Though water supply in various parts of the city improved on Friday, many areas remained parched as the Delhi Jal Board (DJB) could not release potable water from the Wazirabad and Chandrawal Water Treatment Plants (WTP) due to high level of pollution in Yamuna.The ammonia concentration rose in the river after the Tajewala Barrage near Yamunanagar in Haryana released water.“Effluent from the tanneries in Karnal reached Delhi with water from the Western Yamuna Canal,” a DJB official said.Officials said there was some improvement in the quality of raw water, but the shortage may prolong till Saturday evening.On Thursday and Friday, large areas of North, Central and West Delhi, which fall under the Wazirabad and Chandrawal WTPs went without water.On Friday parts of South Delhi and areas falling under the New Delhi Municipal Corporation (NDMC) remained parched with Karol Bagh, Paharganj, Azad Market, Civil Lines, Metcalf House, Hindu Rao Hospital, Rajender Nagar, Patel Nagar and Baljeet Nagar.“The situation is improving and we hope to normalise the water supply by Saturday,” R K Garg, Member (water supply), DJB, said. “The level of ammonia in the river has reached 0.6 parts per million (pmm). We are flushing out the polluted water by opening the barrage gates at Wazirabad, ITO and Okhla.” For potable water, the permissible limit of ammonia concentration is 0.3 ppm.DJB officials said the matter has been taken up with the Central Pollution Control Board. According to experts, water becomes untreatable when ammonia concentration goes beyond 0.4 ppm. To treat this level of ammonia, a large amount of chlorine is needed, which can affect health.
