PFAS: New standards and Oshkosh

‘Forever chemicals’ largely unregulated


Willem Flaugher / Advance-Titan – People are exposed to per- and polyfluoroalkyl substances (PFAS) in the products they eat and drink. They do not break down over time and show multitudes of health affects depending on the concentration exposure.

Josh Lehner, Assistant News Editor

The Environmental Protection Agency (EPA) has proposed new standards in the regulation of per- and polyfluoroalkyl substances (PFAS), a group of human-made chemicals used in industry and consumer products since the 1940s.

Though the standards would drastically alter Wisconsin’s current PFAS laws, they should have little impact on Oshkosh given the low PFAS levels in Lake Winnebago, according to one Oshkosh official.

PFAS easily get into the soil, water and air, but they don’t break down over time, which has earned them the nickname “forever chemicals.”

On top of this, PFAS are very toxic to humans and animals, said Shannon Davis-Foust, a UW Oshkosh biology and environmental studies professor.

“When they get into a water body, they can have all sorts of health effects, particularly birth deformities and cancers,” she said. “It, of course, depends on the concentration you’re exposed to.”

People are most commonly exposed by eating and drinking products containing PFAS. Davis-Foust said that the effects of PFAS-laden materials are observed particularly in animals.

“If you have a pet bird and you use Teflon, the fumes that come off of Teflon can kill a bird because their respiratory system is so sensitive,” she said.

While scientists are still learning about the health effects of PFAS, two particular variants — perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) — have been linked to increased cholesterol levels, changes in liver enzymes, decreased vaccine responses in children and increased risk of kidney and testicular cancer.

But very few of the nearly 12,000 chemicals in the PFAS group have been adequately studied, nevermind regulated.


What’s new?

In a movement toward regulating the chemical group, the EPA proposed the first national PFAS standards for public water supplies on March 14. Many states with lenient PFAS standards, such as Wisconsin, would have to update their standards if the measure is approved.

Courtsey of Pexels

However, stricter standards carry a price tag, as updated filtration technology and drilling for cleaner water sources may increase water bills.

The EPA’s proposed standard, which would likely take effect later this year or early next year, would monitor for six specific PFAS compounds, including PFOA and PFOS, and would require systems to notify the public if contamination levels exceed the proposed standards.

PFOA and PFOS levels would each have to remain under 4  parts per trillion (ppt). Four other types of PFAS — PFNA, PFHxS, PFBS and GenX chemicals — would also be regulated under the proposal.

The EPA stated that, if fully implemented, the new regulation could prevent thousands of deaths and reduce tens-of-thousands of serious PFAS-related illnesses.


Testing for PFAS

PFAS were largely unregulated in past decades but have become the center of attention recently.

In 2020, the Wisconsin Department of Natural Resources (DNR) conducted background testing of surface waters at 43 locations across Wisconsin. A test conducted on the Fox River in Oshkosh showed PFOS amounts of 0.85 ppt and 0.83 ppt for PFOA.

Additionally, testing of Lake Winnebago in Neenah indicated 2.17 and 1.17 parts per trillion for PFOS and PFOA, respectively.

The standard for PFAS in groundwater, set by the State of Wisconsin Department of Health Services (DHS), is 20 ppt for any PFAS chemical.

The DNR’s 2020 test also listed water tested in Merrill, Wisconsin Dells, Muscoda, Biron, Johnson Park and in the Mississippi River near Sturgeon Lake as having high levels of PFOS and PFOA concentrations.

In August 2022, the state’s safe drinking water code was revised to include standards for PFOS and PFOA, setting a maximum contaminant level of 70 ppt individually or combined.

This means that legal action to address contamination cannot take place until the contamination exceeds 70 ppt. However, if the level is above the DHS standard of 20 ppt, no legal action is taken, although residents must be notified by the water system

DNR Public Water Supply Section Chief Adam DeWeese said that about 130 systems across the state participated in voluntary sampling before the August 2022 update to the state’s code. The DNR then worked with systems above the 20 ppt DHS threshold.

