(8) oily rags, (9) medical waste, (10) chlorofluorocarbons (CFCs), (11) halons, (12) hazardous waste, and (13) antifoulants.
Items 1 through 3 are the main focus of this report, and their management is discussed in Chapter 2 and Chapter 3. Items 4 through 9 are not regulated under Annex V, but they could be managed with an integrated system that would destroy paper and cardboard, food waste, black water sludge, gray water residue, bilge oil, oily rags, and medical waste. Metal, glass, and ash, a small fraction of the total waste volume, would be stored for transfer to shore facilities, other ships, or ocean discharge outside Special Areas. Items 10 through 13 do not fit into the systems discussed in this report. CFCs are being phased out worldwide in favor of chemicals that do not destroy ozone in the stratosphere. Halons are being retained in essential applications, as no substitutes are known, but their release to the atmosphere is being tightly controlled. Hazardous waste materials, containing radioactive waste, mercury, cadmium, and other noxious substances, are held on board and transferred to shore facilities for recycling or disposal. Advanced technologies could prove effective in dealing with hazardous waste and antifoulants.
A sound strategy is to eliminate as much waste as possible during the loading phase. This method is practiced in an exemplary manner by the submarine service and may be adaptable to surface ships to some degree. The practice can be adopted without installation of complex machinery, and the importance of minimizing and husbanding packaging materials should be impressed on the crew. The committee has considered modification of packaging materials, i.e., arranging for suppliers to favor one packaging material over others. This approach is probably difficult and possibly expensive, since the Navy must acquire supplies at many far-flung ports. In addition, which material class to favor is not obvious. However, there are choices that are clearly correct, for example, the elimination of chlorine-containing plastics, which the Navy has already initiated.
The keystone technology of an integrated system at this time is incineration. As noted, incinerators are large, heavy, and expensive. In addition, there are issues of safety and crew training and indoctrination that would attend installation of this equipment. Older models of incinerators exhibited problems that have turned many Navy people against the process. The committee believes that these problems have been successfully addressed in the design of modern incinerators, and their installation should be analyzed without prejudice. Further, modernization of existing shipboard incinerators should be pursued in the context of the integrated system concept. It is likely that air pollution standards will be tightened as time goes by, but compliance by modern incinerators will be maintained through the evolution of incineration practice.
In the fullness of time, new technologies may emerge that will allow the incinerator to be replaced with equipment that is smaller, lighter, less expensive, functionally superior, and characterized by more benign by-products. There are many such technologies under investigation today, referred to herein as long-range options, and the committee is unable to distinguish any one of these that has a clear inside track for displacement of incineration. The Navy has a demonstration project in place for plasma arc treatment, and in that sense this technology might be considered ahead of other candidates. Even so, the committee regards plasma arc processing as at least a decade away from marine application to the shipboard waste considered in this report. A demonstration of supercritical water oxidation is being carried out (funded by ARPA) for the destruction of Navy hazardous waste. Other technologies could win, in the long run.
Storage space is a factor in any scheme to manage shipboard waste streams, and it is particularly important in the Navy context. Navy ships are plainly crowded, and any excess space as may be found can immediately be assigned to some mission-related purpose. Bulk alone is not the only problem. Storage of combustible materials constitutes a dangerous situation on any ship; but when combat is considered, the danger is greatly enhanced. Food-contaminated materials in storage can cause odors and the development of dangerous organisms. Thus, there are good reasons for minimizing waste volume and avoiding the presence of food contamination in the waste. Incineration, or one of the long-range options for waste destruction, achieves the maximum reduction of volume and leaves the ash sanitized, which may simplify storage and disposal problems. This is an area that is not clear-cut, however. Metal and glass residues