Présentations Colloques

India is the global epicentre for open defecation where it is practised by an estimated 600 million people. There has been a strong political drive to eliminate the practice for decades, with the current Prime Minister declaring this a national priority and pledging to provide a toilet in every home by 2019. However, there are concerns that developing on-site sanitation within rural communities could contaminate groundwater, which these populations are heavily dependent upon for the self-supply of domestic water. To investigate this link 150 domestic groundwater supplies in four villages in Bihar State currently undergoing sanitary interventions were tested for thermotolerant coliforms. These selected sites were at varying distances from recently installed on-site sanitation. Currently, local NGOs recommend a lateral separation of 10 m between a supply and on-site sanitation, but this was evidently not adhered to due to the high housing density and proliferation of self-supply. Overall, 91% of contaminated supplies were located less than 10 m from on-site sanitation, which was statistically identified as the only significant risk factor. This was despite the aquifer being confined beneath 25 m of clayey silt and, thus, suggesting that it was the vulnerability of the supply completions that was leading to contamination. The results from the study suggest that the ongoing sanitisation development in India is likely to lead to the increasing faecal contamination of water supplies which are critical drinking water sources across rural India.