EPA-670/2-75-058
June 1975 Environmental Protection Technology Series
ENVIRONMENTAL ASSESSMENT OF
FUTURE DISPOSAL METHODS FOR
PLASTICS IN MUNICIPAL SOLID WASTE
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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EPA-670/2-75-058
June 1975
ENVIRONMENTAL ASSESSMENT OF FUTURE DISPOSAL METHODS FOR
PLASTICS IN MUNICIPAL SOLID WASTE
By
D. A. Vaughan, C. Ifeadi,
R. A. Markle, and H. H. Krause
Battelle
Columbus Laboratories
Columbus, Ohio 43201
Grant No. R803111-01-1
Program Element No. 1DB314
Project Officer
Donald A. Oberacker
Solid and Hazardous Waste Research Laboratory
National Environmental Research Center
Cincinnati, Ohio 45268
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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REVIEW NOTICE
The National Environmental Research Center—Cincinnati
has reviewed this report and approved its publication.
Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental
Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation
for use.
11
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FOREWORD
Man and his environment must be protected from the
adverse effects of pesticides, radiation, noise and other
forms of pollution, and the unwise management of solid
waste. Efforts to protect the environment require a focus
that recognizes the interplay between the components of our
physical environment—air, water, and land. The National
Environmental Research Centers provide this multidisciplinary
focus through programs engaged in
° studies on the effects of environmental contaminants
on man and the biosphere, and
o a search for ways to prevent contamination and to
recycle valuable resources.
Among these many areas of concern are plastics and
the disposal procedures used for the increasing plastic-
containing products in the nation's solid waste streams.
Plastics not only behave differently in the various waste
disposal processes, but they can potentially add new problems
as a result of the additives they contain. As with any chang-
ing situation, the best procedure is to try to understand the
problem by keeping as well informed as possible. This study
evaluates the potential impacts, both desirable and undesirable,
of increasing amounts of plastics in the years ahead.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
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ABSTRACT
The environmental impact of plastics in solid waste in the United
States up to the year 2000 has been assessed. The total solid waste
that will be collected from a predicted population of 297 million has
been estimated to be 222 million tons per year by the year 2000,
based on a waste-generation rate of 4. 5 pounds per person per day.
Production of plastics for engineering and consumer items in the
United States has been predicted to reach 113 million tons per year
by the year 2000. This figure does not include the production of
polymer used for synthetic fiber or fabric. Production of these ma-
terials normally is considered separately, as is the waste problem
associated with their disposal. From 31 to 38 million tons of the
plastic produced is expected to reach the solid waste stream, depend-
ing on the basis of estimation. The largest amount will go to sanitary
landfills, and the next largest amount will be thermally treated using
such methods as power generation, heat recovery, incineration, and
pyrolysis. Relatively small amounts of plastic are expected to be
disposed of in open dumps or as litter. No resource recovery is
predicted for plastics in municipal refuse up to the year 2000.
The land-area requirement for plastics is predicted to be 20 percent
of sanitary landfills and 3 percent of open dumps in the year 2000.
Air pollution as a result of plastics in the landfills and open dumps
will be negligible, even if there is still some burning of open dumps
in 2000. The contribution of plastics to water pollution also will be
negligible, and by introducing aerobic conditions, plastics may lower
the BOD of the leachate.
Thermal treatment of plastics will result in some emissions of carbon
monoxide, particulates, and hydrocarbons, but these are expected
to be only a small fraction of the total U. S. emissions of these ma-
terials from other sources. Hydrogen chloride from disposal of
IV
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plastics by thermal treatment is predicted to amount to 380, 000 tons
per year by the year 2000, but this will constitute a minor portion of
the total air pollutants in the U. S., which will still be measured in
millions of tons.
The difficulty of sorting and processing plastics of different types in
municipal refuse is expected to make recycling of plastics negligible
up'to the year 2000. Plastic is predicted to be a large fraction of
the litter up to the year 2000, but as a result of education of the
public and the introduction of degradable plastics, it is expected to
constitute only about 15 percent of the litter at that time.
v
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Page
Abstract iv
List of Figures viii
List of Tables ix
Acknowledgments xi
Sections
I Conclusions 1
II Recommendations 5
III Introduction 7
IV Analytical Program 9
Quantitative Analysis of Total Solid Waste 9
Quantitative Analysis of Plastics Production ... 10
Analysis of Developments in the Solid-Waste
Disposal Technology 24
Developments in the Throw-Away Methods
of Solid-Waste Disposal 24
Developments in Thermal Treatment of
Solid Wastes 31
Developments in Resource Recovery 33
Projections of Solid-Waste Disposal by
Various Methods 37
Estimates for Land Disposal (Throw-Away) ... 39
V Environmental Impacts of Plastics Disposal 45
Land Disposal of Plastic Wastes 46
Water-Pollution Effects 46
VI
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CONTENTS
(Continued)
Page
Air-Pollution Effects 51
Land-Pollution Effects 54
Ecological Effects 58
Aesthetic and Human-Factors Effects 59
Impact of Resource Recovery 62
Air-Pollution Impact of Thermal Treatment .... 63
Carbon Monoxide Emissions From Plastics ... 64
Particulate Emissions From Plastics 66
Hydrocarbon Emissions From Plastics .... 66
HC1 Emissions From Plastics 66
Nitrogen Oxide Emissions From Plastics .... 68
Other Emissions From Plastics 68
VI References 69
VII
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FIGURES
No. Page
1 Plastics Production Projections to the Year 2000 ... 20
2 Projected Plastics Waste to the Year 2000 21
3 Projected Plastics Waste to the Year 2000 Based on a
29 Percent Discard Rate of Minirmim-to-Maximum
Production 22
4 Projected Plastics Waste to the Year 2000 Based on
a 22 Percent Discard Rate of Minimum-to Maximum
Production . . 23
5 Projection of Waste Disposed by Various Disposal
Systems, as Developed in This Program 38
via.1
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TABLES
No. Pace
1 Forecast of Population and Amount of Solid Waste to
the Year 2000 11
2 1973 Plastics Production by Plastic Type and
Waste Volume 16
3 Annual Plastic Total Production (SPI Data) 16
4 Plastic Waste Volume Based on Life Expectancies
of End-Use Categories 17
5 Future Market and Waste by Plastic Type 17
6 Projected Plastic Production and Waste 19
7 Composition of Litter 25
8 Distribution of Refuse Incinerators by Type
and Number 42
9 Forecast of Annual Distribution of Solid Waste
Generated by Disposal Method to the Year 2000 in
Amounts (10& Tons), Percentage of Total, and
Percentage of Plastic in Disposal Category 44
10 Characteristics of Leachate From Sanitary Landfills . 50
11 Air-Contaminant Emissions by Plastics During
Open Burning of Refuse 53
12 Classification of Waste Acceptable for Disposal
at Disposal Sites 55
13 Open-Dump and Sanitary-Landfill Land Require-
ment in Acres . 57
IX
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TABLES
(Continued)
No. Page
14 Emissions From Controlled Combustion of Plastics
in Solid Waste 65
15 Projected HC1 Emissions From Controlled Combustion
of Polyvinyl Chloride (PVC) 67
x
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ACKNOWLEDGMENTS
The assistance of Mr. Donald Oberacker of the Solid and Hazardous
Waste Research Division of the National Environmental Research
Center, Cincinnati, Ohio in collecting data for this analysis is grate-
fully acknowledged. The help of Mr. Howard Kibbel of the Society of
the Plastics Industry in providing data was important to this study.
Discussions with Mr. Truett DeGeare, Mr. Stephen Lingle, and
Mr. Robert Lowe of the Office of Solid Waste Management Programs,
Washington, D.C. also were of assistance. Mr. Norman Broadway
of Battelle's Columbus Laboratories assisted in the analysis of the
data.
XI
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SECTION I
CONCLUSIONS
An assessment has been made of the environmental impact of plastics
in solid waste in terms of future disposal methods up to the year 2000.
Population growth as projected by the U. S. Bureau of Census indicates
a total U. S. population of 297 million by that time. The urban and
rural populace of about 285 million have been considered to be the
chief contributors to collectable solid waste. The amount of solid
waste generated per capita is predicted by this study to decrease from
today's 5 pounds per person per day to 4. 5 pounds by the year 2000.
This decrease will be the result of material and energy conservation,
recycling, and education of the public. At the same time, the per-
centage of the waste generated that will be collected for municipal
disposal will increase from the current 75 percent to 95 percent by the
year 2000. The net result of these two factors is predicted to be an
increase in the total solid waste collected from 139 million tons in
1975 to 222 million tons in the year 2000.
A projection of growth in the U. S, plastics industry indicates that
annual production will increase from about 13.3 million tons in 1973
to 113 million tons by 2000 A. D. The latter value represents a median
between an estimated maximum of 144 million tons and a minimum of
85 million tons. The rate at which these plastics will enter the solid-
waste stream was estimated using the "useful life concept". This
approach involves an evaluation of the num.ber of years that will pass
before a plastic item is discarded. Hence the useful life may' vary from
1 year for a packaging use to 50 years for use in building and construc-
tion. On this basis it was estimated that the amount of plastic waste
will increase from a 1973 value of 3.4 million to 30. 7 million tons per
year by the year 2000. Another approach to this estimate, based on
production by types of plastic, leads to a value of 37. 9 million tons
per year of plastic waste by 2000. As a result of resource .recovery
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and recycling efforts, the projection indicates that the percent of
plastic in the solid waste will increase from about 2. 8 percent in
1975 to 13.4 percent by 2000, The amount of plastic waste collected
for disposal is expected to undergo a similar increase from 3. 9 mil-
lion tons in 1975 to 29, 7 million tons by the year 2000.
In terms of waste-disposal technology, increasing amounts of the solid
waste are expected to go to sanitary landfills, to be treated thermally,
or to be processed in resource-recovery handling. At the same time
the amount of waste going to open dumps and being discarded as Utter
will decrease.
These trends will be reflected in the plastics portion of the solid
waste, which should follow the same pattern, except that resource
recovery is not likely to apply to plastics up to the year 2000. The
plastic waste predicted by the two approaches is averaged in the
following tabulation:
Plastics Waste,
millions of tons
Disposal Method 1975 2000
Open dumping 4.1 3.6
Sanitary landfill 0.84 17.8
Thermal treatment 0. 55 12. 5
Resource recovery 0 0
Litter 0.35 0.05
The environmental impact of the plastics in solid waste differs accord-
ing to the method of disposal. For disposal in open dumps and sani-
tary landfills the volumetric contribution of the plastic waste is more
important than its weight. Although the number of open dumps is ex-
pected to decrease significantly by the year 2000, the increasing
percentage of plastic in the solid waste will increase the land require-
ment that can be attributed to plastics. However, even by the year
2000, plastic waste will probably require only about 3 percent of the
land area devoted to open dumping.
The increase in sanitary landfill disposal of all waste means a similar
increase in the total amount of plastics disposed by this method, as
shown above. The land requirement for the plastics portion is expected
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to increase about twenty-fold between 1975 and 2000. This contribu-
tion of plastics will constitute about 20 percent of the land require-
ment for the sanitary landfills in the year 2000.
The fact that plastics degrade very slowly means that they will have.
a long lifetime in both open dumps and sanitary landfills. The
presence of plastics in these areas will not contribute to the leachate
in any significant amount, but the plastics may tend to prolong aerobic
conditions where they do not compact effectively. These conditions
may result in lowered BOD level.
The burning of refuse in open dumps is expected to be practically
eliminated by the year 2000. Consequently, the air pollution resulting
from the burning of plastics in the open dumps is predicted to be only
about 5, 000 tons in total, of which the major portion will be carbon
monoxide and hydrogen chloride. Minor amounts of metal compounds
also may be emitted.
The thermal treatment of solid waste by ordinary incineration is
expected to decrease, while heat recovery and power generation from
burning of the refuse will increase. The development of pyrolysis
methods should be sufficient by the year 2000 to make this method
important in the total. A comparison of the anticipated distribution of
solid wastes in these disposal methods for 1975 and for 2000 is given
below:
Solid Waste,
millions of tons
Disposal Method 1975 2000
Incineration 12.5 0.5
Heat recovery 6.0 24.0
Power generation Negligible 32.0
Pyrolysis Negligible 6.0
The air-pollutant emissions resulting from these controlled com-
bustion processes applied to solid waste will increase as larger amounts
are consumed. The contribution of plastics to these emissions also
will increase, but it will still constitute only a small fraction of the
total U. S. emissions of carbon monoxide, particulates, and
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hydrocarbons. With respect to HC1, thermal treatment of plastics is
expected to produce some 380, 000 tons of this gas by 2000. This
amount will still be small compared to other forms of air pollution,
but the acidic nature of this gas may necessitate control in the form
of water scrubbers.
Resource recovery in general as applied to components of solid waste
such as paper, metals, and glass is predicted to increase very sub-
stantially, from 2.2 to 65.2 million tons by 2000, but plastics are not
expected to be involved. The difficulty of sorting and processing dif-
ferent types of plastics for recycling from municipal refuse is ex-
pected to make this type of resource recovery negligible, even to the
year 2000.
The amount of litter is predicted to decrease from 4. 3 million tons in
1975 to 300, 000 tons by 2000, at which time it will constitute only
about 0. 1 percent of the total solid waste. However, a large fraction
of the litter usually is plastic, because of its predominance in pack-
aging materials. Introduction of photodegradable plastics for
packaging will reduce the impact of plastics in litter because its de-
composition will be enhanced.
Aesthetic, human, and economic factors as applied to the plastics in
solid waste are considered to be in proportion to their percentage in
the waste disposed by litter, open dumping, and sanitary landfill.
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SECTION II
RECOMMENDATIONS
As a result of this analysis of the future environmental impact of
plastics it is recommended that the situation be reevaluated in 1980
to compare the actual circumstances with the forecast, and to make
any necessary revisions. These forecasts necessarily have increas-
ing amounts of possible error as the time interval becomes greater,
and reevaluation will be important in about 5 years.
The rate of refuse generation and the plastics production from 1975 to
1980 should be compared with what has been predicted for that period,
so the extrapolation to the year 2000 can be either confirmed or cor-
rected. The progress of resource recovery by 1980 and the use of the
newer disposal methods such as power generation and pyrolysis should
be evaluated at that time.
During the interim period (from 1975 to 1980), adequate data collec-
tion should be made to insure more accurate prediction of future
trends than was possible for this analysis. The changes in plastic
content of solid waste should be followed to determine whether the
forecasts are being borne out in practice. The impact of the educa-
tional and legislative programs on the solid-waste stream should be
considered during this interim period. This aspect would be particu-
larly important for the litter problem, where the forecast has been
based on a successful outcome of these approaches in reducing litter,
together with the introduction of photodegradable plastics. Considera-
tion also should be given to the promotion of resource recovery by
separation of plastics in refuse at the homeowner source to encourage
recycling. This method has not been considered feasible up to the
year 2000, but it is possible that by 1980 an educational and economic
incentive program may offer more promise for recycling the plastics
now being collected in municipal refuse. The data acquisition should
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also include the air-pollution emissions from the newer incinerators
which incorporate steam generation, and from the combined firing of
refuse and fossil fuels. These data will be needed to verify the pre-
dicted trends toward increased impact of plastics as their concentra-
tion in refuse increases and emissions from other sources are
reduced.
Another area which needs to be investigated is the effect of additives
to plastics on waste and on the methods of handling waste. Although
for this study, the amount of these additives (heat and light stabilizers,
colorants, flame-retardants, and biodegradable and photodegradable
agents) was considered as being negligible, the effects could become
important in the future. For example, on incineration or pyrolysis,
smoke or corrosive gases such as HC1 and HBr may be formed. In
some plastics, the additive consists of compounds based on heavy
metals, and their release could become sufficient to cause local pollu-
tion problems. These pollution possibilities are just beginning to be
explored. The by-products formed under the various waste-handling
methods are not fully known. An investigation is needed in this area
to determine the potential contribution of additives to the pollution
problem.
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SECTION III
INTRODUCTION
Although plastics account for a small (2-5) percentage of the present
solid-waste stream, a large (40-50) percentage of the total plastic
production becomes a waste product. With an anticipated growth of
10 percent per year in plastics production and the continued increase
of the portion that enters the solid-waste stream plus the possible
reduction in other components in solid waste through recycling and
resource recovery, the relative amount of plastic in refuse could
become much larger. Hence, it is important to evaluate the environ-
mental impact of plastic-refuse disposal by present-day methods and
anticipated developments in solid-waste-disposal technology.
During the past 5 years, the United States has modified its concern
with regard to the treatment of solid waste from methods of disposal
to.methods of conserving natural resources (land, air, water, raw
material, and energy)r This concern has enhanced the development of
solid-waste technology which can be expected to alter significantly the
distribution of"solid waste into various disposal systems. Ultimately,
only small percentages of what is now considered to be solid waste will
be disposed of without further recovery of energy or material. In ac-
complishing this ultimate objective, it is important that the processes
required for each component of the solid-waste stream be evaluated in
terms of their contribution to the overall environment and to the con-
servation of resources. Thus, an analysis of the rapid growth in the
plastics industry versus developments in solid-waste-treatment tech-
nology has been made to assess the environmental impact of this .
component of the solid-waste stream over an extended period of time.
The solid wastes considered in this analysis were those generated by
households and commercial establishments, since much of the
industrial-type wastes are sufficiently segregated to be economically
recycled, reprocessed, or otherwise disposed of by the industry in
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an environmentally acceptable or regulated manner. The volume and
mixture of components in household and commercial waste has been
of much concern to the waste-disposal technologists.
To provide a basis for comparison of the environmental impact of
plastic wastes, the magnitude of the plastic component in the total
municipal solid-waste stream was analyzed and projections of these
data to the year 2000 were forecasted as was the distribution of waste
into various disposal systems.
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SECTION IV
ANALYTICAL PROGRAM
The analytical program consisted of three tasks:
A. Quantitative Analysis of the Total and Plastic Component of Solid
Waste
B. Analysis of Developments in Waste Disposal Technologies
C. Analysis of Environmental Impact of Plastic Waste for Various
Disposal Methods.
QUANTITATIVE ANALYSIS OF TOTAL SOLID WASTE
The method selected to estimate the total amount of solid waste is based
upon projected population growth1 over the period of interest (1974-2000)
and changes in the per capita rate of waste generation as discussed
here. A number of factors (such as economical, political, social,
educational, legislative, medical, and promotional influences) can
significantly alter the forecast so that its reliability decreases as the
time interval increases. It would be reasonable to expect an increase
of 1 percent per year in the uncertainty of any forecasted data; that
is, a reliability of ±10 percent in current 1974 population or waste
generation could be expected to increase to ±36 percent of the respec-
tive numbers by the year 2000. Although the reliabilities are not
shown in the tables or in the following discussion, it is important to
recognize that the magnitude of the uncertainty increases with-time
for the numerical data given in the projected forecast.
Our analysis of the total amount of solid waste and the magnitude of
the plastic components is presented in Table 1. The data for total
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solid waste are divided into that generated by the entire U.S. popula-
tion and that generated by the municipal plus rural portion, of which
the latter is most likely to be collectable for common disposal treat-
ments developed in the foreseeable future. Although the population
growth, by categories, has been forecasted by the U.S. Bureau of
Census, the amount of refuse generated per person is a matter of
considerable uncertainty. A linear extrapolation of the amounts col-
lected in various sections of the U.S. for the years 1960-1970 would
indicate an amount approximating 9 Ib per capita per day by the year
2000.2 This amount is believed to be excessively high as a result of
the rapid increase in collection facilities over the 1960-1970 time
period rather than a large increase in the amount of solid waste gen-
erated. Therefore, our analysis assumes a constant generation rate
for 1970 and 1975. The emphasis on conservation of materials, re-
cycling of specific products and materials, plus government regulations,
energy conservation, and public opinion will result in a slight decrease
(0. 1 Ib/capita/day for each successive 5-year period) in the amount
of solid waste generated after 1975. However, the percentage of
solid waste collected for the municipal plus rural population is expected
to continue to increase at a rate of 1 percent per year until 90 or 95
percent is collected. Based upon these parameters, the total annual
amount of solid waste generated is expected to increase from 187 x
106 tons in 1970 to 244 x 106 tons by the year 2000. with the collected
amount increasing from 125 x 10& tons to 222 x 10° tons over the same
period.
QUANTITATIVE ANALYSIS OF PLASTICS PRODUCTION
A projection of growth in the United States plastics industry is required
for an analysis of the future contribution of plastic materials to solid
waste. The analysis covers a 20-year period; hence, projected
plastics consumption to the year 1994 is needed. To obtain the neces-
sary data, a literature search and a telephone survey were conducted.
The prime literature information source used was Predicasts^, a
quarterly abstract service which provides complete coverage of all
published data relating to materials produced or consumed in the
United States. The section of this publication listing data on polymers
(plastics, rubbers, and fibers) was carefully reviewed. The period
10
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TABLE 1. FORECAST OF POPULATION AND AMOUNT OF
SOLID WASTE TO THE YEAR 2000
Population
Total x 106
Farm x 106(a)
Urban x 106
Rural x 106
Solid Waste Generated
Pounds / Capita/ Da y*a)
Total - 106 tons/year
Municipal + Rural - 10 tons/year
Solid Waste Collected
Percent of Municipal and Rural
Amount - 10 tons /year
Plastic Wastes
Total Amount - 10 tons/year
Percent of Total Solid Waste
Amount Collected - 10 tons /year
1970
205
9.8
143.5
51.7
5
187
178
70
125
4.3
2.3
2.9
1975
217
10. 0
161.6
45.4
5
198
185
75
139
5.6
2.8
3.9
1980
232
10.3
179.' 7
42. 0
4.9
207
198
80
159
7.8
3.8
6. 0
1985
249
10.7
197. 7
40.6
4.8
218
209
85
177
12.3
5.6
9.9
1990
265
11. 0
215.8
38.2
4.7
227
218
90
196
17.8
7.8
15.3
1995
280
11.5
233.9
34.6
4.6
235
225
95
214
24.5
10.4
22.3
2000
297
11.
252.
33.
4.
244
234
95
222
32.
13.
29.
9
0
1
5
8
4
7
(a) See text for justification of estimates.
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covered included the second quarter of 1972 through the first quarter
of 1974, the most recent quarterly issue available at the time of the
search. The published items containing data judged pertinent to this
study were then collected. A review of these items was conducted and
the principal journals in which pertinent data most often appeared
were then surveyed issue by issue from the last date covered in Predi-
casts to the present. Journals surveyed in this fashion included
Modern Plastics, Plastics World, The Chemical Market Reporter,
Chemical Week, Chemical and Engineering News, Modern Packaging,
Rubber World, Rubber Agg, and Automotive News.
In addition to this literature search, a telephone survey was conducted.
The Society of the Plastics Industry (SPI), the Manufacturing Chemists
Association (MCA), Predicasts, Inc. , and the editorial offices of
Plastics World and Modern Plastics magazines were contacted. The
phone calls were made to request any unpublished information that
might be available as well as to identify any significant reports or data
sources not previously found. Accurate 1973 plastics production fig-
ures (plastic type) were obtained from the SPI and production figures
(end use) were obtained from Plastics World as a result of these calls.
No sources of future production figures were obtained that had not al-
ready been identified from the literature search.
Two factors affecting future production of plastics are availability of
feedstock and the cost or price of the plastics. If supply cannot keep
up with demand, not only will consumption be less than anticipated,
but also the cost of the material will eliminate its use in some of the
lower priced markets.
Celanese Plastics Company marketing experts'* analyzed current and
future projected positions of the commodity resins (polystyrene, ABS,
PVC, and polyethylene) as well as the engineering materials (acetal,
nylon, polybutylene terephthalate, phenylene oxide-based resin, and
polycarbonate). Although the supplies of polystyrene, AIjJS, and PVC
are hardest hit by shortages, a substantial improvement should be
seen in 1977 for polystyrene and ABS. Similarly, polyethylene and
polypropylene, which are in tight supply, should be more available in
1977. It is anticipated that it will be somewhat longer before PVC
production catches up with demand.
12'
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Most marketers agree that feedstocks will be short through the end of
this decade and perhaps well into the 1980's. ^ However, Owings,
manager of marketing economics for Gulf Oil, is quoted in this article
as saying that 2-3 million bbl/day of additional feedstock will be added
during the next 7 years.
An article on growth of oil-derived products worldwide starts out by
saying that prospects for continued growth of the major plastics are
assured despite higher feedstock and energy costs. Similarly, an
article in the Chemical Marketing Reporter7 states that, although the
plastics business will undergo some gradual but significant changes
over the next 5-10 years as basic resin producers struggle to cope
with extended raw-material shortages, overall consumption is ex-
pected to continue to grow, despite the negative aspects of higher
prices, pollution-control problems, and the energy crunch.
Polyvinyl chloride is not only under a cloud because of a shortage in
feedstock, but is also under attack because of health and environmen-
tal problems. However, even for PVC, a growing market is forecast.
Although it is expected to grow by only 2 percent in 1974, it is antici-
pated to increase by a total of 30-40 percent by 1980. ° A total pro-
duction capacity of 7. 12 billion pounds is forecast for 1980.
Thus, although sources of materials may change, and production be-
tween the present and 1980 may be somewhat less than was previously
anticipated, there should be a small growth during that period which
will increase after 1980. This is the position taken by Industrial
Marketing and the SPI. ^ An article in Industrial Marketing? states
that although a slowdown may be imminent, plastic producers are op-
timistic about long-term prospects. Whether or not an actual crisis
will occur depends on the severity of the petroleum shortage and the
resolution of allocation procedures by Congress or the White House.
Two publications of prime importance to this study were identified and
obtained. The most important report is one prepared for the SPI by
Stanford Research Institute (SRI), entitled "The Plastics Industry in
the Year 2000". 10 Projections of plastics production in the year 2000
are given. Projections are reported in two breakdown categories,
total resin production by plastic type and total market consumption by
end-use distribution. For both categories, the projections are given
as minimum, most probable (or median), and maximum figures.
13
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According to this study, total plastic production by the year 2000 will
probably total 1.13. 5 x 10° tons, with the range given as 85. 0 to
14Z. 0 x 106 tons.
The second report, entitled "The Role of Plastics in Resource Re-
covery", was prepared by Midwest Research Institute (MRI) for
MCA. 1* Projections are made for total plastics production for the
years 1975, 1980, 1990, with a breakdown into the major plastic types
(polyethylene, polystyrene, polyvinyl chloride, and polypropylene).
The only breakdown by end-use markets is the projected consumption
of plastics in packaging applications. However, it should be pointed
out that MRI's analysis indicates that plastics packaging accounts for
about 72 percent of all plastic waste, so this end-use category is by
far the most important. By comparison, the Battelle useful-life con-
cept indicates that either 63 or 85 (average 74) percent of plastic
waste is derived from packaging materials. ^ The two different fig-
ures arise from different calculated values for total plastic waste
(1973 data) based on analyses of, respectively, type of plastic (cf this
report, Table 2) or end-use markets (cf of this report, Table 4).* It
should be noted that MRI does not give a range of projection figures.
However, this report has been quite valuable to the present study since
it provided an independent analysis of projected plastic waste, both in
terms of absolute amounts of discarded plastics and of percentages of
total waste for the years 1980 and 1990.
Additional data on projections of future plastics production were ob-
tained from, other published sources. However, no other comprehen-
sive report comparable to the two described above was obtained.
Furthermore, most of the figures found turned out to be extracted
from one or the other of these two primary sources. Data which ap-
peared to be of independent origin were always for isolated plastic
types or end uses. When tabulated, these data were insufficient to
calculate totals which could be used to crosscheck the projections of
the two main sources. Furthermore, most of these data were for the
immediate future (1975-1980). Independent projections beyond 1980
were rare and of little use to this study.
•1973 packaging volume of 2.91 x 106 tons Is divided by either 4.61 x 106 tons (plastic-type analysis)
or by 3.44 x 106 tons (end-use analysis). The 4.61 x 10^ ton figure is a corrected value for Table 6,
Reference 6, based on newly available total plastic production figures (see Table 1 of this report).
14
-------
The pertinent data from the two prime references 10> ^ cited above,
as well as the actual production figures for 1972-1973, are presented
in Tables 2-6 and shown graphically in Figures 1-4. Plastics produc-
tion figures for 1973 are given by plastic type in Table 2. Wastage
figures are calculated based on the assumed percentage discard rate
per year as derived from the useful-life concept. ^ The total (4. 61 x
10" tons) is slightly lower than the figure given in Table 6 of Refer-
ence 12 (5.05 x 10" tons), since the earlier figure was based on a
slightly higher sales estimate. The data in Table 3 (1970-1973 pro-
duction figures) are given as background information and for use in
graphing the actual production curve.
The most probable plastic production figures for the year 2000 by end-
use categories from Reference 10 are listed in Table 4. Also included
are the 1970 figures taken from the same reference. Table 4 also
contains the actual 1973 data and the calculated waste figures based on
the discard rate as derived from the useful-life concept. The total
plastic-waste figures are 2. 67 x 106 tons for 1970, 3. 44 x 106 tons for
1973, and 30. 7 x 106 tons for 2000. These figures are 32, 26, and
27 percent of the respective actual and projected production totals.
These percentages are higher than those resulting from the MRI analy-
sis (Reference 11, page 6) which average 22 percent. In Table 5, the
data from both References 10 and 11 for projected market volume
based on end-use categories for the years 1975, 1980, 1990, and 2000
are given. Again, waste plastic volume is calculated based on the
percentage discard rate. The rounded percentages used for calcula-
tion are taken from Table 6 of Reference 12. The percentage of the
"other" category is a calculated weighted average. Plastic-waste
figures arising from this method of calculation are 5.4, 8.7, 18.3,
and 37.9 x 10& tons, respectively, for the years 1975, 1980, 1990,
and 2000. These waste volumes represent 31, 29, 33, and 33 percent
of the respective year's projected plastic production figures. Again,
these are higher than the 22 percent figure of Reference 11. Also, it
should be noted that the waste percentage for the year 2000 is 6 per-
cent higher than the result obtained (27 percent, Table 4) from the
direct calculation based on estimated useful life of end-use categories.
However, the amounts of plastic waste based on the useful-life con-
cept were calculated from individual production years rather than a
summation over the period evaluated. This summation would result
in only a small increase in the total waste contribution.
15
-------
TABLE 2. 1973 PLASTICS PRODUCTION BY PLASTIC
TYPE AND WASTE VOLUME
Type of Plastic
Production x 10 Tons
Assumed
Percentage
Discard/Year
Waste x 10° Tons
Ethylene
Styrene^
Vinyl chloride
Polyesters*0'
Propylene
Phenolics
Urethane
Urea - Melamine
Acrylics
Epoxy
Nylon
Cellulosic
Acetate
Carbonates
Other
Total
4.22
2. 51
2.28
0.52
1.08
0.69
--
0.43
--
0. 11
0. 10
--
0.05
--
1.30
13.29
65.6
38. 1
17.9
--
27.5
__
--
--
--
--
--
--
--
_-
13.4
34.7
2.77
0.95
0.41
--
0.30
--
--
--
--
--
--
--
--
0. 18
4.61
(a) Source: Mr. Howard Kibbel. SPI, private communication.
