CHAPTER 4

Case Examples

This chapter summarizes the findings of eight case example interviews conducted to gain a more nuanced understanding of how state DOTs are addressing PFAS contamination. The interviews were conducted with selected survey respondents to gather more detailed feedback. They covered both informal and formal policies, procedures, and guidance related to PFAS contamination. The interviews also discussed any effects PFAS have had on state DOT construction and operations. This information can help other state DOTs plan appropriate next steps for managing PFAS contamination and contextualize their own policies relative to those of other DOTs.

The selection of these cases was systematic, with a goal to collect feedback from state DOTs with different extents of PFAS-related policies and procedures. Feedback from state DOTs with different policies at either the state or agency level illustrates the spectrum of the development of PFAS-related procedures. All four AASHTO regions were represented, as were states with formal, informal, and no procedures, policies, or guidance. A final factor in the case example selection was a state DOT’s willingness to participate in the interview.

The following sections summarize the findings of the case examples, including detailed accounts of the information gathered during the interviews. The responses represent the perspectives of respective DOT representatives and not necessarily best practices. The initial interview questions focused on the objective findings of the survey. Follow-up questions sought to garner more detail on the effects of PFAS on maintenance and construction operations at the state DOT. The questions asked of each state DOT are included in Appendix C. Some respondents were able to provide more detail than others, but in all instances, the willingness and generosity of participants facilitated the collection of useful information. Table 4.1 provides the state DOT selection information for the case examples.

Colorado DOT

The Colorado DOT indicated in their survey response that they currently do not have formal or informal policies or guidance related to PFAS. This DOT was selected for a case example because of their efforts to identify and inventory PFAS within their agencywide system.

Policy on Identifying and Mitigating PFAS Contamination

As noted, at the time of their interview, the Colorado DOT did not have formal policies or guidance on identifying and mitigating PFAS contamination. However, the agency is aware of a need for PFAS policies and guidance and is beginning to develop them.

The Colorado DOT did conduct an agencywide investigation and inventory of where they own and maintain substances containing PFAS. The DOT identified two long tunnels where firefighting equipment and trucks outfitted with firefighting materials containing PFAS were stored for

use. This equipment was specialized to these tunnels, as other fires on roadways are managed by local firefighting forces. The containers have been removed from service and are awaiting a buy-back program from the health department. The Colorado DOT has no PFAS-containing material remaining in their inventories.

The Colorado DOT noted that PFAS are sometimes used and contaminate their right-of-way. In these cases, the agency seeks mitigation from the responsible parties or uses their own contracts to mitigate the contamination.

Screening for PFAS Contamination on Construction and Maintenance Sites

There is no state requirement for testing sites for PFAS, but the Colorado DOT is prepared to test for PFAS if known sources are suspected of being on project sites. The respondent noted concerns about ground dewatering permits being denied because such an incident occurred at a small regional Colorado airport. The DOT is aware that PFAS are becoming a concern for the

Colorado Department of Public Health and Environment, and although the DOT currently does not test for PFAS, they believe the need to do so is forthcoming. Still, the Colorado DOT is taking steps to minimize their PFAS-related impacts.

The Colorado DOT has taken action to make sure they are no longer a source of PFAS contamination, but they acknowledge that they could still be responsible for the remediation of PFAS contamination on their rights-of-way.

The Colorado DOT understands that PFAS removal is expensive and difficult. They view PFAS as unique hazardous wastes that are especially difficult to dispose of. Therefore, potential contamination presents concerns for DOT construction and maintenance operations.

Methodologies for Mitigating PFAS Impacts

There are other sources of PFAS beyond the Colorado DOT itself on agency rights-of-way. Some fires have been fought on rights-of-way using PFAS-containing materials, which then became elicit discharges. These areas have been identified as hazardous spills. State authorities are attempting to require responsible parties to clean these sites, or they have used their own hazardous materials services to clean them.

Identifying Materials or Containers That May Contain PFAS

In approximately 2020, the Colorado Department of Public Health and Environment sent a survey to the DOT asking about materials containing PFAS. The Colorado DOT quickly inventoried and investigated their materials. The identification of PFAS in this investigation highlighted a concern, and the agency immediately addressed the situation.

Coordination and Communication Between State Agencies on PFAS

The Colorado DOT stated that there is no guidance or policy on PFAS from health or environmental agencies in Colorado. State agencies are still defining the problem and are limiting new sources of PFAS. The DOT has staff with hazardous materials expertise who keep up to date with PFAS and related regulations. While the Colorado DOT is awaiting direction and pending regulations from the state or federal authorities, DOT leadership supports being proactive in eliminating PFAS use and investigating PFAS management.

