Naval Station Mayport is a major U.S. Navy port area on the east coast of Florida at the mouth of the St. Johns River. The basin is located south of the river, with an entrance channel that enters the river immediately west of the south jetty.
Recently, a portion of the Mayport Turning Basin (MTB), the Mayport Entrance Channel (MEC), and Bar Cut 3 (BC3) were deepened to accommodate a nuclear carrier and supporting vessels. Approximately 5,000,000 cubic yards (cy) of material were excavated and disposed of in the Jacksonville and Fernandina Beach ODMDS. Routine maintenance dredging includes material from the non-deepened portion of the MTB (MTB42), Destroyer Slip (DS), Small Boat Basin (SBB), and the recently deepened portions of the MEC, MTB50, and the BC3 east of Station 210+00. These areas are maintenance-dredged approximately every 2 years. In the past, material from maintenance cycles was placed in two upland sites on Naval Station Mayport; however, these sites have a limited capacity. Therefore, material from Naval Station Mayport has been disposed of in the Jacksonville ODMDS.
There were two sampling events for this project. The first sampling event included the MTB42, DS, and SBB. The second sampling event had two parts and included the MTB50, MEC, and BC3 east of Sta. 210+00. Material sampled from BC 3 was evaluated under CFR227.13(b) to determine if exclusionary criteria were met and if further analysis would be required. During the second sampling event, nine vibracore samples were also collected for a geotech study. ANAMAR coordinated and directed operations for this project and worked closely with USACE to develop sampling and analysis schemes, schedules, and deliverables. ANAMAR summarized the results of the physical, chemical, and toxicological testing of sediment, elutriate, water, and tissue samples. These results are used to evaluate the suitability of proposed dredge material collected from the project area for ocean disposal.