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Fact Sheet: Important Information about PFAS

What is sparking the current interest in PFAS?
The U.S. Environmental Protection Agency (EPA) on June 15, 2022, set new interim Health Advisory Levels for four per- and poly-fluoroalkyl substances (PFAS).

Des Moines Water Works (DMWW) is and has been proactively monitoring for PFAS in our source waters and finished drinking water for several years.

First of all, what are PFAS compounds?
PFAS is a category of man-made chemicals designed to resist heat, oil, stains and water in items such as Teflon, Gore-Tex and even pizza boxes and fast-food wrappers. It is also found in certain firefighting foam used at airports and on military installations. During production and use, PFAS can migrate into soil, water and air. Drinking water can be an additional source of exposure in communities where these chemicals have entered the water source such as a river.

The U.S. Environmental Protection Agency (EPA) regulates the safe levels for hundreds of compounds in drinking water. Currently, there is no federal regulation for PFAS. Many water utilities, including our scientists at Des Moines Water Works are conducting research to determine the levels of PFAS in our water and what treatment options can reduce levels.

What is the EPA’s health advisory level, and what does it mean?
Health advisories are not enforceable like regulations. Health advisories are interim guidance before the EPA develops a formal regulation. Sometimes, the advisory is lower than current analytical methods can detect, which is the case today with the new PFAS advisory.

The new interim health advisory levels were set by EPA at 0.004 parts per trillion for perfluorooctanoic acid (PFOA), and 0.02 parts per trillion for perfluorooctanoic sulfonate (PFOS). For perspective, 1.0 part per trillion is equal to one second in 35,000 years. In 2016, the EPA established the first Drinking Water Health Advisory for PFAS, at 70 parts per trillion.

What are DMWW and EPA recommending to consumers?
DMWW customers may continue to drink tap water. The EPA interim advisories do not recommend that consumers stop using tap water, nor do they recommend the use of bottled water.  DMWW’s treated drinking water continues to meet all state and federal regulatory requirements.

What are the levels in DMWW finished water? 
Our scientists have been proactively testing for PFAS since the utility learned that PFAS compounds were found at the Iowa Air National Guard base at the Des Moines International Airport. Frink Creek, which drains portions of the Air National Guard base, flows through Des Moines Water Works Park on its way to the Raccoon River. The Raccoon River is a water source for DMWW.

Samples taken Feb. 25, 2021 revealed, for the first time, detectable levels of PFAS in DMWW finished (treated) drinking water. Samples since then have shown levels between “No Detection” up to 3 parts per trillion – which is significantly less than the previous advisory (70 parts per trillion) but higher than the new interim advisory levels.

PFAS Monitoring Results at Fleur Drive Treatment Plant
(All samples at other treatment plants showed non-detectable levels of all PFAS tested)

PFAS Compound

Previous EPA Health Advisory Level

Des Moines Water Works
Monitoring Averages

New Interim EPA Health Advisory Level (ppt*)


70 ppt combined with PFOS


0.004 ppt


70 ppt combined with PFOA

2.1 ppt

0.02 ppt

Gen X



10 ppt




2,000 ppt

*ppt = parts per trillion

What is DMWW doing about PFAS?
We recognize the level of PFAS in our monitoring is higher than the EPA’s new health advisory levels. That’s why research is a priority. Our team of scientists and engineers need to learn more, specifically:

  • Determine the levels of PFAS in our water with additional monitoring and identify any patterns
  • Understand established and emerging treatment options
  • Develop practical and feasible strategies to reduce levels of PFAS as the EPA finalizes its future drinking water standards

The lower the level, the lower the risk. Public health and the quality of your drinking water is our top priority.

DMWW continues to work closely with regulators at the EPA and the Iowa DNR, as well as keeping in close touch with our Congressional delegations in hopes of bringing focus and solutions to addressing PFAS in drinking water supplies.

If you have questions, please contact Des Moines Water Works at (515) 283-8700. We are always available to talk about how we produce and deliver your safe drinking water to 600,000 central Iowans.

For more information, please see EPA's Frequently Asked Questions

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