Quality analysis of the water supplied for public from collector wells

Abstract

The study was aimed to determine the water quality of the collector wells in the Vallipuram area of the northern Sri Lanka and to determine the suitability of the water for domestic utilization. Because of the infection of well water by iron and coliform bacterial species in 2016, public water supply was temporarily stopped and after a complete sterilization and clean-up process using chlorination and integrated control methods only, the water supply restarted after six months. Since then, there had been no steps made to check the quality of the drinking water supplied to the public from these wells. Water samples (36) were collected from the four major water supply collector wells in both top, middle and bottom randomly in triplicates during the rainy season of 2018. Samples were analyzed for pH, Electrical conductivity (EC), Turbidity, Total iron, Colour, Coliform test and Bio chemical tests such as Indole production test, Methyl red test,Voges-Proskauer test, Oxidase test and Catalase test. The results were compared with WHO and SLS standards and it was concluded that all the water samples from the collector wells tested, did not have any contaminants thus the quality of those samples was good for drinking.Based on the biochemical and molecular analysis,the bacterial species presented in some water samples was identified as Bacillus thuringiensis. Exactly similar conclusion was reached when the same research study was repeated after 6 months from the earlier study and the values obtained for the physico chemical factors tested were not significantly different with that of the previous study. Therefore, water in all the collector wells could be used for domestic and sustainable agricultural purposes continuously in the future too.