SOLID WASTE [C+] |
The nation's operating municipal landfills are declining in total numbers, but capacity has remained steady due to the construction of numerous regional landfills. In 2002, the United States produced 369 million tons of solid waste of all types. Only about a quarter of that total was recycled or recovered.
In 2002, the United States produced 369 million tons of solid waste of all types, according to unofficial industry estimates. This included municipal solid waste (MSW) that was generated by households, businesses, construction sites, and other sources.[1]
Of the 369 million tons of solid waste generated in 2002, 98.7 million tons (26%) were recycled or composted, 28.5 million tons (8%) were burned in waste-to-energy (WTE) plants, and 242 million tons (66%) went to landfill.[2]
In 1986, the Environmental Protection Agency (EPA) counted 7,683 municipal solid waste landfills in the United States. In October 1991, the EPA adopted stringent new federal regulations for landfill design and operation. By 1992, the number of U.S. landfills had declined to 5,345 facilities. By 1995, the EPA landfill census recorded only 3,581 facilities. In 2001, the agency counted 1,858 landfills--a decline of 78% in 15 years.
The nation's disposal capacity, however, has remained relatively constant, because new landfills are much larger than in the past, according to EPA. Nationally, states have disposal capacity for another 19-20 years, according to the National Solid Wastes Management Association (NSWMA). Nevertheless, a number of states are nearing the end of their ability to manage MSW within their borders. In 2000, five states reported that they had less than 10 years of landfill capacity. Two other large states--Massachusetts and New York--had 5-10 years of capacity remaining.
In addition, such waste-to-energy facilities as incinerators are at capacity and growing older, with little potential for the construction of new facilities.
The closing of thousands of landfills, and the construction of regional mega-landfills, have contributed to the increased shipment of municipal wastes across state lines for disposal. In 2003, states shipped 39 million tons of MSW to other states. Pennsylvania was the largest importer of MSW in 2003; New York, the largest exporter.
The nation must also experiment with newer technologies for solid waste management. One promising technology involves the use of bioreactor landfills to manage a growing volume of waste. A bioreactor landfill rapidly transforms and degrades organic waste. The increase in waste degradation and stabilization is accomplished through the addition of liquid and air to enhance microbial processes. This bioreactor concept differs from the traditional "dry tomb" municipal landfill approach.
Given the reduction in the number of landfills and the need to extend the life and capacity of the existing landfills, the operation of the landfills as bioreactors is a growing trend. Decomposition and biological stabilization of the waste in a bioreactor landfill can take place much more quickly than it can in a traditional "dry tomb" landfill, providing a potential decrease in long-term environmental risks and landfill operating and post-closure costs.
According to EPA, the potential advantages of bioreactors include:
- Decomposition and biological stabilization in years vs. decades in "dry tombs"
- Lower waste toxicity and mobility due to both aerobic and anaerobic conditions
- Reduced leachate disposal costs
- A 15- 30% gain in landfill space due to an increase in density of waste mass
- Significantly increased landfill gas generation that, when captured, can be used for energy onsite or sold
- Reduced post-closure care
- The American Society of Civil Engineers opposes legislation that would restrict the interstate movement of municipal solid wastes to new regional landfills that meet all the requirements of federal law.
- ASCE supports legislation and regulations that would allow the use of alternative covers, the introduction of non-indigenous liquids, and other operational changes, to increase the effectiveness of solid-waste landfills.
- Project XL (eXcellence and Leadership), an EPA program begun in 1995 to provide limited regulatory flexibility for U.S. businesses to conduct pilot projects to operate bioreactor landfills, stopped receiving project applications in January 2003. Although research projects approved for funding before 2003 are continuing, EPA should reopen the bioreactor research program to new projects, in order to build upon the progress made in the 1990s.
Environmental Protection Agency), Municipal Solid Waste Landfills, http://www.epa.gov/epaoswer/non-hw/muncpl/landfill/index.htm#list (last updated October 2004)
Congressional Research Service, Interstate Shipment of Municipal Solid Waste, September 2004
The National Safety Council, Recycling of Selected Electronic Products in the United States, http://www.nsc.org/ehc/epr2/baseline.htm
Kaufman, Scott M., et al., "The State of Garbage in America," 45 BioCycle 31, January 2004
Environmental Protection Agency, Municipal Solid Waste in the United States: 2001 Final Report, October 2003
Environmental Protection Agency, EPA-530-R-02-001, June 2002
National Solid Wastes Management Association, Landfill Capacity: How Much is Left in the United States? October 2000
ASCE Policy Statement 299, "Infrastructure Improvement Policy", 2003
ASCE Policy Statement 453, "Federal Capital Budgeting," 2000
[1] In 2001, the last year for which official government data are available, approximately 229 million tons of MSW were produced in the United States, according to the EPA, a decrease from 2000. The industry estimates are greater because they include a larger universe of wastes, such as construction debris, agricultural wastes, wastes from overseas, industrial wastes, and other non-hazardous wastes.
[2] A growing contributor to the waste stream is consumer electronics. Approximately 20.6 million personal computers became obsolete in the United States in 1998. Of those, only 11%--about 2.3 million units--were recycled, according to the National Safety Council. The EPA has begun a nationwide program to address the issue.
