STP Operating Without Consent: Risks for Societies and Builders

A sewage treatment plant in a housing project that discharges or reuses treated water generally needs consent from the State Pollution Control Board, first to establish and then to operate. Running one without it exposes whoever is in charge to show-cause notices, directions, environmental compensation and, in some cases, complaints before the NGT. Before handover, that is the builder. After handover, the RWA or apartment owners' association running the plant is the one the board writes to, even if the builder never obtained consent in the first place. The fix is almost always to regularise quickly, not to argue.

This guide is for two groups who often end up on opposite sides of the same file: RWAs and apartment owners' associations that have taken over a plant, and builders and developers who built one. It covers when consent is needed, who must hold it at each stage, what the board actually does when it finds an STP running without consent, and how to put things right. It is part of our work on STP non-compliance and sewage pollution.

If your dispute with the builder is wider, covering environmental clearance and green areas as well, read housing society vs builder disputes. If sewage from a town rather than a society is the problem, see municipal sewage into a lake or river.

The essentials

Does a housing society STP really need consent from the pollution board?

In most cases, yes. Section 25 of the Water Act requires the board's consent before anyone establishes a plant or system likely to discharge sewage, or brings a new outlet into use, and before that system starts operating. An STP that sends treated water into a municipal sewer, a drain or onto land, or sends surplus water out of the campus, falls within that. Boards treat the consent to establish (CTE) and consent to operate (CTO) as separate stages. If the project also runs DG sets, the Air Act consent under Section 21 is usually dealt with in the same application.

Large residential projects are also tied to environmental clearance. Building projects of 20,000 sq m built-up area and above need prior EC under the EIA Notification 2006, usually from the SEIAA, and the EC almost always requires an STP of a stated capacity, reuse of treated water and consent from the board. So a project without STP consent is often breaching its EC conditions as well.

Two caveats. First, the CPCB's red, orange, green and white categories decide which consent regime applies, and white category activities are exempt. Second, central and state notifications in 2024 and 2025 changed some consent requirements, including exemptions for certain categories. Small buildings may fall outside the regime. Check the current rule for your state and project size before assuming either way.

What the consent conditions usually require once you have it

Getting consent is half the job. The consent order comes with conditions, and boards inspect against those conditions, not against the bare fact that a certificate exists. Read the order line by line and give a copy to the maintenance agency, because the agency is usually the one who has to do what it says.

The common conditions are similar across states. Treated water must meet the notified standards for sewage treatment plants, tested at stated intervals by a recognised laboratory. A logbook must record running hours, power failures, chemical dosing and breakdowns. Flow meters at the inlet and outlet are often required. Treated water is expected to be reused for flushing, horticulture or cooling, with only the surplus going to a sewer, and never into a stormwater drain unless the consent allows it. Sludge must be dried and disposed of lawfully, not dumped on the nearest plot. No bypass line may be used.

Consent holders are also expected to file the annual environmental statement under the Environment (Protection) Rules and to apply for renewal well before expiry. Missing a renewal puts you back in the position of running without consent, with the same exposure, even though you once held it.

Who must hold the STP consent at each stage

The maintenance agency running the STP day to day is a contractor. It does not carry the consent, and the board will not accept that the agency was supposed to deal with it.

What happens when the board finds an STP running without consent

The process usually starts with an inspection, either routine or after a resident's complaint. The inspector notes that there is no valid consent, checks whether the STP is running, takes an outlet sample and records the condition of the plant. A show-cause notice follows, asking why action should not be taken under the Water Act and why environmental compensation should not be imposed. The notice normally gives a short period to reply.

If the reply is weak or does not come, the board can issue directions under Section 33A. For an industrial unit that often means closure and disconnection of power and water. Against a residential society, boards are wary of disconnecting water to hundreds of families, so directions more commonly order the STP to be made functional, consent applied for within a deadline, and compensation paid. But disconnection directions are not unheard of, especially where a builder still controls the project, and some boards have used them to force builders to act.

Environmental compensation is calculated using the CPCB's formula, which multiplies factors including the pollution index for the category, the number of days of violation, a scale factor and a location factor. The days factor is why delay is expensive: every month without consent adds to the figure. After the Jan Vishwas and Water Amendment changes, separate monetary penalties can also be imposed by an adjudicating officer. Our guide on penalty for operating without consent explains how these work.

We took over the STP and found it never had consent. Are we liable?

For the period after handover, in practice yes. The board's question is who is running the plant now, and once the association has taken over the STP, it is the natural addressee of notices. That can feel unfair when the builder never applied, but the board cannot leave a working sewage plant with nobody accountable.

