Consent to Establish (CTE) for STPs: The SPCB Application Guide — What a Consent to Establish is, when your project needs one, and exactly how to apply to the State Pollution Control Board — the documents, the design details, and where your STP drawings fit in the file.

An Indian environmental engineer in a hard hat reviewing STP construction drawings on a clipboard beside newly poured aeration tanks at a residential project site under a clear sky

Before a single tank is dug for a sewage treatment plant, one piece of paper decides whether the project can legally begin: the Consent to Establish, or CTE. It is the pollution-control regulator's up-front approval to build the STP (and the development it serves), granted on the strength of your design — long before any water is treated. Get it wrong or skip it, and the plant you build may never be allowed to run.

This guide is the practical procedural walkthrough for developers, facility managers, RWAs and their consultants. It covers what a CTE actually is, when it is triggered, how the application moves through the State Pollution Control Board (SPCB), the documents you must assemble, and — crucially — where the STP design report sits in that file.

A CTE is permission to build; a Consent to Operate is permission to run. The CTE is granted on your design and drawings; the CTO is granted later, after inspection, on the plant you actually built. Confusing the two is the single most common — and most expensive — mistake in STP compliance.

A note on currency: India's sewage-discharge standards have been contested and revised repeatedly, and consent procedures, fees and forms vary by state and change often. Treat every specific figure below as indicative, and confirm the current requirement with your own SPCB before you file.

What a Consent to Establish actually is

Indian consultants and a pollution-control board officer reviewing sewage treatment plant layout drawings across a desk in a government office

The CTE is a statutory permission issued under two central laws:

The Water (Prevention and Control of Pollution) Act, 1974 — under Section 25, no person may establish any industry, operation, process, or any treatment and disposal system likely to discharge sewage or trade effluent, without the previous consent of the State Board.
The Air (Prevention and Control of Pollution) Act, 1981 — under Section 21, the same prior consent is needed for operations in an air-pollution-control area (an STP's blowers, DG sets and sludge handling bring it within scope).

In practice, an STP-bearing project — an apartment complex, hotel, hospital, IT park or township — applies for a combined CTE under both Acts through its SPCB. The Board reviews the proposed treatment scheme on paper and, if satisfied that the design can meet discharge norms, issues the CTE. Only then can construction proceed. For the wider picture of how the CTE sits among all the clearances an STP touches, see STP regulations in India and SPCB approvals for STPs.

When is a CTE required?

Not every building needs its own consent, and the trigger is driven by pollution potential and size, not by whether an STP happens to be present. Two thresholds matter:

Industry categorisation. The CPCB classifies activities as Red, Orange, Green or White by pollution load. White-category units (the least polluting) are generally exempt from consent and need only file an intimation. STPs and the developments around them typically fall into the Orange category, which requires full consent. Confirm your project's category with the SPCB — it also sets your consent validity and fee.
Project size / built-up area. Larger residential and commercial projects cross state and municipal thresholds that make an on-site STP — and therefore a CTE — mandatory. These thresholds vary by state and are often tied to the building bye-laws; see building bye-laws and STPs.

A separate but related question is Environmental Clearance (EC). Big projects above the EIA-notification thresholds need prior EC from the environment ministry in addition to the SPCB consent — the two run in parallel, not instead of each other. Our environmental clearance for STPs guide untangles which projects need both.

One clarification that saves confusion: a domestic STP treats sewage, while an ETP treats industrial effluent. If your site has industrial process wastewater, a different (and stricter) consent regime applies — see STPs vs ETPs.

The application process, step by step

Almost every SPCB now runs applications through an Online Consent Management and Monitoring System (OCMMS) portal, which has standardised much of what used to be a paper chase. The typical sequence:

Step	What happens	Who acts
1. Categorise & register	Confirm Red/Orange/Green category; create an account on the state OCMMS portal	Applicant / consultant
2. Prepare the file	Assemble drawings, STP design report, land and project documents	Applicant / consultant
3. File Form 1 + fee	Submit the CTE application (often "Form 1") with the prescribed scrutiny fee	Applicant
4. Scrutiny	SPCB officer reviews documents; may raise queries or seek clarifications	SPCB
5. Site inspection	Physical verification of the location and proposed layout	SPCB field staff
6. Grant of CTE	Consent issued with conditions, or returned for correction	SPCB / Board

The fee is set by each state and is usually pegged to project cost or capital investment, so it is neither a flat number nor uniform across India — do not rely on a figure quoted for another state. Under the newer uniform consent framework being rolled out nationally, a CTE is commonly valid for around five years (with a short extension possible) to let you complete construction; states may vary this, so check the condition printed on your own consent letter.

Once the plant is built and commissioned, you file separately for the Consent to Operate — the CTE does not let you run the STP, only build it.

