RAVENSDALE, Wash. - State Department of Ecology officials on Monday said they plan to seal up a toxic threat inside an old King County mine instead of trying to remove it.
The Rogers Coal Seam is a mine inside the so-called Landsburg Mine site. It was mine out decades ago, and over time, the long mine collapsed forming a 1.5 mile long trench in the woods near Ravensdale.
In the late 1960s several companies used the deeper parts of the trench for an industrial landfill. Ecology investigators estimate some 4,500 barrels of solvents, paints and other liquid and solid waste were dumped there. After removing a few hundred barrels officials decided it was too dangerous to try to retrieve those buried deeper in the trench. They installed monitoring wells all along the trench and at each end.
They have not discovered any chemical leaks yet but do not want to take the chance that heavy rain, an earthquake or some other event could break open the barrels. The PCBS and other chemicals could contaminate the ground water and nearby streams.
The plan is to cover the site in clean fill dirt then put a hard cap over it that would repel water. They also installed catch basins and pipes to handle waste that may seep out. It’s a big action for a spill that may never happen but with responsible parties available to pay for the system, The Department of Ecology said it’s worth the effort.
In the early years the mine provided coal for the University of Washington and corrections facilities in Monroe and Shelton.