Water supply to be hit in Delhi after spike in ammonia levels

In an official advisory on Monday, DJB said ammonia levels are up to eight parts per million (ppm) in the Yamuna near Wazirabad, leading to curtailment of water treatment in Wazirabad and Chandrawal plants

With the pollutant level on the rise, water supply in various parts of Delhi is likely to be disrupted on Tuesday, officials of Delhi Jal Board (DJB) said.

Yamuna River near the Wazirabad Water Treatment Plant. Of the total 952MGD of Delhi’s average daily water supply, around 230 MGD is supplied by Chandrawal and Wazirabad plants, both of which draw water from the Wazirabad pond fed by the Yamuna. (HT Photo)

In an official advisory issued on Monday, DJB said ammonia levels are up to eight parts per million (ppm) in the Yamuna near Wazirabad, leading to the curtailment of water treatment in two of the largest plants of Delhi--Wazirabad and Chandrawal. 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.

“Due to high level of pollutants (ammonia more than 8ppm) in the Yamuna at Wazirabad pond, water production has been curtailed by 25-50% in water treatment plants of Wazirabad and Chandrawal. Therefore, water supply will be available at low pressure from the evening of April 3 till the situation improves,” the DJB statement said.

To be sure, long-term consumption of water with a high concentration of ammonia can cause poisoning and damage the human organs. Symptoms of ammonia poisoning include coughing, chest pain, wheezing, and difficulty in breathing (if the person inhales vapours). The problem of increased ammonia levels in the Yamuna is witnessed throughout the year, but the concentration of ammonia recorded in winters (between December and March) is relatively higher.

According to the DJB advisory, water supply is likely to be impacted in the north, central and parts of south and west Delhi. “The areas likely to be affected are Civil lines, Kamla Nagar, Shakti Nagar and adjoining areas, Karol Bagh, Pahar Ganj and NDMC areas, Rajinder Nagar, Patel Nagar, Baljeet Nagar, Prem Nagar, Kalkaji, Govindpuri, Tugalkabad, Sangam Vihar, Delhi Gate, Subhash Park, Model Town, Gulabi Bagh, Punjabi Bagh, Jahangirpuri, Moolchand, South extension,Greater Kailash and parts of cantonment and South Delhi,” the advisory said.

A senior DJB official said that around 9pm on Monday, the Chandrawal water treatment plant was operating at 30% capacity while the Wazirabad plant was running at 50% capacity. Of the total 952MGD of Delhi’s average daily water supply, around 230 MGD is supplied by Chandrawal and Wazirabad plants, both of which draw water from the Wazirabad pond fed by the Yamuna.

This is the second time in a week DJB has had to issue such an advisory. On March 28, DJB had issued the advisory when the ammonia levels had reached 5ppm. “After staying normal for 3-4 days, the problem has returned,”a DJB official added.

Over the last month, Delhi’s water supply as been fluctuating due to low water levels in Yamuna, disruption of supply from 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.