Identification of Factors Affecting the Groundwater Quality in Velanai Divisional Secretariat Area, Jaffna

Abstract

Groundwater is a precious natural water resource. In Sri Lanka, 72% of the rural population and 22% of the urban population are depending on groundwater. Jaffna district is only depending on groundwater sources. Velanai Divisional Secretariat area groundwater resources are a danger due to salinity problem. In the dry season, people most affected to obtain good quality water. A detailed literature review was carried out to understand the reasons and how to overcome them. A survey with a questionnaire was conducted and chemical parameters analyzed also done. According to the analysis only one well’s water, the quality was below the permissible level. 97.50 % of wells were not suitable for drinking. The quality is depending on the soil geology and elevation from the mean sea level. The maximum elevation of Velani area is 9m and Pungudutivu is the flat terrain and average ground surface elevation from MSL is 2m. The groundwater table is 0 – 1.85m in the Pungudutivu area and the major reason for water pollution is mixing saline water with fresh water. The main reasons were seawater intrusion into the wells, over extraction and the solutions were water treatment plant for desalinization and alternative water resources should be identified.