Currently, the water treatment plants that source raw water from the Yamuna and the carrier lined channel from Haryana are running at 70-80 per cent capacity, a DJB statement said.
"The ammonia level has risen to 1.6 ppm against the treatable limit of 0.9 ppm, in the raw water available at the Yamuna pondage.
"The affected areas: whole West, North, Central Delhi, part of South, including Delhi Cant and NDMC areas," it said.