When deciding whether to install an underground storage tank (UST) or an aboveground storage tank (AST) for petroleum or hazardous substance storage, or when managing the daily tank operations, you need to consider the very different regulations related to ASTs and USTs.

These tips will help you make informed decisions related to USTs or ASTs storing petroleum or hazardous substances.

Tip #1: Check with Your State

These suggestions are based on federal regulations, and states and territories (but not Indian lands) are free to impose more stringent requirements. Therefore, before you follow these suggestions, you must confirm their status with your state AST or UST authority.

Some UST owners or operators mistakenly think they can avoid environmental and safety requirements by changing to ASTs. However, ASTs are not regulated under any single federal regulatory scheme and are generally regulated on the local level by state fire codes and industry standards. In addition, many states have included ASTs in their UST regulatory program.

AST management programs are primarily administered by states. State regulations may require that an applicant submit an application for AST installation together with an application fee, site plan, and installation information for review and approval by the state agency.

States may also require a permit from the state fire marshal for gasoline and diesel fuel tanks, stricter spill prevention planning, spill response, tank registration, inspection and notification requirements, as well as secondary containment.

Thirty-eight states plus the District of Columbia and the commonwealth of Puerto Rico have approved UST programs. State program approval eliminates the duplication and confusion that result from having separate state and federal requirements. In states without approved programs, UST owners and operators must comply with the stricter of both federal and state standards.

Tip #2: Know Which Fire Code Applies

At a minimum, most ASTs need to meet state and local fire codes, which usually have some mix of construction, installation, operation, and maintenance requirements that are intended to prevent fires and other hazards that can come from mismanaged or substandard ASTs. For more information, check with your local authority having jurisdiction, such as your local fire marshal.

Current editions of major codes establish criteria for the equipment required, level of fire resistance, and separation of the tank from buildings and property lines. Each model code, state, or local jurisdiction varies regarding definitions, minimum separation distances, tank sizes, or limitations imposed. However, a typical tank separation distance from a building is 50 feet on a 1-acre site, with reduced distances for smaller sites.

Tip #3: Tanks Storing Hazwaste Follow Different Rules

Different sets of federal rules regulate tanks. To determine which set applies, you need to know whether the substance being stored or treated in the tank is a hazardous waste, a petroleum product, or a hazardous chemical.

Federal laws that regulate ASTs include the Clean Water Act, the Oil Pollution Act, the Clean Air Act, and the Resource Conservation and Recovery Act (RCRA).

EPA established UST regulations under RCRA Subtitle I. USTs that store hazardous substances identified under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) are subject to the same requirements as petroleum UST systems, except that hazardous substance tanks must have secondary containment.

Section 1530 of the Energy Policy Act of 2005 requires states receiving federal funds under Subtitle I of the Solid Waste Disposal Act to require either secondary containment and under-dispenser containment for new and replaced petroleum UST systems or evidence of financial responsibility and installer certification. Tanks that store hazardous waste are regulated under RCRA Subtitle C and are, therefore, not covered by the federal UST regulations.

Tip #4: Know If Federal UST Regulations Apply to You

EPA’s UST regulations apply to any person who owns or operates a UST or a UST system. Covered USTs are those that:

• Contain a regulated substance
• Have at least 10 percent of volume (including piping) underground
• Have a capacity greater than 110 gallons

Federal rules exempt certain groups of tanks from the definition of a UST. Some exemptions are full and some are partial. Partially exempt facilities must comply only with release reporting, corrective action, and financial responsibility standards.

Many states require UST owners and operators to obtain an operating permit. Contact your state regulatory authority for specific permit requirements.

Tip #5: Recognize When a Release Occurs

Releases from UST systems can originate from one or more system components, including tanks, piping, and pumps, as well as from spills and overfills. A release includes visual or analytical verification, a failed line, or a failed tank tightness test.

Since most of the UST components are buried, methods other than sight and smell must be used to determine if a leak has occurred.

