Waste Management

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Waste management


The way that we manage our waste materials is a sign of the times. In our agrarian past, throwing garbage out into the street for roving pigs to eat seemed like a perfectly reasonable method of waste management, since most of what we threw away was organic material that increased the bulk of the pig and eliminated residuals we did not want. As manufacturing became a larger part of industry and materials had potential for recycling we saw the advent of the another kind of scavenger , the "junk man," who pulled from the waste stream those materials that had value. This practice increased during the Great Depression and even more so during World War II. During the war there were shortages of metals and cloth as many raw materials were diverted from domestic use to war needs. People got into the habit of conservation . Things were not thrown away unless they had no further use either as is or in a remanufactured state. The situation has changed in modern times.

As Jim Hightower points out in the foreword to War on Waste (1989), "Every year we toss into city dumps 50 million tons of paper, 41 million tons of food and yard waste , 13 million tons of metals, 12 million tons of glass, and 10 million tons of plastic." In addition, he points out that the Environmental Defense Fund has calculated that, as a nation, we throw away enough iron and steel to supply domestic auto-makers continuously; enough glass to fill the twin towers of New York City's World Trade Center every two weeks; enough aluminum to rebuild our commercial air fleet every three months; and enough office and writing paper to build a 12-ft (3.7 m) Great Wall coast to coast every year. The examples go on and on. The opportunity to manage this tremendous resource through careful waste management practices is urgent. Waste is indeed a renewable resource. This renewable resource, if managed well, could provide us with the ability to reserve our natural non-renewable resources until we really need them.

Most states and major metropolitan areas have a hierarchy of waste management options that guide state and local planning. Although there are refinements of this list in some areas, the standard hierarchy, in order of preference, is: reduce, reuse , recycle, compost, waste-to-energy (incineration ), and landfill . Looking at each of these options individually gives a better understanding of an integrated waste management system.

Managing waste through a process of reduction is almost always the first line of defense and viewed as most desirable by waste management professionals. Reduction is an attempt not to generate waste in the first place. This means making certain consumer decisions that eliminate the potential for waste generation. Buying produce in bulk so that packaging is kept at a minimum is one simple consumer decision that can have a profound effect, since over 40% of the waste stream is packaging material. To further reduce waste, consumers can bypass disposable items, such as disposable razors and cameras, and have small appliances repaired rather than buy new ones. Using cloth dishtowels and diapers eliminates paper towels and disposable diapers from the waste stream.

Reuse is often the second line of defense. This is the small area between avoiding waste and recycling post-consumer materials. A creative way to support reuse of materials is to make them available to those who can use them. Some cities have put in place a center where containers and various post-consumer materials that have been cleaned and source-separated are available to elementary school teachers for art projects. Another example of reuse is consignment shops. These stores will take clothing and small household items on consignment from people and then sell them and divide the profit with the owner.

Recycling is on the increase. Goals of recycling 15%, 25%, and even 50% of waste material have been called for in cities all across the United States. Many believe recycling is a major waste management solution. Industries in the United States are able to recycle quite a variety of materials. Paper, glass, metals, plastics , yard and food waste , motor oil, batteries, tires, asphalt, car bumpers, and all manner of scrap metal can be recycled. There is truly little that cannot be recycled, but in some cases, industry is not ready. Manufacturing equipment has not yet been retrofitted to accommodate the heterogenous nature of the waste stream. Also, communities are a dispersed source of "raw" material for manufacturers, and the cost of gathering sufficient tonnage of glass, tin, or other "raw" material for manufacturing is prohibitive. Probably the single most restrictive obstacle to full scale recycling is human behavior. As we look at recycling as a closed-loop waste management process we realize that we must source-separate and clean post-consumer waste materials, then we must get them to the point where they can be used and made into a new product. To close the loop, someone must buy that product. All of these activities demand a behavioral change on the part of consumers and manufacturers.

Composting is the biological breakdown of organic matter under aerobic conditions. Composting is seen as a major waste management option for large and small communities. The most common form of composting is the layering of leaves, grass and twigs and sometimes kitchen waste in a backyard compost bin. This very simple technology can also be done at the municipal level, as a community picks up leaves and other yard waste at the curb and trucks it to a central location where it is composted in long tent-shaped piles of refuse called windrows, or inside buildings where mechanical systems speed the compost process. Like recycling, composting requires a behavioral change on the part of homeowners. People must prepare the material and get it to the curb on the appropriate day. Some drawbacks to composting are that the process can generate unpleasant odors if the compost pile is not managed well. This means turning the pile frequently and maintaining aerobic conditions so that decomposition proceeds rapidly.

Incineration is not really a new waste management option. Incineration of solid waste was practiced in the early 1900s. However, not until the early 1970s did we began to look seriously at solid waste incineration with energy recovery as a major goal. There really are two types of waste-to-energy systems. One is a mass burn technology which does very little to the waste stream before it reaches the furnace. The other system is a refuse-derived fuel (RDF) in which waste is shredded before being delivered to the furnaces. Drawbacks to this system are ash disposal and control of air emissions. Concerns over dioxins in stack emissions has caused many supporters to think twice about waste-to-energy. In addition, the issue of where to dispose of the sometimes toxic ash residue must be dealt with.

Landfills are still the most common waste management option. Between 75% and 85% of the nation's waste still goes to landfills. Three types of landfills are constructed for different types of waste materials.

Type III landfills are the least expensive to build and can accommodate construction debris and other inert material. Most common are sanitary Type II landfills. These are constructed according to the criteria in subtitle D of the Resource Conservation and Recovery Act (RCRA). Newer municipal solid waste landfills are usually equipped with synthetic liners, leachate collection systems, monitoring wells and in some cases methane wells to draw off the gas that collects in landfills. Type II landfills will take any waste except hazardous waste . Hazardous waste can only be disposed of in a Type I landfill. These landfills are constructed in a more rigorous manner and are used primarily for contained chemicals and such waste as asbestos .

The biggest challenge surrounding modern landfills is the issue of siting. Not in my backyard (NIMBY) is a well-known syndrome. Current landfill construction has slowed and many of the old landfills have closed or are slated for closure. There are currently about 3,000 Type II landfills in the continental United States. As more landfills close, the life span of those remaining is shortened. Large multinational companies in the waste management business are attempting to site large regional landfills. In some cases, large companies are offering very attractive incentive packages to communities that are willing to site a landfill within their jurisdictions. Whatever method of disposal is used, the process of managing waste must bring into play a cooperative effort between manufacturers, merchants, citizens, and waste management experts if it is to be successful.

See also Renewable resources; Source separation

[Cynthia Fridgen ]


RESOURCES

BOOKS

Blumberg, L., and R. Gottlieb. War on Waste. Covelo, CA: Island Press, 1989.

Kharbanda, O. P., and E. A. Stallworthy. Waste Management: Toward a Sustainable Society. Westport, CT: Auburn House/Greenwood, 1990.

Underwood, J. D., et al. Garbage: Practices, Problems, and Remedies. New York: INFORM, 1988.

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