Ammonia level rises in Yamuna, 2 plants shut down (Times of India 14 March 2012)

NEW DELHI: Chandrawal and Wazirabad water treatment plants were shut for production in the early hours of Tuesday due to a high level of pollution in the water. A rise in the level of ammonia from a permissible 0.5 mg to 1 mg prompted Delhi Jal Board to ask residents to boil drinking water.

"At 6am, we had to shut down both plants that supply water to north, northwest, south and NDMC areas. However, the situation had improved significantly by 5pm when partial operations were resumed. Supply will be normalized by Wednesday morning," said a DJB official.

The problem started when Haryana released water for Delhi into the Yamuna where water levels had been quite low. "Usually Haryana supplies water up to the Wazirabad Barrage through drain no 8 and not the main river channel. However,Haryana had not been maintaining the channel properly and due to a possible plant growth inside, the amount of water coming to Delhi had reduced. When we brought this to Haryana's notice, it took up maintenance of the drain but since it has to maintain a certain level of water at the Wazirabad pond, it started releasing water into the main river," said an official.

The sudden flow dislodged industrial pollutants that had been collecting in the dry river for the past few months. These pollutants travelled to Delhi with the water and their levels were too high to be treated by DJB. "Haryana Irrigation Department was requested to release additional quantity of water at Munak to dilute the concentration of pollutants," said an official.