EPA/600/R-93/122
                                      December 1993
    PUBLIC HEALTH, OCCUPATIONAL SAFETY,

      AND ENVIRONMENTAL CONCERNS IN

MUNICIPAL SOLID WASTE RECYCLING OPERATIONS
   Environmental Criteria and Assessment Office
   Office of Health and Environmental Assessment
       U.S. Environmental Protection Agency
             Cincinnati, OH 45268
                                        Printed on Recycled Paper

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                               DISCLAIMER
      This document has been reviewed in accordance with U.S. Environmental
Protection Agency policy and approved for publication.  Mention of trade names or
commercial products does not constitute endorsement or recommendation for use.

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                                  PREFACE

      The United States faces the challenge of effectively managing municipal
solid waste (MSW) as the amount of waste generated per capita increases.  In
response to this challenge, recycling is actively being promoted and integrated into
solid waste management plans. The Environmental Criteria and Assessment Office
has initiated an effort to evaluate  and identify the potential hazards associated with
MSW recycling.
      The purpose of this document is not to compare recycling with other MSW
methods but to provide a general  overview of possible hazards associated with this
practice.
      This report identifies the possible public health, occupational, and
environmental hazards associated with MSW recycling.  The report identifies
activities that might present hazards to health or the  environment but does not
assess actual risks to health or the environment.  Such a risk assessment requires
further study, particularly quantitative data on exposure. The scope of the
document is thus limited, in line with an intent to survey for potential hazards and
identify need for further work.
                                      in

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                              CONTENTS


Preface	     iii

List of Abbreviations	......	 .     x

Authors, Contributors, and Reviewers  . .	     xi

Acknowledgments	    xii

1.   INTRODUCTION	   1-1

    1.1.  PURPOSE	   1-1
    1.2.  SCOPE	   1-1
    1.3.  LIMITATIONS  	,	   1-4
    1.4.  REPORT ORGANIZATION	   1-5

2.   PROJECT METHODOLOGY	   2-1

    2.1.  APPROACH	   2-1
    2.2.  METHODOLOGY ,	   2-1

3.   RECYCLING AS A MUNICIPAL SOLID WASTE MANAGEMENT
    METHOD	   3-1

    3.1.  INTRODUCTION	   3-1
    3.2.  MUNICIPAL SOLID WASTE MANAGEMENT METHODS 	   3-1

4.   OVERVIEW OF RECYCLING PRACTICES AND PROCESSES	   4-1

    4.1.  INTRODUCTION	   4-1
    4.2.  CONSUMER COLLECTION	   4-3
         4.2.1.  Consumer Separation and Storage	   4-3
         4.2.2.  Consumer Transport	   4-3
         4.2.3.  Drop-Off and Buy-Back Facilities  	   4-4
                4.2.3.1.  Drop-Off Facilities	   4-4
                4.2.3.2.  Buy-Back Facilities	• •  • •   4-4
    4.3.  CURBSIDE COLLECTION	   4-5
         4.3.1.  Curbside Handling	   4-5
         4.3.2.  Loading 	   4-6
                4.3.2.1.  Manual-Loading Trucks  	   4-7
                4.3.2.2.  Automated-Loading Trucks	   4-7
                4.3.2.3.  Compactors and Crushers	   4-8
                                  IV

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                          CONTENTS (continued)

         4.3.3.   Unloading	    4-8
         4.3.4.   Transportation Associated With Curbside
                   Collection  	    4-8
                 4.3.4.1.  Dedicated Recyclable and MSW
                            Collection Vehicles	    4-9
                 4.3.4.2.  Combined Trailer and Truck Collection	   4-10
                 4.3.4.3.  Collection of Recyclables and  MSW
                            Using Same Truck 	   4-10
                 4.3.4.4.  Cocollection	   4-11
    4.4  SORTING RECYCLABLES  	   4-11
         4.4.1.   Transportation Associated With Sorting	   4-12
         4.4.2.   Materials Recovery Facilities	   4-12
         4.4.3.   Waste-to-Energy Facilities/Transfer
                   Stations/Landfills	   4-20
    4.5.  MATERIAL-SPECIFIC RECYCLING PROCESSES	   4-20
         4.5.1.   Introduction	   4-20
         4.5.2.   Aluminum	   4-22
                 4.5.2.1.  Composition of Aluminum Recyclables	   4-22
                 4.5.2.2.  Process Technologies	   4-26
         4.5.3.   Glass	   4-31
                 4.5.3.1.  Composition of Glass Recyclables  	   4-31
                 4.5.3.2.  Process Technologies	   4-32
         4.5.4.   Paper	   4-39
                 4.5.4.1.  Composition of Paper Recyclables	   4-39
                 4.5.4.2.  Process Technologies	   4-40
         4.5.5.   Plastic	   4-53
                 4.5.5.1.  Composition of Plastic Recyclables   	   4-53
                 4.5.5.2.  Process Technologies	   4-53
                 4.5.5.3.  Resin-Specific Processing	   4-68
                 4.5.5.4.  Commingled Plastics 	   4-70
         4.5.6.   Steel/Tin  	   4-71
                 4.5.6.1.  Composition of Ferrous Metal Scrap	   4-71
                 4.5.6.2.  Processing Technologies	   4-72

5.  SAFETY CONCERNS ASSOCIATED WITH RECYCLING AND
      MITIGATION OPTIONS	    5-1

    5.1.  INTRODUCTION	    5-1
    5.2.  REGULATIONS APPLICABLE TO RECYCLING OPERATIONS  ....    5-2
         5.2.1.   Occupational Regulations 	    5-2
         5.2.2.   Environmental Regulations	    5-6
    5.3.  SHARP OBJECTS	    5-6

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                        CONTENTS (continued)

    5.4.  ERGONOMIC AND LIFTING INJURIES	   5-9
    5.5.  FIRES AND EXPLOSIONS  	  5-12
    5.6.  FLYING AND FALLING DEBRIS .	  5-14
    5.7.  TEMPERATURE AND PRESSURE EXTREMES  	  5-17
    5.8.  MOVING EQUIPMENT AND HEAVY MACHINERY	  5-20
    5.9.  NOISE 	  5-24
    5.10. AESTHETIC IMPACTS	  5-28
    5.11. TRAFFIC	  5-30
    5.12. PROCESS CHEMICALS AND CONTAINER RESIDUES	  5-33
    5.13. GASEOUS RELEASES	  5-36
    5.14. PARTICULATE RELEASES	  5-40
    5.15. WATERBORNE RELEASES	  5-44
    5.16. SOLID WASTE AND SLUDGE	  5-47
    5.17. MICROBIOLOGIC HAZARDS	  5-51
    5.18. PESTS	  5-54

6.   SUMMARY AND CONCLUSIONS  	   6-1

7.   ADDITIONAL RESEARCH NEEDS	   7-1

8.   REFERENCES	   8-1

APPENDIX A: GLOSSARY  	A-1

APPENDIX B: COMMON RECYCLABLES: AMOUNTS AND MARKETS  ....  B-1

APPENDIX C: FEDERAL, STATE, AND MUNICIPAL INVOLVEMENT  	 C-1

APPENDIX D: BIBLIOGRAPHY ON MUNICIPAL SOLID WASTE
            MANAGEMENT OPTIONS	 D-1
                                VI

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                              LIST OF TABLES
1-1

4-1

4-2


4-3

4-4

4-5

4-6

4-7

4-8

4-9


4-10


4-11

4-12

5-1


5-2

5-3

5-4

5-5

5-6
Recyclable Materials Collected by the 50 Largest U.S. Cities

Typical Elemental Composition of Aluminum Scrap  ..;...
Typical Organic Components of Coatings Applied to
Beverage Cans	
Typical Glass Compositions	

Gullet Requirements for Primary Markets	

Amount of Colored Gullet Accepted by Container Manufacturers

Typical Wastepaper Contaminants  	

Specific Processes Associated With Wastepaper Categories .  . .

Deinking Chemicals  	
Primary Feedstock Chemicals Used in Commonly Recycled
Thermoplastic Resins	•  •
Categories of Additives Used in Plastics, Use Concentrations,
and Major Polymer Applications (1987)	 .  .
 Characteristics and Uses of Plastics Additives

 Resin-Specific Processing Issues	
 OSHA Health and Safety Standards Applicable to
 the Recycling Industry  	
 Sharp Objects Hazards  	

 Ergonomic and Lifting Injuries  .  . .  .

 Fire and Explosions	

 Flying and Falling Debris	

 Temperature and Pressure Extremes
 1-3

4-23


4-24

4-33

4-34

4-35

4-41

4-42

4-46


4-54


4-56

4-60

4-69


  5-4

  5-7

5-10

5-13

5-15

5-18
                                     VII

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                         LIST OF TABLES (continued)



5-7    Moving Equipment and Heavy Machinery	  5-21



5-8    Noise Hazards	  5-25




5-9    Aesthetic Impacts  .	  5-29



5-10   Traffic Hazards  	;	  5-31




5-11   Process Chemicals and Container Residues (Direct Impacts)	  5-34




5-12   Gaseous Releases	  5-37




5-13   Particulate Releases  	  5-41




5-14   Waterborne Releases	 .  5-46




5-15   Solid Waste and Sludge  	  5-48



5-16   Heavy Metal Concentrations in Deinking Sludges  	  5-50




5-17   Microbiologic Hazards	  5-52



5-18   Hazards From Pests  	  5-55




6-1    Summary of Public Health Concerns	   6-3



6-2    Summary of Occupational Safety Concerns   	   6-4




6-3    Summary of Environmental  Safety Concerns	   6-5
                                    VIII

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                              LIST OF FIGURES


3-1    Municipal Solid Waste Disposal for 1990	   3-2

3-2    MSW Generation, 1960-2000	   3-4

4-1    Recyclables Flow Through Primary Recycling Stages	   4-2

4-2    General Materials Sorting Process at an MRF	  4-14

4-3    High-Technology Materials Sorting Process at an MRF	  4-15

4-4    Generalized Aluminum Recycling Process	  4-27

4-5    Generalized Glass Recycling Process	  4-37

4-6    Generalized Paper Recycling Process .	  4-44

4-7    Overview of Plastics Recycling  Process	  4-63

4-8    Postconsumer Vinyl Purification Process and Percentage
       of Byproducts from Akron, Ohio, Facility	  4-66

4-9    Detinning Process Utilizing Caustic Soda	  4-75
                                     IX

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                           LIST OF ABBREVIATIONS
 DPE




 HGD




 LDPE




 MP




 MRF




 MSW




 NIHL




 NPDES




 OCC




 ONP




 OSHA




 PET




 PP




 PS




 PVC




 RCRA




V
 High-density polyethylene



 High-grade deinking




 Low-density polyethylene



 Mixed paper




 Material recovery facility



 Municipal solid waste



 Noise-induced hearing loss




 National Pollution Discharge Elimination System



 Old corrugated containers



 Old newspaper




 Occupational Safety and Health Administration



 Polyethylene terephthalate



 Polypropylene




 Polystyrene



 Polyvinyl chloride




 Resource Conservation and Recovery Act



Vinyl

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                AUTHORS, CONTRIBUTORS, AND REVIEWERS
AUTHORS
Eletha G. Brady-Roberts, Document Manager
Environmental Criteria and Assessment Office
Office of Health and Environmental Assessment
U.S. Environmental Protection Agency
Cincinnati, OH 45268

Andrew Hargens
Arlene Levin
David Fratt
TRC (formerly Alliance Technologies Corporation)
Boott Mills South, Foot of John St.
Lowell, MA  01852
 CONTRIBUTORS AND REVIEWERS

 Randall Bruins
 Office of Technology Transfer and Regulatory Support
 U.S. Environmental Protection Agency
 Washington, DC 20460

 Norman Kowal
 Michael Dubowe
 Michael Dourson
 Environmental Criteria and Assessment Office
 Office of Health and  Environmental Assessment
 U.S. Environmental Protection Agency
 Cincinnati, OH 45268

 Steven Levy
 Office of Solid Waste
 U.S. Environmental Protection Agency
 Washington, DC  20460

 Lynnann Hitchens
 Risk Reduction Engineering Laboratory
 U.S.  Environmental Protection Agency
 Cincinnati, OH 45268
                                     XI

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                            ACKNOWLEDGMENTS


      The Environmental Criteria and Assessment Office (ECAO) would like to

acknowledge the invaluable assistance of the multidisciplinary group of municipal

solid waste experts who commented on this document and provided suggestions
for improvements. The expert panel was identified by the  International Life

Sciences Institute (ILSI) Risk Science Institute through a cooperative agreement

with EPA  based on recommendation provided by both ECAO scientists and the
Municipal Solid Waste Recycling Subcommittee of the Science Advisory Board's

Environmental Engineering Committee. ILSI convened the  expert panel on two
occasions: February 25-26,  1991, and January 7-8, 1992.  Special

acknowledgment is given to the cochairs of the two meetings.  The cochairs were
Dr. Carol Henry of ILSI and Dr. Michael L. Dourson and Ms. Cindy  Sonich-Mullin,

both of ECAO. The participating expert panel members are as follows:
Dr. Eula Bingham
University of Cincinnati
  Medical Center

Dr. Diana Gale
Seattle Solid Waste Utility

Mr. John Legler
National Solid Waste  Management
  Association

Ms. Alair MacLean
Data Facts Resources
          *

Dr. Martha Radike
University of Cincinnati
  Medical Center

Dr. Michael Van Derveer
U.S. Food and Drug Administration
Dr. Lawrence Fishbein
ILSI Risk Science Institute

Dr. Charles Gerba
University of Arizona

Dr. John Liskowitz
New Jersey Institute of
 Technology

Dr. W. Lamar Miller
University of Florida
Department of Environmental
 Engineering Sciences

Mr. Tom Rattray
Procter and Gamble Company

Dr. Ron Wyzga
Electric Power Research
 Institute
                                     XII

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Note:  The views expressed in this reports do not necessarily reflect those of the
expert panel. Participation on the panel does not imply complete endorsement of
this document.
                                     XIII

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                             1.   INTRODUCTION

1.1.   PURPOSE
      The U.S. Environmental Protection Agency's (EPA) Environmental Criteria
and Assessment Office (ECAO)  initiated an effort to characterize safety in
municipal solid waste (MSW) recycling operations. The objective of this effort
includes assisting MSW managers in developing waste management programs by
providing information on recycling options and the potential hazards associated
with their implementation.

1.2.   SCOPE
      This  report qualitatively identifies safety issues (public health, occupational,
and environmental) associated with MSW recycling.  Hazard identification is the
first step in the more complex process of risk assessment.  The report does not
attempt to  assess risks because insufficient information exists to fully quantify
exposures and because of the potential for adverse effects associated  with
recycling operations. Future research that will advance the risk assessment
process is identified.
      The primary audience is the  local solid waste manager who requires safety
information for decisionmaking. An overview of processing methods identifies
hazard types and points of exposure. Specific details of materials processing
technologies are not provided.  This report addresses the following  questions:
         What is the nature of recycling hazards?
         Are recycling hazards potentially significant?
         What steps can be taken to prevent or mitigate these hazards?
      This identification of hazards considers recyclable materials from the time
they are separated from the MSW stream by the consumer or waste handler to
when they are formed into new products or become indistinguishable from virgin
                                     1-1

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feedstocks.  The relative newness of the recycling industry, coupled with local
requirements and regional trends, has created an industry with diverse solutions to
meet individual MSW management needs.  This overview addresses commonly
used recycling practices and processes.
      Many of the practices and processes addressed are applied in other
industries, such as the collection and handling of MSW and the use of virgin
material to produce goods.  In addition, many of the potential hazards can be
mitigated. Mitigation options are noted in the report where applicable.
      The report is devoted to five materials selected on the basis of their relative
amounts (refer to Appendix B) in the municipal solid waste stream, available
recycling technologies, and established markets:
         Aluminum
         Glass
         Plastic
         Paper
         Steel/tin
These materials are most widely recycled by the 50 most populous U.S. cities
(Table 1-1).
      Recycling is a growing waste management practice. In 1990, there were
104 materials recovery facilities (MRFs) planned or operating in the United States;
in 1992, there were 222 (Roumpf, 1992). Average-capacity MRFs (131 tons per
day) employ an average of 18 workers; larger facilities may need 27 workers.  The
trend is therefore toward greater processing capacity and increased average
employment. Employment levels may also rise because of increased reliance on
labor-intensive manual sorting (65 percent of facilities in 1992 versus 50 percent in
1990) compared with automated sorting technologies.  MRFs are also expected to
handle additional  materials such as household batteries, compostables, and
different grades of paper.  Full evaluation of MSW management options includes
consideration of benefits as well as potential costs.  Primary benefits of recycling

                                     1-2

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TABLE 1-1
Recyclable Materials Collected by the 50 Largest
U.S. Cities
Material Number of cities Percent of cities
Aluminum cans
Glass containers
Old newspapers
Tin/bimetal containers
PET containers
HOPE containers
Old corrugated
containers
Other
46
44
42
40
36
36
11
14
92
88
84
80
72
72
22
28
HOPE:  High-density polyethylene
PET: Polyethylene terephthalate

Source: Smith and Hopkins, 1992.
                                    1-3

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are reducing the MSW stream and extending the lifetimes of landfills.  It is not
coincidental that the number of recycling programs has increased mostly in
geographical areas where landfills are near capacity and space for new landfills is
scarce. This trend is most visible on the east and west coasts of the United
States. The cost savings associated with recycling is also a benefit because
limited landfill  space increases tipping and hauling fees for MSW disposal.  Also,
there are benefits to the environment from recycling programs.  The potential for
environmental pollution associated with more traditional methods of MSW disposal
is reduced by diverting recyclables from the waste stream  (personal communication
between TRC Environmental Corporation and  Rosalie Green, Senior Recycling
Expert, U.S. Environmental Protection Agency on July 24, 1992).
1.3.  LIMITATIONS
      Lack of data to quantify exposures in the recycling industry currently limits a
more complete hazard evaluation.  Available data on recycling hazards are biased
toward reporting of episodic occupational hazards. Physical injury is probably the
best documented of all recycling hazards.  Few data have been collected to
characterize chemical or biologic hazards that might otherwise be measured in
ambient air monitoring or emission/effluent studies. Subtle effects, long-term
health effects, and ergonomic injuries also have not been characterized.
Quantitative data that are available tend to come from small-scale studies with
limited goals.  No large-scale monitoring programs have been undertaken.
      Variability in recycling industry practices somewhat limits the broad-based
applicability of hazard information presented in this report. The degree of
automation in  MRFs, for example, greatly influences the type and magnitude of
certain hazards. Program variability also makes it impossible to characterize each
process and its associated hazards. This variability may  decrease as the industry
matures.
      The degree to which recycling processes and associated hazards can be fully
described further limits conclusions about the magnitude of  potential hazards. A
                                     1-4

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number of the parties contacted for this report cited the proprietary nature of a
practice or process and were unwilling to provide information.  Industry
representatives also were reluctant to discuss hazards associated with their
activities.

1.4.  REPORT ORGANIZATION
      This report is organized to facilitate its use as a tool for solid waste
managers.  Chapters 2 and 3 provide background information on project
methodologies and recycling as a solid waste management method, respectively.
Chapter 2 summarizes the information sources used to prepare the report, data
collection methods, and the limitations of the data.  Chapter 3 describes recycling
as a municipal solid waste management method.  Chapters 4 and 5 constitute the
main body of the report.  As a preface to the enumeration and discussion of
hazards, Chapter 4 summarizes common recycling practices  and processes.
Subsections address collection, sorting, and transportation of recyclables and the
processing of aluminum,  glass, paper, plastic, and steel/tin.  Chapter 5 describes
recycling hazards by type, including the nature of the hazard and prevention or
mitigation options.  Included in Chapter 5 are tables that indicate
preventive/mitigative options and rate the significance of each hazard. Chapter 6 is
a summary of findings and conclusions.  A list of additional research  needs is
provided in Chapter 7. References  are provided  in Chapter 8.
                                      1-5

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                        2.  PROJECT METHODOLOGY

2.1.  APPROACH
      The "boundaries" for an evaluation of recycling hazards can vary depending
on the goals of the effort. The present study covers hazards encountered from the
point consumers or waste handlers separate recyclables from MSW to the point the
recycled material is formed into a new product or is considered to be a feedstock
comparable with virgin material.  Practices and processes that are generally unique
to recycling are emphasized, but many  specific recycling technologies and
equipment are encountered in  other industrial settings, including other MSW
management activities.  For example, conveyors, which are widely used on sorting
lines in materials recovery facilities, are components of many industrial operations.
Although this equipment is not unique to recycling, recycling presents new
industrial applications that may create different hazards.
      The relative newness of recycling both as an MSW management option and
as an industry required a flexible approach for obtaining information for this report.
Where available, process overview information was obtained from published
government or industry reports.  More  commonly, articles from trade journals and
•other publications and information obtained from industry contacts were used to
document current trends in recycling.

2.2.  METHODOLOGY
      Much of the information for this  report was obtained through telephone
interviews with government and industry sources.  Specific sources contacted are
provided in Chapter 8.  General sources included the following:

       •  State and local solid waste officials including local recycling coordinators
       •  State and Federal regulatory agency  representatives
                                     2-1

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       •  Federal occupational health and safety representatives (Occupational
          Safety and Health Administration, National Institute for Occupational
          Safety and Health)
       •  Representatives of regional and local solid waste planning organizations
       •  Plant managers and other company representatives for all phases of
          recyclable processing, including MRFs and material-specific industrial
          facilities
       •  Recycling technology company representatives
       •  Academic resources
       •  Private consultants
       •  Recycling industry publication representatives
       •  Trade association representatives

       Efforts were made to obtain information reflective of common practices
across the country by contacting several representative sources.  National
organizations, such as the U.S. Conference of Mayors, were contacted to obtain
profiles of municipalities with progressive recycling programs. Sources of
information were obtained through reviews of these profiles.  Formal tallies of the  '
frequency with which practices were employed were not possible in the absence of
a comprehensive survey. Where available, information on emerging technologies
and practices was included, but this was not the focus of the research effort.
       Documentation of recycling hazards was found to be very limited and
nonexistent in some areas.  Few data are available to characterize the frequency of
occurrence o'r magnitude of hazards related to the recycling industry.  Few
comprehensive,  industrywide studies of hazards were located. As a result, it was
necessary to rely on anecdotal  accounts from facility representatives,  regulators,
and occupational health and safety professionals as a primary source of hazard
information. In addition, the existence of certain  recycling hazards was
extrapolated from analogous situations in other industrial settings.
                                     2-2

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      Limited information on the magnitude of recycling hazards precludes
quantitative evaluation of the significance of the hazards (i.e., risk).  However, the
relative significance of recycling hazards to each other, to those associated with
other MSW management options, or to those associated with other industrial
processes is of paramount importance to the solid waste manager. This study
rates hazards based on a Delphi approach.  Hazards are rated as low, medium, or
high based on a qualitative assessment of the following criteria:
      •  The frequency or severity of the hazard
      •  The ability to control the hazard with current technologies
      •  The ability to control the hazard through regulations
      •  The prevalence of the hazard in related industries
                                      2-3

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   3.  RECYCLING AS A MUNICIPAL SOLID WASTE MANAGEMENT METHOD

3.1.   INTRODUCTION
      The United States faces the challenge of effectively managing municipal
solid waste as the amount of waste generated per capita increases.  Recycling is
one of the solid waste management options of the integrated waste management
system outlined by U.S. EPA's Agenda for Action (1989). U.S. EPA (1989)
recommends the use of an integrated waste management system that requires the
complementary use of a variety of waste management practices to handle safely
and effectively the MSW stream with the least adverse impact on human health
and the environment.
      To most effectively reduce waste management problems at the national
level, the waste management industry, state governments, and municipalities
should use the following hierarchy of integrated waste management:  (1) source
reduction (including reuse of products),  (2) recycling (including composting),
(3) waste combustion  (with energy recovery), and (4) landfilling. Recycling and
composting are near the top of the hierarchy because they prevent potentially
useful materials from being combusted or landfilled and preserve waste disposal
capacity (U.S. EPA, 1989).  Section 3.2 discusses MSW management methods and
the role of recycling.  Information about Federal, state, and municipal efforts to
regulate and encourage recycling is located in Appendix C. A  description of the
amount generated and a market  summary for each of the five recyclable materials
addressed in this report are provided in Appendix B.

3.2.  MUNICIPAL SOLID WASTE MANAGEMENT METHODS
      Three primary MSW management methods are currently available:
landfilling, incineration, and recycling.  As Figure 3-1 shows, of the 195.7 million
tons of MSW generated in 1990, 67 percent was landfilled,  16 percent was
incinerated, and 17 percent was recycled. The  amount of MSW generated is
projected to increase to 208 million tons in 1995 and 222 million tons in the year
                                     3-1

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Landfill, 66.6%
                          Incineration, 16.3%
                  Total Weight = 195.7 Millions Tons
  Source:  U.S.  EPA.1992
                            FIGURE 3-1
             Municipal Solid Waste Disposal for 1990
                                                                   Recovery, 17.1%
                                                                   (Recycling and Composting)
                                  3-2

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2000 (U.S. EPA, 1992).  Figure 3-2 illustrates the projected increase of specific
MSW components.
      Although MSW generated in the United States is disposed in landfills, the
capacity of existing landfills is declining and siting new landfills has become
difficult. Many older landfills were sited before environmental regulations were in
place to control the potential  for environmental contamination. Proposed facilities
thus face problems  in ensuring the protection of public health and the environment.
Despite these difficulties, landfills will continue to handle nonrecoverable and
noncombustible materials and the residues of incinerators and other waste
treatment methods.
      Municipal waste combustors reduce the volume of MSW that must
eventually be landfilled. Most combustors are mass burn systems that burn
commingled MSW;  some systems recover energy that is sold to industries or
utilities. Like landfills, incinerators are perceived as potentially hazardous to public
health and the environment.  Although new incinerators are being sited,  the
process is long and costly because of public concern about impact on local real
estate values and potential toxic releases from the incinerated waste.  Although
issues such as operating cost, compliance with stringent air emissions standards,
and incinerator ash disposal problems have impeded  progress, it is predicted that
incinerators increasingly will be used as a major management method for MSW.
      In response to the challenge of effective and safe management of MSW, EPA,
established a national goal of reducing the amount of waste to be disposed by 25
percent through source reduction and recycling.  In several cases, recycling
conserves energy and natural resources by substituting waste materials  for virgin
materials.  It also reduces the volume of waste that ultimately will be landfilled or
incinerated.  As discussed  in Appendix A, markets for recyclable materials strongly
influence the success or failure of municipal recycling programs. The availability of
technologies to handle and process recyclables also influences these programs.
Clearly, recycling has significant hurdles to surmount before it can capture a
greater share of the MSW generated.
                                      3-3

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      MILLIONS OF TONS
3OO
25O
2OO
15O
 5O
M Plastics

  Other
  Food/Yard

  Glass/Metal
100-
  196O  197O  198O   1988  1995  2OOO
                      YEAR
 Source: U.S. ERA, 1992
                    FIGURE 3-2
              MSW Generation, 1960-2000
                      3-4

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      Appendix D provides a brief bibliography on MSW management options,
including landfilling, incineration, and composting, a form of recycling for organic
material such as food and yard waste.
                                     3-5

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         4.  OVERVIEW OF RECYCLING PRACTICES AND PROCESSES

4.1.  INTRODUCTION
      The municipal solid waste recycling industry uses a variety of equipment and
program strategies to meet expanding needs.  In general, recyclables are collected
from the consumer, sorted and prepared to meet market specifications, and used in
the manufacture of new products.  Recycling program strategies range from simple
community drop-off centers to automated systems employing state-of-the-art
collection vehicles and sorting facilities.  Technologies and program organization
are selected and integrated to increase the volume and quality of the salable
recyclable stream. Program features vary to match numerous community-specific
factors, including location, demographics, market specifications, existing
equipment, and funding.  Increasing program participation rates and lowering costs
are often the primary considerations in selecting collection and sorting systems.
      Although an array of organizational and technical recycling options is now
available, some type of collecting and sorting followed by material-specific
processing is fundamental to both private and public programs.  Some programs
rely more heavily on consumers or collection workers to sort recyclables at the
point of collection, whereas other programs collect mixed recyclables and sort
them at a dedicated  sorting facility. A transportation mechanism must be in place
to transfer recyclables from the consumer and  among subsequent processing
facilities.  Although most municipalities are concerned about the aspects of
recycling that directly affect their communities, namely collection and sorting,
material-specific processing that is unique to the recycling industry also should be
considered. The materials addressed  in this section include aluminum, glass,
paper, plastics, and  steel/tin. Figure 4-1 illustrates representative  recyclables flow
pathways through various stages of the recycling industry. This chapter, an
overview of some of the more common program alternatives, discusses the basic
industry segments in four sections (4.2, Consumer Collection; 4.3, Curbside
Collection; 4.4, Sorting Recyclables; and 4.5, Material-Specific Recycling
                                      4-1

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  Generation
     of
  Recydablcs
     by
  Consumers
                            Curbside
                            Collection

1 Materials Recovery
Facilities (MRFs)



Waste-to-Energy
Facilities
(front-end separation)

1 Transfer Stations
and Landfills
(front-end separation)

Drop-off
and
Buy-back Facilities


1






•**
•^

                                                                 Material-
                                                                 Specific
                                                                Processing
Generation
Collection
Sorting
Processing
                                          FIGURE 4-1
                    Recyclables Flow Through Primary Recycling Stages
                                              4-2

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Processes).  The information can be used as a guide to identify appropriate
technologies that relate to pertinent hazard information in Chapter 5.

4.2.  CONSUMER COLLECTION
      Consumers are responsible for the initial stages of recycling postconsumer
recyclables generated in the home.  With few exceptions, municipal recycling
programs require the consumer to segregate recyclables from municipal solid waste
(MSW) and  prepare and store them for collection or deliver them to a drop-off or
buy-back facility.

4.2.1.  Consumer Separation and  Storage
      Both curbside and drop-off recycling programs require consumers to
separate, sort, clean, and store recyclables. The degree of sorting and preparation
required  of the consumer varies depending on how recyclables are collected  and
the degree of postcollection processing they are to receive.  For example,
recyclables  destined for a materials recovery facility outfitted to separate containers
by material  need not be sorted  as thoroughly as recyclables  bound directly for a
material-specific reprocessing facility.  Some programs require consumers to wash,
delabel, and flatten containers, while others accept recyclables mixed with the
remainder of the waste stream.  Programs that  require separation of recyclables
usually expect consumers to store materials in 4:he home between collections or
deliveries to a drop-off facility.
      It is common for programs to provide barrels, bins, or bags that residents can
use to store recyclables and transport them to the curb. Apartments and multi-unit
complexes sometimes provide residents with a  centrally located recyclables
collection area that serves a number of units or buildings.

4.2.2.   Consumer Transport
      Communities that operate drop-off or buy-back facilities generally  require
residents to transport  recyclables to the facility (see Section 4.2.3 for more
                                     4-3

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information on collection facilities).  The use of personal vehicles to drop
recyclables at collection centers results in increased traffic in the vicinity of the
collection facility. However, recyclables may be dropped off during trips that
include other local errands and therefore may represent only a minor increase in
overall travel distance and time for the consumer.  It is common in states that have
enacted a bottle  bill for beverage container collection facilities to be located at
stores where beverages are sold.

4.2.3.  Drop-Off and Buy-Back Facilities
      Drop-off and buy-back facilities are technically simple collection operations.
After preparation, sorting, and storage in the home, recyclables  are delivered to
one of these collection facilities at the consumer's discretion.

4.2.3.1.  Drop-Off Facilities
      Drop-off facilities are often established by municipalities as an initial, low-
cost method for collecting recyclables. They function as either independent
facilities or a front-end operation in conjunction with a  landfill or transfer station.
The public delivers recyclables to the facility and may be required to sort them by
material into collection bins or dumpsters.  Containers used at facilities to
segregate recyclables by material  include indoor storage bays, outdoor bins and
dumpsters,  and truck trailers. Facility workers may perform a "casual" inspection
and sort to remove major contaminants before shipping.  To conserve space during
storage or shipping, recyclables may be baled or shredded. Drop-off facilities use a
variety of material-handling equipment (e.g., forklifts, balers, shredders, conveyer
belts) to move, consolidate, and load recyclables.

4.2.3.2.  Buy-Back Facilities
      Buy-back facilities are operations that pay the public  for recyclables (usually
aluminum, glass, plastic, and steel beverage containers) that are collected and
delivered to the facility.  Buy-back facilities are often managed as private, over-the-
                                      4-4

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counter operations in conjunction with a retail beverage outlet or as large scrap
yards.  In states that have enacted bottle bill legislation, beverage vendors may be
required to operate an in-store buy-back facility where consumers can redeem
bottle deposits.  Self-service machines that pay the collector for materials
deposited in the machines are also available.
      Consumers are responsible for sorting and collecting recyclables in the home
before delivering them to the buy-back facility.  The facility staff may perform
additional sorting depending on the end-market specifications. Redeemable
containers are frequently sorted by distributor, whereas nonredeemables are sorted
by material. Sorting is usually performed manually when the  recyclables are
received. Mechanical systems also may be used for baling or shredding before
shipping or storage.  Recyclables at buy-back centers are typically stored in plastic
bags or cardboard boxes.

4.3.  CURBSIDE COLLECTION
      Recyclables that are not delivered by the consumer directly to some type of
collection facility are picked up from the public through a regular curbside collection
program. These collection programs have become increasingly common as
municipalities have attempted to increase participation  rates by making recycling
more convenient for the consumer. A wide variety of collection  alternatives have
evolved in attempts to maximize collection  efficiency, improve material quality, and
reduce costs.  Many municipalities offer a system that  combines both curbside
collection and drop-off options.

4.3.1.  Curbside Handling
      Curbside handling can range from loading bags of mixed recyclables (without
handling individual materials) to manually sorting individual recyclables by type.  At
a minimum, this process requires that the collection worker step to  the curb, lift
bins or bags to the side of the truck,  and sort or dump materials into the collection
vehicle.  System variations include automated  loaders that require the worker to
                                     4-5

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 hook or fasten barrels or buckets to dumping mechanisms and trucks with low-
 mounted  body designs that allow the worker to hold bins of commingled
 recyclables at waist level while sorting the materials to compartments along the
 side of the truck.  The type of container handled by workers varies with the
 community.  Plastic bins, barrels, buckets, carts, and bags are used to collect
 recyclables.  Collection carts are gaining in popularity because they can be rolled to
 the curb rather than carried. Some specialized carts are designed to be hoisted by
 automatic loading equipment.
      Although sorting recyclables at the point of generation (i.e., in the home or at
 the curbside) greatly increases the purity of the materials collected, it requires more
 work by consumers or collectors.  Many communities have moved to simplify their
 collection systems, eliminating consumer sorting by collecting commingled batches
 of recyclables.  Consumers  place all recyclable materials in bins or bags for pickup.
 Workers do not sort at curbside; they simply empty the bins or throw the bags into
 the collection vehicle.  To increase the volume of material that can be collected per
 route, compactor trucks are often used to collect bagged recyclables.  Some
 programs  collect bagged recyclables in the same vehicle with other MSW.

 4.3.2.  Loading
      There has been a proliferation of specialized trucks and trailers designed
 specifically for collecting recyclables at the curbside. Vehicles intended for both
 manual  or automated loading include features to make collection faster and safer.
 Design parameters depend primarily on the nature of the program  being served.
 For instance, programs that  collect commingled recyclables at the curb may require
 a truck with only one or two compartments. Programs that rely on curbside sorting
 must have trucks with  enough compartments to accommodate all  types of
 materials collected.
      A number of design innovations have facilitated curbside recycling for
collection  workers.  One variety of truck has sorting compartments positioned
much lower to the ground, decreasing the  height that workers must lift materials
                                     4-6

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during loading and sorting.  Some recycling collection trucks are also fitted with a
second steering wheel and a full driver compartment on the curb side of the truck
to limit worker exposure to traffic on the street side of the vehicle.  Others allow
recyclables to be loaded on both sides of the truck cab.  Cab floors lowered to curb
height and taller doors reduce the strain of continually adjusting to or from seat
height when entering or exiting the vehicle. Although modern truck designs allow
one worker to efficiently drive  and collect recyclables, some communities still  use
two-person crews.

4.3.2.1.   Manual-Loading Trucks
      Vehicles designed for manual collection are less expensive and more flexible
than automated equipment.  These trucks or trailers vary in complexity from
traditional dump or pickup trucks to specialized vehicles  featuring an assortment of
compartments for holding different types of recyclables.  One type of specialized
truck requires workers to lift materials into side-loaded compartments with metal
panels that are raised as the vehicle is filled. These trucks may have  built-in steps
or perches along the side and back of the truck on which workers can stand as
they lift and dump materials.  Another type of collection  vehicle is the low-profile
truck that places collection compartments as much as 10 inches lower than on
standard trucks (Keller,  1989).  Both types  of trucks can be designed to allow
sorting on either side of the vehicle.

4.3.2.2.   Automated-Loading Trucks
      Semiautomated and automated collection systems have beerrdeveloped in an
effort to  make curbside collection faster and more efficient for  a single worker.
Side- and top-loading vehicles are the predominant automated collectors.  Overhead
loading trucks include a sorting container along the side  of the vehicle. When the
container is full, a worker initiates an automatic hydraulic load  sequence that lifts
the container to the top of the truck and dumps the materials into separated
compartments. Side- and rear-loading vehicles often  feature automatic hydraulic
                                     4-7

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hoists or arms that hook or grab barrels or other containers, lift them, and dump
their contents into compartments.

4.3.2.3.  Compactors and Crushers
      Conventional compactor trucks are also used to collect recyclables. This
equipment works well for programs that collect loose or bagged commingled
recyclables.  Both traditional MSW collection vehicles and recycling vehicles fitted
with compactors effectively reduce the volume of recyclables during collection,
increasing route efficiency. The primary drawback to compacting recyclables is the
high levels of broken glass that may result with excessive compaction ratios.
Because some recyclables such as plastics pose a particular collection problem due
to their high volume, compactors and crushers are included on some manual
collection trucks solely to reduce the volume of containers and other recyclables.

4.3.3.  Unloading
      Most collection trucks are designed to unload from the rear.  On vehicles
with multiple compartments, the operator releases partitions between
compartments to separately discharge the different materials at the receiving
facility. Some sophisticated compartment trucks hydraulically lower each
compartment's contents to the side of the truck. This method allows materials to
be unloaded to material-specific bins and at the same time reduces the distance the
recyclables are dropped (Combs, 1991). Drop distance  and potential breakage are
concerns with glass containers, which are much easier to handle when collected
intact.
4.3.4.  Transportation Associated With Curbside Collection
      Transportation equipment and program alternatives adopted by a community
to collect recyclables at the curbside vary depending on a wide range of factors,
including the availability of equipment and funding, the size and layout  of the
community, and the proximity and capacity of the processing facility.  In general,
                                    4-8

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the selection of transportation alternatives reflects the importance of increased
program efficiency at the least cost.  Municipalities face the challenge of
integrating the additional transportation demands of recyclable collection with the
management of an existing MSW fleet. Some of the more common vehicle and
schedule options are described below.
      The proportion of recyclable collection vehicles to other MSW collection
vehicles varies in both the private and public sectors. In Hampton, New
Hampshire,  BFI uses only two manual-loading compartmentalized trucks to collect
recyclables whereas 13 compactors collect MSW (personal communication
between TRC Environmental Corporation and Mike Hastings, Portsmouth District
Manager for BFI, in August 1991). Recycle America, a division of Waste
Management, Inc., operates a curbside collection program in Seattle, Washington,
using a one-to-one ratio of recycling trucks to MSW trucks (personal
communication between TRC Environmental Corporation and Jim Yaniglas,
operations manager for Recycle America, Waste Management, Inc., Seattle, WA, in
August 1991).  The City of Austin, Texas, uses 11 straight-bed  trucks with
compartmentalized trailers and two compartmentalized-bed trucks to collect
recyclables. Approximately 60 compactor trucks collect MSW (personal
communication between TRC Environmental Corporation and Alan Watts, recycling
coordinator  for Solid Waste Services, a division of the Environmental Conservation
Services Department, Austin, TX, in  August 1991).

4.3.4.1.  Dedicated Recyclable and MSW Collection Vehicles
      The addition of a curbside recycling program necessitates an increase in a
municipality's hauling capacity through rerouting the existing fleet or by adding
vehicles to the fleet. In many cases, programs choose to add vehicles to their
MSW collection fleet..  These vehicles may be intended exclusively for the
collection of recyclables.  Truck manufacturers build vehicles on request with
customized  cab, chassis, and body combinations. In general, specialized recycling
bodies tend to  be mounted on smaller, light-duty cab-chassis combinations with
                                     4-9

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smaller, more efficient engines than those of heavy-duty mixed MSW collection
vehicles.

4.3.4.2.  Combined Trailer and Truck Collection
      Collection trailers provide a flexible alternative that can be added easily to
existing collection equipment.  Trailers can be designed to hold any number of
recyclables in separate compartments and can be towed by recycling or MSW
collection vehicles.  Depending on how it is implemented, this alternative may not
represent a significant increase in collection truck trips.

4.3.4.3.  Collection of Recyclables and MSW Using Same Truck
      Some programs use the same trucks to carry out separate recyclable and
MSW collections. The collections may take place on the same day, different days,
or even staggered weeks. A program in Pittsburgh, Pennsylvania, uses the same
vehicles to serve  up to 80,000 households (Magnuson, 1991). Twenty trucks
were added to an existing fleet of 66 when recycling services were implemented
{personal communication between TRC Environmental Corporation and Sean
McHugh, environmental planner,  Recycling Division, Environmental Services,
Pittsburgh, PA, in August 1991). Although this represents an increase of about 30
percent in the total  number of trucks, the total distance traveled by all vehicles was
approximately doubled because each truck used for recycling was able to cover
three of the standard MSW routes.
      In some cases, the same general truck type, with modifications, will be used
to collect MSW and recyclables.  In Boulder, Colorado, a truck bed specifically
designed to collect recyclables was mounted on the same cab-chassis as the
traditional collection truck, representing little or no change in  transportation-related
emissions (personal communication between TRC Environmental Corporation and
Leanne Connelly,  recycling coordinator, Western Disposal Services, Boulder, CO, in
July 1991).
                                    4-10

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4.3.4.4.   Cocollection
      Cocollection refers to the collection of recyclables and MSW in the same
collection truck at the same time.  Recyclables and MSW are collected in separate
bags, dumped into the same collection truck, and separated when the truck
unloads its contents at the sorting facility. In Houston, Texas, BFI used  this
method with traditional compaction trucks in a pilot study serving 19,000
households (Magnuson,  1991). Western  Disposal uses this same method to serve
1,500 to 2,000 households in Boulder, Colorado (personal communication  between
TRC Environmental Corporation and Leanne Connelly, recycling coordinator,
Western  Disposal Services, Boulder, CO, in July 1991).

4.4.  SORTING RECYCLABLES
      Once collected, recyclables must be sorted into homogeneous material
streams (i.e., aluminum, glass, paper, plastic, and steel) and prepared to meet
market specifications. A large number of technologies are available from which to
select the most appropriate sorting system for a given community.
      Historically, recyclables have been separated from the waste stream at
landfills,  transfer stations,  and waste-to-energy facilities. Sorting has also  occurred
at drop-off and buy-back centers as discussed previously.  As programs  have
moved to collect mixed or partially sorted recyclables at the curbside, it  has
become necessary to sort  recyclables after collection. The MRF, or intermediate
processing center, has emerged as a popular sorting alternative. Most MRFs
include a combination of manual and automated sorting and preparation  for
shipping.  An exception  to MRF-based systems is the limited number of programs
that collect recyclables mixed with general MSW, which are handled at a waste
processing facility. These facilities separate recyclables from MSW in addition  to
isolating  them by material.
                                    4-11

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4.4.1.  Transportation Associated With Sorting
      In addition to the transportation associated with consumer drop-off (Section
4.2) or curbside collection (Section 4.3), recyclables must be transported between
a variety of intermediate processing facilities. The method of transportation used
to haul materials to these facilities varies greatly according to the type of material
recycled and the specifics of the recycling program.
      The most common destination for recyclables following collection is a sorting
facility or an intermediate transfer station. In some programs, the sorting facilities
are located within close proximity to the travel routes (0 to 12  miles in Austin,
Texas [personal communication between TRC Environmental Corporation  and  Dave
Anderson, Acco Waste Paper Co., Austin, TX, in August 1991]).  In other
locations, curbside collection vehicles deliver recyclables to a local landfill, but
"roll-off" trucks must then transport the material to a sorting center farther away
{approximately 50 miles in Hampton, New Hampshire [personal communication
between TRC Environmental Corporation and Mike Hastings, Portsmouth District
Manager for BFI, in August 1991]).

4.4.2.  Materials Recovery Facilities
      As with many recycling technologies, there  is no precise definition of an
MRF. One common definition is a facility that sorts a stream of commingled
recyclables that has already been separated from MSW. MRFs accept materials
from myriad sources, including curbside collection programs, drop-off centers,
commercial collectors,  and  institutions.  They sort recyclables,  remove gross
contaminants, and bale or otherwise consolidate recyclables for shipment to
marketers, reprocessors, or manufacturers, depending on the material.
      Since MRF design is so variable, the material-handling systems used at
recycling facilities are supplied by a range of manufacturers, including distributors
of equipment traditionally used in farm and construction applications that now
market products for recyclable processing applications. A few vendors market
complete recycling systems. Many recycling programs assemble the necessary
                                    4-12

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equipment one piece at a time as it is needed (or as it can be afforded) and add it
to an existing system.                               )
      MRFs are generally designed with two major recyclable processing lines: one
for paper and paperboard products and another for mixed containers (aluminum,
glass, plastics).  Small-scale MRFs, which may process less than 100 tons of
recyclables per day, rely on manual sorting  (Figure 4-2).  Automated sorting
systems (Figure 4-3) are most often found in larger facilities designed to handle
several  hundred tons per day (Glenn, 1990).
      Recyclables usually enter the MRF when they are discharged from collection
vehicles to the tipping  floor and  pushed or loaded to process conveyors.  If
recyclable paper products and containers enter an  MRF commingled, an initial sort
separates the two streams. Paper, cardboard, and paperboard materials are  sorted
by hand and baled or compacted before shipping.  Ferrous metals are magnetically
extracted from the mixed containers.  Aluminum, glass, and plastic are then  sorted
manually or automatically.  Few satisfactory automated technologies exist to sort
certain  materials such  as colored glass or mixed plastic resins, so these materials
must be sorted manually for shipping.  Aluminum,  plastic, and  steel are frequently
baled, shredded, or flattened before shipping.  Glass is either shipped in  its sorted
form (usually broken) or it  is crushed or ground.
      The remainder of this section summarizes the following features and
equipment that are often implemented  in MRFs:
         Tipping floors
         Bag breakers
         Conveyor systems
         Material sorters
         Trommel screens
         Air classifiers
         Magnetic separators
Aluminum separators
Glass crushers/grinders
Slicers
Shredders
Plastic perforators
Balers and compactors
      Tipping Floors.  Collection vehicles dump recyclables onto the tipping floor,
 generally an indoor concrete pad, when they arrive at the MRF.  Forklifts, overhead
                                     4-13

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cranes, and front-end loaders are used to move recyclables from the floor to
conveyors.

      Bag Breakers.  Single bag curbside collection (see Section 4.3} delivers
commingled recycfables to the MRF in plastic bags that must be broken and
removed before processing.  Front-end bag-breaking equipment is designed to tear
open bags with as little glass breakage as possible.  Technology is still under
development, but one system currently available uses a slowly spinning (15 rpm)
tine wheel to tear open collection bags (Katz, 1991).

      Conveyor Systems.  Conveyor belts are common to nearly all MRFs.  At
facilities that rely on either manual sorting or gravity-based automated systems to
sort materials, conveyors are used to move recyclables past sorting stations or to
the top of processing equipment.  Specialized conveyor systems are engineered to
turn paper over or spread  recyclables to a uniform depth to assist manual sorting
(Egosi and Romeo, 1991). Conveyors are often mounted at or below floor level on
the tipping floor so that material may be pushed directly onto the belt.
      Material Sorting.  Although recyclables processing has become increasingly
automated, manual sorting remains the dominant means of sorting commingled
materials. Paper or glass, plastic, and metal container streams are usually sorted
on a conveyor belt that passes the workers. Both positive and negative sorting
techniques are used.  Positive sorting removes the desired recyclable material from
a mixed waste stream, resulting in low contaminant levels.  Negative sorting is the
removal of contaminants from the stream of desired recyclables.  This method is
marginally effective because sorters inevitably overlook some contaminants that
remain mixed with the recyclables.
      Sorters traditionally stand beside a conveyor belt, reaching over it to remove
and divert materials. Head-on sorting stations have also  become popular.  At these
stations, material moves toward the sorter on a belt that  discharges to a hole
                                    4-16

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directly in front of the sorter. This arrangement allows the sorter to use both
hands to remove material to both sides of the belt. To eliminate the number of
times recyclables must be handled, many MRFs elevate sorting stations, placing
them directly over conveyor belts or processing equipment. This configuration
allows workers to drop sorted recyclables or waste into chutes that carry it below
for further processing by balers or shredders.
      An example of an automated sorting system is the Bezner System distributed
by New England CRInc of Billerica, Massachusetts, currently in use at the Rhode
Island Solid Waste Management Corporation's MRF in Johnston, Rhode Island.
The  German-engineered technology uses gravity and  a series of three hanging
chain "curtains" to sort a falling stream of mixed containers, including glass,
aluminum, and plastics. As the containers fall down  an inclined ramp, the chains
divert the lighter fractions (aluminum and plastics) from the ramp to one processing
line, while the heavier glass falls through the chains to a separate processing line.
Although this system still requires manual sorting of glass and plastics, it  eliminates
the primary manual sorting step.

      Trommel Screens.  Trommels are inclined screen cylinders that are used to
sort fine materials (e.g., glass fragments) from the remainder of the material
stream.  Material is fed  in one end of a rotating trommel screen by a conveyor and
discharged to a conveyor or storage container at the  other end. Fine material that
falls through  the trommel screen is collected by a trough that lines the outside of
the screen.  The trough diverts the fine material to a  separate conveyor or storage
container.

      Air Classifiers.   Air blowers are  frequently used to separate and classify
(sort) lightweight recyclables. A mixed stream of materials is usually dropped from
a conveyor or thrust from a shredder chamber into a  vertically oriented chamber or
cylinder  that contains a constant, upward-blowing column of air.  The heavier
fractions fall  from the air stream, and the lighter materials are blown to a  separate
                                     4-17

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bin or chute. Lightweight materials such as paper and plastics are commonly
separated from heavier recyclables such as glass and metals by air classification.
Air classification can also be used to separate light contaminants (e.g., scrap
paper, foam plastics) from recyclables.

      Magnetic Separators.   Magnetic separators separate ferrous metals from the
waste stream.  A variety of cross-conveyor magnets are used to remove ferrous
metals from material on conveyor belts (Morgan, 1987).  The magnet is suspended
over the conveyor belt at a height inversely proportional to its force.  A belt and
magnet system suspended across the material supply belt moves the attracted
ferrous  material to the side.  Separated material is dropped to a bin or another
conveyor when it passes out of the magnetic field.

      Aluminum Separators.  Automated aluminum  removal can be achieved using
electrostatic and eddy-current separators. The material stream is charged  with a
high-voltage ion source and then passed over the edge of a conveyor onto a
rotating, electrically grounded drum.  Highly conductive material such as aluminum
rapidly dissipates its charge to the drum and falls into a waste bin. Nonconductive
material such as plastic and glass clings to the  drum's surface longer and is
scraped from the drum onto another conveyor (U.S.  EPA,  1977b).  Another system
uses a combination of rare earth magnets and steel poles to create a magnetic field
that can actually pull aluminum from the waste stream (Koch and Ross, 1990).

      Glass Crushers/Grinders.   Crusher and grinder systems are used in some
MRFs to densify glass.  A variety of impact and jaw crushers use steel  plates,
rotors, or both to grind and crush glass into small fragments (commonly called
cullet) (personal communication between TRC Environmental Corporation and Steve
Apotheker, journalist, Resource Recycling Magazine,  on August 14, 1991). Glass
is usually fed to the crusher by conveyor belt.  Impact crushers break glass against
steel rods or chains mounted along an inclined chute. Jaw crushers grind  glass
                                    4-18

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between two plates (personal communication between TRC Environmental
Corporation and Bill Boxell, corporate process manager, Foster-Forbes, Inc., on
August 28, 1991).

      Slicers.  Slicers employ a series of spinning blades to flatten containers and
remove labels from containers. A stream of air blown over the sliced containers
removes the labels for disposal.

      Shredders.   Shredders are sometimes used at MRFs to reduce aluminum,
paper, plastic, or steel to a uniform size and minimum volume. Shredder designs
vary depending on the material they are intended to reduce. Most include blades
or sharp rotors that chop or tear the waste within a shredder compartment.
Material is generally fed  to the shredder compartment by a conveyor system that
provides an even introduction of material and allows inspection before processing
(personal communication between TRC Environmental Corporation and Susan
Dumas of Herbold Equipment, Sutton, MA, on July 26, 1991). When the material
scraps have been reduced to the target dimension, they either fall through a screen
or are blown from the shredder.

      Plastic Perforators.  Perforators puncture multiple holes in plastic containers
to release air from the containers during  baling, resulting in a denser bale.  The high
pressures that can result within bales of  nonperforated, capped containers can
break bale ties or otherwise compromise the integrity of the bales.

      Balers and Compactors. Recyclables (except for glass) are frequently baled
or compacted to conserve space during storing and shipping. Recyclables are
loaded to the baler chamber by conveyor belt, front-end loader, or by hand. Baler
technology used in MRFs employs some  type of hydraulic  ram to compress
recyclables, which are then secured with steel or plastic strapping.  Bales of
malleable materials (i.e., aluminum, steel) do not necessarily require strapping  to
                                    4-19

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maintain their integrity.  Some balers use a second press to eject bales from the
baler chamber.

4.4.3.  Waste-to-Energy Facilities/Transfer Stations/Landfills
      In addition to MRFs, a number of waste-to-energy facilities, transfer stations,
and landfills have started to include front-end sorting operations as part of their
processing.  Some communities have tried to save money by adding a complete
separation operation to existing transfer stations, and others have opted to
separate only those materials that are easiest to remove, such as ferrous metals.
Waste-to-energy plant manufacturers have recently started encouraging
communities to include MRFs in their plans to build incinerators  (J.A.S.,  1988).
Not only does the removal of glass and steel from MSW provide a potential source
of revenue for these facilities, but it also reduces wear on incinerator equipment
and reduces the amount of ash and residue that must be landfilled.
      Sorting at these facilities may exist as a few front-end process steps or as
an operation independent of the main facility.  Regardless of their configuration,
they include much of the same equipment found in MRFs.  Collection vehicles
deliver mixed MSW to the tipping floor where it is visually inspected and initially
sorted before proceeding to a process line designed to remove target materials
(Peluso, 1989).

4.5.  MATERIAL-SPECIFIC RECYCLING PROCESSES
4.5.1.  Introduction
      Material reclamation, including the manufacture of new products,  follows the
collection, sorting, and associated transport of MSW recyclables.  This phase of
processing generally begins when the segregated materials (i.e., aluminum, glass,
paper, plastic, and steel/tin) are received at a reclamation facility. For the  purposes
of identifying processes unique to recycling, the reclamation phase ends when the
processing becomes equivalent for virgin and recycled materials.  This end point is
different for each material but is generally the point at which a homogeneous solid
                                     4-20

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or liquid, free of "contaminants," is available for mixture with virgin material for
product manufacture.
      Transportation between and within facilities occurs throughout subsequent
processing of recyclables.  For example, separated paper must be hauled to
deinking facilities; scrap metal is loaded and unloaded and transferred to different
locations at steel mills.  The type of transport required is both material and program
specific. Trucks as well as rail cars and cargo ships can be used to transfer
materials between facilities. Forklifts, front-end loaders, cranes, and other heavy
equipment are used within facilities.
      Market factors may affect the distances traveled and the types of vehicles
used to transport recyclables to processing facilities. For example, if glass
manufacturing plants are located too far away, transportation of cullet over the
large distances by rail cars or cargo ships may become prohibitively expensive
(Meade, 1991).  However, other recyclables destined for markets abroad are
containerized and exported (personal communication between TRC Environmental
Corporation and Pat Schatz, office manager, Hooksett Recycling and Processing
Center, Inc., Hooksett, NH, in August 1991).
      The sections that follow summarize material-specific processing for the five
target MSW recyclables, as follows:
         Section 4.5.2 - Aluminum
         Section 4.5.3 - Glass
         Section 4.5.4 - Paper
         Section 4.5.5 - Plastic
         Section 4.5.6 - Steel/Tin
      Each section begins with an overview of the composition of each recyclable
material.  Knowledge of the material itself and any contaminants in the
postconsumer material is essential to fully characterize processing byproducts and
any associated hazards.
                                     4-21

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      The second part of each material-specific section provides an overview of
 process technologies from which hazards can be identified in Chapter 5.  The
 process descriptions are general and not intended to detail all possible steps or
 technologies.  For materials for which it is impractical to address all possible
 feedstocks (e.g., scrap ferrous metal), one or more specific postconsumer products
 (e.g., food and beverage containers) are selected for discussion on the basis of
 their contribution to MSW and percent recovery. Figures on the percentage of
 each material recovered from MSW are discussed in Appendix B.

 4.5.2.  Aluminum
 4.5.2.1.  Composition of Aluminum Recyclables
      Aluminum finds applications  in numerous consumer products that may
 ultimately contribute to MSW. The elemental composition of aluminum products
 varies by product type.  Table 4-1  lists elements, in addition to aluminum, that are
 present in different types of aluminum scrap.  Aluminum used beverage containers
 (UBCs) constitute between 95 and  98 percent of all aluminum recycled from MSW
 (Franklin Associates, Ltd., 1990).  Aluminum UBCs are typically treated with water-
 based, solvent-based, or a combination of surface coatings that are applied to both
 interior and exterior surfaces to isolate the can's contents from the metal body,
 improve appearance, protect lithography,  and increase can mobility during filling
 (U.S. EPA, 1980a). Coatings and inks used in exterior labeling contribute a variety
 of organic and inorganic chemicals  to the overall content of aluminum recyclables.
 Organic components typically used  in surface coatings are summarized in Table
4-2. Pigments found in inks can  be both organic and inorganic compounds.
Although the trend is to use more organic pigments, the following inorganic
pigments are used:  cadmium, chromium,  copper, iron, lead, mercury, molybdate,
and zinc (U.S. EPA, 1992).
                                    4-22

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TABLE 4-1
Typical Elemental Composition of Aluminum Scrap
Source
UBCs (directly
reclaimed)
Municipal
(mostly UBCs)
Automotive
(automobile
shredder residue)
Element %
Silicon Iron Copper Manganese Magnesium Zinc
0.2
0.8
5.0
0.6
0.5
0.8
0.15
2.4
1.3
0.9
0.6
0.3
1.1/1.3
0.1
0.1
—
2.0
0.6
Source: Henstock, 1988.



- =  Negligible
                                   4-23

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                                TABLE 4-2
                  Typical Organic Components of Coatings
                          Applied to Beverage Cans
Interior Base Coat
   Butadienes                      Epoxies
   Rosin esters                     Vinyls
   Phenolics                       Organosols
Overvarnish Coat
   Polyesters
   Alkyds
   Acrylics
Primer (size) Coat
   Epoxy                           Acrylic vinyl
   Epoxy ester                     Polyester resin
Solvents (used for interior and exterior base coats, overvarnish, and size coats)
   Mineral spirits                   Ethylene glycol monoethyl ether acetate
   Xylene                          n-Butanol
   Toluene                         Isopropanol
   Dicatone alcohol                 Butyl carbinol
   Methyl iso-butyl ketone          Paraffins
   Methyl ethyl ketone              Propylene oxide
                                   4-24

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                           TABLE 4-2 (continued)
    Isophorone
    Solvesso 100 and 150 (TM)
    Di-isobutyl ketone
    Ethanol
 End sealing compound
    Synthetic rubber
    Heptane
    Hexane
Resityl oxide
Aliphatic petroleum hydrocarbons
Nitropropane
Cyclohexanone
Source:  U.S. EPA,  1977a.
                                   4-25

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4.5.2.2.  Process Technologies
      Secondary aluminum production from scrap aluminum began shortly before
World War I and has grown at a constant rate since World War II. The technology
of aluminum recycling has remained generally the same throughout the years, with
changes primarily found in the method of casting ingots and the introduction of
emission-control devices.
      Recyclable aluminum is obtained by several means, including UBCs collected
from consumers by retailers in states with deposit legislation; UBCs,  other
aluminum cans, foil, and closures collected from municipal recycling  programs; and
aluminum in many forms purchased directly from the public by scrap dealers. A
relatively small quantity of aluminum is recovered and recycled from  front-end
separation at incinerators. Depending on the aluminum source and end-market
specifications, aluminum may or may not have to be sorted by type.  Large
companies  like ALCOA and Reynolds that manufacture beverage cans require
separated aluminum. The aluminum recycling process consists of several steps,
including the following:
      •  Baling and compacting
      •  Bale breaking
      •  Shredding
•  Drying/delacquering
•  Smelting
•  Casting and cooling
Figure 4-4 presents a general overview of aluminum recycling.  If scrap aluminum is
to be transported over a long distance to a reclamation facility, it may first be
densified to reduce its volume and cut transportation costs. At the reclamation
facility, usually a secondary smelter, bales are broken, and the scrap is shredded,
dried or delacquered, smelted, and .cast.  The recycling process and technologies
described below emphasize UBCs because they constitute the majority of aluminum
recycled from MSW.
                                    4-26

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      Balers and Compactors.  Sorted aluminum scrap may be compacted to
reduce its volume before transport to the secondary smelter.  Aluminum UBCs
typically arrive at the compactor in the form of loose, .flattened cans.  The "loose
flats" are unloaded from the truck to high-density balers by forklift or front-end
loader.  Balers are of two types, either vertical (loaded on the top) or  horizontal
(loaded on one side). These machines compact the aluminum into bales generally
weighing 700 to 1,200 pounds each (personal communication between TRC
Environmental Corporation and John Vandevender of the Aluminum Company of
America (ALCOA) of Knoxville, TN, on August 2, 1991;  personal communication
between TRC Environmental Corporation and Gene Brown of Maine Beverage
Container Service, Inc., of  Portland, ME, on August 13,  1991).  Alternatively, the
aluminum can be compacted into 35-pound biscuits that are packaged into 2,500-
pound bundles (personal communication between TRC Environmental  Corporation
and John Vandevender of the  Aluminum Company of America (ALCOA) of
Knoxville, TN, on August 2, 1991). The exact size of the bales and the choice
between baling or biscuiting depend on the cost of production and transport as
well as operational limits such as the size of machinery of both the facility
producing the compacted aluminum and the customer buying it.

      Bale Breakers.  Aluminum bales can be broken apart with a hammer mill or
other type of bale breaker.  The hammer mill  uses a conveyor belt to feed the
aluminum  under a hydraulic or weight-driven  mechanism, which  crushes and breaks
the bale into fist-size pieces (TRC, 1978).

      Aluminum Shredders. Scrap aluminum is often shredded into small pieces
before smelting to allow magnetic removal of iron contaminants and more efficient
cleaning and melting. Within the shredder, the aluminum is sheared and cut into
small pieces, the exact size of which varies depending on the specifications of the
machinery and the size desired by the  customer purchasing the shredded
aluminum. The equipment  uses high-speed blades that produce aluminum with
                                   4-28

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sharp edges.  The shredded aluminum is usually blown into the back of a trailer for
transport to the secondary smelter. See Section 4.4.2 for further discussion of
shredders.
      Scrap Dryers/Delacquerers.  Before aluminum scrap can be melted for
remanufacture, impurities such as paints, coatings, container residues, and other
contaminants must be removed.  Impurities are removed through a process that
involves drying the aluminum scrap (referred to as delacquering when recycling
UBCs) or heating it in a rotary furnace or kiln until the contaminants  have burned
off.  Aluminum fragments are exposed to heat as they tumble through an inclined,
rotating kiln chamber. Paint and coatings that burn off the aluminum may produce
additional heat that can be captured and used to increase kiln fuel efficiency and
the combustion of contaminants.  The aluminum leaving the delacquering kiln is
considered clean, free of paints, coatings, and residues.

