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Release Detection for Underground Piping

Your UST may have suction piping or pressurized piping. Release detection requirements for piping differ somewhat from those for tanks. Release detection methods for piping include secondary containment with interstitial monitoring, vapor monitoring, groundwater monitoring, continuous in-tank leak detection, statistical inventory reconciliation, and tightness testing. Pressurized piping must also have an automatic line leak detector.

What are the regulatory requirements for suction piping?

Piping installed or replaced after April 11, 2016 must have secondary containment.

The line tightness test must be able to detect a leak at least as small as 0.1 gallon per hour with a probability of detection of at least 95 percent and a probability of false alarm of no more than 5 percent.

Interstitial monitoring, vapor monitoring, groundwater monitoring, continuous in-tank leak detection, and statistical inventory reconciliation have the same regulatory requirements for piping as they do for tanks. See the Release Detection Requirements Table for more information.

What are the regulatory requirements for pressurized piping?

Each pressurized piping run installed on or before April 11, 2016 must have one release detection method from each set (A and B) below:

A. An Automatic Line Leak Detector (ALLD): B. And One Other Method:

Each pressurized piping run installed or replaced after April 11, 2016 must have secondary containment with interstitial monitoring and have an automatic line leak detector.

How do the leak detection methods for pressurized piping work?

Automatic line leak detectors (ALLDs)

Line tightness testing

Secondary containment with interstitial monitoring Vapor or groundwater monitoring

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