News & Events

PFAS Implications on Drinking Water & Remediation in Connecticut

At a Glance


On June 15th, 2022, the Connecticut Department of Public Health (CTDPH) updated their Drinking Water Action Levels (DWALs) for four PFAS compounds (Circular Letter Nos. 2022-27 and 2022-29.) These DWALs are for four (4) PFAS specific compounds replacing the sum of five (5) PFAS compounds equal to or lower than 70 nano-grams per liter (ng/L or parts per trillion). The CTDPH made these reductions based upon the latest evolving science associated with EPA human toxicology studies. The CTDPH’s update coincided with EPA releasing their new Interim Drinking Water Health Advisory (HA) for PFOS/PFOA (0.02 ng/L / 0.004 ng/L) and the final HA for PFBS and Gen-X (2,000 ng/L / 10 ng/L). The new individual CTDPH DWALs are as follows.

CT DWAL chart

The Connecticut Department of Energy and Environmental Protection (CTDEEP) is reassessing the Remediation Standard Regulations (RSRs) for soil and groundwater taking into consideration these updated DWALs. Because much of the groundwater in Connecticut is considered suitable for direct human consumption, the PFAS revisions to the RSRs will likely be lower than the current sum of five (5) PFAS compounds equal to or lower than 70 ng/L. Changes may also be made to the soil direct exposure criteria (human contact) and pollutant mobility (leaching into the groundwater) criteria. The CTDEEP is also considering issuing new surface water criteria for PFAS which are not currently included within the RSRs.

These changes will have a wide impact on industry (site investigations, remediation, and wastewater discharge permits), water supplies (treatment to lower action levels), wastewater dischargers (biosolids, and surface water discharges), municipalities (application of firefighting foams (AFFF) and Brownfields), and real estate transactions.

Because of these regulatory changes and that PFAS is ubiquitous in the environment, GZA recommends that our clients develop a sampling plan to prevent cross-contamination, evaluate the use of forensic assessments to differentiate between sources (should a release of PFAS be identified), develop a stakeholder communication plan should a release of PFAS be identified, and develop risk management strategies and associated cost estimates to manage the remediation of PFAS.