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AST Inspections

On Oct. 11, 1997, DEP adopted regulations pertaining to periodic in-service and out-of-service inspections. Service inspections determine the tank system's integrity and suitability for continued use, including leak detection systems, structural integrity of the tanks and associated equipment, and release prevention measures.

Service inspections are required on aboveground storage tanks that are:

  • Greater than 5,000 gallons capacity; and
  • Highly hazardous substance tanks greater than 1,100 gallons capacity.

An initial inspection is defined as the first inspection after Oct. 11, 1997.

Tank owners are reminded that only inspectors certified by DEP in the aboveground tank inspector categories, IAM (manufactured tanks) or IAF (field-constructed tanks), may perform inspections.

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). Choose an inspection company with aboveground inspectors (IAM or IAF).

Storage Tank Certified Companies Search

In-service inspections for AST with a capacity > 21,000 gallons are due:

Tank Description Inspection Requirement
New tanks (installed after Oct. 11, 1997) Initial inspection within five years of installation. 
(For example: A tank that is installed on Nov. 1, 1997 would have to be inspected by no later than Nov. 1, 2002.)
Existing tanks installed between Oct. 12, 1992 and Oct. 11, 1997, that have never been inspected Initial inspection by Oct. 11, 1999, or within five years of installation, whichever is later
Existing tanks that are more than five years old (installed before Oct. 11, 1992), that have never been inspected Initial inspection by Oct. 11, 1999.
Existing Tanks that were inspected before Oct. 11, 1994 Initial inspection by Oct. 11, 2000.
Existing tanks that were inspected between Oct. 11, 1994 and Oct. 11, 1997 Initial inspection due within six years of last inspection. (For example: A tank that was inspected on March 1, 1995 would have to be inspected again no later than March 1, 2001.)

* Additional in-service inspections must be completed within 1/4 the corrosion rate life of the tank system, with a maximum interval of five years.

Out-of-service inspections for AST with a capacity > 21,000 gallons are due:

Tank Description Inspection Requirement
Tanks installed after Oct. 11, 1997 Initial inspection based on either measured or similar service corrosion rates. Corrosion rates can be determined by the inspector.
Existing tanks (installed before Oct. 11, 1997) without a known corrosion rate Initial inspection within 10 years after installation, or by Oct. 11, 2000, whichever is later.
Existing tanks (installed before Oct. 11, 1997) with a known corrosion rate Initial inspection at 1/2 the corrosion rate life after either installation or previous Out-of-service inspection, or by Oct. 11, 2000, whichever is later.

Additional out-of-service inspections must be completed within 1/2 the corrosion rate life, with a maximum interval of 20 years.

NOTE: New large AST installations must be inspected at the time of installation. Major modifications or relocations, must be inspected before placing the tank system back into service.

For more information or for printed copies of AST Inspection forms, write or call:

DEP, Bureau of Environmental Cleanup and Brownfields
Division of Storage Tanks
P.O. Box 8762
Harrisburg, PA 17105-8762
Phone: 1-800-42- TANKS (within PA) or 717-772-5599.

Inspection Forms

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