Client Profile
Inactive Industrial Property
Project Profile
A multi-acre, inactive historical industrial property was known to have soil and groundwater impacted with volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), metals, and polychlorinated biphenyls (PCBs), based on previous environmental investigations. Letterle performed an environmental investigation to assess the full extent of soil and groundwater quality impact. The results of the environmental investigation were used to prepare a current conceptual site model (CSM) to assess if additional investigation and response actions at the site were needed and to assess possible needs for approaching site closure. Based on multiple site conditions including the future site use and a SSS closure strategy, no active remedial technologies were necessary.
Letterle also aided the client by characterizing and delineating an area of suspected clean fill at the site to determine if soil from the was suitable for future on-site use as temporary and/or permanent clean fill material.
Project Summary
The remedial investigation assessed surface and subsurface soil via soil borings and test pits, groundwater, subsurface light non-aqueous phase liquid, and soil vapor. The source(s) were characterized and the specific constituents of concern (VOCs, SVOCs, metals, and PCBs) were identified and their distribution within soils and groundwater was delineated. An assessment for sensitive receptors was completed to include surface water bodies, water usage, ecological receptors, and potential vapor intrusion. Considering the sensitive receptors, a CSM was completed inclusive of a fate and transport analysis related to surface water impact, exposure pathway analysis for surface soil, subsurface soil, and groundwater, and a risk evaluation (including a quantitative Focused Risk Evaluation to evaluate the current exposure pathways). Surface water quality criteria for any analyzed constituent and the contaminated groundwater plume will not have unacceptable limits on surface water quality. With an updated EC, which rendered the remaining pathways incomplete, SSS via pathway elimination (combination of engineering and institutional controls) was demonstrated.
The fill determination activities included a subsurface investigation (excavation, soil sampling/compositing, field screening of soil samples via x-ray fluorescence technology, laboratory analysis of soil samples, and backfilling), classification of materials, and analytical result assessment.
Project Results
A Relief of Liability for multiple property owners via a PADEP-approved Final Report was achieved utilizing a SSS and a comprehensive EC to restrict groundwater use, a soil handling plan requirement, and the stipulation for the use of engineering controls to eliminate potential future exposures upon the possible future development of the property.
The fill determination resulted in a significant quantity of available native soil for potential future on-site use as clean fill.
