Deep Ocean Disposal Research Articles

Disentangling the History of Deep Ocean Disposal for DDT and Other Industrial Waste Off Southern California.

Ocean disposal of industrial waste from technical DDT [mainly 1,1'-(2,2,2-trichloroethane-1,1-diyl)bis(4-chlorobenzene), or 4,4'-DDT] manufacture occurred historically in the Southern California Bight. However, the paucity of historical records highlights uncertainties as to the mode, location, and timing of disposal or ongoing ecological effects of these wastes. This study combines sampling, chemical analysis, and numerical modeling of deep San Pedro Basin sediments revealing substantial DDT contamination that extends at least 25 km from the mainland. These findings narrate bulk DDT waste disposal to the offshore that peaked in the 1950s, prior to the onset of formal regulations; was agnostic to later-designated disposal sites; and has experienced sluggish transformation. Our findings further indicate an attenuating secondary source for the DDT daughter product, 1-chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethenyl]benzene (4,4'-DDE), which still deposits into deep San Pedro Basin sediments. While demonstrating the severity of DDT contamination to the region, these findings further define the burial potential of DDT wastes and inform the past, present, and future contamination potential that is needed to understand and predict ecological consequences. This work also points firmly to bulk, not containerized, disposal of DDT waste and to potential alternative contents of collocated waste.

Relative risk assessment of cruise ships biosolids disposal alternatives

A relative risk assessment of biosolids disposal alternatives for cruise ships is presented in this paper. The area of study encompasses islands and marine waters of the Caribbean Sea. The objective was to evaluate relative human health and ecological risks of (a) dewatering/incineration, (b) landing the solids for disposal, considering that in some countries land-disposed solids might be discharged in the near-shore environment untreated, and (c) deep ocean disposal. Input to the Bayesian assessment consisted of professional judgment based on available literature and modeling information, data on constituent concentrations in cruise ship biosolids, and simulations of constituent concentrations in Caribbean waters assuming ocean disposal. Results indicate that human health and ecological risks associated with land disposal and shallow ocean disposal are higher than those of the deep ocean disposal and incineration. For incineration, predicted ecological impacts were lower relative to deep ocean disposal before considering potential impacts of carbon emissions.

<p class="HeadingRunIn"><strong>Two new species of <em>Aphelochaeta </em>(Polychaeta: Cirratulidae) from deep water off northern California</strong></p>

Two new species belonging to the genus Aphelochaeta (Polychaeta: Cirratulidae) are described from continental slope sediments off northern California. Specimens were collected during extensive monitoring of the San Francisco Deep Ocean Disposal Site off the Farallon Islands from 1996 to 2004. The genus Aphelochaeta is one of the more speciose genera collected from depths of 2400–3200 m. A. bullata sp. nov. is characterized by the presence of four peristomial annulations, a pronounced dorsal crest, and elongated, natatory-like simple capillaries in the noto- and neuropodia of the thoracic region. A. guttata sp. nov. has a unique methyl green staining pattern consisting of speckles all over the body, thoracic segments that are swollen ventrally, and weakly inflated posterior segments. Comparison is made with the type species A. monilaris (Hartman, 1960) and other continental shelf and slope species from California. Morphological characters important for differentiation of these species are discussed; these include characters related to the peristomium, shape of abdominal segments and methyl green staining patterns. The generic definition is emended to include numbers of asetigerous peristomial annulations.

