Gurugram: Residents of Westend Heights in DLF 5 who fell ill after consuming “drinking water” supplied by the GMDA, claimed that the water was so dirty that even water purifiers were ineffective.
A resident, who requested anonymity, said: “Of the 360 or so families living here, most use RO systems to filter water. However, the water that is ‘filtered’ is also so dirty that we can not consume it at all. ”
There are 380 apartments in the residence, of which 365 are occupied.
Most apartments have RO installed systems (reverse osmosis, a water purification process that removes contaminants from water by using pressure to force molecules through a semipermeable membrane), residents said, adding that they now only buy bottles of water.
“We have asked residents to drink bottles of water and use sea water for cooking,” said Ashok Tandon, an RWA member.
Last week, after at least 205 residents of Westend Heights became ill in DLF Phase 5 – the youngest of them was a two-year-old boy who was hospitalized for diarrhea – after consuming allegedly contaminated drinking water, authorities rushed in. action to discover the source of the problem
Abhinav Verma, executive engineer, Gurugram Metropolitan Development Authority (GMDA), Division of Infrastructure 2, said the blame did not end there – the authority supplied water to several companies in the area, none of which reported any problems. Plus, they tested the master water pipes leading to the area, but no source of pollution was found.
However, when they collected samples from the company on Saturday, they found that the TDS (total dissolved solids, referring to the amount of minerals, metals, organic matter and salts dissolved in water) was worth the water that houses within the community is higher than the TDS value of water supplied by GMDA, indicating that the water may be contaminated by other sources within the community. However, the GMDA did not disclose the exact values.
“Ether contamination took place in the society’s underground or top storage tanks, or in the mixing of borewell water installed in the society. In addition, the lack of disinfection in the stored water could also be a cause,” Verma said.
Ranjana Chaudhuri, a hydrologist and expert in water resources management, said the TDS value could be high due to anthropogenic resources such as sewage pollution, fertilizer, industrial wastewater, etc. “It is important to identify the source of high TDS. It means that potassium is as high as sodium or calcium or magnesium and anions such as nitrates, sulfate, carbonate are high. TDS up to 1,000-1,500ppm can be treated by RO systems, “she said.
Chaudhuri said that if left untreated, the water tastes salty. If TDS is high due to impurities, then the RO membrane may not be enough to treat it and it may need RO + UV (ultraviolet) + ultrafiltration to absorb all salts, however, the chance of demineralization of water becomes a problem . “In short, identifying the source of contamination is essential to reduce the TDS,” she said.
Another expert said that if the water from the RO tastes saltier than usual, one should call a professional for a maintenance check and change the cleaner or filter. “The process has to be done every six months,” he said.
Krishna Vihari, a technician working with a reputable RO company, said that water with a maximum of 300ppm is considered good for drinking and water with a TDS level of 1,000ppm or higher is not recommended for drinking. “In Gurugram, the TDS level is around 300ppm on Sohna Road and below 250ppm on Golf Course Road. The RO systems in Gurugram require more service compared to other cities and we have to change filters every quarter for better results because it TDS levels in the water here are high, “he said.
According to the World Health Organization (WHO), TDS level less than 300ppm is considered excellent, between 300 and 600ppm is good, 600-900ppm is fair, 900-1,200ppm is bad and TDS level more than 1,200ppm is unacceptable.
A 20-liter bottle of mineral water can maintain a TDS level of 120ppm, making it suitable for drinking, said another water expert.
Verma said they regularly check the TDS of the water GMDA supplies and perform regular tests to make sure water is safe for drinking. “We have water supply from canals, so the TDS differs. The water supply is also monitored by the irrigation department and we do not release the supply if the TDS levels are not safe,” he said.