Here is what you should know about water pollution, effluent discharge, etp, CETP and ZLD compliance before you act or reply to anyone. Legals365 is the legal platform of Advocate B.K. Singh and associates, based in Delhi NCR.
In short. Anyone discharging trade effluent or sewage into a river, drain, sewer, land or the sea needs consent from the state pollution control board under the Water Act 1974 and must meet the discharge standards in that consent. Units treat effluent in their own ETP, send it to a CETP, or recycle it fully under ZLD. Breaches lead to directions, closure, compensation or penalties, appealable to the NGT.
Water pollution law in India rests on one simple rule: you cannot put polluting matter into water without the permission of the state pollution control board, and when you have permission, you must stay within its limits. Almost everything else, from ETP design to online monitoring, CETP membership, zero liquid discharge and the treatment of sewage in housing projects, is a way of meeting that rule and proving that you have met it.
This page explains the Water Act and the standards under the Environment (Protection) Act, how consent works, what ETPs, CETPs and ZLD systems are expected to do, how boards inspect, sample and act, how notices and closure directions are answered, and what people affected by effluent can do. It also covers discharges into the sea and coastal waters, into lakes and wetlands, and from roadside establishments, because those situations raise questions of their own.
- Law
- Water (Prevention and Control of Pollution) Act 1974, especially sections 24, 25, 26, 27, 32, 33 and 33A, as amended in 2024 for adopting states; Environment (Protection) Act 1986 and the discharge standards in the Environment (Protection) Rules 1986; Coastal Regulation Zone Notification 2019; Wetlands (Conservation and Management) Rules 2017.
- Regulator
- State pollution control board or, in a Union Territory, the pollution control committee (for example DPCC, UPPCB, HSPCB); CPCB for national standards, guidelines and directions.
- Key permissions
- Consent to establish before setting up, consent to operate before starting discharge, renewed periodically; groundwater permission where groundwater is drawn.
- Challenge
- Consent orders: appeal to the state appellate authority, generally within 30 days, then to the NGT. Directions under section 33A and penalty orders: appeal to the NGT, generally within 30 days, extendable by up to 60 days.
- Documents
- Consent orders with conditions, ETP design and capacity details, flow meter and OCEMS records, analysis reports from recognised laboratories, CETP membership agreement, sludge disposal manifests, water balance.
What water pollution compliance means
Water pollution compliance means three things in practice: having valid consent for every outlet, treating effluent so that what leaves the premises meets the standards in that consent, and keeping records that prove it day after day. A unit that does all three rarely has trouble. A unit that has a good ETP but an expired consent, or a valid consent but no records, is exposed.
Trade effluent is the liquid discharged from an industry, process or operation. Sewage is the domestic waste water from toilets, kitchens and bathing. Both are covered. A factory, a hospital, a hotel, a housing society, a car wash, a dairy, a slaughterhouse and a municipal sewage system all discharge something, and each needs to know where it goes and whether that is permitted.
The answer changes with where the discharge ends up. Water released into a river, a stormwater drain, a municipal sewer, onto land for irrigation, or into the sea must meet different limits. Discharging untreated effluent into a borewell or into groundwater is treated as one of the most serious violations, and is never permitted.
The law that applies
Section 24, Water Act
No person may knowingly cause or permit any poisonous, noxious or polluting matter, determined by the board's standards, to enter a stream, well, sewer or land. In states that have adopted the Water Amendment Act 2024, a contravention of this section now leads to a monetary penalty fixed by an adjudicating officer instead of imprisonment, with an appeal to the NGT. Other states continue under the older provisions until they adopt the amendment.
Sections 25 and 26, Water Act
No one may establish an industry or process likely to discharge effluent, or bring a new outlet into use, without the board's previous consent. Consent is granted with conditions, including the quantity and quality of discharge and the point of discharge. The 2024 amendment also allows the Central Government, after consulting CPCB, to exempt categories of industries from consent, and requires boards to follow central guidelines on consent. Check whether your category has been exempted before assuming consent is needed or not.
