Overview
Water & Air completed environmental site assessments and remedial activities to characterize the horizontal and vertical extent of petroleum impacts in the soil and groundwater beneath the former gasoline station in Alachua County, Florida. The work resulted in development of a soil and groundwater treatment system through a program offers landowners and/or responsible parties the opportunity to assess, remediate, and monitor petroleum impacts from leaking underground storage tanks on their property. The Florida Department of Environmental Protection’s program helps to protect our important water resources, and to ensure safe, potable water supplies.
Task Summary
- Determined groundwater elevation and flow in different water bearing zones beneath the site, and seasonal groundwater table fluctuations.
- Characterized soil lithology beneath the site for groundwater monitoring wells and remediation system design.
- Prepared off-site access permits and traffic control plans for work in the city right-of-way.
- Determined horizontal and vertical extent of petroleum impacts in soil and groundwater.
- Characterized soil impacts above the groundwater table in the unsaturated zone.
- Prepared regulatory reports that document assessment, monitoring, and remediation results.
- Installed a groundwater recovery system with re-injection and soil vapor extraction (SVE) as specified in the approved Remedial Action Plan (RAP).
- Implemented post remediation monitoring and continued until contaminant concentrations rebounded and required additional short-term remedial efforts to reduce the contaminant concentrations and assist in natural attenuation.
- Prepared and implemented a Pilot Test Plan to obtain site specific data from air sparge and vapor extraction pilot tests.
- Prepared a Remedial Action Plan for approval by FDEP.
- Prepared bid specifications and construction drawings for the system installation.
- Installed a horizontal well network to cleanup contaminants under the street, right-of-way and building.
- Constructed an air sparge and vapor extraction remedial system.
- Performed Post Active Remediation monitoring.
Results
Through comprehensive assessment, remediation, and monitoring this site has been cleaned up to a point where only groundwater monitoring is currently required. The presence of manmade features such as overlying structures, pavement, and roadways coupled with extreme drought conditions added to the complexity of the assessment and remediation technologies required to address site impacts. However, Water & Air scientists and engineers were able to develop and implement successful technical strategies to overcome these obstacles.
