- (a) The tightness test for a UST system or system component shall be capable of detecting a system leak rate of 0.10 gallon per hour with a probability of detection of 0.95 and a probability of false alarm of 0.05, accounting for all variables including vapor pockets, thermal expansion of regulated substance, temperature stratification, evaporation, pressure, end deflection, water table, and tidal action.
- (b) When line tightness testing is used for suction or atmospheric piping, the pipe pressure tightness test shall have a detection limit equivalent to 0.1 gallon per hour at 1.5 times operating pressure.
Source. (See Revision Note #1 at chapter heading for Env-Or 400) #10393, eff 9-1-13; ss by #12643, eff 10-10-18 (formerly Env-Or 406.12) (See Revision Note #2 at chapter heading for Env-Or 400)