FOUNTAIN, Colo. (CBS4) – People in Fountain are being asked to conserve water ahead of mandatory water restrictions.

Toxic chemicals were discovered in the Widefield aquifer last year. The chemicals came from firefighting foam used for decades at nearby Peterson Air Force Base.

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Water faucet (credit: CBS)

That aquifer is a key water source for fountain.

PFCs have been linked to prostate, kidney and testicular cancer, along with other illnesses. The Air Force announced in August 2016 it would switch to some other type of foam.

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Air Force officials haven’t said how high the levels of PFCs were in the wastewater released at Peterson.

The Colorado Springs wastewater treatment system isn’t set up to remove PFCs, so they were still in the water when it was discharged into Fountain Creek, officials said. State officials said no communities take water directly from the creek downstream from the treatment plant.

The water was in a storage tank used to recirculate the water to a fire training area, officials said. It would have been re-used in firefighting exercises.

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Crews will continue to try to get rid of the rest of the chemicals during mandatory water restrictions later this summer.