Low levels of potentially harmful chemicals used in firefighting foam and manufacturing have been found in suburban Denver drinking water wells.
The Colorado Department of Public Health and Environment said Thursday that compounds called PFCs were detected in wells used by the South Adams County Water and Sanitation District, which has about 50,000 customers in Commerce City.
The health department says the concentrations are below the federal government's advisory limit. The water district says its water is safe.
Some kinds of PFCs have been linked to cancer and other illnesses.
The utility says its treatment plant is already removing some PFCs from the water. Officials say they're increasing the amount of water they get from other sources.
Federal, state and local agencies are looking for the source of the PFCs.