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The South Oahu and Hilo ocean dredged material disposal sites (ODMDS) were, designated by EPA Region 9 and actively used beginning in the 1980s. The primary objective of site monitoring is to assess performance and site conditions relative to disposal operations, including determination of the horizontal extent of the dredged material deposit footprint relative to site boundaries, no adverse impacts of disposal of dredged material, and confirmation of pre-disposal sediment. 

ERG contracted ANAMAR to assist in the ODMDS monitoring surveys at the South Oahu and Hilo sites. The surveys were performed using the NOAA ship Hi’ialakai. Tasks included:

• Sediment Sampling and Analysis – collection of grab samples at designated stations using a Van Veen grab sampler inside and outside the ODMDS.
• Benthic Sampling – collection of benthic grab samples at designated stations using a Van Veen grab sampler within and outside the ODMDS. The samples were filtered through a sieve and the retained material was preserved.
• Sediment Profile Imaging (SPI) – assistance in deployment of SPI equipment to determine thickness variation and areal distribution of dredged material deposition on the seabed within and outside the site.