Context: In a significant judgment, the Supreme Court ruled that the unchecked discharge of untreated effluents by tanneries has severely polluted the Palar River in Tamil Nadu’s Vellore district.

• These directions were issued in accordance with a judgment passed in Vellore Citizens Welfare Forum vs. Union of India (1996). 

• In this judgement, the SC observed that "Precautionary Principle" and "Polluter Pays Principle" are essential features of "Sustainable Development."

• Polluter pays’ principle is a practice where those who produce pollution should bear the costs of managing it to prevent damage to human health or the environment.

• Precautionary principle enables decision-makers to adopt precautionary measures when evidence of environmental or human health hazard is uncertain.

Key Highlights of SC Directions 

• The State Government to pay compensation to affected individuals which is to be recovered from the polluters as per ‘polluter pays’ principle.

• The SC asked State to constitute an expert committee to assess and audit the ecological damage and suggest remedial measures.

Palar River Pollution due to Tanneries

• The Palar River in Tamil Nadu is heavily polluted by tanneries which discharge untreated chemical effluents, including toxic heavy metals like chromium.

• Tanneries are factories where animal hides are processed and transformed into leather. 

• The untreated discharge from tanneries causes irreversible damage to the water bodies, groundwater and agricultural lands etc.

SC Judgements Regarding Constitutionalization of Environmental Issues

• Rural Litigation and Entitlement Kendra vs. State (1988): Recognized the right to live in a healthy environment as part of Article 21 of the Constitution.

• M.C. Mehta vs. Union of India (1987): Acknowledged the right to live in pollution free environment as a part of fundamental right to life under Article 21 of the Constitution.

• T.N. Godavarman Thirumulpad vs Union Of India & Ors (1996): Expanded 'forest' meaning to preserve green expanses, irrespective of their nature, classification or ownership.