues at sea, and FoE with issues on land, but FoE like to be informed, O suggested that newspaper articles (try Thierry Chateau joumnalist with special interest in tthe environment at 'Le Mauricien')and public meeting in area of affected community would be a good idea (try District Councils), so that people know what's happening, 0 she does not normally advocate extreme tactics for the group, but lobbying on particular issues to ensure politicians in possession of the correct facts. O members such as herself (PhD Microbiology) or Pamela Leste would be able to comment on technical aspects of project and EIA, Joseph Gueho (or his assistant Danielle) from the herbarium, the botanical.

6.0. Ministry of Agriculture, Conservation Unit: Mr. Sookun

0 his main concern was if the development would affect 'his' birds - mainly whimbrels, tumstones, plovers etc. some of which are migratory, but mainly feed on the mud-flats around the port.

0 the main feeding area was first out at Bain des Dames, but this developed as a picnic area and the birds moved further north towards the container terminal.

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0 they are now proposing to fence the area, and pass legislation to formally declare it as a sanctuary, as these bird populations have caused problems in terms of the port development and are likely to be under even more pressure in future, 0 at present the food supply is ample - the mud flats are rich in invertebrate infauna, and there is certainly no shortage of food - could cessation of sewage discharges affect food supply, as there will be reduced organic matter supply to flats ? 0 there have been no formal assessments of either the food supply available to these populations, or of water quality, but data on the bird populations themselves will soon be published. 0 contact Mr. Munro to get the ministry official view regarding the project.

7.0. Association des Pecheurs, Pointe-aux-Sables : Mr. Dennis Jackson

0 condition of the reef has deteriorated steadily over the past 10 or more years and there still seems to be progressive deterioration to the southern end of the reef. They have seen the reef gradually die-off to the point where there are no commercially valuable fish to be caught there, 0 water quality in the lagoon is terrible most of the time - there are frequent algal blooms, and the water is visibly discoloured with sewage most of the time, often with dyes used in industry too, 0 people used to come to the Pointe-aux-Sables beach for picnics, swimming, fishing - but no more as there is a constant foul odour and sewage debris always present in the water, 0 they are particularly worried that, unless something is done urgently to address the sewage discharges on the west coast, the entire coast will be like Pointe-aux-Sables in a few years time. 0 there are some fish species and communities which are particularly sensitive - for example, for a few weeks each year they fish the caves at Albion for a species of especially valuable mullet (the stupid mullet ?) - they have not seen any at all this year (perhaps they are not so stupid after all!) 0 thought that taking the pipeline through the lagoon may possibly be a better option than along the road, but the pro's and con's would need to be looked at. If through the lagoon, it should be closer to the shore than the reef, buried and with the bottom restored flush with the surrounding area. 0 contact Mr. Munboth, Chief Scientific Officer at Ministry of Fisheries regarding sites assessed during 1990/91 EU study. He thinks that there was a site right off Pointe-aux-Sables.

8.0. Irrigation Authority: Mr. Dabeesingh

0 the main issues to consider regarding waste water re-use are the cost of water and the system of irrigation. 0 he calculated the break-even price on the Baie de Tombeau project to be RS 1.80/m3, but he has heard that after tertiary treatment the cost of water will be RS6/m3 - why should the farmer bear the cost of treating water to this standard ? 0 there are about 35,000 small planters in Mauritius, 30% of sugar is produced by them, and the GoM doesn't want to lose them. In general, they have the poorer, dryer, rockier land and have no resources to improve their land/operations, so the GoM are trying to consolidate them into co-ops, and assisting them with land development projects. Consequently, all projects are aimed at improving the situation for small farmers, because the large ones can manage fine,

0 all proposals must be cost effective and appropriate to local conditions - drip irrigation requires high quality water because of problem of blocked nozzles; overhead systems not appropriate for wastewater re-use

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systems because of increased risk of risk of contact with spray and residue on the cane, open channels may not be appropriate, because of other uses for water, centre pivot no good where many smallholders (

9.0. Mauritius Export Processing Zone Association: Mrs Wong

0 industry is feeling under pressure from all quarters at the moment - (including environmentalists) but there are few signs that they are taking action to improve their environmental performance, 0 industry sees the requirement for higher standards as obstructing industrial development and financial success, and has not apparently seen this as directly linked to market expansion into the most lucrative world markets, 0 ISO 9000 / 14000 being advertised like a household cleaner in the media - and following conviction of several companies in SA after they simply bought the certification, everyone is very sceptical in Mauritius! 0 MEPZA has recently developed an award system to reward corporate achievement and committment to improving environmental performance, through for eg. improving waste management systems, but there is little interest in Mauritius at present (5 nominations last year, none this year), 0 industry is reacting to forces around them - and not looking ahead. Water shortages and the increased cost of pollution abatement measures are bound to have a major impact on profitability in future, but there is a head in the sand attitude now.

10.0. Central Water Authority: Mr. Rogbeer

0 serious problems of water supply shortages from their own systems - which mean they could not possibly supply industry, 0 the municipal dyke on the GRNW diverts water from the river in three pipes into the municipal filter beds, where the water is sand filtered and chlorinated before entering municipal supply, 0 problems arise during heavy rains when the sewers overflow into the river and water is contaminated with municipal and industrial waste, but this is below their water intake, so potable water is not normally affected, 0 the main industrial areas around the port including Coromandel receive water from an aquifer in the Corps de Garde area, transported in a tunnel flowing by gravity direct to the industrial estates. 0 industry is proposing to set up an additional supply with Development Bank funding, by constructing a small impoundment in the lower GRNW below the municipal dyke and to pump water from the river which will be treated at industry's cost to augment the existing supplies. 0 GRNW is not heavily polluted although the sugar estate at Highland occasionally discharges into the river and they suspect that other industries discharge at night, 0 they will gladly allow us to look at such monitoring information as they have,

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0 contact Mr. Rogbeer for introductions, 0 industry definitely needs to install pre-treatment prior to discharging liquid effluent into municipal sewer, and Development Bank in fact has a programme to support investment by industry in appropriate technology to do this. 0 industry appears to be concerned that it will soon be facing both higher charges for raw water, but also for effluent disposal, 0 water used by industry could be managed much better than it is at the moment by ensuring water re-cycling systems are introduced, water re-use where possible, by ensuring that high quality water not used for processes that dont need it, good housekeeping in plants etc.

11.0. Ministry of Export Development and Investment Authority

O MEDIA promotes industry for the GoM, provides sites and facilities but none in the proposed Montagne - Jacquot service area, 0 have strategies for encouraging industry to locate in Mauritius including tax breaks etc. and in the past have tried to locate industries with similar requirements together eg. liquid effluent disposal, but has not worked very well. 0 they know that new development will be constrained by water requirements and availability of land, so they try to identify state land to develop industrial estates to avoid acquisition of land being the main constraint to development, 0 they expect that increasing numbers of industries will want to come to Mauritius as result of COMESA / SADEC, but identifying compatibility/feasibility takes time. They do not want Mauritius to get a bad name through allowing industrial operations which are heavily polluting a licence to site here, 9 their problems will probably be much less difficult once industry does start to pre-treat, as they will be able to discharge into sewers (as they do now ! - but how many more industries should they allow to come here without a committment to treat and dispose of their waste responsibly).

12.0. Ministry of Environment and Quality of Life:

First meeting: Mr. Keshore Heeramun 0 essentially the legislation is unchanged since the 1991 Enviromnental Protection Act, which details EIA procedures, excepting the formal EIA review procedure and appeal process.

0 see Aslam Yadalee of the Standards Division regarding water and effluent standards for the project,

O see Mrs Ng regarding liaison with the Ministry during the EIA, and technical comment on EIA report prior to submission (since they require 15 copies better to make sure is OK first

0 suggested an orientation session for the entire MOEQL staff might be appropriate.

Second Meeting: Mrs Ng (other MOEQL staff) 0 the reuse of treated effluent for irrigation will be a good thing 0 there are no standards, at present, for effluent diposal into the marine environment. Mauritius will use probably use a world health organisation's standards as a reference. The best approach would be to have two

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scenarios with two different sets of standards (stringent and not so stringent set of standards) and assess the impact of both on the marine environment. 0 It is very important to look at the impact the project will have on the socio-economic environment i.e. the communities being affected by the project e.g. the landfill site project, in the north of Mauritius, had to be abandoned due to public pressure. 0 the Sociologist must investigate the concerns of the residents at Pointe aux Sables 0 Would there be an odour problem with the new WWT works ? - depends on design and prevailing winds in the area - the prevailing winds blow in the opposite direction to the nearest communities in the study area 0 What sort of personnel are employed at the WWT works ? - it is important to include this in the EIA report. 0 Are we including baseline/background information in the report ? yes 0 Are we including a monitoring programme in the report ? yes 0 The assessment of the EIA report will take ; 3 months. All EIA reports are made available to the public for comment 0 Have we heard about the approved area of land purchased in the study area ? 0 What is the recommended buffer zone ? GIBB used a buffer zone of 400m - but there are no guidelines 0 Are we putting limits on the industrial effluents ? i.e. will the new WWT plant be able to cope with the industrial effluent which has heavy metals etc. in it. Certain percentages of these properties of the effluent will be removed.

13.0. Mauritius Sugar Industry Research Institute: Mr. Daniel Ah Koon

0 crazy to treat water to tertiary standard then use for irrigation, 0 what is required is a proper evaluation of the health risks in particular communities, cultivating particular crops or for particular markets and whether they are food crops or not before the idea is dismissed, 0 health impacts can be,addressed by a variety of management measures, including changing crops to non-food cash crops, stopping irrigation some weeks before harvesting, washing fruit before marketting etc. education also helps, 0 there may be some practical problem associated with different irrigation systems (drip systems as already mentioned - but insert filter before site, not hecessary to have fully treated water, as drip system not exposed to workers anyway.

14.0 Ministry of Economic Planning and Development: Mr R. Parboteah (Economist)

0 The Sewerage Master Plan for Montagne Jacquot must have priority - the Pointe aux Sables reef is in a bad state - if the effluent was discharged outside the reef it would be better i.e. it is important to discharge effiuent in the right place where impact will be minimal. The Pointe aux Sables outfall is too shallow and does not disperse effluent properly. 0 The new WWT plant is a very good thing since it will cater for industrial effluent.

0 The MEPD is responsible for monitoring and overseeing projects - they closely follow the implementation of projects. They are also responsible for the financial side of the projects. 0 What is the Montagne Jacquot Projects time scale ? - it is important to complete the Montagne Jacquot Project as soon as possible

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15.0 Ministry of Energy and Water Resources: Dr. Sharma, and assistant

0 will the effluent be treated before discharge?depends on cost and time. The effluent may be reused for irrigation only after secondary treatment (B). What will be the quality of the water effluent be after secondary treatment? i.e. they seem very inerested in the reuse of treated effluent for irrigation since water is a scarce resource O the quality of irigation water is more important for other food crops but not sugar cane. The assistant will obtain the International Standards for treated water for irrigation purposes since Mauritius does not have standards for irrigation water or ocean outfall effluents, only for inland water. There are standards for drinking water. 0 at present, drip irrigation comprises 10% of irrigation methods used in Mauritius but will increase this to 27% to conserve water. Other irrigation methods are > 60%. 0 the problem of people using the irrigation channels for washing will decrease since the next generation of people are more educated and there is better technology 0 the assistant suggested that we need joint evaluation of the St. Martin project and the Montagne Jacquot project, since there are similarities. 0 how much irrigation water is needed in the Montagne Jacquot area? and how much will be availabe for irrigation from the WWT plant? 25 000m3 per day (B) 0 why should the agriculture industries pay the cost of treating water? (since they are the ones who will use the treated effluent). They agreed that since agriculture needs the water and uses most of it - they should pay since someone must bear the cost. The MEWR predict that before the year 2020 they will need recycled water. O because of the lack of surface water, agriculture will eventually depend on treated/recycled water for their source of water. When is the Montagne Jacquot study to be completed? O- contact Mr. Toolsee at the Irrigation Authority for information on areas under .irrigation. The main responsibility of the MEWR is to provide water for whatever it is needed - they locate the source of water then provide it. The MEWR is also responsible for the control of water pollution. 0 the accumulation of pesticides from irrigation runoff can become a problem over time. O is water coming into the WWT works both from industries and sewage? if so, what about the presence of heavy metals in the marine environment? There should be special regulations for industrial effluents. 0 near the Montagne Jacquot project Study Area there is a planned dam development at the confluence of the Remipart River and the R. Papayes River - this is to supply more water to the westem agricultural estates.

16.0 Ministry of Health: Mr. L Hurpaul (Principal Sanitary Engineer

0 this department has received a number of complaints from the public on the pollution on the beach at Pointe aux Sables. O the present standards for effluent are too low - the new WWT plant would need, at the very least, primary and secondary treatment. 0 one of the main problems that the sewage situation has got to this bad state is the lack of skilled maintenance people in Mauritius to service the pump stations of the sewer network. If equipment stops working - it stays that way for many years i.e. never gets fixed. A good example is at the Fort Victoria works where only two pumps are working (in fact, all four pumps, when they were all working, are never run simulataneously since

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at peak flows the system cannot cope). Therefore, for the new WWT works it is important to use good quality,simple equipmentwhich requireslittle maintenance. O skepticalabout the pumpingstations (whichwill be built to pump sewerageto new WWT work) being able to cope with maximum flow levels. 0 who is fundingthe project? World Bank & GOM (40%) and the Japan EconomicDevelopment Fund (60%). 0 the local conditions of the sewer system, and the factors affecting it, are very important to consider when designingand buildingthe new WWT plant. The present sewer networks are old with a high filtrationrate. 0 the main responsibilityof this department is to address complaints about sanitary problems from the public, and to inspectthe facilitiesin buildingse.g. kitchensin hotels and restuarantswhere grease is a big problem- they should maintaintheir grease traps which they do not do. 0 how will the MontagneJacquot project deal with the problemof sludge? disposal of sludge is a big problem since the landfill site is far away.

