COMPREHENSIVE STUDIES OF SOLID WASTE MANAGEMENT

              First and Second Annual Reports
  These interim reports (SW-Srg)  on work performed under
               Research Grant No.  EC-00260
(formerly successive Grant Nos.  were UI-00547 and SW-00003)
              to the University  of California
     were prepared by C.  G.  GOLUEKE and P. H. McGAUHEY
   and have been reproduced as received by the grantee.
     U.S.  DEPARTMENT OF HEALTH,  EDUCATION,  AND WELFARE
         Public   Health   Service
               Environmental Health Service
             Bureau of Solid Waste Management
                           1970

-------
          ENVIRONMENTAL ri-.G'LXT-O-N  AGENCY

            Public Health Service Publication No.  2039
For sale by the Superintendent of Documents, U.S. Government Printing Office
                    Washington, B.C. 20402 - Price $4.2;5

-------
                                 FOREWORD






     At the time of passage of the Solid Waste Disposal Act (PL 89-272)




in 1965, few, if any, studies of a truly comprehensive nature had been




undertaken to develop solutions to problems in all aspects of solid




waste management.  Although earlier research studies have made




invaluable contributions to knowledge in the field, they tended to




focus primarily upon discrete facets of the total solid waste problem.




     The present report represents the first major effort to examine




the solid waste problem from the standpoint of systems analysis.  An




overall solid waste generation and evaluation model was developed,




demonstrating interrelationships between land use, technology, economics,




population, and other system elements.  Practical implications were




drawn from this model, as they relate to planning, public health, and




application of technology.




     A further example of the systems approach to solid waste management




is given in the final report of a Bureau of Solid Waste Management




demonstration project, A Systems Study of Solid Waste Management in




the Fresno Area (Public Health Service Publication No. 1959).






                                     —RICHARD D. VAUGHAN, Director




                                       Bureau of Solid Waste Management
                                    iii

-------

-------
   COMPREHENSIVE STUDIES




OF SOLID WASTE MANAGEMENT







       First Annual Report

-------

-------
                                      PREFACE
NATURE AND SCOPE OP REPORT

        The report herein presented is of the nature of a progress report covering
the first year of a comprehensive study of solid wastes management made possible by
a grant (SW-00003-Ol) to The Regents of the University of California by the Public
Health Service.

        The research plan on which the grant was based called for an initial organi-
zational and general data-collecting phase, covering a major part of the first year,
followed by a second phase of definitive research on such aspects as operations
research, planning, economics, public health, and technology of wastes management
systems.  The first phase having been successfully completed, the report on this
aspect is essentially a final report intended to acquaint the reader with the
underlying concepts of the solid wastes problem and with the details of the multi-
disciplined research program set up to attack the problem.  On the definitive
research phase of the program, progress and preliminary findings of a number of
coordinated research teams are presented in detail.


ACKNOWLEDGMENTS

        The project is indebted to many private individuals and public agencies
throughout California and the nation for information and assistance in the conduct
of the study.  The list of those who have been particularly helpful includes the
following:

        P. A. Rogers, California State Department of Health

        F. Stead, California State Department of Public Health (Retired)

        P. P. Maier, California State Department of Public Health

        F. R. Bowerman, Assistant to Vice President — Development,
           Aerojet-General Corporation

        D. A. Hoffman, Utilities Department, City of San Deigo

        R. E. Schwegler, County Sanitation Districts of Los Angeles County

        R. D. Whitley, County Sanitation Districts of Los Angeles County

        L. Howell, County Sanitation Districts of Los Angeles County

        S. A. Armogida, Engineering Department, County of San Mateo

        J. Moscone, President, Golden Gate Scavenger Company,
           San Francisco,  California

        L. Stefanelli, President, Sunset Scavenger Company,
           San Francisco,  California

        0. Dyer,  Director  of Services (Retired),  Berkeley,  California

        J. L. Chapman, Planning Department,  Santa Clara County

        W. Stevenson,  Department of Public Health,  Santa Clara County
                                      vii

-------
        W. D. Trewitt,  President,  Easley & Brassy Corporation,
           San Francisco,  California

        S. Choates, Agricultural Extension Service,  University of California

        W. C. Hanley (City Manager), R.  C. Gazlay (Director of Services),


and other officials of the City of Berkeley for their cooperation in the study
concerned with Berkeley refuse generation.

        Authorship credit  for individual sections of this  report  is  due  to the
following participants  in  the project:

        Characteristics and Amounts of Solid Wastes  in Santa_ Clara County — J. Becker

        Operations Research — H. Stern and Professor C. R. Glassey

        Planning — Dr.  S.  A. Rao and R.  Drake

        Incineration — H.  Wasmer and Professor P. B. Stewart

        Anaerobic Digestion — S. A. Klein and D. B.  Chan

        Wet Oxidation — J. Bicho and Dr. D. L. Brink

        Biological Fractionation of Solid Wastes — S. Cherney,  R. Rosenbluth,
           and Professor C. R. Wilke

        Salvage — J. Becker
                                      VI11

-------
                                TABLE OF CONTENTS

                                                                              Page
                                      PART I
                                    BACKGROUND
Chapter

     I.  INTRODUCTION 	      1

         Need for Study	      1

            Urbanization  	      2

            Economic Considerations 	      3

            Technology  	      3

            Public Health 	      k

            Education 	      4

            Conclusion  	      5

         Nature and Rationale of Study  	      5

         Objectives of Study	     10

         Organization for Study 	     10

         Plan of Research	     11
                                     PART II
                           PHASE I OF THE INVESTIGATION
    II.  DATA COLLECTION AND EVALUATION	     15

         Literature Survey and Information Retrieval  	     15

            Papers	     15

            Reports	     15

            Journals  	     l6

         Personal Interviews  	     l6
                                       IX

-------
                          TABLE OF CONTENTS (continued)

Chapter                                                                       Page

         Characteristics and Amounts of Solid Wastes  	      17

            Introduction  	      17

               Need for Refuse Analysis Studies	      18

               General Estimates of Refuse Composition  	      18

               Specific Estimates of Refuse Composition 	      19

            Waste Generation in Santa Clara County  	      19

               Domestic Wastes  	      20

               Industrial Wastes  	      21

               Agricultural Wastes  	      21

            Change in the Composition of Berkeley Wastes  	      30

               Introduction	      3o

               Equipment and Procedure  	      31

               Results	      32

               Discussion	      36

            Definition and Coordination of Research Areas 	      39
                                     PART III
                          PHASE II.  DEFINITIVE RESEARCH
   III.  OPERATIONS RESEARCH  	     4l

         Introduction	     4l

         Waste Generation and Evaluation Model  	     4l

         Waste Collection-Treatment-Disposal Model  	     44

            General Description 	     44

            Mathematical Formulation  	     45

         Waste Generation Input and Management System Inputs  	     48

            Management System Inputs  	     48

            Waste Generation Model  	     48

               Regional Economic Model (Productive Sector)  	     50

               Waste Generator (Consumption Sector) 	     51

               Spatial Distribution of Waste  	     52

                                         x

-------
                          TABLE OF CONTENTS (continued)

Chapter                                                                       Page

         Future Extensions and Tasks  	      5^


    IV.  PLANNING AND ECONOMICS	      55

         Introduction 	      55

         Approach and Methodology 	      55

            Model Formation	      56

            Development of Pertinent Data on Quantity
              and Types of Solid Wastes	      57

            Solid Waste Generation and Land-Use Planning  	      57

            Incorporation of Technical Changes in Transportation
              and Disposal of Solid Wastes	      58

            Implications of Present and  Future Methods  of Disposal
              on Private and Public Expenditure 	      58

         Santa Clara County Study 	      59

            Introduction  	      59

            Location of Disposal Sites and Definition
              of Disposal Service Areas  	      59

            Land-Use and Employment Data	      60

            Solid Waste Data	      67

            Composition of Solid Wastes  	      67

            Regression Study  	      67

         Data Collection Plans  	      73


     V.  PUBLIC HEALTH	      75

         Introduction 	      75

         Objectives  of Public  Health Research  	      75

         Relationship of Wastes Management to  Health   	      76

         Relation of Wastes  Components to  Health   	      79

            Agricultural Wastes 	     80

            Industrial Wastes  	     80

            Methods  of Disposal	     8l

               Incineration  	     8l

               Sanitary Landfill  	     86

                                      xi

-------
                          TABLE OF CONTENTS (continued)




Chapter




               Composting	     89




         Occupational and Health Hazards  	     91






    VI.  TECHNOLOGY OF SOLID WASTES MANAGEMENT  	     93




         Introduction 	     93




         Incineration 	     93




            Concept and Rationale	     9^




            Objectives	     94




            Refuse Pretreatment Studies 	     95




            Pyrolysis Studies 	     96




         Composting	    100




            Concept and Rationale 	    101




            Objectives	    101




            West German Studies	    102




         Landfill	    Wk




         Salvage	    105




            Concept and Rationale 	    105




            Objectives	    106




            The Investigation	    106




               Metals	    106




               Paper	    108




               Glass	    Ill




               Rubber	    113




               Plastics	    11^




               Rags	    116




               Summary and Conclusions  	    11?






   VII.  ANAEROBIC DIGESTION WITH SEWAGE SLUDGE 	    118




         Introduction 	    118




         Concepts and Rationale  	    119




         Objectives	    119





                                        xii

-------
                          TABLE OF CONTENTS (continued)




Chapter                                                                       Page




         The Investigation	     120




            Development of Equipment and Procedures 	     120




               Preparation of Raw Materials 	     120




               Sewage Sludge  	     120




               Digester Units and Ancillary Equipment 	     120




               Gas Lines and Collectors	     123




            Analyses  	     126




               Total and Volatile Solids	     126




               Volatile Acids 	     126




               Gas Analysis	     126




               Alkalinity	     126




         Experimental Procedures and Results  	     126




            Procedure - Specific  	     128




            Results	     129




               Volatile Acids 	     129




               Gas Production	     129




               Gas Composition	     133




               Alkalinity	     133




               Hydrogen Ion Concentration (pH)	     136




               Reduction in Volatile Solids 	     136




            Discussion and Conclusions  	     136




            Future Work	
  VIII.  WET OXIDATION OF ORGANIC WASTES  	




         Introduction 	     Ik2




         Description of the Process	     142




            Historical	     ikk




            Pilot- and Large-Scale Applications  	     1^5



         Recent Research  	     151




         Application to Solid Wastes   	     152







                                      xiii

-------
                          TABLE OF CONTENTS (continued)

Chapter                                                                       page

         Objectives of Study	    154

         The Investigation	    15^

            Program and Methodology 	    155

               Phase 1:  Determination of Basic
                 Reaction Relationships 	    155

               Phase 2:  Oxidation of Organic Solid
                 Waste Materials	    157

               Phase 3:  Process Design	    159

               Progress in Equipment Modification 	    159

         Discussion	    159

         Future Work	    l6o


    IX.  BIOLOGICAL FRACTIONATION OF ORGANIC WASTES 	    l6l

         Introduction  	    l6l

         Waste Treatment Organisms  	    l6l

            Rumen Bacteria	    l6l

            Clostridia and Related Forms  	    l6l

            Fungi Imperfect!	    162

         Application to Solid Wastes  	  .    163

         Objectives of Study	    164

         The Investigation	    164

         Summary  ......... 	    165



                                     PART IV


     X.  SUMMARY	    167

         Introduction  	    167

         Nature of Research Program 	    168

         Research Activities and Findings 	    169

            Phase I	    169

            Phase II	    170

            Operations Research  	    170

                                       xiv

-------
                          TABLE OF CONTENTS (continued)

Chapter                                                                       Page

            Planning and Economics  ....................    170

            Public Health .........................    171

            Technology  ..........................    172

         General Summary of Progress  ...................
REFERENCES  ................................     175


APPENDICES

     A.  Application of the Evaluation Model to Special Cases .......     185

     B.  Design of Transfer Station Characteristics ............     186

     C.  Comparable Data on Solid Waste and Related
            Economic Variables  ......................     192

     D.  Questionnaires to Refuse Collectors and Disposal Site
            Operators for Analysis of Refuse Collection and Disposal  .  .  .     19^

     E.  Codification of Data .......................     199
                                       XV

-------
                                  LIST OP TABLES


Table                                 Title                                   Page

   1.  Summary of Participants in the Program	      13

   2.  Estimate of Gross Refuse Generation in Santa Clara County (1967) .  .      20

   3.  Estimate of Components of Domestic Refuse in
         Santa Clara County (196?)  	      20

   k.  Principal Expected Wastes from Manufacturing and/or
         Processing Industries, Santa Clara County, California  	      22

   5.  Classification of Manufacturing Firms in Santa Clara County,
         California, by Numbers and Employee Groups 	      23

   6.  Sources and Types of Industrial Wastes,  Santa Clara County 	      24

   7.  Distribution of Dairy Manure Generation in Santa Clara County  ...      26

   8.  Pountry Manure Generation in Santa Clara County  	      28

   9.  Quantities of Prunings by Crops in Santa Clara County  	      29

  10.  Weight of the Individual Loads of Refuse and the Percentage
         of Total Refuse Per Route That Was Segregated	      33

  11.  Type of Account Receiving Refuse Service 	      33

  12.  Composition of Berkeley Refuse in Terms of Weight  	      34

  13.  Composition of Berkeley Refuse in Terms of Percentages 	      3^

  14.  Comparison of the Composition of Refuse in 1967 With That in
         1952 in Terms of Weight	      35

  15.  Changes in Composition of Refuse Over 15-Year Period 	      35

  l6.  Information Flow for Regional Waste Generation and
         Evaluation Model 	      43

  17-  Solid Waste Disposal Sites in Santa Clara County 	      6l

  18.  Disposal Service Areas and Corresponding Disposal Sites
         in Santa Clara County	      63

  19.  Definition of Disposal Service Areas by Planning Areas
         and Census Tracts in Santa Clara County   	      64

  20.  Land Use by Planning Areas and Portions of Planning Areas
         for Selected Land-Use Categories, 1962, Santa Clara County ....      65

  21.  Land Use by Disposal Service Areas for Selected Land Use
         Categories, 1962, Santa Clara County 	      66

  22.  Employment by Planning Areas, July 1964, Santa Clara County  ....      68
                                        XVI

-------
                             LIST OF TABLES  (continued)


 Table                                 Title                                   Page

   23.  Employment by Disposal Service Areas,  196k,
           Santa Clara County  ........................     69

   2k.  Summary of Information from Questionnaire   .............     70

   25.  Disposal Site Operating Costs — Imputed and Reported  ........     71

   26 .  Estimates of Solid Wastes by Broad Categories
           in Santa Clara County, 1965  ...................     72
    27.  Data Used  for Regression Analysis, Santa Clara County

    28 .  Santa  Clara County Waste Generation, Summary of Linear
          Regression Results
   29.   Possible Health  Problems in Solid Wastes Management   ........     77

   30.   Air Pollutant Emissions from Solid Waste Disposal   .........     83

   31-   Tons  of Contaminants Introduced into Los Angeles
           County Atmosphere, 1962   .....................     8k

   32.   Summary of Air Pollutant Emissions in St. Louis
           Area Study, 1963    ........................     85

   33-   Concentration of Leachate from Simulated Landfills
           Contained in Concrete Cylinders   .................     87

   34 .   Estimation of Pollution from Refuse Beds of Various Depths
           During Percolation of the Equivalent of 45 in. of Rainfall  ....     87

   35-   Composition and  Analysis of a Composite Municipal Refuse (1966)   .  .     98

   36.   Chemical Analysis of Raw Refuse   ..................     99

   37-   Chemical Analysis After Drying and Separation   ...........     99

   38.   Summary of the Material Balance Concerned with the Pyrolysis
           of  Municipal Refuse   .......................    100

   39-   German Composting Plants ......................    103

   kO.   Prices Paid FOB  Stockton for Papermaking Stock  ...........    110

   4l.   Daily Feed Composition  .......................    128

   k2.   Nitrogen and Oxygen Content of Digester Gas  ............    133

   kj.   Volatile Solids  Reduction   .....................    139

   kk.   Average Chemical and Physical Properties of Spent Neutracel
           Liquor Before  and After Oxidation  ................    146

   4-5.   Average Performance of Pilot-Scale Sewage Sludge Wet
           Oxidation Studies  ........................    148

   k6.   Average Chemical Characteristics of Process Effluent from
           Pilot-Scale Sewage Liquor Sludge Wet Oxidation Studies ......    148

                                       xvii


388-229 O - 70 - 2

-------
                            LIST OF TABLES (continued)


Table                                 Title                                   Page

  kl.  Summary of Typical Operating Conditions for Existing
         Sewage Sludge Wet Oxidation Plants  	  	     148

  h-8.  Unit Costs for the West-Southwest Wet Oxidation Plant of the
         Metropolitan Sanitary District of Chicago, Illinois   .  	     150

  U9.  Unit Costs for the Wet Oxidation Plant at Wheeling, West Virginia   .     150

  50.  Unit Costs for the Blind Brook Wet Oxidation Plant
         at Rye, New York	     151

  51.  Potential Value and Volume of Organic Acid Production from
         Spent Pulping Liquors	     153

  52.  Distribution of Fermentation Products by Pure
         and by Mixed Cultures	     162
                                       XVlll

-------
                                 LIST OF FIGURES


Figure                                Title                                   Page

    1.   Types of Waste Disposal Systems  	      8

    2.   Organization of Study	     12

    3-   Planning Areas and Distribution Dairies in Santa Clara County  .  .     27

    k.   Setup for Segregating Refuse at the Berkeley
           Waste Disposal Site	     32

    5-   Weighing Segregated Refuse Items 	     32

    6.   Typical Glass Waste Segregated in the Berkeley Study 	     36

    T.   Typical Plastics Segregated from Domestic Refuse 	     37

    8.   Tin Cans Segregated from Domestic Refuse	     37

    9-   Regional Waste Generation and Evaluation Model 	     39

   10.   Mathematical Model of Waste Generation 	     42

   11.   Waste Flow Network	     45

   12.   Management System Inputs and Waste Generation Model  	     4-9

   13.   Solid Waste Disposal Sites and Service Areas,
           Santa Clara County	     62

   14.   Schematic Description of Overlapping Disposal Sites  	     63

   15.   Material Flow in Refuse Pyrolysis	     97

   l6.   Experimental Digester  	    121

   17.   Stirring Device Layout 	    122

   18.   Incubator Containing Four Digesters	    123

   19.   Liquid Displacement Gas Collector  	    124

   20.   Inverted Tube Gas Collector	    125

   21.   General View of Gas Collection Apparatus	    127

   22.   Effect of Green Garbage on Volatile Acids
           Production of Digesters  	    130

   23.   Effect of Green Garbage Loading on Gas Production  	    131

   24.   Effect of Green Garbage on Digester Performance  	    132

   25.   Effect of Green Garbage Loading on Methane Concentration
           of Digester Gas	    134
                                       XIX

-------
                           LIST OF FIGURES (continued)


Figure                                Title

   2.6.   Effect of Green Garbage Loading on Carbon Dioxide
           Content of Digester  ......................    135

   27.   Effect of Green Garbage on Alkalinity of Digesters ........    137

   28.   Effect of Green Garbage Loading on pH of Digesters ........    138

   29.   Schematic Diagram of Continuous Wet Oxidation
           Process Developed by Zimmermann  ................
   30.   Schematic Diagram of the Proposed Batch Wet Oxidation Process  . .    156

   31.   Schematic Diagram of Air System Designed for
           Wet Oxidation Process  .............. ........    158

   32.   Direct Transfer Station and Disposal Station .... ........    187

   33'   Indirect Transfer Station and Disposal Station ... ........    187
                                        XX

-------
                                      PART I
                                    BACKGROUND
                                  I.   INTRODUCTION
NEED FOR STUDY

        The need for comprehensive studies of solid wastes  management,  to  which  the
investigation herein reported is directed, derives from a long history  of  inadequate
public attention to problems of resource management and environmental control, with
the result that when solid wastes problems reached critical proportions in the 1960's,
jurisdictional arrangements, economic concepts,  social attitudes,  and technology
were all found ill-suited to their resolution.

        The origins of these four interrelated areas of inadequacy are  perhaps to be
found in the abundance of natural resources our ancestors found on the  American
continent and in the wasteful manner in which they exploited these resources  in
establishing an agricultural and, later, an industrial economy. While  it  may be
argued that to a considerable degree destruction of some resource  values was  an
inescapable aspect of occupying a wilderness by agrarian people, it did establish
a spendthrift attitude which persists as a part of the cultural heritage of Americans
and is reflected today both in the amount and the nature of solid  wastes as well as
in public attitudes toward unwanted residues.

        Concerning the attitude of citizens and public officials toward the residues
of resource utilization it might be said that any material becomes a "waste"  when
its owner or producer no longer considers it of sufficient value to retain.  Thus no
question of the intrinsic value of the material either as a resource or as an object
of further utility is involved in the reaction.  Once it is no longer valued  by  the
owner, any suggestion that he should further invest money in it, for the sake of
disposal or any other financially unrewarding goal, is likely to be considered
absurd, however inclined he may be to deplore polluted water, smog, unsightly debris,
rodents, or other conditions which result from his loss of interest in  ownership.

        Reflecting the attitude of the citizen, engineers and officials responsible
for wastes management in the community have tended to apologize for the fact  that
their systems cost anything at all, often retreating from expedient to  expedient on
the basis of minimum immediate expenditure of money.  Thus there is at  work in the
community little which might make for a public realization that wastes  management is
worth whatever it costs within the framework of sound engineering  and the  health and
social goals of people.  Correlated with this attitude has been a  tendency of some
municipal officials to consider a policy of no-spending-at-all as  the ideal goal of
municipal government or, more recently, to direct spending to more popular social
objectives or to monumental works having greater cultural appeal than the  refuse dump.

        The result of all facets of the public attitude has been a very low estimate
of the cost the public can "afford" to pay for waste disposal and  a hesitancy to
dedicate land and other resource values to such an end.  This does not  mean,  however,
that little money goes into our attempts at solid wastes management. The  Public
Health Service has estimated that some three billion dollars is spent by the  public
each year in collecting, transporting, and disposing of solid wastes.  When it is
noted that this is second only to the annual investment in public  education and  that
it is yet hopelessly inadequate to the task of solid wastes management, citizen  and
public official alike may justifiably wonder if there  is not some better  approach
to the problem.

