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Title: | Environmental impact assessment for the proposed water supply and sewerage system in Hulhudhuffaru, Raa Atoll, Maldives |
Authors: | Sandcays |
Keywords: | Water supply system Sewerage system Legislative and regulatory considerations Existing environment Existing terrestrial environment Existing socio-economic environment Constructional impacts Operational impacts Mitigation measures Environmental monitoring Environmental impact assessments |
Issue Date: | Mar-2016 |
Citation: | Sandcays. (2016). Environmental impact assessment for the proposed water supply and sewerage system in Hulhudhuffaru, Raa Atoll, Maldives. Male': Maldives |
Abstract: | This report discusses the findings of an environmental impact study under the proposed
water supply and sewerage system project at Raa Hulhudhuffaru. The project is proposed
by the Ministry of Environment and Energy.
The project entails establishment of a proper island-wide water and sewerage system. The
proposed project involves installing a water distribution network to supply desalinated
water supplemented with treated rainwater to all households and a comprehensive
sewerage system to dispose of domestic sewage and wastewater. At present rainwater
tanks of 2500litres connected to household roofs are used for drinking and cooking
purposes while groundwater is used for all other purposes. Sewage and wastewater at
household level is disposed to the lagoon via multiple outfalls causing contamination of
lagoon areas and contributing to seagrass growth while catch pits in households leak into
the aquifer contaminating the groundwater. Groundwater wells are also fixed with electric
pumps to draw water which has been the main reason for excessive drawdown and
subsequent salinization of the freshwater lens. The small water collection facilities at
household level presents water shortage issues during the dry season while contamination
of the groundwater lens with wastewater effluent and salinization of the lens has become
an increasingly important public health issue. Hence, it is important to provide adequate
supply of potable water and provide appropriate wastewater disposal systems to minimize
faecal contamination and foul smell in the groundwater.
In addition, a number of alternatives to the proposed project components have been
identified in this document. Some of these alternatives consider alternative means of
wastewater disposal including treatment, alternative means of water supply, alternative
outfall locations and alternatives to sustainable groundwater. Treatment is considered as a
favourable option while it has been argued that if the effluent can be disposed of at an
appropriate location, there would not be a need for treatment since there will be good
mixing and flushing in such areas. It has also been recommended to use solar desalination
technologies since the initial demand would be low and production capacity minimal.
Environmental impacts were assessed for both the construction and operational phase of
the project. Most of the environmental impacts identified for the construction phase of the
project were minor negative; these include excavation and related difficulties to road
uses, sedimentation from installing the outfall and temporary salinization of groundwater
from de-watering to lay out the pipe network and pump stations. However, the impacts
identified for the operational phase of the project were mostly moderate to major positive;
improvement of groundwater quality from stopping the current sewage disposal practise
and reduction of related health hazards. Disposal of sewage via a sea outfall is considered
as minor negative impact while the lack of multiple lagoon outfalls will help to improve
the quality of the lagoons which is a primary recreational area of the island. The provision
of safe and adequate supply of potable water enhances living environment and provides
economic opportunities such as tourism establishments including guest houses and city
hotels.
The main mitigation measures for this project during the construction phase are similar to
other water and sewerage projects such as dust control plans, working during low- tide as
much as possible and rigorous supervision. In case of deterioration of groundwater
quality due to potential dewatering during construction of lifting stations in residential
area, measures to water plants in the area that may be affected due to dewatering shall be
in place. The design shall also ensure that dewatering is minimized. As for the operational
phase trained maintenance staff to service the water and sewerage system and regular
check-ups has been suggested in addition to monitoring water quality as well as reef
health for potential impacts. Increasing awareness on groundwater conservation and
promoting sustainable groundwater aquifer management, especially the skimming well
technology has been suggested.
In conclusion, it appears justified from a technical, administrative, socio-economic, health
and an environmental point of view, to carry out the proposed water and sewerage system
development project. The alternative of wastewater treatment will involve greater
operational costs; therefore, it is recommended to proceed the project as proposed while
keeping the option open for future wastewater treatment, as and when required. |
URI: | http://saruna.mnu.edu.mv/jspui/handle/123456789/4645 |
Appears in Collections: | ތިމާވެށި Environment A
|
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