The deadly waters beneath the city

There are reports in the media about the last date of registration of borewells in Bangalore. The  Government had made it mandatory for borewell owners to register them.

This is the first step in regulating and monitoring the borewells and through them the quality and quantity of groundwater.

There is no data needed to buttress the point that the groundwater table in Bangalore has gone down drastically over the last few decades. But what is not all that well–known is that the quality of groundwater in several places leaves much to be desired and in some cases are unfit for human consumption.     

The Department of Mines and Geology, Karnataka, recently released a report on the hydrology and ground water level of Bangalore.

The report studied the ground water, its quality, quantity, availability and usage in and around Bangalore. The report warns of the scramble to sink borewells and it estimates that 570 MLD (million liters a day) of Bangalore's water comes from groundwater.

The borewells are being made use of to make up the shortfall from supply of water through Arkavathi and Cauvery. The department says between February 2009 and January 2010, Bangaloreans happily sunk 14483 borewells in the core area of 330 sq. km. covered by the Bangalore Water Supply and Sewerage Board (BWSSB).

The Department says as on January 2010,  there were 105,501 borewells registered with the BWSSB in the core area. If the newly added areas of  380 sq km. is also covered, the total number of borewells would be 2.25 lakhs.

The department checked the water quality by analyzing 2209 groundwater samples covering all of Bangalore. Nitrate content was in excess of the permissible limit in 29 per cent of the samples, iron in 10 per cent,  total hardness in 8.5 per cent and fluoride in 0.6 per cent.

It found that  31 per cent of the groundwater samples were not up to drinking water standards. An earlier study of  2003 had found that 50 per cent of the samples tested were unfit. The reason for the improvement of quality is beyond any scientific reason and it is a cause for mystery.

The current study covered 741 sq km., and the TDS (Total Dissolved Solids) ranged from500mg/L to 2000 mg/L in 68 per cent of samples. Water with high TDS might have an undesirable taste and may not be comfortable to bathe in, but it is dangerous. Mahadevapura and Dasarahalli zones had TDS per litre of water exceeding 1,600 mg, as against the prescribed limit of 500 mg per litre. This is probably due to agricultural and industrials runoffs in these areas.

Regular use of water with high TDS leads to hair loss. Drinking this water leads to tooth-related problems.

However, what is worrying is the Nitrate contamination. The permissible limit is 45 mg/L and nitrate is harmful particularly to babies. Twenty nine per cent of the samples tested had higher than permissible nitrate content.  What is more worrisome is that the samples are also evenly distributed throughout the city. Thus, the entire city suffers from this contamination.

Fluoride contamination seems to be making inroads in Bangalore which till recently was unheard of. Bangalore. Sixteen of the 2209 samples tested higher than permissible limits for fluoride.

Some samples recorded fluoride as high as 5.54 mg/l in borewell water in Bellandur. The permissible limit for human consumption is 1.5 mg/l. Borewells in Uttarahalli recorded 5.06 mg/l of fluoride

Special testing was done for heavy metals in industrial areas.

The fluoride contamination shows how deep borewells have sunk into the aquifer, especially in south, southeast and north Bangalore. While Bellandur village recorded fluoride ranging between 2.3 to 5.5 mg/l, Bellahalli cross in Yelahanka and Sapthagiri layout in Seegehalli (Whitefield) were found to have 2.3 mg/l of the chemical each.

The report says  as borewells have begun to sink to depths between 800 to 1,000 feet, they struck groundwater rich in fluoride, a natural component of rock chemistry in these parts of Bangalore.

Samples from the industrial areas showed high levels (much above drinking water standard) of contaminants:

Zinc: Gollahalli (Bommanahalli), Hosapalya(including CMC supply), Somasundarapalya (HSR 2nd Sector), ITI Layout (Hosapalya), Anu Polymers (Rajajinagar Industrial Town), Reshma Dyeing Factory (Rajajinagar Industrial Area)

Manganese: Peenya Industrial Area (11th Cross, 4th Phase), Hegganahalli (Srigandhanagar), Hosapalya (BBMP Nursery), Rajajinagar Industrial Town (Anu Polymers), Rajajinagar (Agrahara Dasarahalli), Old Madras Road Industrial Area (Virgonagar)

Chromium: 3rd Phase Peenya Industrial Area, Peenya 2nd Stage (Adrahalli Main Road), Peenya 2nd Stage (Andrahalli Main Road, Kaverinagar), Peenya 2nd Stage (Rajagopal Nagar), Hegganahalli (Srigandhanagar), Yelahanka New Town, Rajajinagar Industrial Town (Swadesh Industrial Supplier), Rajajinagar Industrial Town (Anu Polymers)

The report said groundwater resources are being overexploited.

If you want to get water tested, the Department of Mines and Geology, will do so at its office on Kanija Bhavan on Race Course Road.

The website of the department is: http://mines.kar.nic.in/.

Another report on ground water by Centre for Sustainable Development found almost all ground water samples in newly added areas of BBMP had high TDS.

The high TDS is an indication that ground water contains inorganic and organic solids in excess of the prescribed standards - 500 mg per litre of water.

A Bangalore Water Supply and Sewerage Board (BWSSB) survey says sample reports for 2011 show that coliform content was high in April and June. Water with coliform is not potable and it causes  gastroenteritis and fever.

Generally, a mix up of sewerage water with drinking water results in coliform. Most of water quality-related complaints come from east and west zones, which have some of the oldest pipeline networks in Bangalore.
The Karnataka Legislature passed the Karnataka Ground Water (Regulation and Control of Development and Management) Bill, 2011, in March last year. The bill is meant to provide for the constitution of the Karnataka Ground Water Authority which in turn will control indiscriminate exploitation of groundwater, especially in the notified areas like city-corporation, municipality limits or drought hit areas.

The authority came into being on May 5, 2012. It functions under the Department of Mines and Geology and it  held its first meeting to frame guidelines for the new Act.
Such an act is already in operation in Maharashtra, Punjab, New Delhi, Andhra Pradesh, Kerala, Tamil Nadu and West Bengal.