In-Situ Bioremediation-Sages Dry Cleaners
Earth Systems is directing cleanup of the Sages Dry Cleaners site under a contract with the Florida Department of Environmental Protection’s Bureau of Waste Cleanup. The site has residual PCE DNAPL and associated dissolved CEs in three zones. Earth Systems recommended and is implementing In-Situ Bioremediation (ISB) that consisted of injecting a slow-release electron donor substrate. The ISB optimizes natural attenuation to control costs better than other more aggressive treatment technologies and is less disruptive to current site use. ISB increases the rate of DNAPL dissolution while controlling plume migration via reductive dechlorination. ISB is appropriate for this site because of the residual source, relatively homogenous and permeable lithology, and sufficient buffer zone to insure no impact to potential receptors. In addition, ISB has worked at most sites in Florida.
AS / SVE – Former Kerr-McGee Pipeline
A buried pipeline transferred fuel from ships at the Jacksonville Port Authority (JPA) dock, under the JPA shipping container storage yard, and to the landlocked Kerr-McGee bulk storage terminal. Earth Systems completed assessment of a leak from the pipeline, a source removal to remove free product and the associated pipeline, and design and installation of an AS / SVE system.
Earth Systems smoothly coordinated the assessment and system installation work under highly sensitive JPA security procedures and rigorous construction standards specific to the container storage area. The pipeline discharge site was granted a No Further Action status and the AS / SVE system was re-used at another site.
Bioremediation – Hogan & Associates
Hogan & Associates received a Notice of Violation (NOV) for improper storage of haz-ardous substances. Earth Systems subsequently detected, assessed, and remediated soil and groundwater contaminated with low levels (a high of 82 µg/L) of dissolved Trichloroethene (TCE). Dissolved TCE degradation products cis-1,2-Dichloroethene (cis 1,2-DCE) and Trans 1,2-DCE were detected at concentrations below DEP Maximum Contaminant Levels (MCLs).
The depth to water was approximately 4 feet below land surface (ft bls). The surficial aquifer beneath the site consists of fine sands with varying amounts of shell material to approximately 30 ft bls. Sandy clays are present from approximately 30 ft to approximately 50 ft bls, where hard clay was encountered.
Earth Systems efficiently used direct push technology and a mobile laboratory to evaluate the hydrogeology and define the soil and groundwater impacts underlying an area of approximately 3,500 sq. ft. Low levels of contamination were detected in vadose zone soil and in groundwater extending to approximately 25 feet bls.
Approximately 60 tons of impacted soil were excavated and disposed offsite. The presence of degradation products indicated ongoing microbial remediation. The site conditions were conducive to effective injection of bio-enhancing reagents to accelerate the ongoing microbial activity. The reagents were injected with direct-push technology with tight spacing (15 ft centers) to ensure good reagent distribution. Three injection events were spaced two months apart.
Following 5 quarters of post remedial monitoring, a Site Rehabilitation Completion Order was issued for the site.