Orange water was found flowing through a shallow creek in Boulder County.
Investigators figured out the water was seeping from the historic Swathmore Mine in Eldora.
The mine seepage flowed into the creek when a plug from the mine came loose, allowing orange-colored minerals and metals to enter the nearby creek water.
The Nederland Fire Department managed the containment of the mine seepage while it underwent testing and evaluation.
Water in the area was shut off as a precaution but EPA determined the substance was non-toxic.