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Explainer: What is Biological Oxygen Demand (BOD)?

Biological Oxygen Demand (BOD) is one of the most widely used indicators of water quality, measuring the level of biodegradable organic pollution in surface waters. In India, BOD has an enforceable statutory threshold of ≤ 3 mg/L, as notified under the Primary Water Quality Criteria for Bathing Waters (2000), and forms the legal basis for…

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Cauvery River Inside Cauvery WLS

Timeline: Polluted River Stretches of Karnataka

The Polluted River Stretches (PRS) assessment by the Central Pollution Control Board (CPCB) provides a national snapshot of river health using a statutory, Biological Oxygen Demand (BOD)-based criterion. This page traces the timeline of PRS assessments, with a particular focus on Karnataka’s rivers, including those in the Cauvery basin. 2000Statutory Threshold for River Pollution The…

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Timeline: The Toxic Legacy of Endosulfan (1950- 2025)

This timeline traces the history of Endosulfan—from its production in the 1950s to the deaths and chronic illnesses of thousands in India, and the scientific evidence and legal action that culminated in national and global bans. It also documents the illegal and unethical dumping of unused Endosulfan after the ban, and the ongoing citizen-led litigation…

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CPCB inspecting stockpile of Endosulfan in Kerala

After the Ban: Endosulfan Dumping in the Western Ghats and the NGT Case

Between 1978 and 2001, the Plantation Corporation of Kerala (PCK) aerially sprayed approximately 57,560 litres of toxic Endosulfan across its plantations, contaminating air and drinking water and causing widespread mortality and chronic illness. Endosulfan was banned worldwide only in 2011, leaving PCK with a stockpile of the toxic pesticide, which was subsequently dumped illegally, unscrupulously,…

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