This chapter covers conditions and trends through calendar year 1998 using data and information available as of December 31, 2000.
By most accounts, the environment is cleaner today than it was several decades ago. This chapter examines trends in the generation and disposal of municipal (non-hazardous) solid waste, hazardous waste, and nuclear waste; the release and management of industrial toxic chemicals; the cleanup of abandoned hazardous waste sites; and the persistence of long-lived toxic chemicals that threaten human health and the environment. Success stories include:
TRENDS
Municipal Solid Waste
Municipal solid waste (MSW) consists of everyday items such as product packaging, newspapers, clothing, furniture, alliances, food scraps, bottles, and other types of residential and commercial garbage. Households generate 55 to 65 percent of U.S. municipal solid waste while schools, some industrial sites where packaging is generated, and businesses generate the rest. Not included in MSW are materials such as construction and demolition debris, municipal wastewater sludges, and non-hazardous industrial wastes, although these materials may be disposed in the same type of landfills as MSW.
Over the last several decades, the MSW landscape has changed substantially (Figure 8.1). Gross solid waste generation has nearly tripled, from 88 million tons per year in 1960 to 220.2 million tons per year in 1998. Total per capita waste generation grew from 2.7 pounds per person per day in 1960 to 4.5 pounds per person per day in 1994, and then declined slightly in successive years. Waste generation would be even higher if not for waste prevention practices that keep materials out of the waste stream, such as backyard composting of yard waste and using mowers that leave grass clippings on the lawn. In 1998, Americans sent 27.7 million tons of yard trimmings into the waste stream, down from 35.0 million tons in 1990.
Strong growth in recovery for recycling (including composting) has led to a proportional decline in waste discards. Total material recovery has increased ten-fold from 5.6 million tons in 1960 to 62.2 million tons in 1998, making the nation’s current recycling rate 28.2 percent of total waste generation.
Much of the increase in material recovery is due to the growing number of curbside recycling programs and population served as well as the growing number of large-scale composting operations, facilities that pull recyclables out of mixed waste, and facilities that process recyclables. In the eleventh annual State of Garbage in America survey, BioCycle reported that 9,349 curbside recycling programs were operating throughout the United States and serving close to 139.5 million people (Figure 8.2). The survey also reported significant gains in programs that compost yard trimmings (Figure 8.3).
Discards remaining after recovery are either incinerated or landfilled. The importance of incineration for waste disposal declined over the 1960-1998 period from 30 percent of total generated waste to 17 percent. At present, 55 percent of generated waste is landfilled, down from 63 percent in 1960. Over the past ten years, the number of landfills operating in the United States declined (Figure 8.4) while average landfill size has increased.
By weight, paper and paperboard make up the largest component of MSW generated, followed by yard trimmings; however, increasing tonnage of these organic materials is recovered for recycling or composting. In 1998, recycling of paper, paperboard, and yard trimmings, combined, diverted over 21 percent of MSW from landfills and incineration. Recovery programs for aluminum and other metals also showed strong growth, climbing from 0.5 to 36.4 percent of metal MSW generated over the 1960-1998 period. Recovery of glass showed a similar pattern, growing from 1.5 to 25.5 percent of glass MSW generated over the period.
For other waste types, including plastics, rubber, and textiles, recovery programs remain a relatively small percentage of MSW generation for each material. In the case of plastics, for example, total waste generation in 1998 was 22.4 million tons, while only about 1.2 million tons (or 5 percent) was recovered. Other underutilized MSW materials, such as food scraps and wood residuals, are prime targets for improved recovery efforts.
RCRA Hazardous Waste
Information on hazardous wastes regulated under the Resource Conservation and Recovery Act of 1976 (RCRA), as amended, is published by EPA on a biennial basis. In the latest report on the generation, management, and final disposition of hazardous waste, 20,316 large quantity generators (LQG) reported generating 40.7 million tons of RCRA waste in 1997. Compared to 1995 RCRA data (excluding wastewater data which would otherwise make comparison of 1997 and 1995 data misleading), the number of LQGs declined by 551 in 1997 while the quantity increased by 4.4 million tons, or 11 percent. (Changes in EPA reporting requirements and generators’ wastewater management practices prevent comparison with prior RCRA data reports). LQGs in five states (Texas, Louisiana, Illinois, Ohio, and Mississippi) accounted for 72 percent of the national total hazardous waste generated in 1997.
In 1997, there were 2,025 facilities permitted by RCRA to treat, store, or dispose of hazardous waste, up from 1,982 facilities in 1995. Using the wastewater exclusion, the total quantity of non-wastewater hazardous waste managed in 1997 was 37.7 million tons, an increase of 2.6 million tons, or 7 percent, since 1995. Land disposal accounted for 76 percent of the national non-wastewater management total (Figure 8.5). Deepwell or underground injection was preferred land disposal practice, accounting for 26 million tons of 1997 hazardous waste, followed by landfill disposal (1.5 million tons), surface impoundment (1 million tons), and land treatment, application, or farming (19 thousand tons).
