Dredge Material Sediment Sampling, Characterization and Reuse/Disposal Reporting and Consultation Services - Suisun Bay Channel and New York Slough

Client: U.S. Army Corps of Engineers, San Francisco District (USACE)

Location: Suisun Bay Channel and New York Slough

Period of Performance: June - July 2009

Project Overview: Approximately 17 miles long and 300 feet wide, Suisun Bay Federal Channel and New York Slough are vital deep-draft shipping channels extending from the Carquinez Strait at Martinez to Antioch and serve commercial vessels en route to ports from Concord to Sacramento. The USACE proposed to conduct currently authorized dredging of the Suisun Bay Channel and New York Slough as part of its Operations and Maintenance Dredging Program, and to conduct advance maintenance dredging to a portion of Bull's Head Reach (at the western end of Suisun Bay Channel) in order to maintain the authorized depth for a longer period of time.

Scope of Services: Based upon the USACE's Suisun Bay Channel and New York Slough 2009 Maintenance Dredging Sampling and Analysis Plan (SAP), ADH developed and managed all technical aspects of this 8(a) sole-sourced, Firm Fixed-Price contract including contracting with a research vessel operator, vibracoring subcontractor, and a National Environmental Laboratory Accredited Program (NELAP) certified analytical laboratory. ADH staff in association with our vessel and vibracoring subcontractors performed all sediment vibracoring and site water sampling from four dredge areas. Composite samples were analyzed for grain size (for confirmation of Tier I assumptions), total solids, total organic carbon (TOC), and dissolved metals by a modified Waste Extraction Test (mWET). All chemical analyses were performed in accordance with the SAP, the Master Sampling and Analysis Plan - USACE San Francisco District O&M Dredging, the Inland Testing Manual, and the Upland Testing Manual. Data results from the analyses were required to determine the suitability of the sediments for the proposed disposal options specified in the SAP, including in-Bay disposal and upland beneficial reuse.

Results from the physical and chemistry analyses were evaluated in relation to guidelines established in the above mentioned documents, and water quality criteria relevant to in-Bay and upland disposal options, including: the California Toxics Rule, the San Francisco Bay Basin Water Quality Control Plan (Basin Plan); and Waste Discharge Requirements (WDRs) criteria for various upland reuse/disposal sites, including Sherman Island (referenced from several WDRs, including that for the Stockton Deep Water Ship Channel); and the California Drinking Water Standards' Primary Maximum Contaminant Levels. The report followed guidelines provided in the SAP and Public Notice 99-4: Sampling and Analysis Plan (Quality Assurance Project Plan) Guidance for Dredging Projects within the San Francisco District.

The project was overseen by the USACE and the final report incorporated comments from the Dredged Materials Management Office (comprised of the San Francisco Bay RWQCB, Bay Conservation and Development Commission, USEPA Region 9, and California Department of Fish & Game), NOAA Fisheries, U.S. Fish & Wildlife Service, and the California Coastal Commission.