The Port of Seattle has issued a Determination of Non-Significance (DNS) consistent with State Environmental Policy Act Rules and Port of Seattle Commission Resolution 3650 for the Terminal 91 Interim Action West Berth Maintenance Dredge Project.
According to the Port, dredging work will be performed using a barge‑mounted crane or hydraulic excavator with conventional or enclosed buckets.
Dewatering of dredged sediment will occur on the barge, using geotextile and/or straw bale filtration prior to return water entering Elliott Bay at the point of dredging.
Also, dewatered sediment will be transported by barge to an offloading facility and then moved by lined trucks or railcars to an approved Subtitle D landfill for disposal.
After dredging is complete, post‑dredge sediment sampling will support MTCA cleanup evaluations. In the eastern dredge area, approximately 100 cubic yards of clean sand will then be placed as a nominal 9‑inch layer to meet sediment antidegradation standards and provide a temporary suitable benthic surface.