The Yerba Buena Island Transition Structure #1 is part of the new Bay Bridge seismic retrofit project linking Oakland and San Francisco under the oversight of Caltrans. This segment of construction initiated in September 2010 and is planned for completion in December 2013. The subject Transition Structure #1 is the easternmost transition structure onto the island which comprises construction of three series of bents to support the new bridge deck as well as slope construction and access roads.
Since August 2010, ENGEO assumed the role of the project Qualified SWPPP Developer (QSD) in order to certify the project under the new State Water Resources Control Board (SWRCB) Construction General Permit (Order No. 2009-0009 DWQ) for stormwater dischargers. This project was determined to be a Risk Level 2 site, which requires BMP monitoring and stormwater effluent sampling and testing for sediment pollutants (pH and turbidity). Caltrans expanded ENGEO’s role to include the project Water Pollution Control Manager (WPCM), the Qualified SWPPP Practitioner (QSP), and the stormwater sampling/testing agency for the project.
As the project’s WPCM/QSD, ENGEO’s main role is to provide on-going SWPPP documentation services including SWPPP Amendments, Updates, Compliance Reports, Notices of Discharge, and NAL Exceedence Reports to satisfy Caltrans and SWRCB regulations. As required by Caltrans, ENGEO is also providing daily visits to monitor site BMPs within active and inactive construction, staging and storage areas and attending weekly site meetings with the General Contractor (MCM Construction Incorporated) and Caltrans engineers and environmental specialists.
To satisfy the requirements of Order No. 2009-0009 DWQ for a Risk Level 2 site, ENGEO is also providing site visits and preparing monitoring checklists on a weekly, before, during, and after a storm event basis for BMP conditions and effectiveness, as well as quarterly visits to observe non-stormwater potential pollutants. During storm events producing runoff, ENGEO performs daily stormwater effluent sampling and field testing for pH and turbidity at each site discharge location.