Elizabeth Denly
Vice President, PFAS Initiative Leader & Chemistry Director

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 risk liability assessment/management plans, 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; (4) evaluation of sampling/analytical approaches for the measurement of PFAS in ambient air; and (5) evaluation of the effects of particulates on PFAS results in aqueous samples.

Ms. Denly is currently serving on the Interstate Technology and Regulatory Council (ITRC) PFAS team, is a co-leader on the PFAS History & Use Naming Conventions sub-team, serves as a trainer for this team, and won the 2017 and 2022 ITRC Industry Affiliates Award for her contributions to this team. She was also a co-leader on the ITRC 1,4-Dioxane Team for Sampling & Analysis and currently serves as a trainer for this team.

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.

PROJECT EXPERIENCE

Select PFAS Project Experience:

• 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. Ms. Denly also provides workshops on the challenges of evaluating PFAS analytical data.
• Massachusetts Department of Environmental Protection (MassDEP).
  • Contracted to develop the required analytical protocol for PFAS.
  • Assisted with the development of the MassDEP PFAS fact sheet.
  • Assisted with sampling program evaluating PFAS in pesticide products. The program involved (1) sampling of different pesticide products from various mosquito control districts (MCD) in Massachusetts, (2) working with the laboratory on the PFAS analytical requirements, and (3) evaluating the analytical results associated with the pesticide products and other analyses performed (i.e., sample containers, sampling equipment). Provided a final deliverable, summarizing the results of the products, a detailed data quality evaluation, and results of an investigation into potential false positive results for perfluorooctane sulfonic acid (PFOS).
  • Assisted with sampling program to evaluate PFAS in drinking water and wastewater treatment chemicals. The program involved the following tasks: (1) identification/selection of bulk treatment chemicals and facilities, (2) sample collection of bulk treatment chemicals, (3) working with the laboratory on the PFAS analytical requirements, and (4) data review, compilation, and interpretation. Provided a final deliverable, summarizing the results of the chemicals, a detailed data quality evaluation, and recommendations for future studies.
  • Provided data review services and training for MassDEP staff on the review of PFAS data generated from wastewater treatment plants under the National Pollutant Discharge Elimination System (NPDES) program and residual facilities.
• 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.
• City of Portsmouth, NH – Evaluation of PFAS in Synthetic Turf: The City of Portsmouth installed a synthetic turf ballfield. Due to concerns raised by community members, the material used for the synthetic turf was evaluated for the potential presence of PFAS. TRC prepared a sampling and analysis plan (SAP) which provided details and requirements on sampling procedures for the materials under investigation: carpet/grass, in-fill material, and the shock pad; requirements for packaging of these materials by the manufacturer and shipping of these materials to the analytical laboratory; cryo-mill procedures to be used by the analytical laboratory for the homogenization/compositing, extraction; requirements for standard isotope dilution PFAS analysis, TOP Assay analyses, and non-target analysis using quadrupole time of flight mass spectrometry; reporting limit goals for the individual PFAS analyses in each material; and required field and analytical QC samples and measurement criteria. TRC worked directly with the synthetic turf manufacturers to establish an appropriate procedure for the collection of representative samples for analysis. TRC also worked directly with the analytical laboratory to ensure appropriate procedures would be used by the laboratory for the handling of these materials and that the resulting data would be representative of the materials under evaluation. TRC performed an evaluation of the analytical results which included a usability review and a preliminary risk evaluation, which found that there was not a human health risk to those using the synthetic turf ballfields. Results were presented to the mayor of Portsmouth and the City Council.
• Bowdoin College, Brunswick, ME – Evaluation of PFAS in Synthetic Turf: Bowdoin College was in the process of designing and permitting improvements to their athletic fields. There was a strong desire to use synthetic turf, similar to their peer institutions, due to challenges with natural grass fields for spring sports. To satisfy concern about the safety of turf products, Bowdoin College engaged with TRC to further evaluate the material used for the future planned synthetic turf fields for the potential presence of PFAS. TRC reviewed and verified the documentation provided by the current synthetic turf vendor and their claims related to the lack of PFAS for five different synthetic turf materials. Based on the isotope dilution and synthetic precipitation leaching procedure (SPLP) results provided by the manufacturer, TRC performed an initial evaluation of potential risk, which found that based on trace levels of PFAS being below groundwater screening criteria combined with the understanding that the leachate would be diluted upon entering the aquifer, PFAS leachability and mobility from these materials will not be of concern. In addition, the evaluation also showed that there was not a human health risk to those using the synthetic turf fields from PFAS. TRC presented the results of this evaluation to the Brunswick, ME Select Board who provided Bowdoin College with the ability to move ahead with the project with the requirement to test the material being used prior to installation. Analyses of all materials were in accordance with the permit condition specified by the Town of Brunswick and were used to demonstrate compliance with the State of Maine Interim Drinking Water Standard of 20 nanograms per liter (ng/L) based on the results of an SPLP analysis for the sum of six state-regulated PFAS compounds, and compliance with United States Environmental Protection Agency (USEPA) regional screening levels (RSLs) for residential soil, based on the results of the TOP Assay and standard PFAS analyses.

SELECT PFAS PRESENTATIONS AND SEMINARS

• 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.

PFAS PUBLICATIONS

• Denly, E., & Morin, K. (2022). A review of draft Environmental Protection Agency Method 1633: A data user’s perspective. Remediation Journal, 1–5. https://doi.org/10.1002/rem.21713
• Denly E, Occhialini J, Bassignani P, Eberle M, Rabah N. Per‐ and polyfluoroalkyl substances in environmental sampling products: Fact or fiction? Remediation Journal. 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.
• 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. https://doi.org/10.1002/rem.21707
• 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 Journal. 2019; 29:31–48.