
Choose a system that meters process water, towers, RO and effluent reuse line by line. It should report water per unit produced and show reuse from meters, not estimates.
How a plant uses water
Plant water splits into process water used in the product or for washing, cooling water for towers and heat exchangers, boiler feed, and sanitary use. Treatment adds its own lines: RO feed, permeate and reject, and effluent treated for reuse or discharge.
Cooling choices matter enormously. EPA notes that single-pass cooling uses about 40 times more water than a cooling tower to remove the same heat load, so finding one forgotten single-pass line can change a plant's total.
Scarcity is rising. WRI estimates 31 percent of global GDP will be exposed to high water stress by 2050, up from 24 percent in 2010.
What the system must do
| Requirement | Why it matters here | Ask the vendor |
|---|---|---|
| Meter by process line. | A plant-level meter hides which line is wasting. | Which lines would you meter first? |
| Report water per unit. | Production swings make totals misleading. | Can you normalize by production count? |
| Track RO and effluent treatment. | Recovery and treated flow decide how much is reused. | Do you report RO recovery and treatment efficiency? |
| Close the balance. | Unaccounted water points to leaks and undocumented uses. | Show unaccounted loss by hour. |
Rules and what is coming
Singapore requires sites using 60,000 cubic meters a year or more to meter key usage areas and file an annual water efficiency plan, and new wafer fabs must recycle at least 50 percent of their water from 2024. The revised ESRS E3 asks for consumption in water-stressed areas, withdrawal, discharge, recycled water and storage. Disclosures increasingly need metered reuse, not an engineer's estimate.
How to evaluate one
- Draw the water mapSupply, process lines, towers, RO, effluent plant and discharge.
- Meter the biggest usersUsually towers and wash-down first.
- Add production dataLink output counts to report water per unit.
- Report reuse from metersUse RO permeate and treated effluent flow, not design values.
Where Aqueduct fits
aQ WaterGuard draws the plant's water system as a live twin, block by block, with RO feed, permeate, reject and recovery, and STP inlet, treated flow and efficiency. The balance runs every minute, so unaccounted loss shows by line and hour. Expected use is modeled from past bills, weather and production, and rate configuration prices the difference.
Sources
| Source | Link |
|---|---|
| US EPA WaterSense, Best Management Practices | epa.gov |
| World Resources Institute, Aqueduct 4.0, 2023 | wri.org |
| Singapore PUB, Mandatory Water Efficiency Requirements | pub.gov.sg |
| EFRAG, ESRS E3 delegated act | knowledgehub.efrag.org |


