Underground storage tanks and the soil under your feet
Source: ArcGIS Online UST Finder · EPA
737,077 registered tanks across the country. Here's the playbook.
What it is
The federal record
Underground storage tanks are the most common source of soil contamination near American homes and gardens. The EPA's UST Finder database tracks 737,077 registered tanks — most are gas stations, fuel depots, and commercial fuel storage. When tanks corrode, they release petroleum hydrocarbons, including benzene, toluene, ethylbenzene, and xylenes (collectively BTEX). Lawrence Livermore plume studies show these subsurface plumes typically self-limit at around 800 ft from the source. Within that radius, native-soil contamination is the primary concern. Beyond it, risk drops sharply, but groundwater in the path of an active leak still warrants testing.
Key facts
At a glance
Registered tanks
737,077
EPA UST Finder
Plume self-limit
~800 ft
LLNL studies
Analysis radius
0.6 mi
Growable Ground
Why it isn't a verdict
The constructive read
UST proximity is one of the most actionable contamination signals you can get. Raised beds with clean imported soil eliminate the root-contact pathway entirely, and BTEX compounds have low translocation to above-ground fruit — meaning tomatoes, peppers, and tree fruits accumulate very little even when nearby soil is affected. Tank status matters, too: closed and remediated tanks pose substantially lower risk than active leaking ones. The data carries enough resolution to make decisions, not just to worry.
What to do
The playbook
Look up the tank's status first — many in the EPA registry are closed or remediated. If your land sits within 800 ft of a known leaking UST, switch root crops and leafy greens to raised beds with imported soil. If you irrigate from a private well, test for BTEX and MTBE — treated municipal water is safe. For most parcels with an inactive UST nearby, the path forward is straightforward: fruiting crops and tree fruits in native soil, leafy greens and root crops in raised beds. The pathway is well-studied, and the mitigations work.
Mitigation steps
Concrete moves, in order
- 1Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
- 2Check tank status: closed and remediated tanks pose significantly lower risk than active leaking tanks.
- 3If using a private well for irrigation, test for BTEX compounds and MTBE.
- 4Avoid planting root crops in native soil within 800 ft of a known leaking UST.
- 5Municipal water is safe for irrigation — petroleum contamination does not affect treated water supplies.
Frequently asked questions
What's the difference between an active and closed UST?
Closed tanks have been removed from service and often remediated; active tanks are still in operation. The EPA registry tracks status. Closed-and-remediated tanks pose substantially lower risk than tanks with documented releases or active operation.
Can I grow vegetables near a former gas station?
Yes — with adjustments. Raised beds with imported clean soil sever the soil-contact pathway. Fruiting crops and tree fruits accumulate very little BTEX even from contaminated native soil. The combination of bed type and crop family is the lever, not the proximity alone.
How does UST contamination reach groundwater?
Petroleum from a leaking tank migrates downward through soil, then laterally along the water table. Plumes self-limit around 800 ft. If you draw irrigation from a private well within that distance of an active leak, testing for BTEX is the right call.
See what's near your land
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