Cases and solutions Environmental Geology 34 (2/3) May 1998 7 Q Springer-Verlag 151 Groundwater pollution due to sugar-mill effluent, at Sonai, Maharashtra, India N. J. Pawar 7 G. M. Pondhe 7 S. F. Patil Received: 30 April 1997 7 Accepted: 23 September 1997 N. J. Pawar (Y) Department of Geology and Environmental Science, University of Pune, Pune 411007, India Tel.: 91 212 351195x2121 7 Fax: 91 212 350087 e-mail: njpawar@unipune.ernet.in G. M. Pondhe 7 S. F. Patil, Vice-chancellor, North Maharashtra University Jalgaon (Y) Department of Environmental Science P.V.P. College, Pravaranagan, Dist-Ahmednagar Abstract Analyses of 126 samples collected from 18 dug wells in the shallow basaltic aquifer over a period of 7 months have revealed spatial as well as temporal changes in the chemical properties of groundwater. While the temporal changes have been attributed to dilution and concentration phe- nomena governed by climatic factors, the spatial variations in the geochemical characteristics of groundwater appeared to be related to pollution due to effluents from the Mula Sugar Factory. The cause of groundwater pollution is the effluent car- ried by a stream flowing through the area. Fluctua- tions in the groundwater table, influent water qual- ity character of the stream, less capacity to accom- modate large volume of effluent and occurrence of zero base flow (under natural conditions) in the stream are the factors favoring infiltration of con- stituents of waste water into the underlying weath- ered basaltic aquifer. Pollutants have entered into the shallow aquifer by downward percolation through the zone of aeration to form a recharge mound at the water table and, further, lateral movement below the water table. The plume of polluted groundwater has a lateral extent of a few meters in the upstream area and more than 400 m on either side of the stream in the downstream part. The zone of polluted groundwater has an ar- eal extent of more than 3.5 km 2 . Groundwater is the only source available for drinking and agricul- tural purposes. It is recommended that the base of the lagoons and the stream used for release of plant effluent should be waterproofed for the pro- tection of groundwater in the Sonai area. Key words Groundwater 7 Sugar mill 7 Basaltic aquifer 7 Pollution Introduction The sugar industry in Maharashtra, India, is a key factor in the rural economy of the state. It has initiated devel- opmental economic activities, like cooperative dairies, pa- per mills, and poultry farms, in their respective regions. Some of them have opened educational institutions and technical colleges and have been responsible for changing the social structure of rural areas. The growing demand for more sugar factories in all parts of the state is an in- dication of the importance of the industry to the rural development and general economic prosperity (Anand 1987). In spite of the fact that the sugar industry is the back- bone of the rural economy of Maharashtra, the need has arisen to review and recognize environmental problems associated with it. It is noteworthy that the rapid increase in sugar industrialization has led to unprecedented in- creases in urbanization and population and hence the de- gradation of environmental resources. The enormous quantities of wastes (solid, liquid, and gas) generated by these rural industries has led to problems of air, water, and soil pollution. The problems of water quality and wa- ter pollution are particularly severe in many sugar factory areas and are threatening the rural population. In the re- cent past, several studies (Manas 1976; Kundra and Pur- thy 1979; Handa 1981; Krupanidhi 1984) have reported that receiving water bodies are becoming increasingly contaminated due to domestic and industrial waste wa- ters. However, few studies regarding the nature of groundwater pollution due to effluents from sugar mills have been carried out. Therefore, in this article ground- water pollution probably caused by the disposal of ef- fluent from the Mula Sugar Factory is discussed.