OSCODA, MI -- Investigators say decades-old water found inside forgotten fire hydrants at the former Wurtsmith Air Force base may prove to be the best evidence yet that military veterans and families stationed in northern Michigan were drinking water poisoned by an emergent class of toxic chemicals.

According to a pending Michigan Department of Environmental Quality report, catch basins inside hydrants previously connected to the base water system have tested positive for high levels of perfluorinated chemicals (PFCs), a class of compounds tied to thyroid, kidney, liver and reproductive problems.

Although the new evidence comes from water at least 20 years old, PFCs are still leaching through Oscoda groundwater in expanding plumes that a joint Air Force, DEQ and state health department investigation are trying to map.

There's hope the hydrant data could help push for an epidemiological health study of Wurtsmith veterans who have reported chronic health problems they suspect are connected to chemical exposure and contaminated base water. Veterans who've become ill said they hope the data can prod the U.S. Department of Veterans Affairs to act on claims with more urgency.

"We are in limbo," said Mike Bussey of Canonsburg, Pa, who was stationed at Wurtsmith from 1989 to 1992. "I don't think anybody is taking us seriously."

"This is a step in the right direction."

The old water samples were collected in 2015 from 22 hydrants plus an old water softener tank and old water heater found in abandoned buildings on the former military base, which closed in 1993 and has since been partially redeveloped.

Of the 24 samples, 10 were for perfluorooctanoic acid (PFOA) and perfluorooctyl sulfonate (PFOS) at concentrations above the Environmental Protection Agency's health advisory level of 70 parts-per-trillion (ppt) for the two chemicals. The level was established in May.

One hydrant, No. 57, tested at 7,400-ppt for PFOS/PFOA -- far above the health advisory level, which some academics think should be lower. Another hydrant, No. 75, tested at 4,380-ppt. The water heater in Building 5065 tested at 960 ppt.

According to Bob Delaney, DEQ site manager who ordered the testing, it's "fairly solid evidence" that base personnel and families connected to the Wurtsmith system were unknowingly drinking water contaminated with PFCs at concentrations above the EPA advisory level.

Delaney said the base water system was turned over to the Huron Shores Regional Utility Authority (HSRUA) in 1997 and the mains were connected to the municipal supply from Lake Huron, but some hydrants were never flushed.

Before the switchover, base drinking wells pumped groundwater from areas Delaney says were very near some of the worst PFC plumes discovered on the base. The DEQ examined about 240 hydrants and found measurable water in 22. The stagnant water has sat untouched in catch basins outside the pipes that connect the hydrants to the mains.

The catch basins are underground, but above the water table level.

"We don't have an idea when the municipal wells would have been hit, but the earliest would maybe have been in the mid -to late-1970s," he said. That about the time the Air Force began using a fire fighting foam on base made with PFCs.

Christina Bush, a toxicologist with the Michigan Department of Health and Human Services who has been helping analyze well-testing results in the Oscoda groundwater investigation, concurred that because PFCs aren't known to evaporate -- the chemical chains are too long -- the hydrant data suggests "PFCs were in the water that base personnel were drinking when the base was active."

The number of people potentially exposed is large. Military bases are known for significant staffing turnover. In 1985, Wurtsmith maintained an $80 million annual payroll with 3,600 military and civilian personnel.

What's hard to say is at what level any individual person was consuming toxic water at any given time, because the data "is all over the board," she said. Some hydrants were flushed when HSRUA took over the system. Others weren't. Some hydrants had low concentrations of PFCs. Other had high concentrations.

"Even though PFCs are fairly stable in the environment, this water has been sitting in those pipes for more than 20 years," Bush said.

"Could there have been some changes? Those types of questions remain and could put qualifications on the data."

Next steps include further data analysis to model PFC concentration levels at different areas of the base in the past. Depending on those conclusions, "it's possible we could conclude further study is needed," said Bush.

An epidemiological health study would be welcomed by hundreds of Wurtsmith veterans and family members who began organizing and comparing disease symptoms online after the PFC contamination came to light earlier this year. Common ailments reported within the group include chronic gastrointestinal issues, heart problems, thyroid problems, fertility issues, degenerative joints, neuropathy, lung, kidney and liver diseases, birth defects and cancer.

Whether those symptoms are connected to PFCs or other base pollution is unknown. The state of Michigan sued the Air Force in 1979 over carcinogenic industrial solvents like trichloroethylene (TCE) and jet fuel that had contaminated the base groundwater. Cleanup systems for those pollutants have been in place since the 1980s. The DEQ began testing for PFCs in Michigan in 2010, but the first sampling for PFCs at Wurtsmith took place in November 1998 and June 1999, according to an Oregon State University study published in 2003.

The hydrant testing has yet to be peer-reviewed, but Delaney, DEQ coordinator with the U.S. Defense Department, said he believes checking old hydrants is not a technique that's been used at other military bases grappling with PFC plumes.

More than 600 current and former U.S. military installations are now dealing with some kind of PFC problem related to the use a PFC-laden fire suppression tool called Aqueous Film Forming Foam (AFFF), which the military and airports around the world have used since the 1970s to quash jet fuel fires.

Perfluorinated chemicals, also called perfluoroalkyl substances (PFASs), are unregulated contaminants. As such, the EPA can only set unenforceable exposure guidelines. There are no U.S. drinking water standards for PFCs.

In Oscoda, 19 different PFCs are being found in the groundwater -- some at concentration levels well above the PFOS/PFOA health advisory level. One PFC, perfluorohexane sulfonic acid (PFHxS), is in numerous wells at high levels, but not enough testing has been conducted on that or other PFCs yet for the government to officially quantify the health risk.

University studies put the safety threshold for PFOS/PFOA exposure much lower than the EPA. In 2015, researchers Philippe Grandjean at Harvard School of Public Health and Richard Clapp of the University of Massachusetts-Lowell pegged 1 ppt as the safe level of PFOA in drinking water.

"There's still a lot of new information that keeps coming out that needs to be folded into what we already know, as far as the toxicity," said Bush.

As far as the extent of the current plume investigation, Bush said they are still trying to figure out "just how far this goes." In September, the DEQ said PFCs had crossed Van Etten Lake into another residential area along U.S. 23.

The hydrant revelation follows a bill passed by the Michigan Legislature this month that would require the military to cover the costs of cleaning up the plumes, which have made hundreds of private wells unsafe to drink from. Presently, state and local authorities are handing out tap filters and expanding municipal mains, but many feel the Air Force should be footing the bill.

The Air Force has argued they are prohibited from paying for safe water unless a property owner has a well testing above the EPA advisory level.

The legislation is awaiting a signature from Gov. Rick Snyder, who said last week the federal government should "step up" and deal with a base legacy problem.

"We're continuing to have dialogue with the Air Force on what can be done and how they can be more proactive on this," Snyder said.

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