Specialty · Insurance Term
Aboveground Storage Tank (AST)
Definition
An aboveground storage tank (AST) is a tank that sits on or above the ground surface, often used to hold fuel, used oil or chemicals. Leaks and spills from these tanks can cause pollution cleanup costs and lawsuits that standard property and liability policies usually exclude.
In Plain English
Many commercial properties have an AST without thinking of it as a risk: a diesel tank for an emergency generator, a used-oil tank at an auto shop, or a fuel tank at a warehouse yard. Because the tank is visible, leaks are easier to spot than with an underground storage tank. But a spill can still reach soil, storm drains and groundwater.
Most general liability policies carry a broad pollution exclusion, so a fuel spill is usually not covered there. Owners typically look to storage tank liability insurance or pollution legal liability for cleanup costs and third-party claims. Insurers will usually ask the tank's size, age, contents, construction (single- or double-walled) and whether it has secondary containment.
Separate from insurance, federal rules may apply. Under the EPA's oil spill prevention (SPCC) rule, a facility whose total aboveground oil storage is more than 1,320 gallons, counting containers of 55 gallons or more, generally needs a spill prevention plan if a spill could reasonably be expected to reach waterways. Check with an environmental professional about which rules apply to your site.
Not sure how your policy handles this? Have us review it, or get a quote.
Example
Hypothetical: a warehouse keeps a 2,000-gallon diesel tank for its backup generator. A fitting fails over a weekend and fuel runs into a storm drain. The cleanup and a neighbor's claim are typically excluded under the general liability policy, so the owner's tank or pollution policy would be the place to look.
Why It Matters for Texas Property Owners
In Texas, petroleum storage tank programs are administered by the TCEQ. If you own both underground and aboveground tanks (common at gas stations), confirm with TCEQ and your environmental consultant which registration and compliance rules reach each tank.
What to Watch For
- List every tank on the property, including generator day tanks and used-oil tanks, on your insurance application.
- Ask whether your pollution or tank policy covers aboveground tanks, underground tanks, or both.
- Keep records of inspections, containment and any past spills; underwriters will ask for them.
- Confirm whether the SPCC rule applies to your site's total aboveground oil storage.
Sources
Last updated October 14, 2026 · Primesure editorial team · How We Write