      Smelting.  Reverberatory and rotary furnaces are the two primary types of
charge furnaces used in secondary aluminum smelting. Gas- or oil-fired
reverberatory furnaces at medium to large secondary aluminum smelting operations
typically range in capacity from approximately 10 to 90 tons (TRC, 1978).
Shredded aluminum scrap is usually introduced to the furnace through a charge
well positioned beneath the surface of the already molten aluminum. This
facilitates the  capture of fume  emissions through the use of a collection  hood and
also minimizes aluminum oxidation.
      Rotary furnaces have relatively small capacity and usually operate on a per-
batch basis.  Crucible or pot-type furnaces are used to melt even smaller quantities
(up to 1,000 pounds) of aluminum (TRC, 1978).
      When aluminum is in its  molten form, several processes can be used to
change its composition and melt characteristics.  These processes include the
addition of fluxing or alloying agents, the  removal of excess magnesium, and the
removal of dross or slag that forms  on the surface of the molten aluminum.
                                    4-29

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      Additives.  Fluxing agents are usually added to the furnace with scrap to
remove extraneous contaminants and reduce losses of aluminum. As aluminum
reaches the molten stage, the fluxing agents react with leftover contaminants such
as inks and coatings to form insoluble materials, which float to the top of the melt.
The accumulated flux and associated contaminants are known as slag.  This layer
reduces loss that is due to oxidation of aluminum exposed at the surface. Flux
may contain sodium chloride, potassium chloride, calcium chloride, calcium
fluoride, aluminum fluoride, and  cryolite.  A typical flux composition is 47.5 percent
sodium chloride, 47.5 percent potassium chloride, and 5 percent cryolite (TRC,
1978).
      Alloying agents may be added to molten aluminum to produce a desired melt
composition.  Typical alloying agents include copper, silicon, manganese,
magnesium, and zinc.  However, little or no additional alloying is necessary when
UBCs are recycled for use as new beverage cans.

      Demagging.  The tops of  used beverage containers possess a higher
concentration of magnesium than the rest of the can, and it is necessary to remove
some of the magnesium to produce a homogeneous aluminum end product
(Copperthite,  1989).  Demagging, the process of removing excess magnesium from
aluminum, uses chlorine or chlorinating agents (anhydrous aluminum chloride or
aluminum fluoride) to react with  the magnesium  in the melt (U.S. EPA, 1989). For
example, chlorine demagging introduces pressurized chlorine gas to the bottom of
the aluminum melt. The chlorine bubbles upward, combining with magnesium to
form magnesium chloride.  As the magnesium becomes scarce in the melt,
aluminum chloride, a volatile compound, is formed. Fluoride may be used to form
magnesium fluoride in a process  similar to chlorine demagging.

      Skimming.  Skimming is a procedure that  removes dross (layer of oxidized
aluminum) and slag (layer of flux and contaminant) from the surface of molten
aluminum.  Cooled slag and dross are removed and transported to either a residue
                                   4-30

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processor, recycler, or disposal facility.  Based on industry reports, water
consumption for recycling slag/dross may vary from 30,000 to 80,000 liters per
metric ton of slag/dross recycled (U.S. EPA, 1989). The wastewater may contain
suspended solids (aluminum oxide and hydrated alumina), ammonia (approximately
200 mg/L), and metals such as aluminum, copper,  and lead.

     Casting and Cooling.  After the furnace has  been completely charged and
the aluminum adjusted to meet the end-product specifications, molten aluminum is
poured into casts.  Ingot conveyor casting is the predominant casting method used
in secondary aluminum processing (U.S. EPA, 1989).  This method consists of
pouring molten aluminum into molds that travel on  a conveyor system.  Water is
commonly used to cool ingot casts.  Direct chill is another method of ingot casting
and involves the continuous solidification of the metal while it is being poured (U.S.
EPA, 1989). Molten aluminum is allowed to flow through a distribution channel
into a shallow  mold.  Circulating within the mold is noncontact cooling water that
solidifies the aluminum.  The base of the mold is attached to a hydraulic cylinder
that is gradually  lowered into a tank of water as pouring continues.  When the
cylinder reaches its lowest point, pouring is stopped.  The ingot is then  removed
and sprayed with cooling water.  Stationary casting is a method that involves
pouring the molten aluminum into cast iron molds and allowing it to cool.  Spray
quenching may be  used to cool the exposed surface of the aluminum.  At some
facilities, the end product is molten aluminum, which is transferred to a preheated
crucible or mold  for transport.

4.5.3.   Glass
4.5.3.1. Composition of Glass Recyclables
     The four common types of glass are soda-lime, borosilicate, lead silicate,  and
opal.  The primary  constituent of each of these is silica, but depending on end-
product specifications, various minerals and chemicals can be added to the virgin
material ("the batch"). Additives such as boron oxide, which causes the glass to
                                    4-31

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withstand higher degrees of thermal shock, and lead oxide, which elevates
electrical resistivity, ultimately define the properties of the glass (U.S. EPA,  1979).
Table 4-3 lists the constituents of the major glass types.
      Postconsumer glass can be divided into three primary functional groups:
container glass, flat glass, and pressed and blown glass.  Nearly 100 percent of all
MSW glass recycled are containers manufactured exclusively of soda-lime glass.
Glass containers received for reclamation include a significant fraction of nonglass
materials. These include paper and plastic labels affixed with adhesives; paints,
inks, and  dyes; and plastic and metal caps. Container residues, both nonhazardous
(e.g., beverage residues) and hazardous (e.g., pesticides), may also be present.
The focus of subsequent discussions is soda-lime glass containers, given their
predominance in recycled MSW.

4.5.3.2.  Process Technologies
      Glass processing facilities usually prefer to receive glass that has been color
sorted by the consumer or at a materials recovery facility. In  some cases, glass
processing facilities do not accept unsorted containers. Facilities that do accept
commingled glass need to assess the specifications of the cullet (crushed scrap
glass) markets.  If the market requires one color, then the facility must separate the
glass.  The cullet color and size, as well as the amount of foreign objects present in
a cullet load, are highly regulated for certain markets.  Some  glass cullet market
specifications are presented in Table 4-4.  In general, only a small amount of green
or amber  glass can be added to  a batch of flint glass (clear).  Manufacturers also
control the percentage of off-specification glass in green and amber batches.
Table 4-5 summarizes the specifications that are generally met by cullet dealers for
each cullet type.
      Before cullet can be added to a virgin glass batch, it is  necessary to remove
as much of the associated nonglass and off-specification  glass material as markets
require.  Since  metal, plastic, or other contamination in a  batch causes
                                     4-32

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TABLE 4-3

Major components
Soda-lime glass
Silica
Soda
Lime and magnesia
Alumina
Other oxides
Borosilicate
Silica
Alumina
Boron oxide
Sodium oxide
Magnesia plus calcia
Potassium oxide
Typical Glass
Percent by
weight

72
15
10
2
1

60-81
1-17
5-24
1-15
4-17
1-8
Compositions
Major components
Opal glass
Silica
Alumina
Calcium oxide
Potassium oxide
Fluorine
Lead glass
Silica
Lead oxide
Sodium oxide
Potassium oxide
Alumina


Percent by
weight

71.2
7.3
4.8
2.0
4.2

35-70
12-60
4-8
5-10
0.5-2.0

Source:  U.S. EPA, 1979.
                                 4-33

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TABLE 4-4
Gullet Requirements for Primary Markets
Market Specifications required
Container glass
Brick and concrete aggregate
Foamed glass
Ceramic tile
Terrazo tile
Building panels
Glass wool
Slurry seal
Glasphalt
Gullet must be noncaking, free flowing,
show no drainage of liquid and 140 U.S.
mesh; contain <0.02% organics, <0.14%
magnetic metal contaminants, and < 1
nonmagnetic particle per 1 8 kg
Can use up to 50% cullet; should be free of
metal or organics
Can use up to 95% cullet; no specifications
Can use up to 60% cullet; unsorted; sized
to 200 mesh
Can use up to 60% cullet; must not contain
any metal
Can use up to 94% cullet with no metal or
rehyd ratable materials; must be sized to 200
mesh
Can use 10-50% cullet; accept up to 2%
foreign material
Can use 100% cullet; must have neutral pH
and contain very little metal
Can use 77% cullet; smaller than 1/2 inch;
up to 15% nonglass material is acceptable
Source:  U.S. EPA, 1981.
                                 4-34

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                               TABLE 4-5

                     Amount of Colored Gullet Accepted
                        by Container Manufacturers
Container color
Amber
Flint
Green
Gullet color (percent of total cullet)
Amber Flint Green
90-100
0-5
0-35
0-10
95-100
0-15
0-10
0-1
50-100
Source:  U.S. EPA, 1981.
                                  4-35

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imperfections in the product, a major portion of the glass recycling process
consists of separating and sorting stages.
      In general, when glass arrives at a processing facility, a combination of the
following steps and equipment is employed:
      •  Manual sorting
      •  Magnetic separators
      •  Air classifiers
•  Glass crushers and grinders
•  Screens
•  Aluminum separators
Depending on the cullet grade and its expected market, glass may also be rinsed
with water following the above steps.
      Numerous variations of this process are in place, but an estimated 90 to 95
percent of the glass processing facilities in the United States use these basic
techniques (personal communication between TRC Environmental Corporation and
Roger Hecht, vice president, Bassichi's Company, on July 31, 1991).  Few
technologically advanced separation methods are employed,  primarily because the
prices of cullet are sufficiently low that most companies cannot afford expensive
machinery.
      The following discussion describes the most  conventional process used to
produce glass cullet.  Figure 4-5 presents a schematic diagram of a typical glass
recycling process. Although the steps outlined below are used consistently in glass
recycling facilities, the order of processing steps varies from facility to facility. For
example, one facility may magnetically separate the waste before crushing, another
may do so after crushing, and still another may use magnets before and after
crushing.  Facility operators rely on trial  and error to determine the most effective
means of producing cullet in their setting. No single method has been proven to
work most effectively under all circumstances.

      Manual Sorting.  Glass arriving at a processing facility has usually been
presorted by color.  It is first emptied into a surge hopper that feeds the glass onto
                                    4-36

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POSt- f?«neiimar
    Glass
r|   w^

J   ^
 Surge
Hopper
Manual
Sorting
                                Contaminants:
                                  Stones
                                   Wood
                                   Paper
                                  Plastic
                                     Large
                                   Fragments
 Crusher/
 Grinder
                                   Screens
Magnetic
Separator
  Air
Classifier
                                                                                f
                                                                    Ferrous
                                                                   Materials
                                                               Contaminants:
                                                                  Plastic
                                                                  Paper
                                                                Aluminum
                                      Fine
                                   Fragments
                    Electrostatic
                     Separator
                                                     I   ^   f Reusable   |
                                                     |        ^   Cullet    J

                                                     ^
                                              Aluminum
                                FIGURE 4-5
                Generalized  Glass Recycling Process
                                     4-37

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a conveyor belt.  A facility often processes different colored glass on dedicated
lines or at different times to avoid mixing them (personal communication between
TRC Environmental Corporation and Steve Apotheker, journalist, Resource
Recycling Magazine, on August 14, 1991). The glass passes along the conveyor
where workers remove any large debris such as stones, branches,  or other
nonglass material (personal communication between TRC Environmental
Corporation and Roger Hecht, vice president, Bassichi's Company,  on July 31,
1991). Most facilities process glass at a rate that requires two or three sorters per
conveyor.

     Magnetic Separators.  Magnetic separation of ferrous material from glass or
glass cullet typically follows hand sorting. The most common type of magnet used
to remove ferrous material is the cross-conveyor magnet (personal  communication
between  TRC Environmental Corporation and Bill Boxell, corporate  process
manager, Foster-Forbes, Inc., on August 28, 1991).

     Air Classifiers.   Glass passed through magnetic separators is often
processed using an air classifier or vacuum to remove lighter contaminants.  Some
facilities use one or a series (up to 150) of powerful vacuums placed over the
material supply conveyor to remove glass fines and light contaminants from heavier
glass fragments (personal communication between TRC Environmental Corporation
and Roger Hecht, vice president, Bassichi's Company, on July 31,  1991).  Another
system uses an upward air flow to blow light material away from the glass as it
passes across a vibrating screen.

     Glass Crushers and Grinders.  After the glass is separated from the
extraneous waste, it is ready to be crushed or ground into cullet. Impact and jaw
crushers  are commonly used (personal communication between TRC Environmental
Corporation and Steve Apotheker, journalist, Resource Recycling Magazine, on
August 14, 1991).
                                    4-38

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      Screens.   Gullet passes onto a vibrating screen that allows smaller glass
fragments to pass through to the next stage of the recovery process.  Larger
pieces, including any contaminants, are conveyed back to the sorters, magnetic
separators, or crushers and grinders for reprocessing. Gullet is screened and
reprocessed through the separators and crushers and grinders until it meets size
specifications (personal communication between TRC Environmental Corporation
and Steve Apotheker, journalist, Resource Recycling Magazine, on August 14,
1991). This process may be repeated three or four times before the cullet reaches
the desired size.

      Aluminum Separators.  Most processing facilities use an electrostatic or
eddy-current magnet to remove aluminum fragments from screened cullet (personal
communication between TRC Environmental Corporation and Bill Boxell, corporate
process manager, Foster-Forbes,  Inc., on August 28,  1991).

4.5.4.  Paper
4.5.4.1.   Composition of Paper Recyclables
      In 1988, recycled wastepaper in the United States was made up of
newspapers (16.2 percent), corrugated (49.8 percent), mixed papers (11.0
percent), and high-grade deinking paper (8.5 percent), with additional volumes of
in-plant pulp substitutes (14.5 percent).  In total, wastepaper contributed
approximately 25 percent of new supply production in 1988 (Franklin Associates
Ltd., 1990).
      Paper is predominantly made of cellulose fibers from wood and cotton and
other sources.  Mechanical or chemical techniques reduce hardwood and softwood
to fiber-rich pulp. Chemical methods may use caustic soda, sodium sulfate, and
various sulfides. In addition to fiber,  paper consists of numerous coatings, sizing
agents, and colorants.  Coatings, used to make paper strong and smooth, include
clay, titanium oxide, calcium carbonate, zinc sulfide, talc, and synthetic silicates.
Sizing agents make  paper water resistant and include rosin, hydrochemical and
                                    4-39

-------
natural waxes, starches, glues, and cellulose derivatives.  Colorants are made of a
wide range of inorganic elements. The most commonly used pigments are carbon
black (black) and titanium oxide (white).
      Inks are another major constituent of paper recyclables. They generally
consist of pigment and a vehicle.  Carbon-derived black pigments are the most
common.  Other common pigments include titanium oxide, zinc sulfide, and zinc
oxide. Although the vehicle is not actually applied to the paper with the pigment,
vehicle residues may remain on the paper. Printing vehicles include a  variety of
oils, waxes, and solvents.  Letterpress and lithographic inks, which print well on
newsprint, make use of mineral oil, resin, and solvent vehicles. Xerographic, UV-
cured, and laser printing inks use solvent, acrylic, and polyester-based vehicles
(Carr, 1991). Flexographic inks, a relatively new category, have wide applications
and are gaining in popularity. These inks use numerous solvents as the printing
vehicle.

4.5.4.2.   Process Technologies
      Plants that recycle postconsumer wastepaper receive it from commercial
collectors, wastepaper dealers, or directly from municipal collection programs.
When paper arrives at the facility, it is inspected and  passed through a series of
sorting stages to remove gross contaminants. Many contaminants are found in the
wastepaper stream that must be removed manually or by screens or filters
throughout the process. Contaminants are listed in Table  4-6 by the paper grade.
Next, the paper is pulped, and the pulp is cleaned, deinked, and bleached.
Processes used in wastepaper recycling plants vary depending on the  paper  grades
accepted (Table 4-7). Pulp used in low-grade products such as brown paper bags
and cardboard often requires no deinking and little bleaching, whereas pulp used in
high-grade products may undergo more thorough cleaning.  Most facilities include
some combination of the following types of steps and equipment:
                                    4-40

-------





















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-------
                                  TABLE 4-7
           Specific Processes Associated With Wastepaper Categories
  Wastepaper category
 Process
 Finished products
  Pulp substitutes
  (in-plant scrap)
  Deinking grade paper
 Newspaper
 Mixed papers
 Corrugated
 Pulping

 Pulping
Screening
 Cleaning
 Deinking
 Pulping
Screening
 Cleaning
 Deinking
 Pulping
Screening
 Cleaning
 Pulping
Screening
 Cleaning
    Fine paper
      Tissue
      Tissue
    Fine paper
     Newsprint
  Folding cartons
      Packing
     Packaging
  Molded products
Corrugating medium
     Linerboard
    Kraft towels
Source: Broeren, 1989.
                                    4-42

-------
         Material inspection and storage
         Manual sorting
         Magnetic separators
         Trommel screens
         Pulpers
         Screens
         Separators (deinking)
         -   Flotation
         -   Washing
Bleaching
Dewaterer/thickener
Wastewater clarification
Effluent treatment
Sludge disposal
Paper milling
Figure 4-6 depicts the generalized process flow of a paper recycling plant.

     Material Inspection and Storage.  Wastepaper must be carefully inspected
for quality before it can be used as a pulp supply. Levels of contaminants, aging,
and water damage must be evaluated when the wastepaper arrives at the recycling
facility.  Aged or water-damaged papers are often discolored, which limits their use
in high-quality end products.  With current technology, roughly 70 percent of the
mixed wastepaper that enters a facility can be used for recycled paper, and 20 to
3O percent must be discarded, usually landfilled or incinerated (Patrick, 1990).
     The inspection and storage area is generally arranged much like the tipping
floor of an MRF.  Trucks deliver loads of loose tfr baled wastepaper and  dump
them on a concrete receiving floor.  Paper is stored  in piles or in concrete bins or
compartments.  Bucket-loaders and forklifts are used to move the paper around the
facility.

      Manual Sorting.  Unless a consistently high-quality wastepaper stream is
available (i.e., in-plant scrap), most paper plants  perform some degree of sorting
before pulping. Sorting wastepaper by quality, color, or grade is essentially a
manual operation. The wastepaper stream is usually sorted by workers along a
conveyor belt.  Both positive and negative sorting techniques are used to remove
contaminants and sort paper by grade (Andrews, 1990).  See Section 4.4.2 for
more discussion of sorting methods.
                                     4-43

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-------
      Magnetic Separators.  Magnetic separators are used in some wastepaper
processing facilities to separate ferrous metal contaminants (e.g., paper clips,
staples, wire) from papers.  In general, magnetic separators in paper plants employ
a suspended magnet to remove ferrous metals from a conveyor belt passing
beneath it (Morgan, 1987). See Section 4.4.1 for more discussion of magnetic
separator technology.

      Trommel Screens.  Trommels are inclined screen cylinders that are used to
sort fine materials such as glass fragments from the wastepaper stream.  See
Section 4.4.2 for a description of their use.

      Pulpers.  After passing through some combination of the processes
discussed above, wastepaper enters the pulper.  Pulpers generally consist of a
large mixing vat with spinning paddles or blades that churn the paper in a water-
based slurry to "fiberize" it and break down contaminants with a minimal amount
of fiber degradation. Wastepaper bales that have been broken apart are evenly fed
to open pulping vats.  Some pulpers use metal rotors and disks to grind the paper
to fibers, and others rely on fiber-to-fiber contact to break down the paper. Heated
            •
water (generally below 150°F) and caustic chemicals such as sodium hydroxide are
added to facilitate the pulping process.  A number of process-enhancing chemicals
may also be added to the system at the pulper to ensure complete mixing with
wastepaper (Table 4-8).  The pH of pulper  slurry is raised to between 10 and  12,
which swells fibers and releases inks into suspension.  The alkalinity also
hydrolyzes ink vehicles and binders. Some screening of large contaminants takes
place as the pulp is drained from the pulper and the pulp slurry, or "stock," is
carried by pipes to subsequent process steps.
      Recently, high-consistency pulpers have gained  popularity.  These pulpers
rely on a higher fiber concentration (roughly 15 percent) to break down the paper.
High fiber concentrations are obtained by using less water. This method reduces
the amount of chemicals  and energy required and permits larger contaminant
                                    4-45

-------
TABLE 4-8
Deinking Chemicals
Deinking
chemical
Sodium hydroxide
Sodium silicate
Sodium
carbonate
Sodium or
potassium
Nonionic
surfactants
Solvents
Hydrophilic
Structure/formula
NaOH
Na2SiO
(hyd rated)
Na2CO3
(NaPO3)n = 15
Hexametaphosphate
Na5P3010
Tripolyphosphate
Tetrasodium
pyrophosphate
Ethoxylated linear
alcohol
Ethoxylated alkyl
phenols
Cj-C.,4 aliphatic
saturated
hydrocarbons
CH2CHC = OOH(Na)n
Function
Fiber swelling
Ink breakup
Hydrolyzes
Ink dispersion
Wetting
Peptization
Ink dispersion
Alkalinity ledger
and buffering
Peroxide
stabilization
Alkalinity
Buffering
Water softening
Metal iron
sequestrant
Ink dispersion
Buffering
Alkalinity
Detergency
Peptization
Ink dispersion
Wetting
Emulsification
Solubilizing
Ink removal
Ink softening
Solvation
Ink dispersion
Dosage
(% of fiber)
3-5
3-5
3-5
0.2-1.0
•
0.2-2.0
0.5-2.0
0.1-0.5
4-46

-------
TABLE 4-8 (continued)
Deinking chemical
Polymers
Fatty acid soap
Hydrogen
peroxide
Sodium
hydrosulfite
Chlorine
Structure/formula
Polyacrylates
CH3(CH)16COOR
Stearic acid
H2O2
Na2S2O4
CI2
Function
Antiredeposition
Ink flotation acid
Bleach
Bleach
Bleach
Dosage
(% of fiber)
0.1-0.5
0.5-5.0
1.0
0.5-1.0
0.2-1.0
Source: Amoth et al., 1991.
                             4-47

-------
particles to remain unbroken in the pulp, which facilitates subsequent flotation
separation.
      Stake Technology Ltd. (StakTeck) of Ontario, Canada, has developed a
steam explosion pulping method that pressurizes shredded paper and water by
using a  screw press. The pulp is released under high pressure against a rotating
blade, causing an explosion-like reaction and chopping the pulp into small bits.  The
system  operates at temperatures as high as 400°F and pressures as high as 400
psi (Stinson, 1991).  The process can replace standard pulping, and StakTeck
claims it requires substantially less  water and energy (MSW Management,  1991).

      Screens.  Most plants include a number of screening steps. Screens varying
in coarseness are used to remove a range of progressively finer contaminants from
pulp. Rotors may be used to press pulp through the screens.

      Separators.  Separation, often referred to as deinking,  is the process that
removes ink particles from pulp.  Flotation and washing are the primary deinking
technologies.  Systems that float large ink particles from pulp slurry have
traditionally been popular in Europe; systems that wash dissolved inks from pulp
have been more common in the United  States.  Recent advances  in flotation
technology have led to its increased popularity in the United States.  Both
techniques generate ink-laden residue, which  is  either in the form of a froth or is
dissolved in wastewater.  Table 4-8 lists additives used in the deinking process.
These chemicals are added at many points throughout the system, depending on
the technology used and the degree of  pulp quality required for end products.
Chemical additives remaining in washwater  and  sludge are handled by onsite
wastewater and sludge treatment systems.

      Flotation Separators.  Small  ink particles are agglomerated  into larger
clusters that float to the surface attached to bubbles of air, which has been
                                    4-48

-------
injected into the bottom of the flotation tank.  The resulting inky foam or slurry is
mechanically skimmed from the surface and usually dewatered before disposal.
      For flotation to work effectively, ink must be stabilized as insoluble particles.
Fatty acids are added to the pulp to form calcium soaps that act as stabilizers
(Schriver,  1990). Fatty acid soaps and ethoxylates are commonly used along with
calcium chloride, which assists the fatty acid conversion to insoluble soap. Typical
concentrations are approximately 80 pounds of surfactant per ton of dry pulp
produced (Basta et al., 1991). In addition, clay enhances the process of ink
removal and is frequently added to flotation systems.

      Washing Separators.  Washing separation systems operate by dispersing ink
into tiny particles that can be washed from the pulp.  Classes of alkylphenol
ethoxylates and linear alcohol ethoxylates are commonly used as dispersants in
washing systems {Schriver,  1990).  A variety of washing systems are available.
The most common types of washers are described below (Horacek, 1983):

      Sidehill  screens are, in simple terms, inclined troughs lined  with a
      screen.   Pulp released at the top of the screen gradually tumbles to the
      bottom  under its own weight.  Water passes from the fiber and
      through the screen into a collection tank below.
      Gravity  deckers use spinning horizontal screen drums that accept a
      coating  of pulp slurry.  Water drains to the center of the drum and is
      removed. The pulp cake is scraped off the drum as it dries.
      Inclined screw extractors use a screw to pull the pulp slurry up and
      through an inclined screen cylinder. Water drains away as the pulp
      rises in  the cylinder.
      Vacuum filters draw water from the slurry by pulling the pulp against
      screens.
      Screw presses extract water from  the slurry by compacting the pulp in
      an enclosed chamber with a large screw. Water is forced  from the
      pulp through perforations in the chamber walls.
                                     4-49

-------
      All of these types of equipment are enclosed systems, except for the sidehill
screen. Wastewater drawn from the pulp is usually sent to a clarifier for treatment.
Because of required chemicals and water volumes, it is not practical to use clean
water during washing. Instead, recycled wastewater streams are commonly used
throughout washing systems  (Horacek, 1983).

      Bleaching.  A majority  of paper recycling plants bleach pulp fibers to improve
their brightness for end products.  Bleaching is accomplished by adding bleaching
agents to  pulp before  it enters a mixer.  After  mixing, the fiber and bleach  mixture
is often allowed to soak or react in a holding tank or tower.  Water flowing from
the reaction is clarified and reused or released.
      Chlorine-based bleaches, such as hypochlorite, are commonly used
throughout the paper  industry. A 1987 survey of paper mills by U.S. EPA
Region V revealed that 12 of  14 deinking facilities surveyed  used  chlorine bleaching
(Barney, 1987).  Concerns about the use of chlorine-based bleaching agents  has
spurred the use of alternative bleaching agents.  Hydrosulfite, peroxide, and
oxygen-based bleaches are frequently used as alternatives when lower brightness
levels are  acceptable.

      Dewatering Equipment/Thickeners.  Some deinking facilities operate in
conjunction with a papermaking mill,  in which  case pulp can be sent directly  to the
paper mill. Otherwise, pulp must be stored or transported before  being used in
paper production. To  reduce  the volume and weight of the pulp, it is processed
through a  dewaterer.  There are numerous dewaterer designs.  They use screens,
screws, presses, and vacuum systems to draw water from the pulp.

     Wastewater Clarification. Process wastewater is commonly treated and
reused to conserve process chemicals.  Wastewater from washing and flotation
operations is discharged to the clarifier where  ink and other contaminants are
removed.  The clarified liquid can then be reused throughout the recycling process
                                    4-50

-------
to wash and dilute the pulp. Paper facilities generally pass unclarified water
backward through the process. Cleaner water passes from the final washing stage
to earlier and dirtier stages.  The water is drained when it reaches the first washer
and is then sent to the clarifier, where it is treated and reused. A large percentage
of the liquid and solid plant wastes is generated at the clarifier.
      Most clarifiers are designed as large open vats or enclosed tanks.  Filtration
is often the first clarification stage, to reduce the loss of fiber and remove large
contaminants.  During washing, dispersants break inks into tiny particles.
Clarification reverses this process by adding flocculants to reagglomerate the ink
into larger particles that can then be floated or settled and removed. Low-
molecular-weight cationic liquid polymers and high-molecular-weight anionic
polymers  are used as flocculants depending on the wastewater makeup (Schriver,
1990).  Dissolved air flotation  is generally used to float the flocculated particles to
the surface of the clarifier.  The flotate is skimmed from the surface by a center-
mounted scoop mechanism that slowly circles the tank.  A sediment sump draws
heavy material from the bottom of the tank. Skimmed material and sludge are
usually thickened and incinerated or landfilled.  Wastewater is reused within the
plant or treated and released.

      Effluent Treatment Systems.  Water is an integral part  of wastepaper
processing and, as a result, large quantities of wastewater are generated.  Pulp
generally  consists of between  2 and 15 percent fiber; the rest is primarily water.
During washing, dewatering, and other processes, depending on the system
configuration, large quantities  of water are removed from the pulp. Plantwide
wastewater streams are collected and often sent to an onsite treatment facility to
stabilize pH, remove suspended solids, improve biochemical oxygen demand, and
remove significant hazardous chemicals.  Many paper processing facilities have had
to install effluent treatment plants to meet effluent quality standards. Systems are
similar to those in standard wastewater treatment plants.  They commonly employ
                                     4-51

-------
primary as well as secondary treatment using clarifiers and conventional biologic
methods such as aerated stabilization basins and activated sludge.
      Sludge Disposal.  Sludge disposal is a significant issue for paper recycling
facilities.  Several wastepaper treatment processes (e.g., washing, flotation, and
screening) as well as effluent treatment systems generate a waste sludge. A
deinking plant processing 250 tons of pulp per day, operating at 75 percent fiber
yield, can generate approximately 70 tons of sludge per day (Carroll and Gajda,
1990).  Sludge received from a variety of sources throughout the facility is usually
dewatered before disposal. The  effluent from this process can be sent to the
facility's effluent treatment system.
      The primary sludge management options are landfilling, incineration, reuse,
and landfarming. Landfilling is the disposal of dewatered sludges directly into a
landfill designed to accept pulp and paper industry sludge.   Incineration reduces
sludge volumes, but the high inorganic content of deinking plant sludges (50 or 60
percent from inks) results in only a 20 to 30 percent volume reduction during
incineration  (Sixour, 1991).  Reuse includes incorporating sludge in building
products and other applications,  but reuse of the sludge occurs infrequently.
Landfarming, in which sludge is applied to forests and agricultural crops as a soil
supplement, is also done on a limited basis.  Drawbacks to this technique include
the large tracts of land that are required, concern about heavy metals, and other
technical problems.

      Paper Milling. Paper milling is the process of forming paper from pulp. Pulp
is filtered, dewatered, rolled, and pressed into a pulp mat.  Paper milling may occur
at the facility where deinking takes place, or it may be done at a completely
separate plant. The two processes are not interdependent. Secondary fiber is
commonly added to virgin feedstock and run on standard paper-milling equipment.
      Some  plants that run high  percentages of secondary  fiber have  encountered
problems with adhesives, or "stickies," and other contaminants that have not been
                                     4-52

-------
adequately removed from the pulp during deinking.  Stickles adhere to the filter
screens and mill felts, which must be cleaned regularly.  Caustic solvents are used
to dissolve stickies when they begin to hamper production.  The solution is
sprayed from a batch tank using a spray boom. Solvent runoff is often diverted
directly to the wastewater sewer.  Air emissions are removed and vented by
exhaust stacks that operate continuously to remove warm, moist air from the paper
machines.

4.5.5.  Plastic
4.5.5.1.  Composition of Plastic Recyclables
      As defined in Appendix B, there are six industry-defined categories of
recyclable thermoplastic resins, commonly known as PET, HOPE, LDPE, PVC, PP,
and PS.  A seventh category, "Other," includes multiresin and multimaterial plastic
products. Tables 4-9 and 4-10, respectively, present primary feedstock chemicals
and additives used in producing thermoplastic resins.  Table 4-11 defines the
characteristics and uses of the  principal additive categories. The plastic recyclable
stream also includes packaging material (labels, adhesives, inks) and container
residues.

