MNR finds ‘forever chemicals’ in West Des Moines drinking water

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Treated drinking water that goes to homes, businesses and schools in parts of West Des Moines contains tiny amounts of toxic synthetic chemicals that have been linked to certain cancers.

These contaminations were discovered in recent weeks by the Iowa Department of Natural Resources. The state agency seeks to assess the prevalence in drinking water of perfluoroalkyl and polyfluoroalkyl substances – commonly known as PFAS, or “forever chemicals” because they persist indefinitely in the environment.

The DNR tests water in at least 59 cities at their sources and after treatment for human consumption. West Des Moines, the sixth largest city in the state with a population of approximately 68,700, was the only city to have detectable levels of two significant PFASs in its treated drinking water, according to initial results from Iowa Capital. Dispatch. Des Moines treated water did not have one.

The chemicals have been commonly used in nonstick cookware and stain resistant clothing and furniture. Groundwater contaminations in Iowa have already been identified near airports, which have used fire-fighting foams containing the chemicals. Some manufacturing plants and landfills are also sources of environmental contamination.

“Overall, statewide, the risk is very low,” Roger Bruner, MNR’s office water quality supervisor, said in October before testing.

But concerns about the chemicals have increased in recent years as researchers have shown that they cause cancer and are widely distributed in the environment. The vast majority of people in the United States are believed to have detectable amounts of chemicals in their bodies, and a recent study also found traces of the chemicals in rural Iowa’s streams and rivers.

Based on recent MNR test results, at least three of West Des Moines Water Works groundwater wells contain the two most studied PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) . It is not known why the wells contain the chemicals, Bruner said.

“The ministry’s surveillance sampling program is not designed to identify the source area (s),” he said.

The two chemicals were detected at concentrations of 2.9 and 2.4 parts per trillion, respectively, in treated drinking water in West Des Moines. Their concentrations reached 29 and 16 parts per trillion in the wells.

That’s well below current federal health advisory levels of 70 parts per trillion for drinking water, but the United States Environmental Protection Agency has said it plans to revise the levels. next year based on new research suggesting the safe threshold should be more restrictive. Chemicals have been shown to build up in people’s bodies over time.

“We’re talking parts per trillion,” said Christina Murphy, general manager of West Des Moines Water Works. “People describe it as falling into an Olympic-size swimming pool. We are talking about incredibly tiny amounts of a contaminant.

Contaminated well

Murphy said she first learned of the DNR test results about two weeks ago and planned to notify water customers after the DNR posted the results on its site. Web, which Bruner expected to happen later this week.

West Des Moines Water Works shut down the well with the highest amount of PFAS contamination, Murphy said, but it is not known what effect this had on the treated water. There has been no further testing of this water, she said, and there are 18 other wells that were not part of the initial testing.

An investigation into the source of the contamination is underway and Water Works will test its treated water for PFAS every three months, Murphy said. There are methods to filter out contaminants, but the water utility does not intend to implement them unless peak PFAS concentrations or federal advisory levels are significantly reduced.

“You could drink 70 parts per trillion water your entire life and see no effect from PFAS,” Murphy said, based on the EPA’s current health advisory. “We would like the water to be free of everything, but that is not our reality. We treat the water so that it is drinkable.

But David Cwiertny, director of the Center for Health Effects of Environmental Contamination at the University of Iowa, warned that more testing is needed to fully understand the extent of the problem in West Des Moines. He reviewed the data obtained by Capital Dispatch.

“It’s just a snapshot,” Cwiertny said. “It’s a sample at one point. He just tells us he’s there. How far can he go? How far does it go? “

Water from West Des Moines wells is treated and pumped to most of the city’s residential areas. About 30% of the city’s water is supplied by Des Moines Water Works, which goes to customers south of the Raccoon River and the far west and northwest of the city, Murphy said. Des Moines water is used as an additional source elsewhere during peak summer water demand.

Previous tests in 2014 had not revealed the presence of PFAS in West Des Moines water, but those tests were not as sensitive, Murphy said. Therefore, it is difficult to say how long they have been in the water.

Changing safety tips

New data and analysis “indicates that negative health effects may occur at much lower levels of exposure to PFOA and PFOS than previously believed and that PFOA is a probable carcinogen,” said the EPA in November. “The EPA will not wait to take action to protect the public from exposure to PFAS.”

Some states have established their own more restrictive health guidelines for PFAS contamination. In 2020, Michigan set limits of 8 and 16 parts per trillion for PFOA and PFOS in drinking water.

In July, the California Environmental Protection Agency suggested that PFOA should be limited in drinking water to 0.007 parts per trillion because of its risk of kidney cancer.

The EPA plans to update its PFAS health advisories in fall 2022. It is still assessing the toxicity of several other related chemicals that have also been found in Iowa’s water supplies. One of them, perfluorobutyrate, a degradation product of PFAS, has been widely detected in water sources and treated water by recent DNR tests. But research has shown its effects on people to be less potent, and in 2017, the Minnesota Department of Health set a safe threshold of 7,000 parts per trillion for drinking water.

An Iowa City water source also contained detectable amounts of PFOS – at 2.4 parts per trillion in the Iowa City sand pit – but the chemical was not detected in the city’s treated water .

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