The National Green Tribunal (NGT) has turned its spotlight on Ganga’s Water Quality in West Bengal, asking state and central agencies for a full, itemised affidavit and detailed data on sewage generation, STPs (sewage treatment plants), water monitoring stations, and compliance reports. This move comes after mounting evidence that, despite years of clean-up projects under the Namami Gange Mission, pollution levels in several stretches of the river remain alarmingly high. The Tribunal’s concern reflects the growing frustration among environmental experts and citizens alike, as untreated sewage, industrial discharge, and poor infrastructure continue to threaten the ecological and cultural lifeline of eastern India: the sacred Ganga.

Why the NGT Stepped in: What it asked for

In hearings held mid-2025 the NGT noted gaps in implementation of the Ganga action plan in West Bengal and asked the State, the National Mission for Clean Ganga (NMCG) and the Central Pollution Control Board (CPCB) to specify deficiencies in an affidavit — including precise STP capacities, how many STPs are operational, which meet discharge standards, drain-wise volumes of untreated sewage and timelines for remedial action.

A short, sharp summary of what the tribunal demanded:

• A list of all STPs on the West Bengal stretch, with installed capacity and utilisation
  
• Drain-wise sewage discharge volumes and whether they are diverted to working STPs
• Identification of stretches where water fails bathing/eco standards and corrective action timelines

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The State of The River Today: Key Numbers and What They Mean

Here are the most important data points that explain why the NGT wants answers now:

• Number of STPs reported along the West Bengal Ganga stretch: 42 total; 31 operational; only 7 meeting required discharge norms. (figures reported in tribunal proceedings).
• BOD (Biochemical Oxygen Demand) standards for primary outdoor bathing: CPCB uses 3.0 mg/L as the benchmark — values above this indicate the water is not fit for bathing.
• Sample at Diamond Harbour (WBPCB lab data): BOD = 2.70 mg/L (a monitored sample result).
  
• State-wide monitoring ranges observed in recent academic / monitoring for WB: Dissolved Oxygen (DO) ranged 4.3–13.4 mg/L, BOD ranged 0.3–8.2 mg/L, and Faecal Coliform values reported in sampled stations ranged from 700 to 1,100,000 MPN/100 ml — showing extreme variability and some locations with very high contamination.
• National monitoring programme (NWMP / CPCB) continues to expand sites and frequency of monitoring along the Ganga, and data consolidation remains ongoing — the CPCB/NWMP dataset is the backbone for tribunal scrutiny.

(Each numeric point above is from monitoring reports or tribunal filings cited inline.)

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Why Water Quality is Uneven Across West Bengal’s Ganga Stretch

Several, often overlapping, reasons explain the problem:

1. Untreated sewage and broken links: Multiple monitoring and tribunal documents say sewage from urban drains still reaches the river because interception/diversion and major collector STPs are either non-existent, non-operational, or operating below capacity. The NGT explicitly asked for drain-wise data to fix this.
2. STP performance and compliance gaps: Of the 42 STPs referenced in filings, only 31 are operating, and just seven reportedly meet discharge standards — indicating maintenance, operation, or design deficits rather than just a lack of infrastructure.
3. Hotspots and point-source pollution: Industrial effluents, untreated domestic waste, and localised pollution (ports, slaughterhouses, unsewered localities) create pockets with high BOD and faecal contamination; the huge range in faecal coliform counts illustrates this.
4. Monitoring and data gaps: Authorities have been increasing monitoring locations and frequency (CPCB/NWMP), but the tribunal has demanded clearer consolidated figures on installed capacity vs utilisation — the absence of easily accessible, audited operational data slows corrective action.

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What’s Being Done (and What the NGT Wants to See Happen)

• Namami Gange / NMCG projects: ongoing investments, city-level STPs, and riverfront interventions continue under central schemes\; the NGT’s demand for affidavits is aimed at forcing transparency on exactly how those resources are used and how much sewage load they actually treat.
• Increased monitoring: CPCB and state boards have added monitoring sites and raised frequency in 2025 to produce more granular evidence.
  
• Local action plans: the tribunal has directed district and municipal bodies in affected towns to submit timelines, budgets, and execution plans — the next hearings will test whether paperwork translates into on-ground results.

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Hotspots in West Bengal to Watch

Monitoring and studies single out stretches such as Tribeni, Howrah-Shivpur, Garden Reach, Uluberia, and Diamond Harbour as locations where bathing standards are intermittently unmet and where BOD / faecal loads spike; therefore, these are priority zones for action.

Final Thoughts

The NGT’s move to ask for a detailed, audited report is significant because it forces a shift from broad program statements to detailed, plant-by-plant, and measurement-based accountability. West Bengal’s stretch of the Ganga displays both encouraging signs (some monitoring points within limits at times) and troubling evidence of localised contamination and underperforming infrastructure. To improve Ganga’s Water Quality in West Bengal sustainably, the state and central agencies must close the data-to-action loop: publish drain-wise sewage volumes, ensure STPs are functional and compliant, and transparently track progress against the NGT’s demanded milestones.

A Short Data Table (snapshot)

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Frequently Asked Questions on Ganga’s Water Quality in West Bengal

Q1. What exactly did the NGT ask West Bengal to provide?

NGT asked for a detailed affidavit specifying STP installed capacity and utilisation, drain-wise untreated sewage volumes, stretches failing bathing criteria, and timelines/budgets for corrective action.

Q2. How many STPs are on the West Bengal Ganga stretch, and how many work properly?

According to the CPCB figures presented in tribunal filings, 42 STPs were listed for the stretch; 31 were operational, and 7 met discharge standards in the report reviewed by the NGT.

Q3. Is the river safe for bathing in West Bengal?

It depends on location and time. CPCB and state monitoring show some sites meet bathing criteria while others (Tribeni, Howrah-Shivpur, Garden Reach, Uluberia) record BOD/faecal coliform levels above safe limits at times. The CPCB benchmark for outdoor bathing BOD is 3.0 mg/L.

Q4. Where can I see the raw monitoring data?

CPCB’s NWMP portal and the West Bengal Pollution Control Board EMIS publish monitoring data and sample results; the NMCG and CPCB status reports submitted to the tribunal also contain consolidated figures.

Q5. What will happen next after the NGT’s demand?

The NGT expects consolidated affidavits and specific remediation plans; future hearings will assess whether those plans address STP performance, drain-wise pollution, and timelines, and may direct penalties or further action if responses are inadequate.

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