Sections 32, 33 and 33A, Water Act
Section 32 lets a board take emergency measures when a stream or well is polluted by an accident. Section 33 lets it ask a magistrate to restrain a person likely to cause pollution. Section 33A lets it issue directions, including closure and stoppage of electricity and water, and, as the Supreme Court held in 2025, demand compensatory damages and bank guarantees where harm is caused or imminent, through a procedure set out in subordinate legislation.
Environment (Protection) Rules 1986
Schedule I contains industry-specific standards, and Schedule VI contains general standards for discharge into inland surface water, public sewers, land for irrigation and marine coastal areas. The consent usually incorporates the stricter of the applicable standards, and boards can impose stricter limits for a polluted river stretch.
Section 49, Water Act
Courts take cognizance of offences under the Act on a complaint by the board or by any person who has given the board at least 60 days' notice of the offence and of the intention to complain. This lets affected people start proceedings where the board does not act.
Consent to establish and consent to operate
Consent to establish is needed before construction of a unit starts, and consent to operate before it begins operation and discharge. Industries are classified into red, orange, green and white categories according to pollution potential, and the category decides the documents, the time a board takes and the validity of consent. Units in the white category have been exempted from consent requirements; check the current notification.
The consent order is the unit's rulebook. It states the permitted quantity of effluent, the parameters and limits, the point of discharge, the treatment required, the monitoring frequency and the reporting schedule. Read every condition. Many notices are not about pollution at all but about a condition nobody in the unit had noticed, such as a requirement to install a flow meter at the final outlet or to submit quarterly analysis reports.
Renewal applications should be filed well before expiry. A unit that keeps operating after its consent has expired, even while a renewal is pending, should keep proof of the application and the fee. Our page on consent to establish and consent to operate explains the process and the common objections.
ETPs: what boards expect from an effluent treatment plant
An effluent treatment plant must be designed for the actual quantity and quality of effluent the unit produces, and must be run continuously, not only when an inspection is expected. Boards look at capacity against flow, the treatment stages provided, whether each stage is working, the condition of tanks and pumps, the chemical dosing records and the quality at the final outlet.
The logbook is the heart of an ETP file. It should record daily flow, chemical dosing, sludge removed, breakdowns and repairs, signed by the operator. A plant with a good logbook can explain a single bad sample. A plant with no logbook cannot explain anything.
ETP sludge is usually hazardous waste and must be stored in a covered, lined area and sent to an authorised treatment, storage and disposal facility with manifests. Sludge dumped on open land or mixed with municipal waste is a frequent cause of notices. See our page on hazardous waste authorisation and TSDF.
CETPs: shared treatment and shared responsibility
A common effluent treatment plant serves a cluster of small and medium units, usually in an industrial area, and is run by a society or special purpose company formed by the member units. Each member must pre-treat its effluent to meet the inlet standards the CETP sets, and the CETP must meet the outlet standards in its own consent.
Disputes in CETP clusters follow a pattern. When the CETP outlet fails, the board acts against the CETP, and the CETP blames members that sent effluent above inlet limits. Members, in turn, complain that charges are unfair or that the CETP is under capacity. Boards sometimes act against all members together, including those that complied. The membership agreement, inlet monitoring data and the CETP's own records decide who bears the consequences.
A member unit should keep its own inlet analysis reports, flow records and invoices from the CETP. If the CETP is overloaded or not running properly, the member should raise it in writing with the CETP and the board, rather than wait for a joint notice. A unit that cannot connect to the CETP must treat effluent fully in its own ETP or adopt ZLD.
Zero liquid discharge
Zero liquid discharge means the unit releases no liquid effluent outside its premises; all waste water is treated, recovered and reused, and the remaining concentrate is evaporated, leaving solids for disposal. ZLD is imposed through consent conditions and CPCB or state directions, most often for water-intensive and highly polluting sectors such as textiles and dyeing, distilleries, tanneries, pulp and paper, and pharmaceuticals, and in sensitive river basins.
