WSDOT and its contractor, Granite Construction Company, are currently working to replace the existing SR 529 Ebey Slough Bridge with a wider, fixed-span bridge. We are going to great lengths to ensure that the aquatic environment surrounding the project is protected. Great consideration and careful planning has gone in to making sure we successfully work in the slough without significantly influencing the quality of the water and surrounding ecosystem.
What is WSDOT doing to protect the environment surrounding the Ebey Slough?
To minimize potential impacts to fish we will limit our work in the water from August 1 to February 15 each year. This window of time was chosen because it is the time in which the fewest juvenile fish inhabit the slough. We are also working closely with the appropriate agencies to develop measures to protect marine mammals near the project area.
The new bridge will be built on steel pile piers. To reduce noise when we install the piles in water greater than 2 feet in depth, we will install a temporary noise reducing bubble curtain around the pile. This is important to protect fish and marine mammals from higher-than-usual sound levels in the slough.
Water quality protection:
When crews are working in the water, we have a boat in the slough with crew members testing the quality of the water every hour to make sure our construction work does not stir up sediment in the water. Because of tidal changes, crew members testing the water have to differentiate between the influence from the construction work and the tidal influence, which often brings turbid water into the slough.
We will remove the creosote-soaked timbers that acted as bridge rests for the existing bridge. Once the timbers are removed, crews will cap the holes left behind with clean, washed sand.
We will also build an enclosed storm water system for roadway runoff and install a storm water treatment vault and a grassy swale to help clean roadway runoff.
The project was designed to minimize impacts to wetlands and the slough. During construction, crews will use tools such as straw blankets and silt fence to ensure soil does not migrate from the work site.
We will remove potentially contaminated soil located on the north side of the existing bridge. Crews will remove the material from the site and fill the area with new roadway material.
We will remove potentially contaminated material from the new roadway fill area, areas surrounding the bridge rest, material removed within the new bridge piers and material removed when excavating the existing bridge piers.
The existing SR 529 Ebey Slough Bridge is painted with lead paint. This bridge will be removed as part of the project, reducing the potential for migration of lead paint into the environment.
Visit our Flickr site for more construction photos.