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Corrosion Protection for Petroleum Storage Tanks

Find out if your petroleum storage tanks (PSTs) need corrosion protection and what options there are.

Why You Need Corrosion Protection for PSTs

All underground storage tank (UST) systems need corrosion protection to slow or prevent metal components from rusting or otherwise corroding or oxidizing. This helps prevent accidental releases of petroleum products from your system, which could result in soil and groundwater contamination, as well as a costly clean-up for you.

All underground metal components of a UST system that contain, store, or convey regulated substances must have proper corrosion protection regardless of age, date of installation, or operational status. These metal components include, but are not limited to:

  • Tanks.
  • Vent lines.
  • Spill containers.
  • Flexible connectors.
  • Submersible pump housings.
  • All piping, including riser and fill pipes.

Our guide Adobe Acrobat PDF Document Protecting Underground Storage Tanks Against Corrosion (RG-475f) discusses options for corrosion protection, testing frequency, record-keeping requirements, and how to verify tank material. Following are some of the available options.

FRP Tanks and Piping

Tanks and piping made of FRP (fiberglass-reinforced plastic) do not need additional corrosion protection, because FRP is noncorrosive. You may still have other corrosion protection requirements if you have underground metal components.

STI-P3 and ACT-100 Tanks

STI-93 tanks meet Steel Tank Institute STI-P3 construction requirements. They are carbon steel tanks with high-quality dielectric coating, cathodic protection (anodes), and isolation devices to protect them from other underground structures.

ACT-100 tanks meet Steel Tank Institute ACT-100 construction specifications. For more information, see their webpage on ACT-100 tanks .

Jacketed-Steel Tanks and Composite Tanks

Both types are steel tanks with some form of corrosion-resistant external cladding. While they are slightly different, they need to meet the same requirements, and are grouped together in the rules.

Sacrificial Anodes in Water-filled Sumps

This is acceptable if you can show that the sacrificial system is designed to work in the sump’s condition.

3-Year Corrosion Tests

If you use cathodic protection for any component of a UST system, all underground components need 3-year corrosion tests. They must be inspected and tested by a qualified corrosion specialist or corrosion technician to make sure the protection is adequate.

More Information

See the following resources for more on PST rules and requirements:

TCEQ's Small Business and Local Government Assistance section offers free, confidential help to small businesses and local governments working to follow state environmental regulations. Call us at 800-447-2827 or visit our webpage at