ZLD is expensive to run, and the weak points are well known: evaporators or reject management that do not keep pace with production, treated water stored in open lagoons that seep into the ground, and secret bypass lines used when the system breaks down. Boards check water balance, comparing water drawn with water reused and lost, and a balance that does not add up invites a closer inspection.
If a ZLD condition is technically or financially impossible for a small unit, the honest route is to apply to the board for a modification with supporting data, or to explore connection to a CETP, rather than declare ZLD on paper and discharge at night. In effluent cases that reach Advocate B.K. Singh's office, a discovered bypass line is usually the point after which a defensible case becomes very hard to defend.
Treatment options compared
| Option | Who uses it | What the board checks | Typical problem |
|---|---|---|---|
| Own ETP with discharge | Medium and large units with a permitted outlet | Final outlet quality, flow meter, logbook, sludge disposal | Under-capacity plant, irregular operation |
| Pre-treatment and CETP | Small and medium units in industrial clusters | Inlet quality to CETP, membership, CETP outlet | Joint action when the CETP fails |
| Zero liquid discharge | Highly polluting sectors and sensitive basins | Water balance, evaporator and reject handling, no outlet | Bypass lines, overflowing lagoons |
| STP for sewage | Housing societies, hotels, hospitals, offices, townships | Treated water quality, reuse, sludge handling | Plant not commissioned or not maintained |
| Discharge to municipal sewer | Units in sewered areas with permission | Sewer discharge standards, permission of the local body | Pre-treatment skipped |
Online monitoring and sampling
Highly polluting industries, including the 17 categories identified by CPCB and grossly polluting units in river basins, must run online continuous effluent monitoring systems connected to the servers of CPCB and the state board. Alerts from these systems are now a common starting point for notices. Data spikes can come from calibration drift, sensor fouling or power interruptions, so keep calibration records and investigate every alert the day it happens. Our page on OCEMS and online monitoring covers this in detail.
Manual sampling by the board follows the procedure in section 21 of the Water Act: the occupier is to be given notice of the intention to analyse, the sample is divided into parts and sealed, and analysis is done by a recognised laboratory. These requirements bind strictly in prosecutions and are expected before serious administrative action. Ask for the sample form and analysis report whenever a notice relies on a sample.
Keep your own monthly analysis reports from a laboratory recognised under the Environment (Protection) Act. They are your best evidence of a consistent compliance record when a single result goes wrong.
Responding to a water pollution notice or direction
Most notices allow 7 to 15 days to reply. Start on the day the notice arrives.
Identify the stage
Check whether the paper is an inspection report, a show cause notice proposing action, or a direction already passed. The response is different for each.
Ask for the evidence
Write to the board for the inspection report, sample forms, analysis results and any OCEMS data relied on.
Check the plant
With the ETP operator, confirm whether the alleged problem existed and whether it still exists. Take a fresh sample through a recognised laboratory.
Correct and document
Repair, upgrade or adjust the treatment, and keep invoices, photographs and fresh reports showing the correction.
Reply and seek a hearing
Answer each allegation with documents, offer a realistic action plan for anything that needs time, and ask for a personal hearing.
Prepare for appeal
If an adverse order is passed, note the date of receipt and file the appeal before the appellate authority or the NGT within time, with a stay application if operations are affected.
Our page on replying to a pollution board show cause notice explains the reply in detail, and the page on closure orders covers what to do if power and water have already been disconnected.
