Ammonia levels in Yamuna may affect water supply: Delhi Jal Board

DJB, in an official statement issued on Tuesday, said the ammonia levels of the Yamuna near the Wazirabad pond area has crossed 5 parts per million (ppm) — five times more than the maximum treatable limit of water treatment plants.

The water scarcity faced by residents of north, west and central Delhi are likely to worsen in the coming days, after operations at two water treatment plants catering to these areas were affected by very high pollution levels in the Yamuna, Delhi Jal Board (DJB) officials aware of the matter said on Tuesday.

Toxic foam floats on the surface of the polluted Yamuna river in New Delhi on March 21. (PTI)

DJB, in an official statement issued on Tuesday, said the ammonia levels of the Yamuna near the Wazirabad pond area has crossed 5 parts per million (ppm) — five times more than the maximum treatable limit of water treatment plants — due to which operations at the Wazirabad and Chandrawal plants have been curtailed by between 10% and 50%.

Officials said that due to curtailed operations at these two plants, parts of north, west and central Delhi will receive water at low pressure till the situation improves.

The areas likely to be affected are Civil Lines, Kamla Nagar, Shakti Nagar, Karol Bagh, Paharganj, areas under NDMC, New Rajinder Nagar, Patel Nagar, Baljeet Nagar, Prem Nagar, Delhi Gate, Model Town, Gulabi Bagh, Punjabi Bagh, Moolchand, South Extension, Greater Kailash, Kalkaji, Govindpuri, Tughlaqabad and Ambedkar Nagar, the water utility stated.

HT reached out to DJB vice chairperson Somnath Bharti, but he declined to comment.

DJB’s plants can treat up to 1ppm of ammonia in raw water through chlorination, but using the chemical beyond this limit leads to the production of toxic compounds. Whenever ammonia levels breach the 1ppm mark, operations at water treatment plants are hit.

Of Delhi’s 952 million gallons per day (mgd) average water supply, around 230mgd is supplied by the Wazirabad and Chandrawal plants, both of which draw water from the Wazirabad pond, which is fed by the Yamuna.

Over the last month, Delhi has been facing fluctuation in water supply due to low water levels in the Yamuna, the disruption of supply from the Upper Ganga Canal from Uttar Pradesh due to desilting of the canal, industrial pollutants, as well as excessive levels of algae in raw water being supplied to the city.

Speaking of the high ammonia levels near the Wazirabad pond area, a senior DJB official said, “The problem started from Tuesday morning and during the day ammonia levels were higher than 6.2ppm. The pollutants are coming from Panipat and Sonipat industrial units via the DD6 and DD8 drains. Rainfall over the last week may have also contributed to flushing down of pollutants in these two drains.”

A second DJB official, who is associated with plant operations, said operations were fluctuating. “The Wazirabad plant, which supplies 131mgd water, was operating at 40% of its capacity. The Chandrawal plant has also been hit. It was operating at 40% level during the day but some restoration of operations is being carried out by diluting water from other sources, and it is currently running at 90% level,” the official said.

DJB in its official advisory has directed people to make judicious use of water over the coming days.

Last week, chief minister Arvind Kejriwal had said that DJB will set up an ammonia removal plant to treat polluted water entering the Yamuna from Haryana in the next six months.