4.5.5.2.  Process Technologies
      Resins are purchased by reprocessors as single (homogeneous) or mixed
resins (heterogeneous). In general, recyclable plastics are separated into pure  resin
streams before being used as supplements to virgin feedstocks. The need for
separation is primarily due to differences  in melt characteristics.  Commingled
plastics recycling represents the significant exception to this rule.  This technology
allows a mixed stream of plastic wastes to be manufactured into dense products
such  as plastic lumber for outdoor applications. This section  presents an overview
of the general processing steps necessary to reclaim plastics.  Subsequent sections
detail resin-specific processes and describe commingled resin processing.
                                     4-53

-------
                                TABLE 4-9

              Primary Feedstock Chemicals Used in Commonly
                       Recycled Thermoplastic Resins
Resin
         Feedstock chemicals
Polyethylene terephthalate (PET)
High-density polyethylene (HOPE)
Low-density polyethylene (LDPE)
Polyvinyl chloride (PVC)
Polypropylene (PP)
Dimethyl terephthalate
Ethylene glycol
Terephthalic acid
Titanium oxide
Triaryl phosphites
Phenolic compounds

Butane
Ethylene
Polypropylene

Butane
l-Butane
Ethylene
Octane
Propane
Vinyl acetate

Acetylene
Acrylic esters
Acrylonitrile
Butadiene
Cetyl vinyl ether
Chlorotrifluoroethylene
Divinylbenzene
Ethylene
Methacrylic esters
Propylene
Vinyl chloride
Vinylidene chloride

Ethylene
Propylene
                             4-54

-------
                            TABLE 4-9 (continued)
 Resin
Feedstock chemicals
 Polystyrene (PS)
 Acrylamide
 Acrylic acid
 Alkyl esters
 Aromatic acids
 Benzene
 Methacrylic acid
 N-vinyl-z-pyrolidone
 Styrene
 Vinyl chloride
Acrylonitrile
Source: Enviro Control, Inc., 1978; Radian Corporation, 1985; U.S. EPA,
1990.
                               4-55

-------
                               TABLE 4-10
        Categories of Additives Used in Plastics, Use Concentrations,
                   and Major Polymer Applications (1987)
Additive
                 Additive concentration in
                    plastic products3
                 (Ib additive/100 Ib resin)
Largest
polymer
markets
              Fillers
Inorganics
Minerals
Calcium
 carbonate
Kaolin and other
Talc
            Plasticizers
Mica
Other minerals
Other
 inorganic
Natural
Phthalates
Dioctyl (OOP)
Diisodecyl
Phosphates
Polymerics
Diaikyl
adipates
Diethyl             Trimellates
Dimethyl           Others
Others             Oleates
Epoxidized oils     Palitates
Soya oils           Stearates
Others
        Reinforcing agents
Fiber glass         Cellulose
Asbestos           Carbon
                      High, 10-50
                      High, 20-60
  PVC
  PVC
                      High, 10-40
Various
                             4-56

-------
                        TABLE 4-10 (continued)
Additive
                  Additive concentration
                    in plastic products3
                    (Ib additive/100 Ib
                          resin)
 Largest
 polymer
 markets
          Flame Retardants
Additive Flame
 Retardants
Aluminum trihydrate
Phosphorous
 compounds
Others
Reactive flame
 retardants
Epoxy reactive
Antimony oxide      Polyester
Bromine compounds  Urethanes
Chlorinated
 compounds
Polycarbonate
Boron compounds    Others
              Colorants
Inorganics
Titanium dioxide
Iron oxides
Cadmium
Chrome yellows
  (includes lead)
Molybdate orange
Others
Organic pigments
Carbon black
Phthalo blues
Organic reds
Organic yellows
Phthalo greens
Others
Dyes

Nigrosines
Oil solubles
Anthroquinones
Others
                       High, 10-20
 Various
                        Low, 1-2
Numerous
                            4-57

-------
                         TABLE 4-10 (continued)
Additive
                                                Additive
                                             concentration in
                                             plastic products3
                                             (Ib additive/100
                                                Ib resin)
 Largest
 polymer
 markets
Acrylics

MBS


ABS
              Impact modifiers

                       CPE
                       Ethylene-vinyl
                        acetate copolymers
                       Others

                Lubricants

Metallic stearates       Fatty acid esters

Fatty acid amides       Polyethylene waxes

Petroleum waxes

              Heat stabilizers

Barium-cadmium        Calcium-zinc

Tin                    Antimony

Lead

           Free radical initiators'1
               Antioxidants
Sterically hindered
 phenols
                       Others


          Chemical blowing agents
Azodicarbonides
                       High temperature
                        CBSs
Oxbissulfonylhydrazide  Inorganic
                                               High, 10-20
                                                Low,
                                              Moderate, 1-5
                                                Low,
                                                Low,
                                              Moderate, 1-5
  PVC
 PVC, PS
   PVC
LDPE, PS,
 PVC, PE

   PS
PVC, PP,
   PS
                            4-58

-------
                          TABLE 4-10 (continued)
 Additive
                       Additive
                    concentration in
                  plastic products8 (Ib
                    additive/100 Ib
                         resin)
  Largest
  polymer
  markets
           Antimicrobial Agents

            Antistatic Agents
 Quaternary
  ammonium
  compounds

 Fatty acid amides and
  amines
Fatty acid ester
 derivatives
Others
 Phosphate esters

              UV Stabilizers
 Benzotriazoles

 Benzophenes
 Salicylate esters
 Cyanoacrylates
Malonates

Benzilidenes
Others
                Catalysts0

                 Others
                       Low,

                       Low,
                       Low,
                       Low, <1

                       Low, < 1
 PVC, PE

   PVC
PE, PP, PS,
   PVC
 Numerous
Estimates refer to concentrations in those products where the additive is
used.
blncludes organic peroxides only, as reported by source.
Includes urethane catalysts only, as reported by source.

Source: U.S. EPA, 1990.
                              4-59

-------
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4-61

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      Plastics reclamation systems vary widely depending on the type of raw
 materials processed, the degree of processing, and the specific technology used.
 Regardless of the materials accepted at a reclamation facility or the physical
 condition of the waste, plastics are generally processed using some combination of
 the following steps:
      •   Manual sorting
      •   Shredders and grinders
      •   Washers
      •   Separators
          -  air classifiers
          -  flotation tanks
          -  hydrocyclones
Dryers
Aluminum separators
Extruders
 Because soda bottles are some of the most frequently recycled postconsumer
 plastic products, the discussion that follows generally describes their reclamation.
 Figure 4-7 presents an overview of a plastics recycling system with process inputs
 and outputs.
      Because of their large volume, more and more plastics arrive at processing
 centers either shredded, in bales, or in some other compacted form. A hydraulic
 bale breaker or piece of heavy machinery can be used to break bales apart. Some
 facilities prefer to receive unaltered containers because of unique sorting and
 separation methods.
      Manual Sorting.   Because few reliable automated sorting technologies exist
for separating plastics by resin and color, the first processing step performed at
many plastics recycling  facilities is hand sorting, except when plastics are received
preshredded. Facilities accepting presorted or homogeneous plastics may use hand
sorting to remove contaminants.  Manual sorting systems are usually arranged as
picking lines, a series of workers stationed along a moving conveyor or carousel
that carries a steady stream of recyclables. Depending on the configuration of the
sorting system, workers remove either desirable or undesirable materials and drop
                                    4-62

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                                4-63

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them in bins or on other conveyors. Workers are required to handle large quantities
of the waste stream at a constant rate.  For example, at Plastics Recycling Alliance
(PRA) plants in Chicago and Philadelphia, workers hand sort between 300 and 375
pounds of waste per hour on average (Schut, 1990).

      Shredders and Grinders.  Most plastics processors convert raw plastic waste
into a stream of plastic flakes of uniform size (0.25 to 0.50 inch on a side) that can
be accepted by cleaning and separation equipment.  Plastics are generally "flaked"
by using one of a variety of grinders, shredders, or granulators.  Shredding allows
caps, labels, HOPE base cups, security closure rings, and other impurities to be
separated from the bulk of the container during washing and automated separation.
A second grinding stage may be employed after initial shredding for some
processes requiring smaller particles. When flakes are reduced to the target
dimensions, they either fall through a screen or are blown from the shredder or
grinder to transport ducts.
      Some recently developed grinding systems process film scrap (e.g., plastic
bags and sheeting) and other particularly dirty plastic waste streams with a wet
grinding method (Modern Plastics, 1988).  This technology uses a stream of water
to wash film scrap as it is carried past cutting knives. The water both washes
impurities from the plastic flakes and minimizes temperatures in the grinder
chamber.
      Washers.  Washing usually occurs after the plastics are shredded to
facilitate the removal of labels and other impurities. Certain systems under
development do some washing before shredding (Modern  Plastics, 1988).
Washing methods vary depending on the type of plastic being cleaned, the degree
of contamination, and the specific machinery being used.  However, most systems
consist of a water bath, a mechanical or air agitator, and possibly a solvent rinse.
Wash water may be heated to temperatures as high as 160°C to dissolve label
adhesives and other contaminants. A mild caustic detergent may also be added to
                                    4-64

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remove labels and kill bacteria.  Such detergents can be effective in concentrations
as low as 1 percent.  For example, a vinyl recycling operation in Akron, Ohio, uses
a 1 percent solution of Electrosol automatic dishwasher detergent agitated in hot
water (Summers et al., 1990).  Mechanical paddles or air streams are used to
accelerate cleaning. Washed plastics are frequently rinsed in one or more water
rinse steps.

      Separators.   One of three separation methods is typically used to generate a
clean,  single-resin product:  air classifiers, flotation tanks, or hydrocyclones. In
facilities using flotation tank or hydrocyclone systems to separate mixed resins,
plastic containers  must first be reduced to  a single-resin chip or flake that can  be
skimmed from the surface or scraped from the bottom of a tank.

      Air Classifiers.   Air classification systems separate wastes by using an air
stream.  This technology can be used to isolate a lightweight target material by
removing it from the waste  stream or to remove lightweight impurities from  a
heavier resin. Polystyrene or plastic film wastes are often separated from heavier
contaminants with air classification.

      Flotation Tanks.  Flotation is an effective means of separation because of
differences in resin densities.  Flotation can also be used to separate contaminants
from the target resin.  Most flotation systems use water as the separation medium.
A stream of  mixed plastics is added  to the flotation tank.  Lighter fractions,
polyethylene film for example,  can be mechanically skimmed from the water
surface, and heavier components scraped from the bottom. Solutions such  as
calcium nitrate are sometimes used to  adjust the specific gravities of the flotation
bath to separate the target  material  from the contaminant (Summers et al., 1990).
A surfactant may also be added in low concentrations to prevent plastic flakes
from adhering to the equipment or to each other.  Figure 4-8 illustrates how a
                                     4-65

-------
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processing system incorporating flotation technology can be used to purify a PVC
resin stream.
      Because materials separation represents one of the greatest hurdles to
recycling the large variety of resins being manufactured, separation technology is
constantly under development.  Research is under way at Rochester Polytechnic
Institute on an advanced flotation system that uses a heated chemical bath to
dissolve and separate mixed resins (personal communication between TRC
Environmental Corporation and George Heath of Chem Systems, Inc., of
Tarrytown, NY, on November 29, 1990). A batch of mixed resins is heated to the
melting point of the most unstable resin. The molten resin is then removed from
the bath.  The bath temperature is raised to the next lowest melting point and that
resin is removed.  The process continues until all recoverable resins are isolated.
This method requires a solvent filtration and recirculation system to process a
waste stream consisting of solvents and various resin wastes.

      Hydrocyclones.  Hydrocyclone technology, adapted from the mining
industry, has been recently applied to MSW handling.  The equipment is essentially
a centrifuge that separates plastic wastes and contaminants based on their specific
gravities.  Air, water, or oil is used to enhance the separation process.  The
separation medium can be filtered and reused.  The fluid  requirements are generally
less than for flotation separation systems.

      Dryers.  Plastic flakes must be dried  before they can be extruded into pellets
or packaged for shipping. Cyclone driers are often used initially to dewater
plastics.  This may be followed by an air drying system that dries flakes as they
pass under a stream of hot air on a conveyor.  Air hopper dryers are also used.
Heated air streams in the range of 120 to 160°C are common to most  drying
systems.  Some systems also incorporate industrial dehumidifiers.
                                    4-67

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      Aluminum Separators.  Many PET reprocessing systems grind soda bottles
together with their aluminum caps and safety rings. The aluminum fragments must
be removed from the plastic flakes to  a concentration of < 100 ppm.  Aluminum
removal is commonly accomplished with an electrostatic separator.

      Extruders.  The form and composition of recycled resins required by end-
product processors vary widely.  Plastics scrap processors commonly supply
cleaned or separated resins as flakes or  pellets depending on the needs of the
buyer. Although plastic flakes can be added directly to virgin feedstocks, extruded
pellets are generally preferred for the following reasons:  (1) pellet extrusion
involves additional filtration that  results in a higher quality end product;
(2) necessary compounding agents can be added during  extrusion; and (3) extruded
pellets can be tailored to match the size, density, and composition of virgin
feedstocks to which  they are to be added.
      Typical extruder designs include a screw-shaped mechanism that uses
friction to heat and melt the feedstock of plastic flakes in a closed chamber.  The
plastic is softened and compounded with additives as it passes through the
chamber.  Brydson (1990) indicates that as the flakes or granules melt, they fuse
together, trapping air and possible chemical degradation  products. Such gases
must be forced from  the melt before it reaches a mold or pelletizer. Once pellets
have been formed, they are commonly cooled in a recirculated water bath.

4.5.5.3.   Resin-Specific Processing
      Plastics reclamation alternatives vary by resin type. Recycling options for the
seven industry-defined resin categories include some combination of the
technologies discussed above. Resin-specific characteristics  (i.e., melt
temperatures, source products, process techniques) are summarized in Table  4-12.
                                    4-68

-------







to
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4.5.5.4.  Commingled Plastics
      Commingled plastics recycling, although limited in its end-market application,
offers a relatively simple and flexible reprocessing alternative to sorting and
cleaning mixed plastics.  Most programs that collect plastics for recycling
concentrate their efforts on one or two  resins, but the opportunity to collect large
quantities of multiresin materials exists. Separating this growing variety of plastics
presents a significant technical challenge.
      A number of ventures have successfully applied extruder and compression
mold technology to the reprocessing of unsorted, mixed plastics into dense
products such as lumber, automobile curbstops, and playground equipment.
Generally, higher solid contaminant levels  and decreased tensile strengths restrict
this process to the manufacture of thick-walled end products.
      Several commingled plastics processing systems currently are used in the
United States.  Most facilities use extruder technology that incorporates the same
basic features discussed in the previous section. These systems are capable of
handling a wide range of unsorted and uncleaned or moderately cleaned scrap.
Most systems also use one segregated resin, preferably  polyethylene, as a base or
matrix to which the unsorted scrap is added as filler.,  The resin mixture is
shredded, mixed, and extruded into molds.  Because multiple resins, each  with
distinct melt temperatures, may be used in commingled processing, process
temperatures must be carefully monitored  to prevent overheating and
decomposition of any of the resins.
      Additives are often  used to improve the quality and expand  the range of
products manufactured from commingled plastic wastes. Recent research has
explored the use of wood and glass fibers, calcium carbonate and mica crystals,
and reinforced plastics to strengthen these products (Salas et al.,  1990). In
addition, colorants, impact modifiers, flame retardants, UV stabilizers, and
compounding agents may be added to meet the desired end-product specifications.
These additives are similar to those used in the manufacture of products from
virgin feedstock (see Tables 4-9 and 4-10).
                                     4-70

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4.5.6.   Steel/Tin                                  •
4.5.6.1.   Composition of Ferrous Metal Scrap
     This section focuses on steel food containers and beverage cans, which
constitute the largest single source of ferrous metal scrap recovered from MSW
when durables (e.g., white goods) are excluded. The grouping of steel containers
in one category incorporates bimetal cans, tin-plated cans, and all-steel cans.
Bimetal cans contain aluminum ends attached to a steelbody that may or may  not
be tin-plated.
     The tinplating used in steel  can construction is composed of 99 percent steel
and 1 percent tin (Carlin, 1989).  Steel is an alloy of iron that contains  <1 percent
carbon and is produced by oxidizing carbon, silicon, phosphorous, manganese,  and
other impurities present in molten iron and steel scrap to specified minimum levels
(U.S. EPA, 1982). Tinplate is produced either by passing steel sheets through  a
bath of molten tin or by electroplating in a continuous process  (Grayson and
Echroth, 1980).  The tin coating on steel cans protects the container's  contents by
creating a layer between the steel and the contents, eliminating the possibility of
reactions between the two.
      Steel cans include labels, adhesives, associated inks and pigments, and
container residues.  In many recycling programs, either consumers or collection
facilities are responsible for removing labels and cleaning containers.  However,
contaminants may still remain on  recyclables received by reclamation facilities.
Cans may also include surface coatings that contain both organic and inorganic
chemicals.
      The quantity of steel can scrap that can be used for iron and steel fabrication
depends on the product to be manufactured; the facility's  ability to handle the
scrap; the density, chemical composition, and the tin content of the bales; and the
amount of tin in the  facility's other scrap (Copperthite,  1989).  The most important
parameter is the quantity of tin in the can scrap. If the steel cans have not been
detinned, the scrap can contribute only 1 to 4 percent of the steel mill's scrap  mix.
If the can scrap  has  been detinned, the quantity of steel cans used may rise to 10
                                     4-71

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to 20 percent, depending on the tin content of the remainder of the mix and the
product that is to be manufactured.

4.5.6.2.  Processing Technologies
      The industrial processes that steel cans follow during reclamation include iron
and steel manufacturing and detinning.  Iron and steel manufacturers and detinning
facilities acquire steel cans from the collection and sorting facilities discussed
earlier.  The steel cans that arrive at these facilities may be baled, shredded,
flattened, or unaltered.  Because the steps involved in the recycling of steel cans
are distinctly different for each of the  two industries, this section discusses the
processes separately.

      Iron and Steel Manufacturing.   The iron and steel manufacturing industry in
the United States uses two furnace types, the basic oxygen furnace and the
electric arc furnace, to produce iron and steel. The basic oxygen furnace, which is
used to produce about 60 percent of the steel in the United States,  uses an
average of 30 percent scrap feedstock, whereas the electric arc furnace,  which
produces about 40 percent of the steel, uses virtually  100 percent scrap (Heenan,
1991).  The methods  used  to introduce (charge)  ferrous metal scrap to the furnace,
where it mixes with virgin materials, vary slightly for each type of furnace and are
discussed separately.  Despite the differences in  the furnace charging steps, the
equipment used and raw material charged are comparable.

      Basic  Oxygen Furnace.  A basic oxygen furnace is a large, open-mouthed
vessel lined  with a refractory material. The furnace is mounted on trunnions that
allow it to be rotated 360 degrees in either direction.  A typical vessel is 12 to 14
feet across and 20 to 30 feet high. The furnace receives a charge composed of
scrap and molten iron. The feedstock is composed primarily of virgin materials (at
least 70 percent molten iron) (U.S. EPA, 1982).  Iron is produced in a blast furnace
using iron ore and other materials. Steel scrap is added to the furnace by dumping
                                    4-72

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it from a large "charge box" or container that is loaded in the scrap yard (U.S. EPA,
1980a).  Steel is produced  in the furnace by introducing  a high-speed jet of pure
oxygen, which oxidizes the carbon and the silicon in the  molten iron (U.S. EPA,
1980b).  Emissions including metallic oxides,  particles of slag, carbon monoxide,
and fluoride are typically released from this process.

      Electric Arc Furnace.   Electric arc furnaces consist of a cylindrical vessel
made of heavy welded plates, a bowl-shaped hearth, and a dome-shaped roof.
Three graphite or carbon electrodes are mounted on a superstructure located above
the furnace and can be lowered and raised through holes in the furnace roof. The
electrodes carry the energy for melting the scrap charge. Bladders located at the
holes in the furnace roof cool the electrodes  and also minimize the gap between
the openings in the roof and the electrodes to reduce emissions, noise, heat losses,
and electrode oxidation. When the electrodes are raised, the furnace roof can be
swung aside so that charge materials may be deposited in the furnace.  Ferrous
scrap is added to the furnace from a large bucket, where it is typically placed
following removal from railroad cars or other forms of transport. Any required
alloying agents are added to the furnace through the side or slag door.  Alloying
agents used in the electric arc furnace include ferromanganese, ferrochrome, high
carbon chrome, nickel, molybdenum oxide, aluminum, and manganese-silicon (U.S.
EPA, 1982).

      Detinning.   The  chemical detinning process, which removes tin from tinplate
scrap and tin-coated food and beverage cans, is the only significant domestic
source of tin metal in the United States (Grayson and Echroth, 1980). This section
describes the following primary steps involved in detinning:
         Unloading of tin-plated scrap
         Shredders
         Air classifiers and magnetic separators
         Chemical detinning
                                    4-73

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         Separation
         Tin removal
The chemical detinning and separation steps take place at all detinning facilities,
whereas the other steps are not always performed. Figure 4-9 illustrates the
primary processing steps involved in detinning plated scrap.  The more efficient,
continuous process  is used at most modern detinning facilities, although older
facilities may use a  batch process.

      Unloading of Tin-Plated Scrap.   Heavy equipment is used to unload tin cans
from incoming vehicles and place them on a conveyor system that feeds the
shredding mill.  Equipment most commonly used to load and unload tin cans are
cranes equipped with magnets and grapples. Once placed on the conveyor
system, the tin cans are automatically fed into a shredder.

      Shredders. Tin cans must be shredded for two reasons.  First, shredding
loosens and separates contaminants such as paper, glue, lacquer, plastic, organics
(e.g., food residues, dirt), and aluminum ends from the bimetal food and beverage
cans so they  can be removed during magnetic separation and air classification.
Second, shredding exposes a greater area of the tin cans to chemicals used to
remove tin from the cans. The area exposed may be up to one square acre per ton
of tin cans (personal communication between TRC Environmental Corporation and
Jerry Bailey of Proler International Corporation on July 31, 1991).  See Section
4.4.2 for further discussion of shredders.
      Air Classifiers and Magnetic Separators.  Once shredded, the cans are
carried by a conveyor system to an air classifier, a magnetic separator, or both to
remove contaminants.  These contaminants, depending on their density, either fall
or are blown into disposal containers, which are then transported to a landfill.
Industry sources have reported that the combination of shredding, magnetic

                                    4-74

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1 Tinplate Scrap 1
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r
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Detinning Process Utilizing Caustic Soda




            4-75

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separation, and air classification removes 98 percent of nonmetallic contaminants
and 99 percent of the aluminum (Process Engineering, 1989).  See Section 4.4.2
for further discussion of air classifiers and magnetic separators.

      Chemical Detinning.  After tin cans have passed through the shredder, air
classifier, and magnetic separator, they are considered clean and have enough
surface area exposed to increase the efficiency of the chemical detinning step.
Detinning is accomplished by treating cans with a hot alkaline solution, usualJy
caustic soda, which contains an oxidizing agent to dissolve the tin and precipitate
it as sodium stannate (Grayson and  Echroth, 1980).  This step also removes any
contaminants remaining on the scrap such as paints and glues.  The cans are
placed in the detinning solution by steel baskets lowered into solution tanks (typical
of batch  processes) or  a tube-like device that works like a screw conveyor
(Watson, 1989).

      Separation.  Detinned cans are separated from the detinning solution by
rinse trommels (cylindrical rotating screens). The cans are rinsed with hot water
that is recycled into the detinning tanks.  The residual tin remaining on the surface
of the detinned scrap is usually <0.06 percent (Watson, 1989).  The detinned
scrap is baled and sold to iron and steel manufacturers for use in new  products.

      Tin Removal.   Tin remaining in the detinning solution is removed through an
electroplating process,  which uses electricity to turn the sodium stannate  back into
tin metal (Watson, 1989). The tin is then melted off the plates and cast into ingots
that are sold.  In older  detinning plants, process residues, the spent caustic soda,
and "detinner's mud" are recovered and used by other industries, and  any rinse
water is treated and  reused.  In newer facilities, the spent caustic soda is  also
reused by the system.  The detinner's mud or sludges are usually sold  to tin
smelters  as low-grade ore (CBNS, 1988).
                                    4-76

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            5.  SAFETY CONCERNS ASSOCIATED WITH RECYCLING

                          AND MITIGATION OPTIONS


5.1.  INTRODUCTION

      This section considers each of the public health, occupational safety, and

environmental hazards that are associated with the recycling practices and

processes summarized in Chapter 4.  The hazard-specific discussions address the
following:
      •   Sources of the hazard
      •   Nature of the hazard
      •   Prevention/mitigation options
Narratives for each hazard are supported by tables that provide a comprehensive
list of the process steps or technologies that are potential sources of a particular
hazard and summarize the prevention and mitigation options.  In addition, the
tables indicate the relative significance  (low, medium, high) of the hazards, based
on a qualitative assessment of the following criteria:
      •  The frequency or severity of the hazard
      •  The ability to control the hazard
      •  The ability to regulate the hazard
      •  The prevalence of the hazard in related industries
It should be stressed that the ranking is based on a database that is incomplete.

Much information available to characterize recycling hazards is anecdotal in nature.
Measures of hazard magnitude are generally unavailable.

      Many prevention and mitigation options discussed in this section reflect the

requirements of Federal, state, and local regulations.  Such regulations may affect
facility,  process, and equipment design as well as day-to-day work  practices and

procedures. Properly implemented, they may reduce direct hazards to workers and
                                     5-1

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facility-related hazards to public health and the environment, which, range from
traffic accidents to facility emissions.
      Compliance with certain regulations and implementation of safe work
practices may be reflected in facility operating plans used at MRFs and other
processing facilities. Although operating  plans vary from facility to facility, they
may incorporate the following:
          Functions of employees
          Operation of equipment
          Fire contingency
          Contaminant isolation and removal
          Staffing contingencies
          Medical emergencies
          Personal protective equipment
          Summaries of applicable regulations
5.2.  REGULATIONS APPLICABLE TO RECYCLING OPERATIONS
      Occupational health and safety and environmental protection are two broad
regulatory categories that apply to the recycling industry to prevent and mitigate
the hazards addressed in this section.  Because of the industry's relative infancy,
there are few laws that specifically target recycling.  However, there  are significant
Federal, state, and local laws that apply to operations commonly used in recycling.
Some of the more important regulations that serve to control or prevent recycling
hazards are outlined below.

5.2.1.  Occupational Regulations
      The safety of workers employed in the recycling industry falls under the
auspices of the U.S. Occupational Health and Safety Administration (OSHA),
established in 1970.  As defined in 29 CFR 1910, OSHA health and safety
standards apply to workers employed by private sector businesses. OSHA
regulations do not cover the occupational safety of public employees, who are
employed by Federal, state, county, municipal, and other government bodies
                                     5-2

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(Council on Environmental Quality, 1987-1988). Many municipalities operate their
own recycling programs rather than contracting the work to the private sector;
therefore, the population of workers not covered by Federal regulations is
potentially large.  One survey indicates that municipal employees collect
recyclables in 33 of the 50 largest U.S. cities that have recycling programs (Smith
and Hopkins, 1992). Some states have established their own occupational health
and safety regulations.  State legislation may extend health and safety coverage
under these programs to include government workers. Volunteer workers,
however,  also a potentially large population, may be beyond the jurisdiction of both
Federal and state  occupational health and safety regulations.
      OSHA regulations are grouped  into  specific categories by equipment type,
operation  type,  or hazardous material (Table 5-1), along with a small number of
industry-specific rules (e.g., pulp, paper, and paperboard mills). Much of the
machinery used in recycling is common equipment that has been adapted from
other industries and is covered under general OSHA regulations. There is no OSHA"
rule that specifically targets the recycling  industry or its workers.  Some recycling
program managers have expressed concern over the fact that there are no
recycling-specific  rules, whereas others feel current general regulations are broad
enough to cover most hazardous activities that would be encountered in the
recycling  industry (Combs, 1992).
      Additional regulations and guidelines that may have a bearing on worker
health and safety have been issued by the following organizations and
associations:
          American National Standards Institute (ANSI)
          American Society of Mechanical Engineers (ASME)
          American Society of Testing Methods (ASTM)
          National Solid Waste Management Association (NSWMA)
          National Fire Protection Association (NFPA)
          National Institute of Occupational Safety and Health (NIOSH)
                                     5-3

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TABLE 5-1
OSHA Health and Safety Standards Applicable
to the Recycling Industry
OSHA standard
Part 1904
Part 1910
Subpart C
Subpart D
Subpart E
Subpart F
Subpart G
Subpart H
Subpart I
Subpart J
Subpart K
Coverage
Record Keeping
Safety and Health Standards
Access to Employee Medical Records
Walking and Working Surfaces
* Floor and wall openings
* Stairs and ladders
* Scaffolds (proposed changes include
falls)
Means of Egress
Manlifts and Platforms
Environmental Control
* Ventilation
* Noise
Hazardous Materials
* Acetylene
* Flammable liquids
* Others
Personal Protective Equipment
* Eye and face protection
* Respiratory protection
* Head protection
* Foot protection
* Electrical protective devices
General Environment
* Signs and tags
* Hazard identifications
Medical and First Aid
5-4

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TABLE 5-1 (continued)
OSHA standard
Subpart L
Subpart M
Subpart N
Subpart O
Subpart P
Subpart Q
Subpart R
Subpart S
Subpart Z
Coverage
Fire Protection
* Fire suppression equipment
* Fire protection systems
Compressed Air Systems
Materials Handling and Storage
* General rules
* Servicing vehicles
* Trucks
* Cranes
Machines and Guarding
* General rules
* Power presses
* Mechanical transmission apparatus
Portable Power Equipment
Welding, Cutting, and Brazing
Special Industries
* Pulp, paper, and paperboard
Electrical
* Systems
* Work protectors
* Maintenance
Hazardous Substances
* Airborne contaminants
* Asbestos
* Bloodborne pathogens
* Hazard communication standard
Source: Combs, 1992; 29 CFR 1910.
                                 5-5

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5.2.2.   Environmental Regulations
      Most environmental regulations that apply to recycling facilities are based on
Federal regulations that are administered by state or local agencies or offices.
Local laws and ordinances regarding issuance of permits to facilities may also
apply.

