Water supply will be affected in parts of Delhi on Friday due to ammonia pollution in the river Yamuna, the Delhi Jal Board said.

The utility said ammonia concentration in the river has increased to two particles per million (ppm) due to pollution from Haryana. The water level in the Wazirabad pond is also low -- 670 feet as against a normal of 674.5 feet.

Operations at the Wazirabad, Chandrawal and the Okhla WTPs have been hit. Water supply will remain affected till the situation improves, it said.

Water will be available at low pressure in parts of northeast Delhi, west Delhi, north Delhi, central Delhi, south Delhi, including Delhi Cantonment, and New Delhi Municipal Council areas.

The Chandrawal, Wazirabad and the Okhla WTPs have a treatment capacity of 90 MGD, 135 MGD and 20 MGD, respectively. The acceptable maximum limit of ammonia in drinking water, as per the Bureau of Indian Standards, is 0.5 ppm. At present, the Delhi Jal Board can treat up to 0.9 ppm.

(With PTI inputs)