Quantitative environmental impact assessment on groundwater quality using geoinformatics techniques

Availability of quality freshwater is one of the most critical environmental issues of the twenty first century (UNEP, 2002). Urbanization leads to the environmental pollution, i.e., urban growth leads to the increasing of slums, solid waste disposal, provision of transport facilities, conjection and groundwater contamination. Groundwater is an important water resource for domestic and agriculture in both rural and urban parts of India. Pollution of groundwater comes from many sources. Groundwater contamination in a major issue, especially in industrial areas especially like Dindigul. The presence of large number of tanniers and allied industrial unit such as dyeing and bleaching units in and around the town are the main factors, which affect the environmental quality of the town. Dindigul town is not having the physical expansion since 1981 with an area of 14.01sq.km. Only wards are increased by enjoying the rapid growth of population. Dindigul is the main industrial hub for the Tanneries. Effluents from the tanneries are discharged in to streams which drain into ponds, thereby polluting the ground water sources and cultivable land. These values are more than the permissible limit in and around the tannery cluster compared to other parts of the area. The pH,CO3, Na, Ca, Mg, NO3, and SO4 values of all groundwater samples are within the permissible limits but all the EC, TDS, HCO3and K values are exceeding the permissible limit. According to TH and Cl 6 samples are exceeding the prescribed limits. There are about 80 tanneries spread within 4-6 kms radius in the south western part of the town i.e., near Paraipatti, so ground water pollution is very high compared to other places. Madurai road tanneries are located so in Begampur near Annamalayar school pollution is high. R. M. Colony is having the highest household wastages because of its vertical expansion so in that areas also pollution is high.