Former Gasoline Dispensing Facility

Elkins, NH

Project Highlights

  • Implemented ground water and soil corrective actions under the NH Petroleum Reimbursement Program
  • Performed sequential soil excavation programs under road, near public lake/beach, and near residential supply wells
  • Utilized fate and transport model to predict soil removal effects on ground water contaminant plume and time to achieve ground water cleanup goals
  • In response to a release of gasoline detected during the closure of gasoline underground storage tanks at a former gas station, initial soil excavation and ground water monitoring were performed to remove highly impacted soils and evaluate the extent of ground water contamination caused by the release. Soil excavation was performed in 2003 and 2004 near a residential private well and under the main road passing by the station requiring monitoring of the private well and sequential excavation to allow continued road access.

    After soil excavation, a fate and transport model was applied to simulate dissolved-phase contaminant migration in ground water to evaluate natural attenuation effects on ground water cleanup duration. Based on the modeling results, the New Hampshire Department of Environmental Services agreed to perform additional soil excavation and ground water dewatering to further remediate soil and ground water near a public lake/beach area. Soil excavation near the lake was performed in the fall of 2006 and resulted in the removal of approximately 300 tons of soil.

    Currently, ground water monitoring is being performed under a Groundwater Management Permit to monitor ground water impacts between the excavation area and the lake, and to make sure private wells are not impacted by the release.

    The corrective actions presented above were performed under the NH Petroleum Reimbursement Fund where corrective actions and monitoring costs have been reimbursed to the property owner. By keeping the NHDES project manager involved and updated on site characteristics, and integrating HNDES ideas into our work plans, we have been successful in maximizing the reimbursement of cleanup and investigation costs incurred by the property owner.