Documents to keep in a water compliance file
Permissions
- Consent to establish and consent to operate with all conditions
- Renewal applications and fee receipts
- Groundwater permission, if water is drawn from a borewell
- Local body permission for sewer discharge
- CRZ clearance for coastal units
Plant records
- ETP or STP design basis and capacity
- Daily logbook signed by the operator
- Flow meter readings at inlet and outlet
- Chemical purchase and dosing records
- Maintenance and breakdown records
Monitoring
- Monthly analysis reports from a recognised laboratory
- OCEMS data and calibration logs
- Water balance statement
- Annual environmental statement
Waste and third parties
- Sludge manifests and TSDF receipts
- CETP membership agreement, inlet reports and invoices
- Agreements with operators and laboratories
- Board notices, replies and orders
Environmental compensation and penalties
When a board finds a violation, it may seek environmental compensation for the period of violation, a penalty through the adjudicating officer in states that have adopted the 2024 amendment, or both. Compensation is meant to restore damage, not to punish, and since the Supreme Court's 2025 ruling it should rest on a finding that harm was caused or was imminent and on a procedure set out in subordinate legislation.
The amount usually depends on the category of the unit, its scale and the number of days of violation. The number of days is where most disputes lie. When Advocate B.K. Singh examines a compensation demand in an effluent case, he looks first at how the start and end dates were fixed, because boards often assume the violation ran from one inspection to the next when the unit's own records show it was corrected much earlier.
Pay attention to whether the demand also seeks a bank guarantee or restoration work, such as cleaning a drain or remediating soil. Those obligations can cost more than the compensation itself. Our page on environmental compensation explains how to examine and challenge the figures.
Sewage, STPs and housing projects
Large housing projects, hotels, hospitals, malls and townships must treat their sewage in a sewage treatment plant where the consent or the environmental clearance requires it, and reuse treated water for flushing, gardening or cooling as conditions specify. A society that inherits an STP from the builder inherits its compliance problems too.
The usual disputes are about STPs that were never commissioned, plants too small for the occupancy, treated water discharged into stormwater drains, and sludge not removed. Builders, maintenance agencies and associations often disagree about who should fix what. These questions are covered on our page on sewage discharge and STP compliance for societies and builders.
Sea, coast, rivers, lakes and wetlands
Discharge into the sea or coastal waters needs the board's consent like any other discharge, with standards for marine coastal areas, and coastal units face additional restrictions under the Coastal Regulation Zone Notification 2019, which limits discharge of untreated water and effluent into coastal waters and creeks. Pollution from ships is governed separately by merchant shipping law and India's obligations under the MARPOL convention, administered by the Directorate General of Shipping, with the Coast Guard leading response to oil spills at sea. Ports, shipyards and fish processing units sit at the meeting point of these regimes; our page on CRZ clearance, wetlands and floodplains deals with the coastal side.
Rivers carry the strictest scrutiny. CPCB has identified polluted river stretches across the country, and the NGT has for years monitored action plans for them, which leads to tighter limits and more frequent inspections for units and local bodies discharging into those stretches. Units in the Ganga basin face particular directions, including ZLD for certain sectors.
Lakes and wetlands are protected under the Wetlands (Conservation and Management) Rules 2017, which prohibit discharge of untreated waste and effluent into notified wetlands. Lake rejuvenation projects run by local bodies and development authorities raise questions about sewage diversion, encroachment and the duties of residents' associations around the lake. Contamination that spreads into soil and groundwater from a spill or leak is dealt with on our page on chemical spills and soil remediation.
Roadside and highway establishments
Effluent problems are not limited to factories. Petrol pumps with service stations, vehicle washing centres, dhabas and restaurants along highways, cold storages and small food units all produce waste water with oil, grease, detergent or organic load. Many need consent or must follow conditions attached to their category, and many discharge into roadside drains that lead to fields or water bodies.
Typical requirements include an oil and grease trap, a settling tank, recycling of wash water and a soak pit or connection that the board accepts. Boards in several states have run drives against unauthorised washing centres and dhabas, and highway authorities sometimes act where drains along the highway carry effluent. Small operators usually solve these problems with modest civil work and a consent application, and it is far cheaper to do that before a notice than after.
If you are affected by effluent: complaints and cases
If effluent from a unit is reaching your land, well, pond or the river you depend on, start with a written complaint to the regional office of the state pollution control board, with photographs, dates, the location of the outlet and, if possible, a water test report from a recognised laboratory. Copy the district administration and the local body. Keep proof of delivery.
If the board does not act, there are several routes. You can approach the National Green Tribunal under section 14 of the NGT Act for directions, or under section 15 for compensation and restoration, within the time limits of 6 months and 5 years respectively, each extendable by 60 days. See our page on filing a case in the NGT. You can give the board 60 days' notice under section 49 of the Water Act and then file a criminal complaint yourself. A civil suit for injunction and damages is possible where a specific unit has caused specific loss, such as a failed crop or a ruined well.
Farmers and fishing communities often have the strongest cases but the weakest records. A simple diary of dates, photographs of discoloured water or dead fish, crop loss assessments from the agriculture department and test reports, collected over a few weeks, can make the difference between a complaint that is closed and one that leads to a joint inspection.
Common mistakes in effluent compliance
- Running on an expired consent. Units sometimes forget renewal dates. Keep a calendar entry months in advance.
- Designing the ETP for yesterday's production. When production grows, effluent grows. An ETP that was adequate five years ago may now be undersized.
- Keeping no logbook. Without daily records, a unit cannot explain a bad sample or prove continuous operation.
- Ignoring OCEMS alerts. An unexplained alert that sits for weeks becomes a notice. Investigate and record the cause the same day.
- Storing sludge in the open. Uncovered sludge heaps leach into the ground and attract separate action under hazardous waste rules.
- Bypass lines. A hidden outlet turns a compliance problem into a case where tribunals show little sympathy.
- Groundwater recharge with effluent. Putting effluent into borewells or recharge pits is treated very seriously and often leads to closure and heavy compensation.
A made-up example: a CETP failure and a compliant member
Here's a made-up example. A small electroplating unit in an industrial area is a member of the local CETP. After a fish kill in a drain downstream, the state board inspects the CETP, finds its outlet far above limits, and issues show cause notices to the CETP and all forty member units proposing closure and environmental compensation.
The electroplating unit asks for the inspection report and the CETP's inlet data. Its own records show monthly reports from a recognised laboratory meeting inlet standards, a pre-treatment system with a logbook, and invoices from the CETP for the quantity sent. The CETP's inlet data, once obtained, show that two other units have been sending effluent with very high metal content for months.
The unit replies within the time, attaches its records, points out that the notice does not allege any breach by it individually, and offers to install an inlet flow meter at its connection point. At the hearing it asks that action be confined to the CETP and the units whose inlet data show violations. The board passes an order directing the CETP to upgrade within a fixed period, imposes compensation on the CETP and the two units, and closes the proceedings against the others on condition that they install flow meters. A member without its own records would have had a much harder time.
How the position differs by unit, party and city
A red category unit discharging large volumes is held to the strictest scrutiny and needs engineering support in every reply; a small orange or green unit can often resolve a notice with modest corrections. Hospitals discharge both effluent and bio-medical liquid waste and must treat them as their consent requires. Builders and societies deal mostly with STPs. Local bodies are themselves regulated, and NGT orders against municipal bodies for untreated sewage in rivers and lakes are common.
In Delhi the regulator is the DPCC, and most industrial units sit in notified industrial areas connected to CETPs. In Noida, Greater Noida and Ghaziabad, the UPPCB regional offices regulate, and the Hindon river basin has seen sustained NGT attention. In Haryana, HSPCB regional offices at places such as Gurugram, Faridabad and Panipat regulate a large industrial base. Coastal states and port cities add CRZ and marine questions, and states with water-intensive industry, such as textile clusters, often impose ZLD more widely. Where groundwater is drawn, the groundwater authority's permission matters too; see our page on groundwater NOC and borewells.
What to do this week
Check the validity date and conditions of your consent to operate, and confirm that your ETP, STP or ZLD system matches your current production. Look at the logbook and the last few analysis reports. If anything is missing, start keeping it today.
