Innovative techniques to protect wildlife during construction

From ODOT- As important as the Interstate 5 Willamette River Bridge is to drivers, so is protecting habitats for local wildlife and safeguarding the river below.



During construction, we are required to protect fish populations from loud noise that can impact them or their communication and migratory patterns.



To muffle the noise from underwater pile driving, crews place a “bubbleator” in the water. The “bubbleator” is a custom-made foam oval protected by sheet metal. Aluminum pipes deliver 1,600 cubic feet of air per minute to froth the water during pile driving, creating a sound curtain to protect fish. Due to its large size, the frame of these devices also serves as a safe, sturdy work platform for crews during pile driving. Environmental consultants mount hydrophones and monitor the resulting noise from the curtain of bubbles.



Each time we prepare to drive piles, we must conduct hydroacoustic monitoring to make sure we continue to avoid harming fish. Thus far, each time has shown that the “bubbleator” maintains noise levels below required thresholds.



Crews will begin another round of hydroacoustic monitoring next week as they prepare to drive piles to support the new work bridge.

Hamilton Construction crews using a “bubbleator” to reduce noise impacts

to fish during pile driving for the new Willamette River Bridge.