| PARAMETER | US CUSTOMARY | SI METRIC |
|---|---|---|
| Concentration | mg/L or ug/L | mg/L or ug/L |
| Demand | (see Flow units) | (see Flow units) |
| Diameter (Pipes) | inch | millimeter |
| Diameter (Tanks) | foot | meter |
| Efficiency | percent | percent |
| Elevation | foot | meter |
| Emitter Coefficient | flow unit/ (psi)1/2 | flow unit/ (meter)1/2 |
| Energy | kilowatt – hour | kilowatt – hour |
| Flow | CFS (cu foot/sec) GPM (gal/min) MGD (Million gal/day) IMGD (Imperial MGD) AFD (ac-foot/day) | LPS (liter/sec) LPM (liter/min) MLD (Megaliter/day) CMH (cubic meter/hr) CMD (cubic meter/day) |
| Friction Factor | unitless | unitless |
| Hydraulic Head | foot | meter |
| Length | foot | meter |
| Minor Loss Coefficient | unitless | unitless |
| Power | horsepower | kilowatt |
| Pressure | pounds per square inch | meter |
| Reaction Coefficient (Bulk) | 1st-order 1/day | 1st-order 1/day |
| Reaction Coefficient (Wall) | 0-order mass/L/day 1st-order ft/day | 0-order mass/L/day 1st-order meter/day |
| Roughness Coefficient | Darcy-Weisbach 10-3foot Otherwise unitless | Darcy-Weisbach millimeter Otherwise unitless |
| Source Mass Injection | mass/minute | mass/minute |
| Velocity | foot/second | meter/second |
| Volume | cubic foot | cubic meter |
| Water Age | hour | hour |