Sewage treatment plants
Sewage treatment plants for societies, schools and offices
An STP that is too small overflows; one too large wastes money and runs badly at low flow. We size the plant from how many people use the building, pick the technology that suits the space and budget, build the civil tanks, install the equipment and set up reuse of the treated water.
Sizing: how many KLD?
Sewage flow is about 80% of the water used. A flat of 5 people using 135 litres each makes about 540 litres of sewage a day, so 200 flats need roughly a 125 KLD plant after a 20% margin. Work it out for your building with the STP capacity calculator.
Which technology
| Plant size | Usual choice | Why |
|---|---|---|
| Up to 50 KLD | Packaged MBBR or FAB unit | Factory built, small footprint, little civil work |
| 50 to 500 KLD | MBBR or SBR in RCC tanks | Robust, easy to run, handles variable flow |
| Above 500 KLD, or little space | SBR, or MBR | Higher treated quality, smaller footprint, higher running cost |
What we do
- Flow and load survey, and a check of the existing plant if there is one.
- Process design, drawings and BOQ, and the papers for State Pollution Control Board consent.
- Civil tanks, equipment, piping and electrical panel, then commissioning with lab tests.
- Treated water piped back for flushing, gardens and cooling towers, which cuts fresh water use by a third or more.
- Upgrades for old plants that fail their tests, and operation and maintenance contracts.
Check the numbers for your area
Frequently asked questions
When is an STP mandatory?
Most states require an STP for group housing, commercial buildings and institutions above a set built-up area, usually linked to environmental clearance for projects above 20,000 m², and for any building not connected to a public sewer. The State Pollution Control Board's consent to operate sets the treated water standards.
Can treated water be used for drinking?
No. Treated sewage is used for flushing, gardening, car washing and cooling towers through a separate pipe network. It must never be connected to drinking water lines.
Our other services
- Services
What we build
Rainwater harvesting, borewell recharge, pond rejuvenation, sewage treatment plants and school buildings, designed and built by TerraSetu from Gurgaon.
- Borewell recharge
Borewell recharge
How TerraSetu recharges a failing borewell with roof and yard rainwater: recharge pit, filter and recharge bore. Method, drawing sizes and cost per recharge point with GST.
- Pond rejuvenation
Pond rejuvenation and desilting
Pond rejuvenation by TerraSetu: survey, DPR, desilting, inlet silt traps, embankments, stone pitching and handover. What it costs per acre and who pays: MGNREGA, Amrit Sarovar, CSR.