Environmental impact assessment for the construction and setup of an island sewerage system in Dhiggaru Island, Meemu Atoll, Maldives

Abstract

This report discusses the findings of an environmental impact study undertaken by Water Solutions Pvt. Ltd in order to fulfill obligatory requirements of the National Environment Protection and Preservation Act, Law No. 4/93 for the proposed setup of the sewerage system (hereafter referred to as the project) in Dhiggaru island, Meemu Atoll, Maldives. The purpose of this EIA is to identify and minimize potential adverse environmental impacts related to this project and enhance the overall quality of the project. By examining the project location, the legal framework and the existing environmental components such as marine ecology and the socio-economic aspects, this EIA provides useful information regarding the extent, nature and the magnitude of impacts that are likely to occur. The EIA will also help to identify the long term socio-economic benefits to the community after implementing this project. It also provides a framework for future monitoring of the environment, so that changes can be monitored and corrective measures can be undertaken. The proposed project aims to establish an island wide sewerage collection and disposal system. At present household wastewater is disposed on site by the use of septic tanks and this has contributed to the contamination of the groundwater to a state that it cannot be utilized. There is also a private sewer main pipes laid in some roads which outfalls into the shallow lagoon by gravity. This is a basic system of pipes that was constructed at the community level, but without any proper assessment or design. The project therefore involves the following components: a) Installation of an island wide sewage collection network. b) Installation of new catch pits for each house / institution. c) Construction of pump stations in strategic locations to collect and convey raw sewage from the households and to the final disposal station. d) Construction of a sea outfall. The proposed project will ensure that the groundwater of the island does not get contaminated through improper sanitation systems. It will also ensure that the surrounding marine environment will improve in terms of environmental quality and will ensure pollution from sewage does not occur on the near shore environments. The project is expected to bring several positive impacts on the environmental quality of the island and the surrounding reef. Particularly, the most significant benefit would be achieved through improvement in the groundwater quality. The health benefits of the project are also worthy of noting as the improvement in water quality are going to bring significant health benefits to the community. Various alternatives to the proposed system were also studied. One of the options identified include deep bore well disposal and gravity systems among others. Based on the assessment, these alternatives were assessed to identify their potential application in the island against the proposed system. Several environmental impacts of this proposed project have been examined through a number of processes. These include consultations with the project development team, field surveys, observations and assessment, and field experience gained from similar development projects implemented throughout the country. Potential positive and negative impacts on the environment have been considered. The assessment indicates environmental impacts both during the construction and operation stage. During the construction period, impacts are likely to occur on the marine and terrestrial environment (groundwater) as the proposed project does necessitate construction of an outfall but avoids large scale construction activities such as clearing trees. Most of the impacts during the construction period are impacts related to construction waste, dust emission, damage to the reef during outfall construction and noise. During the operational stage of this project, there will be both positive and negative impacts. Positive impacts include the improvement of the ground water quality of the island and also the quality improvement of the near shore environment. Negative impacts include the increased in extraction of groundwater for toilet flushing. This project does not foresee many negative impacts even during the construction stage and is geared towards improving the environmental quality of the island, most notably the environmental health. The project does not pose serious threats to the marine or terrestrial environment and will directly benefit the environment and the community, both in the short and long term. Nevertheless, negative impacts with varying significance will occur as the project is implemented. Based on this assessment, it is advised to undertake this project.