Colorado health authorities have stopped monitoring the plume of groundwater contaminated with PFCs at levels exceeding a federal health advisory limit that is spreading south from Colorado Springs toward Pueblo, state and federal officials confirmed.

This widens the challenge of dealing with the perfluorinated chemicals, or PFCs, which do not break down and have been linked to birth defects, cancers and other health harm.

Pueblo leaders on Thursday said they expect tracking of contaminated water to continue as PFCs seep south through the Fountain Creek watershed toward the Arkansas River.

“Pueblo County has not been notified by the Colorado Department of Public Health and Environment (CDPHE), Environmental Protection Agency or the Air Force that they have stopped monitoring, testing or sampling groundwater to track the plume,” county commissioner Terry Hart said. “If they have indeed stopped, we would most definitely be interested in learning why they stopped.

“Pueblo County is concerned about any and all groundwater contaminants. We are working aggressively to ensure that any waterway, but particularly Fountain Creek, is clean so they can be assets to our community instead of being a problem.”

State tests for PFCs in drinking water have not been done since November 2016, Colorado Department of Public Health and Environment records show. And CDPHE hasn’t measured PFCs in groundwater since February, the records show.

It’s unclear how far the PFCs contamination has moved in groundwater. Back in April 2016, groundwater samples taken south of Fountain, along Hanover Road north of Pueblo, showed PFC contamination higher than 100 parts per trillion — well above the federal EPA health advisory limit of 70 ppt.

CDPHE officials on Thursday confirmed they stopped sampling water and told The Denver Post that’s because EPA funding that enabled the tests ran out. They could not say whether the agency is still monitoring other contaminated groundwater plumes, such as those spreading PCE from dry cleaning.

“The Water Quality Control Division is not conducting any further PFC sampling. ​We expended the funds from the EPA to complete sampling,” CDPHE spokeswoman Jan Stapleman said.

EPA officials in Denver said state water sampling stopped but that the U.S. Air Force still is monitoring PFCs contamination as part of a military investigation at Peterson Air Force Base. That base is strongly suspected as a source of PFCs, a family of chemicals found in aqueous film-forming foams that firefighters use to douse fuel fires.

Drinking water supplies for more than 6 million Americans have been tainted by PFCs, federal data show.

“EPA provided funding to assist CDPHE with well testing and to evaluate potential sources. That work has been completed and the Air Force has since assumed responsibility for additional activities, including characterizing and monitoring groundwater,” EPA spokeswoman Lisa McClain-Vanderpool said.

“EPA will continue to work with CDPHE, and also with the Air Force and local water utilities, as they collect and evaluate new information and address public health concerns,” she said. “At this point, we are confident that CDPHE, El Paso County and the Air Force have taken necessary actions to protect the public from any potential exposure to PFCs in drinking water. As a result of the sampling and assessments done thus far, there’s no immediate risk of PFC contamination to Pueblo drinking water.”

CDPHE spokeswoman Meghan Trubee also said “the U.S. Air Force is testing groundwater as part of its source investigation.”

However, Air Force officials said this week they are not conducting or funding tests in the Fountain watershed.

“The Air Force does not have any plans to move sampling into the community in the near future,” Peterson AFB spokesman Stephen Brady told The Post.

An Air Force assessment of potential sources of PFCs spreading from Peterson, promised this summer, was not yet available. U.S. Department of Defense officials who visited Peterson AFB last year said the military will spend $2 billion on PFCs cleanups nationwide.

CDPHE officials still are waiting on that assessment.They plan to review it and “evaluate next steps at that time,” Trubee said.

A different CDPHE spokeswoman, Gaby Johnston, told The Post late Thursday that an Air Force official indicated water testing of private wells would continue. Johnston said the CDPHE will work collaboratively with the Air Force to get water testing done.

PFCs are also used to make products resistant to grease including carpet, cookware, clothing and fast-food wrappers. The same properties that make PFCs useful suffocating fires prevent them from breaking down in the environment.

The government does not regulate PFCs. They rank among the worst of hundreds of unregulated chemicals that federal scientists are detecting in drinking water supplies, including hormones, pesticides, antibiotics and antidepressants — because they cannot easily be removed.

Some companies voluntarily stopped producing and using PFCs, starting with the “long-chain” PFCs called PFOA and PFOS. The shorter-chain PFCs touted as safer alternatives may cause harm, too. Health data is scarce because epidemiological studies haven’t been done.

Firefighting foam used at U.S. military bases including Peterson Air Force Base east of Colorado Springs emerged in 2016 as a likely source of PFCs contamination.

Nationwide, PFCs have been found in 108 U.S. public water systems, according to a recent presentation by CDPHE toxicologist Kristy Richardson to state water quality control commissioners. Those systems including municipal wells in Security, Widefield and Fountain, south of Colorado Springs, which traditionally have relied on underground water drawn from the Widefield Aquifer, Richardson told commissioners. More than 65,000 people drink water from that aquifer.

But, after news reports a year ago revealed the water contamination, CDPHE officials working with El Paso County public health officials ramped up water testing. Water quality data on drinking water and groundwater helped show where PFC was spreading southward between Colorado Springs and Pueblo.

This area ranks among the most-populated among 63 hard-hit areas around the country. PFC contamination at sites near Philadelphia and Seattle also threatens thousands of people.

Fountain utility officials have lined up alternative water sources and say their public drinking water no longer is contaminated at levels above the EPA health advisory limit. Security officials also shifted away from using contaminated wells and purchased mountain river water delivered via a pipeline from a reservoir west of Pueblo to Colorado Springs. Widefield installed equipment to treat its well water.

This story was updated at 3:16 p.m. on June 16, 2017, to clarify that Widefield installed equipment to treat its well water.