These chemicals are in our water. Here are 15 things you should know if you drink Dayton water.

Dayton’s water is safe to drink by federal guidelines, city officials say, but it does contain some PFAS — chemicals believed to cause health problems.

The Dayton Daily News Path Forward project digs into solutions for the most pressing issues facing the community, including protecting the region's drinking water that serves more than 400,000 people in Montgomery County.

That’s why we examined scientific research, public records, lawsuits and other sources to find out what’s really going on. Here are answers to some of the most common questions about the chemicals.

What are PFAS?

PFAS stands for per- and polyfluoroalkyl substances. These are human-produced chemical compounds containing fluorine and carbon atoms.

About 5,000 different types of PFAS exist. This article focuses on two forms known as perfluorosulfonates, or PFOS, and perfluorocarboxylic, or PFOA.

» Contaminants in Dayton water above what some states consider safe

These PFAS resist heat, stains, grease, oil and water. The substances have been used in carpet and waterproof clothing treatments, nonstick coatings on pans, popcorn bags, cardboard packaging, firefighting foam and other items.

PFAS are extremely persistent and can travel long distances. Studies show certain PFAS have been found in bald eagles, walrus, narwhals, beluga whales and polar bears. They can move up the food chain into fish and other animals. When humans consume contaminated fish or shellfish, we consume the PFAS inside them, too.

Another way for PFAS to enter the human body is through contaminated water.

Some people can be exposed to PFAS through their jobs, such as firefighting or manufacturing. And the U.S. Centers for Disease Control and Prevention said certain food packages like popcorn bags, fast food containers and pizza boxes contained PFAS until recently.

Why are PFAS found in Dayton’s water?

PFAS can be used in a foam to extinguish fires involving fuel. The foam is sprayed on the fire and coats it to block oxygen feeding the fire.

Firefighters trained for decades with the foam in at least two sites in our region for decades: Wright-Patterson Air Force Base and the Dayton Fire Training Center. Both of these locations are located above the Great Miami Buried Valley Aquifer, the source for the region’s drinking water.

» Should Ohio set its own limits for chemical in drinking water?

The city of Dayton and state of Ohio have sued PFAS manufacturers.

The state’s lawsuit alleges the foam “releases these toxic chemicals directly into the environment in a manner enabling them to seep freely into the groundwater — potentially contaminating drinking water supplies — and travel long distances to cause further, widespread environmental contamination.”

“A single firefighting event or training exercise may result in the release of thousands of gallons of foam solution,” Ohio’s complaint says. Dayton’s complaint says plumes of PFAS “can persist in underground aquifers for many decades. Once the plume reaches the well, it continues to contaminate the water drawn from that well.”

What are the health concerns?

Most people in the U.S. and other industrialized countries have measurable amounts of PFAS in their blood, according to the CDC, and at much lower levels in urine, breast milk and umbilical cord blood.

The chemicals are considered “emerging contaminants” by the U.S. Environmental Protection Agency, meaning they are chemicals characterized by a perceived, potential or real threat to human health or the environment, or by a lack of published health standards.

Dayton’s lawsuit alleges PFOA exposure can lead to “kidney and testicular cancer, thyroid disease, high cholesterol, ulcerative colitis, liver damage, and pregnancy-induced hypertension.” The complaint alleges PFOS exposure can lead to “immune system effects, changes in liver enzymes and thyroid hormones, low birth-weight, high uric acid, and high cholesterol.”

Can I still breastfeed if I drink Dayton’s water?

Newborns can be exposed to PFAS through breast milk, but the CDC recommends nursing mothers continue to breastfeed their babies, because “the advantages of breastfeeding continue to greatly outweigh the potential risks in nearly every circumstance.”

The CDC says older children might be exposed to PFAS through food and water, similar to adults. Younger children could be exposed through carpet cleaners and similar products, largely due to time spent lying and crawling on floors.

What does the manufacturer say about the chemical?

In the 1940s, the 3M Co. began to experiment with a process to create key components of PFAS, the Ohio Attorney General’s Office alleges in its Lucas County Common Pleas Court filings.

3M says it started making firefighting foam in 1963 and stopped in 2000.

» Dayton sues PFAS manufacturers

PFAS are “top of mind” for 3M, the company’s top leader said last week while pushing back on claims the substances are harmful.

“The scientific evidence does not show that PFAS cause harm to people at past or current exposure levels,” 3M Chief Executive Mike Roman said Thursday during a company earnings call.

