Florida Department of Environmental Protection
Water & Air Research, Inc. (Water & Air) provided petroleum remediation services for this former gas station and convenience store under the Florida Department of Environmental Protection’s (FDEP) Petroleum Remediation Program.
Water & Air began the initial soil and groundwater assessment for this facility as a newly assigned site in June 2020. Once the assessment was completed and both the soil and groundwater plumes delineated, an air sparge (AS) and soil vapor extraction (SVE) Pilot Test was performed. The final results of the Pilot Test indicated that AS/SVE would work well at the site. During Remedial Action Plan (RAP) preparation, it was determined that three AS wells were necessary to cover the groundwater plume, and flows of 3 scfm per well, with corresponding pressures of 11 psi were needed. Because most of the treatment zone is grass covered and unpaved, a total of eight SVE wells were required to provide sufficient cover to extract the anticipated vapors, as well as ensure no vapor intrusion into the adjacent building. The SVE system was designed to operate at 7 inches Hg and a flow of 45 scfm per well. The RAP was approved without comment in February 2022.
Negotiations between Water & Air, FL Department of Transportation and the Tampa Bay Rays began, since a large portion of the dissolved plume was located on the adjacent FDOT property, which is utilized by the Rays for parking for the nearby Tropicana Field. Following approval of offsite access agreements and space lease agreements, Water & Air began remedial action construction and implementation. Remediation wells were installed in October 2023. However, delays related to the power drop pushed back the startup of the remediation system until September 2025.
The first quarter of system operation was completed in December 2025 and showed an average contamination concentration decrease of 77% across the dissolved plume. The second and third quarters continued to show a significant downward trend in petroleum concentrations, a substantial decrease in plume area and all monitoring well concentrations dropping below Natural Attenuation Default Concentrations (NADCs) for the first time.
The end of the first year of AS/SVE system operation was completed in September 2026, and the annual sampling results showed a tremendous decrease when compared to the pre-startup baseline results. The overall area of the plume had decreased from 1,283 square feet to just 170 square feet. The cleanup at this site is well ahead of schedule and shows successful AS/SVE operation.