Municipal Sewage Into a Lake or River: Who Is Responsible?

When a town's sewage runs into a lake or river, the body that collects or is meant to treat that sewage is answerable first. Usually that is the municipal corporation, nagar palika or a sewerage agency such as a Jal Board or Jal Nigam. The State Pollution Control Board is the regulator that must stop the discharge, and the state government funds and supervises both. The National Green Tribunal can direct all of them to act on a timeline and can impose environmental compensation, including on public bodies.

This guide is for people living near a lake, pond, river or canal that has turned into a sewer: colony residents on the bank, villagers downstream of a town outfall, fishing families and RWAs. It explains who is responsible in law, what the pollution board can actually do against a municipality, and how a case before the National Green Tribunal usually unfolds in sewage matters.

If the sewage comes from a private source such as a housing society or a hotel, the route is different and faster. See our main page on STP non-compliance and sewage pollution, and the guides on STPs running without consent and hotel and hospital sewage rules.

The essentials

Sewage from the town is going into our lake or river. Who is responsible?

Start with the pipe. Whoever owns the drain, sewer line or treatment plant carrying the sewage is the first party responsible. In most towns that is the municipal corporation or nagar palika. In some states a separate agency builds and runs the sewer network and the sewage treatment plants (STPs), such as a Jal Board, a Jal Nigam or a state sewerage board, while the municipality handles roads and stormwater drains. In new colonies and sectors, the development authority may still own the drains until they are handed over.

Next comes the regulator. The State Pollution Control Board, or the Pollution Control Committee in a Union Territory (DPCC in Delhi), enforces the Water Act. It is supposed to sample the outfall, issue directions to the local body and impose environmental compensation where needed. The board does not build sewers, but it answers for failing to enforce.

Then there is the state government, through its urban development department. Most municipal STPs are funded by state and central schemes, and when a town has no treatment capacity at all, the real gap is usually money and planning at state level. A good complaint names all three, so nobody can pass the file to another office and close it.

Which authority answers for which part of the problem

Names differ from state to state, but the roles are broadly the same.

If you do not know which agency runs the drain, file one RTI with the municipal body asking who owns and maintains the drain at a stated location. The answer often settles the question in thirty days.

Is it legal for a municipality to let sewage into a river or lake?

No. Section 24 of the Water Act bars anyone from knowingly letting poisonous, noxious or polluting matter enter a stream or well, and the Act defines a stream widely enough to cover rivers, watercourses, inland water such as lakes and ponds, and underground water. Raw sewage is polluting matter. Section 25 requires the board's consent before anyone brings a new outlet for sewage into use or starts discharging sewage, so a municipal STP and its outfall need consent and must meet the treated sewage standards notified under the Environment (Protection) Rules.

Local bodies sometimes argue that, as a public service provider, the pollution law does not bind them in the same way. It does. The Water Act makes no exception for public bodies, and the NGT has applied the polluter pays principle under Section 20 of the NGT Act to municipalities and states as much as to industry.

The Jan Vishwas Act 2023 and the Water Amendment Act 2024 replaced many Water Act offences with monetary penalties. For a sewage case against a city that rarely matters, because residents want the drain stopped, not a fine paid from one government account to another. The tools that achieve that are directions and timelines. For a notified wetland, the Wetlands Rules 2017 separately prohibit the discharge of untreated waste.

Why sewage ends up in the water even when the town has an STP

Very few cases are about a city deliberately pointing a pipe at a lake. Most are about gaps. The STP treats only part of the town's sewage, or was built for a population passed years ago. The plant is complete but the sewer network feeding it is not, so sewage still flows through open drains built for rainwater. Or thousands of houses were never connected and their septic tanks overflow into the stormwater drain.

Then there is operation. Plants stop when the electricity bill is unpaid, the operating contract lapses or pumps fail. Bypass channels meant for emergencies carry sewage around the plant on ordinary days. And on the edges of towns, sewage tankers that empty septic tanks often dump the sludge into the nearest nala instead of taking it to a treatment facility.

Knowing the cause matters because the remedy differs. If a drain just needs to be tapped and diverted to an existing STP, a board direction with a three-month deadline may be enough. If the town has no treatment capacity, you are looking at a multi-year project, and the realistic goal is a binding timeline plus interim measures such as in-situ treatment of the drain.

What the pollution board can and cannot do against a municipality

The board can inspect, sample the outfall, issue a show-cause notice, issue directions under Section 33A and assess environmental compensation using the CPCB's formula-based method. Many boards now do impose compensation on local bodies for untreated discharge.