Long-term benthic infaunal monitoring at a deep-ocean dredged material disposal site off Northern California

One hundred and thirty-five benthic infaunal samples were collected from the San Francisco Deep-Ocean Disposal Site (SF-DODS) over a 10-year period from January 1996 to September 2004. Each sample was 0.1 m2, cut to a depth of 10 cm, and sieved through a 300-μm mesh. A total of 810 species of benthic invertebrates were identified; the majority of taxa (65.4%) new to science. The fauna represents a rich lower slope infaunal assemblage that rivals similarly studied locations in the western North Atlantic. No regional impact or degradation of benthic infauna due to dredged material disposal was detected. All reference stations and stations on the site boundary maintained high species richness and diversity during the monitoring period. Exceptions included an occasional sample with anomalously high numbers of one or two species that reduced the diversity and/or equitability. Within SF-DODS species richness and diversity were often reduced. Stations within the disposal site were recolonized by the same taxa that normally occurred in adjacent reference areas. Initial colonizers of fresh dredged material included spionid and paraonid polychaetes that were typical dominants at the site. At least one polychaete species, Ophelina sp. 1, sometimes colonized dredged materials containing coarse sand. One sample at Station 13, located in the middle of SF-DODS (September 2002), contained 57 species of benthic invertebrates, suggesting that colonization of fresh dredged material is rapid. It seems unlikely that larval dispersal and settlement account for this rapid recolonization; therefore it is postulated that adult organisms from adjacent areas move to the disturbed sites via boundary layer currents. The steep continental slope adjacent to SF-DODS is subject to turbidity flows and the resident fauna are likely pre-adapted to rapidly colonize disturbed sediments. Larval dispersal, especially by spionid polychaetes such as Prionospio delta, may also be important in colonizing newly deposited sediments. Subtle year-to-year shifts in faunal assemblages were evident at stations on the boundary of SF-DODS. At these stations species richness and diversity remained high, but numerically dominant taxa differed, possibly due to changes in sediment grain size associated with the dredged material. However, some year-to-year changes appeared to be regional in nature. Large epifaunal organisms such as the elasapoid holothurian Scotoplanes globosa appeared to be locally important in modifying surficial sediments: it moves through the sediment like a bulldozer, disturbing the surface and disrupting resident infauna as it ingests sediment. Other deposit-feeding holothurians such as Ypsilothuria bitentaculata were found throughout the study area including sediments with fresh dredged material. A long, narrow-bodied tube-like agglutinated foraminiferan of the genus Bathysiphon is commonly found in sediments containing dredged material. This foraminiferan is poorly understood, but may be opportunistic on soft dredged material.

Characteristics and Performance of a Deep-Ocean Disposal System for Low-Purity CO2 Gas via Gas Lift Effect

Ocean sequestration of CO2 is a hopeful option to solve the global warming problems. We proposed the Gas Lift Advanced Dissolution (GLAD) System for efficient sequestration of pure CO2 at deep sea. The GLAD system is an inverse-J pipeline set in the ocean between 200 and 3000 m in depth. We have recently improved it to treat low-purity CO2 gas to reduce the cost for separation and capture of CO2 from exhausted gas. The newly developed system, named the Progressive Gas Lift Advanced Dissolution (P-GLAD) System, is to dissolve low-purity CO2 bubbles into seawater at a depth of 200−300 m and at the same time sequestrate CO2 at the deep sea of 1000−3000 m. Previous ideas of deep-sea sequestration of CO2, including storage of liquid CO2 on the deep-sea floor and direct releasing of liquid CO2 into the deep sea, necessitate the consumption of a huge amount of energy, because the realization of these ideas requires both high-purity capture of CO2 from exhausted gas and liquefaction of the CO2. To realize deep-sea sequestration of CO2 with low energy consumption and low environmental impact, we utilize a gas-lift effect to simultaneously dissolve low-purity CO2 gas into shallow seawater and transport the CO2 solution to a great depth. The present paper describes basic characteristics and performance of the P-GLAD system for low-purity CO2 gases, experimentally and numerically. It is demonstrated that the system has satisfactory ability to both dissolve CO2 gas and pump the CO2 solution. To confirm economic feasibility of the P-GLAD System, we also discuss the overall cost estimation including an additional system for CO2 capturing as well as the construction of P-GLAD. The cost for the P-GLAD is estimated to be half of those for previous ideas.

