Rather than shale that is mined though, Harbor Rock would “cook” river-bottom sediment that the Army ... at 2,000-degree Fahrenheit would break down the toxins. He does, though, admit that ...

The U.S. Army Corps of Engineers continues to monitor sediment levels. Mountain runoff carries ashen remains of what was the volcano’s peak into the North Fork Toutle River and down to the Toutle.

An "intense rain event" has caused sediment from the former Black Hill landfill site to escape into the Yarrowee River, triggering concerns.