ANN ARBOR, MI – PFAS levels in Ann Arbor’s drinking water have been on the rise this year, and seven types of the “forever chemicals” have been detected so far, city records show.

Previously unreleased test results obtained by The Ann Arbor News/MLive under the Freedom of Information Act shed new light on the problem, showing a concerning trend that city leaders are hoping new carbon filters at the water treatment plant will help reverse.

The good news: PFOS and PFOA, the two types of PFAS the city has been most closely watching, have mostly stayed below minimum-risk levels set by a federal public health agency.

But those two compounds account for only a fraction of the total PFAS in the city’s drinking water, and the overall levels have more than quadrupled since April, the records show.

PFAS are per- and polyfluoroalkyl substances that have links to cancer, liver damage, birth defects and autoimmune diseases.

The detected levels have been as high as 119.6 parts per trillion in Ann Arbor’s intake water from the Huron River this year and 88.1 ppt in the treated water delivered to roughly 125,000 customers.

City officials aren’t sure what’s causing the increases or what to make of the larger numbers at this point, since there aren’t regulations or health standards for some of the compounds, and thousands of them are still going untested.

The fact that Ann Arbor has seen PFAS in its drinking water steadily climb from 12.6 ppt in April to between 53.2 and 88.1 ppt in recent months is problematic and poses a health risk, Richard DeGrandchamp, a University of Colorado toxicology professor, said.

“The problem with these compounds is once they get in the body, it’s the end of the story,” he said, noting the compounds bind tightly to protein in the blood and stay in people’s bodies for decades.

DeGrandchamp, a University of Michigan alumnus who co-authored a Michigan Department of Environmental Quality report six years ago that warned of widespread PFAS pollution, said the science on PFAS is evolving and study after study has shown the chemicals are more dangerous than previously believed.

Ann Arbor officials, without sharing much information publicly about overall PFAS levels, have repeatedly assured residents their tap water is safe to drink since PFOS and PFOA levels are well below a 70-ppt health advisory level set by the U.S. Environmental Protection Agency in 2016.

“We all drink it at city hall,” said Robert Kellar, a city spokesman.

The EPA advisory is outdated, DeGrandchamp said. Current science says the level should be in the single digits or low teens, he said.

The city should stop citing the EPA advisory and instead look to the federal Agency for Toxic Substances and Disease Registry, DeGrandchamp said.

“It’s 2018 now and ATSDR is the only health agency in the United States that is chartered by Congress to look solely at the toxicity of these compounds. It’s not the EPA,” he said.

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ATSDR recently published new minimum-risk levels for four types of PFAS, including child-exposure screening levels of 14 ppt for PFOS, 21 ppt for PFOA, 21 ppt for PFNA and 140 ppt for PFHxS, with adult-exposure levels nearly four times those amounts.

“If you wait another year, these numbers are going to go down. That’s the trend that we’re seeing,” DeGrandchamp said.

Exposure below the minimum-risk levels is not expected to result in adverse health impacts, according to ATSDR. Ann Arbor has mostly stayed below the ATSDR-recommended levels, with the exception of an Oct. 9 reading showing 22 ppt of PFOS in treated water.

But there aren’t any standards for five other types of PFAS found in the city’s water: PFBA, PFPeA, PFBS, PFHxA and PFHpA.

“This is an emerging issue,” said Brian Steglitz, the city’s water treatment plant manager. “Because our customers are consuming the water, we want to make sure they feel comfortable, but we also have limited knowledge on certain things, so we are trying to stay on top of the science as it’s developed.

“I can’t answer the question on what is the health impact associated with things that the science just isn’t there yet.”

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Ann Arbor gets most of its drinking water from Barton Pond, an impoundment on the Huron River, which has been contaminated with PFAS by upstream pollution, including a Wixom manufacturing plant that makes chrome-plated auto parts.

Because the compounds can linger in the environment without breaking down, they’re a threat to drinking water supplies around the world. The chemicals have been found in municipal drinking water serving more than 2 million people around Michigan.

They were first detected in Ann Arbor’s water at 43 ppt in March 2014 after the EPA required testing.

After months of testing for PFOS and PFOA, usually resulting in single-digit readings, the city began testing at least monthly for 21 different PFAS compounds in April.

Total detected PFAS in the city’s intake water gradually climbed from 16.9 ppt in April to 64.1 ppt in September, before spiking at 119.6 ppt in October, and then ticking down to 99 ppt in November.

The levels remaining in the city’s treated drinking water steadily climbed from 12.6 ppt in April to 53.2 ppt in September, before spiking at 88.1 ppt in October, and then ticking down to 53.6 ppt in November.