Chemical gradients in sediment cores from an EPA reference site off the farallon islands — Assessing chemical indicators of dredged material disposal in the deep sea

Heavy metal and organic contaminants have been determined in undisturbed sediment cores from the US Environmental Protection Agency reference site for dredged material on the continental slope off San Francisco. As expected, the concentrations are significantly lower than toxic effects guidelines, but concentrations of PCBs, PAHs, Hg, Pb, and Clostridium perfringens (a bacterium spore found in sewage) were nearly two or more times greater in the surface sediments than in intervals deeper in the cores. These observations indicate the usefulness of measuring concentration gradients in sediments at the San Francisco deep ocean disposal site (SF-DODS) where a thin (0.5 cm thick) layer of dredged material has been observed beyond the boundary. This thin layer has not been chemically characterized by the common practice of homogenizing over the top 10 cm. An estimated 300 million cubic yards of dredged material from San Francisco Bay are expected to be discharged at the SF-DODS site during the next 50 years. Detailed depth analysis of sediment cores would add significant new information about the fate and effects of dredged material in the deep sea.

« The ecology of the deep ocean and its relevance to global waste management » Martin V. Angel, Tony L Rice. Journal of Applied Ecology, vol. 33, n° 5, octobre 1996, pp. 915-926

1. As global human populations continue to grow uncontrollably, there is a foreseeable medium to long-term need for the utilization of deep ocean environments for disposal of waste materials to maintain sustainability of global environmental resources. 2. The assimilative capacity of deep ocean ecosystems is likely to be high relative to the quantities of waste that cannot be dealt with through alternative options such as waste minimization, recycling and incineration. 3. Deep ocean disposal may not be an acceptable option for the disposal of industrial organic compounds, which are persistent in the environment but for which alternative destructive procedures are available. 4. The choice of either a dispersive or accumulative regime for a disposal will need be based on the characteristics of the waste. Waste that is biologically or chemically degradable may best be dispersed. 5. Present knowledge of deep ocean ecosystems would suggest that disposal of inert, metal-rich, or even organic-rich wastes into accumulative regimes on the floor of the abyssal ocean would not create major deleterious impacts on living resources or other uses by Mankind of the oceans. Thus, under the present definition adopted by the Law of the Sea Convention this would not constitute large-scale pollution. 6. These tentative conclusions need to be evaluated by appropriately scaled experiments. Results from small-scale experimental procedures, based on the disposal of a few tonnes of waste and effecting a few square metres of sea-bed, cannot be extrapolated to predict confidently the impact of industrial scale disposal. Experiments approaching a tenth the size and extent of a full industrial exercise will be needed, but conducting such an experiment will not, in itself, carry significant environmental risk. 7. There are also some basic biological questions, mostly concerning the diversity of benthic assemblages and the processes that maintain their diversity, that will need to be resolved before deep-ocean disposal could be adopted. 8. There are major socioeconomic problems about the global management of the abyssal ocean as a non-living resource which will have to be addressed internationally.

The Ecology of the Deep Ocean and Its Relevance to Global Waste Management

1. As global human populations continue to grow uncontrollably, there is a foreseeable medium to long-term need for the utilization of deep ocean environments for disposal of waste materials to maintain sustainability of global environmental resources. 2. The assimilative capacity of deep ocean ecosystems is likely to be high relative to the quantities of waste that cannot be dealt with through alternative options such as waste minimization, recycling and incineration. 3. Deep ocean disposal may not be an acceptable option for the disposal of industrial organic compounds, which are persistent in the environment but for which alternative destructive procedures are available. 4. The choice of either a dispersive or accumulative regime for a disposal will need be based on the characteristics of the waste. Waste that is biologically or chemically degradable may best be dispersed. 5. Present knowledge of deep ocean ecosystems would suggest that disposal of inert, metal-rich, or even organic-rich wastes into accumulative regimes on the floor of the abyssal ocean would not create major deleterious impacts on living resources or other uses by Mankind of the oceans. Thus, under the present definition adopted by the Law of the Sea Convention this would not constitute large-scale pollution. 6. These tentative conclusions need to be evaluated by appropriately scaled experiments. Results from small-scale experimental procedures, based on the disposal of a few tonnes of waste and effecting a few square metres of sea-bed, cannot be extrapolated to predict confidently the impact of industrial scale disposal. Experiments approaching a tenth the size and extent of a full industrial exercise will be needed, but conducting such an experiment will not, in itself, carry significant environmental risk. 7. There are also some basic biological questions, mostly concerning the diversity of benthic assemblages and the processes that maintain their diversity, that will need to be resolved before deep-ocean disposal could be adopted. 8. There are major socio-economic problems about the global management of the abyssal ocean as a non-living resource which will have to be addressed internationally.

Concepts for sediment restoration on the palos verdes shelf, California

AbstractThis article summarizes a study conducted by the U.S. Army Engineer Waterways Experiment Station to develop technical information and to evaluate the engineering feasibility of restoration alternatives for DDT‐and PCB‐contaminated sediments on the Palos Verdes shelf and slope near Los Angeles, California. The study evaluated the nonremoval alternative of in‐place capping of contaminated sediments on the shelf and slope; removal of contaminated sediments using conventional and specialized dredging equipment and deep ocean mining equipment; treatment of contaminated sediments; and disposal of contaminated sediments in confined (diked) disposal facilities (CDFs), contained aquatic disposal (CAD) sites, upland landfills, and deep ocean basin sites. Cost estimates of the various alternatives were also prepared.This article concludes that restoration of the contaminated sediments is technically feasible. Sediments on the shelf and slope can be removed using available dredging technologies for deep water environments. In‐place capping, CAD, and CDF alternatives are technically feasible. The deep ocean basin disposal alternative is not feasible from the technical or regulatory standpoint. The treatment alternative is not feasible from the implementability and economic standpoint.

Ocean disposal of CO 2: Feasibility, economics and effects

The ocean represents a hugh natural reservoir for carbon dioxide disposal, since it covers 70% of the Earth's surface and has an average depth of 3800 m. Most importantly, the deeper layers are highly unsaturated with CO 2, containing typically 0.1 kgm −3, whereas the solubility is in the order of 40 kgm −3. The problems of deep ocean disposal are of technical, economic and ecological nature. In order to assure a sufficiently long residence time in the ocean, CO 2 has to be injected below the thermocline, 1000 m or deeper. Current pipe-laying and servicing technology extends only to 500 – 1000 m. However, it is possible to release liquid CO 2 in that region in a manner that it will form a dense solution of CO 2 in seawater and/or solid particles of CO 2 hydrate. Both the solution and hydrate are heavier than ambient seawater, and hence sink to greater depth or to the ocean floor. Pipe laying costs are estimated in the $1–2 million per km, exclusive of the release system cost. While global effects of CO 2 disposal in the ocean are considered negligible, local effects on aquatic life around the discharge point may raise concerns. The turbulent, anoxyc, acidic plume may have adverse effects on mesopelagic organisms, and the sinking hydrate particles may bury benthic creatures.

Turbulence modelling for deep ocean radionuclide disposal

AbstractIn this study the adequacy of the k‐ϵ turbulence model and the feasibility of the three‐dimensional hydrodynamic‐transport models TEMPEST and FLESCOT for deep ocean radionuclide disposal assessment were evaluated qualitatively. TEMPEST and FLESCOT were applied to a hypothetical, two‐dimensional, deep ocean case with and without stratifications. TEMPEST with the k‐ϵ model was applied to obtain quasi‐steady state eddy viscosity distributions. With calculated eddy viscosity distributions as part of the input, FLESCOT then calculated distributions of velocity, water temperature, sediment and the dissolved and sediment‐sorbed radionuclide, assuming that the radionuclide was disposed on the ocean bottom.Results revealed that the computed eddy viscosity increased almost linearly with vertical distance near the ocean bottom, then rapidly decreased towards a molecular viscosity value when the vertical gradient of the velocity distribution became very small. The results also demonstrate the importance of the density gradient to suppress the turbulent kinetic energy production, resulting in reduced eddy viscosity, producing the maximum computed eddy viscosity of 0·2 Pa s, which compares well with the reported value of 0·07 Pa s in the deep ocean. Thus the k‐ϵ turbulence model appears to be qualitatively applicable to the deep ocean environment.