PFAS Impacts on DOT Operations

The Colorado DOT stated that PFAS have had no impacts on operations. In the absence of specific requirements, the agency aims to be as proactive as they can.

Lessons Learned Regarding PFAS Identification and Mitigation

The Colorado DOT noted that dealing with PFAS can be problematic because of a lack of regulations. Airport officials have reported that insurance agencies once required hangars to have firefighting foams containing PFAS as a condition to insure aircrafts. While that practice has since changed, it indicated that not all divisions may be aligned in the elimination of PFAS use.

The Colorado DOT noted that assessment and review to locate and identify PFAS are difficult. Internal investigations can be ignored or postponed by groups. The respondent recommended building a network of personnel who understand the problem and want to be proactive. Prompted by the survey, the Colorado DOT used their network of resources to quickly search for PFAS sources and then took those sources out of service for disposal.

The Colorado DOT indicated that, from their perspective, being proactive is key: The first step should be to eliminate use of PFAS. The respondent also noted the need for research and support for alternatives to PFAS, for PFAS destruction, and for guidance in identifying and mitigating PFAS at DOTs.

Illinois DOT

Responses to the survey from the Illinois DOT indicated that the agency has informal policies and guidance related to PFAS, as do other Illinois state agencies. The agency further indicated that they have been testing intact soil for PFAS contamination at construction sites on a limited basis. With the goal of gaining more details about these policies, the synthesis team requested an interview with an Illinois DOT representative, who agreed to participate.

Policy on Identifying and Mitigating PFAS Contamination

The Geologic and Waste Assessment (GeoWaste) unit of the Illinois DOT has independently developed informal policies on PFAS because the state has passed no substantive regulations related to PFAS in soil. (However, the state has passed some groundwater regulations.) Unlike formal policy changes, these informal DOT policies currently do not require approval from agency directors. The unit has been in close communication with the Illinois EPA to verify that they operate in a manner consistent with their intent and current rules or regulations.

The GeoWaste Unit of the Illinois DOT is observing how the problem of PFAS contamination evolves and aims to develop strategies proactively, especially to minimize the costs associated with PFAS contamination. There is particular concern about the cost of treating dewatered groundwater. For example, it is much more cost-effective to discharge water under a National Pollutant Discharge Elimination System permit using a bag filter than to treat the water as special waste, which can cost 25 to 50 cents per gallon to dispose. There is also concern that many Illinois landfills will not accept PFAS-containing soil for disposal.

Screening for PFAS Contamination on Construction and Maintenance Sites

In the absence of a previously identified PFAS source, the standard list of contaminants for which the Illinois DOT tests does not include PFAS. However, during a Preliminary Environmental Site Assessment, the Illinois DOT identifies locations of likely PFAS contamination through professional judgment and a review of the site’s history. Locations that were former sites of industrial activity or car fires extinguished using firefighting foams often receive special attention. The agency flags these locations as potential recognized environmental conditions and collects samples for PFAS.

One of several environmental firms under contract with the Illinois DOT collects samples and produces reports outlining potential restrictions based on test results. Testing is performed by labs approved by the National Environmental Laboratory Accreditation Program, with the contract typically awarded to the lowest bidder, usually Eurofins.

Methodologies for Mitigating PFAS Impacts

The Illinois DOT does not remediate sites but will manage the materials excavated during construction. Particularly when contamination affects the right-of-way, the agency accounts for the health and safety of workers, the public, and the environment. The agency tends to adopt the site and material classifications most protective of human health and the environment.

Identifying Materials or Containers That May Contain PFAS

The Illinois DOT does not identify materials or containers that may contain PFAS or may be cross-contaminated by PFAS. The DOT evaluates construction and maintenance sites only on a case-by-case basis.

Coordination and Communication Between State Agencies on PFAS

The Illinois DOT expressed a desire to maintain compliance with any regulations. Because the agency believes that PFAS regulations are in their preliminary stages, they communicate regularly with the Illinois EPA. Several former Illinois EPA employees currently work in the GeoWaste unit, are sensitive to issues related to PFAS contamination, and can provide context to assist with potential regulation from the Illinois EPA.

