Theresa Gabris, P.G.

Theresa Gabris is a Professional Geologist based in Washington, D.C. with experience in contaminant fate and transport, conceptual site modeling, and site remediation.

Theresa Gabris is a Professional Geologist based in Washington, D.C. with experience in contaminant fate and transport, conceptual site modeling, and site remediation.


She primarily manages projects involving vapor intrusion (VI), working closely with other VI leaders in the firm to advance the state of the science and apply advanced characterization technologies and approaches to address her clients' most challenging VI projects.

Theresa's portfolio of VI projects include those for the U.S. Department of Defense, the U.S. Department of Energy, as well as a variety of industrial, insurance and legal clients. Under a DoD-funded research grant, she was an integral member of a team developing advanced VI sampling techniques such as building pressure control and high-volume sampling to rapidly evaluate mass flux and reasonable worst-case conditions in residential and commercial buildings. She has applied these sampling techniques and other forensic investigation approaches to limit necessary sampling over neighborhood-wide plumes, differentiate comingled groundwater sources, and identify background indoor air sources. She has also used them to test the effectiveness of mitigation systems, prioritize sampling at a large campus facility, and perform an investigation in a 128-acre manufacturing building.

For a number of environmental site investigations, Theresa has led the assessment and remediation of soil, groundwater, sediment, surface water, coal combustion residuals, and munitions debris. Under contract with the U.S Army Corps of Engineers and U.S. Army National Guard, she led Phase II investigations at bases in 38 states, employing specialized field design and assessment techniques like Visual Sample Plan (VSP) software and randomized composite soil and sediment sampling. Across her diverse projects, she has implemented remedial technologies such as enhanced in situ bioremediation, soil vapor extraction, air sparging, in situ chemical oxidation, hydraulic control pump and treat, soil excavation, and site capping. Theresa is also currently assisting with a human health risk assessment for a large PFAS manufacturing site.

Theresa has been part of environmental liability valuation teams providing support for confidential litigation matters and insurance claims. She has been involved in several VI and sediment litigation projects, assisting in expert reporting and testimony. She has also participated in largo-portfolio environmental compliance and environmental due diligence projects (e.g., Phase I Environmental Site Assessments) for numerous commercial and industrial facilities.

Contact Theresa Gabris at This email address is being protected from spambots. You need JavaScript enabled to view it. or +1-202-370-4350.

Career Summary of Theresa Gabris, P.G.

  • Specialties: Vapor intrusion; Environmental investigations and remediation; Environmental due diligence; Litigation support
  • Practice Areas: Contaminated Site Assessment and Cleanup
  • Disciplines: Environmental Sciences, Geology
  • Education: M.S., Environmental Science and Policy, Johns Hopkins University, Baltimore, Maryland, 2015; B.A., Geology, Hamilton College, Clinton, New York, 2011
  • Registration: Professional Geologist, Virginia No. 2801002228

Quick Qual

No pages found in your document. What is a Quick Qual?