Pollution Consent (CTE/CTO) for a Factory in Tamil Nadu: TNPCB Process and Documents

A factory in Tamil Nadu needs consent from the Tamil Nadu Pollution Control Board (TNPCB) to establish and then to operate, applied for only through the Board's online system, OCMMS. Red, orange and green units apply; a listed set of white-category sectors only intimate. TNPCB's own charter gives consent validity of 5 to 7 years for establishment and 5 to 14 years for operation, depending on category.

How does TNPCB sort units, and who decides?

TNPCB uses a two-way matrix. One axis is pollution potential: red (highly polluting), orange, green and white (non-polluting). The other is size by gross fixed assets: large above ₹10 crore, medium ₹5 to 10 crore and small below ₹5 crore. A further set of "17 category" industries, taken from the Central Pollution Control Board's list of highly polluting sectors, is handled separately. The size axis matters because it decides who signs the consent.

The charter we used is the 2020 edition, the latest on TNPCB's website. Delegations and time limits can change by Board order, so treat the table as a map and confirm the current position with the district office.

What is the CTE to CTO sequence in Tamil Nadu?

Consent of the Board is needed for both establishment and operation of a new or existing industry, under the Water and Air Acts. The steps run as follows.

1. Apply for Consent to Establish (CTE) on OCMMS. TNPCB introduced the Online Consent Management and Monitoring System on 19 January 2015 and says applicants must apply only through it. The system takes applications, documents, online fee payment, replies to queries and shows status. Care Centres at district offices help applicants.
2. Complete application, then inspection. TNPCB processes a complete application and inspects the site. The matter then goes before the committee that has authority for the category, and CTE is issued if the file is in order.
3. Environmental clearance where it applies. For projects under the EIA Notification 2006, TNPCB issues CTE only on receipt of environmental clearance from the Ministry or the State Environment Impact Assessment Authority, and after the siting criteria are met. Projects in the Coastal Regulation Zone need coastal zone clearance before applying.
4. Build, then apply for Consent to Operate (CTO). TNPCB asks industries to apply for CTO two months before commissioning. The District Officer inspects to check that the CTE conditions are met, and the committee grants it.

How long is consent valid and how fast is it granted?

TNPCB's charter, citing a Board proceeding of 2 August 2016, sets the following. The brackets show the number of annual fees that the single payment covers.

The charter prescribes a maximum time for processing CTE and CTO applications: 45 days for red large and medium units, and 30 days for red small, orange and green units. These are the Board's limits for complete applications, so incomplete files and queries add to them. For renewal, the unit applies online and pays the fee; TNPCB says it also grants auto-renewal without inspection to red small units and to all orange and green units, on an undertaking that the earlier consent conditions are being met.

Which documents go with the application?

TNPCB's application page offers separate application forms for consent under the Water Act and under the Air Act, in English and Tamil, and a comparative statement form for expansion. Supporting documents are uploaded on OCMMS. TNPCB does not publish a single checklist on that page, so use the list that the central consent guidelines require, which the Gujarat board reproduced in a June 2025 circular and which is a fair guide to a file in any state: land papers, environmental clearance where the EIA Notification applies, a chartered accountant certificate of capital investment, a layout plan with the effluent treatment plant, a process write-up with a flow chart, membership of a common treatment facility where relevant, and technical details on the portal. Ask the district office for the Tamil Nadu list on the day you file. The approvals overview shows the other approvals that ask for the same layout.

Which site and equipment rules affect a factory plan?

Two state government orders limit where certain highly polluting industries can stand. G.O. (Ms) 213 of 30 March 1989 bars the scheduled industries from within one kilometre of the embankments of water sources, and G.O. (Ms) 127 of 8 May 1998 bars them from within five kilometres of specified rivers. The scheduled list includes distilleries, tanneries, sugar, dairies, fertiliser, pulp and paper with a digester, textile dyeing, ceramics and basic drug manufacture. If your site is near a river or tank, ask the district office before you buy land.

For power systems, the TNPCB guidelines page carries a guideline on retrofitting emission control devices to diesel generator sets in the 61 kW and above range in Tamil Nadu. If your factory plan includes a DG set, ask the Board for the current text and put the device, stack and acoustic enclosure on the electrical drawings from the start. White-category units are handled separately: TNPCB runs an online intimation page for them and publishes the list of sectors it treats as white.

What if the central rules differ from the state charter?

The central position has moved since 2020. The Centre's consent guidelines of 2025 were amended on 23 January 2026 (G.S.R. 63(E)), and the Centre exempted 86 white-category sectors from consent in October 2025. The amendment says consent to operate stays valid until cancelled and lets a State charge a one-time fee for a chosen period of 5 to 25 years. The Water Act amendment behind those guidelines applies to Himachal Pradesh, Rajasthan, the Union Territories and States that adopt it by resolution, and we could not confirm Tamil Nadu's position. The Central Pollution Control Board is also moving boards to a common online portal. For now TNPCB's site links OCMMS as its consent system, so confirm the portal with the district office before you file.

How Secured Engineers helps

Design is in-house, so the water balance, effluent or sewage treatment layout, DG and boiler stack details and electrical load are drawn on one set. Fire NOC, CEIG and DISCOM net-metering filings are done in-house. MEPF and solar can sit under one contract. We work from our Noida (Delhi NCR) and Ludhiana offices, across 535+ projects in 18+ states, and 89.77% of our clients return. For consent, our role is the engineering inputs and drawings, alongside your environmental consultant. Read our SPCB consent guide for the national picture and the design and approvals service for how we work.

If you are preparing a CTE or CTO application, send us the layout, the process flow and the water balance, and we will check the drawings before upload. Message us on WhatsApp, call +91 70099 85817, or ask for a free proposal.