Requirements for Placing Underground Storage Tanks Temporarily Out-of-Service in Pennsylvania

From the desk of Zachary Weaver, PG, LSRP

Underground storage tank leak experts in Pennsylvania

New underground storage tanks are installed at a fueling station in Pennsylvania.

The Pennsylvania Department of Environmental Protection (PADEP) requires that Underground Storage Tanks (UST) systems, that are no longer needed or are unsuitable for continued use, be emptied and placed temporarily out-of-service, closed-in-place, or removed.  Let’s take a closer look at PADEP requirements for placing UST systems temporarily out-of-service and maintaining the temporarily out-of-service status.

What does temporarily out-of-service mean?

Placing a UST temporarily out-of-service means that the UST system is emptied, but is intended to be return to operation after a limited period of time.

What is required to place and maintain a UST system temporarily out-of-service?

UST owners and operators must perform the following items to place a UST temporarily out-of-service:

  • Empty the UST system within 30 days of being placed temporarily out-of-service.  Lines must be drained and all materials removed so that no more than one inch of residue or 0.3 percent by weight of the total capacity of the UST system remains.
  • Notify the PADEP within 30 days of placing a UST system temporarily out-of-service by submitting an amended Storage Tanks Registration/Permitting Application Form or Storage Tank Registration Amendment Forms.
  • After three months, the product lines, pumps, manways, and ancillary equipment must be capped and secured.  The vent lines must remain in service.
  • Continue to perform the Facility Operations Inspections of the UST system.
  • Continue operation and maintenance of the corrosion protection (if equipped).
  • If there is an indication of a release, complete an investigation within seven calendar days.
  • If a reportable release is confirmed, notify the PADEP within 24 hours and complete corrective action.

How long can a UST system be temporarily out-of-service?

The duration that a UST system can be temporarily out-of-service depends on if the UST system meets either the performance standards for new USTs or the upgrade requirements for existing USTs and whether the PADEP approves an extension.

  • If the UST system does not meet performance standards for new USTs or upgrade requirements for existing USTs, it should be permanently closed after 12 months.  Alternatively, site assessment may be completed and a request for an extension can be submitted to the PADEP.
  • If the UST system does meet performance standards for new USTs or upgrade requirements for existing USTs, it should be permanently closed after 3 years, unless an extension is granted by the PADEP.

For more information, refer to the PADEP Technical Guidance Document 263-4500-601, Closure Requirements for Underground Storage Tank Systems or contact our team of underground storage tank management experts at 800.305.6019 or via email at