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Issues Of The Environment: Ann Arbor Moves Forward In Addressing PFAS Chemicals In Drinking Water

Brian Steglitz

Detectable levels of PFAS and PFOS chemicals are in the Ann Arbor municipal drinking water.  Progress was made in 2018, and more is expected in the new year.  In this week's "Issues of the Environment," WEMU's David Fair discusses next steps with Brian Steglitz, manager of the City of Ann Arbor's Water Treatment Services unit.


  • In December 2018, the Huron River Watershed Council sponsored an information session regarding PFAS in the Huron River and its tributaries.  The panel included the MDEQ, the city of Wixom, the Michigan Department of Health and Human Services, the City of Ann Arbor Water Treatment division, and the Washtenaw County Health Department.  At the forum, it was revealed that the level of PFAS in both the river and treated drinking water had spiked between the September and October sampling dates. 
  • The city’s test results for the spike show that raw intake water from the Huron River increased form 64.1 parts per trillion to 119.6 ppt.  PFAS toxins detected in water post-treatment went from 53.2 ppt to 88.1 ppt.  Craig Hupy, public services area administrator for Ann Arbor, noted that levels of PFOA and PFOS (two chemicals that the state has set health advisories for) were still below the current standard of 70ppb during that spike (22ppb).
  • Ann Arbor is in the process of changing all of its granular activated carbon (GAC) filters to the F400 type, which are better at removing these chemicals than the filters that have been used since 1989.  Additionally, during the December budget retreat the city called for spending of $80-90 million on plant and infrastructure upgrades for the water treatment system.  The design phase will begin in 2019. The goal of the improvements is to protect the city’s water form know contaminants (PFAS, cryptosporidium, etc...), and the potential for 1,4 dioxane as an emerging threat. The alternative would be connecting to the Detroit water system which would likely cost more that $300 million.
  • Testing for PFAS in Ann Arbor drinking water began in 2014, and in 2016 it was confirmed that the source of PFAS in treated drinking water is the Huron River.  In June 2018, one strong source of PFAS entering the river system was confirmed to be from Tribar Manufacturing Plant 4 in Wixom, showing concentrations of PFOS starting at 28,000ng/L.  Tribarhas since reduced their output of PFAS to about 250ng/L.  The MDEQ continues to look for other sources of PFAS entering the river.
  • Brian Steglitz, Manager of the Water Treatment Services unit for the city of Ann Arbor, maintains that despite the worrisome spike, the water coming from the treatment plant is safe to drink.  Discussions are being held this month about whether or not the city will conduct more frequent tests, independent of the MDEQ.

A History of PFAS Testing and Detection in the Huron River

  • 2014: First detection of PFAS in A2 drinking water
  • March 2016: Sampling results show that the Huron River, not groundwater wells, is PFAS source
  • 2016 - 2017: Ongoing monitoring of PFAS in Huron River and A2 drinking water
  • November 2017: Initiate pilot of new granular activated carbon (GAC) for better PFAS removal
  • 2017 - present: Ongoing monthly monitoring of PFAS in Huron River and A2 drinking water
  • January – August 2018: Evaluate data from GAC pilot (Average PFOS+PFOA decreased from 7.2 ppt in 2017 to 3.2 ppt)
  • September 2018: Staff recommends changing all filters to new GAC type, City Council approves
  • October 2018: GAC in 6 filters changed to new GAC type (F400)
  • November 2018 – 2020: WTP will participate in research on new PFAS treatment technologies
  • 2019: GAC in remaining filters will be changed to F400

GAC Filtration

GAC filtration is the best available technology for PFAS removal from drinking water.  Ann Arbor has used GAC filtration since 1989.  Various types of GAC absorb different chemicals at different rates.  (Source: slides from the December forum on PFAS at Washtenaw Community College)

Mlive FOIA of Drinking Water Results

[In December}, MLive/The Ann Arbor News requested the latest PFAS test results from the city, prompting the release of October numbers.  They show the PFAS count in the city’s raw intake water from the Huron River jumped from 64.1 parts per trillion to 119.6 ppt.  The amount of the toxic chemicals remaining in the city’s drinking water after treatment was up from 53.2 ppt to 88.1 ppt.  “The results indicate that the PFAS concentrations in the Huron River increased significantly between the September and October sampling dates, which resulted in increased concentrations in the city’s drinking water,” Hupy wrote in his memo.  Hupy’s memo indicates the combined PFOS and PFOA count in raw Huron River water jumped from 11.7 ppt to 50.5 ppt in October.

