The U.S. Environmental Protection Agency (EPA) announced on June 15, 2022, it has significantly lowered Health Advisory levels for two chemicals and issued new Health Advisory levels for two additional chemicals. All four chemicals are part of a family often referred to as “forever chemicals.” Ames drinking water currently exceeds two of the new advisory levels (PFOA and PFOS).
“The Ames Water Plant has been closely monitoring both the science and the emerging regulatory framework around PFAS for several years,” said Water & Pollution Control Director John Dunn. “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.”
Testing of the finished water in Ames has been performed on four different occasions since December 2021, with different combinations of wells operating each time.
| Chemical | Ames Drinking Water Advisory Level (Avg Dec ’21 – Apr ’22) |
Old EPA Health Advisory | New EPA Health Advisory |
| Perfluorooctanoic acid (PFOA) | 2.2 ppt | 70 | 0.004 ppt |
| Perfluorooctane sulfonate (PFOS) | 4.6 ppt | 70 | 0.02 ppt |
| Perfluorobutane sulfonate (PFBS) | 1.3 ppt | None | 2,000 ppt |
| Hexafluoropropylene oxide (HFPO or GenX) | Not detected | None | 10 ppt |
A complete summary of all detected compounds, including concentrations from individual wells, is posted to the City’s website at www.cityofames.org/pfas
These chemicals are part of a class of chemicals known as per-and polyfluoroalkyl substances, commonly referred to as “PFAS.” The acronym PFAS refers to a huge class of manmade compounds that includes more than 5,000 individual chemicals. PFAS compounds have been extensively used for more than 70 years in applications such as: non-stick coatings; stain-resistant carpeting; water-repelling clothing and fabrics; paper packaging for food; metal plating operations; and, aqueous fire-fighting foams (AFFFs). There is emerging scientific data indicating that in even small concentrations, PFAS can pose a health risk.
Even before the new advisory levels were released on June 15, the Ames Water Plant was already taking measures to reduce PFAS. One of the utility’s 22 wells has been removed from the normal rotation. The utility has contracted with researchers at Iowa State University to complete a full source water assessment for PFAS chemicals and try to identify where they originated. And the utility has already reached out to an engineering firm to prepare possible treatment options and cost estimates.
Because PFAS chemicals have been used so extensively in a wide array of consumer products, they can be found everywhere in the environment. It was only within the past few years that analytical test methods have allowed PFAS to even be detected. The new advisory levels announced today for PFOA are almost 500 times lower than what today’s state-of-the-art analytical test methods can even detect, and PFOS is almost 100 times lower.
Home filter systems may provide an additional option for consumers. A study performed by the New Hampshire Department of Environmental Services found two classes of home filters that can be effective at removing PFAS compounds. Granular Activated Carbon (GAC) filters can be effective, as long as the customer regularly replaces the carbon filters at the interval recommended by the filter manufacturer. Reverse Osmosis (RO) systems can also be quite effective. But RO systems tend to waste two to four gallons for every gallon treated, so their use should be limited to points where water is used for drinking. 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/.
Original source can be found here.
