Sewage Treatment Plant (STP) Manufacturer & Supplier in Delhi

A Sewage Treatment Plant (STP) is a facility that processes domestic and municipal wastewater to remove contaminants before the treated water is discharged or reused. The process involves physical, biological, and chemical treatment stages that remove suspended solids, organic matter, nutrients, and pathogens.

Modern STP systems use technologies including MBBR (Moving Bed Biofilm Reactor), MBR (Membrane Bioreactor), SBR (Sequencing Batch Reactor), and conventional activated sludge processes — each suited to different capacities and site conditions.

In India, STPs are mandatory for residential societies above 20,000 sqm built-up area, commercial complexes, hotels, hospitals, and all industrial facilities discharging domestic effluent — as per CPCB norms and local Pollution Control Board regulations.

As Delhi continues to expand, demand for dependable STP capacity has grown alongside it, particularly around the city's established industrial belts. This is especially true around Okhla Industrial Area, Wazirpur Industrial Area, Lawrence Road Industrial Area, where DPCC inspection has become more consistent in recent years.

Optima Water Solutions delivers STP projects in Delhi end to end — design, manufacturing, installation, commissioning, and Annual Maintenance Contracts — so clients are not left coordinating multiple vendors for one system.

Delhi's wastewater problem is one of scale and space. The city produces far more sewage than its municipal network has historically treated, and the National Green Tribunal's Yamuna proceedings have shifted attention from how much is treated to how clean the treated water really is. Tribunal filings and audits have repeatedly flagged faecal coliform and suspended solids at municipal plants, so regulators now look much harder at any private STP that discharges or reuses water.

For a developer or facility manager the practical problems are more specific. Plots are tight, so the plant usually goes into a basement with limited ventilation and no room for large settling tanks. Groundwater is being extracted faster than it recharges, which pushes owners towards reuse and makes tanker bills hard to justify. And Delhi's mixed-use buildings — flats above shops, nursing homes inside residential colonies, hotels in dense markets — create kitchen grease, laundry and clinical load that a plain residential design never anticipated.

How Optima solves it: we design Delhi plants around the footprint first. That means compact MBBR or MBR trains, fine screening and grease removal ahead of the biology, and a disinfection stage (UV or chlorination, chosen by the reuse application) so that faecal coliform is controlled by design rather than assumed. Treated water goes back to flushing, horticulture and, where the building has chillers, cooling-tower make-up after extra polishing. AMC visits can include scheduled sampling of BOD, TSS and residual chlorine so your consent file stays current.

Three layers apply to an STP in Delhi. The Delhi Pollution Control Committee (DPCC) grants Consent to Establish and Consent to Operate under the Water Act, and the operating consent is needed before the plant runs and the building is occupied. Building sanction through DDA, MCD or NDMC requires the water, sewerage and drainage schemes to be cleared with the Delhi Jal Board, which is where STP provision is checked at design stage. Projects above 20,000 sq m of built-up area also need environmental clearance, and that approval writes STP, reuse and monitoring conditions into the project.

On quality, the NGT order of 30 April 2019 set a BOD ceiling of 10 mg/L for new STPs in large cities, with limits on suspended solids, nitrogen and faecal coliform alongside. In the Yamuna matter the Tribunal went further for municipal plants, directing Delhi Jal Board STPs to be upgraded to 10/10 mg/L BOD/TSS. Published summaries quote some of these figures differently, and boards apply them through each project's own consent letter, so we design to the numbers written into yours rather than to a generic table.

Reuse is the direction of travel. The Delhi Jal Board has approved a reclaimed-water policy, reported in 2026, that aims to move construction and horticulture demand onto treated water. Confirm the notification status for your project, but design for reuse from day one, because that is where an on-site plant earns its money back.

Sizing by building type. Sewage is normally taken as about 80% of the water supplied. A 300-flat society with roughly 1,350 residents at 135 litres per head per day uses about 182 KLD and returns around 146 KLD of sewage, so a 175 KLD plant leaves sensible headroom. A 120-room hotel (about 240 beds at 180 litres per bed) draws near 43 KLD before banquet and laundry load, which is why we usually quote around 60 KLD with a grease trap and an equalisation tank. A 100-bed nursing home at 340 litres per bed uses about 34 KLD and needs a stricter disinfection stage than a residential plant.

MBBR, MBR or SBR for Delhi sites? MBBR is the default for most residential and commercial projects: compact, tolerant of load swings and simple to operate. MBR suits basement plants, tight plots and premium buildings where treated water feeds flushing or cooling towers, because the membranes give very low suspended solids and a firmer pathogen barrier in the smallest footprint, at the price of higher energy use and periodic membrane replacement. SBR works well for schools, government campuses and offices with strong day-night swings, since batch cycles absorb variable flow and can be tuned for nitrogen removal, but it depends on reliable automation. Small units in Okhla, Wazirpur or Naraina rarely need more than a domestic STP for staff and canteen; where a unit is connected to a common effluent treatment plant, process wastewater is handled separately from the STP.