CPCB Effluent Discharge Standards
A complete reference guide to Central Pollution Control Board effluent discharge standards for industrial units in India — general standards and industry-specific limits for food processing, pharma, textiles, distilleries, and more
Updated March 2026 | Based on Environment (Protection) Rules, 1986 — Schedule VI
Overview
What Are CPCB Effluent Discharge Standards?
The Central Pollution Control Board (CPCB) is India's apex environmental regulatory authority for air and water pollution. Under the Environment (Protection) Act, 1986, CPCB has notified effluent discharge standards in the Environment (Protection) Rules, 1986 (Schedule VI). These standards set legally enforceable limits on the concentration of pollutants in wastewater (effluent) that industrial units are permitted to discharge to different receiving environments.
Compliance with CPCB effluent standards is mandatory for all industrial units in India. Violation can result in show-cause notices, production closure orders, criminal prosecution of company officers, and National Green Tribunal (NGT) penalties. State Pollution Control Boards (SPCBs) enforce CPCB standards through the Consent to Establish (CTE) and Consent to Operate (CTO) framework — an industrial unit cannot legally operate without a valid CTO, which requires demonstrated compliance with CPCB/SPCB standards.
CPCB standards are structured in two levels: General Standards that apply to all industries for discharge to different receiving environments (inland surface water, land, marine/coastal, and public sewers); and Industry-Specific Standards that override or supplement the general standards for defined industrial categories. Where industry-specific standards exist, the more stringent of the two applies.
Note: This guide is for informational purposes. Always refer to the current CPCB notification and your State PCB's specific conditions. CPCB standards are periodically revised, and SPCBs may impose stricter conditions. Consult a qualified environmental consultant or ETP engineer for compliance-specific advice.
General Standards
CPCB General Effluent Discharge Standards — All Industries
These standards apply to all industrial effluent discharges in the absence of industry-specific standards. Source: Environment (Protection) Rules, 1986, Schedule VI.
| Parameter | Inland Surface Water | Land Disposal | Marine / Coastal | Public Sewer |
|---|---|---|---|---|
| pH | 6.5–8.5 | 5.5–9.0 | 5.5–9.0 | 6.0–9.0 |
| BOD (5-day, 20°C) | ≤30 mg/L | ≤100 mg/L | ≤100 mg/L | ≤350 mg/L |
| COD | ≤250 mg/L | — | ≤250 mg/L | — |
| TSS | ≤100 mg/L | ≤200 mg/L | ≤100 mg/L | ≤600 mg/L |
| TDS | ≤2,100 mg/L | ≤2,100 mg/L | — | — |
| Oil & Grease | ≤10 mg/L | ≤10 mg/L | ≤20 mg/L | ≤20 mg/L |
| Ammonical Nitrogen (as N) | ≤50 mg/L | — | ≤50 mg/L | ≤50 mg/L |
| Total Kjeldahl Nitrogen | ≤100 mg/L | — | ≤100 mg/L | ≤100 mg/L |
| Phosphate (as P) | ≤5 mg/L | — | ≤5 mg/L | ≤5 mg/L |
| Arsenic (as As) | ≤0.2 mg/L | ≤0.2 mg/L | ≤0.2 mg/L | ≤0.2 mg/L |
| Mercury (as Hg) | ≤0.01 mg/L | ≤0.01 mg/L | ≤0.01 mg/L | ≤0.01 mg/L |
| Lead (as Pb) | ≤0.1 mg/L | ≤1.0 mg/L | ≤2.0 mg/L | ≤1.0 mg/L |
| Chromium, Hexavalent | ≤0.1 mg/L | ≤1.0 mg/L | ≤1.0 mg/L | ≤2.0 mg/L |
| Chromium, Total | ≤2.0 mg/L | ≤2.0 mg/L | ≤2.0 mg/L | ≤2.0 mg/L |
| Zinc (as Zn) | ≤5 mg/L | ≤10 mg/L | ≤15 mg/L | ≤15 mg/L |
| Cyanide (as CN⁻) | ≤0.2 mg/L | ≤0.2 mg/L | ≤0.2 mg/L | ≤2 mg/L |
| Phenols | ≤1.0 mg/L | ≤1.0 mg/L | ≤5.0 mg/L | ≤5.0 mg/L |
| Temperature | ≤40°C at point of discharge | — | — | — |
| Colour (Hazen units) | ≤100 | — | — | — |
Selected parameters only. For the complete schedule of parameters, refer to the Environment (Protection) Rules, 1986, Schedule VI, as amended.