(b) Includes polystyrene, ABS, SAN, and other styrenlcs.
(c) Unsaturated polyesters.
TABLE 3. ANNUAL PLASTIC TOTAL
PRODUCTION (SPI DATA)
Year
Production x 10 Tons
1970
1971
1972
1973
8.36
10.33
11.22
13.31
16
-------
TABLE 4. PLASTIC WASTE VOLUME BASED ON LIFE EXPECTANCIES OF END-USE CATEGORIES**'
End Use
Packaging
Transportation
Furniture /House wares
Electrical/Electronics
Appliances
Building /Const ruction
Other
Total
(a) Plastic production
Approximate
Life, years
1
5
10
10
10
50
50
Per Year, 1970
Volume, 10° tons
1973
percent Production Waste Production10'
100 2.25 Z.
20 0.86 0.
10 0.79 0.
10 0.75 0.
10 0.28 0.
2 1.98 0.
2 1.45 0.
8.36 2.
data taken from: Glauz. R. L. , Jr., Kridl, A.
the Year 2000", April, 1973, p. 24.
(b) Private communication from Plastics
Report prepared by Stanford
World.
' TABLE 5. FUTURE MARKET
Type of Plastic
Polyethylene
Polystyrene
Polyvinyl chloride
Polypropylene
Other
Total
Assumed
Percentage
Discard/Year
66
38
18
28
13«M
1975(a)
Production Waste
4.4 2.9
1.9 0. 7
2.8 0.5
1.2 0.4
7.3 0.9
17.6 5.4
25 2.91
17 0.69
08 1.23
07 0.82
03 0. 47
04 2.57
03 4.61
67 13.30
G. , Schwaar, R. H. ,
Waste
2.91
0. 14
0. 12
0.08
0.05
0.05
0. OS
3.44
and Soder, S.
Research Institute for the Society of
Waste
2000 bvEnd Use
Production Waste 1970 2000
23.7 23.7 84.3 77.
17.0 3.4 6.4 11.
13.8 1.4 3.0 4.
10.4 1.0 2.6 3.
2.2 0.2 1.1 0.
28.0 0.6 1.5 2.
18.2 0.4 1.1 1.
113.3 30.7 100.0 100.
L. , "The Plastics Industry in
the Plastics Industry (SPI).
2
1
6
3
6
0
2
0
AND WASTE BY PLASTIC TYPE
Volume
1980t»l
, 106 tons
1990<») 2000(b)
Production Waste Production Waste Production Waste
6.7 4.4
2.8 1.1
4. 0 0. 7
1.7 0.5
14.9 2-0
30.1 8.7
15.
6.
9.
4.
20.
55.
5 10.2 33.0 21.8
5 2.5 9.9 3-8
0 1.6 15.4 2.8
0 0.5 15.4 4.3
0 2.6 39.6 5.2
0 18.3 113.3 37.9
Current Impact ot Elastic Keiuse uisposai upon m«= ^nvirw»unc**t , j«»7 ., -*- ..
for Office of Research and Monitoring, U. S. Environmental Protection Agency.
(d) Weighted average percentage from same source as (c).
(e) Median value (minimum value i 85.0, maximum value = 144.2).
-------
Projected plastic production and waste volumes for the years 1980,
1985, 1990, 1995, and 2000 are listed in Table 6. The projected pro-
duction figures for all the years listed except ZOOO were obtained from
Figure 1. Thus, they are extrapolated values derived from a smoothed
curve graphical representation of the projected plastics production data
of References 10 and 11 (reproduced in Tables 5 and 6, except for the
minimum and maximum figures for the year 2000). Waste volumes
were calculated on the basis of both 22 percent and 29 percent rates of
discard of annual production. The lower figure represents the MRI
estimate while the higher figure represents an average Battelle figure
based on the useful-life concept. Both sets of calculations were done
for minimum, median (most probable), and maximum projected plas-
tics production figures.
The projected future plastics production figures were plotted in Fig-
ure 1, which includes the 1970-1973 production figures to show hqw
the projected curves merge with the actual data. The plots are drawn
as curves rather than straight lines because calculated growth curves
(not shown) based on either an average compound growth rate of 8 per-
cent per year or on a slowly declining plastic production growth rate
(from 13 percent growth in 1971 to 3 percent growth by 2000) follow
such a pattern. A declining growth rate is predicted in Reference 11,
page 2.
The projected plastic-waste data from Tables 4 and 5 are plotted in
Figure 2. Data from Reference 11 are also plotted in Figure 2. In
addition, a projected waste figure from a report entitled "Solid Waste
Management of Plasticsnl3 jg plotted. The curve plotted using the
Battelle useful-life concept is based on the most probable (median)
projected plastics production data from Reference 10.
The 4ata from Table 6 are plotted in Figures 3 and 4. Figure 3 is
based on calculations made using the 29 percent discard rate, while
Figure 4 is based on the 22 percent discard rate calculations. There
is an interesting overlap region on the two graphs. Thus, the area
between the minimum and most probable curves of Figure 3 can be
superimposed on the area between the most probable and maximum
curves of Figure 4, indicating the wide range that is likely to occur in
projections of this type. The data presented in Table 1 for plastic
waste are based upon the mean figures for the 29 percent discard rate.
18
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TABLE 6. PROJECTED PLASTIC PRODUCTION AND WASTE
Production,
Waste,
10*1 Tons Based on
Indicated Percentage
Year
1980
1985
1990
1995
2000
Range
Minimum
Median
Maximum
Minimum
Median
Maximum
Minimum
Median
Maximum
Minimum
Median
Maximum
Minimum
Median
Maximum
106 tons
22.8
27.0
31.0
33.5
42.5
52.0
46.0
61.5
76.5
63.0
84.5
107.0
85.0
113.0
144.0
22W
5.0
5.9
6.8
7.4
9.3
11.4
10. 1
13.5
16.8
13.9
18.6
23.5
18.7
24.9
31.7
29(b)
6.6
7.8
9.0
9.7
12.3
15. 1
13.3
17.8
22.2
18.3
24.5
31.0
24.6
32.8
41.8
(a) 22 percent average rate of discard of plastic production projected in "The Role of Plastics
in Resource Recovery", Midwest Research Institute, May 23, 1973, p. 6 (report prepared
for MCA).
(b) 29 percent average rate of discard of plastic production projected on the useful life
approach of end -use categories.
19
-------
140
130
120
110
100
g 90
^ 80
.§
y ro
ol
8 60
'I
jg
0- 50
40
30
20
10.
0
Q >X
-X..
X*5*^
Legend
O SPI Projection Data, "Plastics in the Year 2000 "
a MCA Projection Data, "The Role of Plastics in
Resource Recovery"
x SPI Production Data
I I
1970 1973 1975
1980
1990
2000
Year
FIGURE 1. PLASTICS PRODUCTION PROJECTIONS
TO THE YEAR 2000
20
-------
40.0
35.0 —
30.0 -
25.0
I
2O.O —
S
a.
Battelle Projections based on the Useful
Life Concept
MCA Projections, "The Role of Plastics in
Resource Recovery" May, 1973
(MRI Report)
O MCA Projections, "Solid Waste Management of
Plastics". Dec., 1970
IDS R Report)
Estimate based on
plastic type (Table 5)
Estimate based on end-use category (Table 4)
1970
2000
FIGURE 2. PROJECTED PLASTICS WASTE TO THE YEAR 2000
21
-------
40.0
35.0
30.0
25.0
in
O
"Q
20.0
S
a
15.0
10.0
9.0
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
1972 1975
I960
1965
Year
1990
1995
2000
FIGURE 3.
PROJECTED PLASTICS WASTE TO THE YEAR 2000
BASED ON A Z9 PERCENT DISCARD RATE OF
MINIMUM-TO-MAXIMUM PRODUCTION
22
-------
35.0
3O.O —
2000
FIGURE 4. PROJECTED PLASTICS WASTE TO THE YEAR 2000
BASED ON A 22 PERCENT DISCARD RATE OF
MINIMUM-TO-MAXIMUM PRODUCTION
23
-------
It should be pointed out that plastics production figures, such as
those used for the basis of future projections in the SRI and MRI re-
ports, 10> 11 do not include synthetic polymers used for the production
of man-made fiber. Since textiles have historically been considered
as a separate category from plastics when analyzing the impact of
plastics waste upon the environment, they were not included in this
study. Textile polymers can be a substantial amount of the solid-
waste stream, for in 1973 production of synthetic fibers amounted to
3. 4 million tons, equal to about 25 percent of the plastics production
that year. Similarly, rubber is another category that becomes part of
the solid waste. Production in 1973 amounted to 2.4 million tons of
synthetic rubber and 0. 6 million tons of natural rubber. At the pres-
ent time additives in plastics do not constitute an important item, but
if the amount of additives is increased in future years, their effects
should be evaluated.
ANALYSIS OF DEVELOPMENTS IN THE SOLID-
WASTE DISPOSAL TECHNOLOGY
An orderly classification of present and future developments in solid-
waste-disposal technology may be grouped into three primary cate-
gories: throw-away, thermal treatment, and utilization or resource
recovery. The classification is for ease of impact assessments and
it will be recognized that some methods of disposal may encompass
more than one objective. For example, sanitary landfill with the pri-
mary objective of throw-away may simultaneously involve in-land
reclamation, while thermal treatment involves volume reduction with
or without energy or other product recovery. Furthermore, the only
final disposal of solid waste is indeed the landfill (throw-away)
method, since residues from other waste-treatment processes, which
range from about 8 to 40 percent, may be relegated to landfill.
Resource-recovery processes temporarily postpone final disposal
until a later time when the materials, either in the original form or
transformed into other products, have no further economic value.
Developments in the Throw-Away
Methods of Solid-Waste Disposal
Throw-away-disposal methods are the earliest solid-waste-disposal
methods and they have seen many changes in the last several decades,
24
-------
progressing from litter, to open dump, to what we have today as the
best disposal method in this category — the sanitary landfill.
Litter consists of articles of all types and sizes discarded at random,
being most prevalent alqng roadsides, playgrounds, parks, and
beaches.
The persistence of the litter will depend upon the climate, the wind,
the effect of convenience-oriented human institutions and activities
(which tend to dispense it) and on any efforts which may be made to
collect it. Littering problems will be solved by creating an attitude
of mind and a behavior pattern in homes, schools, and public places
that would prevent its incidence. Public education programs can be
used to inculcate this code of behavior. However, improved collection
facilities and, if necessary, punitive measures can aid in reducing the
incidence of littering. Once collected, litter can be dealt with by the
processes of solid-waste disposal. Litter can be prevented if every
step is taken to put all waste, irrespective of size and nature, through
the solid-waste-disposal systems.
The amount of plastics in the litter varies considerably according to
the location of the litter. In Table 7, the plastics fraction is shown
to vary from 6 percent by volume to about 10 percent by weight.
TABLE 7. COMPOSITION OF LITTER
U.S. Highways, U.S. Cities,
Material volume percent weight percent
Paper 59 55.0
Metal 16 18. 1
Plastics 6 10.2
Glass 6 4.2
Miscellaneous 13 12.5
25
-------
The portion of plastics in the litter fraction is generally assumed to
increase in the years ahead due to increased usage of plastics in pack-
aging consumable goods. However, the total amount of litter may be
expectjed to decrease significantly through local and state law enforce-
ment and public awareness of the environment.
i
Disposal by open dumping involves dumping a collection of refuse on
land "without any efforts towards altering or modifying its appearance
or nature". Open dumping historically has predominated all other
forms of disposal methods because of its immediate expediency and
low cost. However, because of the associated air pollution, odor
nuisance, potential fire hazards, unsightliness, water pollution, and
assorted health hazards, open dumping is an unsuitable method for
solid-waste disposal. Consequently, recent ecological concern to-
gether with the EPA program to close 5000 open dumps, has produced
a downward .trend in the use of open dumps. Beginning with a little
over 74 percent of the total solid waste headed to open dumps in 1970,
this study estimates that this fraction will reduce to about 11 percent
by the year 2000. Another factor that will influence this trend is
urban encroachment on the traditional dumping areas such as natural
depressions, flat lands, etc.
Sanitary landfill consists of four main processes:
(1) The sanitary landfill site is selected and a portion of the site
is prepared;
(2) The solid wastes are deposited in a controlled manner in the
prepared portion, spread, and compacted in thin layers
(about 2 feet);
(3) The solid wastes are covered daily or more frequently, if
necessary, with at least 6 inches of compacted earth layer; and
(4) The completed sanitary landfill consisting of several cells of
daily operations is covered with at least 2 feet of compacted
earth layer.
Sites properly selected and operated in this manner meet the criteria
for sanitary landfills, that is, "a land-disposal site employing an en-
gineered method of disposing of solid waste on land in a manner that
26
-------
minimizes environmental hazards by spreading the solid waste in thin
layers, compacting the solid waste to the smallest practical volume,
and applying and compacting cover materials at the end of each op-
erating day. "15
Through legislation and public acceptance, the number of sanitary
landfills are increasing and are expected to become final deposit sites
for approximately 40 percent of the municipal and rural solid wastes
collected by the year 2000, on a national basis.
Site selection for any sanitary landfill is dependent on three main fac-
tors: technical factors, sociolegal factors, and economic factors.
The aspects of the technical factors are the volume and characteristics
of the waste to be landfilled, the topography of the land, and the geol-
ogy and soil condition of the site. A major concern in sanitary landfill-
ing is the potential danger of polluting ground- and surfacewater. Con-
sequently, nonwater-soluble, nondecomposable inert waste materials
may be landfilled in low-lying areas with high water tables, near water
bodies, or in places with high permeability with less danger to water
pollution, while decomposable organic materials and toxic materials
are unacceptable in such sites.
The need for site selection for sanitary landfill to comply with the
local and state ordinances and zoning restrictions will be increasingly
more pressing in years ahead. Urban sprawl presents serious con-
flict to waste disposal and this conflict will increase in/the years ahead
as more solid wastes are generated and land for disposal becomes
limiting.
Land cost,' hauling distance, and availability of cover materials/'are
main economic factors in site selection. Usually land areas that are
hardly usable for any other purposes such as low-lying areas which
have drainage problems with high potential for surface- and ground-
water pollution are reserved for the sanitary landfilling. Hence, the
importance of well-engineered sanitary landfill where pollution-
control measures are employed, can hardly be overemphasized. Also
of economic importance is the available land for landfilling, for the
area or volume of land required depend on the character and quantity
of the wastes, the depth of the fill, the efficiency of compaction of the
wastes, and the desired life of the landfill.
27
-------
The economic factor associated -with hauling distance will vary from
locality to locality depending upon capacity of collection vehicles,
hauling time, and size and method of collection agency. The larger
the quantity of waste hauled per trip and the shorter the hauling time
(due to express roads, freeways, etc.), the greater the distance the
solid wastes can be hauled for the same cost. The cost of hauling
cover materials can be appreciable. A site that has cover material
close by will keep these costs at a minimum.
Construction and operation of the sanitary landfill site may simply be-
gin with the clearing of shrubs, trees, and other obstacles that could
hinder vehicle travel and landfilling operations. In some instances it
may also involve the construction of roads and other structures.
Specifically, the prevailing methods of sanitary landfill construction
are generally divided into three categories. The choice of construc-
tion method depends on the constraints of the particular site.
The trench method (or cut-and-cover method) is used when the ground-
water is low, and the soil is more than 6 feet deep, and usually on flat
or gently rolling land. Starting at one edge of the first trench, waste
materials are dumped. At the end of the day's dumping, spreading,
and compacting, the waste is covered with the earth excavated from
the second trench on the far side of the dumping edge. A minimum of
6 inches of compacted earth cover on the cell is generally recom-
mended. Spoil material not needed for daily cover may be stockpiled
and later used as a cover for an area-fill operation on top of the com-
pleted trench fill.
