U.S. Army Corps of Engineers, San Francisco District - Pinole Shoal Channel, 2009 Advance Maintenance Dredging - Sediment Sampling, Characterization, Reporting and Consulting Services
As a part of its Operations and Maintenance Dredging Program for 2009, the U.S. Army Corps of Engineers (USACE) developed a sampling and analysis plan to characterize sediments proposed for advance maintenance dredging within the Pinole Shoal Federal Channel. Approximately 11 miles long and 600 feet wide, the Pinole Shoal Federal Channel is a vital deep-draft shipping channel located along southeastern San Pablo Bay that serves commercial vessels en route to ports from Concord to Sacramento. The USACE contracted with ADH to carry out the sampling and analysis plan and evaluate the sediments for multiple disposal/reuse options.
Based upon the USACE’s Pinole Shoal Channel 2009 Advance Maintenance Sampling and Analysis Plan (SAP), ADH developed and managed all technical aspects of this contract. In association with our vessel and vibracoring subcontractors – TEG Oceanographic Services and Monterey Canyon Research Vessels – ADH staff performed all sediment coring and site water sampling from four channel composite areas and two in-Bay disposal sites.
Technical challenges to vibracore sediment collection were minimized by scheduling sample collection to coincide with favorable wind, sea state and slack-tide conditions, and during periods of low vessel traffic. Surficial sediment composite samples from the in-Bay disposal areas were efficiently collected with a stainless-steel pipe dredge sampler.
Analytical results were evaluated to determine the channel sediment’s suitability for multiple disposal/placement options including upland placement at the Hamilton Wetland Restoration Project (HWRP), in-Bay disposal at sites SF-09 or SF-10, and ocean disposal. Sediment chemistry and toxicity results were evaluated in relation to criteria established in the U.S. Fish and Wildlife Service’s Biological Opinion (HWRP BO) on placement of dredge materials at the HWRP, as well as to San Francisco Bay Ambient Sediment Concentrations, and historical data from the San Francisco Deep Ocean Disposal Site Reference Area. Draft and final sediment evaluation reports were prepared by ADH for the USACE and followed published quality assurance guidelines for dredging projects within the San Francisco District.
The project was overseen by the USACE, and the final report incorporated comments the Dredged Material Management Office (DMMO), comprised of USACE, USEPA Region 9, San Francisco Bay RWQCB, Bay Conservation and Development Commission, State Lands Commission, California Department of Fish & Game. ADH project staff accompanied USACE staff for presentation of the draft report before the DMMO for granting of a suitability determination for the placement of dredged materials for this project.