The wood preserving facilities at the 54-acre Camilla Wood Preserving Superfund site were active from 1947 to 1991. Facility operations resulted in soil and groundwater contamination. The remedy for the Site included a barrier wall to contain creosote DNAPL and in situ remediation to treat dissolved phase contamination outside the barrier wall.
Geosyntec’s Scope of Services
Geosyntec provided hydrogeological characterization, treatability testing, remedial design, and remedy implementation for groundwater impacts in the Upper Floridan Aquifer (UFA), well known for its karstic, weathered, and fractured characteristics, and serving as a local to regional potable water source. The purpose of the assessment was to support remedial design to treat pentachlorophenol (PCP) and petroleum hydrocarbons (e.g., naphthalene).
Geosyntec prepared the Deep Bedrock Investigation Work Plan, Tracer/Aquifer Test Work Plan, in situ chemical oxidation (ISCO) and enhanced in situ bioremediation (EISB) Treatability Testing Work Plan, Slurry Wall Mix Design and Compatibility Testing Work Plan, and Remedial Action Plan (RAP). A slurry wall compatibility testing program was designed and implemented to evaluate various mixes and slurry wall performance to contain creosote NAPL in the shallow aquifer. Rotasonic drilling with Iso-Flow sampling and a mobile laboratory were utilized to delineate the vertical extent of naphthalene and PCP impacts to depths of 200 feet into the limestone bedrock. This information was utilized to develop a 3-D conceptual site model (CSM), evaluate the potential for groundwater receptors via public water supply wells, and support remedial alternatives evaluation and design.
Hydraulic testing of the UFA was performed using slug tests and a combined aquifer performance test (APT)/dye tracer test. The slug tests and APT provided estimates of the hydraulic parameters of the UFA and information on the radius of influence at the extraction well. The tracer test, conducted under a forced gradient, provided estimates of travel time, radius of influence, and reliability of capture to support the remedial design.
Geosyntec designed and implemented ISCO (permanganate and persulfate using several activators) and EISB treatability tests for naphthalene and PCP in the fractured rock aquifer. Collectively, the treatability test results and UFA hydraulics testing, further refined the CSM and led to the selection of ISCO using potassium permanganate for the full-scale remedy using permanent injection wells. The 3-D CSM served as a design tool to identify the treatment areas/volume and to select injection well locations and screen intervals. The design included injecting approximately 200,000 gallons of a 4% potassium permanganate solution into the UFA.
Geosyntec provided field oversight during the installation of 39 injection wells, one extraction well, 8 performance monitoring wells, and self-performed the oxidant injection. Baseline groundwater sampling and slug testing of the injection wells was completed and the ISCO injections were implemented.
The Remedial Design was accepted without comment from USEPA and with one minor comment from GA EPD. Geosyntec fast tracked the assessment activities, design, and remedy implementation phases at the Camilla site to achieve EPA’s construction completion deadline.
- Location: Camilla, Georgia
- Client: Black & Veatch/USEPA Region 4
- Project Practice Areas: Water & Wastewater
- Type of Facility: Superfund Site
- Services Provided: Remedial Investigation, Treatability Testing, Remedial Design, Remedial Action, Performance Monitoring
- Type of Work: Remedial Design and Implementation
- Governing Regulation: State and local