Site loading image

Meet The Team

Elizabeth Denly
Vice President, PFAS Leader & Chemistry Director

Ms. Denly leads the TRC Center of Research & Expertise (CORE) PFAS Team, a group of scientists devoted to staying informed of current PFAS issues, science, and regulations.

Elizabeth Denly serves as TRC’s per- and polyfluoroalkyl substances (PFAS) Initiative Leader & Chemistry Director. As a project QA chemist at TRC, Ms. Denly is responsible for providing QA/quality control (QC) oversight in support of different environmental investigations, including remediation programs, ambient air monitoring, and human health/ecological risk assessments.

She currently works on many different types of PFAS investigations with a specific focus on chemistry, sampling procedures, data interpretation, forensics, QA/QC, and analytical methodologies. She has recently collaborated with laboratories on research activities including (1) evaluation of the leachability of PFAS from environmental sampling products; (2) evaluation of analytical approaches (isotope dilution liquid chromatography/dual mass spectrometry, total oxidizable precursor assay, and total fluorine) on samples collected from aqueous film forming foam sources and paper mill sources; (3) evaluation of the solubility of perfluorooctane sulfonic acid; and (4) evaluation of sampling/analytical approaches for the measurement of PFAS in ambient air.

Ms. Denly has also served on advisory committees related to analytical methodologies for the Massachusetts Department of Environmental Protection. Her major areas of expertise include emerging contaminants, data evaluation, quality assurance project plans, data usability assessments, field and laboratory audits, and consulting for regulatory agencies. Ms. Denly has a BA in chemistry from the University of New Hampshire and is a Certified Manager of Quality/Organizational Excellence from the American Society of Quality.


Select PFAS Project Experience:

  • Assisted the Massachusetts Department of Environmental Protection (MassDEP) in the development of their PFAS fact sheet and worked with MassDEP on the development of regulatory standards. Currently contracted to provide expertise on evaluation of PFAS analytical data as needed.
  • Provides QC support for programs involving PFAS data. Ms. Denly has performed full validation of laboratory results, including review of raw data, chromatograms, peak integrations, and calculations. She provides oversight of field investigations involving the collection of groundwater, drinking water, soil and sediment samples for PFAS under different regulatory authorities. Ms. Denly has written QualityAssurance Project Plans (QAPPs) for PFAS sampling programs. She has also been responsible for the update of TRC’s field sampling SOPs to include collection of samples for PFAS.
  • Merrimack, NH: Ms. Denly provided litigation support to assist with review of existing chemical emissions data used to support a permit application for a coated fabric and film manufacturer. Ms. Denly provided a data useability analysis, conducted data validation, and provided consultation and documentation of the findings. The focus of this review was to evaluate PFAS data generated for the 155 samples collected at the site and the use of these data in stack test emissions calculations. Although the majority of the PFAA and HFPO-DA or Gen-X results were valid and properly identified, Ms. Denly’s review identified errors in the data that resulted in significant underestimation by the consultant of the potential to emit air emissions calculations relating to PFAS. These errors included (1) correction of PFAA data performed at high dilutions using inappropriately labeled surrogate recovery; (2) inaccurate laboratory QA/QC samples for Gen-X; and (3) use of method detection limits or zeros instead of reporting limits for air emissions calculations.
  • Confidential Pulp & Paper Clients: Ms. Denly provides technical and QA assistance for three different pulp & paper clients in different regions of the United States. Her role is to provide oversight of sampling and analytical programs, evaluation and interpretation of analytical data, and assist in recommendations for potential future remedies.
  • New York State Department of Environmental Conservation (NYSDEC) Sites: Ms. Denly serves as the QA officer for several projects under the NYSDEC program, all of which involve the collection of various media for PFAS analyses. Ms. Denly is responsible for guiding the field team in the selection of appropriate sampling procedures and materials and for the preparation of Data Usability Summary Reports (DUSRs) for all analytical data. Sites which Ms. Denly has worked on under the NYSDEC program, which involve PFAS include the following: Hoosick Falls Landfill, Brillo Landfill, Fortino Tire, Fashion Care Cleaners, and Solvent Finishers.
  •  Former Microelectronics Manufacturing Facility Site, New England: Ms. Denly has provided QA support for this program, which has included the development of a QA plan for collection of soil, sediment, groundwater, and treatment samples for PFAS analysis at a former RCRA site (state lead). The QA plan included detailed protocols for sampling several media for PFAS while preventing cross-contamination.
  • Sampling of the existing groundwater treatment system demonstrated that enhanced liquid phase granular activated carbon effectively removed PFAS. TRC completed the design and constructed replacement groundwater treatment systems for volatile organic compounds (VOCs), including resin absorption components for contingent treatment of PFAS. Ms. Denly also provided oversight on an extensive data validation program for these analyses, which included full validation of the PFAS data. She worked with the laboratory to ensure consistent integration of branched and linear PFAS isomers, as this was not always performed consistently at the onset of the program.
  • Former Chromium Plating Site, New England: Ms. Denly is the QA officer for a Remedial Investigation / Feasibility Study at a former metal plating facility, which is now a federal-lead Superfund Site. She was responsible for the development of the QAPP in the Uniform Federal Policy (UFP) format. PFAS were sampled in a variety of matrices at this site, including groundwater, drinking water, soil, sediment, and surface water. Ms. Denly oversees the data validation program and works with the field team to ensure proper protocols are being used for sampling PFAS and other parameters. She developed analytical specifications for the analysis of PFAS for all media that the laboratories were required to bid on and follow, with many of the requirements coming from the Department of Defense Quality Systems Manual.
  • Superfund Site, International Airport, New Jersey: Ms. Denly is the QA officer for this program under EPA Region 2, which includes the investigation of PFAS in a former fire training area. Responsibilities have included the development of a QAPP in the UFP format and data validation oversight.