Steglitz said the city hasn’t been sharing those larger totals publicly until now because there haven’t been any regulations or health advisory levels to put them into context.

“That’s one of the things we’re struggling with as a utility, because no one knows — when you add up all of those PFAS, there’s no metric to compare that to,” Steglitz said, adding the city’s goal is to get the numbers as low as possible.

This map shows average PFAS levels in Ann Arbor's intake water and treated drinking water, based on test results from April to November 2018. The city has detected seven types of PFAS, including PFOA and PFOS.

The city and the University of Michigan are experimenting with a pilot filter system inside the water treatment plant, using a series of floor-to-ceiling tubes to test techniques.

That research is not related to PFAS, but a two-year PFAS study using the same tubes is expected to begin next summer, Steglitz said. With a grant from the nonprofit Water Research Foundation, the city plans to partner with North Carolina State University and the Colorado School of Mines to study and refine techniques for filtering out PFAS.

They’ll be exploring new ways to optimize removal of longer-chain molecules such as PFOS and PFOA, as well as shorter-chain molecules that not much is known about, in hopes of helping the water industry better understand and tackle PFAS, Steglitz said.

In the meantime, as part of a roughly $1 million undertaking, the city is replacing filters at the plant with new granular activated carbon to better filter out PFAS in the water delivered to customers.

The city is moving as aggressively as it can, Steglitz said. Ten of the plant’s 26 filters have had the new carbon installed since October and the rest are expected to be changed out by the end of May

The city plans to keep up with regular replacement of the carbon material to optimize PFAS removal. PFAS sticks to the carbon as water filters through, so filter efficiency decreases over time.

“They’re not fail-safe and they certainly don’t pick up everything they were intended to,” DeGrandchamp said.

Test results between April and October suggest, at best, only about a quarter of the total detected PFAS was being removed from the city’s water before the city started the transition to GAC filters. The latest test results from November show an improvement, with nearly half the PFAS filtered out, including about two-thirds of PFOS.

The issue was discussed at the City Council’s annual retreat last week. Council members are hopeful the carbon filters will work.

“It’s going to be interesting to see that data as it comes in,” said Council Member Ali Ramlawi, D-5th Ward, who sees PFAS as an added concern on top of the dioxane plume spreading through the city. “It’s alarming."

City officials are hopeful the state will do more to identify and cut off sources of pollution in the Huron River watershed.

An MLive investigation earlier this year found that, since 2017, 18 wastewater plants in Michigan were in violation of the state’s surface water quality standard of 12 ppt for PFOS due to the industrial pollution passing through their systems.

The Wixom wastewater plant, as of July, had discharged effluent with as much as 290 ppt of PFOS and 10,927 ppt of total PFAS.

Lab tests have shown several types of PFAS in the Wixom plant’s discharge, including those found in Ann Arbor’s water.

Testing at Norton Creek by the state on July 24 showed a reading of 5,500 ppt of PFOS.

Testing of PFAS-laced foam on the Huron River in the Ann Arbor area showed as much as 56,868 ppt.

Tribar Manufacturing was identified earlier this year as a major source of the PFAS pollution that has channeled through the Wixom plant to the Huron River watershed.

The company, which claims it stopped using the chemicals in 2015, is now taking steps to filter its wastewater.

PFAS chemicals, which have been used over the years in many consumer products and in industrial manufacturing, probably have been in Ann Arbor’s water for decades, Steglitz said.

As Ann Arbor officials seek to better understand and address threats posed by the toxic chemicals, much remains unknown.

“We’re learning every day,” Steglitz said. “The capability to test for some of these compounds is increasing. We can test for 21 now and it’s going to be 24 imminently. They’re working on the methods.”

Ann Arbor officials also are looking to the federal government for more regulatory guidance.

“This is a dynamic issue and it’s unique, because there are not many other contaminants that are in this situation where all states are taking a different approach,” Steglitz said.

“It would be great if EPA came in and said, ‘Here’s what you need to meet,’ and then we’ll achieve that.”

Ann Arbor will implement the best-available technology and meet the most stringent regulations, Steglitz said.

While PFAS is a problem that needs to be addressed, Steglitz said, he’s an Ann Arbor resident and he’s confident the tap water he drinks every day is safe. He said there are home filter systems people can install if they’re concerned, but he doesn’t have one.

“I feel very comfortable drinking the water, and I have kids and they drink the water,” he said. “It’s important for me that our customers know and believe and trust us to deliver safe water to their homes.”

DeGrandchamp suggests the city needs to do more frequent testing of its water for PFAS, at least weekly, if it wants to make sure residents are being protected.