Petroleum Storage Tanks - Spill and Overfill Prevention

Why You Need Spill and Overfill Prevention Equipment

When filling an underground storage tank (UST), spill and overfill prevention equipment helps prevent releases to the environment. Without this equipment, overfills and spills can result in significant cleanup costs and lost product from your UST system.

With few exceptions, all UST systems must have spill and overfill prevention equipment.

Exceptions include:

• Facilities that do not exceed 25 gallons per transfer.
• UST systems equipped with alternative equipment that we have reviewed and approved.

Aboveground storage tanks typically do not need spill and overfill prevention equipment but may have requirements if subject to the Spill Prevention, Control, and Countermeasures (SPCC) regulation.

• See EPA’s SPCC Applicability webpage for more information.

Equipment Requirements

Read our PST Spill and Overfill Prevention and Control module (RG-475e) of the PST Super Guide (RG-475) for equipment requirements.

• See EPA’s guide to Inspecting and Maintaining Sumps and Spill Buckets for more help.

You may also need to meet requirements under EPA’s Spill Prevention, Control, and Countermeasures regulation .

Inspection Requirements

You must inspect spill and overfill prevention equipment every 30 days and inspect containment sumps every year.

30-Day Inspections

Inspect spill and overfill prevention equipment every 30 days to make sure it is in good working condition. Keep a logbook with dates of inspections, any results, and names of inspectors.

During this inspection:

• Remove any liquid and debris within 96 hours and properly dispose of it.
• Make sure fill pipes do not have obstructions and the cap fits securely.
• If there is double-walled spill prevention, check for leaks in the interstitial area.

Annual Inspections

Inspect containment sumps each year. During an annual inspection check all containment sumps for damage, leaks, or evidence of potential releases. Keep a logbook with dates of inspections, any results, and names of inspectors.

Other annual inspection requirements depend on whether:

• Your USTs were built before or after January 1, 2009.
• You use any containment sumps for interstitial monitoring.

For sumps used for interstitial monitoring and USTs built after January 1, 2009: ensure any sump secondary containment is liquid tight and check for leaks in the interstitial area.

For single-walled sumps not used for interstitial monitoring and USTs built before 2009: check for functioning cathodic protection if metal components in the sump are in contact with water.

• Remove any liquid and debris within 96 hours and properly dispose of it.

Liquid Tightness Tests for Sumps

You must test your sumps for liquid tightness if your equipment was installed on or after January 1, 2009, or meets both conditions below:

• Your containment sump is not double walled.
• Your primary release detection method is interstitial monitoring.

Conduct tightness tests at least once every 3 years using any of the following:

• Manufacturer guidelines.
• Accredited lab testing procedures.
• Petroleum Equipment Institute’s 1200 testing procedures.

If you do not know when your sumps were installed, check your facility’s information in our Central Registry. You can also find a licensed UST contractor to determine if your containment sumps are single-walled, contained, uncontained, or used with interstitial monitoring.

Wastewater from Tightness Testing

You need a permit to dispose of wastewater from tightness testing, but your authorization depends on how you plan to dispose of the wastewater. See Disposing of Wastewater Contaminated with Petroleum for more information.

If you discharge hydrostatic testing wastewater within the boundaries of a Municipal Separate Storm Sewer System (MS4), always let the MS4 operator know before discharging, even if you have a permit. City partnership is very important, and it lets them know the discharge was intended.

Recordkeeping

For spill and overfill prevention records, keep logs of 30-day and annual walkthrough inspections, installation records for your UST system, and any documentation of overfill-prevention devices while the equipment is in use.

More Information

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

• PST: Compliance Resources
• PST Super Guide (RG-475)
• PST Program

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 TexasEnviroHelp.org.