        From such a question one senses a need for some sort of comprehensive study
of the whole matter of solid wastes management.  To get at  the nature of such a  need,
however, it is necessary to look at aspects other than traditional economic attitudes
of the public and our heritage of wastefulness.   One of the most significant  factors
is the nature of a modern urban community.

                                          1

-------
 2

 Urbanization

         The  jurisdictional,  or political, subdivisions of a modern community were orig-
 inally founded on  a  spectrum of valid social and political needs which ranged from the
 distance one could travel by horseback in one day to the need of settlers for stores,
 services,  or protection  from Indians.  Resources management, and above all management
 of the residues of resource  use, were simply not problems which confronted pioneer
 America to a degree  sufficient to influence the nature of his settlements.  As settle-
 ments  grew into cities,  however, the problem of waste disposal grew likewise, but no
 new dimension appeared at once.  Cities throughout the world, wherever men have achieved
 a  high degree of consciousness of health and aesthetics, have traditionally dealt with
 wastes by transporting them  beyond their own immediate confines and discarding them in
 the least  expensive  way  the  public might tolerate, advancing from open dump, to sanitary
 landfill or  incinerator, as  local necessity compelled.  No serious problems need arise
 from this  practice as long as cities or jurisdictions are separated by space occupied
 only sparsely by human beings.  And such was the case for many decades.

        The rapid spread out of cities,  popularly known  as  the  "urban-sprawl,11 which
followed World War  II is now widely recognized  as having revolutionized  our  concepts
of urban life.  Less  well understood,  however,  is its  effect  in  expanding the problem
of solid wastes management to area-wide  proportions beyond  the resolving power of
any one of the myriad jurisdictions that make up the  overall  modern  community.  Even
in situations where one  city is located  at  some distance from another, particularly
where explosive increase in population has  had  a maximum impact, urbanization has
progressed beyond the limits of cities and  their satellite  suburbs to become a
characteristic of rural  areas as  well.   With high land values and heavy  investment
in fixed installations dedicated to such specialty enterprises as dairies, poultry
and egg production, and  animal  feeding,  this rural sector of  the community now
surrounds the urban-industrial-suburban  sector  as a shell which has  lost the
elasticity traditionally associated with rural  areas.  Moreover, it  exists in suf-
ficient depth to have a  profound effect  on  both its own  and the  city's problem of
wastes management.

        The high-investment rural sector of the community constrains the city's
freedom to dispose  of wastes by the traditional export method.   In some  cases, such
as California, there  are desert areas  beyond the rural shell  but the long haul dis-
tances involved are currently judged to  be  prohibitively expensive.  In  other
sections of the United States there is simply no area  beyond  the limits  of the city
where high-value agriculture gives  way to marginal or  worthless  land.  The alternative
to export is, of course,  disposing  of  solid wastes within the city limits.   In most
cases this is an unsatisfactory alternative. Land area  is  at a  premium  and  land use
planning generally not sufficiently advanced to include  refuse disposal  objectives.
Moreover, the constraint is often three-dimensional as air  pollution considerations
limit the freedom to  burn combustible  wastes.   Within  the city itself transportation
needs and efforts to revitalize the urban environment  in other ways  contribute a new
problem of solid wastes  in the  form of demolition debris, thus compounding an already
complex internal problem of managing municipal  and industrial residues.

        Just as the city is confined by  the surrounding  rural sector, it in  turn
exerts pressure against  the freedom of that sector to  manage  its wastes  by tradition-
ally cheap methods.  Air pollution  control  limits the  burning of orchard trimmings
and other agricultural residues;  water pollution considerations  bring to an  end the
practice of placing animal fattening pens astride streams and pushing manure into
the water; and the fly-producing potential  of manures  triggers nuisance-abatement
actions by burgeoning suburbs.   Collection  of manures  is expensive and,  with
agriculture's current disinterest in manures, the collected material is  as undispos-
able as the city's  refuse.  The city's response to the urban  problem is  often an
extension of its limits  to overwhelm agricultural enterprise  with ruinous taxes,
thus leading to more subdivisions and  a  loss of agriculture which is in  no way
beneficial to the economy.

        In many communities the situation is made more complex than  that of  an urban-
suburban core impinged on a rural sector by the fact  that the urban  core itself

-------
consists of several contiguous incorporated cities,  each confined by its  own
geographical and jurisdictional limits.   For example,  in the San Francisco  Bay area
some 83 separate "but impinged jurisdictions and agencies seek to deposit  their solid
wastes in each other's "back yard at 77 locations.

        Obviously there is need for a study of the ways in which an overall urban
community can organize itself to deal with all types of solid wastes generated in
its several sectors.


Economic Considerations

        Implicit in public attitudes toward waste materials and in the unintegrated
situation arising from urbanization is the problem of economics.  Concern in this
sphere, however, transcends both the concept of what the public can "afford" to pay
and the question of why the expenditure of three billion dollars each year  has not
staved off a crisis in solid wastes management.  The truth is that our national
economy depends to a significant degree upon the generation of wastes. While there
is reason to presume that a departure from our traditional wastefulness of  resources
might reduce the problem of solid wastes management by reducing the volume  of wastes
to be managed, there is no clear answer concerning its effect on the American standard
of living.  From the obvious premise that in the long run we shall have to  conserve
resources, it may be concluded that also in the long run the volume of wastes will
be reduced.  However, the problem of wastes management is immediate and no  immediate
change from an economy based on consumption of goods (production of wastes) is in
view.  Therefore there is a need for studying ways in which wastes themselves may be
salvaged, reworked, and recycled back into the resources that are being exploited
for economic good.


Technology

        Closely related to economic considerations are the technological  aspects of
wastes management.  Here two levels of concern are evident:  the technology that
produces consumer goods from natural resources, and the technology of disposal of
the residues of such production and of goods themselves when they are discarded by
the consumer.  With the exception of the new detergent introduced in 1965,  and
current efforts in the field of pesticide formulation, there is essentially no
instance in which one of the objectives of the product designer has been  its ultimate
disposability.  In fact "disposability" has been interpreted only in terms  of con-
venience to the user; a convenience characterized by single usage, with increased
consumption and consequent magnification of the volume of solid wastes generated.
Similarly, new types of materials are developed for all manner of objectives ranging
from intrinsic properties to appeal to the user.  Markedly absent, however, is the
objective of the ultimate disposal.  Thus a synthetic plastic, for example, may be
far better than the product of nature for commercial and industrial products — for
toothbrush handles, ball point pens, and breakable toys — and yet they increase
rather than decrease the problem of ultimate disposal.

        At the more common level of technology — that of solid waste disposal —
numerous deficiencies exist.  To begin with, attention has largely been directed to
the disposal of municipal refuse, i.e.,  the refuse collected from households and
commercial establishments within an urban community.  Thus technology of  disposal
has not developed in relation to the entire solid wastes problem of the community.
Agricultural residues, animal manures, demolition debris, industrial wastes, sewage
sludge, old automobiles and junk, and food processing wastes have each been viewed
as a separate problem of concern to some segment of the community rather  than to
the public as a whole.  In this circumstance there is little knowledge of the logistic,
economic, or technological problems of disposing of the collective refuse of an urban-
industrial-agricultural community.

        Attention to the technology of disposal of the municipal fraction of solid
wastes has, as previously noted, been handicapped by public attitudes toward wastes

-------
and overwhelmed by the advance of urbanization.   Specifically,  incineration is  con-
fronted with new constraints arising from air pollution problems  in many areas  as
well as with a greater variety of materials to be burned;  landfill operations are
beset by rising land costs., shortage of available landfill sites,  and increasingly
restrictive environmental objectives of society;  and composting,  never quite
commercially successful in the United States where applied to municipal refuse,
is further delayed by the rise of plastics and theinknown factors in community-wide
wastes management.  Essentially no experience exists in the technology of reprocessing
wastes to produce raw materials for industrial use.

        Thus it may be said that there is need for study of ways  to:  l) adapt
existing technology to area-wide waste disposal;  2) develop new technology for
reprocessing and reestablishing resource values  of wastes; and  3) relate the
technology of production to the objective of the ultimate fate  of the product.


Public Health

        Inasmuch as the least expensive method of disposing of  unwanted materials
is to throw them into an open dump, public health considerations  long ago became a
factor in solid wastes management.  Primarily the problem is one  of identifying and
controlling the conditions under which flies, mosquitoes,  rodents, and other vectors
of disease are sustained by refuse in the household, the collection system, or  the
disposal procedure.  Urbanization and the community-wide nature of solid wastes
problems have, of course, served to enlarge the  scale of this aspect of public
health.  Changing industrial technology, with its creation of new and exotic
materials which find their way into waste, may or may not add a new dimension to
public health concern.  Little is known of the environmental hazards that might
result from routing such materials through waste disposal processes.  At the same
time, the goals of environmental control have transcended the objectives of pre-
vention  of nuisance and infection of people with disease.  "Quality of the
environment" and "quality of life itself" are today commonly expressed objectives
of environmental management which in a broad sense involve public health concern.
Consequently there is need for a restudy of the  relationship of solid wastes manage-
ment methods to man's health and welfare, and for an entirely new look at the
components of refuse and their fate in waste disposal practices.   It may well be
that no new public health concern accompanies the growing problem of solid wastes
management but the truth in this matter is presently not known.


Education

        One of the major facets of the current crisis in solid  wastes management is
the historic and contemporary ignorance by both  the public and  its officials of the
nature of the problem.  Brief attention has been called to the  basis of this
ignorance in a discussion of public attitudes.  Other contributing factors are  the
complexity of problems in a modern community on  which people ought to be informed,
the absence of the subject from the context of formal educational programs, and the
near absolute misinformation in the public press.

        In the absence of educational contact with the solid wastes problem, urban
land-use planners have almost universally ignored solid wastes  disposal as one  of
the necessary considerations.  Similarly the broad humanistic program of the
administrator, the economist, and the political  scientist has little room for  such
mundane concerns as refuse.  Engineers have been traditionally  oriented to water
pollution problems, and even the public health official receives  but a minimal
orientation to solid wastes problems.  While it  may not "be realistically contended
that the professional education of such people should include a course in refuse
management, the truth remains that those who (as public officials) are to be
confronted with the solid wastes problem face such confrontation  with little more
knowledge than that of any other citizen.

-------
        The citizen gets his information largely from the popular press.   Within
the past two years there have appeared in several magazines extremely well-written
analyses of various pollution problems.  Unfortunately these serve largely to make
the citizen aware that a. problem exists, and that it is going to cost (presumably
the federal government) a vast sum to correct it.  Details of the problem reach the
citizen through the local newspaper concerned with the local problem.  It is  at
this point that information seems to break down.  Officials and citizens  alike
persist in such mistaken assumptions as that incineration is an alternative to
landfill, that land simply cannot be found for solid wastes disposal, and that by
refusing to accept feasible solutions to the solid wastes problem "somebody"  will
find a way to make wastes disappear, albeit not into the air.  In perusing news-
paper articles over an 18-month period in 1966-67 the authors of this report  found
no instance where the public was told, for example, that some 50 percent  of solid
wastes must be disposed of upon land regardless of how wastes are managed short of
recycling to the resource.

        These and other limitations of public information, however understandable,
indicate that a major need exists for education in the area of solid wastes manage-
ment at two major levels:

    1.  Education of planners, public administrators, engineers, economists,
        political scientists, public health officials, and others who are
        confronted with the problem of solid wastes management in the course
        of their professional service to the public.

    2.  Education of the public itself concerning the solid wastes problem
        and the role of the public in its solution.


Conclusion

        From the foregoing summary of the origin and nature of several aspects of
the problem of solid wastes management it is concluded that:

    1.  There is a need for a comprehensive study of solid wastes management
        on an area-wide scale.

    2.  The needed study should involve the coordinated effort of investigators
        with a wide variety of backgrounds.


NATURE AND RATIONALE OF STUDY

        The study herein reported is of the nature of a research program designed
to achieve a maximum of education of professional personnel through participation
of graduate students and faculty from the wide spectrum of disciplines described
in a subsequent section (Organization For Study).  It is derived from the needs for
study outlined in the preceding section and is based upon a number of general and
specific concepts.

        First it is recognized that all wastes are for the foreseeable future
destined to remain somewhere in the earth or its gaseous envelope.  Within such
a system the ocean is the only ultimate sink, although for practical purposes of
solid wastes management the dry land may also be considered a sink.  The  atmosphere
and flowing streams represent transport systems and cannot be made to function as
sinks.  They have a limited capacity to accept wastes however cheaply they may
deliver their loads to the sea or land.  Thus the general problem of research is  to
find the optimum way to sequester wastes in the earth without interfering with man's
freedom to use the earth's resources as he sees fit.

        A second general concept is that "wastes" are more properly defined as
residues of resource use which result from the application of current technology
under present concepts of economics and social objectives.  Thus both the amount

-------
and nature of solid residues are subject to change with either time  or the  objectives
and concepts of people, or both.  If such residues are conceived as  "resources  for
which we have not yet found a use/' technological research might be  expected to take
the direction of methods of stockpiling residues until such time as  they are needed.
Such research might relate to methods for segregating, transporting,  preserving,  and
sequestering valuable material.  If conceived as resources which should be  utilized
immediately, research would be concerned with how to make products more reusable and
with the technology of segregating and recycling them as well as of  minimizing  their
volume and, hence, the cost of their reclamation.  If conceived as forever  worthless
material, then research should continue along the lines of how to collect,  transport,
process, and sequester whatever uncontrolled volume and variety occurs without  in-
hibiting man's freedom of movement, unduly contaminating his environment, or
seriously interfering with his use of land, water, and air resources.

        For the immediate future it is expected that the "resources"  concept of
residues is less likely to prevail than the "wastes" concept for the reason that
there is a big backlog of immediately urgent problems begging solution;  and that
the long-range effects of the results of research will be to make it possible to
recycle and reclaim resource residues.

        A third general concept is that a program of research can simultaneously
achieve many of the objectives of the needed educational program while contributing
to the solving of jurisdictional, planning, economic, and technological problems
of solid wastes management.

        Within the framework of the foregoing general rationale the  research program
involves a number of more specific concepts of which the following are the  most
important.

    1.  The problem of solid wastes management must be attacked on a community-
        wide basis and must take into consideration residues characteristic of
        all sectors of the community — urban, industrial, and agricultural.
        This involves studies of both the jurisdictional system necessary to
        implement such a concept and the physical system necessary to handle
        wastes pursuant to any combination of disposal methods.  Thus a need
        exists for the application of the techniques of systems analysis and
        operations research.

    2.  As a prelude to technological solutions, a preliminary dimensioning of
        the community-wide problem of wastes management should include con-
        sideration of the meteorological and ecological effects of feasible
        methods, as well as of the economics of reuse of land which  serves  as
        the sink for solid wastes either within or outside the confines of
        the community.

    5.  It is not necessary to accept the idea that the volume of wastes and
        the scarcity of sinks requires that disposal be the principal objective
        of a sanitary landfill.  Conversely, land use planning cannot ignore the
        necessity for residues to be returned to the earth.  Thus the role  of
        refuse disposal in land use planning needs to be studied and widely
        recognized.

    4.  Long-distance hauling of refuse has generally been considered uneconomical.
        However, no analysis of the technical and economic potential of the U.S.
        transport system underlies this assumption.  It is conceivable that the
        facilities of rapid transit systems, railways, highways, and waterways  could
        be organized to transport solid wastes to remote areas where in properly
        managed landfills it would be stored until some later generation finds  a
        way to utilize its resource potential.  Here again a systems and economic
        analysis is in order.

    5.  The sewerage system of a modern community is designed to transport  peak-
        hour loadings of quite dilute wastes and to apply treatment  processes

-------
     likewise based on the removal or stabilization of low concentrations  of
     solids.  Most efficient use of a transport system,  however,  requires  that
     it be loaded to capacity at all times.   It is therefore conceivable that
     during the night hours of low flow,  trunk sewers could be flushed with
     return effluent, possibly pumped from the treatment plant at high pressure
     through small lines laid in the sewer itself, and made to transport large
     amounts of shredded refuse to the waste water treatment plant.   There
     known processes, modified as necessary, might be used to stabilize the
     material and so make it more acceptable for long-term storage on the  land
     or for discharge to the sea.

 6.  It is conceivable that the reuse of many components of refuse may require
     intermediate processing rather than simple salvage and recycling.  For
     example, a sand derived from glass bottles might be usable in ornamental
     concrete or in the manufacture of fiberglass, whereas neither industry
     could use old bottles directly.  It is  further conceivable that  raw
     materials for some industry as yet undeveloped might be derived  from
     the processing or fractionation of major components of solid wastes.

 7.  The full potential of known technology has not been realized in  solid
     wastes management for a number of reasons ranging from neglect to
     economics.  To explore such potential the adaptability of current
     technology to the handling of community-wide wastes should be investi-
     gated, with special attention to the unit processes and design parameters
     necessary for successful and economic application of such technology.
     In addition, improvement of present methods is necessary to meet such
     emerging social objectives as resource conservation, clean air and water
     per se, quality of environment, etc.

 8.  The problem of solid wastes will not be resolved by some great scientific
     breakthrough akin to splitting of the atom; and no single solution suited
     to all communities is in prospect.  Nevertheless there is need for, and
     prospects of, imaginative and ingenious ways of adapting known principles
     to the improvement of technologies which in various combinations will
     provide economical and socially acceptable solid wastes management to the
     urbanized community.

 9-  The range of possible methods of managing solid wastes is described by
     the seven major types of activity shown in Figure 1.  As indicated in the
     figure there will always be some residue which will return to the "sink,"
     i.e., the land or the ocean.  The goal of solid wastes management in
     general will be the minimizing of the volume of this waste stream. All
     present technologies, as well as foreseeable future ones, for dealing
     with the total mass of solid wastes or  selected fractions of it  fit well
     into the seven categories noted.  Typical current examples of each type
     are shown in the figure.

10.  In the past, public health concern for  solid wastes management have been
     largely those of vector control, air pollution,  and perhaps,  the effect
     of leachings on ground water quality.  The result is that little is known
     concerning the levels of toxic compounds resulting from current  methods
     of wastes disposal, or from proposed modifications  of such methods.
     Toxic metals, particulate matter, gases, and vapors from incineration;
     virus or other vectors of disease in compost or  sludges from animal
     manures, agricultural .wastes, and human sewage;  and the contribution  of
     wastes management to the stresses of urban life,  are all a part  of the
     problem of solid wastes management.   Although difficult to isolate from
     other factors in urban life there is no question that handling refuse
     in the home, transporting it through the streets, and concealing it some-
     where in the physical environment of man adds to the stress  of urban
     living.   In some cases the citizen is outraged by affronts to his
     aesthetic sense or indignant over filling of shoreline areas; in others
     there is definite danger to health through vectors  or air pollution.

-------
Type 1:  Reduction at  Source
           /*""" Reduction
Source
S
cd
CD
P>
CO
W
(U
W
x/'







_ I
                Process
                  Reduction of
                  materials
                  vasted
       \/
    Sink  (land)
                                  Type 2:  Diversion at Source
                                           Source
                                            (U
                                            f-i
                                            -p
                                            CD
                                        -p
                                        to
                                        I
                                                            Land or
                                                            Water
                                                            Resource
Process
  Discharge to
  streams
  piling or
  spreading on
  land
                                      Sink (land)
                                      or other  type  of
                                      disposal  system
Type 3:  Disposal to Sink
    Source
                                  Type 4:  Change of State
                                                       Atmosphere
                                                      (Air Resource'
                                           Source
      g
      05
      (U
      ^
      -P
      to
      w
      0)
      -p
      CO
      1
         Process
           Sanitary Landfill
                                                            Incineration
Sink (land)
                                          Sink (land)
           FIGURE I.  TYPES  OF  WASTE  DISPOSAL  SYSTEMS

-------
Type 5:   Direct Recycling
     Source
                     Salvage
      Sink (land)
                                      Type 6:  Indirect  Recycling
                                                     Atmos .
                                                     (Air
                                                     Resource)
                                           Source
                                                                Basic
                                                                Resources
ctf
0)
•
M
CQ
M
CD
-p
r


i
w
•i

y
__S
                                            _
                                          Sink (land)
                                    Process
                                      Pyrolization
                                      Wet Oxidation
                                      Biooxidation
                                      Rendering
                                      Reprocessing
                                      Animal Feeding
Type 7:   Conversion
     Source
CO
CD
-P
to
tn
Waste
(

r
1
1
                Atmos.
                (Air
                Resource) Land
                          Resource

                             /\
fL
               I
                  Process
                           I
                          ._(
                 Process
                   Composting
                   Digestion
    Sink (land)
                            FIGURE I.  Continued

-------
10
        Noise and traffic congestion are increased by the refuse handling
        operations; and no one wants to reside next door to a disposal
        operation.

        Consideration of the impact on man's physical and mental health must there-
fore be a factor in the planning as well as in the technology of wastes management.


OBJECTIVES OF STUDY

        The general objective of the study is to contribute, through research and
research participation, significant advances in knowledge of the systems and
technology, as well as informed professional personnel,  needed in managing solid
wastes in a manner which minimizes their effects in degrading the human environ-
ment and in inhibiting man's use of the earth's natural  resources.  Pursuant to
this general objective the research program is directed  to several more specific
goals, including:

    1.  To bring the competence of people in the wide variety of disciplines
        involved in planning, financing, and administering a community into
        effective combination with that of engineers and environmental health
        specialists in seeking solutions to problems in  solid wastes management
        which are technically sound, economically feasible, and politically and
        socially acceptable.

    2.  To bring the techniques of modern operations research to bear upon the
        organizational problems of managing solid wastes on an area-wide or
        community-wide basis; and on the physical and logistic problems of
        collecting, transporting, and disposing of wastes.

    3-  To seek through experiments and other research techniques improvements
        in conventional methods of wastes disposal and the development of new
        procedures for reclaiming or recycling fractions of the refuse mass.

    4.  To identify and seek answers to problems involving man's health and
        well being that may be associated with solid wastes and related to
        his use of land, water, and air resources.

    5.  To develop, through participation in research, greater understanding
        and knowledge on the part of engineers, planners, administrators,
        economists, public health specialists, and others who are confronted
        with the problem of solid wastes management in the course of their
        professional service to the modern urban-industrial-agricultural
        community.