The area method (or fill-and-cover method) can be used in most to-
pographies, but is usually employed in low-lying areas such as
marshes or swamps or in land depressions such as abandoned quar-
ries, ravines, or canyons. Waste is dumped on the existing ground
surface, spread in horizontal layers, and compacted. At the end of
each day's work the waste surface is covered as needed with earth
excavated from the area directly in front of the working face of the
landfill (progressive excavation). If excavation is not possible, the
fill is covered with imported cover material.
The ramp method (or the progressive-slope method) is employed ex-
clusively in filling depressions, such as ravines, canyons, or quar-
ries. In this method, the waste is deposited and spread in layers on
28
-------
the slope of the depression. Cover material is obtained directly in
front of the working face and is used to cover the slope sides and top
of the waste-cell structure. This technique allows for more efficient
use of the disposal site since cover materials are usually available
nearby.
Waste treatment prior to landfilling involves methods that reduce the
volume of waste. In sanitary landfill, density is the prime considera-
tion. With good equipment, solid waste can be compacted, shredded,
or baled to achieve an appreciable volume reduction and to obtain a
satisfactory fill material. Improvements in the baling, shredding,
compaction, and other operations preceding the actual landfill are all
calculated to increase the density (decrease the volume) of wastes to
extend the landfill site lifetime.
Such treatment applied to the solid waste takes three forms:
(a) Physical treatment: size reduction and mixing in a pulverizer,
or high-density baling
(b) Biochemical treatment, composting by controlled fermentation
of the degradable organic content
(c) Thermal treatment: incineration in an enclosed furnace.
Pulverization is a mechanical process for chopping, tearing, and
shredding. This is accomplished by passing refuse through a chamber
containing swiftly rotating knives or hammers. Pulverization in a
hammer mill can reduce 95 percent of the refuse to 25 mm or less,
with most of the remainder below 100 mm. Some machines are large
enough to accept a piano and strong enough to cut steel as thick as
auto wheels. All the machines are designed to reject high-strength
materials such as crackshafts, and some reject rubber tires. 16
Pulverization improves the solid-waste density, with resultant reduc-
tion in transport cost. Furthermore, a pulverized waste is less ob-
jectionable and less likely to ignite or to attract rats and flies. When
deposited in a sanitary landfill, the constituents are small and well
mixed; thus litter is less of a problem, decomposition is more rapid,
and the complete absence of voids prolongs site life and reduces the
risk of uneven settlement. ^
29
-------
It is estimated that, at the time of collection, about nine-tenths of the
volume of residential and commercial refuse is air, and if this can be
expelled, subsequent handling cost and space problems can be greatly
reduced. This volume reduction has been achieved by plants in Japan,
and experimentally in the United States and Britain. The waste vol-
ume has been reduced to about 1/7 of the original amount by a high-
pressure baling press. 17 The real importance of baling would be the
subsequent facility and economy of handling and transporting refuse in
large high-density blocks. An added benefit is that settlement during
land reclamation would be reduced.
The burning of inflammable materials in the municipal solid waste can
reduce the total volume of solid waste to be disposed of to about 16
percent of the incoming material. The residues which are fly ash,
bottom ash, and screenings will require subsequent disposal on land-
fill sites. The high density of incinerator ash makes it an economical
material to transport, and because the organic content is very low, it
may sometimes be used for filling sites at which there would be a risk
of water pollution from crude or pulverized refuse. Ash can cause
water pollution, however, because it may contain soluble inorganic
salts.
Composting biochemically converts municipal waste into a useful soil
conditioner. The volume reduction has distinct advantages over nor-
mal landfilling:
(1) Leachate from a compost dump is not as potent and objectionable
as that from landfill
(2) Many pathogens and objectionable organisms will have been de-
stroyed in the composting process.
Compost has very little nutrient value, for the nitrogen content is only
about 1 percent and phosphate and potash even less. Its most useful
characteristic is its humus content, which enables it to improve the
performance of soils which lack organic matter.
In spite of this potential technical advantage, however, such a combi-
nation of compos ting-plus-landfilling, thus far, has not gained ac-
ceptance in this country, presumably because the added cost of the
composting step is still considered unjustifiable. In the future, as
30
-------
landfill sites become less available, the importance of preliminary
volume-reduction techniques will increase.
Developments in Thermal Treatment
of Solid Wastes
Thermal treatment of solid waste includes both combustion and py-
rolysis. The former has been employed for many years as a means
of reducing the volume of waste to conserve landfill area. Although
burning at landfill sites was general, the practice has been reduced
significantly through state and local law enforcement. Open burning
has been replaced by municipal incinerators. As a result of the in-
creased concentration of refuse at local sites, the problems associated
with disposal of solid waste by incineration became more evident in
terms of gaseous and particulate emissions, scenic blights, health and
accident hazards, depreciated land values, and public nuisances.
Hence, Federal air-pollution regulations were enacted and state or
local controls reduced significantly the open burning of refuse with a
resulting growth in the number (322) of municipal incinerators con-
structed. However, since 1967, the number of operating incinerators
has declined to approximately 140 because of obsolescence, emission-
control regulations, and repair or construction costs. 18 Further-
more, over 95 percent of the operating municipal incinerators have
incorporated emission-control systems in the off-gas chambers or
stacks. Unfortunately, corrosion is a major problem in these
emission-control systems. Also, corrosion has been a major deter-
rent to the installation of heat-recovery systems in municipal incin-
erators. Considerable effort has been made to circumvent these
problems so that solid waste can be used to conserve other fuels.
Hence, although incineration for volume reduction purposes only is
decreasing, the combustion of solid waste for heat or power genera-
tion is increasing. It is expected that the amount of thermally treated
solid waste will increase from less than 10 percent of that generated
in 1970 to 36 percent of that generated in 2000, as discussed in the
following paragraphs.
The recovery of heat from the incineration of refuse through conver-
sion to low-temperature steam has become attractive in several loca-
tions where there is a market for this product. As other forms of
fuel become more expensive, solid waste becomes more attractive,
31
-------
even though the most promising use of solid waste as a fuel requires
considerable processing. This processing will improve combustion
conditions and may be expected to reduce the magnitude of boiler-tube
corrosion that results from burning bulk refuse. Hence, although
only 5 x 10° tons of solid waste was used to provide heat in 1973, this
amount is expected to increase to 24 x 10° tons by 2000 as central
heating and cooling for industrial parks, office complexes, and down-
town buildings increases.
The utilization of solid waste as a supplemental fuel for power genera-
tion is receiving much attention at the present. Several utility com-
panies are investigating the potential of solid waste as a fuel source
and as a benefit to the communities they serve. An analysis *° of the
theoretical and practicable amounts of solid waste that could be util-
ized in existing coal-fired electric utilities shows that a 20 percent
heat value replacement of coal with solid waste would utilize all the
waste forecasted to be generated through the year 2000. It is difficult
to predict to what extent this potential will be realized. In many
areas, it would not be practicable to collect, process, and haul refuse
to the point of consumption. Large metropolitan areas and some en-
tire states are developing resource-recovery facilities for solid waste
which provides a component equivalent to 70 percent of the waste that
is 92 percent combustible. In view of these current developments, the
amount of waste utilized in electric power generation is expected to
become significant by 1980 and expand to 32 x 10° tons per year by
2000.
As a result of the anticipated growth in the utilization of solid waste
for heat and energy generation, the growth in resource-recovery op-
erations, plus the enforcement of air-pollution regulations with
attendant costs of construction, the incinerator method of reducing
the volume of solid waste is expected to decrease markedly in popu-
larity as the existing equipment becomes obsolete. Hence, the dis-
posal of solid waste by incineration will probably remain at a constant
level for the next 10 years and then decrease to less than 1 x 10° tons
per year by 2000.
In contrast, the pyrolysis of solid waste to gas or liquid components
plus char products that can be subsequently burned in an environ-
mentally acceptable manner or utilized as a raw material has received
much attention and several pilot plants are under construction, It is
32
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not expected that this method of disposal will contribute significantly
to the disposal of solid waste before 1980, but its use will probably
increase after that because of convenience in storage and transfer of
the resulting products.
Developments in Resource Recovery
For impact-assessment purposes, resource recovery is narrowly de-
fined in this section to include only the use of materials and products
(except energy) reclaimed from solid waste. The energy aspects of
the resource recovery are discussed under thermal treatments. Most
specialists in solid-waste management tend to agree on some broad
areas of solid-waste management, viz: solid-waste generation rates
will increase, suitable land for disposal of waste will become less
readily available, additional processing of waste will become neces-
sary prior to disposal, and the cost of solid-waste management will
increase. Based on these premises, national attention is being
focused on resource recovery as an answer to the nation's solid-waste
management problems.
Specific advantages of resource recovery are:
(1) The volume of refuse to be disposed after extracting various
materials from the waste stream is reduced.
(2) These reclaimed fractions serve as raw products, thus reducing
the amount of virgin materials needed.
(3) Less energy is generally required in the total manufacturing
process when secondary materials are used.
The different resource-recovery options for utilizing waste materials
are reuse, recycling, and reclamation. These are briefly defined as
follows:20 Reuse denotes use of a material or product - as is — more
than once. Recycling takes the product and reintroduces it into the
production cycle for the production of the same product. Reclamation
consists of processing for reuse as a different product. Examples
are: a plastic bottle, which is reused when the bottler or the house-
wife refills it; the same bottle, which is recycled when ground into
particles for the manufacture of new soft-drink bottles; and the same
33
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bottle, which is reclaimed (or salvaged) when ground up and used to
make a totally different product, such as drainage tile.
Reuse of municipal wastes that are disposed of by the "reuse option"
as defined here is regrettably insignificant and the future disposal of
a sizable quantity by this process is not promising. Firstly, few ma-
terials in the municipal wastes could be salvaged and reused without
some form of reprocessing. Secondly, the problem of separating
these waste materials from a heap of mixed municipal wastes is enor-
mously expensive. Much of the cost of salvaging may be avoided by
keeping the desired materials separate at source — a process that
would ultimately involve every household.
Beverage-bottle return by consumers is widely practiced today and
the efforts to do so will probably increase in the years ahead. Other
waste candidates that can be reused as defined here are canning bot-
tles, plastic covers, and cardboard. These are the only widely used
materials that may be reused without reprocessing. The fraction of
this reuse process in the total solid-waste picture is hard to estimate.
Both industrial and government packaging wastes have been reduced
by the promotion of reuse designs and specifications. However, there
has been little or no attempt to promote this for household items.
Thus, reuse is not expected to change municipal solid-waste generation
in the foreseeable future.
Recycling is defined as reintroduction of waste materials into the pro-
duction cycle for the manufacture of the same product. If the waste
material, for example, plastics, is to be used as a substitute for
virgin raw material, manufacturers require that the salvage waste
material must satisfy three requirements:^!
(1) Homogeneity, because mixed grades of plastic will not possess
the required properties for most processes or products
(2) Cleanliness, because contaminants (such as dust, oil, etc. )
would degrade the quality of the product
(3) Satisfactory form (granules, pellets, powders, etc. ).
Recycling of certain plastic wastes from fabrication plants is prac-
ticed. In industrial plants, it is possible to keep different types of
34
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plastics (e. g., polyethylene, polystyrene, and polyvinyl chloride)
separate at the source. Once the plastics have been discarded into
the waste stream, the recovery of the plastic from the mixed waste
is a difficult operation, and commercially of doubtful value at present.
The quantity of plastics appearing in the refuse is small, and sepa-
rating it is neither easy nor economical, and it is difficult to mech-
anize the process (flotation and elutriation is a possible method under
investigation). Further, to make the best use of plastics they should
be separated into their various types, e. g. , polyethylene, polypro-
pylene, polystyrene, polyvinyl chloride in its rigid form, polyvinyl
chloride in its flexible form, and all the others which appear in minor
quantities. Thermosetting types would be rejected because they could
not be recycled directly. After segregating the recyclable plastics,
cleaning and processing is necessary. The plastics are then softened
or melted and converted into a suitable raw material form, e. g. ,
granules. The properties and processing characteristics required for
a particular application and production method may demand additional
treatment. Much exploratory work is being done on all aspects of the
reclamation of thermoplastics from, refuse. Cost and limitations of
use because of difficulties in achieving the quality required are among
the major problems yet to be solved. If cleansing to the required
level is not possible, other means of dealing with the waste will have
to be developed. Therefore, because of the lack of homogeneity and
cleanliness, direct recycling of recovered plastics from the municipal
waste stream is not promising.
Reclamation (indirect recycle) is defined as processing of the waste
material for reuse as a different product. For plastics, this may in-
volve the manufacture of products or the use of the waste material in
some other way, having a less demanding specification due to non-
homogeneity and impurities.
Various studies are underway to develop methods of separating the
various components of the solid waste into individual reclaimable ma-
terials. 5 Scrap metals, paper, glass, and foils have good salvage
prospects. However, there are problems with reclaiming plastics.
In this country, no method has been developed on reclaiming plastic
from the municipal solid waste. In a recent European development,
the Mremaker"21 accepted plastic bottles, without precleaning, and
many other kinds of thermoplastic wastes after they had been
35
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shredded or pulverized, and then transformed them into shoe soles,
bicycle saddles, household utensils, and toys. A typical limitation in
the use was a requirement that products must have a minimum wall
thickness of 1/8 inch. The operation of the machines is said to be
somewhat slow compared with those using virgin materials.
Flintoff describes a municipal enterprise in reclamation by the
Japanese City of Funabashi.21 Two types of machinery were installed
to produce flowerpots, pipes, and poles from mixed thermoplastic
wastes. The most interesting aspect of the project was that the city
obtained its raw materials segregated by persuading householders to
keep plastic wastes separate from other household wastes.
A process for indirect recycling would normally commence with
shredding and mixing of the thermoplastic wastes, and, perhaps, the
incorporation at this stage of fillers such as wood chips or wood
fibers. This product would then be compacted into granules and fed
to an injection-moulding machine for the production of, say, flower-
pots, or to an extruder or a press to form profiles or building boards.
Thus, reclamation of plastics has some potential for the future if the
plastic waste can be salvaged and accumulated in sufficient quantities.
Composting as discussed earlier, is a controlled biochemical conver-
sion of waste to useful soil conditioner, and thus may be considered a
reclamation process. Composting has not been a popular means for
municipal solid-waste reduction and disposal in the United States.
Some reasons are: (1) limited market because of wide use and low
cost of chemical fertilizer, (2) high operating and distribution costs,
(3) limited number of successful composting installations, (4) reluc-
tance of municipalities to enter commercial ventures, and (5) failure
to recognize composting as a method of solid-waste disposal.
At a typical compost plant, ferrous metal would be extracted by elec-
tromagnets and there would probably be facilities for hand-picking to
'remove unsuitable materials such as bottles, man-made textiles,
nonferrous metals, and plastics. Pulverization might follow in order
to facilitate subsequent bacterial action by reducing particle size and
by thorough mixing.
The municipal solid waste may be combined with sewage sludge or
other waste types; studies have shown this approach to be a great
36
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improvement because of the improved composting characteristics.
The improved composting parameters are: carbon to nitrogen ratio,
moisture content, aeration, temperature, and particle size. However,
plastics cannot be treated by composting since they do not biodegrade
within the same time span as the other biodegradable materials.
