Introduction
In India, industrial and non-industrial establishments — whether manufacturing units, hospitals, commercial complexes, malls, residential societies, or hotels — are required to comply with environmental laws before beginning operations.
As per the Water (Prevention and Control of Pollution) Act, 1974 and the Air (Prevention and Control of Pollution) Act, 1981, every such project must obtain Consent to Operate (CTO) NOC from the respective State Pollution Control Board (SPCB) after completing construction and installing pollution control systems.
The CTO NOC certifies that the unit’s air emissions, wastewater discharges, and noise levels conform to the standards prescribed under the Environment (Protection) Rules, 1986, ensuring the industry operates sustainably without degrading environmental quality.
Simplicomp Tech LLP, a leading pollution compliance consultant in India, helps industries secure CTO NOCs, prepare documentation, conduct environmental monitoring, and maintain long-term compliance with SPCB and CPCB norms.
⚖️ Legal Framework
The CTO process derives its authority from:
- The Water (Prevention and Control of Pollution) Act, 1974
- The Air (Prevention and Control of Pollution) Act, 1981
- The Environment (Protection) Act, 1986
- CPCB Guidelines on Consent Management System (CMS)
- State-specific Pollution Control Board Regulations
These laws empower the Pollution Control Boards to monitor, regulate, and control water and air pollution caused by industrial and commercial activities.
🧾 Classification of Industries
Every project or industrial unit is categorised under one of the following as per CPCB guidelines:
- 🔴 Red Category: Highly polluting industries (chemical, fertilizer, thermal power, etc.)
- 🟠 Orange Category: Moderately polluting industries (food processing, textile, engineering)
- 🟢 Green Category: Low-polluting units (assembly, packaging, light manufacturing)
- ⚪ White Category: Non-polluting industries (software parks, education, R&D labs)
The Consent to Operate (CTO) is mandatory for Red, Orange, and Green category units, while White category units are exempt but must intimate SPCB before operation.
🧩 Process for Obtaining CTO NOC from Pollution Control Board
Step 1: Submission of CTO Application
The project proponent must submit an online CTO application to the respective State Pollution Control Board (SPCB) — such as HSPCB, UPPCB, UKPCB, DPCC, or MPCB — in the prescribed format along with required documents and fees.
Step 2: Compliance of CTE Conditions
While applying for CTO, the industry must attach proof of compliance with all the conditions mentioned in its Consent to Establish (CTE) NOC.
Non-compliance with any CTE condition can lead to rejection or delay in granting CTO.
Step 3: Payment of Testing and Analysis Fees
Industries are required to deposit the testing fee for analysing air emission, wastewater, and noise samples at the SPCB laboratory. These results help determine whether the industry meets prescribed environmental standards.
Step 4: Inspection by Pollution Control Board
An authorised officer from the SPCB conducts an on-site inspection to verify:
- Functionality of pollution control systems such as ETP (Effluent Treatment Plant) and STP (Sewage Treatment Plant)
- Adequacy of air emission control devices (e.g., chimneys, scrubbers, ESPs)
- Compliance with waste disposal and hazardous waste management norms
- Noise pollution control measures in operation
Step 5: Sampling and Testing
Samples of treated effluent, stack emissions, and ambient noise are collected and analysed at SPCB laboratories. The results must comply with CPCB/State norms for parameters like pH, TDS, COD, BOD, SPM, and dB(A).
Step 6: Grant or Refusal of Consent to Operate
If the inspection report and lab analysis indicate compliance with environmental standards, the SPCB grants CTO NOC with specific operational conditions.
If the results exceed permissible limits or non-compliance is observed, the CTO is refused, and the performance security or bank guarantee submitted during the CTE stage is forfeited.
📋 Key Documents Required for CTO Application
Document | Purpose |
Copy of CTE NOC & Compliance Report | To verify adherence to pre-establishment conditions |
Manufacturing Process Flow Chart | For assessment of pollution load |
Details of Raw Materials & Finished Products | To estimate effluent and emission generation |
ETP/STP Design & Performance Data | Verification of pollution control systems |
Water Balance Sheet | For total water usage and discharge data |
Air Pollution Control Device Specifications | Chimney height, filters, and scrubbers |
Waste Disposal Plan | For hazardous and non-hazardous waste |
Lab Analysis Reports | For air, water, and noise parameters |
Site Layout & Photographs | Physical verification of installations |
Payment Receipt for Consent & Testing Fee | Proof of statutory charges paid |
📆 Validity of CTO
The validity of CTO NOC varies based on industry category:
- Red Category: 1–3 years
- Orange Category: 3–5 years
- Green Category: 5–10 years
Renewal must be applied for at least 90 days before expiry, ensuring continued legal operation of the unit.
⚠️ Consequences of Non-Compliance
Operating an industry without a valid CTO or violating pollution norms can lead to:
- Closure of industrial operations by SPCB
- Disconnection of power and water supply
- Environmental compensation under NGT orders
- Prosecution under Section 41 & 44 of the Water Act, 1974
- Forfeiture of performance security/bank guarantee
🌿 Role of Simplicomp Tech LLP
Simplicomp Tech LLP provides expert consultancy and end-to-end assistance in obtaining and renewing CTO NOCs from Pollution Control Boards across India.
Our services include:
✅ Preparation & submission of CTO application with complete documentation
✅ CTE compliance reporting and audit support
✅ Environmental testing coordination for air, water, and noise
✅ SPCB inspection support and liaison services
✅ CTO renewal and post-approval compliance management
✅ Environmental audits and sustainability reporting
Whether you’re setting up a manufacturing plant, commercial building, or healthcare facility, Simplicomp ensures your operations remain compliant with all CPCB, SPCB, and MoEFCC environmental laws.
❓ FAQs — Consent to Operate (CTO)
Q1. What is CTO NOC?
CTO (Consent to Operate) is a mandatory permission from the State Pollution Control Board that allows an industry to begin operations after ensuring compliance with environmental standards.
Q2. When should I apply for CTO?
After completing project construction and installing all pollution control systems as per CTE conditions.
Q3. Who issues CTO NOC?
The State Pollution Control Board (SPCB) — such as UPPCB, HSPCB, UKPCB, DPCC, or MPCB — depending on the project’s location.
Q4. What happens if pollution parameters exceed limits?
SPCB will refuse CTO, and the performance security deposited at the CTE stage may be forfeited.
Q5. Can Simplicomp help with CTO documentation and compliance?
Yes, Simplicomp Tech LLP assists in every step — from preparing applications and compliance audits to securing timely CTO approval.