The city has been closely tracking two specific types of PFAS for which there are health advisories: perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA).  The amount remaining in treated drinking went up from 5.3 ppt to 22 ppt, which is the highest level in the last few years, though still below a high of 43 ppt from the first PFAS tests in March 2014.

Ann Arbor Water Treatment Plant to be Updated

In the beginning of December 2018, Ann Arbor held a budget retreat.  The city’s public services staff estimated they will need to spend about $80 million to $90 million upgrading the city’s water treatment plant.  Some structures date to the 1930’s and need replacing.  Designs will begin this year, but construction is not estimated until 2024-25.  City staff mentioned the upgrades being necessary to ensure a safe and reliable water supply, with PFAS and dioxane as pollutants of concern.  (Connecting to the Detroit water system was mentioned as a costly backup plan.  This route would likely cost more than $300 million, so the city would prefer to work toward cleaner water at the current plant.)

A Timeline of Tribar Industries and PFAS in the Huron River

Wixom Waste Water Treatment Plant (WWTP) Industrial Pretreatment Program (IPP)

- June source of PFOS was found at Tribar Plant 4 showing concentrations of PFOS starting at 28,000 ng/L
- Since August, Wixom issued an Administrative Compliance Order to Tribar requiring treatment to
remove PFOS in their sanitary discharges
- By October, an Activated Carbon Treatment system was set up at Tribar to remove the contaminants from their sanitary sewer discharges
- Weekly monitoring at Tribar and monthly monitoring at the Wixom WWTP has demonstrated the treatment system at Tribar has had a very positive, and ongoing, impact with the WWTP effluent PFOS levels declining from 4,800 to 940 to 530 to 240 ng/L

(Source: slides from the December forum on PFAS at Washtenaw Community College)

Wixom WWTP Effluent Sample Date PFOS (ng/L) Results: 

PFOA (ng/L)

  • 6/4/2018: 290 9.7
  • 8/29/2018: 4800 12
  • 9/25/18: 2100 14
  • 10/11/2018: 940 11
  • 10/15/2018: 530 7.1
  • 11/6/2018: 240 6.2

(Source: slides from the December forum on PFAS at Washtenaw Community College)


PFAS (an acronym for perfluoroalkyl and polyfluoroalkyl substances) are toxic, synthetic chemicals.  The PFAS family of chemicals contains more than 4700 similar contaminants.  Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) are most commonly addressed in the media.

PFAS are called “forever chemicals” because they are persistent, meaning they do not break down in the environment.  They also bioaccumulate, which means they build up in tissues and organs over time.  Human exposure to PFAS has been linked to:

  • decreased fertility and low birth weights in newborns
  • behavioral disorders in children
  • increased cholesterol levels
  • thyroid, kidney, liver, and immune dysfunction
  • cancer

The EPA issuesadvisory guidelines for PFAS, but federal regulations do not limit PFAS pollution, and it is not banned.

PFAS in drinking water is not regulated by federal law.  So far, public drinking water in the Huron River Watershed has tested as below the EPA advisory level of 70 parts per trillion.  Michigan law accepted this level as “safe to drink” in 2018.  However, the CDC has suggested that the standard is too high and should be lowered to 10 ppt.  Concerned residents on private wells should contact their county health departments.

PFAS are widespread in Michigan and have been found in the Huron River.  The Michigan Department of Health and Human Services (MDHHS) issued a “Do Not Eat Fish” advisory for the entire Huron River in 2018, and fish from the river and connected bodies should not be consumed.  Swimming in water containing PFAS is considered safe.  PFAS concentrates in foam, so do not ingest river foam.  For current guidelines relating to PFAS fish contamination, visit Michigan.gov/pfasresponse.

PFAS has been used in consumer products and manufacturing since the 1950s.  They are still being used to produce many common products including:

  • Non-stick cookware coated with Teflon and other synthetic treatments
  • Cleaning products, paints, varnishes, sealants, and waxes (look for “fluoro” ingredients)
  • Cosmetics, personal care products, and dental floss (look for “PTFE”)
  • Food packaging materials, including fast food packaging
  • Stain resistant carpet and fabric treatments; water-resistant clothing
  • Firefighting foam

To stay up to date on PFAS in Washtenaw County, please listen to WEMU’s coverage on 89.1 FM during “Issues of the Environment” and the “Green Room.”  Have questions?  Contact the Michigan PFAS Response Action Team | Michigan Environmental Assistance Center (MDEQ): (800) 662-9278.  (Source: Washtenaw County RiverSafe Homes newsletter, January 2019)

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— David Fair is the WEMU News Director and host of Morning Edition on WEMU.  You can contact David at734.487.3363, on twitter @DavidFairWEMU, or email him at dfair@emich.edu

Contact David: dfair@emich.edu
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