[1] That, in addition to a large amount of precipitation received in Washington state each year, makes for prime landsliding conditions.
[2] There is a lack of vegetation on the toe of the landslide because it is over steepened and constantly sliding, providing no stable area for trees to grow.
[citation needed] The main ingredient in this landslide is serpentinite, which is formed from serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle.
The possible reason why there was conglomerate bedrock underneath the serpentinite could be because of the glacial till or delta deposits flowing out of the Cascade mountain range as it was forming millions of years ago.
About the time that all this was happening, 45 mya, the Chuckanut Formation was ceasing to gain deposits and the volcanic activity known as the North Cascades was in its youth.
Previously dredged materials remaining alongside the creek banks were sprayed with an EPA approved "tackifier" (tinted green) to keep asbestos from blowing off the surface.
Agencies at the local, state, regional and federal level are working together to address the situation, communicating with the public about the health risks while seeking funds and authorities for interim approaches.
Naturally occurring asbestos is found in other communities across the United States, and in some counties in California and Virginia is factored into land use planning and permitting.
The Sumas Mountain landslide, with the sedimentation and flooding issues combined with the mobility of the asbestos adds to the challenges to this site.
The ABS measures the amount of asbestos in the breathing zone of personnel (with respiratory protection) performing routine activities, such as raking, running or biking, and digging/loading.