The company was the only foam manufacturer that used PFOS, according to both the city and Ohio’s lawsuits. The other foam manufacturers used PFOA.

The highest levels of contamination in Dayton’s water are PFOS, according to Ohio Environmental Protection Agency documents.

How much PFAS in water is considered dangerous?

The U.S. EPA currently doesn’t regulate PFAS in drinking water, but its understanding of the substance has evolved over time.

In 2009, it issued a health advisory that said “action should be taken to reduce exposure” to drinking water containing levels of PFOA exceeding 400 parts per trillion and PFOS exceeding 200 parts per trillion.

In 2016, the U.S. EPA said drinking water concentrations for PFOA and PFOS, either singly or combined, should not exceed 70 parts per trillion.

These advisories aren’t enforceable. As the Dayton Daily News has previously reported, other states have set their own levels. Michigan officials set a non-enforceable screening level of 9 parts per trillion for PFOA and 8 parts per trillion for PFOS.

A 2018 report from the CDC proposed health thresholds about 10 times lower than the U.S. EPA’s health threshold.

How much PFOS and PFOA are in Dayton’s water?

Earlier this year, the Dayton Daily News obtained a map showing PFOS and PFOA levels in groundwater monitoring wells. The map is from March and April 2018. It says Dayton measured PFOS at 1,500 parts per trillion near the Dayton Fire Training Center, and PFOA at about 79 parts per trillion near Huffman Dam. Certain wells have been turned off at both sites.

“The source of contamination at both well fields is separate and distinct, while the contamination is the same,” says an April 2018 memorandum of understanding between Dayton and Montgomery County.

The Dayton Daily News recently reported that PFAS is still measured in water leaving the Ottawa Treatment Plant — one of Dayton’s two drinking water treatment plants — even though the contaminated wells have been turned off.

Earlier this month the newspaper reported Dayton tested water leaving the Ottawa plant in September 2018 and found PFOA and PFOS combined at nearly 19 parts per trillion. That’s below the U.S. EPA’s advisory, but above the levels set by other states.

If PFAS causes problems, why was it used?

Fire departments say they didn’t know the chemicals in firefighting foam were dangerous.

Dayton’s lawsuit against the manufacturers, for example, alleges “instructions, labels and material safety data sheets were provided … which, at least at significant times, did not fully describe the health and environmental hazards,” of the foam.

What can I do about PFAS?

The CDC says a home water filtration system can reduce contaminant levels in drinking water, but also says researchers are still clarifying how to best use those systems for PFAS contamination. The agency says a home filtration system or pitcher-type filter might reduce PFAS levels, but not enough to meet the U.S. EPA’s advisory limit (which Dayton is now below).

NSF International has developed a certification standard for removing PFOA and PFOS in water and has certified some charcoal filters and reverse osmosis filters, according to the Ohio EPA.

What can Dayton do about PFAS?

The Dayton Daily News reviewed an April 2018 agreement between Dayton and Montgomery County. The agreement says the city could use its Source Water Protection Fund to mitigate PFAS in the Tait’s Hill well field. The fund is funded through a surcharge to water customers. The agreement says a loan from the capital reserve fund also could be made to cover clean-up costs.

“Further, the city anticipates using the water department’s capital reserve fund to mitigate the potential threat to the Huffman Dam well field,” the agreement says.

The agreement doesn’t spell out how the city would clean up the contamination.

After that agreement, the city of Dayton sued PFAS manufacturers “to recover damages incurred and to be incurred by the city in investigating, monitoring, remediating, treating and otherwise responding to the PFAS water contamination … and ensure the cost of the water treatment be borne by the polluters; not the City of Dayton and its hard working, rate-paying residents.”

Dayton also could build a filtration system. Wright-Patt built a charcoal filtration plant for $2.7 million, according to Ohio EPA records, though Wright-Patt’s overall water system is much smaller than Dayton’s.

Who are Ohio and Dayton suing?

The Dayton lawsuit has been filed against 3M, Buckeye Fire Equipment, Chemguard, Tyco Fire Products, National Foam, E.I. Du Pont de Nemours, and Chemours, a company that spun off from DuPont. The lawsuit has been moved to the U.S. District Court for the District of South Carolina, where other PFAS-related lawsuits also are pending.

The Ohio Attorney General has sued 3M, Tyco, Chemguard, Buckeye Fire Equipment, National Foam and Angus Fire for compensatory and punitive damages. Ohio’s complaint, while filed in Toledo, includes PFAS contamination in Dayton and other places across the state.