    6.  To insure, through close coordination and effective communication with
        public and private agencies, the pertinence of research to real problems
        and the prompt availability of the results of research to professional
        practitioners.
ORGANIZATION FOR STUDY

        Four faculty investigators representing the College of Engineering and the
School of Public Health (Sanitary Engineering Research Laboratory) on the Berkeley
campus and the departments of Civil Engineering and Agricultural Engineering on the
Davis campus, were responsible for the management of the research program.  In the
conduct of the research these individuals were assisted by six additional partici-
pating faculty members responsible for guiding specific research teams and an
additional six faculty members interested in facets of the program currently beyond
the budgetary provisions but expected to be activated in future years.

-------
                                                                                 11
        During the report period (1966-67) one faculty investigator was on Sabbatical
leave from the University but engaged in an intensive study of composting — one of
the important technological aspects of the program.  The remaining three faculty
investigators and the six additional faculty members actively engaged in research
teams served as a Board of Directors to guide and coordinate the research activities.
In this they were assisted by a full-time project coordinator and a staff engineer.
The Board met regularly at two-week intervals to review, discuss, and redirect the
research effort as deemed necessary.  Each meeting of the Board was attended and
participated in by the professional personnel and graduate students participating
in the program, and by additional graduate students pursuing group study of solid
wastes, for formal University course credit.  The general organization for the
research program herein reported, together with the participating personnel is out-
lined schematically in Figure 2.

        A breakdown of the classes and disciplines of personnel involved during the
report period and anticipated for the future is presented in Table 1.

        During the period of study herein reported (1966-67) the organizational
structure proved to be so satisfactory and effective that it is expected to be
continued during the 1967-68 period, for which funds are available, and farther
into the future if financial support of the program develops.  The values shown
in Table 1 reflect the actual number of participants during the report period.
Identification of the discipline involved may be made from Figure 2.  As indicated
in footnotes to the table it is anticipated that the economist serving in an
advisory role in 1966-67 will in 1967-68 lead a research team closely integrated
with the Planning and Operations Research teams.  At the same time a reduction in
professional research personnel will be offset by an increase in graduate student
participation.  The total number of graduate student participants further rises
because of increased budgetary support in 1967-68.  Subject to funding, the entire
faculty group will become engaged on active research teams in 1968, adding such
facets to the program as are important at that time.  Present expectations are that
these will include such areas as public administration and such technological
problems as hydraulic transport, diffusion of solid wastes in ocean waters, and
management of the metals component of refuse.

        Cooperation with other federally and state financed projects on solid wastes
management is a feature of the organization for study.  Through a cooperative arrange-
ment with the California State Department of Public Health the type of information
required by the University research teams is included in questionnaires being used
by the Department in its state-wide survey and its demonstration project at Fresno,
California —both financed by the Public Health Service.  A similar arrangement
with the PHS makes available to the University group the results of a survey of
industrial solid wastes being conducted by the Food Machinery Corporation under a
federal grant.  Thus only one group seeks information and so improves the degree
of cooperation of the numerous public and private agencies from which data are
needed.

        To insure a constant two-way flow of information the project coordinator
serves on the Advisory Board of the State Health Department's solid waste program,
and frequent staff level discussions are arranged.  In addition, good working
relationships are maintained with numerous public and private agencies.


PIAN OF RESEARCH

        Pursuant to the general and specific objectives of the study, the research
program was designed to be conducted in two essentially sequential phases:   (l) data
collection and evaluation, and (ll) definitive research.  It was anticipated that
during the first phase all participants in the program would function as a single
research team to become fully acquainted with all aspects of the solid wastes
problem and to collect and evaluate data on current technology and management
techniques.  Specific activities of the group scheduled for this phase included:

-------
12
                   K K   W
3%3£&S
                                                                                       Q
                                                                                      
-------
























tn
-p
S3
cd
ft
•H
O
•H
-P
cd
p ,

O

CJ
£

p
p3^


























, — ,
rd
CJ
-P
cj cd
^ ft
pi -H
•P 0
5 -H
PR -P
C3
o
















co -d
VO CJ
1 -p
C— CJ
VO W)
OA >d
r-l P
FQ
^•^















t^— f — -.
VO r-l
i cd
vo ^3
VO .p
OA O
H <;





to
CJ
S3
•H
1 — 1
•H

tn
•H
p)



tn
H
P
-d
't>
•H
•d
d


0
d
•rl
H

•H
CJ
to
•H
O





tn
r-1
fd
fd

[>
•H
'd
d
H
ra
Cj
•H
i — 1
ft
•H
O
tn
•H
O




H
ccj
•d
•H

•H
H
H
CJ
0
tn
O
CJ
ft




, — )











03









O
H












c8
CM
H






CJA












H
H

d
o
CJ
> tn
SI
O CD
cd -P
Professors
research




i











o









^














UA







UA












VO


O
CO
•H
S
cd
Professors,




LT\
, — |











^O
r-l








_jj-
H













r-
H






_-j.
H











D--
H


H
cd
0
-P W
Professors,
active pi
advisory




VO











vo









HA














NA







LTN












LTN




H
Professiona
research




KA
	 i











o
OJ








OA














VD
H






VO












0
H

0
CQ
-P tg
CD cd
33
Graduate st
research




O s~^
\

i

i


i
i
i

o
i

i
i
i
i
i

i

-^ i


•d
(IJ
•"CJ -P
(D 
S3 -p
o to
•d to
pi H -P
Graduate st
individua
assignmen




i











LTA









1














_-j-







,












NA



O
tn
•H CJ
S -p
as
^ hD pi
Clerical an
(includin
undergrad
students)





















vS
t—
VD
OA

S
o3
CJ
-p
(-;
CJ
J_j
cd
CJ
to
in
S3
O
CJ
•H
4=
CJ
cd

QJ
g
O
CJ

•H
S
SH
CD

CD
•d
CJ

o
EH
CJ

-------
    1.  Collection and evaluation of published information  on  the technology
        and management of solid wastes.

    2.  Establishment of an information  retrieval  system.

    3.  Interviews and discussions with  officials  and operating personnel
        of public and private agencies concerned with solid wastes manage-
        ment in the San Francisco Bay and Los  Angeles areas.

    k.  Collection and evaluation of data on the composition and amount  of
        the various fractions which in combination constitute  the overall
        solid wastes of a community.

    5.  Definition and coordination of discrete areas of research to be  under-
        taken in Phase II by the individual research teams.

        It was expected that by the end  of the first year of study Phase I  would be
completed and Phase II sufficiently advanced that  its direction could be clearly
defined and evaluated; further, that the individual research teams would continue
data collection and evaluation in their  specific areas and  initiate experimental
work at the appropriate time.  Thus not  all aspects of the  definitive research  were
expected to begin simultaneously or at the same level of experimental effort.
However, all were expected to fit into and be  an integrated part of an overall
regional evaluation model capable of generating management  systems on the basis of
waste generating inputs.

        During the period reported research proceeded in accordance with this plan
and at a somewhat more rapid pace than was originally expected.

-------
                                    PART II
                        PHASE  I OF THE INVESTIGATION


                       II.  DATA COLLECTION  AND EVALUATION
LITERATURE SURVEY AND INFORMATION RETRIEVAL

        The first two aspects of Phase I described in the  preceding  section of this
report were begun in June 1966.  During the following six  months more than 500
documents dealing with solid wastes were collected and abstracted.   The abstracts,
rather detailed in nature, were typed on 6.5 in.  x 7-5 in. edge-notched cards.  The
cards were then codified and a manual information retrieval system  [l] was set up.

        An evaluation of the literature surveyed, with particular reference to its
pertinence to the overall problems of solid waste management,  as contrasted with
details of technology, revealed some interesting  facts.
        Generally, published papers concerned with refuse disposal  are written in a
"popular" style, i.e., nontechnical and slanted toward the "layman."  Those  con-
cerned with agricultural wastes, especially the animal manures,  are more technical
in nature.  Prior to the 1960's composting seemed to be the most popular subject of
papers on refuse disposal.  Occasionally an article on landfill  would appear, in
which case the subject usually would be on the advantages of abandoning an open dump
disposal operation in favor of a sanitary landfill.  Articles on the  management of
agricultural wastes were concerned more with handling than with  disposal,  probably
because agricultural waste disposal did not constitute the problem  which it  does
now. In those days individual operations were not as big as today's and satisfactory
disposition of most of the agricultural wastes generated by many of the operations
could be made by spreading on adjacent fields.

        As time advanced in the 1960's, the number of published  papers on  refuse
disposal increased.  However, the papers continued to remain mostly "popular" in
style.  Papers of a general nature were less common than those of a particular
nature.  The articles usually dealt with a description of a particular installation
or a particular community.  Incineration received more and more  attention, while
landfill constituted a close second.  On the other hand, the use of composting
declined as a subject of papers, and authors once blindly optimistic  became  more
skeptical, and downright pessimistic in many instances.  Authors of papers on the
management of agricultural wastes became quite prolific and the  style of their
papers continued to be technical.


Reports

        As was true with papers published prior to the 1960's, reports on  the
handling of agricultural wastes far outnumbered those on urban wastes.  In fact,
before the 1960's, reports on refuse disposal and management were quite rare.  The
reason for the paucity undoubtedly was the scarcity of money to  conduct the  research
on which reports are based.  Some of these reports are listed as numbers  [2] through
[9] in the REFERENCES.  Noteworthy among them are those published by  the Inter-
national Research Group on Refuse Disposal [7].

        During the 1960's reports on wastes management became more  numerous, the
increase being directly proportional to the increase in influx of federal  funds
into research on the subject.  Now the number is legion.  Especially  worth
mentioning is the series of reports issued by the Incineration Committee of  the
Division of Process Industries (ASME), the National Sanitation Foundation, and by
various regional groups and public agencies.  Randomly selected  examples of  these

                                         15

-------
16
reports are listed as numbers [lo]  through [17]  in the  REFERENCES.   The  subject
matter of the reports ranges from surveys of existing practices  in  solid wastes
management to comprehensive planning for environmental  health, and  from  waste
disposal methods to legal implications.


Journals

        Prior to the 1960's, American Journals devoted  solely to Solid Wastes Manage-
ment were limited to Compost Science and to the Refuse  Removal Journal.   As  the  name
implies, Compost Science was and is concerned chiefly with various  aspects of
composting, although it did occasionally treat other aspects  of  solid wastes manage-
ment, but only insofar as they could be  related to composting.   The Refuse Removal
Journal is primarily a trade journal and is more concerned with  the collection and
haul aspects of waste management than with disposal technology.   It is a strong
advocate of landfill and incineration; composting finding little favor with  its
editorial staff.

        Public Cleansing, a journal published in England,  has been  in circulation
for years.  The journal covers all  aspects of solid wastes management and invariably
contains interesting and informative articles.

        Although no new journals devoted exclusively to solid wastes appeared in the
1960*3, the problem of solid wastes management began to receive  more and more
attention, and finally achieved a position approaching  that of water supply  and
waste water treatment in the more widely distributed periodicals.   Thus  The  American
City and Public Works generally have a section devoted  to solid  wastes.   Among other
commonly-read periodicals whose orientation is toward the environmental  sciences
and in which solid wastes are receiving  increasing attention  are Environmental
Science and Technology, and Western City.  Compost Science and the  Refuse Removal
Journal continue to be geared to solid wastes management.

        From the trends observed in the  survey of literature  it  seems evident that
the pre-1960 situation of the scarcity of papers and reports  on  solid wastes
management is changing to one of abundance; and as is the case with so many  of the
newly popular subjects, will eventually  develop into one of superabundance.


PERSONAL INTERVIEWS

        Personal interviews with managing and operating personnel involved in solid
waste handling and disposal was a particularly important aspect  of  Phase I of the
project as they served to orient the members of the research  group— many of  whom
hitherto had had no direct contact  with  refuse other than as  a householder.  This
orientation served both to give an  idea  of the actual nature  of  refuse as it exists
at the disposal site and to promote an understanding of the day-to-day problems
confronting officials charged with  the task of managing refuse.   It was  particularly
revealing of the extent of public apathy and the nature of pressures from special
interests.

        The investigator group visited a total of 12 refuse disposal sites,  all
utilizing the landfill method since no refuse incinerators are in operation  at
present in either the San Francisco Bay  or Los Angeles  area.  Practice in these
12 situations ranged from that of meeting all the criteria of a  well-operated
disposal method to that of the slightly  improved open dump.  Salvage operations  were
also observed.  These ranged from the sorting and processing  of  tin cans to  the
classification and bailing of paper.  The can operation involved the use of  a
specially designed machine into which unsegregated refuse was dumped into one end
and the separated cans and refuse were discharged at the opposite end.   Two  or three
passes had to be made to bring about satisfactory separation.

        The officials of Ik public  and private agencies located  in  the San Francisco
Bay and Los Angeles areas were visited.   In each case the agency was either  directly

-------
                                                                                  17
responsible for waste management or concerned with it as a regulatory agency or as
one having a special mission involving refuse.  Responsibility for waste management
was found to rest in a variety of departments, the identity of which varied from
agency to agency-from the county health department in one instance to the county
highway department in another.  The impression gained from the interviews was that
long-range plans for waste management have been, are, or are being drawn up by the
professional personnel but that the changes for the implementation of these plans
generally are not good until public feeling is aroused and exerted.

        The investigator group was impressed with dedication and the generally
foresighted character of the personnel involved in wastes management despite the
evident lack of cooperation that is their common lot.  The interviews drove home
the need for a broad attack on the waste management problem, one that would encompass
not only technological aspects but the sociological as well.


CHARACTERISTICS AND AMOUNTS OF SOLID WASTES
Introduction

        In parallel with the survey of literature and establishment of an information
retrieval system, an intensive review was made of the amount of wastes of various
categories generated in a community and of the components of each.  Literature search,
personal interviews, case histories, and field analyses were all utilized in efforts
to get data on the kinds and nature of material appearing as solid wastes.  Of major
importance were cooperative arrangements with the California State Department of
Public Health and the Public Health Service, under which data on municipal and
industrial wastes generated in ongoing demonstration projects in California became
available to the research project herein reported.  As improbable as it might seem
from a rational viewpoint, long experience with refuse disposal has not produced
information on the composition of solid wastes in the detail now needed for manage-
ment purposes.  For this deficiency there are several reasons, including:

    1.  Traditional concepts of management.

    2.  Scope of concern with solid wastes.

    3.  Dislocation of systems.

    k.  Change in industrial technology.
  •
    5.  Cultural and sociological changes in America.

        These and related factors are so closely intertwined that they are not
separated sharply for discussion herein.  Instead, attention is called to some of
their separate or combined effects.

        Disruption of traditional concepts of management, with resulting need for
new approaches, has come about in recent years partly because of an increase in the
variety of wastes with which the public found it necessary to become concerned.
Historically, refuse disposal by any but the most primitive methods of dumping on
land or open burning has been concerned with refuse collected from individual house-
holds and commercial establishments within a city.  But, as noted in a previous
section, in the modern community industrial and agricultural residues (cannery wastes,
animal manures, demolition and construction debris, and automobile bodies and other
junk) have also become a part of the residue to be managed in a manner suited to
man's health, aesthetic, and social objectives.  Thus, by extending the scope of
the problem there has resulted a dislocation of technology as well as of the
jurisdictional and physical systems of wastes management.

        Dislocation of past inadequate systems of waste management is further
rendered critical by the sheer magnitude of the material to be handled.  The

-------
18
traditional 2 pounds per capita per day has now reached an estimated 6-8  pounds  in
many localities.  At such a rate the refuse from 130 million urban Americans  is
enough each year to cover 50 square miles with a compacted fill 10 feet deep.

        Further dislocation of technology derives from the changing  nature of
municipal refuse itself.  A historical spendthrift attitude toward resources  is
reflected both in a disconcern for wastes and a proliferation of such residues.
So great were our national resources that we became an affluent society in spite
of our wastage; and once the natural harvest of the earth had been reaped by  simple
extractive enterprise, American energy and inventiveness was turned  to a  sophisti-
cated industry capable of maintaining and extending that affluence.   One  by-product
of this development has been the never-ending variety of new waste products from
our industry.  With opulence also grew the desire for greater convenience of  living.
The result is disposable containers, nonreturnable bottles, short-lived plastic
objects, urban renewal, planned obsolescence, and all the other gadgetry and  concepts
which magnify the amount as well as the types of wastes which must be managed within
a community.  Garbage grinders now discharge to the sewers some 30$  to 80$ of organic
matter once collected as solid wastes; plastics and nonreturnable containers  have
increased in volume, with profound effects on combustibility and degradability of
refuse; metal cans without a salvable tin content are coming into use;  and industry
creates some 2,000 new products each year.  Furthermore, the domestic economy has
come to depend to a considerable degree upon the continued replacement of goods.


        Need for Refuse Analysis Studies.  As long as technology remained relatively
simple, there was no important need to obtain accurate estimates of  the relative
amounts of various components of solid wastes.  For landfill, volume of the mixed
refuse and its compactability are the important factors.  For incineration, the
percentage of noncombustibles and the problem of separating these out are most
important.  For salvage, the amount of specific salvable items and the cost of
removing them from the mass are important.  It is only where management of solid
wastes makes the objective of returning materials to the resources of the nation by
some of the more complex methods illustrated in Figure 1 (page 8), that a need is
felt for a greater knowledge of the composition of refuse.  Since these are the
objectives of today and tomorrow rather than of yesterday, it is to  be expected  that
detail is lacking on the actual weights and volumes of specific components.

        The general values so repeatedly quoted, including those stated in the
previous paragraph, are based more on estimates than on actual observations.  Those
which are based on actual observation usually are the results of isolated or  'one-
time-only' studies.  The validity of the more general of these findings is unknown
because of the absence of extensive and prolonged surveys.  The need for accurate
information on these subjects is quite obvious.  To rationally design a management
system, including collection, technology, and reclamation, a prime requisite  must
be that the nature and volume of the material to be managed is known. In addition,
the effects of time (as brought about by changes in standard of living, economy,
living habits, and neighborhood patterns) must be known so that reliable predictions
can be made, and hence make it possible to design long-term management systems.
Climatological and large-scale regional characteristics also exert an influence  on
the nature of wastes.  Thus, a management system suited to one section of the United
States or to a given geographical location would not necessarily be applicable  to
another section or location.
        General Estimates of Refuse Composition.  Reported estimates on the size of
the garbage fraction of refuse range from 5$ to 15$ [l8-26].  Reported values for
the ratios of combustible-to-noncombustible rubbish also vary, the range in these
classifications extending from 15$ to 25$ for the noncombustibles and 64$ to 75$ for
the combustibles.  A range of reported values also exists for breakdowns of these
totals.  Examples of the more common constituents are:  paper 42$ to 57$, metals
1.5$ to 8$, glass 2$ to 15$, rags 0.6$ to 2$, garden debris 10$ to 12$, and ashes
5$ to  19$  [l8-26].  As might be expected, the low value for ashes was found in a
report on the average composition of municipal wastes in California [l8].  Despite

-------
                                                                                  19
the differences in reported values for each of the constituents,  a general agreement
exists with respect to their relative positions in the total refuse in terms of
volume and weight.  Thus, paper always is ranked as the major component of the
rubbish fraction, followed successively by ashes (except in the southern,  south-
western, and southeastern tiers of the states), garden debris (plant debris),  metals,
glass, and the remaining constituents of rubbish.

        Estimates of the nature and quantities of industrial wastes, i.e., wastes  to
be disposed of outside the industries themselves, are few.  The absence of such
information stems partly from the reluctance of industries to publish it,  and from the
lack of persons or agencies interested and equipped for making such surveys.  Another
important class of wastes for which facts and figures are either nonexistent or are
highly speculative is that of the demolition wastes.  In this case, the problem is
one of developing feasible methods for collecting the information.

        Agricultural wastes are not as difficult to classify as are the other general
types of waste since basically they are the residues from animal and crop  production.
Difficulty arises in estimating quantities, however, since these are functions of
type of crop and seasonal variations.  As for animal manure production, the difficulty
stems from variation in reported values [27-29].


        Specific Estimates of Refuse Composition.  Major efforts are now being made
by various groups to bridge the information gap.  Thus, the U. S. Public Health
Service in conjunction with agencies of various states is making a county-by-county
survey to obtain information on waste generation and other aspects that would be
useful in developing systems of waste management.  Locally, the California State
Department of Public Health is engaged in comprehensive studies on waste generation
on a state-wide scale, and more intensively in two selected regions, viz., San
Francisco Bay area and Fresno (California) and its environs.  Another local investiga-
tion on waste generation is being conducted by the Food Machinery Corporation (FMC)
as a part of its attempt to develop, through a systems analysis,  functional
specifications for a multiprocess solid waste disposal and resource recovery system
based upon an improved incineration process.

        During Phase I of the research herein reported, the investigative  group
conducted two studies concerned with the nature of wastes.  One consisted  of making
a survey of types and an estimate of the amounts of various wastes generated in
Santa Clara County (California).  The second involved a determination of the change
in waste composition that has occurred during the past l6 years in domestic refuse
generated in Berkeley, California.


Waste Generation In Santa Clara County

        Santa Clara County was selected as a suitable place on which to base
estimates of the composition of solid wastes on an area-wide basis because it
represents a rapidly urbanizing area with heavily impinged urban, suburban,
industrial, and rural sectors.  The county has an area of 833,000 acres, and in
1966-67 supported a population of 980,000 [30].  In line with a change from an
agriculturally-oriented economy to one that is of a light industrial-service type,
the percentage of the total revenues derived from agricultural income has  declined
from 70$ in 1950 to 5$ in 1963.  Orchards and truck farms have given way to sub-
divisions and industry in the northern sector of the county.  This, of course, is
reflected by the changing nature of the wastes generated in the county. The most
recently published report on the generation of solid wastes in the county  lists a
daily per capita production of 5«3 lb [26].  A perusal of the report reveals,
however, that this value does not do full justice to the agricultural waste production
taking place in the county.  If the latter were taken into consideration,  a more
realistic total would be 8 lb/capita/day.  To arrive at this estimate a 'manufactured'
breakdown of the observed total mass of wastes into its major components had to be
devised.  Such a breakdown, illustrated in Table 2, was done by artifically
establishing a series of common denominators for the comparison of data collected

-------
20
in various social, climatic,  and geographic  regions  at  different  times  and seasons
of the year.  The information used in arriving at  these denominators was  gleaned
from several reports and publications [19,26,31-35]- With  this information at hand,
it was possible to give weight to specific components for values  where  agreement
exists and to compensate for  strictly local  conditions  and  for the  changing nature
of wastes.