Documents you need to assemble

The exact checklist differs by state and category, but a CTE file for an STP-bearing project almost always includes:

Completed application form (typically Form 1) with the applicant's and occupier's details.
Site / location plan and layout showing the STP's position on the plot, with distances from water bodies, boundaries and habitation.
Land documents — sale deed, lease deed or allotment letter establishing possession.
Detailed Project Report (DPR) — project description, built-up area, occupancy/population, capital cost, and a full water balance (fresh-water source, consumption, sewage generated, treated-water reuse and surplus discharge).
STP design and process report — the technical heart of the file (see below).
Proof of the scrutiny fee payment.
Municipal / planning approvals, building-plan sanction, and — where applicable — the Environmental Clearance or its acknowledgement.
Authorisation of the signatory (board resolution, partnership authority, or similar).

Keep the file internally consistent: the population in the DPR, the flow in the water balance, and the capacity in the STP design must all tell the same story. Inspectors notice when they don't.

Where the STP design fits in the file

Indian design engineer studying detailed sewage treatment plant process drawings at a drafting desk beside a partially built aeration tank

This is the part most applicants under-prepare. The SPCB is not granting consent to a building in the abstract — it is granting consent because your proposed treatment scheme can demonstrably meet the discharge and reuse standards. The STP design report is therefore the document the Board actually scrutinises. It should establish:

Design flow (capacity in KLD/MLD) — derived from occupancy and a realistic per-capita sewage figure. This must reconcile with the water balance. Our how to size an STP guide walks through the calculation, and the STP Capacity Calculator turns a headcount into a design flow in about a minute.
Raw sewage characteristics — expected inlet BOD, COD, TSS and pH. If you are hazy on these parameters, start with wastewater characteristics: BOD, COD, TSS, pH.
Treatment technology and process train — the chosen process (SBR, MBBR, MBR, extended aeration, etc.), unit sizing, and the tertiary/disinfection steps that get you to reuse quality.
Target outlet quality — a table showing your design outlet values meet the applicable norms.
Reuse and disposal plan — how much treated water is reused for toilet flushing and landscaping, and the mode of any surplus discharge.

A design that plausibly hits the numbers moves through scrutiny; one that hand-waves the outlet quality invites queries and delay.

The discharge standards — and why they are contested

Here honesty matters, because the numbers you design to are the numbers the CTE is judged against — and they have a genuinely tangled history:

In October 2017, the MoEF&CC notified STP-specific standards that varied by location — broadly BOD 20 mg/L / TSS 50 mg/L for metro cities and state capitals, and the more relaxed BOD 30 mg/L / TSS 100 mg/L elsewhere, with pH 6.5–9.0. (CPCB STP standards notification)
In April 2019, the National Green Tribunal set aside that relaxed, tiered approach and directed a single, stricter, uniform standard across the country — reported as BOD 10, TSS 20, COD 50, pH 5.5–9.0 and Fecal Coliform around 230 MPN/100 mL — to apply to new and existing STPs alike. (NGT order, April 2019, via Business Standard)
That direction was itself debated by experts as technically demanding, and implementation has been uneven across states — several SPCBs notify their own consent-condition values, some stricter than others. (Down To Earth on the STP-norms dilemma)

The practical takeaway: there is no single, uncontested pan-India number you can quote with certainty. Many SPCBs today apply the tighter, NGT-aligned band (BOD ≤ 10, TSS ≤ 10–20, COD ≤ 50), but the exact figures that bind your plant are the ones written into your consent conditions. Design to the numbers your SPCB specifies, and see treated-water quality standards and treated-water reuse standards for how these values translate into a reuse-grade design. For the regulatory backdrop, CPCB guidelines for STPs and MoEF rules for STPs go deeper.

Common mistakes that delay a CTE

Filing after starting work. The CTE is a prior consent — establishing the project before it is granted is itself a violation.
Mismatched numbers. Population, water balance and STP capacity that don't reconcile trigger queries.
Ignoring the Air Act. Applicants file only under the Water Act and forget the DG set and blower emissions.
Designing to the wrong standard. Using an outdated or another state's outlet values instead of the SPCB's current consent conditions.
Treating CTE as the finish line. It is not — the Consent to Operate and ongoing compliance (see the STP compliance checklist) follow.

The bottom line

A Consent to Establish is the regulator's informed bet that your STP, as designed, can keep the water clean — placed before you build so mistakes are caught on paper, not in a lake. Get the categorisation right, file a consistent, design-led application through the SPCB portal, and treat the STP design report as the centrepiece rather than an afterthought. Because norms, fees and forms genuinely do shift, always confirm the current requirements directly with your SPCB.

From here, continue through the Sewage Treatment Plants guide library for the neighbouring steps — sizing, standards and the Consent to Operate — or size your plant now with the STP Capacity Calculator, the number every CTE application is built around.

Sources: CPCB effluent & emission standards · CPCB STP standards notification (2017) · NGT 2019 order (Business Standard) · Down To Earth: the STP-norms dilemma · Lawrbit: Consent to Establish & Operate Guidelines · MPCB: consent under Water & Air Act