If a system had a well that recorded high PFAS levels, the water system could take that well offline and rely on other wells. This is one of four primary methods in ameliorating contamination levels, DeWeese said.

Another method involves mixing water from a higher source and a lower source to bring down the contamination level.

A system can also find a location with lower PFAS levels and drill a new well.

Finally, a system can treat water with granular activated carbon, which absorbs natural organic compounds.

Assuming the EPA’s standards go into effect, DeWeese said that there will be a grace period for water systems.

“Once the final rule is published, we’ll have three years to put those levels into state regulations,” he said. “We’re still operating under 70; that’s standard. The feds publish a number and the states have three years to promulgate those numbers.”

Had the DNR conducted their 2020 sampling under the EPA’s proposed standards, PFOA levels in water taken from Wisconsin Dells, Muscoda, Biron, Johnson Park and in the Mississippi River near Sturgeon Lake would have exceeded the EPA’s 4 ppt standard. Water in Merrill would contain more than three times the regulatory standard.

But DeWeese said that many systems across the state have been working to lower their PFAS levels — though not required by law to do so — and the most recent reports show that water in all of these systems is under the DHS recommended level.

Going forward, DeWeese said that the EPA’s standards are constantly updating with improved technology and that the state will respond appropriately.

DeWeese said that the EPA may release stricter PFAS standards as new science becomes available. Last year, the EPA released interim drinking water health advisories of 4 parts per quadrillion for PFOA and 20 parts per quadrillion for PFOS.

“As new science becomes available, it is possible that they could propose an even lower level … and also because technology might continue to improve to test and remove PFAS,” he said.

The DNR has also released PFAS fish consumption advisories for specific areas. Information on affected areas can be found at


What about Oshkosh?

An Oshkosh Water Filtration Department report from February indicates PFOS levels at 1 ppt and PFOA levels estimated at 0.97 ppt for water taken from Lake Winnebago — Oshkosh’s source for drinking water.

This is far below both the current DHS standard and the EPA’s proposed 4 ppt standard.

The other four compounds regulated under the EPA’s new standard — PFNA, PFHxS, PFBS and GenX Chemicals — must remain below 1 ppt when added together.

Oshkosh Director of Public Works James Rabe said that Oshkosh also measured these PFAS chemicals.

“I asked our utilities staff to work through the calculations as we understood it,” he said. “Ours worked out to 0.05.”

Given the low levels of PFAS found in Lake Winnebago, Rabe said that the EPA’s regulations shouldn’t affect the city.

“Presuming the regulations, as currently proposed, are what’s implemented, I do not foresee major changes being required to our water treatment process,” he said. “Our treatment process currently results in numbers well below the threshold.”

Recently, Oshkosh residents received a notice about an approximate 18% increase in residents’ water bills. Rabe said that this isn’t attributable to PFAS, but to the Wisconsin Public Service Commission (PSC), which regulates water utilities.

“We have not done a water utility rate increase in five or six years,” he said. “We had to send them (PSC) all of our documents, and they did their accounting math and said, ‘OK, this is how much of a rate increase you need to have to cover your costs.’”

Rabe said that PFAS testing has only started recently, due in part to firefighting foam testing on airfields in Marinette and Madison.

“A number of states have been working on regulations over the past couple of years,” he said. “[Oshkosh] started testing in August of last year, participating in the DNR’s voluntary testing program.”

Despite the quickly changing technology and science around PFAS, Rabe said he’s confident in Oshkosh’s water filtration process.

“I think in the near term, unless we see some very dramatic changes, our treatment process is going to be OK,” he said. “From what I’ve learned, our treatment processes of using ozone and granular activated carbon are very effective processes for removing PFAS.”

Rabe said that a redesign would be necessary if the EPA creates tighter regulations beyond the 4 ppt.

“We just may have to redesign particularly the granular-activated carbon filters, since they’re not designed for PFAS, if the regulations start getting close to where we’re at, but not a major construction project,” he said. “We are staying very much on top of these regulations, and we will adapt quickly as the regulations change.”