Characterization and seasonal variation of intake wells for drinking water at Vadamarachchi Aquifer of Jaffna District in Sri Lanka.

Abstract

Jaffna peninsula is depending on groundwater for their entire water requirement. Seasonal variation of groundwater quality is a matter of serious concern for Jaffna. Groundwater quality becomes crucial during dry periods. There is a tendency for increased concentration of geo chemical parameters in groundwater. The intake wells, which are used for water supply activities are comparably used for extracting more water during the whole year in the identified aquifers. They can easily respond to the seasonal impacts and over extraction than domestic wells. This paper discusses the characteristics and suitability of the water supply in the identified aquifers by analyzing the seasonal water quality and geochemical parameters. Secondary Water quality data of intake wells from 2013 to 2017 and the seasonal and periodical variation of geochemical parameters intake wells and control wells of the aquifer water were analyzed. All intakes are showing periodical degradation due to the seasonal impacts and increased consumption rate. Comparably the control wells are showing less quality variation with the season. Prominently chloride ion is increasing in the intake wells; it may be due to the influence of sea water. The aquifers are adjacent to salty water area, in these sand dune aquifers and there is a high possibility of the salt water intrusion. Geochemical parameters have shown sea water influences other than the geological influences. Therefore, all the aquifers are vulnerable to sea water contamination. Pointpedro scheme needs additional water sources to meet the increasing consumption.