5.3.  SHARP OBJECTS
      Source Activity:   Opportunities to contact sharp objects are greatest at
points where recyclables are manually separated from MSW, sorted by material, or
otherwise handled (e.g., cleaned, crushed, transported, or stored) are shown in
Table 5-2. The extent of handling required of the consumer and the  waste worker
varies depending on program-specific collection and sorting  methods. Programs
that require consumers to separate, clean, and sort recyclables may present a
higher potential for public contact with  sharp objects than those that collect
commingled recyclables and sort them at an MRF.
      The degree and type of mechanization employed in collecting and sorting
also affect the potential  for workers to  contact sharp objects.  Glass sorting, a
process that has proven difficult to automate, routinely exposes workers
performing manual sorting to sharp objects.  Some forms of mechanization may
increase the occurrence of sharp objects such as broken glass and shredded metal.
During collection, for example, compactor trucks and elevated loading systems that
dump recyclables into bins from above  can cause higher percentages of broken
glass (Glenn, 1990; O'Brien, 1991).  Shredding and slicing equipment used in
aluminum, rigid plastics, and steel processing produces a sharp-edged flake or chip.
      Hazard Type:  Sharp objects found among recyclables fall into two primary
categories:  process fragments and contaminants.  Rigid recyclables  (i.e., glass,
plastic,  steel) broken or shredded during collection, sorting, or processing
frequently result in sharp-edged fragments. Hypodermic needles and razor blades
are among the sharp contaminants found mixed with recyclables.  Injuries that can
result from contact with sharp objects include cuts, lacerations, punctures, and
                                     5-6

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                                  TABLE. 5-2
                            Sharp Objects Hazards
 Type of
 hazard
    Source activity
 Prevention/mitigation
 Significance of
     hazard
 Collection
 and sorting

 Public health
 Occupational
Separation in the
home
Drop-off centers
Buy-back centers
Curbside sorting
Dumping
Tipping floor
Bag breakers
Conveyor  systems
Sorting stations
Slicers
Front-end  separation
at transfer stations,
  landfills, waste-to-
  energy plants
Public education
Personal protective
  equipment

Public education
Worker training
System  and
  equipment design
Personal protective
  equipment
Low
Medium
 Material
 processing

 Occupational
AL - Drying and
  delacquering
GL - Manual sorting
PA - Manual sorting
S/T - Unloading scrap
S/T - Air classification
S/T - Magnetic
  separation
Public education
Worker training
System and
  equipment design
Personal  protective
  equipment
Low
AL - Aluminum processing
GL - Glass processing
PA - Paper processing
S/T - Steel and tin processing
                                     5-7

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abrasions.  These injuries are primarily an occupational hazard, especially to
workers handling recyclables during collection or sorting operations, but may also
be a public health hazard.
      Any break in the skin caused by sharp objects can become the site of
infection following exposure to bacteria, viruses, fungi, or parasites (Clayton and
Clayton, 1991). Risk of infection, although  uncharacterized, may be significant in
cases where container residues exist. In addition, the Center for Plastics Recycling
Research reports that workers regularly find hypodermic needles inside HOPE milk
jugs (personal communication between TRC Environmental Corporation and Wayne
Pearson, executive director of Plastics Recycling Foundation,  on February 11,
1992).  Although potential for puncture wounds is the greatest hazard associated
with needle exposure, exposure to infectious agents cannot be precluded.
      Prevention and Mitigation Options:  Contact with sharp objects can be
minimized through the use of personal protective equipment such as gloves, hard
hats, boots, safety glasses, and overclothes. This equipment must be available to
workers and its use required. Automated sorting systems as  well as practicable
design controls effectively reduce sharp object  hazards, because there is less
human contact with broken materials.  Education is the most  effective method to
warn consumers about potential sharp object hazards associated with recycling,
because it is not realistic to expect all consumers to use protective equipment  in
the home.  In addition, educating the public to  avoid mixing sharp  contaminants
with recyclables can reduce  potential worker exposures during collecting and
sorting operations. Process  and facility modifications can limit the generation of
sharp recyciables and the degree to which they must be handled.  For instance,
recent trials with collection vehicles fitted with internal nets and baffles designed to
catch falling glass during loading have been found to reduce  breakage.  Within the
MRF, wooden floors, drop chutes at conveyor ends, and rubber bumper guards on
steel sorting tables have reduced glass breakage (Keller, 1992).
                                      5-8

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5.4.  ERGONOMIC AND LIFTING INJURIES
      Source Activity:  Table 5-3 summarizes collection and sorting activities that
often require repeated lifting and twisting motions, a common source of ergonomic
injuries. The public may sustain injuries while carrying heavy bins of recyclables to
the curb for collection.  Worker injuries that occur during collection result from
lifting and dumping heavy bins, twisting and reaching during curbside sorting, and
repeatedly climbing in and out of vehicles. Manual sorting activities that occur at
an MRF commonly require reaching, lifting, and twisting motions.  A 1988 study of
working conditions in Danish MRFs reported that inappropriate and monotonous
working conditions at conveyor belts resulted in ergonomic strain (Malmros and
Petersen,  1988). Falls and other miscellaneous ergonomic injuries may occur
throughout MRFs, drop-off centers, or other material processing facilities.  Elevated
platforms, floor-mounted conveyor belts, and sunken bins or dumpsters increase
the opportunity for falls.
      Hazard Type: The potential for ergonomic injuries is a significant
occupational concern for numerous recycling activities. Poorly designed work
stations and improper manual materials handling and lifting practices can  result in
various injuries or disorders.  These problems are not generally associated with a
single accident,  but with repeated, low-level insults to a localized body region. The
back and upper extremities are the most commonly affected areas (Levy and
Wegman, 1988).  For example, manual lifting and loading of waste materials into
trucks or containers can result in lower back injury and pain.  Driving-related
injuries include back injuries as well as vibrational fatigue.  Frequent or repetitive
forceful hand motions with awkward posture can affect the musculoskeletal
system or the peripheral nervous system at the fingers, hand, wrist, elbow,
forearm, and shoulder resulting in inflammation of tendons and joints and nerve
compression.  The following are examples of repetitive motion disorders (Clayton
and Clayton, 1991; Levy and Wegman, 1988):
                                      5-9

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                                 TABLE 5-3
                         Ergonomic and Lifting Injuries
  Type of
  hazard
    Source activity
 Prevention/mitigation
Significance
  of hazard
  Collection
  and sorting

  Public health
  Occupational
Separation in the home
Drop-off centers
Buy-back centers

Curbside sorting
Loading and dumping
  of collection vehicles
Transportation during
  curbside collection
Tipping floor
Conveyor systems
Sorting stations
Balers
Drop-off centers
Buy-back centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Public education
Equipment design


Worker training
System and  equipment
  design
Rotating worker
  activities
Personal protective
  equipment
Low
Medium
  Material
  processing

  Occupational
GL - Manual sorting
PA - Manual sorting
PL -  Manual sorting
S/T - Unloading scrap
Lifting
Equipment operation
Worker training
System and equipment
  design
Rotating worker
  activities
Personal protective
  equipment
Low
GL - Glass processing
PA - Paper processing
PL -  Plastic processing
S/T - Steel and tin processing
                                     5-10

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         Carpal tunnel syndrome (nerve disorder of the wrist)
         Degenerative joint disease
         DeQuervain's disease (inflammation of the tendons of the thumb)
         Trigger finger
         Epicondylitis ("tennis elbow")
         Rotator cuff tendinitis (shoulder)
         Tension neck syndrome
         Pain in the upper extremity and neck
      Prevention and Mitigation Options:  Poorly designed collection vehicles and
other equipment that require workers to make repeated awkward motions during
collection and sorting increase the possibility of ergonomic injuries. In many cases,
these hazards can be successfully eliminated through design improvements. Truck-
mounted automated lift systems, for instance, are now available to hoist and dump
containers of recyclables into collection vehicles. The distance workers must reach
to sort recyclables at the curbside is minimized on newer collection truck bodies
designed with "low-profile" sorting bins.  The lower bin position on these models
reduces lifting heights, making sorting safer and more efficient.  Taller driver
compartments with lowered floors and full-length doors allow workers to step from
the vehicle to the curb more easily.
      Within the MRF, the potential for ergonomic  injuries during material sorting
can be minimized substantially through the redesign of equipment and methods.
Stations where workers manually sort recyclables can be engineered to lessen the
range of motion required of the workers. Head-on  sorting stations are believed to
minimize the physical strain during sorting, which often results from reaching and
twisting across a conveyor belt. The head-on method balances the workers' range
of motion to both sides, minimizes motion extremes, and eliminates the need to
stretch  across the belt.  Adjusting the height of conveyor belts or working surfaces
to meet worker dimensions also has been shown to reduce strain at sorting
stations and other operations (Solomon-Mess, 1991).  To limit ergonomic stress
during sorting, some recycling firms rotate workers to other activities on a regular
basis (Powell, 1992).  Cushioned floors  in working areas and  elevated foot rests
                                     5-11

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effectively reduce the strain on workers' legs. The potential for falls can be
minimized by using guardrails, warning tape, and signs.
      As new materials are recycled and members of the public become more
efficient recyclers, larger bins will be required to separate and store recyclables in
the home.  Some consumer recycling bins already are designed with wheels to
facilitate moving recyclables from the home to the curb.
5.5.  FIRES AND EXPLOSIONS
      Source Activity:  The sorting and storage of combustible paper products and
the presence of flammable chemical residues pose the primary fire and explosion
hazards associated with recycling (Table 5-4).  Large volumes of paper stored in
the home or MRF are a fire hazard whether wet or dry.  Dry paper easily can be
ignited in areas where it is stored or processed. Explosions may occur in shredder
chambers, slicers, crushers,  and balers when residues of flammable or explosive
substances (e.g., gasoline, propane, cleaning solvents, mineral spirits, batteries) are
ignited (Kohn,  1989; Nollet,  1989a, b; Engineering  News Record, 1990).
Explosions are more likely when an unsorted mixture of MSW is shredded.  Many
of the heating  methods and chemicals used in reprocessing recyclables also can
cause fires or explosions.  When aluminum is melted, for example, moisture
trapped in the  melt has been known to explode.
      Hazard Type:  Hazards associated with fire or explosions are primarily
occupational and environmental. Burns are the greatest hazard posed by a fire or
an explosion and can vary in severity from minor superficial burns to deep tissue
damage. Explosions can result in damaging noise exposure (Section 5.8).
Environmental impacts include fire-related air emissions.
      Prevention and  Mitigation Options:  Frequent collection and processing
reduces combustible paper stockpiles in the home and MRF.  Because loose paper
is more flammable than baled,  baling can minimize the potential for fires.  Storing
baled paper  in a dry, well-ventilated location reduces the chance of spontaneous
combustion. Shredder explosions can be avoided by visually inspecting and using
                                    5-12

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                                     TABLE 5-4

                                 Fire and Explosions
 Type of hazard
     Source activity
  Prevention/mitigation
 Significance
  of hazard
  Collection and
  sorting

  Public health
  Occupational/
  Environmental
Storage in the home

Drop-off centers


Curbside handling
Sorting stations
Shredders
Drop-off centers
Front-end separation at
  transfer stations,
  landfills, waste-to-
  energy plants
Proper storage
Public education
Frequency of
  collection (paper)

Public education
Frequency of
  collection and
  processing (paper)
System design (e.g.,
  ventilation,
  equipment isolation)
Emergency response
  equipment/
  procedures
Flammables removals
  during sorting
Low
Medium/low
  Material
  processing

  Occupational/
  Environmental
AL - Smelting
PA - Material storage
PL - Shredding and
  grinding
S/T - Shredding
Public education
Frequency of
  collection and
  processing (paper)
System design (e.g.,
  ventilation,
  equipment isolation)
Emergency response
  equipment and
  procedures
Flammables removals
  during sorting
Low
AL - Aluminum processing
PA - Paper processing
PL - Plastic processing
S/T - Steel and tin processing
                                        5-13

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magnetic detectors and separators to identify potentially dangerous metal
containers (e.g., propane tanks, aerosol cans) within the recyclable stream so that
they can be removed before shredding.  Auxiliary ventilation systems that exhaust
flammable vapors and circulate fresh air through the shredder chamber also can
reduce explosion hazards.  Locating shredders in dedicated, sealed rooms designed
to contain an explosion is an additional precaution that isolates the equipment and
protects workers throughout the facility. Adequate fire detectors, sprinkler
systems, and firefighting equipment should be installed in all recycling facilities.

5.6.  FLYING AND FALLING DEBRIS
      Source Activity:  Debris can fly or fall during most stages of processing
(Table 5-5).  Flying materials can result at drop-off centers where the public is
often required to sort recyclables by throwing or dropping them into uncovered bins
or dumpsters. Recyclables may fall on workers during operations when the
recyclables are being loaded into collection vehicles, sorted in overhead booths, or
conveyed through  an MRF  by belts or cranes.  Collection vehicles  fitted with
automated hoist loaders, for instance, lift bins high over  the side of the truck where
recyclables are dumped and possibly fall onto workers below.  In many MRFs, it is
customary for workers performing  manual sorting to drop or throw sorted
recyclables down chutes into collection  bins located below.  Fast-moving
equipment commonly used in MRFs and other processing centers (i.e., bag
breakers, metal and plastic shredders, glass crushers and grinders) can throw
recyclables from the equipment at  high velocities. For example, it is reported that
glass is  frequently  projected from the top of crushing or  grinding equipment
(personal communication between  TRC Environmental Corporation and Steve
Apotheker, journalist, Resource Recycling Magazine, on August 14, 1991).  Heavy
bales of recyclables also represent potential falling object hazards when they are
transported or stacked precariously.
      Hazard Type:  Flying and falling objects may  lead to a variety of
occupational injuries to unprotected workers.  Items accidentally dropped from
                                     5-14

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                                TABLE 5-5
                          Flying and Falling Debris
Type of
hazard
   Source activity
Prevention/mitigation
 Significance of
     hazard
Collection and
sorting

Public health

Occupational
Drop-off centers
Loading and
  dumping
  collection vehicles
Tipping floor
Sorting stations
Air classifications
Magnetic separators
Glass crushers
Slicers
Shredders
Drop-off centers
Front-end separation
  at transfer
  stations, landfills,
  waste-to-energy
  plants
Public education
Equipment design
Worker training
System and
  equipment design
  (e.g., equipment
  isolation,
  shielding)
Personal  protective
  equipment
Low

Medium
Materials
processing

Occupational
AL-Shredding
GL-Crusher and
  grinder
PA-Manual sorting
PA-Magnetic
  separators
PL-Shredding and
  grinding
Worker training
System and
  equipment design
  (e.g., equipment
  isolation,
  shielding)
Personal  protective
  equipment
Medium
                                   5-15

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TABLE 5-5 (continued)
Type of
hazard
Occupational
(continued)
Source activity
S/T - Iron and
steel
manufacture
S/T - Separation
Prevention/mitigation

Significance of
hazard

AL - Aluminum processing
GL - Glass processing
PA - Paper processing
PL - Plastic processing
S/T - Steel and tin processing
                                    5-16

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overhead may cause head, neck, and shoulder injuries, such as fractures,
concussions, and lacerations {Levy and Wegman, 1988).  Objects also can be
dropped during material handling (lifting or carrying) and cause injuries to feet and
toes, such as crushing injuries, fractures, and contusions.  Flying objects can cause
cuts and lacerations or strike unprotected eyes and result in eye injuries, including
blindness. To a lesser extent, the general public is susceptible to similar hazards as
recyclables are handled at drop-off centers.
      Prevention and Mitigation Options:  Personal protective equipment such as
hardhats and safety glasses helps prevent injuries from both flying and falling
debris.  In addition, establishing and maintaining safety zones beneath elevated
equipment and in dumping areas are an effective means of limiting worker exposure
to falling objects.  Objects hurled from processing equipment can be contained by
proper guards and housing on shredders and other equipment. Most new
equipment is sold as completely enclosed units; however, custom-made or adapted
equipment may lack adequate housings.  In some cases, additional plastic sheeting
or other guards added to the mouth of a shredder will help to contain flying
objects.  Employees should be trained to use equipment only when aii guards are in
place.  Physically isolating equipment  that can produce flying  or falling objects in a
separate room whenever possible will further reduce  hazards to workers.

5.7.  TEMPERATURE AND PRESSURE EXTREMES
      Source Activity:  Recycling operations potentially expose workers to
temperature extremes during outdoor  collection activities and indoor processing at
facilities with inadequate climate controls (Table 5-6). Indoor temperature
extremes are a particular concern because operations frequently occupy large
buildings, have numerous delivery doors and openings, and are therefore difficult to
heat and cool adequately. Because of prohibitively high costs, it is not uncommon
for small municipalities to operate facilities without a climate control system in
place.  A variety of recyclable reprocessing techniques may expose workers to
temperature and pressure extremes.  The primary concerns are heated liquids
                                     5-17

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                                 TABLE 5-6
                     Temperature and Pressure Extremes
 Type of
 hazard
   Source of activity
 Prevention/mitigation
Significance
  of hazard
 Collection
 and sorting

 Occupational
Tipping floor
Drop-off centers
Collecting and sorting
  on route
Worker training
Facility design
 (e.g.,  climate
 control systems)
Personal protective
 equipment
Low
 Material
 processing

 Occupational
AL - Dying and
  delacquering
Al - Smelting
AL - Casting and
  cooling
PA - Pulper
PL - Washing
PL - Separation
PL - Extrusion
S/T - Chemical
  detinning
Worker training
System and equipment
  design (e.g.,
  shielding, equipment
  isolation)
Process modifications
Personal  protective
  equipment
Low
AL - Aluminum processing
PA - Paper processing
PL -  Plastic processing
S/T - Steel and tin processing
                                    5-18

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generated during container  washing, plastic separation, or pulping operations and
hot machine parts such as extruder blades or aluminum and steel furnaces.  Plastic
extruders and some paper pulping equipment also operate at high pressures.
      Hazard Type:  Exposure to high or low ambient temperatures and contact
with hot materials are primarily occupational hazards.  Processes that involve
heating of materials or wash water (temperatures can be at least 160°F) can result
in burns. Many facilities have inadequate or no climate control, thus potentially
exposing workers to extreme temperatures. Prolonged exposure to high ambient
temperatures (e.g.,  in or around furnace or kiln areas or collection activities during
warm times of the year) may result in heat-related illnesses. Susceptibility to heat
stress also is dependent on physical fitness, the level of exertion required, and
clothing. Heat-related illnesses include  heat exhaustion, heat cramps, and heat
stroke (Zenz, 1988).
      Heat Exhaustion:  Heat exhaustion occurs from increased stress on various
body organs. Signs and symptoms include general weakness and dizziness,
excessive perspiration, cool moist skin,  and a  weak pulse.
      Heat Cramps:  Heat cramps are caused by heavy sweating with inadequate
water and electrolyte replacement. Heat cramps are characterized by pain in the
hands, feet, and abdomen as well as muscle spasms.
      Heat Stroke:  Heat stroke, which is the most serious form of heat stress,
occurs when the body's temperature regulation mechanism fails and the body's
temperature rises to critical levels.  Symptoms include  hot dry skin, severe
headache,  nausea, dizziness, and a strong rapid pulse. Left untreated, heat stroke
can lead to coma and death.
      Exposure to severe or prolonged  cold temperatures (in unheated process
areas) also can result in various adverse health effects. Cold weather injuries
include the following:
      Frostnip and Frostbite:  Frostnip  is characterized by sudden blanching or
whitening of the skin. Superficial frostbite results in firm, waxy, or white skin with
                                    5-19

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the tissue beneath remaining resilient. Deep frostbite results in cold, pale, and
frozen tissue.
      Hypothermia:  Hypothermia is a fall in the deep core temperature of the
body. Symptoms generally appear in five stages:  severe shivering; apathy,
drowsiness, and rapid cooling of the body to less than 95°F; unconsciousness,
glass stare, slow pulse, and slow respiratory rate; freezing of the extremities; and
death, if left untreated.
      Prevention and Mitigation Options:  Exposures to indoor temperature
extremes can be controlled through the installation of adequate climate control
systems.  A popular solution to the challenge of heating or cooling a large, open-air
building is to isolate workers within small enclosed booths.  Sorting workers, for
instance, can be housed within a climate-controlled booth within the larger facility.
Collection workers can be encouraged to wear appropriate clothing and provided
with training on the symptoms and prevention of thermal stress.  Training, in
addition to guards, shields, and personal protective equipment, also can prevent
exposure to temperature and pressure extremes associated with processing
equipment.  Process  modifications  that minimize the use of temperature extremes
also can be implemented.  One plant in Alabama has developed an aluminum
melting  process that drastically reduces its use of high temperatures, minimizing
the potential for worker exposures (personal communication between TRC
Environmental Corporation and Mitch Chow of Alabama Reclamation of Sheffield,
AL, on August 7, 1991).

5.8.  MOVING EQUIPMENT AND HEAVY MACHINERY
      Source Activity:  Stationary as well as mobile equipment present hazards to
workers in recycling facilities (Table 5-7). Examples of stationary equipment
include balers, conveyors, crushers, shredders, slicers, overhead cranes, and an
assortment of reprocessing equipment such as plastic extruders, paper pulpers,  and
steel furnaces.  Moving mechanical parts on this equipment, even under normal
operating conditions, present potential hazards. To meet the unique processing
                                    5-20

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                                    TABLE 5-7
                      Moving Equipment and Heavy Machinery
Type of
hazard
    Source activity
 Prevention/mitigation
  Significance of
      hazard
Collection and
sorting

Public health
Occupational
Drop-off centers
On-route collection
Loading and dumping
  collection vehicles
Operation of heavy
  equipment
Tipping floor
Bag breakers
Conveyor systems
Sorting stations
Slicers
Shredders
Balers
Drop-off centers
Front-end separation
  at transfer
  stations, landfills,
  waste-to-energy
  plants
Personal protective
  equipment
Worker training
Public education
Facility design

Worker training
System and
  equipment design
  (e.g., shielding,
  emergency shut-
  off, safety zones,
  emission controls,
  ventilation)
Low
Low
Material
processing

Occupational
AL - Balers and
  compactors
AL - Bale breaking
AL - Shredding
AL - Dying and
  delacquering
AL - Casting and
  cooling
Personal protective
  equipment
Worker training
System and
  equipment design
  (e.g., shielding,
  emergency shut-
  off, safety zones,
  emission controls,
  ventilation)
                                       5-21

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                               TABLE 5-7 (continued)
 Type of
 hazard
    Source activity
Prevention/mitigation
Significance
 of hazard
 Material
 processing

 Occupational
 (continued)
GL - Manual sorting
GL - Magnetic
  separation
GL - Velocity trap
  and air classifier
GL - Screening
PL - Material storage
PL - Conveyor
  systems
PL - Screening and
  cleaning
PL - Separators
PL - Manual sorting
PL - Shredders and
  grinders
PL - Washing
PL - Separation
PL - Drying
PL - Aluminum
  separation
PL - Extrusion
S/T - Iron and steel
  manufacture
S/T - Unloading
  scrap
S/T - Shredding
S/T-Air
  classification
S/T - Magnetic
  separation
                       Low
AL - Aluminum processing
GL - Glass processing
PL - Plastic processing
S/T - Steel and tin processing
                                        5-22

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and handling demands of recyclables, recycling operations often adapt equipment
from farming or other uses. Safety attachments may be removed or hazardous
equipment configurations created in customizing equipment of processing systems.
      Mobile equipment includes vehicles used during collection and transport and
within an MRF or other facility.  Dedicated recyclable collection vehicles now
include a variety of hoists and loading mechanisms that increase hazards such as
pinch points and the  opportunity for a vehicle to contact overhead trees and
electrical wires.  Standard waste collection vehicles pose similar physical hazards.
Within recycling  facilities, the close interaction of workers and equipment (e.g.,
forklifts, loaders), particularly on the tipping room floor, poses a considerable
accident hazard. The public also can be put at risk at drop-off centers if access to
areas where machinery is used is not strictly controlled.
      Workers may endanger themselves if they do not take proper precautions
when they perform equipment maintenance.  Balers, conveyor belts, shredders,
moving parts on collection vehicles, and other types of equipment can become
jammed with recyclables (e.g., plastic or metal containers, broken glass, paper).
Dislodging jams and other on-the-spot repairs may endanger worker safety because
of accidental start-ups if proper electrical lock-out procedures are not followed.
      Hazard Type:  Moving equipment and heavy machinery pose primarily
occupational safety hazards, although accidents can occur when consumers handle
recyclables at drop-off centers.  Injury can be caused by the crushing, squeezing,
or pinching of a body part between a moving object and a stationary object or
between two moving objects (Levy and.Wegman, 1988).  Examples of such
injuries include catching fingers and other body parts in conveyor belts (Martin,
1991), workers falling onto conveyors and being killed in a shredding  machine (DPI,
1989), and workers contacting moving  parts by climbing into trucks or bailer
chamber bins to  dislodge jammed material (Keller, 1989).
      Another hazard related to recycling equipment includes accidents  (tipovers)
and emissions associated with forklift and loader operations (carbon monoxide [CO]
and particulates):  A study conducted at the Langard Demonstration Project (a
                                    5-23

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resource recovery facility in Baltimore, Maryland) measured carbon monoxide levels
of 100 ppm to 900 ppm on the facility's tipping floor when more than two trucks
were present (STC, 1979). The OSHA permissible exposure limit for CO is 35
ppm.  Early signs of CO poisoning include headache, weakness, lassitude, and
mental confusion.  If exposure is prolonged, CO prevents the normal uptake  and
distribution of oxygen in the body and may ultimately have lethal effects (Section
5.12 "Gaseous  Releases").
      Prevention and Mitigation Options:  Injuries associated with material
processing and  handling equipment can be avoided through the appropriate
placement of guards  and shields.  Consideration of equipment interfacing is
especially important because unique hazards can exist when equipment of various
makes are integrated.
      Injuries during  equipment maintenance can be reduced by positioning
multiple emergency power shut-off buttons, cords, and switches along process
lines that include hazardous equipment (e.g., balers, conveyor belts, shredders).
As a result of incidents of crushing injuries associated with balers,  easily accessible
safety switches are now being placed within baler chambers (Dessoff,  1991).
Strictly observed electricity lockout practices during the maintenance of automated
equipment limit the possibility of accidental start-ups.
      Training regimens stressing safety practices for the use of specialized
equipment help prevent injuries resulting from equipment misuse. Safety zones and
warning signs alerting employees to hazardous areas and equipment also help
prevent accidents.
      Proper ventilation and vehicle emission controls can help reduce  worker
exposures to vehicle  emissions during loading and unloading operations.
5.9.  NOISE
      Source Activity:  A summary of recycling activities that generate significant
levels of noise, including collection, sorting, and general material handling, is
provided in Table 5-8.  Aside from the noise associated with equipment motors and
                                    5-24

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                                                                       Significance
                                                                        of hazard
                                Prevention/mitigation
 Collection and
 sorting

 Public health
 Occupational
Material
processing

Occupational
 Consumer drop-off at
   collection centers
 Curbside collection
 Transportation during
   processing

 Tipping floor
 Air classification
 Magnetic separators
 Aluminum separators
 Glass crushers
 Slicers
 Shredders
 Front-end separation at
   transfer stations,
   landfills, waste-to-energy
   plants
 Residential drop-off at
   collection centers
 Curbside collection
 Transportation during
   processing
AL - Shredding
GL - Manual sorting
GL - Crushers/grinders
PA - Magnetic separators
Vehicle and
  equipment design
Collection and
  transport scheduling


Vehicle and
  equipment design
System design (e.g.,
  equipment isolation,
  shielding)
Personal protective
  equipment
                                                                      Low
                                                                      Medium
                                             Vehicle and
                                               equipment design
                                             System design (e.g.,
                                               equipment isolation,
                                               shielding)
                       Low
                                      5-25

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TABLE 5-8 (continued)
Type of
hazard
Occupational
(continued)
Source activity
PL - Shredders and
grinders
S/T - Shredders
Prevention/mitigation
Personal protective
equipment
Significance
of hazard

AL - Aluminum processing
GL - Glass processing
PA - Paper processing
PL - Plastic processing
S/T - Steel and tin processing
                                     5-26

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engines, significant noise is generated by contact between aluminum, glass, and
steel containers when they are loaded on a collection vehicle, dumped on the
tipping floor, or transported on conveyor belts. Specific processing equipment
such as air classifiers, metal and plastic shredders, and glass crushing and grinding
equipment are also noisy.  Noise may result from the use of heavy trucks,
compactors, and automated loaders and compactors during neighborhood
collection.
      Hazard Type:  Excessive noise is primarily an occupational hazard but also
can be a public health concern associated with certain collection activities. The
effects of  noise on the ear are related to the duration of exposure and the intensity
of the noise.  Noise can  have  direct effects on both the middle and inner ear.  The
current OSHA standard for continuous noise for 8 hours is 90 dBA, with higher
levels permissible for shorter periods of time.  The American Conference of
Governmental Industrial  Hygienists (ACGIH) Threshold Limit Value is 85 dBA.
Noise levels above these standards are considered damaging. One study of noise
levels measured throughout the front-end processing stages at a resource recovery
plant revealed levels ranging from 85 to 90 decibels on the tipping floor and at the
shredders. Levels between 90 and 100 decibels were measured at the primary and
secondary shredders  and at the magnetic separator  (Mansdorf et al., 1981).
      The primary health effect associated with noise exposure is noise-induced
hearing loss (NIHL). There are three categories of NIHL (Levy and Wegman, 1988;
Zenz, 1988; Clayton  and Clayton, 1991): (1)  acoustic trauma, which can be the
effect of a single intense noise followed by ringing in the ear and a shift in the
hearing threshold; there  also can be damage to the  eardrum if peak exposure levels
exceed 160 dBA; (2) temporary threshold shift (TTS), which is temporary hearing
loss with recovery within a few hours or days following removal from the noise if
the noise has not been too loud or the exposure too long; the cumulative effect of
noise levels of less than  85 dBA also  can lead to TTS; and (3) permanent threshold
shift (PTS) can result if the noise is of sufficient intensity and duration to damage
the sensory cells in the inner ear.  Diminished  ability to understand speech in a
                                    5-27

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setting with noisy background is a pronounced effect of NIHL.  Some individuals
also experience ringing ears and headaches in addition to their hearing loss.
      Prevention and Mitigation Options:  A simple and inexpensive means of
reducing worker noise exposure is to require the use of earplugs or headphone-
style protectors. Another option is the use of engineered controls that reduce the
levels of noise generated. Using soundproof sorting booths as a means of isolating
workers from noisy operations is gaining popularity in MRFs nationwide. Sound-
deadening panels and dividers also can be used effectively to separate areas where
noise is generated, such as the tipping floor, from areas where workers are
stationed.  Noisy equipment (e.g., shredders and grinders)  can be fitted with
sound-deadening attachments, or it can be isolated in a separate room or
enclosure.  Selecting quieter collection vehicles or reducing the number of vehicle
trips to collect all MSW can minimize noise effects on the public.

5.10.  AESTHETIC IMPACTS
      Source Activity:  Collection vehicles and recycling facilities can constitute
aesthetic impacts themselves or generate other impacts including overall
appearance effects, odors, and litter (Table 5-9).
      In general, the release of litter is a concern  more during recyclable materials
collection than it is during MSW collection (personal communication between TRC
Environmental Corporation and Alan Watts, recycling coordinator for Solid Waste
Services, a division of the Environmental Conservation Services Department,
Austin, TX, in August 1991).  Drop-off centers can be a source of litter and often
have an unkempt appearance because they are frequently  unmanned.  Discarded
items frequently are left on the ground when bins are full or the items are not
recyclable.  In addition, people scavenging recyclables for  profit can leave a drop-
off center in disarray.  Odors may be emitted from unclean recyclables during
storage or reprocessing.  For example, plastics that  have absorbed  butyric acid
have been knpwn to emit an acrid odor on exposure to heat during extrusion
(Hernandez et al., 1988).
                                     5-28

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TABLE 5-9
Aesthetic Impacts
Type of
hazards
Collection and
sorting
Public health

Source activity


Consumer collection
Curbside collection
Drop-off centers
Transportation
during processing
MRFs
Prevention/mitigation


Public education
Facility design (e.g.,
screening
elements, secure
storage areas,
fences)
Significance
of hazard


Low

5-29

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       Hazard Type:  Aesthetic impacts are primarily a public health concern.
Although aesthetic impacts do not directly impair health,  indirectly they affect the
psychologic confidence of individuals.  Excessive odors and litter can diminish the
public's support and result in complaints and opposition to MSW programs.
       Prevention and Mitigation Options:  Visual impacts can be minimized
through  the thoughtful use of screening elements (e.g., bushes, fences, walls,
trees,  earth berms). New facilities can be designed  with  greater attention paid to
aesthetic quality.  Litter and odors can be controlled by avoiding the use of
uncovered, outdoor material storage areas.  Odors can be reduced by effective
washing of recyclables.  Perimeter fences also can help to control windborne litter.
Stationing an overseer at drop-off facilities or restricting access to the facility
during nonstaffed hours will limit inappropriate dumping and scavenging.   Garbage
containers placed at drop-off facilities will help decrease litter.

