<p>The authorities seem to be clueless on means to prevent contamination of drinking water with sewage and industrial effluents, even as residents risk contracting deadly diseases.<br /><br /></p>.<p>Rapid urbanisation, mindless development, erratic industrialisation coupled with poor sewage and solid waste management have not only depleted the groundwater levels, but have also irreversibly contaminated the water table in Bangalore.<br /><br /> With the Bangalore Water Supply and Sewerage Board (BWSSB) distributing Cauvery water to only six lakh-odd households, a large population depends on groundwater for potable and non-potable purposes.<br /><br />Most residents, especially those living in the fringe areas, either buy water or adopt reverse osmosis or RO (a filtration methodology) for purifying drinking water, as groundwater is unsafe for direct consumption. However, experts say RO water is not good for health as it is devoid of minerals.<br /><br />According to a study conducted by the Mines and Geology Department last year on ‘groundwater hydrology and groundwater quality in and around Bangalore City’, polluted/contaminated groundwater cannot be easily converted into drinking water, as the treatment cost is enormous.<br /><br />Nitrate presence<br /><br />Out of the 2,000-odd samples tested by the department, the maximum number of samples had nitrate content in excess of the desirable or permissable limit. The reason for such heavy presence of nitrate in groundwater is mainly due to the absence of underground drainage system in the newly added BBMP areas and bad management of the existing sanitary lines in core areas.<br /><br />The department findings revealed that groundwater in Nayandahalli, South Layout and MS Road has 554 milligram per litre of nitrate against the permissible limit of 45 mg/l. Other areas, including KR Puram, Ramamurthynagar, Mahadevapura, Varthur, Bommanahalli, Anjanapura, Rajarajeshwari Nagar, Nayandahalli, Dasarahalli, Herohalli, Byatrayanapura, Kempegowda Nagar, Thanisandra, Lakshmidevi Nagar in the West and Vishwanathanagenahalli in the East also recorded high content of nitrate in groundwater samples.<br /><br />Unaware of the contamination of water, residents in these areas constantly use groundwater for all purposes. KR Puram is a classic example of both groundwater depletion and contamination. Even at a depth of 1,000 feet, borewells do not yield water.<br /><br /> The existing ones yield only salty water. The main reason is the absence of underground drainage system, which has forced residents to construct soak pits and let out waste water. This unscientific method is a major contributor to groundwater contamination, especially nitrate.<br /><br />Gopalswamy, a resident, regrets buying a house in Ramamurthy Nagar. “What kind of development this is? People here can afford to buy high-end mobile gadgets and satellite television services, but fail to understand the basic need for water. The borewell yields salty water. People living in slums are exposed to all kinds of infection and diseases,” he said.<br /><br />At Kodigehalli in Bytarayanapura constituency, borewell water contains high levels of nitrate. Kiran Kumar, a resident, says 51mg/litre of nitrate was reported in one of the samples tested recently, which was much more than the permissible limit of 45 mg/litre. “The borewell water is highly contaminated here. People suffer from diarrhoea and vomiting and the cases increase during summer,” he added.<br /><br />BWSSB role<br /><br />A geologist from the Mines and Geology Department says sewage management is essential to stop groundwater contamination. But Bangalore is not able to treat all the sewage it discharges. The BWSSB treats less than 50 per cent of the total sewage generated, using 16 secondary and tertiary treatment plants across the City. <br /><br />Out of the 900 million litres of water supplied to the City, 20 per cent goes for drinking purpose; the remaining 80 per cent is generated as sewage. Of the 720 million litres of sewage generated, nearly 370 million litres of sewage gets treated and is let out into Bellandur Lake, Varthur Lake. It then reaches Hosur via Periyar river. The remaining filth enters Arkavathi river.<br /><br />According to a BWSSB engineer, people in Hosur and Dharmapuri are utilising this water, treating it to tertiary level and using it for potable purpose. The BWSSB is not able to treat a large portion of the sewage, mainly because the Board is unable to link the sewage lines to the treatment plants, resulting in untreated disposal.<br /><br />The official said the newly added areas do not have sanitary lines at present. The existing ones are not managed well as sewage also runs in the stormwater drain.<br /><br />The study by the Mines and Geology Department revealed that low and high values of pH (acidic or alkaline nature of water) and the presence of e-coli and total coliform bacteria are mainly due to the discharge of untreated sewage waste into the natural drainage system (soak pits, stormwater drains and lake beds).