The State has failed in its duty to bring about groundwater regulations and set up sewage treatment facilities, which has led to the pollution of groundwater.
A study by the State Mines and Geology Department found heavy metals, including zinc, copper, lead, manganese, chromium and aluminium, beyond permissible limits in borewells, especially in industrial areas. Industrial waste disposals contain high amounts of nitrates and have recorded high and low levels of pH — a measure of the acidity or basicity of an aqueous solution.
Another striking revelation is the presence of chromium at 572 milligrams/litre (mg/l), much beyond the desirable limit of 0.05 mg/l. Many places in Peenya Industrial area showed high levels of chromium in borewell water, which has caused skin eruption among residents. Chromium levels were also high in the borewells of Rajajinagar Industrial Estate area and Yelahanka New Town area.
Manganese was found in the borewells of Rajajinagar industrial area at 31.20 mg/l, whereas the permissible limit is 0.30 mg/l. Besides, lead content in borewell water was found to be very high in Bommanahalli at mg/l (the permissible level is 0.05 mg/l).
E-coli in water
The study found e-coli and total coliforms in groundwater, mainly due to contamination with sewage water, municipal waste water or leachate from garbage dumps.
Groundwater was found contaminated near petrol bunks where the oil content varied from 33 mg/l to 91 mg/l (permissible limit is 0.01 mg/l and 0.03 mg/l), mainly in Mahalakshmi Layout, West of Chord Road, Gayathrinagar, Basaveshwarnagar and Govindarajanagar.
High fluoride levels
The study also found exceptionally high levels of fluoride in groundwater in Uttarahalli at 5.06 mg/l and in Bellandur at 5.54 mg/l, which is beyond the permissible limit of 1.5 mg/l.
The Peenya Industrial Area showed high levels of aluminium at mg/l, much beyond the permissible limit of 0.20 mg/l. The long-term consumption of water with aluminium causes dementia, according to the study.
Increase in water level
On the brighter side, however, the study found that potable groundwater in Bangalore had increased from 31 per cent in 2003 to 50 per cent in 2010.
Revealing these figures, Mines and Geology Director H R Srinivasa said the increase in potable groundwater levels was mainly due to the remedial measures implemented by the various government agencies to prevent groundwater pollution.
“Our department only monitors and gives statistics about the present status of groundwater. Other government agencies like the BWSSB and the Karnataka Pollution Control Board should take measures to prevent groundwater pollution,” he said.
Admitting that measures must be taken to conserve groundwater in the State, Chief Secretary S V Ranganath said: “The rules for the recently passed Groundwater Regulation Bill will be framed shortly. A committee will be constituted to act quickly on it.”