The City of Woodinville has valid reasons to dispute recent findings issued by King County that there is no evidence of active earthquake faults under the Brightwater regional wastewater treatment facility. Brightwater meets the definition of “critical facility” as defined by the International Building Code (IBC), adopted by Washington state, because if its operations were to fail, the results could be catastrophic. The IBC is indisputable that a critical facility cannot be built over active earthquake faults. The City seeks assurances from King County as the developer and Snohomish County as the regulatory agency that construction meets all applicable codes to ensure public safety.

Brightwater will be constructed within the Southern Whidbey Island fault zone (SWIF), identified by the U.S. Geological Survey (USGS) in 2003 as an active earthquake fault. The City is rightfully concerned that trench excavations by King County to evaluate seismic conditions were too limited in their depth and scope and that construction of the facility on an active earthquake fault violates the IBC, placing a great risk to public health and safety and Woodinville’s natural environment.

King County recognizes SWIF as an active fault, but it has addressed only the potential for seismic shaking, not rupture of the ground surface.

The worst case scenario described in King County’s Final Environmental Impact Statement is not realistic for Woodinville. What is most frightening for the community is a major toxic chemical spill and release of untreated sewage into local waterways should an earthquake occur.

More information is needed and can be obtained with additional trenching throughout the site, taking advantage of the offer by the USGS to help in analysis of trench exposures. Trenching performed with “standard and professional care” exposes faults within the earth’s surface that can be radiocarbon-dated. In my professional opinion, King County has not done its due diligence because trenching has not occurred in every place where a surface building is proposed.

Although Brightwater is located north of city limits, the City will be most impacted should a disaster event associated with the facility occur. The City deserves assurances that Brightwater’s worst case scenario doesn’t become the citizens’ burden to bear.

Dr. Robert S. Yeats, Ph.D, Earth Consultants International, Corvallis, Oregon. (1-541-754-0622), (yeatsr@geo.oregonstate.edu) is a consultant for the City of Woodinville. He is emeritus professor of geology at Oregon State University and author of Living with Earthquakes in the Pacific Northwest (Oregon State University Press, 2004.)