<br /><br />Solid waste<br /><br />Another major contributor to water contamination is the unscientific disposal of solid waste. With no waste segregation in practice, wet and dry garbage are put together and at many places dumped on roadsides. Garbage left in the open for a long time emits leachates (toxic liquid that discharges from garbage) that seep into the ground and causes groundwater contamination, says M V Shashirekha, former chief chemist, Mines and Geology Department.<br /><br />“Dyes and detergents used in fabrics contribute to groundwater contamination to a large extent since our underground drain systems are not up to the mark. Disposal of e-waste, especially electrical batteries which are dumped in the open, cause lead poisoning,” she added.<br /><br />Other contaminators<br /><br />High content of iron in groundwater samples is attributed to corrosion of casing pipes of borewells. The permissible limit stands at 1.0 mg/litre and 10 per cent of the 2,000 samples tested undesirable limits of iron in water. Areas like HMT Layout in Vidyaranyapura, Police Quarters in Cox Town, Gokula Extension in Mathikere, Dodda Nekundi in Marathahalli and HSR Layout recorded high levels of iron content in groundwater. <br /><br />The presence of fluoride in Bangalore’s groundwater is exceptionally high at Uttarahalli and Bellandur. The presence of zinc, copper, lead, manganese, chromium and aluminium in large quantities in groundwater is mainly due to untreated industrial effluents let out into lakes and drains.<br /><br />In Mahalakshmi Layout, West of Chord Road, Rajajinagar, Basaveshwarnagar and Govindarajnagar, groundwater was found contaminated due to the presence of petrol bunks. High oil content was found beyond the permissible limit in water samples collected there.<br /><br />Solution<br /><br />Lake rejuvenation and rainwater harvesting are the recommended solutions to the growing groundwater contamination in the City. S Vishwanath from Rainwater Club says a technology must be adopted to tackle groundwater contamination.<br /><br /> A de-nitrification plant can be a boon to remove nitrate in water. “Lake rejuvenation must be campaigned for aggressively, which will also increase the groundwater table. Rainwater harvesting should be made compulsory for all residents,” he added.<br /></p>
<p>The authorities seem to be clueless on means to prevent contamination of drinking water with sewage and industrial effluents, even as residents risk contracting deadly diseases.<br /><br /></p>.<p>Rapid urbanisation, mindless development, erratic industrialisation coupled with poor sewage and solid waste management have not only depleted the groundwater levels, but have also irreversibly contaminated the water table in Bangalore.<br /><br /> With the Bangalore Water Supply and Sewerage Board (BWSSB) distributing Cauvery water to only six lakh-odd households, a large population depends on groundwater for potable and non-potable purposes.<br /><br />Most residents, especially those living in the fringe areas, either buy water or adopt reverse osmosis or RO (a filtration methodology) for purifying drinking water, as groundwater is unsafe for direct consumption. However, experts say RO water is not good for health as it is devoid of minerals.<br /><br />According to a study conducted by the Mines and Geology Department last year on ‘groundwater hydrology and groundwater quality in and around Bangalore City’, polluted/contaminated groundwater cannot be easily converted into drinking water, as the treatment cost is enormous.<br /><br />Nitrate presence<br /><br />Out of the 2,000-odd samples tested by the department, the maximum number of samples had nitrate content in excess of the desirable or permissable limit. The reason for such heavy presence of nitrate in groundwater is mainly due to the absence of underground drainage system in the newly added BBMP areas and bad management of the existing sanitary lines in core areas.<br /><br />The department findings revealed that groundwater in Nayandahalli, South Layout and MS Road has 554 milligram per litre of nitrate against the permissible limit of 45 mg/l. Other areas, including KR Puram, Ramamurthynagar, Mahadevapura, Varthur, Bommanahalli, Anjanapura, Rajarajeshwari Nagar, Nayandahalli, Dasarahalli, Herohalli, Byatrayanapura, Kempegowda Nagar, Thanisandra, Lakshmidevi Nagar in the West and Vishwanathanagenahalli in the East also recorded high content of nitrate in groundwater samples.<br /><br />Unaware of the contamination of water, residents in these areas constantly use groundwater for all purposes. KR Puram is a classic example of both groundwater depletion and contamination. Even at a depth of 1,000 feet, borewells do not yield water.