Note: This story has been updated from its original version with information about PFHxS studies in animals and humans.
This summer, tests showed Rhinelander’s Municipal Well 7 was contaminated with PFAS chemicals.
However, the most recent tests show no detection of the two main chemicals in the PFAS family, PFOA and PFOS. Even so, that well remains offline, and is not contributing to the city’s drinking water supply.
But a different type of PFAS has been steadily rising in another city well.
That well, Well 8, is still providing water to Rhinelander.
Well 8 has readings in excess of 90 parts per trillion (ppt) of PFHxS, a lesser-known chemical in the PFAS family. It’s the same chemical – in roughly the same concentration – that led the Oneida County Health Department to declare a nearby artesian well “Do Not Drink” in August.
Todd Troskey, an environmental health specialist with the health department, reviewed tests that showed the level of PFHxS at 92.6 ppt in the Crescent Spring, a popular public artesian well just west of Rhinelander. That led him to put up bright orange ribbons and signs advising people not to drink from the spring.
“Don’t drink the water,” Troskey said in an interview Thursday. “[Crescent Spring has] always been drink-at-your-own risk. But at this point, because we know that PFHxS can be detrimental to someone’s health based on other states that have been advising against drinking water with that compound in it, we just needed to make sure that people are aware that they really shouldn’t drink the water at all at this point.”
The city of Rhinelander didn’t have a say in declaring Crescent Spring “Do Not Drink.”
But the city has taken no action on Well 8, a well it controls, that has the same contaminant at about the same level.
A WXPR open records request found Well 8, located at the Rhinelander-Oneida County Airport, tested at 90.1 ppt for PFHxS in a sample collected Oct. 2.
According to City Administrator Daniel Guild, the well is still providing water to the city because of a lack of hard data on negative health risks of PFHxS.
“There are no human studies. There are no human trials. There are no animal studies. There are no animal trials on any of these other hundreds and hundreds and hundreds of compounds,” he said.
In fact, the New Hampshire Department of Environmental Sciences (NHDES) referenced six animal studies and two human studies (see Page 59 of this summary) in setting its proposed PFHxS level at 18 ppt.
“There appears to be limited evidence that PFHxS affects the thyroid gland and liver, with subtle effects on growth and development,” the NHDES wrote in its summary.
New Hampshire relied on one study in particular. In the study, giving PFHxS to mice appeared to negatively impact their fertility and led to reduced litter sizes. However, New Hampshire noted the same effect wasn’t observed in rats in earlier studies.
Human studies found women with higher PFHxS levels had increased infertility, but the studies couldn’t prove PFHxS caused the results.
“Additional epidemiological studies are needed to determine if there is a causal relationship between PFHxS and human reproduction,” the NHDES noted.
Although New Hampshire has a recommendation for PFHxS limits, neither the federal government nor Wisconsin’s state government does.
But, for comparison, Wisconsin’s neighbor, Michigan, is working on finalizing a rule that would set the PFHxS limit at 51 ppt.
Well 8’s latest reading was almost double that level.
A test of a May sample showed Well 7, also at the airport, had a PFHxS level of more than 10 times Michigan’s suggested limit. It tested at 590 ppt.
The city turned off Well 7 in June. It did so not because of a high PFHxS level, but because the combined contaminant levels of PFOA and PFOS, the two best-known PFAS chemicals, were higher than both state and federal recommendations.
Since then, PFOA and PFOS levels in Well 7 have steadily slid lower, with test results most recently showing no detection.
In a message to city residents Tuesday night, Guild suggested the original test, which led to the high PFOA and PFOS results, might have been inaccurate.
“We’re speculating and theorizing about what has happened, and as we speculate and theorize, we’re going to share those thoughts with the public, not because we want them to know that we’ve definitively discovered the answer, but because we’re exploring ideas and alternatives,” he said in a Thursday interview.
“One theory, as in, speculation, supposition, that we wondered about was whether the sample collection process potentially tainted the results," Guild said.
The city sends its tests to Northern Lake Service, a nationally-known lab in Crandon.
RT Krueger is its president.
“I’ll certainly defend the data that we generated. In looking at it, there is absolutely no indication of problems with the testing or problems with the sampling,” Krueger said.
Krueger said the city has never contacted him with sampling or testing concerns.
If there was an issue with the original test, he said, he’d expect to see an abrupt spike and fall of PFAS levels for Well 7, not the gradual decline observed since May.
Test records showing the rising levels of PFHxS in Well 8, which is located at 3400 Fox Ranch Road, are available here. Results showing falling values for PFOA, PFOS, and PFHxS in Well 7, at 3401 Fox Ranch Road, are here. Relevant parts of the documents are highlighted in red type.
The DNR said Thursday afternoon it knows about the new information and is considering a response.