The Environmental Protection Agency says some metals escaped into a Colorado creek from a wastewater treatment plant after heavy rains near the site of an earlier mine waste spill.
The EPA hasn't identified the metals or quantities that were released in the incident Tuesday near the Gold King Mine.
Local officials told the Durango Herald the release wasn't big enough to warrant a public advisory.
The agency said Thursday the metals had been at least partially treated. Officials say the problem was corrected in about two hours.
An EPA-led crew inadvertently triggered a 3-million-gallon spill at the mine in August 2015, tainting rivers in Colorado, New Mexico and Utah. The treatment plant was installed to clean up water still flowing from the mine while a long-term solution is sought.