Minor levels of PFAS, a class of chemicals that can cause serious health effects, have been found at eight testing sites in Leadville and Lake County, a state-funded study shows.
The study, which was conducted by an environmental nonprofit, found no detectable levels in the city's drinking water supply, but questions remain about the exact source of the contamination and how levels of PFAS might fluctuate seasonally, according to Emily Osborn, executive director of Blue Elements, an environmental nonprofit that works to protect Colorado watersheds and did the sampling.
"While we're relieved to confirm the safety of Leadville's public water supply, our findings highlight the need for ongoing monitoring into PFAS contamination in our region," Osborn said in a statement.
PFAS, or per- and polyfluoroalkyl substances, are human-made chemicals used for decades for a wide range of uses and products, including firefighting foam, waterproof coatings and microwave popcorn bags. Certain PFAS do not fully degrade in the environment or the human body, earning the moniker “forever chemicals.”
Scientific studies have shown that exposure to certain PFAS can cause decreased fertility and increased high blood pressure in pregnant women, developmental delays in children and increased cancer risk, according to a review by the United States Environmental Protection Agency. Since there are thousands of PFAS in use, other risks are still being studied by scientists.
Most Americans have some detectable PFAS in their blood, and one 2020 study estimated nearly 200 million Americans received drinking water with PFAS. The chemicals are notoriously hard to break down because of how they are molecularly structured.
Janel Owens, a professor and PFAS researcher at the University of Colorado Colorado Springs, who briefly evaluated the Blue Elements study, said PFAS are formed around a carbon-fluorine chemical bond — one of the strongest found in nature.
“The persistence of these chemicals has been one of the key issues with assessing their toxicity because they will build up within tissues. And they don’t go away.”
The Blue Elements study detected certain PFAS when averaging four samples taken across sites between August 2023 and May 2024. The group sampled four groundwater and four surface water locations, including a private well near Tennessee Pass, two public drinking water intake sites and a site downstream of a landfill.
The Colorado Department of Public Health and Environment paid for the study as part of its PFAS grant program, which funds nonprofits, water systems, tribes and other groups to sample PFAS levels across the state.
In April, the EPA finalized a long-awaited rule to reduce exposure to six particularly harmful PFAS for millions of Americans who rely on public drinking water. While the agency set maximum limits for all six compounds, it also said there was no safe level without risking health effects for two particular chemicals: PFOA and PFOS. PFOA was once used to make Teflon.
In the Blue Elements study, the average levels for all six regulated PFAS — if they were detected — were far lower than the federal limits. But results showed that trace levels of PFOA and PFOS were also found, which could pose public health risks.
"It's crucial for residents using private wells or surface water sources to be aware of the potential risks,” Osborn said in a statement.
Across the country, researchers have found PFAS in drinking water, soil and water near landfills, fertilizers and other industrial facilities. In Colorado, varying levels of PFAS have been detected in drinking water supplies across the state, as well as groundwater wells near Peterson Air Force Base, in Colorado Springs.
“[PFAS] take a long time to leach [through soil], but once they hit the groundwater, they’re on the fast track,” said Christopher Higgins, an engineering professor at Colorado School of Mines who studies PFAS and conducts research with the state health agency.
Higgins briefly evaluated the Blue Elements summary findings and cautioned there were additional research questions that should be answered, including how concentrations varied between groundwater and surface water sites, and how accurate test results were when PFAS concentrations were just above detectable levels.
Still, Higgins said the study is a good start in understanding how PFAS exposure can vary across the state.
“The data are consistent with our understanding that there are places where there’s higher levels and there’s places that have lower levels,” Higgins said.
Blue Elements received an additional $100,000 from the state to continue sampling this year and expanded the study to 23 sites in Leadville and Lake County, including near Turquoise Lake, which supplies millions of gallons of drinking water to Aurora.
Osborn, of Blue Elements, hopes that the state will continue funding the study for multiple years, so her group can drill into the exact sources of contamination.
“The tests are so expensive,” Osborn said. “Are we going to have enough rounds of testing to be able to actually say this is where it’s coming from so that we can actually do something about it?”
