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Senior Scientists

Education
M.S., Geology (Hydrology), University of South Carolina
B.S., Geology, James Madison University
Expertise
- Remedial Investigation & Design
- Hydraulic Fracturing
- NAPL
- Contaminant Fate and Transport
- Environmental Cost Analysis
- Groundwater-Surface Water Hydrology
Matthew P. Tymchak, M.S.
Senior Hydrologist
Mr. Tymchak is a Hydrologist at Gradient who specializes in analyzing the source, transport, and fate of a broad range of chemicals through soil, groundwater, and bedrock. As a consultant for the past 10 years, he has managed investigations at a variety of sites including upstream oil and gas development, refineries, solid waste landfills and one of the nation’s largest groundwater National Priorities List sites. Mr. Tymchak's water resources background includes evaluating impacts of agricultural pumping on aquifer storage and streamflow, and conducting data analysis and modeling studies of rainfall runoff dynamics in a variety of watersheds. He has applied his expertise in water resources to solve complex challenges in a large-scale water-allocation cases and in a national-scale case involving contaminate transport to water suppliers throughout the country.
Education
M.S., Geology (Hydrology), University of South Carolina
B.S., Geology, James Madison University
Expertise
- Remedial Investigation & Design
- Hydraulic Fracturing
- NAPL
- Contaminant Fate and Transport
- Environmental Cost Analysis
- Groundwater-Surface Water Hydrology
Services
Representative Projects
Water Rights Dispute: Provided technical evaluation for an equitable water allocation request before the U.S. Supreme Court (Original Action 142). Evaluations included assessments of watershed hydrology, groundwater flow and human water use.
Hydraulic Fracturing Risk Evaluation: Provided a review of potential risks to water resources related to hydraulic fracturing in the Marcellus Shale in Pennsylvania. Analyses included potential land use impacts and risks related to fluids migrating upward from the hydraulically fractured formation.
Stray Gas Migration Investigation: Evaluated whether methane migrated upward from the Marcellus Shale to shallow water supply wells in Pennsylvania. Analyses included methane, gas isotope, and groundwater geochemistry data, in addition to an evaluation of hydraulic fracture growth in the vicinity of shale gas wells.
Remedy Evaluation and Cost Analysis: Performed remedy alternative analysis for addressing TENORM waste in a landfill. Developed remedial action objectives for the impacted media and analyzed costs for each remediation alternative. Resulted in the acceptance of a Corrective Action Plan by the state agency.
NCP Consistency Evaluation: Evaluated the NCP consistency of response actions and their costs undertaken by a municipal water purveyor at one of the nation's largest groundwater NPL sites.
Product Release at a Refinery: Evaluation at a refinery to determine the timing, storage and transport of a product release. The analysis included forensic chemical data, potential groundwater and contaminant transport pathways, and a review of historical site information to understand the nature and extent of contaminants.
Former Petroleum Storage Facility: Analyzed potential pathways for pollutant transport from a petroleum storage facility to nearby surface water body. Estimated chemical travel times and evaluated other sources of contamination to quantify the proportion of contaminants attributable to the facility.
Selected Publications
Tymchak, M; Stahl, M. 2017. "The secret life of rain." Gradient Trends - Risk Science & Application 69 : 3,5.
Fitzsimmons, M; Flewelling, SA; Tymchak, MP. 2014. "Will earthquakes shake up the shale wastewater debate?" Law360
Flewelling, SA; Tymchak, MP; Warpinski, NW. 2013. "Hydraulic fracture height limits and fault interactions in tight oil and gas formations." Geophysical Res. Lett. 40 : 3602-3606.
Tymchak, MP; Flewelling, SA. 2013. "Evaluating the Gutenberg-Richter Relationship for Induced Seismicity." American Geophysical Union 46th Annual Fall Meeting, San Francisco, CA
Tymchak, MP; Collins, D; Slater, B; Brown, C; Conrad, JA; Papadeas, P; Goldberg, D; Olsen, PE. 2012. "Evaluation of the Newark Basin for Carbon Sequestration: Data Acquisition and Preliminary Results." Presented at the US DOE NETL Carbon Storage R & D Project Review Meeting, Pittsburgh, PA, August 21-23
Tymchak, MP. 2007. "Effects of variable rainfall intensity on the unsaturated zone response of a forested sandy hillslope." Water Resour. Res. 43 : W06431.