Info About PFAS and Drinking Water

What is PFAS?

PFAS – or per- and polyfluoroalkyl substances – are manmade chemicals 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

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. The monitoring wells allow scientists and water professionals to act before contaminants reach drinking water.

Recent testing of monitoring wells detected PFAS at low levels. 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.

Here is a chart showing the levels of PFAS detected in our water with respect to the Health Advisory Limit:

2020 Ottawa Results Slide

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 year 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 Dayton going to be another Flint, Michigan?

Absolutely not. What is happening here is the opposite of what happened in Flint, Michigan.

The City operates a robust early warning monitoring system. 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.

Why didn’t the City do anything before now?

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

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 about 10 different locations. 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 quarterly. 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.”

What are you doing about PFAS? Is there a way to fix this? What are next steps?

Yes, this can 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.

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 the testing 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. 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.

Who will pay to fix this 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 the people 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.

What can I do if I have questions about this? Who can I call if I think the water is making me or a family member sick?

If you have questions or think the water is making you or a family member sick, 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

Why aren’t you telling Montgomery County about your test results?

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.

We also have had numerous communications with Montgomery County Environmental Services personnel about PFAS. Montgomery County also receives our tests results.

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. We share this information openly with our stakeholders, including Montgomery County.

Why shouldn’t Montgomery and Greene County also test for PFAS – doesn’t that just make the water safer?

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. 

Montgomery and Greene Counties want to test for PFAS in the distribution system. That’s different from the Ohio EPA approved testing we already conduct. There are no Ohio EPA approved methods for this type of testing. Testing using unapproved methods can produce unreliable results.

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

Will it cost City of Dayton residents more if the counties also test for PFAS?

No. It will not cost City of Dayton residents more if Montgomery and Greene Counties also test for PFAS.

Montgomery County says the City has denied requests for more information about PFAS. Why would you do that?

This simply is not true. The City continues to work with our partners across the region, including Montgomery County. We regularly communicate with Montgomery County Environmental Services personnel about our PFAS testing and remediation efforts. In fact, the City, Ohio EPA and key stakeholders meet on a monthly and quarterly basis to work on sampling, testing and monitoring PFAS and figuring out how to contain PFAS migration, and we share this information with our customers, including Montgomery County. 

Is Dayton water really prepared for an emergency, like the tornadoes of 2019?

Absolutely. The first half of 2019 brought two of the biggest challenges we’ve encountered. The water main break and the tornadoes caused water outages. These events led to boil advisories. But we were prepared for each event.

Each Dayton water treatment facility has Emergency Response Plans. These plans address all types of emergencies. We update those plans annually – that’s an Ohio EPA requirement. We go beyond requirements. Every year, we practice for natural disasters and other catastrophes. These exercises include our community partners, such as Public Health, Ohio EPA, businesses, universities, Public Works, Police and Fire.

We use case studies of actual events from other water utilities to test the capabilities of our water system and evaluate our response under similar conditions. We also test the systems with simulations of manmade disasters, natural disasters, cyber-terrorism, and more. 

By simulating emergencies, in detail, we prepare for the real thing. The lessons learned from all these exercises are used to improve operations.

Here are two charts showing our water system and compliance with best practices:

2020 Water System Overview Slide

2020 Established Best Practices Slide

What is redundancy and how does redundancy work? 

Redundancy refers to duplicate systems that lessen service interruptions to our customers. A separate back-up source of electricity would be a redundancy.

The City of Dayton has built-in redundancy in its water system. We have two separate water treatment plants. Each treatment plant has an independent pump station that can support the entire system’s demand. And each plant can treat enough water to meet the region’s current need. 

Our two independently operated well fields can each produce enough water for every customer. The City has over 100 drinking water wells. Less than half are used at any time. And the City has an undeveloped well field for redundancy.

Dayton uses primary and secondary electrical feeds to each plant, pump station, and well field. We also have backup generators. These can be sent to strategic locations during an emergency.

Here’s a chart that shows Dayton’s water plant redundancy:

2020 Water Plant Redundancy Overview Slide

What’s the cost to me to increase redundancy? And why don’t we buy more generators that could run the whole system if needed, not just strategic locations?

What we currently ask our customers to pay is enough for the current level of redundancy in Dayton’s water system. The City has continuously invested in redundancy by maintaining two water treatment plants with dual electric feeds. It simply does not make sense to add backup generators to power the entire system. 

For example, we would need six or seven generators the size of train engines at each of the two plants to fully backup our system. While that is physically doable, it would cost around $45.2 million. That would mean each customer would pay about another 2%, in addition to the required annual rate increases being added to your City of Dayton water bill, for something, quite frankly, we do not need. 

You say we don’t need even more generators for the water plants because these emergencies are so rare. But we had two such emergencies in the first half of 2019. So, are they really rare?

Yes. Since 1954 – 66 years – the City has had only two service disruptions, including a system-wide boil advisory. Both happened in 2019.

Why can’t the City and Montgomery County work together on these problems? 

We do work with Montgomery County. Per our contract, the City has five work groups in coordination with Montgomery County. These work groups meet regularly. The groups discuss a wide range of topics. They annually report progress to the Montgomery County Administrator and Dayton City Manager.

What is SCADA?

Supervisory Control and Data Acquisition (SCADA) is a software and hardware system. This system lets us control water treatment and well field processes locally or at remote locations. It also allows us to monitor, gather, and process real-time data from devices such as sensors, valves, pumps, motors, etc. And, we can easily maintain a record of events.

SCADA systems are crucial for our water treatment plants. They help maintain efficiency. They process data for smarter decisions. They communicate system status to help minimize process disruptions.

Was the City really prepared to fight a fire when the water supply was down from the tornadoes?

Yes. We reacted quickly and effectively. Four water tankers were brought in and strategically located throughout the region to provide a water supply for crews to support fire suppression activities. Each of these water tankers carried 3,500 gallons of water. That was in addition to the 500-750 gallons of water carried on each fire engine. We also added staff and equipped two fire engines with the tools necessary to draw from natural water sources, such as ponds, rivers and lakes. When dispatching for emergency calls, the Regional Dispatch Center would include requests for any of these additional resources when needed.