ENVIRONMENTAL IMPACT ASSESSMENT
For the Proposed Development of Sewerage System
Naifaru, Lhaviyani Atoll, Maldives
Proponent: Ministry of Housing, Transport and Environment, Maldives
Ahmed Zahid (EIA08/07)
January 2010 EIA for the Development of Sewerage System in Lh. Naifaru
Table of Contents
TABLE OF CONTENTS ...... I
TABLE OF FIGURES ...... V
TABLE OF TABLES...... VI
NON TECHNICAL SUMMARY ...... VII
1 INTRODUCTION ...... 1
1.1 INTROD UCTI ON...... 1
1.2 AI MS AND OBJECTI VES OF THE EIA...... 1
1.3 METHODOLOGIES...... 2
1.4 EIA IMPLEMENTATION...... 2
2 PROJECT DESCRIPTION...... 3
2.1 GENERAL CONTEXT OF THE STUDY ...... 3
2.2 THE PROPONENT ...... 3
2.3 PROJECT LOCATION AND STUDY AREA...... 3
2.4 DESCRIPTION OF THE EXISTING SEWERAGE SYSTEM ...... 5
2.5 THE PROJECT ...... 5 2.5.1 Design Data ...... 6 2.5.2 Type of Sewerage System...... 7 2.5.3 Design Year ...... 8 2.5.4 Design Criteria for Sewerage System ...... 8 2.6 ENVIRONMENTAL COMPONENTS OF THE PROJECT ...... 11 2.6.1 Sewer network ...... 11 2.6.2 Treatment System ...... 12 2.6.3 Pump station...... 14 2.6.4 Marine outfall ...... 16 2.6.5 Sludge Treatment and Management ...... 16 2.7 PROJECT INPUTS AND OUTPUTS ...... 17
2.8 CONSTRUCTION METHODOLOGY...... 17 2.8.1 Construction strategy...... 17 2.8.2 Work methods for terrestrial based activities...... 17 2.8.3 Works methods for marine based activities ...... 18 2.9 PROJECT DURATION ...... 18
Proponent: Ministry of Housing, Transport and Environment Page | i Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.10 OPERATION AND MAINTENANCE ...... 18
2.11 NEED AND JUSTIFICATION ...... 19 2.11.1 Why install a new sewerage system?...... 19 2.11.2 Why Naifaru? ...... 20 2.11.3 Why Proposed Design? ...... 20
3 THE SETTING ...... 21
3.1 APPLICABLE POLICIES, LAWS AND REGULATIONS ...... 21 3.1.1 Environmental Protection and Preservation Act...... 21 3.1.2 Second National Environment Action Plan (1999)...... 22 3.1.3 National Biodiversity Strategy and Action Plan ...... 23 3.1.4 Consultation and public participation laws...... 24 3.1.5 Population Policy ...... 24 3.1.6 Regulation on Cutting Trees...... 24 3.2 RELEVANT INTERNATIONAL ENVIRONMENTAL LEGISLATION ...... 25
3.3 ENVIRONMENTAL PERMITS REQUIRED FOR THE PROJECT ...... 25 3.3.1 EIA Decision Note...... 25 3.3.2 Wastewater disposal permits ...... 26 3.4 WATER AND WASTEWATER REGULATIONS, POLICIES, STAND ARD S AND GUIDELINES ...... 26 3.4.1 Water and Sanitation Policy Statement...... 27 3.4.2 General guidelines for domestic wastewater disposal ...... 28 3.4.3 Design Criteria for Sewerage Systems ...... 29 3.5 ROLES AND RESPONSIBILITIES OF GROUPS INVOLVED ...... 29 3.5.1 Environment Ministry ...... 30 3.5.2 Project Proponent...... 31 3.5.3 Environmental Consultants...... 31 3.5.4 The Public ...... 31 3.6 ADDRESSING SHORTCOMI NGS ...... 32
4 METHODOLOGY ...... 33
4.1 GENERAL METHODOLOGIES OF DATA COLLECTION...... 33 4.1.1 Mapping and Location identification ...... 33 4.1.2 Quality of groundwater ...... 34 4.1.3 Quality of surface water ...... 34 4.1.4 Bathymetry and Ocean Currents...... 34 4.1.5 Condition of the housereef ...... 34 4.1.6 Socio-economic condition and public consultation...... 34
Proponent: Ministry of Housing, Transport and Environment Page | ii Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5 EXISTING ENVIRONMENT...... 36
5.1 TERRESTRIAL ENVIRONMENT ...... 36 5.1.1 Soil and Topography...... 36 5.1.2 Vegetation...... 37 5.1.3 Groundwater ...... 37 5.2 GENERAL METEOROLOGICAL CONDITIONS ...... 41 5.2.1 Ra i nfall ...... 42 5.2.2 Wind ...... 42 5.2.3 Waves...... 44 5.2.4 Tides ...... 44 5.2.5 Currents ...... 45 5.2.6 Natural Vulnerability of the Island of Naifaru...... 46 5.3 COASTAL AND MARINE ENVIRONMENT ...... 47 5.3.1 Site 1: Proposed outfall...... 48 5.3.2 Site 2: Alternative Outfall Location...... 49 5.3.3 Site 3: Potential Outfall at Proposed PS1 Area ...... 50 5.3.4 Other observations ...... 50 5.3.5 The Seagrass Ecosystems ...... 51 5.3.6 Marine Water Quality ...... 51 5.4 SOCIO-ECONOMIC ENVIRONMENT...... 54 5.4.1 Socio-economic profile ...... 54 5.4.2 Status of Environmental Infrastructure ...... 56 5.4.3 Solid waste disposal ...... 57 5.4.4 Community Preferences, Expectations and Awareness ...... 57 5.4.5 Willingness to Pay ...... 58
6 STAKEHOLDER CONSULTATIONS ...... 59
6.1 MINISTRY OF HOUSI NG, TRANSPORT AND ENVIRONMENT ...... 59 6.1.1 Environment Protection Agency ...... 59 6.2 PROJECT CONSULTANTS ...... 61
6.3 LOCAL PIU STAFF AND COUNCILLOR ...... 61
6.4 NORTHERN UTILITIES LIMITED ...... 62
6.5 COMMUNITY...... 63 6.5.1 Perceptions of the Community ...... 63 6.5.2 Conclusion and Follow up Issues...... 64 6.6 LIST OF PERSONS CONSULTED ...... 65
Proponent: Ministry of Housing, Transport and Environment Page | iii Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7 IMPACTS AND MITIGATION MEASURES...... 66
7.1 IMPACT IDENTIFICATION...... 66
7.2 IDENTIFYING MITI GATI ON MEASURES ...... 67 7.2.1 Mitigation Opti ons...... 68 7.3 EXISTING ENVIRONMENTAL CONCERNS ...... 68 7.3.1 Natural hazard vulnerability ...... 68 7.3.2 Existing solid waste disposal impacts...... 68 7.3.3 Existing sewage disposal impacts ...... 69 7.4 CONSTRUCTIONAL IMPACTS ...... 69 7.4.1 Civil works ...... 70 7.5 OPERATIONAL IMPACTS ...... 73 7.5.1 Groundwater ...... 73 7.5.2 Lagoon and seawater quality...... 76 7.5.3 Coral Reef and Marine Biodiversity ...... 76 7.5.4 Socio-Economic Impacts ...... 78 7.6 UNCERTAINTIES IN IMPACT PREDICTION ...... 80
7.7 SUMMARY OF IMPACTS...... 80
8 ALTERNATIVES...... 83
8.1 NO PROJECT OPTION ...... 83
8.2 ALTERNATIVE SEWERAGE SYSTEMS ...... 83 8.2.1 Sewage collection ...... 84 8.2.2 Sewage treatment ...... 85 8.2.3 Disposal...... 86 8.2.4 Other Alternatives ...... 87 8.3 PREFERRED ALTERNATIVE SEWERAGE SYSTEMS ...... 90 8.3.1 First Preference ...... 90 8.3.2 Second Prefer ence...... 90
9 MONITORING AND ENVIRONMENTAL MANAGEMENT PLAN ...... 92
9.1 INTROD UCTI ON...... 92
9.2 MONITORING REQUIREMENTS ...... 92 9.2.1 System P erformance and Water Quality ...... 92 9.2.2 Monitoring dewatering impacts...... 93 9.2.3 Socio-Economic Aspects ...... 93 9.3 RECOMMENDED MONITORING PROGRAMME ...... 94 9.3.1 Project Specific Monitoring Programme ...... 94
Proponent: Ministry of Housing, Transport and Environment Page | iv Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
9.4 COST OF MONI TORI NG...... 95
9.5 MONITORING REPORT ...... 95
10 DECLARATION OF THE CONSULTANT ...... 98
11 SOURCES OF INFORMATION ...... 99
APPENDIX 1: TERMS OF REFERENCE ...... 102
APPENDIX 2: COMMITMENT LETTER FROM THE PROPONENT TO UNDERTAKE MONITORING ...105
APPENDIX 3: DRAWINGS...... 106
Table of Figures
Figure 2-1: Project Location: Naifaru in Lhaviyani Atoll (source: Water Solutions 2006) ...... 4 Figure 2-2: Proposed Activated Sludge Treatment system for sewage for Naifaru ...... 12 Figure 5-1: Conceptual Illustration (not to scale) of freshwater lens in a small coral island (after Falkland)...... 38 Figure 5-2: Daily safe yield per capita, which can be drawn from the Naifaru aquifer ...... 41 Figure 5-3: General wind rose diagram for the Maldives (source MEEW 2005)...... 43 Figure 5-4: Lee of the island during the two monsoons based on general wind rose diagram ...... 43 Figure 5-5: Cyclonic and related storm surge hazard zones (adapted from RMSI/UNDP 2005)...... 46 Figure 5-6: Site conditions and results of surveys undertaken during field mission in October 2009 ...... 53 Figure 5-7: Distribution of household income ...... 54 Figure 5-8: Household assets ...... 55 Figure 5-9: Willingness to pay for a septic tank system ...... 58 Figure 5-10: Willingness to pay for a sewage treatment system ...... 58 Figure 7-1: Illustration of simple skimming well technology ...... 75 Figure 8-1: Schematic diagram of the Vacuum System (Source: Roevac Manual)...... 90
Proponent: Ministry of Housing, Transport and Environment Page | v Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table of Tables
Table 2-1: Summary of design data and design criteria ...... 6 Table 2-2: Population estimations for the proposed sewerage system in Naifaru based on GIM...... 6 Table 2-3: Water Use and Waste Streams ...... 7 Table 2-4: Design parameters for Naifaru wastewater treatment plant ...... 14 Table 2-5: Main inputs of the proposed project...... 17 Table 2-6: Matrix of major outputs...... 17 Table 3-1: Recommended effluent quality standards...... 27 Table 3-2: Roles and responsibilities by EIA process stage...... 30 Table 5-1: Results of groundwater samples taken from proposed pumping station locations ...... 38 Table 5-2: Water quality results for Naifaru groundwater undertaken on 11 July 2007 ...... 39 Table 5-3: Key meteorological information ...... 42 Table 5-4: Water quality results ...... 52 Table 5-5: Monthly average household expenditure...... 55 Table 5-6: Existing Water Supply System...... 56 Table 5-7: Problems with drinking water and type of purification used...... 56 Table 5-8: Types of toilet facilities in household ...... 56 Table 5-9: Methods of garbage disposal ...... 57 Table 5-10: Preference for sanitation and the reasons for the preferences ...... 57 Table 7-1: Existing sewage disposal systems and their impacts...... 69 Table 7-2: Impact matrix scale ...... 81 Table 7-3: Impact Matrix for the proposed sewerage system ...... 81 Table 7-4: Product of the impact matrix...... 82 Table 8-1: Advantages and disadvantages of the no project option ...... 83 Table 8-2: Comparison of pressure system (gravity system with pumps) and vacuum system ...... 91 Table 9-1: Monitoring performance and water quality...... 93 Table 9-2: Indicators for monitoring of socio-economic aspects of the project ...... 94
Proponent: Ministry of Housing, Transport and Environment Page | vi Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Non Technical Summary
This report discusses the findings of a social and environmental impact assessment (EIA) study undertaken for the development of a comprehensive sewerage system in Naifaru in Lhaviyani Atoll. This EIA is the culmination of a three-step environmental management process that involves mitigation and monitoring as an integral part. Mitigation measures and monitoring programme has been outlined and a summary Environmental Management Plan has been given in this EIA report.
This project is initiated by the government of Maldives with funding from Asian Development Bank (ADB) as part of the technical assistance loan under the Second Phase of the Regional Development Project. At this stage, there is no funding for the project implementation but the design and EIA only. Naifaru, being the fifth most populated island and the third most densely populated island in the country before the reclamation is in need of an upgrade of its sewerage system. Overall, there are other environmental problems such as solid waste management and water supply and the overall environmental management of the island is poor owing to congestion and other reasons. Community consultations revealed that the most urgently required environmental improvement is a comprehensive sewerage system that cuts down the number of outfalls and does not pollute the island environment. Naifaru has a gravity flow sewerage system with small catchpits and with 24 outfalls disposing into the beach or lagoon. The system is old and has been continuously contaminating the beach and lagoon environment with sewage and wastewater.
Environmental impacts were assessed for both the construction and operation phase of the project. Most of the environmental impacts of the project have been identified as positive resulting mainly from improvements to groundwater and lagoon water quality and resulting reduction in water-borne and water-related diseases and general ill-health. The main negative impact of the project would be that of excessive drawdown on the aquifer resulting from the flushing needs of the improved sewerage system. There are other minor negative impacts such as small amount of excavation to lay the sewer network in some areas including dewatering for the construction of manholes, lift stations and sumpwell at the pumping station. These impacts are considered to be moderate but short-term. The socio-economic benefits of the project may be considered to outweigh the negative impacts of the project.
Mitigation measures for anticipated negative impacts have been identified and outlined in detail, including minimizing dewatering, laying the sewers properly including the outfall, locating the outfall at adequate depth, removal of existing sewers and outfalls and improvements to lagoon and coastal conditions in order to attain the benefits of the project. The main mitigation measure would be water conservation and measures to minimize drawdown on the aquifer. Skimming wells that draw water from close to the water table has been suggested as an important mitigation measure. These measures require community awareness, involvement and participation from
Proponent: Ministry of Housing, Transport and Environment Page | vii Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru the planning stages and even during the operational phase. Social benefits of the project will be enhanced if community consultation and participation mechanisms are strengthened including the development and implementation of Grievance Redress Mechanisms, which simply involve letting people the access to express their grievance with assured confidentiality. This will help to improve project performance.
It is inevitable that there would be some negative environmental impacts. However, these are minor compared to the positive effects of the proposed system. Yet, monitoring to ensure the effectiveness of the proposed system would be necessary in order to evaluate the actual performance of the proposed system and to ensure future systems are remedied of design faults in the present and proposed systems. Therefore, a monitoring component has been suggested. Monitoring is specifically focussed on ground and marine water quality changes. Groundwater monitoring is essential for ensuring that the effects of dewatering to lay the pipes is minimized during the construction phase and to measure the level and speed at which salinisation of the groundwater occurs as a result of groundwater use for toilet flushing during the operational phase. Reef monitoring is considered inappropriate given the scale of anthropogenic damage to the reefs of Naifaru including the impacts of the dredging and reclamation that was recently undertaken, the effects of which have not been monitored. Therefore, an island-wide environmental monitoring programme is suggested. However, proposed marine water quality monitoring will help establish the long term environmental performance of the proposed sewerage system.
In conclusion, it appears justified from a technical, social, economic and environmental point of view, to carry out the proposed project to improve sanitation in Naifaru.
Proponent: Ministry of Housing, Transport and Environment Page | viii Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
1 Introduction
1.1 Introduction
This Environmental Impact Assessment (EIA) report has been prepared in order to meet the requirements of Clause 5 of the Environmental Protection and Preservation Act of the Maldives to assess the impacts of proposed project for the development of a sewerage system in Lh. Naifaru. This report will identify the potential impacts (both positive and negative) of the proposed project. The report will look at the justifications for undertaking the proposed project components. Alternatives to proposed components or activities in terms of location, design and environmental considerations would be suggested. A mitigation plan and monitoring programme before, during and after the works would also be included.
The impact assessments given in this report are based on qualitative and quantitative assessments undertaken during site visit from 15-17 October 2009, socio-economic report for the project, technical and engineering specifications for the project given in the concept design report, design changes shared by the Proponent, discussions with key stakeholders in the field as well as other relevant stakeholders, issues raised by the regulating authority regarding the design and experience and professional judgment of the EIA consultant. The assessment was also based on available long term data such as meteorology and climate from local and global databases.
This EIA has been produced in accordance with the EIA Regulations 2007, issued by the Ministry of Environment, Energy and Water on preparing Environmental Impact Assessment studies. The scope of the EIA has been finalized by consultations between the Proponent, Environmental Protection Agency (EPA) and the Consultant.
1.2 Aims and Objectives of the EIA
This report addresses the environmental concerns of the proposed sewerage system development in Naifaru in Lhaviyani Atoll. It helps to achieve the following objectives.
. Allow better project planning, design and implementation . Assist in mitigating impacts caused due to the project . Promote informed and environmentally sound decision making . Demonstrate the commitment by the proponent towards environmental protection and preservation . Aid in the better planning, design and implementation of future projects of similar nature
Proponent: Ministry of Housing, Transport and Environment Page | 1 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
1.3 Methodologies
Internationally recognized and accepted methods have been used in this environmental evaluation and assessment. The impact assessments given in this report are based on qualitative and quantitative assessments undertaken during site visit from 15-17 October 2009, socio-economic report for the project, technical and engineering specifications for the project given in the concept design report, design changes shared by the Proponent, discussions with key stakeholders, issues raised by the regulating authority regarding the design and experience and professional judgment of the EIA consultant. The data collection methods are described in detail under Section 4.
The evaluation of impacts and alternatives has been based on impact matrices that have been developed specifically for the proposed project and its alternatives. These are given in the relevant sections of impacts and alternatives.
1.4 EIA Implementation
This EIA has been prepared by Ahmed Zahid, a registered EIA consultant who has number of years of experience in Environmental Impact Assessment in the Maldives and has been involved in most of the sewerage EIAs undertaken in the Maldives so far.
The different steps involved in the implementation of the EIA and the time frame for those steps/activities are indicated below.
. EIA application submission 5 Sep 2009 . Scoping meeting 30 Sep 2009 . Submission of TOR 1 Oct 2009 . Field mission 15-17 Oct 2009 . Approval of TOR 4 Nov 2009 . Draft report submission to Client 23 Nov 2009 . Comments received from Proponent 16 December 2009 . Submission of final EIA report 4 February 2009
The Terms of Reference (TOR) for this EIA has been attached as Appendix 1. This EIA has been prepared based on the Terms of Reference. Once the EIA has been submitted it is expected that the review process will take about 4 weeks. The review process may result in the requisition of additional information, which the Consultant or the Proponent may have to provide in writing or during the post review meeting.
Proponent: Ministry of Housing, Transport and Environment Page | 2 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2 Project Description
2.1 General context of the study
Naifaru is among three islands selected for Environmental Infrastructure and Management component under Phase II of the Regional Development Project (RDPII) undertaken by the Government of Maldives with loan assistance from Asian Development Bank (ADB). RDP II is targeted at improving environmental infrastructure because it is the key to sustainable social and economic development. Environmental infrastructure being the focus of its mandate, the Ministry of Housing, Transport and Environment (known as the Ministry of Environment, Energy and Water at the initiation of the project) is the Implementing Agency for the project.
The project aims to propose, design and construct suitable infrastructure for Naifaru to manage its sewage and wastewater in a socially acceptable and environment-friendly manner. The main consideration being environmental protection (based on existing policies on sewage and wastewater disposal), the cost of construction, operation and maintenance are of secondary importance. The present sewerage system in Naifaru was installed during the very infant stage of sewerage systems development in the Maldives and is seen to have huge environmental costs associated with it. Therefore, there is an urgent need for a comprehensive sewerage system for Naifaru.
2.2 The Proponent
This project is proposed by the Government of Maldives with Ministry of Housing, Transport and Environment (MHTE) as the Implementing Agency. MHTE is the government agency responsible for the development and regulation of the water sector with the Ministry focusing on the planning, policy and implementation while the Environment Protection Agency (EPA) under the Ministry focuses on the regulatory aspects. When RDPII and the planning and design of Naifaru sewerage system began, water was under the jurisdiction of the Ministry of Environment, Energy and Water with the Maldives Water and Sanitation Authority responsible for regulating the sector.
2.3 Project Location and Study Area
The project site is the island of Naifaru, in Lhaviyani Atoll, as seen in Figure 2-1. The geographical coordinates of the island are 5°26’40”N and 73°22’10”E. Naifaru is the most populated of the 5 inhabited islands of Lhaviyani Atoll with a population of 4577 (in 2007) and a land area of 14.27 hectare with 625 m in length and 325 in width (MOAD 2007). During that time, Naifaru was one of the most highly congested islands with some of the house plots on falling on to the low tide line. Therefore, a land reclamation project was undertaken in 2006 reclaiming
Proponent: Ministry of Housing, Transport and Environment Page | 3 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru the island to about 53 hectares within the new shoreline. The reclamation not only provided extra space but also improved the coastline and general environment of the island.
Figure 2-1: Project Location: Naifaru in Lhaviyani Atoll (source: Water Solutions 2006)
The island of Naifaru lies on its own reef system on the western rim of Lhaviyani Atoll. The reef is about 152.5 hectares. There is an extensive lagoon covering a reef extent of about 375m on the western side all the way from the southwest corner to the northewest corner. This lagoon is almost completely covered with seagrass of predominantly thalassia hemprichi species except the dredged area towards the northwest. The lagoon also has shallow depths varying from 0.3 to 0.7m on average. Some areas on the western and southeastern shoreline get dry during low tide. The area in which the proposed outfall is located has clear lagoon close to the beach followed by an area dredged to about 5m and reef flat beyond that.
Main activity in the island is fishing. However, some are engaged in tourism activities, government service and few in business area. Education can be obtained up to advance level and 24 hours power supply exists in the island. Banking, internet access and telecommunication services are available. Health services can be obtained from Atoll Hospital employing 5 doctors and 19 paramedic staff. There are seven Non-Governmental Organizations within the community, however only two are fully operative. The major activities of the two NGO’s are related to garbage cleaning, sport activities, training and drug rehabilitation (PMU, 2007).
Proponent: Ministry of Housing, Transport and Environment Page | 4 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.4 Description of the existing sewerage system
An understanding of the existing sewerage system was made during the field trip on 15-17 October 2009. It was gathered that the sewerage system is a simple, gravity flow sewer network with multiple outfalls discharging raw sewage into the nearshore environment. This system is often referred to as a “small bore sewerage system”. Due to inherent design and construction issues with this type of sewerage system, it was discontinued in the late 90s until an appropriate solution can be found. These inherent problems include:
. Catchpits getting clogged too soon or too often. . Sewers leaking in some areas due to poor construction causing groundwater pollution. However, this is quite an insignificant issue given the improvements that the system brought to the biological quality of the groundwater. . Nearshore outfalls discharging raw sewage aggravates the pollution of the lagoon making it unsuitable for swimming, adding to the incumbent problems of lagoon water pollution due to beach defaecation and inappropriate fish handling and fishwaste disposal in the past. . Salinisation of the groundwater lens in coastal areas due to flooding of the pipes at high tide. This also caused backflow and maintenance problems in some areas. . Lack of sufficient gradient in the sewer network reduced self-cleansing capacity of the sewers, thereby causing more frequent maintenance and rehabilitation.
Nearshore outfalls may be considered as the main environmental design fault in these sewers. In a prime beach environment such as the Maldives, this is not acceptable. There are 24 nearshore outfalls around Naifaru with three outfalls discharging into the enclosed harbour (see Figure 5-6).
Although groundwater quality may be considered to have improved due to the installation of the existing sewerage system, there has been a lack of awareness on the control of pumping rates and sustainable groundwater abstraction practices. This is evident in that almost all households have wells drawing water from a single point at about a meter below the water table using electric pumps.
2.5 The Project
The project involves the design and installation of a comprehensive sewerage system that would replace the tsunami-damaged sewerage system of Naifaru, which has several problems associated with design as well as construction. The proposed project will, therefore, replace the existing system.
The concept design for the proposed sewerage system has been done based on environmental condition of the site that included topography, bathymetry and socio economic surveys on the island. The input that was provided by the community during various community and stakeholder consultations has been incorporated in the design. The design was also scrutinized by the Water Section of the Environment Protection Agency.
Proponent: Ministry of Housing, Transport and Environment Page | 5 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The proposed design layout for the sewerage system in Naifaru is given in Appendix 1. The design of the sewerage system has been based on the concept design criteria indicated and summarized below.
Table 2-1: Summary of design data and design criteria Description Design Value Remarks 1 Sewerage System Conventional Type Wastewater combines sewage (black water) and sullage (grey water) both 2 Design period 30 years 3 Domestic Average flow 110 lpcd Return Factor 1.0 4 Total Present population 4577 2007 5 Total Design Population 7055 2037 6 Peak Factor 3.0 Indian CPHEEO Manual 7 Institutional consumption 10% of Total Consumption 8 Commercial Consumption 2% of Total Consumption 9 Infiltration 5% of Peak Flow Sewer pipe will have flexible joints and infiltration will be less 10 Pipe material Wastewater collection uPVC Pressure Main Sea Outfall HDPE HDPE
11 Minimum velocity 0.6m/sec 12 Minimum Pipe diameter 110mm 13 Minimum Pipe Cover 450mm For main sewer 14 Maximum depth 1500mm 15 Manholes Circular Corrugated Polyethylene 16 Inspection Chamber Corrugated PVC 17 Pumping System for 15 Two submersible pumps each capable to handle One Mobile backup years design period peak flow generator Set to be provided in each SPS 18 Sewage Treatment for 15 Off-site STP Extended Aeration Activated Sludge years design period process with Diffused Aeration. Dilution By Dispersion without Conventional Sewer Outfall will be 18 m below Treatment beyond Reef. 19 Outfall Minimum 160 mm OD, HDPE 20 Sewer cleaning Equipment High Pressure Sewer Hydro Jetting truck Jetting Machine
2.5.1 Design Data
2.5.1.1 Population
The population of Naifaru Island as per 2006 census was 4517 and the registered population as on March 2007 is 4577. The population projection has been done based on growth rate 1.6% upto 2015 and 1.4% after 2015 as per MPND. Geometrical Increase Method has been adopted to forecast the population projection. Pn=P0 (1+r)n, where Pn is population nth year and P0 is population in present or Base year and r is growth rate percentage.
Table 2-2: Population estimations for the proposed sewerage system in Naifaru based on GIM Year Population 2007 4577 2015 5196 2020 5570 2022 5727 2027 6139 2037 7055
Proponent: Ministry of Housing, Transport and Environment Page | 6 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.5.1.2 Water Use Estimates
The estimated per capita water use as domestic demand in Focus Island as per PPTA is given below. The values are considered appropriate and shall be adopted.
Table 2-3: Water Use and Waste Streams Water Use Source Consumption (lpcd) Waste Stream Drinking & cooking Rainwater 10 Black water Toilet flushing, washing (pour flush) Groundwater 20 Black water Toilet flushing, washing (cistern flush WC) Groundwater 50 Black water Washing clothes /bathing Groundwater 50 Grey water
2.5.1.3 Wastewater (Quantity & Quality)
The wastewater is basically black water (sewage from toilets) and grey water generated from bathing and washing.
At present wastewater generation will be about 95 lpcd and for year 2020 and later of year 2020, it will increase to 110 lpcd. The quantity of wastewater for design year is 110 lpcd considering Return Factor (Sewage/ Water consumption) of 1.0
Sewage Characteristics:
. BOD5 200C assumed 40 gm/capita/day
. BOD5 in wastewater for 110 lpcd is 364 mg/l
. Faecal Coliforms is about 5x 107 nos. per 100ml. . pH 6.8-8.0
2.5.2 Type of Sewerage System
Conventional Sewerage System + Pumped Interceptor + Deep Sea discharge through Sea Outfall with Suspended Growth System Extended Aeration Activated Sludge process (EAASP).
2.5.2.1 Conventional Sewerage with Pumped Interceptors
Conventional sewers are buried pipes designed to carry black and grey water both. The sewer pipes are constructed at a sufficient depth to be safe from traffic loading and at sufficient slope to maintain a minimum self cleansing velocity to prevent the deposition of solids. Conventional sewer to collect wastewater generated from individual household and transfer through conventional sewer network for treatment / disposal through pumped Interceptors i.e. sewage pumping stations.
