In October 2020, the Delhi Jal Board (DJB) was forced to shut two water treatment plants after ammonia levels in the Yamuna reached nearly six times above the acceptable level.
- Ammonia levels had reached 3 parts per million (ppm) in raw Yamuna water on October 29, 2020 and came down to 1.7 ppm by 30 October.
- The US National Academy of Science recommends, and many European nations have adopted, a drinking water standard of 0.5 mg/l (ppm).
- DJB’s Bhagirathi and Sonia Vihar water treatment plants, having a combined treatment capacity of 250 million gallons per day (MGD), had to be closed for around 24 hours on October 29, 2020.
- According to the World Health Organisaiton, natural levels in groundwaters are usually below 0.2 mg of ammonia per litre.
- Higher natural contents (up to 3 mg/litre) are found in strata rich in humic substances or iron or in forests.
- Surface waters may contain up to 12 mg/litre. Ammonia may be present in drinking-water as a result of disinfection with chloramines.
- The presence of ammonia at higher than geogenic levels is an important indicator of faecal pollution.
Sources of Ammonia
- Cement mortar used for coating the insides of water pipes may release considerable amounts of ammonia into drinking-water (WHO).
- Ammonia is produced for commercial fertilizers and other industrial applications (US-EPA).
- Natural sources of ammonia include the decomposition or breakdown of organic waste matter, gas exchange with the atmosphere, forest fires, animal and human waste, and nitrogen fixation processes (US-EPA).
- Ammonia can enter the aquatic ecosystem via direct means such as municipal effluent discharges and the excretion of nitrogenous wastes from animals, and indirect means such as nitrogen fixation, air deposition, and runoff from agricultural lands (US-EPA).
Impacts
- Higher levels of ammonia in water makes it difficult for aquatic organisms to sufficiently excrete the toxicant, leading to toxic buildup in internal tissues and blood, and potentially death (US-EPA).
(Source: United States Environmental Protection Agency, WHO, Indian Express)
CLICK HERE FOR UPSC PRELIMS CURRENT AFFAIRS MCQ
