Best Management Practices to Identify and Mitigate Per- and polyfluoroalkyl Substances (PFAS) Impacts on State DOT Construction Projects and Maintenance Operations
Research Idea Scope
Per- and polyfluoroalkyl substances (PFAS) are a group of manmade fluorinated chemicals that have been manufactured and used in a variety of industries since the 1940’s. They are persistent in the environment and the human body, and there is evidence that exposure to PFAS can lead to adverse health effects and ecological risks. PFAS are considered contaminants of emerging concerns, with regulatory standards that are evolving due to new science, detection capabilities, and transport pathways. The Environmental Protection Agency has issued Health Advisories at parts per trillion levels in drinking water for two PFAS compounds (PFOA, PFOS), and many State Environmental Agencies are regulating additional PFAS compounds and lowering groundwater standards for PFOA and PFOS. Without Federal Maximum Contaminant Level standards for PFAS compounds, States have regulated various PFAS compounds at varying standards and in varying media. Many of the States regulating PFAS in drinking water have just as stringent standards for groundwater. Additionally, large industrial PFAS air deposition areas exist, with no Federal guidance yet on soil leaching standards, leaving Transportation Agencies to evaluate the risk and liability of relocating PFAS-impacted soil.
DOT agencies like New Hampshire DOT, Michigan DOT, and Minnesota DOT are navigating PFAS-related issues, at significant expense, due to, but not limited to, the following situations: DOT-owned legacy sites with PFAS impact; road construction and improvement through PFAS-contaminated soil and groundwater due to aerial deposition, stormwater runoff and groundwater migration; increased assessment and analytical cost for soils to be graded, cut, or excavated; storage and disposal of spoil materials from road way maintenance in areas with PFAS aerial deposition; PFAS impact in dewatered construction groundwater and the requisite parts per trillion treatment goals; and, landfill testing requirement and restrictions leading to increased transportation and disposal costs.
Literature Search Summary
Research exists related to airports, but there is a lack of DOT-focused research. The National Academies of Sciences, Engineering, and Medicine (2017) published a comprehensive resource document for airport industry practitioners on the fundamentals and recommended best practices for management and remediation of PFAS found at airport sites. Currently, no analogous document exists that addresses PFAS management as for general transportation infrastructure. Based on the current literature, no state DOTs have developed an analogous comprehensive guide for identifying and/or managing PFAS that may be encountered when constructing or repairing transportation infrastructure outside of airport source sites.
While a number of states directly address PFAS, their action plans focus on the following: biosolids and wastewater treatment; drinking water sources (e.g. groundwater and soil near the water table); sources that impact air quality, landfills or other waste disposal sites; food safety; and/or airports where firefighting foams containing PFAS (AFFF) were known to have been used (Alaska DEC 2021; Massachusetts DEP 2021;MPART 2019; among others). With these focus areas in mind, several states have formed interagency groups to address minimizing human exposure to PFAS within their state. These groups are charged with developing PFAS management strategies, such as locating likely contaminated areas, sample collection and analysis, remediation/removal strategies, surveying inventory and improving storage practices of unused supplies of products containing PFAS, etc. For example, the state of Connecticut formed the Connecticut Interagency PFAS Task Force to develop an action plan addressing the challenges related to PFAS (Connecticut Interagency PFAS Task Force 2019). The CT Task Force consists of 16 different organizations and is led by the CT Department of Public Health and the CT Department of Energy and Environmental Protection. Other states with similar interagency groups include Michigan (MPART 2019), Minnesota (Greene and Neuschler 2021), Pennsylvania (PFAS Action Team 2019), and Wisconsin (WisPAC 2020). However, none of the identified state action plans explicitly address the impact of PFAS contamination on state transportation agency construction and maintenance sites.
The objective of this research is to provide DOTs a reference document with technical guidance on status of PFAS regulatory requirements and risks, current PFAS impacts on DOTs, tools to screen and identify locations of potential PFAS contamination that could impact DOT operations, and methods to mitigate identified PFAS impacts.
The research objectives will be met through the following tasks and related activities:
Task I: Review and Summarize Regulatory Literature:
• Status of the U.S. regulatory environment for PFAS as it pertains to Transportation Agencies, particularly in light of EPA PFAS Action Plan
• State Requirements
Task II: Survey and Summarize Current DOT PFAS Case Studies and DOT-Developed PFAS Guidance or Other PFAS Guidance Used by DOTs
• Screening tools used to determine potential areas of concern for PFAS during the NEPA process
• Guidance or current practice to identify nearby sources
• Guidance on when to sample and the sampling approach for a DOT project
• Guidance for geotechnical explorations in known or suspected PFAS-impacted areas
• Current practices and resources for evaluating PFAS impacts to DOT projects and operations
Task III: Conduct a comprehensive literature review of potential PFAS sources adjacent to and within existing DOT right of ways.