Industry-Specific Standards
CPCB Standards for Key Industrial Categories
Industry-specific standards apply in addition to or in place of general standards. Key sectors relevant to Spans Envirotech's industrial client base.
| Industry | BOD Limit | COD Limit | TSS Limit | Oil & Grease | Notes / Special Conditions |
|---|---|---|---|---|---|
| Food Processing / FMCG | ≤30 mg/L (inland); ≤100 mg/L (land) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | High FOG loads require DAF primary treatment. CIP chemical discharge (pH excursions) requires equalisation + pH correction. |
| Dairy and Milk Processing | ≤30 mg/L (inland); ≤100 mg/L (land) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | BOD from milk protein and fat: 500–2,000 mg/L raw. DAF + MBBR treatment standard. Phosphorus from CIP chemicals also regulated. |
| Pharmaceutical (Formulation) | ≤30 mg/L (inland) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | API trace contaminants and active compounds require AOP or activated carbon polishing. Many units face ZLD conditions in water-stressed states. |
| Textile Dyeing & Finishing | ≤30 mg/L (inland) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | TNPCB/GPCB mandate ZLD for dyeing units. High TDS (3,000–10,000 mg/L) and colour from reactive dyes require advanced treatment (MEE/MVR + crystalliser for ZLD). |
| Distillery (Spent Wash) | No effluent discharge to land or water permitted (ZLD mandatory) | ZLD mandatory | ZLD mandatory | — | CPCB issued ZLD mandate for distilleries. Spent wash (BOD 30,000–60,000 mg/L) must be composted, bio-methanated, or concentrated and incinerated. No liquid discharge permitted. |
| Sugar Manufacturing | ≤30 mg/L (inland) | ≤250 mg/L | ≤100 mg/L | — | Molasses and press mud present. Anaerobic + aerobic treatment for high-BOD streams. Condensate from sugar process must be treated before discharge. |
| Tanneries | ≤30 mg/L (inland) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | ZLD mandatory for tanneries in Vellore (TNPCB). Chromium (trivalent) from chrome tanning requires precipitation and recovery. Sulphide (unhairing) requires aeration/oxidation. |
| Hotels & Hospitals | ≤30 mg/L (inland sewage treatment) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | Classified under municipal-type sewage treatment norms. Hospital ETP must achieve additional disinfection (chlorination or UV) for pathogen removal. CPCB hospital STP guidelines apply. |
| Electroplating / Metal Finishing | ≤30 mg/L | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | Critical: Hexavalent chrome ≤0.1 mg/L (CPCB), total chrome ≤2.0 mg/L, nickel ≤3.0 mg/L, zinc ≤5.0 mg/L, cyanide ≤0.2 mg/L. Chrome reduction (ferrous sulphate) and precipitation required. |
| Slaughterhouse / Meat Processing | ≤30 mg/L (inland) | ≤250 mg/L | ≤100 mg/L | ≤10 mg/L | High FOG and pathogen loads. DAF for grease removal, MBBR biological treatment, UV disinfection required. Blood and offal handling dictates primary treatment design. |
Indicative standards based on CPCB Schedule VI and industry-specific notifications. Actual limits in your CTO may differ — always verify with your State PCB.
ZLD Mandates
CPCB Zero Liquid Discharge — Which Industries Are Mandated?
CPCB has progressively expanded ZLD (Zero Liquid Discharge) mandates for industries that pose significant risk to water bodies or groundwater. ZLD means that the industrial unit generates no liquid effluent for external discharge — all water is recovered, treated to reuse quality, and recycled within the plant, with only solid waste for disposal.
The following industrial categories are currently subject to CPCB ZLD mandates or have been placed under ZLD conditions by SPCBs in practice:
- Distilleries: CPCB issued ZLD mandate — no spent wash discharge to land or water bodies. Bio-methanation, composting, or incineration of concentrated spent wash required.