                                      TABLE  2

                        ESTIMATE OF GROSS REFUSE GENERATION
                           IN SANTA CLARA COUNTY  (1967)
Type
Domestic
Industrial
Agri cultural
Special
Total
Ib/capita/day
3-5
0.5
1.7
2.3
8.0
tons/year
x 103
627
89.4
304
415
1,435-4
        Domestic Wastes.  Table 3 presents an estimated breakdown of domestic waste
production into its major components,  the percentage of the total weight  constituted
by these components, daily per capita  production,  and total annual production.  A
per capita production of 8 Ib/day, of  which 44 percent is domestic refuse,  was
assumed in arriving at the estimated values.

                                      TABLE 3

                     ESTIMATE OF COMPONENTS OF DOMESTIC REFUSE
                            IN SANTA CLARA COUNTY  (1967)
Classification
Garbage
Rubbish
Paper
Wood
Cloth
Rubber
Leather
Garden Wastes
Metals
Plastics
Ceramics & Glass
Wonclassified
Total
Percentage
of Total
12

50
2
2
1
1
9
8
1
7
7
100
Ib/day
0.42

1-75
0.07
0.07
0.04
0.04
0.31
0.28
0.04
0.24
0.24
3-50
tons/yr
75,240

313,500
12,540
12,540
6,270
6,270
56,430
50,160
6,270
43,890
43,890
627,000

-------
                                                                                   21
        Industrial Wastes.  Data on the types of wastes  generated by industries  in
Santa Clara County were collected as a part of Phase I of this study.   Estimates of
the amounts of each of these types is "being prepared by the  Food Machinery Corpora-
tion (PMC) under terms of a Public Health Service demonstration grant.   They were
not available at this writing but will accrue to the study in due time.   The collected
data, however, do permit an evaluation of the relative waste-generating  potential of
various industries.  Later, on the basis of the FMC data,  the planning and economic
research teams will be able to predict industrial waste  production on the basis  of
statistical and census-type information available in any community.

        According to a 1966 survey [36], 1,237 manufacturing firms are  functioning  in
Santa Clara County.  If the standard Industrial Classification Group Code [37] is
followed, these firms fall into 28 major groups.  These  groups, together with the
type of waste expected to be generated by each group, are listed in Table 4. The
number of firms belonging to each group as well as the number of employees hired by
them are presented in Table 5 •

        It may be expected that two types of solid wastes will be generated by the
28 major industrial groups listed in Table 5:

    1.  Wastes that are common to all types of industry.

    2.  Wastes that are peculiar to the individual industry  by reason of the
        nature of the raw material processed and the product produced.

        In the first grouping is included such items as  wood, fiber, paper, metal,
and plastic containers in which raw materials and supplies for maintenance and
operation are received by the industry; scraps of metal, wood, paper, and plastics
used by the industry in painting, crating, or otherwise preparing its product for
shipment; and the normal debris from general housekeeping and operating  and
maintaining an industrial plant.  In this latter category are such items as waste
paper, floor sweepings, broken wooden pads, rubber tires,  storage batteries, broken
glass, and junk which results from obsolescence or breakage  of equipment or equip-
ment parts.  Residues of paint, industrial chemicals, dyes,  adhesives,  and solvents
remaining in discarded containers are likewise common to all industries, although
the amount and kind varies from industry to industry and from plant to  plant.

        The type of wastes peculiar to individual industries is suggested in the
summary as presented in Table 6.

        In the foregoing list of solid wastes generated by specific industries
residues from plating, pickling, painting, and similar operations have been included.
For the most part these processes produce liquid residues which are managed separ-
ately from the solid wastes.  Nevertheless, oils, paints,  dyes, plating and pickling
liquors, solvents, adhesives, etc. do appear on such solid wastes as metal cuttings,
sawdust, paper, wood, cloth, and junk.  Without adding to the amount of wastes to be
managed, they might have a public health or nuisance significance in certain methods
of disposal, hence their presence is noted in the list of industrial waste materials.


        Agricultural Wastes.  Although at present a large portion of agricultural
wastes does not require special handling in Santa Clara County, inasmuch as it is
left in the field, the time may soon come when even this fraction will  have to be
handled.  For example, prunings now routinely burned in the  field may have to be
disposed of in some other fashion when air pollution legislation makes  the practice
illegal.  When this comes to pass, it may be necessary to transport the  prunings to
some disposal site.  Approximately 71 percent of agricultural wastes which do require
special handling occurs in the form of animal manures and 29 percent in  the form of
prunings.  In terms of tonnage, approximately 212,000 tons of animal manures and
88,000 tons of prunings must be disposed of annually in Santa Clara County.  These
numbers are the results of computations based on the size of the animal  population
as given in the records (1965-66) of the county of Santa Clara and the  city of
San Jose on reported manure production per animal [33l,  and  on data on  production

-------
22
0
•s
1
H
0)
8
a
p CQ
3£
0 -H
-P ft
W> 08 O

III
4>
4)
,£)
,0
Plastic
08 0

o o
FH

-P

!
08 a
•H
•x rH -p
5 pll
13 W
-d
5
CO
1






Industry

-------
                                        TABLE 5

             CLASSIFICATION OF MANUFACTURING FIRMS IN SANTA CLARA COUNTY,
                       CALIFORNIA BY NUMBERS AND EMPLOYEE CROUPSa
Standard & Industrial Classification Group
Code
17
19
19
20
22
23
24
25
25
26
27
28
28
29
30
31
32
33
3^
35
36
36
37
38
39
39
39
39

Classification
Plumbing, Heating & Air Conditioning
Ordnance & Accessories
Ordnance - Explosives
Food & Kindred Products
Textile Mill Products
Apparel & Other Finished Products
Lumber & Wood Products
Furniture - Wood
Furniture - Metal
Paper & Allied Products
Printing, Publishing & Allied
Industries
Chemical & Allied Industries
Chemical - Explosives
Petroleum Refining & Related Industries
Rubber & Misc . Plastic Products
Leather & Leather Products
Stone, Clay & Glass Products
Primary Metal Industries
Fabricated Metal Products
Machinery except Electrical
Electrical - Tubes
Electrical
Transportation Equipment
Professional, Scientific & Controlling
Equipment
Misc. Mfg. - Jewelry & Toys
Misc. Mfg. - Nuclear Products
Misc. Mfg. - Missiles
Misc. Mfg. - Industries
Total
Number
of Firms
9
1
2
1^5
1
23
21
44
15
21
166
60
1
9
31
3
63
22
123
164
5
145
38
59
22
2
2
37
1,234
(A)
9


64

22
18
38
13
9
137
47
1
4
27
3
38
15
96
132

74
29
42
21


32
871
(B)


2
38
1

2
6
2
6
22
12

5
2

17
6
20
26

31
7
10
1
i

4
221
(c)



35

1
1


6
6
1


2

4
1
5
4
4
29
1
4



1
105
(D)



8






1





4

2
1
1
5

1


1

24
(E)

1

















1

6
1
2

1


12
(F)


























1

1
Key to Number of Employees:  (A) 1 - 25, (B) 26 - 100, (C) 101 - 500, (D) 501 - 2,000,
                             (E) 2,001 - 10,000, (F) Over 10,000.

aBased on information contained in the 1966 report of the Food Machinery Corporation.
 Reference [38].
See

-------
                                                           TABLE 6




                                  SOURCES AND TYPES OF INDUSTRIAL WASTES,  SANTA CIAEA COUNTY
Code
17
19
20
22
?3
2lf
25
25
26
27
28
29
30
31
32
33
J^
35
36
37
38
39
S- & I C. Group Classification
Plumbing, Heating, Air Conditioning
Ordnance and Accessories
Food and Kindred Products
Textile Mill Products
Apparel and Other Finished Products
Lumber and Wood Products
Furniture, Wood
Furniture, Metal
Paper and Allied Products
Printing and Publishing
Chemicals and Related Products
Petroleum Refining and Related
Industries
Rubber and Miscellaneous Plastic
Products
Leather and Leather Products
Stone, Clay, and Glass Products
Primary Metal Industries
Fabricated Metal Products
, it "1

Electrical
Transportation Equipment
Professional, Scientific,
Controlling Instruments
Miscellaneous Manufacturing
Waste Generating Processes
Manufacturing and installation in homes,
buildings, and factories
Manufacturing and assembling
Processing, packaging, and. shipping
Weaving, processing, dyeing, and
shipping
Cultirg, sewing, sizing, and pressing
Sawmills, mill work plants, wooden con-
tainer manufacture, and manufacturing of
misc. wood products
Manufacture of household and office
furniture, partitions, office and store
fixtures, and mattresses
Manufacture cf household apd office fur-
niture, locVers, bedsprings, ard frames
Paper manufacture, conversion of paper
ana paperboard, manufacture of paper-
board boxes and containers
Newspaper publishing, printing, litho-
graphy, engraving, and bookbinding
Manufacture and preparation of inorganic
chemicals (ranges from drugs and soups
to paints and varnishes, and explosives)
Manufacture of paving and roofing
materials
Manufacture of fabricated rubber and
pro
Leather tanninr and finishing; manu-
facture of leather belting and packing
Manufacture cf flat glass, fabrication
or forming of glass; manufacture of
concrete, gypsum, and plaster products;
forming and processing of stone and
stone products, abrasives, asbestos, and
mi£.c. non-mineral products

rolling, forming, and extruding
operations
Manufacture of metal cans, hand tools,
general hardware, non -electric heating
apparatus, plumbing fixtures, fabricated
structural products, wire, farm machine-
ry and equipment, coating and engraving
of metal
Manufacture of equipment for construc-
tion, mining, elevators, moving
stairways, conveyors, industrial trucks,
trailers, stackers, machine tools, etc •
Manufacture of electric equipment,
appliances, and communication apparatus,
machining, drawing, forming, welding,
stamping, winding, painting, plating,
baking, and firing operations
Manufacture of motor vehicles, truck,
and bus bodies, motor vehicle parts and
accessories, aircraft and parts, ship
and boat building and repairing motor-
cycles and bicycles and parts, etc
Manufacture of engineering, laboratory,
and research instruments and associated
equipment
Manufacture of jewelry, silverware,
plated ware, toys, amusement, sporting,
and athletic goods, costume novelties,
buttons , brooms , brushes , s igns , and
advertising displays
Expected Specific Wastes
Scrap metal from piping and duct work,
rubber, paper, and insulating materials;
msc . construction and demolition debris
Mecals, plastic, rubber, paper, wood,
cloth, and chemical residues
Meats, fats, oils , bones, offal vegetables,
fruits, nuts and shells, and cereals
Cloth and fiber residues
Cloth and fibers, metals, plastics, and
rubber
Scrap vood, shavings, sawdust, in some
instances metals, plastics, fibers, glues,
j P - >
Those listed under Code 2.k, and in addition
cloth and padding residues
Me tals, plastics , res ins , glass , wood,
rubber, adhesives, cloth, and paper
Paper and fiber residues, chemicals, paper
coatings and fillers, inks, glues, and
fasteners
Paper, newsprint, cardboard, metals,
chemicals, cloth, inks, and glues
Organic and inorganic chemicals, metals,
plastics, rubber, glass, oils, paints,
solvents, and pigments
Asphalt and tars, felts, asbestos, paper,
cloth, and fiber
Scrap rubber and plastics, lampblack,
curing compounds, and dyes
Scrap leather, thread, dyes, oils,
p o s^ing an u g co pounds
Glass, cement, clay., ceramics, gypsum,
asbestos, stone, paper, and abrasives

slag, sand, cores, patterns, bonding
agents
Metals, ceramics, sand, slag, scale,
coatings, solvents, lubricants, pickling
liquors
Slag, sand, cores, metal scrap, wood,
plastics, resins, rubber, cloth, paints,
solvents, petroleum products
Metal scrap, carbon, glass, exotic metals,
rubber, plastics, resins, fibers, cloth
re s i due s
Metal scrap, glass, fiber, wood, rubber,
plastics, cloth, paints, solvents,
petroleum products
Metals, plastics, resins, glass, wood,
rubber, fibers, and abrasives
Metals , glass, plastics, resins, leather,
rubber, composition, bone, cloth, straw
adhesives, paints, and solvents
aStandard Industrial Classification Group Code.   See  Reference  [36].

-------
                                                                                  25
of prunings published in various local reports [30,33,3^1.  Other information herein
reported was gathered from:

    1.  The files of the county of Santa Clara Public Health Department,
        Vector Control Division;

    2.  Visits to the University of California Agricultural Extension Service,
        Santa Clara County;

    3.  The city of San Jose Public Health Department, Milk Inspection Division;

    k.  County of Santa Clara 1965 Agricultural Report; and

    5.  Visitc to livestock producers in the county.

        The principal agricultural wastes generated in the county are animal
manures — chicken and cattle, animal carcasses, grape and orchard prunings,  crop
harvesting residues, greenhouse horticultural wastes, and pesticide containers.
(The pesticide containers are listed as an agricultural waste because these  are
used and are discarded in agricultural operations, i.e., their use has become an
essential feature of agricultural practice.) Problems arising from presently
improper management of these wastes are air pollution in operations involving the
incineration of the wastes, breeding of insects and rodents as a result of improper
storage, and generation of offensive odors through improper handling.  A distinct
health problem arising from the presence of pesticide containers is the release of
the toxic materials remaining as residue in the cans to the surrounding environment.


        Animal Manure:  The major portion of the manure that must be handled in
Santa Clara County originates in 6l dairies, 60 chicken ranches, and one feed lot.
The total animal population of the 6l dairies is approximately 8,520.  These
animals produce about 99>600 tons (moisture content - Qk%) of manure per year.  The
distribution of this waste generation in the county is indicated by the data listed
in Table 7 (see Figure 3 for identification of planning areas).  Although a  few of
the dairies sell or dispose of the manure they produce, the majority have the
manure hauled away by private collectors, usually for use on truck gardens in the
Salinas area.

        At present only one feed lot is in use in Santa Clara County (San Martin
area, see Figure 3)-  The lot is used as a site for fattening steers for the market,
and as such, augments the natural pasture when it is not in full use, viz.,  from
late summer until early spring'-about nine months per year.  According to the
operator, approximately 17,000 cattle were fed on the lot during this nine-month
period in the past year.  Assuming an average residence time of three months per
steer, the year-round average would have been 5,666 steers.  Again assuming  that
each steer produces 60 Ib (wet weight) of manure per year, the year's production
on the lot was 510 tons wet weight or 8l.6 tons dry weight.  Unfortunately,  the
arrangement of the pens on the feed lot is such that manure is allowed to accumu-
late rather than be trampled and thus promote its dehydration.  A consequence of
this typically poor arrangement is the development of a fly problem so severe as
to warrant action by the County Health Department.  The visual amenities  are met
by interposing a white picket fence between the nearby highway and the barbed wire
fence of the lot itself.  The picket fence partially conceals the animals and the
manure from the public view.  With respect to disposal, periodically the  manure
is hauled to Salinas for use in truck gardens.

        Fixty-six of the chicken ranches are devoted primarily to egg production
and four to raising fryers.  The 56 egg producers have a layer and brooder popula-
tion of 1.2 million.  The four fryer producers average about 27,500 birds/year
(about 4-1/2 'generators'/year).  The distribution of this waste generation  in the
county is indicated by the data listed in Table 8 for the several planning areas
presented in Figure 3.  The egg laying age for the layers begins at about six months
and end at 30 months.  At the end of their optimum egg laying age,  they are  sold  to

-------
26
                                     TABLE 7

                     DISTRIBUTION OP MIRY MANURE GENERATION
                              IN SANTA CLARA COUNTY
Planning
Area
1
1
11
13
14
15
16
18
19
20
21
22
23
24
Total
No.
Animals
744
390
40
6ll
530
l4o
400
531
660
400
205
2,008
1,761
100
8,520
Percent
of Total
8.7
4.6
0.5
7-2
6.2
1.6
4.7
6.2
7-7
4-7
2.4
23.6
20.7
1.2
100.0
Wet Weight
tons/yr
8,670
4,580
498
7,180
6,180
1,593
4,684
6,180
7,670
4,685
2,390
23,485
20,610
1,195
99,600
Dry Weight8"
tons/yr
1,384
732
80
1,146
987
255
748
987
1,226
748
382
3,758
3,296
191
15,920
Volume
cu yd/yr
14,430
7,630
830
11,930
10,290
2,655
7,800
10, 290
12,770
7,800
3,985
39,150
34,350
1,990
166,000
           On basis of solids content at 16 percent.

           On basis of solids content at 1200 Ib/cu yd.
food processors for use in products in which chicken meat  is  the  principal constit-
uent.  The egg layers generate about 55,100 tons (29$ solids) manure/yr.   The  manure
is rather wet and amorphous in texture.  Generally,  it is  hauled  away.  However,
one operator dries and sells his chicken manure, while another quite successfully
disposes of his chickens' waste with the use of an anaerobic  lagoon. The fryers
generate approximately 12,570 tons (29$ solids) of manure/yr.  Waste generated
in the raising of fryers differs considerably in nature from  that of wastes from
egg-laying operations.  Fryers are raised on a sawdust litter and consequently
wastes produced in the operation are relatively dry and easy  to handle.   Because
of the improvement in texture and in overall quality brought  about by the incorpora-
tion of the sawdust, the material is easily disposed of through sales to  local
nurserymen, by whom it is in great demand.  The manure is  used primarily  within the
country.


        Carcasses:  The disposal of dead animals is not a  problem in the  county at
present, since tallow rendering plant operators will pick  up  the  carcasses, provided
they are placed in metal containers.  Dead chickens constitute a  large  portion of
the yearly collection of carcasses.
        Grape and Orchard Prunings:   In 1965 there were 56,731 acres of bearing
and nonbearing trees and vines in Santa Clara County.   Data concerned with

-------
27
        I


        I
        o

        <
        DC
        <

        O

        tn
        UJ
        a:

        s
        m


        1
        o
        s
        LJ
        tr
        CD

        Z
        <


        Q.
        tO


        UJ

        cn

-------
28
                                      TABLE 8




                  POULTRY MANURE GENERATION IN SANTA CLARA COUNTY
LAYERS AND BROODERS
Planning
Area
6
7
11
15
14
16
IT
18
19
20
21
22
23
TOTAL
No.
Birds
4,500
7,000
13,000
8,500
5,800
15,000
9,000
11,000
5,000
72,400
229,000
407,000
421,000
1,208,700
Percent
of Total
•37
•58
1.08
• 70
.48
1.24
•75
•91
.41
6.00
18.95
33.70
34.83
100.00
Wet Weight
tons/yr
204
320
595
386
265
683
413
501
226
3,300
10,437
18, 570
19,200
55,100
Dry Weight3-
tons/yr
59
93
173
112
77
193
120
145
66
958
3,027
5,385
5,570
16, ooo
Volume^
cu yd/yr
255
400
743
482
331
854
517
627
283
4,128
13,030
23,200
24,000
68,850
FRYERS
Planning
Area
Ik
19
21
22
TOTAL
Avg. No.c
Birds
45,000
45,000
160,000
25,000
275,000
Percent
of Total
16.4
16.4
58.1
9-1
100.0
tons/year
@ 29$ T.S.
2,060
2,060
7,310
1,140
12, 570
Total Solids
tons/year
598
598
2,122
332
3,650
Volume
cu ydd
5,150
5,150
18,300
2,850
31,450
      a
       On basis of solids content at
of wet weight.
      bOn basis of 1500 Ib/cu yd.




      cBased on 4-1/2 generations per year.
       One cu yd =
                       Ib.

-------
quantities produced with type of crop are listed in Table 9-   As listed in the
table, the yearly production of prunings amounts to approximately 75,000 tons.
Orchard prunings constitute about 91 percent of this amount.


                                     TABLE 9

               QUANTITIES OF FRUNINGS BY CROPS IN SANTA CLARA. COUNTY
Crop
Apples
Apricots
Cherries81
Grapes
Peaches
Pears
Plums
Prunes
Walnuts
Misc.
Bearing Land
Land
(acres )
170
7,571
1,915
3,303
69
5,105
96
26,4o8
7,120
280
Prunings
tons/acre/yr
2.250
2.125
0.4125
2.000
1-835
2.250
1-350
1.150
1.000
-
tons/yr
582
16, 100
790
6,606
127
11, 500
130
30,450
7,120
18
73,223
Non -Bear ing Land
Land
acres
14
261
607
66
3
714
in
2,361
381
-
Bearing
w
50
25
50
50
50
33-1/3
25
25
50
-
Prunings
tons/acre/yr
1.125
0-534
0.206
1.000
0.902
0.750
0.340
0.290
0.500
-
tons/yr
16
l4o
125
66
3
536
14
686
191
-
1,777
    Cherries not pruned after 6th year.
        Burning is the usual method of disposing of prunings.  They either may be
buckraked to the site for burning or may be carted there on a sled or trailer.
Generally, apples, apricot, cherry, peach, and pear trees are pruned and the
prunings burned in the winter.  Grape vines, prune trees, and walnut trees are
pruned and the trimmings burned during the late winter and spring months.  This
means that 90 percent of the total wastes from deciduous fruit and nut trees and
from grapevines are burned during the winter months.  Waste burning exercised as
a means of apricot and pear tree disease control is done in June and September,
since cytospore infected apricot wood should "be removed during June, and fireblight
infected pear wood should be eliminated by the end of September.  Dead or dying
trees generally are burned during January, February, and March.  Burning generally
has been replaced by disking as a means of disposing of grapevine prunings in
modern vineyards.  Burning continues to be practiced in the older vineyards in
which close planting precludes a disking operation.