• An overview of current and historic PFAS uses and applications with potential impacts for transportation agencies
• A summary of products currently or historically used by Transportation Agencies which are known or suspected to contain PFAS
Task IV: Develop general mitigation and management strategies
• Temporary storage, management, disposal or relocation and treatment options for waste construction water or soil impacted by PFAS
• On-site remediation technology options for PFAS-impacted construction dewatering
• Development of draft specification templates
• Decision tree with potential options depicted
Task V: Production of final report synthesizing results of Tasks I through IV.
The primary drivers of implementation for the proposed work will be DOT staff involved in environmental management, sustainability, and waste management. Another important target includes regulatory agencies that are responsible for developing regulatory approaches to address PFAS impacts and approving waste management plans associated with PFAS impacted soil and groundwater. Deliverables shall be created with both end users in mind, as DOTs will likely need to present technical justification to regulatory agencies to gain approval for PFAS waste management.
Alaska Department of Environmental Conservation (2021). “Per- and Polyfluoroalkyl Substances (PFAS)”, https://dec.alaska.gov/spar/csp/pfas/ . Accessed May 20, 2021.
Connecticut Interagency PFAS Task Force (2019). PFAS Action Plan. Led by the Connecticut Department of Public Health and the Connecticut Department of Energy and Environmental Protection, https://www.ct.gov/CTPFASTaskForce . Accessed May 26, 2021.
Greene, S. and Neuschler, C. (2021). Minnesota’s PFAS Blueprint: A Plan to Protect Our Communities and Our Environment from Per- and Polyfluorinated Alkyl Substances. February 2021, PFAS Lateral Team. https://www.pca.state.mn.us/sites/default/files/p-gen1-22.pdf. Accessed May 27, 2021.
Massachusetts Department of Environmental Protection (DEP) (2021). “Per- and Polyfluoroalkyl Substances (PFAS)”. https://www.mass.gov/info-details/per-and-polyfluoroalkyl-substances-pfas. Accessed May 27, 2021.
Michigan PFAS Action Response Team (MPART) (2019). Fiscal Year 2019 Accomplishments Report. December 2019, Steve Sliver, Executive Director. https://www.michigan.gov/documents/pfasresponse/Michigan_PFAS_Action_Response_Team_MPART_Fiscal_Year_2019_Accomplishments_Report_674473_7.pdf Accessed May 27, 2021.
National Academies of Sciences, Engineering, and Medicine (2017). Use and Potential Impacts of AFFF Containing PFASs at Airports. Washington, DC: The National Academies Press. https://doi.org/10.17226/24800. Accessed May 20, 2021.
Pennsylvania PFAS Action Team (2019). PFAS Action Team Initial Report. Patrick McDonnell, PFAS Action Team Chair and Secretary of Pennsylvania Department of Environmental Protection. https://files.dep.state.pa.us/Water/DrinkingWater/Perfluorinated%20Chemicals/Reports/20191205-PFAS-Action-Team-Initial-Report-Pennsylvania.pdf. Accessed May 26, 2021.
Wisconsin PFAS Action Council (WisPAC) (2020). Wisconsin PFAS Action Plan. Preston D. Cole, Secretary of Wisconsin Department of Natural Resources. https://widnr.widen.net/content/d4vyg9qqwj/pdf/EM_PFASActionPlan.pdf. Accessed May 27, 2021.
Potentially Interested AASHTO Councils and/or Committees
TRB Committee on Resource Conservation & Recovery; TRB Committee on Geo-Environmental and Climatic Impacts on Geomaterials
Supported by: David Wilson, Virginia DOT; Angel Palomino, University of Tennessee-Knoxville; Gordon Box, North Carolina DOT, Anjuliee Mittleman, Volpe Center; Harrison Roakes, Sanborn Head; Laura Lyle, Minnesota DOT; Kuo Tian, George Mason University; Helen Corley, Wood; Vincent Ogunro, University of North Carolina-Charlotte; Billy O’Conner, University of Alaska; Andrew Graettinger, University of Wisconsin, Milwaukee
Urgency and Payoff
Urgency and Potential Benefits
With the increase in knowledge about the existence of PFAS in all environmental media, and concern about environmental and human health impacts, DOTs are in need of guidance on how to manage PFAS on their properties and projects. DOTs lack a full understanding of where PFAS may be present within DOT Rights of Way, and when PFAS are found, there are concerns with limited and expensive disposal options and a need for management strategies.
Potential benefits enabled through the proposed technical guidance measures include:
• Assist DOT with understanding the emerging impacts on construction and maintenance projects associated with PFAS
• Avoidance and Minimization strategies
• Greater predictability for construction and maintenance costs
• Public relations with respect to DOTs being proactive about PFAS; these “forever chemicals”