The Phillipsburg, NJ Case Study presents the successful application of Gas Thermal Remediation (GTRTM) to remediate Tetrachloroethylene (PCE) and Trichloroethylene (TCE). The site was located in Phillipsburg, NJ, where Thermal Conduction Heating (TCH) was employed to generate subsurface heat for effective remediation. The target treatment zone covered an area of 5,000 square feet, with heating extending from the surface down to an average depth of 41 feet below ground surface (bgs). The site’s lithology was characterized by sandy clay loam, heavy loam, clay loam, and silt loam, with dolomite bedrock encountered at varying depths ranging from 7 to 40 ft bgs. Groundwater was present at 50 ft bgs, though the groundwater itself was not the primary focus of the remedial effort(Phillipsburg, NJ).
Remediation Technology and Approach:
Heater Wells: A total of 44 heater wells were used to heat the treatment area, which was set to reach a target temperature of 100°C. The heating period spanned 102 days.
Soil Vapor Extraction (SVE) Wells: To enhance vapor extraction, 12 deep Dual-Nested SVE wells (d-SVE) were operated to manage pneumatic control across the vadose zone. Additionally, 5 shallow SVE wells (s-SVE) were installed to further manage the uppermost heated zones and prevent accumulation of vapor-phase contaminants beneath the surface cover.
Treatment of Extracted Contaminants: The vapors extracted during the remediation were treated using C3 Technology along with a Granular Activated Carbon (GAC) system, ensuring compliance with air quality permits. Condensed water and other extracted liquids were fully treated using the GAC system to remove any residual contaminants(Phillipsburg, NJ).
Geological Overview: The site geology consisted primarily of sandy clay loam to heavy loam, transitioning into clay loam and silt loam. Various fill materials were also observed throughout the treatment area from surface to 40 ft bgs, with dolomite bedrock encountered at different depths.
Remediation Results:
The thermal remediation achieved a 98% mass removal rate of all identified VOCs, far exceeding the original remedial goal of 75% removal. This outcome demonstrates the significant success of the thermal remediation approach in reducing PCE and TCE contamination at the site.
The completion report confirmed that the In-Situ Thermal Remediation (ISTR) application was effective in removing substantial VOC mass from the treated soil, thereby achieving the project's environmental objectives(Phillipsburg, NJ).
System and Energy Efficiency:
The dual-layer vapor extraction approach, utilizing both deep and shallow SVE wells, was essential for ensuring comprehensive vapor recovery and minimizing any reaccumulation of contaminants.
The extracted vapors were effectively managed by integrating C3 Technology with GAC systems, which not only ensured regulatory compliance but also maximized the treatment efficiency of VOCs.
Summary: The Phillipsburg project successfully utilized Gas Thermal Remediation combined with Thermal Conduction Heating and dual-nested SVE systems to remediate PCE and TCE contamination. The heating phase lasted for 102 days, leading to a 98% reduction in contaminant mass across the site. The use of advanced vapor control and treatment techniques, such as C3 Technology and GAC systems, contributed to the effective cleanup of the site, meeting and exceeding the initial remedial goals. This project highlights the adaptability and effectiveness of thermal remediation technologies in treating complex subsurface VOC contamination in diverse geological settings.
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