        Shredding followed by incorporation of the shredded wastes in the soil has
been tried as a means of disposing of orchard wastes in the county.  Advantages of
the shredding-burying system of disposal are: l) avoidance of the air pollution
  388-229 O - 70 - 4

-------
which results from burning the primings,  and 2) returning organic matter to the
soil.  Because of the,hot dry climate characteristic of the region in which orchards
are situated, the shredded wastes are decomposed within a period of six months or
less.  However, decomposition proceeds at a much slower pace in the moist soils and
cooler climate characteristic of those regions adjacent to the Bay.  A grave dis-
advantage inherent in incorporating the shredded material into an infected soil is
that the chips can provide an excellent harborage and source of nutrient for certain
fungi, as for example Armlllaria mellea (oak root fungus).  As such, the chips would
make it possible for the fungus to survive long beyond the time it would otherwise
have persisted.  Moreover, if the chips do not decompose sufficiently rapidly,
there is the strong possibility that they may serve as a means of spreading the
fungus to noninfected soils.  Another hazard is the possibility that the chips may
serve as a food for subterranean termites.  The persistence of these termites is a
problem in the older apricot and prune orchards in the Bay area.

        Until means are found for controlling the survival of plant pathogens in the
buried plant wastes, burning will continue to be the only safe way (with respect
to plants) of disposing of orchard and vineyard residues.  Research concerned with
finding these means is now under way at the University of California at Riverside.
Disinfection by chemicals would seem to be one way of circumventing the spread of
the fungal diseases.  Unfortunately, chemical control is not presently feasible
with respect to pests which bore into branches or twigs.  Among such organisms are
the shot-hold borer, the branch and twig borer, and the cane maggot.  The overall
problem of disposal is further complicated by the refusal of the San Francisco Bay
Area Air Pollution Control District to allow burning of agricultural debris beyond
the next two-year period.


        Greenhouse Wastes and Harvesting Residues:   At present greenhouse wastes
are hauled to sanitary landfills for disposal.  Although not constituting a refuse
disposal problem per se, residues left in fields and orchards do give rise to
problems with respect to vector breeding and to aesthetics.


        Pesticide Containers:  Accumulations of pesticide containers were observed
in several locations.  Such a practice is fundamentally unsatisfactory, especially
where, because of the pesticide residue remaining in them, the accumulated containers
may constitute a hazard to children, pets, and livestock, or to adults who may
attempt to put the containers to other uses.  Unfortunately, the containers in which
pesticides are distributed are especially attractive for such uses.  Combustible
containers should be burned directly after having been emptied; and noncombustible
containers should be treated along with other noncombustible refuse.

        Prom the study of Agricultural Wastes in Santa Clara County it is concluded
that, because of the nature and quantity of the wastes generated, the disposal
problem of agricultural wastes is as acute as that of municipal wastes.  While the
problem in Santa Clara County is intensified because of the large quantity of
agricultural wastes generated per capita, along with the ban placed on burning by
the Bay Area Air Pollution Board, the situation underscores a need for agricultural
wastes to be considered in any community-wide plan of solid wastes management.


        Special Wastes:  Included under the heading "Special Wastes" are all wastes
not covered in the categories domestic, industrial, and agricultural.  Included in
this broad category are wastes ranging from street sweepings and demolition debris
to sewage sludge.  At present, quantitative data on the wastes falling into the
'special' category are either nonexistent or are too fragmentary to be of use.


Change in the Composition of Berkeley Wastes

        Introduction.  The second field investigation of the composition of refuse
made during Phase I of the study was an intensive short-term analysis of municipal

-------
                                                                                 31
refuse of the City of Berkeley, California.  Several considerations made  such an
analysis desirable and suggested Berkeley as the appropriate place to undertake it.

        First is the necessity, as pointed out in the Santa Clara County  study, of
using values reported from widely scattered sources in the past in estimating the
waste generating potential of the domestic sector of a specific community today.
Second is the current belief that the characteristics as well as the per  capita
production of wastes have changed with the years.  This belief is easily  sub-
stantiated rationally by the general knowledge of changes in the packaging industry  -
the development of "TV" dinners, the multiplication of uses for plastics,  the non-
returnable bottle, and similar innovations.  It is not, however, easily documented,
particularly as to its effects on estimates of refuse production based on the
analytical data which have been produced in the past.  Even in a single specific
community for which data are available, predictions based on the passage  of time
must always assume that conditions remain similar to those under which the basic
observations were made, subject only to modifications to compensate for increased
per capita output and shifts in the nature of the area affected (e.g., from
residential to commercial, etc.).  The underlying rationale of the study  herein
reported, however, is that the foregoing assumption must be seriously questioned
and that a knowledge of the effect of time on change in composition of refuse is
essential in predicting waste generation, and hence in designing waste management
systems.

        The selection of Berkeley as a place to spot check changes in the composition
of municipal refuse with time was a result of more than simple geographical con-
venience.  Because of the dearth of information on work done prior to the past few
years, studies concerned with the effect of time, at least extended periods of time,
are generally not feasible except in isolated cases.  Berkeley is just such a case.
In June of 1952, as a part of a project concerned with the reclamation of municipal
refuse by composting, the Sanitary Engineering Research Laboratory analyzed incoming
domestic and light commercial refuse from selected areas of the City of Berkeley.
This was classified as to chemical and physical composition and origin over a period
of one month [2].  With this information at hand it seemed probable that  a repetition
of the analysis might yield important evidence of the changes in composition and
amount of refuse over the years.  Therefore, in May 19^7 the 1952 survey  was repeated
under closely similar conditions.  Refuse was again collected from the same areas
and was classified as in the 1952 study.


        Equipment and Procedure.  Facilities for conducting the study consisted of
a 15-in. wide by 27-ft long conveyor belt, suitable containers (44-gal "toters"),
a scale, rake, and pitch forks.  A picture of the setup is shown in Figure k.  The
procedure was relatively simple.  Each day a truckload of refuse collected on a
route identical with that followed in 1952 was dumped into a chute leading to a
conveyor belt.  (The truckload of refuse was weighed on a public weighing scale
prior to coming to the dump.)  The compacted refuse was loosened by means of the
rake and pitch forks and then gradually fed to the conveyor belt.  Here the items
were handpicked, classified, and then deposited in nearby containers.  As each
container was filled its contents was weighed and recorded, as is shown in Figure 5.

        It requires two loads to handle the daily route of each City of Berkeley
collection crew.  During the segregation study, only the first load collected in
each route was processed.  However, since the area served by each route is relatively
uniform throughout with respect to economic level and class of dwellings,  no
substantial difference should exist between the compositions of the first and
second loads.  The weights of the various loads from the various routes and the
percentages of the total refuse that was segregated in the study are given in Table
10.  According to the table, about 30 tons of refuse was segregated, or about 60
percent of the total refuse collected in the areas.

        An idea of the types of accounts served by the various routes may be gained
by consulting the data in Table 11, in which is given a breakdown of the  various
dwellings receiving service.  The principal change in type of dwelling over the

-------
32
FIGURE  4.   SETUP  FOR  SEGREGAT-
ING  REFUSE   AT  THE  BERKELEY
WASTE  DISPOSAL SITE
plastic rain-shoes,  "thongs" (zories),
and tennis shoes, as well as the leather
varieties.  Interestingly, in 1952 shoes
of the leather variety constituted the
greater part of the  items in this cate-
gory; whereas in 1967 they were only a
small fraction of the total.  Most of
the glass waste was  in the form of
bottles or jars, as  is shown in Figure 6.
It is interesting to note that there were
more and better grade liquor bottles from
the medium and high  level income areas
than from the low income areas .  The
reverse was true with respect to beer
cans.

        The compostable material listed
in Table 14 and 15 includes paper and
other material which could be amenable to
composting.  The heading is not intended
to convey the impression that the material
would be suited to composting as it is,
i.e., as having the  proper C:N ratio for
good composting.  For example, the wastes
from the light-commercial district,
although compostable, could not be com-
posted without the addition of nitrogen.
The garbage and garden debris were grouped
with soiled paper under "compostable"
refuse in the 1952 studies.  However,
past 15 years was the reduction in number
of homes and increase in number of apart-
ment houses.
        Results.   The  weights of the var-
ious components of the refuse are listed
in Table 12, and their percentages in
Table 13.  The changes in respective
weights of the components which took place
over the 15-year period between 1952 and
1967 is indicated by the data listed in
Table 14; and that in  percentage composi-
tion, in Table 15.

        The material listed under "Garbage
and Garden Debris" was, with respect to
weight, about 80 percent in the form of
garbage.  The reverse  was true in terms
of volume, since the garden debris was
much bulkier than the  garbage.  In general,
the garbage fraction of the garbage-
garden debris mixture  was higher in the
low income neighborhoods than in the
high income districts.  Large items of
garbage were mostly in the form of bones
and wastes too large or unsuited to dis-
posal in the home garbage grinder.  Items
classified as shoes included rubbers,
   FIGURE 5.   WEIGHING  SEGREGATED
            REFUSE  ITEMS

-------
                                                                      33
                          TABLE 10

 WEIGHT OF THE INDIVIDUAL LOADS OF REFUSE AND THE PERCENTAGE
        OF TOTAL REFUSE PER ROUTE THAT WAS SEGREGATED
Route
H-2
West
Special
L-4
0-1
A -2
R-3
C-4
Total
Type of District8
Low -Me d.
Residential
Low
Residential
Low
Residential
Low -Me d .
Residential
Med. - High
Residential
Apts . and
Light Commercial
Med. - High
Apt. Residential

Weight (Ib)
1st Load
9,210
8,940
10,270
7,590
8,720
6,210
8,420
59,360
2nd Load
6,900
5,130
5,9^0
T,530
6,390
1,680
5,9^0
39, 510
Total
16, 110
14,070
16,210
15,120
15,110
7,890
14,360
98,870
Percentage
Segregated
56
64
63
50
58
79
59
60
Income level.
                          TABLE 11

          TYPE OF ACCOUNT RECEIVING REFUSE SERVICE
Route
H-2
West
Special
L-4
0-1
A -2
R-3
C-4
Income Level
Low to Med.
Low
Low
Low to Med.
Med. to High
Med. to High
Med. to High
Residences
407
272
353
3^5
423
-
310
Apartment
Houses
37
21
23
22
-
28
64
Stores
5
24
14
15
-
72
2
Total
449
317
390
382
423
100
376

-------
                                                            TABLE 12




                                        COMPOSITION  OF BERKELEY REFUSE IN TERMS OF WEIGHT8
Route
H-2
West
Special
L-l*
0-1
A -2
R-3
c-i*
Total
Day
of
Week
Tues.
Wed.
Thurs.
Mon.
Tues.
Wed.
Thurs.

District
Low - Med.
Resid.
Low
Resid.
Low
Resid.
Low - Med.
Resid.
Med. - High
Resid.
Apts.
Light Comm.
Med. - High
Apt. Resid.

Load
9,210
8,91*0
10,270
7,590
8,720
6,210
8,1*20
59,360
Paper
Soiled0
3,005
3,139
l*,ll*0
2,852
3,219
1, 578,
2,670
20,603
Clean4
813
342
278
11*3
306
2,661
1,335
5,878
Garbage
& Garden
Debris
1,783
2,1*02
2,769
2,281
2,620
955
2,077
li*,887
Bottles,
Broken
Glass
1,277
1,037
1,036
869
1,157
355
996
6,727
Tin
Cans
913
958
864
669
625
206
722
4,957
Plastics
257
159
191*
151
163
72
101
1,097
Rags
153
103
176
32
82
17
69
632
Metal
29
18
1*1*
15
1*1
26
15
188
Shoes
38
1*1
52
9
25
Tr.
12
177
Misc.f
91*2
71*1
717
569
1*82
31*0
1*23
l*,2ll*
 Expressed as pounds.




 Based on income level and type of dwelling.




CPaper which had been in contact with garbage;  no market  as  salvage.
T^aper which would have a market value .




eAt least 80$ garbage.
                                                                                  Dirt,  rocks, wood, etc.
                                                             TABLE 13




                                      COMPOSITION OF BERKELEY REFUSE IN TERMS  OF PERCENTAGES

Route

H-2

West
Special
L-U

0-1

A -2

R-3

c-i*

Average
7 Loads
Day
of
Week
Tues.

Wed.

Thurs.

Mon.

Tues.

Wed.

Thurs.



District51

Low - Med.
Resid.
Low
Resid.
Low
Resid.
Low - Med.
Resid.
Med. - High
Resid.
Apts.
Light Comm.
Med. - High
Apt. Resid.

Paper
b
Soiled
32.6

35-1

1*0.3

37.6

36.9

25.1*

31-7

34.7
c
Clean
8.8

3-8

2.7

1-9

3-5

1*2.9

15-9

9-9
Garbage
& Garden
Debris
19.1*

26-9

30.0

30.1

30.1

15.4

21*. 7

25.1
Bottles,
Broken
Glass
13-9

11.6

10.1

11.5

13-3

5-7

11.8

11-3

Cans

9-9

10.7

8.1*

8.8

7-2

3-3

8.6

8.1*

Plastics

2.8

1.8

1-9

2.0

1-9

1.2

1.2

1-9

Rags

1-7

1.2

1.7

0.1*

0.9

0.3

0.8

1.1

Shoes

0.1*

0.5

0.5

0.1

0.3

Tr.

0.1

0.3

Metal

0-3

0.2

0.1*

0.2

0.5

0.1*

0.2

0.3

Misc.6

10.2

8.3

7-0

7-5

5-5

5-5

5-o

7-1
   T3ased on income level and type of dwelling.




    Paper which had been in contact with garbage; not marketable.




   cPaper having a market value.
 At least 80$ garbage.




SDirt, rocks, wood, etc.

-------
                                                  TABLE 14
                               COMPARISON OF THE COMPOSITION OF REFUSE IN 1967
                                    WITH THAT IN 1952 IS TSBMS OF WEIGHT3
Route
H-2
West
Spec.
L-4
0-1
A -2
R-5
C-4
Total
(7 Loads)
Year
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
Load
9,210
6,400
8,9^0
6,200
10,270
7,240
7,590
6,100
8,720
6,760
6,210
5,080
8,1*20
4,240
59,360
42,020
Tin
Cans
91?
70J
958
1*99
864
903
669
668
625
706
206
355
722
354
^,957^
4,188
Bottles,
Broken
Glass
1,277
689
1,037
6l4
1,036
977
869
842
1,157
740
355
357
996
550
6,727
^,769
Rags
153
103
103
164
176
49
32
93
82
111
17
55
69
65
632
64o
Metals
29
49
18
63
44
35
15
Tr.
4l
Tr.
26
100
15
Tr.
188
247
Shoes
38
32
41
25
52
22
9
Tr.
25
Tr.
Tr.
Tr.
12
Tr.
177
79
Plastics^
257
Tr.
159
Tr.
194
Tr.
151
Tr.
163
Tr.
72
Tr.
101
Tr.
1,097
Tr.
Compos table
Material
5,601
^3<»3
5,883
^,350
7,187
4,826
5,276
4,o47
6,145
4,683
5,19"*
3,792
6,082
2,944
41,568
28,985
Wastes ofd
No Value
942
481
741
485
717
428
569
450
482
520
340
421
423
327
4,212
Height in pounds.
 Plastics were not measured in 1952 because they were insignificant as  a refuse  component  at  that  time.
cThe 1967 figures include soiled paper,  clean paper,  garbage,  and garden debris.
Tfestes which can be used neither for compost nor as  a marketable salvage.
                                                  TABLE 15
                            CHANGES IN COMPOSITION OF REFUSE OVER 15-YEAR PERIODa
Route
H-2

West
Spec.
L-4

0-1

A-2

R-3

C-4

Average
(7 Loads)
Year
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
1967
1952
Type of
District
Low - Med.
Resid.
Low
Resid.
Low
Resid.
Low - Med.
Resid.
Med. - High
Resid.
Apts .
Light Comm.
Med. - High
Apt. Resid.


Tin
Cans
9-9
11.0
10.7
8.0
8.4
12.5
8.8
11.0
7-2
10.4
3-3
7.0
8.6
8.4
8.4
10.0
Bottles,
Broken
Glass
13-9
10.8
11.6
10.0
10.1
13-5
11-5
13-8
13-3
10.9
5-7
7-0
11.8
13.0
11.3
11.4
Rags
1.7
1.6
1.2
2.6
1.7
0.7
0.4
1.5
0.9
1.6
0.3
1.0
0.8
1.5
1.1
1.5
Mstals
0-3
0.8
0.2
1.0
0.4
0-5
0.2
Tr.
0-5
Tr.
0.4
2.0
0.2
Tr.
0.3
0.6
Shoes
0.41
0.50
0.46
0.04
0-51
0.03
0.12
Tr.
0.28
Tr.
Tr.
Tr.
0.14
Tr.
0-3
0.2
Plastics0
2.8
Tr.
1.8
Tr.
1.9
Tr.
2.0
Tr.
1-9
Tr.
1.2
Tr.
1.2
Tr.
1-9
Tr.
Compostable
Material
60.8
67-8
65.8
70.2
70.0
66.6
69-5
66.3
70.5
69.4
83.6
74.7
72.2
69.4
69-7
69.0
Wastes of
No Value
10.2
7-5
8.3
8.2
7-0
6.2
7-5
7-4
5-5
7-7
5-5
8-3
5-0
7-7
7.1
7-4
 Values are those for percentage  of total load.
 Based on income level and type of dwelling.
 Plastic content of 1952 refuse was practically  nonexistent.
 1967 - report on compost figures includes soiled paper,  clean paper,  and garden  debris.
 Wastes usable neither for compost nor as a marketable salvage.

-------
 36
FIGURE 6.   TYPICAL  GLASS  WASTE SEGREGATED   IN  BERKELEY   STUDY
 judging  from observations made in the 1952 and 1967  studies, the garbage fraction in
 the  1952 studies was about twice that of the 1967 study.
        Discussion.  In interpreting the data in Tables  12 and 13, it should be noted
 that  they concern paper which had been stuffed into  a  common container, had been
 compacted, and had been dumped in one big pile — all with other refuse.  Hence,
 opportunities for the paper to become soiled by contact  with garbage were more than
 ample.  Obviously if the paper had been segregated at  the source, the ratio of soiled
 to clean paper, as found in the present study, might well have been reversed.  Most
 of the  paper, soiled and clean, was in the form of newspapers.  When garbage was
 encountered it usually was contained in a paper bag.

        The weights of the plastics and of the garbage-garden debris are not
 indicative of their relative volumes in the total refuse volume.  Plastic is
 extremely light in weight, especially since most of  it was in the form of film or
 wrappers, as is shown in Figure 1.  On the other hand, garbage and garden debris,
 because of their high moisture content, are quite dense. Using tin cans as a
 comparison (shown in Figure 8), a filled container of  the type used in the studies
 would contain from 60 to 90 lb of tin cans, from 10  to 20 Ib of plastics, or from
 150 to  200 lb of garbage.

        A comparison between the 1952 and 19^7 studies indicates that the load
 weights increased materially, as is shown by the total weights of 7 loads in 1952
 and 1967 — the total weight of 7 loads was approximately ^0 percent greater in
 1967  than in 1952.  Since in both studies the first  load of the day was the one
 being studied, no doubt exists as to fact that the trucks were loaded to capacity
 in each study.  (A common complaint among dump operators is about the tendency of
 the collection crews to pack the first load of the day.)

        In the fifteen-year interim, the percentages of  tin cans, bottles and
 broken  glass, rags, metal, shoes, and the wastes of  "no  salvage value" changed
 very  little.

        As stated earlier, the garbage fraction of the 1967 refuse was only about
 50 percent that of the 1952 refuse.  The decrease in the garbage fraction is due,
 as is true throughout the U. S. to:

-------

FIGURE 7   TYPICAL  PLASTICS SEGREGATED  FROM  DOMESTIC
                         REFUSE
FIGURE 8.  TIN CANS  SEGREGATED  FROM  DOMESTIC  REFUSE

-------
38
    1.  Increase in the number of homes equipped with garbage disposal units  in
        the medium and high income areas;

    2.  Increase in frozen food consumption;  and

    3-  Increase in the comsumption of "TV" dinners.

The increase in the -frozen food consumption was accompanied by an increase in the
generation of soiled paper.  According to this small  study,  the increase in the
consumption of "TV" dinners was especially pronounced in the low income areas —
as judged by the number of empty "TV" dinner containers in their refuse.

        Undoubtedly the compostable fraction of the 196? refuse would be less
desirable than that of the 1952 refuse for a compost  operation.  The former had
a much larger fraction of paper and garden debris than did the latter.  For example,
meat scraps and green vegetable trimmings were far more abundant in the 1952  refuse,
whereas they were almost nonexistent in the 1967 refuse.  As stated before, the
1967 compostable material would have to be fortified  with nitrogen in any practical
composting operation; whereas in 1952 only the light  commercial refuse had a  sub-
optimum C:N ratio (i.e., excessively high C:N ratio).

        An interesting sidelight on the change in living standards or habits  is
given by the change in the nature of the items constituting the "shoe" category.
As noted in a preceding paragraph, discarded shoes in 1952 were mostly of the
leather variety, and more shoes than shoe substitutes and rain gear were discarded.
In 1967.) however, the leather variety of shoe was far less abundant than the  sub-
stitute, i.e., zories (thongs) and tennis shoes.  More rain gear (plastic rainguards
for women's shoes) also were noted in 1967.  Reasons  for the changes are that Japan
had not begun exporting the zori, and plastic "booties" had not been produced to
any great extent in 1952-  Probably the greater part  of the leather variety of shoes
ends up in Goodwill or Salvation Army collection centers.

        Except for the items listed under "rags" and "shoes", and of course other
than those in the apartment-light commercial district, in 1967 no significant dif-
ference was observed between neighborhoods (i.e., low, medium, and high income
districts) with respect to percentage composition of the refuse collected in  each
of them.  Interestingly, the amount of rags in the refuse from the low income
districts averaged 70 percent more than that from the medium-high and 39 percent
more than that from the low-medium income neighborhoods.  The differences were
even more pronounced with respect to shoes, with the  low income neighborhoods dis-
carding more than three times the amount of "shoes" as did the medium-high income
neighborhoods, and twice that from the low-medium income neighborhoods.  In 1952
rag production was about the same in all districts.  It is difficult to state what
the case was with respect to "shoes" in 1952, since the amount of the discard was
so small that it was recorded as a trace amount and no actual weights are at  hand.
The higher production of the rags in the low income districts probably is due to
the fact that items that have outlived their usefulness to their owners in the
low income bracket have no direct reuse potential, and hence end in the refuse can.
On the other hand, cloth items (clothing)  discarded  in the medium and high income
neighborhoods can be used again, and hence ends either in a "Used Clothing" store
or at Goodwill Industries or the Salvation Army.

