Arsenic and Microbial Contamination in Drinking Water Wells: A Field Study in West Bengal, India

The co-occurrence of arsenic (As) and microbial pathogens in groundwater represents a serious threat to public health. The complex interactions between chemical and microbial parameters can increase mobility and bioavailability of As, exacerbating water quality challenges in affected regions. The present study deals with the screening of As and microbial contamination in drinking water wells in rural villages of West Bengal, India. The percentage of As contaminated tube wells (i.e., >10 mg/L) is highest in Dewli (81.66%), followed by Ghentugachi (72.37%), Dubra (60.37%) and Sorati (54.72%). The presence of microbial parameters (i.e., total and fecal coliform bacteria) is highest in Silinda-II (68.21%), whereas lowest percentage in Madanpur-I (7.94%). Additionally, the co-occurrence of As contamination and total and fecal coliform bacterial populations in tube wells is also determined. Silinda-II has the highest As and microbial presence in 34.65% of the tube wells, whereas, the lowest percentage was observed in Tatla-II, constituting 1.47% of the tube wells. The co-occurrence of As and microbial pathogens in tube wells varies geographically across several villages in the study area. Such observation is primarily linked to rural land use, tube well depths, and the location of tube wells close to the pit latrine, pond, and agricultural land. This study highlights the necessity for immediate intervention to improve water quality in rural villages, such as the improvement of sanitation infrastructure, and monitoring of tube wells to ensure safe drinking water supply.