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The PFAS challenge: fate, transport, and cleanup

Miao Zhang moderates the 2020 Northwest Remediation Conference

Associate Engineer Miao Zhang recently co-moderated a plenary panel discussion, “The PFAS challenge: fate, transport, and cleanup,” at the virtual Northwest Remediation Conference. He was joined by fellow moderator Halah Voges of Anchor QEA and panelists Jennifer Field of Oregon State University, John McCray of the Colorado School of Mines, Richard Hunter Anderson of the United States Air Force, and Irina Marakow of the Washington State Department of Ecology.

The group discussed current dilemmas facing environmental professionals seeking solutions to per- and polyfluoroalkyl substances (PFAS) contamination. Key takeaways included:

  • Consultants and regulators cannot look at PFAS through the lens of conventional contaminants because PFAS have unique properties and there are at least 4,000 individual PFAS compounds.
  • The PFAS transport processes in the vadose zone and near-source zone are complicated and not well understood.
  • To make progress at PFAS sites, we need to focus on high-priority chemicals such as perfluorinated compounds.
  • Many PFAS biodegrade under aerobic conditions. Biodegradation is sensitive to oxygen content as well as biological activities.
  • We need faster and more reliable methods to define the extent of contamination and monitor the mass discharge between the vadose zone and groundwater table before and after remediation.
  • Fluctuations of the water table could cause PFAS to migrate deeper via the air-water interface. Under such conditions, PFAS would then be released into groundwater when the water table rises.

View the full video of this panel discussion: