MoEFCC Rules Affecting STPs: How the EIA Notification 2006 Brings Sewage Treatment Into the Approval Net

When people talk about "STP rules" in India, they usually mean the discharge numbers — the BOD and COD limits a plant has to hit. But those numbers are downstream of a much bigger decision made far earlier: whether your project needs environmental clearance from the government at all. That decision is governed by the Ministry of Environment, Forest and Climate Change (MoEFCC), and the instrument it uses is the Environmental Impact Assessment (EIA) Notification, 2006, issued under the Environment (Protection) Act, 1986.

The EIA Notification is the gate. It sorts projects by size, decides who must obtain clearance and from whom, and — crucially for anyone building in India today — it makes a properly designed, operated and monitored Sewage Treatment Plant a condition of that clearance, not an afterthought. This guide explains how the MoEFCC rules reach the STP, where the thresholds sit, and how the honestly messy history of discharge standards has played out.

The MoEFCC does not usually regulate your STP by name. It regulates your project — and then attaches the STP, water balance and reuse plan as binding conditions of the environmental clearance without which you cannot build or occupy.

The one framework behind it all: the EIA Notification 2006

The EIA Notification 2006 is still the operative law. A draft EIA Notification 2020 was floated to replace it, drew heavy opposition, and as of 2026 remains unfinalised — while the 2006 version continues to be amended piecemeal through office memorandums. So when you plan compliance today, you plan against the 2006 framework and its amendments, not the draft.

The notification does two structural things:

• It classifies projects into Category A and Category B. Category A projects are appraised and cleared centrally by the MoEFCC (through an Expert Appraisal Committee). Category B projects are handled at the state level by the State Environment Impact Assessment Authority (SEIAA), advised by a State Expert Appraisal Committee (SEAC).
• It lists the activities and size thresholds that trigger clearance in its Schedule. Buildings, construction, townships and area development sit at Item 8 of that Schedule.

Everything else — the STP requirement, the reuse mandate, the monitoring conditions — flows from landing inside that Schedule.

Which projects get pulled in: the built-up-area thresholds

For real estate, two sub-items matter. The exact wording and any recent amendment should always be checked against the current notification, but the long-standing structure is:

The practical takeaways:

• A project below 20,000 m² built-up area does not need environmental clearance under the EIA Notification. It still needs local sanction, building bye-law compliance, and — separately — pollution-control consents for its STP. Falling outside EC does not mean falling outside the Water Act and Air Act.
• Most large apartment complexes, IT parks, malls, hotels and hospitals clear the 20,000 m² line comfortably and therefore do need EC before construction.
• B2 building projects are generally spared the full EIA study and public hearing; larger B1 townships can face a more detailed appraisal. Which track applies decides how much documentation the STP has to survive.

If you are still at the sizing stage, the STP capacity calculator converts occupancy into a design flow in litres per day — the number that anchors the water balance the SEIAA will scrutinise. For the design logic behind it, see how to size an STP.

Where the STP enters the approval file

Once a project is inside the net, the STP stops being an engineering detail and becomes a regulatory commitment. The environmental clearance application (Form 1 / Form 1A for building projects) asks for, among other things:

• A water balance diagram — fresh water in, wastewater generated, treated water recovered, and where every litre goes.
• STP details — capacity, technology, and the discharge standard it is designed to meet.
• A treated-water reuse plan — flushing, landscaping, cooling, groundwater recharge — usually with dual plumbing so recycled water can be piped back for non-potable use.
• Rainwater harvesting, solid-waste handling and energy provisions that sit alongside the STP in the environmental management plan.

The SEIAA then issues the EC with conditions. Those conditions typically fix the STP capacity, mandate that treated water meet the applicable discharge norms, require reuse rather than disposal, and demand periodic monitoring reports. This is the mechanism by which an MoEFCC-level rule reaches down to your plant room. For the STP-specific view of this stage, see environmental clearance for STPs.

Two things run in parallel with EC, not instead of it. Before you build the STP you need Consent to Establish (CTE) from the State Pollution Control Board, and before you operate it you need Consent to Operate (CTO). EC, CTE and CTO are three separate approvals — and the STP appears in all three. See SPCB approvals for STPs for how the state layer works.