        No estimates are given at this time regarding change in per capita production
of refuse.  Such estimates would require some searching of the City of Berkeley's
records with respect to population or census tracts.   The time interval between the
computation of the observations at the dump and the writing of this report was not
long enough for such a search.  However, it will be made during the coming year, and
further appropriate analyses will be made at that time.

-------
Definition and Coordination of Research Areas

        The fifth and final aspect  of Phase I of the study was that of defining and
coordinating the areas of research  to be undertaken by the separate research teams
during Phase II of the study.  Initially, of course, certain decisions had to be
made regarding Phase II in order  to constitute the overall investigative group which
was to participate in Phase I. Thus it was known from the beginning of the project
that planning, operations research, public health, and technology would all be given
special attention.  Furthermore,  it was expected that coordination of the ongoing
research would be maintained by the participating faculty, as outlined in Part I.
During the course of Phase I,  however, it became clear that economics should be
given greater attention by the planning and operations research teams and that
salvage, biological oxidation, and  wet oxidation studies should be added to the
planned studies of technology  of  landfill, incineration, and composting.

        The most important feature  of the final aspect of Phase I, however, was the
development of a Regional Waste Generation and Evaluation Model into which the entire
project activity could be fitted  in such a manner that the product of each research
team was coordinated with that of every other team toward a common goal.  This model
is presented in Figure 9 and explained in some detail in the following chapter.


1
Regional
Economic
Model



Waste &
(Cons.
Mo
1
1
Interregional
Analysis
Model

1

National
Economic
Model






snerator
Sector)
iel
L


Spatial Distrib.
of Wastes
Model


Population
Model






1
Land Use
Model
i

Process
Technology
Model
1


Public


Health
Model
1






1

Waste Collection
Treatment and
Disposal Model




  FIGURE  9.   REGIONAL  WASTE  GENERATION  AND  EVALUATION  MODEL
        From the figure it is evident that the model designed to describe waste
collection, treatment,  and disposal  for an individual region or community depends
upon inputs and feedbacks from a  number of other models or subsystems.   The activ-
ities of each of the several research teams are associated with one or  more of the
subsystems.  The place  of public  health and of technology in the overall model is
clearly shown in Figure 9-  The planning team is simultaneously concerned with land
use, population, spacial distribution, and economic models.  Operations research is
concerned with the whole system and  with the economics, transportation, and analytical

-------
aspects.  (See Chapter III.)  Operations  research  likewise  serves to maintain the
framework and to develop further the subsystems  on which success of the overall
waste generation evaluation model depends.

        With the development of the model and its  subsystems  the study was prepared
to proceed with Phase II, although various  aspects of Phase I must continue  in-
definitely.  Specifically the collection  and evaluation  of  data maintenance  of
retrieval system, and compiling of information on  components  of refuse are all
continuous activities which form a part of  several of the subsystems depicted in
Figure 9-

-------
                                    PART  III
                       PHASE  II.   DEFINITIVE RESEARCH


                             III.  OPERATIONS RESEARCH
INTRODUCTION

        Investigative work of the operations research team proceeded from the basic
concept that the need for engineering and technological advances in the treatment,
disposal, and recovery of solid wastes is subordinate only to the need for effective
management and operation of such systems.  Furthermore, the systems are themselves
so complex and large in scale that tenable plans and decisions concerning their
future nature and operation may be considerably enhanced by the application of
'systems analysis' types of studies [39,ko].  Such studies lend themselves to broad
interdisciplinary approaches such as might be required for the solid wastes problem,
in which such diverse factors as economics, public health, engineering, law, soci-
ology, political science, city planning, geography, and demography need to be
considered.  Examining the effect of such factors on some meaningful measure of
worth in order to obtain an optional plan of decisions and operations is the
traditional domain of operations research.  Recognizing, of course, that optimizing
a system in which some of the inputs are qualitative while other are quantitative
in nature is no simple routine task, the study herein reported is nevertheless based
on the concept that effective management of solid wastes in a community involves  the
type of complex interrelationships to which systems analysis methods are well suited.

        The broad objective of the study was to explore the potential of operations
research to help in the definition and solution of the solid waste disposal problem.
Initially the task was to develop an overall conceptual model which would integrate
the research efforts of all research teams in the four definitive research areas,
and which would provide the framework for evaluating alternative solutions to the
total refuse disposal problem.  The expectation was that the model would be flexible
enough to be applicable to a wide spectrum of alternatives such as, for example,
ocean disposal and use of transfer stations, mobile treatment units, stationary
processing plants, or home disposal units; it would be sensitive to environmental
constraints and governmental controls; and useful in determining location of inter-
mediate and final master transfer points, collection routes, etc.

        The second task implicit in the general objective of the research was to
convert the conceptual model into a mathematical model by which the inputs from the
various research teams in the several areas of definitive research could be utilized
to develop the optimum decisions and operational procedures on which management
depends.   It was envisioned that this overall mathematical model would probably
make use of digital computational techniques, and be programmed and coordinated by
a systems analysis team under the primary responsibility of the operations research
and planning and economics research teams.

        The first of the two tasks was completed during Phase I of the study.  The
results are summarized in Figure 9-  Progress in the development of the mathematical
model is the subject of the remainder of this section of the report.


WASTE GENERATION AND EVALUATION MODEL

        The overall or regional waste generation model depicted in Figure 1 (page 8)
consists of several elements or subsystems which are in themselves complex in nature.
However, before a waste system can be evaluated it is necessary to know something of
its properties and interrelationships with outside factors, the physical nature of
the system, and how to estimate its inputs.  In the case of solid wastes management
the most important prime mover of the system is the input waste load.   For this
reason, it was decided to develop some method of predicting the waste  profile for an
arbitrary region and time period.  The result of such a development is the mathematical
model of wastes generation presented in Figure 10 and the related Table 16 which
defines the symbols used.

-------
                    A
                   0

                   ISI
UJ



o

oT
C+G+E
           m  uj

           E  «
SPE
              U.

              o
a:


I
a:
ui

S
CO
          i
           V
          I oo
          UJ U O
          o: uj 2
                   * LJ  —*
                   Jr 2  UJ
                   i5§
                     UJ


                   ^ <

                   £ £
                   i i-
                    A
                 C
                   o
^O
                                 0^

                                 03"
                    I

                    o
                             A
                    o
                    a
                           0

                           CO
                     =<
                  V
AL
RRE

                         o
                                     0>

                                     CO
                                     CO
                               §


                               I
                                     \7
O
                                              o
                                              UJ
                                                      CM
                                                      (M
                                                        UJ


                                                        UJ

                                                        o
                                                                   u.
                                                                   o
                                                  UJ
                                                  o
                                                  o
                                                        o
                                                        H


                                                        UJ

                                                        I
                                                        UJ

                                                        (T


                                                        CD

-------
                                                  TABLE 16

                                    INFORMATION FLOW FOR REGIONAL WASTE
                                      GENERATION AND EVALUATION MODEL
Symbol
                                                       Definition
             The n x n national technological coefficient matrix  with general  element  {a^j\ representing
                the value of goods or services of type i in millions of dollars  required for the pro-
                duction of one million dollars of goods or services  of type  j.
  Y

  Sc


  Be

  Sg

 nil
  He

  Ng


  He


  P
The n x 1 yearly final demand vector for the nation.

Population figures of the two regions under consideration in terms of their consumption
   characteristics .

The imports and exports of the n basic commodities between the two regions.

The proportion of the government consumption sector in each of the two regions.

Same as A tut for the region under consideration.

Same as Y but for the region under consideration.

An n x m matrix whose general element {a^i} represents the value of commodity i in millions
   of dollars required by the waste disposal activity to dispose of one ton of waste of
   type j.

An m x m matrix whose general element |a^ A represents the number of tons of type i waste
   disposal service required per ton of operation of waste disposal service industry j .

An m x n matrix whose general element {a^j} represents the number of tons of type i waste
   disposal service required per one million dollars worth of production by industry j.

An m x v matrix whose general element {cjj} represents the annual number of tons of waste
   of type i generated by all households in household category j .

An m x q matrix whose general element {gji} represents the annual number of tons of waste
   of type i generated by all government units in government category j .

An m x r matrix whose general element {e^j} represents the annual number of tons of waste
   of type i generated outside of the region by import category j for disposal within the
   region.

Demographic data required for household categories used in waste regression analysis.

Data on number and type of government categories which produce waste to be used in waste
   regression analysis.

Data on waste generated outside of the region under consideration and accepted for disposal
   by the waste industries inside the region.

An m x m + n matrix whose general element {p^.V represents the annual number of tons of
   waste of type i generated by industrial category j .

An m x s [where s=m + n + v + g + r] matrix whose general element {v^ A  represents the
   annual number of tons of waste of type i generated by all sources of category j .
An s x k matrix whose general element
   category i located in area j .

An m x k matrix whose general element
   of type i generated at location j .
                                                        represents the proportion of sources of


                                                        represents the annual number of tons of waste
             The node-arc incidence matrix  of the transportation network of the regional waste col-
                lection and disposal model.

             The set  of disposal  site waste  capacities.

             The set  of Public Health constraint functions.

             The set  of coefficients representing the material balance equations of the waste interchange
                (treatment ) stations .

             The cost row vector  representing the collection, treatment, and disposal costs of each arc
                in the collection,  treatment,  and disposal network.

             The minimum yearly cost of collecting, treating, and disposing of set of wastes W.

             The allocation of waste flows and corresponding collection routes resulting from the
                solution of Z°.

-------
        Three basic steps are involved in  the  construction  of  the general model
(Figure 10):

    1.  Establish the general structure of the waste  collection-treatment-
        disposal system.

    2.  Estimate its inputs for the location and time under consideration.

    3-  Perform an optimization study of the system and establish its
        feasibility and measure of worth.

        These steps are indicated in Figure 10 in terms of  the information  flow
required for the. analysis.

        The Waste Collection-Treatment-Disposal Model is the central core of the
analysis.  It describes the system in terms of a set  of mathematical equations,
called the constraints of the system, which include the transportation  network (T),
the process technology (B), public health  constraint  (H), five disposal capacities
(D), and the initial location and magnitude of the waste sources  (w).   These con-
straints are obtained from the various sub-studies indicated on the flow chart.
The Operations Research team proposes to predict (W)  through the use of a number of
sub-studies and models.  The basic data required for  this waste generator are
obtained from a National Economic Model, a Population Model, and various studies
from the Process Technology, Land-Use Models.

        The third step, which is the determination of some  measure of worth in terms
of an economic objective function, may be  initiated upon completion of  the  first two
steps.  Data for this mathematical function may be obtained from Process Technology
in terms of cost coefficients (R).  The objective function  is  then optimized subject
to the constraint equations and produces the optimal  collection plan F° and/or
measure of worth Z°.  A more detailed description of  these  steps in terms of the
nature of each sub-block in Figure 1 appears in the sections which follow.


WASTE COLLECTION-TREATMENT-DISPOSAL MODEL


General Description

        In many megalopolis areas today, solid waste  collection and disposal systems
are rapidly approaching environmental or economic limits.   Herein  lies  the  charter
for seeking innovative and alternative methods of carrying  out large-scale  waste
collection, treatment, disposal, and recovery  operations.   Initially, a single-period
(one year) mathematical model is formulated to deal with the broad problem  of
handling total waste flows from generation points through intermediate  treatment
and/or transfer locations to final recovery or disposal areas. A  fixed technology
is assumed throughout this static analysis. The objective  of  this evaluation model
is to ascertain the optimal operating characteristics for a single period given the
cost and waste generation profiles (in magnitude, types of  waste and  space).  Part
of the optimal solution will be given in terms of location, capacity, and type of
waste handling activities.  In addition, the optimal  allocation of waste flows
between waste activities will be found. The optimization criterion will be to
minimize the operating costs plus amortized investments subject to city planning,
public health, and political-legal constraints.

        The model is designed for regional (megalopolis size)  areas although it may
be utilized for single towns or rural areas as well.   However, the waste problem  of
small communities and rural areas may be solved by a  much simplier analysis.  The
regional model described at this time is presented in general  form so as to be ap-
plicable to any specific urban waste handling  and environmental control system.
It must be stressed at the outset, however, that the  interrelationships between
conversion of types of wastes in solid, liquid, and gaseous forms  play  an important
role in the analysis of alternative technologies and  waste  management  systems.

-------
It is not the intention here to develop new engineering technologies,  as  such, but
only to evaluate the effect of their incorporation into a general waste flow manage-
ment system.

        By a waste flow management system,  is meant the handling and conversion
operations of various types of waste flow from its generation to its final  absorption
into the physical environment or economy.  Of course,  the system over time  is a
closed loop but initially the static analysis considers the generation and  disposal
activities as being independent.  The interactions over time between the  regeneration
and reabsorption of waste flows will be considered in the dynamic Leontief  Model  and
the multiperiod analysis of the next phase  of the study.  Indispensible building
blocks for the multiperiod situations, however, are the single-period optimal plans
hereinafter developed.


Mathematical Formulation

        The essential structure of the waste collection treatment and disposal model
is that of a minimum cost flow multicommodity network.  The network (Figure 11) is
represented by the node-arc incidence matrix T composed of rows  with index  set N
and columns with index set A.  Each row represents an interchange point,  which may
be divided into three sub-node sets[j3, I, Ejwhere

                N = [S, I, E],

            and S = The set of source nodes representing the waste generation
                    locations of different  types of waste.

                I = The set of intermediate points.  These may represent
                    treatment plants or transfer stations.

                E = The set of sink nodes.

Treatment plants may be of two types, viz., those which primarily accept  liquid
sewage flows and convert them to solid sludge for final disposal or recovery, and
those which primarily accept solid waste input flows and convert them to  solid and
liquid resultant flows in addition to salvage material through the operations of
grinding and sorting.  Transfer stations are points where solid  wastes are  stored
and/or transferred to different haul vehicles for further transport.
         W,
           W2
                 W
               FIGURE  II.    WASTE   FLOW   NETWORK
  388-229 O - 70 - ;

-------
14-6
        The sink nodes are points  representing final disposal areas.  They may take
two forms, i.e., recovery destination where the reclaimed waste residues (composting,
salvage) are returned to the economy as  raw resources, and dump areas such as oceans,
landfill, incineration, etc.,  where wastes are returned to the physical environment.

        Corresponding to each column of  the T matrix is a directed arc of the form
(i, j) representing the possible directional routes or connections from node i to
node j for waste flow of type k.* Fictitious arcs may be included to represent paths
of flow through a node when node costs are considered.  By partitioning the index
set of the columns of T into four subsets representing arcs between the three node
subsets defined earlier, one can see from Figure 11 that the matrix T has a special

structure.  Here  V  represents sections of T which may have nonnegative elements

and C^) indicates blocks which contain  all zero elements.  The set of arcs of the

network may be partitioned into four subjects, viz.,

                         A = t(S, I),  (S, E),  (I, E),  (I, I)]
                                      ARCS
                     (S,l)       (S,E)       (I,E)       (1,1)
                                                                        NODES
          Multiple arcs are allowed between pairs  of nodes.

-------
        A column vector of waste flow variables, F, is now defined with the general
element ff. equal to the amount of waste flow of type k passing from node i to node
j measured in tons per year.  The vector column F is of dimension  A|, where  A
indicates the number of elements of the arc set A,

        At each intermediate point in the waste flow network some form of inter-
change is possible between the flow variables.  These conversions are determined
by the technology of the operation represented by the node.  Thus, the general
                         ^
interchange coefficient b.  . is defined as the amount of type i flow input to station
                         1J                            k
k per unit of type j flow output from station k.  The b..  comprise the set of
coefficients B obtained from the process technology model.  One may now represent
the conversion of waste and salvage flows in the form of material balance equations.
By combining these coefficients with the matrix T, the new coefficient matrix T is
obtained which represents a network with gains.

        Utilizing the set W and D obtained from the waste generator and land use
studies, we may now represent in compact form a set of inequalities defining the
feasible waste flow as:
                                  T F     ^   W                       (l)
        The first block of equations (corresponding to the = 0 right-hand side)
are the conservation of flow equations.  The next block (corresponding to § W)
represents the requirement that_ all the generated waste be disposed of.  The
elements of the column vector W are numbers w^j representing the annual number of
tons of waste of type_ i generated at location j, a source node.  The last block
(corresponding to = DRepresents the requirement that^disposal area capacities
are not exceeded.  The elements of the column vector D are numbers cLji representing
the annual number of tons of waste of type i that can be deposited in sink j.

        Additional constraints may be imposed by public health.  Included in the
public health or environmental constraint, H may be the set of upper bounds on
the total amount of gaseous waste flow (smog control).  Upper bounds on solid or
liquid waste flows on particular arcs may reflect vehicle transportation or sewage
trunk line limits.  Upper bounds on such flows may also be reflected by plant
capacities when considered fixed.  Incorporating these upper bounds and the fact
that waste flows may not be negative in our model requires the following additional
set of constraint equations.

                                     0 ^ F =s K                        (2)

        Where:  K represents the vector of upper bounds on the set
                of waste flows.

        The objective Is to minimize the total cost of the waste handling system.
Thus, we shall define a cost function at each node and arc as some linear function
of its flow and location. " For the arcs, this function may represent the cost  of
transportation from node i to node j .  If there is a cost on a node we may use the
method of expanding it into two nodes and one arc and placing node costs and flow
constraints on the simulated arc.

        These cost coefficients are arranged in the vector R which we may obtain
from the Process Technology (and Land Use) models.  Thus,  the objective function
becomes

-------
                              Z = RF (to be  minimized)                 (3)

                Where:    Z = The total  cost  of collecting,  treating
                             arid transporting  all  types  of  waste  to
                             disposal areas.

                         R = Cost row vector representing the  collection
                             arid disposal costs of each  arc .

                         F = Column vector of  waste flows of all  types
                             through the network.


        The problem now is one of minimizing the total cost function Z over the
feasible set of constraints defined by  Equations 1 and 2.  The minimum cost and
optimal allocation of flows are designated Z°  and  F°, respectively.   The constraints
(Equations 1 and 2) and objective function (Equation 3)  may be combined to obtain
a standard linear program whose special structure  may allow the application of more
efficient programming techniques.


WASTE GENERATION INPUT AND MANAGEMENT SYSTEM INPUTS


Management System Inputs

        The evaluation of alternative waste management systems requires two major
types of input data:  l) a description  of the  collection-treatment-disposal
system under study, and 2) a prediction of the waste load for  the region and year
considered.  The former will be in terms of the data represented  by  [T, D, H,  B,  R]
as described previously.  The latter will be in terms of an array of waste quantities
(tons per year of type i from source j) represented by the  matrix W.

        Figure 3 indicates the flow of  information required for an evaluation of
alternative management systems.   The input  data from the bottom  of  the chart
indicates that a separate set of inputs is required for  each regional system under
evaluation.  These inputs are obtained  from the Land Use, Public  Health, and Process
Technology Models shown in Figure 2. The behavior of each  management system is
evaluated for the same waste input load W.  It is  the process  of  estimating W that
is the function of the Regional Waste Generation Model.


Waste Generation Model

        The input data required to predict W are shown in Figure  12.  Most of these
data are required to describe the economy of the region  under  study.  Once the
economy is adequately defined, with the use of the model an estimate can be made  of
the level of activity of the economy and its corresponding  production of waste in
the form required by the evaluation model.  We have shown in the  figure that the
regional economy may be divided into its productive and  consumption  sectors.  The
activity levels of each of these sectors and their corresponding  levels of waste
production are determined by the Regional Economic Model and Waste Generator
(Consumption Sector) sub-studies indicated in Figure 10. The  results of these two
studies may be combined to form an array of waste  output quantities  represented by
the matrix V, whose elements are in terms of annual number  of  tons of waste of
type i generated by all sources of category j.  The sources are categorized in terms
of specific industries or consumption units within the regional economy,  the
categories being determined on the basis of different waste generation properties.
For example, household units and government units  will be treated differently in  the
         Examples of alternative management systems may be found in Appendix 2.

-------
                             Q
                             O
1

1
1

1

1
L

T
*H ^
-P O
O -P
3 O

O CO
£


r §
i -H
1 ^




1 g
1

--

o

CJ
D
03



|


|

1
1
1
J

 G -,
 O  w
 O  03
 CL>  S

H  O
 cd +3
 a
 O  w
•rt Tf
 to  a
 cu  o
 S-t  ft
    w
 O  QJ
-P  fn
    fn
 w  O -
T3  O
 £
 O  ^
 ft  o
 CQ -p
 OJ  O
 h  CD
 ^  [0
 O
 O  G

 nS

5^
 o  a
 D  3
 tfl  CQ
    SU •
 (D  O
 t> O
•H
-p
 a  •
 3 H
fd  a;
 o TJ

CM  S
 fl  o

.s  c
 CO  O
 k .H
 (D 4J
 >  3
 g p
    CO
 • -ri
^-d
 ^
 O r-l
-P  03
 t) vH
 CD  U
G D)
O
•H O
-P -P
CO Ti

g  §
0  ft
 O  Hi
 e -p
 cu  aj
 M)T3
                             a:
                             UJ
                             z
                             UJ
                             UJ
                             I
                             i
                             a.
                             UJ
                             CO
                             I-
                             LL)

                             UJ

                             S
                             OJ


                             UJ
                             cr

-------
consumption sector.  Since the form of waste data required by the  evaluation model  is
in terms of type of waste and location of origin,  the matrix  V must "be  appropriately
translated.  This is achieved by the Special Distribution of  Waste sub-study shown
in Figure 11.  The three basic sub-studies comprising the Regional Waste  Generation
Model will now be described in detail.


        Regional Economic Model (Productive Sector).  The activity levels of the
productive sectors of the regional economy may be determined  in  first approximation
through the use of an interindustry input-output  model  [Ul-43-1 •  The input-output
model takes the following form:

                                    X = [l-A]"1!

                Where:  X = The vector of total output  of goods  from the
                            productive sector (dollars).

                        Y ~ The vector of final demand  for goods.

                        I = The unit matrix.

                        A = The regional technology matrix.


The primary input to the regional economic model  will be  the  n x n technological
coefficient matrix A11 representing the n basic industrial sectors of the region
under study.  The matrix A11 will be a result of  breaking down A,  the larger state
or national input-output matrix, in the Interregional Analysis part of  this study.