Projections of Solid-Waste Disposal
by Various Methods
Although for many years bury, or burn and bury the residue, were the
only methods of solid-waste disposal, recent developments in solid-
waste technology brought on by public awareness of our environment,
legislation, inflated costs of virgin materials, plus depletion of our
natural resources, and the energy crisis have brought about methods
to reuse, recycle, and recover much of the value from solid waste
which heretofore was lost from the nation's economy with attendant
high disposal costs. Solid-waste-disposal technology may now be di-
vided into three major categories: resource recovery, thermal
treatment, and landfill. The last method encompasses that which has
not been processed plus the residue from the other two.
A national inventory that gives the precise amounts of municipal refuse
handled by various disposal methods is nonexistent. Studies have de-
pended largely on best estimates which in all probability differ widely,
simply because of great diversity in source of generation, problems of
collection, and the fact that some of the waste may never be collected.
The three main categories of the municipal solid-waste disposal have
received considerable attention during the past 5 years as a result of
national interest in the environment, Federal and state legislation re-
garding air, land, and water pollution, and interest in conservation of
materials and resources. We define throw-away or land disposal to
constitute litter, open dump, and sanitary landfill; thermal treatment
consists of incineration with or without energy recovery, and pyroly-
sis; while utilization or resource recovery consists of materials re-
covery and composting.
In the previous section of this report, attempts have been made to
estimate the magnitude of the change in various forms of disposal
from 1970 to the year 2000, as illustrated graphically in Figure 5.
37
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Total collected
Sanitary landfill (Including
thermal treatment residues)
Thermal
treatment
Open dump and
open burning
Resource
recovery
1975
I960
1985 1990
Year
1995
2000
FIGURE 5. PROJECTION OF WASTE DISPOSED BY VARIOUS
DISPOSAL SYSTEMS, AS DEVELOPED IN THIS
PROGRAM
38
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Estimates for Land Disposal (Throw-Away)
In 1965, a survey by APWA showed that in the U. S. there were about
1175 "noncaptive" sanitary landfills and 19,400 "noncaptive" open
dumps. ^ Noncaptive installations were defined as those that are not
operated for the disposal of the owner's refuse exclusively. It was
estimated that about 91 percent of the sanitary landfills were supported
by urban and "semirural", while 9 percent were in rural communities.
Also, about 51 percent of the open dumps were supported by the urban
and semirural, while 49 percent were supported by the rural. A ma-
jority of the rural refuse is disposed of on the privately owned sites,
which are largely open dump and not included in this count.
According to Warner et al, 23 in 1966, "79 percent of all U. S. cities
with populations over 25, 000 utilized landfilj. with almost 81 percent
of the solid waste in these communities disposed of in this manner".
The estimate of the sanitary landfill was 6 percent of 12,000 U. S.
solid-waste land-disposal sites or about 720 sites. Another estimate
by Black24, who stated that only 5 percent of the 14, 000 authorized
land disposal sites were sanitary landfills, approximates Warner's
estimates.
In 1971, EPA data estimated that 175 million tons of municipal refuse
were disposed of on the land25: 25 million tons sanitary landfilled,
52. 5 million tons open dumped and burned, and 97. 5 million tons
open dumped without burning. In 1970, about 92 percent (or 171.9
million tons) of the total municipal refuse generated was deposited on
or in the land, but this is expected to decrease significantly by the
year 2000 to around 47. 5 percent or 115. 9 million tons. Based upon
our evaluation, trends that will effect this change are as follows:
• There will be an increasing efficiency in the municipal refuse
collection over the years evaluated. The percentage of the total
.refuse collected is expected to increase from 67 percent in 1970
to 91 percent by 2000. Furthermore, litter is estimated to de-
crease approximately linearly, that is, from about 10 percent
(or 6.2 million tons) of the uncollected refuse in 1970 to about
2 percent (or 0.4 million tons) by the year 2000.
• Regulations against open dumping with or without burning will
reduce this disposal method, with approximately a linear
39
-------
decrease from about 79. 7 percent (or 149 million tons) of the total
household and commercial refuse generated in 1970 to about 11 per-
cent (or 27 million tons) by the year 2000.
• "Wherever possible, it is expected that open-dump sites will be con-
verted to sanitary landfills. The quantity of the refuse placed in
sanitary landfill is estimated initially to increase linearly from
about 15 percent of the collected refuse in 1970, to about 33 per-
cent in 1987, after which it will begin leveling off as other meth-
ods develop. The maturing of other technologies such as energy
recovery and other material recovery processes will bring about
this leveling effect. Hence, by the year 2000, it is estimated that
about 41 percent (or 89 million tons) of the collected municipal
refuse will be placed in the sanitary landfill.
The components of solid waste that enter open-dump landfill sites will
be in proportion to their respective generation rates, since no pro-
cessing or resource recovery is expected to be conducted on this frac-
tion. Thus, it is expected that the plastic component will follow its
generation rate as shown in Table 1. The impact of plastic on this
disposal method is discussed in the next section.
In sanitary landfill and thermal treatment operations, the amounts of
various components entering the disposal method will differ from that
generated by the amount of materials removed by resource-recovery
operations from which the residuals will be relegated to sanitary land-
fill or thermal treatment for disposal. Assuming metals, glass, and
long fibers to constitute the major recoverable materials from solid
waste, the cost of processing for recovery purposes would probably
be recoverable if 30 percent of the processed waste were obtained as
useful marketable material. The remaining 70 percent of the pro-
cessed waste would go to landfill or be thermally treated for energy
recovery. As plastic materials are not considered to be recoverable
from household and commercial waste through the year 2000, the
amount of plastic in the residue from resource recovery will increase
and thus contribute more of an impact upon these disposal methods.
Resource recovery was given a new impetus in 1970 by a law providing
Federal assistance to overcome certain technical and product market
limitations. It has been estimated that 70 percent of the collected
waste is the maximum potential quantity that can be processed for
40
-------
recovery of specific materials and energy values ("roughly equivalent
to the waste collected in the U. S. Standard Metropolitan Statistical
Areas as defined by the U. S. Department of Commerce"). ^° How-
ever, the actual recycling rate in the United States today is much
lower. Darnay and Franklin provided five reasons for the low re-
cycling rate^?;
(1) The cost of virgin raw materials to the manufacturer is almost
as low as the cost of secondary materials; and virgin materials
are usually qualitatively superior to salvage. Consequently,
demand for secondary materials is limited.
(2) Natural resources are abundant and manufacturing industries have
deployed their operations and perfected their technologies to ex-
ploit them. No corresponding deployments and technology to ex-
ploit wastes have developed.
(3) Natural resources occur in concentrations while wastes occur in
a dispersed manner. Consequently, acquisition of wastes for
recycling often is costly.
(4) Virgin materials, even in unprocessed form, tend to be more
homogeneous than waste materials. Sorting of wastes is costly
and, in an age of affluence and convenience, repugnant to those
who would have to engage in it — the urban householders.
(5) The advent of synthetic materials made from hydrocarbons, and
their combination with natural materials, cause contamination of
the latter, limiting their recovery. The synthetics themselves
are virtually impossible to sort and recover economically.
Recent shortages of some natural resources have brought attention to
the recovery of materials from mixed municipal refuse. This re-
covery requires that the products in the refuse be separated into basic
materials classes - paper, ferrous metals, clear glass, dark glass,
plastic, etc. The traditional technique of separation by hand is too
expensive, hence various separation technologies are currently under
development.
In 1970, a very small fraction of the collected municipal refuse was
being recycled. This study estimates that by the year 2000, about
41
-------
28 percent (or 42. 5 million tons) of the collected municipal refuse will
be recycled. This increase will result from: (1) a greater demand
for the salvage materials by the industry as virgin materials become
more costly, and (2) the development of improved separation
technologies.
Thermal treatment of solid waste as a disposal method has consider-
able merit for purposes of volume reduction and for purposes of en-
ergy recovery, as over 70 percent of bulk household waste is com-
bustible. After processing and removing recoverable material, over
90 percent is combustible! The exothermic reaction of combustion
provides a heat source that may be converted to low- or high-pressure
steam.
In 1965 about 300 municipal incinerators were in operation. 22 By
1971 the number of operating incinerators declined, as shown in
Table 8, to approximately 195 because of obsolescence, emission-
control regulations, and repair or construction costs. 28 A 1974 sur-
vey has shown that the number is now down to 140. 29 Furthermore,
over 95 percent of the operating municipal incinerators have incorpo-
rated emission-control systems in the off-gas chambers or stacks.
Unfortunately, corrosion is a major problem in these emission-
control systems. Also, corrosion has been a major deterrent to the
installation of heat-recovery systems in municipal incinerators.
TABLE 8. DISTRIBUTION OF REFUSE INCINERATORS
BY TYPE AND NUMBERO2)
Type(a)
I
II
III
Number
8
144
43
Capacity,
ton/day
700
48,000
21,500
Estimate of
Volume Processed'"',
ton/ year
0. 17 x 106
11.63 x 106
5.20 x 106
Total 195 70,200 17.00xl06
(a) I = No emission control or heat recovery, II = emission control, III = heat recovery and
emission control.
(b) Estimate made at 2/3 capacity to correct for downtime and less than 24 hour/day
operations.
42
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Incinerators, which do not incorporate emission controls or heat-
recovery systems, are in general, constructed of refractory mate-
rials resistant to attack by refuse combustion products. However,
this equipment may be damaged by overheating.
With improved application of the present technology, municipal incin-
erators can provide a significant means of disposing the municipal
refuse. Economic considerations will force the smaller capacity
plants to close. Baun and Parker^O suggested that something on the
order of 200 tons/day represents the minimum economic capacity.
Smaller communities may unite in joint efforts to justify a plant of
this or larger capacity. It is expected that, because plants of this ca-
pacity will have heat-recovery capabilities, incineration merely for
volume reduction of solid waste will be less common. In the face of
the energy crisis, waste-heat reclamation will become more attrac-
tive, especially for larger plants in central locations, operating 24
hours a day.
Projections made in this study stipulate that an increasing percentage
of the collected municipal refuse will be thermally processed — from
about 11. 5 percent (or 14. 5 million tons) in 1970 to about 28 percent
(or 62 million tons) in the year 2000. As a comparison, Niessen^
projected the percentage of total collected municipal refuse that is in-
cinerated as follows:
1970 - 14 percent or 30 million tons
1975 - 20 percent or 45 million tons
1980 — 23 percent or 50 million tons.
Although our estimates are somewhat higher than previous projections,
we believe that power generation will be a major contributor to the
disposal of solid waste. A breakdown of the amounts thermally pro-
cessed by incineration, heat-recovery combustion, power generation,
and pyrolysis is presented at the bottom of Table 9, which presents
our forecast of the annual distribution of the total solid waste gen-
erated in 5-year increments to 2000. Included in this table are the
amounts and percents of plastic handled by the various disposal
methods.
43
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TABLE 9. FORECAST OF ANNUAL DISTRIBUTION OF SOLID WASTE GENERATED BY DISPOSAL METHOD TO THE YEAR 2000
IN AMOUNTS (106 TONS), PERCENTAGE OF TOTAL. AND PERCENTAGE OF PLASTIC IN DISPOSAL CATEGORY
1970
Open Dump With/Without
Burning
Plastics ( )(D)
Sanitary -indfill
.Plastics ( )(b)
Thermally Treated'*'
Plastics ( Xb>
Resource Recovery
Plastics
Litter
Total
Total Plastics
(a) Heat Recovery
Power Generation
Pyrolysi*
Incineration
Amt
149
3.4
18
0.42
14.8
0.34
0.2
0
5.0
187
4.3
2.0
NU
NU
12."
*
79.7
(2.3)
9.6
(2.31)
8.0
(2.32)
0.1
2.6
100
2.3
1.0
—
..
7.0
1975
Arm
145
4.1
28
0.84
18.5
0.55
2.2
0
4.3
198
5.5
6.0
NU
NU
12.5
*
73.2
(2.8)
14.1
(2.99)
9.5
(2.99)
1.1
2.1
100
2.8
3.0
—
--
6.5
1980
Am
133
5.1
40
1.68
23.8
1.0
7.0
0
3.2
207
7.9
8.0
2.0
1.0
12.8
*
64.1
(3.8)
19.3
(4.2)
11.5
(4.2)
3.6
l.S
100
3,8
3.9
1.0
0.6
6.1
1985
Amt
112
6.3
S3
3.56
33.4
2.25
17.4
0
2.2
218
12.2
11.0
8.0
2.0
12.4
*
51.6
(S.6)
24.3
(6.7)
15.2
(6.7)
7.9
1.0
100
5.6
5.0
3.6
0.9
5.7
1990
Amt
82
6.4
6»
6.90
43.3
4.33
31.5
0
1.2
227
17.7
15.0
18.0
3.0
7.3
*
36.2
(1.8)
30.4
(10.0)
19.0
(10.0)
13.9
0.5
100
7.8
6.6
7.9
1.3
3.2
1995
An*
51
S.3
81
11.48
53.6
7.60
44.9
0
0.5
235
24.4
20.0
24.0
S.O
4.6
*
21.9
(10.4)
34.5
C14.2)
22. »
(14.2)
20.7
0.2
100
10.4
8.5
10.2
2.1
2.0
tooo
Amt
27
3.6
89
17.85
62.5
12.50
65.2
0
0.3
244
32.7
24.0
32.0
6.0
0.5
*
11.0
(13.4)
36.4
(20.0)
2S.6
(20.0)
2S.9
0.1
100
13.4
9.9
13.1
2.4
0.2
(b) Percentage numbers In ( ) represent the plastic component In the amount disposed of by respective disposal method.
-------
SECTION V
ENVIRONMENTAL IMPACTS OF PLASTICS DISPOSAL
An overall impact of plastic-refuse disposal upon the environment can
be obtained by analyzing the effects of major solid-waste-disposal
methods upon the major environmental categories. This approach
becomes applicable when the distribution of the plastic component
within the solid waste among the various disposal methods can be
estimated. Unfortunately, while some disposal methods (e.g.,
incineration) create direct and immediate impacts upon the environ-
ment by their specific emissions to the environment, other disposal
methods, such as landfill, do not create such direct and/or immediate
environmental impacts (except, of course, the physical impact of its
weight and volume) because of the much lower rate of plastic degrada-
tion and pollutant emission to the environment. A gross and rather
simplistic approach that can be used to analyze impacts of plastic dis-
posal (for disposal processes where plastic wastes do not significantly
decompose within the normal time frame of solid-waste decomposition)
is to assume that the impacts are merely physical, being directly pro-
portional to plastic volumetric and/or weight percentage in the refuse.
Such an approach assumes that the presence of plastics may either aug-
ment or lessen the environmental impact of the solid-waste disposal.
Therefore, the direction of the environmental impact due to plastic
will depend on (1) the nature and magnitude of the environmental param-
eters due to slow releases from plastic degradation, if any, and (2) the
relative importance on some numerical scale of specific impacts.
The former must be clearly established before any attempt to estimate
the latter is possible. Where neither is possible, environmental im-
pact assessment will rely merely on qualitative statements.
Previous sections provide projections of plastic-waste components in
the solid-waste generation, and estimates of the quantities that may be
disposed of by the respective disposal methods: (1) throw-away or
45
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landfill, (2) thermally treated, and (3) resource recovery. The
environmental stress of the plastics disposed by these methods is
assessed by evaluating contributions to certain environmental impact
categories: (1) water pollution, (2) air pollution, (3) land pollution,
and (4) aesthetic and human factors. A discussion of the ecological
impacts - the biotic and abiotic interactions within and between the
impact categories — is necessary to complete the required impact-
analysis scenario.
