Water pollution and river rejuvenation

Prelims and Mains

The test of a river cleaning programme is not the plants it builds but whether a stretch of the river stops failing the bathing water standard. In the Central Pollution Control Board's count for 2025, one stretch of the Ganga did.

• 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.
• 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.
• The CPCB'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.
• Minimum environmental flow norms for the Ganga, notified in October 2018, are monitored by the Central Water Commission.
• 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.

Prelims and Mains

Sewage that is treated and then let into the river uses the treatment capacity once. A reuse policy sends that water to a farm or a factory instead, and two States have now written one.

• The National Framework on Safe Reuse of Treated Water, 2022, asks every State to frame its own reuse policy.
• 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.

Prelims and Mains

The Jojari carries industrial effluent rather than sewage, and the remedy asked of the court was distance rather than treatment. In August 2026 the Supreme Court fixed that distance in metres.

• 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.

Prelims and Mains

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.

• 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.
• 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.

Prelims

The Central Pollution Control Board counts a river stretch as polluted when its biochemical oxygen demand exceeds 3 mg a litre, and publishes the count periodically as the national measure of river pollution.