5.11.  TRAFFIC
       Source Activity:  Traffic hazards are attributable to trucks collecting
recyclables at the curbside, private vehicles delivering recyclables to drop-off and
buy-back centers, and vehicles (e.g., trucks, trains,  barges) transporting
recyclables between processing and within facilities. Traffic hazards are
summarized in Table 5-10.  Specifics of program organization and equipment type
dictate the nature of traffic hazards.  A drop-off or buy-back operation  may have a
higher occurrence of vehicle accidents involving private vehicles, whereas a
curbside program may have a higher rate of accidents involving collection  trucks.
       Hazard Type:  Traffic poses public health, occupational, and environmental
           *
hazards.  Vehicular accidents (including pedestrian accidents), release of materials
from collection vehicles, emissions (hydrocarbons, NOX, carbon monoxide, and
particulates) and  maintenance-generated wastes, and noise are all traffic related
hazards.
      Workers collecting  recyclables may be subject to traffic-related hazards
during collection and truck-loading activities.  Two-sided sorting  may result in a
                                      5-30

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                                TABLE 5-10
                               Traffic Hazards
Type of
hazard
    Source activity
Prevention/mitigation
 Significance
  of hazard
Collection and
sorting

Public health
Occupational
Environmental
Drop-off centers
Buy-back centers
Consumer drop-off at
  collection centers
Curbside collection
Transportation during
  processing
Drop-off centers
Buy-back centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Curbside collection
Transportation during
  processing
Drop-off centers
Buy-back centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Curbside collection
Transportation during
  processing
Vehicle maintenance
Public education
Vehicle design (e.g.,
  emission controls,
  safety features)
System design (e.g.,
  traffic flow)
Collection and
  transport
  scheduling
Worker training
Vehicle design (e.g.,
  emission controls,
  safety features)
System design (e.g.,
  traffic flow)
Collection and
  transport
  scheduling
Personal protective
  equipment
Vehicle design (e.g,
  emission controls)
Proper waste
  handling
Vehicle equipment
Low
Low
Low
                                    5-31

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higher accident rate because it has the potential to place workers in the path of
traffic (personal communication between TRC Environmental Corporation and
Pamela Harris, director of Loss Control Services for Browning Ferris International
[BFI], Houston, TX, on September 13, 1991).
      Although it is difficult to draw conclusions from the limited existing data on
traffic accidents associated with recycling operations, statistics from a program in
Austin, Texas, suggest that recycling vehicles can be more prone to accidents than
other MSW collection vehicles. Statistics from 1986 and 1987 reveal that
recycling vehicles accounted for approximately 30 percent of accidents involving
collection vehicles and approximately 20 percent of the total vehicles in the
collection fleet (personal communication between TRC Environmental Corporation
and Sergio Martinez, safety specialist for Solid Waste Services, a Division of the
Environmental Conservation Services Department, Austin, TX, in August 1991).
Specific vehicle design and route organization features (e.g., truck size, loading
design, number of workers assigned to each collection crew) are possible factors
contributing to these higher rates.
       Prevention and Mitigation Options:   A thorough, safety-conscious traffic-
flow plan can minimize potential accident hazards at all types of recycling facilities.
Traffic safety zones can  be established within which no vehicles are allowed.  A
well-organized collection strategy that anticipates and avoids periods and routes of
high traffic will help reduce road accidents. Conducting safe-driver training,
recognizing good drivers, and installing safety signs, mirrors, and other equipment
can reduce traffic hazards at facilities and on the road.
       Emerging collection strategies such as those that utilize efficient, lightweight
collection vehicles that unload to larger vehicles for distance driving have the
potential to reduce energy use and emissions.  The type of truck chassis and
engine used and the amount of stop-and-go driving required during collection
influence fuel efficiency and  related vehicle emissions.  Keeping vehicles well
maintained reduces emissions.
                                     5-32

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5.12.  PROCESS CHEMICALS AND CONTAINER RESIDUES
      Source Activity:   A summary of process chemicals and residues of
hazardous chemicals in recyclable containers that pose direct hazards at a number
of processing points (Sections 5.13 through 5.18 for indirect hazards associated
with these chemicals and other residues and contaminants) is provided in Table
5-11. Examples of common process chemicals include chlorine and other paper
bleaching and pulping agents, aluminum fluxing agents and compounds, plastics
additives, and equipment cleaning solvents.  In some cases (e.g., paper deinking
and pulping), chemicals are used in open vats or  other containers from which
splashing may endanger workers.
      Container residues may include insecticides, herbicides, and other lawn and
garden products; paints, stains, and construction products; automotive oils and
cleaners; gasoline, kerosene, and other fuels; and miscellaneous household
cleaning  products. Individuals may be exposed to these residues during collection,
cleaning  (rinsing), and storage of recyclables in their homes.  Workers are exposed
to residues primarily during collection, sorting, and washing steps. For example,
elevated  pesticide levels also have been  reported in wash  water resulting from
pesticide-saturated paper labels (personal communication between TRC
Environmental Corporation and George Pisacano of the Center for Plastics Recovery
Research, Rutgers University, on February 12, 1992). Certain container and label
materials may be more likely than others to absorb and retain chemical residues.
      Hazard Type:   Mishandled or mismanaged process  chemicals or residues can
cause adverse effects to workers and the public.  Direct skin contact, inhalation,
and incidental ingestion exposures are possible.  The health hazards associated
with the  chemicals and residues that may be encountered are summarized below.
      Process Chemicals:  Chlorine and fluorine, process chemicals used to
remove magnesium  from  aluminum cans, are strong  eye and respiratory irritants
(Sittig, 1991).   Fluoride compounds also are associated with central nervous
system and skin disorders.  Certain chemicals used in the  deinking process could
result in adverse health effects if proper  controls  are not in place.  Repeated
                                    5-33

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                                TABLE 5-11

                  Process Chemicals and Container Residues
                               (Direct Impacts)
 Type of
 hazards
    Source activity
 Prevention/mitigation
Significance
  of hazard
 Collection and
 sorting

 Public health
 Occupational
Consumer collection
Curbside sorting
Dumping
Bag breakers
Sorting stations
Drop-off centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Public education

Public education
Worker training
Personal protective
  equipment
System and
  equipment design
  (e.g., storage
  practices,
  ventilation)
Low
Medium
 Material
 Processing

 Occupational
AL - Smelting
PA - Pulper
PA - Screening and
  cleaning
PA - Clarifier
PA - Bleaching
PA - Effluent treatment
PA - Sludge disposal
PL -  Manual sorting
PL -  Washing
PL -  Separation
PL -  Extrusion
S/T - Chemical
  detinning
Public education
Worker training
Personal  protective
  equipment
System and
  equipment design
  (e.g., storage
  practices,
  ventilation)
Medium
AL - Aluminum processing
PA - Paper processing
PL -  Plastic processing
S/T - Steel and tin processing
                                    5-34

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exposure to corrosive alkaline solutions such as sodium hydroxide can cause   ,
dermatitis.
      Chemicals used during plastics processing are not generally hazardous.
Difficulty in handling and disposing of hazardous solvents is one reason why more
benign detergents usually are used in washing steps.  Plastic resins and container
labels can absorb organic residues such as pesticides. Health effects associated
with exposure to pesticides include primarily skin and  central nervous system
disorders.  Long-term exposures to certain pesticides can cause liver and  kidney
damage.  Some pesticides are carcinogens.
      Container Residues:   Potential effects associated with container residues
vary widely according to the type of residue.  Possible effects range from short-
term irritant effects to long-term toxicity and cancer.  Hazardous constituents
banned or reduced in concentration in current products may be present in old
containers collected  for recycling.  Potential health and safety issues associated
with residues are addressed under the regulatory authority of the Food and  Drug
and Cosmetic Act.  Fire and explosion hazards associated with chemical residues
are discussed in Section 5.5.
      Prevention and Mitigation Options:  Personal protective equipment including
glasses, gloves, and aprons is recommended for reducing chemical exposures.
Requiring workers to shed dedicated work uniforms before leaving the facility also
will help reduce exposures to chemical spills (Solomon-Hess, 1991).  In addition,
showers and eyewash stations  can help to minimize contamination.  Adequate
enclosures on processing vats,  secure storage practices, and enhanced ventilation
systems also prevent worker exposures to process chemicals.  To minimize a
release in the event  of a chemical spill, some recycling facilities have installed
separate run-off collection systems that are designed to collect and treat  water
contaminated with oil and other waste substances (Combs, 1991). Both
occupational and public health exposures  can be prevented by educating  the public
to avoid recycling containers with exceptionally  hazardous contents and to  properly
wash or decontaminate containers before  disposal.
                                     5-35

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5.13.  GASEOUS RELEASES
      Source Activity:   Gases released are summarized in Table 5-12.  Aside from
occasional gaseous releases attributable to container residues (Section 5.12.),
releases from recycling operations often are associated with heating or melting
process stages or gases or volatile chemicals used to clean or refine recycled
materials (Sections 5.8. and 5.11. contain information on emissions from
equipment and vehicles). Potential release may vary with the material processed.
Emissions from aluminum delacquering  processes that burn paint and coatings may
include organic contaminants and heavy metals such as lead and cadmium. Steel
melting and demagging operations typically release metallic oxides and chlorides as
well as acid and  chlorine gases.  Heavy metals contained in label inks also may be
released. Bleaching agents (e.g., chloroform and chlorine) are released from
processing and wastewater treatment operations associated with wastepaper
recycling.
      Plastics processing involving heating, particularly drying and extrusion
molding operations, has the potential to release gaseous degradation products such
as acids, volatile organic compounds (VOCs), carbon dioxide, and carbon monoxide
(Allen, 1983). When most  resins are melted, there is the possibility of releasing
small quantities of unreacted monomer  as well as any additives, dyes, and
compounding  agents.  HOPE extruder operations have been found to release 0.63
kg of VOCs per mg of resin  processed (Radian Corporation, 1985).  One study has
confirmed that some degradation of HOPE resin can occur during heating (Gibbs,
1990). Melting polystyrene above 280 degrees also has been shown to produce
styrene monomer emissions (Brighton et al.,  1979).  Plastic degradation  from
overheating, scorching, and burning usually occurs by accident and is usually
caused by equipment malfunctions,  operator error, or improper equipment
maintenance.  Commingled plastics  processing also raises the likelihood  of
exceeding resin degradation temperatures because it can involve simultaneously
heating resins with different melt temperatures.
                                    5-36

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TABLE 5- 12
Gaseous Releases

Type of hazard
Collection and
sorting
Public health/
environmental








Occupational









Material
processing
Public health/
occupational/
environmental






Sources


MRFs
Front-end separation at
transfer stations,
landfills, waste-to-
energy plants
Consumer drop-off at
collection centers
Curbside collection
Transportation during
processing
Shredders
Front-end separation
Transfer stations.
landfills, waste-to-
energy plants
Consumer drop-off at
collection centers
Curbside collection
Transportation during
processing


AL - Drying and
delacquering
AL - Smelting
PA - Screening and
cleaning
PA - Bleaching
PA - Milling
PL - Extrusion

Prevention/mitigation


System and
equipment design
(e.g., emission
controls, chemical
reuse)





System and
equipment design
(e.g., emission
controls,
ventilation.
chemical reuse)
Personal protective
equipment




System and
equipment design
(e.g., emission
controls.
ventilation.
chemical reuse)
Personal protective
equipment
Significance
of hazard


Low









Low











Low







5-37

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TABLE 5-1 2 (continued)
Type of
hazard

Sources
S/T - Iron and
steel
manufacturing
S/T - Shredding
Prevention/mitigation

Significance of
hazard

AL - Aluminum processing
PA - Paper processing
PL - Plastic processing
S/T - Steel and tin processing
                                        5-38

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      Hazard Type:  Gaseous releases associated with various recycling
operations may result in potential exposure of workers, the public, and
environmental receptors to a variety of toxic substances if proper controls are not
employed.  The magnitude of releases from recycling facilities that can affect the
public and the environment is difficult to characterize.
      In a remanufacturing facility, organic and metal oxide contaminant releases
are possible during the  delacquering and smelting of aluminum to remove impurities
such as paints, coatings, and container residues. Exposure to metal oxides,
including zinc, copper,  magnesium, aluminum, antimony, cadmium, copper, iron,
manganese, nickel, selenium, silver, and tin, may result in a flu-like condition
known as metal fume fever. The symptoms of metal fume fever include chills,
increased sweating, nausea, weakness, headache, muscle pain, and cough.  The
fever often begins with thirst and a metallic taste in the mouth (Levy and Wegman,
1988).  In general, acute effects of solvent exposure include irritation of the
respiratory tract, skin irritation, and central nervous system effects.  Long-term
health effects associated with organic compound exposure include liver, kidney,
and gastrointestinal disorders. Certain  solvents that may be used in or generated
during certain recycling processes are classified  by EPA as potentially carcinogenic
to humans.  In the paper deinking process, use of chlorine-based bleaches has been
associated with the releases of dioxins  and chloroform, both of which are
potentially carcinogenic to humans.  Exposure to dioxins also is associated with
disorders such as chloracne, nervous system disorders, and liver damage (Sittig,
1991).
      Many of the emissions from thermal decomposition of plastic resins are
similar to those associated with the processing of virgin feedstock and include
various classes of organic compounds.  Possible acute health effects associated
with worker exposure to  organic compounds include irritation of mucous
membranes and the respiratory system, dermatitis, and central nervous system
effects (U.S. Department of Health and Human Services, 1990). Long-term
exposures may cause liver, kidney, and gastrointestinal damage.
                                     5-39

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      Prevention and Mitigation Options:  Public exposure can be minimized
through emission control technologies that are available to reduce gaseous releases
from recycling facilities.  Depending on their size and complexity, systems can
reduce worker exposures by venting gases outdoors or eliminating harmful
emissions altogether. Cost is the primary factor that limits the application of state-
of-the-art air filtration systems, particularly at small, start-up operations with limited
capital reserves.  Fixed carbon-bed absorbers, electrostatic precipitators, distilling
equipment, and fractionalizers all can be  used effectively to reduce air emissions.
For example, the acidic degradation byproducts of PVC processing can be
neutralized using a sodium hydroxide mist (personal communication  between TRC
Environmental Corporation and Brian Doty, plant manager, Innovative Plastic
Products, Inc., Greensboro, GA, on July  29, 1991).  Wet scrubbers can be used to
control gaseous emissions from drying and delacquering operations.  In the
absence of emission control systems, personal protective equipment such as
respirators will reduce worker exposures.

5.14.  PARTICULATE RELEASES
      Source Activity:   Virtually every operation within an MRF or processing
facility generates some airborne particulates. A summary  of particulate releases is
provided in Table 5-13.  Sorting activities, trommel screens,  air classifiers, glass
crushers, shredders, and other equipment that moves or manipulates recyclables
are potential dust sources. Shredding  and blowing equipment tends to generate
the most particulates. Studies conducted at the Langard resource recovery facility
in Baltimore, Maryland, identified high dust levels in the material receiving area
(STC, 1979).
      Certain materials produce more particulates, or particulates that are more
hazardous, when they are shredded  or processed.  Paper, because of its fibrous
nature, generates significant dust when it is sorted or shredded.  Other dusts
include fine glass shards from crushing or grinding, plastic fines from shredding,
and aluminum and steel  bits from shredding and demagging and detinning.  The
                                     5-40

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                                   TABLE 5-13

                                Particulate Releases
Type of hazard
    Source activity
 Prevention/mitigation
   Significance
    of hazard
Collection and
sorting

Public health/
environmental
Occupational
Drop-off centers
MRFs
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Curbside collection
Transportation during
  processing
Most other processing
  facilities

Tipping floor
Trommel screens
Air classifiers
Shredders
Drop-off centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy  plants
Curbside collection
Transportation during
  processing
System and
  equipment design
  (e.g., emission
  controls)
System and
  equipment design
  (e.g., emission
  controls, ventilation)
Personal protective
  equipment
Low
Medium
                                        5-41

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                             TABLE 5-13 (continued)
Type of hazard
     Source activity
  Prevention/mitigation
Significance
  of hazard
Material
processing

Public health/
occupational/
environmental
AL - Drying and
  delacquering
AL - Smelting
GL - Crusher and grinder
GL - Screening
GL - Aluminum
  separation
PA - Trommel screens
PL - Shredding
S/T - Iron and steel
  manufacture
S/T - Shredding
S/T - Separation
System/equipment
  design (e.g., emission
  controls, ventilation)
Personal protective
  equipment
Low
 AL - Aluminum processing
 GL - Glass processing
 PA - Paper processing
 PL -  Plastic processing
 S/T - Steel and tin processing
                                      5-42

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processing technique, material processed,,and the ventilation conditions all affect
the amount of airborne particulate material. Although some recycling facilities
report dust to be a significant problem, an inspection conducted by the Vermont
Health Department in a facility that regularly grinds PVC scrap found nuisance dust
to be below allowable levels (personal communication between TRC Environmental
Corporation and Fred Satink of the Vermont Department of Health on July 29,
1991).
      Hazard Type:  Particulate releases from recycling activities may pose
potential public health, occupational, and environmental hazards.  Uncontrolled
dust may be inhaled or swallowed with food or saliva.  In general, the principal
potential health effects of particulate exposure include the aggravation of asthma
or other respiratory or cardiorespiratory symptoms, increased cough and chest
discomfort, and increased mortality.  In addition, the toxic action of some gases
may be enhanced when they are adsorbed to respirable particles.  The health
effects associated with inhalation of particles is dependent on the location and
extent of their deposition in the respiratory system.  Several factors influence
particle deposition, retention, and clearance, including the anatomy of the
respiratory tract, particle size,  and breathing patterns.  Children are considered to
be more  susceptible to particulate pollution. Environmental effects of particulate
emissions include soiling and deterioration of  building materials and other surfaces,
cloud formation, and interference with plant photosynthesis (Clayton and Clayton,
1991).  Dust levels measured in studies at resource recovery plants have ranged
from 118 to 202 mg/m3 in the vicinity of a shredder to as low as 38 mg/m3 (Diaz
et al., 1981).  The OSHA Permissible Exposure Limit (PEL) for inert or nuisance
dusts is 15 mg/m3 for total particulates and 5 mg/m3 for the respirable fraction.
      Some dusts generated during certain recycling activities contain metal fines.
Acute exposure to metal dusts can cause irritation of the upper respiratory system
and eventually severe pulmonary irritation (Levy and Wegman, 1988).  Heavy
metals reported in air emissions from MRFs include cadmium, chromium, nickel,
lead, and mercury (Visalli, 1989).  Cadmium,  chromium (hexavalent), lead, and
                                     5-43

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nickel are carcinogenic to animals and humans when inhaled.  Chronic exposure to
mercury and lead can result in adverse effects to the central nervous and
gastrointestinal systems; lead is also a probable carcinogen.
      Exposure to fine glass particles  can result in the development of silicosis
because silica is a primary component of glass.  Particles less  than one micron in
diameter present the greatest danger because they can penetrate to respiratory
bronchioles and  alveoli (Last and Wallace, 1992; Zenz,  1988).  Such particle sizes
are typically associated with grinding or  sandblasting glass. Crushing of glass
during recycling activities is not likely  to produce particles that small.
      Prevention and Mitigation Options:  Ventilation and filtration systems and
personal  protective equipment are two approaches to controlling dust and
protecting workers from elevated levels of airborne particulates. Filtration systems
collect contaminated air and feed it to a  bag house or an air scrubber  system that
removes  contaminants. The latter  method has proved effective for removing glass
and other particulates from ambient air (U.S. EPA, 1977).  Building-wide, negative
air flow systems also have  been used  to draw air to a central filtration unit, but
these systems are difficult to implement in large facilities like MRFs with many
openings. An alternative is dust collection hoods on specific pieces of equipment
that generate dust (e.g., shredders, air classifiers, plastics grinders).  Operating
equipment such as shredders at slower speeds has been found to further reduce
dust generation rates (Toensmeir, 1987). The use of isolated  booths to house
sorting workers in a climate-controlled environment also is  gaining acceptance as  a
method for limiting exposures to airborne contaminants. Dust masks and
respirators can reduce the hazard to workers; however, the equipment must be
properly selected, consistently used, and replaced when necessary. Workers often
do not use masks because  they are uncomfortable and considered a nuisance.
5.15.  WATERBORNE RELEASES
      Source Activity:  Wastewater is generated by recycling operations ranging
from washing containers in the home to industrial paper pulping and plastic
                                     5-44

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washing systems (Table 5-14).  The public generally washes food and paper
particles down the drain.  MRFs and other facilities that receive recyclables and
commingled wastes can generate effluents containing a variety of liquids from
container residues to rain water.  Run-off from the tipping floor and other
processing areas within a  recycling facility often is discharged to the storm or
sanitary sewer.
      Water-based cleaning and sorting processes have the potential  to generate
large volumes of waste water.  For example, water is  used extensively at several
stages of wastepaper pulping and cleaning. Effluents containing  chlorine and its
byproducts, inks, and dyes are generated by screening, bleaching, washing, and
filtering operations.  The levels of chemical and physical contaminants vary
depending on the type of paper being processed and  the degree of wastewater
treatment that takes place before release.  Several types of plastics shredding or
grinding, cleaning, and separation equipment also  use water to wash and transport
plastic flakes.  A B.F.  Goodrich vinyl recycling operation in Akron, Ohio, adds a
1-percent solution of dishwasher detergent to hot-water wash solutions (Summers
et al., 1990).
      Another source of facility effluents is water-based air filtration systems (e.g.,
wet scrubbers) used to control air emissions.  Air filtration skimming and scrubbing
processes are frequently used at aluminum and steel facilities. Contact cooling
waters also can include a number of contaminants.
      Hazard Type:  Process wastewater and effluents from emission control
systems result in primarily environmental hazards.  Wastewater from aluminum
processing may contain metals, phenolics, oil and  grease, and suspended solids.
Wastewater from paper processing may include chlorine-derived dioxins,  PCBs, and
heavy metals and solvents from inks. Although toxic constituents in manufactured
goods are increasingly regulated, recycling of older products can  contribute to the
release of these contaminants. These substances  exhibit both carcinogenic and
noncarcinogenic health effects in humans. The primary environmental concerns are
BOD loading of receiving waters and toxic effects  on  aquatic organisms.
                                    5-45

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                               TABLE 5-14
                           Waterborne Releases
Type of
hazard
    Source activity
Prevention/mitigation
 Significance
  of hazard
Collection and
sorting

Public health/
environmental
Separation in the home
Tipping floor
System and
  equipment design
  (e.g., collection,
  treatment, reuse)
Low
Material
processing

Public health/
environmental
AL - Scraping, drying,
  and delacquering
AL - Smelting
AL - Casting and
  cooling
PA - Separators
PA - Clarifiers
PA - Bleaching
PA - Dewatering and
  thickening
PA - Milling
PA - Separation
PA - Washing
PL - Separation
PL - Washing
S/T- Iron and steel
   manufacture
System and
  equipment design
  (e.g.,collection,
  treatment, reuse)
Low
  AL - Aluminum processing
  PA - Paper processing
  PL - Plastic processing
  S/T - Steel and tin processing
                                   5-46

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      Prevention and Mitigation Options:  Dedicated systems can be installed to
collect and treat facility effluents before release. Standard treatment techniques
include primary and secondary clarifiers, neutralization, activated sludge, aerated
stabilization, and anaerobic processes. Certain anaerobic processes can reduce
BOD by as much as 95 percent (Amoth et al.,  1991).  The use of alternative
chemicals such as nonchlorine bleaches and other nonhazardous process chemicals
has reduced the quantity of dioxins released by secondary paper plants. Most
wastewaters from cleaning, sorting, reprocessing, or air filtration also can be
recycled to minimize effluent discharges. For instance, paper recycling plant
effluents have been successfully filtered and recycled (Horacek, 1983).

5.16.  SOLID WASTE AND SLUDGE
      Source Activity:  Residual material is generated as a result of sorting and
refining operations that purify waste materials for remanufacture (Table 5-15).  An
assortment of gross solid discards and sludge  byproducts generated as recyclables
is initially processed at the MRF.  More rigorous sorting, filtering, and refining that
occur during subsequent processing generate a variety of sludges and finer
contaminants.  These discards are generally landfilled, incinerated,  landfarmed,  or
discharged with wastewater.
       A survey of 41 operating and proposed  MRFs found residue  generation rates
ranging from less than 1. to 25 percent of the material entering a facility.  Most of
the discards frpm  the MRFs generating more than 10  percent waste were found to
be mixed-color cullet (Glenn,  1989).  The remainder of the residue  is difficult to
categorize and is not generally salvageable.
       Aluminum reprocessing generates both solid and sludge discards. Fabric
filters  used to collect aluminum fines, slag and dross collected during skimming,
and  demagging residues captured  by  emission control equipment are examples of
aluminum reprocessing wastes.
       Paper recycling generates large quantities of sludge and a variety of solid
discards including plastic, bindings, cellophane, rubber bands, staples, and paper
                                     5-47

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TABLE 5-15
Solid Waste and Sludge
Type of
hazard
Collection and
sorting
Public health/
environmental






Material
processing
Public health/
environmental
















Source activity


Front-end separation
at transfer stations,
landfills, waste-to-
energy plants
MRFs





PA - Manual sorting
PA - Magnetic
separators
PA - Trommel
screens
PA - Pulper
PA - Screening and
cleaning
PA - Separators
PA - Clarifier
PL - Washing
PL - Separation
PL - Extrusion
S/T - Air classifiers
S/T - Magnetic
separation
S/T - Tin removal

Prevention/mitigation


Process and system
design (e.g., careful
sorting, reuse of
waste, glass
breakage reduction)
Treatment and
disposal facility
design


Process and system
design (e.g., careful
sorting, reuse of
waste, glass
breakage reduction)
Treatment and
disposal facility
design









Significance
of hazard


Low









Low
















PA - Paper processing
PL - Plastic processing
S/T - Steel and tin processing
                                     5-48

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clips (Sixour, 1991).  It is estimated that deinking and pulping operations will
produce as much as 700,000 tons of sludge in 1995 (Usherson, 1992). This is
caused primarily by fiber losses and high clay and ink content of certain waste
paper grades. Heavy metals, PCBs, and dioxins are contaminants of concern  in
paper processing sludges.
      Plastics cleaning, sorting, and filtration often generate soil, rocks, off-
specification plastics, metals, labels,  detergent, and solvents. Filtrate quantities
vary widely depending on the type and quality of the plastic being processed.  A
filtration system that uses a coarse wire screen on an extruder for processing PET
bottles may collect 4 to 5 chips of aluminum (averaging 3 mm2  in size)  per 10 kg
of PET processed (Wissler, 1990). One plastics recycling facility reported
landfilling  more than 16,000 pounds of wet filtrate (as much as 50 percent water)
for every 5 to 10 cubic feet of plastics processed  (personal communication
between TRC Environmental Corporation and Garry Thompson. M. A. Industries,
Inc. Peachtree City, GA, in July 1991).
      Hazard Type:  Many of the process chemicals and contaminants found in
effluent streams also can occur in sludge. Trace quantities of heavy metals, PCBs,
dioxins, and other chlorinated organic compounds are found in recycling plant
sludge. Metals measured  in deinking sludges are listed in Table 5-16.  As
mentioned previously, exposure to these contaminants can  result in  both
carcinogenic and noncarcinogenic toxic effects. Extent of exposure and the
bioavailability of chemicals in the  waste and sludge will affect the potential for
adverse effects.  Public health and environmental hazards can result from releases
during  solid  waste and sludge treatment and disposal.
      Prevention and Mitigation Options:  Solid waste and  sludge residues from
recycling processes usually are landfilled or incinerated.  Because there  are no
completely satisfactory methods to dispose of these wastes, limiting the quantity
that must  be discarded is the most effective alternative.  Some communities have
begun to write contract clauses requiring waste haulers to  limit the percentage of
                                    5-49

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TABLE 5-1 6
Heavy Metal Concentrations in Deinking Sludges (ppm)
Municipal
heavy metal
Cadmium
Chromium
Copper
Lead
Manganese
Nickel
Zinc
Lowest
concentration
0
16.0
31.0
3.0
31.0
1.0
36.0
Highest
concentration
<0.02
118
400
210
880
25
1,000
Source:  Hoekstra, 1991.
                                  5-50

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residue per volume of recyclables processed.  Such agreements encourage
contractors to perform more careful sorting, which results in fewer residuals.
      To reduce glass residue discards, MRFs are being designed to include fewer
handling steps for glass containers.  At a large facility in Las Vegas, Nevada, glass
that has been sorted at the curbside is dumped from the truck directly into sorting
bins, which are delivered to the processor. This system not only limits the mixing
of glass types at the MRF, it also requires that each container be handled only once
when it is collected  at the curbside (Combs, 1991).
      Another modification that reduces the amount of broken glass is the
installation of wooden floors in glass-handling areas (Salimando,  1989). Recently
developed equipment (glass beneficiation systems) has been aimed at  purifying
glass residues to create a higher percentage of reusable product.
      In some cases, wastes are reclaimed because of the value of certain
constituents. For example, detinning sludges  are often  reused for their high alkali
content (Grayson and Echroth, 1980). Reuse of other wastes such as paper mill
sludges, which may contain heavy metals, can be more difficult.  Paper mill sludges
traditionally have been landfilled or incinerated; however, 58 percent of sludges
were landfarmed in  1990 (Diehn, 1991). Recently, landfarming has become a
popular sludge disposal method, but concerns about heavy metal concentrations
remain. Developing alternative uses for typical waste materials (e.g., the use of
mixed cullet in glasphalt).can reduce the quantity of residue that must be disposed
of.

5.17.  MICROBIOLOGIC HAZARDS
      Source Activity:   Microorganisms such as  bacteria, fungi, and viruses often
grow within recyclable containers or on paper products. A summary of source
activities is listed in  Table  5-17.  Newspapers  used in animal litter boxes provide a
growth medium for microbes. Infectious agents also can be present on hypodermic
needles that contaminate the recyclable waste stream.   Microbiologic agents are of
particular concern when recyclables are mixed with MSW  before sorting,  but
                                    5-51

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                               TABLE 5-17
                           Microbiologic Hazards
Type of
hazard
    Source activity
Prevention/mitigation
 Significance
  of hazard
Collection
and sorting

Public health
Occupational
Separation in the home
Drop-off centers
Buy-back centers


Curbside sorting
MRFs
Drop-off centers
Buy-back centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Public education
Frequency of
  collection and
  processing

Public education
Frequency of
  collection and
  processing
Personal protective
  equipment
Vehicle and
  equipment
  cleaning
Worker training
  (cleanliness)
Low
Medium
                                    5-52

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separated recyclables also provide suitable substrate for microorganisms.  The
public can be exposed to these hazards when dirty recyclables are stored  in the
home for extended periods of time.  Operations that increase the risk of worker
exposure to microbiologic hazards include commingled MSW and recyclable
collection, the use of the same vehicles to collect both MSW and recyclables, bag
breakers and other equipment that stir up contaminated materials and potentially
disperse microorganisms, and manual sorting operations that require workers to
handle recyclables and remove putrescible wastes.  Facilities that wash plastic
materials, however, report no significant bacterial problems  (personal
communication between TRC Environmental Corporation and Garry Thompson, M.
A. Industries, Inc., Peachtree City, GA, in July 1991).
      Hazard Type:  Although the public may be exposed to microorganisms on
recyclables, exposure potential appears to  be  greatest among workers. Individuals
may be exposed to microorganisms in aerosols, on  dust particles, or on objects
they contact.  Pathogenic microorganisms of concern include coliform bacteria
species such as Escherichia co/i and fungi such as Aspergillis (Pahren, 1987).  The
most common health problems associated with these pathogens include respiratory
infections, diarrhea, and skin diseases.  Contact dermatitis can occur from contact
with fungi.
      Worker illnesses have been reported at  indoor waste processing facilities
where microbial densities tend to be higher. A 1987 study evaluated dust and
biologic airborne contaminants at Danish waste processing plants and measured
"demonstrated endotoxins {poisonous substances produced  by bacteria) in excess
of recommended normal values for air content" (Malmros and Petersen, 1988).
Half the staff members at these facilities were found to  suffer from some type of
respiratory system ailment. Additional symptoms included flu-like symptoms,
fever, and eye and skin irritation.
      Prevention and Mitigation Options:   Teaching the public to wash containers
before recycling will reduce microbial growth.  Washing vehicles and other
processing equipment regularly also minimizes the build-up of microorganisms.
                                    5-53

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Frequent collection minimizes public exposure in the home.  Personal protective
equipment such as water-resistant gloves have been shown to effectively protect
workers (personal communication between TRC Environmental Corporation and
Pamela Harris, director of Loss Control Services for Browning Ferris International,
Houston, TX, on September 13, 1991).  Respiratory protection reduces
occupational inhalation exposures to airborne pathogens.