Ten (10) percent of the national non-wastewater managed hazardous waste was recovered in 1997 while nine (9) percent was subjected to thermal treatment. Recovery operations included fuel blending (1.5 million tons), metals recovery for reuse (1.1 million tons), solvents recovery (617 thousand tons), and other recovery (443 thousand tons). Thermal treatment included energy recovery for reuse as fuel (1.7 million tons) and incineration (1.7 million tons). Other methods included stablization (1.4 million tons), sludge treatment (411 thousand tons), and other disposal techniques (251 thousand tons).
Nuclear Waste
Low-Level Nuclear Waste
The U.S. Department of Energy (DOE ) generates low-level nuclear waste (LLW) through its defense activities, naval nuclear propulsion program, and various research and development (R&D) activities. The annual amount of LLW disposed at DOE sites grew steadily from 1975 to 1987, reaching a peak of 154,000 cubic meters and then declining to about 29,762 cubic meters in 1998. The rate at which LLW is generated from routine DOE operations (excluding disposal of contaminated material from environmental restoration activities) decreased by 29 percent over the last five years.
Commercial LLW is generated by five sectors: academic (includes university hospitals and university medical and nonmedical research facilities); government (includes state and non-DOE federal agencies); industrial (includes private entities such as R&D companies, manufacturers, nondestructive-testing operations, mining works, fuel fabrication facilities, and radio/pharmaceutical manufacturers); medical (includes hospitals and clinics, research facilities, and private medical offices); and utility (includes commercial nuclear reactors).
The trend in commercial LLW disposal has paralleled the DOE-government sector, reaching a peak in 1980 of 92,400 cubic meters. Since 1980, the annual additions declined to an estimated 9,400 cubic meters in 1998. This represents about 24 percent by volume of all LLW in 1998.
High Level Nuclear Waste
At the end of 1998, DOE had an inventory of 342,281 cubic meters of high-level nuclear waste (HLW). HLW is generated by the chemical reprocessing of irradiated targets, naval propulsion fuel, and spent reactor fuel (although chemical reprocessing has been phased out except when needed to reprocess deteriorating spent nuclear fuel). Most of the current inventory of HLW is stored at DOE facilities in Idaho, New York, South Carolina, and Washington until geologic disposal at a proposed facility located at Yucca Mountain, Nevada.
Spent Nuclear Fuel
Inside nuclear power reactors, the nuclear fission process involving uranium-enriched, fuel-rod assemblies produces heat that is used to generate steam and make electricity. After about three or four years in an operating nuclear reactor, the energy remaining in the fuel rods is no longer efficient enough to produce usable heat and the "spent" nuclear fuel is removed and replaced with fresh fuel. The spent nuclear fuel (SNF) is highly radioactive and must be isolated from the environment for thousands of years until the radioactivity decays to natural background level. SNF is currently stored at nuclear reactor sites in specially designed, water-filled pools and above-ground dry storage facilities until a permanent geologic repository is in operation. In 1998, the national cumulative inventory of SNF from non-DOE nuclear reactors is estimated to be 83,800 metric tons of heavy metal.
DOE produced SNF for many years for national defense and programmatic missions. Historically, SNF was managed by reprocessing it whereby nuclear material (uranium or plutonium) was chemically removed from the waste. As DOE’s need for uranium and plutonium decreased, reprocessing of SNF was discontinued, leaving significant amounts in storage at most DOE sites until permanent disposal at the proposed Yucca Mountain facility. The 1998 DOE inventory of SNF was 2,480 metric tons of heavy metal.
Toxic Releases
Total releases of toxic substances tracked by EPA’s Toxics Release Inventory (TRI) have decreased from 3.40 billion pounds in 1988 to 1.86 billion pounds in 1998 (Figure 8.6). [Note: Because reporting requirements have changed, data for ammonia, hydrochloric acid, and sulfuric acid are not included in the 1988-1998 analyses. Reporting facilities added to TRI in 1998 are also not included.] On-site releases fell by more than half (51.9 percent), from 2.97 billion pounds in 1988 to 1.43 billion pounds in 1998. As shown in Figure 8.8, most of the overall reduction occurred in air emissions, a decrease of 1.26 billion pounds (from 2.18 billion pounds to 920.7 million pounds). This amounted to a 57.8 percent decrease in air emissions. The largest percentage reduction appeared in surface water discharges, which declined 72.9 percent (from 164.6 million pounds to 44.7 million pounds). For off-site releases, the overall trend in transfers to disposal over the 1988-1998 period showed almost no net change. From 1988 to 1995, these releases declined from 428.0 million pounds to 289.4 million, only to increase to 428.9 million pounds in 1998. This increase is partly due to a sharp increase in solidification/stabilization of metals from 1996 to 1997. Some of this increase, however, was offset by reductions in other types of off-site releases. Amounts sent to landfills and surface impoundments, the largest type of off-site release, decreased overall during the period, but increased in recent years.
