Village environs as source of nitrate contamination in groundwater: a case study in basaltic geo-environment in central India.

Nitrate is one of the common contaminants in the present day groundwaters resulting from increased population associated with poor sanitary conditions in the habitat area and increased agricultural activity. The hydrochemical measurements on water samples from a virgin watershed, situated in the basaltic geo-environment, have become necessary as the groundwater is the only source of drinking water for the villagers of the area. High preferential recharge conditions prevail in the area due to fractures in the solid basaltic lava flows. Instead of dilution due to fresh recharge, the post-monsoon hydrochemical concentrations in the groundwater are observed to have increased probably due to fast migration of pollutants to the aquifer through preferential recharge. As a result, the deep aquifer waters are more contaminated with hazardous nitrate than the shallow waters. Further, the village environ wells are more polluted with nitrate than the agriculture areas which could be attributed to the unhygienic sanitary conditions and livestock waste dump pits in the villages. This study suggests proper management of the sewage system and creation of suitable dump yard for the livestock and household waste to minimize the level of nitrate pollution in the well waters of village environs.