Fidalgo Bay causeway removal

The purpose of this environmental impact assessment (EIA) is to determine the effects of removing the Fidalgo Bay Causeway portion of the Tommy Thompson Parkway, located in Fidalgo Bay, Washington, (Figure 1). The riprap filled portion and the trestle (formed of creosote-coated pilings) are designated for removal and eventual replacement with a new structure resting upon steel or concrete pilings (Figure 2). This EIA investigates the positive and negative impacts associated with the removal including the proposed action, two alternative actions, and if no action was taken. The delineation of impacts are in accordance with the State Environmental Policy Act (SEPA). The proposed action completely removes the causeway, including the filled portion and the creosote pilings with the use of the vibrating hammer removal method. The first alternative removes only a 200-foot stretch of the filled portion and removes the creosote pilings via vibration removal. The second alternative is a last resort measure, created in the event that the creosote pilings are unsound and cannot be removed via the vibrating hammer method. It consists of the unsound pilings being removed by cutting of the pilings below the sediment line. The filled portion is completely removed in this alternative. If no action is taken, the causeway will be left untouched. A potential replacement process is briefly described at the end of the document, in Section 5