A Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA) Section 103 disposal site is proposed offshore of Coos Bay, Oregon, to support major improvements proposed within the Coos Bay federal navigation channel by the Oregon International Port of Coos Bay. The proposed improvements include deepening and widening a portion of the existing Coos Bay federal navigation channel from the entrance channel up to approximately river mile (RM) 8.2
If the improvements proposed within the Coos Bay federal navigation channel are approved, up to approximately 26.5 million cubic yards (mcy) of dredged material will require disposal. Based on this estimated volume, an ocean disposal site is proposed to provide a suitable offshore location for dredged material disposal in support of this new work project.
The need for an ocean disposal site is also based on an alternatives evaluation that considered a full suite of existing and alternative disposal sites including existing ODMDSs, upland disposal sites, in-water disposal sites, and beneficial use. The analysis identified a number of issues and deficiencies for all alternatives, leading to the conclusion that a Section 103 one-time-use site was necessary to provide adequate capacity for disposal of dredged material generated from the deepening project.
The ocean disposal site selection process requires that baseline site characterization studies be conducted at the proposed site and surrounding areas. The purpose of the baseline study is to describe the existing environment within and around the proposed site including sediment characteristics (physical and chemical), macroinfauna, macroepifauna, and water quality characteristics. The study results will be used to inform the regulatory decision on the final site location and configuration and to provide baseline data to assess whether future disposal activities would have an unacceptable impact on the marine environment.
ANAMAR was contracted by David Miller and Associates to lead the baseline site characterization studies in support of designating an ODMDS for the Coos Bay channel improvement project. The proposed site is approximately 2.5 nautical miles offshore of the mouth of Coos Bay, OR. ANAMAR coordinated with the port team, USACE, and EPA to develop a sampling and analysis plan for the baseline studies. The study was designed to provide flexibility in final site selection.