Environment › Pollution › Water and rivers
Water pollution and wastewater
India's water pollution is two problems at once: sewage, a matter of treatment capacity, and industrial effluent, which stays toxic long after it is diluted. Namami Gange can now show a Ganga stretch off the Central Pollution Control Board's polluted list, while the courts fence off the Jojari in Rajasthan and hexavalent chromium sits in the groundwater of the Kanpur region. The newer question is whether treated water is reused.
UPSC has asked
- Prelims 2025: what a circular economy reduces
- Prelims 2017: what biological oxygen demand is a standard criterion for
- Prelims 2016: key features of the National Ganga River Basin Authority
- Prelims 2015: India's national aquatic animal
- Prelims 2013: chromium and other metals released as e-waste
- Prelims 2013: pollutants found in drinking water in parts of India
How a river stretch is judged, and how it is cleaned
- The Central Pollution Control Board (CPCB) lists a river stretch as polluted when its biochemical oxygen demand stays above the bathing water standard, and drops the stretch once it complies.
- Namami Gange, launched in 2014 and run by the National Mission for Clean Ganga, pays for sewage treatment in the Ganga basin and for the surveys of the river's fauna.
- Minimum environmental flow norms for the Ganga, notified in October 2018, are monitored by the Central Water Commission.
What hexavalent chromium does
- It is a carcinogen, and long inhalation raises the risk of lung cancer.
- Swallowed in water, it injures the liver, kidneys and gut.
- Skin contact causes ulcers and allergic dermatitis.
From treatment to reuse
Treat
Sewage treatment capacity built under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT)
Match the quality
Fit-for-purpose reuse: treat only to the standard the end use needs
Use it
Treated water reaches farms and industry, and reuse is tied to river rejuvenation
- The National Framework on Safe Reuse of Treated Water, 2022, asks every State to frame its own reuse policy.
What has happened
31 Aug 2026
Uttar Pradesh and Uttarakhand notified policies for the reuse of treated wastewater, one written for the plains and one for hill conditions.
- Each builds in fit-for-purpose reuse, blended finance and digital monitoring, and ties reuse to river rejuvenation.
The Hindu, 31 Aug 2026: Mainstreaming reuse of treated wastewater (opens in a new tab)
24 Aug 2026
The Supreme Court barred construction within 100 metres of the Jojari and hazardous industry within 500 metres of its flood line.
- The Jojari carries Jodhpur's industrial effluent to the Luni near Balotra, as the Bandi carries Pali's.
- Effluent in the Jojari, Bandi and Luni affects about two million people in Rajasthan.
17 Aug 2026
Groundwater in about a dozen areas of Kanpur Nagar, Kanpur Dehat and Fatehpur was reported to hold hexavalent chromium, from decades of waste dumped by factories making chromium sulphate for tanneries.
- A 2025 State report found excess chromium (VI) in 73 to 96 per cent of the blood samples tested.
- National Green Tribunal orders in 2005 and 2017 had sought closures and the removal of the dumps.
6 Aug 2026
The Central Pollution Control Board's Polluted River Stretch report 2025 left the Haridwar to Sultanpur stretch in Uttarakhand off the list.
- Stretches in Uttar Pradesh and West Bengal improved in part.
- Namami Gange has created 4,263 million litres a day of sewage treatment capacity, and 146 of its 219 sewage projects are complete.
- Surveys counted 3,037 gharials, and a National Gharial Conservation Action Plan followed.
- The Gangetic dolphin estimate for 2021 to 2023 is 6,327, and India's first Dolphin Rescue Ambulance is in service.