Environment and Disaster Management › Pollution
हिन्दी — Read in HindiWater pollution and river rejuvenation
The quality of India's rivers and drinking water: polluted stretches, sewage treatment, contaminants such as fluoride and arsenic, and the programmes that clean rivers. Prelims has asked what biological oxygen demand measures and which pollutants are found in drinking water in parts of India.
Foundation note: How a river is judged polluted: the classes, the standards and the sewage gap
All 5 articles shown; the 0 that changed from 1 to 31 July 2026 are marked.Show only these
Namami Gange
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Namami Gange, launched in 2014 and run by the National Mission for Clean Ganga, is the programme to clean the Ganga: it pays for sewage treatment in the Ganga basin and for the surveys of the river's fauna.
- Its test is not the plants it builds but whether a stretch of the river stops failing the bathing water standard.
- The Central Pollution Control Board (CPCB) lists a river stretch as polluted when its biochemical oxygen demand stays above the bathing water standard of 3 mg a litre, and drops the stretch once it complies.
- The Board now counts 296 polluted river stretches nationally, down from 351 in 2018.
- Minimum environmental flow norms for the Ganga, notified in October 2018, are monitored by the Central Water Commission.
What changed
6 Aug 2026New
- The CPCB's Polluted River Stretch report 2025 left the Haridwar to Sultanpur stretch in Uttarakhand off the list.
- Surveys of the river's gharials were followed by a National Gharial Conservation Action Plan.
- The Gangetic dolphin estimate for 2021 to 2023 is 6,327.
- India's first Dolphin Rescue Ambulance is in service for the Gangetic dolphin.
UPSC has asked
- Prelims 2016: key features of the National Ganga River Basin Authority
Reuse of treated wastewater
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Reuse of treated wastewater means sending sewage, once treated, to a farm or a factory instead of letting it into the river.
- Sewage that is treated and then let into the river uses the treatment capacity once.
- The National Framework on Safe Reuse of Treated Water, 2022, asks every State to frame its own reuse policy.
- About 14 States have reuse policies, and under a third of urban sewage was treated in 2021.
Treat
Sewage treatment capacity built under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT)
Match the quality
Treat only to the standard the end use needs
Use it
Treated water reaches farms and industry, and reuse is tied to river rejuvenation
What changed
31 Aug 2026BriefUttar 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)
The Jojari
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The Jojari is a river of Rajasthan that carries Jodhpur's industrial effluent, rather than sewage, 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.
- The remedy asked of the court was distance rather than treatment.
What changed
25 Aug 2026BriefThe Supreme Court barred construction within 100 metres of the Jojari and hazardous industry within 500 metres of its flood line. The Hindu, 25 Aug 2026: Supreme Court bans construction near polluted Jojari river (opens in a new tab)
Hexavalent chromium in the Kanpur region
Copy link to Hexavalent chromium in the Kanpur regionPrelims and Mains
Hexavalent chromium, chromium (VI), is a toxic form of chromium, and around Kanpur it has reached groundwater from decades of waste dumped by factories making chromium sulphate for tanneries.
How it got there
- Chromium sulphate for the tanneries was made around Kanpur for decades, and the waste from making it was left on the ground.
- It has since worked its way down into the water people drink.
- National Green Tribunal orders in 2005 and 2017 had sought closures and the removal of the dumps.
What it 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.
What changed
17 Aug 2026New
- 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.
Urban River Management Plans
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Urban River Management Plans shift urban planning from city centric to river centric, a shift set out at the National Ganga Council in Kanpur in December 2019.
- Their agenda runs from floodplain regulation and pollution abatement to wetland rejuvenation and reuse of treated water, using nature based solutions such as constructed wetlands, sponge parks and phytoremediation of drains.
- A constructed wetland treats sewage where it flows, with stone structures that slow the water, rock filters and plants that take up nutrients, so it needs far less energy than a mechanical plant.
What changed
24 Jun 2026BriefThe National Mission for Clean Ganga (NMCG) and the National Institute of Urban Affairs have completed plans for 13 cities, toward all 97 main stem Ganga cities. PIB, 24 Jun 2026: NMCG Scales Up Urban River Management Plans Across 63 Ganga Basin Cities (opens in a new tab)
See also: Reuse of treated wastewater · Namami Gange
Also filed elsewhere
- Fluorosis · on Non communicable diseases, nutrition and food safety
Fluorosis is the harm done to the teeth and the bone by years of drinking groundwater that carries fluoride.