Microbial water quality variations in different water sources in the Pussalla Oya catchment and pollution contributions by communities

Abstract

Natural water sources in Pussalla Oya catchment are prone to faecal pollution and it was reflected by Hepatitis A outbreak in May 2007. Although the faecal pollution is a common problem in the catchment, pollution contribution and severity could vary among the communities. A study was conducted to compare the water related issues among different communities in the Pussalla Oya catchment, assessing the variations in water quality and pollution contributions. Communities selected were Rothschild estate, Pussallawa town and Black Forest colony to represent estate, peri-urban town and village, respectively. Water quality analysis (total Coliform and Escherichia coli), questionnaire survey and field observations through transect walks were conducted to find the disparity in water quality and pollution contributors. Main consumptive water sources in all three communities exceeded the Sri Lankan drinking water quality standards. Higher E. coli count is found in wells closer to Rothschild estate dwellings and Black Forest colony reflecting potential groundwater contamination. Quality of consumptive water sources has statistically significant differences between dry and wet seasons in all communities. Comparatively higher pollution levels have been found at the outflow points in Pussallawa town due to unavailability of onsite wastewater treatment facilities and mismanagement of wastewater. The onsite wastewater treatments are not possible with respect to limited land availability and shallow groundwater levels. But the groundwater quality in Pussallawa town is comparatively better.