PFAS Impacts on DOT Operations

When the Illinois DOT has encountered PFAS contamination, it has had difficulty disposing of it in landfills. The DOT has found that most landfills do not want to accept PFAS-contaminated waste. Additionally, the remaining permitted hazardous waste landfill in Illinois only accepts waste from a single client. Therefore, all hazardous waste from Illinois DOT projects is required to be transported to Michigan. This is impractical and expensive, particularly for sites in southern Illinois. Costs for disposal may be $400 to $500 dollars per cubic yard, which is prohibitive given the scale of some projects.

Further, sampling for PFAS is complicated. Environmental firms must be trained on specific requirements from testing labs before sampling. The firms the Illinois DOT uses have been trained and understand the procedures. Nonetheless, sampling for PFAS is time consuming and expensive.

Lessons Learned Regarding PFAS Identification and Mitigation

The Illinois DOT believes that managing PFAS contamination will be expensive in the future, particularly when soil regulations are implemented. The agency would like to balance good stewardship of the environment with financial responsibility, particularly if landfills are unwilling to accept even low-level concentrations of PFAS.

The agency believes that unless there is a specific reason to expect PFAS contamination to be present at a site, PFAS should not be tested for. However, if there is a reason to expect contamination, then samples should be taken for PFAS analysis.

Maine DOT

Responses to the survey from the Maine DOT indicated that both the Maine DOT and other state agencies have informal policies and guidance related to PFAS. Responses further indicated that the agency does track potential sources of PFAS contamination at construction and maintenance sites and that they have special considerations for the management and disposal of PFAS-impacted soil and water. With the goal of gaining more details about these policies, the synthesis team arranged an interview with the Maine DOT.

Policy on Identifying and Mitigating PFAS Contamination

The Maine DOT explained that Maine has informal policies or guidelines regarding PFAS but that nothing is set in writing yet. The DOT indicated that they are waiting for regulatory agencies

to clarify PFAS final regulations before developing formal policies. Though federal regulations have some influence, the Maine DOT primarily deals with the Maine Department of Environmental Protection (DEP).

The Maine DOT has not actively searched for PFAS contamination, and regulatory agencies have not yet pushed the issue. Motivators for the approach include the logistical challenges of disposal and the high cost associated with transporting PFAS-contaminated material to landfills. The simplest disposal of PFAS-contaminated waste involves transporting it to Wayne, Michigan, or Montreal, Canada.

The agency has conducted more thorough investigations of selected sites with potential PFAS contamination near military bases and a field affected by wastewater sludge application. These sites were identified through a web-accessible geographic information system (GIS) database maintained by the state. Among other PFAS sources, Maine tracks the locations where sludge has been spread.

Screening for PFAS Contamination on Construction and Maintenance Sites

The Maine DOT has sampled for PFAS at construction sites near military bases and at a field in the northern part of the state where sludge has been applied. After careful consideration, Maine DOT employees collected samples for analysis. Sampling focused on characterizing media in soils; groundwater was not a concern.

Methodologies for Mitigating PFAS Impacts

The Maine DOT has developed special provisions based on the Maine DEP’s guidelines. This guidance focuses on managing and containing the PFAS on-site. Greater concern arises regarding surplus material, which is difficult and costly to dispose. The agency expressed worry that such disposal could become increasingly difficult as detection limits for PFAS become smaller.

Identifying Materials or Containers That May Contain PFAS

The Maine DOT has not had concerns with PFAS in materials or containers. In the absence of regulation, the agency has limited its focus to ongoing construction. The Maine legislature considered an initiative on products, but that initiative has been delayed. The agency acknowledged that they have not yet addressed PFAS in personal protective equipment and similar materials.

Coordination and Communication Between State Agencies on PFAS

The Maine DOT noted that they have a good rapport with regulatory agencies and work collaboratively to address the issue of PFAS contamination. They articulated that being in a small community and state has fostered this collaborative relationship. The Maine DOT stated that they believe the DEP understands PFAS to be a major cost concern.

PFAS Impacts on DOT Operations

PFAS contamination has not affected the Maine DOT’s daily operations. However, at locations with known contamination, a special provision has been put in place that outlines procedures for contractors. These provisions are largely designed to protect worker health and address right-to-know concerns for those workers who may come into contact with PFAS.

Lessons Learned Regarding PFAS Identification and Mitigation

The Maine DOT acknowledges the challenges posed by PFAS and the increasing awareness of their presence. The agency mentioned the need for regulations to catch up with this awareness and the difficulty of minimizing PFAS use in various everyday products. The Maine DOT acknowledges that PFAS is an issue they will have to address, though the issue could take many years to resolve.

