According to Delhi Jal Board officials, the production of drinking water had to be curtailed at all water treatment plants fed from the Yamuna after ammonia levels shot up to 1.6 parts per million as opposed to the acceptable limit of 0.6 parts per million. WITH AMMONIA levels in Yamuna spiking to almost twice the permissible limit on Monday, Delhi stares at a water crisis yet again. According to Delhi Jal Board (DJB) officials, the production of drinking water had to be curtailed at all water treatment plants fed from the Yamuna after ammonia levels shot up to 1.6 parts per million as opposed to the acceptable limit of 0.6 parts per million. The supply of raw water in the Munak Canal, according to DJB officials, has also been reduced. Affected areas include the entire west, north and central Delhi, and parts of south Delhi, including Delhi Cantonment and NDMC areas. According to DJB sources, the recurrent problem of a spike in ammonia levels in the water supply is because there is not enough water in the river. Ecological flow of Yamuna — which is the minimum amount of water that must flow in the river at all times to sustain riverine ecosystems — is supposed to be 10 cubic meter per second (cumecs) as per a MoU signed between Delhi and Haryana in 1994. “This means that the flow should be 10 cumecs at any given time. In December and January, which are the driest in the whole year, this level invariably falls. Discharge from polluting industrial units in Panipat and Sonipat add to the problem,” a senior DJB official said. Residents of affected areas can call 1916, 23527679, 23634469 for tankers, the DJB said in a statement.