If you have received a notice, note the deadline, ask the board for its evidence, take a fresh sample and fix what can be fixed before replying. If you are affected by effluent, file a dated, documented complaint with the board and keep a record of every incident.
If you want your consent, records or notice checked before you act, the team of Advocate B.K. Singh at Legals365 can review them and tell you the next step through the talk to a lawyer page.
Frequently asked questions
Do I need consent from the pollution board to discharge effluent?
Yes. Under sections 25 and 26 of the Water Act, any industry, operation or process that discharges trade effluent or sewage into a stream, sewer, land or the sea needs the state board's consent, unless its category has been specifically exempted. Consent to establish comes before construction and consent to operate before discharge begins.
What is the difference between ETP and CETP?
An ETP is a unit's own effluent treatment plant. A CETP is a common plant serving a cluster of units, which pre-treat their effluent to meet inlet standards before sending it. The CETP must meet outlet standards in its own consent, and disputes often arise over who caused a CETP failure.
Is zero liquid discharge compulsory for all industries?
No. ZLD is imposed through consent conditions and directions for certain water-intensive and highly polluting sectors, such as textiles, distilleries, tanneries and some pharmaceutical units, and in sensitive river basins. Check your consent order and any sector-specific directions for your state.
What happens if my effluent sample fails?
The board may issue a show cause notice proposing directions, closure, compensation or a penalty. Ask for the sample form and analysis report, check whether the sample was taken correctly, take a fresh sample through a recognised laboratory, correct any real problem, and reply within the time with documents.
Is water pollution still a criminal offence after the 2024 amendment?
In states that have adopted the Water Amendment Act 2024, many contraventions, including those under section 24, now lead to monetary penalties fixed by an adjudicating officer instead of imprisonment. Some offences still carry imprisonment. States that have not adopted the amendment continue under the earlier provisions, so check your state's position.
Can I complain about a factory polluting my well or field?
Yes. Complain in writing to the regional office of the state pollution control board with photographs, dates and, if possible, a water test report. If the board does not act, you can approach the NGT for directions or compensation, or give the board 60 days' notice under section 49 of the Water Act and file a criminal complaint yourself.
Who regulates discharge into the sea?
Discharge from land-based units into the sea needs consent from the state pollution control board, and coastal units must also follow the Coastal Regulation Zone Notification 2019. Pollution from ships is governed by merchant shipping law and the MARPOL convention, administered by the Directorate General of Shipping, with the Coast Guard handling oil spill response at sea.
Do car wash centres and dhabas need pollution board consent?
Many do, depending on their category and the state's classification, and all must avoid discharging untreated waste water into drains or open land. Typical requirements include an oil and grease trap, settling tanks and recycling of wash water. Check your state board's current classification.
Where do I appeal against a closure order for water pollution?
A direction under section 33A of the Water Act is appealable to the National Green Tribunal, generally within 30 days, extendable by up to 60 days for sufficient cause. Consent refusals or revocations go first to the state appellate authority. You can ask for a stay when filing the appeal.
Can the board demand environmental compensation for effluent discharge?
Yes, where harm has been caused or is imminent. The Supreme Court held in 2025 that boards can demand compensatory damages and bank guarantees under section 33A, through a procedure laid down in subordinate legislation. Check how the period of violation and the amount were worked out.
Is OCEMS data enough to prove a violation?
OCEMS data is commonly used to start action, but readings can be affected by calibration drift, sensor fouling or power interruptions. Keep calibration logs and manual sample reports, investigate alerts promptly, and raise any technical fault in your reply with supporting records.
What should a housing society do if its STP is not working?
Get the plant inspected, find out whether the problem is capacity, maintenance or design, and fix it with documented repairs. If the builder has not handed over a working STP, raise it in writing with the builder and, if needed, with the board or RERA. Do not discharge untreated sewage into stormwater drains meanwhile.
Need help with Marine Law? Send your papers or a short note of what has happened. An advocate from the team of Advocate B.K. Singh will read it and tell you the next step.