Michigan DOT

Responses to the survey from the Michigan DOT indicated that the agency has informal policies and guidance related to PFAS, and other Michigan state agencies have formal policies and guidance related to PFAS. The DOT further indicated using a variety of procedures to identify and mitigate PFAS contamination. The Michigan DOT also indicated that they do consider active remediation of PFAS-containing materials. With the goal of gaining more details about these policies, the synthesis team secured an interview.

Policy on Identifying and Mitigating PFAS Contamination

During the interview, the Michigan DOT explained that they do not have formal policies associated with PFAS; however, their agency is part of the Michigan PFAS Action Response Team (MPART). This multi-agency team provides regulatory direction under the auspices of the Michigan Department of Environment, Great Lakes, and Energy (EGLE).

The Michigan DOT stated that they endeavor to identify locations with PFAS contamination before contractors are on-site. Projects that involve significant earth moving or are near sites of PFAS contamination are often flagged for soil assessment. The Michigan DOT shares data from these soil assessments with MPART.

Screening for PFAS Contamination on Construction and Maintenance Sites

The Michigan DOT begins screening for possible PFAS contamination early in the construction and maintenance phases. EGLE provides a mapping tool to help locate known contamination. Additionally, Michigan maintains high-quality, accessible property records for its right-of-way and adjacent properties, which can be reviewed for indications of PFAS contamination. The DOT conducts a random sampling around sites with elevated risk for PFAS contamination following Michigan’s prescribed procedures for sampling.

Most landfills in Michigan request a PFAS screening before accepting waste from the Michigan DOT. Many will not accept waste with any detectable PFAS.

Methodologies for Mitigating PFAS Impacts

If PFAS are identified at concentrations below the hazardous threshold, the Michigan DOT may put impacted soil back in place or move it to another similarly contaminated location on the same site. Taking soil off-site often becomes expensive.

Identifying Materials or Containers That May Contain PFAS

The Michigan DOT does not identify materials or containers that may contain PFAS. The only DOT materials that may be contaminated are the linings of herbicide containers. No firefighting

foams are within the purview of the Michigan DOT’s Environmental Services Section, though a separate Aeronautics Division exists within the DOT.

Coordination and Communication Between State Agencies on PFAS

The DOT stated that Michigan maintains leadership on PFAS issues, resulting in strong coordination among state agencies. The most visible result of this coordination is the formation of MPART.

PFAS Impacts on DOT Operations

The Michigan DOT indicated that they are not responsible for any contamination if they are not the polluter. Nonetheless, if PFAS are identified at a site, the Michigan DOT still has a responsibility to be compliant with due care. This frequently means precautions are taken to ensure that workers and contractors will not come into contact with the toxic contaminants. The prevailing expectation in Michigan is that PFAS will be addressed when they are found at a construction or maintenance site.

Lessons Learned Regarding PFAS Identification and Mitigation

The Michigan DOT has found that, in general, they are more easily able to address PFAS contamination if it is identified early in projects.

The Michigan DOT stated that they have benefitted from maintaining strong communication with regulatory agencies. The DOT finds it helpful to clearly understand the expectations of these regulatory agencies when PFAS are discovered at DOT project sites. Similarly, the Michigan DOT stated that they have benefitted from working to build their capacity to characterize sites rather than assuming a defensive posture. The Michigan DOT would rather find solutions than engage in regulatory disagreements.

Minnesota DOT

Responses to the survey from the Minnesota DOT indicated that they have informal policies and guidance related to PFAS, as do other Minnesota state agencies. They further indicated that the Minnesota DOT has been testing soil for PFAS contamination at construction and maintenance sites near potential source areas. Responses showed that state regulatory agencies use GIS tracking, but such tracking is not performed by the DOT. With the goal of gaining more details about these policies, the synthesis team obtained an interview with the Minnesota DOT.

Policy on Identifying and Mitigating PFAS Contamination

The informal policy related to PFAS at the Minnesota DOT is influenced by two state regulatory authorities, the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH). The MDH is responsible for drinking water contamination, whereas MPCA has purview over soil and groundwater contamination. These two agencies provide guidance on what constitutes PFAS sources and what levels of contamination are subject to regulation. The Minnesota DOT stated that MPCA’s regulations are typically more stringent than federal regulation. The Minnesota DOT’s Office of Environmental Stewardship is not a regulatory authority but rather responsible for ensuring that the Minnesota DOT remains in regulatory compliance.

