Naval Facilities Engineering Command Southwest: Evaluation of Proposed Dredged Materials

Marine terminal maintenance and improvements involving the deepening and removal of accumulated sediment were evaluated from US Naval facilities in San Diego, California. The objective of this ongoing program is to characterize the potential dredged materials from navigational and berthing areas from three naval facilities to determine suitability for open ocean disposal (LA-5 Ocean Dredged Material Disposal Site). Sediment evaluations included solid-phase toxicity testing using amphipod and polychaetes species; water-column toxicity testing on fish, mysids, and bivalve embryos; and bioaccumulation potential exposures on bivalve and polychaete species. Projects conducted in support of this program included the shipping of up to 60 discrete sediment core samples over the course of a sampling event. Samples were received within 24 hours of shipping and sample temperature and holding times objectives were met without incident. Individual core samples were combined to create dredging unit composites with sufficient volume to conduct the full suite of biological and chemical evaluations (typically 25-30 gallons). All testing was conducted following the quality control objectives consistent with the National Environmental Laboratory Accreditation Program.The material under consideration for ocean disposal was evaluated using criteria outlined in the project specific Sampling and Analysis Plans and in accordance with the Ocean Testing Manual (OTM; USEPA/USACE 1991), and the Inland Testing Manual (ITM; USEPA/USACE 1998). In addition, EcoAnalysts staff provided statistical analyses and technical reporting of the toxicity data. Data from all toxicity tests were compared to the interpretation guidelines to determine compliance with the applicable sediment quality standards.