Using original-industry data for chemicals that have been reportable since 1988, many industries reduced their on-site and off-site releases of toxics by more than half over the 1988-1998 period. Significant reductions have been made by industry manufacturing codes for textiles (-72.1 percent), apparel (-59.5 percent), furniture (72.7 percent), printing (-60.7 percent), chemicals (-56.8 percent), leather (-57.8 percent), machinery (-76.9 percent), electrical equipment (-81.8 percent), transportation equipment (-54.7 percent), and measurement/photographic industries (-88.0 percent). Only the food industry category showed an increase (16.8 percent) in toxics releases over the period. Although total releases in the food products industry declined from 8.5 million pounds in 1988 to 5.4 million pounds in 1997, releases increased to 10.0 million pounds in 1998. The chemical manufacturing industry showed the largest absolute reduction, from 1.05 billion pounds in 1988 to 455.5 million pounds in 1998. (Part III, Table 8.7)
Many states have cut on-site and off-site releases by more than 70 percent over the 1988-1998 period, including Alaska (-91.5 percent), California (-74.5 percent), Colorado (-77.3 percent), Connecticut (-84.4 percent), Delaware (-74.0 percent), Massachusetts (-79.8 percent), Minnesota (-73.2 percent), New Hampshire (-83.2 percent), New Jersey (-76.3 percent), New York (-78.3 percent), Rhode Island (-79.5 percent), Vermont (-88.1 percent), and Wyoming (-94.3 percent).
Superfund Inventory
The EPA Superfund program was launched in 1980, with the passage of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), to protect human health and the environment from the dangers posed by abandoned or uncontrolled hazardous waste sites. The early years of the program were spent identifying and assessing sites, and cleaning up short-term emergency problems. By 1994, the number of sites in the Superfund inventory had grown to 1,360 National Priorities List (NPL) sites, the roster of the nation’s most serious hazardous sites, and to 39,099 non-NPL Superfund sites. EPA reduced the Superfund inventory in 1995 by moving over 24,000 low-priority, non-NPL Superfund sites to the Brownfields Program for cleanup and reuse. The non-NPL Superfund inventory was reduced further through cleanup removal actions to 9,404 in 1998. The NPL site inventory has been reduced also, dropping from a high of 1,374 in 1995 to 1,192 in 1998 (Figure 8.7). By the end of 1998, cleanup construction had been completed at 588 NPL sites since Superfund’s inception.
Contaminants in Fish and Wildlife
Long-lived toxic contaminants such as dichlorodiphenyl trichloroethane (DDT) and polychlorinated biphenyls (PCB) still persist in all segments of the environment, although in declining concentrations since their manufacture and use was banned or restricted. Concentrations of DDE (a derivative of DDT), PCBs, and other contaminants in eggs of herring gulls from colonies on the Great Lakes, for example, declined over period from 1974 to 1998. In Lake Superior, PCBs in herring gull eggs were measured at 76.24 parts per million (ppm) in 1975; by 1998, the level had dropped to 12.96 ppm. In Lake Michigan, PCBs concentrations show similar trends, declining from 118.42 ppm in 1976 to 24.61 ppm in 1998 (Figure 8.8). In both Lake Superior and Lake Michigan, DDE concentrations in herring gull eggs dropped sharply in the late 1970s and remained fairly stable in the 1980s and 1990s (Figure 8.9). Downward trends have been generally similar at other Great Lakes herring gull colonies and for other chemicals, including Dieldrin, Mirex, and HCB. (See also Fish Consumption Advisories in Chapter 6. Aquatic Resources.)
Pesticide Residues in U.S. Domestic Food Samples
Surveillance monitoring has measured substantially reduced pesticide residues in some food commodity groups over the 1978-1998 period. Milk, dairy products, and eggs, for example, have improved steadily during this period, with the percent of samples with no residues found rising from 57 percent in 1978 to 97 percent in 1998. Fish and shellfish also have improved to 68 percent of samples with no residues in 1998, compared to 20 percent in 1978. For other groups, including grains, fruits, and vegetables, there is no clear trend; residues have been found in about 40 to 60 percent of samples as a general rule. Taken as a whole, the percentage of domestic surveillance food samples without pesticide residues increased from 53 to 66 percent over the 1978-1998 period.
