Drinking water problem arises in Delhi as ammonia levels rise in Yamuna

According to a Hindustan Times report, the ammonia level in the Yamuna river water at Wazirabad in Delhi has reached 1.5 to 2 parts per million (ppm). This figure is much higher than the stipulated limit of 0.9 ppm, due to which a serious impact has started on Delhi's water supply system. Ammonia is a nitrogen-based compound that enters rivers mainly through untreated sewage, industrial waste, and agricultural run-off. A high proportion of ammonia in water makes the process of making it potable extremely difficult.

According to Delhi Jal Board (DJB) officials, their water treatment plants can remove ammonia up to about 1 ppm through normal chlorination. However, when the ammonia content increases above this level, toxic chloramines can form during the chlorination process. In this situation, the contaminated raw water has to be diluted by mixing it with clean water to purify it. The Wazirabad and Chandrawal water treatment plants are seeing the maximum impact of this problem, as these plants get water directly from the Yamuna. When the ammonia level rises, water production has to be reduced, and the DJB tries to dilute the polluted water by using water coming through the Munak canal. According to officials, ammonia up to 2 to 2.5 ppm can be controlled by this method.

Meanwhile, the NDMC has issued an advisory that the supply in areas getting water through the Sonia Vihar plant may be affected. Generally, the Sonia Vihar plant gets water from the Upper Ganga Canal, but supply is uncertain as the annual maintenance work of this canal has recently been completed. A long-standing dispute has been going on between Delhi and Haryana regarding the source of ammonia pollution. The DJB alleges that industrial waste is dumped into the river upstream of Wazirabad, in which the mixing of industrial waste into the Panipat industrial drain and Sonepat canals are the main reasons. On the other hand, the Haryana government has denied these allegations and stated that work to prevent pollution through pipelines is underway as per National Green Tribunal directives.

During winter from November to March, due to low water flow in the river, the dilution of pollutants is low, resulting in increased ammonia levels. Such incidents occur on an average of 15 to 22 times every year in Delhi. The situation is more serious in the downstream of Wazirabad, where 69 percent of Delhi's total pollution merges into the river through the Najafgarh drain. The 22 km stretch of Yamuna in Delhi contributes 75 percent to the river's total pollution, due to which the level of oxygen required for aquatic life becomes zero.