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Wastewater treatment plants may have to start testing for presence of PFAS “forever chemicals” in biosolids as early as next year, and those plants may be required to investigate upstream sources of the toxic substances, Colorado regulators say. 

State water quality officials also said Colorado’s PFAS grant program is also open to help communities test for PFAS in groundwater in areas where biosolids have been spread for decades as fertilizer, state officials said. They responded to Colorado Sun queries for an update on a biosolids expert working group that began meeting in June. 

More testing can’t happen soon enough for longtime Eastern Plains residents like Pam Wheldon and her ranching family, surrounded by farms from Last Chance to Deer Trail where mysterious biosolids have been spread for decades. She has spent years questioning the landfills, hazardous waste sites and biosolid-using farms that Front Range interests place at remote Eastern Plains locations. 

“They just ended up buying the land and doing whatever they wanted, and there wasn’t anything to do about it,” Wheldon said. She and her daughter see materials being spread when they walk on their arrowhead hunts, and have watched crops treated with biosolids wash across eastern Arapahoe County during rainstorm flooding.

“They say the water wouldn’t travel that far. It did,” Wheldon said. “You know darn good and well if we get a big gully washer, it will just wash right on down through here.” She plans to contact the state about testing her family’s water sources for PFAS. (PFAS is an abbreviation for perfluoroalkyl and polyfluoroalkyl substances.)

Colorado regulators say they are developing the new PFAS and biosolids policies as part of a public process launched in June, after a flurry of test results and news stories about the spread of PFAS contamination in areas previously free from testing requirements

There is currently no state requirement to test for PFAS in biosolids, though wastewater agencies that do test find forever chemical levels that independent scientists call concerning. 

“The division may propose monitoring requirements for PFAS in biosolids as soon as 2023,” the Water Quality Control Division said, in response to written questions. “Facilities may be required to investigate potential nondomestic sources for PFAS in biosolids and report to the division on measures taken to reduce those sources.”

Dozens of community water systems have signed up for state grants to test their drinking water sources for PFAS, the division said, after a change in Environmental Protection Agency guidelines dramatically lowered the acceptable amounts of the forever chemicals in consumable supplies. 

Colorado now appears likely to take a path similar to Michigan in testing biosolids before they are applied, said Barbara Biggs, general manager of Roxborough Water and Sanitation District and one of the experts testifying to an interim legislative committee on water and agriculture on Aug. 4. Her district serves about 11,000 people in southwest metro Denver with supply that comes through Aurora Water, and has not tested at levels that raise concerns.

Michigan has a three-tiered approach for testing and handling PFAS in biosolids. While Michigan has suffered from far more concentrated industrial sources of PFAS than Colorado has, some of the same principles can apply, Biggs said. 

Michigan requires all utilities to test biosolids. If PFAS concentrations are low, the biosolids can be used as fertilizer. If the testing reaches a medium tier, the utilities must start looking for upstream sources, and notify farmers how to handle the biosolids safely. At the highest tier, the biosolids cannot be used on the land, and an intensive search for upstream PFAS sources begins, Biggs said. 

At the interim legislative committee, regulators told lawmakers that Colorado has for years regulated the actual application of biosolids more closely than some of the states now finding serious PFAS problems in groundwater. Colorado has barred spreading of biosolids from industrial wastewater likely to contain far higher levels of PFAS chemicals. Colorado also has multiple rules dictating how biosolids are spread, including setbacks from surface water and recommendations on frequency of use. 

Water regulators and utility leaders told the lawmakers they are not aware of any currently viable technology that removes PFAS from biosolids. They praised passage of a 2022 bill ending the sale of many consumer products containing PFAS in Colorado. 

“The only cost effective answer is to stop putting PFAS in products that generate wastewater,” one regulator said. 

Utilities had to make similar efforts when the cleaning chemical perchlorate was found to be dangerous, and dry cleaners across the country had to meet zero discharge standards. 

“We’ve done this before,” Biggs said, in a later interview.

The public has the right to know more, but they should not be unduly scared about new PFAS guidelines that are aimed at preventing lifetime accumulations, she said. “With the public concern, we just need to give the scientists time to figure out exactly what the right levels are. Do we need to deal with the hot spots? Absolutely. Do we need to panic? No,” Biggs said. 

Reducing PFAS levels in either drinking water or wastewater remains an expensive puzzle, though manufacturing industry and utility researchers are scrambling to solve it. A recent study published in the journal Science offered some hope, with researchers able to break the previously insoluble bonds of some PFAS chemical versions by adding relatively common substances and heating to a boil. 

But even if the proposed treatment could scale up to utility levels, PFAS must still be filtered out of water or wastewater first. All the treatments being studied are so expensive that Colorado utilities are racing to put in applications for federal stimulus money to build new filtration systems.

South Adams County Water and Sanitation District, which includes Commerce City, needs to find $130 million for a new drinking water treatment plant, after tests revealed unacceptable levels of PFAS and other contaminants. The district has shut down contaminated wells, and is spending millions to buy additional clean water from Denver Water; officials don’t believe county customers can afford a major boost in rates to build the plant. 

Frisco and other Colorado cities and towns have made similar moves, with Frisco shutting down contaminated wells and bringing a renovated treatment plant back online to avoid using tainted water. 

“We’re doing everything we can to find the high levels,” Biggs said. “There are treatment technologies out there. But it does take time to raise the funds, get the money, and construct. Things just take time.”

Though at times it feels to Wheldon like her portion of the state is emptying out, there are still residents who deserve to know what’s being put on their land, and what ends up in their water, she said. She wants to see more testing, and an education effort to get the results out to Eastern Plains counties. 

“They think they bring it out here and nobody cares,” she said. “Well, guess what, we do care.” 

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Michael Booth

Michael Booth is a Colorado Sun reporter covering health, health policy and the environment. Email: booth@coloradosun.com Twitter: