What is Airport water balance?
An airport water balance accounts for all water entering an airport against every metered and estimated use, reporting the difference as unaccounted water that points to leaks or unmetered draws.
What goes into the balance
Inputs are utility connections, wells and any reclaimed supply. Outputs include terminal restrooms and concessions, cooling towers, aircraft and vehicle wash, irrigation, fire systems, tenant buildings and potable water for aircraft servicing. Many airports run long, aging mains under aprons and roads, with tenant connections that were never sub-metered, so the unaccounted term can stay large for years. Facilities, environmental and finance teams all rely on the result.
Federal thresholds that bear on it
EPA WaterSense guidance says a facility that cannot account for more than 10 percent of its water use may have leaks. Deicing runoff is regulated separately under 40 CFR Part 449. Airports with at least 1,000 annual non-propeller departures must certify they use no urea pavement deicers or meet an ammonia limit of 14.7 mg/L. New airports in areas above 3,000 heating degree days, expected to exceed 10,000 annual departures, must collect at least 60 percent of available aircraft deicing fluid.
The balance equation in aQ WaterGuard
aQ WaterGuard shows the balance as a live equation, main supply equal to metered branches plus fire system plus unaccounted loss, refreshed every 60 seconds. A rise in unaccounted loss overnight, when terminal demand is low, narrows a leak to the zones whose meters do not explain it. A top 25 US airport went live on Aqueduct in two weeks with 5,000 meter points.