5.18.  PESTS
      Source Activity:  Pests such  as insects and rodents may be attracted  to
containers and other recyclables as  a food source or nesting medium. A summary
of the source activities is provided in Table 5-18. Pests are a concern when
recyclables are stockpiled in the home or at a recycling facility before collection or
processing.  Recyclables contaminated with food residues are particularly
susceptible to pest infestation. Home refuse containers with accumulated residues
have been shown to produce more than  1,000 fly larvae per week (Chanlett,
1979).
      Hazard Type:  Insects and  rodents represent both an occupational and
public health hazard.  Flies are contaminated with hundreds of species of
pathogenic microorganisms that can be transmitted to humans (Last and Wallace,
1992). Some culex mosquitoes are  wastewater breeders and will breed in dirty
water pools, including rainwater accumulated in stored cans and bottles and other
discarded items (Chanlett, 1979). Rats harbor the pathogens for leptospiras, rat-
bite fever, and salmonellosis (Chanlett, 1979).
      Insect bites usually present nuisance conditions such as localized  swelling,
itching, and minor pain. However, a hazard and common cause of fatalities from
insect bites—particularly bees and wasps—is a sensitivity  reaction.  Anaphylactic
shock from stings can include severe reactions by the circulatory, respiratory, and
central nervous systems, which may lead to death.
      Prevention and Mitigation Options:  Educating the public to  avoid mixing
garbage and recyclables and to thoroughly clean containers before storage or
                                    5-54

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                               TABLE 5-18
                            Hazards From Pests
Type of
hazard
    Source activity
Prevention/mitigation
 Significance
  of hazard
Collection and
sorting

Public health
Occupational
Separation in the home
Drop-off centers
Curbside sorting
MRFs
Drop-off centers
Buy-back centers
Front-end separation
  at transfer stations,
  landfills, waste-to-
  energy plants
Public education
Frequency of
  collection and
  processing

Public education
Frequency of
  collection and
  processing
Personal protective
  equipment
Vehicle  and
  equipment
  cleaning
Low
Low
                                   5-55

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collection reduces pest hazards.  Frequent and regular collection and processing
reduces excessive recyclable stockpiling, limiting pest habitats and food sources.
Pesticides also can be us.ed to eliminate rodent and insect pests, although their use
is discouraged because of their deleterious environmental effects.
                                     5-56

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                      6.  SUMMARY AND CONCLUSIONS

      This report presents an overview of the practices and processes used to
recycle municipal solid waste and the associated public health, occupational safety,
and environmental concerns. Aluminum, glass, paper, plastics, and steel and tin
recyclables are tracked through collecting, sorting, and processing.  Many safety
concerns identified are generic to the overall handling of MSW,  regardless of
whether the materials are recycled or whether the recycling program includes
simple community drop-off centers or automated systems with state-of-the-art
collection vehicles and sorting facilities. Other recycling hazards are specific to the
material or product type being recycled.
      Solid waste managements methods, including recycling, pose physical,
chemical, and biologic hazards to workers, the public, and the environment.
Workers typically encounter physical hazards when they handle recyclables during
the collection and sorting stages and also during material-specific processing.
Contact with sharp objects, moving parts, or flying or falling debris can cause
physical injury. Ergonomic injuries can result from poorly designed collection
vehicles or the repetitive motions required of workers  at sorting stations within
MRFs.  Traffic noise  is a safety concern when recycling programs increase the
number of vehicle trips.  Noise levels within some MRFs also are known to exceed
OSHA standards. Fires and explosions, although infrequent, are physical hazards
in addition to affecting property.
      Chemical hazards can result from airborne (gaseous and particulate),
waterborne, and sludge and solid releases at recycling facilities.  Postconsumer
recyclables can contain chemical residues or contaminants.   The chemical
composition of the recyclable itself, the coatings and paints applied to products
and packaging, or other additives and process chemicals can contribute to chemical
releases during processing.
      Microbes and pests present biologic hazards.  Microbiologic agents can enter
MSW directly as a result of consumers discarding contaminated materials such as
                                     6-1

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newspapers from pet litter boxes.  Container residues and recyclables composed of
materials that provide suitable substrate present indirect means for the introduction
of opportunistic microorganisms.  Rodents and insects are common pests
encountered at facilities handling MSW, regardless of whether the facilities are for
recycling.
      Preventive and mitigative options exist to control most hazards encountered
in the recycling industry.  Many specific hazards and their sources  (equipment or
activities) are  not unique to recycling and exist in other industries or  in the
collection and disposal of MSW by other options. Although existing  standards of
practice do not specifically target the recycling industry, Federal (OSHA, EPA),
state, and other standards apply to many practices and processes used in  recycling
and serve to reduce or prevent hazards.
      Pollution control technologies exist for most processing operations, but the
extent to which controls are used is difficult to quantify.  There are documented
cases in which failure or lack of control equipment has resulted in unacceptable
worker exposures (e.g., noise, fugitive dust). In addition, it is difficult to control
occupational hazards occurring at the initial material-handling stages  because some
manual sorting of recyclables is inevitable.  Advanced sorting technologies have
the potential to limit worker exposure to recyclable materials and their byproducts,
but as yet the technologies are not widely applied.
      Safety procedures, emission control devices, wastewater treatment  systems,
and responsible solid waste management practices reduce many of the public
health, occupational, and environmental hazards. In  addition, public  and worker
education is essential to  implementing a safe and successful program.
      The significance of hazards identified in this report is summarized  in Tables
6-1, 6-2, and  6-3.  Each table presents ratings for hazards that occur during
collection and sorting and material-specific processing. The overall processing of
recyclables appears to  contribute to increased occupational hazards because of
excessive worker contact through  handling and separation of recyclables.  The
types of occupational hazards appear to be reasonably similar between material
                                      6-2

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TABLE 6-1
Summary of Public Health Concerns
Public health concerns
Sharp objects
Ergonomic and lifting injuries
Fires and explosions
Flying and falling debris
Moving heavy machinery
Noise
Aesthetic impacts
Traffic
Process chemicals and container residues
Gaseous releases
Particulate releases
Waterborne releases
Solid waste and sludge
Microbiologic
Pests
Activities
Collection and
sorting
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Low
Material-specific
processing
NMS
NMS
NMS
NMS
NMS
NMS
NMS
NMS
NMS
Low
Low
Low
Low
Low
Low
NMS  = The hazard identified is not specific to any particular material.
                                      6-3

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TABLE 6-2
Summary of Occupational Safety Concerns
Safety concerns
Sharp objects
Ergonomic and lifting injuries
Fires and explosions
Flying and falling debris
Temperature and pressure extremes
Moving equipment and heavy machinery
Noise
Traffic
Process chemicals and container residues
Gaseous releases
Particulate releases
Microbiologic
Pests
Activities
Collection and
sorting
Medium
Medium
Medium
Medium
Low
Low
Medium
Low
Medium
Low
Medium
Low
Low
Material-specific
processing
Low
Low
Low
Medium
Low
Low
Low
NMS
Medium
Low
Low
NMS
NMS
NMS  = The hazard identified is not specific to any particular material.
                                       6-4

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TABLE 6-3
Summary of Environmental Safety Concerns
Environmental concerns
Fires and explosions
Traffic
Gaseous releases
Particulate releases
Waterborne releases
Solid waste and sludge
Activities
Collection and
sorting
Low
Low
Low
Low
Low
Low
Material-specific
processing
Low
NMS
Low
Low
Low
Low
NMS  = The hazard identified is not specific to any particular material.
                                       6-5

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types. Available data suggest that the number of hazards potentially affecting
public health and the environment is smaller than that potentially affecting workers.
The separation and sorting of recyclables in the home is a popular collection
strategy.  However, programs that require the public to handle and store
recyclables, especially containers and their contents, increase public health
hazards. Moreover, the additional preparation of recyclables that is required to
meet  market specifications generates solid  discards and cleaning byproducts (e.g.,
material rejects, detergents, effluents).
      Generally, recycling increases the number of vehicle trips  necessary to
collect MSW. Training and new truck designs can be used effectively to reduce
certain hazards and to increase efficiency.
      Lack of data to characterize recycling hazards results  from the newness of
recycling programs and certain processes, the proprietary nature of technologies,
and chemical formulations.  Occupational health studies and databases on
workplace hazards will permit the significance of occupation hazards to be
assessed. More data to characterize and quantify  emissions and effluents leaving
recycling facilities are required to estimate the magnitude of many public health and
environmental hazards.
                                      6-6

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                      7.  ADDITIONAL RESEARCH NEEDS


      Insufficient data exist to fully characterize the nature and significance of

MSW recycling hazards.  The lack of data is caused in part by recent increases in

recycling activities and innovations in recycling technologies and the corresponding

lag in time required to conduct studies and collect information. The following

research activities would assist in filling key data gaps.
      •   Characterize the air quality within recycling facilities (e.g., MRFs) and
          emissions from these facilities.

      •   Study pollution and safety control devices and systems to determine the
          frequency with which they are being implemented and their applicability,
          effectiveness, and  cost to the industry.

      •   Study the ergonomic effects of various practices and processes in
          recycling programs. For example, evaluate curbside collection versus
          drop-off centers or manual versus automated sorting stations within
          MRFs.

      •   Characterize and quantify wastewater discharges from various types of
          recycling facilities to ambient waters.

      •   Evaluate the impacts of waste-handling facility capacity on the
          magnitude of facility-related activities.

      •   Conduct an epi.demiologic study of workers with acute and chronic
          exposures attributable to recycling activities.

      •   Monitor changes in health biomarkers and the associated health status of
          workers.

      •   Identify sources of microbial hazards associated with recycling facilities,
          especially mixed waste processing facilities.

      •   Conduct a quantitative risk assessment for workers with microbial
          exposures.

      •   Identify inhalation and dermal risks attributable to infectious agents in
          MSW.
                                      7-1

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Develop databases of occupational injuries and chemical exposures in
recycling.
                           7-2

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                             8.  REFERENCES


Chapter 1.  INTRODUCTION

Roumpf, J.  (1992) The MRF industry: an update. Resource Recycling. May 1992.

Smith, S. J.; Hopkins, K. M. (1992) Curbside recycling in the top 50 cities.
Resource Recycling. March 1992.


Chapter 3.  RECYCLING AS A MUNICIPAL SOLID WASTE MANAGEMENT OPTION

U.S. EPA. (1989) The solid waste dilemma: an agenda for action. Office of Solid
Waste and Emergency Response. EPA/530-SW-89-019.

U.S. EPA. (1992) Characterization of municipal solid waste in the United States:
1992 update. Office of Solid Waste and Emergency Response. EPA/530-R-92-019.


Chapter 4.  OVERVIEW OF RECYCLING PRACTICES AND PROCESSES

Amoth, A.;  Lee, J., Jr.;  Seamons, R. (1991) Anaerobic treatment of secondary
fiber mill effluents. Environmental conference. Technical Association of Pulp and
Paper Industry; Atlanta,  GA.

Andrews, W.  (1990) Contaminant removal, timely use vital to quality ONP fiber
yield. Pulp & Paper. 64(9): 126-127.

Barney, J. (1987) Summary of dioxin data for paper mill sludges. U.S.
Environmental Protection Agency, Region V.

Basta, N., Gilges, K.; Ushio, S. (1991) Recycling everything: part 3, paper
recycling's new look. Chem Eng. 98(3):  46-48F.

Broeren, L.  (1989) New  technology, economic benefits give boost to secondary
fiber use. Pulp & Paper.  63(11): 69-74.

Brydson, J. A. (1990) Handbook for plastics processors. Oxford, England:
Heinemann  Newnes.

Carlin, J. F. (1989) Minerals yearbook 1989. U.S. Department of Interior, Bureau of
Mines.
                                   8-1

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Carr, W. (1991) New trends in deinking technology. Tappi Journal. February: 127-
132.

Carroll, R; Gajda, T. (1990) Mills considering new deinking line must answer
environmental questions. Pulp & Paper. 64(9): 201-205.

CBNS. (1988) Development and pilot test of an intensive  municipal solid waste
recycling system for the town of East Hampton. Center for Biology of Natural
Systems, Queens College (CUNY), Flushing, New York.

Combs, S. (1991) Silver State Disposal Service, Inc. Waste Age. 22(7): 54.

Copperthite, G. (1989) Rigid container recycling status and impact on the rigid
container industry. U.S. Department of Commerce, Office of Metals and
Commodities, Iron and Steel Division, Basic Industrial Sector.

Egosi, N.; Romeo, E. (1991) Meeting high expectations through MRF design. Solid
Waste & Power. June: 48-53.

Enviro Control, Inc.  (1978) Engineering control technology assessment for the
plastic and resin industry.  Prepared for U.S. Department  of Health, Education, and
Welfare by Enviro Control, Inc., Rockville, MD.

Franklin Associates, Ltd. (1990) Characterization  of municipal solid waste in the
United States, 1960 to 2010. Prepared for U.S. Environmental Protection Agency,
Municipal Solid Waste Program.

Glenn, J. (1990) New look in  materials processing. BioCycle. January.

Grayson, M.; Echroth, D.,  eds. (1980) Kirk-Othmer's encyclopedia of chemical
technology, 3d ed. New York, NY: Wiley Interscience Publication, John Wiley and
Sons.

Heenan, W. M. (1991) The recycling magnet. Steel Can Recycling Institute (SCRI).

Henstock, M. E. (1988) Design for recyclability. The Institute of Metals. Brookfield,
VT.

Horacek, R. (1983)  Recycling of papermaking fibers. Technical Association of The
Pulp and Paper Industry, Inc., Secondary Fiber Pulping Committee of the Pulp
Manufacture Division, Atlanta, GA.

J.A.S. (1988) Plant vendors are pushing recycling! Waste Age. 19(7): 127-129.
                                     8-2

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Katz, S. (1991) Preparing for the new wave of recycling facilities. Solid Waste &
Power. August : 54-60.

Keller, J. (1989) Rhode Island learns at the curb. Waste Age. 20(7): 56-62.

Koch, P.; Ross, M. (1990) Separation  of PET and aluminum. Presented to the
Society of Plastics Engineers, ANTEC; Pennsylvania State University at Erie,
Behrend College; p. 1457-1458.

Magnuson, A.  (1991) Bag-based system helps keep recycler's blues away. World
Wastes. 34(7): 36-40.

Meade, K. (1991) Recycled glass grows greener. Waste Age. 22(9): 30-32.

Modern Plastics.  (1988) Wet granulation cleans up film scrap in complete recycling
system. May: 17.

Morgan, D. (1987) Everything you never knew about magnetic separation. Waste
Age. 18(7): 110-112.

MSW Management. (1991) New paper recycler to use "steam explosion" process.
Industry update.  MSW (Municipal Solid Waste) Manag Mag. March/April: 16.

Patrick, K. (1990) Legislation pushing paper industry despite limited recycling know
how. Pulp & Paper. 64(9): 161-163.

Peluso, R. (1989) Transfer stations can recycle, too! Waste Age. 20(7): 125-126.

Process Engineering. (1989) Recycling domestic waste: a processing challenge.
Spring: 44-45.

Radian Corporation. (1985) Industrial  process profiles for environmental use.
Chapter 10, The plastics and resins production industry. Prepared for the U.S.
Environmental Protection Agency by the Radian Corporation, McLean, VA.

Salas,  M.; Johnson, M.; Malloy, R.; Chen, S.  (1990) A study on the effect of fillers
and reinforcements on the properties of post consumer plastic waste profiles.
Presented to the Society of Plastics Engineers, ANTEC; Department of Plastics
Engineering, University of Lowell.

Schriver, K. (1990) Mill chemistry  must be considered before making deink line
decision. Pulp & Paper. 64(9): 76-79.
                                    8-3

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Schut, J. H. (1990) A barrage of news from the recycling front. Plastics
Technology. July: 109.

Sixour, V. (1991) Environmental consideration in the design and siting of a
secondary fiber mill. Environmental conference; Technical Association of Pulp and
Paper Industry; Atlanta, GA.

Stinson, S. (1991) Steam process  recycles variety of paper waste. Chemical &
Engineering News. 69(1): 22.

Summers, J. W.; Mikofalvy, B. K.; Wooton, G. V.; Sell, W. A. (1990) Recycling
vinyl packaging materials from the city of Akron municipal wastes. Presented to the
Society of Plastics Engineers, ANTEC; BF Goodrich,  Geon Vinyl Division.

TRC Environmental Consultants, Inc. (1978) Screening study on feasibility of
standards of performance for secondary aluminum manufacturing. Prepared for
U.S. Environmental Protection Agency, Research Triangle Park, NC.

U.S. EPA. (1977a) Control of volatile organic emissions from existing stationary
sources. V. II: Surface coating of cans, coils, paper, fabrics, automobiles, and fight-
duty trucks. Research Triangle Park, NC. EPA 450/2-77/008.

U.S. EPA. (1977b) A technical, environmental, and economic evaluation of the
glass recovery plant at Franklin, Ohio. Prepared by Systems Technology
Corporation. Solid Waste Management Programs.

U.S. EPA. (1979) Summary report on emissions from the glass manufacturing
industry. Prepared by Batelle Columbus Labs. EPA-600/2-79-101.

U.S. EPA. (1980a) Beverage can surface coating industry - background information
for proposed standards. Draft EIS.  EPA-450/3-80-036a.

U.S. EPA. (1980b) Revised standards for basic oxygen process furnaces -
background information for proposed standards. Preliminary draft. Office  of Air
Quality Planning and Standards. EPA-450/3-82-005b.

U.S. EPA. (1981) Resource recovery from plastic and glass wastes. Prepared by
Municipal Environmental Research  Laboratory.

U.S. EPA. (1982) Development document for effluent limitations guidelines and
standards for iron and steel manufacturing, point source category: v. Ill, Final. EPA-
440/1-82/024.
                                    8-4

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U.S. EPA. (1989) Development document for effluent limitations guidelines and
standards for the nonferrous metals manufacturing point source category: v. 2.
Washington, DC. EPA/440/1-89/019.2.

U.S. EPA. (1990) Methods to manage and control plastic wastes, report to
Congress. Office of Solid Waste.

U.S. EPA (1991) Handbook: material recovery facilities for municipal solid waste.
Office of Research and Development. EPA/625/6-91/031.

U.S. EPA. (1992) Control of VOC emissions from ink and paint manufacturing
processes. Office of Air Quality Planning and Standards. EPA-450/3-92-013.

Watson, T. (1989) A force in detinning. Resource Recycling. January/February: 18.
Chapter 5.   POTENTIAL HAZARDS AND MITIGATION OPTIONS

Allen, N. (1983) Degradation and stabilization of polyolefins. London and New
York, NY: Applied Science Publishers.

Amoth, A.; Lee, J., Jr.; Seamons, R. (1991) Anaerobic treatment of secondary
fiber mill effluents. Environmental conference; Technical Association of Pulp and
Paper Industry; Atlanta, GA.

Brighton, C.; Pritchard, A. G.; Skinner, G. A. (1979) Styrene polymers: technology
and environmental aspects. London: Applied Science Publishers,  Ltd.

Chanlett, E. (1979) Environmental protection, 2nd ed. New York: McGraw-Hill
Book Company.

Clayton,  G.; Clayton, F., eds. (1991) Patty's Industrial Hygiene and Toxicology, 4th
ed., v. I, parts A and B. New York: John Wiley and Sons, Inc.

Combs, S.  (1991) Building safety into MRF design. Waste Age. 22(8): 95-96.

Combs, S.  (1992) Caution: OSHA hits MRFs with inspections and fines. Waste
Age. 23(4): 85-92.

Council on  Environmental Quality. (1987-1988) Environmental quality. Annual
report.

Dessoff,  A. (1991) Planning safe MRFs. Waste Age. 22(5): 79-80.
                                    8-5

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Diaz, L.; Golueke, C.; Savage, G. (1981) Resource recovery from municipal solid
wastes: v. II. Boca Raton, FL: CRC Press, Inc.

Diehn, K. (1991) Recycling a deinking mill's waste through landfarming. TAPPI
Proceedings: 1991 Environmental  Conference; p. 739-746.

Engineering  News Record. (1990)  Explosion raises issue on confining shredders.
April 26: 22.

Gibbs, M. L. (1990) An evaluation of post-consumer recycled high density
polyethylenes in various mold applications. Presented to the Society of Plastics
Engineers, ANTEC; Quantum Chemical Corporation.

Glenn, J. (1989) Materials recovery facilities move ahead. BioCycle. May: 66-70.

Glenn, J. (1990) New look in materials processing. BioCycle. January.

Grayson, M.; Echroth, D., ed..(1980) Kirk-Othmer's encyclopedia of chemical
technology,  3d  ed., v. 19. New York, NY: Wiley Interscience Publication,  John
Wiley and Sons.

Hernandez, R.;  Lai, C.; Selke, S.; Kirloskar, M. (1988) Butyric acid retention of
post-consumer  milk bottles. Presented to the Society of Plastics Engineers, ANTEC;
School of Packaging, Michigan State University.

Hoekstra, L. (1991) Paper recycling creates its own set of environmental problems.
American Papermaker. April: 30-34.

Horacek, R.  (1983) Recycling of papermaking fibers. Technical Association of The
Pulp and Paper  Industry, Inc., Secondary Fiber Pulping  Committee of the Pulp
Manufacture Division, Atlanta, GA.

Keller, J. (1989) Rhode Island learns at the curb. Waste Age. 20(7): 56-62.

Keller, J. (1992) The nitty-gritty of glass recycling: reducing glass breakage in
collection gnd processing. Resource Recycling.  February: 46-55.

Kohn, D. (1989) Plant explosion kills worker. Engineering News Record. October:
16.

Last, J.; Wallace, R., eds. (1992)  Maxcy-Rosenau-Last public health and preventive
medicine, 13th  ed. Norwalk, CT: Appleton and  Lange.
                                     8-6

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Levy, B.; Wegman, D., eds. (1988) Occupational health, recognizing and
preventing work-related disease. Boston/Toronto: Little, Brown and Company.

Malmros, P.; Petersen, C. (1988) The working conditions at Danish sorting plants.
International Solid Waste Conference; September.

Mansdorf, S.; Glembiewski, M. A.; Fletcher, M. W. (1981) Industrial hygiene
characterization and aerobiology of resource recovery systems. Midwest Research
Institute, Kansas City, MO, for the National Institute of Occupational Safety and
Health.

Martin, G. (1991) Personal communication between TRC Environmental
Corporation  and Gordon Martin of the Wellesley, MA, Department of Public Works
on September 5, 1991.

Nollet, A.  (1989a) Designing shredder plants that don't go up in smoke. Manag
World Wastes. June: 50-51.

Nollet, A.  (1989b) How to prevent shredder plant explosions.  Management of
World Wastes. July: 56-60.

O'Brien, J. (1991) Integrated collection: the key to economical curbside collection.
Solid Waste  & Power. August: 62-70.

Pahren, H. R. (1987) Microorganisms in municipal solid waste and public health
implications. CRC Critical Review on Environmental Control. 17(3): 187.

Powell, J. (1992) Implementing a MRF project: some helpful hints. Resource
Recycling. March: 44-51.

Radian Corporation.  (1985) Industrial process profiles for environmental use.
Chapter 10,  The plastics and resins production industry. Prepared for the U.S.
Environmental Protection Agency by the Radian Corporation, McLean, VA.

Salimando, J. (1989) Rhode Island's state-of-art plant. Waste  Age. 20(9):  126-
130.

Sittig, M. (1991) Handbook of toxic and hazardous chemicals  and carcinogens, 3rd
ed., v. I and  II. Park Ridge, New Jersey: Noyes Publications.

Sixour, V. (1991) Environmental consideration in the design and siting of a
secondary fiber mill. Environmental conference; Technical Association of Pulp and
Paper Industry, Atlanta, GA.
                                    8-7

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Smith, S.; Hopkins, K. (1992) Curbside recycling in the top 50 cities. Resource
Recycling. March: 101-104.

Soiomon-Hess, J. (1991) Recycling may be hazardous to workers' health.
Recycling Today.  April: 68-72.

STC. (1979) A technical and economic evaluation of the project in Baltimore, MD;
v. II. Prepared for the Environmental Protection Agency by Systems Technology
Corporation, Xenia, OH.

Summers, J. W.; Mikofalvy, B. K.; Wooton, G. V.; Sell, W.  A. (1990) Recycling
vinyl packaging materials from the city of Akron municipal wastes. Presented to the
Society of Plastics Engineers, ANTEC; BF Goodrich, Geon Vinyl Division.

Toensmeir, P. (1987) Granulators are coming into the mainstream at affordable
prices. Modern Plastics. November: 81-83.

UPI. (1989) Man falls to death in shredding machine.  United Press International.
From Lexis/Nexis information services, Regional News Service on April 13, 1989.

U.S. Department of Health and Human Services. (1990) NIOSH Pocket Guide to
Chemical Hazards.

U.S. EPA. (1977)  A technical, environmental, and economic evaluation of the glass
recovery plant at Franklin, Ohio. Prepared by Systems Technology Corporation.
Solid Waste Management Programs.

Usherson, J. (1992) Recycled paper and sludge. Resource Recycling. March: 95-
100.

Visalli, J. R. (1989) The similarity of environmental impacts from all methods of
managing solid wastes. Albany, NY: New York State Energy Research and
Development Authority.

Wissler, G. E. (1990) Commingled  plastics based on recycled soft drink bottles.
Presented to the Society of Plastics Engineers, ANTEC; Exxon Chemical Company.

Zenz,  C., ed. (1988) Occupational  medicine, principles and practical applications,
2nd ed. Chicago, IL: Year Book Medical Publishers, Inc.
Appendix B.  COMMON RECYCLABLES:  AMOUNTS AND MARKETS

ALCOA. (1991) Recycling: it's nature's way. Knoxville, TN.
                                    8-8

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Amoth, A.; Lee, J., Jr.; Seamons, R. (1991) Anaerobic treatment of secondary
fiber mill effluents. Environmental conference. Technical Association of Pulp and
Paper Industry; Atlanta, GA.

Apotheker, S. (1991) Glass containers: how recyclable will they be in the 1990s?
Resource Recycling. June.

Bennett, R. A. (1989) Market research on plastics recycling. Technical Report #31.
Center for Plastics Recycling Research, Rutgers University, NJ; February 13,  1989.

Copperthite, G. (1989) Rigid container recycling status and impact on the rigid
container industry. U.S. Department of Commerce, Office of Metals and
Commodities, Iron and Steel Division, Basic Industrial Sector.

Franklin Associates, Ltd. (1990) Characteristics of municipal solid waste in the
United States, 1960 to 2010. Final draft.

Goldberg, D.  (1990) It's a small,  small world. Waste Age. 21(8):  158-160.

Grayson, M.; Echroth, D., eds. (1980) Kirk-Othmer's encyclopedia of chemical
technology, 3d ed., v. 19. New York, NY: Wiley Interscience Publication, John
Wiley and Sons.

Heenan, W.M. (1991) The recycling magnet. Steel Can Recycling Institute (SCRI).

ISRI (Institute of Scrap Recycling Industries),  Inc. (1990a) Recycling: nonferrous
scrap metals. Washington, DC.

ISRI (Institute for Scrap Recycling Industries), Inc. (1990b) Facts: 1989. Yearbook.
Washington,  DC: ISRI, Inc.

Misner, M. (1991)  Six months of recyclable prices show market instability. Waste
Age. 22(9): 36-44.

Modern Plastics. (1991) Resin sales rise to 61.5 billion Ib (1990 resin sales and
markets summary). January: 113.

Schottman, F. J. (1985) Iron and steel, a chapter from mineral facts and problems.
Bureau of Mines, U.S. Department of the Interior.

SPI. (1988) Society of Plastics Industry. Washington, DC.

U.S.  EPA. (1979) Summary report on emissions from the glass manufacturing
industry. Prepared by Battelle Columbus Labs. EPA-600/2-79-101.
                                    8-9

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U.S. EPA. (1989) The solid waste dilemma: an agenda for action. Office of Solid
Waste and Emergency Response. EPA/530-SW-89-019.

U.S. EPA. (1990) Characterization of municipal solid waste in the United States:
1990 update. Office of Solid Waste and Emergency Response. EPA/530-SW-90-
042A.
Appendix C.  FEDERAL, STATE, AND MUNICIPAL INVOLVEMENT

Apotheker, S. (1992) State and provincial recycling organizations get busy.
Resource Recycling. May 1992.

Glenn, J.;  Riggle, D. (1991) The state of garbage in America. Biocycle. 32(5):
30-35.

NWSMA. (1989) Special report. Recycling in the states update.

Ramay, S. (1992) Southern states ban together to improve recycling. World
Wastes. June 1992.

U.S. Conference of Mayors. (1991) Profiles of the nation's resourceful cities.
Washington, D.C.

U.S. EPA.  (1989) The solid waste dilemma: an agenda for action. Office of Solid
Waste and Emergency Response. EPA/530-SW-89-019.
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                                 APPENDIX A

                                 GLOSSARY


      Recycling is a rapidly evolving  industry in which numerous technical terms

are used, many with several meanings or interpretations.  The following list of

definitions is provided to assist the reader of this report.


Additive - A substance added to another material (e.g., plastic) in relatively small
amounts to impart or improve desirable properties or suppress undesirable
properties.

Alloy - A mixture or solid solution of two  or more metals.

Baler - A machine used to compress recyclables into bundles to reduce volume.

Bottle bill - A law requiring deposits on beverage containers.

Buy-back facilities - A facility where consumers bring recyclables for payment.

Charge - The quantity of a material to be  used  or consumed that  is loaded at one
time into an apparatus (e.g., furnace).

Commingled - Two or more recyclable materials or objects mixed together.

Gullet - Broken glass used to manufacture new glass.

Curbside collection - A MSW management program option in which materials are
collected at the curb and brought to processing facilities,

Drop-off facilities - A collection or processing facility to which consumers bring
recyclables.

Dross - The solid layer that forms on  the surface of a molten or melting metal
largely as a result of oxidization or the rising of contaminants and impurities to the
surface.

Ferrous - Types of metal containing iron.

Flux - A substance used to promote fusion of metals by removing impurities or
contaminants.
                                     A-1

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Hazard - A source or condition that can create or increase the potential for danger.

Incinerator - A facility in which combustion of solid waste takes place.

Landfill - An engineered structure designed to isolate waste from man and minimize
environmental risk.

Municipal  solid waste - A mixture of household, commercial, and institutional solid
waste.

Nonferrous - Types of metal containing no iron (e.g., aluminum).

Plastic - Any complex synthetic or natural  organic compound formed by
polymerization.

Polymer -  Any of numerous natural or synthetic compounds consisting of linked
molecules. The words plastic and polymer are used interchangeably.

Recover -  The process to regain useable material from waste.

Recyclable - A component of municipal solid  waste that can be collected and
reused or  processed for use in new products.

Recycling  - The process during which an item is subjected to physical or chemical
alterations between the time it is separated from waste and processed into its final
form.

Resin - A class of solid or semisolid organic substances derived from plants or
synthetic materials.

Resource recovery facility or waste-to-energy plant - A facility that accepts and
combusts  municipal solid waste as a  means of generating energy.

Reuse -  An activity in which a material is subjected to small or no alterations in its
physical form and is employed in the  same function for which it was originally
designed or built.

Risk - The quantitative estimate of injury, disease, or death under specific
circumstances.

Scrap - Fragments or small  pieces of  recyclables (generally refers to metals).

Separation - Segregation of recyclables from  municipal solid waste.
                                     A-2

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Slag - A substance that floats on molten metal during refining, protects the metal
from oxidation, and removes contaminants.

Smelting - Purifying or separating alloys or ores by melting.

Sort - To manually or automatically select specific recyclable materials and place
them into homogeneous material streams.

Trommel screen - A large, rotating cylindrical screen that is  used in MRFs and
paper sorting facilities to  remove small  and heavy contaminants (e.g., sand,  rocks,
paper clips) from a material stream.
                                     A-3

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                                APPENDIX B
             COMMON RECYCLABLES:   AMOUNTS AND MARKETS

INTRODUCTION
      Aluminum, glass, paper, plastics, and steel and tin represent a large
percentage of the MSW generated in the United States.  In 1988, these recyclables
accounted for approximately 63 percent (113 million tons) of the MSW generated
(Table B-1).  A report by Franklin Associates (1990) states that in 1988, 19.5
percent (22.3 million tons) of recyclables generated, 12.4 percent of total MSW,
was recovered. Table B-1  lists the material-specific recovery rates.  The remainder
was landfilled or incinerated.  Recyclables that were disposed of in landfills
accounted for 68 percent of landfill volume. The 1988 recycling rate (12.4
percent) was nearly twice the 1960 rate of 7 percent. It is estimated that recovery
rates will approach 30 percent by the year 2000 (Franklin Associates,  1990).
Given recovery rate increases, markets must expand to absorb recovered materials.
To date, however,  market growth for recyclables has not kept pace with recycling
rates. As states continue to pass legislation mandating recycling (see  Appendix C),
the supply of recyclables will continue to increase. Although some market
development has occurred,  recyclable markets are weak for some materials.  This
creates supply excesses that lower the market prices paid for recyclables, making
their collection less desirable.

