A stormwater drainage outfall pipe near the Golden Gate Bridge needed to be widened and extended to prevent blockage from sand buildup which contributed to flooding problems upstream in the Crissy Field and Mason Street areas in San Francisco.
Environmental Impact Mitigation
To protect the fish and marine wildlife, underwater best management practices were established before dredging and repair of the pipe began. An ELASTEC Type III RuffWater Screen turbidity curtain was installed to minimize construction impacts and silt flow to this sensitive habitat.
Turbidity Curtain Used
This is a heavy-duty premium turbidity curtain for use in demanding waters such as tidal areas, nearshore ocean environments with strong currents, rivers, bays, harbors and lakes. An ELASTEC RuffWater Screen controls the migration of silt and turbid water in the construction zone, keeping the surrounding water and marine wildlife safe.
In the Crissy Field project, 500 ft. of the 8 ft. skirt curtain was configured in a “U” shape to encompass the work site. The curtain installation was conducted by Elastec and monitored by the media, California Department of Transportation (Caltrans) and marine biologists. Crissy Field falls under the National Park Service jurisdiction. Powers Engineering Construction was the project contractor.
Eltora Charles, Civil T.E. of the California Department of transportation had this to say about the curtain and its performance: “On behalf of Caltrans I would sincerely like to thank you and your crew for our turbidity control curtain. Thank you to the Elastec family for assisting Caltrans in designing a Best Management Practice that has been both cost effective and has exceeded our expectations in performance. Recently I was observing the waves onsite crashing against the shoreline – the winds were so strong they were blowing our plastic covers about; however, the turbidity curtain remained intact and during dredging operations there was no visible notice of turbidity outside of the curtain! It performed like a champ!”
