Condominium Heating UST Leakage
Pollard Environmental investigated a petroleum release from an approximately6,000-gallon underground heating oil tank at a condominium property in central Virginia. Ourinitial underground oil tank inspectionincluded three soil borings around the tank. Laboratory analysis identified #2 heating oil contamination at 6,500 mg/kg TPH-DRO in soil approximately 12.5 to 13.5 feet below grade. The release was reported to the Virginia Department of Environmental Quality, which required Category 3 corrective action. We later removed the bare-steel tank under a local permit and inspection; the tank exhibited moderate to heavy corrosion with several visible holes.
Our team removed the remaining petroleum from the tank, removed it and then excavated approximately 87.52 tons of petroleum-contaminated soil from beneath the former UST, extending the excavation to approximately 18.5 feet below grade. Soil staining was observed from about13 to 17 feet, and confirmation sampling showed that petroleum-saturated soil remained at the north end of the excavation at 18.5feet.
Groundwater and free petroleum product were not observed during excavation, but the depth to groundwater remained unknown, so the possibility of petroleum impact to the groundwater could not be excluded. The property used municipal water; no active drinking-water wells or surface-water bodies were identified within at least 500 feet, and the assessment characterized the immediate human-health and surface-water risks as low. We backfilled the excavation with crushed stone, installed a new underground tank, graded the disturbed area, and repaved the parking lot.