17.0 Ministry of Industry: Mr. Domun

0 The ministry is aware of the Montagne Jacquot project, and previous studies (e.g.Sogeti) relating to the present sewer problem. Mr. Domun mentioneda study done in 1987/88 (EnvironmentalIndustry Pollution Initiative?)and funded by World Bank, which was undertaken to try and deal with the pollution resulting from industrial effluents. The project identifiedan area for an Industrial Park where future industriescould operate under more controlled condition - this project was, however, shelved due to lack of funds. In addition, the existing industries were not able to accommodatechanges to their present systemsto try and avoid pollution. 0 the Montagne Jacquot project is long overdue - most of the dye houses are set up adjacent to the sewer system - which is convenientfor the disposal of their effluents. O the Ministry of Industry has some responsibilityto the quality of discharge produced by industries. In the past, the development of industries in certain areas have been restricted to try and alleviate the existing pollutionproblem in those areas. e.g. Coramandel. O the fisherman in and around Port Louis have complaineda lot about the effluent discharginginto the sea. O for 7 to 8 years the dye houses have wanted to expand but have been restricted by the lack of water and the pollution problem. 0 the present trend in industries in Mauritius is in the textile industry where an increase in textile developments is evident. In other words, the demand for water will increase since the textile industry uses a large amount of water. The textile industry is very important for economic growth in Mauritius. In fact, the Minsitry is relying on the MontagneJacquot project so that they can expand more. The Ministry is also trying to expand into other types of industries. 0 they import labour for the textile industry (which is very labour intensive) because there is a short supply of labour in Mauritius. 0 two ways to reduce the present sewer problem is (1) divert the industrial effluents to a separate system, (2) control the problem at the source i.e. the factoriesshould have screening systems which are maintained. 0 there are too many regulatory authorities responsible for monitoring the different aspects of the industry operation (water effluent, building structuresetc.) - so there is a problem of "who's responsiblefor what".

Black & Veatch International XXiX Appendices Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

18.0 Ministry of Housing & Lands, Town & Country Planning Board: Ms Koo

0 the Town & Country Planning Board has already given plans for a housing developmentand a lease area on the land adjacent to the prison i.e. the proposed site for the Montagne Jacquot WWT works. She foresees a big problemwith this - the Baie de Tombeau project has a problem with landowneres(who are now sueing). She advises us to move the site to avoid compensationcosts - it costs 45 million rupees for 1 acre of land if the owner has already been given permissionto build on a site. O what size will the WWT plant be? it would cover an approx area of 15ha with a 400m buffer zone around it. O in the NPDP MontagneJacquot was earmarkedfor urban development.

19.0 Chamber of Agriculture (private company): Mr. Juwaheer, Mr Poisson

O their main worry is that we avoid potential agriculturalland - since the site for the Montagne Jacquotproject is not on potential agricultureland they do not have a problem with the project. They would have a problem if the wind directionwas such that they would be adverselyaffected. 0 is one of the main aims of the project to use treated effluent for agriculture ? yes. They were not sure as to what the limitations of water quality of treated effluent are if used to irrigate sugar cane - contact Dr. Soopramanienat the at the MSIR1for informationon the effect of treated effluent water on sugarcane. The high sodium chloride in industrialwaste would be a problem - not suitablefor irrigation. O what is the effect of heavy metals on the marine environment? what are effects on groundwaterresources (an indirect impact) - would need to examine geologyof area.

20.0 Ministry of Tourism: Mr. I. Mijjoo

o there are no active tourism facilities and no known plans for future development of tourism facilities in the vicinity of the proposed Montagne Jacquot site. The nearestfacilities are proposed near Albion. O the improvementsto water quality in the vicinity of pointe aux sables lagoon and reef and Fort Victoriawould be welcome, although there are no active touroism facilitiesin those areas at present, 0 the ministry recognises the importance of marine resourcesto the tourism industry and strongly supportsthe enhancementand maintenanceof water quality.

MINUTES OF PUBLIC MEETINGS

1.0 Issues raised at the Pointe aux Sables community meetings

0 High crime rate in the region. 0 Drug abuse and prostitutionis a major concem in this area. 0 The negative impact of pollution created by the sewage effluent 0 Inability to use the beach and the sea for recreation 0 Numerous requests to the authority, about cleaning up the area, have not been respondedto. 0 Some residents themselvesare contributing to the pollution in the area. e.g. some residents regularly defecate and urinate on the beach at Pointe aux Sables, a few hundred metres away from the Ddbarcadere.This occurs because the area is not cleaned regularly enough and therefore encourages people to pollute the area.

Black & Veatch International xxx Appendices Montagne Jacquot Sewerage and SanitationProject Environmental Impact Assessmenit

0 The youngsters were particularly worried about the lack of recreational facilities. Instead, they tend to hang around on road sides, which is seen as suspicious behaviour by the police. 0 All the fisherman felt that the sea around the Debarcadere area is totally destroyed due to the polluted discharge, which makes it impossible to walk in the sea. 0 Divers in the area reported seeing a 'desert' area on the sea bed at Pointe aux Sables. This area is clearly visible and forms a zone with no visible marine life. 0 Fishing nets get tangled in rubbish deposited in the sea making it is impossible to use fishing nets in this area. This problem seems to have been accelerated in the past eight to ten years. 0 The fishermen pointed out that when the existing Pointe aux Sables pipeline was built, they used rocks on the beach to build a wall for the pipeline. This wall has not yet been removed and has become clogged with debris and is an obstruction to vessels in the lagoon. The sane problem occurs at Bain des Dames. 0 Sewage discharged at Bain des Dames is reaching Pointe aux Sable due to wind action. 0 Resident are willing to assist in the cleaning up of the affected areas, provided they receive the support of the authority. 0 Fishermen are conscious of the way in which the pollutants are affecting the marine life in the lagoon. At low tide, the polluted discharge is trapped in the lagoon and the north wind blows the polluted water and debris towards the land. This happens about four to five times a year. 0 The fisherman are selling contaminated fish to the 'baignans' (wholesale fish merchants), who in turn sell the fish at the market. Although the fishermen are aware of the health hazards, they need the income.. 0 The fishermen are catching 'Mule', a local fish species found in their area, even though is fetches a low price. They used to catch about 300 - 400 kgs of Mule six to eight years ago, but populations of this species have declined considerably. Although this is probably from fishing pressure - the fish are being affected by the sewerage discharge in the lagoon since the fish smell of kerosene (hence the name "Mule petrol". The fish are sold to the fish merchants , however the residents of the area are aware of the health hazard and do not buy them. 0 The coast of living for the fishermen in the Pointe aux Sables and Bain des Dames areas (about 50 professional fishermen at Pointe aux Sables and 60 to 70 at Bain des Dames) has increased considerably due to a combination of reduced fish stocks in their area and the fact that Pointe aux Sables is adjacent to the restricted zone of Port Louis Harbour. They therefore have to fish in other areas further away (e.g Pointe aux Piment, Trou aux Biches, Albion, Medine, Balaclave, Flic en Flac) which is costing up to Rsl 200 just for fuel for one boat per month. For a fisherman who earns Rs.30 to Rs.40 per kg of fish and only manages to catch about 10 to 15 kg of fish only occasionally, they cannot afford to travel too far to fish.

2.0 Issues raised at the Bain des Dames community meetings

0 Discharge of polluted water - coloured water through the canals leading to the Bain des Dames is a common feature observed by all residents interviewed. 0 Residents have often observed trucks discharging full loads of polluted liquids, with a strong odour, in the open tank at the treatment works station. Sometimes complaints are registered and the discharge is stopped but only for a short while. O Discharge of human waste occurs often within the sight of residents. This discharge flows through a canal and reaches the sea on the southern side. It seems that the existing sewer pipes cannot cope with the waste load since they often over flow. 0 The canals carrying waste from inland from the Port Louis area is a constant problem since they carry waste from the Port-Louis and Cassis residents and the waste from industries (e.g. factories, dry cleaning plants). During high rainfall, these canals transport non perishable solid wastes such as plastics and dead animals. 0 The deterioration of the environment is a major problem in this area. 0 The Ministry of Environment and Quality of Life are presently constructing a green area in the centre of Bain des Dames, which is used as a football field. However, recently a construction company started digging the drains next to the football field and dumped the rocks etc. adjacent to football ground. This "dumping ground" covers an area of about I 000 m2 and now consists of a rocky/muddy area. Recently the rocks were removed but rehabilitation of the site will take some time. 0 There are no recreational areas in Bain des Dames, for either adults or children. The only area used by residents seems to be the fish landing station area. It seems that residents, mainly the elderly, spend their

Black & Veatch International xxxi Appendices Montagne Jacquot Sewerage and Sanitation Projeca Environmental Impact Assessment

evenings there playing cards, 'petanque', or chatting. Children cannot play on the beach or swim in the sea and usually end up "socialising"with the adults. O There are obvious health hazards associated with the level of pollution at Bain des Dames. The residents cannot do anything about it and seem to just accept it as being part of the developmentand growthof the country. They do, however,expect the authorityto take steps to reduce the health hazards. O The fishermensuffer constantlyfrom skin diseaseswhich they get from being in the water - but they feel they have no alternativesince their livelihoodis at stake. Similar skin problems also occur amongst the children,and hair loss has also been reportedamongst the adults. *0 Children often fall into the water, when they are assisting their fathers when they go fishing, and it is often imnpossibleto get rid of the smell from the body. 0 Fishermengoing diving report prolonged stomach problems, headaches and vomiting. Such problems have been reported even in areas as far as La Pointe, south of Pointe aux Sables, which is where local residentsswim. 0 The fishernen at Bain des Dames are struggling financially since the fish populations have declined substantially. Contaminatedalgae and worrnson the shore are used as bait in fish traps. The fisherman used to use salmon as bait but they need a permit and only one permit is given to six or eight fishermen. The decline in salmonpopulations has resultedin this permit system.. 0 The fishermen in this area have to go furthernorth up to Cap Malhereux or south-westto Flic-en-Flacto find fish. This is obviouslymore costly.

!

Black & Veatc*LInternational XXXsII Appendices IMontagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

APPENDIX I: Waste water characteristics from a representative selection of key industries (pers.comm Sam-Soon 1997)

Vogetable [ F__h-l [ Candy | Ch.eic.l [ Soap Pnn iog P.int Food Parameters Canning PI Manoracinre Conditioning Msnufact.re Ind.stmr Indostr, Procesing

COD mg/I 13598 809 1423 1757 2143-51 744 430952 4150 737 BOD5 mg/I 8650 685 850 543 1125-27589 N.D. 1497 345 Cond.us/cm 13500 1116 13000 279 3120 - 3730 85 12900 5040 pH 4.1 6.5 5.1 6.5 9.3 -10.1 7.3 7. 6.4 lTKN mgAl 7 20.3 67.8 47.4 20.3 6.8- 12.2 284.6 6.8 27.1 NH4-N mg/l nil 50.8 nil nil nil 42.4 nil 25.4 Ptotal mgA 14-5 4.6 1.8 5.6 6.4 - 7.1 22.1 12.5 2.9 Detergent mgI nil 0.8 nil 0.2 0.7 - 1.3 N,D. 0.8 0.2 Oii&Gr-ase mg/l 102 262 64 1.5 320 - 2758 22450 850 304 TSS mg/l 873 203 1140 295 585 - 4760 76850 2938 167 Fe mg/A Sulphate mg S04/1 Phenols mg/i

CCu mg/ oa ) = = ______

Cr (6+) mg/I ______OX microgm/i - _ _

I______Dairy Edible Oil Galennising Dyohouse Dyehoux Dyebouse Dyehouse i Dyohon. | Parameters Procesing Refinery P|at Cotton Wool/Coton| Colto/?Poiyester Wooi/Cotton Co.on

1104 14151 5712-21930 967 622 737-1290 872 700 030D5 mgli 604 9247 - 743 176 232 450 62 cond.us/cm S17 16400 90250-1105000 3900 5630 713-10430 1812 1880 nF-^ 6.7 12.2 0.2- 1.9 9.5 8.9 10.4 - 11.3 10.1 9.4 TKN mg/l 20.4 23.7 19.2 16.7 17.1 - 147 6.4 nil NH4-N mg/t 3.3 1.S 13.6 - 2338 nil nil 0 - 22.6 1.5 nil Ptota 4.9 1IS 5 14.1 12.3 1.8 -8.6 8.4 5.1 Detergent mg/ 0.9 222.2 2.2 023 1.0 - 32.0 0.8 0.3 il&Cleaen mgAI 128 3244 - - 0-76 2.5 - TSlxiSmgil <1 160 1700 2368-13595 155 403 60-240 150 135 emg/i 18975-47438 Sulphatersmg S04/i | | | . 437 2774 0 - 661 627 1406 |Phenols mg0I ______- 0.0 - 0.6 0.05 - Ni mgli _____ - nil nil nil nil - 021 0.02-0.23 0.05 02 ______- nil nil nil nil Cu mg/I J______Dnil nil nil 0.27 nil Cr(total) mg/I i______I______I______nil nil nil nil nil r(6-*) mg/I _ _ _ _ nil _ I nil nil nil AOX micrognA | 502 _ 277 383

Black & Veatch International xxxiii Appendices Montagne Jacquot Sewerage and SanitationProject Environmental Impact Assessment

APPENDIX J: Vegetation types at the Montagne Jacquot proposed site for the WWT plant.'

Vegetation Type/Species Common name Family

rasses Agerarum conyzaides herbebouc Compositeae Dactylocteniumctenoides Gramineae Heteropogoncontostus herbepolisson Graminaeae Panicum maxinum fataque Gramineae Setaria sp. Gramineae Themedaquadrivalrus herbeesquire Gramineae Tribulusterristris herbe tricome Zygophyllaceae

hrubs Albizia lebeck boisnoir Mirnosaceae Amaranthus Jtybridus brede malabar Amaranthaceae Cassiatora Caesalpinioideae Cleome viscosa bredecaya Capparaceae Flacourtia indica prune Flacourtiaceae Ipomoea obscura cilian(creeper) Convolvulaceae Labiatae mont au ciel Latana camara viellefille Urbainaceae Leucaena leurcophala acacia shrubs/fooderplant Mimosaceae Melochiapyrmidata Sterulariaceae Passiflorafoehd a grenadinesauvage Passifloreaceae Phyllanthus uriaria curanellie Euphorbiaceae Waltheria indica Tiliaceae Wikstroemiaindica herbe tourterelle Thymeleaceae

rees Boerhavia coccinea herbe pintade Boraginaceae Crotalaria cascavelle Papilionaceae uncea Euphorbia hirta jean robert Euphorbiaceae Pithecellobiumdilui cassie de marille Leguminoseae Ponjama glabra la coqueluche Papilinaceae Tephorsia perpuria Papilinoideae Trichodesmazeylaica bourache sauvage Boraginaceae Ziziphus mauritania masson Rhamnaceae Dr Joseph Gueho,MSIRI

X

Black A Veatch&International xxxiv Appendices Montagne Jacquot Sewage and Sanitation Project Environmental /mpact Assessment

APPENDIX K: Coral reef community key (English el aL 1994)

Z 1

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Black & Veatch International xxxv Appendices Montagne Jacquot Sewage and SanitationProject 'Environmental Impact Assessment

APPENDIX L: The National Monuments Act 1985, Government of Mauritius

Governmen t liootice No. 755c 1985. T.- NAT:CNLL

Regulatorns made by t:ie Miriste= undez secticns 4 ancd9 of the National *"cr.=nen-.s Act 1985

1. These e,-dLations may be cited az the National Monuments (Deziga:.ai;r.) - egula tions 19C05.

2. Tne monuments sDecif-ed in te Sc:-edu_e a_e designated as nat_cna' monuments.

Made by the Minister or. 1 June 1925.

