Thank you to our 2026 Speakers

Isabel Plower is a Human Health and Ecological Risk Assessor with the Georgia Environmental Protection Division Risk Assessment Program. In this role, she quantifies and analyzes risks at a variety of Resource Conservation and Recovery Act, Brownfields, Voluntary Remediation Program, and Hazardous Site Response Act properties. She also helps derive risk reduction standards, review risk assessments for compliance with state and federal regulations, and draft guidance documents, like the 2026 Georgia Risk Assessment Guidance. 

Isabel has been a Risk Assessor with the Georgia Environmental Protection Division since June of 2024. Prior to joining the Risk Assessment Program, Isabel attended Columbia University and received a B.A. in Earth and Environmental Science.  

Outside of work, Isabel enjoys volunteering at th Tellus Science Museum’s fossil dig, playing trivia games with her friends and family, and embroidering.

Jennifer Stackhouse is an Associate Toxicologist with the Human and Ecological Risk Office (HERO) at the California Department of Toxic Substances Control (DTSC) and a doctoral candidate at the University of Idaho.  She has over 20 years of experience in applied toxicology, human health and ecological risk assessments, and the application of risk-based approaches for environmental investigation and remediation. Her work spans a wide range of regulatory programs and site types including RCRA Corrective Action sites, active military bases, Superfund sites, and voluntary cleanup programs.

Ms. Stackhouse’s areas of expertise include contaminant fate and transport, soil vapor intrusion, and risk-based communication strategies, soil vapor intrusion evaluations for both occupied and unoccupied structures, as well as the sampling and risk evaluation of soil, groundwater, and surface water, indoor air, and outdoor air. She also has significant experience in environmental data management and laboratory coordination.

She joined DTSC in November 2023 following her role as a Senior Environmental Toxicologist at Kleinfelder. In addition to her work as a toxicologist in HERO, she is an active member of both the CalEPA and DTSC Vapor Intrusion Workgroups. She holds a Master of Science in Environmental Science with a focus in environmental toxicology from the University of Idaho.  Ms. Stackhouse is also pursuing her doctorate at the University of Idaho where her doctoral research focuses on mercury soil vapor and impacts affecting vulnerable communities.

Matthew Williams is a volatilization to indoor air specialist specializing on mitigation strategies and vapor intrusion, serving as the Volatilization to Indoor Air Specialist at the Michigan Department of Environment, Great Lakes, and Energy Remediation and Redevelopment Division (EGLE-RRD). In this role, he spearheads the development and implementation of methodologies to investigate and assess the vapor intrusion pathway, ensuring the safety and well-being of indoor environments.

As a program specialist and technical lead for the Vapor Intrusion Technical Assistance and Support Team, Matt has led numerous stakeholder groups and authored pivotal guidance documents, papers, and standard operating procedures. His expertise extends to conducting extensive trainings and delivering talks on sampling methods, vapor intrusion, petroleum vapor intrusion, mitigation, and indoor air quality both nationally and internationally.

Noteworthy among his contributions is Matt's leadership role in the Interstate Technology & Regulatory Council (ITRC), where he served as a section leader for the Petroleum Vapor Intrusion: Fundamentals of Screening, Investigation, and Management training in 2014. He also co-led both classroom and internet-based training teams and served as a co-leader for ITRC’s Vapor Intrusion Mitigation Team. Currently, Matt plays a crucial role as a co-leader for ITRC’s ongoing update for vapor intrusion, overseeing a collaborative effort involving nearly 200 professionals across the United States.

Matt holds a Bachelor of Science degree in Geology from Central Michigan University, earned in 1993, laying the foundation for his distinguished career in environmental science and indoor air quality management.

Nicole is a Research Scientist for the NJDEP’s Bureau of Environmental Evaluation and Risk Assessment in the Site Remediation Program. She is responsible for providing  technical support for all aspects of site remediation, particularly vapor intrusion and soil contamination, and handles the technical regulatory oversight of several high-profile contaminated sites in New Jersey. Nicole is the NJDEP contact for vapor intrusion  investigation and mitigation and serves as the Chair of the NJDEP Vapor Intrusion Technical Guidance Committee. 

She is also a co-lead for technical guidance in the evaluation of extractable petroleum hydrocarbons (EPH) and is an ecological risk assessor. Nicole holds a Master of Science in Environmental Management and Policy from the University of Denver in Denver, Colorado, and a Bachelor of Science in Marine Science and Biology from Coastal Carolina University in Conway, South Carolina.