Matthew Traister, P.E. is a Vice President with Ramboll and is a subject matter expert on air quality. A registered Professional Engineer (chemical), Mr. Traister has more than 32 years of environmental consulting experience involving air permitting, emission inventory development, air dispersion modeling, and air and odor pollution control design projects. The author of more than 40 technical papers and publications, Mr. Traister routinely provides project management and technical oversight functions for complex regulatory compliance programs (e.g., EHS audits, new/modified facilities, agency enforcement proceedings) including those under the Clean Air and Clean Water Acts, the Emergency Planning and Community Right-to-Know Act, and the Resource Conservation and Recovery Act (RCRA). He also has experience in providing expert testimony during litigation for similar matters.
Investigating the Connection Between PFAS Air Emissions and Stormwater and Drinking Water Contamination at a Site in the Northeastern U.S.
Background Routine monitoring of a public water supply well servicing a village in the northeastern United States revealed the presence of environmentally-persistent per- and polyfluorinated alkyl substances (PFAS) in the aquifer, more specifically PFAAs, the concentrations of which exceeded the state’s drinking water guidelines of a combined 70 parts per trillion (ppt) for PFOA, PFOS, PFNA, PFDA, PFHxS, and PFHpA. An investigation by the state regulatory agency identified a small surface coating operation as one probable source of this contamination. Atmospheric deposition was suspected as a primary pathway by which PFAS entered the environment from this source. The facility has been operating the same coating processes for more than 40 years. Over the past 10-15 years, the PFAS concentrations in the coatings used by the facility have been reduced by several orders of magnitude, consistent with the PFOA Stewardship program launched by USEPA in 2006. Thus, it is possible that the facility’s historical discharges - resulting from aerial deposition and subsequent stormwater transfer of these contaminants to the subsurface - rather than existing emissions, were a significant contributor to current drinking water excursions. Approach To better understand the potential implications of PFAS releases on soil/groundwater concentrations, it was important to understand several factors, including the historical PFAS content of materials used at the facility and PFAS emissions as a percentage of coating applied. A review of facility records, including Safety Data Sheets and purchase records were used to evaluate the former, while stack testing was performed to calculate the latter. Air dispersion modeling of current facility emissions was conducted and, when combined with annual precipitation data for the site, allowed for a prediction of stormwater discharge concentrations. Stormwater concentrations were then used as to support this holistic fate and transport study, environmental data were collected for comparison to model predictions and included:
• Soil Results
The data collected under this site investigation were used to enhance the conceptual site model (CSM) and will be summarized. These studies helped establish whether PFAS retention is site soil served as an on-going long-term contaminant source, the extent to which PFAS movement was retarded within the subsurface, the connection between stormwater discharges and its impact on local ground water concentrations, and whether current or historical air emission discharges are responsible for the excursions observed in the public water supply well. Presented as a case study, this presentation illustrates the effect that even small atmospheric discharges of PFAS, or other environmentally-persistent species (e.g., heavy metals) can have on local soil and groundwater resources. In addition, anecdotal information from similar sites is used to support the hypotheses raised in the presentation.