Table ES.1 Quantities of Materials Generated on Navy Surface Ships

Material

WEIGHT

ESTIMATED COMPACTED VOLUME

Paper

1.1 lb/person/day

0.056 ft3/person/day

Metal

0.5 lb/person/day

0.005 ft3/person/day

Glass

0.1 lb/person/day

0.001 ft3/person/day

Plastics

0.2 lb/person/day

0.010 ft3/person/day

T OTAL

1.9 lb/person/day

0.072 ft3/person/day

In its 1993 program plan (U.S. Navy, 1993), the Navy considered the use of compactors as an interim solution, and the committee views this technology as one that should be reexamined to help achieve compliance before 2000. A study of the effect of systematic, fleetwide use of compaction, similar to the recent Center for Naval Analyses study (Speer, 1995), would be valuable in this connection.

A good strategy for minimizing the amount of waste that must be stored is to leave as much packaging as possible on the dock. Submariners have achieved a significant reduction in this area, and the USS Kamehameha has reported (U.S. Navy, 1995) waste generation of only 0.56 lb/person/day or about 0.028 ft3 of compacted volume, a reduction of about 60 percent relative to quantities generated on surface ships. This approach is a good first step in any waste reduction program, and it has been used to some extent on Navy surface ships.

The problem assigned to the committee was to identify and evaluate the technologies that will make Navy management of nonfood solid waste under Annex V as effective as possible. Analysis was carried out in terms of mechanical, incineration, and long-range options, and these approaches are discussed in detail in Chapter 2, Chapter 3, Chapter 4, and Chapter 6. Mechanical methods are intended to minimize the volume of waste that must be stored until it can be off-loaded to other ships for shore disposal or recycling or can be discharged outside Special Areas. Incineration is intended to destroy the organic waste, and long-range options include advanced techniques that may eventually supercede incineration.

It must be decided at the outset whether the waste streams will be separated or processed mixed. Paper can be incinerated with little ash. Metal and glass waste, on the other hand, are not burnable. Plastic burns readily and can be burned with quite acceptable emissions, notwithstanding environmental objections to incineration of plastics at sea (NRC, 1995). These waste streams may be kept separate to enable recycling of one or more types of material. In some ports, separated waste may be more acceptable for shore disposal. If the Annex V waste materials are contaminated with food, the problem is particularly difficult. Although ground-up food waste can be put into the water even in Special Areas (outside the 3-mile limit), food-contaminated solids are subject to Annex V restrictions. Food-contaminated solids are a problem to store because of odors and sanitation factors. This fact could influence the waste management technologies chosen by the Navy.

Currently available compactors, shredders, crushers, pulpers, and other processors enable the conversion of voluminous waste to compacted waste. These machines are available in robust models, and they do not require large amounts of space. For example, a station capable of compressing and crushing the waste for a large ship could be accommodated in a room 10 ft × 20 ft × 8 ft. Additional space to accommodate crew access and temporary storage of incoming waste materials would more than double the floor area required. The cost of commercial apparatus to equip the station could range from $100,000 to more than $200,000. Storage volume of the order of 0.1 ft3/person/day between off-loading would be required. If the waste is contaminated with food, the waste would need some form of odorproof packaging (of high integrity). Only the Navy can decide whether this space is available for this purpose. Whether the waste is to be stored for the duration of a mission (as long as 60 days for surface ships) or could be



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement