Stephen Sherman, P.G.

Groundwater and Soil Investigations for PFAS at Multiple Fire Facilities, San Francisco Bay Area, California — Managed and led the initial assessments at fire stations and fire training facilities while working closely with regulators and stakeholders to develop and implement sampling plans to investigate potential historical usage of aqueous film-forming foam. The site investigations consisted of collecting and analyzing various subsurface soil, groundwater, drain sediment, stormwater, simulated runoff, and chip samples. Performed a comprehensive review of the sample results using comparisons to potential screening criteria and per- and polyfluoroalkyl substances (PFAS) interpretation tools such as reviewing diagnostic ratios, relative abundance, transformation of precursors, and contributions from ambient background and comingled sources. Assisted stakeholders in the design and costing of stormwater mitigation and subsurface remediation scenarios.

Sub-Slab Investigation at Former Dry Cleaner, Santa Rosa, California — Led the collection and reporting for indoor air and sub-slab sampling inside a restaurant developed on the site of a former dry-cleaning facility.

Soil and Soil Vapor Investigations at Former Fillmore and North Beach Manufactured Gas Plants, San Francisco, California — Acted as the field team lead and project geologist for soil and soil vapor intrusion investigations at residential properties in San Francisco’s Marina District. The properties were in the footprint of historical manufactured gas plant operations, and primary chemicals of concern were volatile organic compounds, PAHs, and metals. The investigations typically involved installing soil vapor wells beneath, or adjacent to, the concrete slab foundations for the evaluation of air quality and assessment of potential exposure pathways.

Soil Vapor Investigation at Former Orchard, Mountain View, California — Led the soil and air sampling effort for a residential development site potentially impacted by pesticides. Oversaw the advancement of shallow soil borings and installed and sampled soil vapor wells.

Groundwater and Sub-Slab Vapor Investigations at a Former Industrial Plating Facility, San Carlos, California — Managed and led vapor intrusion and groundwater investigations at a former industrial plating facility with dissolved-phase chlorinated solvent and metals impacts to groundwater. Acted as main resource for stakeholders in navigating local regulatory requirements during commercial redevelopment of the property. Planned and implemented indoor and sub-slab air sampling events; cone penetrometer (CPT), membrane interface probe, and hydraulic profiling tool (MiHPT) advancement; and temporary and permanent monitoring well installation and sampling.

Soil, Groundwater, and Soil Gas Investigation at Former Gas Station and Paint Factory, Brunswick, Georgia — Led the field investigation for a Phase II ESA that included more than 100 surface and subsurface soil samples, roto-sonic soil borings, grab groundwater samples, and 70 passive soil gas samplers. The primary chemicals of concern for the site were benzene, PAHs, PCBs, and metals.

Soil and Groundwater Investigation at Former Allied Engineering Facility, Alameda, California — Oversaw the installation and sampling of groundwater monitoring wells and hydropunch locations to further delineate the vertical and horizontal extent of chlorinated solvent dissolved-phase plumes at a former metal working facility.

Soil Investigation at Former Aggregate Processing Facility, Pleasanton, California — Led the direct-push soil sampling effort involving more than 50 soil borings as part of a Phase II ESA in the footprint of processing buildings and machinery at a former aggregate facility.

DNAPL Subsurface Delineation at Potrero Power Plant, San Francisco, California — Performed extensive subsurface delineation of dense nonaqueous-phase liquid (DNAPL) at a diesel and natural gas power plant built over a historical manufactured gas plant site. Oversaw the advancement of more than 60 soil borings using roto-sonic drilling through sandy artificial fill and landfill debris overlaying lean Bay Mud clay. Soil samples were collected for chemical and geotechnical properties, including composited soils in the DNAPL saturation zone for reagent batch testing as part of a predesign soil stabilization study.

Soil Investigations at San Francisco Refinery, Rodeo, California — Performed an impacted soil and waste delineation study using direct-push sampling in a multiacre, artificially filled valley overlying sandstone bedrock. Used an x-ray fluorescence tool to identify heavy metals in the soil along with traditional environmental field screening methods and observations to map waste layers and create comprehensive cross sections of the valley.

Mud Logging for Natural Gas Production Wells at Multiple Central Valley Drilling Locations, California — Created boring log reports using data from sample cuttings, gas monitoring, and depth projection techniques during mud rotary drilling for exploratory gas production wells drilled to depths ranging from 3,000 to 6,000 ft at various locations within California’s Central Valley.

Aquifer Testing at Chlorinated Solvent Cleanup Site, Macon, Missouri — Performed aquifer testing on groundwater wells using submersible pumps to acquire site-specific hydraulic conductivity and transmissivity for groundwater transport modeling.

Remediation Design and Implementation at Chlorinated Solvent Cleanup Site, Felton, California — Designed and oversaw the construction of injection wells for in situ remediation at a former dry-cleaning facility that combined enhanced reductive dechlorination, zerovalent iron chemical reduction, and colloidal activated carbon to address a dissolved-phase chlorinated solvent plume. Worked closely with a local consultant team to implement pilot testing and mass flux measurements to advise on the full-scale injection design.

Investigation and Remediation at a Chlorinated Solvent Cleanup Site, South San Francisco, California — Managed and led the field effort for the predesign investigation and in situ remediation at a former industrial dry-cleaning site containing a dissolved-phase chlorinated solvent plume underlying multiple properties. The predesign investigation results filled vapor intrusion and hydrogeologic data gaps in the existing conceptual site model sufficient for design of an enhanced reductive dechlorination injection remedy. Managed site field activities, including soil vapor sampling, CPT and MiHPT advancement, temporary and permanent monitoring well installation and sampling, passive flux meter deployment, and remedial injection program implementation.

Soil, Groundwater, and LNAPL Investigations and Remediation for Multiple Release Sites at Golden Eagle Refinery, Martinez, California — Acted as the field lead and project geologist for soil and groundwater investigations at refinery pipeline release sites. Managed groundwater monitoring and sampling programs, performed remediation system tracking, and reported performance. Evaluated the effectiveness of remedial systems, made recommendations for augmentation or decommissioning based on assessment of light nonaqueous-phase liquid (LNAPL) mobility using decline curve analysis, and calculated LNAPL transmissivity values from pump data and testing.

Injection of Calcium Polysulfide at Former Wood Treatment Facility, Windsor, California — Performed groundwater sampling and oversaw the injection of calcium polysulfide to address hexavalent chromium contamination in the footprint of a former wood treatment facility.

Remediation Design and Implementation at Chlorinated Solvent Cleanup Site, Felton, California — Designed and oversaw the construction of injection wells for in situ remediation at a former dry-cleaning facility that combined enhanced reductive dechlorination, zerovalent iron chemical reduction, and colloidal activated carbon to address a dissolved-phase chlorinated solvent plume. Worked closely with a local consultant team to implement pilot testing and mass flux measurements to advise on the full-scale injection design.

Phase I and Phase II ESAs at Multiple Car Rental Locations in California, Illinois, New York, and Indiana — Performed multiple Phase I ESAs following ASTM International (ASTM) Standard E1527-13 and performed follow-up Phase II soil, soil vapor, and groundwater investigations to further assess identified recognized environmental conditions (RECs) at active and inactive car rental and maintenance facilities in California, Illinois, New York, and Indiana.

Phase I and Phase II ESAs at Rural Ranch-Style Property in Sonoma, California — Performed Phase I ESAs following ASTM Standard E1527-13, supplemented by Standard E2247-08, for two adjacent rural properties with a combined area of 360 acres. Oversaw a follow-up Phase II ESA to further assess RECs identified during the Phase I ESA, which included digging test pits to delineate the lateral and vertical extent of a historical burn pit.

Soil Investigation and Remediation at a Former Veneer Plant Maintenance Facility, Weed, California — Performed site investigation and excavation oversight activities in the footprint of a demolished maintenance facility. The investigation activities included the identification of historical features, soil sampling, the creation of test pits, and field screening using x-ray fluorescence and hydrocarbon testing tools. Remediation involved the removal of more than 2,100 yd³ of primarily metals-contaminated soil and the collection of confirmation soil samples.

Construction Management for Soil Remediation at a Former Metal Salvage Facility, North Kona, Hawaii — Assisted with construction management for a 7-acre soil remediation project involving the removal of more than 22,000 yd³ of lead-impacted soil.

Construction Management for In Situ Soil Stabilization at Golden Eagle Refinery, Martinez, California — Assisted in construction management for a soil stabilization and capping project at a 6-acre historical waste management unit that was an acid-sludge landfill. The yearlong project involved clearing the waste management unit of obstacles using excavators and injecting and mixing cement grout into the soil using a 10-ft-diameter hollow auger. The auger was advanced in overlapping columns to approximately 15 ft and into the underlying bay mud. Duties involved assisting project designers to communicate with the environmental contractor and track the contractor’s daily progress in the field.

Construction Oversight for Water Supply Production Well, Eureka, California — Oversaw construction of a new 475-ft-deep water supply production well and the demolition of retired production wells.

Stormwater Pollution Prevention Plan Inspection and Implementation at Santa Susana Field Laboratory, Simi Valley, California — Performed field inspections for best management practices and made recommendations based on existing requirements in the stormwater pollution prevention plan developed for the 2,668-acre former rocket and nuclear reactor testing facility. Performed surface water runoff sampling, rain gauge maintenance and data collection, and surveying and mapping tasks.