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Underground Storage Tanks (UST)


A UST is a device consisting of a tank or combination of tanks, and the underground piping connected to it. A UST system consists of a UST, its containment structures and all connected piping and ancillary equipment. Underground means below the surface of the surrounding soil (ground or pavement), but not in an area which is completely open for tank inspection such as some mines or basements. Systems that will be used to contain, have contained or currently contain products with more than a very small concentration of regulated substances (PDF), where the system volume is greater than 110 gallons and where at least 10 percent of the UST volume is beneath the surface of the ground are regulated in Pennsylvania by the Storage Tank Program as a UST.

A UST must be registered, by the owner, with the department and an annual registration fee paid. A valid operating permit is required before it is operated; that is, before putting a regulated substance into a UST. Unless its operating permit is currently approved, the UST must be emptied. Tank permit statuses, and a searchable list where the permit has not been approved, are available here. The department routinely withholds the operating permit of tanks that have been emptied and taken out of service. Where significant violations of the rules exist DEP may suspend or revoke an operating permit until the system is brought into compliance.

UST must be installed, maintained, operated and repaired in accordance with department rules and nationally recognized standards. This list of standards and practices (PDF) may be used to comply with Storage Tank Regulations.

The Storage Tank Division has noticed an increasing number of reported problems with early, nonmetallic piping systems. In July of 2005 UL updated their pipe standard to address the causes of many of the problems. The Mississippi Department of Environmental Quality has produced a guide to nonmetallic piping (PDF) to aid owners and inspectors in identifying the specific type of piping that may be installed at a facility. Types that are prone to deterioration should be checked frequently and replaced before they cause a release of regulated substance.

Work (except for routine maintenance) on a regulated tank system must be performed by a properly certified tank handler(installer certified by DEP). Maintenance activities are described in department guidance Storage Tank Modification and Maintenance Issues (PDF) (263-0900-011). Work requiring a certified tank handler should be documented on a modification report, a copy of which is retained by the owner. Inspections required by the storage tank regulations must be performed by a properly certified tank inspector (third-party inspector certified by DEP). Owners can choose from the list of certified companies when searching for one to work on their tank systems.

Click the link below to access a list, updated daily, of Storage Tank Certified Companies. You may search by DEP Region, County, and Certification Category. This list may be exported in a variety of formats, or to obtain a printed copy of the latest list, call the customer service unit at 1-800-42-TANKS (toll-free within PA) or 717-772-5599 (local and out-of-state).

Storage Tank Certified Companies Search

People who want to perform tank handling activities on regulated tanks in the Commonwealth of Pennsylvania must be certified. See the certification page for more information.

New and replacement UST systems must have total secondary containment. On existing systems, when more than 50 percent of the piping that routinely contains product is replaced, the main piping run must be double walled with containment sumps at the tank top and dispensers. New, replacement or repaired piping sumps and spill buckets must be tested (PDF).

When new petroleum dispensers are installed, under dispenser containment (PDF) is required. Under dispenser containment is also required when replacing an existing petroleum dispenser when work performed involved a major modification.

Certified tank handling companies and installers, who perform tank handling activities on underground storage tanks (UST), must participate in the Tank Installers' Indemnification Program (TIIP). This program is overseen by the Department of Insurance, Underground Storage Tank Indemnification Fund (USTIF). Owners and operators of USTs should verify that the certified company and tank handler meets the TIIP requirements before the tank handling activity commences. More detailed information is available at USTIF's web site, or by calling 1-800-595-9887 (PA only) or 717-787-0763.

Underground storage tank systems that are no longer needed or are unsuitable for regulated substance storage must be properly closed-in-place (when allowed by local jurisdiction) or removed.

Further information on Storage Tanks as well a storage tank search capabilities can be found at our at Regulated Tanks Listing page.

One method of release detection allowed in Pennsylvania is Statistical Inventory Reconciliation (SIR). The details of using this method can be confusing. See the booklet, Introduction to Statistical Inventory Reconciliation for Underground Storage Tanks (PDF), for more information regarding the use of SIR.

Facility Operations inspections (FOI) verify that USTs at a facility have been installed and are being operated in accordance with department rules. Since Nov. 10, 2007, each active facility must be inspected at least once every three years. 

Commonly Asked Questions by Storage Tank Owners Concerning Facility Operations Inspections (PDF)

For a summary of inspection frequency requirements, click on the following document: Inspection Frequency Summary (PDF)

Links to the Facility Operations Inspection Form, form instructions, and guide have been provided below for your convenience.