Analyzing the Factors Contributing to Bacterial Contamination of Domestic Water Sources in Estuarine Islands of Coastal Karnataka, India

Contamination of domestic water sources is a major concern in estuarine islands of coastal Karnataka. Awareness about practices for waste management and protection of water sources on these islands is poor. Using water having bacterial presence for domestic purposes can lead to various health risks in humans. The research investigates various factors leading to bacterial contamination of domestic water sources at Mudukudru island of Swarna river, in the Udupi district of Karnataka. Samples were collected during the Pre-monsoon (December–May) and Monsoon (June–September) seasons from 43 wells of individual houses on the island. The total concentration of bacteria, in the water samples was determined from microbial analysis. The multiple tube, most probable number (MPN), fermentation technique was adopted to determine the total coliform in the samples. Factors like the presence or absence of well lining, well housing, wellhead above or below ground level, the distance of well from sewage pits, and the distance of livestock from the wells were correlated. The results indicated bacterial contamination in 32 wells during the monsoon as compared to pre-monsoon data, with the total coliform count exceeding the standard of 500 MPN/100 mL. A significant relation between total coliform count in the water samples and the absence of well lining with sanitary protection is observed with p-value =.00 (p ⩽.05) and wells located near (<10.0 m) to sewage pit with p-value ⩽.05, were recorded respectively during both the seasons of sampling. The study highlights the major factors leading to bacterial contamination of wells on the island. Awareness about the planning of domestic wells through community-driven programs and hygiene education can be beneficial for the sustainable future of these islands.