Quantifying the costs and benefits of EPA's PFAS rule to limit ‘forever chemicals’ in drinking water

ICF supported EPA in establishing its first-ever national drinking water standard for six per-and polyfluoroalkyl substances (PFAS), finalized on April 10, 2024. The final rule will reduce PFAS exposure for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious illnesses. Leveraging the latest science and our complex modeling capabilities, ICF supported the EPA in estimating the costs and health benefits of reducing PFAS in drinking water. This work helped EPA determine that the investment in improving treatment at public water systems is justified by the resulting health risk reductions.

Challenge

PFAS are manufactured chemicals that have been used in industry and consumer products since the 1940s. Often referred to as “forever chemicals,” they tend to break down slowly in the environment and can accumulate in humans and animals. PFAS are present in the nation’s drinking water and can contribute to adverse health effects including cardiovascular disease, low birth weight, cancers, and suppressed immune responses.

In accordance with the Safe Drinking Water Act (SDWA), EPA determined to set legally enforceable limits on certain PFAS levels in public drinking water to protect human health. Under SDWA, EPA must demonstrate that the benefits of new drinking water standards justify the costs.

The level of modeling complexity required to support this rulemaking was a challenge. The PFAS National Primary Drinking Water Regulation (NPDWR) simultaneously regulates multiple PFAS contaminants. Therefore, a multi-contaminant benefit cost modeling approach was essential. EPA also needed to combine complex information on pharmacokinetic modeling, exposure-response relationships, and economic valuation to evaluate the health benefits of reducing exposure to multiple PFAS contaminants. The EPA also needed to quantify co-benefits of the rule related to reduced disinfection byproduct formation associated with the implementation of treatment to reduce PFAS.

Solution

ICF staff supported EPA in developing a new variant of its SafeWater CBX model to estimate the compliance costs and health benefits of the PFAS drinking water standards. The new SafeWater Multi-Contaminant Benefit Cost (MCBC) estimates the costs and benefits associated with regulating multiple co-occurring contaminants. Compared to the SafeWater CBX model, SafeWater MCBC has the following additional features:

• Tracks each public water system’s level of multiple PFAS contaminants and compares them against each regulated maximum contaminant level
• Handles multiple co-occurring contaminants
• Allows for assignment of one or more technologies to achieve regulatory requirements and calculates changes in contaminant concentrations for use in estimation of benefits

ICF also supported EPA in developing state-of-the-art benefits modeling approaches to quantify reductions in cardiovascular disease and cancer risk. These approaches used life table modeling methods to estimate path-dependent health effects. The approaches were peer reviewed and received support from the EPA’s Science Advisory Board.

Results

The EPA’s finalized PFAS drinking water standards establish legally enforceable levels for six PFAS contaminants in drinking water and are estimated to reduce PFAS exposure for approximately 100 million people, prevent thousands of deaths, and reduce tens of thousands of serious illnesses. The annualized costs and health benefits of the PFAS drinking water standards will both be $1.5 billion. Additional benefits are expected beyond those that were quantifiable, further enhancing public health protection.