(regu'aticn 2)

NiTTONAkL?MDXTf-CS

PO.RTLOUIS DISTRICT

1. Rum Wa=ahouse Build.ing (14? Immigr:ation Scuare) - P-roclaimed 2. The General Post Office 3. Signal o-bwer(Earbouz apnd Qu'ys) 4. Cnien de Plomb 5. Abreuvcnr (New 'oks. Street) 6. Fountalir(Artillery Square) 7. Fountain (St. Louis Cathedral) 8. Fort Adelaido (Citadelle) 9. Line -2a--acks 10. M1la-tic Tomb (Champ de I-ars) 11. Trou Fanfaron Police Station 12. French Datteries Dumas 13. French Retrc-nchements(Pamplomousses Road) 14. Sir Lionel Smith's Tomb (Wer2ernCcmetexry) 15. General Jacob de Cordemoy (westcrn Cemetery) 16. Canal Dayot Aqueduct 17. Donjon St. Louis and surrourn-A- 18. Flour Mill (GR.N.W.) 19. Rospital (C.F.N.W.) 20. Vagrant Depot- 21. Colonel Joseph Yates Tomb ( Cemetery) 22. Moonumenton Remy Ollier's Toab (WesternCemetery) 23. Tomb of Commodore Xouse (Cemetcr-r 24. Dominus Arthur Chichester Tomb (Western Cemnetery) 25. Wenccslas Bojer Tomb (Western Cemezery) 26. Dl'Archibald de Litchfield Tomb (Western Cemetery) 27. Swinny Tomb (';estern Cemeteryj) 28. Lislet Ceotrroy Tomb (Western Cemetery) 29. Proaper d'EDinay Tomb (western Cemctery) 30. Dr. F. Dauban Tomb (Western Ceceter-)

Black & Veatch Iniernalonal xxxvi Appendices ,)ontagne Jacquot Sewage and Sanitation Project Environmental Impact Assessment

f cmel:Uc Sc~~~Fvd m-. e -.< e"rd.scczuel -,ci;-cm (:Jes-er.. emetery)' SR. Cha=l es Leal Tom- (Western Cmeney) ,it Si_ Rooert 3zBarclay Toni ('.es"-.rn CemecerJ) 55. One mc.nz.enter-cted :.emor o^: .c deaci oC i092 cyclon.e (o'ur^ de Wester Cemeterv)

36. One r,conco.enterecter in mn,O- Dr. Horace 3eaugead (cutstc.e 'Westre Ce.meterfy) 37. muncipa. Thncat-e 38. Goverrzen-. House ;C ,53d Gas (Plzasur2Wr'wrc, 40. Monument-^n Reveend Je'_-. Le n' s r-cmb(Western Cemetezv) 4t. .M4Dnumenti on Dr. Aime fcsesh :a-illovc's Tcmb (kWest2rn Ccmc:en.) 42. Lou4s Leceealc'sTomb (';We:terCemetery) 42. Leov_Ile '-csHc=.e Tcmb (Westrn Ce.meser-) 44. The Stone and Iron dorks ofr tor Lous Mar-ket (YMarohe Central ) 45. The cipreme Cou=t Buildingz 46. Ther ha-rlles Daissac's Tomb (Viostern Cemetery) 47. The Dr. Onesioho 3eauge-_-'sTomb (Weste=n Cemetery) 45. The Edit Czvel '' ove_-.mo-.t chool(Port Louis) 49. Sta-tue cf ,Whe de Laccurdcnnai-, Place Labourdonnais, Por- Louis I SO.Statue of Sir John Pope He=nesssy, KCE1G,Place Sookdeo 3issoondoyal _Port Lou4s. 51. Sta.ue of Sir Wi1i iam Nowtc-n. Place Sookdeo Bijssoondoyal, Port Louis 52. Statue of ; r Majesty Quicn Victoria, Governmeent Hlouse Com:poune,- ?ort Louis. 53. Statue of Sir W. Stevenson,KCD, GcvernmentHouse Coanound, Port Louis 54. Statue of A. Remy Cllic:-,Jacdin deCla Compagnile,Port Louis 55. State of Adrien d'Epiinay,Jadin d.ela Comnagnie, Port--Louis 56. Statue of Leoville LHo=ne, Jr-di. de la Comnagnie, Port Lou4s 57. Stat_e of Brown Sequard,Jardin de la Compagnie, Port Louis t 58.Statte of riin-ilallDoctor, Jardin de la Comnpagnlie,Port Louis 59. Monument commemoratingtheolAlat anniversaxy of the abolition of slave-y in Maurit.ius,Jardin de la Comnagnle,-Port Louis. 60. Monument in memory of Soeur MzarieBarthelemy, Ja.rdinde la Coimzagnie, Port-Louis 61. Statue of iiis Majesty Kinr,g7ldAr=d V1_, Champ de Mars, Port Louis 62. Statue of V. T. Lenin, nobart rdwariRaLt Garden, Port Louis 63. Monument cormnemorattin the landin.mof Commandant Guillaume Defersne on 20th Seytember 1715, Fgobert Edwa:cd Hart G.-rden, Port Louis 64. The Treasu-ryBuildings, Port Louis 65. The MercantIr BanikBui1dinr, Port Louis 66. Tomb of .JeanPascal Dijonc de foisquenay,Western Cemetery (Old Cemetery), Port Louis 67. Sir S. Ramgoolactold woodcn house, Plaine Verte.

1- Old Lighthouse (CannoniurrPointz 2. Ruins of French Arsenal (DL.icau. Tortues) 3. Princi ,helepolatsMonument 4. Tower of Old Powder Mill 5. J bbe Duovanita Tomb (Pmnlemousses Ceimetery)

Black,& VeatchInternational xxxvii Appendices MontagneJacquat Sewage and SanitationProject EnvironmentalImpact Asszssment

56 Ad=--en d_ii-.a ?._e se Ce.emete~ry) .Ma.;c ie la V_ ba.e's Xrn ._.emcusses Ce.n^-c-r-- . Ce=e cmc n?:.emo'e sses sa_ 5. cr.-'o2_5- c-cemnms__ '- '.^,7 (. :e.usses

.2. 02.d F--t (Tombez'a 13. Suga= Fc:ot ,. (actnda--,sa, 14. Wfnjzilj Tcwcr oi Fticne Tor:e 15. Batte= e des Grenad erz (?oi .- e _x ? .nen s) 16. Charles P.-anel's Tomb (?-n: :e-soes Cemetery) 17. C;ha.res Th.ome T tot's Tont (?t.t'e.mousses C.rnete- y) e. Dr. Coomanyls Tonb (acn.or: -. ^.t)

T=ansit of the ?lanc- Yenus ? ':a (St. Antcine) 2. Monument co-nernc :_ng,the :-=ecckof St. Cezan (?oud-e d Cr 3 Windmill Tower of :crbacle 4. Wind. ill Tower- of Belle Rive, Ca. M'a heure-u-x, Petit P?quet

1. Comrerson's 4Monruoens - 2. Dist=ict Court 3. Sugar Factory of flole 4. Prisons of Delle Ma=e 5. -. ineC of .Žuat=e Coccs -ac-c-%: 6 Tomb o' Le Conte Caud Lou's HRavanel (St. Julien Cemetecy)

GRAY,,41-P.T DISTRICT

1. Ruins of French 7latte-ies (?cinte du Diable) 2. Old Cemetezy (Ci Grard Fort) 3. Tour "'ollandairs' (Old G_and Port) 4. Monument to c =emnozl-e ent-,ror suear cane 5. -utch Mcnumient (Ferntey) 6. Grand Port Dattle Mencrial at Poi:nte des flet.Ates 7. Monuinent facing RailwzyStation S. Maison Historioue de C--nd ?^-t C. Old French 'atteries - 10. le do la Passe 11. Lighzthouse at Ile aux Fouqc,:s 1 12. Chateau Ziche en __au

SAVAININ DISJTRICT

1. Telffair Monunent 2. Trevessa, Monument ( Bel ore) 3. Bacn dlUrUcr.ville's Tomb at Souliilc

Black & Veatch International xxxviii 4rnendiFre Montagne Jacquot Sewage and Sanitation Project Environmental Impact Assessmneent

D71:~~~~~Ir-- 7Cf~--'

1. L I.H^xmc..-e 3'!ae r- 2. Colonel Drarer's Tomb (7a ŽLNoie Cene-ery) 3. t:tello Tower (;a Preneuse) 4. La Tour: Koenia

PLTINES lI-,,IMSD-TI.-CT

1. Dr. StidtmantsTcmb (Chebe') 2. L.a-^erouse -emc=_ipal ( su Coulee) 3. Abbe de la Ci Ile Memorial (CCurerepe Town .a'l Comp^ r-w) 4. Flinder's Memorial (La -M--ie) 5. The Royal College (Cu-enic-ee) 6. The Monumen.taux Morts (Cu_eim-e% 7. h'.eCureLeor. Town Hal' (Curepi e) S. The Fmaxiuel's Tomb (St. Jec:: Cemetery), 9. The °napman's Tomb (St. T.cmas Cemete=r', Beau-Bassin') 10. Old Labcurer's QLarters (close to the Ž-icgar'neFactory), (owned by Trianon) 1I..Statue of Aime de Sorney, 2ur.i::al_ityof Curepipe Comrnound.,CU=-^i-:e 12. Statue of P. J. Toulet, Murnicinalitof Curepipe Comound, Curepipe 13. Statue of Paul et Virg-inie,Municipality of CQ.renipe Co=roound, Curepgipe 14. Tomb of John Comber-Drowne, St. T!homs Churchyard, Beau-Bassin

1. Covernment Hiouse, Le Redu-it

Black & Veatch International xxxiX Anpendices Pt-. mgPremierenitzdClrenzement su lake

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.o.. o. ioJ .ogtto.soil on amnnoan tojtotononW 0.0EMnYM N srto1tcm , t ,n o U -iVItIe,NARIsMG A ORd el Jl-'so do nnWl -. %d.tow un hn!ned!ta a eawmipelrlUltoym ila YV _l alt fn '.n d. _...... 'Welts is.ndsI .. dosohto t. doiatkp nl nloe ln i-olnnndh 0 nisA bdlk .Aooonndbi o pen do.n.5'Okpo.. ta (im t 1--tematta~~ba l NibDiybIe |1n- iSto . rl Sh- ptOp* umEiNrW.tc . Pos - ...Dk u,ftQIa- pmnoosMruAtleAsdgosoo5cYd IFdCflO attiS Co- Je"g 2 atma>s l.,,a P. riviti J.Y@Scampgn otnontoiudIts 7" Groom gono clotsl;b5edontu1*.0isai oblocti. onootttnp,Anshon ii ri_noton. Dmtot ino.ounntOpIns S nodwln e,ennon nntoinnotoodtgn * p nossoAnotsotsooco rib2lveduns;lfqura q"pnoridoeniolonl.do connptnon'r 1*1nclt otgicltoo boonu onln d oSiltnttoltLdtEtooniegpwttmcn wiindnoIonoo,00 o cel (~~~~ q.pwaueels,tsnOssobsb ,lc .. ekOtwima.dACOcm tt.. doo o doJnnooo lb EaMPLOYMENT Su $s i;tg>;¢^ ey : str sr * s-"r J AAoo onWAt..bom oonotno , r 5""a"h*""sBdin 'I..ssgAr*t Joocnddpogne;S,sootmnps totlntlelanrer,n Mb lnSbnnsq o1 onto no ono foodtosIonio r i odoonknopontold RooponIn nonoon non Sbniet .. lontiooin do rido dncono too,doposnd. polint dwlolgbosfnenisoWed,OC.no.oOnoo,ttndttouqui. Ptftdan pls.oobt tlotsstloOn SN notnsotonok oods o onmu]. onoll;.i;d ndo o ttot nd Isp petnoetibaleemplnytnmnt 5 oe laot. . ompotontp docOnoooc o t nonidn-o.A onn-neboooodo onoitp0te o n ~ ~ ~ ~ ~ ~ ~ ~ ~ donoAts. otot~~-.ibdf Hoon Jtmoctnoto nei fOnd dinocos OdotToiro nolont noW o-nnpaotimono olson toot totn . amW0<,c `t EMIL ObY MustpNoTl oOootisJo 000 Ito doo~~~~~~~~~~~~~~~~~~~~~~~ceLi.M thorpin loin do , .tc.tOb.ttsOnnoOs ictbssOS I nnil MNGEILDmlto e adnpsed sStctotlto t no IoteamGotg tot.iol itenntuk n t'osoo *AH-AdPItI.dctosnlltqonn oie - otOotsoonosototttotootrotnsontotdosototbO5. ~~~~~geotte coptao lo s ontom. .i-j, bnllmo ont, .e oo4o~~~~~~~~~~lNobUMQUALIFO.ICAnTIO0o.NS *. tolntLent.l ,n AtOosoion. Tt,,im.ohontnt * . ssngn0*tnttton. loo conoio slois,nl .OnnmakatO d. g. p. tum . -- dIt'otea l t ac-domt In a,dotnnooi.. PnonilmeN.Lwh didyn-Tos,il .. IN*nnooocstdo.. "i_ mt Pa f am' ~~ se" flotonodotAtposoo l on..=1 ~~~~~~~~~~,-irton mammaotog-.oO oo ntl . lod-,.dos pIlk, d . .d.atv.6P. (itohodonegot oseoe" lmyjl~~~~i4wdt we 1 n o i on nntn 00 on`O o,oO col4ns .S r,inttutortOtOJetoatlason t nonn gt, agah ksoolodu onn etdon raonlouaolin 1* on -lb Odlbt totiotoete o.tntsodo y.Tlcin .utI 1 do tcamen.Macegn m.i-,i TRot Pc,non aud,ObotOnsclu. tB~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t -. jaketibiflejuaOi(P. Conn It tk it Kali- on11nnitptus lo d.n leJGpoon ploqn F., Jnditt no o epo 0000 lotbls li cnolnt moooySt oti t notu. T ooonAbn PoneuLdctmsn apau uDmd ~~'t(4i k..L!=the follovWng postr., 2 Gol al.S 1 ulopdonto l a qnuto,o nIMANg ol ~ ~ ~ ~ ~ Is Jt s oob itntqo tobtOtu do font ws.oointde o dola Dompuit O!". dameatla. gnpotD~~~~~~~~~~~ 0 gn moonia. un cot q slu enond entcnnns0. iooC,o.pootSnlonood ott. avp d ok TWton belli. 0 ln optco,dctct 1itSod lao

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.. e.. Mivi ... W Voice. md.Ml.. MVontagneJacquot Sewerage and Sanitation Project Environmental Impact Assessrnent

APPENDIX N: Assessment criteria for evaluation of impacts

FIRST STEP CRITERION CATEGORIES Extent or spatial influence of impact Local or site specific Regional National International Magnitude of Impact at that spatial scale High: Natural and/or social functions and/or processes are severely altered Medium: natural and/or social functions and/or or processes are notably altered Low: Natural and/or social functions and/or processes are negligibly or minimally altered

Duration of Impact Short term: 0-5 years Medium term: 5-15 years Long term: 15+ years SECOND STEP CRITERION CATEGORIES Risk associated with impact Low High An impact is considered to be high risk when: there is uncertainty, or a level of confidence, in predicting the impact, AND the impact could be severe, irreversible and/or have severe, cumulative affects. Reversibility of impact Yes No An impact is considered to be irrevesible if: it is permanent, i.e. will not be reversed over time Cumulative Yes No An impact is considered to be cumulative if: the impact will have severe indirect and/or synergistic effects Probability that impact will occur unlikely possible probable definite

DEFINITION OF SIGNIFICANCE RATINGS

SIGNIFICANCE FIRST STEP CRITERIA: MAGNITUDE, EXTENT, DURATION RATINGS VERY HIGH Impacts could be: Significance EITHER of high magnitude at a national level, in the medium to long term OR have an impact at an international level HIGH Impacts could be: Significance EITHER of high magnitude at a regional level, and endure in the medium to long term; OR of high magnitude at a national level in the short term; OR of medium magnitude at a national level in the medium to long term

Black & Veatch International xli Appendices hl

Montagne Jacquot Sewerage and SanitationProject Environmental Impact Assessment

MEDIUM Impacts could be: Significance EITHER of high magnitude at a local level and endure in the medium to long term; OR of medium magnitude at a regional level in the medium to long term; OR of high magnitude at regional level in the short term; OR low to medium magnitude at a national level in the short term; OR of low magnitude at a national level in the medium to long term.

