Abyssal Seafloor Waste Isolation: Environmental Report.

Abstract : The Naval Research Laboratory (NRL), with industry and academic participation, has completed a study of the concept of isolating industrial wastes (i.e., sewage sludge, fly ash from municipal incinerators, and dredged material) on the oceans' abyssal seafloor. In this study, the advantages and disadvantages, economic viability, and environmental impacts of potential isolation techniques were identified and assessed. The technical and economic assessment portion of the study is reported in detail in five NRL Contract Reports. Four of these, prepared by Oceaneering Technologies, Inc., report the results of technical analyses of five techniques for transporting wastes through the water column and emplacing wastes within an easily monitored area on the abyssal seafloor. Three of these techniques are shown to offer technically sound and economically comparable options for emplacement of wastes. The fifth report, by the Marine Policy Center, Woods Hole Oceanographic Institution, shows these three technically viable options to offer cost effective waste management options when compared with present-day waste management techniques in higher-priced areas, such as the New York/New Jersey area. The results of the technical and economic assessment reports are summarized in this report in Section 1.4.1, Engineering Concepts. The environmental assessment portion of the study sought first to identify optimal areas that maximize environmental isolation of wastes on the abyssal seafloor, and second, to assess impact of proposed waste emplacement on such optimal areas. A PC-based site assessment model was developed to quantitatively compare the suitability of 10 squares of the seafloor for waste isolation. Included in the analysis were environmental and anthropogenic factors.