Proponent: Ministry of Housing, Transport and Environment Page | 7 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.5.2.2 Sewage treatment Plant (STP) for wastewater (black water + grey water)
STP is required for treating collected wastewater before disposal to land or sea. Diffused Extended Aeration Conventional Activated Sludge Process (EACASP) Treatment has been selected but electric power consumption will be high.
2.5.2.3 Sea Outfall
Discharge to deep water beyond reef edge through sea outfall to ensure adequate dispersion of pollutants mainly faecal coliform and dilution of nutrients.
2.5.3 Design Year
Land Acquisition for Sewage Treatment Plant & Sewage Pumping Station-30 Years (2037).
Sewer and Appurtenances -30 years (Year 2037)
Sewage Pumping Station Civil works-30 Years (Year 2037)
Design Year for Mechanical & Electrical component -15 years (Year 2022)
Design Period of STP-15 Years (Year 2022).
Pumping main and outfall pipe design for 30 years (Year 2037)
2.5.4 Design Criteria for Sewerage System
2.5.4.1 Sewerage network
Peak Factor
For Conventional Sewerage, Peak Flow Factor shall be 3.0 as population is less than 20,000 and per capita water supply is limited to maximum 135 lpcd.
Pipe material
Wastewater collection: uPVC non-pressure pipes and fittings Wastewater pumping main: uPVC pressure pipes & fittings.
Sea outfall: HDPE pipes and fittings
Proponent: Ministry of Housing, Transport and Environment Page | 8 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Infiltration
Sewer pipe will have flexible joints and infiltration of ground water will be about 5%.
Hydraulic design
Manning’s Equation has been used to design the sewerage system.
Minimum velocity
Velocity of gravity sewer primarily depends upon slope/gradient of sewer and it is little influenced by sewer size.
Minimum velocity for Conventional sewer at present peak flow 0.6 m/sec and 0.8 m/sec for ultimate flow.
Depth of flow
For conventional sewer, depth shall be restricted to 80% of full pipe i.e. d/D=0.80 maximum.
Pipe Size
But minimum pipe diameter and house Laterals shall be 110 mm OD. Main sewer size may be 160 mm OD and above as per hydraulic design.
Discharge capacity of sewer depends on size of sewer and flow velocity.
Minimum size of conventional gravity main sewer 160 mm diameter.
Pipe Gradient
Minimum slope required for 160 mm conventional sewer is 1 in 250 (0.4%)
Minimum Pipe Cover (Clear cover)
Minimum pipe cover over sewer pipes shall be 300mm in narrow road and 450mm (but not less than 450mm) in wide or major roads where traffic expected.
Sewer bedding
The sewer pipe must be embedded in wet well graded, compacted bedding material. If the original soil is unsuitable, suitable bedding materials should extend at least 100 mm below the bottom of the pipe to 300mm above the crown of the pipe.
Proponent: Ministry of Housing, Transport and Environment Page | 9 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Maximum depth of sewer line
Principle of gravity sewer shall be followed with respect of ground water table. The maximum depth shall be restricted to 1.5 m from ground level.
Manholes and Inspection chamber
Option A: Cast in situ concrete manholes and GRP lined Inspection chamber.
Option B: Pre-fabricated HDPE circular corrugated shafts for manholes and Ribbed PVC chambers 315mm diameter as standard size for Inspection Chamber. Option B will be considered as per practice in Maldives.
Manholes shall be provided at major junction, major changes in direction, intersections, high points and at all upstream terminal and depth of manhole shall be restricted to 1.5m.
For conventional sewer manhole spacing should not be more than 60 m c/c. The recommended spacing is 30 m as pipe diameter is less and about 160mm OD.
Ventilating Shaft
Ventilating shaft shall be provided by household vents as well as vents in the pumpingstation to expel the foul gas generated in sewer network. PE or uPVC vent shaft ofsuitable height shall be considered.
House connections
House connections to sewers comprise the pipe work from Household inspection Chamber to small bore sewer in the street. The recommended pipe diameter is 110mm.
The connection to the sewer main is by wye (Y) or Tee (T) joint.
The sewer from house toilet to Inspection Chamber will need to carry solids and must be designed with steeper slope between 1 in 50 and 1 in 100.
2.5.4.2 Pumping Stations
General Conditions
Pumping Stations are likely to be necessary in any sewerage system of reasonable size in Focus Island due to the flat terrain and the expense of deep excavation in soft soil with high ground water table. The pumping station will lift the flow from deep sewer to discharge to a manhole of a shallow sewer or to treatment facility through pumping main or force main.
Proponent: Ministry of Housing, Transport and Environment Page | 10 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The pumping station generally comprises a wet well, submersible sewage pumps (one duty and one stand by) and an adjacent Valve chamber/discharge chamber. The pumping station will be below ground level with an adjacent weather proof and vandal proof cabinet housing the pump controls.
Location Selection
Proper location of pumping station requires a comprehensive study of the area to be served to ensure entire tributary can be adequately drained with respect to future overall development of the area. . Site should be aesthetically satisfactory. . Site should not be flooded at any time. . Pumping station should be easily accessible under all weather conditions. . Availability of land with respect to further growth and future development. . Proximity to population . Minimum adverse impact considering wind direction . A bye-pass from pumping station to be easily connected to sea outfall.
The availability of land, scope of expansion, the type of equipment and their arrangement, structure, external appearance and general aesthetics are the basic consideration in design of pumping stations.
2.6 Environmental Components of the project
Similar to any other project, the proposed sewerage project has several elements that are interrelated to the environment. In order to identify the impact on the environment, these elements need to be defined, assessed and evaluated from an environmental perspective. The environmental elements of this project have been identified by breaking down the project in to the different processes that was incorporated into the design. The elements identified have various environmental benefits and negative consequences, details of which are outlined below.
2.6.1 S ewer network
Sewer lines networked throughout the island will collect wastewater from individual households and convey the wastewater to the pump stations through gravity. Inspection chambers will be strategically located at selected locations for inspection and maintenance purposes. Several size pipes may be used but the most common sizes are 4 inch diameter. This size pipes have been used in all other islands for gravity flow networks. There could be high concentrations of H2S in the wastewaters. Pipes and materials will therefore be selected to withstand the corrosive conditions that may arise in the different parts of the system
Proponent: Ministry of Housing, Transport and Environment Page | 11 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The sewer network consists of 4 inch house laterals and 6 inch secondary pipes on the narrow roads of Naifaru talking sewage and wastewater to lift stations in three specific locations. These lift stations convey the sewage to treatments works and pumping station, which pumps the clarified effluent to sea at the end of the outfall.
2.6.2 Treatment System
The selection of a particular process for sewage treatment is affected by diurnal and seasonal flow variations, sewerage strength (variability of wastewater constituents) infiltration / inflow, ambient temperature and its induced septicity, degree of treatment required, magnitude and direction of wind and ocean currents at outfall, etc. The treatment works proposed consist of preliminary treatment (screening and grit removal), secondary treatment by bio-remediation (oxygenations by means of Aerations followed by clarification-separation of effluent and sludge), effluent treatment (effluent subjected to disinfection by chlorination) and sludge treatment/removal (sludge dewatering /digestion/ disposal).
Figure 2-2 shows the sewage treatment system that would be adopted for Naifaru under this project. The Figure 2-2 shows the layout of treatment process proposed with the locations of treatment identified, the overall area would be limited to 30m x 20m in Naifaru. Sewage treatment process will be based on Diffused Aeration Activated Sludge process which can treat sewage for BOD 20mg/l and SS 30mg/l.
RAW SEWAGE (BOD= 220 mg/L)
BAR SCREEN
DISINFECTION EXTENDED AERATION SECONDARY SETTLING (OPTIONAL) GRIT CHAMBER ACTIVATED SLUDGE PROCESS SEA OUTFALL EFFLUENT
SLUDGE REMOVAL
Figure 2-2: Proposed Activated Sludge Treatment system for sewage for Naifaru
A basic extended aeration activated sludge process consists of several interrelated components: An aeration tank is where the biological reactions occur (see Figure 2-2). An aeration source provides oxygen. A tank, known as the clarifier, is where the solids settle and is separated from treated wastewater. Solids are collected either to return them to the aeration tank (return activated sludge), or to remove them from the process (waste activated sludge). Aerobic bacteria thrive as they travel through the aeration tank. They multiply rapidly with sufficient food and oxygen. By the time the waste reaches the end of the tank (between four to eight hours), the bacteria has
Proponent: Ministry of Housing, Transport and Environment Page | 12 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru used most of the organic matter to produce new cells. The organisms settle to the bottom of the clarifier tank, separating from the clearer water. This sludge is pumped back to the aeration tank where it is mixed with the incoming wastewater or removed from the system as excess, a process called wasting. The relatively clear liquid above the sludge (the supernatant) is sent on for further treatment as required.
The extended aeration process holds wastewater in an aeration tank for 18 hours or more and the organic wastes are removed under aerobic conditions. Air is supplied for aeration. This process operates at a high solids retention time, resulting in a condition where nitrification may occur. The microorganisms compete for the remaining food. This highly competitive situation results in a highly treated effluent with low solids production. The wastewater is screened to remove large suspended or floating solids before entering the aeration chamber, where it is mixed, and oxygen is added. The solids settle out and are returned to the aeration chamber to mix with incoming wastewater. The clarified wastewater flows to a collection channel before being diverted to the disinfection system.
Extended aeration does not produce as much waste sludge as other processes; however, wasting still is necessary to maintain proper control of the process. Significantly less sludge is produced compared to conventional systems. In Aeration tank (Extended aeration), suspended microbial growth is maintained for the biological oxidation of organics. Diffused aeration system is provided to meet the oxygen requirement of microorganisms and to keep the liquor in completely mixed regime. The process usually does not require any primary settling, and sewage after equalization directly goes to the aeration tank. However, in case of higher loadings, primary settling or grit chamber may be required. Elimination of primary settling reduces the initial cost, and also the sludge after extended aeration and secondary settling, is relatively more stabilized. Extended aeration produces the minimum amount of sludge and can handle widely varying hydraulic and biological flows. The sludge is periodically removed from the units.
For the above reasons, the activated sludge process is most suitably used where land is limited and expensive and can be treated without creating nuisance to neighbourhoods. The advantages of the system has been summarised in the concept design document as follows:
1. Land requirement is less (0.2 m2/capita) 2. Higher efficiency, better BOD, COD, SS removal (95-99%) 3. System is adaptable for shock load condition 4. No primary Treatment required 5. Nutrients removal is higher. 6. Better effluent quality about 15mg/l BOD 7. Depth of Aeration unit may be 1.5m 8. Capital cost is lower but power requirement is 20 KWH/capita/year.
Proponent: Ministry of Housing, Transport and Environment Page | 13 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.6.2.1 Design Parameters
The following table shows the different design parameters considered for the wastewater treatment system proposed for Naifaru.
Table 2-4: Design parameters for Naifaru wastewater treatment plant Description Design value Remarks 1 Population 4577 2022 2 Peak factor 3.0 3 Average Wastewater Flow 740 m3/d Wastewater Treatment Plant Capacity 4 Raw Sewage Parameters Wastewater =Sewage + Sullage BOD 350 mg/l COD 400 mg/l SS 300 mg/l Faecal Coliforms 105-107/100ml
5 Treated Sewage Parameters BOD 20mg/l SS 30mg/
Naifaru Wastewater Treatment Plant is designed to be completely a new unit based on Extended Aeration Activated Sludge Process (EAASP) to treat the domestic wastewater. The Plant will be installed in two phases namely Phase-I and Phase-II. The Phase-I will cater the sewage (wastewater) flow for the year 2022 with 15 years design period and Phase-I and Phase-II both will cater the wastewater flow for the period up to year 2037 (Population-7055) with provision of additional STP units to be constructed in future. In the design wastewater flow has been calculated as follows.
Phase-I: Total Average Flow (Year 2022-Population 5727): 741 m3/day
Total Peak Flow (Year 2022): 2223 m3/day
Phase-I and Phase-II: Total Average Flow (Year 2037-Population 7055): 913 m3/day
Total Peak Flow (Year 2037): 2738 m3/day
Phase-II: Total Average Flow: 172 m3/day
Total Peak Flow: 516 m3/day
2.6.3 Pump station
The pumping station is designed to dispose the wastewater beyond the reef to avoid disposing in the near shore environment or the reef. Installation of the pumping station will minimize the chance of backflow of saltwater in to the sewers and will not cause any additional adverse impact on the marine ecology. Pump station will also be designed and constructed so that foul odour will not become a nuisance for the surroundings.
Proponent: Ministry of Housing, Transport and Environment Page | 14 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.6.3.1 Treated Effluent Pumping Station
Treated Effluent Pumping Station is designed based on Treated Effluent:
. Average Flow 741 m3/day and Peak flow 2223 m3/day for Year 2022 . Average Flow 913 m3/day and Peak flow 2738 m3/day for Year 2037
For Electro Mechanical component flow is considered 93 m3/ hour
For Civil works Flow is considered 141m3/hour.
Pumps shall be 2 W + 1 S (Stand-By for 50 % Flow).
Treated Effluent Pumping Station Working Pump each capacity required 46.5 m3/hour.
Provided each Pump capacity (duty and stand-by) about 50 m3/hour.
Design of Treated Effluent Pumping System is enclosed.
2.6.3.2 Treated Sewage Sump
Detention time in sump shall be for 1 hour. One working and one stand by pump shall be considered and it will be pumped to sea outfall.
2.6.3.3 Sewage Pumping Main (SPM)
110mm mm dia uPVC pressure pipe shall be adequate for peak discharge of various sewage pumps as sewage pumping main. Design velocity estimated may be acceptable to avoid the high head of pump.
a. Size of Pumping Main/ Force main: 110mm OD HDPE pressure pipe
b. Maximum Length of Sewage Pumping Main: 950 Metre (approximately)
Length and Size of Sewage Pumping Main
From SPS-1 to STP: 950 m and diameter 110 mm OD HDPE pressure pipe.
From SPS-2 to STP: 700 m and diameter 110 mm OD HDPE pressure pipe.
From SPS-3 to STP: 120 m and diameter 110 mm OD HDPE pressure pipe
From SPS-4 to STP: 260 m and diameter 110 mm OD HDPE pressure pipe.
From SPS-5 to STP: 30 m and diameter 110 mm OD HDPE pressure pipe ( to be constructed in Future Phase).
Proponent: Ministry of Housing, Transport and Environment Page | 15 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.6.4 Marine outfall
Treated Sewage from Treated Effluent pumping station will be pumped to the deep sea through sea Outfall. The length of Sea outfall shall be about 630m. Other design parameters are given below.
Design discharge = Average flow (110 lpcd) X Peak Factor (3.0)
For ultimate design Population (Year 2037) 7055, Design Peak Flow = 2738 m3/day which includes other flows (12%) and infiltration quantity (5%).
160 mm OD HDPE is adequate for treated effluent discharge from Treated Effluent Sewage Pumping
Station to cater Peak flow 2738 m3/day (0.0316 m3/sec).
Velocity through Sea Outfall pipe shall be about 1.79 m/sec.
The construction method will be a float-tow-sink operation. The outfall will be anchored to sea bed and extending beyond the reef edge where maximum dilution will take place. A detailed, bathymetric survey has been completed determining water depths around the final outfall location. An outfall route has been selected along the full length of the outfall where bathymetry has been undertaken. However, the details of the outfall profile and layout have not been made available so far.
2.6.5 Sludge Treatment and Management
The sludge settled at the bottom of the solid separation chamber would be periodically pumped into drying beds. Once the sludge dries its volume is much reduced and it will then be disposed off in designated landfill areas or disposed to deep sea outside the atoll lagoon.
Design Parameter for Sludge Drying Bed
Minimum dry solids content after dewatering shall be 30%.
Maximum Thickness of Sludge depth in Drying Bed is 450mm. 300mm thick feed is recommended.
Handling capacity of drying bed shall be such that maximum 7 days continuous feed and the next feed shall be after 21 days from the last feed to enable the sludge to undergo effective drying during that period i.e. 4 weeks cycle on 300mm thick feed.
Proponent: Ministry of Housing, Transport and Environment Page | 16 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.7 Project Inputs and Outputs
The project has inputs in terms of human resources and natural resources such as water and fuel. The main output of the project is a comprehensive sewerage system that produces sludge and a final effluent of acceptable quality which may be disposed to land and could be used for gardening or crop cultivation. These inputs and outputs are summarised in Table 2-5 and Table 2-6.
Table 2-5: Main inputs of the proposed project Input resource(s) How to obtain resources Construction workers Contractor’s responsibility Operational Staff Utility company staff, who will be trained by contractor. Existing PMU staff may become Company staff once the company takes over Construction materials. PVC pipes, reinforcement steel bars, Import and purchase where locally available at competitive prices – sand, cement, aggregates, packaged treatment plants, etc. Contractor’s responsibility. Maintenance material Managed by Northern Utilities Company Water supply (during construction) Ground or rainwater Electricity/Energy (during construction) Diesel-based electricity from island mains Electricity/Energy (during operation) Diesel-based electricity from island mains
Table 2-6: Matrix of major outputs
Products and waste materials Anticipated quantities Method of disposal/treatment Treated effluent with BOD of 20-60 mg/l Estimated to be at peak of 110m3/day Treated wastewater reuse for gardening, road wetting, etc. Sludge Very small quantities (about 0.07m3/day) Dried and used as fertilizer or disposed to designated location or deep sea outside the atoll Constructional waste (demolition of existing Moderate quantities Reused and rest sent to landfill system) Smell Moderate levels at pumping Venting and appropriate location so that station/treatment works smell does not reach living environment
2.8 Construction methodology
2.8.1 Construction strategy
The sewerage project will be undertaken in the planned time period to reduce cost and minimize socio- environmental concerns. Both terrestrial and marine based construction activities will be done in parallel to complete the work in the least possible time frame.
2.8.2 Work methods for terrestrial based activities
The land based components of the project include the construction of the sewer network, pumping/lifting stations and treatment system. Excavation will be the main terrestrial based activity that would impact have social and environmental implications.
Small excavator and manual methods would be used to excavate trenches for laying pipes and also for backfilling. The engineers have defined the maximum depth of excavation for the pipe network to be 1.5m in
Proponent: Ministry of Housing, Transport and Environment Page | 17 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru order to minimize excavation as well as dewatering. It is important that the engineers maintain this given that Naifaru has narrow paths in many areas and advanced excavation methods would not usually be applied during construction.
Dewatering would be required for pipe connections in areas below the water table and for constructing the lift stations and pump stations. It is estimated that dewatering will be required only for pump station areas where the pipe may have to be laid at depths below the groundwater table. Dewatering would be done using smaller pumps to reduce the zone of influence and minimize saltwater intrusion into the groundwater aquifer. Alternative means such as hydro-fusion may be considered during pipe installation.
2.8.3 Works methods for marine based activities
The work related to the marine environment of the project is mainly in the component of the construction of the ocean outfall. The material for the ocean outfall will be high density polyethylene (HDPE) and the construction method will be a float-tow-sink operation. The outfall will be anchored to sea bed and extending beyond the reef edge. Divers will fix the anchor blocks and the pipe in position. Major coral formations will be avoided when the outfall pipe will be laid and fixed to the seabed.
2.9 Project duration
A summary schedule is given in the table below. The detailed design, EIA approval and tender documents is expected to take around 4 months. The tendering process will also take similar time but with one month overlap between the two activities. Construction, including handing over, is expected to be completed in ten to twelve months. Detailed schedule for the project could not be provided at this stage as the funding for the construction of the sewerage system remains to be sought or finalised by the Government.
2.10 Operation and Maintenance
Design, installation, operation and management of community water supply and sanitation projects in the Maldives have been considered a responsibility of the government so far. However, several projects that have been undertaken in the past have been managed by communities themselves. Naifaru is one such island, where the sewerage system was maintained by the community apart from major repairs, which are covered by the Government. However, even then, the responsibility of the sewerage system management (operation and maintenance) lies with the Island Office. Since these infrastructures are developed using national funds, it is important for the government to provide appropriate management mechanism to ensure sustainable service provision. Therefore, the government has been thinking of forming local level cooperatives for the management of utilities on islands other than Malé. Hence, the Government introduced Utilities companies this year, of which
Proponent: Ministry of Housing, Transport and Environment Page | 18 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Northern Utilities Limited (NUL) will take-over the operation and maintenance of water supply, sewerage and power utilities of Naifaru. Although the water supply and power management has been handed over to NUL recently, sewerage remains to be incorporated into the services provided by NUL for Naifaru. Therefore, NUL would possibly take over the sewerage system from the end of the design phase. Hence, it is important that the engineers consult NUL before finalising the design.
According to the Concept Design Report, the sanitation maintenance equipments shall be provided for sewer cleaning of small dia. Pipe (100mm to 200mm dia). Mobile sewer jetting equipment is required for sewer cleaning. The operation and Maintenance protocol (Institutional Arrangement) will be developed based on MEEW’s policies, as such MEEW has provision for providing technical as well as some managerial staffs for the project. After commissioning of the sewerage system, sewage pumping station and Wastewater Treatment Plant, the Contractor will do the operation and maintenance for at least one year which will be included in the contract package. However, with the new setup under Northern Utilities Limited, it is likely that the operation and maintenance would fall under the functions of NUL. It is likely that the final design as well as the construction would also become the responsibility of NUL.
2.11 Need and Justification
The primary justification to undertake this project is to mitigate the several environmental impacts of the existing sewerage system on Naifaru. There is an immediate need to address the health and environmental concerns associated with the existing system.
2.11.1 Why install a new sewerage system?
Appropriate sewage disposal or wastewater management has always been a high priority for the islands of the Maldives. Maldives being a premium tourist destination promoting sun, sand and sea as the main tourism products has much to offer in terms of pristine environmental quality. However, in Naifaru, the lagoon waters have been deteriorated to the extent that they are not even suitable for swimming. If people do swim, skin rashes and other health effects become prevalent especially in young children who are fond of the lagoon/near shore environment. Additionally, the increased nutrient levels in lagoons aid the growth of sea grass making marine waters aesthetically unpleasant. Therefore, the people of Naifaru deserve to improve their living environment for their own sake and for the sake of future generations who would inhabit Naifaru.
In addition, the existing sewerage system had several problems inherent in its design and workmanship, owing to which the Government had stopped funding for additional sewerage systems of the same design since 1998 and up to the tsunami of 2004 and increased political pressure for improved service and infrastructure. Hence, a new design was required to address the issues related to the existing sewerage system in Naifaru.
Proponent: Ministry of Housing, Transport and Environment Page | 19 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
2.11.2 Why Naifaru?
Naifaru was chosen for several reasons, as follows:
. Naifaru has a population of over 4000 people, one of the highest populated inhabited islands in the country. It is the fifth most populated island and was considered the third most densely populated island in the country before the reclamation. . Naifaru sewerage system has been in need for upgrade for a long time. . Efforts are underway to improve the living environment of Naifaru and getting rid of the 24 sewage outfalls would be of great importance and create favourable conditions for an improved coastline.
2.11.3 Why Proposed Design?
The proposed sewerage system with treatment has been chosen for the following reasons.
. Groundwater aquifer is the primary water resource for the people of the Maldives. Even in Malé, the capital, where the aquifer is highly contaminated and salty, most people depend on the groundwater aquifer to meet their non-potable water demands. Therefore, people of Naifaru should protect their aquifer from faecal contamination for longterm sustainability. The proposed system has no components disposing wastewater (treated or untreated) into the aquifer. . As mentioned earlier, white sandy beaches and clear azure blue lagoon are important natural assets for the islands of the Maldives, and the quality of the beaches and the lagoonal waters needs to be protected and preserved for the benefit of present and future generations. Therefore, the proposed system does not have multiple, nearshore outfalls. The existing system in Naifaru has 24 such outfalls and is considered a major environmental problem. . Septic tanks have not been considered for three reasons: (1) the initial cost of the system would be considerably high if septic tanks had been incorporated, (2) septic tanks pose the risk of groundwater contamination if they had not been properly constructed and maintained, and (3) the maintenance of household tanks being the responsibility of the households themselves it places an unnecessary burden on the consumer, especially small households. . Wastewater treatment is considered in order to minimize the impact on the marine environment, mainly due to policy consideration that treatment has to be considered.
Proponent: Ministry of Housing, Transport and Environment Page | 20 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
3 The Setting
The project takes place in the Maldives Environment. Therefore, the extent to which the project conforms to existing plans, policies, guidelines, regulations and laws of the Maldives needs to be considered. Hence, this section will look at the context in which the project activities take place and the legal and policy aspects relevant to those activities. It is important to note that the project is of a local and regional scale and also has some bearing at a national context.
3.1 Applicable Policies, Laws and Regulations
There are few environmental policies, regulations and standards of specific relevance to the project. These are considered in this section. The main legal instrument pertaining to environmental protection is the Environmental Protection and Preservation Act (Law No. 4/93) of the Maldives passed by the Citizen’s Majlis in April 1993. This Act provides the Ministry of Housing, Transport and Environment with wide statutory powers of environmental regulation and enforcement. This umbrella law covers issues such as environmental impact assessment, protected areas management and pollution prevention.
Water and Sanitation regulations, standards, guidelines and design criteria are of specific relevance to the proposed project in Naifaru. However, there are no regulations on water and wastewater in force except the National Desalination Regulation, which was passed by the Government in 2001. A set of regulations on water and sanitation was drafted by an international consultant in 1999. However, there was no further development of these draft regulations reflecting the lack of political will and commitment.
A set of guidelines on wastewater disposal in inhabited islands was later drafted in 2005 as a result of requests from international NGOs and aid agencies that provided assistance in rebuilding entire sewerage networks in islands affected by the tsunami of December 2004. These guidelines are now adopted as the guiding document pertaining to wastewater disposal and management in the islands. The important elements of these guidelines are considered in this chapter after providing an overview of current environmental regulatory framework in the Maldives.
3.1.1 Environmental Protection and Preservation Act
The main legal instrument pertaining to environmental protection and preservation for sustainable development in the Maldives is the Environmental Protection and Preservation Act (Law No. 4/93) passed by the Citizen’s Majlis in April 1993. The following clauses of the Environmental Protection and Preservation Act (Law No. 4/93) are relevant to the project:
Proponent: Ministry of Housing, Transport and Environment Page | 21 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Clause 5a: An impact assessment study shall be submitted to the Ministry of Housing, Transport and Environment before implementing any development project that may have a potentially detrimental impact on the environment.
Clause 5b: The Ministry of Housing, Transport and Environment shall formulate the guidelines for EIA and shall determine the projects that need such assessment as mentioned in paragraph (a) of this clause.
Clause 6: The Ministry of Housing, Transport and Environment has the authority to terminate any project that has an undesirable impact on the environment. A project so terminated shall not receive any compensation.
Clause 9a: The penalty for minor offences in breach of this law or any regulations made under this law, shall be a fine ranging between Rf5.00 (five Rufiyaa) and Rf500.00 (five hundred Rufiyaa), depending on the actual gravity of the offence. The fine shall be levied by the Ministry of Housing, Transport and Environment or by any other government authority designated by that Ministry.
Clause 9b: Except for those offences that are stated in (a) of this clause, all major offences under this law shall carry a fine of not more than Rf100,000,000.00 (one hundred million Rufiyaa), depending on the seriousness of the offence. The fine shall be levied by the Ministry of Housing, Transport and Environment.
Clause 10: The government of the Maldives reserves the right to claim compensation for all damages that are caused by activities that are detrimental to the environment. This includes all activities mentioned in Clause No. 7 of this law as well as those activities that take place outside the projects that are identified here as environmentally damaging.
Clause 5 is of specific relevance to this EIA. The EIA Regulations, which came into force in May 2007 has been developed by the powers vested by the above umbrella law. This EIA and, therefore, the project adheres to the Environment al Protection and Preservation Act.
3.1.2 Second National Environment Action Plan (1999)
The aim of NEAP II is to protect and preserve the environment of the Maldives and to sustainably manage its resources for the collective benefit and enjoyment of present and future generations.
Main strategies of the NEAP II are:
Proponent: Ministry of Housing, Transport and Environment Page | 22 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
. Continuous assessment of the state of the environment in the Maldives, including impacts of human activities on land, atmosphere, freshwater, lagoons, reefs and the ocean; and the effects of these activities on human well-being . Development and implementation of management methods suitable for the natural and social environment of the Maldives, and maintain or enhance environmental quality and protect human health, while at the same time using resources on a sustainable basis . Consultation and collaboration with all relevant sectors of society to ensure stakeholder participation in the decision making process . Preparation and implementation of comprehensive national environmental legislation in order to provide for responsible and effective management of the environment . Adhering to international and regional environmental conventions and agreements and implementation of commitments embodied in such conventions. . NEAP II specifies priority actions in the following areas. . Climate change and sea level rise; coastal zone management; . biological diversity conservation; integrated reef resources management; . integrated water resources management; . management of solid waste and sewerage; . Pollution control and management of hazardous waste; . sustainable tourism development; . land resources management and sustainable agriculture . human settlement and urbanisation
NEAP II contains environmental policies and guidelines that should be adhered to in the implementation of the proposed project activities, especially impact assessment, stakeholder consultation, biodiversity conservation and human settlement and urbanisation. These policies and guidelines are taken into consideration during the planning, design and implementation of the proposed project.
3.1.3 National Biodiversity Strategy and Action Plan
The goals of the National Biodiversity Strategy and Action Plan are:
. Conserve biological diversity and sustainably utilize biological resources. . Build capacity for biodiversity conservation through a strong governance framework, and improved knowledge and understanding. . Foster community participation, ownership and support for biodiversity conservation.
In implementing the proposed project activities due care has to be taken to ensure that the national biodiversity strategies are adhered to. In fact, surveys were undertaken at the design stage to find out if biological resources of value and protected nature are affected by the proposed project.
Proponent: Ministry of Housing, Transport and Environment Page | 23 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
3.1.4 Consultation and public participation laws
In the Maldives public participation has been limited to the review stages of the EIS until recently with the EIA Regulation, which considers public consultation as an important and integral part of the EIA process. Hence, this EIA has also taken public views into consideration. In fact, public consultation was conducted in order to take public opinion, views, suggestions and expectations into consideration in the design of the project and not simply to fulfil the obligations under the EIA Regulation. A chapter on public consultation is dedicated to discuss the findings of public consultations held.
3.1.5 Population Policy
The objective of the Population Policy of Maldives is to contribute to improve standard of living and quality of life of the Maldivian people through socio-economic development with a sustainable balance between population and development. One important aspect of the Population Policy is the strategy of population and development consolidation, which focuses on organising human settlements in such a way that sustainable development is fostered and economies of scale are met. The proposed project in Naifaru is expected to facilitate the strategy of population and development consolidation.
3.1.6 Regulation on Cutting Trees
The Regulation on cutting down, uprooting, digging out and export of trees and palms from one island to another was issued by the Ministry of Environment, Energy and Water in 2006. Clause 5 (a) of the regulations states that Prior to the commencement of any project(s) that would require the indiscriminate removal and export of trees/palms from one island to another for the purpose of agriculture, development/redevelopment, construction or any other purpose, it is mandatory under the Regulation to prepare and Environmental Impact Assessment Report stating clearly the details of the Project(s) with all necessary information and submit the same through the relevant Ministry to Ministry of Environment Energy and Water, and the project(s) can only commence upon the grant of written approval from the Ministry of Environment, Energy and Water (now the Ministry of Housing, Transport and Environment).
Article 8 (a) requires permission be obtained from Ministry of Housing, Transport and Environment, if more than 10 coconut palms that are of a six of 15 ft (from base of the palm to the tip of the palm frond) are cut, uprooted or relocated to another island. The regulation also ensures the replacement of the vegetation that is lost by imposing the planting of two palms for every palm tree that is cut or uprooted (Article 2 (d)). Logging on inhabited islands must be done under supervision of the islands chief or an official appointed by the island chief (Article 8 (c)).
The proposed sewerage project does involve clearing land since the proposed treatment plant and pumping station would be located in reclaimed land. However, it is worthwhile mentioning here that trees are expected to
Proponent: Ministry of Housing, Transport and Environment Page | 24 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru be planted in the treatment plant building and in pumping station areas as part of the landscaping efforts during the construction and, especially the operational stage.
3.2 Relevant International Environmental Legislation
Maldives is party to several international conventions, treaties and protocols on environmental protection and preservation as well as sustainable development. These include:
. United Nations Convention on Climate Change (UNFCCC) and the Kyoto Protocol which aims at minimising greenhouse gases to reduce or combat potential impacts of global climate change, global warming and associated effects such as sea level rise, which are thought to have devastating impacts on the Maldives, a fragile small island nation. The aspects of the proposed project that apply to this convention are the importation and transport of raw material to site using diesel based vessels, use of excavators and other machinery in the construction phase, especially their emissions as well as the use of pumps which consume electricity from diesel generators emitting greenhouse gases. These are unavoidable impacts; however, efforts should be made to minimize all such impacts. These are discussed in the impacts mitigation section. . United Nations Convention on Biological Diversity (UNCBD) with the objective of “the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources, including by appropriate access to genetic resources and by appropriate transfer of relevant technologies, taking into account all rights over those resources and to technologies, and by appropriate funding”. Maldives was one of the first nations to ratify UNCBD. Maldives has developed the National Biodiversity Strategy and Action Plan (NBSAP) in 2002. Formulation of NBSAP was through wide consultation and extensive stakeholder participation. As mentioned earlier, there has been extensive consultation and environmental surveys undertaken to ensure that biological diversity is not affected due to the implementation of this project.
3.3 Environmental Permits required for the Project
3.3.1 EIA Decision Note
The most important environmental permit to initiate construction work in Naifaru would be a decision regarding this EIA from the Ministry of Housing, Transport and Environment. The EIA Decision Statement, as it is referred to, shall govern the manner in which the project activities must be undertaken. This EIA report assists decision makers in understanding the existing environment and potential impacts of the project. Therefore, the Decision Statement may only be given to the Proponent after a review of this document following which the Ministry may request for further information or provide a decision if further information is not required. In some cases, where there are no major environmental impacts associated with the project, the Ministry may provide the Decision Note while at the same time requesting for further information.
Proponent: Ministry of Housing, Transport and Environment Page | 25 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
3.3.2 Wastewater disposal permits
Wastewater disposal permit is required according to the General Guidelines for Domestic Wastewater Disposal issued in 2006. According to these Guidelines, once the design together with the EIA Decision Statement has been issued to the Maldives Water and Sanitation Authority (MWSA), it will check if the applicant fulfils the requirements of the Guidelines and provide a commencement of works permit. This is perhaps the only guideline in the Maldives which has legally binding statements written into it. These Guidelines are discussed in more detail in the following sections.
3.4 Water and Wastewater Regulations, Policies, Standards and Guidelines
In the past decade or so, as regulator of water and wastewater, Maldives Water and Sanitation Authority (MWSA) has mainly focused on regulating the service provider, Malé Water and Sewerage Company, MWSC and environmental controls have not been given adequate emphasis. With the functions MWSA incorporated into the functions of Environment Protection Agency formed in early 2009, it is believed that much will be done in improving the regulatory framework for water and sewage disposal.
Although several attempts have been made to introduce regulations and standards, they are still at a draft stage. Consequently, upon increasing requests from donors under the tsunami relief assistance programmes, the Maldives Water and Sanitation Authority drafted the General Guidelines for Domestic Wastewater Disposal in the Maldives.
The Maldives adheres to WHO guidelines for its drinking water standards. However, due to the small size of the islands and the time water remains within the waterworks, free chlorine levels have been set below WHO guideline values. This adjustment has been mainly due to public complaints of chlorine levels in their drinking water but has not been technically justified.
Currently, there are no surface water quality standards for the Maldives, but this issue has been addressed in the “Guidelines for Domestic Wastewater Disposal” in the Maldives. The pristine nature of the Maldivian waters requires high standards to be met. Given the existing concerns of raw sewage disposal and wastewater disposal within the coastal zone, there should be surface water quality standards that ensure that the pristine state of the coastal waters of the country as a whole is not affected. There are also standards set by the Ministry of Tourism and Civil Aviation for the tourist resorts. These are derived from stringent international standards.
Effluent quality standards are also non-existent in the Maldives. Therefore, for reference, the standards given in Table 3-1 may be used. These effluent quality standards are based on standards of some developed countries and, especially WHO standards.
Proponent: Ministry of Housing, Transport and Environment Page | 26 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 3-1: Recommended effluent quality standards Parameter Description Standard Temperature An important determinant because of its effects on chemical reaction, reaction <40 o C rates, aquatic life and suitability for beneficial uses pH Hydrogen ion concentration is an important quality parameter of both natural 5-9 water and wastewater. Concentration range suitable for the existence of most biological life is quite narrow and critical
BOD5 Most widely used parameter of organic pollution applied to both wastewater 20-60 mg/l
and surface water is the 5-day biochemical oxygen demand (BOD5). Treated effluents should usually meet this criterion. COD Chemical oxygen demand (COD) test is used to measure the contents of 120 mg/l organic matter of both wastewater and industrial water. This test is also used to measure organic matter in wastewater that contains compounds that are toxic to biological life. COD of wastewater is in general higher than BOD, because more compounds can be chemically oxidized than can be biologically oxidized. Total Suspended Solid This is also one of the most important contaminants of concern in wastewater 150 mg/l (TSS) treatment. Suspended solids can lead to the development of sludge deposits and anaerobic conditions when untreated wastewater is discharged in the environment.
3.4.1 Water and Sanitation Policy Statement
The policy statement for water and sanitation was made public on Environment Ministry’s website in 2008. The document was finalised in April 2006. Although the policy document states that “dissemination of information regarding the policy will be given a very high priority”, to this day, there has been little information dissemination with regard to the policy document. However, the present Government has shown keen interest in improving the water supply and sanitation infrastructure in the country.
Seventeen key policy principles have been outlined in the policy document. These include political commitment, supportive legal framework, integrated approaches, private sector participation, environmental protection, participatory planning and management, community empowerment and ownership, incremental development, equitable service provision, and information dissemination. The document also considers sector objectives and targets which include:
. Universal access to safe water supply and adequate sanitation . Remove disparities in service provision . Reduce maternal and child morbidity and mortality through improved access to safe water and sanitation . Protect the country’s vital freshwater resources . Strengthen legal framework to improve sector performance . Develop institutional capacity to meet growing needs and challenges . Ensure there are adequate water and sanitation services to support economic growth centres . Regulate and monitor the disposal of industrial wastes from industrial and economic centres
Different strategies to meet the objectives and targets as well as institutional responsibilities in the implementation of the water and sanitation policy are also addressed in this document. One important aspect of
Proponent: Ministry of Housing, Transport and Environment Page | 27 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru the policy statement that is of specific relevance to the project in Naifaru or similar projects is the twelfth principle on encouraging community ownership. It states that,
“The communities served by these schemes must take ownership of the water supply and sanitation schemes and they must take responsibility for the operation and maintenance of the systems. The MEEW will continue to provide a supporting role where needed but only for as long as it is needed. MEEW will encourage all communities to shoulder their responsibility to support their community water sanitation facilities by paying an appropriate tariff approved by Maldives Water and Sanitation Authority (MWSA) in consultation with the local community. The tariff will at least cover the cost of operation and local maintenance of the schemes”.
A critical analysis of the policy statement would reveal that the policies are dramatised rather than real and measurable, period-specific objectives and targets are not clearly stated. As a result, the policy document on water and sanitation lacks support even within the sector itself. It is apparent from the recent introduction of utilities companies for the management of water and sewerage services that the new Government understands the issues and it appears to be an important step towards addressing those. However, it is worth mentioning that there still is information and planning gaps that remain to be addressed as soon as possible.
3.4.2 General guidelines for domestic wastewater disposal
“General Guidelines for Domestic Wastewater Disposal 2006” was a result of a series of questions raised by donors following the tsunami of December 2004 due to the absence of any regulations or guidelines to follow in the design of sewerage systems. Although the Guidelines were the first public document demanding the application for a permit and subsequent approval before installation of a sewerage system in the Maldives, the guidelines lack legal backing. The guidelines require all wastewater management systems to meet prescribed criteria for the use of groundwater, design for easy access for maintenance and durability and undertake monitoring and provide facilities for sampling final effluent. Monitoring requirements have been set for monthly monitoring and annual monitoring of groundwater quality.
It is evident from the guidelines that the guidelines have been set for domestic wastewater since it is stated that industrial effluents require special permits from the Authority. Also, the guidelines have been set specifically for wastewater disposal into the groundwater aquifer as receiving water quality objectives have been set only for groundwater and analysis schedule is also for groundwater. The guidelines also focus mainly on on-site wastewater disposal systems, with specific reference to septic tanks. However, it is stated that:
“Where a sea outfall is used it should be placed away from areas such as commercial harbours or areas designated for recreational purposes. The sea outfall must be placed in such a way that the effluent will be flushed out into the deep sea, where it can be diluted and dispersed so that the impact on the marine environment is reduced. Untreated wastewater shall not be disposed into the near shore lagoon.”
The Guidelines also provides for Environmental Impact Assessment for sewerage project and states that:
Proponent: Ministry of Housing, Transport and Environment Page | 28 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
“All sewerage projects have to undertake the Environmental Impact Assessment (EIA) as required by Ministry of Environment, Energy and Water (now Ministry of Housing, Transport and Environment) and then submit the EIA Decision Note to the Authority. The EIA must in particular assess the impact of the proposed project upon the island’s water resources and receiving waters, including an assessment of the groundwater sustainable yield, quality and anticipated impacts/changes resulting from the project.”
The Guidelines are a good starting point but needs to be reviewed in view of existing concerns, especially with regard to legitimacy and authority.
3.4.3 Design Criteria for Sewerage Systems
In early 2007, MWSA prepared design criteria for sewerage systems. These include design standards, testing requirements, submittals and drawing standards, impact analysis procedures and service fee requirements. Some important considerations are that:
. All buildings shall be connected to sewer lines . Storm water drainage can be deviated to sewers with special permission . Sewerage system design shall allow for sewage resulting from future landuse and new reclamation . Sewerage systems shall be designed with a single outfall. If multiple outfalls are required, pumping stations shall be provided . All systems shall have a bypass sea outfall . An operation and maintenance manual shall be furnished for all sewerage projects
These design criteria established by the Maldives Water and Sanitation Authority has been taken into consideration in finalizing the design for the proposed sewerage system in Naifaru. Since its implementation, the Design Criteria has been used by engineers in designing sewerage systems for the islands of the Maldives. However, as for the water and sanitation policy statement, there is a need to increase awareness about the Design Criteria and further discussion with engineers and other technical personnel working in the sector to address current concerns is important. It is believed that the Design Criteria has been subject to some criticism especially with regard to specific references to water consumption and pipe diameters. Such issues are being given further consideration by the Water Section of the Environment Protection Agency.
3.5 Roles and Responsibilities of Groups involved
There are various organizations and parties involved in the EIA process. There are national agencies responsible for environmental protection as well as the key stakeholders and the project proponent, each with a role and responsibility within the EIA process. One key principle in EIA implementation is to involve these groups and provide them the opportunity to participate in the EIA process so that their concerns are addressed. This section discusses the roles and responsibilities of national groups involved in the EIA system, with specific focus on the
Proponent: Ministry of Housing, Transport and Environment Page | 29 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru proposed project. Table 3-2 provides a summary of the roles and responsibilities of each group in the different stages of the EIA process.
Table 3-2: Roles and responsibilities by EIA process stage Stage Environment Proponent EIA Consultants Other Govt Agencies Public and Interest Ministry (EPA) Groups Screening Screen Project Provide necessary Provide technical Raise issues and information advice concerns Scoping Approve TOR Provide TOR Prepare TOR Provide comments/ Participate in Review IEE Provide IEE Prepare IEE feedback consultation EIA study Provide scope/ Provide EIA Prepare EIA Participate Approve TOR Comment Review Review EIA Revise EIA Assist in review Comment Approval Approve EIA Attach Provide technical Approve relevant terms advice components Environmental Implement Conduct monitoring Implement Management mitigation Monitoring measures and monitoring programme Post Audit and Evaluate project Provide necessary Assist in the audit Provide info to Evaluation information auditors
Source: Adapted from Lohani et al (1997)
3.5.1 Environment Ministry
The Ministry of Housing, Transport and Environment plays the main role within the Government for implementing EIA and other environmental matters. It has central control over environmental protection and related issues. Water has specific focus and a Section within the Ministry has been established for water and sanitation. This section has two wings: a planning wing and an implementation wing.
The Environment Protection Agency (EPA) under the Ministry has responsibility for efficient operation of the EIA process. This encompasses a number of tasks, including screening of projects and provision of general procedural advice to the project proponents throughout the EIA process. EPA manages the review of the EIA report and is responsible for any approvals or recommendations associated with the EIA. EPA has a commendable role in the EIA administration process and its capacity to undertake audits and enforce environmental monitoring during construction and post-construction stage has been improved in the past few months since its establishment.
With the incorporation of the functions of the Maldives Water and Sanitation Authority (MWSA) into the functions of EPA, there is a Water Section within the EPA dealing with water and wastewater. Its regulatory functions and capacity are still at an infant stage. For the EPA to take independent regulatory decisions, it may be necessary for the EPA to become an independent body within the Government.
Proponent: Ministry of Housing, Transport and Environment Page | 30 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Under the proposed project, EPA will be the Authority determining the appropriateness of the proposed design based on certain principles as per the Design Criteria and the General Guidelines for Domestic Wastewater Disposal. The EPA also finalises the scope of the EIA and evaluates this EIA proposed for the project. Based on the design and EIA review, EPA would finally issue a permit to install the proposed sewerage system based on the EIA Decision Statement and review of final design, which would be undertaken at the same time. During the scoping meeting, EPA’s concerns about the proposed design and shortcomings of the Design Criteria in evaluating the proposed design were discussed between the Engineers from the Consultant as well as the EPA.
3.5.2 Project Proponent
The project proponent is the party responsible for the effective implementation of the project. The proponent for the proposed project is Ministry of Housing, Transport and Environment (MHTE). MHTE is also the executing authority for the EIA process in the Maldives. Therefore, as has been described earlier, the Proponent is directly involved in the finalisation of the Terms of Reference and environmental clearance for the proposed project. These create issues that demand the EPA to be an independent body.
The Proponent, being the Implementing Agency, hired the services of Technical and Environmental Consultants in order to commission a study to design the system and undertake the Environmental Impact Assessment. The proponent provided access to information about the project activities and the environmental setting of those activities. The proponent would be responsible for the implementation of mitigation measures and shall implement the proposed monitoring measures if it was required to conduct environmental monitoring based on the review of the EIA.
3.5.3 Environmental Consultants
As the EIA forms an integral part of the feasibility study and design of the proposed sewerage system, the EIA component needs to be integrated into the sewerage system study, which would help in the design of the project in a sustainable manner. The Environmental Consultant was assigned soon after the concept design for the purpose of the EIA report. Therefore, environmental input in to the design and social consultations was lacking. However, there has been good communication between the EIA consultants and the design engineers during the EIA stage. Consequently, some important aspects of the EIA including public consultation and dialogue between the designers and EIA consultants is expected to be taken into consideration in finalising the design.
3.5.4 The Public
Public consultation has been conducted in order to take public opinion, views, suggestions and expectations into consideration in the design of the project and not simply to fulfil the obligations under the EIA Regulation. Since
Proponent: Ministry of Housing, Transport and Environment Page | 31 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru public consultation is an important element of Environmental Impact Assessment, this EIA has considered public consultation held during project planning as the project components directly influence public interests or necessitate public participation and involvement. No public consultations were undertaken during the EIA stage in order to avoid public dismay as the project had been in planning and design for a long time and project implementation funds are not available at this stage. Nevertheless, this EIA would be subjected to public review for a ten day period stated in the EIA Regulations 2007 during which time public comments would be welcomed and taken into consideration by the EPA before making a final environmental decision regarding the project.
3.6 Addressing Shortcomings
As has been indicated earlier, there are several shortcomings in the water and sanitation sector, which needs to be addressed soon. The new MDP-led Government of the Maldives is trying to address the shortcomings of this very important sector by formulating policies and strategies which are discussed in the recently published Strategic Action Plan, “Aneh Dhivehiraajje”. In this strategic plan, water and sanitation is recognized as a basic human right and universal access without prejudice is the key target and strategy. The goals of the sector highlighted in the Action Plan includes protection and preservation of freshwater resources, private sector involvement for service provision regulated by the Government, renewable energy use for water supply and sanitation and groundwater protection. Some of the important policies outlined in the Action Plan include improving accessibility, prioritize water and sanitation in development planning and implementation, establish effective maintenance procedures, facilitate private sector investment, strengthening legal and institutional framework, water resource management for environmental preservation and water safety for enhanced public health.
In terms of strengthening the legal framework, the Strategic Action Plan refers to the existence of a draft National Water Act, and stresses the need for a separate Sanitation Act. While there is ample research and strategic planning throughout the world to integrate water and sanitation, it is questionable why the Maldives is opting to two different pieces of legislation for Water and Sanitation. The Action Plan also identified that there would be a legal framework for the establishment and management of provincial utilities companies, which have been formed recently with the objective of managing water supply, sewerage and electricity services in the islands.
In addition to the Act(s) or legislative aspects, some of the important strategies that have been highlighted include (1) seeking the most appropriate sewerage systems for the Maldives, (2) establishing mechanism for wastewater research in the country, (3) seeking immediate measures to stop groundwater pollution, (4) integrating water resource planning into landuse planning, (5) establishing effective water resource monitoring programmes, (6) preparing an inventory of natural catchments and (7) developing water safety plans and water quality monitoring capacity at island level.
Proponent: Ministry of Housing, Transport and Environment Page | 32 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
4 Methodology
The section covers methodologies used to collect data related to the existing environment. The key environmental and socio-economic components of the project that were considered are physical environment, social and economic environment and the marine environment.
Hence, data collection was undertaken for the above components. In order to study the existing environment of the island, the following data collection methodologies were used during the field visit to Naifaru during 15 to 17 October 2009.
4.1 General Methodologies of data collection
Existing environmental condition of the island with respect to existing sanitation facilities, daily and seasonal variation of peak and average sewage flows, population, population growth rate, number of houses, road network, land use, terrain, depth to water table, tidal variations etc. was collected from surveys undertaken specifically for the design of the sewerage system.
Field surveys were undertaken to get further understanding of the existing environment of the island. Field surveys were carried out during field visit to the island in October 2009 to collect baseline data. Before the trip was undertaken all existing information regarding the site was gathered including possible treatment processes, location of outfalls and concept design. InterContinental Consultants and Technocrats (India) in association with UBI Development Technologies (Maldives) provided project details.
The following components of the existing environment of Naifaru were assessed.
. Socio-economic aspects . Groundwater quality . Terrestrial flora, fauna, topography and soil . Coastal environment including the status of coastline and the lagoon . Drogue studies at proposed and possible outfall locations
4.1.1 Mapping and Location identification
Mapping of island boundaries and household had been undertaken by Water Solutions Pvt. Ltd. during the design phase. Bathymetry of the outfall area was also included in this mapping. Therefore, mapping during the environmental surveys undertaken in the field trip from 15 to 17 October concentrated on the existing outfalls, proposed pumping station locations, water sampling locations, drogue spaghettis and the reef survey locations. This mapping was undertaken using hand held differential GPS. These are shown in Figure 5-6.
Proponent: Ministry of Housing, Transport and Environment Page | 33 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
4.1.2 Quality of groundwater
Extensive groundwater quality data has been gathered during the planning and design phase by hydrogeologist assigned for the project. The data provided in the hydro-geological report have been used in this report. However, it has been recommended as part of the monitoring to undertake groundwater quality monitoring immediately before construction stage of the proposed sewerage project in Naifaru. This will provide a more appropriate baseline for construction phase and post-project monitoring.
4.1.3 Quality of surface water
Quality of the surface water around the island was determined by taking samples for testing for pH, electrical conductivity, BOD, COD and nitrates. Sampling was done at the two proposed outfall locations and an additional location identified as an alternative. Further tests may have to be undertaken prior to construction in order to establish additional baseline values for the outfall locations.
4.1.4 Bathymetry and Ocean Currents
Bathymetry around Naifaru was provided by the Proponent together with the basemap used for concept design. Ocean currents at the location of the proposed outfall and other possible outfall locations were studied by doing drogues at these locations on the day of the field surveys. The results have been used to interpolate general current patterns and subsequent effluent dispersion and dilution potential.
4.1.5 Condition of the housereef
The overall health of the reef at three locations including the two proposed outfall locations and an additional location was studied. General observations were recorded on slate by swimming along the length of the proposed pipe and other possible pipe locations and photographs were taken to represent site conditions. This was considered adequate as there was minimal live coral cover and the reef areas were mainly dead and silted from previous reclamation and poor environmental management in the past. The locations the reef surveys are shown in Figure 5-6.
4.1.6 Socio- economic condition and public consultation
The report of the sociologist assigned for the project has been used to gather information relating to socio- economic condition and public consultations. In addition to consultations with Island Chiefs and Island Development Committees, a structured questionnaire-based survey was undertaken by the sociologist.
In addition to the sociologists work, extensive discussions (key informant interviews) were held with some members of the Island Development Committee and PIU staff as well as the Atoll Councillor residing in Naifaru in
Proponent: Ministry of Housing, Transport and Environment Page | 34 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru order to gather their views about the project and overall development. Discussions were focussed on the sewerage system development and operation and maintenance issues. Further stakeholder consultations were held with the Proponent (Ministry’s Project Implementation Unit) and the future operator of the sewerage system, Northern Utilities Limited.
Socio-economic data is mainly based on secondary sources of data, including island office records. Socio- economic data relating to the population, literacy rate, housing, economic activities, educational status, health services, electricity and other infrastructure existing in the island were collected from secondary sources.
In addition to socio-economic survey information and key information interviews and discussions with Proponent, personal observations of the socio-economic conditions were made to harmonize the information collected from other sources.
Proponent: Ministry of Housing, Transport and Environment Page | 35 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5 Existing Environment
This section covers the existing environmental conditions of Naifaru, especially those areas which may be impacted by the proposed works. The key environmental, social and economic components of the project under consideration are described below.
Vital Environmental, Social and Economic Components
. Soil and topography . Vegetation . Groundwater aquifer – quality and quantity . Coastal environment and oceanographic and hydrodynamic conditions . Marine water quality . Coral reef at impacted areas . Human health and well being . Socio-economic status . Environmental infrastructure and their current status . Land use – availability and constraints . Capacity to pay and operation and maintenance cost considerations
5.1 Terrestrial Environment
5.1.1 Soil and Topography
The geology of Naifaru is largely sandy soil. The soil is a mixture of coral dust which has been transformed in to sand that is highly alkaline with pH varying from 8.0 to 8.8 at the top with calcium carbonate formations beneath the sand. About a meter of sand layer shall be expected. Visual inspection and assessment on site revealed that the composition and texture of the soil varies between those found in the island and the beach. Along the coastline, the soil is white and very fine resulting from the wave action whereas the soil is darker in colour inland. The soil in the reclaimed area is of the same nature, however, more compact from the reclamation. Typical estimate of sand porosity in the islands of Maldives is 30% (Falkland 2001, Carpenter 2006). Soil in the original island is fairly uniform making it highly permeable and subsequently easily susceptible to pollution. However, the porosity and permeability of the reclaimed area would be less due to compaction with different sizes of material from dredging.
The topography of Naifaru varies slightly. The topographic surveys determined that ground level is generally level varying from 0.7 m to 1.3 m with average elevation of around 1 m from MSL. There is one small area on the southwest centre of the original island with 1.4m elevation. The reclaimed area is higher than the original island
Proponent: Ministry of Housing, Transport and Environment Page | 36 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru on average. Levels were taken around Naifaru in order to design the sewer lines and to estimate the amount of material to be excavated for laying sewer pipes, etc. Detailed drawings in the Appendix give levels of roads and coastal areas in Naifaru.
5.1.2 Vegetation
Vegetation survey of the island was not made as the island’s vegetation cover is low and no vegetation clearance will be required for the project. The island has some mature trees, which are generally found inside house plots or in few public areas where bare land is available (see photo below). The rest of the existing island has been reclaimed and no mature vegetation can be found in these areas. No components of the proposed project affect the vegetation of the island. The proposed location of the sewage treatment plant is also on reclaimed land with a less developed soil column.
Plate 5-1: A view of the most vegetated area of the island
5.1.3 Groundwater
Generally, the islands of the Maldives have superficial groundwater lenses below about a metre of coralline sandy soil with a very narrow humus layer on top. The groundwater lenses so formed are formed due to density differences between percolated rainwater and saltwater beneath the island. The freshwater lens floats on top of the saltwater. This makes it extremely fragile and prone to saltwater intrusion due to over-abstraction.