What do these lawsuits allege against 3M?

Both complaints make similar allegations.

Ohio alleges 3M’s documents say the company knew as early as the 1950s that PFOS and PFOA were toxic. The complaint alleges 3M scientists in the 1970s concluded the chemicals “were even more toxic than anticipated” and by 1979 “recognized that fluorochemicals may pose a cancer risk.”

“3M nonetheless continued to assure its customers … that its products were ‘biodegradable and will have no adverse effects on the environment.’ That assurance was knowingly false,” Ohio’s complaint alleges.

Ohio's complaint cites a 3M scientist's 1999 resignation letter, which says, "I have worked within the system to learn more about this chemical and to make the company aware of the dangers associated with its continued use. But I have continually met roadblocks, delays, and indecision."

“3M waited too long to tell customers about the widespread dispersal of PFOS in people and the environment,” the letter says.

The scientist copied the U.S. EPA on his resignation letter, the complaint says. In 2006, 3M paid the federal government more than $1.5 million for “its failure to disclose pertinent studies regarding PFOA and PFOS,” Ohio’s complaint says.

What else do the lawsuits allege?

Ohio’s complaint also alleges the other companies that manufactured PFOA-based foam “knew, or at a minimum, should have known that in its intended and common use … would injure the natural environment and threaten public health.”

Ohio has sued DuPont in a different case, but not in the firefighting foam case. Ohio alleges DuPont was a founding member of a group formed to dispel concerns about firefighting foam.

“By 1961, DuPont’s own researchers had concluded that PFOA was toxic and should be ‘handled with care’ and a few years later, DuPont had acknowledged that PFOA caused adverse liver reactions in dogs and rats,” Ohio alleges. Through the pro-firefighting foam group, manufacturers and DuPont “worked together closely to protect” the foam from regulatory scrutiny.

What do the defendants say?

Several of the defendants in the Dayton and Ohio lawsuits provided statements to the Dayton Daily News.

“3M cares deeply about the safety and health of Ohio’s communities,” said Fanna Haile-Selassie, a 3M spokeswoman. “3M acted responsibly … and will vigorously defend its record of environmental stewardship.”

On Thursday, 3M said in public filings the company recorded litigation-related charges of $548 million in the first quarter of 2019, including PFAS-related litigation. The company paid $897 million in 2018 in a PFAS-related settlement with the state of Minnesota.

Tyco and Chemguard “acted appropriately and responsibly at all times in producing our firefighting foams,” said Fraser Engerman, a spokesman for Johnson Controls, the Tyco and Chemguard parent company.

“We make our foams to exacting military standards, and the U.S. military and civilian firefighters have depended for decades on these foams to extinguish life-threatening fires,” Engerman said. “They continue to use them safely and reliably for that purpose today. We will vigorously defend this lawsuit.”

DuPont said it wouldn’t comment on pending litigation, but company spokesman Dan Turner said they would “vigorously defend our record of safety, health and environmental stewardship.”

Chemours does not manufacture or sell firefighting foam, its spokesman David Rosen said. Rather it’s a supplier whose products are used to make certain foams and cannot break down into the form of chemicals found in contaminated water.

“Historically most of firefighting foam was manufactured using PFOS. Chemours has never manufactured or used PFOS at any of its sites, nor do we use PFOA in any of our manufacturing processes,” Rosen said.

Are there other lawsuits?

Yes. In total, 3M’s 2018 annual report says the company faces 85 punitive class action lawsuits and other lawsuits in state and federal courts in Arizona, Colorado, Delaware, Florida, Massachusetts, New Jersey, New York, Ohio, Pennsylvania and Washington.

3M says it and other defendants, including DuPont and Chemours, were named in a class action lawsuit in the U.S. District Court for the Southern District of Ohio. The case was filed by a firefighter who says he was exposed to PFAS while using foam. He has brought the case on behalf of “all individuals residing in the United States who … have detectable levels of PFAS materials in their blood serum.”

The next hearing in that case is scheduled for Aug. 27 in Cincinnati.

Read more Dayton Daily News water coverage:

» City: ‘We do not need’ more generators for water system, would cost $45M

» Dayton blames county contractor for February water outage

» Understanding Dayton’s drinking water issues

» Progress slow in addressing chemicals in local water systems

About the Path Forward

Our team of investigative reporters digs into what you identified as pressing issues facing our community. The Path Forward project seeks solutions to these problems by investigating the safety and sustainability of our drinking water. Follow our work at or join one of our Facebook groups.

About the Author