- Textile Dyeing & Processing: ZLD mandatory in Tamil Nadu (TNPCB — Tirupur, Erode), Gujarat (GPCB), and other states with water-stressed conditions. Full water recovery with RO + MEE/MVR + crystalliser.
- Tanneries: ZLD mandatory in Vellore (TNPCB). Chrome recovery and zero-discharge of chrome-bearing effluent required. CETP (Common ETP) in tannery clusters must achieve ZLD.
- Integrated Caustic Chlorine: ZLD for mercury-based and diaphragm cell plants. Mercury-bearing effluent may not be discharged.
- Dye & Dye Intermediate Manufacturers: Several states have imposed ZLD conditions for dye manufacturers, particularly in Gujarat's chemical clusters (Ankleshwar, Vapi).
- Pharmaceutical (API): Not universally mandated but ZLD conditions increasingly imposed in CTO renewals for API manufacturers near sensitive water bodies. UPPCB, MPCB, and HPCB have imposed ZLD on specific pharma units.
- Food Processing (Water-Stressed Areas): Large food processing units in water-stressed areas (Rajasthan, Maharashtra arid zones, Tamil Nadu) face ZLD or near-ZLD conditions in CTO renewals as CPCB ZLD framework expands.
Compliance Process
How to Get PCB Consent to Operate (CTO) for Your ETP
The CTO (Consent to Operate) issued by the State PCB is the legal authorisation for an industrial unit to operate with an ETP. The process requires:
- 1
Consent to Establish (CTE)
Apply to State PCB before constructing the ETP. CTE application requires: ETP process design, P&ID, equipment list, effluent characterisation (raw and treated), mass balance, layout drawing, and statutory declaration. CPCB Red/Orange/Green category classification determines the application process.
- 2
ETP Construction
Construct the ETP as per approved CTE design. Any deviation from approved design requires amendment application. Civil, mechanical, electrical, and instrumentation work must be completed as per approved drawings.
- 3
Commissioning and Trial Run
Commission the ETP with actual process effluent. Run for minimum 30–90 days (PCB-specified trial run period) collecting influent and effluent samples for accredited laboratory analysis. Maintain daily operation and maintenance records.
- 4
CTO Application
Submit CTO application with: trial run effluent analysis reports (from PCB-accredited NABL laboratory), commissioning certificate from EPC contractor, process flow diagram, layout as-built drawing, and compliance declaration signed by authorised officer.
- 5
PCB Inspection
State PCB inspector visits site to verify ETP installation and operation. Inspector checks physical installation, maintenance records, operator competence, and sample from ETP outlet. Report submitted to PCB for CTO processing.
- 6
CTO Issuance and Renewal
CTO is issued for 1–5 years depending on state and industrial category. Renewal requires submission of annual compliance monitoring reports (conducted by PCB-accredited laboratory) and any required upgrades to meet current standards.
How We Help
Spans Envirotech — CPCB-Compliant ETP Design and CTO Support
Spans Envirotech has been designing and commissioning CPCB-compliant industrial wastewater treatment systems since 1993. Our projects for clients including Britannia Industries, Hindustan Unilever/GSK, Lotte India, KRBL Limited, and Devyani Food Industries have been designed from the start to meet CPCB General Standards and industry-specific conditions, and to support the CTE/CTO approval process.
Our EPC scope includes compliance documentation as standard: process design calculations, effluent characterisation, P&ID drawings, equipment specifications, and effluent guarantee letters — all formatted and ready for State PCB CTE application. After commissioning, we provide trial run support and effluent monitoring to generate the data required for CTO application.
For industries facing ZLD mandates — distilleries, textile units, tanneries, pharmaceutical manufacturers, and food processors in water-stressed areas — we design complete ZLD systems that achieve CPCB and SPCB ZLD compliance, integrating RO with MEE, MVR, or ATFD evaporation for >95% water recovery.
Need a CPCB-Compliant ETP for Your Plant?
Spans Envirotech designs ETPs that meet CPCB/SPCB discharge standards and supports the full CTE/CTO approval process. Request a free techno-commercial proposal for your specific industry and effluent profile.