Leak Detection For Underground Piping Will you be in compliance? When installed and operated according to the manufacturer's specifications, the leak detection methods discussed here meet the federal regulatory requirements for the life of underground piping systems. Your UST may have suction or pressurized piping, which are discussed below. What are the regulatory requirements for suction piping? No leak detection is required if the suction piping has (1) enough slope so that the product in the pipe can drain back into the tank when suction is released and (2) has only one check valve, which is as close as possible beneath the pump in the dispensing unit. If a suction line is to be considered exempt based on these design elements, there must be some way to check that the line was actually installed according to these plans. If a suction line does not meet all of the design criteria noted above, one of the following leak detection methods must be used: A line tightness test at least every 3 years; or Monthly interstitial monitoring; or Monthly vapor monitoring (including tracer compound analysis); or Monthly groundwater monitoring; or Monthly statistical inventory reconciliation; or Other monthly monitoring that meets performance standards. The line tightness test must be able to detect a leak at least as small as 0.1 gallon per hour at 1.5 times normal operating pressure with certain probabilities of detection and of false alarm. Interstitial monitoring, vapor monitoring (including tracer compound analysis), groundwater monitoring, and statistical inventory reconciliation have the same regulatory requirements for piping as they do for tanks. See the earlier sections of this booklet on those methods.
Leak Detection For Underground Piping Will you be in compliance? When installed and operated according to the manufacturer's specifications, the leak detection methods discussed here meet the federal regulatory requirements for the life of underground piping systems. Your UST may have suction or pressurized piping, which are discussed below. What are the regulatory requirements for suction piping? No leak detection is required if the suction piping has (1) enough slope so that the product in the pipe can drain back into the tank when suction is released and (2) has only one check valve, which is as close as possible beneath the pump in the dispensing unit. If a suction line is to be considered exempt based on these design elements, there must be some way to check that the line was actually installed according to these plans. If a suction line does not meet all of the design criteria noted above, one of the following leak detection methods must be used: A line tightness test at least every 3 years; or Monthly interstitial monitoring; or Monthly vapor monitoring (including tracer compound analysis); or Monthly groundwater monitoring; or Monthly statistical inventory reconciliation; or Other monthly monitoring that meets performance standards. The line tightness test must be able to detect a leak at least as small as 0.1 gallon per hour at 1.5 times normal operating pressure with certain probabilities of detection and of false alarm. Interstitial monitoring, vapor monitoring (including tracer compound analysis), groundwater monitoring, and statistical inventory reconciliation have the same regulatory requirements for piping as they do for tanks. See the earlier sections of this booklet on those methods.
EPA-Straight_Talk_on_USTs_4-6-09.docx