&EPA
United States
Environmental Protection
Agency
Solid Waste and
Emergency Response
(OS-305)
EPA/530-SW-90-042A
June 1990
Characterization of
Municipal Solid Waste in the
United States: 1990 Update
Executive Summary
o \Js*a
Printed on Recycled Paper
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EPA/530-SW-90-042A
Characterization of Municipal
Solid Waste in the United
States: 1990 Update
Executive Summary
June 13,1990
United States Environmental Protection Agency
Office of Solid Waste
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Acknowledgements
The report, Characterization of Municipal Solid Waste in the United States: 1990 Update,
was developed under EPA contract No. 68-01-7310 under the direction of Paul Kaldjian at EPA.
Appreciation is extended to the many individuals in the Office of Solid Waste who reviewed and
commented on drafts of the report. EPA also wishes to give special thanks to Jo Nord, the artist
of the cover illustration.
Ordering Information
The complete report is available through the National Technical Information Service
(NTIS). To order, call NTIS at (703) 487-4650. A fact sheet highlighting the major
findings of the report is also available. To obtain additional copies of this Executive
Summary (EPA/530-SW-90-042A) or the fact sheet (EPA/530-SW-90-042B) at no charge,
call the RCRA/Superfund Hotline at (800) 424-9346; TDD (800) 553-7672 for the hearing
impaired. In Washington, DC, the number is (202) 382-3000; TDD (202) 475-9652.
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EXECUTIVE SUMMARY
Many areas of the United States currently face serious problems in
safely and effectively managing the garbage they generate. As a nation, we are
generating more trash than ever before. At the same time, we are finding
that there are limits to traditional trash management practices. As the
generation of municipal solid waste (MSW) continues to increase, the
capacity to handle it is decreasing. Many landfills and combustors have
closed, and new disposal facilities are often difficult to site. As a result, many
communities face hard choices when weighing trash management options.
Some communities end up paying premium prices to transport their garbage
long distances to available facilities. Others try to site facilities nearby and
encounter intense public conflict. Of course, not all communities face such
problems; numerous communities have found creative solutions through
source reduction and recycling programs. Still, for much of the nation, the
generation and management of garbage presents problems that require our
focused attention.
Identifying the components of the waste stream is an important step
toward solving the problems associated with the generation and management
of garbage. MSW characterizations, which analyze the quantity and
composition of the municipal solid waste stream, involve estimating how
much MSW is generated, recycled, combusted, and disposed of in landfills.
By determining the makeup of the waste stream, waste characterizations also
provide valuable data for setting waste management goals, tracking progress
toward those goals, and supporting planning at the national, state, and local
levels. For example, waste characterizations can be used to highlight
opportunities for source reduction and recycling and provide information on
any special management issues that should be considered.
Features of This Report
This report is the most recent in a series of reports released by the U.S.
Environmental Protection Agency (EPA) to characterize MSW in the United
States. It characterizes the national waste stream based on data through 1988
and includes:
• Information on MSW generation from 1960 to 1988.
• Information on recovery for recycling, composting, and
combustion from 1960 to 1988.
• Information characterizing MSW by volume as well as by
weight.
• Projections for MSW generation to the year 2010.
• Projections for MSW combustion through 2000.
• Projections (presented as a range) for recovery and recycling
through 1995.
ES-1
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Unlike previous EPA characterization reports, this report does not
include long-range projections for materials recovery. This is due to the
significant uncertainties in making those projections. For example, rapid
changes are now taking place at the federal, state, and local level that may
have profound effects on such projections. In addition, shifts in consumer
attitudes and behaviors, industry practices and efforts, and technological
advances will greatly influence recovery and recycling. The potential impact
of all of these changes is very difficult to predict.
Readers should note that this report characterizes the municipal solid
waste stream of the nation as a whole. The information presented here may
not, therefore, correlate with individual state or local estimates of waste
generation and management.
Methodology
There are two primary methods for conducting a waste characterization
study. The first is a site-specific approach in which the individual
components of the waste stream are sampled, sorted, and weighed. Although
this method is useful for defining a local waste stream, extrapolating from a
limited number of studies can produce a skewed or misleading picture if used
DEFINITIONS
Municipal solid waste includes wastes such as durable goods, nondurable goods,
containers and packaging, food wastes, yard wastes, and miscellaneous inorganic wastes
from residential, commercial, institutional, and industrial sources. Examples of waste
from these categories include appliances, newspapers, clothing, food scraps, boxes,
disposable tableware, office and classroom paper, wood pallets, and cafeteria wastes.
MSW does not include wastes from other sources, such as municipal sludges, combustion
ash, and industrial nonhazardous process wastes that might also be disposed of in
municipal waste landfills or incinerators.
Generation refers to the amount (weight, volume, or percentage of the overall waste
stream) of materials and products as they enter the waste stream and before materials
recovery, composting, or combustion (incineration) takes place.
Recovery refers to materials removed from the waste stream for the purpose of recycling
and/or composting. Recovery does not automatically equal recycling and composting,
however. For example, if markets for recovered materials are not available, the
materials that were separated from the waste stream for recycling may simply be
stored or, in some cases, sent to a landfill or incinerator.
Discards include the municipal solid waste remaining after recovery for recycling and
composting. These discards are usually combusted or disposed of in landfills, although
some MSW is littered, stored, or disposed of on site, particularly in rural areas.
ES-2
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for a nationwide characterization of waste. Any errors in the sample or
atypical circumstances encountered during sampling would be greatly
magnified when expanded to represent the nation's entire waste stream.
The second method, used in this report to estimate the waste stream on
a nationwide basis, is called the "material flows methodology." EPA's Office
of Solid Waste and its predecessors in the Public Health Service sponsored
work in the 1960s and early 1970s to develop the material flows methodology.
This methodology is based on production data (by weight) for the materials
and products in the waste stream, with adjustments for imports, exports, and
product lifetimes.
Report Highlights
This report underscores the problems we face in municipal solid waste
management: the generation of MSW continues to increase steadily, both in
overall tonnage and in pounds per capita. In addition, the report indicates
that materials recovery for recycling and the combustion of MSW have
increased in recent years, while discards to landfills have decreased. Major
findings include the following:
• In 1988,180 million tons, or 4.0 pounds per person per day of
MSW were generated. After materials recovery for recycling,
discards were 3.5 pounds per person per day. Virtually all of
these discards were combusted or sent to a landfill.
• Without source reduction, the amount of waste generated in
1995 is expected to reach 200 million tons, or 4.2 pounds per
person per day. By 2000, generation is projected to reach 216
million tons, or 4.4 pounds per person per day. The per capita
figure for the year 2000 is a 10 percent increase over 1988 levels.1
• Based on current trends and information, EPA projects that 20 to
28 percent of MSW will be recovered annually by 1995.
Exceeding this projected range will require fundamental changes
in government programs, technology, and corporate and
consumer behavior.
1 This report updates generation projections and estimates from previous reports. The projected
per capita generation estimate for the year 2000 has been increased from just under 4 pounds to
4.4 pounds. This report also increases the 1986 per capita generation estimate by 6 percent—
from 3.6 to 3.8 pounds. These projections and estimates have been adjusted because the 1990
report includes additional items in the data base, such as automotive batteries and disposable
diapers, corrections for imported packaging materials, and changes in the detail available in
the data base, e.g., natural rubber in tires and additional plastic items.
ES-3
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• Recovery of MSW materials for recycling was 13 percent in 1988.
