Specialties
Vapor Intrusion; Attenuation Factors; Multiple Lines of Lines Assessments; Data Analysis and Modeling; Fate and Transport; Regulatory Risk Management
Practice Areas
Contaminated Site Assessment and Cleanup; Civil Infrastructure
Education
MBA University of California, Irvine, 2001; MS Environmental Enginering, Newark/Rutgers College of Engineering, Newark, New Jersey, 1990; BS Civil Engineering, N.E.D University of Engineering and Technology, Karachi, Pakistan, 1988
Registration
Registered Professional Civil Engineer: California
Client Service
Rafat is a trusted advisor to responsible parties and landowners, guiding them through complex regulatory, legal, and technical challenges associated with brownfield redevelopment. With extensive knowledge of the Comprehensive Environmental Response Compensation and Liability Act (CERCLA), the Resource Conservation and Recovery Act (RCRA), the California Health and Safety Code, and California Environmental Protection Agency Department of Toxic Substances Control (DTSC) policies, he is a resource for property owners, developers, attorneys, and consultants working under voluntary agreements and enforcement orders. He was an architect of and responsible for investigation and remediation of one of the largest lead-contaminated sites in United States.
Before Geosyntec, Rafat served as Chief of Site Mitigation and Brownfield Program at the California Environmental Protection Agency DTSC. There, he helped develop the RCRA Corrective Action program and more than two dozen vapor intrusion guidance documents. Rafat also served as a trainer for the Interstate Technology Regulatory Council (ITRC) and developed or peer-reviewed vapor intrusion guidance documents. He has been responsible for several ASTM International standards for site investigations. While at DTSC, Rafat worked with Robbie Ettinger to update the Johnson and Ettinger Model that calculates vapor migration to indoor air. The updated version allows for the use of DTSC-recommended model input values for toxicity factors and building parameters and refines the algorithm to calculate vapor transport across the capillary fringe. After DTSC released the modified version in 2024, Rafat helped roll it out to industry and regulatory stakeholders.
In addition, Rafat was a primary author for the DTSC guidance document, “Evaluation of Biogenic Methane,” that informs methane investigations at California dairy sites. This guidance changed California’s approach for assessing sites at risk for explosions, resulted in significant cost savings in, and protected the public from methane explosive risk.
Rafat often presents at agency meetings, workshops, and conferences. In 2023, he published “Empirically Derived California Attenuation Factors,” which addresses subslab to indoor air, deeper soil gas to indoor air, and groundwater to indoor air. The study also provides an analysis of variables that could impact attenuation of soil vapor into buildings and addresses important lines of evidence in vapor intrusion investigations.
Contact Rafat at Rafat.Abbasi@Geosyntec.com.
