Ground water quality evaluation with special reference to nitrate pollution in the Sangamner area, Ahmednagar district, Maharashtra, India

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 Ca,Mg, Na,K,CO3, HCO3,CI,SO4 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 www.witpress.com, ISSN 1743-3541 (on-line) WIT Transactions on Ecology and The Environment, Vol 164, © 201 WIT Press 2 Water Pollution XI 79 doi:10.2495/WP120071 effect. The present study is helpful in avoiding the hazards of nitrate contamination and avoids major health problems in the area. Undertaking investigation in such areas would thus reduce the cost of studies and in implementing groundwater quality management programs to avoid the hazards of contamination.