In 1999, the United States generated 230 million tons of municipal solid waste, compared with 195 million tons in 1990, according to Environmental Protection Agency (EPA) estimates. On average, each person generated 4.6 lb (2.1 kg) of such waste per day in 1999, and the EPA expects that amount to continue increase. That waste includes cans, bottles, newspapers, paper and plastic packages, uneaten food, broken furniture and appliances, old tires, lawn clippings, and other refuse. This waste can be placed in landfills, incinerated, recycled, or in some cases composted.

Landfilling—waste disposed of on land in a series of layers that are compacted and covered, usually with soil—is the main method of waste management in this country, accounting for about 57%of the waste. But old landfills are being closed and new ones are hard to site because of community opposition. Landfills once were open dumps, causing unsanitary conditions, methane explosions, and releases of hazardous...