Throughout this chapter we have described a variety of ways of managing solid waste, from creating less of it to burying it in a landfill to burning it. Each method has both benefits and drawbacks. Because there is no obvious best method and because waste is a pervasive fact of contemporary life, the problem of waste disposal seems overwhelming. How can an individual, a small business, an institution, or a municipality best deal with solid waste? The answer is highly specific to each case and varies by region. Every method of waste disposal will have adverse environmental effects; the challenge is to find the least detrimental option. How do we decide which choices are best? Life-cycle analysis and a holistic approach are two useful approaches to gaining insights into the question of what we should do with our solid waste.

Learning Objectives

After reading this module, you should be able to

580

Recall the beginning of the chapter where we attempted to make an objective assessment of solid waste disposal options by comparing paper and polystyrene cups. This process, known as life-cycle analysis, and also known as cradle-to-grave analysis, is an important systems tool that looks at the materials used and released throughout the lifetime of a product—from the procurement of raw materials through their manufacture, use, and disposal. As we saw when we compared a paper cup with a polystyrene cup, the full inventory of a life-cycle analysis sometimes yields surprising results.

In theory, conducting a life-cycle analysis should help a community determine whether incineration is more or less desirable than using a landfill. However, such an analysis has limitations. For example, it can be difficult to determine the overall environmental impact of a specific material. It is not possible to know whether the particulates and nitrogen oxides released from incinerating food waste are better or worse for the environment than the amount of methane that might be released if the same food waste were placed in a landfill. So in the case of waste that contains food matter, it is not possible to directly compare the full environmental impact of disposal in a landfill versus incineration. Similarly, we saw that it is a challenge to compare the sulfur dioxide released when making a paper cup with the volatile organic compounds released when making a plastic cup. Although life-cycle analysis may not be able to determine absolute environmental impact, it can be very helpful in assessing other considerations, especially those related to economics and energy use.

In terms of economics, the municipality might compare the costs of different disposal methods. For example, a glass manufacturing plant might pay $5 per ton for green glass that it will recycle into new glass. Economically, a municipality might do better if it received $5 for a ton of glass from a bottle manufacturing plant than if it paid a $50 per ton tipping fee so it could throw the material into a landfill. But the municipality must also consider the lower cost of transporting the glass to a relatively close landfill rather than to a distant glass plant.

In some parts of the country, the cost of waste disposal is covered by local taxes; in other locations, municipalities, businesses, or households may have to pay directly for disposal of their solid waste. Whether direct or indirect, there is always a cost to waste disposal. Normally, disposal of recyclables costs less than material destined for the landfill because the landfill always involves a tipping fee while recyclables either incur a lower tipping fee or generate revenue. However, as we have seen, costs change depending on many factors, including market conditions. For example, in a particular year, there may not be a market for recycled newspapers in the United States, but in the following year a huge increase in Japanese demand for newsprint may cause the price to go up in the United States. It is therefore essential for municipalities to have many choices and to be able to modify these choices as market environments change.

From the perspective of energy use, a life-cycle analysis should also consider the energy content of gasoline or diesel fuel used and the pollution generated in trucking material to each destination, as well as the monetary, energy, and pollution savings achieved if the new glass is made from old glass rather than from raw materials (sand, potash, lime). Reconciling all these competing factors is very challenging and the ultimate decisions based on such analyses are often debatable.

A more holistic method seeks to develop as many options as possible, emphasizing reduced environmental harm and cost. Integrated waste management employs several waste reduction, management, and disposal strategies in order to reduce the environmental impact of MSW. Such options include a major emphasis on source reduction and include any combination of recycling, composting, use of landfills, incineration, and whatever additional methods are appropriate to the particular situation. FIGURE 55.1 shows how a nation or a community could consider a series of steps, starting with source reduction during manufacturing and procurement of items. After that, behavior related to use and disposal can be considered and possibly altered in order to obtain the desired outcome: less generation of MSW. According to this approach, no community should be forced into any one method of waste disposal. If a region makes a large investment in an incinerator, for example, there is a risk that it would then need to attract large quantities of waste to pay for that incinerator, thereby reducing the incentive to recycle or use a landfill. Landfill space may be abundant or scarce, depending on the location of the community. If the municipality is free to consider all options, it can make the choice or choices that are efficient, cost effective, and least harmful to the environment.

581

The architect and former University of Virginia dean William McDonough looks at holistic waste management from a more far-reaching perspective. In the book Cradle to Cradle, McDonough and coauthor Michael Braungart propose a new approach to the manufacturing process. They argue that it is first necessary to assess existing practices in order to minimize waste generation before, during, and after manufacturing. Beyond that, manufacturers of durable goods such as automobiles, computers, appliances, and furniture should develop plans for disassembling goods when they are no longer useful so that parts or materials can be recycled with as little as possible becoming part of the waste stream.

Some industries are already developing new approaches to waste. Volkswagen, for example, manufactures some of its cars so that they can be easily taken apart and materials of different composition easily separated to allow recycling. Certain carpet manufacturers design their carpets so that when worn out they can be easily recycled into new carpeting (FIGURE 55.2). This is typically done by making a base that is extremely durable with a top portion of the carpet that can be changed when the color fades, is worn out, or is no longer desired. Finally, McDonough and Braungart point out that many organisms in the natural world, such as the turtle, produce very hard, impact-resistant materials, such as a shell, without producing any toxic waste. They suggest that humans should examine how a turtle creates such a hard shell without the production of toxic wastes. Humans can use this example as a goal for other kinds of production where no toxic wastes would be produced. More recently, McDonough and Braungart have introduced the term upcycle to describe the conversion of a waste material to something of higher quality and greater value than the original product.

582

Although we can still greatly improve our handling of solid waste, there is some evidence that the nation as a whole has taken source reduction seriously; per capita waste generation has been level since 1990. It appears that recycling has been taken seriously, too, since recycling rates have increased since 1985. However, considering both the amount of waste generated in this country and the recycling rates found in other countries, we have a long way to go.