UST Interim Response Action – Gas Station – Marysville, Ohio
STONE completed a Tier I and II Evaluation for an active gas station. Following the Tier II Evaluation, an Interim Response Action (IRA) was proposed by STONE in the attempt to excavate and remove the known areas of petroleum contaminated soil (PCS) based on boring logs. STONE focused four cavities for the IRA excavation on areas with soil concentrations above Ohio Bureau of UST Regulations (BUSTR) Action Levels (ALs). To account for groundwater infiltration into the cavities or excess rain water, and to reduce costs for the client, STONE set up an activated carbon filtration system on-site to pump and filter the water before discharging to a nearby storm sewer. During the excavation in one cavity, two 15,000-gallon abandoned USTs were encountered. All accessible PCS and petroleum contaminated water (PCW) surrounding the USTs were removed and properly disposed. The excavation continued until soil sample results (analyzed using an on-site mobile laboratory, also used as a cost savings to the client and to expedite the contractor activities) were below BUSTR Action Levels.