Interactive Planner · 2026
Commercial STP Planner
Plan a sewage treatment plant for any commercial building. Pick the building type, enter the occupancy, and get the required STP capacity in KLD (kilolitres per day) plus the technology best suited to it.
Water demand → sewage generated → installed STP capacity
Your commercial building
≈180–220 L per bed/day
Water demand ≈ 200 LPCD × occupancy.
Share of water supplied that becomes sewage — CPCB/NBC take ≈80%.
Demand, sewage and installed capacity
Fresh-water demand becomes sewage (≈80% return); the plant is sized ≈20% above that.
A MBBR plant of 39 KLD comfortably treats the 32 KLD of sewage this occupancy generates each day.
Recovering ≈26 KLD of treated water for flushing, landscape and cooling can cut a building's freshwater purchase by roughly a third.
Which technology fits which size
| Capacity band | Recommended technology | Typical fit |
|---|---|---|
| Below 50 KLD | MBBR | Small offices, restaurants |
| 50 – 200 KLD | MBBR/SBR | Malls, mid hotels |
| 200 KLD & above | SBR/MBR | Hospitals, large hotels |
How this works
- Water demand = occupancy × LPCD = 200 × 200 = 40 KLD.
- Sewage generated = demand × 80% return = 32 KLD.
- STP capacity = sewage × 1.2 (20% margin), rounded up = 39 KLD.
- Technology is picked from the capacity band above → MBBR.
- Reusable water = sewage × 0.8 = 26 KLD of treated water.
Indicative sizing for concept planning per NBC/CPCB norms. A detailed design must also fix peak factor, tank volumes and equipment — confirm with a qualified consultant before procurement.
Related Guides — Deep-dive reading
STP for Shopping Malls: Mixed Loads, Big Reuse
Why a mall's wastewater is unlike any other building's — a punishing mix of food-court grease, washroom peaks and huge cooling-tower thirst — and how to size, site and choose an STP that turns all of it back into usable water in the basement.
Sewage Treatment PlantsSTP for IT Parks & Campuses: Central-Plant Design, Reuse & Redundancy Guide
How to plan a campus-scale sewage treatment plant for a multi-building IT park in India — the daytime flow pattern, the right technology, sizing for a central plant, and a reuse network feeding landscape, flushing and cooling towers.
Sewage Treatment PlantsApartment STP Planning Guide: Sizing, Space & Compliance
How to plan a sewage treatment plant for an apartment complex — sizing it from occupancy, choosing the right technology, finding space for it, plumbing it for reuse, and keeping it compliant and running for years.
Sewage Treatment PlantsRelated Tools — You may also find these useful
STP AMC Evaluation Checklist
Interactive checklist that scores any STP annual maintenance contract across scope, service levels and commercials, giving a live readiness score before you sign.
ChecklistSTP Annual Operating Cost Calculator
Total up a sewage treatment plant's yearly running cost from monthly electricity, chemical, manpower and annual AMC spend, with the monthly total and biggest cost driver.
STP CalculatorSTP Building Approval Checklist
An interactive checklist that tracks every sewage-treatment-plant requirement from building-plan sanction through Consent to Establish/Operate to occupancy, showing live completion and readiness.
Checklist