AST Inspections
On Oct. 11, 1997, DEP adopted regulations pertaining to periodic inspections of AST systems. AST 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.
Periodic 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.
Inspection activities conducted to meet DEP’s inspection requirements must be performed by DEP-certified individuals holding appropriate AST inspector certification, IAM (manufactured tanks) or IAF (field-constructed tanks).
Click the link below to access a list of DEP-certified storage tank companies. You may search by DEP Region, County, and Certification Category. To complete a required In-Service or Out-of-Service Inspection, choose an inspection company that employs aboveground inspectors (IAM or IAF).
Certified Storage Tank Companies Search
The table below describes the maximum inspection intervals for different ASTs. Inspection due dates are set by the DEP-certified inspector at each inspection based upon conditions at the time of the inspection:
| Inspection Type | Tank Description | Initial Inspection | Subsequent Inspections |
| In-Service | ASTs > 5,000-gallon capacity | Within 5 years after installation | 5 years maximum |
| Highly hazardous substance ASTs > 1,100-gallon capacity | Within 5 years after installation | 5 years maximum |
| ASTs in Underground Vault > 5,000-gallon capacity | 6-12 months after installation | 3 years maximum |
| Out-of-Service | ASTs > 21,000 gallon-capacity | Within 10 years after installation of a new tank or tank bottom | 20 years maximum |
| Lining | Internally lined ASTs > 21,000-gallon capacity | Within 10 years after lining installation | 10 years maximum |
NOTE: ASTs greater than 21,000-gallon capacity must be inspected at installation, reconstruction, or relocation, and when a major modification is performed on the AST system.
Field-constructed ASTs (regardless of capacity) must be inspected at installation, reconstruction, or relocation, and when a major modification is performed on the AST system.
For more information, contact the Division of Storage Tanks:
Phone: 1-800-42-TANKS or 717-772-5599
Email: tanks@pa.gov
DEP, Bureau of Environmental Cleanup and Brownfields
Division of Storage Tanks
P.O. Box 8762
Harrisburg, PA 17105-8762
Inspection Forms