LOW Impact could be: Significance EITHER of low magnitude at a regional level and endure in the medium to long term; OR of high magnitude at a local level and endure in the short term; OR of medium magnitude at a regional level in the short term; OR of medium magnitude at a local level and endure in the medium to long term. VERY LOW Impacts could be: Significance EITHER of low magnitude at a local level and endure in the medium to long term; OR of low magnitude at a regional level and endure in the short term. OR of low to medium magnitude at a local level and endure in the short term.

• If the impacts associated with an issue are unlikely, then the significance rating of that Issue should be labelled "U". * If the impacts associated with an Issue are likely to be either Irreversible, or cumulative, or of high risk, as defined in table above, then the significance rating of that Issue should be labelled "I" , "C", or "R" accordingly.

Black & Veatch International xlii Agvendices I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

aEr'OF MC5r}fAURITtUS1

MINISTRY OF PUBLIC INFRASTRUCTURE

Consultancy Services for Institutional Study (Operational Setting up of the Waste Water Authority and the Cost recovery Sistemii)

Preliminary Report

June - 1997

CONSULTINGENGINEERING SERVICES (I) PVTLTD +-39. Avenue des Glaieuls 57. NehruPlace ( 5th Floor) Mauritius New'Delhi - 110019.India dd:j.. INSTIrUrONALSTUDY FOR WArn WATER AUMl1ORYf__

(vi) Operation and Maintenance (O & M) of the Pumping Stations and Treatment Plants

Routine 0 & M works of the pumping stations and treatment plants are carried out by the departmental staff of the WWA with assistance from other Government Departments for electrical and mechanical problems. Major repairs are executed through contracts following standard procedures.

2.6 Environmental Protection

Apart from the role for management of the waste water system within the country, the WWA has the additional responsibility of advising the Department of Environment on industrial wastes. These comprise the following activities:

* Reviewof reports of analysis of industrial wastes carried out by the industries. • Independentcollection and analysis of samples of industrial wastes by the in- house laboratory of the WWA and also foi Hospitals and Hotels.

U Advice on Reports on Environmental Impact Assessment from industries including scrutiny of design of treatment plants. * Advice on sewer systems for institutions and public buildings (new systems and trouble shooting for existing systems). l Advice to public. * In-house analysis of samples from WWA Treatrnent Plants, rivers, estuaries and lagoons. According to the latest records, there are 496 industries in the country out of which 113 industries are connected to the sewer system of the WWA while the remaining have on-site disposal. These industries are located in major industrial estates in Plaine Lauzun, Coromandel, Vacoas and La Tour Koenig and in addition medium industries are in 16 locations. The industries are thus spread over the entire country. Most of the industries relate to Textiles, Tannery, Brewery, Refinery and Food processing.

The staff potential in the WWA dealing with pollution control is not consistent with the expanding industrial scene with the result that review of analysis of industrial wastes (especially those entering the sewers which require careful review to ensure performance of treatment plants) is sporadic and not systematic. Presently one Engineer and one Technical officer are in charge of the subject and in addition, services of the in-house laboratory headed by a Biochemist are available. This laboratory was started in 1993 with a nucleus and has recently moved to its own building which is part of the laboratory of the Department of Environment. A review of the number of samples analysed in the laboratory between July to December 1996 indicates the following monthly averages

* Domestic .. 14 * Industries .. 21 * National waterbodies .. 15 * Hotels and Restaurants .. 8

NVWAPrcRcp/Scc.2 2-8 P..j.d: INSTLrtMONAL STUDY roR WASIE WATER AtMIORrrY

To discharge its role as a support agency to the Department of Environment for protection of environment in addition to its own work of quality control for the waste water system, the pollution control unit of the WWA requires to be expanded.

2.7 Interim Measures

While the major thrust of the present consultancy is to recommend the structure of a comprehensive organisation for the Waste Water Authority with parastatal - status and an adequate legal statute to back it up, it is clear that the installation of such a system will take time. Adoption of a statute by the National Assembly and its promulgations have their own time frames depending upon the pressure on the legislature; transfer of staff from a division of the Government to a parastatal body has its own procedural complications; persons qualified in handling and management of waste water are at a premium in the country. On the odter hand, a massive work prograrnmeof about Rs 4 billion has already been lined-up with funding arrangements from national and international sources. All these calls for the setting up of a unit specifically meant for project implementationin the WWA as an interim step. This is being dealt with in the next section of this Report.

L

WWAl'rcRcp)Sec.2 2-9 PT.ject: INSITIUMlONAL SllJDY FOR WASIE WAlER AIJMIORT

3.0. PROJECT MANAGEMENTUNIT

3.1. Role of the Project Management Unit (PMU)

The role of the Project Management Unit is to function as a centralised agency to be in charge of the new investmentprogramme being taken up by the WWA. The unit will be responsible for all the activities from Planning to Implementation and Evaluation of the Projects. A more detailed appreciation of the activitiesof the PMU will be evident from the component of a Project Cycle listed in Annex 3.1.

The PMU will be headed by a Deputy General Manager (Projects) who will be an officer of the rank of a Chief Engineer and who will be full-time, reporting directly to the General Manager. The DGM (Projects) will be responsible for all capital Projects irrespective of the source of funding and the PMU is to he recognised as the sole agency for project implementation in the entire WWA.

3.2. Composition of the PMU and Job Specifications

In discharging his functions the DGM (Projects) will be assisted by

m Full time personnel directly reporting to him, * An advisorv Consultant and * A Project Monitoring Cell. Figure 3.2. gives the Organisation Chart for the PMU.

3.2.1. Full-Time Personnel

This will consist of:

A. A Technical group B. A Finance cum Personnel group.

A. The Technical group will be divided into three wings - namely Design Wing, ImplementationWing and Quality Control Wing.

(i) Design Wing

This wing will be responsible for all activities of the Project Cycle from identification of a Project to fixing contractors for implementation - that is, Activity A(l) to F(1) of Project Cycle in Annex 3.1. The wing will coordinate the work of all Consultants and also respond to queries from Implementation unit seeking clarification on design based on site conditions.

The Design Wing will also he responsible for Management Information System relating to all the Projects. IFigure 3.2. 1.(A)l

l

WWAP=RrlcKcpI.3 3 1 r -

Ii

II

Ll fl Figitre 3.2 0 ORGANISATION CIIART PROJECT MANAGEMENT UNIT(~~~~~~~~~~~~~~~~~~~~~~ (Proposed)

DIRECTOR GeneralManager) t,3~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

MonitoringCell I"Project Dy GeneralManager AdviisoryConsultant I I ~~~~~~~~~~~~~(Projects)I

Destg ing ImplementationWing QiualityControl WVing Finance/Personnel Wing SeeFigure 3..1 (A) SeeFigure 3.2.1 (3) See-'iguire 3.2.1 (C) SeeTable 3.2.1 (B) i

-1~~~~~~ i

I-

L.7

I

1-

I

I I P,j.d: INSTrRnMONALSTUDY FOR WASIE WATER AtMIORrry

(ii) ImplementationWing

This wing will be responsible for all activities relating to Implementationand handing over to Operation and Maintenance - that is, Activity F(2) to G (3) of Project Cycle in Annex 3.1. The wing will also be responsiblefor reporting to the design wing any variation in site conditions leading to change in design and would seek the concurrence of the design wing where the change is of major nature. [Figure 3.2.1.(B)I

(iii) Quality Control Wing

This wing will have two separate units

(a) an Engineering unit and (b) a Scientific unit

The Quality Control Wing has been framed to carry out activities H(1) to H(3) of Project Cycle - namely evaluation of the Project. In addition, the Quality Control Wing will also be responsible for preserving the quality of ambient environment as provided for in WWA's statute. The role of the WWA in carrying out the objectives of the Environment Protection Act for safeguarding the waterfront will be achieved only by assigning important role to this wing. For this purpose, this wing will be responsible for scrutiny of proposals relating to treatnent of industrial wastes and regular monitoring of samples of industrial effluent. The wing will also provide laboratory facilities. [Figure 3.2.1.(C)I

A specific role has been entrusted to the Quality Control Wing, namely quality surveillance of project implementationlike cube tests for concrete, materials used for construction, etc. (Random tests)

B. The Finance cum Personnel Wing will provide support services to the Technical group - namely correspondence, passing of bills of contractors. consultants, monitoring capital expenditure etc.

3.2.2. Advisory Consultant

As works proposed to be implemented involve technical expertise and as the works of many Consultants have to be supervised, it is recommended to have a full-time Consultant on contract basis in an advisory capacity. This Consultant will be with global experience in the field'of waste water and his contribution will be all the more necessary if in-house personnel with local experience only is considered for the post of (DGM Projects). The Advisory Consultant will offer technical advice on all issues relating to the PMU referred to him by the senior personnel of the PMU.

WWAIPrcRcp/Scc.3 3-4 r 1

r-~~~~~~

I. I

-n

I;

I >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Figutre3.2.1 (C) C QUALITY CONTROL WING - ORGANISAI'ION CHART

MANAGER (QUALITY CONTROL) (PrincipalBiochemist)

-Engineering Unit Scientific Unit Common Pool

SeniorEnginecr Senior Biochemist I lil ing of Personnel or Privatised for Clerical (PollintionControl) I' j n dditional Teclcal Suppor t (future) Typist 1

.ra|TechnicalOMeer 2 LaborhatorTechniiian 4

.loh Descriptions: Enelneerinets nit Joh Desc rinflons: Scienilfl,tJnit I) EIA Reponti Review I) Collection and Analisis of samples 2) Emtient Treatment Plants from Industries 2) Suipportseraices to Engineering unit 3 ) Quality Control on Construction works (Random Test) 3) Monitoring Discharge from Industries entering sewers 4) Quality Control on materials (Random Test) used for works 4) Perfornance Evaluation of l'reatment Plants 5) TFecisnicalAuidit on completed works 5 'I'echnical Audit on Consuimables Energy r- , i ' i i i I IJ I I I IW

O-_ r, S p 14 , . .. I *.

f.~~~~ A, ~b1 ANNEX 3.3.2(B) (Sheet I of 2)

P"ajd: INSTMUTI1TONALSY FOR WAS WAMERAMIfORrry

PROJECT MANAGEMENT UNIT

Key Personnel - Qualification Requirements

1. Principal Engineer:

Essential: (i) Degree in Civil/Electrical/Mechanical/ Chemical Engineering- or equivalent from Universities and Registered as Professional Engineers or equivalent. (Preference to Civil Engineers)

(ii) Minimum 12 years of experience in water supply and waste water system out of which at least 6 years should be in waste water sector including design/implementation/operation maintenance.

Preferred Additional: (i) Post Graduate in Environmental Engineering Requirements or Management

(ii) Experience in working with consulting firTnseither directly or as counter-part staff

2. Senior Engineer:

Essential: (i) Degree in Civil/Electrical/Mechanical/ Chemical Engineering or equivaient from Universities and Registered as Professional Engineers or equivalent. (Preference to Civil Engineers)

(ii) Minimum 8 years of experience in water supply and waste water system out of which at least 4 years should be in waste water sector including design/implementation/operation maintenance.

Preferred Additional: (i) Post Graduate in Environmentai Engineering Requirements or Management

(ii) Experience in working with consulting firms either direct or as counter-part staff

3. Engineers

Essential: (i) Degree in Civil/Electrical/Mechianical/ Chemical Engineering and Registered as Professional Engineers

Preferred Additional: - 2 years experience in water supply/waste water Requirements systems at least as trainee.

WWAPIeRcp ANNEX 3.3.2(B) (Sheet 2 of 2)

Prijed: INSTTMUONAL SllDYM FOR WASTE WATER AuMIOrrY

4. Graduate Engineer

Essential: (i) Degree in Civil Engineering or equivalent with at least 2 papers in Environmental Engineering

or

Degree in Mechanical/Electrical Engineering

5. Technical Officer - A diploma in Civil or Mechanical/Electrical Engineering from University of Mauritius

6. Principal Bio-Chemist:

Essential: Degree from a recognised University in Chemistry or Biochemistry with at least 15 years experience in laboratory practice in water/waste waturl industrial wastes with preference for waste water experience.

7. Senior Biochemist

Essential: Degree from a recognised University in Chemistry or Biochemistry with at least 10 years experience in laboratory practice in water/waste Water/industrial wastes with preference for waste water experience

8. Biochemist

Essential: A degree from a recognised University in Chemistry or Biochemistry

Preferred Additional Microbiologyas optionalsubjects Requirements

WWAI'rtRep/Annex 3.3.2 Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

APPENDIX 0: Extract from CES Institutional Study showing WWA linkages with other organisations

C~~~~~~~ z~~~~~~

0~~~9 u ..