LAND DISPOSAL OF PLASTIC WASTES
The traditional plastics (polyethylene, polyvinyl chloride, and poly-
styrene) comprise about 90 percent of the plastic wastes found in the
municipal solid wastes which are disposed of on and/or under the soil
(open dump, litter, sanitary landfill). These materials do not decom-
pose significantly within the normal time frame of solid-waste decom-
position, and consequently do not immediately contribute pollutants
into the environment except when they are burned. What is not known
is the rate of the slow but prolonged emissions or release into the
environment from such plastic wastes. On the other hand, if plastics
that can degrade under various environmental conditions by various
mechanisms - biodegradation, solubility, and photodegradation -
would be present in the solid-waste stream in large amounts, then
plastic-waste environmental impact will be significant.
Water-Pollution Effects
Environmental parameters used as indicators of ground- or surface-
water quality comprise BOD, suspended solids and turbidity, total
dissolved solids and COD, macronutrients, dissolved oxygen, and
toxic substances. These indicators of water pollution are influenced
to a different extent by land-disposal practices applied to solid waste.
Under suitable environmental conditions of temperature, moisture
and oxygen, organic and inorganic wastes are utilized by micro-
organisms through aerobic and anaerobic synthesis.
Water entering into the disposal site naturally by rainfall or from
adjacent sources moving horizontally through the filled site may
initiate surface runoff and leachate of varying chemical compositions.
46
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Depending on the land topography, soil characteristics, and attenua-
tion potential, the leachate may reach surfacewater or percolate
through the soil profile to pollute groundwater. Based on the above
background on water pollution from land disposal of solid wastes,
the respective land-disposal methods are sequentially analyzed.
Litter, a nonpoint source of pollution, creates more surfacewater
pollution than groundwater pollution. Its main water-pollution indi-
cator is suspended solids or floating plastic materials in lakes,
streams, and rivers. Most litter materials come from consumer
packaging goods, and plastics contribute a major portion of this
fraction. Consequently, the percentage of plastics in the litter is
usually greater than that in other collected solid waste.
It is difficult to predict the quantity of the littering plastics floating
in the nation's water bodies since this is influenced by many factors
such as climate, wind, topography, and the effect of human activities
and closeness to the water body. It is reasonable to assume that the
percentage of plastics will be sizeable.
Emissions from litter plastics into the environment will tend to be
greatly increased when photodegradable plastics (plastic sensitive
to ultraviolet light) are used extensively. Photodegradation is time
and temperature dependent and varies with the polymeric structure
thickness, and the concentration and content of additives such as
pigments, ultraviolet accelerators and promoters, ultraviolet ab-
sorbers, and antioxidants. 30 By their constant exposure to sunlight,
the litter plastic will absorb ultraviolet energy having wave lengths
below 320 microns from the sun. When enough energy is absorbed,
the bonds between carbon and hydrogen are broken and oxygen-reactive
free radicals are formed. Being constantly exposed to"oxygen, these
free radicals react with oxygen to produce peroxides and the hydro-
peroxides which decompose further to produce carbonyl groups,
hydroxyl groups, water, and carbon dioxide. 0 The plastics thus
broken up into short-chain, low-molecular-weight fragments may be-
come part of the soil or be carried away by natural erosive forces
such as rain and wind to surface waters as suspended or dissolved
solids.
Open dump water-pollution problems arise more often from runoff
than leachate. However, where the dump site is on a high watertable
47
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with a pervious soil profile, leachate can be equally as serious. Many
open dumps are located in low-lying and swampy areas in attempts
to reclaim such areas, but unfortunately, such practices cause water-
pollution problems because no attempts are made to contain the water
leaving the dump. Major water-pollution indicators which an open
dump can contribute are suspended solids, BOD, COD, macronutrients,
and toxic materials. There is a lack of data on the ranges of the indi-
cators associated with open dumps. The amount of each will depend
on many variable factors such as solid-waste composition at the site,
the degree of decomposition, whether anerobic or aerobic, and site
characteristics such as topography, soil condition, drainage, etc.
Specific impacts of the plastic fraction in solid waste on water pollu-
tion are equally uncertain. Again, because the dump is usually not
covered and, thus, exposed to sunlight, photodegradation of the ultra-
violet-sensitive plastics will take place. Since most modern plastics
are typically inert and nonbiodegradable, they do not by themselves
increase the BOD or other dissolved chemicals content of the leach-
ates and runoff from the dump. However, since plastics are light
weight and provide a loose packing in the dump, their presence will
tend to increase the packed volume of the waste. This packing will
improve the aeration and rate of decomposition of the degradable
fractions of the solid waste. Furthermore, since leachates resulting
from aerobic decomposition are lower in BOD content (about 5 times
lower)^ than their anaerobic counterparts, the presence of plastic
appears to be advantageous with respect to BOD level. On the other
hand, increased use of plastic bags to contain household and commer-
cial wastes does concentrate the refuse. The bags increase the pack-
ing of refuse and encourage anaerobic conditions.
Sanitary landfiiris regarded as the most accepted land-disposal
method for solid waste because it provides an engineering approach
to solid-waste disposal with minimum \environmentaI impact. The
greatest water pollution from landfill arises from leachate when it
is not contained within the fill and is allowed either to percolate
through the soil profile to the groundwater or to run off to the surface-
water. Major water-pollution indicators of the leachate from landfill
are BOD, COD, dissolved solids, and toxic substances such as phenols
and some metal ions.
48
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The leachate from a sanitary landfill is complex and the compositions
vary widely. Factors which are considered to have influence on the
production and characteristics of leachate include:
• Material in the fill consists of both organic and inorganic
or degradable and nondegradable materials, resulting in
the production of soluble and insoluble products in the
leachate.
• Varying conditions in the fill — such as temperature,
dissolved oxygen, pH, moisture - result in different types
of decomposition, (aerobic and anaerobic) taking place
at different stages of oxidation and permeability of the
fill.
• Surrounding soil characteristics will influence the pH,
organic matter, etc.
• The incoming solvent water will contribute some changes
in the leachate characteristics such as attenuation and
dilution, depending on the source and quantity of the
influent.
Many studies on the characteristics and amounts of leachates from
sanitary landfills have been conducted. Zanoni^l reviewed the experi-
mental data available and Thornton and Blanc^2 presented "average"
values for the characteristics of leachates from sanitary landfills.
Zanoni^l and Stone et a I, ^3 pointed out qualitative differences between
leachates obtained from refuse decomposition under both aerobic and
anaerobic conditions. Again it can be stated that leachates resulting
from aerobic decomposition are lower in BOD content (about 5 times
lower) than those formed anaerobically. Also both organic and in-
organic species present in the former are in a higher state of oxida-
tion than in the latter.
The characteristics of the leachate resulting from landfills are given
in Table 10.
The presence of plastics in sanitary landfills may be considered to
have no immediate impact on the ground- and surfacewater quality,
because it does not decompose within the same time frame as do
other degradable materials in the fill.
49
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TABLE 10. CHARACTERISTICS OF LEACHATE FROM
SANITARY LANDFILLS12
Constituent
pH
CaCO3
Alkalinity (CaCO3)
Calcium
Magnesium
Sodium
Potassium
Total iron
Ferrous iron
Chloride
Sulfate
Inorganic phosphate
Organic nitrogen
Ammonia nitrogen
BOD
Minimum
Value
5.60
650
730
115
64
85
28
6
2
96
39
0.2
2
0.2
81
Average
Value
6.55
3,633
4,629
1,047
181
940
959
110
24
1,814
248
7
163
437
10,850
Maximum
Value
7.63
8, 120
9,520
2,570
410
1,805
1,860
305
93
2,350 ,
730
29
550
845
33, 100
Note; All data with the exception of pH values are in milligrams per liter.
Plastics ultimately decompose; the span of most plastic decomposition
is between 10 and 30 years. Plastic degradation in the landfill may
take even longer depending on the prevailing mode of degradation,
biodegradation, solubility, or photodegradation. Photodegradation
should not be significant in covered landfills unless the plastics have
absorbed enough ultraviolet energy prior to being covered. The most
likely prevailing modes will be biodegradation and solubilization.
Most of the products released will form part of the soil. Any part
entering the leachate will result in higher COD, dissolved solids,
and suspended solids rather than higher BOD. An area of uncertainty,
where more data are needed, is the rate of release of decomposition
products of plastics to the environment particularly for such plastic
types as PVC.
A simplistic approach to analyzing the impact of land disposal of
plastics on water pollution was based on the volume effects of the
50
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plastic. ^ Since plastics comprise about 5 percent by volume of the
waste, it was assumed that the landfill surface area will be increased
about the same ratio. Thus more putrescible components of the
solid waste would be exposed to more moisture and dissolved oxygen
and the rate of decomposition would be increased accordingly. With
BOD as a measure of water pollution, the annual BOD produced by
landfill was calculated on the basis of 1.85 x 103 tons BOD leachate
per ton of landfilled refuse.31 Five percent of this quantity was
assumed to be attributable to the presence of 5 volume percent plastic
component of the solid waste. This deduction is misleading because
the presence of plastic may tend to lower the BOD of the leachate
by promoting aerobic conditions instead of increasing it. As properly
assumed, the presence of plastic will increase the area and volume
of the landfill site, but it may also provide a loosely packed landfill
with trapped air pockets. Such an occurrence will provide an aerobic
rather than an anaerobic condition, which will tend to decrease the
BOD content of the leachate. If plastics were not present in the solid
waste, other materials such as paper could have taken their place
thus providing more degradable materials and thus more BOD.
The main effect of plastic disposed in landfills on water pollution will
be in the increase of COD, dissolved solids, and perhaps suspended
solids of the leachate. However, the lack of a carefully controlled
experimental study in this area makes firm conclusions difficult to
reach, and research is needed on this aspect of solid-waste disposal.
Air-Pollution Effects
Air pollution from land disposal of municipal refuse results from
(1) gas generation from the biodegradation of putrescible components
of the refuse, and (2) accidental or deliberate burning of the refuse
at the dumps. The various land-disposal methods are assessed on
the above air-pollution-emission processes.
Litter contribution to air pollution is considered negligible. Litter is
not concentrated in one spot to support fire or encourage decomposi-
tion to the extent that air pollution will result. Plastic litter can
decompose, but the rate would be very low and the emission quantities
insignificant.
51
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Open dumps create air pollution by two processes: (1) anaerobic
decomposition of the refuse and (2) accidental or deliberate burning
of the refuse.
Since the dump is not covered with soil, ga^es at different stages of
decomposition are emitted with minimum restriction. These gases
may consist of decomposition end-products of the degradable nitro-
genous, carbonaceous, and sulfurous organic materials, such as
ammonia, CH,, CC>2, moisture, and H^S or their intermediate prod-
ucts such as organic acids, alcohol, mercaptans, etc.x It is important
to note that air pollution will not result from an aerobic decomposition
process which produces CC^ as an end-product. The condition exist-
ing in the dump is rarely aerobic, however, but usually anaerobic
with the production of gases such as I^S, mercaptans, or alcohols,
that are highly odorous even in small concentrations. This is one
major reason why the open dump is an environmentally unacceptable
disposal method. Methane also may be produced. This gas is explo-
sive in concentrations from 5 to 15 percent by volume and could be
a fire hazard when it accumulates in small pockets. The presence
of plastic in the dump will improve aeration and thus encourage aerobic
decomposition processes, and so, may reduce the production of odor-
ous gases that will cause air pollution.
Open burning of the solid waste on the other hand will contribute to
air pollution. Plastics being a high-heat-value material will sustain
combustion and contribute to air pollution. Deliberate open burning
reduces the volume of solid waste but emits pollutants, such as,
particulates, CO, hydrocarbons, HCl, and NOX, that generally cause
adverse public reaction. Many states have banned uncontrolled open
burning, and'it is expected that by the year 2000,. open burning will
be an insignificant practice of waste disposal.
Table 11 gives estimated yearly emissions of pollutants from the open
burning of plastics, based on the emission factors for open burning of
municipal refuse.
The table'shows that reasonable reduction in emissions from burning
plastic waste may not take place until after 1980.
Sanitary landfill'ing of municipal refuse may create air pollution when
degradable portions of the refuse decompose anaerobically, and the
52
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TABLE 11. AIR-CONTAMINANT EMISSIONS BY PLASTICS DURING
OPEN BURNING OF REFUSE
Ul
OJ
Pollutant
Percent Burned
Particulates
CO
Hydrocarbons
as (CH4)
NOX
HCl
Emission
Factor,
Annual Pollutant Emissions, thousands of tons
lb/ton(a) 1970
60
19.8(b) 20.
105 7.
95(e) 96.
2
1
7
8
9
1975
50
20.
107.
37.
7.
97.
3
6
9
8
4
1980
40
20.
107.
37.
7.
96.
1985
30
2
1
7
8
9
18.
99.
35.
7.
89.
7
2
0
2
8
1990
30
12.7
67.2
23.7
4.9
60.8
1995
10
5.2
27.8
9.8
2.0
25.2
2000
1
0.4
1.9
0.7
0.1
1.7
(a) Assuming 81 percent combustible of municipal refuse.^34)
(b) Percent of the open-dump refuse burned. It is assumed that the same percentage is applicable to plastics fraction.
(c) For CO and hydrocarbons the combustible materials in municipal refuse are sufficiently similar in chemical composition
to plastics that using the same emission factors is probably warranted.
(d) While some plastics (like urea-melamine) contain nitrogen, the contribution to the total NOX emission will probably
be negligible since in open burning a reducing atmosphere probably is prevalent.
(e) The HCl emission factor from open burning was computed by assuming that all chlorine in PVC is converted to HCl.
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gaseous products are emitted to the atmosphere. Sanitary landfill is
usually covered with earth, and under the reduced presence of oxygen,
the prevailing anaerobic decomposition of the putrescible materials
takes place in three phases: liquification, acidification, and gasifica-
tion. The complex organic compounds (carbohydrates, proteins, and
fats) are first liquified by enzyme action and then broken down into
organic acids by the action of heterotrophic organisms present in the
soil. The final phase is a gasification process during which the
organic acids are further broken down into CC^ and CH^ gases by
methane bacteria.
The presence of plastics in the landfill will have no direct impact on
the quantity of gaseous production because plastics by themselves
do not decompose. However, the presence of plastics makes the
landfill difficult to compact efficiently with ordinary equipment
(tractors, draglines, or steel-wheeled compactors). ^ Therefore,
the fill tends to contain air pockets, thus encouraging aerobic condi-
tions which generally promote a higher rate of oxidation than do
anaerobic conditions. Methane will be produced at much lower rates,
and the gases emitted may be diluted with air.
Since plastics are not decomposed within the normal time frame of
the solid-waste decomposition, the presence of plastic will tend to
delay the reuse of the landfill site, Under the projections shown in
Table 9, a significant effect on the ultimate use of the Landfill site
may not be evident until 1990 when the amount of plastic becomes
10 percent or more.
Land-Pollution Effects
Land pollution results when some activity renders the land unusable.
This rarely occurs with most municipal-refuse disposal. Because
municipal refuse rarely contains hazardous wastes, most sanitary
landfills or open dumps, when completed and allowed to stabilize,
may be converted to a playground, parking lot, or agricultural land.
A better approach however, is to classify landfill sites according to
the kinds of waste materials to be landfilled at a particular site that
will give minimum adverse environmental impact. A typical classi-
fication is shown in Table 12. In the years ahead, separation of
54
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TABLE 12. CLASSIFICATION OF WASTE ACCEPTABLE FOR
DISPOSAL AT DISPOSAL SITES
Class 1 Disposal Sites — No limitation of type of material, liquid,
or solid.
Group 1 Waste
Saline brines
Liquid or soluble toxic chemicals
Class 2 Disposal Sites - Decomposable organic wastes or solid-waste
mixtures containing decomposable organic material, and some ma-
terials unacceptable at Class 3 sites.