At least 0.8 percent of domestic surveillance food samples exceeded tolerance levels in 1998 compared to 3.6 percent of domestic compliance food samples that were violative. (Surveillance samples are random; that is, there is no prior knowledge or evidence that a specific food shipment contains illegal pesticides residues. Compliance samples, on the other hand, are collected when a pesticide residue problem is known or suspected.) Data on violations of import surveillance and compliance food samples for 1998 are reported to be of questionable value and not included here.
Lead
In the United States, average blood lead levels (BLLs) for both children and adults have dropped by more than 80 percent since the late 1970s. The reduction is primarily the result of removal of lead from gasoline as well as from other sources such as household paint, food and beverage cans, and plumbing systems.
Average BLLs in children ages 1-5 years decreased from 15.0 to 2.7 micrograms per deciliter according to National Health and Nutrition Examination Surveys (NHANES) performed between 1976-1980 and 1991-1994 (Figure 8.10). However, there are still close to one million children in the United States who continue to have BLLs that are greater than or equal to 10 micrograms per deciliter, a level associated with adverse effects in children. Elevated BLLs among children most often results from residence in houses built prior to 1978 (when lead-based paint was banned) with chipping or peeling paint or with excessive amounts of lead-contaminated dust resulting from remodeling efforts. Other sources of lead exposure include soil contaminated by paint, residues from past emissions of leaded gasoline, and emissions from smelters, battery plants, and industrial facilities that process lead.
The results of the NHANES survey also showed an income-associated gradient in the prevalence of high BLLs among race and ethnic groups examined. About 12 percent of children living in poor families had an elevated lead level, compared to about 2 percent of children in high-income families. The gradient was strongest for non-Hispanic black children; 22 percent of black children in families below poverty had elevated BLLs, compared to only 6 percent in high-income families.
References
U.S. Department of Health and Human Services, Food and Drug Administration, Pesticide Program Residues Monitoring, 1999 (FDA, Washington, DC, 2000), and earlier annual reports. (http://vm.cfsan.fda.gov/~dms/pesrpts.html)
U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention. Update: Blood Lead Levels, United States, 1991-1994. Morbidity and Mortality Weekly Report 46(07):141-146, February 21, 1997. (http://www.cdc.gov/mmwr/preview/mmwrhtml/00048339.htm)
--. Elevated Blood Lead Levels Among Internationally Adopted Children — United States, 1998. Morbidity and Mortality Weekly Report 49(05):97-100, February 11, 2000. (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm4905a3.htm)
U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Center for Health Statistics. Health, United States, 1998 With Socioeconomic Status and Health Chartbook (HHS, PHS, CDC, NCHS, Hyattsville, MD, 1998). (http://www.cdc.gov/nchs/data/huscht98.pdf)
U.S. Department of Energy, Office of Environmental Management. Waste Management Fiscal Year 1998 Progress Report (DOE, EM, Washington, DC, 1998).
--. Central Internet Database (DOE, EM, Washington, DC, as of September 20, 2000). (http://cid.em.doe.gov/Default_Text.htm)
--. Integrated Data Base Report - 1996: U.S. Spent Fuel and Radioactive Waste Inventories, Projections, and Characteristics, Revision 13 (DOE, EM, Washington, DC, 1997). (http://www.em.doe.gov/idb97/index.html)
U.S. Environmental Protection Agency, Office of Children’s Environmental Health, The EPA’s Children’s Environmental Health Yearbook (EPA, Washington, DC, 1998). (http://www.epa.gov/children/whatwe/ochpyearbook.pdf)
U.S. Environmental Protection Agency, Office of Emergency and Remedial Response, Superfund Cleanup Figures (EPA, Washington, DC, 2000). (http://www.epa.gov/superfund/action/process/mgmtrpt.htm)
--. The Superfund Progress Report: 1980-1997 (EPA, Washington, DC, 1998). (http://www.epa.gov/superfund/resources/17yrrept/index.htm)
U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, 1998 Toxics Release Inventory: Public Data Release (EPA, Washington, DC, 2000). (http://www.epa.gov/tri/tri98/index.htm)
U.S. Environmental Protection Agency, Office of Solid Waste and Emergency Response, Municipal Solid Waste Generation, Recycling and Disposal in the United States: Facts and Figures for 1998. Environmental Fact Sheet. (EPA, Washington, DC, 2000). (http://www.epa.gov/epaoswer/non-hw/muncpl/msw99.htm)
--, The National Biennial RCRA Hazardous Waste Report (Based on 1999 Data) (EPA, Washington, DC). http://www.epa.gov/epaoswer/hazwaste/data/brs99/index.htm