-Etn txi0 z~~~~~~~~~~~~~~~~~~~~~~~~~

Black & Veatch International xliii Appendices Montagne Jacquot Sewerage and SanitationProject Environmental Impact Assessment

APPENDIX P: General requirement for safety, security and environmental protection and more specific mitigatory actions for contractors to be carried out during construction of transmission pipelines

1.0 General requirementsfor safety, security and environmentalprotection

The requirements for safety, security and protection of the environment shall be applied to the construction contractors in accordance with industry standards in Mauritius, and as stated in paragraph 19.1 of the General Conditions of the Contract (FIDIC, 1987), which state,

"The Contractor shall, throughout the execution and completion of the Works and the remedying of any defects therein:

(a) have full regard for the safety of all persons entitled to be upon the Site and keep the Site (so far as the same is under his control) and the Works (so far as the same are not completed or occupied by the Employer) in an orderly state appropriate to the avoidance of danger to such persons, (b) provide and maintain at his own cost all lights, guards, fencing, warning signs and watching, when and where necessary or required by the Engineer or by any duly constituted authority, for the protection of the Works or for the safety and convenience of the public or others, and (c) take all reasonable steps to protect the environment on and off the site and to avoid damage or nuisance to persons or to property of the public or others resulting from pollution, noise or other causes arising as a consequence of his methods of operation."

In addition, the General Conditions of the contract shall include the following paragraph 29.1 dealing with interference with traffic and adjoining properties:

" All operations necessary for the execution and completion of the Works and the remedying of any defects therein shall, so far as compliance with the requirements of the Contract permits, be carried on so as not to interfere unnecessarily or improperly with:

(a) the convenience of the public, or (b) the access to, use and occupation of public or private roads and footpaths to or of properties whether in the possession of the Employer or any other person...."

In addition to the requirements imposed by these general conditions of the construction contract, more specific requirements shall be imposed by the technical specifications.

2.0. Specifc mitigatory actons to be carried out by contractors during construction of Transmission main pipeline: land-basedroute (alternative1)

Constructionlmethods

In addition to specific construction methods specified in the Section 6.00 series, the following general requirements shall apply to the work under this Contract:

In performing the work described in the Sequence of Construction, the Contractor shall limit the amount of ditch open at any one time to approximately 200 m. The work, including excavation, pipe laying, backfilling and temporary paving, shall be completed before proceeding with the work in the next section.

The Contractor may employ more than one installation crew but not less than 400 m shall separate any two open trench sections as defned hereinbefore.

Should any portion of the work lag, the Engineer will suspend other portions until the lagging portion is brought up to schedule. Such action by the Engineer shall be for the purpose of confining the construction work to as small an area as possible and shall not be used asjustification to request an extension of completion time.

Temporary paving, where required, shall be placed the same day as the ditch backfill.

Black & Veotch International xliv Appendices Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

Pipe and fittings shall at all times be handled with great care to avoid damage. In loading and unloading, thev shall be lifted with cranes or hoists or slid or rolled on skidways in such manner as to avoid shock. Under no circumstances shall this material be dropped or allowed to roll or slide against obstructions. Pipe and other material shall be distributed along the right-of-way in advance of installation only to the extent approved by the Engineer. Such materials shall be so placed as to keep obstruction to traffic at a minimum.

Any work within the pipe and fittings shall be performed with care to prevent damage to the lining. Damaged lining shall be repaired or the pipe section or fitting replaced as required by the Engineer. No cables, lifting arms, hooks or other devices shall be inserted into the pipe or fitting. All lifting, pulling or pushing mechanisms shall be applied to the exterior of the pipe or fitting.

During construction the Contractor shall, by sprinkling with water or by other means approved by the Engineer, eliminate dust annoyance to adjacent property owners. No additional compensation will be paid to the Contractor for any costs incurred in complying with this provision.

Use of public streets

The use of public streets and alleys shall be such as to provide a minimum of inconvenience to the public and to other traffic. Any earth or other excavated material spilled from trucks shall immediately be removed by the Contractor and the streets cleaned to the satisfaction of the governing authority.

Vehicles must be loaded within all legal weight limits and operated safely within all traffic and speed regulations.

Access to businesses along the route of the work must be provided by the Contractor at all times.

Care of trees, shrubs and grasses

In the course of the work, it may become necessary to remove trees if they interfere with construction. The Contractor shall obtain a permit from the Employer and/or other regulatory agencies having jurisdiction over the work area before removing, relocating and/or pruning any tree. The Contractor shall abide by all requirements and conditions of the permit, and shall include all costs under the various Bill of Quantities Items, and no other compensation will be provided.

The Contractor shall be fully responsible for maintaining in good condition all cultivated grass plots, trees and shrubs. Where maintained shrubbery, grass strips or area must be removed or destroyed incident to the construction operation, the Contractor shall, after completion of such work in said area, or as directed by the Engineer, replace or restore to the original -condition all destroyed or damaged shrubbery or grass areas. -Tree limbs which interfere with equipment operation and are approved for pruning shall be neatly trimmed and the tree cut coated with a tree paint

Weeded areas need not be replaced with grass, but shall be restored to a "green" area by sowing a variety of permanent type grass seed, over the area as approved by the Engineer. The grassed or seeded area shall be watered and maintained until the Engineer is assured a good grass growth has developed, but not to exceed a maximum period of 60 days.

In order to protect himself from being held liable for any existing tree damage, the Contractor is advised to notify the Engineer in Writing (with photographic documentation) before proceeding with any work.

Protection of existing utilities. structures and other facilities

Underground utilities, structures and other facilities shown on the Plans are located according to the best information available, but may vary from both the position and elevation shown. The Contractor shall explore far enough in advance of his main trench to determine the exact location and condition of such utilities, structures or facilities so that, before the pipe is installed, the Engineer may change the line or grade of the pipe, should that become necessary to avoid a conflict.

Black & Veatch International xlv Appendices Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

All cost for changingthe gradeof the proposedmain downwardI m or less in order to clear obstructionslocated differentlythan shown on the Plans, or to clear obstructionsnot shown on the Plans but the locationof which could have becomeknown or should have becomeknown by properobservation of fieldconditions or the proper exploratoryprocedure, shall be includedin the pricesquoted under the variousitems of the Bill of Quantitiesand no additionalcompensation will be allowed.

Additionalcost, if any, for changing the grade of the proposedmain downward more than I m for the same reasons,will be paid for as "Extra Work"in accordancewith the GeneralConditions.

Changingthe grade of the proposedmain by rising deflections,or the alignment by horizontaldeflections, will not be consideredas extra work, or extra cost, to the Contractor,and in some casesa credit to the Employermay be warranted.

In all cases where the main is deflected either horizontallyor vertically,and the Engineerrequires additional work and items such as paving, air release valve assemblies,and similar items for which a pay item was establishedin the Quotation,then such additionalwork and items will be paid for at the prices quoted.

The Contractorshall determinethe locationsof recentadditions to the systems not shownon the Plans. Extreme cautionshall be exercisedto eliminateany possibility of any damageto utilitiesresulting from his activities.The locationof all overheadutilities shall be verifiedand the Engineernotified of any conflictwhich might occur. The Contractorshall be responsiblefor determiningwhich poles will need shoring during excavationand shall provide such shoringand supportas is required.

Where it is necessaryto temporarilyinterrupt house or buildingservices, the Contractorshall notify the houseor building owner or occupant, both before the interruptionand again immediatelybefore service is resumed. Beforedisconnecting any pipes or cables,the Contractorshall obtain permissionfrom the owner,or shall make suitablearrangements for their disconnectionby the owner. The Contractorshall be responsiblefor any damage to any such pipes, conduits or cables, and shall restore them to service promptly as soon as the work has progressedpast the point involved.

Variousdrainage culverts and drainageditches may be encounteredalong the route of the work. Any culverts which are disturbed, damaged or removed shall be repaired, restored or reinstalled. The Contractor shall document any existing damage to the drainagesystems, or if it needs cleaning,prior to doing any work in the vicinity, so he will not be held responsible:Drainage ditches shall be restored to the original cross sections existingprior to constructionof this work. Ditchesshall be left cleanand free of all excavatedmaterials or other materials depositedin them as a result of this construction. All existingheadwalls, removed or damagedas a result of this construction,shall be restored as directed by the Engineer, and the work shall be consideredan incidentalitem and the cost included in the other itemsof the Quotation -

All existing drainagestructures and piping shall be consideredclean at the start of construction. The Contractor shall checkto verify that this is so. He shouldnotify the governingagency of any damagedor dirty structuresor piping to avoid repair or cleaning at his expense. Copiesof such noticesshall be sent to the Engineer.

Relocationof existingutilities

The relocationof existing utilities as noted on the Plans, or for the convenienceof the Contractorshall be the responsibilityof the Contractor. This work shall be completedby either the forces of the existingutility or the Contractors forces at the discretionof the responsibleutility. If the work is to be performedby the Contractor, all work shall be done in accordancewith the utility company'srequirements. Under no circumstancesshall the Contractorbe authorizedextra payment for this work,and all cost for the relocationshall be the responsibilityof the Contractor.

The Contractor shall also be responsible for the coordination of all existing utility relocations with the appropriateutilities. Where temporarysupports or protectiveencasements are required during the construction, the Contractorshall be responsiblefor this work at no additionalcost.

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Any conflicts between the field investigation and the information shown on the Plans shall be brought to the attention of the Engineer. There shall be no additional payment for adjustments in grade or alignment resulting from locations of existing utilities.

Representatives of utility companies, the traffic and transportation authorities, etc., shall be notified in accordance with standard practices.

Traffic control

The Contractor shall abide by all applicable laws, regulations and codes pertaining to maintenance of public -streets, detour of traffic, traffic control and other provisions as may be required for this Project.

The Contractor shall be fully responsible for providing all measures necessary for the maintenance of traffic. The Contractor shall prepare and submit a maintenance of traffic plan for approval by the Engineer. The maintenance of traffic plan shall be revised as necessary to meet all requirements of the Police, the City of Port Louis or Ministry of Infrastructure. The maintenance of traffic measures provided shall conform to the approved plan.

The Contractor shall be fully responsible for the maintenance of public streets, detour of traffic (including fumishing and maintaining regulatory and informative signs along the detour route), traffic control, and other provisions, throughout the Project. No street shall be completely blocked nor blocked more than one-half at any time, keeping the other one-half open for traffic, without specific approval.

If required by the Traffic Plan, the Contractor shall make arrangements for the employment of uniformed off- duty policemen to maintain and regulate the flow of traffic through the construction area. The number of men required and the number of hours on duty necessary for the maintenance and regulation of the traffic flow shall be subject to their approval. The cost of such labor shall be included in the Bill of Quantities items, and no additional compensation shall be paid for this labor.

If required by Traffic Control Plan or required elsewhere in the specifications or project description, the Contractor shall work odd or night hours as required for traffic control reasons and the cost of such work shall be considered as incidental to construction and no extra compensation will be allowed.

The Contractor shall provide all barricades and/or flashing warning lights necessary to warn motorists and pedestrians of the construction throughout the Project.

Excavated or other material stored adjacent to or partially upon a roadway pavement shall be adequately marked for traffic safety at all times. The Contractor shall provide necessary access to all adjacent property during construction.

The Contractor shall be responsible for the provision, installation and maintenance of all traffic control and safety devices, in accordance with standard practice or as provided in the Traffic Control Plan. In addition, the Contractor shall be responsible for the resetting of all traffic control and information signing removed during the construction period.

Pavement markings damaged during construction shall be remarked promptly by the Contractor.

3.0. Transmission mains pipeline : offshore-basedroute (alternative 2) and ocean oultfall

The Contractors are responsible for carrying out the following mitigatory actions to minimise environmental impacts associated with the construction of the transmission mains pipeline offshore:

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The Contractorshall carry out works in such a manner as to minimiseadverse impacts on the water quality, marine and estuarine benthic and fish populations during the execution of works. He shall organise his methodof workingto minimiseimpacts on the dredgingand dumping areas, and adjacent affectedsites.

All marine plant and methods of workingshall be such as to minimisewater pollution.

The RE may inspectplant to be used to ensure it is suitableto minimise impactsof works. Mechanicalgrabs should be designedand maintainedto avoid spillagewhile liftingand barges should be properly maintained so as to avoid leakageof material

The Contractorshall designand implementmethods of workingwhich:

* minimisedisturbance to the seabed whiletrench diggingand laying pipeline, * minimiseleakage of dredgedmaterial during liftingand removal, *ensures that spoilswhich have to be removedare taken to approvedareas (eg. for land reclamnation), *prevent avoidabledeterioration in water quality at the site by use of silt curtains etc.

The Contractorshall present to the RE for approval a detailedplan of work method (as well as times and tides to mfinimisedisruption of other vessels, imnpactson marine/ estuarine life) to describehow he proposesto carry out pipeline- layingoperation, includingprocedures to be adopted for securing barge, equipmentto be used, managementof trench digging operationsetc..

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APPENDIX Q: Industrial Waste Water Management

1. Industrial Activities in the Montagne Jacquot Project Area

In the Montagne Jacquot project service area, there are three main industrial zones, namely:

* Plaine Lauzun; * Coromandel; and * La Tour Koenig.

In general, within the Port Louis South area, industrial and tertiary activities (commercial and service sectors mainly) are predominant.

The 1992 Gibb Sewerage Master Plan (SMP) estimated that about 100,000 employees (non residents) use the sewerage system of Port-Louis south in addition to the perrnanent residents. Moreover the perimeter groups together a very important industrial activity where textile manufacturing predominates.

1.1 Plaine Lauzun Industrial Zone

The Plaine Lauzun industrial zone is located at the south entrance to Port Louis and is occupied by more than 80 factories. The activities are varied and include textile manufacturing including dyeing, laundering, chemicals processing; galvanising, metal plating, soap and detergent manufacture, fish canning, and alcohol bottling & distillation plant among others. The factories are spread over about 100 hectares.

Within this industrial zone, the Development Bank of Mauritius (DBM) has developed an export processing zone consisting of buildings, roads, and other infrastructure which occupies an area of 6 to 7 hectares. The main industrial activities are garment manufacturing (textile), printing, wood work, metal plating, chemical blending, among others.

1.2 Coromandel Industrial Zone

The Coromandel industrial zone infrastructure was developed by DBM. It is located at the southern entrance to Port Louis and just outside the boundaries of Port Louis District It covers about 30 hectares and groups about 70 industries; the main activity being textile manufacturing including dyeing, and washing. Other industrial activities that generate waste waters include soap manufacturing, corned beef processing & canning (agro-industry), galvanising plant and some services such as warehousing, electronic repair workshops and offices among others.

J.3 La Tour Koenig Industrial Zone

La Tour Koenig industrial zone is the more recent industrial zone set up by the DBM; this zone is situated downstream of Coromandel. The Lower Beau Bassin/Coromandel trunk sewer extends to this industrial zone before reaching the pre-treatment works at Pointe aux Sables.

The main waste water generating industries are a dye house and a galvanising plant. The industrial zone also includes an Informatic park which generates domestic-type effluents.

* Demand for industrial space is on the increase since 1996 after a slump between 1990-1995. According to DBM, at present there are about 20 industrial projects which will be implemented during the next two years; the type of industrial activities will include: dyeing (textile), food processing and other water consuming activities. Hence it is expected that volume of industrial effluent from within the La Tour Koenig will increase substantially in the future.

