Seasonal Dynamics of Coliform Contamination in Groundwater Associated with Onsite Sanitation: A Case Study of Peri-Urban Village Nawada, Patna, India.

Abstract:

Water is essential for the living world. Life cannot exist without water. For drinking purposes, water is obtained from many sources. Available sources of water on Earth are rivers, streams, groundwater, etc. In India, a major source of drinking water comes from groundwater through hand pumps, boring, or bore wells. Aquifers are the geographical formation of groundwater. An onsite sanitation system (OSS) is commonly used by the rural population of Bihar. Poorly designed or closely spaced OSS, like soak pits, lead to bacterial contamination of shallow aquifers, which poses a severe public health hazard in peri-urban and rural areas of Bihar. The present study investigates the microbial water quality of twenty different groundwater sources situated at variable lateral distances from the soak pit at Nawada village, Patna, Bihar, over three seasons, i.e., pre-monsoon (summer), monsoon, and post-monsoon (winter). By using the standard MPN technique, the most probable number of total coliforms per 100 ml of water sample was quantified. Based on the obtained result, it was found that groundwater was severely and widely contaminated with microbes during the monsoon season, due to a rise in water level, which accelerates the subterranean transport of bacteria. Most of the samples during the monsoon period show the presence of coliform, with the highest number of 1600. These results highlight the necessity of distance in sanitation-groundwater interaction, especially during the monsoon. Targeted intervention, development program, and public awareness campaign are recommended to reduce bacterial contamination in groundwater and improve the community health of Nawada.