For the period before handover, the builder remains answerable, and any environmental compensation for that period should be assessed against the builder. When replying to a notice, say clearly when the association took over, attach the handover documents, and ask the board to assess the earlier period against the developer. Boards do accept this when the papers are clear.

The other half is recovery. If the plant is undersized for the actual population, never had its tertiary treatment units installed, or lacks the reuse plumbing the EC promised, those are construction defects. The association can demand that the builder fix them or pay, through a legal notice, a complaint to the RERA authority where applicable, or a case before the NGT where the defects mean the EC and consent conditions are breached. Our page on builder environmental violations covers that route.

Builders: what running an STP without consent puts at risk

For a developer the exposure is wider than a fine. In many cities the development authority looks for the board's consent and EC compliance before granting an occupancy or completion certificate, so a missing STP consent can hold up the OC and, with it, registrations and sales. Our guide on occupancy without environmental compliance covers that problem.

EC conditions are the second risk. A project that has not built or run the STP as promised is in breach of its EC, which shows up in the half-yearly compliance reports and in any inspection by the SEIAA or regional office. Residents increasingly file before the NGT on exactly this ground, and the tribunal can order compliance, environmental compensation and, in serious cases, stop further construction. See our guide on EC conditions not followed.

Third, the liability does not disappear at handover. If the builder hands over a plant with no consent and defects, the board can still pursue the builder for the period it was in control, and the association will pursue the builder for the defects. Builders who get consent in place, transfer it formally and hand over a plant that works with its records intact are the ones who are rarely dragged back.

How to regularise an STP that is running without consent

This sequence works for an RWA that has inherited the problem and for a builder still in control. The aim is to show the board a working plant and a complete application as soon as possible.

Advocate B.K. Singh's usual advice to an RWA that has just received a notice is to apply for consent first and argue about the builder's liability second. A pending application with a working plant behind it changes the tone of the board's next hearing.

Documents the board will usually want

The list differs by state. Our guide on documents for consent to operate sets out what boards commonly ask for.

What if the board refuses consent or imposes harsh conditions?

Refusal of consent, or conditions that cannot be met, can be appealed to the state appellate authority under Section 28 of the Water Act (and Section 31 of the Air Act for DG sets) within 30 days. A further appeal lies to the NGT under Section 16 of the NGT Act within 30 days of the appellate order, with a possible extension of up to 60 days for sufficient cause.

Directions under Section 33A, such as closure or disconnection, are appealable directly to the NGT under Section 33B within 30 days. Do not let these deadlines pass while writing letters to the board; a letter does not stop time running. Our pages on the pollution appellate authority and on replying to a closure notice explain both routes.

Not every hard condition needs an appeal. Where a condition is simply unworkable, for example a requirement to send surplus water to a sewer line that does not yet exist near the project, a reasoned application to the board for modification, with an engineer's note and an interim arrangement such as tanker transport to a municipal STP, often resolves it faster. Keep the appeal deadline in view while that request is pending.

Residents complaining about their own society's STP

Not every STP dispute is between the RWA and the builder. Sometimes it is a group of residents against their own association: the plant smells, the blowers run all night under someone's bedroom, mosquitoes breed in the open tanks, or residents suspect sewage is being pumped out untreated to save on electricity. A resident can complain to the board like anyone else, and the board will inspect the plant regardless of who runs it.

Before doing that, it usually pays to ask the managing committee in writing for the consent order, the last three lab reports and the logbook. Under most society bye-laws and apartment ownership laws members can inspect such records. If the papers show the plant is running without consent or failing its standards, a complaint to the board backed by those papers is hard to ignore. If the problem is noise or smell from a plant that is otherwise compliant, the remedy is often engineering, such as covering tanks or acoustic enclosures for blowers, and a measured request to the committee may get further than a board complaint.

Is your STP on safe ground? Check these

Mistakes societies and builders make

Societies often ignore the first notice because they assume it is the builder's problem. The board then proceeds on the record it has, and the association is left challenging an order instead of shaping it. Reply on time, even if the reply is that the builder is responsible.

Builders often apply for CTO only when the OC is stuck, by which time the plant has run for months without consent and the days of violation have piled up. Applying late is still better than not applying, but the compensation exposure is real.

Both sides sometimes switch the STP off to save electricity and pump raw sewage into the municipal line. That turns a paperwork problem into a pollution case, and residents who notice tend to complain. And neither side should treat the maintenance agency's assurance that everything is in order as a substitute for checking the consent status themselves.

Where to go from here

For commercial buildings, see hotel and hospital sewage discharge rules. For timelines on fresh applications, read how long consent to operate takes. If the board has already assessed a figure, see environmental compensation demands.