Interactive Calculator · 2026
Water Carbon Savings Calculator
Every kilolitre of treated water you reuse is a kilolitre of fresh supply you never had to source, pump and treat. Enter your reuse volume and an emission factor to see the CO2 emissions you avoid each year.
CO2 saved each month by reusing treated water (kg)
Your reuse & emission factor
Kilolitres per day of treated STP water you reuse in place of fresh supply.
CO2 to source, pump and treat one kilolitre of fresh supply. Typical range 0.3–1.5 kg CO2/KL.
CO2 saved through the year
Reusing 160 KLD avoids ≈40.9 t of CO2 annually — spread across the months below.
Fresh water is carbon-intensive long before it reaches your tap — abstraction, long-distance pumping and treatment all burn energy. Reusing treated water displaces that entire chain.
At 0.70 kg CO2 per kilolitre, your 58,400 KL of yearly reuse keeps roughly 40,880 kg of CO2 out of the atmosphere.
How this is calculated
- Water reused / year = reuse × 365 = 160 × 365 = 58,400 KL.
- CO2 avoided = annual water × emission factor = 58,400 × 0.70 = 40,880 kg = 40.9 t CO2/yr.
- Tree-equivalent = CO2 (kg) ÷ 21 (a tree absorbs ≈21 kg CO2/yr) = 1,947 trees.
Indicative estimate for awareness and reporting. Actual emission factors vary by source, pumping distance and grid carbon intensity — use a locally measured factor for formal accounting.
Related Guides — Deep-dive reading
Reducing an STP's Carbon Footprint: The Net-Emissions Guide
An STP burns power around the clock — but the treated water it produces displaces tankered and pumped freshwater. This guide shows how to weigh the two, then shrink the net carbon footprint with efficient aeration, solar and biogas.
Sewage Treatment PlantsSTPs and Net-Zero Buildings: How On-Site Water Reuse Powers (and Tests) Net-Zero Goals
Why a sewage treatment plant is central to a net-zero water building, why its power draw quietly works against a net-zero energy target, and the practical strategies that turn an STP from an energy liability into an energy-neutral asset.
Sewage Treatment PlantsConstructed Wetlands & Root Zone Systems: Natural STPs Explained
How engineered gravel beds planted with reeds and canna clean sewage using roots and microbes instead of blowers and motors — the low-energy, low-maintenance natural STP, and exactly where it fits in India.
Sewage Treatment PlantsRelated Tools — You may also find these useful
Water Recycling Dashboard
Enter fresh supply, sewage and treated-water reused (KLD) to see your building's reuse percentage plus the money, water and CO₂ saved each year, with live charts.
DashboardWater Reuse Savings Calculator
Estimate the money you save by reusing STP-treated water instead of buying fresh supply, with daily, monthly and annual savings.
STP CalculatorRainwater + STP Integration Calculator
Combine rooftop rainwater harvesting with STP treated-water reuse to estimate the total non-potable water your building can supply in KL per year.
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