摘要: |
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. There are no federal maximum contaminant level standards for PFAS compounds. However, states have regulated various PFAS compounds at varying standards and in varying media.
Some state departments of transportation (DOTs), such as New Hampshire DOT, Michigan DOT, and Minnesota DOT, are navigating PFAS-related issues, at significant expense, due to situations such as: 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, landfill testing requirements and restrictions leading to increased transportation and disposal costs.
A number of states directly address PFAS in their action plans with the focus on biosolids and wastewater treatment, sources that impact drinking water, air quality, landfills, and food safety, or airports where firefighting foams containing PFAS were known to have been used. 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. However, none of the identified state action plans explicitly address the impact of PFAS contamination on state DOT construction and maintenance sites.
The objective of this synthesis is to document state DOT current practice for identifying locations of potential PFAS contamination and for mitigating the impacts of PFAS related to highway construction and maintenance operations. The synthesis will look at PFAS impact and mitigation efforts in all phases of highway project development (planning, design, right-of-way acquisition), construction, and maintenance activities. The synthesis will consider impacts to soil, groundwater, surface water, and storm water. |