What the board will not do in practice is close a city's sewage system or cut its electricity, because that would make things worse. So its directions against a municipality are about timelines: tap these drains by this date, restore the STP, submit monthly outlet reports. The weakness is follow-up. Residents often discover a year later that the board issued a strong letter and then did nothing more.

So ask the board for specific things: a joint inspection with the local body, sampling upstream and downstream of the outfall, a written Section 33A direction with a deadline, and a copy of the sample report. Then use RTI to check what happened after the deadline. That paper trail is what the NGT looks for when deciding whether the authorities have failed.

When residents should go to the NGT, and what usually happens there

Go to the NGT when the board and the local body have had a fair chance and have not acted, or when waiting is unreasonable: a fish kill, a contaminated drinking water source, or a notified wetland filling with sewage. Sewage in a lake or river plainly raises a substantial environmental question under the Water Act, so jurisdiction is rarely in doubt.

The tribunal's usual first order is a joint committee, often of the CPCB, the State Board and the District Magistrate, to report on the drains, their flow, the STP's capacity and actual running, and a timeline. The local body and state file action plans. Parties can object to the committee's report, which is your chance to point out drains it missed or data that does not match what you have seen.

Many applications end with directions: interception of named drains within a fixed period, STP operation to notified standards, a ban on septage dumping, restoration and environmental compensation for past discharge. If deadlines are missed, file an execution application; an NGT order is executable as a civil court decree under Section 25, and non-compliance is punishable under Section 26.

Daily discharge is generally argued as a continuing cause of action, so a drain running for years does not by itself bar an application, though a record of complaints helps. Our guide on NGT cases against government inaction covers framing a case where every respondent is a public authority.

How to get a sewage outfall into a lake or river stopped

Do the first four steps even if you expect to end up before the NGT, because they become your evidence.

Advocate B.K. Singh's usual advice to RWAs in sewage matters is to photograph the same outfall from the same spot every month. A year of identical photos showing the same black flow is harder for a local body to explain away than any expert report.

What to collect before you file anything

Why a lake case is different from a river case

A river moves the sewage on. A lake holds it. Nutrients build up, weeds and algae take over, oxygen drops and fish die, usually in the hottest weeks. Restoring a lake means not only stopping the inflow but removing sludge and managing weeds, which is expensive and slow.

Ownership is also messier. A lake may stand in the name of the revenue department, irrigation department, development authority or gram panchayat. Ask by RTI who owns it, because the owner must be a party to any restoration case, and so must the state wetland authority if the lake is notified. See our guides on who pays for restoring a polluted lake and, if the lake is also being filled or built upon, the hub on lake, pond and wetland encroachment.

For rivers, the NGT has long-running supervision over polluted river stretches, and a complaint about one town's drains may be heard alongside those larger matters. That is a reason to keep your facts local and specific so they are not lost in a state-wide report. Where factories rather than the town are the source, see industrial discharge into a river.

Board, SDM, court or NGT: what each route gets you

Can residents or farmers claim compensation for sewage pollution?

Yes, in principle. Section 15 of the NGT Act allows relief to victims of pollution and restitution of damaged property within five years, and Section 18 lets a representative body such as an RWA or a fishermen's society apply. Fishing families, farmers with damaged fields and residents with spoilt wells can all claim.

In practice, individual compensation is harder to get than directions, because the loss must be linked to the discharge and quantified with catch registers, crop loss assessments or well test reports. Against public bodies, compensation is more often paid into a fund for restoring the water body. Our page on compensation for pollution damage explains how claims are built.

Before you file before the NGT, check these

Common mistakes, and when not to file

The most common mistake is suing only the pollution board. The body that can actually build or fix the sewer must be before the tribunal, or the order binds nobody useful. The second is filing on news reports without a single document showing the drain, its owner or the STP data; such cases tend to end with a general direction to the authorities, which is where you started.

The third is asking for the impossible. An order to stop all sewage into a river by next month cannot be complied with. Ask for interception of named drains, interim treatment, a time-bound STP plan, a ban on septage dumping and restoration. Those are orders the tribunal regularly makes.

Do not file if the problem is one blocked sewer overflowing in your street; the ward office will fix that faster. And check whether the tribunal is already monitoring your river or lake. When Advocate B.K. Singh takes up a sewage matter, the first thing he checks is whether such a case exists, since joining it with fresh local evidence can move faster than starting again.