What Happens to Waste from LUST Sites?

Ever wonder what becomes of the contaminated soil and groundwater generated during environmental work at a Leaking Underground Storage Tank (LUST) facility? In most cases, it ends up in a permitted landfill—but not without careful evaluation and regulatory oversight.

Under the federal Resource Conservation and Recovery Act (RCRA), hazardous waste is strictly regulated. However, petroleum-contaminated media and debris from Underground Storage Tanks (USTs) are specifically exempt from RCRA regulation. This exemption opens the door to a range of disposal options, depending on contaminant levels, waste volume, transport feasibility, cost considerations, and approval from the Oklahoma Corporation Commission Petroleum Storage Tank Division.

Disposal Options for UST-Exempt Waste 

Landfill Disposal (Non-Hazardous): Permitted municipal or industrial landfills may accept petroleum-contaminated soil if it meets acceptance criteria. Requires analytical testing, documentation of exemption status, and pre-approved waste profiles.

55-gallon drums of groundwater containing petroleum hydrocarbons

are properly disposed of at the Southern Plains Landfill's solidification pit.

Land Treatment Units (LTUs): Soil is treated on-site or at a permitted facility using bioremediation or natural attenuation. Often used for low-level contamination and must comply with Oklahoma-specific standards.

Thermal Desorption or Incineration: For highly contaminated soils, thermal treatment removes hydrocarbons. More costly, but effective for meeting cleanup goals.

Groundwater Treatment and Discharge: Pump-and-treat systems remove dissolved contaminants. Treated water may be discharged under an NPDES permit, reinjected under UIC Class V, or sent to a POTW with pre-treatment.

Beneficial Reuse (Conditional): Soil may be reused as fill or cover if contamination is below risk thresholds. Requires site-specific risk assessment and regulatory approval.

Why Solidification Matters Landfills do not accept liquid waste, so aqueous waste must be solidified before disposal. This is done by mixing the liquid with binding agents such as Portland cement, lime, clay, or gypsum. These materials reduce contaminant mobility and transform the waste into a stable, non-leachable solid.

How Priority Environmental Supports You As your environmental consultant, Priority Environmental manages the entire disposal process. We collect representative samples and coordinate laboratory analysis for benzene, toluene, ethylbenzene, xylenes (BTEX), total petroleum hydrocarbons (TPH), lead, pH, and flash point. Depending on the landfill and contamination level, additional analyses may be required. We prepare and submit the waste profile for landfill approval, and all waste is tracked “cradle to grave” using manifests—from generation to final disposal.

For LUST cases funded by the Oklahoma Indemnity Fund, all lab results and manifests are submitted to the Oklahoma Corporation Commission’s Petroleum Storage Tank Division for regulatory review.