Info About PFAS and Drinking Water


What are PFAS?


PFAS – or per- and polyfluoroalkyl substances – are a group of manmade chemicals including PFOA and PFOS found in a wide range of everyday products. These products are used by consumers and industry. For example, PFAS have been used in coatings for textiles, paper products and cookware, so most people have been exposed to these chemicals at very low levels. They have also been used to make some firefighting foams, in the aerospace and aviation industries and at military bases across the nation. For detailed information about PFAS, go to the U.S. EPA’s website on PFAS, Information is also at the Agency for Toxic Substances and Disease Registry. Its website is


Are PFAS harmful to me? Can I get cancer?


The health effects of PFAS exposure at low levels in people are uncertain. The early stages of animal studies suggest that exposure to high doses of PFAS may lead to adverse health effects in people. Even so, the substances have been used for years in many common products, such as fast-food wrappers, stain-resistant carpets and rugs, non-stick cookware, water-resistant clothing, cosmetics, and dozens of other items. So, most people have probably already been exposed to it. For detailed information about PFAS, go to the U.S. EPA’s website on PFAS, Information is also at the Agency for Toxic Substances and Disease Registry. Its website is


Is my water safe?


Yes!  The EPA describes Dayton’s drinking water quality in one word: Excellent.


Dayton uses monitoring wells to provide early warning of possible risks. These wells ensure the quality of our water. They do not send water to our customers. This monitoring well network allows scientists and water professionals to act before contaminants reach drinking water.


Testing of monitoring wells detected PFAS at low levels in some of the wells. Dayton took quick action. Dayton shut down 8 nearby production wells. Production wells send the water to the treatment plants. This was a precautionary action and did not affect our water customers. The aquifer has over 1.5 trillion gallons of water. Dayton customers only use about 60-65 million gallons of water each day. So, we have plenty of safe water for our customers. 


We are proud of our 600 monitoring wells. We are proud of the safety steps we take. We are proud of our high-quality water.


The chart at the top of this page provides the levels of PFOA/PFOS compounds in the effluent at our Ottawa Water Treatment Plant.  The levels of PFOA/PFOS compounds at our Miami Water Treatment Plant are non-detect.



How did PFAS get in the groundwater?


PFAS gets into the groundwater through the runoff of substances with PFAS in them.  PFAS in the groundwater has been identified at multiple sites.  The migration of the PFAS in the groundwater toward the City’s wellfields is carefully monitored.



How is Dayton ensuring that my water continues to be safe? 


The City operates a robust early warning monitoring system discussed above. In fact, the system detected the new PFAS contaminant. We acted, including shutting down production wells closest to possible PFAS sources. 


Our source water protection program is nationally recognized. In 2019, the program received its 25th award as a Groundwater Guardian Community. The award, from The Groundwater Foundation, is for programs that protect groundwater. For information about The Groundwater Foundation, go to:


Dayton proactively and aggressively tests for contaminants. Dayton acts on the information. Dayton communicates with its customers.


What is the City doing about PFAS?


The City has been taking action for years. The City samples its water more than required. We test extensively to make sure that our water meets or exceeds all drinking water standards.


We have around 600 groundwater monitoring wells placed around the City’s production wells and wellfields. These monitoring wells identify groundwater contaminants. They do not produce water used by customers. Production wells produce water used by customers. The system is designed so that monitoring wells can detect contaminants in groundwater before it even reaches the production wells.

Our water distribution system is tested daily from many locations within the city. Also, water treatment plant employees perform process control testing every two hours around the clock.

 We share the results of our testing with the Ohio EPA monthly. We voluntarily and continually work with the Ohio EPA to address PFAS. We work to stop PFAS-tainted groundwater from reaching monitoring and production wells.  


For the protection of all, we have proactively shut down production wells close to potential PFAS sources. In addition, we work to use the smartest approaches to pumping in our well fields to ensure our customers receive the highest quality water. Our efforts are paying off. Our drinking water quality is “excellent.”


How can the migration of PFAS in the groundwater toward the City’s wellfields be fixed?


The migration of groundwater with PFAS can be reduced, and even stopped. This can be accomplished by installing special wells near potential sources. These wells can draw any contaminated water back toward the source.


What if the migration of PFAS in the groundwater toward the City’s wellfields isn’t fixed?

The City is investigating ways it can use technology to treat its water supply for PFAS if ever needed.  This includes studying how to remove PFAS from the aquifer as well as at the water treatment plants. If needed, technology could stop these contaminants before they reach water customers.


How does testing for PFAS work and how long does it take?


U.S. EPA has developed testing protocols. We have worked closely with Ohio EPA. We are following those procedures. This is necessary so that samples are collected without introducing outside contaminants, such as sunscreen, cleaning products, bug spray, food packaging, etc. Currently, these samples are sent to a certified laboratory for analysis. Results are generally available in 6-8 weeks. These results are then shared with the EPA and key stakeholders.


The City’s Water Quality Lab purchased special equipment to perform PFAS testing in house.  This will result in quicker turn around for test results.


Who will pay to fix this PFAS problem since the water system is funded by ratepayers?


The City has engaged an environmental consultant. The consultant is completing a Feasibility Study.   This study will determine how best to address the PFAS issue. Until the study is completed, we won’t know the cost to address the issue. Dayton will look to be repaid for fixing the PFAS issue by those who caused the problem. We have already begun that process by filing a federal lawsuit against five companies. These companies made and sold products that leached PFAS into the aquifer.


How is information shared with others?


One way is through open communication on this website. 


We have and will continue working with our stakeholders. Our stakeholders include wholesale and retail customers. Wholesale customers include Brookville, Clayton, Greene County, Montgomery County, Oakwood, Trotwood, and Vandalia. The Ohio EPA is also a stakeholder.  


The City regularly meets with the Ohio EPA and key stakeholders. These meetings work on sampling, testing, and monitoring. The meetings also work on how to contain PFAS migration. 


Is the water in the distribution system tested for PFAS?


The City does not test for PFAS in the distribution system.  There are no Ohio EPA approved methods for distribution system PFAS sampling and testing.


We absolutely support testing to identify and quantify PFAS levels. And we welcome any testing for PFAS that is done in accordance with Ohio EPA approved methods. These methods have been developed for site specific sampling locations using approved regulatory sampling procedures. These approved methods and procedures are how Dayton tests for PFAS. 


Greene County hired a consultant to test for PFAS at thirteen locations within its distribution system.  The consultant’s January 25, 2021 memorandum reported values well below the Health Advisory Limit at three of the sampling locations.


Montgomery County plans to sample and test within its distribution system as well.


Proper testing using approved methods can and should be used to identify and quantify PFAS levels. 

Click this link:  Water Emergency Preparedness for information about Water Emergency Preparedness.