2. Need for Control of Waste Water Discharges

In general, industries use numerous types of raw materials and chemicals during the manufacture of fnal products. Many of these substances are not retained in the final products and re-appear as pollutants in the waste waters, solid wastes and gaseous emissions. In general, the severity of the impact of the discharge of these pollutants depends on the characteristics of the pollutants and their quantities. They may be relatively harmless in

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low concentrations; they may be effectively removed in waste water treatment systems; or they may adversely impact the natural environment (marine, terrestrial etc.) with short term or long-lasting consequences. Moreover, the presence of some pollutants may be harmless to man-made structures such as sewers and treatment plant process units, or they may be harmful, e.g. concrete works are affected by the corrosiveness and aggressiveness of acidic waste waters. It is necessary to evaluate each industry on an individual basis to determine the characteristics of its effluent, its quantity, and its potential for pollution or harm to physical structures.

Table 2.1 illustrates the different types of industrial activities within the service areas of the Montagne Jacquot project, and pollutants commonly found in waste waters produced by those industries. Specific pollutants in the effluent of a particular facility, and the quantity, depend on the individual plant's industrial activities as well as the specific processes employed in that plant.

Heavy metals are a class of pollutants which are commonly associated with industrial activity, including some of the industries located in the Montagne Jacquots service area. Table 2.2 lists some of the industrial activities which are found in the service area, and the heavy metals sometimes found in that type of waste waters. Heavy metals and some of the other pollutants in industrial waste waters often accumulate in the sludge produced at a sewage treatment plant which effectively removes that portion of them from the effluent to receiving waters. However, their presence in the sludge must be considered in the selection of appropriate disposal methods for the sludge.

Table 2.1: Pollutants, Industrial Sources and Their Impacts

Industrial Generators Potential Pollutants Potential Adverse Impacts Canning, boiler house operation, Suspended Solids Blockage of sewer lines and agro-industries equipment, damage to watercourses by deposit of solids and oxygen depletion. Engineering workshops, fish Oil & Grease Blockage of sewer lines and processing plant, meat canning equipment, scum formation on plant, soap manufacturing. water surfaces preventing oxygen transfer, unpleasant smells. Fish processing plant, meat canning Organic Wastes Overloading of conventional plant, Vegetable canning. treatment plant, depletion of oxygen in rivers. Chemical, food processing, textile. Insecticides, Pesticides Impair biological treatment plant, toxic to aquatic life. Paint manufacturing, printing, Solvents Toxic to aquatic life Engineering workshops. Galvanising, Chemical Acids (mineral and organic) Corrosion to sewer line, conditioning, textile. cement structure. Textile, soap manufacturing, metal Alkalis Toxic to aquatic life, plating,. corrosion to steel pipes. textile, metal finishing, Laundries, Detergents Foaming. Soap manufacturing,. Galvanising, metal plating, Heavy metals Toxic to biological treatment engineering workshops, vehicular plant, aquatic life. repair shops -e Metal plating Cyanide Toxic to biological treatment plant, aquatic life. Textile. Colour Visually objectionable. Hospitals. Pathogens, viruses, worm eggs Spreading of disease. Chemical plants, Engineering Halogenated Compounds Toxic to biological treatment Workshops, Adhesives plant, aquatic life. manufacturing.

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Table 2.2: Potential Sources of Heavy Metals in Waste Waters

Metals Potential Sources Copper Electroplating, Chromium Electroplating, engineering workshops. Cadmium Electroplating, engineering workshops, vehicle repair shops. Cobalt Textile. Iron Galvanising, engineering workshops. Lead Printing, battery industries, paint manufacturing Mercury Pharmaceutical, pesticides, chemical industries, laboratory waste waters. Nickel Textile, electroplating, printing, vehicle repair shops. Zinc Galvanising plant, pharmaceutical, cosmetics, domestic wastes.

3. Chemical Audits of Industries in Mauritius

In an endeavour to characterise the waste waters from the industrial zones, chemical audits were carried out by ERM-SETEGUE-SIGMA-SAMSOON on two types of industrial activities namely textile dyeing and metal plating. The dye houses were selected because the textile industry is the dominant industry in Mauritius, and the dye houses produce the vast majority of the waste water from the textile industry. Also, it was believed that the main source of heavy metal pollutants would be the metal plating industry. Waste water flows from the dye houses represent about 90 percent of the total industrial flow from service areas in Montagne Jacquot project.

Table 3.1 identifies the main types of chemicals used by textile dye house. It was established that metallic- based salts of copper, zinc and cobalt were used only occasionally and in low quantities. Consequently the waste water characterization study focussed on the other pollutants. Chromium (total and hexavalent) was included even though it was established that chromium dyes were no longer in use. This observation was supported by both the local suppliers of chemicals as well as the specifications from overseas textile buyers which prohibit this metal from the textile products.

Table 3.1: Main Chemicals Used in Textile Dye houses.

Chemicals Types Function Acids Acetic, sulphuric pH control Bases and Sodium hydroxide, sodium pH control alkaline salts carbonate. Buffers Phosphate based pH control Sequestering agents Ethyl di-amine tetra-acetic acid pH control Dispersing agents Anionic, cationic and non-ionic Disperse dyes and control rate of dyes fixation on material, fibre softening. Oxidising Agents Hydrogen perodide, sodium Precipitate dyes. hypo-chlorite. Bleaching. Reducing Agents Sodium sulphate. Solubilise copper and sulphur based dyes. Neutralise residual dyes after dyeing process. Heavy Metals Copper, Chrome and Cobalt Improve fixing of dyes on fibre. based salts. Dyes Direct, acid, basic, azoic, Impart colour to products. reactive, sulphur. Salts Sodium chloride, sodium Displace dyes from aqueous phase to sulphate. fibre.

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The industrialwaste water characterizationsurvey found that the metal plating industry was using highly toxic chemicals such as potassiumcyanide and salts of lead, copper, and nickel. The effluent flow was of the order of 10 m3 /d with a measuredcyanide load of 103 g per day. Source eliminationwas recommended for this compoundas well as metal precipitationvia a full treatmentunit.

For the galvanisingplants, zinc amnmoniumchloride and hydrochloricacid were the main chemicals used during the galvanisingprocess. Iron and zinc are the metalsfound in high concentrationsthat can re-appear in waste waters. The acid bath containediron in concentrationof 1OOgll. The high concentrationof iron in the acid bath and other solids have a tendencyto reduce the etching efficiency of the acid. Iron and other solids are precipitatedfrom the acid solution,but the acidity remains high so that neutralisationof this bath is necessary to protect the sewer pipes fromthis discharge.

From the chemical audits at the selected industries and the industrial survey carried out for industries within the service areas of the MontagneJacquot project, a waste water characterisationprogramme was established.Both compositeand grab sampleswere taken from various types of industrialactivities as well as combinedwaste waterswithin the sewer networksof the industrialzones.

4. Waste Water Characteristics of the Major Wet Industries

The effluent characteristicsof selected wet industries within the Montagne Jacquot project area were established and are given in Appendix I. The industries were selected on the basis that one or more pollutantspresent in their waste waterswill need abatementbefore dischargeinto the sewer networks.

As shown in Appendix 1, the main characteristicsof the waste waters from dyeing and washing processes are:

- Alkaline pH; high sulphate concentration;low inorganic and organic nitrogen content; the range of COD concentrations is similar to reported values for dye houses with similar product range and processes.

The absence of heavy metals such as cobalt, nickel, and chromium in the waste waters confirms observationsmade duringthe chemicalaudits stated in the previous section. However, zinc was detectedin most compositesamples at concentrationbelow 0.25 mg/l whereas copper was measured in one case only at a concentration of 0.27 mg/. These concentrations of copper and zinc are within the range of concentrationsof 0.12 to 1.6 mg/I and 0.13 to 1.22 mg/l respectively reported for a typical dye house in South Africa.

The presence of organic halides is to be expected given that these substances are present in some of the chemicals used such as dyes, dispersingagents or chemicals that are precursors for AOX.

As shown in Appendix I, it is seen that waste waters from printing industry, soap manufacture, paint industry and vegetablecanning plant are characterisedby high concentrationsof:

* COD and BOD(S),oil & grease,total suspendedsolids and salinity (conductivity).

With regard to waste waters from the fish canning plant, high concentrations of COD, total suspended solids, total Kjedahl nitrogen and oil & grease are normally observed, even though they were not found in the grab sample taken.

As shown in Appendix L the waste waters from a galvanising plant are characterised by very high concentrationsof COD, iron, and total suspendedsolids. Moreover the residual acid concentrationremains and varies between2.4 to 12.1%.

5. Waste Water Flows from Worst Polluting Industries

Within the three industrial zones of Plaine Lauzun, Coromandel and La Tour Koenig, waste waters from dye houses and laundry units represent approximately90 percent of the waste water generated. The waste

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water flowsfrom the selected industrieswere estimatedand are given in Table 5.1. It was concludedthat the waste water from these industrieswould require abatementbefore discharge to the sewer system.

Table 5.1: Waste Waters Flows from Worst Polluting Industries

Industries Activity Estimated Waste Water Flow 3 ______t ,(m /d) M.T.C.E(Caudan) * Tuna canning 400 Marisa Button(Plaine Lauzun) ButtonManufacture 3 Multimark(Plaine Lauzun) Printing 3 DYNACHEM(Plaine Lauzun) ChemicalBlending 10 SAIL(Plaine Lauzun) Soap manufacturing 50 Unigly (Coromandel) Soap manufacturing 10 Seskel Foods(Coromandel)' Agro-industry 400 Novel Garments(Coromandel) ) Stonewashing plant 700 SOFAPLtee (Coromandel) PaintManufacture 5 Cathayprinting (Plaine Lauzun) Printing 5 Galvanising Ltd. (Plaine Lauzun) Galvanising Plant I GalvanisingLtd. (La Tour Koenig) GalvanisingPlant 1 Neetoo Industries(Coromandel) GalvanisingPlant 1 Galvabond Ltd.(PlaineLauzun) GalvanisingPlant 1 Metalcast(PlaineLauzun) Metalplating 10 Arvind Overseas(LaTour Koenig)*' Dye house 300 l - Total 1900 Notes: 1. MTCE(tuna canning plant) will be relocated in Riche Terre by 1998 and hence will not dischargeinto the Port Louis Southsewerage system. 2. A stone washing plant generateshigh concentrationof sand particles that need to be settled and removed from the waste waters so as to avoid their settlement in the sewers and hence causing overflows. 3. This unit manufacturesdenim cloth (for jeans) and generates high concentrationof suspended solids from usage of starch in the process.

6. Permissible Limits for Discharge into a Sewer Network

The types and loads of various pollutants from a range of industrial activities have been describedin the previous sections. The extent to which these pollutantsneed to be decreasedat sourcedepends on the:

* Assimilativecapacity of the receivingmedium, * Loads of the pollutants, * Capacity of the treatment works (assuming that the sewer networks will eventually discharge to a treatmentplant) among others. * Effect of pollutantson seweragesystem.

Consequentlyit is necessary for the waste water discharges into the sewer networks to be monitoredand controlled so that the sewer networks as well as the treatment works operate efficiently. The control of waste water discharges at the source implies that regulatory measures are required such as permissible limits for some pollutants. In this regard the 1992 Gibb Sewerage Master Plan made recommendationsfor discharge standards for various receiving medium including discharge into sewers. Table 6.1 shows the parameters identifiedin the SMP, as well as the compliancelimits.

For discharges to public sewers, the compliance limits suggested in the SMP for some parameters need more flexibility. For example, the recommendedpermissible limit for COD was 1000 mg/I. This limit is consideredto be low if cognisanceis taken the fact that the quantity of flow must also be a factor. That is,

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a waste water with a higher COD concentration (say 2000 mg/1) but with a low flow rate mieht be acceptable for discharge to the sewer system. This quantity of COD would not affect the operation of a waste water treatment plant if it was designed to take that COD load. On the other hand the maximum permissible limit for suspended solids appears too high (2000 mg/I) if deposition and resulting blockages in the existing sewer networks are to be minimised.

Overall, the recommendations of the SMP with regard to sewer discharges set the frame work for regulatory measures for control of waste water discharges.

7. Pre-treatment of Industrial Waste Waters

The need for industries to pre-treat their waste waters is governed by the necessity to preventing blockages and damage to the sewers, and controlling toxic pollutants. Appropriate pre-treatment systems to meet these objectives are described below.

7.1 Blockages in Sewers

To minimise blockages in sewers the following processes are recommended.

* Coarse and Fine Screens Coarse screens followed by fine screens can be effective for reducing suspended solids from most waste waters. These screens are installed in the waste water canals within a factory. For the textile industry, loose fibres, pumice stones and plastics are solids that need to be removed by the screens.

* Dissolved Air Floatation A dissolved floatation unit can be effective in reducing the floatable matter in an effluent. In the case of a meat canning plant, the fats, oil and grease load needs to be reduced substantially (about 90 percent reduction) in order to prevent sewer blockages.

Table 6.1: Recommendations for Effluent Standards (Sewerage Master Plan)

LIST DETERMINAND UNITS NATURE OF RECEIVING WATERS WI-W27 W3 W4 W5 W6 W7 WS River Other Irrigaion Lagoon Ocean Sewers ______Aquifer Rivers EFFLUENTQUALITY CLASS E4 E3 E2 E5 El E6 A Temperature UC 30* 30 30 30 50 40 pH 5-9 5$9 5-9 5-9 4-10 5-9 Colour Hazen 20 30 - 20 - ChemicalOxygen Demand mg/l 60 90 90 60 750 1000 BOD . (10) (20) (30) (250) - SuspendedSolids 15 30 45 15 100 2000 Chloride . 250 1000 250 - B Sulphate 250 500 500 - S00 NitrateN 15 . 5 20 AmmoniaN . 5 10 5 100 Total dissolved solids . 1000 2000 2000 . PhosphateP 5 - I 30 Cadmium gg/I 20 20 20 20 20 20 Chromate chromium / 50 50 50 50 100 100 Copper mgA 0.5 0.5 1 0.1 20 C Lead mg/I 0.1 0.2 2 0.1 - 10 Mercury 1g 20 20 20 20 20 20 Nickel mg/I 0.1 0.2 0.5 0.5 10 10 Zinc mg/I 0.5 1.0 5 0.1 - 30 Oil & Grease - mg/I N_ovisible Oil 50 Detaergents mg/I 5 l 50 D Pesticides Carbamate jig/I 100 100 100 251 250 Chlorinated lag/I 10 10 10 5 | 50 Phosphorous jig/ 100 100 100 25 - 250

Notes: Other toxic substances to be set on a case by case basics in line with intemational standards. Lists A, C, D are 99% compliance limits. List B is 95% compliance limits.

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* Degritter Tank For a stone washing plant, most of the pumice stones used in the process are convertedto particlesof size and with a granulometry similar to sand. The degritter tank allows sand particles to settle at the bottom section of the tank from which they are removedby pump to a sand pit.

7.2 Damage to Sewers due to Corrosion

Some waste waterscan be corrosiveand aggressivetowards the sewers. Acidic and basic waste waterscan degrade the walls of sewers and eventually dissolvedthe cement matrix (in the case of asbestos cement), resulting in leakageof waste waters in the soil.

Waste waters from a dye house treating polyester generally have high pH (10 to II). pH correction of these waste waters to 8 to9 will be necessary.

In contrast, waste waters from a galvanisingplant are very acidic and complete neutralisationwill be necessary. This pH adjustmentwill also causethe iron to precipitateout simultaneously.

7.3 Minimising Toxic Compounds in Waste Waters

The concentrationof toxic pollutantsmust be controlled in order to protect the aquatic environmentand the prevent of impairmentto any biologicalprocesses provided at the waste water treatmentplant.

Chemical blending plants, including insecticides/pesticidesbottling plants, will require containment structures around holding tanks and operating areaas so that any spills can be cotained, collected and disposed of in acceptableways. The containmentstructures should be properly shelteredagainst rain with no drains.

For the metal plating industry, the all waste water discharges must be treated to completely oxidize the cyanide and precipitateall dissolvedmetals to acceptable levels.

7.4 Pre-treatment Systems and Capital Costs

Industrial waste waters that need to be pre-treated prior to their disposal in a sewer network have been identified. Pre-treatmentsystems are recommendedfor installationat specific industrial sites, and estimates for capital costs were developedfor these systems. The informationis presented in Table 7.4.1.

For most of the dye houses, only coarse screening is recommendedfor removal of fibres. It is estimated that the supply and installation of coarse galvanised screens inside waste water canals within the factory and just outside the premises should not exceed Rs 50 000 per factory.

8. Control of Industrial Discharges

8.1 General

Chemical analyses carried out by ERM-SIGMA-SAMSOONon both industrial waste waters only and combined industrial and domestic waste waters, have shown that heavy metal concentrations(chromium, copper, nickel etc.) are below the discharge levels as recommended in the SMP. However, due to the variabilityin the quality of the industrial effluents and the evolution of the industrial activitieswithin these industrial zones, it is essential to carry out regular monitoringof industrial waste waters so as to ascertain that permissiblelimits are not exceeded.

8.2 Determination of Appropriate Parameters to Monitor

For each type of industrial activity, a set of parameters was identified for monitoring and control of effluents.

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Table 7.4.1: Pre-treatment Systems and Associated Capital Costs for Different Industries. Industries Type Pre treatment Systems Estimated Capital Costs (Rs) Food Canners (Plaine Lauzun) Vegetable & Suspended solid removal 1 060 000 fruit canning Fine screen and lift pumps M.T.C.E (Caudan) Tuna canning Suspended solids, oil & grease ll 850 000 removal, with an equalisation tank. Dissolved Air Floatation. Marisa Button (Plaine Lauzun) Button Solid removal. 50 000 Manufacture Settling tank Multimark (Plaine Lauzun) Solvent recovery, suspended solids, 650 000 oil & grease. Solvent recovery & settling tank. DYNACHEM( Plaine Lauzun) Chemical Suspended solids, clarification, 1 300 000 Blending neutralisation. Settling tank. SAIL (Plaine Lauzun) soap Coarse solids, equalisation tank, 7 300 000 manufacturing aerated grease removal, neutralisation Unigly (Coromandel) soap Coarse solids, equalisation tank, 3 000 000 manufacturing aerated grease removal, neutralisation Seskel Foods (Coromandel) agro-industry Fat, oil & Grease removal, fine 4 400 000 screening. Dissolved Air Floatation Unit Novel Garments (Coromandel)*' stone washing Sand removal. Degritter units. 750 000 plant SOFAP Ltee (Coromandel)*' Paint Suspended solids removal. 850 000 Manufacture Coagulation unit/settling tank. Arvind Overseas(La Tour Koenig) dye house Solid separation, neutralisation 1 500 000 Settling tank. Metal Cast (Plaine Laizun) Metal Plating pH control, elimination of cyanide, 1 000 000 removal of metals (nickel, copper, chromium etc.) Galvanising Ltd (Plaine Lauzun) Galvanising- pH control, Removal of metals 750 000 such as iron,zmc Galvanising Ltd.(La Tour Koenig) Galvanising pH control, Removal of metals 750 000 such as iron, zinc Neetoo Industries (Coromandel) Galvanising pPH control, Removal of metals 750 000 such as iron, zinc TOTAL 35 960 000 Note 1: Pre-treatment systems already in operation.

For dyehouses, the parameters that need to be monitored are COD, pH, salinity, TSS, phenols, chromium (Total and Cr+), nickel, zinc, and cobalt The metal concentrations should be determined on both the aqueous and solid phases of the waste waters.

For printing industry, the parameters that need to be monitored are COD, TSS, lead, solvent, oil & grease.

For agro-industry and fish canning plant, the parameters that need to be monitored are COD, BOD(5), TSS, TKN, oil & grease, conductivity, pH and total phosphate. For gaivanising plants, the parameters that should be monitored are COD, pH, TSS, zinc, iron, salinity and acid percent. These parameters should be determined on both the aqueous and solid phases of the waste waters.

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For metal plating plant, the parameters that should be monitored are COD, TSS, pH, cyanide, chromium, nickel, and copper. These parameters should be determined on both the aqueous and solid phases of the waste waters.

For chemical blending plants, including insecticides/pesticides bottling plants, periodic inspection visits are recommended so as to ascertain that chemical spill control measures are being utilized. The waste water efluents should be monitored for pesticide residues and organic halides.

8.3 Current Industrial Monitoring Program

At present, many wet-processing industries carry out chemical analyses on their waste waters every month. In most cases, a private analytical laboratory is commissioned by the industry to collect a grab sample for characterisation. The analytical reports are submitted to either the Waste Water Authority or Central Water Authority or the Department of Environment. The Waste Water Authority and Department of Environment collect samples from specific industries on an irregular basis.

Guidelines for an organized waste water monitoring program are included in the Environmental Management and Training section of this EIA.

9. Monitoring Agency

The Waste Water Authority is the enforcement agency for waste water discharges into its sewerage system, and will be responsible for the monitoring of discharges into the sewer networks. WWA has laboratory facilities to carry out sampling and chemical tests. However some testing for some parameters such as heavy metals, pesticides, organic halides, will have to be performed by the Central Environmental Laboratory which operates under the Ministry of Environment. As part of the monitoring function, WWA will increase the frequency of visit to industries, carry out a regular assessment of the results submitted by the industries, and initiate follow-ups when abnormal results are reported.

10. Time Frame for the Installation of Individual Pre-treatment Systems

Once it is recognised that an industry needs to pre-treat its waste waters then a programme of works should be established by the industry in collaboration with WWA for implementation of the pre-treatment system. The time frame for the installation of any pre-treatment system should take cognisance of:

e The existing industrial set-up as well as infrastructures; * Surveys that are required for waste water characterisation leading to establishing the design criteria; * Options that favour investments in increasing efficiency of productive equipment inside the industry so as to minimise material losses.

During all stages, WWA should be fully involved and ascertain that progress is made and any delays can be accounted fully.

In the case of textile industry, the installation of screens is not a time consuming exercise and the costs involved are considered reasonable. The installation should be completed within three months after actions are initiated by WWA.

For the metal plating and galvanising industries, ERM-SETEGUE-SIGMA-SAMSOON has provided the design criteria as well as the sizing of the process tanks and equipment for individual industrial enterprises. Consequently WWA together with the industries should elaborate on an implementation plan within one year after action is initiated by WWA.

For other industries requiring pre-treatment systems, WWA must set a time frame for their installations not later than 1999, i.e. before the coming into operation of the Montagne Jacquot WWT plant.

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APPENDIX R: Sludge Disposal

1. General

Sludge is the principle byproduct of waste water treatment plants treating both domestic and industrial waste. waters. In general, the amount of sludge generated will depend on the type of treatment processes provided as well as the characteristics of the waste waters. Due to the nature of these waste waters, a number of contaminants are normally present in the sludge, as follows:

* pathogens such as enteric, rota and hepatitis viruses, Salmonellae, Shigellae bacteria and many varieties of helminths such as Ascaris Lumbricoides etc.; * heavy metals and elements such as cadmium, cobalt, lead. chromium; boron. arsenic fluoride etc. from industrial activities, and * organic contaminants from industrial waste waters such as organic halides (AOX), poly-cyclic aromatic hydrocarbons, etc..

The quantity, form and concentrations of the heavy metals and other toxic pollutants will depend on the extent of industrial activity that uses raw materials containing these metals. A summary of the industrial activity in the Montagne Jacquots service area is presented in Appendix Q.

The sludge produced by a waste water treatment plant requires management with appropriate stabilization, processing and disposal so as to avoid possible contamination of land, pollution of sea and underground water and to minimise health risks to humans.

Generally the treatment of sludge involves stabilisation process as well as a de-watering process. The stabilisation process involves the controlled degradation of the organic matter either chemically, aerobically or anaerobically. The de-watering process is necessary so as to concentrate the sludge, resulting in a lower volume and hence facilitating its disposal.

2. Sludge Production from Mauritius Sewerage Projects

Four main sanitation projects will be implemented in Mauritius by 2003, at: * Montagne Jacquot; * Baie du Tombeau; St Martin; and * Grand Baie.

From the feasibility study report for each project, design loads were used (Tables 1, 3 and 5) to estimate the quantity of sludge that will be generated per day (Tables 2, 4 and 6). Table 7 summarises the sludge production per day (mass and volume)from the four waste water treatment plants for different time horizons.

For the Baie du Tombeau project, only preliminary treatment will be provided. Consequently no sludge will be produced and sludge disposal will not be required.

Table 1: Montagne Jacquot Project: Design Loads Montagne Jacquot 2005 2013 Project Flow (m3/d) 48075 57195 COD (kg/d) 28000 32800 BOD5(kg/d) 16400 19600 TSS(kgld) 19200 22400 TKN(kg/d) 2150 2575

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Table 2: Montagne Jacquot: Sludge Production( Primary Sludge Only) Montagne Jacquot Project 2005 2013 Sludge Production (kg/d) 14800 3700 Volume of Sludge @ 2.5% (m3/d) 592 148 Lime (kg2d) 2200 550 Total Sludge(kg/d) 17000 4250 Volume of Sludge @ 25% (m3/d) 68 17

Table 3: St Martin Project - Design Loads St Martin Project 1995 2000 2005 2010

Population connected 93000 155542 222679 316739 Flow (m3/d) 29380 44200 58845 78315 BOD5(kgld) 4520 8630 14260 19955 TSS(kg/d) 5690 11215 18985 26575

Table 4: St Martin Project - Sludge Production St Martin Project 1995 2000 2005 2010

Primary Sludge (kg/d) 3414 6729 11391 15945 Excess Biological Sludge (kg/d) 2690 5135 8485 11875 Total sludge Production (kg/d) 6104 11864 19876 27820 Volume of sludge @ 1.5% (m3/d) 407 791 1325 1855 After Thickening _ Volume of sludge @3.5% (m3/d) 175 339 568 795 After Anaerobic Digestion Mass of Sludge(kg/d) 4273 8305 13913 19474 Volume of sludge @3.5% (m31d) 122 237 398 556 De-watering Lime Added(kgld) 1282 2492 5427 7595 Total Solids (kg/d) 5555 10797 18090 25316 Volume of sludge @25% (m3/d) 22 43 72 101

Table 5: Grand Baie - Design Loads jGrand Baie Project 2000 2005 Flow (m3/d) 5500 11500 COD (kg/d) 4830 9660 J BOD5(kg/d) 1932 3864 TSS(kg/d) | 2898 5796 TKN(kg/d) 322 644

Table 6: Grand Baie Project - Sludge Production Grand Baie Project 2000 2005 Primary Sludge (kg/d) 1739 3478 Excess Biological Sludge (kg/d) 1642 3284 Total sludge Production (kg/d) 3381 6762 Volume of sludge @1.5% (m3/d) 225 450

After Thickening ______Volume of sludge @3.5% (m3/d) 97 193 After Anaerobic Digestion

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Mass of Sludge(kg/d) 2198 4395 Volumeof sludge @3.5%(m31d) 63 125 Dewatering Lime Added(kgld) 660 1320 Total Solids(kgfd) 2858 5715 Volumeof sludge @25% (m3/d) 12 23

Table 7: Summary of Sludge Production from Four Main Sanitation Projects 2000 2005 Project Mass (Kg/d) Volume Mass (Kgld) Volume (m3/d) (m3/d) MontagneJacquot nil nil 17000 70 St Martin 10800 40 18100 70 Grand Baie 2900 10 5800 25 Baie du Tombeau Nil Nil Nil Nil Total 13700 50 40900 165 Note: Volumeof sludge is estimatedat a concentrationof 25%

3. Other Sources of Sludge

At present excess sludge is also generated by the existing small treatment plants around the island (Hotels, Industries, Housing Estates etc.). Current methods of disposal for these small facilities include reuse as soil conditioner for landscaping after de-watering via drying beds (Hotels, industries) and tankering to existing Governmentalsewerage works (Industries,Housing estates).

4. Disposal Options

Three disposal options for the excess sludgewere considered:

* Reuse in agricultureparticularly on the agriculturalland close to the WWT plants; * Disposalat a landfill site; and * Incineration.

4.1 Reuse of Stabilised Sludge in Agriculture

Sludge disposal by applying it to agriculturallands is an option that is implementedin various countries and can be an efficientdisposal option. In addition to its soil conditioningproperties, sewage sludge has a nutrient content in the form of nitrogen and phosphorusand to a lesser extent, potassium,calcium, magnesiumand trace metals.

Duringthe manufactureof sugar, scum is generated.Every year an estimated amount of 245 000 tons of scum are generated during the milling season (June to November).This material is applied to sugar cane fields that will bc re-plantedwith sugar cane or on rotational land.

The characteristicsof sludge from a WWT plant treating domestic waste waters only and scum from sugarcane processing are given in Table 8. From the table it is seen that both sludge and scum are deficient in nutrients.

Table 8: Characteristics of Sludge (DomesticWastewater) and Scum from Sugarcane Processing

Nitrogen N (%) 3.5 - 4.0 0.8 l Phosphateas P20, (%) 2.0 - 3.0 1.1 Potassiumas K20 (%) 0.5 - 1.0 0.1 Humidity (%) _ 80 Organiccontent (%) 0.5- 1.0 -

Black & Veateh Tnter'rnaional I* Montagne Jacquot Sewerage and SanitationProjecl Environmental Impact Assessment

In Mauritius the application of sludge to agricultural land in sugar cane plantations is limited for the following reasons:

* sugar cane is planted in ratoons and only after every seven years (or more) are the sugar cane fields either replanted with sugarcane or crop rotation is implemented. Hence the surface area available for sludge reuse every year is only a fraction of the total surface area under cultivation (20 percent available yearly).

v Scum produced from sugar manufacturing is currently applied to the land, which makes it unavailable for application of sludge.

