More water districts added to study on ‘forever chemical’ levels 

Residents in several Carmel water districts may soon see new treatment systems installed after testing found levels of so-called “forever chemicals” above New York State standards. 

Town officials say water districts 3, 4, 5, 6, 7, 9 and 12 have recorded levels of PFOA and PFOS—industrial chemicals linked to health concerns—above the state’s legal limit of 10 parts per trillion. Because of those results, the districts are currently considered out of compliance with the New York State Sanitary Code, and the Putnam County Department of Health has directed the town to pursue treatment options. 

PFOA and PFOS are part of a class of chemicals known as PFAS. They have been used for decades in products such as non-stick cookware, firefighting foam, and stain-resistant materials. Because they break down extremely slowly in the environment, they are often referred to as “forever chemicals.” 

To address the issue, the Town Board authorized engineering firm J. Robert Folchetti & Associates in September 2022 to study possible treatment methods that could remove the chemicals from the town’s drinking water. 

Engineers later recommended conducting a pilot study to determine which treatment technology would work best under real conditions in Carmel’s water system. 

During the course of the study, federal regulations also changed. The U.S. Environmental Protection Agency lowered its recommended limit for PFAS chemicals in drinking water to 4 parts per trillion, a much stricter standard than the previous 10-ppt level used by New York State. 

Because of the tighter federal guidance, Water Districts 7 and 14, which previously met the state standard, now also require treatment planning. 

The study ran for about 13 months, from April 2024 through May 2025, and tested three different treatment materials commonly used to remove PFAS from water: granular activated carbon (GAC), ion exchange resin, and OrganoClay. 

According to engineers, the carbon filter system lasted about nine months before it became saturated, meaning it could no longer effectively remove the chemicals. The other two technologies—ion exchange and OrganoClay—remained effective for about 12 months during the trial. 

Town engineers now plan to expand their report to include those districts and to incorporate the findings from the year-long pilot program. State health officials also require the pilot project results to be submitted as a separate technical report. 

The original engineering contract for the PFAS investigation was $147,000, paid for through the operating budgets of the affected water districts. 

Town officials are now considering a $26,200 contract amendment to allow engineers to complete the expanded study, add the newly affected districts and prepare the required pilot study report. 

Engineers say the final report will help determine the most effective treatment systems for each district and estimate both construction costs and long-term operating expenses. 

Once that analysis is complete, town officials will decide how and when to move forward with installing permanent treatment systems to ensure Carmel residents continue to receive safe drinking water.