The depth of the freshwater lens or aquifer depends on the height of the groundwater lens above mean sea level on small islands. The typical ratio between the height of the water lens above mean sea level compared to the depth of freshwater below mean sea level is of the order of 1:20. Groundwater levels above mean sea level on small islands may be 0.10 to 0.50m above sea level, resulting in a freshwater lens depth of 2-10m thick. Measuring absolute water level elevations is difficult in small flat islands, so the investigation techniques used target the thickness of the freshwater lens and its aereal extent. The water lens in small islands is illustrated in Figure 5-1.
Proponent: Ministry of Housing, Transport and Environment Page | 37 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Evapotranspiration Rainfall
2-3m Water table Mean sea level
Lagoon Ocean
Freshwater zone
Seawater 10-20m Unconsolidated Holocene sediments (low permeability) e on n z itio ns Tra
Pleinocene limestone (high permeability) 300-1000m
Figure 5-1: Conceptual Illustration (not to scale) of freshwater lens in a small coral island (after Falkland).
The above is typical of most of the islands. Borehole test carried out in Malé (MWSC site) indicates an upper zone with loosely packed sandy soil increasing in permeability until a very permeable zone is reached at about 20m below the surface. The freshwater lens is generally formed up to a depth of about 10m and a brakish transition zone occurs below this depth up to about 20m, below which it is saltwater. The water table in Naifaru is expected to vary between 0.5m to 1.1m from the ground surface. The water table would also fluctuate with tide. It has also been established that there there is no hydraulic connection between the upper zone and the lower zone and lower zone is hydraulically connected to the sea. Further, the upper zone is observed to be not affected by tides. Falkland (2001) also observed that there existed a liner relationship between the size of the island and the size of the aquifer. 3).It was observed that as island width gets narrower, the salinity of wells becomes greater and vice versa. At a width of less than 250m, the groundwater salinity is likely to be brackish at the surface.
Groundwater investigations in Naifaru were done as baseline for the proposed sewerage system at or close to the proposed sewage pumping stations. These are given in the table below.
Table 5-1: Results of groundwater samples taken from proposed pumping station locations Location SPS1 SPS2 SPS3 SPS4 SPS5 Name of house Dhanbu White Rose Aabin
Date sampled 19/10/09 19/10/09 19/10/09 19/10/09 19/10/09 Sample ID 201009wc230 201009wc230 201009wc230 201009wc230 201009wc230 Clear with clear with clear with clear with Physical Apperance clear suspended solid Suspended solid Suspended solid Suspended solid pH 8.5 8.7 7.5 7.7 9.5 E-Conductivity (µS/cm) 2320 1467 340 561 939 Nitrate (mg/l) 3.09 4.86 5.31 3.98 4.42
Proponent: Ministry of Housing, Transport and Environment Page | 38 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The above results are similar to groundwater tests carried out in mid July 2007 by the Hydrogeologist. However, the conductivity value at White Rose is very much lower than expected and may be attributed to low water usage in that area. Also, earlier in 2003, MWSC carried out studies of the groundwater in Naifaru. The following is a summary of the findings of the MWSC study and the investigations carried out by the Hydrogeologist.
Studies carried out by MWSC (2003) established that the existing sewerage system has not ameliorated the contamination of pathogens in groundwater and high salinity in ground water is noticed in many areas. The malady is due to high population density and increasing use of electrical pumps. Contour maps based on the results of random water sampling from wells indicated that ground water is potable in most parts of the island except in areas near the coast line in the southern, south-western and north-eastern most parts of the island. A contour of the faecal coliform is generally not very indicative of pollution patterns, however, the study by MWSC concluded that ground water in the eastern and western parts of the island is free of faecal coliforms and faecal contamination is more prevalent in the central portion.
Project specific investigations undertaken in mid July 2007 focused on twenty five household open wells selected at random and also included those wells selected during MWSC water quality study. The findings of the survey indicated that the depth of the wells is less than 2.5m from land surface and the depth to water level (depth of water table) vary from 0.55m and 1.17m below land surface and pH ranged from 7.70 to 9.44. Out of 25 samples, water from three wells had turbidity levels exceeding the threshold value of 5. Electrical conductivity of water generally ranged from 198 to 1790 uS/cm except three wells showing values between 2580 and 4470uS/cm at temperatures ranging between 26.90C and 28.50C. Dissolved Oxygen values varied from 0.12 to 3.21 mg/l. Salinity values ranged between 0.02 and 0.17mg/l. In most of the wells, white or pale green filamentous algal growth was seen. This indicated high levels of nutrients (nitrates mainly) in groundwater. Results of the samples are given in Table 5-2.
Table 5-2: Water quality results for N aifaru groundwater undertaken on 11 July 2007 Depth to Distance Dissolved EC Faecal Place water level from septic pH Oxygen (uS/cm) Ammonia Phosphate Nitrate coliforms (m) tank (mg/l) (mg/l) (mg/l) (mg/l) (count/100ml) Rose Bank 1.1 1.7 7.71 705 0.65 0.07 0.64 15.94 >100 Fenboavalhuge 0.85 1.7 7.9 638 1.34 0.01 0.98 31.43 0 Guraha 0.8 2 7.7 655 1.76 0.12 0.49 27 49 Fiari 0.92 2.5 7.72 4470 0.43 0.4 0.44 75.26 >100 Yamha 0.82 9.5 8.34 582 0.45 0.01 0.93 1.77 >100 Hasthee 0.85 1.5 7.14 1160 0.12 2.19 1.04 1.33 >100 Hiriya 0.55 2.6 8.27 1790 2.92 0.22 0.49 3.1 >100 Qupid 0.96 5.3 8.15 1700 3.01 0.16 0.8 14.17 >100 Moonimaage 0.95 1.7 7.8 658 2.36 0.01 1.5 20.81 22 Kinaara 0.7 1 7.81 1530 0.4 1.21 1.32 0 3 Feskoge 1.17 1 8.25 631 2.57 0.04 0.61 33.65 >100 Hilaaleege 1 9.7 7.98 2580 0.56 0.28 0.5 14.17 26 Nookandu 0.57 1 7.88 3380 0.73 0.8 1.67 6.2 >100 Thakandhooge 0.8 2 8.22 920 1.64 0.1 1.31 24.35 >100
Proponent: Ministry of Housing, Transport and Environment Page | 39 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Ummeedhu 0.72 0.5 8.2 1370 3 0.5 0.57 1.33 2 Fusthulaage 1.02 3 8.17 960 3.21 0.16 0.81 16.38 >100 Family 0.68 1 8.38 653 0.5 0.35 0.2 0.44 >100 Bunyaadhu 0.99 1 8.08 1460 0.98 0.13 0.14 6.64 14 Nooru 0.74 5.5 8.84 597 1.78 0.1 0.46 2.21 0 Rediyamge 0.85 1.5 8.07 821 0.95 0.07 0.47 51.8 >100 Uduvilaage 0.84 1.8 9.44 198 2.62 0 0.34 7.87 >100 Anoanaage 0.76 1.5 8.14 802 2.2 0.08 1.18 26.56 0 Funafaru 0.9 14.2 8.3 685 1.9 1.45 0.9 0 >100 Kastoorige 0.95 3 8.32 640 2.8 0.06 0.69 45.16 >100 Aasaan 1.14 2.5 8.37 1230 2.86 0.09 2.25 68.18 0
These results indicate that over 84% of the samples have faecal contamination and nitrate and phosphate values are quite high, which also indicates contamination mainly by faecal matter. Such high degree of faecal contamination is further aggravated by the closeness of the wells to household catchpits (septic tanks, as mentioned in the report).
A comparison of the results between the recent study and the one undertaken by MWSC in 2003 indicates that the conductivity has lowered since 2003, which was mainly attributed to the massive reclamation, which would have increased the size of the aquifer manifold. Such an increase in size of the aquifer (i.e. volume of groundwater resource and sustainable yield of that resource) has little relevance in the design of the sewerage system. However, they may be useful in longterm water and wastewater management strategies of the island. Nevertheless, an estimation of the groundwater lens was made using empirical methods. The estimated sustainable (daily) yield was based on the size of the freshwater lens based on the size and shape of the island, recharge from rainfall, evapotranspiration and other determinants. The aquifer is expected to exist within 30-50m inside the shoreline, which is approximately 39 hectares in area providing a sustainable yield of 159m3/day. This estimate has been based on the assumption that the average recharge is about 35% of annual rainfall (based on hydro-geological report, pp41-42) and taking the reclaimed area into consideration whereas the sustainable yield of 66m3/day given in the hydro-geological report is based on the original island size of the island. Daily safe yield depending on population growth up to 7,000 people is shown in Figure 5-2.
Proponent: Ministry of Housing, Transport and Environment Page | 40 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
300
250 Worst case Best Case 200
150
100
50
0 0 1000 2000 3000 4000 5000 6000 7000
Figure 5-2: Daily safe yield per capita, which can be drawn from the Naifaru aquifer
Understanding the type of wastewater generated on site is important for the design of sewerage systems. Only domestic wastewater was generated on site as there are no industries. However, a site specific analysis of the wastewater was not undertaken. Therefore, average national wastewater loads and domestic wastewater quality criteria have been used in the design.
5.2 General m eteorological conditions
The climate of the Maldives varies slightly from North to South of the country. General meteorological conditions prevailing in the central region based on meteorological data for Hulhulé has been used to understand climatic factors affecting the island of Naifaru.
The Maldives, in general, has a warm and humid tropical climate with average temperatures ranging between 25°C to 30°C (MHAHE, 2001) and relative humidity ranging from 73 per cent to 85 per cent. The country receives an annual average rainfall of 1,948.4mm. Table 5-3 provides a summary of key meteorological findings for Maldives.
Monsoons of Indian Ocean govern the climatology of the Maldives. Monsoon wind reversal plays a significant role in weather patterns. Two monsoon seasons are observed: the Northeast (Iruvai) and the Southwest (Hulhangu) monsoon. Monsoons can be best characterized by wind and rainfall patterns. These are discussed in more detail in the following subsections. The southwest monsoon is the rainy season which lasts from May to September and the northeast monsoon is the dry season that occurs from December to February. The transition period of southwest monsoon occurs between March and April while that of northeast monsoon occurs from October to November.
Proponent: Ministry of Housing, Transport and Environment Page | 41 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 5-3: Key meteorological information Parameter Data Average Rainfall 9.1mm/day in May, November 1.1mm/day in February 1900mm annual average Maximum Rainfall 184.5 mm/day in October 1994 Average air temperature 30.0 C in November 1973 31.7 C in April Extreme Air Temperature 34.1 C in April 1973 17.2 C in April 1978 Average wind speed 3.7 m/s in March 5.7 m/s in January, June Maximum wind speed W 31.9 m/s in November 1978 Average air pressure 1012 mb in December 1010 mb in April
5.2.1 Rainfall
Naifaru would receive rainfall during the wet season with monthly average ranging from 125-250mm. The northeast monsoon is known as the dry season with average monthly rainfall of 50-75mm. The intensity of rainfall is a concern in the Maldives since intensity is high with low frequency. However, excessive rainfall is not a concern for Naifaru since the island does not cup towards the middle but rather diverts the runoff towards shore on all sides. Percolation through original ground is also high and the percolation in the reclaimed land is expected to improve in time.
It is sometimes believed that the interval of rainfall (frequency) is important in considering the recharge potential of precipitation. However, the amount of rainfall (intensity) is more important. According to the USGCRP team (Carter et al 2001), “the size of the groundwater lens is directly related to the size of the island… (and) also related to the normal amount and type of precipitation (e.g., heavy downpours recharge lenses, while light rain generally does not)”. Therefore, the type of rainfall that occurs in the Maldives with high intensity-high duration- low frequency rainfall is useful for the development of groundwater lenses in low-lying islands. It is also important to note that the aquifer (like a rainwater tank) has its own capacity and not every drop of rainwater will percolate to contribute to the freshwater lens. This argument also supports the belief held by the consultants that aquifer recharge is not easily possible by grey water recharge. This is discussed in the Impacts section.
5.2.2 Wind
Wind has been shown to be an important indirect process affecting formation, development and seasonal dynamics of the islands in the Maldives. Winds often help to regenerate waves that have been weakened by travelling across the reef and they also cause locally generated waves in lagoons. Therefore winds are important here, as being the dominant influence on the hydrodynamics around the island (waves and currents). With the
Proponent: Ministry of Housing, Transport and Environment Page | 42 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru reversal of winds in the Maldives, NE monsoon period from December to March and a SW monsoon from April to November, over the year, the accompanying wave and current processes respond accordingly too.
The two monsoon seasons have a dominant influence on winds experienced across Maldives. These monsoons are relatively mild due to the country’s location close to the equator and strong winds and gales are infrequent. However, storms and line squalls can occur, usually in the period May to July; gusts of up to 60 knots have been recorded at Male’ during such storms.
N NNW 20 NNE NW 15 NE
10 WNW ENE 5
W 0 E
WSW ESE
SW SE SSW SSE S
Figure 5-3: General wind rose diagram for the Maldives (source MEEW 2005).
Changes in wind directions need to be taken into consideration in determining the location of outfalls. The following figure shows the locations of the island that may be considered to be the lee of the island during both monsoons and these areas need to be avoided when locating outfalls.
Direction of drogue on a dead calm day (16 October 2009)
3-4 knots Proposed outfall (570m)l Wind on field day (16 October 2009)
STP
Lee of the island during SW Monsoon
Harbour
Lee of the island during NE Monsoon
Figure 5-4: Lee of the island during the two monsoons based on general wind rose diagram
Proponent: Ministry of Housing, Transport and Environment Page | 43 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.2.3 Waves
Wave energy is also important for the movement and settlement of sediments, suspended solids and other matter in sewage, and is also a crucial factor controlling coral growth and reef development. Although waves would help to mix sewage effluent to a great extent, it has greater potential to move the material closer to the lagoon and shore paving way for greater nutrient and sediment loading. Therefore, direct and incident waves may be avoided to the greatest possible extent when locating outfalls.
Studies by Lanka Hydraulics (1988a & 1998b) on Malé reef indicated that two major types of waves on the coasts of Maldivian islands: wave generated by local monsoon wind and swells generated by distance storms. The local monsoon predominantly generates wind waves which are typically strongest during May-July in the south-west monsoon period. During this season, swells generated north of the equator with heights of 2-3 m with periods of 18-20 seconds have been reported in the region. Local wave periods are generally in the range 2-4 seconds and are easily distinguished from the swell waves.
Distant cyclones and low pressure systems originating from the intense South Indian Ocean storms are reported to generate long distance swells that occasionally cause flooding in Maldives (Goda, 1988). The swell waves that reached Malé and Hulhule in 1987, thought to have originated from a low pressure system of west coast of Australia, had significant wave heights in the order of 3 metres.
Similar to winds, wave climate of the island has been considered in the location of outfalls. The proposed outfall location would be subject to wind waves that break on the reef facing Baraveli Kandu. Although this is the western rim of the atoll, this side could not be considered as rim reef as this reef is protected from oceanic swells. There were no waves here on the day of the survey as long period swells do not affect this reef. Therefore, the effect of swell waves which results in material being washed ashore constantly would not be felt at the proposed outfall. Instead, faecal matter would flow towards and past the channel, where a strong current exists due to funnelling of the water body passing through the narrow channel between Naifaru and Madivaru. This is also seen from the drogue studies undertaken on the day of the field visit, which would represent worst case scenario for the proposed outfall. Also, the proposed outfall is at about 10-15m depth and away from wave breaking zone, which would minimize wave wash of particles to a great extent. These are discussed in the impacts too.
5.2.4 Tides
Tides affect wave conditions, wave-generated and other reef-top currents. Tide levels are believed to be significant in controlling amount of wave energy reaching an island, as no wave energy crosses the edge of the reef at low tide under normal conditions. In the Maldives, where the tidal range is small (1m), tides may have significantly important influence on the formation, development, and sediment movement process around the island. Tides also may play an important role in lagoon flushing, water circulation within the reef and water
Proponent: Ministry of Housing, Transport and Environment Page | 44 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru residence time within an enclosed reef highly depends on tidal fluctuations. Therefore, tidal movement would also need to be considered in identifying appropriate location of outfalls for nearshore outfalls. However, in the case of ocean outfalls, tides are of little use in determining the location. Tides will, however, be an important factor in cleansing the contaminated shores and lagoon areas of Naifaru, once the 24 nearshore outfalls have been removed (or abandoned) upon completion of the proposed sewerage project.
5.2.5 Currents
Studies on current flow within a reef flat in Male’ Atoll suggests that wave over wash and tides generate currents across the reef platforms, which are also capable of transporting sediments (Binnie Black & Veatch, 2000). However, available information suggests that tidal currents are not strong due to small tidal range.
Generally current flow through the Maldives is driven by the dominating two-monsoon season winds. Westwardly flowing currents are dominated from January to March and eastwardly from May to November. The change in currents flow pattern occurs in April and December. In April the westward currents flow are weak and eastward currents flow will slowly take place. Similarly in December eastward currents flows are weak and westward currents will take over slowly.
Studies on current flow process within a coral atoll have shown that waves and tides generate currents across the reef platforms, which are capable of transporting sediments on them. Currents, like waves are also modified by reef morphology. Under low-input wave conditions (0.5m heights) strong lagoonward surge currents (>60cm/sec) are created by waves breaking at the crest. Studies on current flow across reef platforms have shown that long-period oscillations in water level cause transportation of fine-grained sediments out of the reef- lagoon system, while strong, short duration surge currents (<5sec.) transport coarse sediments from the breaker zone to seaward margin of the backreef lagoon. Always sediment accumulates at the lee of high-speed current zones. Generally zones of high current speed (jets or rips, 50-80cm/sec) are systematically located around islands.
Data on current speed and direction around Naifaru was collected during the field visit by undertaking drogues at appropriate locations. The directions of the drogues are shown in Figure 5-6 and Figure 5-4. From the latter, it can be seen that the lee of the island during the two monsoons need to be avoided when locating wastewater outfalls as sediment accumulates at the lee of current zones. Figure 5-4 also indicates that the current flows towards and past the channel between Naifaru and Madivaru when the winds blow from the west. This current is expected to reverse during the northeast monsoon when winds blow predominantly from the east. This means that there will be no particle flow towards the island during the two monsoons.
Proponent: Ministry of Housing, Transport and Environment Page | 45 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.2.6 Natural Vulnerability of the Island of Naifaru
An island’s natural vulnerability depends on geographic and geomorphologic characteristics of the island. These include geographic features of the island like the side of the country where the island is located, the formation of the island, location of the island respect to the atoll, orientation of the island, region of the country where island is located, level of protection to the island from the reefs and other islands; area of the inland lake found on the island, width of the island’s house reef, coastal defence structures on the island, shape of the island and the area of the island.
Naifaru is considered among the top ten most physically vulnerable islands in the Maldives. Although Maldives is generally considered to have moderate risk to natural hazards or disasters, Naifaru is considered to be in a highly vulnerable zone when cyclonic winds and storm surges over the Maldives are concerned but low risk when tsunamis and earthquakes are concerned (RMSI/UNDP 2005). According to the report, the northern atolls are at greater hazard from cyclonic winds and storm surge with very low hazards in southern atolls. While the maximum probable wind speed in zone 5 is 96.8 knots (180 kmph) with a cyclonic storm category being a lower CAT 3 on Suffir-Simpson scale, Naifaru is in Zone 4.
Except for Seenu, Gnaviyani and Gaafu atolls the earthquake hazard is low across the country. Sea level rise due to climate change has uniform hazard throughout the country (RMSI/UNDP 2005).
Figure 5-5: Cyclonic and related storm surge hazard zones (adapted from RMSI/UNDP 2005)
Proponent: Ministry of Housing, Transport and Environment Page | 46 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.3 Coastal and Marine Environment
Naifaru is a pea-shaped island lying on its own pea-shaped reef on the western rim of Lhaviyani Atoll. The reef is about 152 hectares within which the island (including the recent reclamation) occupies 53.7 hectares. The reef extent on the eastern and the western sides vary as 85m and 350m respectively. The eastern side faces the atoll lagoon while the western side faces the rim reef of the atoll.
The coastline of the island covers about 3500m of which 382m is the harbour area and 1700m of the coastline on the western side from the southwest corner to the northeast corner has sandy beach areas following the reclamation. The rest of the coastline is covered by waste, especially construction debris. There are 23 outfalls (4-inch pipes) disposing raw sewage and wastewater on the beach all around the island except for the northwest corner (the proposed STP and outfall area) and 1 (8-inch pipe) had been recently placed and was extended into the deeper lagoon on the southwest side. There are 3 outfalls disposing directly into the harbour, which is a cause for concern not only because the harbour is semi-enclosed but also because some children were seen swimming in the harbour on the day of the survey, the safety of such swimming being another concern.
There is an extensive lagoon on the western and northwestern side of the island covering a reef extent of about 600m. This lagoon is almost completely covered with seagrass of predominantly thalassia hemprichi species. The lagoon also has shallow depths varying from 0.3 to 0.8m on average. Some areas on the western and southeastern shoreline get dry during low tide. The area in which the new harbour is located has seagrass close to the beach within a somewhat enclosed area. Other areas have clear lagoon which gets deeper as it gets closer to the reef slope.
The western side of the island is prone to high energy swells from Baraveli Kandu, the northern corner and the western corner being the most dynamic and with the greatest reef extents. The southwest side of the reef, which is usually calmer than the other areas of the reef, has a dredged area, which was previously used as a harbour.
The lagoon all around the island has somewhat constant depths and the reef flat is less obvious on the lagoonward (leeward) reef on the east than the rim reef on the west. The lagoon has poor visible quality in all areas except the northwest corner due to seepage from waste and waste dumping. The island coastline is poorly managed with solid waste dumping in almost all locations around the periphery of the island. Dumping of fish waste used to pollute the lagoon in the past, however, this practice is very minimal now. Yet, some fish dump is observed at the end of the jetty on the north of the existing harbour. The Island Development Committee members who took part in the survey showed concern over this.
Surveys of coral cover and fish abundance and diversity in three locations was undertaken during the field trip of 15-17 October 2009; one on the northwest side (proposed outfall), the second on the northeastern end (existing
Proponent: Ministry of Housing, Transport and Environment Page | 47 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru seawater intake pipe), which was also one of the locations for the outfall identified at the initial stages and the third at the location of a possible outfall location on the southeast end. From the surveys, it was seen that the reef around Naifaru is mainly dead. However, rapid growth was observed at the northern end of the dredge area. This is a possible result of dredging and low-level sedimentation. Figure 5-6 shows the survey locations.
Plate 5-2: Recent aerial photo of Naifaru after the reclamation (Source: Department of National Planning)
5.3.1 Site 1: Proposed outfall
The day of the field survey was a very calm day with low wind (less than 5knots). However, there was a moderate current in the survey location which was directed towards the channel between Naifaru and Madivaru. There were no waves at the time of the survey. A transect taken from the reef edge towards the island was taken to cover the reef slope and reef flat areas up to the edge of the dredge area.
The reef edge has a sharp cut joining to Baraveli Kandu between Lhaviyani and Baa Atoll. Baraveli Kandu gets quite rough during storms. At the top of the reef edge are mainly small massives (10-20cm) and a few large (1m) massives. The reef slope has bedrock close to the reef edge while there is sandy bottom elsewhere. The reef
Proponent: Ministry of Housing, Transport and Environment Page | 48 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru slope is gentle with small depth difference between reef edge and reef flat. The reef slope area has low coral cover and hence low in fish diversity and abundance.
The reef flat area is higher coral cover than reef slope and edge. Fish diversity and abundance is low to moderate. The total live coral cover on the reef flat area on which the proposed outfall would be laid is about 8-10% with small porites of generally less than 40cm. However, live coral cover and coral growth increases as it gets closer to the dredged area. Lot of regeneration is seen in this area, which is most likely attributed to the dredging and reclamation works. Average depth on the reef flat area varies from 0.6 to 0.8m. Large schools of baitfish were observed at the reef flat areas. While the reef flat covers about 130m from the dredged area, about 50m of reef flat from dredge area is just coral rubble and sand and no reef material can be found.
5.3.2 Site 2: Alternative Outfall Location
This is the location of the existing seawater intake for the desalination plant. The existence of the seawater intake is the main reason why this location was not considered by the island community for the sewage outfall. As for the proposed site, this area was also dead calm during the survey. A transect was taken from the reef edge towards the island. This transect was much shorter and there is no well-formed reef flat in this area. A drogue done from this location indicated that current was moving away from the island and into the atoll lagoon but with a slight deviation towards the island.
The reef edge at the location gradually slopes into the atoll lagoon with no proper reef edge. The reef edge is mainly sandy. The reef slope is also small, however, had a high coral cover. The reef slope in this area had more live coral cover compared to the proposed outfall location but is mainly dead. With about 30% live coral on the reef slope, the seabed is sandy and the slope is steeper compared to the proposed outfall with greater depth difference between edge and reef flat area. There were large dead coral massives on the slope nearer to the edge and fish diversity and abundance in the area is moderate. Ascidians or sea squirts (considered as a diet of hawksbill turtle) were observed growing on several coral massives as well as the seawater intake pipe. Coral regeneration was also observed on the reef slope here.
The reef flat in this area had low coral cover than the reef slope and the reef flat extent is small. With moderate fish diversity and abundance, large schools of yellowback fusilier (dhonnoomas) and convict surgeons (raabulhaa) was seen. The site has about 15-20% live coral cover with mainly small acropora massives and a few branching tabulate acropora. Coral growth reduces as the swimmer gets closer to the clear lagoon area with about 20m without reef material but rubble to sandy bottom.
Proponent: Ministry of Housing, Transport and Environment Page | 49 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.3.3 Site 3: Potential Outfall at Proposed PS1 Area
This is the location of the proposed Pumping Station 1 area. The length of the outfall at this location would also be comparatively much smaller than the proposed location, similar to the first alternative outfall location discussed above. However, PS1 is in a congested residential area with minimal land available for sewage treatment plant. As with other sites, this area was also dead calm during the survey. A transect was taken from the reef edge towards the island. This transect was similar to alternative location discussed above. There is no well- formed reef flat in this area. A drogue done from this location indicated that current was moving away from the island towards the channel between Naifaru and Veyvah (see Figure 5-6).
The reef edge at the location gradually slopes into the atoll lagoon with no proper reef edge. The reef edge is mainly sandy. The reef slope is also small, however, had a high coral cover. The reef slope is mainly sandy with several dead coral massives. Although there is a greater percentage of dead acropora massives than site 2, the live coral cover in this site is estimated to be about 20% on the reef slope. Ascidians were observed to be growing on several coral massives but are much less compared to Site 2. Coral regeneration was also observed on the reef slope here, especially branching tabulates. Fish diversity and abundance is estimated to be moderate.
The reef flat in this area had low coral cover than the reef slope and the reef flat extent is small. Fish diversity and abundance is estimated to be moderate. The site has about 5-10% live coral cover with mainly small acropora massives and a few branching tabulate acropora. Coral growth reduces as the swimmer gets closer to the clear lagoon area with bedrock covered with small branching coral pieces on reef flat. Depth on sandy reef flat area closer to the island is about 1.5m and the bottom is sedimented with several dead massive porites.
5.3.4 Other observations
Swim from proposed outfall location towards the northern end of the island towards the channel between Naifaru and Madivaru indicated high growth of corals with several tables, branching tabulates and acropora massives growing on the edge of the dredged area at the northern corner of Naifaru. There is impressive coral growth possibly following the dredging and reclamation works. Similar growth has been observed in some other places following dredging dredging works. It has been observed that such rapid growth is seen at a distance from the dredge location and at a location with low level of sediment deposition resulting from the dredging whereas high sedimentation kills or displaces corals almost immediately. Therefore, there is evidence to support that dredging results in high coral growth in areas where low level sedimentation occurs but is easily washed by currents. This, however, still remains to be confirmed by further studies.
Proponent: Ministry of Housing, Transport and Environment Page | 50 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.3.5 The Seagrass Ecosystems
Seagrass beds are known to have high ecological value as they provide important food resources to a range of fish and invertebrates (King 1981; SunAqua 2002), both directly (grazing by fish and turtles) and indirectly (through detrital food chains, or provision of shelter to other associated flora and fauna). Furthermore, seagrasses provide structural habitat, shelter and nursery areas to a range of marine flora and fauna, including many species of invertebrates and fish of fisheries value (e.g., King, 1981; Haywood 1995; SunAqua 2002). This may be true for the extensive seagrass beds found in neritic environments. The significance of seagrass ecosystems to Maldivian environment and biodiversity has not been studied yet. However, it is known that seagrass beds play a very important role in protection of shoreline erosion. In the case of the Maldives the presence of seagrass around an island has also been linked to the eutrophication in coastal areas. The presence of seagrass in the reef- flat of many fishing islands including Naifaru is an indicator of this.
Seagrass was observed on the western side of the island from southwest to northern end of the western lagoon of the island. Only one species of seagrass (Thalassia hemprichii) was recorded on the seagrass beds. The density of the sea grass varied slightly. The density of the sea grass is controlled by wave energy and current and this appears to be similar throughout the lagoon on the western side. The depth of the lagoon and reef extent also influenced the density and growth of seagrass. Seagrass is not expected to grow in the dredged area.
No observation was made on the biology of the seagrass beds since seagrass beds were not found in the zone of the proposed outfall location. In fact, it would be difficult to undertake an assessment of the seagrass bed biology given that most of the mollusk and other echinoderms are nocturnal. Fish species could be rarely seen. The emperor fish Lethrinus harak may be considered as an indicator species of the health of the seagrass area. This species generally inhabits in healthy seagrass beds.
5.3.6 Marine Water Quality
The marine water quality samples were tested at the National Health Laboratory. Water samples were taken from two locations and tested at the National Health Laboratory of the Maldives Food and Drug Authority. The two locations are the proposed outfall locations and at the reef edge behind the harbour.
The water quality tests results given in Table 5-4 indicate that the marine water quality at the outfall location is in pristine condition but there is low level contamination in the sample taken behind the harbour with higher BOD. The high COD values are not attributed to chemical pollution but to the high chloride concentration of the natural sea water. The difference in values can be explained to some degree by the difference in electrical conductivity at the two locations. However, the low nitrate value is a little strange, especially for the sample near the harbour and needs to be re-checked. Dissolved oxygen was tested at site.
Proponent: Ministry of Housing, Transport and Environment Page | 51 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 5-4: Water quality results PARAMETER TESTED Unit SW1 (proposed outfall) SW2 (behind harbour) GPS coordinates Latitude Longitude Physical appearance clear clear pH 8.4 8.3 Electrical conductivity uS/cm 47,800 47,400 Nitrate mg/l 0.0 0.0 Dissolved oxygen mg/l 7.5 7.2 Biochemical oxygen demand mg/l 6 28 Chemical oxygen demand mg/l 1,840 1,532
Proponent: Ministry of Housing, Transport and Environment Page | 52 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Figure 5-6: Site conditions and results of surveys undertaken during field mission in October 2009 01 02 08 15
-3.56 09 -2.76 03 16 -2.86 -2.36 -23.94-6.66-4.76 -4.16 -3.76-3.04-2.56-2.06 -35.94 -35.94 -7.56 -4.86 -4.16 -3.04 -36.96 -3.36 -35.96-7.96 -1.66 10 -4.96drogue1-4.04 -3.36-2.66 -10.96 outfall-2.66 -6.66 -2.86 14 -5.56 11 -49.96 -4.46 -2.50 -48.96 -3.76 -2.00 -45.86 -2.86 -33.46 -1.56 -7.66 -2.96 -4.86 -2.86 -0.86 -4.26-3.46 -2.16 -0.62 -0.57 -0.89 -4.96 -5.56 -6.06-6.56 13 05 -6.03 -4.88 -3.96 -1.06 12 -0.96 -0.56 Waste drogue2 -0.73 Management -0.61 15 14 PS 5 04 10 17 04
08 outfall16 Wq5
PS4
outfall17 Wq4
09 outfall18 11 outfall15 outfall19 05 outfall20 06
17 Old fish market PS2 outfall21 outfall14 Wq2 outfall22
outfall12 outfall22-maaolhu only sp 3- maa olhu PS outfall23 0.95
06 12 outfall2-fishoutfall1 market 01 07 0.80 02
outfall3n4 PS outfall5
previous gondu cleared FRC 2006 04 lonumas+goduoutfall6 corner PS1 03 outfall7-0.35 -0.65 -1.03 -1.53 outfall11-8'' proper not visible -2.31 -2.71-5.86 -6.06 16
drogue3 07 13
0 50 100 150
Proponent: Proponent: Ministry of Housing, Transport and Environment Page |53 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.4 S ocio-economic environment
The following account of the existing socio-economic environment of Naifaru has been drawn from the Sociologist’s report and the observations and discussions held by the Environment Consultant during the field survey of 15-17 October 2009. The three senior staff of the Project Implementation Unit of the Regional Development Project Phase II was very helpful and provided an in-depth review of the socio-economic and environmental conditions of the island.
The Sociologist had undertaken survey and collected information from 266 households and among them 211 families headed by male, 53 females and 2 did not mention any category. A summary of the findings including status of environmental infrastructure and community expectation of RDPII and willingness to pay survey results have been incorporated into the subsections below.
5.4.1 Socio- economic profile
The size of the household varies with an average of 7 per household. Of all the households surveyed, 43% of households earn a monthly income below Rf5,000, 39% earn between Rf5,000-10,000 and 12.6 % earn between Rf10,000-15,000. In addition, 2.4% of the sample population earns above Rf15,000. This reflects that overall 57% of the population earn an average income whereby the majority has an average living standard. Mean income is RF5,455 per household.
Figure 5-7: Distribution of household income
The results of the household assets surveyed indicate that the living standard is high compared to other islands and that most of the households are equipped with modern facilities. Different types of vehicles are becoming increasingly common in use although it is at a relatively low level at present.
Proponent: Ministry of Housing, Transport and Environment Page | 54 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Figure 5-8: Household assets
Household expenditure survey revealed that on average 40% is spent on food followed by 13% on medical expenses reflecting the high percentage of income spent on food and medical service.
Table 5-5: Monthly average household expenditure Items Average per Househol d (Rf) Percentage Food 2332 40 Electricity 692 12 Gas 270 05 Water - - Garbage Disposal 42 01 School Fees 120 02 Medical Expenses 753 13 Clothing 263 04 Leisure/Travel 280 05 Transport 70 01 Fuel 68 01 Others 860 15 Total 5750 100
An analysis of the occupational structure indicates that a significantly large proportion is students (30%), 21% is housewives, 13.3% are employed in the civil service and 13.2% are in the private sector. It also shows that 13% of the population is not occupied with only 0.8% being retired members of the community. Data on housing showed that over 99% of the sample live in single units with 94% being the owners of their own units. Electricity is connected to 99% of the houses with 98% with toilets and groundwater wells in all households surveyed.
Survey on health status showed that the incidence of water-borne disease is low with about 1% of the sample reporting water-borne disease in the past three months. However, none of the student or economically-active members reported being sick in the past three months. The types of illnesses reported mainly include diarrhoea and stomach pain.
Proponent: Ministry of Housing, Transport and Environment Page | 55 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
5.4.2 Status of Environmental Infrastructure
5.4.2.1 Water Supply
Water harvesting is carried out using water tanks to collect rainwater at households and is used for drinking and cooking. Well water is used for bathing and washing.
Table 5-6: Existing Water Supply System Query Response Total Number Percentage Do you have water tank at Agree 239 89 home? Do not agree 23 08 Condition of the tank Satisfactory 172 72 Not satisfactory 19 08 Financed by Self 106 44 Grant 135 56 Loan 05 - Main source of water supply Rain water collected at home 248 93 Public water tank 05 02 Own well 251 94 Mosque/public well 21 03 Does the private well electricity Agreed 227 85 operated pump? Not agree 39 15
Table below shows the responses received in relation to the problems with well water.
Table 5-7: Problems with drinking water and type of purification used Total Number Percentage Problems with drinking Bad smell 63 24 water/well water Bad taste 33 12 Color 15 06 Shortage 03 01 Rain water shortage 65 28 Types of purification Boiling 46 17 used for drinking water Filtration 36 15 Chlorination 01 0.4 Others/mineral water 81
5.4.2.2 Sanitation
Sewerage system exists in the island and is reported to be not functioning satisfactorily. The households have traditional septic tanks and are connected to sea through sewers. The answers received when questioned about sanitation are as shown below. It should be noted that the septic tanks referred to here are not actually septic tanks but catchpits. In the table, Gifili refers to a traditional toilet facility with a latrine and without a roof.
Table 5-8: Types of toilet facilities in household Type Total Number Percentage Sanitary toilet with pour flush 133 41 Sanitary toilet with flushing cistern 188 58 Gifili 0 0
Proponent: Ministry of Housing, Transport and Environment Page | 56 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The questionnaire also identified the problems faced by the community due to the present toilet facilities. 7% reported having bad smell while 6% reported getting water polluted, 15% complain of inconvenience and 6% is facing lack of cleanliness.
5.4.3 Solid waste disposal
The issue of the garbage is one of the major problems facing the island community. Though there is allocated site near the beach there is no waste management system. This has been discussed earlier.
Table 5-9: Methods of garbage disposal Total Number Percentage How do you dispose the Back yard 00 00 garbage? Beach 00 00 Designated Area on Island 264 99 Whether family members Yes 54 20 dispose garbage? No 211 79 Whether pay anybody else to Yes 211 79 dispose? No 00 00
Table above does not reflect the actual waste disposal scenario on the island with some garbage still being disposed on beach areas. However, most people dispose garbage on the designated area on the northern end.
5.4.4 Community Preferences, Expectations and Awareness
Community preferences for water supply and sanitation were covered in the survey. However, this section looks at the details of the sanitation preferences. It is worth mentioning, however, that a great proportion of the respondents (about 41%) preferred to have groundwater wells as their sources of water while 58% was desirous of a desalinated water connection. The high proportion of preference for groundwater indicates the need to ensure that groundwater is preserved in the best possible state.
When inquired about sanitation options, a predominant 87% said that they preferred offsite sanitation and when asked about the reason for the preference, 65% referred to space constraints and 34% said onsite sanitation causes pollution of groundwater, which is a cause for concern.
Table 5-10: Preference for sanitation and the reasons for the preferences Total Number Percentage Preference of sanitation Household septic tank 18 06 Offsite sanitation 234 87 Reason for the preference Not enough space 173 65 Pollution of water 91 34
When inquired about community expectation of the Second Regional Development Project Phase II and their level of awareness regarding the project, 83% of the respondents said they expect improvements in sanitation when
Proponent: Ministry of Housing, Transport and Environment Page | 57 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru compared with 50% and 56% for water supply and solidwaste disposal improvements respectively. Sadly, 71% of the respondents were not aware of the project, which indicates that community involvement in the planning phase was poor. It was observed during the EIA consultations also that there was poor community involvement and this issue was also raised by the PIU staff. However, during the social survey, 89% of the respondents said that they would be happy to give suggestions for the project.
5.4.5 Willingness to Pay
Willingness to pay is a tricky subject in the Maldives. Often social surveys during initial stages of a project would result in willingness to pay. However, when people are faced with the reality of actually paying for the service, especially sewerage, there is hardly any willingness on the part of the consumer to pay for the service. Social survey in Naifaru also revealed very positive results for the willingness to pay survey with most people willing to pay over Rf100 per month for septic tank system but about 27% of the respondents are reluctant to respond.
Figure 5-9: Willingness to pay for a septic tank system
The results were even better if sewage treatment was incorporated. Table below illustrates that when entire household sewage is treated and septic tank is eliminated 40% is willing to pay Rf200, while 14% as Rf300 and 4% is ready to pay Rf400.
Figure 5-10: Willingness to pay for a sewage treatment system
Proponent: Ministry of Housing, Transport and Environment Page | 58 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
6 Stakeholder Consultations
This project involves various stakeholders at different levels. Extensive island-level stakeholder consultations have been undertaken by the Sociologist during the initial project planning stage and the outcomes have been discussed in the previous section. For the purpose of the EIA, further community consultations have been avoided because it would increase the frustration of the community over lost promises of improved water and sanitation. Therefore, the EIA stage only focused on key stakeholders such as the island councillor and some members of the island council and Project Implementation Unit, who has been there from the onset of the project. In addition, discussions were held with the relevant staff of the Ministry of Housing, Transport and Environment, EPA (during project scoping) and the Northern Utilities Company.
6.1 Ministry of Housing, Transport and Environment
The Ministry of Housing, Transport and Environment is the Proponent as well as the regulatory body while these two functions are undertaken in an independent manner. As the Proponent, Mr. Ahmed Waheed provides the necessary input and information. Initial consultations were conducted with the Proponent in order to obtain project relevant information. Discussions were focused on gathering preliminary data and information from the Proponent before the field visit. The Proponent also provided information about the present policies and construction practice of the government for sewerage projects.
The Ministry also provides policy directions and is or has been responsible for the effective implementation of sewerage projects in the country. However, the Ministry’s role as implementing agency is to oversee the design and construction works and is, therefore, concerned about the operation and maintenance of the system. This is also a concern of the regulatory arm of the Ministry, the Environmental Protection Agency. This concern was raised during the scoping meeting following which discussions were held with the Project Implementation Unit of the Ministry and the PIU staff at site. During these discussions, the focus was on the recently formed Northern Utilities Limited (NUL). The Proponent strongly suggested to have separate discussions with NUL and provided assistance in organising a meeting with NUL.
6.1.1 Environment Protection Agency
The Water Section of the Environment Protection Agency (EPA) provided technical input required for the project. As Regulator, the EPA has raised several concerns over the proposed design (described by the EPA as major technical discrepancies) which was discussed at length during the scoping meeting. According to the Engineer at EPA, the concerns had been raised a long time ago (24 March 2009 via letter to the Minister) and there has not been any replies from the Consultants so far. Therefore, following the EIA Scoping Meeting, a letter was sent to the Minister as a reminder of these concerns, which are briefly discussed below:
Proponent: Ministry of Housing, Transport and Environment Page | 59 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
. The estimated water consumption of 95-110litres per capita per day (l/c/d) is far less than the 180 l/c/d given in the “Sewerage Design Criteria”. The estimate is the water supply and not the water demand that the Government of Maldives is committed to provide to the Maldives Island Communities in phases through water supply extension programmes. Therefore, the sewerage system so designed on reduced water demand shall not be able to sustain additional water supplies likely to be added in subsequent phases. The ISDB Engineer at EPA believes that there is no rational for the estimated values and consideration was given to the values estimated by reputed International Consultants Cardno for the American Red Cross Project in GA. Villingili, GA Dhaandhoo, GDh. Gadhdhoo. It was concluded that a sewerage system designed on such reduced sewage flows will be under capacity and problematic. It was, therefore, suggested to stick to the 180 l/c/d given in the “Sewerage Design Criteria”, which appears to be realistic. . The values for sewage characteristics such as BOD5, faecal coliforms, etc. are taken on assumption basis. No sewage sampling and testing was conducted to establish the realistic sewage parameters for STP design. This might lead to an unrealistic sizing and costing of the STP, i.e. the plant may be either under capacity or over capacity and in both cases the design approach would be unrealistic. . The Consultants have recommended conventional sewers for Naifaru without evaluating other possible sewerage systems such as small bore sewers and vacuum sewers. Small bore sewers have been in practice in the Maldives for quite some time and currently being installed in American Red Cross projects in Villingilli and Gadhdhoo islands being technically most feasible, very simple and financially viable. Vaccum sewers is also a good option for the Maldives due to its merits since it can follow the saw tooth profile, therefore, shallow depth excavation and simple construction, no chance of groundwater contamination as the system is leak proof, etc. However, the only demerit of the system is that it is not cost-effective due to high capital and O&M costs together with the high degree of O&M skill required to run the system. However, it cannot be ruled out altogether since it is comparable and might become more economical over CGS and SBS for larger islands. . The Consultants have given minimum pipe cover of 300mm in narrow roads and 450mm or higher in wide or major roads where traffic is expected. This is not in line with the “Sewerage Design Criteria”, which allows minimum pipe cover for narrow, non-vehicular streets as 0.6m and 0.9m for wide roads. So, there is clear violation of the “Sewerage Design Criteria” as well as International Practices. . Hydraulic analysis of the sewers done by the Consultants, especially with reference to Lifting Stations 1, 4 and 5 shows that flow conditions are such that none of the sewers in the entire sewer network is going to have the self-cleansing velocities of 0.6m/s for present peak flow and 0.8m/s for ultimate flow even at the end of the design period. Even the sewers falling in catchments of Lifting Stations 2 and 3 will not be safe against blockage problems in the initial periods, due to low velocities and would be subject to heavy siltation, thereby creating permanent O&M issues and liability on the island community. Therefore, it was recommended that the consultants review the hydraulic design of the proposed sewer network. . Without evaluating technical and financial feasibility of treatment processes such as sequencing batch reactors, suspended growth systems, rotating biological contactors, fixed film growth systems and even oxidation ditch process, which is the most simple and improved form of activated sludge process, the consultants have come up with the recommended activated sludge with extended aeration process. Therefore, it is not possible to draw and consensus and recommendations on the selection of type of sewage treatment technology for Naifaru. . The consultants have not produced any preliminary design, i.e. dilution and dispersion modelling on the sea outfalls, in the absence of which, the location and depth of the diffuser cannot be decided and firmed up. . The design period of 15 years means that another STP module shall have to be constructed after 2022 to treat the additional sewage flows. As per international practices, the civil structures of STP
Proponent: Ministry of Housing, Transport and Environment Page | 60 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
are always designed for design life of the material component of at least design period of the sewerage system and other components of STP like pumping machinery etc. are designed for 15 years which on expiry of their life are added. Therefore, the STP design needs to be reviewed in view of this. . The consultants have assumed a peak factor value of 3 for all the quantities of sewage flows, which is wrong since peak factor is never constant for all the flows. The Design Criteria specifies the range of 3 to 5 depending on the volume of sewage flows. The consultants are required to rationalise the sewer network design in light of the Babbit Formula, P.F. = 5/(P)^0.167, where P is population in thousands. . The provision of minimum pipe diameter of 110mm for street sewers is not the right technical size for conventional gravity sewers since international design standards and specifications allow the minimum size not less than 225mm (British Standards) and 300mm (American standards). However, the consultants may choose 150mm sewers to economize the system and design the system accordingly. . The criterion for limiting the maximum depth of sewer as 1.5m from ground level is not based on any local or international design standard and therefore needs to be clarified. . In order to avoid excessive wear and tear of the pump and motor shaft, the speed of pumps should be less than 760rpm instead of 1500rpm recommended by the Consultants. . The consultants should follow EPA standards as given in Table 6.1 of National Wastewater Quality Guidelines December 2006 for treated effluent in place of WHO standards.
6.2 Project Consultants
The project consultants are quite concerned over the issues raised by the EPA after evaluating the concept design. The Consultant feels that while some of the concerns are valid, most of the concerns are based on text book principles and does not appear to take into consideration the practicality of that in the Maldivian context. While reference has been given to the Design Criteria and National Wastewater Guidelines December 2006, these have not been based on any research in the Maldives as a result of which several international consultants have debated over these issues in the past, especially the issue of per capita water consumption estimates.
6.3 Local PIU staff and Councillor
Discussions were held with the councillor and staff of Project Implementation Unit (PIU) of RDPII stationed on site, who are the caretakers of the sewerage project implementation on site. According to them, efforts are underway to improve the environmental conditions of Naifaru. As such, solid waste disposal practices have been improved, however, there still are various issues to be addressed including the waste management center developed on the northern end of the island. Fish waste dumping has been controlled to a great extent although there still are certain points at the harbour area where fish is dumped and this is being monitored. There are other health and environment issues such as salting and drying of fish not being done in designated areas. Effective implementation of the different policies and strategies for environmental improvements would be required to
Proponent: Ministry of Housing, Transport and Environment Page | 61 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru ensure that every citizen abides by them. They pointed out the important role played by the several NGOs operating in Naifaru in addressing key environmental issues and increasing public awareness of those.
According to the staff of PIU, who are also members of the Island Development Committee (IDC), there has been discussions with the Island Office, IDC and other important stakeholders during the initial planning stage. The location of the pumping stations have been finalised after several discussions with the island community. The proposed design, however, has not been communicated to the community in required detail. In fact, community consultations, they believe, shall have taken place during the design and EIA stage so that environmental and design considerations can be discussed with the community.
The councillor as well as the PIU staff identified the role of the Utilities company in the operation and maintenance of the sewerage system. It was noted that there is concern among key groups and members of the island council regarding the manner in which existing public utilities are being taken over by the Utilities Company without adequate discussions over ownership transfer. The powerhouse has been taken over by the Utilities Company, and the request from the Island Council to pay rent to the land allocated for powerhouse has been denied by the Utilities Company whereas Dhiraagu and other utilities pay their monthly rent regularly without issues. During the site visit, there was tension among the council members over the handover of the desalination plant facility to Northern Utilities Limited. The desalination plant was donated and installed by USAID and is apparently the only utility that generates an income despite the small scale of operations. It generates about 10,000 Rufiyaa in revenue from sale of water to fishermen. This money goes into the island development activities organised by the Island Development Committee/Council. Therefore, it is a very promising venture and the community finds it hard to handover such a profiting venture without any returns. One notable aspect of the USAID desalination plant project was the level of community consultations. The PIU staff believes that there has not been any project of that calibre in terms of community involvement. Every single aspect of the project (even the type and colour of the outer walls of the plant house) was finalised in consultation with the community.
6.4 Northern Utilities Limited
Northern Utilities Limited (NUL) was recently formed and is in the process of planning and acquiring its legal status and mandate. Once its functions are well established, NUL would be involved in the planning, design, construction, operation and maintenance of all utilities including gas (apart from waste management) in the north central province. Since access to water and sewerage services is granted as a constitutional right of every individual the government has to provide the services unequivocally and without preference or prejudice. This is why the Government had formed provincial utilities companies at the very early stages. While every island is deserving of decent water supply and sewerage or electricity supply, Naifaru is privileged to be on the top of the list to implement projects for electrification, water supply and sewerage.
Proponent: Ministry of Housing, Transport and Environment Page | 62 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
According to NUL, it is important for communities to understand that the capital costs of such services as water supply and sewerage, especially sewerage which does not generate revenue, is quite high and the economies of scale of such provision to about 200 islands would be prohibitive. Therefore, communities would find it difficult to operate and maintain utilities at their own expense. A great proportion of national funds including grant aids and taxpayers’ money goes into these projects. Therefore, Government’s efforts are to improve service provision and ease the burden of operation and maintenance of utilities and other basic services on the communities. This is where the Utilities companies established by the Government will come handy.
At present, the staff involved in the operation and maintenance of the different utilities at island level is civil servants. However, once the utilities companies are in operation, they will no longer be civil servants but company staff. NUL is working on its organisation structure at the moment and it is envisaged that some utilities in some islands would have to cut down on its staff while several job opportunities would also be created with the newly formed structure under NUL. There will be an integrated system of managing all utilities under one roof, which will minimize operational costs and increase efficiency. Eventually, NUL expects to have a single utilities bill for the ease of customers.
According to NUL, the construction of Naifaru sewerage system would probably be undertaken by NUL. Although NUL has not been involved in the design, NUL feels it important to share the design details with them before finalising the design.
6.5 Community
The following is a summary of community perceptions of the existing system and views and expectations of the new system discussed in the socio-economic report.
6.5.1 Perceptions of the Community
6.5.1.1 Existing System
The existing sanitation system in Naifaru is a gravity pipe system connected to the lagoon where effluent and waste water are discharged into the lagoon or beach. The system is among the first few sewerage systems installed in the Maldives. The system is very rudimentary as far as technical planning and designing as well as implementation are concerned. There are several issues with the system, especially in terms of the repairs and maintenance and issues related to catchpits within household plots.
Proponent: Ministry of Housing, Transport and Environment Page | 63 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
6.5.1.2 Preferred option
As has been indicated in the previous section, community prefers a system with offshore sewage disposal and treatment has been given preference. However, according to Mr. Mohamed Rasheed Bari, who is the consultant engineer for the project and a very experienced engineer in the field of water and sanitation in the Maldives, the preference for sewage treatment is a result of lack of awareness or because of the way treatment process is described to people or simply marketed to them. Also, when treatment was usually explained to people, the advantages are explained in such a way that the economic burden of treatment is often ignored.
6.5.2 Conclusion and Follow up Issues
In the past, work has been carried out in Lhaviyani Naifaru for the provision of gravity sewerage system. The effectiveness of this work has been severely obstructed by poor planning and construction, poor supervision and maintenance. More will be achieved by moving forward starting with an appropriate system with organized planning. Review of the key points from the discussion reveal the community is confronted with blockages and overflows very frequently. The situation is worse during the rainy season.
The community emphasized the need for community consultation and awareness of the proposed and possible options. It is also important to raise awareness on the use of the finalised system. Other important points that need to be taken into consideration in deciding on the type of system to be installed are:
. Lhaviyani Naifaru being an island with limited space, installation of septic tanks within the household compound is not possible . Vacuum Systems are new in the Maldives and the respondents agreed that experiencing a new system is risky.
Since Northern Utilities Limited will be involved in the construction phase as well as the operation and maintenance, the company deserves to be informed of the details of the project in order to gain their approval and appreciation of the proposed system. Also, there needs to be formal as well as informal discussions between the community, NUL and the Ministry regarding the handover of the system to NUL and schedule of implementation from the time NUL takes over.
It is, therefore, important for the Ministry of Housing, Transport and Environment to identify the different types of information that needs to be communicated with the different stakeholders and prepare a schedule with method of information dissemination so that all stakeholders are involved from the very beginning. One very important aspect of such consultation would be to facilitate stakeholder participation throughout the implementation of the project.
Proponent: Ministry of Housing, Transport and Environment Page | 64 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
6.6 List of persons consulted
Following are the names and designation of persons consulted.
1. Shahid Abdul Razzaq, Naifaru Councillor, Lh. Naifaru
2. Nasrulla Mohamed, Manager, PIU, Naifaru
3. Abdul Raheem Nashid, Social Development Assistant, PIU, Naifaru
4. Mohamed Shahid, Landuse Planning Assistant, PIU, Naifaru
5. Abdul Matheen Mohamed, Managing Director, Northern Utilities Ltd.
6. Mohamed Zuhair, Director General, Environmental Protection Agency
7. Moosa Ibrahim, Deputy Director, Environmental Protection Agency
8. Ahmed Waheed, Deputy Director, Ministry of Housing, Transport and Environment
9. Mohamed Rasheed Bari, Managing Director, Development Technologies Maldives (DTM)
Proponent: Ministry of Housing, Transport and Environment Page | 65 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7 Impacts and Mitigation measures
This section covers potential environmental impacts due to proposed sewerage system development in Naifaru, Lhaviyani Atoll. The section also describes the mitigation measures for each identified impact.
Analysis of environmental issues within the lifecycle of the project identifies the major issues and concerns that are likely to evolve over the life of a project. For the proposed project, these issues include location and design, construction of the sewers and longevity of the sewers and constructional and operational impacts of the sewerage system. The environmental aspects of the project would impact upon the following resources or elements of the environment. • Groundwater – quality and quantity • Coral reef areas around the outfall locations – marine biodiversity • Marine and coastal water quality • Lagoon and beaches – aesthetics • Human health and well being • Landuse – availability and constraints • Social and economic development
The potential environmental impacts of various activities pertaining to project components during planning and construction phase of the proposed project components and appropriate mitigation measures are elaborated in the following sections.
7.1 Impact Identification
Impacts on the environment from various activities of the proposed development work (constructional impacts) and operation of the sewerage system (operational impacts) have been identified through: • A consultative process within the EIA team, the Proponent and affected communities • Purpose-built checklists for environmental evaluation of sewerage system development projects • Existing literature and reports on similar developments in small island environments and other research data specific to the context of the Maldives • Engineering specifications and preliminary design layouts available from the Inception Report and final design reports • Baseline environmental conditions described in Chapter 4 • Consultants experience of projects of similar nature and of the areas in which the developments will take place
Proponent: Ministry of Housing, Transport and Environment Page | 66 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Possible negative impacts on the environment have been considered in worst-case scenario to recommend mitigation measures in the best possible ways so that these impacts would be minimized and perhaps eliminated in both constructional and operational phases.
Impacts on the environment were identified and described according to their location/attribute, extent (magnitude) and characteristics (such as short-term or long term, direct or indirect, reversible or irreversible) and assessed in terms of their significance according to the following categories:
1. Negligible – the impact is too small to be of any significance;
2. Minor adverse – the impact is undesirable but accepted;
3. Moderate adverse – the impact give rise to some concern but is likely to be tolerable in short-term (e.g. construction phase) or will require a value judgement as to its acceptability;
4. Major adverse – the impact is large scale giving rise to great concern; it should be considered unacceptable and requires significant change or halting of the project.
Since it is difficult to distinguish between direct impacts (i.e. resulting directly from a specific activity) and indirect impacts (i.e. induced by a series of ecological, social or economic knock on effects and bearing no apparent connection to any specific activity), such distinction has not been made. All possible impacts that may be related to project specific activities have been discussed.
7.2 Identifying Mitigation Measures
Where an impact identified can be mitigated, mitigation measures are identified and discussed along with the identification of the impact. For existing environmental concerns or impacts, mitigation measures have not been identified. The mitigation measures proposed will help to alleviate environmental problems before they occur. Mitigation measures are important because if identified impacts are significant and/or important, it would be necessary to identify and implement mitigation measures. Mitigation measures are selected to reduce or eliminate the severity of any predicted adverse environmental effects and improve the overall environmental performance and acceptability of the project. Where mitigation is deemed appropriate, the proponent should strive to act upon effects, in the following order of priority, to: 1. Eliminate or avoid adverse effects, where reasonably achievable. 2. Reduce adverse effects to the lowest reasonably achievable level. 3. Regulate adverse effects to an acceptable level, or to an acceptable time period. 4. Create other beneficial effects to partially or fully substitute for, or counter-balance, adverse effects.
Proponent: Ministry of Housing, Transport and Environment Page | 67 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7.2.1 Mitigation Options
Possible mitigation options include: • Design alterations (e.g., different locations for sewage outfalls, etc.) • Work method alterations (e.g. changes in construction scheduling) • Provision of environmental protection and health and safety equipment (e.g., provision of first aid or noise mufflers, pollution abatement equipment) • Changes in management practices (e.g., contractor’s awareness on environmental issues, keeping work areas clean, public awareness) • Changes in operation (e.g. operational procedures, specific responsibilities for clean up and maintenance).
7.3 Existing Environmental Concerns
7.3.1 Natural hazard vulnerability
Maldives is not in a hurricane or seismically active region. Therefore, there is no threat of hurricanes or seismic activity such as volcanoes. However, seismic activities have increased in the near vicinity of the Maldives recently, with a recent earthquake in Pakistan killing about 50,000 people.
There is no record of tsunami emanating as a result of earthquake or landslides in the South Asia region. However, tsunamis in the Indian Ocean as far as Indonesia could have devastating impacts on the Maldives mainly due to its low-lying nature. Therefore, the December 2004 Tsunami has been a warning that has raised concerns and need for re-designing for such events. Naifaru is one of the islands that had been affected by the 2004 Tsunami.
Storm surges during southwestern and northeastern halha and corresponding wave scour and subsequent beach erosion during storms is a major cause for concern in the Maldives, which may threaten coastal structures and coastal works such as sewage outfalls.
7.3.2 Existing solid waste disposal impacts
It is evident that like many other inhabited islands of the Maldives, solidwaste is dumped on or close to the beach/coastline in Naifaru. However, a waste management center has been designated on the island, which has not been in operation due to lack of infrastructure to run the site. Hence, solid waste is dumped all around the island on its periphery, which gets washed away during high tide causing pollution of the pristine marine water around the island. This helps in the buildup of nutrients in the nearshore environment causing extensive growth of seagrass around the island. The water quality of the lagoon surrounding Naifaru has been degraded to the
Proponent: Ministry of Housing, Transport and Environment Page | 68 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru extent that the poor quality is visible to the eye and cannot be used for swimming or bathing by Maldivian “standards”.
7.3.3 Existing sewage disposal impacts
The existing sewerage system has been in operation for over a decade and has helped to improve the quality of the freshwater lens in the island. However, there is influx of saltwater through outfall pipes during high tide, which causes saltwater to mix with the freshwater lens in some areas. Measures have been taken to minimize this.
The existing sewerage system disposes sewage effluent into the nearshore environment on the foreshore or immediate lagoon. This adds to the pollution load of the lagoon caused by inappropriate waste disposal. This practice has to stop in order that the lagoon waters return to normal. Table 7-1 outlines the impacts of existing sewage disposal practices.
Table 7-1: Existing sewage disposal systems and their impacts Type of system(s)* Gravity pipes disposing to lagoon via catchpits System Performance Poor, with frequent cleaning in some or many areas Groundwater impact Groundwater pollution from faecal matter is controlled
Marine environmental impact Lagoon waters are polluted High levels of faecal matter in lagoon water Health impacts Bathing in lagoon water causes rashes and other skin conditions Others High level of community participation Frequent maintenance required for the system
7.4 Constructional Impacts
Construction is often a stage where the environmental impacts are underestimated, but in fact is very real and can be damaging. As construction requires lot of processes that typically impact the location by bringing about physical modifications, environmental impacts are felt almost in every aspect. Very often if these impacts are not mitigated, they may result in more significant long term environmental problems which may be more difficult to rectify. The purpose of this section therefore is to summarize the measures that can be undertaken during the construction stage to mitigate the impact on environment during the construction stage. These recommendations may seem exhaustive; nevertheless they must be followed if impacts are to be mitigated. In most instances, these recommendations only require little effort which only needs to be considered during construction stage. These measures reflect the general aspects of the construction phase that involves both land and marine based development activities.
Proponent: Ministry of Housing, Transport and Environment Page | 69 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7.4.1 Civil works
7.4.1.1 Impacts
The undertaking of the proposed sewerage network development on Naifaru involves multiple tasks and use of machinery and other construction processes that will have its related impacts on the environment. The impact from civil works in the construction phase will have some degree of direct shot-term impacts on the island’s terrestrial and marine environment. These impacts will result from the following activities. • Excavation and laying of the outfall of the sewerage network • Possible dewatering for pipe laying and construction of manholes and pump stations • Possibility of sedimentation from excavated soil in case of rain • Excavating on the reef for laying part of the outfall including removal of large coral boulders. • Noise impacts during construction period.
Most of these activities are considered to have minor adverse environmental impacts. Impacts of constructional noise would not be considerable and the possibility of sedimentation from excavated soil is also inconsiderable given the topography of Naifaru. There will also be negligible impact on the flora and fauna of the island as there are no significant species. Excavation of trenches to lay the sewers/pipes is also considered to have minor, short term impact on the groundwater aquifer and does not require detailed analysis. However, the impacts of dewatering and excavation in the lagoon and reef flat would have moderate negative impacts and are discussed in detail.
Dewatering to lay the sewers and construct manholes, lift stations and pump stations
During the construction stage, excavation will occur to lay the sewer networks. However, in some areas, especially where the main sewer lines are laid, the pipes will be laid below the groundwater aquifer. Hence, the project will involve some dewatering of groundwater for laying of the sewer networks. An estimation of the numbers of sewer lines requiring dewatering and the possible extent of dewatering indicates that roughly 10-15% of the sewer laying works would require dewatering. The impacts of dewatering to lay the pipes and construct manholes in these sections would be felt on the groundwater aquifer. However, the impact will be small since dewatering will occur in sections as described in the mitigation section.
The pump stations have been located on the periphery of the island in the 50m boundary which is not considered to fall into the areal extent of the fresh groundwater lens of the island. Also, these locations are at a considerable distance from neighbouring household wells. Therefore, the impacts of small scale dewatering for the construction of manholes, lift stations and pump stations would be inconsiderable and would not influence the neighbouring wells. The impact would also be short-term allowing the aquifer to return to “normal” after rainfall.
Proponent: Ministry of Housing, Transport and Environment Page | 70 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Excavating reef areas at outfall locations
Over 30% of the entire length of the outfall falls on the coral reef areas. However, the impact on the reef would be minimal given that there would be no excavation although there would be some short term siltation during the installation as a result of wading and use of machinery on the housereef. This is confined to a small area along the length of the pipe on the reef. The pipe would be anchored using concrete blocks. The outfall pipe runs along about 70m of the reef flat. The outfall extends to about 7m below the surface from the reef edge. There may be removal of few small corals on the reef flat, slope and edge during the anchoring of the pipeline in these areas. This impact is considered to be minimal given that the live corals removed would be transplanted in the same area or any other area designated or preferred by the island community.
7.4.1.2 Mitigation Measures
General construction impact management
The following measures to minimize general impacts of construction will help to reduce or mitigate the impacts. • During the construction stage all activities should be supervised to ensure that construction is according to the required specification or standards and that no threat or damage to the environment other than that at the specific location occurs. • Appropriate waste handling, transportation and disposal methods for all waste generated during the construction works including parts of the existing system should be implemented to ensure that construction wastes do not pollute the environment. • Ensure that no leaks and accidental spillages of oil occur from vehicles and that they are maintained adequately. • Careful control should be exercised to ensure that no materials and machinery fuels enter the marine environment and cause contamination
Specific measures to mitigate dewatering and excavation impacts
The following measures will help to reduce or mitigate the specific impacts related to dewatering to lay the pipes and construction of manholes and pump stations as well as reduce impacts related to excavation of the reef flat. • No dewatering would be done for making good pipes joints underwater. In such circumstances, underwater fusion of pipes may be considered or pipes may be jointed ex-situ. • Dewatering would be undertaken only for the construction of manholes, lift stations and final pumping station, where necessary. In these areas, work may be restricted to low tides, etc. so that less dewatering would be required. • Outfall pipe would be buried only in the lagoon areas in order to protect the pipes from vessel and anchor damage. The reef section would be anchored to the seabed, thereby minimizing damage to coral.
Proponent: Ministry of Housing, Transport and Environment Page | 71 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
• Anchors would be placed on the reef areas by using manual methods and machinery would not be used on the reef areas.
Public Grievance
Effective grievance handling and redress systems are an important part of good governance for better public service delivery. Allowing people to register their grievance with officials in the field and at management level in various government agencies will ensure speedy corrective action and proactive decisions.
This section covers public grievances during the project planning and construction phase. Given the existing grievances over the project from different stakeholders, it is highly recommended that the Ministry develop a Grievance Redress Mechanism (GRM) and inform relevant parties of the proposed GRM. It is ideal to get written confirmation of the GRM from responsible parties acknowledging their awareness and responsibilities of the GRM. A draft mechanism is proposed here, which would have to be finalised and acknowledged by all concerned.
. The public shall approach the Manager at PIU with their grievances. The Manager will be available from (specific time) to (specific time) on (a particular day of the week) to receive/hear grievances of the Public . The Manager will treat all visitors to his office with courtesy and hear them patiently and try to facilitate solving their problems . In case of non-fulfilment from the Manager at PIU, the griever may approach the Island Councillor or the following officer at the Ministry (state name and designation and contact details of officer) . The Manager at PIU be authorised to redress public relating to their grievances within the same day . If the Manager is not able to redress the grievance, s/he shall forward the matter to the Island Councillor or the Ministry, whichever is applicable. If approached to the Island Councillor, s/he shall inform the Ministry of the grievance together with the response. . Within the Ministry, the person in charge shall be able to redress the grievance within seven days of receipt of grievance.
Impersonality that is an inherent feature of government organisations shall not be present in the grievance mechanism. Direct contacts shall be provided. Also, anyone wishing to lodge a grievance must be able to do so confidentially and so their privacy must be protected, especially if grievance relates to corrupt practices. In addition to the above mechanism, an electronic or web-based grievance lodging and monitoring system may be considered for those wishing to provide their input to design as well as their grievances through such means. In fact, comments to this EIA can be given via mail or phone to the EPA and the document can be accessed from the EPA website for a given number of days.
Proponent: Ministry of Housing, Transport and Environment Page | 72 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7.5 Operational Impacts
7.5.1 Groundwater
7.5.1.1 Impacts
The proposed sewerage system does not have additional benefits to the groundwater aquifer given that the present system minimizes the faecal contamination of the aquifer in the same way as the proposed system except potential leakage from catchpits which corrode due to poor construction. There would not be such corrosion in the case of the proposed system since construction material and workmanship would be carefully supervised by project engineers to ensure that sulphur resistant cement and other appropriate materials are used. The potential to cause increased salinization of the groundwater aquifer due to increased flushing as a result of improved sanitation facilities would also be similar to the existing system. However, this is not necessarily a direct result of the sewerage system but a cumulative impact caused due to increasing population and human needs and quality or standard of life. These two impacts are discussed in more detail in the following sections.
Improved quality of the groundwater lens
The groundwater aquifer of Naifaru has had little direct impact of sewage due to the existing sewerage system. However, there is a possibility that the proposed system would further mitigate the potential for contamination due to leaking catchpits. The proposed system will have improved materials and construction standards that would ensure that sulphuric compounds produced in the sewage would not cause the catchpits and manholes to corrode. In Malé, corroded or damaged catchpits has been the main cause for groundwater contamination resulting in increased levels of hydrogen suphide (sewer gas) in the groundwater aquifer. This gas has taken away lives including one death and few cases of poisoning in the late 90s and a recent incident in which five lives have been claimed. Therefore, further improvements to the system and subsequent positive impacts on groundwater quality expected from the proposed system would eliminate the potential for such incidents in the future.
Potential to aggravate the rate of salinisation of the groundwater aquifer
The most severe impact of a comprehensive sewerage system on the island is increased abstraction of groundwater from the aquifer. This will cause greater salinisation of the groundwater lens due to increased flushing. When the population of Naifaru increases and the water demand of the population increases, this impact would be exacerbated by the fact that the sustainable yield per capita is lower than the net water demand per capita. However, as mentioned earlier, this impact is not directly related to the sewerage system but adds to the stress on the aquifer of increasing population and water demand. It has been seen in many islands, including larger islands such as L. Gan, L. Fonadhoo and even FuahMulah, where there are no sewerage systems, that the main contributor to groundwater salinisation is the use of pumps and high pumping rates. With high pumping
Proponent: Ministry of Housing, Transport and Environment Page | 73 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru rates and increasing population, the groundwater lens is becoming more saline in addition to the deterioration in chemical and biological quality. Therefore, it can safely be argued that an increase in salinisation of the groundwater lens would become apparent in most of the islands, whether a sewerage system exists or not. Even in places where the sewerage system pumps all water out to the lagoon such as K. Gulhi, Lh. Naifaru and Lh. Hinnavaru, there is no data to suggest that the groundwater has become more saline due to the sewerage system. Some of these islands have groundwater of a quality similar to other similar islands where there is no sewerage system.
It has been observed that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. According to the Ghyben-Hertzberg principle for every feet of groundwater drawn from the surface of the water lens, salt water from below the lens pushes the water lens or the freshwater-seawater transition zone by 40feet (Freeze and Cherry, 1979), thereby making the freshwater at a particular location more saline than other areas. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. High rates of pumping are the main contributor to salinisation. This is the case in many islands, where the aquifer has become salty, even when there is no sewerage system. Therefore, as long as pumps continue to be used for groundwater abstraction, groundwater would become saline and no amount of recharge would guarantee a freshwater aquifer.
At present, salinisation of the water lens also occurs as a result of low gradients which aid seawater entering the system at high tide. However, the proposed sewer outfall is not expected to cause such backflow during high tide. Even if it does, the saltwater will not enter the groundwater aquifer unless it backflows from the pump station sump.
7.5.1.2 Mitigation Measures
The main environmental impact would be the potential for increased abstraction of the groundwater. This would enhance the potential for salinisation of the aquifer. Therefore, island sewerage systems development should go hand in hand or integrated with water resource management planning. Population planning would also be an integral part.
The main factors in determining the potential for salinisation of the water lens and how they can be effectively controlled would be: • Construction controls. Construction material and workmanship would be carefully supervised by project engineers to ensure that sulphur resistant cement and other appropriate materials are used.
Proponent: Ministry of Housing, Transport and Environment Page | 74 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
The use of pumps and flush tanks. Pumping has already been evidently causing severe salinisation of the groundwater aquifer in many islands of Maldives. Awareness is low on these issues. Therefore, creating awareness would play an important role in reducing water use. Cistern flush is common place but more people are going for dual flush tanks. So, increasing awareness on dual flush systems and other water conservation measures need to be considered in order to mitigate the impact of salinisation of the groundwater lens. Flushing volumes can be reduced by placing bricks, etc. in the cistern or by promoting dual flush units. Even more important is controlling the size of pumps in household wells. If pumps were to be used, skimming wells which will draw water from a larger area than a single point would also help to alleviate the problem of salinisation. Such technologies need to be tried in all islands of the Maldives for sustainability of the groundwater aquifer. Safe or sustainable yield vs population. Ensuring population does not outgrow safe or sustainable rates of groundwater abstraction is important. The safe yield for Naifaru has been determined based on assumptions of recharge from rainfall and freshwater lens area given by Falkland (2001). The estimates for different population sizes for Naifaru are given in Figure 5-2. Note that the sustainable yield varies with the size of the population. The estimates show that for Naifaru, the current population can sustainably draw a daily volume of 35 litres per person on average. The best estimates for Naifaru gives a sustainable yield of 247m3/day for the current population. This is assuming skimming wells or similar techniques/technologies were adopted.
Pipe to pump
Soil Soil
Inlet hole Inlet hole
Inlet hole
Groundwater
Figure 7‐1: Illustration of simple skimming well technology
Proponent: Ministry of Housing, Transport and Environment Page | 75 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7.5.2 Lagoon and seawater quality
7.5.2.1 Impacts
Marine water quality is not likely to be impacted from wastewater from the current population or even the predicted population as wastewater will be disposed in to the deep sea beyond the reef at a location that is considered to have strong currents moving parallel to the island and not towards the island most of the time. Considering the large dilution potential in combination with the effect from saltwater, most pathogens and nutrients will be dispersed and diluted, though one might assume long term impact, but not with huge impacts on the marine biota. Given that there will be secondary treatment for the sewage effluent that would be disposed at the proposed outfall, the impact would be almost negligible.
There will be positive impact on the lagoon water quality since multiple existing outfalls around the island would be removed and effluent disposal to nearshore environment would not occur. Therefore, marine water quality in the lagoon areas, especially in those locations where the outfall pipes of the existing gravity system are placed, would improve substantially, which can be verified by appropriate long term monitoring. Such improvement paves way for subsequent seagrass removal and management of lagoon waters, which is important for Naifaru.
7.5.2.2 Mitigation Measures
No detailed studies of the currents or modelling of the fate of effluent plume has been done since sewage treatment is considered for this project. Therefore, it is important that proposed secondary treatment process is kept operational at all times. If treatment were to be abandoned at any stage, more detailed assessment of the currents and deeper disposal of raw effluent may have to be considered.
In order to avoid conflicting scenarios with any cumulative impacts of solid waste management, it is important that solid waste is managed properly and its impact on the island’s shore and lagoon are minimized. Only then, would it be possible to directly associate any negative impacts on the environment with the sewerage system.
7.5.3 Coral Reef and Marine Biodiversity
7.5.3.1 Impacts
Discharges of sewage to the marine environment have the potential to cause: • Eutrophication of coastal waters due to chronic inputs of nutrients and organic matter; • Impacts associated with the accumulation of toxicants such as heavy metals in marine organisms and sediments; • Changes to the species composition of marine communities to higher abundances of species that are tolerant to pollution; and
Proponent: Ministry of Housing, Transport and Environment Page | 76 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
• Long-term degradation of sensitive environments such as coral communities and seagrass meadows by chronic exposure to sewage effluent.
The environmental impacts of sewage disposal on coral reefs depending on several factors including the quantity and characteristics of the effluent, level of pollutants, duration and timing of the peak discharges, diffusion efficiency of the outfalls, depth and location of outfalls, the oceanographic and hydrological conditions and the tolerance of marine organisms.
In the Maldives, there are very few studies that have attempted to collate information on the status of the coral reefs and response of reef fauna to sewage discharges. A study by Binnie Black and Veatch showed detrimental impacts of high sedimentation on coral growth and survival. However, the general concentration levels of total suspended solids in municipal sewage discharges have been found to be much below the levels that are generally considered to be lethal for corals. Studies carried out in the Maldives have also shown that: • Generally, the amount of nutrients that might lead to eutrophication was found to be very low in coastal waters • No effect on the level of temperature, salinity or dissolved oxygen were recorded • In many outfall locations in Male, the currents were quite strong that sewage concentrations were found to be diluted quickly and were not seen to affect general quality of the receiving waters • In Naifaru and Naifaru studies have indicated that nearshore outfalls can cause nearshore bathing waters to get dirty in colour and increased nutrient levels thereby promoting seagrass.
Pastorak and Bilyard (1985) had indicated that although a wide range of impacts from sewage on coral reefs have been reported, little or no impact has been observed in well flushed waters, as is the case in the proposed design for Naifaru.
Human population pressures and resultant developments are the greatest threat to coral ecosystems. Studies have concluded that eutrophication and sedimentation from effluent outflows are one of the most damaging anthropogenic activities to coral reefs and reef fisheries (Brown and Ogden, 1993). Effluent outflows from waste treatment plants or septic tanks generally increase the level of sediment and nutrients around its outlet and in shallow reef areas sewage outflows can diminish light penetration and increase algal growth; inevitably leading to coral bleaching and death (Brown and Ogden, 1993). In Maldives, fishermen have noticed a decline in the abundance of coral reef fishes and have also noticed a dramatic increase in algal growth amongst shallow reef areas. Many have attributed these changes to environmental degradation. As previously discussed however, in most of the densely populated islands, sea outfall have been installed using on gravity flow capability, consequently, the short outfall pipes have been located near the shoreline and shallower reef beds (Marine Research Centre, 2003).
Proponent: Ministry of Housing, Transport and Environment Page | 77 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
However, this is not the case for the proposed system in Naifaru. The outfall location has been considered to be in a well flushed channel, where strong currents would exist during both monsoons. The proposed secondary treatment of sewage effluent further minimizes the impact of effluent disposed at the proposed location.
7.5.3.2 Mitigation Measures
Minimising effluent disposal impacts
Based on the United Nations Environment Program the level of impact from sewage pollution on coral reefs is directly related to the level of treatment before discharge and the natural flushing by tides and currents upon discharge (UNEP 2002). Only deep-sloped outfalls can adequately disperse and dilute treated effluent via underwater currents. In Hawaii for example, secondary-tertiary treated sewage displayed no impact on the surrounding coral reef ecosystem because the outlet is at a depth of 35 feet (Dollar and Grigg, 2003).
Similarly, the proposed system in Naifaru would dispose at similar depths and also have a very high level of dilution due to hydrodynamic conditions prevailing at the outfall location. Therefore, the impact of sewage on the reefs or water quality at the outfall location would be almost negligible. Even if the sewage were disposed without treatment, the proposed depth and location is practical for the current or projected population of Naifaru to counteract the effects of outfall pipes on coral reef habitat in Naifaru. It is not anticipated that marine water quality or the reef is to be significantly impacted from the discharge of untreated wastewater due to the oceans large dilution potential in combination with the effect from saltwater. In this environment most pathogens and nutrients will be dispersed and diluted and the resulting impacts on the marine biota should be negligible and limited to the environment in the immediate vicinity of the outfall.
The other mitigation measures are similar to those given in the previous subheading.
7.5.4 Socio- Economic Impacts
The social implications of the proposed sewerage systems have been considered by assessing the projects direct and indirect benefits to the society. The social impacts include improvement of environmental health, increase in property values and additional gain in ecotourism potential. In summary, the social implications of this project are both real and perceived and are discussed below. Following are the potential benefits and other issues outlined by the communities with regard to the new sanitation project that is planned to be implemented
7.5.4.1 Solution to existing problems
One of the potential benefits looked forward by the whole community is a solution to the existing problems that they are experiencing with the current system. In Naifaru the existing problems as outlined earlier includes overflow of the toilets due to backflow at high tide and excessive expenses for cleaning and repairing. In addition
Proponent: Ministry of Housing, Transport and Environment Page | 78 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru contamination of the water is believed to be the cause of diarrhoea and other water borne diseases. All of the respondents are aware of these existing problems and many believe the biggest relief of establishing a suitable sewerage system would be the end of all the existing problems they are encountering at present.
7.5.4.2 Less expensive
It is expensive at the household level to hire workers to clean and repair the overflowing junction. The expenses range from Rf200 to Rf2000 and are as frequent as once a month. For some people of the island it is difficult and cannot afford to pay. So the whole community is looking forward for the new system which they believe would be less expensive and hassle free to maintain at the household level. Also, once the utilities company takes over the operations, sewerage services would not be reflected in the bill as sewerage services but may be integrated as a marginal cost into water tariff.
7.5.4.3 Healthy population
All the participants of the meeting unanimously agreed that the sewerage system will improve the island’s standard of living as they believe the system will reduce the number of diarrhoea cases and resolve the troubles caused as a result of the frequent overflow of wastewater drains. At present diarrhoea is common in the community. Reduced health risks such as skin rashes and diarrhoea associated with contact or ingestion of polluted water will significantly improve the environmental health status of the island with social implications. Generally poor communities are more vulnerable to the effects of environmental contamination as they tend to use, or are forced by circumstances to use. The lagoon in Naifaru is seldom used for recreation, and groundwater is used for washing, and food preparation. With the improved sewerage system proposed, restoration of marine water quality and recreational amenity of the lagoon is expected to take place.
7.5.4.4 Strengthening social cohesion and employment opportunities
Implementation of the sewerage system involves lot of activities and work by the community. Such opportunities of working together will strengthen the community spirit and confidence of the community strengthening social cohesion. The whole community is looking forward for the start of the project.
During the operational stage, there will also be job opportunities for local residents as staffing will be required for operation and maintenance once the system is in place. These new job opportunities will stimulate the economy and mobilize potential residents who are unemployed. Once the system is developed, the job opportunities created will also increase knowledge and capacity of staff on water and wastewater, thus increasing their economic potential elsewhere.
Proponent: Ministry of Housing, Transport and Environment Page | 79 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
7.5.4.5 Willingness to pay
In order to understand the community willingness to contribute in maintaining the sanitation system questions were asked on amount than they can contribute on a household basis. All were very positive with variations in their response and none of them opposed to the idea of fee being implemented as they believe that it is up to them to sustain the system. However, it is not the case anymore. The government has shifted the traditional thinking of community managing their utilities to public management of utilities in a sustainable manner so that communities can focus on other development issues than basic utilities. Since, there is willingness to pay for improved sewerage services, a marginal reflection of the costs of such a service provision in their overall utilities bill or water bill would not be a cause for concern for many.
As indicated earlier, levying charges for sewerage services is difficult, and so is penalizing because disconnecting sewerage service is difficult. A disconnection to a sewerage service would mean provision of several public toilets within easy reach. It may be assumed that over 70% of the households would not pay for sanitation directly but it has to come through indirect taxation. Since sanitation is often regarded as a public service that has to be financed through indirect taxation by the government or municipalities (island communities), discussing measures to cover those who cannot pay and measures to deal with those who would not pay would not be sensible.
7.6 Uncertainties in Impact Prediction
Environmental impact prediction involves a certain degree of uncertainty as the natural and anthropogenic impacts can vary from place to place due to even slight differences in ecological, geomorphological or social conditions in a particular place. There is also no long term data and information regarding the particular site under consideration, which makes it difficult to predict impacts. However, the level of uncertainty, in the case of Naifaru may be expected to be low due to the experience of similar projects in similar settings in the Maldives. Nevertheless, it is important to consider that there will be uncertainties and to undertake voluntary monitoring as described in the monitoring programme given in the EIA report.
7.7 Summary of Impacts
The following table summarises the impacts and provides a matrix that will help evaluate the merits or demerits of the proposed system against other options. However, this has not been done for the alternative options because of time constraints and as it is not within the scope of the EIA. The first matrix gives the values for magnitude, significance/reversibility, duration and extent (spatial distribution) measured according to the following table.
Proponent: Ministry of Housing, Transport and Environment Page | 80 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 7-2: Impact matrix scale Criteria Scale Attribute Magnitude -3 Major adverse Change caused by impact -2 Moderate adverse -1 Minor adverse 0 Negligible 1 Minor positive 2 Moderate positive 3 Major positive Significance 0 Insignificant Impact implications / Reversibility of 1 Limited implications / Easily reversible impact's effects 2 Broad implications / Reversible with costly intervention 3 Nationwide implications / Irreversible Duration 0 Immediate Duration / Frequency of Impact 1 Short term/construction period only 2 Medium term (five years of operation) 3 Longterm/continuous Extent/Spatial Distribution 0 None/within 1m from point of discharge Distribution of impact 1 Immediate vicinity/Household level 2 Specific areas/elements within the island/atoll 3 Entire island/atoll
Table 7-3: Impact Matrix for the proposed sewerage system
KEY COMPONENTS Environment Socio-Economic
PROJECT ACTIVITIES Reefs Seagrass Bait Live Erosion/Accretion Lagoon/seawater Soil and groundwater Wetlands Land/seascape Air/Noise allocation Resource aesthetics and Recreation Services and Infrastructure Safety and Health Employment Diversification Economic Property Value Landuse Costs to consumer/tax payer Life of Quality Construction 3 2 1 1 1 1 -1 0 3 2 3 2 2 1 1 1 2 3 2 2 -2 3 3 2 Removal/modification of existing sewer network 2 3 1 2 1 2 1 1 3 2 3 2 1 3 1 3 3 2 3 3 1 3 3 3 -1 1 -1 0 -1 0 -1 0 -1 1 -1 1 2 1 1 1 -1 0 -2 3 Excavation/backfilling for laying pipes 1 2 1 2 1 1 1 1 1 2 1 1 1 3 1 3 1 1 1 3 -2 2 -1 0 -1 0 -1 1 2 1 1 1 -1 0 -2 3 Dewatering for laying pipes 2 2 1 1 1 1 1 2 1 3 1 3 1 1 1 3 -1 1 -1 0 -1 0 -1 1 -2 1 2 1 1 1 -1 0 -2 3 Excavation/backfilling for lift and pump stations 1 1 1 1 1 1 1 2 1 1 1 3 1 3 1 1 1 3 -2 2 -1 0 -1 0 -1 1 2 1 1 1 -1 0 -2 3 Dewatering for lift and pump stations 2 2 1 1 1 1 1 2 1 3 1 3 1 1 1 3 -2 1 -2 0 -1 1 -1 0 -1 0 -1 0 -1 1 -2 1 2 1 1 1 -1 0 -2 3 Construction of sea outfalls 1 2 1 2 2 3 1 1 1 1 1 1 1 2 1 1 1 3 1 3 1 1 1 3 -1 0 -1 1 -1 1 -1 1 1 1 1 1 2 1 -1 0 -2 3 Machinery, equipment and site installations 1 1 1 1 1 2 1 1 1 3 1 3 1 1 1 1 1 3 -1 1 -1 1 2 1 1 1 2 1 2 2 1 0 Workforce management 1 2 1 1 1 3 1 3 1 1 1 3 1 1
Operation -3 3 -2 3 -2 1 -2 2 -2 1 1 1 Toilet flushing/groundwater abstration 3 3 3 3 3 3 3 3 3 3 3 3 -1 2 1 2 3 2 3 2 1 0 3 2 1 1 2 2 1 1 2 1 2 1 -1 2 2 2 Effluent discharge/management 3 1 3 3 3 3 3 3 3 3 3 3 3 2 3 3 3 2 2 2 2 2 2 3 3 3 -1 1 1 1 1 1 -1 2 Sludge disposal/management 3 1 3 2 3 2 2 3 1 1 1 2 1 1 -1 0 1 1 -1 1 1 0 1 1 -2 2 -2 3 2 0 Treatment plant operation and pumping 3 1 3 3 3 3 3 2 3 2 3 2 3 2 3 2 3 2 3 3 3 3 2 3 2 1 1 1 -1 1 -1 1 1 1 Admin and finance (Tariffs/fee collection) 3 3 3 2 3 3 3 2 3 3 3 3 -1 0 1 1 -1 1 1 1 1 1 -1 1 -1 2 1 1 System maintenance and repairs (technical) 3 3 3 2 3 2 3 2 1 3 3 2 3 3 3 3
M S M = Magnitude S = Significance D E D = Duration E = Extent (spatial distribution)
Proponent: Ministry of Housing, Transport and Environment Page | 81 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table below is the product of the above matrix which gives the activity potential impact index and the environmental component potential vulnerability index. This table indicates that the considering the impacts of all project activities on key environmental, social and economic components of the project, the proposed project has an overall positive impact.
Table 7-4: Product of the impact matrix
KEY COMPONENTS KEC KSC KEcC TOTAL API Soil and groundwater Wetlands Land/seascape Air/Noise allocation Resource aesthetics and Recreation Services and Infrastructure Safety and Health Employment Diversification Economic Property Value Landuse Costs to consumer/tax payer Life of Quality PROJECT ACTIVITIES Reefs Seagrass Bait Live Erosion/Accretion Lagoon/seawater Construction Removal of existing sewer network 0 0 0 0 0.44 0.02 0 0.02 0 0 0.44 0 0.44 0.07 0.04 0.44 0.44 -0.22 0.67 2.8 Excavation/backfilling for laying pipes 0 0 0 0 0 -0.02 0 0 0 0 0 -0.02 -0.01 0.07 0.04 0 0 -0.22 0 -0.16 Dewatering for laying pipes 0 0 0 0 0 -0.2 0 0 0 0 0 -0.02 0 0.07 0.04 0 0 -0.22 0 -0.33 Excavation/backfilling for lift and pump stations 0 0 0 0 0 -0.01 0 0 0 0 0 -0.02 -0.02 0.07 0.04 0 0 -0.22 0 -0.16 Dewatering for lift and pump stations 0 0 0 0 0 -0.2 0 0 0 0 0 -0.02 0 0.07 0.04 0 0 -0.22 0 -0.33 Construction of sea outfalls -0.05 0 -0.07 0 0 0 0 0 0 0 0 -0.02 -0.02 0.07 0.04 0 0 -0.22 0 -0.27 Machinery, equipment and site installations 0 0 0 0 0 0 0 0 0 0 -0.01 -0.02 -0.01 0.04 0.04 0.02 0 -0.22 0 -0.16 Workforce management 0 0 0 0 0 0 0 0 0 0 0 -0.02 -0.01 0.07 0.04 0.02 0 0.15 0 0.25 Operation Toilet flushing/groundwater abstration 0 0 0 0 0 -1 0 0 0 -0.67 0 0 -0.22 0 0 -0.44 0 -0.22 0.11 -2.44 Effluent discharge/management -0.07 0.22 0 0 0.67 0 0 0.67 0 0 0.67 0.07 0.44 0.07 0 0.1 0.1 -0.15 0.44 3.23 Sludge disposal/management 0 0 0 0 0 -0.04 0 0 0 0 0 0 0.07 0.07 0 0 0 -0.15 0 -0.05 Treatment plant operation and pumping 0.04 0.22 0 0 0.11 0 0 0 0 0 0.07 -0.07 0 0.07 0 0 -0.3 -0.67 0 -0.53 Admin and finance (Tariffs/fee collection) 0 0 0 0 0 0 0 0 0 0 0 0.67 0 0.15 0 0.11 -0.07 -0.11 0.11 0.86 System maintenance and repairs (technical) 0 0 0 0 0 0 0 0 0 0 0 0.07 -0.07 0.07 0.04 0 -0.07 -0.22 0.11 -0.07 TOTAL CPVI -0.08 0.44 -0.07 0 1.22 -1.45 0 0.69 0 -0.67 1.17 0.6 0.59 0.96 0.36 0.25 0.1 -2.91 1.44 2.64 API = Activity Potential Impact Index CPVI = Component Potential Vulnerability Index
Proponent: Ministry of Housing, Transport and Environment Page | 82 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
8 Alternatives
This section looks at alternative ways of undertaking the proposed project. There are two basic options: (1) leave the problem as it is (no project option), or (2) take measures to resolve the problem (undertake the project options). If the project were to continue, it would be necessary to take economic, ecological and social aspects of the project into consideration and ensure that these concerns exist within a delicate balance. Neither the economic benefits nor the social and ecological concerns can be avoided. Therefore, it is important to consider all options and ensure that the best available option(s) is/are chosen to solve the issues/problems.
8.1 No project option
It should be noted that the “no project” option cannot be excluded without proper evaluation. In this report this alternative was considered as the baseline against which to evaluate the other options. The no project option takes the following into consideration: • Existing groundwater contamination and pollution of the nearshore environment will be allowed to continue • Existing health and other socio-economic impacts of the project will remain and continue to worsen • Existing public frustration will continue to worsen and may lead to political unrest
The main advantages and disadvantages of the no-project option are given in Table 8-1.
Table 8-1: Advantages and disadvantages of the no project option Strategy Advantages Disadvantages Allow further groundwater contamination Costs related to improving the situation Burden of diseases may increase and pollution of nearshore environment may be avoided in the short term Long term socio-political problems may arise Greater long term costs An important water resource will eventually be lost and alternatives sources sought Try to improve the situation by providing Reduction in groundwater salinisation rate Will not address current concerns appropriate guidelines (soft interventions Short term costs may be avoided adequately such as minimize use of pumps, subsidies Pollution of nearshore environment may not for maintenance, etc.) be a short term issue
8.2 Alternative Sewerage Systems
For the islands of the Maldives, it is preferable to adopt simple and environmentally sound technologies that require minimum maintenance. Therefore, the following options which may be adopted for Naifaru have been selected after careful consideration of socio-economic, technical and environmental aspects. As per MWSA’s Design Criteria, there are certain elements that would be considered common, whatever the system is employed. For instance, even if treatment plant is considered, an overflow pipe for raw sewage/wastewater shall be provided,
Proponent: Ministry of Housing, Transport and Environment Page | 83 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru with outfall discharging to offshore, high current location outside the reef edge using submersible pumps located or housed in a pumping station. So, alternatives for the outfall or overflow pipe would not be discussed.
There are three main alternative considerations. They are alternatives for sewage conveyance (sewer line), alternatives for sewage treatment and alternatives for final disposal. The basic alternatives for each, which have been tried or are under trial in the Maldives are discussed in the following subheadings.
8.2.1 Sewage collection
There are three different options for the collection or conveyance of sewage in a sewer network. These are the gravity system, pressure system and the vacuum system. Of these options, the most practicable option for the Maldives due to several advantages as enlisted in Table 8-2 is the vacuum system. However, the vacuum system has not so far been implemented in the Maldives except in Landaagiraavaru Resort in Baa Atoll. Four more vacuum systems are proposed to be tried under tsunami assistance from UNICEF. These are currently under implementation. As a result, vacuum system has not been considered for Naifaru.
8.2.1.1 Gravity system
The existing system in Naifaru is a gravity flow sewerage system. Gravity sewers convey the sewage with the help of gravity and without the use of pumps or mechanical pressure systems. The advantage of gravity system is that there would not be a need for electrical components. However, adequate gradients in sewer network has to be met, as a result of which trenching or excavation for laying pipes would be deep and outfalls would be quite short and several outfalls have to be used. Gravity systems are often referred to as small bore sewerage systems.
8.2.1.2 Pressure system
A pressure system is a gravity flow system up to a certain depth, after which lifting stations are used to pump the wastewater to a final pumping station that pumps the final effluent from all lift stations directly to an offshore location at the proposed outfall. In this system, the collection system is designed to minimize the multiple outfalls with small bore sewers or gravity sewers. These systems are often referred to as conventional sewerage systems.
8.2.1.3 Vacuum system
A vacuum system conveys sewage and wastewater by sucking the wastewater by creating a vacuum inside the system. In a vacuum system, five or six homes can be connected to one interface valve unit. The vacuum pipeline conveys the sewage to the ejector pump station that creates the vacuum and delivers the influent to the pumping station or treatment works. The ejector pump stations would be similar to lifting stations in the proposed pressure system.
Proponent: Ministry of Housing, Transport and Environment Page | 84 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
8.2.2 Sewage treatment
8.2.2.1 Individual septic tanks
The existing system in Naifaru is a gravity flow sewerage system with catchpits at the household level, which the households find difficult to clean or maintain regularly. Therefore, an improvement to the existing system with septic tanks in place of catchpits would dramatically reduce the frequency of cleaning and maintenance. However, individual septic tanks are not appropriate for Naifaru due to lack of space in house plots. Therefore, this system has not been considered. Also, individual septic tanks would drastically increase the cost of the project. Furthermore, the use of septic tanks improves the quality of the effluent disposed via existing multiple outfalls, however, does not minimize the number of outfalls nor does it help to increase the length of the outfalls. Also, the problem of backflow during high tide would remain to be a cause for concern.
Advantages and disadvantages that have been identified include: • May recharge groundwater but deteriorate groundwater quality since septic tanks only remove less than 50% of the BOD. • High cost of septic tank and soakage pit and land availability need to be checked. • Requires sludge removal by house holders.
8.2.2.2 Communal septic tanks
Communal septic tanks work on the same principle as individual septic tanks. However, communal septic tanks require more single space than individual septic tanks. Therefore, communal septic tanks may also not be suitable for Naifaru given the lack of space.
8.2.2.3 Packaged treatment plants
Packaged treatment plants capable of secondary treatment to reduce BOD and nutrients to acceptable limits have been used in several resorts. However, these are small treatment units, which are costly. Some of the systems proposed under tsunami assistance have been designed with packaged treatment plants, mainly activated sludge treatment systems. The vacuum systems proposed under UNICEF assistance for four islands considers such treatment plants. Project for Th. Vilufushi considered a RBC (Rotating Biological Contactors) unit as the treatment system.
8.2.2.4 Reed beds or leaching fields
Furthermore, treatment beds or filtration beds have been tried in the Maldives in Kulhudhuffushi under the Regional Development Project Phase I in 2003 as a pilot project, the results of which were not so promising. Later in 2006, a project in Isdhoo-Kalaidhoo by the Japanese Government also considered reed beds, which had
Proponent: Ministry of Housing, Transport and Environment Page | 85 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru yet to be evaluated. The system in Isdhoo-Kalaidhoo is also quite expensive that further consideration would be given for replicating the system elsewhere in the Maldives. These system are also suitable for larger islands like Isdhoo-Kalaidhoo due to space requirements and not for Naifaru where there would be space constraints for such a system.
8.2.2.5 Natural treatment
Most of the treatment units discussed above treat sewage by natural means, by allowing aerobic or anaerobic bacteria to decompose the sewage thereby reducing its BOD. However, these systems require confined spaces which are hard to be found in the small islands of the Maldives. So, given the small population of almost every island in the Maldives except Malé and that only residential wastewater effluent would be discharged, it has been shown that if the effluent was disposed directly into the abundant sea, it would provide adequate mixing, dilution and treatment. However, according to MEEW (Water Section), this cannot be considered. That is the current thinking of the Ministry as well as the Maldives Water and Sanitation Authority. Therefore, this system is not considered as the preferred alternative although the Consultant’s believe that Naifaru would not require sewage treatment if the wastewater from the current population can be disposed at an appropriate location and depth as determined by appropriate modelling studies. In fact, it has been shown that for a population less than 10,000 adequate dilution would be provided even under worst case scenario if untreated wastewater were to be disposed off in an appropriate location (Johnson et al, 2007; WS and LHI, 2006). However, MEEW (Water Section) is of the opinion that treatment shall be considered as long as monitoring of those projects that dispose raw sewage have not been able to demonstrate positive results.
8.2.3 Disposal
There are three basic mechanisms considered for wastewater disposal in the Maldives. They are: (1) disposal to ground, (2) disposal to lagoon, and (3) disposal to sea. Disposal to ground and lagoon can only be considered if secondary level of treatment can be provided. However, disposal to sea at appropriate locations may be considered even without treatment if it can be demonstrated that adequate mixing and dilution would be achieved at the given location.
8.2.3.1 Disposal to Ground
This is the common practice in the Maldives due to its cost-effectiveness. In most islands, poorly constructed septic tanks or solid separation chambers are directly connected to an infiltration bed made of coral rubble. Some people have two or more chambers in their septic tank system. However, the level of treatment provided by such septic tanks is not adequate for disposing the effluent to the ground. Due to the superficial nature of the groundwater lens, the water lens gets easily contaminated with faecal coliforms, nitrates and phosphates mainly.
Proponent: Ministry of Housing, Transport and Environment Page | 86 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Recently, the vacuum systems proposed by UNICEF do not have any marine outfalls but treated effluent is proposed to be used for gardening and discharged into ground for groundwater recharge. The EIA for Ungoofaaru specifically states that there would not be much benefit from the proposed recharge but it would increase the nutrient levels of the groundwater thereby making it smelly and making people to refrain from using it (Water Solutions 2007).
8.2.3.2 Disposal to lagoon
In islands, where small gravity flow systems have been designed for reasons of cost-effectiveness, disposal has been primarily via lagoon outfalls. The first few sewerage systems constructed in places such as Naifaru, Naifaru, Thulhaadhoo, Kandholhudhoo, Komandoo, Gulhi and Thinadhoo in the past have failed to achieve the objectives primarily because wastewater effluent is disposed to lagoon or nearshore environment. However, some of these systems with septic tanks have been seen to be working effectively in some places such as Gulhi. Yet, according to the island chief of Gulhi, during a site visit under a previous project, they have made requests to the government to provide pumping stations and pump the effluent away from the clear lagoon areas purely for aesthetic reasons.
8.2.3.3 Disposal to sea
Disposal to sea has been considered by the Government as the most practicable method of disposal. For this reason, emergency by-pass outfalls have been proposed for all systems (with or without treatment) under the Design Criteria prepared by MWSA. Disposal to sea means disposal to an appropriate location off the reef edge and at a suitable depth that mixing and dilution ensures that sewage is diluted before it reaches the surface and also does not directly dispose onto the seabed or reef. Disposal to sea is naturally a suitable option due to its dilution potential and its characteristics such as adequate flow and salinity which ensure that faecal coliforms would not survive for longer periods and distances as in groundwater and lagoon water. However, disposal to sea would be more expensive than disposal to ground or lagoon, yet have clear long term benefits that would over- ride the cost implications. Disposal to sea has economic advantages over other treatment options too.
8.2.4 Other Alternatives
8.2.4.1 Greywater separation
A system which separates grey and black water is also suitable and will enable some recharging of the groundwater (mainly during the dry period) if grey water is recycled back in to the aquifer. However, such a system will require additional reticulation system for grey water separation and ultimate discharge. Although grey water is relatively free from contaminants, it has several harmful substances such as phosphates from soap and detergents. These chemicals can be harmful if they are allowed to enter water bodies. Therefore though grey
Proponent: Ministry of Housing, Transport and Environment Page | 87 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru water disposal is an option, it has also to be treated to some stage prior to disposal. These factors make it unattractive as such a system will increase the capital costs of the project. Furthermore, maintenance is also going to be a significant challenge. Last but not least, the limited space available in the island will be a limiting factor for a complex system.
It is often believed that greywater recharge would help improve groundwater, however, the fact is that greywater recharge would contribute very little to slow down salinisation of the groundwater aquifer and would not be economically feasible given the cost implications of greywater recycling. In fact, the Maldives receives well over 2000mm of rainfall, which would be more than sufficient to recharge the aquifer. Yet, the aquifer, similar to a rainwater tank, has its maximum capacity limits and cannot overgrow the impact imposed by high rates of abstraction. It has been shown that the rate of groundwater pumping is the main factor contributing to salinisation of the lens. Therefore, sustainable rates of pumping can only ensure sustainable management of the aquifer, as has been discussed earlier.
It has been observed from data collected even in the late 90’s for Malé that the freshwater aquifer is of good quality in areas where the abstraction is small and quite saline in areas where there is high abstraction. Even wells in the vicinity of a well with freshwater may have more brackish water. Therefore, it is known that freshwater exists in pockets. Where the drawn down effect is high, due to the size of pumps and rate of pumping, there is a tendency for the water lens to become more saline at the location where the drawdown is greater. According to the Ghyben-Hertzberg principle for every feet of groundwater drawn from the surface of the water lens, salt water from below the lens pushes the water lens or the freshwater-seawater transition zone by 40feet (Freeze and Cherry, 1979), thereby making the freshwater at a particular location more saline than other areas. This draw down or lowering of the water table at the point of abstraction, sometimes referred to as the “coning effect” for the freshwater lens, can only be avoided with the use of appropriate technology such as skimming wells and infiltration galleries. High rates of pumping are the main contributor to salinisation. This is the case in many islands, where the aquifer has become salty, even when there is no sewerage system. Therefore, as long as pumps continue to be used for groundwater abstraction, no amount of recharge would guarantee a freshwater aquifer.
In addition to the use of pumps, it has been observed in Dhidhdhoo that tidal influence also disturbs the groundwater lens. Houses in the areas most severely subject to storm surges have very brackish groundwater. Some of these houses, therefore, have tried and tested a technology that draws groundwater at a near-sustainable rate. This technology, which may be referred to as skimming wells, has been considered in the EIA report as a mitigation measure to overcome the impacts of salinisation of the groundwater lens.
It is not necessarily true that the interval of rainfall (frequency) is important in considering the recharge potential of precipitation. However, the amount of rainfall (intensity) is more important. According to the USGCRP team
Proponent: Ministry of Housing, Transport and Environment Page | 88 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
(Carter et al 2001), “the size of the groundwater lens is directly related to the size of the island… (and) also related to the normal amount and type of precipitation (e.g., heavy downpours recharge lenses, while light rain generally does not)”. Therefore, the type of rainfall that occurs in the Maldives with high intensity-high duration- low frequency rainfall is useful for the development of groundwater lenses in low-lying islands. It is also important to note that the aquifer (like a rainwater tank) has its own capacity and not every drop of rainwater will percolate to contribute to the freshwater lens. This argument also supports the belief held by the consultants that aquifer recharge is not easily possible by grey water recharge.
8.2.4.2 Deep disposal wells
There is also an appropriate technology that can be applied to reduce risks of marine pollution. This method involves the disposal of effluent into deep disposal wells in to the salt water strata, below the upper fresh water zone. The well is designed and constructed so as to isolate the upper zone from any risk of contamination from the effluent being disposed of. The depth of well is approximately likely to be 20 to 40 meter, depending on the hydro-geological situation.
The benefits of disposing sewage effluent to the lower zone are a much-reduced environmental impact and health risk because of the following. • Dispersion and dilution in to a large body of underground water that is very unlikely to come in to contact with man or the near shore environment • Possibility of anaerobic treatment taking place over a significant period of travel time, killing off most of the dangerous contaminants and substantial gentrification before the water flows to the open sea • In islands with large reef systems, the construction of the outfall may require damage to the reef and sometime blasting of hard coral. In such instances, deep disposal wells may be extremely practical though the initial investment may be higher. • Outfalls may be aesthetically unappealing • Likelihood that if the groundwater does flow to the open sea, then the depths encountered probably mean that it would not enter the open sea until far out from land. This will mean that elevated nutrient levels caused by disposal of sewage to near shore environment will not occur, preventing the marine damage that is evident from the existing systems.
The well can be located at the edge of the island where fresh groundwater is unlikely to exist, and reducing risks even further as the groundwater flow will always be from the centre of the island towards the sea. However, this technology requires the use of larger pumps to inject the wastewater into such depths resulting in high initial investment as well as high operational costs. Therefore, deep disposal wells have not been considered appropriate for Naifaru.
Proponent: Ministry of Housing, Transport and Environment Page | 89 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
8.3 Preferred Alternative Sewerage Systems
8.3.1 First Preference
The first preference would be to consider the proposed system without treatment and two outfalls: one is the proposed outfall and the other is the proposed alternative outfall at the southeast corner of the island. Both outfalls will discharge at a depth of 12-15m below the reef edge since there will be no treatment and both outfalls are expected to create appropriate conditions for dilution given that the flow would generally be diverted into the channels between Naifaru and the two islands on the south and north of Naifaru. This option is preferred for the following reasons:
. Environmental impacts of disposing untreated sewage to the open ocean via ocean outfalls discharging at appropriate depths have very low health and environmental impacts . Capital and operational costs as well as odour and physical space issue related to the sewage treatment plant can be avoided . Since emergency overflow outfalls are required for pumping stations (as per the Guidelines for Wastewater Disposal), all pumping stations would require a gravity sea outfalls for emergency use.
8.3.2 Second Preference
The preferred second alternative is the vacuum system with sea outfalls. Since vacuum system has not been considered in detail in this document, some details of the vacuum system is considered below.
Figure 8-1: Schematic diagram of the Vacuum System (Source: Roevac Manual)
While the system has been well tested in many parts of the world the system is new to the inhabited islands of Maldives. While this in itself is not a problem, the fact that it has not been used on the inhabited islands, it does not provide any case studies for comparison with other systems.
The problems that have been put forward include greater maintenance costs, resources and importance for an O&M programme – if this is a comparison between the gravity system and the vacuum system then this is probably true, however as the vacuum system conveys the solid matter as well as the liquid then the gravity
Proponent: Ministry of Housing, Transport and Environment Page | 90 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru system should include the septic tank cost of a team to manage desludging and disposal. The costs of fuel, spares maintenance costs of running a tractor and vacuum pump and tank need to be included. It may be more expensive to operate a team dedicated to sludge removal and disposal rather than a centralized system where a skilled team of utilities workers are based who manage the sewage treatment, island power generation, and water supplies.
The main problem with the existing vacuum sewers in the four islands of R. Ungoofaaru, N. Manadhoo, F. Nilandhoo and Dh. Meedhoo is the electrical cost, which amounts to close to RF60,000 a month. In addition to this, the same systems also require pumping station and ocean outfalls. Therefore, these systems become cost prohibitive.
The other potential problem that has been identified is that if the vacuum system was introduced on few islands it would be only be required for those islands for spares and technical know-how.
Table 8-2: Comparison of pressure system (gravity system with pumps) and vacuum system Gravity System with pumps Vacuum System The island being flat where depth is limited due to high water The vacuum system allows shallow trenching to be used resulting table would require lift pumps and lift stations in substantial excavation cost savings and reduced installation time. The island has high water table and excavation will expensive, The vacuum system on the island will minimize dewatering and time consuming and will require trenching stabilization to avoid eliminate the need for trench stabilization trenches from collapsing on the workers or destabilizing houses
The wide and deep trenches required for the gravity systems will Small diameter mains allow for shallow and narrow trenching play havoc with the roads and narrow lanes on the islands thereby minimizing construction time and environment disturbances With gravity systems it is possible for exfiltration to occur with With a vacuum system – infiltration can occur if a main pipe is contamination of the fresh water lens. It is also possible for broken and this will be detected. Exfiltration does not occur due infiltration to occur which can lead to over loading at the to the nature of the system. treatment plant. To detect where exfiltration or infiltration is occurring is almost impossible to detect.
Unforeseen obstructions such as rocks can cause expensive The vacuum system can easily be laid around an obstruction rerouting of pi pes
200 up to 400 mm diameter concrete pipe and vitrified clay pipe 90 up to 200 mm diameter PVC or HDPE vacuum sewer mains sewer main are typical with material and heavy transport costs are typical. The cost of installing vacuum piping is much lower and unit labor costs than gravity pipes.
Proponent: Ministry of Housing, Transport and Environment Page | 91 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
9 Monitoring and Environmental Management Plan
9.1 Introduction
This section will look at the proposed monitoring programme that shall be undertaken by the PIU in collaboration with environmental consultants first and then summarise the impacts, mitigation and monitoring in an Environmental Management Plan (EMP). The EMP provides a summary of the significant adverse environmental impacts anticipated to arise due to the implementation of the proposed project and the mitigation measures as well as the monitoring programme needs associated with those impacts. The details of the impacts and the proposed mitigation measures have been discussed in the previous section on impacts and mitigation.
The monitoring programme shall continue for a period of at least 5 years in order to understand the impacts and benefits of the system. Annual monitoring reports (summarizing the findings from the annual monitoring) need to be submitted to the Ministry of Housing, Transport and Environment (MHTE) at the end of each year including monitoring records and field inspections during the construction phase.
It is important that information and experience gained through the implementation of the Environmental Management Plan and proposed monitoring activities are fed back into the EIA evaluation and analysis system to improve the quality of future assessment studies.
9.2 Monitoring Requirements
9.2.1 System Performance and Water Quality
For system performance, leaks in the system would be the main parameter to monitor. For water quality, ground, lagoon and marine samples must be monitored. The ground samples will help to establish the impact of groundwater use for flushing and any improvements in biological quality due to improved system. The lagoon water quality results will help to establish that lagoon water is improving because of the improved system with only one or two outfalls and the removal of multiple nearshore outfalls. For sea outfalls, water quality is not expected to have major impacts, however, monitoring for the first two years would be useful. Phosphorus and nitrogen being the concerning pollutants, they would be the main parameters to monitor for the sea outfalls. Research in the Caribbean and in the Great Barrier Reef of Australia has established the critical levels of nitrogen and phosphorous which must not be exceeded if reefs are to remain healthy without being overgrown by weedy algae (Lapointe et al., 1992, 1993, Bell, 1992).These concentrations are: • Nitrogen: 0.014 ppm N or 0.040 ppm NO3 • Phosphorous 0.003 ppm P or 0.007 ppm PO4
Proponent: Ministry of Housing, Transport and Environment Page | 92 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 9-1: Monitoring performance and water quality Impact Area Data sought Min. Frequency Purpose Groundwater pH, E-Conductivity, TDS, total and faecal Every three months To ensure effectiveness of the coliforms, nitrates, nitrites, BOD and initially, then every six proposed systems
phosphorus, H2S gas months To base groundwater protection measures System performance Inspect and report leaks in sewerage Once a year To ensure appropriate system performance No. of blockages reported Lagoon pH, E-Conductivity, TDS, total and faecal Every three months To ensure effectiveness of the coliforms, total nitrogen, BOD and total initially, then every six proposed systems phosphorus months or annually Sea outfall/marine pH, E-Conductivity, TDS, total and faecal Every three months To ensure effectiveness of the coliforms, nitrogen, BOD, phosphorus initially, then every six proposed systems and chlorophyll-A months or annually
9.2.2 Monitoring dewatering impacts
The water quality and water levels of selected houses would be monitored just before, during and after the project to understand the changes due to dewatering. The parameters to be monitored from each well would be pH, E- Conductivity and tidal water level variations. This impact specific monitoring will be undertaken only during the period of the impact.