Transport of Sewage Sludge in a Mixed Water Column

Abstract Sewage sludge from four publicly-owned treatment works was sampled and characterized in terms of parameters affecting transport at the 106-mile deep ocean disposal site as part of the US Environmental Protection Agency's site monitoring programme. Samples from treatment plants in Passaic Valley, Rahway, and Elizabeth, New Jersey and New York City were characterized in terms of dynamic size distribution, suspended solids and density. the transport characteristics of sludge particles were measured using a 2 metre computer-interfaced laboratory settling column. Experiments were conducted at constant salinity (35 ppt) while varying hydrodynamic mixing, sludge type and concentration using a modified factorial experimental design. Hydrodynamic power dissipation was varied so that the vertical dispersion and rms fluid shear rate ranged between 0-6 cm2S−1 and 0-30s−1 respectively. Results indicate that at least 80% of suspended sludge particles will eventually settle under mixed conditions. the average s...

Overview of carbon dioxide removal and disposal in Canada

Canada's present position is to stabilize emissions of greenhouse gases, including CO 2, at the 1990 levels by the year 2000. While the major element to achieve this is efficiency, future options must be kept open. One of the technical options is CO 2 removal and disposal. Several technical studies are underway, notably a pilot project for CO 2 removal from a coal-fired electric generating station for use in enhanced oil recovery (in Saskatchewan) and a large, Alberta-led feasibility study on removal and use in enhanced oil recovery. Potential sinks include exhausted natural gas reservoirs in Canada's western sedimentary basin. Precipitating out salts may be possible by combining CO 2 with the huge subsurface brine (evaporites) occurrences in the Western Sedimentary Basin and elsewhere. Deep ocean disposal is a distant possibility. Technical investigations into removal and disposal should continue.

Review of international HGW deep ocean disposal engineering studies : Milloy, C; Nicholson, D; Dutton, T Proc Conference on Disposal of Radioactive Waste in Seabed Sediments, Oxford, 20–21 September 1988P291–303. Publ London: Graham and Trotman, 1989 (Advances in Underwater Technology, Ocean Science and Offshore Engineering, V18)

Review of international HGW deep ocean disposal engineering studies : Milloy, C; Nicholson, D; Dutton, T Proc Conference on Disposal of Radioactive Waste in Seabed Sediments, Oxford, 20–21 September 1988P291–303. Publ London: Graham and Trotman, 1989 (Advances in Underwater Technology, Ocean Science and Offshore Engineering, V18)

The use of Landsat to monitor Deep Water Dumpsite 106

Since the early 1970's, remote sensing has been used to study ocean dumping at some of the hearshore ocean dump sites off the coast of the United States, but little remote sensing had been done over the deep water ocean disposal sites. This report summarizes what has been learned from the remote sensing of ocean dumping by the Landsat satellites at Deep Water Dumpsite 106. Of the three major types of waste material discharged at Deep Water Dumpsite 106, only the titanium pigment process acid waste has been sighted. From early in 1977 to May 1979, 11 acid dumps were observed by Landsat. All five of the dumps sighted in 1977 occurred within warm core Gulf Stream eddies and the plumes moved clockwise within the eddies. Four of those dumps were seen to be located northeast of the original dump location while the fifth one was sighted south of the original dump location. The six remaining observed dumps, discharged in the absence of an eddy, were seen to be located generally south of the original dumping locations. The average speed of the dump movement was 0.68 kt with a range from 0.17 to 1.17 kts. Plume dispersion showed a tendency toward greater dispersion as the plume got older with the widest plume cross section measured on the order of 2100 m.

A Model for the Evaluation of the Deep Ocean Disposal of Radioactive Waste

A Model for the Evaluation of the Deep Ocean Disposal of Radioactive Waste