PFAS Part IV – PFAS in Major Rivers of the Great Miami River Watershed

By Mike Ekberg, manager of water resources monitoring and analysis

Are PFAS compounds present in our rivers and if so at what levels or concentrations are they present?  Recent river water sampling by the Miami Conservancy District (MCD) shows some Per- and Polyfluoroalkyl Substances (PFAS) compounds present in all of the major rivers. The results also show they only appear to be present at very low concentrations. Our results show concentrations far below any federal or State of Ohio action levels. That’s certainly some good news! There is no reason not to fish, paddle, or otherwise enjoy recreation along our rivers because of PFAS.

These results provide further evidence that PFAS compounds are a growing challenge to our region. A strategic roadmap for dealing with the presence of these chemicals in our natural water is needed to help address this challenge.    

The issue of PFAS toxicity in treated drinking water, as well as natural waters, has gained worldwide attention in recent years. For background information on PFAS read the MCD blog three part series.

Study approach

To evaluate the levels of PFAS in river water, MCD staff designed and implemented a study to look for six PFAS compounds. These same compounds were studied by the Ohio Environmental Protection Agency (OEPA) in samples collected from public drinking water systems as part of a statewide plan. The compounds studied:

  • perfluorooctanoic acid (PFOA)
  • perfluorooctanesulfonic acid (PFOS)
  • perfluorobutanesulfonic acid (PFBS)
  • perfluorohexanesulfonic acid (PFHxS)
  • perfluorononanoic acid (PFNA)
  • hexafluoropropylene oxide dimer acid (GenX)

To conduct the study, samples were collected four separate times (March, July, August, and October) in 2021. The samples were collected at four sites: two on the Great Miami River, the Stillwater River and the Mad River (see map below). The samples were analyzed by Eurofins Eaton Analytical laboratory using US EPA Method 537.1.


None of the detections exceeded any of the current federal or State of Ohio human health advisories for PFAS in drinking water. There were detections of PFOA, PFOS, PFBS, and PFHxS at one or more sites. There were no detections of PFNA and GenX.

Overall, the results suggest some PFAS compounds are widespread in the river water studied, albeit at very low concentrations (see charts below). MCD cannot determine the sources of the PFAS from this dataset alone.

Next steps

The results of this study, combined with the results of the OEPA’s statewide sampling program, and local efforts by the City of Dayton and WPAFB all point to the need for a strategic roadmap to deal with the presence of these compounds in natural water resources.

The US EPA recently released the document PFAS Strategic Roadmap: EPA’s Commitments to Action 2021 – 2024. The roadmap focuses on three central directives:

  • Research. Invest in research, development, and innovation to increase understanding of PFAS exposures and toxicities, human health and ecological effects, and effective interventions that incorporate the best available science.
  • Restrict. Pursue a comprehensive approach to proactively prevent PFAS from entering air, land, and water at levels that are harmful to human health and the environment
  • Remediate. Broaden and accelerate the cleanup of PFAS contamination to protect human health and ecological systems.

The roadmap could place PFAS contamination at military bases and other sites into the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as the Superfund process. This would remove a loophole in the regulatory process and could expedite cleanup actions.

The roadmap could also lead to the establishment of maximum contaminant levels for some PFAS compounds which will help to answer the question of what levels of PFAS are safe. More research into the health effects of PFAS will occur if the roadmap is implemented. 

The roadmap could lead to an increased effort on the part of U.S. EPA and industry to begin to eliminate at least some PFAS compounds from the manufacturing process. Eliminating unsafe PFAS compounds from consumer products is critical to managing the PFAS issue for future generations.  

The key to success or failure will be the willingness of current and future USEPA administrators to commit to this roadmap for the long term. PFAS is a challenge for the Dayton region (see the Dayton Water Quality and Infrastructure Review), but certainly not hopeless. Treatment options are available to remove PFAS from drinking water. WPAFB has successfully implemented a treatment system that removes PFAS from drinking water and provides safe potable water.

MCD will continue to research and report on this challenge as we learn more.


Charts showing detections of PFAS compounds
All of the detections are reported in nanograms per liter (parts per trillion).

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s