        Additionally, the final demand vector Y1  for the  n basic industries will
be obtained from the Interregional Analysis Study. To  incorporate the  inter-
dependence of the waste disposal industry in the  region under consideration with
the rest of the regional economy m new industries are defined.   Each new  industry
indexed j - 1,  ...m represents the service of disposing of waste of a particular
characteristic j.  The grouping of wastes into m  types  may be based on  such charac-
teristics as garbage, durable, construction waste, wrecked automobiles, liquid
wastes, etc.  The new variables x  + .,, ..., xn + j,  ..., x  _._ m are incorporated
in the vector of total output.  The n x n matrix  A  is expanded to an  (n + m)
x (n + m) matrix A through augmentation of A12, A  , A2"~  obtained  from  the Waste
Process Technology Study for the region.   The final demand Y',  also obtained  from
the Interregional Analysis is lengthened to Y by  adjoining the waste service demand
vector Y2 obtained from the Waste Generator (Consumption  Study).  The resultant
input-output functional equation for the region becomes

-------
                                                                                 51
     Basic Industries
     Waste Disposal
     Service Industries
f 1 —
I - A11 -A12
V
f

-A21 I - A22

\









XP
xn

xn + i
xn + j
xn + m
_ _









Y1



Y2


or in matrix form:
        where:  A11 =
                i 12
               [I - A]  X = Y,

    a.•} =  the value of goods or service  i  in millions
      J
    of dollars required in the production  of one million

    dollars of production of goods or service j,
, fa..)
  I *v
                A21 =
 a.. f =  the value of commodity i in millions of

 dollars required by the waste disposal activity

 to dispose of one ton of waste of type j.


\ a.. > =  the number of tons of type j waste disposal
 V -*~ (J j
 service required per one million dollars of produc-

 tion by industry j.
                             =  the number of tons of type i  waste  disposal

                        service required per ton of operation of waste  dis-

                        posal service industry j.
        By solving this equation for the m + n production levels  X enough information
is obtained to ascertain the quantity of waste of each type generated by each  of  the
industries.  The total amount of waste service of type i  required by industry  j may
be interpreted as the total number of tons of waste of type i  generated by industry
j in, say, one year of operation.  This quantity is represented as:
= a.
                            for i = n + 1.  . . .n + m,  j  = 1,  . . .n + m
It is the m x (n + m) matrix of {pji}- which we shall designate P.   This  is  the  output
of the Regional Economic Model.  The matrix P represents the quantities  and types  of
waste generated by the productive sector of the economy and is required  as  an input
to the Spacial Distribution of Waste Study.
        Waste Generator (Consumption Sector).  The purpose of this  model  is  to
generate a final waste service demand (m-diraensional) vector Y2 to  be used in the
Regional Economic Model and the Spacial Distribution of Waste Studies.  This vector

-------
 is  to be  attached  to  the  final demand  (n-dimensional) vector Y1 obtained from the
 Interregional Analysis.   The resultant final demand vector Y is expanded to indicate
 its component parts
                         Y2
     [?]
where
                 C   = The vector of final household demands for the region
                     under  consideration.

                 C   = The vector of household demands for waste disposal
                     service in the region.

                 G1  = The vector of the regional governments final demands
                     for goods and services less waste disposal services.

                 G   = The vector of the regional governments demands for
                     waste  disposal services.

                 I1  = The amount of final demand set aside for investment.

                 E1  = Exports of the basic commodities from the region.

                 E   = Exports of waste disposal service.  (This for waste
                     generated outside of the region for disposal by the
                     regional waste disposal system).
         The  final  demand  vector Y is required by the Regional Economic Model before
 the industrial  production levels and corresponding industrial waste generation
 quantities may  be  obtained.  The quantities C., G., and E are also required in the
 Spacial Distribution  of Waste  Study.

         The  determination of [C, G., E] will be done by the City Planning Group
 through a regression  analysis  study.


         Spacial Distribution of Waste.  The function of the Spacial Distribution of
 Waste Model  is  to  provide the  waste source points for the Waste Collection, Treat-
 ment and Disposal  Model.   Each waste source point is represented by a quantity of
 waste of type i which is  composed of the cumulative sum of all waste of type i
 generated by the industrial government and household units located in a specific
 area k.  In  areas  where waste  is deposited from outside the region the total quantity
 of waste of  type i at point k  must reflect this.  The waste of type i generated at
 source point k  is
Wik "
                                              Vik
                             1=1,  . . -m
                    1,  ...K
where  K = number  of  sources  in the region :
                 (2
                w.,  =  The  amount  of waste of type i, in tons per year generated
                      by all households in location k.

-------
               WT,  = The amount of waste of type i generated per year "by all
                     government units in location k.

               we  = The amount of waste of type i delivered per year to
                     location k from outside the region.

                   = The amount of waste of type i in tons per year generated
                     Toy all industries in location k.
        In order to convert the input waste generation data C, G, E, P from its
present form of category of origin to the desired form additional information is
needed from the Land Use Model.  The information required from the Land Use Model
is a list of source points representing waste collection points of, say, several
blocks square or a census tract.  Corresponding to each source point k a set of
           c    s    e        p
fractions A .-, , A ., , A ., , and A .,  are needed which indicate the proportion, perhaps of
           Jk   Ok   jk       jk
industry j or households of category j located in the area of location k.  The
matrix of such fractions is designated A.

        Using these fractions one may now compute the values, magnitudes of wastes,
as follows:
                                             LP
                                   ik
                                   c         _, c
                                  w.n  =; 2 c.  .A .,
                                   ik      ij o
                                   e    v    , e
                                  w.,  = Z e. .A .,
                                   ik   j  10 o
                                  w..
                                   ik
where
               e. . = The total amount of waste of type i generated outside
                     the region and accepted for disposal by waste disposal
                     service industry j.

               g.. = The total amount of waste of type i generated by
                     government unit j•

               c.. = The total amount of waste of type i generated by
                     household of category j•
               p.. = The total amount of waste of type i generated by
                     industry j.
        By appropriate redefinition of variables one may represent the above
operations in matrix form as follows:
                  W = VA = [P, C, G, E]
A?
Ac
= WP + W° +

-------
5-'+
        The dimensions of the above matrices  are


                WP,  WC,  W8,  W6,  W:   m x K

                              A :   m + n x K

                              A°:   v x K

                              Ag:   q x K

                              AS:   r x K

                                A:   [m+n+v+q+r]xK=sxK

                                P:   m x m + n

                                C:   m x v

                                G:   m x q

                                E:   m x r

                                V:   mx[n +  n+v + q + r]=mxs


        The linear transformation A on the matrix V,  in the  m x s  space  of waste  type
and origin, to the matrix W in the  m x k space of waste type and location is  the
"basic function performed by the  Spacial Distribution of waste operation  in Figure 1.


FUTURE EXTENSIONS AND TASKS

        A number of extensions to the static  evaluation model presented  here  are
considered.  Additionally, special  studies of alternative management  systems  are
of interest.  An outline of some of these extensions and tasks is  given  below.

    1.  Dynamic Model:  Due to the  need for future planning  to cope with the  process
        of urban growth the development of a  multiperiod dynamic regional model is
        needed.  This model utilizing predicted growth rates and technological  change
        may be used to select optimal future  expansion plans of waste management
        systems.

    S.  Recovered Waste:  Include the process of  converting  waste  to  products which
        may be recycled into the economy.

    3.  Specialization:   A number of alternative  management  systems must be defined
        for comparative evaluation.  Parts of the basic evaluation may have to  be
        modified for maximum flexibility.  Some alternative  management systems  are
        mentioned in Appendix 1.

    4.  Supporting Studies:   The optimal design of transfer  station characteristics
        may prove helpful in the evaluation of a  management  waste  collection  system
        composed of a chain of transfer stations.  Appendix  2 indicates  the start
        of such a study.

    5-  Further Development:  Further development of the evaluation model may be
        studied to take advantage of the special  structure of the  programming
        problem.

-------
                            IV.  PLANNING AND ECONOMICS
INTRODUCTION

        Definitive research in the area of planning and economics proceeded from
the general rationale that since some fraction of solid wastes must inevitably "be
disposed of utilizing land, land-use planning for a community must include some
provision for that fact.  Conversely; solid wastes management techniques must include
considerations of the social, aesthetic, and environmental goals of man as well as
his economic attitudes and his technological capabilities at any time.  Moreover,
the types and amounts of wastes generated under any set of cultural realities and
level of economic activity can be predicted on the basis of how many people use how
much land for what purposes within a community.  Thus the research team concerned
with planning and economics directed its particular attention to those aspects of
wastes management which relate land use to waste generation.  In this activity it
worked closely with the operations research team in the establishment and elabora-
tion of appropriate submodels of the overall Waste Generation and Evaluation Model.

        The long-term plan of the research team was to approach a series of principal
objectives essentially sequentially but with whatever degree of overlapping progress
required and the project budget permitted.  These objectives in order of research
attention were:

    1.  Formulation of models for studying the structure and relationships between
        solid waste generation and relevant economic, demographic, and land-use
        information using selected study regions as examples.

    2.  Development of pertinent data on quantity and types of solid wastes and
        related information on economic activities through the establishment of
        appropriate disposal service areas .

    J.  Implications of solid wastes generations with respect to land-use planning.

    k.  Incorporation of technological changes in transportation and disposal of
        solid wastes.

    5.  Implications of present and future methods of disposal on private and
        public expenditure.

        In relating these principal objectives, it becomes evident that the research
team's concern is primarily with supplying the information needed to develop the
submodels for waste generation,  land use, population, regional and national economics;
and, eventually, process technology.

        During the period herein reported, attention was concentrated on the first
three of the five principal objectives.  Although good progress was made, as herein-
after described, a vast amount of data must be obtained and evaluated before these
three objectives can be fully achieved.  However, as results become available and
are elaborated upon,  they will be used in developing the empirical content for the
last two objectives (Nos. 4 and 5).


APPROACH AMD METHODOLOGY

        A research plan and a method of approach was worked out for each of the five
principal objectives  and serve as the basis for a systematic approach to the stated
objectives which is well under way.  Obviously,  all are subject to modification in
the face of realities and the contingencies of research.
                                         55

-------
56
Model Formation

        Models dealing with waste generation are to be formulated with emphasis  on
utilizing available economic information and an appropriate analytical framework.
A definition is to be made of the various types of solid wastes which are generated
in the economy, and the different structures (or models) developed for studying  each
of the defined wastes.  The analytical framework depends mostly on a multiple  re-
gression approach wherever the data permit.   Simple waste factors per unit of
generator will be used only as a last resort when all else fails.  For the purpose
of formulating structural models, the number of data observations are to be developed
on a geographical basis for use in the regression models.  Since consistent and
comparable data on solid wastes and other related variables are not available  for  any
time periods of significant duration, the analysis to be carried out in this regard
must be chiefly a cross-sectional one on  a  spatial basis, rather than a time  series
analysis involving time series data.  The regressions models,  however, will be tested
against two types of uses:  l) structural relations to explain the correlation between
waste generation and related waste generators,  and 2) prediction of future volumes of
waste for use in planning formulations.  Therefore, development of forecasts (future
volumes of solid wastes) will be carried out in two stages with respect to quantity
(tons or cubic yards) and to type (composition changes).  The  latter will have to  be
developed separately from the regression models since the models cannot be used  in
predicting changes in composition on a qualitative basis.  The actual development  of
this work will probably be done in cooperation with the Operations Research team.

        Data on total solid wastes will be divided according to origin into one  of
the following classes:  household wastes, commercial and services establishments,
industrial (manufacturing, food and nonfood), agricultural, and special wastes (such
as junked automobiles, etc.).  These classifications can be further divided as the
need arises.

        Independent variables to be considered in studying each type of waste  may
involve one or more of the following:  population, number of households, per capita
or household income, employment, and land use.   The level of industrial activities
can be introduced either by way of employment figures or, if data are available,
by output.

        As previously mentioned, the analytical approach involves fitting regression
equations by least squares method of estimation for different  types of wastes.  The
success of this approach depends upon the number of independent observations that  can
be collected on a cross section basis for each type of waste.

        The following is a tentative specification of variables for the regression
s tudy.

                  Waste                               As  a Function of

      a.  Household                          Population  and income

      b.  Commercial and  Services           Size  (measured by  employment)

      c.  Manufacturing                     Size*                             ^
                                            Fjnployment  level or activity nature

      d.  Agricultural                      Land use

      e.   Special
            Municipal
              Street refuse                 Population
              Sewage sludge
            Vehicles Abandoned              No. of automobiles and distribution
                                              by age
            Demolition and Construction     No. of old buildings and new developments
                                              (To be elaborated upon)
          To be specified in detail.

-------
                                                                                57

Development of Pertinent Data on Quantity and Types of Solid Wastes

        The development of corresponding sets of waste data and related economic
variables is an essential part of empirical model building to be used throughout
the second year of the project.  The enormity of the amount as well as the com-
plexity of the nature of the data required to accomplish such an undertaking was
demonstrated in a pilot study carried out (and hereinafter reported) with Santa
Clara County as the subject area.  Though of itself the pilot study did not result
in the production of a model, it did provide the necessary insight into the formu-
lation of models, planning of the data requirements, and the amount of resources
that go into development of these requirements.

        With respect to data collection, a disposal service area is herein defined
as one consisting of a group of census tracts for which data on the generation of
solid wastes are available.  For example, if a disposal site receives all of the
wastes generated from a particular region, that region would be defined as a dis-
posal service area.  On the other hand,  if there are two or more disposal sites
that receive solid wastes from two or more overlapping regions, then a single
disposal service area is defined to consist of those disposal sites and the
corresponding larger region.  By resorting to such a definition, the problems
involved in arbitrarily splicing geographic regions are eliminated, and thereby
the computation of consistent and comparable data on wastes and economic activity
is facilitated.  This definition of a disposal area was used in dividing the nine
counties of the San Francisco Bay area into meaningful disposal service areas,
which become the geographical units for the development of primary information for
the regression model.  This arrangement will also facilitate the comparison of
several regions as needed in future work.

        Since the collection of the data necessitates the interviewing of disposal
site operators and various (county and city) public health agencies, and since a
project involving such a collection already has been undertaken by the California
State Department of Public Health, research efforts of the planning team are to be
coordinated with those of the State so as to obtain the data with a minimum number
of contacts with the local public health officials.  Once the disposal service area
boundaries are drawn, the data on several variables can be collected and tabulated
for analysis.  The plan is first to draw up a set of disposal service areas (defined
in terms of actual census tracts) in close consultation with the State Department of
Public Health.  After doing this, the collection of economic information will proceed
county by county by our own group in conjunction with the various local (county and
city) planning groups and other published sources of data.  The various items of
economic data which we shall collect for analysis are listed in Appendix C.


Solid Waste Generation and Land Use Planning

        Since a consideration of waste disposal is an essential feature of any well
conceived plan of land use, a part of the study will be devoted to making an evalua-
tion of the effect of conventional and future methods of waste disposal on land use
planning.  The basic inputs for this item of study consist of data and forecasts
which would become available from the studies of the Bay Area Transportation Study
Commission.  These studies already have utilized in a. large measure all pertinent
and latest information on land use by small geographic parcels (sometimes city
blocks).  The forecasts of land use are developed under alternate traffic generation
plans and vice versa.  The results will be used effectively to provide feedback
effects of the regional evaluation models of waste generation and land use.

        Some of the specific  issues of concern are as follows:

    1.   Projection of solid waste volume - related land-use requirements  based
        on continuation of existing methods  of disposal (landfill).

    2.   Changes in land-use requirements with respect to overall urban land-use
        planning.

    J.   Location of future disposal sites and land-use planning.

-------
        The above items are to be considered in terms  of their regional implications
and regional solutions versus local efforts based on local solutions  to problems.

        Since refuse disposal is recognized as one of  the major items for regional
planning by the Association of Bay Area Governments, Bay Conservation and Develop-
ment Commission, and other agencies,  the regional planning implications will be
explicitly stated in terms of magnitude of the problem and the potentialities that
would arise by a regional approach.  Several considerations in formulating such  a
regional plan consist of investigations of the structure of transportation and
disposal "plant" costs.

        Another item of work consists of communication with the local planning groups
in examining their urban land-use plans and the extent of recognition of waste dis-
posal sites in the overall urban land-use plan.


Incorporation of Technical Changes in Transportation and Disposal  of  Solid Wastes

        As additional information is  made available concerning present and future
methods of waste disposal, it will be used to assess the impact of the practical
application of these methods.  This involves the examination of solid waste data in
greater depth by source, physical content and properties, by different geographic
regions, vis-a-vis new technologies proposed.  This item of work awaits development
in the engineering methods and would be given priority toward the  end of the second
year and subsequent period of research.

        As specification of work items, the following  is contemplated:

    1.  A list will be made of each method of disposal (e.g.,  landfill, composting,
        incineration, blooxidation, wet oxidation, etc.) either as presently
        employed or as proposed.

    2.  For each method of disposal,  obtain in detail  the nature of the physical
        requirements (such as physical/chemical composition,  carbon,  nitrogen
        content, caloric value, etc.) relating to the  solid waste.

    3.  The capital requirements for setting up the plants and recurring maintenance
        expenditures, and related cost information will be determined.

    k.  The method or methods in question in terms of  their feasibility for a
        particular region will be evaluated.


Implications of Present and Future Methods of Disposal
on Private and Public Expenditure

        This area of research will be formulated in greater detail during the
second and third years of the research period.  The development of this item of
research should await a full-scale development of analytical models of waste genera-
tion, associated costs, possible changes in methods of transportation and disposal,
and an elucidation of their implications on land and of new technologies on capital
and maintenance expenditures on the community.  Specific plan of work on this item
will be formulated during the end of the second year of the project.   For the
present, the following breakdown of subiterns of work are suggested for future
reference.

    1.  Analysis of private and public expenditure by  functions,  (transportation,
        disposal, supervision, etc.).

    2.  Changes in present methods — causing changes in tra.nsportation costs,
        and/or disposal costs.

    3.  Effect on existing public expenditures on health, planning, and in
        general on supervisory activities of public bodies.

-------
                                                                                  59
        The analysis of the above items could be carried out in those  areas  for which
the detailed analytical models envisaged in objectives 1 through k are developed.
For example, as a beginning attention could be concentrated on the nine-county Bay
region which may serve as a laboratory for an empirical study.  Other  areas  of the
state could be taken up subsequently to check the general validity of  conclusions
drawn from the test case (Bay region), depending upon the success of data collection
efforts.

        Finally, this item of work could treat the various combinations of solutions
(involving transportation and disposal methods) in the overall perspective or regional
evaluation of waste disposal techniques.


SANTA CLARA COUNTY STUDY
Introduction

        As noted in a preceding chapter Santa Clara County was selected as a suit-
able laboratory area in which to develop generally valid interrelationships because
of its urban-suburban-industrial-agricultural characteristics.  It was therefore
used by the planning and economics research team in an empirical pilot study,  the
objectives of which were to explore the field and to formulate a detailed plan of
work relative to the three initial objectives previously noted.  The study was not
intended to supply definitive answers to the waste management problems of the
county, inasmuch as such an undertaking would require resources and research beyond
the scope of the present project.  The additionally required research work would
center mainly around two areas, viz., forecasting future volumes of waste, and
analysis of private and public expenditures at various local levels.  Instead  of
being considered as a means of attaining a solution, the reported study should be
regarded as an effort to provide the necessary insight into the level and complexity
of the detailed nature of data to be collected for defining, analyzing, and at-
tempting to solve the solid waste management problem.

        Four factors were explored in detail:

    1.  Location of disposal sites and definition of service areas.

    2.  Land use and employment.

    3.  Solid waste generation.

    4.  Composition of solid wastes.

To obtain data on these factors, it was necessary to interview officials of the
planning, health, and other appropriate agencies, as well as public and private
dump operators and scavengers.  The data were then used to formulate a regression
study.


Location of Disposal Sites and Definition of Disposal Service Areas

        There are 27 sites in Santa Clara County which are currently in operation.
These sites can be classified as l) sites primarily used by scavenger companies
with regular collecting schedules and routes, 2) sites primarily used as public
trash sites by the general public and private haulers, 3) sites used for disposal
of cannery wastes, and 4) sites used for special purposes.  This classification is
helpful in making estimates of the volume of solid waste that go into various  sites.
Waste going into class 1 sites can be estimated by interviewing the site operators
or the scavenging company using the sites (sometimes the same as the site operator).
These estimates are fairly accurate depending upon whether or not the material is
weighed on scales.  In the case of class 2 sites, served mostly by the general
public, estimates of quantities are necessarily crude and are separated from other

-------
6o
categories.  Cannery wastes data can be obtained from the special private  haulers
who serve the canneries.  Special sites, class k,  are considered separately because
the nature and volume of material coming into these sites can be highly seasonal and
unique in nature.  Examples of the latter are auto junk yards,  park sites,  special
demolition sites, etc.  A list of the sites in Santa Clara County is given in Table
17, and their locations are shown on the county map in Figure 13.

        Once the sites had been located the next step was to obtain data on the
quantity of solid waste material that was delivered to a given site during a certain
period of time from a specified region that could be defined.  In order to keep the
estimating problem manageable and at the same time establish a concept  that is
extensively used for estimation purposes, the notion of a disposal service area
(DBA) was conceived.  It is arbitrarily defined as an area that consists of a group
of census tracts, contiguous or noncontiguous, and related to one or more  disposal
sites located within or outside the area.  In some cases a census tract is broken
and only the pertinent part of it is included in the DSA.  The notion of DSA is used
in order to define a reference region not too small for practical purposes and yet
not so large as to obscure the different characteristics of the waste data to be
collected.  The idea of DSA is also helpful in avoiding the arbitrary drawing of
boundaries to correspond to each and every disposal site.  It often happens that
solid waste material generated in an area does not always end up in a single disposal
site, and the service boundary for each disposal site overlaps as described schemat-
ically in Figure 14.  In order to avoid the abritrary splicing of boundaries for each
of the sites (A and B) a single DSA is defined, comprised of the two overlapping
regions.