4.1.1 Possible Reuse of Stabilised Sludge in Sugar Plantations around the Island

Western Coast Medine Sugar Estate which is located on the western Coast of Mauritius, produces about 25 000 tons of scum per harvest season. Medine operates a composting unit which converts the scum into compost with augmentation of the potassium, organic and phosphate content with vinasse from a nearby distillery. The compost thus produced is used in the sugar cane fields of the western coast.

The area under cane cultivation in the Westem Coast is estimated at around 7400 hectares of which only 1480 hectares (20 percent) are available every year for sludge application.

Other Regions In the other regions of the island, which consist of the humid to super humid regions, the presence of lime in the lime-stabilised sludge may provide a source of benefit to the planters on account of its alkalinity content.

In the humid to super humid regions on the island, the soil is acidic (pH -4.2) and pH correction is necessary for sugar plantation (pH <5). To increase the pH by one unit, about 5 tonnes of lime is needed per hectare of land. pH correction is normally carried out when sugar cane is re-planted only.

Land Under Cultivation in the Humid to Super-humid Zone. The surface area of sugar cane plantations in the humid to super humid zones around the island is summarised in Table 9 (1993 figures).

Table 9: Land Under Sugarcane Cultivation in the Humid to Super-humid Regions of Mauritius.

Regions Area Under Sugarcane crop (Ha) Centre 8000 South 24000 East 18000 Total 50000

It is estimnated that there are about 50000 hectares of land in the humid to super humid zones under cane cultivation. However only about 20 percent of these lands will be available every year for reuse of stabilised sludge. Assuming that only 50 percent of this area requires pH correction then the amount of lime only needed is estimated at 25 000 tonnes per year (assuming lime application rate of 5t/Ha).

S. Chemical Contaminants in Sewage Sludge

The quantity of sewage sludge that can be applied to agricultural land depends to a large extent on the concentrations of various contaminants present in the sludge and the maximum amount of metal(s) that can be applied to soil.

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The chemical compositionof sewage sludge varies widely from country to country as well as within regions of the same country since they are generatedand dischargedby the activitiesof the serviced community.The data in Table 10 shows the extent of variation observed. Industriesand commercialestablishment are almost always the source of contaminants found in waste water. This is because the amount of these substances that might be discharged by a residential unit would be so small that they would be undetectablewhen diluted with the normal waste water flow in the system. Insecticides,cleansers, paints, automotive products and other chemicalproducts used by individualsare not normallyavailable in the high concentrationsused by industries nor are they disposed of in significantquantities.

In the case of Mauritius,no comprehensivesurveys have been carried out on the chemical compositionof sewage sludge, to determine the extentto which these substancesmay be present.

Table 10: Reported Contaminant Concentrations in Sludge Contaminant Concentrations(mg/kg ,dry basis) Contaminant United Kingdom South Africa United States Range Average Range Average Typical Cadmium 2 - 1500 20 <1-122 12 10 Chromium 40-14000 400 25- 10015 551 - Copper 200 - 8000 650 80 - 17217 654 800 Lead 50- 3600 400 67- 10137 452 500 Nickel 20 - 5300 100 6 - 2660 154 80 Zinc 600- 20000 1500 237-17680 2054 1700 Mercury <1-18 5 <1-22 5 6 Arsenic 3-30 20 <1-34 7 10 Selenium I - 10 3 <1-107 4 5 Molybdenum I - 40 6 1- 24 6 4 Boron 15-1000 30 6-78 31 Fluoride 60 -40000 250 32-1260 128 -

5.1 Estimated Metal Content from Montagne Jacquot Project

With regard to the MontagneJacquot Project, a comprehensivelist of industriesin the service areas was reviewed and chemical analyses carried out on waste waters from selected industries by SETEGUE, ERM-SIGMA- SAMSOON. Chemical audits were also carried out on selected textile and metal plating industries.From these reviews it was concludedthat only a few industries (see section on Industrial Survey) might dischargesome of these contaminantsin either the form or in quantitieswhich can would result in high concentrationsin the sludge.

The latest available data on the characteristicsof industrialeffluent are tabulated in Appendix I of the EIA. Most of the work on industrialeffluents has focusedon the textile industriesbecause they contribute about 90 percent of the total industrial waste water flow. The effluents from five dye houses were analysed for phenol, nickel, zinc, cobalt, copper, Total chromium, and hexavalent chromium, in addition to the other routine water quality parameters such as BOD, COD, TSS, N, and P. From the analysesit was found that virtually no nickel, no cobalt, no chromium, and no hexavalent chromium were present Phenols were found in several samples, ranging in concentrationfrom 0.05 to 0.6 mg/I. Zinc was present in concentrationsranging from 0.02 to 0.23 mg/I, and a sample from one of the five textile plants showed a copper concentrationof 0.27 mg/I.

It is possible to estimate the amount of zinc and copper which could end up in the primary sludge from the Montagne Jacquot plant from these industrial effluent discharges, using reasonable assumptions concerning average waste water effluent quantities and treatment process removal efficiencies. If one half of the textile industries had an average concentrationof copper and zinc of 0.15 mg/Qon a continuous basis, and if the primary treatment process removed 40 percent of the total, the resulting average concentration of copper and zinc in the sludge would be increased by 85 mg/kg. This compares to the typical sludge concentration of these metals shown in Table lIA.3.Iof 650 to 800 mg/kg for copper, and 1500 to 2054 mg/kg for zinc. It was concluded that these concentrationsof copper and zinc in the textile industryeffluent were not significant.

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5.2 Maximum Permissible Contaminant Concentrations in Sewage Sludge for Application to Agricultural Land

The presence of contaminants in sewage sludge can in some cases exceed their levels in the soils and consequently their use for agricultural purposes needs to be assessed and permissible limits defined. Moreover it is essential that sludge destined for agricultural purposes be monitored adequately for the presence of these contaminants. Table II below shows the maximum permissible limits for various contaminants in sewage sludge for application to agricultural land.

Based on the best information available for the waste water at the Montagne Jacquot WWT plant, the primary sludge will meet all of the limits for concentration shown in Table 11. Also, since the concentration of the pollutants will be at acceptable levels, there will not be limits placed on the application rates for sludge to land for disposal.

Table 11: Maximum permissible contaminant concentrations in sewage sludge for Application to Agricultural land. Maximum Permissible Concentrations (mg/kg, dry basis) Contaminants EEC-mandatory France South Africa US EPA Cadmium 40 20 20 85 Chromium - 1000 1500 - Copper 1500 1000 1000 4300 Lead 1000 800 750 840 Nickel 400 200 300 420 Zinc 3000 3000 3000 7500 Mercury - 10 10 57 Arsenic - - is 75 Selenium - 100 15 100 Molybdenum - 20 75

5.3 Maximum Soil Metal Content and Permissible Metal Application Rates.

The National Institute of Water Research (South Africa) has defined guidelines for the maximum soil metal content and the permissible metal application rates; these are reproduced in Table 12. The main reason why metals and to some extent toxic organic are limited is that once they are in the sludge they tend to remain in it as inert materials and become part of the soil matrix. Eventually these substances can be taken up by the crops and the animals grazing on the sludge applied land.

Table 12: Maximum Soil Metal Content and Permissible Metal Application Rates (source: NIWR- South Africa, 1984). Metals Maximum Maximum Amount of Types of Toxicity Permissible Metal Metal that can be glhaly Content in Soil Applied to Soil (mg/Kg) (kg/ha/25y) Cadmium 2 4 160 X Cobalt 20 20 800 X Chromium 80 550 22000 X Copper 100 150 6000 X Lead 56 50 2000 X Nickel 15 40 1600 X Zinc 185 550 22000 X Mercury 0.5 2 80 X Molybdenum 2.3 5 200 X

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Montagne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

5.4 Nitrogen Demand

Nitrogen is usually the nutrient governing the rate of application of fertiliser to crops. For sugarcane typical nutrients in the form of fertilisers that are applied are as follows:

* Nitrogen (as N): 120 kg/Ha/year * Phosphorus (as P205): 56-60 Kg/lHalyear

The nitrogen (N), phosphorus (P) and potassium (K) content for domestic sludge is low. The percentage by weight is around 4,3,1 percent of N, P and K respectively. A typical fertiliser used for agriculture in Mauritius contains 17, 3.5, 20 percent by weight of N, P, K respectively.

As lime-stabilised sludge contains between 2.9 to 3.3 % nitrogen (as N), then the rate of sewage sludge that can be applied to land is between 3.6 to 4.1 tonnes/ha/year. This assumes that the maximum metal concentrations in the sludge do not exceed the permissible metal soil application rates as given in Table 1.4.3.3.1. In South Africa, the application rate of sewage sludge to land under crop cultivation is 8 tonnes/ha/year (source: NIWR-South Africa, 1984).

6. Control and Monitoring

The maximum allowable annual loading rates established by the South Africa and U.S. EPA for sludge that is applied to land for disposal can be used as temporary guidelines until data become available when a review of these guidelines can be effected for local conditions. These rates can be used by the Waste Water Authority to control the allocation of sludge applied to land for disposal, to prevent an excessive amount of the pollutants from being deposited in one location.

The sludge produced at the Montagne Jacquot WWT plant wil be analysed on a regular basis for these pollutants, to determine the acceptability of the processed primary sludge for disposal on land application. Initially, samples of sludge will be collected and analysed approximately once every 3 months for the first year of operation. The frequency of monitoring will thereafter be adjusted, according to the results of the initial monitoring. Moreover industrial activities that can contribute to the presence of these contaminants in the sewers will need to be controlled and monitored regularly( as described in the section Industrial Survey).

Limits have also been proposed in the U.S. for other types of regulated pollutants that can be present in sludge if discharged in significant quantities by industries or other establishments in the service area. These regulated pollutants include pesticides like aldrin, chlordane, DDD/DDT/DDE, dieldrin, lindane, and toxaphene; industrial chemicals such as benzene, PCB, and trichloroethylene. Their presence in the sewerage system will be controlled by the Waste Water Authority through its regulations and its program of monitoring and reporting of industrial waste water discharges.

6.1 Establishing Guidelines for Sludge Reuse for Agricultural purposes

Once, data are available from the monitoring and control programme, then guidelines can be defuned for permissible limits for contaminants, the type of crops to which sewage sludge can be applied and other methods of utilisation or disposal.

Sewage sludge that are to be applied or disposed on land needs to be classified. The classification procedures include the origin, type(s) of treatment and characteristics and quality standards required for particular purposes.

The origin defines the source of the sludge, whether it is sludge from septic tanks, oxidation ponds, secondary activated sludge plant etc. The type of treatment applied to the sludge such as anaerobic digestion, pasteurisation, lime stabilisation, compost, fumigated etc.

Characteristics and Quality standards includes:

* Odour nuisance and fly breeding potential; * Pathogenic content including viable Ascaris Ova per lOg of dry sludge, Salmonella per 1O0g dry sludge, faecal coliforms per 1O0g dry sludge etc;

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Metal content; among others.

6.1.1 Contractual Agreement between Producer and User of Sewage Sludge.

In view of the possible problems and risks associated with the use of sewage sludge for agricultural purposes, a contractual agreement must be established between the producer and the user of the sludge. The essential items forming part of the contract shall include but not limited to:

* Characteristics of the sludge (type, quality etc.) * Limiting metal and maximum application rate (dry weight basis) t/ha/y. * Recommended maximum application rate in terms of nitrogen demand of crop (t/ha/y). * Methods of transport for the sludge. * Site location where sludge will be stored and used. * Area of land where sludge will be applied. * Crops under cultivation. * Metal content of soil. * Name and quantity of materials (scum for example) or chemicals (e.g. lime, potassium) to be added to sludge before use. * Instructions for the usage of sludge. * Defnition of the methods of inspection of the user's activity.

7. Disposal of Sludge at a Landfill Site

Disposal of sewage sludge in a landfill has the economic advantage and at the same time avoiding the risks associated with land application.

Under the Solid Waste Management Plan two landfill sites for solid waste disposal (domestic and industrial) were identified namely: Mare Chicose and Mare D'Australia.

Mare Chicose landfill is due to be in operation towards the third quarter of 1997. No specific provisions for disposal of sludge were made in the planning, design or construction of the landfill. However, sludge can be safely mixed with domestic solid waste and it poses no significant handling problems if the solid content of the sludge is about 30 percent (by mass) or more.

According to the National Solid Waste Management Report (Ministry of Economic Planning and Development, 1994), the estimated wastes from the existing transfer station amounts to 450 tonnes per day. With the shelving of the Mare D'Australia landfill project, it is likely that all these wastes will have to be sent to Mare Chicose, this tonnage is near the nominal design capacity of the landfill. With the implementation of the four sanitation projects, it is estimated that about 25 tonnes per day of sludge (volume 80 m3/d) will have to be disposed, his amount will increase to 40 tonnes per day (volume 165 m3/d) by Year 2005. These sludge masses represents about 6 and 9 percent of the nominal design capacity of Mare Chicose landfill. Thus, the landfill has the capacity to receive and dispose of the total sludge produced by the WWT plants. Once a new landfill is placed into service, the burden on the landfills to dispose of the sludge will be significantly reduced.

The disposal of sludge at the Mare Chicose landfill site can be retained as the disposal option for at least the first five years of operation of the new Montagne Jacquots WWT plant, until 2006.

8. Sludge Incineration

Incineration of sewage sludge can reduce many of the problems associated with disposal of sludge to land. However this method requires high capital investmnentsas well as operating costs.

With sludge incineration, sludge stabilisation is not necessary. However sludge de-watering will be required. For the incineration of excess sludge only, it is estimated that about 15 percent of the total sludge incinerated re- appears as ashes. As these ashes may contain metals, they will have to be disposed in a landfill site.

Typical incinerators operate at temperatures of 750 to 800SC, which is high enough to convert organic matter to carbon dioxide and water.

Black & Veatch International lxv 4nnendiee Monragne Jacquot Sewerage and Sanitation Project Environmental Impact Assessment

The feasibility of sludge incineration will have to be carried out prior to its implementation. Many issues will have to be assessed namely:

* the economic viability of the process; * centralisation of sludge incineration taking due cognisance that other-waste water treatment plants will also generate excess sludge; * Treatment of gaseous emissions and odour minimisation; among others.

Furthernore investigations will be needed into the viability of co-incineration of excess sludge together with domestic wastes.

9. Solid Waste Management Study

The Ministry of Environment has commissioned a study to define, evaluate, and review alternatives for solid waste managment in Mauritius and Rodrigues. The study will include the sludge produced at the WWT plants as part of the overall solid waste stream. The purpose of the study is to develop a master plan for solid waste management, considering all sources of solid waste and all alternative disposal methods. The WWA will be one of the agencies participating in the implementation of the long term solid waste management program.

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