Port growth is an important economic investment and ports are performing infrastructure improvements that include larger cranes, higher capacity backlands for quicker through port transfer, greater inland infrastructure, and deeper drafts. The dimensions of the world-wide fleet of container vessels have increased significantly in the last ten years, and it is anticipated that this trend will continue into the future as shipping companies continue to consolidate. As a result, ports throughout the United States have been actively positioning themselves to accommodate larger vessels to maintain or grow trade opportunities. While market pressures are driving the Ports of Long Beach and Los Angeles to deepen/redevelop their berths, tightening regulations that limit cost effective sediment management options like ocean disposal have created new challenges for Port staff.
Planning for large dredging/redevelopment projects frequently entails unique engineering and environmental challenges. The financial and environmental feasibility of these projects is often dependent on the management of contaminated sediments or large quantities of clean sediment that must be undertaken within region-specific regulatory requirements. In California, several regulatory authorities oversee the movement and disposal of sediment. They make up the Los Angeles Regional Contaminated Sediments Task Force and include: U.S. Army Corps of Engineers, U.S. Environmental Protection Agency, National Marine Fisheries Service, U. S. Fish and Wildlife Service, California Coastal Commission, Los Angeles Regional Water Quality Control Board, and California Department of Fish and Wildlife. Dredging and disposal activities are also watched closely by local non-governmental organizations to ensure that regional initiatives like the promotion of beneficial reuse opportunities are being met. In the Los Angeles region, the preferred management strategy for clean sediments is beach nourishment and port fills. Management strategies for contaminated sediments, in order of preference, include beneficial reuse of sediments in construction fill (e.g., nearshore confined disposal facility), temporary storage in an approved upland area (until a fill project becomes available), treatment and reuse as a marketable product (e.g., cement-stabilized fill), or for other beneficial upland placement areas. The ports do not necessarily have planned fill opportunities to align with maintenance and capital dredging projects; therefore, the ports have been helping the regulators recognize the need for regional opportunities to manage both clean and contaminated sediments effectively and efficiently. Both ports have developed sediment management guidance documents and contaminated sediment management plans to provide clarity in the ports’ decision processes, and to prioritize management strategies that are feasible for implementation within a working port. Through frequent communication with the regulators, the ports have been able to generate renewed interest in confined aquatic disposal facilities and shallow water habitat enhancement opportunities because of the need to identify economical and logistically feasible management alternatives for clean and contaminated sediments beyond use as port fill material. Creation of biologically valuable habitat with dredged material has the added value of providing mitigation credit for port development projects.
This talk focuses on the Ports’ sediment management challenges and discusses the research conducted over the last few years to identify suitable sediment management alternatives at the nation’s largest ports, Port of Los Angeles and Port of Long Beach.