State regulators say a discharge of water from an old mine is the likely cause of orange rocks in the Cheat River.
Boaters reported seeing orange rocks at the mouth of Muddy Creek. The DEP says it believes something happened inside the old mine near Valley Point that created a temporary blockage, such as a roof collapse.
The DEP says in a news release that iron-laden water built up inside the mine and then began discharging into the creek in March. An acid mine treatment system along the creek was overwhelmed by the discharge for three days. Water flows returned to normal in five to six days.
The DEP says engineers and geologists are developing a plan to prevent future incidents.