What is Effluent treatment plant (ETP)?
An effluent treatment plant (ETP) treats industrial wastewater on site, usually through screening, equalization, biological treatment and clarification, so it can be discharged within permit limits or reused.
Who needs an ETP
In India, industrial units that discharge wastewater need consent from their State Pollution Control Board under the Water (Prevention and Control of Pollution) Act, 1974, and the consent conditions fix the effluent quality an ETP must achieve. Dairies, food plants, distilleries, pharmaceutical and textile units commonly run their own plant, while smaller units in industrial estates may send effluent to a common ETP.
Dairy effluent standards
For dairies, Schedule I of the Environment (Protection) Rules, 1986 sets treated effluent at pH 6.5 to 8.5, BOD of 100 mg per liter, suspended solids of 150 mg per liter, and oil and grease of 10 mg per liter. It also sets a wastewater generation standard of 3 cubic meters per kiloliter of milk processed. The BOD limit can be tightened to 30 mg per liter where the receiving water body supplies drinking water.
What the water twin shows about an ETP
On Aqueduct's water digital twin, the treatment plant is a block with inlet flow, treated flow and efficiency, next to RO recovery where treated water is polished for reuse. Metering inlet flow against milk processed tracks cubic meters per kiloliter against that standard every day instead of at the annual return. Lab results and consent filings remain the plant's responsibility.