Author(s)

K. K. Deshmukh

Abstract

Water is an essential natural resource for sustaining life and environment which we have always thought to be available in abundance and a free gift of nature. Though groundwater is the major drinking water source, deterioration in its quality is questionable. In recent years, pollution by nitrate leaching from agricultural land has become an important concern. The notable toxic effect of nitrate is infant methaglobinema. The symptoms of nitrate poisoning are also well recognized in animals. In agro-economy based rural areas, the nitrate contamination is rampant and much attention has not been drawn towards this anthropogenic pollution. In the study area, 68 ground water samples from different hydro geological set up have been collected during pre and post monsoon seasons and analyzed for pH, EC and major ions such as Ca2+,Mg2+, Na+,K+,CO3 2-, HCO3 -,CI-,SO4 2- and NO3 -. The study revealed that the majority of the samples from irrigated agriculture have NO3> 45mg/l. The groundwater found to be unsuitable for drinking purposes. Intensive agriculture practices, excess use of nitrogeneous fertilizers, improper organic waste disposal, monoculture type of cropping pattern, mixing of sugar mill effluents are the possible causes of high concentration of nitrate in the groundwater. The Cl-/NO3 - ratio for the groundwater from irrigated land use is <2 indicating fertilizers as the predominant source of nitrate. High values of nitrate in wells with deeper water table indicate cessation of denitrification processes at greater depth. Lower values of nitrate in the wells with shallow water table depth have been attributed to denitrification process. On the temporal scale, the nitrate decreases in winter and increases in summer. This is possibly attributed to concentration–dilution

Keywords

groundwater evaluation, nitrate pollution, nitrogeneous fertilizers, methemoglobinemia, denitrification, domestic purpose