Group 2 Waste
Garbage
Street refuse
Decomposable demolition materials
Agricultural prunings and culls
Industrial rubbish
Miscellaneous metals
Rubbish
Dead animals
Sewage-treatment residue
Manures
Cannery sludges
Paint sludge
Class 3 Disposal Sites - Water-insoluble, nondecomposable, inert
solids.
Group 3 Waste
Earth, rock, sand, and gravel
Concrete
Plaster and plaster products
Steel-mill slag
Inert plastics
Asphalt-paving fragments
Brick and maso/nrry materials
Inert demolition materials
Glass
Asbestos materials
55
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wastes into specific site classes will become more widely adopted
if the waste material can be separated at the source. It is important
to note that plastics are grouped in Class 3 — the water-insoluble,
nondecomposable, inert-solids group. The major impact of land
disposal of plastic.is that larger land area may be required for refuse
disposal than would otherwise be required because of its density and
compaction effects. Another impact, is the delay in the reuse of the
filled site, because of the long time it takes to stabilize.
Litter is a nonpoint source of pollution, and its influence on the land
can hardly be termed land pollution, but rather unsightliness.
Open dump refuse usually is not compacted, so the quantity of refuse
per unit volume is not as much as that in the landfill, thus requiring
greater land area. Densities of refuse in open dumps varies between
420 and 320 Ib per cu yd, and height varies widely too. Assuming
a height of 20 ft and dump density of 320 Ib per cu yd, Table 13 was
developed giving the land requirement for the open-dump refuse
without plastic through year 2000. The additional land requirement
for plastics disposal is also calculated. The land requirement for
plastic disposal is a very small portion of the overall land use for
open dumping.
A major factor that seems to make open-dump sites unsuitable is lack
of structural stability. Open dumps are known to settle as much as
10 ft per year (during the first year) an
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TABLE 13. OPEN-DUMP AND SANITARY-LANDFILL LAND REQUIREMENT IN ACRES
1970 1975 1980 1985 1990 1995 2000
Percent Open Dump 40 50 60 70 80 90 99
(without burning)
Open Dump 11,298 13,667 14,888 14,354 11,423 11,471 4,494
(without plastic)
Plastic Requirement^) 52 78 116 167 194 181 135
Sanitary Landfill 807 1,247 1,759 2,270 2,851 3,238 3,266
(without plastic)(c)
Plastic Requirement 16 32 64 135 261 435 676
(a) Assumed dump density 320 Ib per cu yd at 20-ft height.
(b) Assumed plastic density 33 cu. ft/ton.(36)
(c) Assumed sanitary landfill density 900 Ib per cu yd at 30 ft.
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Ecological Effects
Ecological impacts are those processes which disrupt or change the
basic relationships between living organisms and their environment.
There is a need to determine whether land disposal of plastics disrupts
or changes the basic relationships which exist at the disposal site, or
its environs, between living organisms and their environment. Such
disruption or changes may result from the leachate and/or gases
emitted from the plastic disposed at the sites.
Leachate from sanitary landfills and open dumps reaching stretches
of natural surfacewaters (streams, rivers, and lakes) may be suf-
ficiently high in BOD and other pollutants but low in others (such as
dissolved oxygen) as to cause fish kills and the destruction of other
aquatic life therein. Leachate from sanitary landfills may be con-
tained by proper drainage or collected and treated. Open dumps,
however, have been major sources of water pollution, since leachates
are usually uncontrolled. There is no direct impact of plastic waste
on leachate characteristics as discussed earlier as long as there is
no direct emissions by the plastics. Until data are available on the
decomposition emissions from plastic waste, no conclusive statement
can be made on the ecological impact.
Because sanitary landfills are covered with soil when completed, the
site can be used to support plant growth such as grasses and shrubs,
even before full stabilization of the site. The site subsequently can
be used as a playground or for light-structure buildings. It is not
possible to put open dumps into such use because high heat and low
dissolved oxygen existing during decomposition do not allow the growth
of all plant life. The open dump site must be reclaimed before the
site can be put to any use comparable to that of a sanitary landfill.
Decomposition-gas movement in sanitary landfills has been known to
cause the destruction of plant life in the immediate vicinity, probably
as a result of the exclusion of dissolved oxygen from the root zone
by methane and carbon dioxide. Again, there is no direct plastic-
waste influence other than its volume and/or weight effects.
Landfill and open-dump encroachment upon the land environment tends
to displace the terrestrial fauna and biota previously inhabiting the
sites. It is-logical to assume that species that are incapable of
58
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adapting to the environment existing at the fills will perhaps disappear
from that area. At present there is no substantiation of such effects
that plastic waste and its decomposition products may have on fauna
and biota. The greatest impact however is that of the open dump,
which provides habitats for rodents, insects, flies, and other disease
vectors. Such an environment may be a threat to wildlife in the vicin-
ity and even to human health. Some plastics, depending on the pig-
mentation, are fly and insect attractants, and so may promote such
infestation.
Aesthetics and Human-Factors Effects
Various methods of refuse disposal have varying degrees of effects on
our well-being. Such important effects are the aesthetic, health, and
economic impacts. Best disposal methods, as are evident from the
preceding sections, are those that are technically efficient, econom-
ically sound, and environmentally safe. Specific impacts of the plastic
component of the solid waste are presently unclear, and so far as is
known, they are insignificant. Some schools of thought feel that plas-
tics are advantageous. 37 The various land disposal methods are se-
quentially discussed according to their aesthetic, health, and economic
impacts. Where possible, plastic impacts are qualitatively discussed.
Litter is ugly, unsightly, and it defaces or mars the appearance of the
landscape. The aesthetic impact of plastic waste is significant be-
cause (1) it is a significant fraction of the packaging industry which
produces nearly all the refuse litter, (2) it is of low bulk density, thus
can be blown about in the air, onto natural surfacewaters, or to other
less accessible areas of the countryside, where it is not possible or
desirable to send in crews of people to pick up the litter, and (3) it has
a long life in the environment. Certainly, if it were possible to assess
aesthetic impacts quantitatively, that of litter should be found to be
more than its volume fraction of the solid-waste. If photodegradable
plastics become a sizable fraction of litter plastics in the years ahead,
the aesthetic impact will tend to decrease because the life span in the
environment will decrease.
Litter is unhealthy. If litter accumulates sufficiently at a spot, it will
provide a breeding place for rats, insects, and disease. Accumulated
59
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litter is hazardous from the viewpoint of being flammable. It is diffi-
cult to put a quantitative figure on this impact since it will depend on
factors of human activity and the environment. There is a need to
study the potential health effects of the degraded plastics, and this
need will become greater with the availability of degradable plastics.
As was indicated earlier, the concern will be greatest with the litter
because it is usually deposited closer to populated areas than are
wastes disposed of by another method. Because of exposure to the at-
mosphere and to photodegradation, its emission rate per unit weight
to the environment may be greater too. No data are available on the
air emissions from plastics degradation. For decomposed plastic
which remains on the soil (plastic sand), studies on polyethylene and
polystyrene have shown that there is no long-term damage to the soil
from the accumulation of photodegraded plastic particles. 37
Litter is costly. One source estimates that about a billion dollars a
year is spent to retrieve the newspapers, wrappers, cans, bottles,
plastics, etc. , tossed carelessly aside. It is further estimated that
(1) half of this tax money is spent to clean up parks and recreational
areas, (2) $28 million is spent recovering trash from primary high-
ways, and (3) business, industry, and labor together are known to be
spending more than $25 million a year to combat litter, both in private
effort and in support of organizations like KAB (Keep America Beau-
tiful). 3° A litter-free state attracts industry. West Virginia claims
to have attracted 46 new industries that created 5, 000 jobs by its
clean-up program. A litter-free state also attracts more tourists.
In Kentucky, the year after its first antilitter campaign, figures
showed that tourists spent an extra $7 million in the state. In general,
it will be assumed that the economic impact of plastic will be in direct
proportion to its volumetric fraction of the refuse litter. Two ap-
proaches have been suggested as means to combat littering - litter
laws with strong teeth for enforcement and education against littering.
Only 28 states have litter laws; in the years ahead, other states prob-
ably will be under increasing pressure to enact such laws. Education
through public communication and persuasion to inform citizens that
they are individually responsible for the attractiveness of their sur-
roundings will be conducted by government and private agencies.
Open dumps are aesthetically objectionable by their unpleasant appear-
ance and the odors they produce. Urban development near open-dump
60
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areas tends to be restricted due to the reduced scenic beauty and psy-
chological, and perhaps physiological, stressful conditions created
by the open dump site. People just don't want to live near such sur-
roundings. The contribution of plastics to this impact is assumed to
be in direct relationship to their volumetric presence in the refuse.
Unless the site is well stabilized, light structures for such activities
as playgrounds and parking lots will be the only activities allowed on
such sites because of low bearing strength of the soil on the site.
The presence of plastic will tend to delay the site stabilization and,
thus, the reuse of the site.
Open dumps threaten human health. Their relationship to disease
potentials in humans has been reviewed by Hanks. 39 They provide a
food source and harborage for rodents, insects, and disease vectors.
Hanks observed that open-dump encroachment upon land which hitherto
had been a wilderness poses the threat of increased interaction be-
tween the wild and "domestic" rodents, thus creating a possibility of
spreading disease. It is hard to put quantitative value on the plastics
impact which may be in direct proportion to its volume percent in the
open dump. As observed previously, the presence of plastics will
cause an increase in the acreage for open dumps, and harborage time
of rodents may be longer because of the delay in stabilization. Be-
sides odor produced during the biodegradation of the materials in the
dump, particulates, odor, intense smoke, and other air contaminants
are also produced from the open burning of the refuse. These instal-
lations not only produce adverse aesthetic reactions in man, but some
of the pollutants emitted are dangerous to health.
The economic impact of open dumping of plastic and other refuse in-
volves collection, transportation, and land cost. No cost is incurred
on site management. Plastic economic impact associated with open
dumping is assumed to be in direct proportion to its percent in the
refuse as shown in Table 9.
Sanitary landfill, when properly designed and operated, is considered
the most technically efficient and environmentally safe method of land
disposal of refuse. However, when improperly designed and misman-
aged it creates aesthetic problems and danger to human and animal
life.
61
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The aesthetic impact is associated with odor generation while the pos-
sible danger to animal life is caused by leachate. Odor production in
landfill is usually not a serious problem since most landfills are cov-
ered with soil. However, leachate can create very serious problems
if land-selection, drainage-design, and filled-site management are in-
adequate. Under this condition, leachate may percolate through the
soil to contaminate groundwater with metal ions, pathogens, nutrients,
etc. , making it unsuitable for drinking and recreational purposes.
Run-off to the surfacewater may also pose the same danger to water
supply. Landfill gases, if not properly vented, can cause asphyxiation
and serious explosions when they accumulate in sufficient concentra-
tions near residential areas.
The main human factor of landfill is the economic impact. Land acqui-
sition constitutes the major investment item, amounting to more than
half the total capital requirement. The next important cost factor is
the cost of transporting wastes from the sources of generation to the
landfill site. The importance of the latter has been increased by the
present energy crisis.
For landfill within 100 miles of the center of generation, cost of dis-
posal may vary from around $2 to $3 per ton per year, while the capi-
tal cost for a 2, 000 TPD landfill capacity may be as much as
$5, 000, 000. ^O The differences in land costs from region to region
can easily cause the capital costs to vary by a factor of 2 or more.
The economic impact of the plastic fraction will be proportional to its
volume fraction in the landfills.
Impact of Resource Recovery
The environmental impacts of resource recovery of plastic wastes
create no major pollution problems for air, water, or land, but rather
it effects some definite economic impacts. Efficient recycling of plas-
tics that are currently disposed on the land will perhaps result in a
cost saving in the manufacture of new end-products. However, major
problems in salvaging plastics for reuse and recycling include the
heterogeneity of the wastes and the diversity of types of plastics in the
municipal refuse, lack of cleanliness, and the fact that they are usually
present in forms not directly usable without reprocessing. Therefore,
62
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this study assumed that plastic recovery will occur only at the manu-
facturing end where different types and forms of plastics can easily be
separated for recycle, and not at the postconsumer end of the spec-
trum, where such separation is presently technically inefficient, and
economically unsound.
Various studies are under way to develop methods or processing and
separating the various components of the refuse into reclaimable ma-
terials. Because of low specific gravity, plastics may present prob-
lems in pulverization, and may be entangled in the refuse-processing
machinery. This aspect of plastic may be an adverse impact on its
recovery.
Because current plastic waste does not decompose readily, its impact
on composting is economically adverse since it has to be sorted out.
When photodegradable and biodegradable plastics appear in the munic-
ipal refuse stream, the requirement for sorting out the plastics may
no longer be necessary, thus providing some cost-saving.
AIR-POLLUTION IMPACT OF THERMAL TREATMENT
The disposal of solid waste by thermal treatment includes ordinary in-
cineration, burning to generate electrical energy, process steam, or
to provide central heating, and pyrolysis. With the possible exception
of pyrolysis, these thermal processes will result in emissions to the
atmosphere that come under regulation as air pollutants. The contri-
bution of plastics to these emissions can be calculated on the basis of
the plastic composition and its percentage in the solid waste. Some
pyrolysis treatment of solid waste is designed to convert the refuse
into useful chemical products that can be returned to the stream of in-
dustrial feedstocks, and this pyrolyzed portion would not be expected
to become a source of air-pollutant emissions.
To determine the extent to which the plastics contribute to emissions,
one must know the emission factors for the various pollutants. Studies
made by the U. S. Environmental Protection Agency have resulted in
the following incinerator-emission factors for air pollutants which are
under control regulations at the present time. ^> 41
63
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Incinerator-Emission
Pollutant Factor, Ib/ton
Carbon monoxide 35.0
Particulates 14. 9
Nitrogen oxides (as NC>2) 3. 9
Sulfur oxides (as 803) 2. 5
Hydrocarbons (as CH^) 1. 5
Although these emission factors have been derived from measurements
made on incineration processes that do not include heat recovery and
power generation, the addition of a boiler to the unit, as projected for
future years, will not have significant effect on the emission factors.
Consequently, the calculations made for this report have been based on
the same factor for all forms of controlled burning of plastics.
The initial data from the experience with combined firing of pulverized
coal and solid waste at the Meramec Station of the Union Electric Com-
pany in St. Louis indicates that the amounts of gaseous components of
the emissions were not affected by the waste. 42 Particulate emissions
were increased, but this effect is considered to be the result of poor
precipitator performance and firing difficulties, rather than any inher-
ent contribution of the solid waste. In this report the incinerator
emission factor has been used for solid waste that would be consumed
in combined firing in future years.
Because it has not come under regulation as yet, HC1 is not included
in the list of official emission factors. However, Achinger and
Baker 18 arrived at an emission factor of 6 pounds per ton from their
data compilation. Recent data on HC1 obtained by the Battelle's
Columbus Laboratories at the Harrisburg, Pennsylvania, incinerator
result in an emission factor of 5. 1 pounds per ton. ^3 Hence, an HC1
emission factor of 5 to 6 pounds per ton of solid waste appears to be
reasonable. \As the amount of chlorine-containing plastic that is
burned increases, this factor will become larger.
Carbon Monoxide Emissions From Plastics
Inasmuch as all plastics contain considerable carbon, they are poten-
tial contributors to the carbon monoxide emissions from incinerators.
64
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If the CO emission factor of 35 pounds per ton of waste is used for the
plastic components, on the assumption that its contribution is propor-
tional to the amount of plastic in the waste, the values shown in Table
14 are obtained. In this table the emission factors have been applied
to the plastic component of solid waste as projected to the year 2000.