9.2.3 S ocio- Economic Aspects
One of the key aspects of sustainable sanitation is the contribution that a proper sewerage system makes towards overall health of the population and community development. Therefore, such systems must be able to demonstrate their contribution towards social and community development through economic contributions and awareness creation.
A healthy environment should in turn mean opportunities for improved health and community development for the residents of Naifaru. Another key indicator of system sustainability will be the community’s capacity to maintain and operate the system without undue financial or mental stress. A monitoring protocol to review costs associated with operation and maintenance of the system should be a component of the operating manual. In the first year following the implementation of the system, resident concerns should be promptly addressed, noted and resolved. A survey of residents to assess and track their level of satisfaction with system should also be undertaken following the first year of system operation, so that issues might be addressed before they become serious.
Proponent: Ministry of Housing, Transport and Environment Page | 93 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 9-2: Indicators for monitoring of socio-economic aspe cts of the project DIRECT IMPACT INDICATORS
Indicator Assessment question Source of information
1. Access to water What are the changes occurring regarding the Island office records access to safe water? Focus Group Discussion No of households using different types of water by purpose
E.g. Households using ground water for cooking / drinking/ washing/ bathing/ agricultural purposes. Households using purified water for drinking/washing/bathing/agricultural purpose 2. Incidence of water borne diseases What are the changes occurring regarding the Atoll hospital records Diarrhoea incidence of water borne disease? Focus group discussions Typhoid Cholera 3.Employment Are jobs and income earning opportunities Record in the island office Number of direct employment created due to created due to the project? the project
4. System performance and satisfaction, e.g. how does the present system compared with previous system, how satisfied are people with the new system on a given scale (Likert)
9.3 Recommended Monitoring Programme
9.3.1 Project Specific Monitoring Programme
Outlined here are minimum project specific monitoring requirements that should be considered. This monitoring programme for the proposed project includes at least three monthly monitoring and covers the three stages of the project implementation.
Stage 1: Immediately before starting works
Stage 2: During civil works
Stage 3: Operational stage for two years
The monitoring needs of each stage are discussed in detail below:
Proponent: Ministry of Housing, Transport and Environment Page | 94 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Stage 1 • Groundwater quality for parameters given in Table 9-1 (to be sampled and tested prior to project implementation) • Marine water quality – parameters as in Table 9-1 (to be sampled and tested prior to project implementation) • Public expectations (covered in this EIA)
Stage 2 • Groundwater quality for parameters given in Table 9-1 (every three months) • Marine water quality – parameters as in Table 9-1 (every three months) • Public complaints and issues raised
Stage 3 • Groundwater quality for parameters given in Table 9-1 (every six months) • Marine water quality – parameters as in Table 9-1 (every six months) • Public satisfaction/dissatisfaction of the system
For water quality monitoring, site conditions during monitoring such as smelly groundwater, rainy day or outfall within 5m of sampling location must be identified. Sampling conditions including sampling depth, time and GPS location shall be provided.
9.4 Cost of monitoring
The monitoring would be undertaken by the Project Implementation Unit who has been trained and facilitated to undertake such monitoring. Therefore, the costs of monitoring are not included in this report.
9.5 Monitoring R eport
A detailed environmental monitoring report is required to be compiled and submitted to the Environment Protection Agency yearly based on the data collected for monitoring the parameters included in the monitoring programme given in this report. EPA may submit the report to the relevant Government agencies in order to demonstrate compliance of the Proponent.
The report will include details of the site, strategy of data collection and analysis, quality control measures, sampling frequency and monitoring analysis and details of methodologies and protocols followed.
Proponent: Ministry of Housing, Transport and Environment Page | 95 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Table 9‐3: Environmental Management Plan Activity 1: Excavation and dewatering for pipe laying and manhole and pump stations Implementing Technology/ Time frame Cost (Rf) Impact 1.1: Drawdown on the water lens responsibility equipment
Design Phase Identify that the maximum depth of excavation to be 1.5m from surface Project engineers N/A Completed N/A
Construction Dewatering would be minimized by ex-situ or hydro-fusion of pipes Contractor On-site water During 150/sample phase quality logger dewatering only monitored Dewatering undertaken only for manholes, lift stations and pumping stations PIU or Env Work may be restricted to low tides Consultant Water quality monitored in neighbouring wells for changes in E-conductivity, pH and DO during dewatering Impact 1. 2: Public concerns due to excavation, dewatering and drawdown of water lens
Design Phase Develop and inform public of a Grievance Redress Mechanism Project engineers N/A To be N/A Design for excavation not more than 1.5m MHTE/PIU finalised soon Completed
Construction Follow Grievance Redress Mechanism MHTE/PIU N/A During N/A phase construction Inform neighbouring houses when excavating narrow roads and address their concerns Contractor Activity 2: Laying outfall pipe Impact 2.1: Sedimentation and death of corals from removal or excavation Design Phase Plan to minimize use of excavator to lay the pipe Project engineer N/A Completed N/A Plan to undertake works at low tide and other windows of opportunity for minimal impact
Construction Use a float-sink method to place the pipeline after making all joints ex-situ Contractor Snorkelling Twice during 10,000 phase gear, marine construction or 5000 per Make all workers aware of the delicate environment in which they work PIU or Env survey tools and monitoring consultant Anchors would be placed using divers and manual methods and no machinery and underwater immediately Transplant any live coral that may have to be removed because it falls in the way of the pipe camera upon completion Make records of all corals that are moved or transplanted Monitor impacts on coral due to construction activities and workforce Develop and follow a Grievance Redress Mechanism
Operation phase Monitor water quality at outfall location(s) and compare with a control point for total nitrogen, phosphorus, PIU or Env Water quality Once a year for 1,200 BOD, COD and chlorophyll-A consultant logger and/or the first 2 years lab
Proponent: Ministry of Housing, Transport and Environment Page | 96 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
Activity 3: Toilet flushing Implementing Technology/ Time frame Cost (Rf) Impact 3.1: Drawdown on the groundwater aquifer and aquifer becoming salty responsibility equipment Design Phase Undertake stakeholder consultations at all levels to ensure stakeholder participation MHTE N/A Completed N/A Increase awareness from design phase to initial operational phase PIU Design for integrated water supply scheme, if possible
Construction and Educate public on the use of skimming wells or similar low abstraction technologies MHTE/PIU N/A Continuous 150/sample Operational phase Monitor groundwater for changes in pH, DO and especially electrical conductivity twice a year PIU/Env consultant Introduce water saving technologies such as dual flush tanks or bricks in cisterns Activity 4: Removing existing pipelines and outfalls Impact 4.1: Waste and waste disposal Design Phase Not incorporate existing design, especially lateral connections from houses into proposed design to minimize Project engineers N/A Detailed design N/A wastage of pipes stage Include removal of existing system within the Bills of Quantities for the project
Construction Construction waste must be disposed to Waste Disposal Site Contractor N/A Construction N/A phase phase Construction waste shall not be disposed in the marine environment PIU Supervise and monitor the waste disposal practices of the contractor Ensure that all existing outfalls are removed Impact 4.2: Changes to lagoon water quality
Construction Ensure that all nearshore outfalls are removed PIU/MHTE N/A Construction 150/sample phase phase Lagoon water quality monitoring at start, then every six months for coliforms, nitrogen, phosphorus, BOD, COD PIU/Env Consultant Operational phase Continue to monitor lagoon water quality every six months PIU/Env Consultant N/A N/A N/A
Activity 5: Machinery and workforce Impact 5.1: Land and resource use
Construction Keep site installations minimal and tidy at all times Contractor N/A Construction N/A phase phase Keep machinery and fuel handling areas (if any) well maintained at all times PIU/MHTE Supervise and monitor site installations and worksite management by contractor PIU/Env Consultant
Proponent: Ministry of Housing, Transport and Environment Page | 97 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
10 Declaration of the consultant
This EIA has been prepared according to the EIA Regulations 2007, issued by the Ministry of Environment, Energy and Water. I certify that the statements in this Environmental Impact Assessment study are true, complete and correct to the best of my knowledge and abilities.
Name: Ahmed Zahid (EIA 08/07)
Date: 3 February 2010
Proponent: Ministry of Housing, Transport and Environment Page | 98 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
11 Sources of Information
B. Lapointe, M. Littler, & D. Littler, 1993, Modification of benthic community structure by natural eutrophication: The Belize Barrier Reef, Proceedings of the 7th International Symposium on Coral Reefs, p. 317-328, Guam
Beswick, R. (2000). Water Supply and Sanitation, A Strategy and Plan for the Republic of Maldives, Parts 1 & 2, Ministry of Health, Republic of Maldives.
Brown, B. E. and J. C. Ogden (2003). Coral bleaching. Scientific American 268:64-70.
Brown, et al (1990), Effects on the degradation of local fisheries in the Maldives. Final Report to Overseas Development Administration.
Brown, et al (1990), Effects on the degradation of local fisheries in the Maldives, Final Report to Overseas Development Administration.
Carter, L. M., et al (2001), Potential Consequences of Climate Variability and Change for the US Affiliated Islands of the Pacific and Caribbean, pp. 315-349 in The Potential Consequences of Climate Variability and Change: Foundation Report, Report by the National Assessment Synthesis Team for the US Global Change Research Program, Cambridge University Press, Cambridge, UK, 620pp., 2001Allison W R. (1996). Snorkeler damage to reef corals in the Maldive Islands, Coral Reefs 15: 215-218
Clark, S., Akester, S. and Naeem, H. (1999). Conservation and Sustainable Use of Coral Reefs: Status of Coral Reef Communities in North Male’ Atoll, Maldives; Recovery Following a Severe Bleaching Event in 1998, MacAlister Elliot and Partners Ltd.
English, S., Wilkinson, C. and Baker, V. (1997). Survey Manual for Tropical Marine Resources (2nd edition), Australian Institute of Marine Science
Falkland, A. (2001), Report on Integrated Water Resources Management and Sustainable Sanitation for 4 Islands, Maldives, Maldives Water and Sanitation Authority, Maldives
Freeze, R.A., and Cherry, J.A. (1979), Groundwater, Englewood Cliffs, N.J., Prentice-Hall Inc., 604 pp
Government of Maldives (2009), “Aneh Dhivehiraajje”, the Strategic Action Plan 2009-2013, GoM.
Great Barrier Reef Marine Park Authority, GBRMPA (2005), Sewage discharge policy March 2005, Sewage discharges from marine outfalls to the Great Barrier Reef Marine Park
Proponent: Ministry of Housing, Transport and Environment Page | 99 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
GWP consultants (2005), Water Resources Tsunami Impact Assessment and Sustainable Water Sector Recovery Strategies, September 2005
GWP consultants (2006), Final Report on Water Resources Assessments in Addu Atoll and Sustainable Water Supply and Sanitation Strategies, Maldives
Johnson, et al (2007), Environmental Impact Assessment for the proposed sewerage system in Kulhuduhuffushi, Haa Dhaalu Atoll, Asian Development Bank
Kenchington, R.A., The Republic of Maldives, pp 184-204. Managing Marine Environment, Taylor and Francis New York Inc. (1990)
Marine Research Centre (2003), Socio-economic assessment and monitoring ofcoral reef resources at Vaavu atoll, Maldives. Ministry of Fisheries, Agriculture and Marine Resources. Global Coral Reef Monitoring Network-South Asia Region. Retrieved on: November 31, 2005 from website http://ioc.unesco.org/gcrmn/MRC%20socioeconomic%20study.pdf
Ministry of Environment and Construction (2004), State of the Environment 2004, Maldives
MWSA (2006), General Guideline for Domestic Wastewater Disposal, Maldives Water & Sanitation Authority
MWSA (2007), Design Criteria for sewerage systems, MWSA, Maldives
NDC, Pakistan and MWSC, Maldives (2003), Final Report on Development of Water Supply and Sewerage System in Atolls, Maldives
P. Bell, 1992, Eutrophication and coral reefs: some examples in the Great Barrier Reef lagoon, Water Research 26: 553-568
RMSI/UNDP, 2005, Developing a Disaster Risk Profile for Maldives, Volume 1: Main Report, UNDP Maldives
Roe D, Dalal-Clayton & Hughes, R (1995), A Directory of Impact Assessment Guidelines, IIED, Russell Press, Nottingham, UK www.starfish.ch/reef/marine-turtles.html accessed on 4 November 2009
Terrados et.al. (1998). Changes in the community structure and biomass of seagrass communities along gradients of siltation in SE Asia, Estuarine Coastal and Shelf Science 46, 757-68.
The United Kingdom Hydrographic Office (2005), Admiralty Tide Tables – Indian Ocean and South China Sea, Vol3 (NP203)
Proponent: Ministry of Housing, Transport and Environment Page | 100 Consultant: Ahmed Zahid (EIA08/07) EIA for the Development of Sewerage System in Lh. Naifaru
USACE (1999), Small wastewater systems, USACE, Washington
Water Solutions (2006a), EIA for the Sewerage System in Gan, Laamu Atoll, IFRC, Maldives
Water Solutions (2006b), EIA for the Sewerage System in Guraidhoo, Kaafu Atoll, IFRC, Maldives
Water Solutions (2006c), EIA for the Sewerage System in Kudahuvadhoo, Dhaalu Atoll, IFRC, Maldives
Water Solutions (2006d), EIA for the Sewerage System in Maafushi, Kaafu Atoll, IFRC, Maldives
Water Solutions (2007), EIA for the sewerage system in R. Ungoofaaru, UNICEF, Maldives
Waterhouse, J. and Johnson, J. (2002), Sewage Discharges in the Great Barrier Reef Region.
WS and LHI (2006), Environmental Impact Assessment for the development of sewerage system in HA. Dhidhdhoo, MEEW, Maldives
Proponent: Ministry of Housing, Transport and Environment Page | 101 Consultant: Ahmed Zahid (EIA08/07) $l
EnvironmentalProtection Agency Male',Republic of Maldives Termsof Referencefor Environmental lmpactAssessment
The following is the TOR is basedon the points discussedin the scoping meeting held on the 30ft September 2009, for undertakingthe EIA of the proposedSewerage System in Naifaru, Lhaviyani Atoll Maldives.
This document is a legally binding document preparedafter consultationwith all relevant stakeholdersand the EIA report must strictly follow the activities under this ToR.
I. Introduction - Identifu the developmentproject to be assessedand explain the executingarrangements for the environmental assessment.Describe the rationale for the developmentand its objectives.Provide the background information on the project and it costs. Justification should be given into consideration purpose and objectivesofthe project.
- 2. Studv Area Specifu the boundaries o f the study area for the assessmentas well qs any adjacent or remote areas that shouldbe consideredwith respect to the project (e.g. dredgedmaterial disposol site/s).
3. Scope of llork - Thefollowing tasks will be performed:
-The Task I. Description of the ProposedProject description of theproject should consider thefollowing.
a) Provide a brief description of the proponent, how the project will be undertaken,futl description of the relevant parts ofthe project, using clearly labeled maps, scaled site plan. b) Provide details of sewer line,. Work methods and type of equipment to be used qnd the manner of deployment including handling and transportation of equipments and materials. c) How proiect related wqstes and emissions will be managed, project inputs and outputs, project schedule; and life span. d) Details of sewer lines, pumping stations, sea outfalls as well as ffiuent discharges and type of treatment and anticipated performances in terms of expected effiuent quality.
Task 2. Description of the Environment - LTherebaseline data is to be collected, carefut consideration must be given to the design of the survey and sampling programme. Data collection mustfocus on key issuesneeding to be examinedfor the EIA. Consideration of likely monitoring requirements should be borne in mind during survey planning. so that the data collected is suitable for use as a bqseline to monitoring impacts.
Assemble, evaluate and present baseline data on the relevant environmental characteristics of the study area (and disposal sites), including the changes to the existing environment in light ofmonitorinq conducted after the commencementof the initial proiect.
a) Physical environment: Physical environment: general meteorologt (rainfall, wind, waves and tides), ocean currents, bathymetry and water quality at proposed and alternative outfall locations and at representative qreas around the island and groundlrtater quality at representative locations around the island. Marine water quality parameters shall include BOD, dissolved oxygen, E-Conductivity, pH, nitrate and phosphate. Groundtvater quality parameters shall include BOD, dissolved orygen, TDS or E-Conductivity, nitrate and phosphate.
ToRfor the proposedDevelopment of the SewerageSystem in Naifaru,Lhaviyani Atoll Maldives. el
b) Biologicol environment: a quantitative assessmentof the coral habitats at the location of the proposed and alternative sea outfalls and that ofa control location at a location that is literallyfreefrom any anthropogenic impact such as waste or wastewater disposal.
c) Socio-cultural environment: population, land use, planned development activities, employment, recreation and public health and community perception of the development.Anticipated Impacts of the development on the island community should be thoroughly investigatedfor the construction and operation of the sew erage facility.
Characterize the extent and quality of the available data, indicating significant information deficiencies and any uncertainties associated with the prediction of impacts. All availqble data from previous studies, if available should be presented. Geographical coordinates of all sampling locations should be provided. All water samplesshall be talrpn at a depth of lm-from the mean sea level or midwater depth.for shallow areas. The report should outline the detailed methodologt of data collection utilized to describe the existing environment.Baseline conditions should be presentedfor the marine environment.
An average of at least 5 measurementsmust be givenfor each parameter testedand analyzedfrom a certiJied laboratory. Provide details of calibrationfor any onsite data analysis.
Task 3. Legislative and Regulatorv Considerations - Describe the pertinent legislation, regulations and standards, and environmental policies that are relevant and applicable to the proposed project, and identifu the appropriate authority jurisdictions that will specifically apply to the project.
Task 4. Determine the Potential Impacts of the Proposed Project - Identifu constructional impacts related to excavation and dewatering for layng pipes and pumping stations. Identifu operational impacts of the sewerage system on groundwater and marine receiving waters. Identifu the impacts of the proposed system on human health and wellbeing. Distinguish between significant impacts that are positive and negative, direct and indirect, and short and long term. Identify impacts that are cumulative, unavoidable or irreversible. Identifu any information gaps and evaluatetheir importancefor decision-making.Special attention will bepaid to:
' Impacts of ffiuent disposal including socio-economic and environmental impacts of treatment and existing eutrophication impacts as well as eutrophication and other impacts on receiving environment at outfall location. ' ultimate fate of contaminants in a sensitive marine environment based on hydrodynamic conditions and existing state of the impacted environment. ' impacts on the ground,uater quality and availability ' impacts of operation and maintenance, including impacts of levying a charge on household income and sensitivity of the impact on the poor and vulnerable with respect to other basic servicesfor which they are being asked to payfor ' impacts on health andwell being of the community
Task 5. Analvsis of Alternatives to the Proposed Project. - Describe the alternatives examinedfor the "no proposed project that would achieve the same objective including the action alternative. This should include; alternative technologies, material, locations to the proposed components of the project with economic, environmental and social factors taken into consideration. Distinguish the most environmentally friendly alternative s.
Tqsk 6. Mitigation and Management of Negative Impacts - identifu possible measures to prevent or reduce signiJicant negative impacts to acceptable levels with particular attention paid to sewage disposal system (STP and outfall (eftluent and sludge disposal). Mitigation measures should be identiJiedfor both construction and
ToRfor the proposedDevelopment of the SewerageSystem in Naifaru,Lhaviyani Atoll Maldives. lFr
opetational phase. Cost of the mitigation measures, equipment and resources required to implement those meqsures.A commitmentregarding the mitigation measuresshould be submittedby the responsibleperson.
- Task 7. Develooment of a Monitoring Plan q reasonable time frame should be outlined for monitoring focused on the construction and operational phase. Identifu the critical issuesrequiring monitoring to ensure compliance to mitigation measures and present impact management qnd monitoring plan sewage collection and disposal operations. Detail of the monitoring programme including the physical and biological parameters for monitoring, frequency, duration and cost commitmentfrom responsibleperson, detailed reporting timetable andways and means of undertaking the monitoring programme shall be provided.
Task 8. Stakeholder Consultation -Stakeholder consultation to include Ministry of Housing, Transport and Environment, EPA, Northern Utilities Ltd., Province Office, Atotl Office and Island Office with regard to design and location of pumping stations, marine outfalls and other related infrastructure and institutional arrangements for implementation, operation qnd maintenance shall be undertaken. Public consultations that have been undertaken for the purpose of planning and design shall be incorporated. In addition, public views regarding the proposed project may be gathered through informal interviews. List of people consulted shall be included in the Appendix to the report.
Task9. Methodolosv Explain clearly the methodologies usedfor data collections, making predictions and data gaps and also the information on the uncertainties and assumptions involved in interpreting the data.
- Presentation The environmental impact assessmentreport, to be presented in digital format, will be concise and focus on significant environmental issues. It will contain the findings, conclusions and recommended actions supported by summaries ofthe data collected and citationsfor any references used in interpreting those data. The environmental assessmentreport will be organized according to, but not necessarily limited by, the outline given in the Environmental Impact AssessmentRegulations, 2007.
Timeframefor submitting the EIA report - The developermust submit the completedEIA report within 3 months from the date of this Terms of Reference.
04 November
ToRfor the proposedDevelopment of the SewerageSystem in Naifaru,Lhaviyani Atoll Maldives. " >,. ox G" '.1.,.._""/ .,I"" "'" ""'t!-.,..,.,.'*,.,. Ministry of Housing, Transport and Environment
Ref: 138-F/EPA ,/2010//0
Mr. Mohamed Zuhair Director General Environmental Protection Agency ~ale' Maldives 03 rd February 2010
Dear Mr.Zuhair,
Sub: ADB Loan No: 2170 MLD (SF), Regional Development Project Phase II, Environmental Infrastructure and Management.
Environmental Impact Assessment (EIA) Report for Lh.Naifaru Sewerage Project.
Please refer to the Environmental Impact Assessment Report (EIA) of Lh.Naifaru prepared under the above mentioned project.
We would like to inform you that the Project Management Unit (PMU) ofRDPII- MHTE will liaise with necessary government agencies in order to undertake the monitoring works during construction and after completion of the works as stipulated in this EIA Report.
The monitoring works will also be facilitated by Project Implementation Unit (PMU) of Lh.:Naifaru established under the project.
Thank you
Yours sincerely, i!J!d*~ ~~~~d Waheed Deputy Director
Amccnee Magu, Tel: +(960) 300 4 300 '1.>::-:" 11 0..-'> Maafannu, Fax: +(960) 300 4 301 :::-::; '-"'-"',.I';;> Male', 20392, Ema,l: [email protected] :J:;;;; ,20392 ,;; Republic of Maldives. Website: www.mhte.gov.mv :;:;;...,:; EIA for the Development of Sewerage System in Lh. Naifaru
Appendix 3: Drawings
Proponent: Ministry of Housing, Transport and Environment Page | 106 Consultant: Ahmed Zahid (EIA08/07) REGIONAL DEVELOPMENT PROJECT -II ENVIRONMENTAL INFRASTRUCTURE AND MANAGEMENT SEWERAGE SCHEME FOR Lh.NAIFARU
GENERAL NOTES: 01. ALL DIMENSIONS ARE IN METER, UNLESS OTHERWISE SPECIFIED.
02. ALL LEVEL ARE GIVEN WITH REFERENCE TO THE PERMANENT DATUM IN NAIFARU
03 LEVELS VARY AT +0.59m TO +1.96m
04 ALL LEVELS ARE W.R.T. MEAN SEA LEVEL
LEGEND
TEMPORY BENCH MARK
SEWAGE TREATMENT PLANT
SEWAGE PUMPING STATION
Waste Management
WASTE WATER PLANT, SPS 5 & STP PS
23.11m
46.73m
S PS 5 35.70m 8.00m
Waste Water Plant 8.00m
STP PS & PS 2 Inside Wastewater Treatment Plant Site
Main Pumping Station Location S 10.70m 4.57m TP 27.70m
20.61m
2.50m
Power House
Desalination (RO) Plant
SPS 4
Pre-School 6.00m
3.05m 4.48m
SPS 4 Safe Play Area
Haruge (temp)
Haruge (temp)
Football Ground
SPS 2 (NEAR Mosque SPS 3 (NEAR OLD FISH Cemetery Green Police Station Area WATANIYA TOWER) Roashanee MARKET) Atoll Mosque Pre-School
Hospital Boat Repair Clubs/NGO Area Cemetery Offices Women's Mosque
Old Fish Market 3.05m
8.36m 4.60m
SPS 3
Open Stage
SPS 2
6.38m 4.60m 6.02m 3.05m Wataniya Atoll Antenna Power House 2.20 Hospital (STELCO)
BM2 Cemetery Cemetery 3.77
Park
Work- Ice shops Plant Friday Mosque
N1
Fuel Supply
Harbour 0.97 Community Centre N0 Madhrasatul Ifthithaah Old School (extention) Madhrasatul Ifthithaah
Women's Mosque
Bank of Maldives
Atoll Office Primary School Green Area
Green Court Stage Area Nooraanee Pre-School Jetty Safe Play Island Area Office Atoll Ravvehige 0.86 BM1
Green Family & Chidren's Area Service Centre Atholhuge Masveringe Fish Market (under const.) Police Hiyaa Volleyball Court
Local Market Green Reserved Cultural Area Centre Water Tanks
WASTE WATER PLANT, Mosque SPS 5 & STP PS
SPS 4
SPS 2 (NEAR SPS 3 (NEAR OLD FISH WATANIYA TOWER) MARKET)
Fire Station
SPS 1
SPS 1
2.84m
4.59m
11.85m
Haruge (temp.) SPS 1 Haruge (temp.) MINISTRY OF ENVIRONMENT , ENERGY AND WATER
INTERCONTINENTAL CONSULTANTS AND TECHNOCRATS PVT.LTD.INDIA
0 50 100 150 200 250m In Association with: BALLOFET INTERNATIONAL USA
Drawn: Sudheera A.K Gunasekara Checked: Rommel Vete Approved: M.R.Bari & S . Mandal Date: 30-07-2008 Drawing Title: Lh. NAIFARU PS LOCATIONS
Drawing No.
Scale: NOT TO SCALE REGIONAL DEVELOPMENT PROJECT -II ENVIRONMENTAL INFRASTRUCTURE AND MANAGEMENT SEWERAGE SCHEME FOR Lh.NAIFARU
GENERAL NOTES: 01. ALL DIMENSIONS ARE IN METER, UNLESS OTHERWISE SPECIFIED.
02. ALL LEVEL ARE GIVEN WITH REFERENCE TO THE PERMANENT DATUM IN NAIFARU
03 LEVELS VARY AT +0.59m TO +1.96m
04 ALL LEVELS ARE W.R.T. MEAN SEA LEVEL
LEGEND
TEMPORY BENCH MARK
SEWAGE TREATMENT PLANT
SEWAGE PUMPING STATION 23.11m
46.73m
SP S 5 35.70m 8.00m
Waste Water Plant 8.00m
STPPS&PS2Inside Wastewater Treatment Plant Site
Main 015050 100 200 250m Pumping Station Location ST 10.70m 4.57m P 27.70m
20.61m
MINISTRY OF ENVIRONMENT , ENERGY AND WATER
2.50m INTERCONTINENTAL CONSULTANTS AND TECHNOCRATS PVT.LTD.INDIA Power House In Association with: BALLOFET INTERNATIONAL USA
Drawn: Sudheera A.K Gunasekara Checked: Rommel Vete Approved: M.R.Bari & S . Mandal Date: 30-07-2008 Drawing Title: Lh. NAIFARU PS LOCATIONS
Drawing No.
Scale: NOT TO SCALE