New EPA test results for PFAS “forever chemicals” in drinking water supplies turn up more Colorado communities with contamination problems, though water agencies say they are staying on top of the issue through dilution and plans for treatment plants.
EPA results from just one-fifth of the U.S. water utilities scheduled for PFAS testing found the potentially dangerous compounds at 431 locations nationwide, serving more than 26 million drinking water consumers, according to the Environmental Working Group, a nonprofit specializing in chemical contamination. Four Colorado communities whose water hadn’t previously tested positive for PFAS showed up in the latest results, EWG said.
The Colorado water agencies with various levels of PFAS in the latest release of EPA testing say they are aware of the contamination in their sources, and have continued more recent sampling as part of their mitigation efforts for the ubiquitous consumer products chemicals. Thornton, for example, said it has been able since last year to bring PFAS levels below the rigorous new EPA standards proposed in March through dilution efforts and activated carbon filtering at the Wes Brown Water Treatment Plant.
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“Last year and this year have been good water years,” said Thornton spokesperson Todd Barnes. “We’re not sure if we could meet regulations in a drought year at Wes Brown, as we anticipate the PFAS would be more concentrated in the river. But the final rule could be less stringent, hence waiting for the final rule.”
Thornton is working on adding a PFAS removal system at the Thornton Water Treatment Plant with construction scheduled for 2025-26, according to Water Quality Manager Martin Kimmes. Thornton will wait for final issuance of the new EPA standards, expected late this year, before deciding whether to add a new form of treatment at the Wes Brown Treatment Plant.
Snake River Water District, serving the Keystone area, is one of the communities that EWG says has new test results showing PFAS variants in its water.
District Executive Director Scott Price said the agency is confirming and analyzing the results through additional testing, evaluating potential removal methods and looking for funds to pay for it. State and federal officials have said assistance for local water agencies dealing with PFAS will be available through grant funds from infrastructure and stimulus spending approved by Congress in recent years.
“We have begun public notification on our website and are executing a mailing to all customers which will include the sample results and our communication method moving forward,” Price said in an email answer to questions. The district serves nearly 10,000 customers.
The first widespread detections of PFAS contamination came around military bases, airports, landfills and industrial complexes. Companies like DuPont and 3M manufactured chemicals that resisted water and heat and didn’t break down over time, and the products went into everything from firefighting foam to stain-resistant carpet to waterproof clothing and consumer food packaging.
Some mountain communities in Colorado have traced sources of PFAS contamination back to fire stations or training centers where foam has been used and has run off into surrounding watersheds.
“We don’t know where it came from, but we plan to find out through our engineers and the state experts,” Snake River’s Price said.
The latest round of EPA testing results show surprising levels of PFAS contamination persisting even in communities that already knew they had a problem with the chemicals, which are part of a family of thousands of variants on per- and polyfluoroalkyl substances.
For some water agencies that already knew about contamination, these new results show the number of PFAS in drinking water are “not really being lowered,” said EWG senior policy analyst Jared Hayes. “Quite a few water agencies nationally had up to 10 different PFAS in their drinking water. So it’s really just about this large scale of contamination.”
The EPA’s sharply lowered draft drinking water regulations in March targeted six variants, with specific levels set for PFOA and PFOS, at just 4 parts per trillion each, well below previous unenforceable “guidelines” of 70 ppt. PFOA was once used in the kitchen utensil coating Teflon, EWG said, and PFOS was used in Scotchgard for fabrics.
Four more chemicals were aggregated into a separate limit, Hayes said. Water agencies across Colorado and across the country are evaluating their test results in regard to the proposed limits, and calculating how much they will have to spend for treatment to get below them.
“But the more we’re finding out, these other contaminants are having similar health effects,” Hayes said. “All these chemicals need to be treated as a class, and not trying to play whack-a-mole and dealing with them one at a time.”
At the pace the EPA is moving to isolate new contaminants for drinking water limits, “It’s going to take us many decades to cover it all,” Hayes said.
Aurora Water, which says it has been well aware of its PFAS results and challenges, said the chemicals are being found everywhere in part because of more sensitive testing technology. The latest EPA release of water agency results is older data than Aurora has collected for itself since, and the city continues to test its water sources and output from its treatment facilities, spokesperson Greg Baker said.
All three of Aurora’s primary water sources have some PFAS, Baker said, including the mountain supply that is barely above detectable levels. PFAS in the Lower South Platte River supply that is returned to the Prairie Waters system is treated with granular activated carbon filters, Baker said, to below the proposed EPA limits. Aurora has had to change out the filtration materials more frequently since the EPA revised its recommendations from 70 ppt down to 4 ppt, in order to avoid a “breakthrough” of the chemicals, Baker said.
The third source, alluvial Cherry Creek wells, are offline for now while Aurora considers treatment options. Those wells are considered a minor water source and were previously used only in springtime to raise alkalinity levels at peak mountain runoff.
Aurora’s results as reported by the EPA showed an aggregate of a handful of PFAS variants testing at 23.9 ppt. While the PFAS detected in that set were not PFOA or PFOS, said EWG’s Hayes, the aggregated number points to the ubiquity of the forever chemicals and the pressing need for the EPA to more closely regulate them all.
“We feel as if this is a case of no good deed goes unpunished,” Baker said. “We test, without requirements, to help us plan for future regulations. Those numbers are now being used not because they are indicative of a problem, they are being used because they are there. Many states don’t have testing data like this, not because they didn’t have PFAS, rather, because they didn’t want to know.”
Aurora’s 2022 testing results displayed on its website show source water at 2 to 15 ppt for PFOA and PFOS. After treatment or dilution, the drinking water sent to residences tests as low as .047 or .030 ppt.