Senior Scientists

Mr. Tymchak specializes in evaluating the source, transport, and fate of a broad range of chemicals through soils, groundwater, and deep geologic formations.  He has consulted on a variety of sites, including CERCLA, Superfund, NY State Class II hazardous waste, and Brownfields sites, as well as industrial facilities, former manufactured gas plants and commercial service stations.  Mr. Tymchak has evaluated deep geologic reservoirs for the storage of carbon dioxide and migration of hydraulic fracturing additives and flowback chemicals.  He has dealt with a wide range of contaminants at other sites, including chlorinated solvents, DNAPL and LNAPL, VOCs, pesticides, PCBs, petroleum hydrocarbons, and metals. 

Hydraulic Fracturing Risk Evaluation: Evaluated a US EPA study of potential hydraulic fracturing (HF) impacts to potable aquifers in Pavillion, WY. Analysis included the assessment of potential migration of HF additives in groundwater, well construction and sampling methods, and inorganic geochemistry of groundwater.

Hydraulic Fracturing Risk Evaluation: Conducted research to derive the limit for fracture propagation during HF of deep shale formations to enhance natural gas recovery. Research included a literature review and a data analysis to provide a practical tool to describe fracture containment.

Geologic Carbon Sequestration: Evaluated the geology of the Triassic Newark Basin (NJ, NY, PA) to determine the potential for long-term geologic storage of carbon dioxide. Evaluation included literature reviews, two-dimensional surface seismic data collection and analysis, supervision of a 6,800-ft exploratory stratigraphic well, as well as rock core and geophysical log analysis.

Herbicide Fate and Transport:  Developed conceptual framework to evaluate herbicide movement through groundwater in settings throughout the contiguous US. Research included literature review, large-scale chemical data assimilation from multiple sources, and groundwater travel time analyses.

Site Characterization and Remediation: As project manager, conducted field sampling efforts to delineate two separate contaminant plumes (petroleum hydrocarbons and DNAPLs) in soil and groundwater. Negotiated a remedial strategy with regulatory agencies. Implemented in situ chemical oxidation to reduce contaminant levels in groundwater. Conducted post-remedial groundwater monitoring.

Site Characterization and Remediation: Delineated soil and groundwater contaminated with heavy metals at NY Class II hazardous waste site. Supervised remedial measures at the site, negotiated site closure and deed restriction with a regulatory agency, and conducted post-remedial groundwater monitoring.