PFAS Update
BY AsphaltPro Staff
ATL offers guidance for potential PFAS contamination from airport millings out of New York
The subject matter experts at Atlantic Testing Laboratories (ATL), headquartered in New York, have examined the issue of per- and polyfluoroalkyl substances (PFAS) occurring in the pavements milled during pavement maintenance activities at airfields. As discussed in the January 2024 issue at this link, PFAS are a group of man-made chemicals, including perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). The PFAS from firefighting foam is the specific concern for the asphalt maintenance and preservation industry that we’ll focus on here because the foam has been used in training operations at airfields and other locations where contractors now mill and overlay.
Cheyenne J. Dashnaw, P.E., is a senior engineer at ATL and wrote recently of the hazards contractors may encounter when milling at airports and other locations with a history of using firefighting foam. Contractors collecting contaminated recycled asphalt pavement (RAP) and/or recycled concrete aggregate (RCA) need to be aware of potential environmental and legal consequences.
“If contaminated RAP or RCA are relocated to a different site, the contractor could be considered a potential generator and transporter of hazardous materials,” Dashnaw wrote. He explained to AsphaltPro readers how the contractor could be seen as a “generator” in this circumstance.
“If you have a project that may require sampling for PFAS or any other environmental analyte, ATL, a WBE certified company, has experienced environmental professionals located throughout New York State to perform sampling and coordinate applicable analysis.”
“The definition for generator is ‘any person, by site, whose act or process produces hazardous waste…or whose act first causes a hazardous waste to become subject to regulation.’” In these cases, the United States Environmental Protection Agency (USEPA) and the New York State Department of Environmental Conservation (NYSDEC) “would generally view the site owner as generators for most hazardous wastes, but could consider site owner and contractor as co-generators of certain hazardous wastes, especially for the scenario of a material being relocated to a different site without yet knowing it is a hazardous waste,” Dashnaw shared. “Additionally, if the materials are used as fill or an ingredient in new pavements, there is a risk of contaminating multiple other sites.”
The New York State Department of Transportation (NYSDOT) allows up to 30% RAP in its mix designs, according to Materials Method 5.16. Of course, the RAP material must meet spec. The NYSDOT Standard Specifications section 703-09 states:
“The aggregate component of the RAP shall meet the requirements of section 703, Aggregates. The bitumen component of the RAP shall be asphalt cement and shall be free of significant contents of solvents, tars, or other contaminating substances that will make the RAP unacceptable for recycling as determined by the Department.”
Dashnaw shared that in January 2021, NYSDEC Division of Environmental Remediation (DER) released a technical guidance document titled, “Sampling, Analysis, and Assessment of Per and Polyfluoroalkyl Substances (PFAS),” requiring sampling and analysis of environmental media for PFAS as part of remedial programs under 6 NYCRR Part 375. This guidance document has since been updated, with the current version dated April 2023.
Currently, NYSDEC DER requires the use of EPA Method 1633 for analysis of PFAS in all environmental media (not including drinking water), Dashnaw wrote. The background on EPA Method 1633 and PFAS cleanup is found at this link.
“Guidance values for limits in soil have been developed for sites in New York State, but soil cleanup objectives (SCO) are not planned to be established until at least a proposal and approval in a future revision to 6 NYCRR Part 375-6. The current guidance gives limit values for PFOA and PFOS based on the anticipated site use for soil and groundwater. While regulations are in progress, it is important to rely on knowledgeable environmental scientists and engineers to ensure that sampling and analysis are completed reliably and in accordance with the most recent and updated regulatory standards.”
Dashnaw clarified: “While the guidelines include soil cleanup objectives based on site use conditions, these are not yet established as regulatory standards and future regulatory standards may differ. If millings are known to be contaminated with PFAS, disposal at a permitted facility should be considered to err on the side of caution. At the very least, I would recommend deferring to the guidance value for Unrestricted Use, which is 0.66 ppb for PFOA and 0.88 ppb for PFOS. If you have samples exceeding these concentrations, disposal should be strongly considered.
“It is important to note that there is a risk that SCO could end up being lower than the current guidance values (and SCO could be developed for additional PFAS compounds other than PFOA and PFOS), but should at least work within the bounds of existing guidance.”
If a contractor suspects PFAS contamination, it’s wise to keep those incoming materials in their own stockpile. “Being able to separate materials is always beneficial, albeit not always obvious or practical,” Dashnaw said. “If a material does end up being discovered as contaminated, and it was managed separately, it is more efficient to track and less costly for subsequent removal and disposal.”
For more information, contact Cheyenne Dashnaw at (315) 386-4578 or info@atlantictesting.com.