Sumas River Sediment Load

The Issue: A large, clay-rich active landslide on the western flank of Sumas Mountain in Whatcom County, Washington, is a significant source of sediment to Swift Creek and the salmon-bearing Sumas River. The landslide contains naturally occurring serpentinite that weathers to chrysotile asbestos and elevated levels of metals. The asbestos load in water as well as deposits along the banks and flood...