Commonwealth of Pennsylvania Department of Environmental Protection www.dep.state.pa.us 2630-FS-DEP4176 Rev. 8/2013

Containment Testing for Underground Storage Tanks (USTs)

Since Dec. 22, 1998, new and upgraded UST systems have been required to have spill containment buckets to prevent spilling of fuel associated with product transfer. Amendments to Storage Tank Program regulations that became effective Nov. 10, 2007, require new or upgraded UST systems to have containment sumps under dispensers and at tank-top penetrations for piping connections that routinely convey product. Spill-containment buckets, dispenser pans and sumps on UST systems must be tested for liquid-tightness at installation, replacement or repair. See 25 Pa. Code, Chapter 245, Sections 245.421 and 245.422 (relating to Performance standards for underground storage tank systems and upgrading existing underground storage tank systems).

The following describes testing procedures that may be used to meet the containment testing requirements and the documentation to be maintained by owners and operators of USTs.

The UST technical regulations require spill-containment buckets and containment sumps to be tested by a method recommended by the containment manufacturer or a nationally recognized organization. The test must be able to determine that the containment is liquid-tight. Typically, the test either uses water or vacuum.

In general, the manufacturer of the spill-containment bucket or containment sump will know the best way to test their product to ensure that it is working properly. For example, one manufacturer recommends applying vacuum to their sumps with a special test apparatus. The equipment includes a vacuum pump, special covers to seal the tank-top or dispenser sumps, and an electronic pressure sensor. The manufacturer recommends testing at four different times during the installation process to ensure any leak is found and repaired prior to backfilling.

Another manufacturer recommends filling the spill-containment bucket with water, marking the water level and waiting at least one hour. If there is any change in the liquid-level, the test fails and the installation should be repaired. The manufacturer recommends conducting this test at least twiceafter initial placement of the containment and after the final tank-field cover is in placeand then again after any necessary repairs are completed.

The water level in the containment should be near the top for best test results. The initial level can be marked with a permanent marker or paint. An accurate measurement with a ruler is also acceptable.

Water used for testing may become contaminated by residue from the equipment manufacturing process or previous use of the containment. Liquids removed from the containment structure should be treated as waste and properly disposed.

In the absence of an equipment manufacturers procedure, a nationally recognized procedure, such as that contained in the Petroleum Equipment Institutes (PEI) Recommended Practice (RP) 1200, should be followed. PEI RP-1200 recommends filling the containment with water, marking the level and waiting at least one hour. If the water level drops 1/8-inch or greater, the containment fails the integrity test and the installation should be repaired and retested.

Documentation of the last liquid-tight test for each spill-containment bucket and containment sump should be maintained for a minimum of one year after the UST system is permanently closed. Documentation should include the name and type of the test used, the data collected during the test, the date of test and test result, and the name and contact information of the individual who conducted the test.

For more information, visit www.dep.state.pa.us, keyword: Storage Tanks.