  • Denly, E., Critical Factors for Interpreting PFAS Data, Engineering Society of Detroit, March 2021.
  • Denly, E., PFAS at Metal-Plating Facilities: Environmental Management & Regulatory Developments, National Association of Surface Finishers (NASF)-CT Chapter, March 2021.
  • Denly, E., PFAS Hot Topics: PFAS Sampling: Results of a Cross-Contamination Study and Effects of Variable Analytical Parameter Suites on the Identification of PFAS Sources, MI EGLE, AWMA, MAEP, February 2021.
  • Denly, E., PFAS in the Chemical Industry: Toxics Release Inventory, Chemistry Council of New Jersey, January 2021.
  • Denly, E., PFAS Forensics, Michigan EGLE Great Lakes PFAS Summit, October 2020.
  • Denly, E., PFAS Chemistry and Use Throughout the United States, American Ground Water Trust, October 2020.
  • Denly, E., PFAS Data Interpretation Issues, Yosemite Law Conference, October 2020.
  • Denly, E., PFAS & 1,4-Dioxane Data Usability Workshop, AEHS East Coast Conference, October 2020.
  • Denly, E., POTWs in California, PFAS Sampling Issues and Quality Control, September 2020.
  • Denly, E., PFAS Forensics: Chemical Signatures in Surface Water and Groundwater, Environmental Business Council, Framingham, MA, February 2020.
  • Denly, E., PFAS Sampling Challenges in the Field, National Council for Air and Stream Improvement (NCASI), Webinar, August 2019.
  • Denly, E., Panel member on discussion of PFAS Chemistry and Analytics, PFAS Experts Symposium, Nathan, Remediation Journal, Arlington, VA, May 2019.
  • Denly, E., Phillips, J., and Wilson, A. (TRC), RWQCB (MacDonald, A.), Vista Analytical (Maier, M.), and Barg Coffin Lewis and Trapp (Metres, D.), Per- and polyfluoroalkyl substances (PFAS): The Latest Information, AEHS West Coast Conference Workshop, San Diego, CA, March 2019.
  • Denly, E., PFAS Analysis: What to Expect and How to Evaluate the Data, AEHS Platform Presentation, March 2019.


  • Denly, E., & Morin, K. (2022). A review of draft Environmental Protection Agency Method 1633: A data user’s perspective. Remediation Journal, 1–5.
  • Fiorenza, S., Denly, E., Vitale, R. J., Nigro, N., Leahy, M. C., Neslund, C., Blye, D. R., & Farmer, N. (2022). PFAS Experts Symposium 2: An update on advances in the chemical analysis of PFAS. Remediation Journal, 1–9.
    Denly E, Occhialini J, Bassignani P, Eberle M, Rabah N. Per‐ and polyfluoroalkyl substances in environmental sampling products: Fact or fiction? Remediation. 2019; 29:65–76.
  • Eberle M, Edelman M, Denly E, Rabah N. Evaluation of the effects of PFAS soil adsorption and transformation in the presence of divalent cations under ambient conditions. Remediation. 2019; 30:15–25.
  • Simon JA, Abrams S, Bradburne T, et al. PFAS Experts Symposium: Statements on regulatory policy, chemistry and analytics, toxicology, transport/fate, and remediation for per‐ and polyfluoroalkyl substances (PFAS) contamination issues. Remediation. 2019; 29:31–48.

Education and Professional Registrations, Certifications and Training

  • B.A., Chemistry, University of New Hampshire
  • Certified Manager of Quality/Organizational Excellence, American Society of Quality
    Professional/Thought Leadership:
  • Currently serving on the Interstate Technology and Regulatory Council (ITRC) PFAS team. Co-leading the sub-team on Naming Conventions and History & Use; Served as presenter for ITRC PFAS training workshops. Led the development of the Naming Conventions & Physical/Chemical Properties fact sheet; Co-led a section on PFAS data evaluation for the Technical/Regulatory guidance document; Ms. Denly won the 2017 ITRC Industry Affiliates Program Award for her contributions to the ITRC PFAS team.
  • Active participant on the PFAS Experts Symposium which began in 2019; currently serving as co-chair of Sampling & Analytical section.
  • Participated as a reviewer in the development of a guidance document entitled Groundwater and PFAS: State of Knowledge and Practice with the National Ground Water Association (NGWA).
  • Leader in TRC’s Center of Research and Expertise (CORE) PFAS team. Ms. Denly educates representatives of regulatory agencies, attorneys, and clients about chemistry, data evaluation/interpretation, investigation, fate and transport, and remediation of PFAS. In addition, Ms. Denly leads a team of TRC scientists to stay informed of current PFAS issues and science.
  • Collaborated with an analytical laboratory to evaluate the leachability of PFAS from common environmental sampling products; published paper on results.
  • Currently working with analytical laboratories to (1) evaluate analytical approaches (isotope dilution LC/MS/MS, Top Assay, total fluoride, and total fluorine) on the evaluation of samples collected from AFFF sources and paper mill sources and (2) evaluate sampling/analytical approaches for the measurement of PFAS in ambient air.
  • Provided technical comments on the Draft PFAS Chemical Action Plan to the State of Washington, Department of Ecology.

Do you have a question for Liz?

Let me know how I can help you.

By clicking "Accept", you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts. Read our Privacy Policy.