This project entails creating a Confined Aquatic Disposal (CAD) site within Port of Hueneme as a regional tool for contaminated sediment management.  The Oxnard Harbor District (OHD), U.S. Navy (USN), and U.S. Army Corps of Engineers (USACE) are all responsible for maintaining authorized depths in different parts of Port of Hueneme Harbor.  Some of these sediments are known to be contaminated with chemicals including pesticides, tributylin (TBT), and polychlorinated biphenyl (PCB). 

If the dredged material were to be disposed at an upland landfill, the maintenance dredging could not be implemented in a cost-effective manner.  To solve this problem, the OHD began working with the USACE to develop a regional solution for contaminated sediment management that could be implemented within the resource constraints of the three participants.  The concept of creating a CAD cell for use by the USN, USACE, and OHD was a result of this work.

The project involves excavating a cell in the USN-owned, USACE-maintained Turning Basin of sufficient size and depth to accommodate the total volume of contaminated sediment produced by maintenance dredging.  The maximum volumes of contaminated sediment from each party will be approximately 30,000 cubic meters from the OHD, 80,000 cubic meters from the USN, and 140,000 cubic meters from the USACE for a total of approximately 250,000 cubic meters.  Clean sand that is excavated to create the cell will be pumped onto Hueneme Beach, located immediately south of the harbor’s Entrance Channel, to nourish the beach.  Subsequently, contaminated sediments from the OHD, USN, and USACE sites will be dredged using mechanical equipment and placed within the cell by using a bottom-dump barge.  These contaminated sediments will then be covered with clean sediments dredged from the uncontaminated remainder of the USACE Federal Channel, as part of USACE’s active and ongoing Operations and Management program (O&M) program.  A layer of gravel will then be placed over a portion of the clean sediment cap to provide protection against scour from vessel propeller wash.

Anchor QEA facilitated negotiation of the cost-sharing agreements and contracting vehicles, drafted the state and federal environmental documents, obtained all of the necessary permits, performed the design and engineering, and provided continuous onsite construction management support, environmental monitoring, and quality control.  Anchor QEA also conducted field sediment sampling during the conceptual development phase of the project, as well as water quality monitoring and sediment sampling during construction.