Combustion was 14 percent of total generation, and the
remaining 73 percent of the municipal solid waste stream was
sent to landfills or otherwise disposed of.2
• For the first time in this series of characterization reports, MSW
is also characterized by volume. The results indicate which
materials in MSW occupy the greatest proportion of volume in
landfills, and compare these percentages to those by weight. For
example, paper and paperboard products make up 34 percent of
the discards (after recovery) by weight and 34 percent by volume;
plastics account for 9 percent by weight and 20 percent by
volume; and yard wastes make up 20 percent by weight and 10
percent by volume.
Municipal Solid Waste in 1988
In 1988, generation of municipal solid waste totaled 179.6 million tons.
Figure ES-1 provides a breakdown by weight of the materials generated in
MSW in 1988. It shows that paper and paperboard products are the largest
component of municipal solid waste by weight (40 percent of generation) and
yard wastes are the second largest component (roughly 18 percent of
generation). Four of the remaining materials in MSW—glass, metals,
plastics, and food wastes—range between 7 and 9 percent each by weight of
total MSW generated. Other materials in MSW include rubber, leather,
textiles, wood, and small amounts of miscellaneous wastes, which each made
up less than 4 percent of MSW in 1988.
The breakdown of how much waste went to recycling, combustion, and
landfills is shown in Figure ES-2. Recovery of materials for recycling and
composting was an estimated 13 percent in 1988. That amount varied
significantly according to the type of waste (Table ES-1). For example, nearly
26 percent of waste paper was recovered in 1988, while less than 2 percent of
plastic wastes were recovered.
The broad categories of materials in MSW are made up of many
individual products. The products are grouped into major product categories
as shown in Figure ES-3. In 1988, containers and packaging were the largest
single product category generated in MSW by weight, at roughly 32 percent of
the total. Nondurable goods (such as newspapers and disposable food service
items) were the second largest category, at 28 percent of the total. Yard wastes
were approximately 18 percent and durable goods (such as furniture and tires)
were 14 percent of total generation in 1988.
2 While essentially all of the 73 percent of the waste stream was sent to landfills, it should be
recognized that some waste may be littered, stored, or disposed of at the site of generation.
ES-4
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MATERIALS GENERATED IN MSW
BY WEIGHT, 1988
Yard Wastes, 17.6%
31.6 million tons
Metals, 8.5%
15.3 million tons
Paper, 40.0%
71.8 million tons
Glass, 7.0%
12.5 million tons
Plastics, 8.0%
14.4 million tons
Other, 11.6%
20.8 million tons
Food Wastes, 7.4 %
13.2 million tons
TOTAL WEIGHT = 179.6 million tons
FIGURE ES-1
ES-5
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MANAGEMENT OF MSW IN U.S.,
1988
Landfill, 72.7%
130.5 million tons
Recovery, 13.1%
23.5 million tons
Incineration, 14.2%
25.5 million tons
TOTAL WEIGHT = 179.6 million tons
FIGURE ES-2
ES-6
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TABLE ES-1
Generation of MSW, Recovery of Materials
and Composting of Food and Yard Waste, 1988
Paper and Paperboard
Glass
Metals
Ferrous
Aluminum
Other Nonferrous
Total Metals
Plastics
Rubber and Leather
Textiles
Wood
Other
Total Nonfood Product Wastes
Other Wastes
Food Wastes
Yard Wastes
Miscellaneous Inorganic Wastes
Total Other Wastes
Total MSW
Weight
Generated
(in Millions
of Tons)
71.8
12.5
11.6
2.5
1.1
15.3
14.4
4.6
3.9
6.5
3.1
132.1
13.2
31.6
2.7
47.5
179.6
Weight
Recovered
(in Millions
of Tons)
18.4
1.5
0.7
0.8
0.7
2.2
0.2
0.1
0.0
0.0
0.7
23.1
0.0
0.5
0.0
0.5
23.5
Percent of
Generation
of Each
Material
25.6
12.0
5.8
31.7
65.1
14.6
1.1
2.3
0.6
0.0
21.7
17.5
0.0
1.6
0.0
1.1
13.1
ES-7
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PRODUCTS GENERATED IN MSW
BY WEIGHT, 1988
Durable Goods, 13.9%
24.9 million tons
Other, 1.5%
2.7 million tons
Nondurable Goods, 28.1%
50.4 million tons
Containers/Packaging, 31.6%
56.8 million tons
Food Wastes, 7.4%
13.2 million tons
Yard Wastes, 17.6%
31.6 million tons
TOTAL WEIGHT = 179.6 million tons
FIGURE ES-3
ES-8
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MSW Volume Estimates
Although solid waste is usually characterized by weight, information
about volume is important for such issues as determining how quickly
landfill capacity is being filled and identifying the rate at which the volumes
of various materials in the waste stream are changing.
