An Air Force-supplied filter being given to Fountain to strain out toxic chemicals from drinking water appears susceptible to a host of newly discovered compounds, a new study shows.
That type of device - called a granular activated carbon filter - wasn't too effective at removing more than two dozen chemicals derived from a toxic firefighting foam used for decades at Peterson Air Force Base.
That means cities relying on those kinds of filters - in this case, Fountain - must replace them more often if they choose to account for the growing list of perfluorinated chemicals, some of which have only been discovered in the last year, said Christopher Higgins, a Colorado School of Mines researcher and the study's author.
And that could mean higher costs for ratepayers.
"The carbon filters will work - you just have to change them more frequently," Higgins said.
At issue is the danger posed by a military-grade firefighting foam that is suspected of fouling the Widefield aquifer - a key source of drinking water for the Security, Widefield and Fountain areas.
The Environmental Protection Agency last year issued health advisories for two chemicals found in the foam - perfluorooctanoate and perfluorooctane sulfonate - because they may cause a host of ailments, including liver damage, low infant birth weight and cancer. (The Colorado Department of Public Health and Environment also added a third, lesser-known such chemical to the list.)
The announcements sent thousands of people rushing to buy bottled water, while spurring water districts to spend millions of dollars upgrading their systems.
None of the area's three largest districts still use untreated water from the aquifer.
But Higgins and other researchers across the nation have identified more than two dozen other similar chemicals derived from the firefighting foam - 13 of them in last six months.
And granular activated carbon filters are quickly overwhelmed by those other chemicals, according to Higgins' study published Tuesday in the journal Environmental Science & Technology.
"This study basically is a way of confirming what we suspected," Higgins said. "Which was that some of those compounds, if they get out into the environment, will likely come through carbon filters much more quickly than PFOA and PFOS do."
The danger posed to residents by these additional chemicals remains unclear, said Jamie DeWitt, a toxicologist at East Carolina University. They include similar chemicals to those touted by the Air Force as safe for replacing its decades-old toxic foam.
"I think the first question anybody should ask is: 'Are these truly safe for me to drink at these concentrations?' " DeWitt said. "And honestly, I don't think anybody at this point can really answer that."
After-hours calls by The Gazette to Peterson and Air Force Civil Engineer Center spokespeople were not returned.
Higgins' study comes as Fountain leaders work to install two Air Force-supplied granular activated carbon filters this summer.
The research hasn't changed those plans, said Curtis Mitchell, Fountain's utilities director.
"We'll certainly work with him (Higgins) on how long the filter run times will be, and just look at what his data is showing," Mitchell said.
Mitchell downplayed concerns about moving forward with installation, because the Air Force's filters can be easily substituted for a different type of treatment system - such as ion-exchange devices.
Widefield Water and Sanitation District recently became the first water district in the nation to use an ion-exchange system to treat water for perfluorinated compounds.
A six-month pilot program showed promise over the winter, and recent test results on the system after it began servicing houses in May showed no trace of six types of perfluorinated compounds, said Brandon Bernard, the Widefield district's general manager.
"This stuff's pretty effective," Bernard said.
Higgins, however stopped short of endorsing such devices. They have yet to undergo the same tests as those Higgins just finished on granular activated carbon filters.
"I don't know how well they work at removing all of these other chemicals," he said.