Ground Water Pollution and Emerging Environmental Challenges of Industrial Effluent Irrigation: A Case Study of Mettupalayam Taluk, Tamilnadu

Industrial disposal of effluents on land and subsequent pollution of groundwater and soil of surrounding farmlands – is a relatively new area of research. Environmental and socio-economic aspects of industrial effluent irrigation have not been studied as extensively as domestic sewage based irrigation practices, at least for developing countries like India. Disposal of treated and untreated industrial effluents on land has become a regular practice for some industries. Industries located in Mettupalayam taluk, Tamilnadu dispose their effluents on land, and the farmers of the adjacent farmlands have complained that their shallow open wells get polluted and also the salt content of soil has started building up slowly. This study attempts to capture the environmental and socio-economic impacts of industrial effluent irrigation in different industrial locations at Mettupalayam taluk through primary surveys and secondary information. This study found that continuous disposal of industrial effluents on land, which has limited capacity to assimilate the pollution load, has led to groundwater pollution. Ground water quality of shallow open wells surrounding the industrial locations has deteriorated, and the application of polluted groundwater for irrigation has resulted in increased salt content of soils. In some locations drinking water wells (deep bore wells) also have high concentration of salts. Since the farmers had already shifted their cropping pattern to salt tolerant crops (like jasmine, curry leaf, tobacco etc.) and substituted their irrigation source from shallow open wells to deep bore wells and/or river water, the impact of pollution on livelihood was minimised. It is observed that with the rise in concentration of electrical conductivity of groundwater samples, revenue from banana cultivation (in Rs. per acre) has gone down. However blending open well water with the river water and/or water from deep bore wells has arrested the fall in revenue. For salt tolerant crop like jasmine, the rise in EC did not seem to have significant impact on productivity. Since the local administration is supplying drinking water to households the impact in the domestic sector has been minimised. It has also been noticed that in some locations industries are supplying drinking water to the affected households. However, if the pollution continues unabated it could pose serious problems in the future.