The Minnesota DOT is not yet subject to strong guidance, rules, or regulations related to PFAS. Their policies are not in active development as they anticipate more regulation from

MPCA. Minnesota DOT policy may soon be affected by the MPCA’s anticipated best practices and background limits for PFAS in soils. The DOT’s current policy is also influenced by some landfills in the state refusing to accept soil with even low or background PFAS levels.

Screening for PFAS Contamination on Construction and Maintenance Sites

The Minnesota DOT chemically monitors for PFAS in locations only where previous land uses indicate a likely or known PFAS-related activity. Early in a project’s timeline, the Minnesota DOT evaluates sites for any observable signs or sources of contamination. Both water and soil may be sampled during the Phase II investigation, but samples are generally not collected during maintenance projects. The department may even conduct sampling during construction but attempts to minimize such testing because the 3- to 4-week turnaround for results may cause delays.

Methodologies for Mitigating PFAS Impacts

The Minnesota DOT relies heavily on their consultant pool to identify sites potentially contaminated with PFAS, including the locations and former locations of metal platers or airports with firefighting training activities. Specifically, the MPCA has published a list of businesses and practices potentially associated with PFAS contamination. The DOT can also evaluate previous land uses and North American Industry Classification System (NAICS) codes associated with sites.

If contamination is located on the site of a construction or maintenance project, the Minnesota DOT may not necessarily be held responsible for mitigation because of the way the MPCA designates liability for contamination. If off-site contamination migrates into the Minnesota DOT right-of-way from an adjacent responsible party, the DOT is the affected party, not the responsible party. Several times, a known plume has resulted in the need to install granular activated carbon filters before water is discharged from sites.

The Minnesota DOT expressed understanding that PFAS are chemicals of emerging concern and expressed worry about the possible designation of PFAS as a hazardous material. Such a designation would make disposal of contaminated soil and water much more expensive and cumbersome.

Identifying Materials or Containers That May Contain PFAS

The Minnesota DOT is not specifically aware of any PFAS-containing materials in their possession and none actively being used. The agency avoids purchasing products that contain PFAS. For example, the firefighting chemicals used in prescribed burns are PFAS-free. Further, the DOT personnel who track and inventory chemicals and hazardous waste are vigilant for PFAS.

Coordination and Communication Between State Agencies on PFAS

The Minnesota DOT indicated that the level of coordination and communication between the Minnesota DOT and other state agencies has been mixed. Much of MPCA’s time and resources have been recently occupied by managing a major settlement with a large PFAS manufacturer in the state. Before finalizing their policies, the Minnesota DOT is awaiting final guidance from MPCA on background PFAS levels and how such ubiquitous low levels of contamination should—or should not—affect landfill disposal of soil and other waste.

Similarly, the MDH dedicates much of its focus to drinking water, with much less attention paid to groundwater. This makes aquifer contamination a bit of a gray area. One member of the Minnesota DOT sits on MDH committees to learn more about possible regulation.

PFAS Impacts on DOT Operations

One major impact on Minnesota DOT has been local landfills’ reluctance to accept any PFAS-containing waste, even if the low PFAS concentrations indicate background levels rather than a spill. On a few occasions, a landfill has rejected soil that subsequently must be treated as hazardous. One state landfill recently created a new cell for PFAS-impacted material and soils but only from locations associated with PFAS manufacturing, so it is unavailable to the Minnesota DOT.

To lessen the effect on construction and maintenance projects, the Minnesota DOT is proactive about evaluating PFAS contamination by testing some sites as early as 3 years before construction if contamination is expected. Further, willingness by the MPCA to designate off-site contamination as a “threatened release” or “identified release” gives the DOT more freedom to avoid delays caused by contamination.

Lessons Learned Regarding PFAS Identification and Mitigation

The Minnesota DOT does not anticipate having a full understanding of PFAS impacts on construction and maintenance policies until pending regulations are finalized. However, the agency explained that PFAS are in the popular culture and consciousness in Minnesota (largely because of a large settlement with a major local PFAS manufacturer). This has resulted in significant conversation about, and awareness of, the topic.

New Hampshire DOT

The New Hampshire DOT was selected for an interview on the basis of having both formal state-level guidance and procedures related to PFAS and informal state DOT guidance and procedures. Their state DOT approaches focus on legacy sites that the DOT owns or has acquired that are contaminated, which require monitoring and the use of consultants for compliance with New Hampshire Department of Environmental Services (NHDES) rules. There are also processes and procedures for New Hampshire DOT design and construction projects when PFAS is identified or suspected. In these projects, consultants may be used to assist with conducting an evaluation, assembling a management plan, and compiling contract documents to manage PFAS during construction.

NHDES has also required extensive water sampling at remediation sites, waste sites, and water supply wells across the state. This sampling program populates a PFAS GIS mapper tool used to catalog PFAS testing results.

Policy on Identifying and Mitigating PFAS Contamination

Mitigation consists largely of long-term monitoring and reporting at active contaminated sites or former landfills owned by the New Hampshire DOT. On November 22, 2016, NHDES issued a letter to responsible parties, site owners, and permittees to include PFAS as part of their groundwater sampling programs for specific contaminated sites. Some of these sites returned PFAS levels above the ambient groundwater quality standards (AGQS) established by NHDES. The requirement is to continue monitoring those sites. If monitoring results show three consecutive rounds of sampling below AGQS levels, testing discontinuation is considered.

On some legacy sites where PFAS is detected, a review to identify private or public water supply wells within a 500-foot radius is requested, which may constitute sampling. This review is conducted to confirm whether sensitive water users are nearby and, if so, to evaluate possible PFAS contamination and mitigative actions (water treatment, bottled water, etc.).

To identify potential contamination on their construction or maintenance projects, the New Hampshire DOT may conduct evaluations in-house or through consultant services. Identification includes the use of the NHDES PFAS GIS mapper, the NHDES OneStop GIS mapper, historical review for potential contamination, site walks, and other techniques. With every project, a 1,000-foot radius search is completed for sources of contamination (e.g., landfills, gas stations), including PFAS and other contaminants of concern. The NHDES OneStop GIS mapper can query for any remediation sites within 1,000 feet (or any other desired distance) of a project with significant excavation, dewatering, or both. These initial evaluations are sometimes performed by a consultant.

If no issues are identified, the project is considered clear. If there is suspicion of contamination, further investigation and coordination with NHDES may be sought.

Screening for PFAS Contamination on Construction and Maintenance Sites

With regard to screening and mitigation, the New Hampshire DOT shared an example of a project occurring near or within an identified PFAS atmospheric deposition site. A consultant was brought on board to assist with screening and mitigation measures. The screening of any project may involve groundwater, soils, and leachability testing. The example project included all PFAS contamination in groundwater and soil. The goal of the project was to reuse the material on-site instead of disposing off-site, such as at a landfill.

Methodologies for Mitigating PFAS Impacts

In the example project or others with PFAS contamination, the New Hampshire DOT prepares contract documents that include procedures for the contractor to follow when handling or managing PFAS contamination. For the example project, a groundwater and soil management plan was developed to maintain current site conditions (i.e., no construction-related increase in contamination). Because New Hampshire has no established rules or standards specific to remediating PFAS-impacted soils, the general approach is to consider reuse where it is geotechnically suitable and determined to be environmentally acceptable through a review or an investigation. The New Hampshire DOT wants to mitigate PFAS responsibly, controlling liability concerns and mitigating in a cost-feasible way. The department also has various approaches for managing construction dewatering liquids contaminated with PFAS.

New Hampshire DOT mitigation approaches are done with the realization that PFAS standards and requirements will be developed for surface water and soils in the future, and groundwater standards will likely become more restrictive. Other mitigation efforts could include removal to landfills, although not every landfill will accept PFAS-contaminated soils. Generally, the New Hampshire DOT tries to keep PFAS-contaminated soil on-site and within the New Hampshire DOT right-of-way in order to maintain control and limit liability. This is not unlike another approach unique to the New Hampshire DOT pertaining to roadside soils that, as indicated by nationwide information and statewide analytical data collected by the department, commonly contain metals (primarily arsenic), polycyclic aromatic hydrocarbons, and total petroleum hydrocarbons at concentrations above naturally occurring background conditions.

Identifying Materials or Containers That May Contain PFAS

The New Hampshire DOT Contamination Program is not aware of the department using any PFAS-containing materials.

Coordination and Communication Between State Agencies on PFAS

The New Hampshire DOT works closely with NHDES related to PFAS, as necessary and on a case-by-case basis.

