The U.S. Environmental Protection Agency (EPA) significantly lowered Health Advisory levels for two chemicals and issued new levels for two more chemicals June 15.

Since December 2021, the tap water in Ames has been tested for chemicals four times and twice exceeded the new levels set last week. These chemicals are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). 

These chemicals are part of a class of chemicals that is part of a group of about 5,000 other chemicals known as perfluoroalkyl and polyfluoroalkyl substances. They are commonly referred to as “PFAS.”  While they are nothing new, the city of Ames said that PFAS could pose a health risk.

Before last week’s changes, the advisory levels for PFOA and PFOS have been 2.2 parts per trillion and 4.6 parts per trillion (ppt), respectively, in Ames. Now, the new level will be set at 0.004 ppt for PFOA and 0.02 ppt for PFOS. Both exceed the amount the advisory suggests.

While the presence of these chemicals may seem discouraging to the public, the city of Ames has been doing its part to keep its citizens safe.

“The Ames Water Plant has been closely monitoring both the science and the emerging regulatory framework around PFAS for several years,” Water & Pollution Control Director John Dunn said. “We have proactively undertaken perhaps the most comprehensive source water assessment of any utility in Iowa so that our customers will have information that is as complete and accurate as possible.”

The Ames Water Plant has already taken measures to reduce PFAS. Researchers at Iowa State University have been contracted to do a full water investigation to keep an accurate account of how the drinking water in Ames is fairing.

Home filter systems can also provide an additional option for the citizens of Ames. Two classes of home filters—Granular Activated Carbon (GAC) filters and Reverse Osmosis (RO) systems—can be effective at reducing these chemicals.

The National Sanitation Foundation (NSF) maintains a listing of products that claim to remove PFOA and PFOS compounds on its website: https://info.nsf.org/Certified/DWTU/. 

A full summary of all the detected chemicals/compounds, including concentrations from individual water wells, is posted on the city’s website at www.cityofames.org/pfas.