Quantifying the Liability of Sites with PFAS
To estimate the cost-to-cleanup at a given property, experience gained from other legal cases is often used to estimate the cost-to-cleanup of similar properties contaminated by well-known contaminants (for example, petroleum hydrocarbons or tetrachloroethylene and its reductive dechlorination daughter products). However, because PFAS is a family of emerging contaminants, there are limited legal cases and the application of some well understood costs associated with common contaminants at similar sites may not apply. While this is the case, tools exist that allow for the quantification of cost-to-closure estimates at PFAS-impacted properties.
Environmental consultants regularly generate environmental cost-to-cleanup estimates in support of property transactions and M&A, even in instances where there is little to no data on hazardous constituent concentrations in environmental media. Reliable PFAS cost-to-closure estimates may be developed using detailed parametric cost evaluation tools to create detailed and reasonable bottom-up cost estimates. Parametric estimating uses a library of unit costs developed from engineering/environmental sources on investigation and remediation activities. Since PFAS are emerging contaminants, there is a smaller amount of data on investigation and remediation techniques, and, therefore, a smaller library of applicable unit costs. Thus, when providing PFAS cost estimates, understanding the latest developments in PFAS investigation and remediation technologies is critical.
Mitigating PFAS Liability Uncertainties
To reduce the uncertainty and better quantify cost-to-cleanup estimates for PFAS-impacted properties, the following items should be considered.
Professional judgment
Professional judgment will be critical in providing reliable cost-to-cleanup estimates for PFAS. Consultants experienced in characterizing PFAS in the environment and in evaluating treatment technologies for PFAS-contaminated environmental media should be relied upon for conducting these estimates.
Establish and refine the conceptual site model (CSM)
Once the regulatory framework is understood, the cost-to-closure is largely driven by the nature and extent of PFAS contamination, the geological and hydrogeological environment, and the potential human health or ecological receptors of the PFAS. This information is typically documented in a CSM, which can be assembled by an experienced environmental consultant. The CSM helps determine the magnitude of the PFAS issues and focus cost estimate parameters. It is also important because cost-to-closure estimates for small or isolated areas will typically contain a higher level of certainty than estimates for areas where there are multiple sources and several different environmental media (i.e., soil, groundwater, or surface water) that have been impacted. Some uncertainty can be eliminated by refining the CSM through Freedom of Information Act requests for publicly available environmental documentation, conducting a remedial engineering evaluation of existing data, and completing investigations at the property. The time frame of the real estate or M&A deal will impact the extent to which these additional activities can be conducted and the amount of uncertainty that needs to be addressed.
Estimating time-to-cleanup
While the cost-to-closure estimate is dependent on the capital cost of installing a remediation system to treat PFAS, the total cost is highly sensitive to the time required to achieve a No Further Action determination. Annual costs associated with groundwater monitoring and remedial operation and maintenance (O&M) are not negligible, particularly at properties that will be subject to perpetual treatment given the extremely low cleanup standards that are being promulgated by applicable regulatory agencies. Due to a limited history of treating PFAS in soil and groundwater, estimating time-to-cleanup for PFAS is more difficult than estimates for more common contaminants. In such cases, U.S. Department of Defense guidance recommends that the maximum time span for projecting recurring O&M costs is 30 years, unless supported by site-specific circumstances.