PFAS Impacts on DOT Operations

Larger projects within the New Hampshire DOT’s Division of Operations are handled as construction projects, as previously described. The DOT has PFAS special provisions, contract documents, pay items, and soil and groundwater management plans. Before contractors can excavate, they must provide a project operations plan demonstrating planned means and methods of managing soil, groundwater, and other potential sources of PFAS contamination.

Lessons Learned Regarding PFAS Identification and Mitigation

The New Hampshire DOT noted several lessons learned that might be useful to other state DOTs. First, they note that tools such as a PFAS GIS mapper are helpful, though DOTs may still need to review historic maps and similar sources for additional investigations. Second, DOTs should not assume that the plan for managing the contamination of one project will fit another project; mitigation needs to be planned project by project. For example, the New Hampshire DOT’s waiver for dewatering worked on one project but not on another. Next, it is important for DOTs to understand the differences between deposition methods (air, point source, etc.) and how PFAS contamination occurs to mitigate it appropriately.

Finally, the New Hampshire DOT finds that the best approach is to be proactive and responsible to the public.

Pennsylvania DOT

The Pennsylvania DOT was selected for a case example interview based on having formal policies at both the state and DOT levels. Pennsylvania DOT staff have been closely monitoring PFAS developments for more than 5 years.

Policy on Identifying and Mitigating PFAS Contamination

Several Pennsylvania DOT publications provide policy regarding PFAS identification and mitigation. Pennsylvania DOT Publication 281 is the Waste Site Evaluation Procedures Handbook, which provides environmental due diligence procedures for transportation improvement projects and procedures for the management of fill. This publication will be updated to align with best practices for PFAS contamination potential by highlighting firefighting training sources, airports, and military bases. Pennsylvania DOT Publication 611, Volume 1, is the Waste Management Guidance Manual for Project Delivery, which details what to do with contaminated materials encountered on projects.

Pennsylvania’s Land Recycling and Environmental Remediation Standards Act governs remediation requirements, procedures, and regulations, as does 25 PA Code Chapter 250, but neither is specific to PFAS. Chapter 250 on the medium-specific concentrations (MSCs) used to demonstrate attainment of statewide health standards does discuss PFAS: This resource provides recent regulations that establish state drinking water MCLs for two PFAS compounds.

Pennsylvania’s DEP has not established soil or groundwater MSCs for PFAS compounds to date. Nonetheless, suspected or known PFAS sites have been included in several environmental site assessments for transportation projects during that time (mostly airports and military bases

with well-equipped firefighter training areas). However, no projects have actually encountered PFAS contamination.

Screening for PFAS Contamination on Construction and Maintenance Sites

The Pennsylvania DOT’s approach has been to first identify PFAS sources near projects and then determine the likelihood that contamination migrated to the project site. DEP does well sampling for PFAS and has prepared a supply well survey presenting areas of known contamination. The associated report and website (https://www.dep.pa.gov/Citizens/My-Water/drinking_water/PFAS/Pages/default.aspx) provide the Pennsylvania DOT with a valuable resource for identifying potential areas of contamination. The Pennsylvania DOT’s current challenge is educating district offices in better understanding PFAS and potential contamination.

Methodologies for Mitigating PFAS Impacts

The Pennsylvania DOT has not yet encountered PFAS on a project. However, they have determined that mitigation would include removal of contaminated materials to landfills. PFAS are not yet in landfill permits in Pennsylvania, and the DOT does not believe PFAS will be identified as a hazardous material. If that is the case, disposal of PFAS-contaminated soils will remain possible at general landfills.

The Pennsylvania DOT noted a challenge in the disposal of dewatering fluids. The leachate can create issues for wastewater treatment facilities and lead to a circular issue of moving the contamination, which could result in future testing. Testing could limit disposal opportunities and create challenges for testing laboratories. Currently, only one laboratory in Pennsylvania is certified for PFAS testing, and testing can cost $500 to $1,000 per sample.

Identifying Materials or Containers That May Contain PFAS

The Pennsylvania DOT has not identified any materials containing PFAS that are used in construction projects or for maintenance operations.

Coordination and Communication Between State Agencies on PFAS

Some Pennsylvania DOT staff communicate with DEP, but these relationships do not exist across each agency. For instance, an interagency task force on PFAS is led by the DEP and involves the Pennsylvania Department of Health, but the DOT is not involved. While involvement might improve the coordination of PFAS efforts, the absence of policy and regulations might make involvement less critical. However, the Pennsylvania DOT would like to be proactive in addressing PFAS contamination.