Warning signals include:

• Unusual operating conditions, such as erratic behavior of the dispensing pump
• Results from leak detection monitoring and testing
• Reports from fuel delivery drivers
• Complaints from neighbors about vapors in their basements or about water that tastes or smells like petroleum

Tip #6: Follow Release Reporting Requirements

You must immediately report hazardous substance spills that meet or exceed their reportable quantities; discharges of oil that violate state water quality standards; or discharges that cause a film, sheen, discoloration, sludge, or emulsion on or beneath the water or adjoining shorelines to the National Response Center at 800-424-8802. State authorities must be notified within 24 hours, or sooner in some cases. Check your state’s release reporting requirements for specific reporting requirements.

Tip #7: Keep Repair Records

Keep records of any repairs for as long as the tank is in service.

A leaking UST may be repaired if standard industry practices are followed. After completion of the repair, the tank must be tested within 30 days. A cathodically protected tank must be tested within 6 months of repair.

Damaged metal pipes may not be repaired and must be replaced. However, a loose pipe may be tightened. Fiberglass-reinforced plastic pipes may be repaired in accordance with manufacturer’s instructions or national standards if tested within 30 days after the repair.

Tip #8: Remember, Size Does Matter

Spill Prevention, Control, and Countermeasure (SPCC) regulations require SPCC plans for non-transportation-related facilities with a total aboveground oil storage capacity of more than 1,320 gallons (gal) or USTs with an oil storage capacity of more than 42,000 gal. The level of SPCC Plan detail and whether the Plan needs to be certified by a licensed professional engineer (PE) are determined by the total aggregate oil storage and the size of the largest tank at a facility.

When replacing or installing new ASTs, consider choosing a tank size that will keep your facility below the following SPCC thresholds:

• Facilities with aggregate aboveground oil storage capacity of 1,320 gal or less and completely buried oil storage capacity of 42,000 gal or less are not subject to SPCC rules.
• Facilities with aggregate aboveground oil storage capacity of 10,000 gal or less and that have not had significant oil spills in the past 3 years are considered “qualified facilities” and may self-certify their SPCC Plan and amendments rather than use a PE.
• Qualified facilities with no individual aboveground oil storage container with a capacity greater than 5,000 gal and no significant oil spill over the past 3 years are considered “Tier 1” qualified facilities and have the option to complete a self-certified SPCC Plan template instead of a full SPCC Plan.

Federal UST rules allow the use of manual tank gauging as the sole leak detection method for USTs 1,000 gal or smaller. Consider using a smaller tank to store products such as used oil to avoid having to employ more costly and complex leak detection methods.

Sections 311 and 312 of the Emergency Planning and Community Right-to-Know Act (EPCRA) require facilities storing hazardous chemicals above certain thresholds to submit safety data sheets (SDSs) or a list of SDS chemicals, as well as an annual inventory of those chemicals to state and local emergency response officials. The storage threshold that triggers reporting for most hazardous chemicals is 10,000 pounds. The threshold is lower for extremely hazardous substances and higher for gasoline and diesel fuel stored in USTs at retail gas stations.

Before adding or replacing tanks at your facility, determine the EPCRA reporting threshold of the chemical or product you plan to store and convert that number to gallons. If facility or process requirements allow, consider using a smaller tank to keep your maximum inventory below the applicable storage threshold. For example, storing heating fuel in a tank with a capacity less than 1,300 gal, provided there is no other heating fuel storage at the site, will enable a facility to avoid EPCRA chemical inventory reporting obligations for that product.

Tip #9: Follow Procedures for Changing the Contents of a UST

A change in the contents of a UST to an unregulated substance (such as water) is considered a change in service. Before implementing a change in service, you must:

• Notify authorities at least 30 days before beginning a change in service.
• Clean the tank, removing all liquid and accumulated sludge.
• Conduct a site assessment as provided in 40 CFR 28.72.
• If contamination is discovered, take corrective action.

If no contamination is discovered, or after corrective action is complete, the tank may be refilled with the unregulated substance.

Tip #10: Double Up on Training

SPCC rules require the training of all oil-handling personnel in spill prevention and response procedures, and the federal Energy Policy Act of 2005 requires states receiving funds under Subtitle I of the Solid Waste Disposal Act to institute training programs for UST operators. If possible, train multiple people at your facility in accordance with the applicable training requirements. This enables you to have backup protection to account for vacations, sick time, and other absences.