Earth Protect Blog

Water sources across state contain potentially hazardous levels of toxins under new plan

By Conrad Swanson

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Dozens of water sources across Colorado previously thought to be safe would now violate the federal maximum contaminant level for PFAS, or toxic “forever chemicals,” under a new standard proposed Tuesday.

The long-anticipated federal proposal slashes the Environmental Protection Agency’s previous standard by nearly 95%, indicating that the chemicals are far more hazardous than previously thought.

The proposal has broad implications for water sources across the country but Colorado is home to more contaminated sites than any other state.

PFAS are linked to cancer, birth defects, diabetes and autoimmune problems.

They don’t degrade naturally and accumulate in the bodies of the people and animals that ingest them. Experts who study the compounds repeatedly say there’s no safe level of exposure.

Previously acceptable levels for two types of chemicals — one called perfluorooctanoic acid (PFOA) and another called perfluorooctanesulfonic acid (PFOS) — sat at 70 parts per trillion. But under the new proposal, anything over 4 parts per trillion would exceed the federal’s contaminant standard.For context, 1 part per trillion amounts to a single drop of chemicals in 500,000 barrels of water.

The EPA’s newly proposed standard would set more concrete and enforceable limitations for chemical levels in water, though they could still take years to finalize. Water suppliers testing above the standard would have to reduce the level of chemicals in their water, the proposal indicates.

Federal officials signaled that the proposal would come last summer and their new proposal strikes a balance between amounts of the chemicals that are safe to consume and amounts that water providers can realistically detect, Christopher Higgins, a professor of civil and environmental engineering at the Colorado School of Mines, said.

If the proposal is finalized, Higgins said many water providers across the country will likely have to install new ways to treat their water and remove the chemicals.

“It’s going to be a challenge but it’s not going to be an intractable challenge,” Higgins said.

And the treatment will be expensive, Timothy Strathmann, another professor of civil and environmental engineering at the School of Mines, said.

Federal funds and other money sources are available to help offset those costs, though, Higgins said.

While testing is limited across Colorado, more than 100 public drinking water sources across the state showed traces of the compounds in 2020. Most of those sources were considered safe under the EPA’s old standards, but under the latest proposal, dozens more would be considered contaminated.

Thornton officials announced last year its drinking water had high concentrations of the chemicals (over 1,000 times the EPA’s health advisory levels) and called the results a concern but not a crisis.

Arapahoe County, Aurora, Brighton, Crowley County, Sterling, Englewood, Frisco and Lafayette are among the additional water providers showing elevated levels of PFAS, according to data collected by the Colorado Department of Public Health and Environment. Schools, campgrounds and fire protection districts also show high concentrations.

PFAS are used in everyday items like clothing, furniture, cosmetics and pots and pans. They’re also used in types of foams used to fight fires, which is another way they can seep into the water supply.

One study published last spring indicated that a substantial portion of PFAS found in Sand Creek and the South Platte River can be traced to the Suncor Energy oil refinery. Commerce City, Brighton, Thornton and Aurora take in water downstream of the refinery.

Thornton sued dozens of companies and people that produce PFAS earlier this year, alleging that cleanup and damage will plague the city “for many years to come.” The city’s lawsuit follows a similar one filed by Colorado Attorney General Phil Weiser.

Groundwater at the Air Force Academy and an aquifer serving the Security-Widefield area have also been contaminated with the compounds. PFAS exposure is considered a global health problem, but Colorado might suffer more than most.

The EPA identified more than 120,000 places across the country where people might be exposed to the toxic compounds and Colorado topped the list with more than 21,000 sites.