Mr. Walker is a hydrogeologist, registered Professional Engineer (PE), and registered Professional Geologist (PG) with GSI Environmental Inc. He received a MS degree in Civil and Environmental Engineering, Environmental Fluid Mechanics and Hydrology, from Stanford University, and a BS degree in Geology from Washington and Lee University. He has over twelve years of professional experience in the environmental field, which includes site investigation and risk assessment at federal, state, and commercial/industrial properties. He has provided litigation support on a variety of environmental matters involving sites located in Ecuador, Puerto Rico, California, Colorado, New Hampshire, Georgia, Florida, Louisiana, Texas, and several other states. Mr. Walker has experience with numerous chemical classes, including chlorinated solvents, hydrocarbons, and per- and polyfluoroalkyl substances (PFAS).

Mr. Walker has performed environmental site assessments and provided remediation support at various facilities across the United States under the applicable state and federal regulatory programs. He has provided engineering support for a former landfill Superfund Site containing multiple contaminants in soil, solid waste, soil gas, and groundwater. His activities have included data and statistical analyses, technology screening, green and sustainable remediation footprint analysis, and development and comparison of remedial alternatives. Mr. Walker was a key developer of the Thermal NSZD Dashboard and has designed and implemented thermal monitoring hardware for natural source zone depletion (NSZD) at LNAPL sites. He has worked closely with the BCarbon soil carbon crediting program and was a key contributor to the Protocol for Measurement, Monitoring, and Quantification of The Accrual of Below-Ground Carbon Over Time. In addition, Mr. Walker has conducted numerous water resource evaluations, with a focus on both water availability and quality, and he has contributed to Class VI Underground Injection Control (UIC) permits to support Carbon Capture and Storage (CCUS) projects along the Texas Gulf Coast.