PFAS Impacts on DOT Operations

The Pennsylvania DOT is aware of potential impacts of PFAS on operations but has not been affected to date.

Lessons Learned Regarding PFAS Identification and Mitigation

The Pennsylvania DOT noted that PFAS expertise is limited within their department, so relying on consultants and building relationships with DEP staff have been vital. The DOT found communication with DEP particularly useful, enabling them to gauge the direction of regulations

and learn about PFAS-related tools. These tools included the EPA, PFAS Analytic Tools (https://echo.epa.gov/trends/pfas-tools), and DEP’s supply well survey.

The Pennsylvania DOT also noted that although other chemicals have a structured approach to mitigation, the lack of PFAS regulations can lead to inaction. They have found that they need a DOT champion to take interest in being proactive about PFAS and stewardship. In the absence of regulatory standards, PFAS-contaminated soil could be used as clean fill. The Pennsylvania DOT does not want that to happen, and they aim to protect property owners, water supplies, and the general public.

Tennessee DOT

Responses to the survey from the Tennessee DOT indicated that the state has informal policies and guidance related to PFAS but that the DOT itself does not have any PFAS-related policies or guidance. The survey responses further indicated that the agency does not test for PFAS contamination, nor has it identified PFAS contamination in any construction or maintenance operations. To gain more details on Tennessee policies and considerations regarding PFAS at both the state and the agency levels, the synthesis team requested an interview with the Tennessee DOT.

Policy on Identifying and Mitigating PFAS Contamination

Tennessee’s informal policies related to PFAS originate from the Tennessee Department of Environment and Conservation (TDEC). TDEC is unlikely to adopt formal state-level PFAS regulations until the U.S. EPA finalizes federal regulations. However, the state agencies’ current policy involves monitoring the federal regulatory landscape and preparing for the possibility of PFAS regulations.

Tennessee DOT policies may be influenced by landfills instituting analytical requirements or restrictions on PFAS-containing waste. However, no such requirements yet exist for any landfills in the state.

Screening for PFAS Contamination on Construction and Maintenance Sites

The Tennessee DOT does not screen for PFAS on construction and maintenance sites. Based on previous uses of—and industry activity on—the Tennessee DOT’s construction and maintenance sites, the agency does not believe that any of its sites are likely to be significantly contaminated by PFAS. For example, no Tennessee DOT sites are associated with large amounts of firefighting chemicals.

The agency expressed concern that, given the many PFAS that exist, any governmental regulations or guidance regarding landfills should clearly indicate which PFAS to screen for. The agency already screens for a long list of chemicals and values keeping that list as concise as possible.

Methodologies for Mitigating PFAS Impacts

The Tennessee DOT does not currently apply any environmental mitigation for PFAS impacts. In any future methodologies, contractors would play a large role in the evaluation of PFAS contamination. These contractors are at liberty to choose the analytical lab they employ for testing. The DOT expressed some concern that if nationwide regulations pertaining to DOTs were to go into effect, analytical labs may be unable to meet the increased demand. The agency has well-established mitigation protocols for other contaminants that would be relevant for developing PFAS-related protocols.

Identifying Materials or Containers That May Contain PFAS

The Environmental Division of the Tennessee DOT does not monitor or identify materials or containers that may have PFAS contamination. However, many of these chemicals are associated with airports and would therefore fall under the purview of the department’s Aeronautics Division. The Aeronautics Division may have separate procedures related to PFAS.

Coordination and Communication Between State Agencies on PFAS

The Tennessee DOT has good communication with TDEC. There is no formal mechanism for TDEC to communicate regulatory changes to the Tennessee DOT; however, personnel at TDEC are cordial with DOT leadership and know to contact the DOT regarding any new regulations. Communications with TDEC occur via phone and e-mail, and TDEC is responsive to the Tennessee DOT’s messages. Several contractors and Tennessee DOT employees formerly worked at state environmental agencies and can assist with communication or regulatory interpretation.

PFAS Impacts on DOT Operations

PFAS have not yet appreciably affected any Tennessee DOT operations. The agency is acutely aware of this family of chemicals and anticipates developing any new procedures after pending regulations on PFAS are finalized either by the U.S. EPA or landfills.

Lessons Learned Regarding PFAS Identification and Mitigation

If PFAS become federally regulated, the Tennessee DOT stated that they would like clear guidance on the implementation of identification and mitigation procedures.