<br /><br /> The existing ones yield only salty water. The main reason is the absence of underground drainage system, which has forced residents to construct soak pits and let out waste water. This unscientific method is a major contributor to groundwater contamination, especially nitrate.<br /><br />Gopalswamy, a resident, regrets buying a house in Ramamurthy Nagar. “What kind of development this is? People here can afford to buy high-end mobile gadgets and satellite television services, but fail to understand the basic need for water. The borewell yields salty water. People living in slums are exposed to all kinds of infection and diseases,” he said.<br /><br />At Kodigehalli in Bytarayanapura constituency, borewell water contains high levels of nitrate. Kiran Kumar, a resident, says 51mg/litre of nitrate was reported in one of the samples tested recently, which was much more than the permissible limit of 45 mg/litre. “The borewell water is highly contaminated here. People suffer from diarrhoea and vomiting and the cases increase during summer,” he added.<br /><br />BWSSB role<br /><br />A geologist from the Mines and Geology Department says sewage management is essential to stop groundwater contamination. But Bangalore is not able to treat all the sewage it discharges. The BWSSB treats less than 50 per cent of the total sewage generated, using 16 secondary and tertiary treatment plants across the City. <br /><br />Out of the 900 million litres of water supplied to the City, 20 per cent goes for drinking purpose; the remaining 80 per cent is generated as sewage. Of the 720 million litres of sewage generated, nearly 370 million litres of sewage gets treated and is let out into Bellandur Lake, Varthur Lake. It then reaches Hosur via Periyar river. The remaining filth enters Arkavathi river.<br /><br />According to a BWSSB engineer, people in Hosur and Dharmapuri are utilising this water, treating it to tertiary level and using it for potable purpose. The BWSSB is not able to treat a large portion of the sewage, mainly because the Board is unable to link the sewage lines to the treatment plants, resulting in untreated disposal.<br /><br />The official said the newly added areas do not have sanitary lines at present. The existing ones are not managed well as sewage also runs in the stormwater drain.<br /><br />The study by the Mines and Geology Department revealed that low and high values of pH (acidic or alkaline nature of water) and the presence of e-coli and total coliform bacteria are mainly due to the discharge of untreated sewage waste into the natural drainage system (soak pits, stormwater drains and lake beds).<br /><br />Solid waste<br /><br />Another major contributor to water contamination is the unscientific disposal of solid waste. With no waste segregation in practice, wet and dry garbage are put together and at many places dumped on roadsides. Garbage left in the open for a long time emits leachates (toxic liquid that discharges from garbage) that seep into the ground and causes groundwater contamination, says M V Shashirekha, former chief chemist, Mines and Geology Department.<br /><br />“Dyes and detergents used in fabrics contribute to groundwater contamination to a large extent since our underground drain systems are not up to the mark. Disposal of e-waste, especially electrical batteries which are dumped in the open, cause lead poisoning,” she added.<br /><br />Other contaminators<br /><br />High content of iron in groundwater samples is attributed to corrosion of casing pipes of borewells. The permissible limit stands at 1.0 mg/litre and 10 per cent of the 2,000 samples tested undesirable limits of iron in water. Areas like HMT Layout in Vidyaranyapura, Police Quarters in Cox Town, Gokula Extension in Mathikere, Dodda Nekundi in Marathahalli and HSR Layout recorded high levels of iron content in groundwater. <br /><br />The presence of fluoride in Bangalore’s groundwater is exceptionally high at Uttarahalli and Bellandur. The presence of zinc, copper, lead, manganese, chromium and aluminium in large quantities in groundwater is mainly due to untreated industrial effluents let out into lakes and drains.<br /><br />In Mahalakshmi Layout, West of Chord Road, Rajajinagar, Basaveshwarnagar and Govindarajnagar, groundwater was found contaminated due to the presence of petrol bunks. High oil content was found beyond the permissible limit in water samples collected there.<br /><br />Solution<br /><br />Lake rejuvenation and rainwater harvesting are the recommended solutions to the growing groundwater contamination in the City. S Vishwanath from Rainwater Club says a technology must be adopted to tackle groundwater contamination.<br /><br /> A de-nitrification plant can be a boon to remove nitrate in water. “Lake rejuvenation must be campaigned for aggressively, which will also increase the groundwater table. Rainwater harvesting should be made compulsory for all residents,” he added.<br /></p>
