Single bay hand held spray or brush wand type vehicle washes shall install a 20-gallon per minute (gpm) interceptor minimum.
Multiple bay vehicle washes having hand held spray and/or brush wands must increase interceptor flow capacity by 12 gpm for each additional wash bay at the facility.
Automated drive through car-wash facilities must install an interceptor(s) with a minimum flow capacity of 40 gpm for each wash bay.
To determine the minimum liquid holding capacity (in gallons) for the interceptor, multiply the gpm flow capacity by the standard 12-minute retention time. Depending upon availability, a 15% ± variance between the calculated volume and the interceptor's actual volume is acceptable.
CAR WASH SAND & GREASE INTERCEPTOR SIZING EXAMPLES: