United States
Environmental Protection
Agency
Solid Waste and
Em^ency Response EPA530-S-96-001
(5305W) March 1996
&EPA
Characterization of
Municipal Solid Waste in
The United States:
1995 Update
Executive Summary
Recycled/Recyclable
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CHARACTERIZATION OF MUNICIPAL SOLID WASTE
IN THE UNITED STATES: 1995 UPDATE
Executive Summary
FEATURES OF THIS REPORT
This report is the most recent in a series of reports released by the U.S.
Environmental Protection Agency (EPA) characterizing municipal solid waste
(MSW) in the United States. The report describes the national waste stream based
on data collected from 1960 through 1994. This historical perspective is useful for
establishing trends and highlighting changes that have occurred over the years,
both in types of waste generated and in the ways they are managed. It does not,
however, specifically address local and regional variations in the waste stream.
Nevertheless, the data in this report can be used to develop approximate (but
quick) estimates of MSW generation and composition in a defined area. Due to
increased interest in the report over the years and the dynamic nature of the
MSW field, EPA plans to provide annual updates of this report as a service to
state and local MSW officials and other interested parties.
The report includes information on:
MSW generation, recovery, and discards from 1960 to 1994
Per capita generation and discard rates
Residential/commercial portions of MSW generation
Trends in MSW management, including recovery for recycling and
composting, as well as combustion and landfilling, from 1960 to 1994
The role of source reduction in MSW management
Projections for MSW generation and management through 2010,
including three scenarios for recovery
An "Additional Perspectives" Chapter devoted to basic information on
the potential climate change implications of various municipal waste
management strategies.
REPORT HIGHLIGHTS
While the total amount of MSW generated annually continues to
increase, the rate of this growth is slowing. Per capita MSW generation (the
amount of MSW generated per person per day) is expected to remain constant at
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4.4 pounds per person per day through the year 2000. The primary reason for this
steady rate is that, while the per capita generation of the products and packaging
component of MSW will continue to rise, efforts to keep yard trimmings out of
the waste management system are beginning to have an effect. Recovery rates for
recycling and composting continue to grow, and this year, for the first time,
composting of food scraps has reached measurable proportions. As MSW
generation continues to increase and recycling matures, however, source
reduction as a management practice will be increasingly important.
1994 MSW Generation and Management
A total of 209 million tons of MSW was generated in 1994. This reflects an
increase of 3 million tons from 1993, when MSW generation was 206
million tons. This increase in total MSW generation is due largely to an
increase in population.
However, the per capita generation rate remained at 4.4 pounds per person
per day, the same rate as 1993.
The per capita discard rate (after recycling and composting) was 3.4 pounds
per person per day in 1994, down from 3.5 pounds per person per day in
1993.
Recycling and composting recovered 24 percent of MSW in 199.4, up from
21 percent in 1993 and up from 17 percent in 1990. As a nation, during 1994
we quickly approached the goal of 25 percent recovery of MSW.
An estimated 49 million tons of MSW were recovered in 1994, while 44
million tons were recovered in 1993.
Recovery of paper and paperboard accounted for more than half (nearly 29
million tons) of total MSW recovery. Composting of yard trimmings
contributed to the next largest fraction of total recovery at 7 million tons.
For the first time, composting of food scraps reached measurable
proportions at the national level. An estimated 3.4 percent of food scraps
was composted (500,000 tons out of 14.1 million tons generated).
Landfills managed 61 percent of MSW generated (127 million tons), and
combustion facilities managed 15 percent of the total MSW generated (32.5
million tons).
Trends in MSW Generation and Management
Annual MSW generation is expected to increase to 223 million tons in the
year 2000 and 262 million tons in 2010. Natural population growth and
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sustained long-term growth in the economy account for this projected
increase.
Per capita generation rates are projected to remain constant at 4.4
pounds per person, per day to the year 2000. Projected decreases in per
capita generation of yard trimmings during this time will be offset by
increases in per capita generation associated with the discard of
products and packaging.
After the year 2000, per capita decreases in generation of yard
trimmings are expected to plateau, while increases in per capita
generation of products and packaging will continue, causing total
MSW per capita generation rates to rise to 4.8 pounds per person per
day by 2010.
Achieving a decline in projected overall and per capita waste
generation will require continued emphasis on source reduction
activities, which prevent waste before it is generated. For example,
State and local efforts to keep yard trimmings out of landfills are
projected to result in a 25 percent decrease in yard trimmings
generation (by the year 2000) from the 1994 estimate of 30.6 million
tons. Primarily through the success of grasscycling and backyard
composting programs, yard trimmings generation is projected to
decrease to 23 million tons by 2000.
Recovery from recycling and composting continues to show
impressive growth. For the year 2000, three recovery scenarios ranging
from 25 percent to 35 percent are presented. The range for the year 2010
is 30 percent to 40 percent. Achieving a 40 percent recovery rate
nationwide would require recovery rates in the range of 50 percent for
many material categories in MSW, including paper and paperboard,
yard trimmings, metals, and glass.
Combustion is expected to remain relatively unchanged through the
year 2000.
While the percentage of MSW being disposed of in landfills is
decreasing, the actual tonnage is expected to increase to the year 2000.
Landfilling is expected to continue to be the single most predominant
MSW management method in future years.
Preliminary research indicates that source reduction and recycling of
MSW have significant potential to reduce greenhouse gas emissions
and mitigate climate change.
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DEFINITIONS AND METHODOLOGY
Municipal solid waste ( MSW) includes wastes such as-durable goods, nondurable goods,
containers and packaging, food scraps, yard trimmings, and miscellaneous inorganic wastes
from residential, commercial, institutional, and industrial sources. Examples of waste from
these categories include appliances, automobile tires, newspapers, clothing, boxes,
disposable tableware, office and, classroom paper, wood pallets, and cafeteria wastes.
MSW does not include wastes from other sources, such as construction and demolition debris,
automobile bodies, municipal sludges, combustion ash, and industrial process wastes that
might also be disposed in municipal waste landfills or incinerators.
Source reduction activities reduce the amount or toxicity of. wastes before they enter the
municipal solid waste management system (see Generation). Reuse of products such as
refillable glass bottles, reusable plastic food storage; containers, or refurbished wood
pallets are examples of source reduction.
Generation refers to the amount (weight or volume) of materials and products that enter the
waste stream before recycling, composting, landfillihg, or combustion takes place.
Recovery of materials means removing MSW from the waste stream for the purpose of:
recycling or composting. Recovery for recycling as defined for this report includes purchases
of postconsumer recovered materials plus net exports of the materials. Recovery of yard
trimmings includes diverting yard trimmings from disposal to a composting facility. For
some materials, recovery for uses such as highway construction or insulation is considered
recovery along with materials used in remanufacturing processes.
Combustion includes combustion of mixed MSW, fuel prepared from MSW, or a separated
component of MSW (such as rubber tires), with or without energy recovery.
Discards include the municipal solid waste remaining after recycling and: composting.. These
discards are usually combusted or disposed of in landfills, although some MSW is littered,
stored, or disposed on site, particularly in rural areas:
Methodology. There are two primary methods for conducting a waste characterization
study. The first is a source-specific approach in which the individual components of the
waste stream are sampled, sorted, and weighed. Although this method is usefuLf or
defining a local waste stream, extrapolating from a limited number of studies can, produce a
skewed or misleading picture if used for a nationwide characterization of waste. Atypical
circumstances encountered during sampling or errors in the sample would be greatly
magnified when expanded to represent the nation's entire waste stream. The second'
method, which is used in this report, 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.
Note that when the report is updated, there are numerical discrepancies in waste
generation, recovery, and discards from previous editions. These differences are due to
revised estimates from source data (e.g., industry associations and federal agencies) made
to the MSW characterization database.
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MUNICIPAL SOLID WASTE IN 1994
Materials in MSW
In 1994, MSW generation totaled 209 million tons. Figure ES-1 provides a
breakdown by weight of the materials generated in 1994. Paper and paperboard
products made up the largest component of MSW generated (39 percent), and
yard trimmings were the second largest component (15 percent). Glass, metals,
plastics, wood, and food scraps each constituted between 6 and 10 percent of the
total MSW generated. Other materials in MSW, such as rubber, leather, textiles,
and miscellaneous wastes, made up approximately 9 percent of the MSW
generated in 1994.
Figure ES-1. Materials generated in MSW by weight, 1994
(Total weight = 209.1 million tons)
Glass 6.3%
13.3 million tons
Paper & paperboard 38.9%
81.3 million tons
Metals 7.6%
15.8 million tons
Plastics 9.5%
19.8 million tons
Wood 7.0%
14.6 million tons
Yard trimmings 14.6%
30.6 million tons
Food 6.7%
14.1 million tons
Other 9.4%
19.6 million tons
In 1994, a portion of most materials in MSW were recycled or composted,
as illustrated in Table ES-1. Each material category (except for food scraps and
yard trimmings) is made up of many different products. Because some of these '
products are not recovered at all, the overall recovery rate for any particular
material may be lower than recovery rates for some products within the material
category.
Nonferrous metals (other than aluminum) have the highest recovery rate
(66 percent), due to high rates of lead recovery from lead-acid batteries.
Approximately 38 percent of aluminum is recovered, even though aluminum
cans are recovered at rates a.bove 65 percent. Likewise, the overall recovery rate
for paper and paperboard is 35 percent, even though corrugated containers are
recovered at rates above 55 percent.
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Table ES-1
GENERATION AND RECOVERY OF MATERIALS IN MSW, 1994
(In millions of tons and percent of generation of each material)
Paper and paperboard
Glass
Metals
Ferrous metals
Aluminum
Other nonferrous metals
Total metals
Plastics
Rubber and Leather
Textiles
Wood
Other materials
Total Materials in Products
Other Wastes
Food Wastes
Yard Trimmings
Miscellaneous Inorganic Wastes
Total Other Wastes
TOTAL MUNICIPAL SOLID WASTE
Weight
Generated
81.3
13.3
11.5
3.1
1.2
,15.8
19.8
6.4
6.6
14.6
3.6
161.3
14.1
30.6
3.1
47.8
209.1
Weight
Recovered
28.7
3.1
3.7
1.2
0.8
5.7
0.9
0.5
0.8
1.4
0.8
41.8
0.5
7.0
Neg.
7.5
49.3
Recovery
as a Percent
of Generation
35.3%
23.4%
32.3%
37.6%
66.1%
35.9%
4.7%
7.1%
11.7%
9.8%
20.9%
25.9%
3.4%
22.9%
Neg.
15.7%
23.6%
Includes wastes from residential, commercial, and institutional sources.
Neg. = Less than 50,000 tons or 0.05 percent.
Numbers in this table have been rounded to the first decimal place.
Products in MSW
The products in MSW are grouped into three main categories: 1) durable
goods (e.g., appliances); 2) nondurable goods (e.g., newspapers); and 3) containers
and packaging (Figure ES-2). These product categories generally contain each type
of MSW material, with some exceptions. The durable goods category contains no
paper and paperboard. The nondurable goods category includes only small
amounts of metals and essentially no glass or wood. The containers and
packaging category includes only very small amounts of rubber, leather, and
textiles.
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Figure ES-2. Products generated in MSW by weight, 1994
(Total weight = 209.1 million tons)
Nondurable goods 27.0%
56.4 million tons
Durable goods 14.3%
29.9 million tons
Containers & packaging 35.9%
75.0 million tons
Food, other 8.2%
17.2 million tons
Yard trimmings 14.6%
30.6 million tons
Table ES-2 shows the generation and recovery of the product categories in
MSW, broken down by materials within each category. Overall, the materials in
durable goods were recovered at a rate of approximately 15 percent in 1994. A
large portion of non-ferrous metals were recovered from lead-acid batteries.
Considerable amounts of ferrous metals were recovered from appliances in the
durables category, and some rubber was recovered from tires.
Overall recovery in the nondurable goods category was approximately 22
percent in 1994. In this category, large amounts of newspapers, office papers, and
some other paper products were recovered.
Recovery from the containers and packaging category is the highest of
these categories34 percent of generation. More than 55 percent of aluminum
packaging was recovered in 1994 (mostly aluminum beverage cans), while more
than 51 percent of steel packaging (mostly cans) was recovered. Paper and
paperboard packaging recovery was estimated at 45 percent, with corrugated
containers accounting for most of that tonnage. Approximately 26 percent of
glass containers were recovered overall, while about 14 percent of wood
packaging (mostly pallets) was recovered. About 8 percent of plastic containers
and packaging was recovered in 1994, most of which was made up of soft drink,
milk, and water bottles. .
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Table ES-2
GENERATION AND RECOVERY OF PRODUCTS IN MSW
BY MATERIAL, 1994
(In millions of tons and percent of generation of each product)
Durable goods
Ferrous metals
Aluminum
Other non-ferrous metals
Total metals
Glass
Plastics
Rubber and leather
Wood
Textiles
Other materials
Total durable goods
Nondurable goods
Paper and paperboard
Plastics
Rubber and leather
Textiles
Other materials
Total nondurable goods
Containers and packaging
Steel
Aluminum
Total metals
Glass
Paper and paperboard
Plastics
Wood
Other materials
Total containers and packaging
Other wastes
Food wastes
Yard trimmings
Miscellaneous inorganic wastes
Total other wastes
TOTAL MUNICIPAL SOLID WASTE
Weight
Generated
8.4
0.8
1.2
10.4
1.2
5.6
5.1
4.4
2.3
1.0
29.9
43.5
4.7
1.3
4.2
2.8
56.4
3.1
2.1
5.2
12.1
37.8
9.5
10.2
0.2
75.0
14.1
30.6
3.1
47.8
209.1
Weight
Recovered
2.1
Neg.
0.8
2.9
Neg.
0.2
0.5
Neg.
0.1
0.8
4.4
11.6 .
Neg.
Neg.
0.7
Neg.
12.3
1.6
1.2
2.8
3.1
17.1
0.7
1.4
Neg.
25.1.
0.5
7.0
Neg.
7.5
49.3
Recovery
as a Percent
of Generation
25.2%
Neg.
66.1%
28.0%
Neg.
3.6%
8.9%
Neg.
4.4%
74.3%
14.8%
26.8%
<1%
Neg.
16.4%
Neg. '
21.9%
51.4%
55.0%
52.9%
25.8%
45.2%
7.5%
14.0%
Neg.
33.5%
3.4%
22.9%
Neg.
-- 15.7%
23.6%
Includes wastes from residential, commercial, and institutional sources.
Neg. = less than 50,000 tons or 0.05 percent.
Numbers in this table have been rounded to the first decimal place.
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Management of MSW
Figure ES-3 shows how much MSW was recycled, composted, combusted,
and, land-filled in 1994. Approximately 49: million1 tons, or 24 percent of MSW,
was recycled and composted; an estimated 32 million tons, or. 15 percent, was
combusted (nearly all with energy recovery);, and the remainder, 127 million tons
(61 percent), was landfilled (small amounts may have been littered or self-
disposed).
Figure ES-3. Management of MSW in, U.S., 1994
(Total weight, = 209P.1:. million tons)
Landfill, other, 60.9%
127.3 million tons
Recovery for recycling
and composting, 23.6%
49.3 million tons.
Combustion, 15:5%
32.5 million tons
Recovery rates have increased steadily since the 1980s. After remaining
constant at 9 to 10 percent in the early to mid-1980s, people; nationwide began
realizing that new approaches to solid waste management were needed.
Recycling and composting rates increased from 13 percent in 1988 to 17 percent in
1990 to 24 percent in 19,94 (Figure ES-4). For the year 2000, three recovery
scenarios ranging from 25 percent to 35 percent are presented. The range for the
year 2010 is 30 percent to 40 percent. Achieving a 40 percent recovery rate
nationwide would require recovery rates in the range of 50 percent for many -
material categories in MSW, including paper and paperboard^ yard trimmings,
metals, and glass.
Residential and Commercial Sources of MSW
Sources of MSW, as characterized in this report/ include both residential
and commercial locations (commercial locations include schools, some
industrial sites where packaging is generated, and businesses). Identifying sources
where MSW is generated is important to developing management techniques,
such as collection for disposal, recycling, or composting. Residential wastes
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1980
Figure ES-4. Recovery for recycling and composting, 1980 tc 2010
(in percent of total MSW generation)
Historical recovery rate
Projected recovery rate
1994 recovery = 24%
2000 recovery = 30% scenario
2010 recovery = 35% scenario
1985
1990
1995
2000
2005
2010
(including wastes from multi-family dwellings) are estimated to be 55 to 65
percent of total generation. Commercial wastes constitute between 35 and 45
percent. Local and regional factors such as climate and level of commercial
activity contribute to these variations.
TRENDS IN MSW GENERATION AND MANAGEMENT
Generation of MSW has grown steadily from 88 million tons in 1960 to
209 million tons in 1994. The total amount of MSW generated is projected to be
223 million tons in 2000 and 262 million tons in 2010. Per capita generation of
MSW increased from 2.7 pounds per person per day in 1960 to 4.4 pounds per
person per day in 1994. This rate is expected to remain constant through the year
2000 based in large part on a projected decrease in the tonnage of yard trimmings
entering the MSW management system, along with an increase in generation of
consumer products and packaging. After 2000, the amount of yard trimmings
diverted from disposal is expected to plateau. Achieving a decline in overall
waste generation after 2000 hinges on continued emphasis on source reduction
of all MSW.
Source Reduction activities include the design, manufacture, purchase, or
use of materials (such as products and packaging) to reduce the amount or
toxicity of materials before they enter the MSW management system. Source
reduction activities include:
Designing products or packaging to reduce the quantity of materials or
the toxicity of the materials used.
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Reusing products or packaging already manufactured.
Lengthening the life of products to postpone disposal.
Managing non-product organic wastes (e.g., food scraps and yard
trimmings) through on-site composting or other alternatives to
disposal.
While most source reduction activities were not quantified in this report,
calculations show that yard trimmings generation could be reduced significantly
if current and planned state and local programs to reduce their disposal are
implemented. While recycling and composting programs are continuing to
decrease the amount of MSW that is disposed of, source reduction can help
decrease MSW discards even more, by preventing waste before it is even
generated.
Recovery (recycling and composting) has increased from approximately
seven percent of MSW in 1960 to 24 percent by 1994. Much of the growth has
occurred over the past five or six years. Projected scenarios for recovery are
between 25 and 35 percent in 2000, and 30 to 40 percent in 2010. To achieve these
recovery rates, some products will have to be recovered at rates of 50 percent or
more. In addition, composting of yard trimmings will have to increase
substantially.
For this report, EPA examined a range of recovery scenarios from 25,
percent to 35 percent nationwide for the year 2000. For the year 2010, EPA
examined recovery scenarios ranging from 30 percent to 40 percent. A mid-range
projected scenario of 30 percent in the year 2000 and 35 percent in 2010 was used
to illustrate the effects of recovery on future MSW management. To achieve this
level of recovery, EPA assumed that local, state, and federal agencies would
continue to emphasize recycling and composting as a priority; that industries
would continue to make the necessary investments in recovery and utilization
of materials; that state and local governments would continue to expand
programs designed to keep yard trimmings out of landfills; and that most U.S.
citizens would have access to some sort of recovery program and that they would
be willing to participate.
Combustion facilities handled an estimated 30 percent of MSW generated
in 1960, mostly through incinerators with no energy recovery and no air
pollution controls. In the 1960s and 1970s, combustion dropped steadily as old
incinerators were closed, reaching a low of less than 10 percent by 1980. In 1990^
approximately 16 percent of MSW was combusted. Between 1990 and 1994,
combustion remained between 15 and 16 percent. All major new facilities have
energy recovery and are designed to meet air pollution standards.
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This report projects that tonnage of MSW combusted will remain
relatively unchanged, particularly in terms of percentage of total MSW
generation. By the year 2000, the tonnage is expected to increase from about 32
million tons (or 15 percent of total MSW generation) in 1994 to 34 million tons
(15 percent of projected 2000 total MSW generation). For 2010, the tonnage of
MSW combusted is projected to be 38 million tons (or 14 percent of projected
2010 total MSW generation). Combustion projections are based on an
assumption that the current number of facilities will remain the same and that
they will operate at around 85 percent of capacity. The projected tonnage increase
in combustion is primarily due to an expected rise in the combustion of source-
separated materials (e.g., wood and tires).
Landfill use fluctuates with changes in the use of alternative solid waste
management methods. For example, when the use of combustion for MSW
management declined and recovery rates were low, the amount of waste sent to
landfills increased (Figure ES-5). Alternatively, when recovery and combustion
of MSW increased, the percentage of MSW discarded in landfills declined. In
I960, approximately 62 percent of MSW was sent to landfills. This increased to 81
percent by 1980 as incineration declined, then decreased to an estimated 61
percent by 1994 due to moderate increases in incineration and dramatic increases
in recovery.
Landfill tonnage is expected to decrease from 127 million tons (61 percent
of generation) in 1994 to 122 million tons in 2000 (55 percent of generation).
Significant diversion of yard trimmings from landfills is the primary reason for
Figure ES-5. Municipal solid waste management, 1960 to 2010
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010
* Recovery scenarios of 30% in 2000 and 35% in 2010 used in this figure. Other scenarios are presented in the report.
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this projection. The amount of waste disposed of in landfills is expected to
increase in tonnage to 132 million tons by 2010, as diversion of yard trimmings
from landfills plateaus and discards from products and packaging increases.
However, as a percentage of total MSW generated, discards to landfills are
projected to decline to 51 percent by 2010 due to increases in recovery.
ADDITIONAL PERSPECTIVES ON MSW
Global Climate Change
. The manufacture and distribution of products and the subsequent
management of solid waste ca;n contribute to the formation of excess
"greenhouse gases." Carbon dioxide, methane, and other gases form an
atmospheric blanket around the planet's surface. These gases regulate the earth's
temperature by trapping some; of the sun's heat. This natural process is
commonly referred to as the "greenhouse effect."
Human activitiesin particular, the burning of fossil fuels (e.g., coal, oil,
and wood)and other factors appear to have increased the amount of
greenhouse gases in the atmossphere. A buildup of these gases could raise global
temperatures, setting off profound changes in the earth's climate and ecosystems,
known as "global climate change." There is growing consensus that global
climate change is occurring and will cause serious environmental dislocations.
Greenhouse gas emissions can be generated throughout the life cycle of a
product, from its manufacture! to its disposal. Source reduction and recycling
activities can help reduce greenhouse gases because they 1) reduce the need to
harvest or extract new raw materials; 2) eliminate the need to manufacture new
products; 3) reduce the amount of energy required in manufacturing (through
the use of recycled rather than virgin materials); and 4) prevent or divert waste
from disposal (greenhouse gas emissions can be released when materials
decompose in landfills or burn in combustors). Source reduction and recycling
initiatives, as outlined in President Clinton's 1993 Climate Change Action Plan,
will make a significant contribution to reducing greenhouse gas emissions.
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