Waste disposal

Waste disposal, disposal of such matter as animal excreta and the waste products of agricultural, industrial, and domestic processes, where an unacceptable level of environmental pollution would otherwise result. Where an ecological balance exists, wastes are recycled naturally or by technological means before accumulations affect the quality of life or disrupt the ecosystem. The most satisfactory waste disposal methods are therefore probably those that involve recycling, as in manuring fields with dung, reclaiming metals from scrap, or pulping waste paper for remanufacture. Recycling, however, may be inconvenient, uneconomic, or not yet technologically feasible. Many popular waste disposal methods consequently represent either an exchange of one form of environmental pollution for another less troublesome one, at least in the short term—e.g., the dumping or burying of nondegradable garbage or toxic wastes—or a reducing of the rate at which pollutants accumulate—e.g., by compacting or incinerating bulk wastes before dumping. Urban wastes are generally disposed of by means of dumping, sanitary landfill, incineration, and sewage processing. Agricultural, mining, and mineral-processing operations generate most solid wastes—and some of the most intractable waste disposal problems: the “factory” farmer's problem of disposing of surplus organic wastes economically without resorting to incineration or dumping in rivers; the problems created by large mine dumps and open-cast excavations; and the culm dumps that result from the processing of anthracite coal. Another increasingly pressing waste disposal problem is presented by radioactive wastes. Those with a “low” level of radioactivity can be safely packaged and buried; but high-level wastes, produced in the course of reprocessing the fuel elements of nuclear reactors, constitute a permanent hazard. Even the practice of encasing these wastes in thick concrete and dumping them on the ocean bottom is considered by many environmentalists to be an inadequate long-term solution.