PFAS Chemicals

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WHAT IS PFAS?

PFAS, or per- and polyfluoroalkyl substances, is a huge class of manmade compounds that have been used for over 70 years in products that are resistant to heat and repel water and oil, such as non-stick coatings; stain-resistant carpeting; water-repelling clothing and fabrics; paper packaging for food; metal plating operations; and aqueous fire-fighting foam. During production and use, PFAS can migrate into the soil, water, and air, remaining in the environment over time as they do not break down easily.

The presence of PFAS in the environment is a national issue and the number of communities around the US detecting the compounds in drinking water is growing quickly. Research is still ongoing to determine how different levels of exposure to different PFAS can impact health, especially effects associated with low levels of exposure to PFAS over long periods of time.

Sioux City began participating in an Iowa DNR program in August of 2022 to proactively determine the prevalence of a PFAS in the city’s drinking water.

The City of Sioux City is one of 54 communities participating in the Iowa Department of Natural Resources’ (DNR) PFAS Action Plan, a statewide water sampling initiative to determine the prevalence PFAS in drinking water. The number of communities around the U.S. detecting the compounds in drinking water is growing quickly and the DNR’s initiative follows new guidance from the U.S. Environmental Protection Agency (EPA) in June that drastically lowered the minimum reporting levels for the chemicals. The new advisories’ exposure levels replace the previous level set in 2016, and were set near zero to provide Americans, including the most sensitive populations, with a margin of protection from a lifetime of exposure. They also take into account other potential sources of exposure to these PFAS beyond drinking water, such as food, air, consumer products, etc. The advisory is nonregulatory and is intended to be in place during the time between initial understanding of health effects and publication of the final health advisory. The EPA anticipates proposing a National Primary Drinking Water Regulation by the end of 2022 and finalizing it by the end of 2023.

Because Sioux City’s drinking water sample collected in August 2022 indicated 4.4 parts per trillion (ppt) of one PFOS compound, exceeding the minimum reporting level of 4.0 ppt, the Iowa DNR is requiring the City of Sioux City to notify residents of this test result.

PFAS PRESENTATION

NEW PFAS REGULATIONS

On June 15, 2022, the US EPA released new Health Advisory Levels for four individual PFAS chemicals. Click here to be taken to the US EPA’s PFAS Health Advisory page. The drinking water in Sioux City exceeds the Health Advisory Levels for two chemicals, PFOS and PFOA. The average values of the four chemicals covered by the Health Advisory are shown in the table below.

The Iowa Department of Natural Resources maintains a database of PFAS test results from individual drinking water systems in Iowa. Click here to view the IDNR’s data for Sioux City and other Iowa communities.

Chemical	Sioux City Southbridge Drinking Water (Avg. March '22 - October '22)	New EPA Health Advisory
Perfluorooctane Sulfonate (PFOS)	4.4 ppt	0.020 ppt
Perfluorooctanoic Acid (PFOA)	5.7 ppt	0.004 ppt
Perfluorobutane Sulfonatae (PFBS)	22 ppt	2,000 ppt
Hexafluoropropylene Oxide (HFPO or GenX)	Not Detected	10 ppt

Data above is reported as "parts per trillion" (ppt).

FAQs

Is Sioux City water safe to drink because of the PFAS?
It is just as safe as it was a month ago, a year ago, and ten years ago. The concentration of PFAS chemicals hasn’t changed. What changed is the non-regulatory Health Advisory from the US EPA.

Current scientific investigation into the potential health impacts of PFAS is rapidly changing. In 2016, EPA published health advisories for PFOA and PFOS based on the evidence available at that time. The science has evolved since then, and EPA has now replaced the 2016 advisories with interim updated lifetime health advisories for PFOA and PFOS that are based on human epidemiology studies in populations exposed to these chemicals.

Based on the new data and EPA’s draft analyses, the levels at which negative health effects could occur are much lower than previously understood when EPA issued the 2016 health advisories for PFOA and PFOS.

There is still considerable debate among leading experts regarding the new levels set by the US EPA.
In a press release, the American Water Works Association (AWWA) noted “The PFOA and PFOS advisory levels are extremely low and do not reflect the draft recommendations of EPA’s own expert Science Advisory Board review.” Click here to read the press release.

Even EPA’s Health Advisory Fact Sheet notes “The EPA Science Advisory Board is reviewing EPA’s analyses, and therefore, these interim health advisory levels are subject to change.” Click here to read the EPA's Health Advisory Fact Sheet.

What is Sioux City doing about PFAS?

The City has entered into a quarterly testing/monitoring program with the Iowa DNR.

As more and more communities find themselves impacted by new regulations and the increasingly present nature of PFAS, Sioux City awaits additional guidance from state and federal agencies on how to best address the issue. While new regulations require communities to report extremely small amounts of PFAS in drinking water, resources and definitive guidance to address the issue are emerging.

Is the source of the detected PFAS in Sioux City water known?
Because of the wide-spread use of PFAS compounds over the past seventy years, these compounds can be found almost anywhere in the environment, including ground water. The US EPA noted in their PFAS fact sheet that PFAS have been detected worldwide in the air, soil, and water. Due to their widespread use and persistence in the environment, most people in the United States have been exposed to PFAS and have traces of PFAS compounds in their blood. The source of Sioux City’s contamination is the use of fire-fighting foams at the 185^th Air Refueling Wing.

Should I drink bottled water?
At this time, EPA is not recommending bottled water for communities based solely on concentrations of these chemicals in drinking water that exceed the health advisory levels.

Individuals who are concerned about PFAS in their wells or in their homes may consider in-home water treatment filters that are certified to lower the levels of PFAS in water. You can find more about these filters. If you are concerned about potential health effects from exposure to these PFAS above the health advisory level, contact your doctor or health care professional.

Is EPA going to establish a national drinking water regulation for PFOA, PFOS and additional PFAS?
EPA is developing a proposed National Drinking Water Regulation for publication by the end of 2022 for PFOA and PFOS. As EPA undertakes this action, the agency is also evaluating additional PFAS and considering regulatory actions to address groups of PFAS. EPA anticipates finalizing the rule by the end of 2023.

Can any changes be made to the treatment process to remove PFAS?
Yes; there are ways to remove PFAS from drinking water, but no changes to the treatment process will be implemented until the final rule is released.

If a customer wants to take extra precautions on their own, what is recommended?
There are some home filters that customers could use. 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 replaced 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 their website. Click here to view the list.

The US EPA has prepared a fact sheet that describes ways to minimize PFAS exposure from additional sources. Click here to view that fact sheet.