Government Facility, Diesel Fuel Tank
Hillis-Carnes was retained by a construction contractor to respond to a release of diesel fuel at a Government Facility project located in Harford County, MD. The release occurred at a newly constructed storage tank area consisting of four double-wall 20,000-gallon diesel fuel aboveground storage tanks (ASTs) located within a concrete spill containment area.
The release occurred when fuel oil was being transferred between two 20,000-gallon ASTs located within the concrete containment area. The Maryland Department of the Environment (MDE) was notified of the release and an Oil Control Program (OCP) case number was assigned by the MDE OCP. It was estimated that approximately 400 gallons of diesel fuel were released from the AST into the concrete containment area and also outside of the containment area due to an inadequate seal on the discharge pipe leading from the containment basin. The diesel fuel that escaped from the concrete containment entered into a storm drain manhole, through approximately 160 feet of 12-inch storm drain pipe, migrated through a culvert under a nearby access road, and was discharged to the surface of a grass-covered area.
Initial response actions were undertaken, including pressure washing the exterior sides of the AST from which the release occurred, the interior of the containment area, and the impacted storm drain piping and manholes. Impacted soils were excavated from the grass-covered area at the storm drain outfall and at the area around the manhole adjacent to the concrete containment basin. Post-excavation confirmatory soil sampling of the excavations was conducted.
Hillis-Carnes also conducted a Risk Assessment of the release using a “Seven Risk Factors” process. The seven factors that required consideration were: a) liquid phase hydrocarbons (LPH); b) current and future use of impacted groundwater; c) potential migration of contamination; d) potential for human exposure above risk-based standards; e) potential for ecological exposure above risk-based standards; f) potential for impact to utilities and other buried services; and g) potential for impacts to other sensitive receptors.