TABLE 14. EMISSIONS FROM CONTROLLED COMBUSTION OF
PLASTICS IN SOLID WASTE
Waste Burned,
106 tons
Plastic Content,
percent
Plastic Burned,
106 tons
CO Emissions,
106 Ib
Particulates,
106 Ib
Hydrocarbons,
106 Ib
1970
14.8
2.32
0.34
11.9
5. 1
0.51
1975
18.
2.
0.
19.
8.
0.
5
99
55
2
2
83
1980
22.8
4.2
0.96
33.6
14.3
1.44
1985
31.4
6.7
2. 1
73. 5
31.3
3. 15
1990
40.
10.
4.
3
0
0
140
59.
6,
6
0
1995
48.6
14.2
6.9
241
103
10.4
2000
56.5
20.0
11.3
396
168
17.0
Current CO emission in the United States from all sources is esti-
mated to be about 150 million tons per year. The CO emissions from
burning of plastics, as projected for 1975 will be about 10, 000 tons.
Hence, today's contribution from plastics is negligible. In future
years, the CO emissions from this source are expected to increase
to about 200,000 tons by the year 2000. The CO emissions from auto-
mobiles in the U, S. , which is the largest source at present, will de-
crease in future years as stricter regulations are applied. Hence the
impact of plastics on the total CO emissions will become greater as
the time passes. However, it is expected that the total CO from other
sources will still be measured in millions of tons when the plastics
contribution reaches the 200,000-ton level.
65
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Particulate Emissions From Plastics
The emission factor for particulates from incineration processes is
14. 9 pounds per ton of waste. There is some question as to whether
this number is strictly applicable to the plastic components, as they
appear to burn well, with a high-Btu flame. Boettner^ presented
data on laboratory-scale incineration of plastics that showed no resid-
ual ash from combustion of polyethylene, polystyrene, or major types
of polyvinyl chloride. This implies that the small metallic content,
from catalysts and additives, is completely volatilized and will appear
as oxides in the flue-gas stream. There could be some unburned car-
bon particulate if the combustion of the plastic occurred in a zone
where insufficient air was present at the time. Although it may be
high, the emission factor of 14.9 pounds per ton was used for Table 14.
On this basis the 1975 value of 8. 2 million pounds is trivial compared
to the 26. 2 million tons that are generated in the United States at the
present time. The projected level for the year 2000 reaches only
84, 000 tons, which will still be only a small fraction of the U. S. total,
even with stricter control on other sources.
Hydrocarbon Emissions From Plastics
Since the chemical structure of plastics is based on carbon-hydrogen
compounds, there is a possibility that some hydrocarbons from the
decomposition of the plastic will survive the combustion process.
Hence it may be assumed that hydrocarbons will be produced in pro-
portion to the amount of plastics in the refuse. Using that basis, the
hydrocarbon factor of 1. 5 pounds per ton of waste was applied to obtain
the values shown in Table 14. The 1975 emissions of 830,000 pounds
will be insignificant compared to the 35 million tons of hydrocarbons
emitted from other sources, chiefly automobiles. Even by the year
2000, when the projected emissions from burning of plastics will be
8500 tons, and auto emissions are greatly reduced, the plastics con-
tribution will still constitute a small part.
HC1 Emissions From Plastics
The unique contribution of plastics to air pollution from, combustion of
solid waste results from the HC1 produced by the combustion of
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polyvinyl chloride (PVC). It has been shown by Boettner et al, 44
that all of the chlorine is released from PVC on combustion and ap-
pears as HC1. Other sources of HC1 are present in the solid waste,
as there is chloride in the plant and food waste, in addition to that
which occurs as inorganic salts. The formation of HC1 from organic
sources would take place readily during incineration. To form it
from the inorganic compounds requires volatilization and reaction
with incinerator flue gases such as SC>2 and CC^, That these reac-
tions occur is evidenced by the chemical changes observed in the in-
cinerator deposits, where chlorides are converted to sulfates as
exposure time increases. ^5
The projections for HC1 emissions as the result of the controlled com-
bustion of PVC are shown in Table 15. In 1975 about 26, 000 tons of
HC1 will be generated in this fashion. This amount is small when
compared to that of the major pollutants presently under regulation.
However, the amount of HC1 will increase in future years as the per-
centage of PVC in the waste increases.
TABLE 15. PROJECTED HC1 EMISSIONS FROM CONTROLLED
COMBUSTION OF POLYVINYL CHLORIDE (PVC)
PVC in Waste, 106 tons
PVC Burned, 106 Ib
HC1 Produced, 106 Ib
1975
0.5
90
52.5
1980
0.7
154
90
1990
1.6
563
329
2000
2.8
1300
760
During the period 1975 to 2000, the amount of HC1 generated will be
greater than that of the other pollutants, namely CO, particulates, or
hydrocarbons. However, it has been claimed that more HC1 is emit-
ted to the atmosphere from coal-burning power plants than from
municipal incinerators, ^o Fortunately HC1 can be removed from flue
gases very efficiently by water scrubbers, and the emissions could be
controlled readily in this fashion.
An air-pollution problem could develop in the immediate vicinity of an
incinerator as a result of HC1 emission. This might occur if
67
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insufficient dispersal of the stack gases were to cause the ambient
concentration of HC1 to exceed the 5-ppm level designated as the al-
lowable limit for health. 47
Nitrogen Oxide Emissions From Plastics
Only a relatively small amount of the U. S. plastic production com-
prises nitrogen-containing plastics, which would be the source of
nitrogen oxide emissions. These plastics would be the polyurethanes,
urea-melamines, nylons, and acrylate materials. It was estimated
that in 1973 these plastics constituted only 0. 1 percent of the total
solid waste. 12 ]\jo breakdown in these plastic categories was avail-
able for projection to future years, but it is reasonable to assume that
they will still represent a very minor contribution in future years as
well. The 1973 estimate showed that if all the nitrogen in the poly-
urethane waste incinerated was converted to nitrogen oxides, the total
would only have been 1200 tons. This can be compared to the total
incinerator emissions of 16,780 tons of nitrogen oxides or the total
from all sources of 22, 800, 000 tons. 18
Other Emissions From Plastics
Only small amounts of plastics contain sulfur (such as polysulfones)
and the contribution to sulfur oxide emissions from such materials
would be negligible.
Several other air pollutants could be formed by combustion of special
plastics, or as a result of some additive in the plastic. Thus, HBr
might result from, bromine compounds added as flame retardants,
Acrylonitrile materials may form some HCN. However, the amounts
of these materials would necessarily be small, and could be a prob-
lem only if a large quantity of one such plastic were being burned at
one time, and stack emissions were swept down to ground level rap-
idly enough to create a toxic concentration in the vicinity of the source.
68
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SECTION VI
REFERENCES
1. United States Department of Commerce, "Bureau of Census,
Population Estimates and Projections", Series P-25, No. 470,
1971.
2. Neissen, W. R. et al. , "Systems Study of Air Pollution from
Municipal Incineration", Vol. 1, Eighth Chapter, PB 192378
(1970).
3. Predicasts, Quarterly publication of Predicasts, Inc., 200 Uni-
versity Circle Research Center, 1001 Cedar Ave. , Cleveland,
Ohio 44106.
4. Plastics Technology, March, 1974, p. 9.
5. Chemical Week, May 15, 1974, p. 34.
6. Chemical and Engineering News, June 17, 1974, p. 10.
7. Chemical Marketing Reporter, April 8, 1974, p. 5.
8. Chemical Marketing Reporter, April 8, 1974, p. 10.
9. Industrial Marketing, January, 1974, p. 14.
10. Glauz, R. L. , Jr. , Kridl, A. G. , Schwaar, R. H. , and Soder,
S. L. , "The Plastics Industry in the Year 2000", April, 1973
(prepared by Stanford Research Institute for the Society of the
Plastics Industry).
69
-------
11. Cross, J. A. , and Park, W. R. , "The Role of Plastics in
Resource Recovery", May 23, 1973 (prepared by Midwest
Research Institute for Manufacturing Chemists Association).
12. Vaughan, D. A. , Anastas, M. Y. , and Krause, H. H. , "An
Analysis of the Current Impact of Plastic Refuse Disposal Upon
the Environment", July 7, 1974 (prepared by Battelle's Columbus
Laboratories for Office of Research and Monitoring, U. S.
Environmental Protection Agency).
13. Warner, A. J. , Parker, C. H. , and Baum, B. , "Solid Waste
Management of Plastics", December, 1970 (prepared by DeBell
and Richardson, Inc. , for Manufacturing Chemists Association).
14. The Litter Fact Book, issued by the Glass Manufacturers Insti-
tute, Inc., New York, New York (197 1).
15. "Thermal Processing and Land Disposal of Solid Waste",
Federal Register, Vol. 39, No. 158, August 14, 1974.
16. Flintoff, F. , and Millard, R. , "Public Cleansing", McLaren &
Sons, London (1972).
17. Flintoff, F. , "The Disposal of Solid Wastes", Hutchison Benham
Limited, London (1973).
18. Achinger, W. C., and Baker, R. L. , "Environmental Asses s-
ment of Municipal Scale Incinerators", Report SW-111, U. S.
Environmental Protection Agency, 1973.
19. Hall, E. H. et al. , "Refuse Combustion in Fossil Fuel Steam
Generators", Battelle Report to EPA, Contract No. 68-02-0611,
Task 9, September 23, 1974.
20. Baun, Bernard, and Parker, C. H. , "Plastic Waste Disposal
Practices in Landfill, Incineration, Pyrolysis, and Recycle",
DeBell and Richardson, Inc. (May, 1972).
21. Flintoff, F. , "Recycling Reuse, and Recovery of Plastics",
The British Plastics Federation, 47 Piccadially, London WIV
ODN (1973).
70
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22. American Public Works Assoc. (APWA), "Solid Wastes - The
Job Ahead", Special Report APWA Reporter, p. 5-11, 25
(August, 1966).
23. Warner, A. J. et al. , "Plastics Solid Waste Disposal by Incin-
eration or Landfill", a report to the Manufacturing Chemistry
Association, Washington, D. C., by DeBell and Richardson,
Inc. (December, 1971).
24. Black, R. J. , "Role of Sanitary Landfilling in Solid Waste
Management", Waste Age (September/October, 1972).
25. Hitte, S. , Office of Solid Waste Management Practice, personal
communication, February, 1973.
26. Second Report to Congress, "Resource Recovery and Source
Reduction", U. S. EPA (SW-122) Publication (1974).
27. Darnay, Arsen, and Franklin, W. E. , "Salvage Markets for
Materials in Solid Wastes", U. S. EPA Study (SW-29C) under
Contract No. CPE G9-3 (1972).
28. Stearn, J. R. , "Municipal Incinerators, "A Review of the
Literature", Environmental Protection Agency Office of Air
Programs Publications No. AP-79 (June, 1971).
29. Fenton, R. , "Present Status of Municipal Refuse Incinerators
with Particular Reference to Problems Related to Non-
residential Refuse Input", ASME Solid Waste Processing
Division, New York, January 29, 1975.
30. Titus, Joan B. , "Plastics Technical Evaluation Center",
Picatinny Arsenal, Dover, New Jersey 07801 (Feburary, 1973).
31. Zanoni, A. E. , "Potential for Ground Water Pollution from the
Land Disposal of Solid Waste", 225-260 in CRC Critical Reviews
in Environmental Control, 3_ (3), CRC Press, Cleveland, Ohio
(1973).
32. Thorton, R. J. , and Blane, F. C. , "Leachate Treatment by
Coagulation and Precipitation", Journal of Environmental
Engineeringing (August, 1973), p. 535-544.
71
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33. Stone, R. et al. , "Land Conservation by Aerobic Landfill
Stabilization", Public Works, 9^(12), p. 9 5-97 (December,
1968).
34. Brunner, D. R. , and Keller, D. J. , "Sanitary Landfill Design
and Operation", Report SW-65 ts, U. S. EPA (1972).
35. Stone, R. , "Sanitary Landfill Disposal of Chemical and
Petroleum Waste", 68th National Meeting, American Institute
of Chemical Engineers, Houston, Texas (February 28 -
March 4, 1971).
36. Midwest Research Institute Report, "The Role of Packaging in
Solid Waste Management (1966-1976)".
37. Guillet, James E. , "Plastics, Energy, and Ecology are
Harmonious", Plastics Engineering (August, 1974).
38. "Fact Sheet - Litter", National Center for Resource Recovery,
Inc., 1211 Connecticut Avenue, N. W. , Washington, D. C.
20036 (March, 1973).
39. Hanks, T. G. , "Solid Waste/Disease Relationship", a Litera-
ture Survey, prepared for the U. S. PHS, Publication No. SW-
Ic (1967).
40. "Cost of Clean Air", EPA Report No. 230/3-74-003, April,
1974.
41. "Compilation of Air Pollutant Emission Factors", 2nd Edition,
U. S. EPA Publication No. AP-42, April, 1973.
42. Shannon, L. J. , Schrag, M. P., Honea, F. I., and Bendersky,
D. , "St. Louis/Union Electric Refuse Firing Demonstration Air
Pollution Test Report", U. S. EPA Report 650/2-74-073,
August, 1974.
43. "Incinerator Gas Sampling at Harrisburg, Pennsylvania",
Battelle's Columbus Laboratories, Contract No. 68-02-0230,
EPA Office of Air Programs, September 4, 1973.
72
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44. Boettner, E. A. , Ball, G. L. , and Weiss, B. , "Combustion
Products from the Incineration of Plastics", Report No. EPA-
670/2-73-049, July, 1973.
45. Miller, P. D. et al. , "Corrosion Studies in Municipal Incin-
erators", SHWRL-NERC Report SW-72-3-3, 1972.
46. Huffman, G. L. , "The Environmental Aspects of Plastics
Waste Treatment", Symposium on the Disposal and Utilization
of Plastics, New Paltz, New York, June 25, 1973.
47. "Threshold Limit Values", American Conference of Govern-
mental and Industrial Hygienists", 1973.
73
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-670/2-75-058
3. RECIPIENT'S ACCESSION-NO.
4. TITLE ANDSUBTITLE
ENVIRONMENTAL ASSESSMENT OF FUTURE DISPOSAL
METHODS FOR PLASTICS IN MUNICIPAL SOLID WASTE
5. REPORT DATE
June 1975
(Issuing Date)
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
D. A. Vaughan, C. Ifeadi, R. A. Markle,
and H. H. Krause
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Battelle
Columbus Laboratories
505 King Avenue
Columbus, Ohio 43201
10. PROGRAM ELEMENT NO.
1DB314 (ROAP 21EFS, Task 017)
R803111-01-1
12. SPONSORING AGENCY NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Production of plastics for engineering and consumer items in the United
States has been predicted to reach 113 million tons per year by the year
2000. This figure does not include the production of polymer used for
synthetic fiber or fabric. From 31 to 38 million tons of the plastic
produced is expected to reach the solid waste stream, depending on the
basis of estimation. The largest amount will go to sanitary landfills,
and the next largest amount will be thermally treated using such methods
as power generation, incineration, and pyrolysis. Small amounts of
plastic are expected to be disposed of in open dumps or as litter.
Resource recovery for plastics in municipal refuse up to the year 2000
is expected to be insignificant. Air pollution as a result of plastics
in the landfills and open dumps will be negligible, even if there is
still some burning of open dumps in 2000.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
*Plastics
*Impact
Waste disposal
*Plastic waste
Solid waste
Future trends
*Environmental
effects
Sanitary landfills
111
13B
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (This Report)
UNCLASSIFIED
21. NO. OF PAGES
86
20. SECURITY CLASS (This page)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
74
•fr U. S. GOVERNMENT PRINTING OFFICE: 1975-657-59V5402 Reg I on No. 5-1
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