Volume estimates of solid waste, however, are far more difficult to
make than weight estimates. A pound of paper is a pound of paper whether
it is in flat sheets, crumpled into a wad, or compacted into a bale, but the
volume occupied in each case will be very different. The figures in this report
are estimations of the volume of materials as they would typically be found
in a landfill (a significant amount of compaction occurs in a landfill). These
estimates are based largely on empirical data that are then used to estimate
density factors (pounds per cubic yard) for components of solid waste under
simulated landfill conditions, with corroboration from actual landfill studies.
Figure ES-4 shows the materials in MSW by volume as a percent of
total MSW discards in 1988. The paper and paperboard category ranks first in
volume of MSW discarded (34 percent). Plastics rank second in volume, at 20
percent of the total, and yard wastes are third, at 10 percent. Paper and plastics
combined account for over one-half of the volume of MSW discarded in 1988.
Table ES-2 compares 1988 volume and weight estimates for materials
in MSW contained in the report. The right-hand column shows the ratio of
volume to weight for each material. A ratio of 1.0 means that the material
occupies the same proportion by volume as by weight. Values greater than 1.0
mean that the material occupies a larger proportion of volume than weight.
Four materials have ratios greater than 2.0: plastics, rubber and leather,
textiles, and aluminum. By contrast, yard wastes, food, and glass each have
ratios of 0.5 or less, indicating that these materials are quite dense and occupy
proportionately less volume in landfills.
Figure ES-5 shows the product categories that make up MSW by
volume of total discards in 1988. Nondurable goods rank first in volume
percentage at 34 percent. Containers and packaging are second in volume
(roughly 30 percent), and durable goods are third (approximately 22 percent).
Trends in MSW Generation, Recovery, and Discards
Generation of municipal solid waste grew steadily between 1960 and
1988, from 88 million to nearly 180 million tons per year. Per capita
generation of MSW increased from 2.7 pounds per person per day in 1960 to
4.0 pounds per person per day in 1988. Between 1986 and 1988, generation
increased from 3.8 to 4.0 pounds per person per day (167 million to 180
million tons per year). By 2000, projected per capita MSW generation is 4.4
ES-9
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LANDFILL VOLUME OF DISCARDS
IN MSW, 1988
Metals, 12.1%
48.3 million cubic yards
Yard Wastes, 10.3%
41.3 million
cubic yards
Glass, 2.0%
7.9 million cubic yards
Paper, 34.1%
136.2 million cubic yards
Plastics, 19.9%
79.7 million
cubic yards
Other, 18.4%
73.4 million
cubic yards
Food Wastes, 3.3 %
13.2 million cubic yards
TOTAL VOLUME = 400 million cubic yards
FIGURE ES-4
ES-10
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TABLE ES-2
Volume of Materials Discarded in MSW, 1988
Paper and Paperboard
Plashes
Yard Wastes
Ferrous Metals
Rubber and Leather
Textiles
Wood
Food Wastes
Other
Aluminum
Glass
TOTALS
1988
Discards
(mil tons)
53.4
14.3
31.0
10.9
4.4
3.8
6.5
13.2
5.6
1.7
11.1
156
Weight
(%ofMSW
total)
34.2
9.2
19.9
7.0
2.9
2.5
4.2
8.5
3.6
1.1
7.1
100
Volume
(%ofMSW
total)
34.1
19.9
10.3
9.8
6.4
5.3
4.1
3.3
2.5
2.3
2.0
100
Ratio
(vol %/
wt%)
1.0
2.2
0.5
1.4
' 2.3
2.1
1.0
0.4
0.7
2.1
0.3
1.0
ES-11
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PRODUCTS DISCARDED IN MSW
BY VOLUME, 1988
Durable Goods, 22.2%
88.5 million
cubic yards
Containers/Packaging, 29.6%
118.1 million cubic yards
Other, 0.6%
2.2 million
cubic yards
Food Wastes, 3.3%
13.2 million
cubic yards
Yard Wastes, 10.4%
41.3 million
cubic yards
Nondurable Goods 34.0%
135.6 million cubic yards
TOTAL VOLUME = 400 million cubic yards
FIGURE ES-5
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pounds per person per day (216 million tons). Projected MSW generation in
the year 2010 is over 250 million tons, or 4.9 pounds per person per day.
Figure ES-6 shows the generation (in millions of tons) of materials in MSW
between 1960 and 1988 with projections to 2010.
Recovery has increased gradually from about 7 percent of the waste
generated in 1960 to 13 percent in 1988. Recovery is projected to reach
between 20 percent and 28 percent of MSW generated in 1995. These
projections are presented as a range because of the many unpredictable factors
that might influence the growth of recovery and recycling over the next 5
years. These factors include possible changes in the Resource Conservation
and Recovery Act (RCRA), which regulates the treatment, storage, and
disposal of the nation's solid waste; other federal and state legislative
proposals; deposit bills; bans; regional and local efforts; municipal waste
combustion and landfill source separation proposals; municipal source
reduction and recycling programs; industry efforts and recycling technology.
While specific predictions about recycling might be misleading, EPA believes
that with fundamental changes in activities and programs related to recycling,
we can achieve even higher recycling rates than those projected.
Combustors handled an estimated 30 percent of MSW generated in
1960, most of them with no energy recovery and no air pollution controls. In
the 1960s and 1970s, combustion dropped steadily as the old incinerators were
closed, reaching a low of less than 10 percent of MSW generated by 1980.
More recently, combustion of MSW has been increasing again (to 25.5 million
tons, or roughly 14 percent of generation, in 1988). All major new facilities
have energy recovery and are designed to meet air pollution standards.
The report projects that more than 45 million tons of MSW will be
combusted in 1995, and 55 million tons will be combusted in 2000. It should
be noted that because of the long lead time in planning, permitting, and
constructing incineration facilities, projections for combustion are easier to
make than projections for recovery. Estimates of combustion projections are
based on assumptions that assume the facilities will operate at 80 percent of
capacity.
Landfill use fluctuates with changes in the use of alternative solid
waste management methods. For example, when the use of incineration for
MSW management declines and recovery rates are low, the MSW percentage
sent to landfills increases. Alternatively, when recovery and combustion of
MSW increase, the percentage of MSW discarded to landfills declines. In
1960, approximately 62 percent of MSW was sent to landfills. This increased
to 81 percent in 1980, then decreased to 73 percent in 1988 due to changing
trends in municipal solid waste management.
ES-13
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U.S. MSW GENERATION,
1960-2010
M
I
L
L
I
O
N
S
O
F
T
O
N
S
300
250
200
150
100
1970
Paper
Other
1980 1988
YEAR
Mil Glass/Metal
.""::::::! r I CL O I I C O
2000
2010
Food/Yard
FIGURE ES-6
ES-14
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As we approach the twenty-first century, integrated waste management
is clearly the solution to our growing waste needs. Through source reduction
and recycling, we can reduce generation and increase recovery, and, in turn,
reduce our reliance on combustors and landfills.
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