Vermiculate Northwest facility produced 200 tons of waste rock

The former Vermiculite Northwest facility annually produced up to 200 tons of waste (known as waste rock or stoner rock) from vermiculite processing, containing some percentage of asbestos.

Furnaces were equipped with baghouses that performed a filtering function to control dust and emissions. After 1975, baghouse dust and waste rock were wetted down and collected in bags.

According to internal memos, the bags were temporarily stored in dumpsters located inside the plant until they were returned to Libby, Montana, for disposal. Other sources indicate that the waste was disposed of at the now closed St. John’s Landfill.

It is unknown whether community members carried the waste rock offsite; however, a former worker reported that employees often removed the waste material (sometimes by the truckload) and applied it for personal uses. It is possible that waste rock from this facility went back to Libby, to the local landfill, or was removed by employees for personal use.