Karnataka has emerged among the top five states in the country with a high level of groundwater contamination, raising concerns about the safety of humans and animals, besides over the food we consume. Studies conducted by the Central Ground Water Board and Ground Water Directorate indicate that concentration of harmful chemicals like nitrates, fluorides and arsenic is beyond permissible limits in 22 of the 30 districts in the state, including in Bengaluru Urban and Rural districts. The continuous drought in North Karnataka and the drinking water shortage in urban centres has led to over-exploitation of groundwater. The failure to recharge groundwater reserves over the years has led to such an alarming situation that in a few taluks where the chemical concentration is above the threshold, a complete ban has been imposed on drilling of borewells.
According to reports of the Karnataka Mines and Geology Department, considerable parts of the state have crossed the safe limit of groundwater extraction. Historical data indicates that groundwater levels are falling in all parts of the state except in some command areas. With the decline in the availability of surface water, the demand for domestic and agricultural purposes will only increase, leading to greater pressure on ground aquifers. This will necessitate digging of deeper borewells which, in turn, will lead to seepage of fluoride into ground water in regions with crystalline basement rocks. Over six lakh people across 635 habitats, particularly in Ballari, Chitradurga, Gadag and Tumakuru, already suffer from fluorosis. High concentration of fluorosis in drinking water causes dental problems, ultimately leading to severe physical disability. The use of contaminated groundwater to grow vegetables is also a serious health hazard. In Pavagada of Tumakuru district, chemicals were found even in breast milk, due to consumption of impure groundwater. This also raises serious fears about the milk available in the market as the same contaminated water is consumed by cattle, too.
Indiscriminate drilling of borewells, unchecked release of industrial and other effluents into water sources and a complete lack of focus on rainwater harvesting have only accentuated the problem. Reviving lakes, ponds and tanks in urban and rural areas is also important as water bodies are the oldest of the natural rainwater harvesting structures that help in maintaining soil moisture and facilitating recharge of groundwater. Though this problem has been staring us in the face for many decades, the government has failed to evolve a comprehensive regulatory mechanism to protect and recharge groundwater. Unless a legal framework is put in place immediately, water will soon turn to poison, endangering the lives of the people.