The clearance journey, step by step

For a building or township project that crosses the threshold, the EC process runs roughly as follows. Timelines are statutory targets and slip in practice, so treat them as indicative:

The STP is examined at the appraisal stage and then re-examined for life through the compliance conditions attached to the EC.

The discharge-standards question — represented honestly

Here the ground is genuinely contested, and anyone who quotes a single "official" number without caveat is oversimplifying. The short version: the target values an STP must hit have been fought over for a decade.

• In 2015, the MoEFCC published draft sewage-treatment standards proposing a tight BOD limit (around 10 mg/L).
• On 13 October 2017, the MoEFCC notified standards under the Environment (Protection) Act that were, for BOD, more relaxed and location-graded — commonly reported as BOD ≤ 20 mg/L for metro cities and state capitals and ≤ 30 mg/L elsewhere, with pH 6.5–9.0. See the CPCB sewage-treatment-plant standards.
• The National Green Tribunal rejected the relaxation and pushed for stricter, uniform norms — reported as BOD ≤ 10, COD ≤ 50, TSS around 10–20, total nitrogen ≤ 10 mg/L, faecal coliform ≤ 100 MPN/100 mL — on the doctrine of non-regression (environmental law should not be weakened).
• State Pollution Control Boards set the number you actually have to meet. The national values are a floor; SPCBs may — and do — impose stricter limits. Karnataka's KSPCB, for example, has notified some of the tightest outlet standards in the country (BOD ≤ 10, COD ≤ 50, TSS ≤ 10 mg/L for surface-water discharge) and mandated online continuous monitoring for larger plants.

Illustrative — not to be treated as the fixed legal value for your site:

The honest instruction: design your STP for the strictest of (a) your SPCB's current outlet standard, (b) the condition written into your EC, and (c) the reuse-quality standard for how you intend to use the water. Where a figure above is contested or superseded, confirm the live value with the CPCB and your SPCB before finalising the design. For the parameter definitions themselves, see BOD, COD, TSS and pH explained; for the applicable outputs, treated-water quality standards and CPCB guidelines for STPs.

The 2016 detour: why the rules did not get easier

It is worth knowing this, because it explains why the process still feels heavy. In December 2016 the MoEFCC amended the EIA Notification to fold environmental conditions into local building permissions and let projects up to 150,000 m² proceed largely on self-certification — pitched as "ease of doing responsible business."

In December 2017 the National Green Tribunal quashed it, holding that a notification could not exempt building projects from consents mandatory under the Water Act, 1974 and Air Act, 1981, and again invoking non-regression. The effect: the SEIAA-led clearance route and the SPCB consent regime both remain firmly in place. There was no shortcut — the STP obligation stayed.

What this means for you

For a developer, facility manager, RWA or consultant, the MoEFCC rules translate into a short, non-negotiable checklist:

• Know your number. Calculate built-up area early; crossing 20,000 m² changes your entire approval path.
• Budget the STP into the EC file, not after it. Water balance, STP capacity, reuse plan and dual plumbing are appraisal items.
• Treat EC, CTE and CTO as three approvals, each of which the STP must satisfy.
• Design to the strictest live standard, then verify it in writing with your SPCB.
• Build for monitoring. Larger plants increasingly need online continuous effluent monitoring; the performance testing and environmental monitoring obligations run for the life of the building.
• Keep the reuse story real. Flushing recycled water — treated water for toilet flushing — is usually the largest and easiest reuse, and regulators expect to see it.

A note that matters more than any single figure here: these norms change. Standards get revised, states diverge, and the 2020 draft could yet reshape the whole framework. Use this guide to understand how the pieces fit — the notification, the thresholds, the clearance, the standards — but confirm every specific number, fee, timeline and clause with the CPCB and your relevant SPCB before you commit a design or a filing.

The bottom line

The MoEFCC does not hand you an "STP rulebook." It hands you the EIA Notification 2006, which decides whether your project needs environmental clearance, routes it to the SEIAA, and then attaches your STP — its capacity, its discharge quality, its reuse and its monitoring — as conditions you must keep for the life of the building. The discharge numbers are contested and state-driven; the obligation to treat, reuse and monitor is not.

From here, walk the approval chain in detail through STP regulations in India, the environmental clearance guide and the STP compliance checklist — or browse the full Sewage Treatment Plants guide library.