Why in news?
Residents of Delhi faced a severe water shortage when high levels of ammonia in the Yamuna River forced the Wazirabad and Chandrawal water treatment plants to shut down. Ammonia levels were reported to be more than 3 parts per million, three times the safe limit, while repair work on the Munak Canal further restricted inflows. Water supply normalised only after ammonia levels fell to around 2.5 ppm.
Background
Ammonia (NH3) is a colourless gas made of nitrogen and hydrogen. It is used widely in fertilisers, cleaning products and as a refrigerant. In water it dissolves to form ammonium, which in small amounts is harmless, but high concentrations can make water unfit for drinking and can cause throat and lung irritation. Ammonia is released naturally from the decomposition of organic matter and is also discharged into rivers through industrial effluents and sewage.
Why do ammonia spikes occur in the Yamuna?
- Industrial pollution: Factories and power plants upstream in Haryana and Delhi release untreated waste into the river, increasing ammonia concentrations.
- Sewage inflow: Untreated household waste and sewage enter the Yamuna, especially when sewage treatment plants are overloaded.
- Low river flow: During winter the water level in the Yamuna drops, reducing its capacity to dilute pollutants. Any maintenance or blockage on canals feeding the city can worsen the situation.
Impacts and responses
- Disruption of water supply: High ammonia levels force shut‑downs of water treatment plants, leading to dry taps and long queues for water tankers across the city.
- Health concerns: Ammonia in drinking water can irritate the eyes, nose and throat. Combining ammonia‑based cleaners with bleach can produce toxic chloramines and must be avoided.
- Need for infrastructure: Delhi announced plans for an ammonia treatment plant in 2022, but the facility is yet to be built. Strengthening sewage treatment and monitoring industrial discharges are crucial for long‑term solutions.
Conclusion
The latest water crisis underscores the fragility of Delhi’s water supply. Controlling industrial pollution, treating sewage and upgrading treatment infrastructure are essential to ensure safe drinking water during dry months.
Source: Hindustan Times
