In a significant move aimed at enhancing water quality and sustainable reuse of treated wastewater, the Karnataka State Pollution Control Board (KSPCB) has issued a circular prescribing revised treated effluent standards for all Sewage Treatment Plants (STPs) operating within the state.
The updated norms apply to both new and existing STPs, whether they are stand-alone units or attached to residential, commercial, or industrial establishments.
📜 Context & References
The circular draws authority from:
- The Hon’ble National Green Tribunal (NGT) Order dated 30/04/2019 in OA 1069/2018, mandating stringent discharge norms for STPs.
- Letter from Ministry of Housing and Urban Affairs (MoHUA) dated 18/12/2023, amending reuse and recycling guidelines in the Manual on Sewage and Sewerage Treatment Systems (2013).
- Recommendations made during the High-Level Technical Committee (HLTC) meeting held on 13/08/2025.
🧪 Revised Effluent Quality Standards
As per the circular, the treated sewage water must meet the parameters outlined in Table 1, depending on the mode of disposal:
| Parameter | Soak Pit / Surface Water | Gardening / Flushing / Non-contact Use | Public Drain |
| pH | 6.5 – 8.5 | 6.5 – 8.5 | 6.5 – 8.5 |
| BOD₃ @ 27°C (mg/l) | < 10 | < 6 | < 6 |
| COD (mg/l) | < 50 | < 25 | < 25 |
| TSS (mg/l) | < 20 | < 20 | < 20 |
| Oil & Grease (mg/l) | < 10 | < 10 | < 10 |
| Total Nitrogen (mg/l) | < 10 | < 10 | < 10 |
| Total Phosphorus (mg/l) | < 1 | – | < 1 |
| Fecal Coliform (MPN/100 ml) | < 100 | < 100 | < 100 |
📌 Note:
- These standards are uniform across residential, industrial, and institutional setups.
- The treated water, especially from high-capacity STPs, is encouraged to be recycled for secondary uses like toilet flushing, gardening, or car washing.
⏳ Compliance Timeline
All stakeholders operating STPs are directed to ensure compliance within six (6) months from the date of issue of the circular (October 2025). Non-compliance beyond this grace period could attract penal actions under applicable environmental laws.
🔍 Why This Matters
- Public Health & Environment: Reduces contamination of natural water bodies.
- Water Sustainability: Encourages reuse of treated water, easing pressure on freshwater sources.
- Legal Mandate: Complies with NGT directives, avoiding legal liabilities for both private and public entities.
- Urban Development: Supports smart city and urban water management goals.
📣 Advisory to STP Operators
KSPCB urges local bodies, residential welfare associations, industries, and STP vendors to:
- Review current STP performance.
- Upgrade technologies, if needed, to meet the prescribed norms.
- Maintain real-time monitoring systems for effluent discharge.
- Document and report compliance regularly as part of the environmental clearance process.
📎 Conclusion
With the rapid urbanization of Karnataka and increasing stress on water resources, the KSPCB’s revised STP effluent standards are a timely intervention. The focus on quality, reuse, and accountability not only aligns with environmental sustainability but also prepares the state for future climate resilience and smart infrastructure planning.