ALUMINUM  AMOUNTS AND MARKETS
Amounts
      Aluminum has many commercial applications, including beverage and other
containers, foil, closures, siding, window frames, roofing, mobile home awnings
and canopies, heating and ventilation applications, curtain walls, copper and
aluminum radiators, and appliances.  In 1988,  more than 4.3 million tons of
aluminum was produced, and an additional 2.4 million tons of scrap aluminum was
reused.
                                    B-1

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TABLE B-1
Materials Recovery From Municipal Solid Waste, 1988

Paper and paperboard
Glass
Weight
generated
(in millions
of tons)
71.8
12.5
Weight
recovered
(in millions
of tons)
18.4
1.5
Percent
recovered
of each
material
25.6
12.0
Discards
(in millions
of tons)
53.4
11.0
Metals
Ferrous
Aluminum
Other nonferrous
Total metals
Rubber and leather
Textiles
Wood
Other
Total nonfood product
wastes
11.6
2.5
1.1
15.3
4.6
3.9
6.5
3.1
132.1
0.7
0.8
0.7
2.2
0.1
0.0
0.0
0.7
23.1
5.8
31.7
65.1
14.6
2.3
0.6
0.0
21.7
17.5
10.9
1.7
0.4
13.0
4.5
3.9
6.5
3.1
109.6
Other wastes
Food wastes
Yard wastes
Miscellaneous
Inorganic wastes
Total other wastes
Total MSW
13.2
31.6
2.7

47.5
179.5
0.0
0.5
0.0

0.5
23.4
0.0
1.6
0.0

1.1
13.1
13.2
31.6
2.7

47.5
157.1
Source:  U.S. EPA, 1990.
                                 B-2

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      Aluminum recycling is widespread because of several factors. Deposit laws
 and dealers who purchase aluminum scrap provide an incentive for the public to
 recycle.  Aluminum manufacturers prefer recycled aluminum because less than 5
 percent of the energy required to make aluminum from bauxite (the principal
 aluminum ore) is used to recycle aluminum (Copperthite, 1989; ISRI, 1990a,b;
 ALCOA,  1991).
      Although aluminum has many applications, the only items recycled in
 significant quantities from municipal solid waste are used beverage cans (UBC) and
 foil and closures (Franklin Associates, 1990). UBC comprises more than 90
 percent of all aluminum recovered from municipal solid waste. Table B-2 shows
 that in 1988, 55 percent of beverage cans and 5 percent of foil and closures were
 recovered from MSW.

 Markets
      The recycling of UBC is a  closed loop because its predominant market is new
 aluminum beverage containers.  Although aluminum is not plagued by the chronic
 oversupply problems of other recyclables,  recent increases in supply have
 exceeded the capacity of remelting mills (Misner, 1991).  UBC prices are more
 dependent on the worldwide price of virgin aluminum ingot than their own supply
 and demand because ingot prices reflect the supply and demand atmosphere for
 aluminum-can sheet that is produced from UBC (Misner, 1991).

 GLASS AMOUNTS AND  MARKETS
Amounts
      Postconsumer glass can be classified irito functional groups depending on
the method used to form it.  Three groups, container glass (bottles and jars), flat
glass (window glass,  plate glass, float glass, tempered glass, and'laminated glass),
and pressed and blown glass (ornamental glass and stemware), constitute virtually
all glass produced (U.S. EPA, 1979). As of 1988, 6.9 percent (12.5 million tons)
                                    B-3

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TABLE B-2
Generation and Recycling of Aluminum Products in MSW, 1988
Product category
Major appliances
Furniture and
furnishings
Miscellaneous
durables
Miscellaneous
nondurables
Beverage cans
Other cans
Foil and closures
Total
Weight
generated (in
thousand of
tons)
107
89
280
240
1,439
67
324
2,546
Weight
recovered (in
thousand of
tons)
0
0
0
0
791
0
16
807
Percent
recovered
0
0
0
0
55
0
5
32
Discards
(in thousands
of tons)
107
89
280
240
648
67
308
1,739
Source:  Franklin Associates, Ltd., 1990.
                                     B-4

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  of all MSW generated in the United States consisted of glass products, 92 percent
  of which was container glass  (Table B-3).
        Nearly 100 percent of the glass recycled from MSW was container glass.
  Plate glass does not provide a consistent market for recyclers, and little is recycled
  because of the intended  durability of the product.  Pressed and blown glass also
  generally is formed into items  considered to be "durable goods."
        The  most common types of glass are soda-lime, borosilicate, lead silicate,
  and  opal. Approximately 77 percent of all glass manufactured is soda-lime glass,
  which is used exclusively in the production of food  and beverage containers
  because of the ease and efficiency with which it is  produced.  Three colors of
  soda-lime glass, clear (flint), green, and amber, are  commonly produced and
  recycled. Green and amber glass are produced by adding minerals such as
^chromium trioxide, iron oxide,  and cupric oxide for green glass and sodium sulfide
  for amber glass to a flint batch (Grayson and Echroth, 1980).  Recyclers generally
  segregate by color because clear glass can be used  in any batch, whereas colored
  glass generally is used to produce  recycled products in a  specific color.

  Markets
       The major market for recycled  glass (cullet) is glass container manufacturers,
 which receive approximately 70 percent of the cullet processed in the United
 States. They maintain strict specifications regarding the cullet color and the
 amount of contaminants present.  In  general,  only a small amount of green or
 amber glass can be added to a batch of flint glass.  In the same regard,
 manufacturers regulate the amount of off-specification glass in green  and amber
 batches.
       Although glass container manufacturers have  promoted their products as
 100 percent recyclable, the current supply created by proliferating collection
 programs is far exceeding domestic furnace capacity.  In addition,  relatively high
 transportation costs associated with cullet, given its high weight-to-volume ratio,
 may make export of the material unprofitable.  Green glass imported from Canada
                                      B-5

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TABLE B-3
Generation and Recycling of Glass in MSW, 1 988
Product
category
Durable
goods8
Weight
generated (in
millions of
tons)
1.2
Weight
recovered (in
millions of
tons)
Negligible
Percent
recovered
Negligible
Discards (in
millions of
tons)
1.2
Containers and packaging
Beer and soft
drink bottles
Wine and
liquor bottles
Food and
other bottles
and jars
Total glass
containers
Total glass
5.4
2.0
3.9
11.3
12.5
1.1
0.1
0.3
1.5
1.5
20.0
5.0
7.7
13.3
12.0
4.3
1.9
3.6
9.8
11.0
aGlass as a component of appliances, furniture, consumer electronics, etc.




Source: Franklin Associates Ltd., 1990.
                                     B-6

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is not taken back by the only manufacturer in that country, Consumers Glass,
because it feels the supply of green bottles to Canadian bottlers by U.S.
manufacturers creates a balanced net flow of green glass across the border
(Apotheker, 1991; personal communication between TRC Environmental
Corporation and Steve Apotheker, journalist, Resource Recycling Magazine, on
August 14, 1991).
      Fiberglass insulation and sandblasting material represent new markets for
green and mixed cullet.  Although the fiberglass industry produces 1.4 million tons
of insulation per year, the market dislocation for green and mixed-color cullet
probably meets or exceeds that entire quantity (Apotheker, 1991; personal
communication between TRC Environmental Corporation and Steve Apotheker,
journalist, Resource Recycling Magazine, on August 14, 1991).  One industry
representative estimates that the sandblasting market could absorb about 200,000
tons of cullet annually, although only about 10,000 tons are absorbed currently
(personal communication between TRC Environmental Corporation and Roger
Hecht, vice president, Bassichi's Company, on July 31, 1991).

PAPER AMOUNTS AND MARKETS
Amounts
      Wastepaper grades have been defined by the U.S. Bureau of Census into five
major grades:  old newspaper (ONP), mixed paper (MP), old corrugated containers
(OCC), high-grade deinking (HGD), and pulp-substitutes (PS) (Amoth  et al., 1991).
PS are basically in-plant scrap and require  little or no preparation aside from
repulping before being used as a fiber source.  ONP, MP, OCC, and HGD may
require cleaning and deinking, but they are still valuable sources of secondary
fibers.
      The major source categories of paper in MSW include corrugated boxes,
newspapers, office paper, and books and magazines. Of the 71.8 million tons of
paper waste generated in 1988, these items accounted for 49 million tons. These
items also accounted for the bulk of the paper that was recycled. Table B-4 lists
                                    B-7

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TABLE B-4
Generation and Recycling of Paper and Paperboard in MSW, 1988

Weight
generated
(in millions
of tons)
Weight
recovered
(in millions
of tons)
Percent
recycled
Discards
(in millions
of tons)
Nondurable goods
Newspaper
Books and magazines
Office papers
Commercial printing
Tissue paper and towels
Paper plates and cups
Other nonpackaging
paper8
Total paper and
paperboard nondurable
goods
13.3
5.3
7.3
4.1
3.0
0.7
5.2
38.9
4.4
0.7
1.6
0.6
Negligible
Negligible
Negligible
7.4
33.3
13.2
22.5
14.6
Negligible
Negligible
Negligible
18.9
8.9
4.6
5.7
3.5
Negligible
Negligible
Negligible
31.5
Containers and packaging
Corrugated boxes
Milk cartons
Folding cartons
Other paperboard
packaging
Bags and sacks
Wrapping papers
23.1
0.5
4.4
0.3
2.9
0.1
10.5
Negligible
0.3
Negligible
0.2
Negligible
45.4
Negligible
7.7
Negligible
7.0
Negligible
12.6
Negligible
4.1
Negligible
2.7
Negligible
B-8

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TABLE B-4 (continued)

Other paper packaging
Total paper and
paperboard containers
and packaging
Total paper and
paperboard
Weight
generated
(in millions
of tons)
1.5
32.9
71.8
Weight
recovered
(in millions
of tons)
Negligible
11.0
18.4
Percent
recycled
Negligible
33.5
25.6
Discard (in
millions of
tons)
Negligible
21.9
53.4
Includes tissue in disposable diapers, paper in games and novelties, posters, tags,
 cards, etc.
X"
Source:  Franklin Associates, Ltd., 1990.
                                      B-9

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the various constituents of waste paper in 1988 and the extent to which they were
recycled.

Markets
      Historically, the use of recycled fibers, or secondary fibers, in the production
of new paper and paper products has been common practice. The contribution of
secondary fibers to  paper production has increased steadily to constitute
approximately 25 percent of new paper production in 1988 (Franklin Associates,
1990).
      Repulping or  grinding paper into reusable fibers uses well-established
technologies.  Removing the ink from newsprint and other inked papers, commonly
called deinking, is one of the primary technical challenges presented  by paper
recycling.
      A growing number of municipal recycling programs have boosted the amount
of newsprint collected and increased the demand for deinking capacity. Federal
and state legislation suggesting or mandating the use of secondary fibers in new
products has begun to play a role in the rise in secondary fiber utilization. It is
estimated that the use of deinked fibers will grow to 5.8 million tons in the next 10
years. Most of this will be used in newspaper production. If collection rates
continue to grow and deinking capacity expands  as expected, it is estimated that
wastepaper utilization rates will rise to nearly 30 percent by 1995 (Franklin
Associates, 1990).  Alternative developing markets for waste paper include the
following:
          Animal bedding
          Egg and fruit boxes from old cartons
          Egg and fruit cartons for wastepaper pulp
          Building material
          Asphalted roofing sheets
          Insulating material
          Fuel
                                     B-10

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Export is one outlet for the domestic oversupply of recycled paper. In fact, many
dealers or processors export nearly all their waste paper (Misner, 1991). For
example, various grades of paper from the United States are imported by countries
in Asia, where lower labor costs allow more economical paper processing.  The
export of waste paper is dependent on the availability of shipping containers
(Misner, 1991).

PLASTIC AMOUNTS AND MARKETS
Amounts
      Plastics are broadly classified by their polymer structure as either
thermoplastic or thermoset resins.  Thermoplastics are commonly recycled because
they can be melted  and reformed, whereas the cross-linked polymers of thermoset
resins cannot.
      In the late 1980s, the Society of the Plastics Industry (SPI) voluntarily
devised and implemented a system of seven codes (Figure B-1) to facilitate the
identification and separation of common thermoplastic resins used in packaging
applications (SPI,  1988).  The symbols usually appear on the bottoms of containers
and other disposable plastic items.   Most postconsumer recycling programs focus
their efforts on reclaiming categories one through six.
      Table B-5 lists the various plastic goods recycled in 1988 and their
contributions to recycling of plastics in general.  At present, containers made from
polyethylene terephthalate (PET) and high-density polyethylene (HOPE) are the
postconsumer plastics recycled  in significant quantities.  Both resins are recycled at
higher rates because of their frequent  use in packaging.  PET is used to
manufacture carbonated beverage containers, 21 percent of which were recycled in
1988.  The high recycling rate is attributable to high collection levels in states with
bottle-bill legislation. HOPE is used in  base cups for PET bottles and milk and
bottled water containers.   HOPE is easily recyclable and is considered  a  resin  of
choice for numerous applications.
                                    B-11

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            x              \
           PET
      HOPE
      \             \
    LPDE
PP
                                     PS
OTHER
               1.   Polyethylene terephthalate
               2.   High-density polyethylene
               3.   Vinyl
               4.   Low-density polyethylene
               5.   Polypropylene
               6.   Polystryene
               7.   Other, including multilayer
                        FIGURE B-1
Society of the Plastics Industry Coding System for Plastic Resins
                            B-1 2

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TABLE B-5
Generation and Recycling of Plastics in MSW, 1988
Product category
Durable goods3
Weight
generated
(in millions
of tons)
4.1
Weight
recovered
(in millions
of tons)
<0.1
Percent
recycled
1.5
Discards
{in millions
of tons)
4.1
Nondurable goods
Plastic plates and cups
Clothing and footwear
Disposable diapers'5
Other Misc. nondurables
Total plastics nondurable
goods
0.4
0.2
0.3
3.8
4.7
0
0
0
0






0
0
0
0
4.7
Containers and packaging
Soft drink bottles
Milk bottles
Other containers
Bags and sacks
Wraps
Other plastic packaging
Total plastics containers
and packaging
Total plastics
0.4
0.4
1.7
0.8
1.1
1.2
5.6
14.4
0.1
Negligible
Negligible
Negligible
Negligible
Negligible
0.1
0.2
25.0
<1.0
Negligible
Negligible
Negligible
Negligible
1.7
1.3
0.3
0.4
1.7
0.8
1.1
1.2
5.5
14.3
aAppliances, toys, furniture, etc.
bDoes not include nonplastic materials in diapers.

Source:  Franklin Associates, Ltd., 1990.
                                     B-13

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      Limitations of collection and sorting systems and other factors have hindered
reclamation of the other coded resins, which include low-density polyethylene
(LDPE), vinyl (V), polypropylene (PP), polystyrene (PS), and others. These resins
appear in a range of products from building materials and luggage to egg cartons
and garbage bags.  In 1990,  these resins together represented more than 34 billion
pounds of potentially recyclable plastics, 8.9 billion  pounds of which were used in
packaging (Modern Plastics,  1991).

Markets
      In a study of recycled  plastics markets (Bennett, 1989), the Center for
Plastics Recycling Research (CPRR) indicated that current PET markets include the
following:

      •  Civil engineering-geotextiles and urethane foam
      •  Recreational-skis,  surfboards, and sailboat hulls
      •  Industrial-carpeting, fence posts, fiberfill, fuel pellets, industrial paints,
          strapping, unsaturated polyester, and paint brushes

Based on the CPRR report, current HOPE markets exist in the following areas:

       •  Agriculture—drain pipes and pig and calf pens
       •  Marine engineering-boat piers (lumber)
       •  Civil engineering-building products, curb stops, pipe, signs, and traffic-
          barrier cones
       •  Recreational-toys  and golf bag liners
       •  Gardening—flower  pots, garden furniture, and lumber
       •  Industrial-drums and pails, kitchen drainboards, matting, milk-bottle
          carriers, pallets, soft-drink base cups, and trash cans
                                      B-14

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 In addition to evaluating the markets for PET and HOPE, CPRR evaluated the
 potential markets for mixed plastics, that is, recycled plastic consisting of several
 resin types.  Six potentially significant markets were identified:
          Treated lumber
          Landscape timbers
          Horse fencing
          Farm pens for poultry, pigs, and calves
          Roadside pots
          Pallets
 Although the diversity of potential plastics markets appears great, the development
 of these markets is not occurring fast enough, creating an oversupply of recycled
 plastics.  Industry representatives indicate that curbside collection programs create
 a steady supply of recycled resins regardless of the ability of end-users to utilize
 the material (Misner, 1991).  Export of recycled plastics may assist in absorbing
 the oversupply (Goldberg, 1990).

 STEEL AND TIN VOLUMES AND MARKETS
 Amounts
      The broad category of ferrous metal scrap consists of all alloyed or unalloyed
 ferrous materials containing iron or steel as the principal component (Schottman,
 1985).  In the model that Franklin Associates, Ltd. (1990) used to calculate MSW
 ferrous metal scrap generation and recovery rates, only durable goods (e.g., white
 goods, furniture, tires) and steel containers and packaging are considered. Durable
 goods are usually collected separately from common recyclables and sent to
 automobile processing facilities for shredding (U.S. EPA, 1989).  This report
excludes durable goods and focuses  instead on food and beverage containers.
      In addition to iron and steel, tin can be a significant component of ferrous
scrap. The main source of tin in MSW is the tinplate that is used for steel food and
beverage containers.  Excluding white goods and other durables, tinplated steel
                                    B-15

-------
cans constitute the largest single source of ferrous metal scrap (approximately 60
percent) recovered from MSW (personal communication between TRC
Environmental Corporation and Gregory L. Crawford of the Steel Can Recycling
Institute on August 13, 1991). The remaining 40 percent falls into a category
called other ferrous scrap, which may include a number of discarded items such as
old, broken, or worn out toys, tools, and automobile parts.
      According to Franklin Associates, Ltd. (1990), approximately 11.6 million
tons of ferrous metals in MSW (including durable goods as well as steel containers
and packaging) were generated in 1988, of which an estimated 400,000 tons was
recovered from steel containers and packaging (Table B-6) (Franklin Associates,
Ltd., 1990).  This figure indicates a recycling rate of 13.8 percent for steel
containers and packaging. The Steel Can Recycling Institute (Heenan,  1991)
reported that the steel-can recycling rate for 1990 had increased to 24.6 percent.

Markets
      In general, ferrous metals markets are the most established of all recyclable
markets.  Ferrous metals have been recycled for more than 50 years into a variety
of products.  Most steel industry experts expect the domestic market for recycled
steel cans to be consistent because of continued growth in the scrap-consuming
minimill sector of the steel industry (Goldberg, 1990).  It is expected that this
growth will accommodate anticipated increases in the amount of steel  cans
collected from MSW.
                                     B-16

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TABLE B-6
Generation and Recycling of Ferrous Metal in MSW, 1 988a
Product category
Weight
generated
(in million
of tons)
Weight
recovered
(in million
of tons)
Percent
recovered
Discards
(in million
of tons)
Durable goods
Ferrous metalsb
8.8
0.3
3.4
8.5
Containers and packaging steel
Beer and soft drink cans
Food and other cans
,Other steel packaging
Total containers and
packaging steel
Total ferrous metals
0.1
2.5
0.2
2.8
11.6
Negligible
0.4
Negligible
0.4
0.7
Negligible
16.0
Negligible
16.0
6.0
0.1
2.1
0.2
2.4
10.9
aNumbers may not add to totals because of rounding.
bFerrous metals in appliances, furniture, tires, and miscellaneous durables.

Source:  Franklin  Associates, Ltd., 1990.
                                     B-17

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                                APPENDIX C
              FEDERAL, STATE, AND MUNICIPAL INVOLVEMENT

FEDERAL INVOLVEMENT
      In response to the 1976 passage of the Resource Conservation and
Recovery Act (RCRA), EPA developed guidelines that outline requirements and
recommendations for the recycling activities of Federal agencies, state and local
governments, and the private sector.
      Throughout the 1980s, EPA made several proposals to encourage the
establishment of recycling programs.  In February 1988, EPA created the Municipal
Solid Waste Task Force to specifically address MSW problems and, 1 year later,
presented its suggestions in a final report titled  The Solid Waste Dilemma: An
Agenda for Action.  The task force recommendations are summarized in the
concept of "integrated waste management."  This concept encourages recycling as
the preferred waste management option, second only to source reduction.  EPA,
therefore, established a national goal of 25 percent source reduction and recycling
by 1992.  The guidelines EPA set forth to achieve this goal include the following:

      •  Stimulation of markets for secondary materials
      •  Enhancement of separation, collection, and processing of recyclables
      •  Establishment of a  national recycling council
      •  A review of the incentives and disincentives  of liability potentially
         affecting  recycling  industries

      The report suggested that all levels of government and the private sector
participate in establishing these guidelines to achieve the 25 percent source
reduction and recycling goal  (U.S. EPA, 1989).
                                    C-1

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      Aside from EPA, other Federal agencies also have begun to address recycling
issues. The U.S. Food and Drug Administration continues to evaluate the use of
recycled plastic in food packaging materials.
STATE INVOLVEMENT
      Because RCRA placed the responsibility for MSW management on state
governments, the majority of laws passed in the United States regarding recycling
have occurred on the state level. An annual nationwide survey conducted by the
journal Biocycle indicates that the first state law to have a significant effect on
recycling efforts was Oregon's "Opportunity to Recycle " Act of 1983 (Glenn and
Riggle, 1991). This law banned many recyclables from landfills and incinerators
and required municipalities to provide recycling services. Connecticut, Rhode
Island, and New Jersey passed similar legislation several years later.  In addition to
the requirements mentioned above, Rhode Island and New Jersey mandated citizen
and business participation. State recycling laws proliferated between 1987 and
1989, with 22 states enacting comprehensive recycling laws (National Solid Waste
Management Association [NSWMA],  1989).  NSWMA defines a comprehensive
recycling law as one providing a framework for statewide recycling and mandating
local government and citizen participation in some cases.
      In 1990, new recycling legislation focused less directly on recycling and
more on waste reduction goals. Requirements of various laws can be separated
into three categories.  The first type requires local governments to pass ordinances
mandating citizens and businesses to source separate and recycle. Connecticut
joined the District of Columbia, New Jersey, New York, Pennsylvania, and Rhode
Island in enacting this type of law.  The second  type of legislation requires
municipalities to provide recycling programs without making participation
mandatory.  Arizona was the only state to pass  such legislation in 1990, joining
nine other states that already had such laws.  The third type, which is generally
combined with one of the first two types, requires municipalities to reach a
specified waste  reduction goal.  Alabama, California, Maryland, Minnesota, North
                                     C-2

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Carolina, Vermont, and Virginia added this type of legislation to mandatory source
separation ordinances.  New Jersey and Rhode Island added goals to mandatory
participation requirements.  Florida, Georgia, Illinois, Iowa, Louisiana, and Ohio
passed waste reduction goals alone (Glenn and Riggle, 199.1).  Table C-1  lists state
recycling goals as well  as whether the states have made these goals mandatory
and the deadlines for meeting goals.
      Land disposal bans are another method states use to encourage recycling of
MSW.  In 1990, only Massachusetts and Wisconsin passed land disposal bans on
traditional constituents of MSW.  Connecticut removed disposal bans in favor of
mandating recycling of the once-banned items.
      Aside from mandating the establishment of recycling programs, many states
encourage recycling by financing market development. Four types of financial
incentives exist:  tax credits, low-interest  loans, grants, and tax exemptions.  As
the promulgation of new recycling legislation waned in 1990, so did the enactment
of financial incentives for market development.  Virginia was the only state to
enact a tax credit program in 1990, joining California, Colorado, Maryland, New
Jersey, North Carolina, and Oregon. Low-interest loan provisions  were enacted in
California and Wisconsin, bringing the total number of states with such provisions
to 11.  As of 1990, 10 states have grant  provisions with Virginia and Wisconsin
being the most recent additions.  In total,  19 states provide some  type of financial
incentive for market development (Glenn and Riggle,  1991).
      Another way in which states can encourage market development is to
establish procurement guidelines for the purchase of products made with some
fraction of recycled feedstock. By the end of 1990, 34 states had procurement
legislation enacted and another 3 had executive orders passed.
      A dilemma shared by many states following enactment of recycling
legislation is finding the funding to support budgets for the various programs. In
states that depend on general tax revenues, the current recession has made
implementation difficult. Fifteen states have some form of disposal tax or
                                     C-3

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TABLE C-1
State Recycling Goals
State
Alabama
California
Connecticut
District of
Columbia
Florida
Georgia
Illinois
Indiana
Iowa
Louisiana
Maine
Maryland
Massachusetts
Michigan
Minnesota
Mississippi
Missouri
New Hampshire
i —
New Jersey
New Mexico
New York
North Carolina
Ohio
Recycling goal3
NS
NS
25%
45%
30%b
NS
25%
50%b
50%
NS
50%
15-20%
25%
20-30%
25-35%
NS
NS
NS
25%
NS
40-42%
NS
25%
Mandate
Yes
Yes

Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Deadline
1991
2000
1991
1994
1995
1996
2000
2000
2000
1992
1994
1994
2000
2005
1993
1996
1998
2000
1990
2000
2000
1993
1994
C-4

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TABLE C-1 (continued)
State
Pennsylvania
Rhode Island
Vermont
Virginia
Washington
Recycling goal3
25%
15%
NS
25%
NS
Mandate
Yes
Yes
No
Yes
Yes
Deadline
1997
1993
2000
1995
1995
Includes yard waste composting (except for New Jersey),
Includes source reduction.
NS  = Not specified.

Source: Glenn and Riggle, 1991.
                                   C-5

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collection fee in place to fund programs. New Mexico enacted a 0.12 percent tax
on business gross receipts in 1990 to fund its recycling program.
                                          t
MUNICIPAL INVOLVEMENT
      The success of state recycling programs requires that municipalities take an
active role in researching, planning, and implementing programs that meet their
specific community and regional needs. Municipalities in turn look to state
agencies for information and funding and to recycling organizations for information
and support.
      The increase in municipal recycling  programs nationwide is reflected in the
growth of state recycling organizations, which have experienced more than a 50
percent increase in membership in the last 3 years (Apotheker, 1992). These
organizations comprise individuals, businesses, nonprofit groups, and governments.
Their efforts concentrate on disseminating information on recycling issues to their
membership and the public.  The newly formed Southern States Recycling
Coalition, which represents individuals from 16 states and Puerto Rico, has
established  objectives that include  seeking to develop, stimulate, and stabilize
markets for recyclables and to promote effective recycling methods (Ramay, 1992).
      To better characterize local programs, the Municipal Waste Management
Association, an affiliate of the U.S. Conference of Mayors, conducted a survey of
the 163 cities applying for the Heinz National Recycling Awards Program  (U.S.
Conference of Mayors, 1991). Although  all 163 cities have recycling programs,
more than  80 percent responded that landfilling and energy recovery through
combustion were still their predominant methods of solid waste disposal.  Sixty-
nine percent of the cities landfilled more than 50 percent of their MSW, whereas
2 percent of the cities  reported combusting for energy recovery more than 50
percent of their MSW.  Of the 163 cities, 104 reported marked increases in the
cost of traditional MSW disposal methods.  The survey noted the correlation
between increased disposal costs and an increase in the number of recycling
                                     C-6

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programs; more than 65 percent of the responding cities started their programs
within the last 3 years.
      The survey also gathered information on the types of recycling programs
implemented and the key recycling issues facing cities in the next 5 years.  For
residential customers, 87 percent  of the cities operate curbside collection systems,
68 percent operate drop-off facilities, and 27 percent operate buy-back centers.
Many cities offer more than one type of program and offer services to  multifamily
dwellings.  The key issues facing cities, in descending order of importance follow:
         Market development and stability for recyclables
         Cost and funding of programs
         Development of waste reduction
         Public education
         Establishing local ordinances and requirements
         Enforcement of recycling ordinances
         Purchasing recycled products
         Increased public participation
         Improved technology
                                      C-7

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                               APPENDIX D

                             BIBLIOGRAPHY ON

             MUNICIPAL SOLID WASTE MANAGEMENT OPTIONS
LANDFILLS
Bingemer, H.; Crutzen, P. (1987). The production of methane from solid wastes.
J. Geophysical Research.  92 (D2):  2181-2187.

Dwyer, J. R., et al.  (1986). Evaluation of municipal solid waste landfill cover
designs.  U.S. EPA, Hazardous Waste Engineering Lab, Cincinnati, OH.  PB88-
171327.

Lu, J.C.S.; Eichenberger, B.; Stearns, R. J.  (1985).  Leachate from municipal
landfills, production and management. Park Ridge, NJ:  Noyes Publications.

Pohland,  F. G.; Harper, S. R.  (1987). Critical review and summary of leachate and
gas production from landfills. U.S. EPA, Hazardous Waste Engineering Research
Laboratory. EPA/600/S2-86-073.

U.S. Congress.  (1989).  Facing America's trash. What next for municipal solid
waste? Office of Technology Assessment.  OTA-O-424.

U.S. EPA. (1986). Critical review and summary of leachate and gas production
from landfills.  PB86-240181/XAB.

U.S. EPA. (1988). Summary of data on municipal solid waste landfill leachate
characteristics; Criteria for municipal solid waste landfills (40 CFR  Part 258).
Office of Solid Waste. EPA/530-SW-88-038.

U.S. EPA. (1989). The solid waste dilemma: an agenda for action. Office of
Solid Waste, Washington, DC.

U.S. EPA. (1989). Decision-makers guide to solid waste management. Solid
Waste and Emergency Response. EPA/530-SW-89-072.

U.S. EPA. (1991). Criteria for municipal solid waste landfills  (40 CFR Part 258;  56
FR 51016, October 9, 1991).  Office of Solid Waste.
                                    D-1

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INCINERATION

Brna, T. G. (1988). State-of-the-art flue gas cleaning technologies for municipal
solid waste combustion. U.S. EPA, Air and Energy Engineering Research Lab,
Research Triangle Park, NC.  PB88-184601/XAB.

Denison, R. A.; Silbergeld,  E. K.  (1989). Comprehensive management of
municipal solid waste incineration:  understanding the risks.  Toxic Chemicals
Program.  Environmental Defense Fund, Washington, DC.

Hahn, J. L.; Sussman, D. B.  (1988).  Municipal waste combustion ash: testing
methods, constituents and  potential risks.  Resource Recovery.  2(5):16-18.

National League of Cities.  (1986).  Waste-to-energy facilities:  a decision maker's
guide. Washington, DC.

Penner, S. S.; Wiesenhahn, D. F.; Li, C. P.  (1987).  Mass burning of municipal
wastes.  Ann. Rev. Energy.  12:415-444.

Radian Corporation. (1989). Database of existing municipal waste combustion
studies.  Database maintained for the  U.S. Environmental Protection Agency;
Research Triangle Park, NC.

U.S. EPA.  (1987). Characterization of municipal waste combustor ashes and
leachates from municipal solid waste landfills, monofills, and co-disposal sites.
Office of Solid Waste.  PB88-127980/XAB.

U.S. EPA.  (1987). Municipal waste combustion study, report to Congress.
Washington,  DC. EPA/530-SW-87-021a.

U.S. EPA.  (1987). Municipal waste combustion study: assessment of health risks
associated with municipal waste combustion emissions. EPA/530-SW-87-02.

U.S. EPA.  (1987). Municipal waste combustion study, characterization of the
municipal waste combustion industry.  EPA/530-SW-87-021h.

U.S. EPA.  (1987). Municipal waste combustion study, emission data base for
municipal waste combustors. EPA/530-SW-87-021b.
 COMPOSTING

 BioCycle. (1988). Composting projects for grass clippings. BioCycle.  29(5):47.
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The BioCycle guide to composting municipal wastes.  BioCycle.  January 1989.

Connecticut Department of Environmental Protection.  (1989).  Leaf composting - a
guide for municipalities.  DEP, Local Assistance and Program Coordination Unit,
Recycling Program; Hartford, CT.

Ernst, A. A. (1988).  30 years of refuse/sludge composting. BioCycle.  29(6): 34-
35.

Finstein, M. S.; Miller, F. C.; Strom, P. F. (1986). Monitoring and evaluating
composting process performance. J. Water Pollut. Control Fed. 58: 272-278.

Illinois Department of Energy and Natural Resources.  (1987).  Economics and
feasibility of co-composting  solid wastes in  McHenry County (Illinois). Springfield,
IL:  Illinois Department of Energy and Natural Resources Clearinghouse.  ILENR/RE-
EA-78-12.

Massachusetts Department of Environmental Quality Engineering. (1988). Leaf
composting guidance document.  DEQE, Boston.

Mayer, M.; Hofer, H.; Maire, U.  (1988).  Trends  in yard waste composting.
BioCycle. 29(6): 60-63.

Ron Albrecht Associates, Inc. (1988). Composting technologies, costs, programs
and markets. Report  prepared for U.S. Congress, Office of Technology
Assessment.

Rosen, C. J.; Schumacher, N.; Mugaas, R.; Proudfoot, S.  (1988).  Composting
and mulching:  a guide to managing organic wastes.  Minnesota Extension Service
Report.  AG-FO-3296.

Taylor, A. C.; Kashmanian, R. M. (1989).  Study and assessment of eight yard
waste composting programs across the United States.  U.S. Environmental
Protection Agency. EPA/530-SW-89-038.
                                    D-3  *U.S. GOVERNMENT PRINTING OFFICE: 1994 - 550-001/80396

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