Earth Systems is an advocate of using source removal as a primary means of remedial action. When properly implemented, source removal quickly and cost effectively reduces contaminant mass levels. All of the excavations successfully reduced dissolved hydrocarbon levels to below NA Monitoring levels, and most of the source removals resulted in approval of a No Further Action status.
Earth Systems has implemented hundreds of source removal excavations at former petro-chemical terminals, active fuel terminals, bulk fuel pipeline locations, active and closed under-ground storage tank facilities, and hazardous waste sites.
The Dwain’s Grocery site in Cypress, Florida had an unusually deep soil plume (extending to 50 feet below land surface) and feasibility studies indicated source removal was the appropriate cleanup alternative. Earth Systems designed a plan for excavation with Large Diameter Auger (LDA) techniques. The LDA method uses a 5-foot diameter auger to excavate a slightly overlapping series of holes to a target depth. A total of 3,292 tons of contaminated soil were removed by the auger and transported off site for treatment and disposal. The holes produced during the LDA excavation were backfilled with an engineered slurry / flowable fill material to ensure the integrity of the area following the source removal. Calcium Oxyhydroxide was mixed with the flowable fill to accelerate the rate of naturally occurring aerobic bacterial degradation. A chemical oxidizer was also mixed with the fill to destroy contaminants in the soil and groundwater.
At the time of discovery at the AWP site, free product was discharging into an onsite creek from two main seeps. Because of the low permeability of the surficial aquifer and the availability of RP equipment and employees, excavation of interception trenches and recovery of free product from the exposed groundwater was the most feasible IRM alternative to stop the seeps.
The excavation-recovery IRM was expanded as subsequent assessment discovered free product beneath approximately 8 acres of the AWP site.
The IRMs generated large volumes of impacted soil. Earth Systems again expanded IRMs during the assessment phase via large scale pilot studies with the excavated soil. This work was performed in conjunction with the EPA, Mississippi State Forest Products Laboratory, and Wildmere Farms (a research group formed by the RP). The pilot studies included extensive research and development of biotreatment technology for PCP remediation.
Free product recovery IRMs were generating large quantities of pentachlorophenol laced diesel fuel. The process of characterizing, handling, and disposing of the hazardous recovered product as a permitted RCRA facility is slow and costly. To streamline and reduce costs for this waste disposal process, Earth Systems assisted the responsible party with licensing for wood treatment. The recovered product was then legally stored onsite and depleted by treating fence posts, which were sold.