What Happened?
- CPCB released updated data (2023) on river water quality.
- Key metric: Biological Oxygen Demand (BOD).
- 3 mg/l → unfit for bathing.
- 30 mg/l → Priority 1 (most polluted).
- Findings:
- Locations unfit for bathing: 807 (2023) vs 815 (2022).
- Polluted river stretches (PRS): 296 (2023) in 271 rivers vs 311 (2022) in 279 rivers.
- Priority 1 stretches reduced to 37 (2023) from 45 (2022).
Relevance
- GS1 (Geography): River systems, water resources.
- GS2 (Governance): Inter-agency coordination, role of CPCB.
- GS3 (Environment): Pollution control, Sustainable Development Goals (SDG 6: Clean Water and Sanitation).
Context
- CPCB monitors 4,736 locations: rivers, lakes, drains, canals.
- A river is classified as PRS if two continuous locations exceed BOD criteria.
- CPCB reports prepared in two-year phases → data is crucial for water policy, NGT orders, Jal Jeevan Mission, Namami Gange.
State-Wise Findings (2023)
- Highest PRS/locations: Maharashtra (54), Kerala (31), MP (18), Manipur (18), Karnataka (14).
- Priority 1 stretches: Rajasthan (5 highest in 2023).
- Earlier (2022): Maharashtra had 55 polluted stretches, followed by MP (19), Bihar (18), Kerala (18), Karnataka (17), UP (17).
Why BOD Matters?
- Definition: Amount of oxygen required by microorganisms to decompose organic matter.
- High BOD = oxygen depletion → aquatic life stress → unsafe for human use.
- Proxy for sewage discharge, industrial effluents, agricultural run-off.
Systemic Issues
- Urbanisation & Sewage: 70–80% untreated sewage flows into rivers.
- Industrial Waste: Effluents without treatment plants.
- Monitoring Gaps: Rural stretches less covered.
- Governance: Multiple overlapping agencies (CPCB, SPCBs, Jal Shakti Ministry).
Positive Signs
- Incremental reduction in polluted stretches (311 → 296).
- Decline in Priority 1 stretches (45 → 37).
- Indicates some improvement from river cleaning initiatives (e.g., Namami Gange, AMRUT 2.0).
Concerns
- Still 807 locations unfit for bathing → unsafe for communities depending on rivers.
- Maharashtra continues to dominate polluted stretches list.
- Priority 1 stretches remain high, showing severe hotspots.
Way Forward
- Expand Sewage Treatment: Universal STPs for cities and towns.
- Industrial Accountability: Strict zero-discharge norms for polluting units.
- Strengthen Monitoring: Real-time water quality sensors across rivers.
- Decentralised Solutions: Phyto-remediation, wetlands, bio-digesters for rural sewage.
- Community Engagement: River monitoring by local communities, citizen science initiatives.
- Policy Integration: Link CPCB data with Namami Gange and Atal Bhujal Yojana for holistic water management.