        In line with this concept of DSA, the service area boundaries for  the various
disposal sites in Santa Clara County were drawn in consultation with the county public
health officials, who are aware of up-to-date information relating to sites and
collection areas.  The boundaries of the DSA's utilized in the study are shown on the
map in Figure 13.  The problem of defining disposal service areas is especially dif-
ficult in the San Jose (a city in Santa Clara County) area, an area in  which there
are nearly 11 sites, each differing in nature.  Drawing on individual boundary for
each of the sites would be most cumbersome.  Therefore, seven DSA's were defined for
the urban areas of the county.  The remainder of the county was defined as the 8th
DSA to complete the statistical picture.  The DSA's and the corresponding  sites are
given in Table 18.

        The DSA's were further defined in terms of the corresponding census tracts
that fall within the area, and in terms of planning areas used by the County Planning
Department for data collection and analysis.  These classifications are indicated in
Table 19.  This information is very useful for collecting and grouping  individual
data items to correspond to the DSA's for comparison and analysis of data  on solid
wastes.


Land-Use and Employment Data

        The basic land-use data are related to 1962 and were given by census tracts
for each major type of activity — agriculture, manufacturing, services, etc.  The
basic employment data were, however, available only by broad categories called labor
market areas.  Therefore, a good deal of splicing had to be done before these data
could be compiled by disposal service area.

        The 1962 land-use data according to census tracts was first grouped according
to planning areas (or portions thereof where needed) and checked against available
information.  The planning area subtotals were then used to develop land use by dis-
posal service areas.  The remainder of the county (8th DSA) was obtained as a residue
from the county total.  The land-use data sources and calculations are  indicated in
Tables 20 and 21.

        As mentioned before, the basic data on employment relate to "labor market
areas" as defined by the labor market analysts of the Department of Employment.

-------
                                                                                  6l
                                     TABLE  17


                SOLID WASTE DISPOSAL SITES IN SANTA CLARA COUNTY



                I.  Sites Served Primarily by Scavenger Companies:

                     1.  Palo Alto Municipal Disposal Site
                     2.  Mountain View Disposal Site
                     3•  Sunnyvale City Disposal Site
                     h.  Gilroy Disposal Site
                     5-  Pacheco Pass Disposal Site
                     6-  Morgan Hill Disposal Site
                     7-  Guadalupe Disposal Site
                     8.  Los Altos Ranch Disposal Site
                     9.  City of Santa Clara Disposal Grounds
                    10.  Newby Island Disposal Site
                    11.  Eastside Disposal Site
                    12.  Customer Utility  Service Site


               II.  Public Trash Sites:

                    13-  Stierlin Road Disposal Site
                    ih-  Edgewater Disposal Grounds
                    15 •  Storey Road Disposal Grounds
                    l6-  Singleton Road Disposal Grounds
                    17-  City of San Jose  Disposal Site
                    l8.  San Martin  Disposal Site


              III.  Cannery Waste Disposal Sites :

                    19.  WoeIfel Ranch
                    20-  Hessler Ranch
                    21.  Silviera Ranch
                    22.  Collier Charcoal  Co. Site
                    23.  Pierce Ranch
                    2k.  Thuer Ranch
                    25.  Carroll Ranch
                    26-  Furtado Ranch
               IV.  Special Sites:

                    27.  Mt. Madonna Park Site (refuse from county
                         park only)
388-229 O - 70 - 6

-------
62
    FIGURE  13. SOLID WASTE  DISPOSAL SITES AND  SERVICE  AREAS ,
             SANTA CLARA COUNTY

-------
                                          NOTE:   SITE A  AND  SITE  B
                                                  HAVE AN  OVERLAPPING
                                                  SERVICE AREA
                                                  BOUNDARY DENOTED  BY
                                                  DOTTED  LINES
FIGURE  14.   SCHEMATIC  DESCRIPTION  OF  OVERLAPPING   DISPOSAL   SITES
                                 TABLE 18


             DISPOSAL SERVICE AKEAS AND CORRESPONDING DISPOSAL
                        SITES IN SANTA CLARA COUNTY
      Disposal Service Area
        Disposal Sites Included
       Palo Alto

       Mountain View


       Sunnyvale

       Gillroy-Morgan Hill
       Los  Gatos
       Los Altos
       San  Jose
Palo Alto Municipal Disposal Site  (l)

Mountain View Disposal Site (2)
Stierlin Road Disposal Site
Sunnyvale City Disposal Site  (j)

Gilroy Disposal Site (k)
Pacheco Pass Disposal Site  (5)
Morgan Hill Disposal Site  (6)
San Martin Disposal Site (l8)
Furtado Ranch (26)

Guadalupe Disposal Site (7)
Pierce Ranch (23)

Los Altos Ranch Disposal Site  (8)
City of Santa Clara Disposal Grounds  (9)
Edgewater Disposal Grounds  (lA)
Woe If el Ranch (19)

Newby Island Disposal Site  (10)
Eastside Disposal Site (ll)
Customer Utility Service Site  (12)
Storey Road Disposal Grounds  (15)
City of San Jose Disposal Site  (17)
Singleton Road Disposal Grounds  (l6)
Thuer Ranch (2k)
Hessler Ranch (20)
Collier Charcoal Co. Site  (22)
Silviera Ranch (2l)
Carroll Ranch (25)
      Note:  The boundaries of the various disposal service  areas are
            defined in such a way that the amount  of total  solid
            wastes generated and the origin of wastes could "be
            identified for the purposes of analysis in this study.
            The boundaries of each of the disposal service  areas are
            defined in terms of the census tracts  (see next table).

-------
64
                                  TABLE 19

     DEFINITION OF DISPOSAL SERVICE AREAS  BY PLANNING AREAS AND CENSUS
                        TRACTS IN SANTA CLARA COUNTY
Disposal Service Area
(l) Palo Alto Disposal Service Area
(2) Mt . View Disposal Service Area

(3) Sunnyvale Disposal Service Area


(4) Gilroy-Morgan Hill Disposal
Service Area

(5) Los Gatos Disposal Service Area





(6) Los Altos Disposal Service Area



(?) San Jose Disposal Service Area









(8) Remainder of County


Corresponding
Planning Area
0
NI
MI
M2
LI
F
X
w
V
RI
K
Q
Jl
AI
I
L2
N2
P
HI
S
A2
R2
B
C
H2
J2
G
D
E
T
U
Y
Corresponding
Census Tracts
106-116
92-99
91A
84-90, 91B
82-83
46-47
125-126
124
123
119B
73-76
118
68A, 68C, 69-72
26-28
62-66, 67
77-81
100-105
117A, 117B
52-57, 59-61
120
1-25, 29-32
119A
33-35
36-42
51, 58
68B
48, 49, 50
43
44-45
121
122
127
         A planning area is a collection of census tracts which in some cases
roughly correspond to municipal limits.  These divisions of the county are the
same as U.S. county census divisions.  The planning areas are identified by
alphabets A through Y.  In the case of some of the definitions of Disposal
Service Areas, it was necessary to break down a planning area to coincide with
the boundaries of service areas.  The corresponding portions of planning areas
are denoted with subscripts l and 2 and are further identified with the census
tracts that fall within those portions.

-------
                                                           TABLE 20


                                  LAND USE BY PIANNIHG AREAS AMD PORTIONS OF PLANNING AREAS
                                            FOR SELECTED LAND-USE CATEGORIES, 1962,
                                                      SAHTA CLARA. COUHTY
County
Planning
Areas
Ai
A2
B
C
D
E
F
G
Hi
Hs
I
Jl
•3s
K
Li
L2
Mi
M2
Hi
N2
0
P
Q
Hi
Rs
S
T
U
V
W
X
Y
Census Tracts
(£6-28)
(1-25, 29-32)
(33-35)
(36-1*2)
(43)
(44-45)
(1*6-1+7)
(W-50)
(52-57, 59-61)
(51, 58)
(62-67)
(68A, 68c, 69-72)
(68B)
(73-76)
(82-83)
(77-81)
(91A)
(81* -90, 91B)
(92-99)
(101-105)
(106-116 )
(117)
(118)
(119B)
(119A)
(120)
(121)
(122)
(123)
(121*)
(125-126)
(127)
Agriculture
678
8,060
20,1+70
5,2lU
8,723
111,875
12,575
6,91*3
3,131*
853
3,31*3
8,1*99
156
7,578
1,079
6,110
980
3,1*50
1,1*1*9
1,073
3,805
29,150
3!*, 070
15,292
1*50
14,872
16,819
61* ,081
20,677
20,071
29,!*95
369, 541
Urban Developed Area
Manuf ac tur ing
0
621
32
47
1*9
213
527
163
500
113
28
ll*
0
10
5
30
100
266
75
1*
362
272
0
0
6
183
i
6
35
18
62
3,o8o
Transportation,
C ommun i c at i on s ,
& Utilities
451
4,199
773
878
468
592
1,862
773
1,372
613
1,265
1,065
101
723
355
94l
172
938
780
755
1,582
809
697
247
75
572
359
511
647
667
949
939
Commercial
(Wholesale & Retail Trade;
Finance, Insurance, + Real
Estate Services)
89
1,270
57
186
189
52
78
88
412
136
299
146
10
54
49
153
54
264
329
118
397
21
8
12
19
33
26
1
67
40
137
12
Government
(Public & Quasi
Public Buildings)
57
732
71
133
20
72
22
778
238
12
173
123
14
167
38
124
10
139
193
215
1,744
216
104
9
23
7
76
2
30
11
40
46
Sources:  Santa Clara County Planning Department, Land Use Summary,  1962--planning Areas,  Information Ho.  142,  and some unpublished
          tables giving data by census tracts.
    ^able A of the above report.


     Table C of the above report.  The information is given as percentage of urban developed area by  four broad  categories.
Urban developed area is defined as equal to total land area less  land in extractive industries,  metropolitan  and regional
parks, agriculture, open, and vacant urban land.

-------
   66
                                                          LAUD USE BY DISPOSAL SERVICE AREAS
                                                        FOB SELECTED LAHD USE CATEGORIES, 1962,
                                                                  SANTA CUBA COUNTY
                                                                        (acres)

County Planning Areas & Corresponding
Disposal Service Areas
Planning Area 0
Palo Alto Disposal Service Area
Planning Area HI
Planning Area MI
Mountain View Disposal Service Area
Planning Area Ma
Planning Area LI
Planning Area F
Sunnyvale Disposal Service Area
Planning Area V
Planning Area W
Planning Area X
Gilroy-Morgan Hill Disposal Service Area
Planning Area Ri
Planning Area K
Planning Area Q
Planning Area Ji
Planning Area AI
Planning Area I
Los Gatos Disposal Service Area
Planning Area L?
Planning Area %
Planning Area P
Planning Area HI
Los Altos Disposal Service Area
Planning Area S
Planning Area AS
Planning Area RS
Planning Area B
Planning Area C
Planning Area H2
Planning Area J^
Planning Area G
Planning Area D
Planning Area E
San Jose Disposal Service Area
Planning Area T
Planning Area U
Planning Area Y
Remainder of County
Total County

Agriculture

3,805
3,805
1,4^9
980
2,U29
3,<*50
1,079
12,575
17,101*
20,677
20,071
29,^95
70,2^3
15,292
7,578
3^,070
8,U99
678
3,3^3
69,^60
6,110
1,073
29,150
3,134
39,^67
14,872
8,060
1*50
20,^70
5,214
853
156
6,943
8,723
111,875
177,616
10,819
64,081
369,541
450,441
830,565

Manufacturing

362
362
75
100
175
266
5
527
798
35
18
62
115
0
10
0
lit
0
28
52
30
It
272
500
806
183
621
6
32
1.7
113
0
163
1.9
213
1,1.27
1
6
3,080
3,087
6,822
Transportation,
Communications,
& Utilities
1,582
1,582
780
172
952
938
355
1,862
3,155
61*7
667
91.9
2,263
21.7
723
697
1,065
">51
1,265
11,1.1.8
91.1
755
809
1,372
3,877
572
It, 199
75
773
878
613
101
773
1.68
592
9,01.1.
359
511
939
1,809
27,130
Commercial
(Wholesale & Retail Trade; Finance,
Insurance,& Real Estate Services)
397
397
329
5lt
383
26".
1.9
78
391
67
1+0
137
2>+l+
12
^
8
11+6
89
299
608
153
118
21
1+12
701.
33
1,270
19
57
186
136
10
88
189
52
2,01.0
26
1
12
39
It, 806
Government
(Public & Quasi
Public Buildings )
l,7lllt
1,71.1+
193
10
203
139
38
22
199
30
11
1+0
81
9
167
1C*
123
57
173
633
12lt
215
216
238
793
7
732
23
71
133
12
•A
778
20
72
1,862
76
2
1.6
12l+
5,639
Source:  Table 20

-------
                                                                                   67
 Six  labor market  surveys have been carried out with respect to different parts of the
 Santa  Clara  County.  The surveys are carried out every two years and the reference
 period is the month of July.  The data used here relate to July 196^.

        Before using the employment data, however, it was necessary to reconcile the
 classifications of economic activity both for land use and for employment data.
 Accordingly, the  following categories were defined:  Agriculture; Manufacturing;
 Transportation, Communication and Utilities; Commercial (wholesale, retail trade,
 finance, real estate, and insurance); and Government — public and quasi public
 buildings.   These classifications are necessarily broad at this stage, but could be
 broken down  in detail according to the Standard Industrial Classification Code.

        The  employment data as obtained from Labor Market Survey (196^) are given
 against each row total in Table 22.

        The  next  step was to develop employment data by disposal service areas based
 on labor market survey totals.  To do this, each labor market area was defined in
 terms  of the component planning area (or portions thereof).  For example, Palo Alto
 community labor market area is "broken down into Planning Areas, 0, P, NI, and N2.
 (The planning areas are in turn defined in terms of census tracts — Table 19, but
 are not needed for this purpose.)  Using the corresponding land-use data by planning
 areas  (Table 20) as the basis for each of the categories of employment, the total for
 the  labor market area is broken down into components.  These calculations are carried
 out  for each of the five categories of employment and for each of the six labor market
 area totals  (see Table 22).  By simply rearranging the planning areas to correspond
 to the DSA's (Table 19), the desired DSA totals may be obtained.  These totals are
 listed in Table 2J.


 Solid  Waste  Data

        Data on solid waste were collected with the use of a questionnaire especially
 designed for the purpose.  A copy of the questionnaire is shown in Appendix D.  The
 various disposal site operators in the county were interviewed with the help of the
 County Public Health Department to obtain data on the volume of solid waste received
 at the site, composition of the wastes, data on site capacities, labor, material and
 equipment employed at the disposal site, and finally cost of disposal.  The data on
 solid  waste  are summarized in Table 2k.  It would appear from a first look, that the
 level  of detail obtained is far from satisfactory for any comprehensive mathematical
 model  building related to solid waste generation.  The composition of waste reported
 is highly aggregated and does not permit detailed classification of total solid waste
 into types of waste and related economic activity.

        The  disposal site cost data were incomplete and a different approach had to
 be used in estimating these costs.  The actual data on labor, material, and equipment
 used on the  site were used in conjunction with rental charges to derive comparable
 costs  of disposal on each disposal site.  The data are summarized in Table 25.


 Composition of Solid Waste

        The data on the composition of solid waste were derived for each of the dis-
 posal  service areas with the use of the data collected in the interviews.  Corresponding
 data on population and employment also were derived from earlier calculations.  All of
 the comparable data are presented in a tabular form in Table 26.  The development of
 such tables in more detail than hitherto has been possible is a prerequisite for any
 systematic approach to solid waste generation studies.


Regression Study

        Some of the data developed in the study can be used for developing regression
models to study waste generation as a function of economic activities.  Due to a

-------
    68
                                                             EMPLOYMENT BY PLMHIHG ABEA3, JULY 196U
                                                                       SANTA CLARA COUNTY

Labor Market Communities
& Corresponding county
Planning Areas

Planning Area 0
Planning Area P
Planning Area NI
Planning Area N2
Palo Alto Community
Labor Market Total
Planning Area Ji
Planning Area Js
Planning Area K
Planning Area Li
Planning Area Ls
Los Gatos Community
Labor Market Total
Planning Area fti
Planning Area As
Planning Area B
lanning Area C
lanning Area D
lanning Area Hi
lanning Area Ha
lanning Area I
Planning Area S
San Jose Community
Labor Market Total
Planning Area F
Planning Area MI
Planning Area H2
Sunnyvale Community
Labor Market Total
Planning Area E
Planning Area G
Mllpltas Community
Labor Market Total
Planning Areas W, X. V
Gilroy Community Labor
Market Survey Total3
Planning AreasL
NOT in Community
Labor Market Surveys
Planning Area Q
Planning Area Ri
Planning Area Ra
Planning Area T
Planning Area U
Planning Area Y

Agriculture

Land,a
3,805
29,150
1,1*1*9
1,073

35,!i77
8,1*99
156
7,578
1,079
6,110

23,1*22
678
8,060
20,1*70
5,21l*
8,723
3,131*
853
3,31*3
lit, 872

65,336
12,575
980
3 >*50

17,005
111,857
6,91*3

118,800






3^,070
15^292
1*50
16,819
614,081
369,51*1

*
10.8
82.2
i*.o
3.0

100.0
36.2
.7
32.1*
l*.6
26.1

100.0
1.0
12.3
31.3
8.0
13.14
It. 8
1.3
5.1
22.8

100.0
73.9
5.8
20.3

100.0
91*. 2
5~.B

100.0













Employ-
3U
:6^
13
10

321
3JO
6
?"7
"0
?;-3

856
39
1480
1,2; 4
3^ 2
5:3
187
51
193


3,906
3014
31
109

534
503
31

531.


1,338










Manufacturing

Land.a
362
272
75
it

713
lit
0
10
5
30

59
0
621
32
it7
It9
500
113
28
183

1,575
527
100
266

893
213
163

376






0
0
6
1
6,
3,080

Dist'n
50.8
38.1
10.5
.6

100.0
23.7
0.0
16.9
8.5
50.9

100.0
0.0
39.5
2.0
3.0
3.1
31.8
7.2
1.8
11.6

100.0
59-0
11.2
29.8

100.0
56.6
k3A

100.0













Employ-
11,278
3,1*58
2,331
133

22 , 200
It02
0
287
Ill6
865

1,700
0
13,983
708
1,062
1,097
11 , 266
2,5Uo
637
14,107

35,1400
l^.Ql+2
2,666
7,092

23,800
1.2145
955

2,200


1,800









Transportation,
Utilities

Land,a
1,582
809
780
755

3,926
1,065
101
723
355
9ltl

3,185
>t51
It, 199
773
878
1*68
1,372
613
1,265
572

10, 588
1,862
172
938

2,972
592
773

1,365






697
21*7
75
359
511
939

*
Dist'n
'40.3
20.6
19.9
19.2

100.0
33.14
3.2
22.7
11.1
29.6

100.0
It. 3
39.7
7.3
8.3
1*.^
12.9
5.8
11.9
5.1*

100.0
62.6
5.8
31.6

100.0
1*3.1*
56.6

100.0













Employ-
81*7
"433
1*17
1403

2,100
267
26
182
89
236

800
288
2,660
1*89
556
295
866
387
797
362

6,700
626
58
316

1,000
1*3
57

100


1*00









(Wholesale & Retail Trade,
Estate Services)

Land,
397
21
329
118

865
11*6
10
51*
kg
153

1412
89
1,270
57
186
189
1*12
136
299
33

2,666
78
51*
261*

396
52
88

ll*o






8
12
19
26
1
12

*
Dist'n
1*5.9
2.1*
38.0
13.7

100.0
35.1*
2.1*
13.1
11.9
37.2

100.0
3.3
1*7.7
2.1
7.0
7.1
15-3
5.1
11.2
1.2

100.0
19.7
13.6
66.7

100.0
37.1
62.9

100.0













Employ-
22,1*1*5
1,171*
18,582
6,699

1*8,900
2,796
190
1,035
91*0
2,939

7,900
2,663
38,1*93
1,695
5,61*9
5,730
12,380
14,083
9,038
968

80,700
2,383
1,61(6
8,071

12,100
519
881

1,1(00


2,000









Government
(Public & Quasi
Public Buildings)

Land,"
1,71*1*
216
193
215

2,368
123
ll*
167
38
121*

1*66
57
732
71
133
20
238
12
173
7

1,1*1*2
22
10
139

171
72
778

851






101*
9
23
76
2
1*6

Dist'n
73.6
9.1
8.2
9.1

100.0
26.1*
3.0
35.8
8.2
26.6

100.0
l*.0
50.7
14.9
9.2
1.1*
16.5
0.8
12.0
.5

100.0
12.9
5.8
81.3

100.0
8.5
91.5

100.0













Employ-
6,621*
819
738
819

9,000
528
60
716
161*
532

2,000
852
10,799
l,0l*l*
1,960
298
3,508
177
2,556
106

21,300
658
296
l*,ll*6

5,100
179
1,921

2,100


900









FrocedtL
              obtaining employment estimates by disposal servic
As part of the Labor Market Survey work, employment data by major categories are published for each of the si_x "labor market communities" in Santa Clara County.
The labor market communities could be defined in terms of planning areas or portions thereof.
For each of the labor market communities, the employment {for each of the major categories) is divided into components corresponding to the planning areas using
the land use information as the basis.   For details, see text.
£Frora Table 00.
 Gilroy Community Labor Market Survey corresponds to the Gilroy-Morgan Hill Disposal Service Area used in this study.   Hence,  no further breakdoi
^Planning areas was necessary.
jThese planning areas of the county are not included in any of the Community Labor Market Surveys.
 This parcel is entirely the United Technology Development Center at Coyote.

-------
69

County Planning Areai> & Corresponding

Planning Area 0
Palo Alto Disposal Service Area Total
Planning Area Ni
Planning Area HI
Mt. View Disposal Service Area
Planning Area M2

Planning Area F
Sunnyvale Disposal Service Area
Planning Areas V, W, X
Gilroy-Morgan Hill Disposal Service Area
Planning Area RI
Planning Area K
Planning Area Q
Planning Area Ji
Planning Area Ai
Planning Area I
Los Gatos Disposal Service Area
Planning Area L2
Planning Area H2
Planning Area P
Planning Area HI
Los Altos Disposal Service Area
Planning Area S
Planning Area A2
Planning Area R2
Planning Area B
Planning Area C
Planning Area H2
Planning Area Jo
Planning Area G
Planning Area D
Planning Area E
San Jose Disposal Service Area

(Planning Areas T, U, Y)
Total County

Agriculture

3^
3^
13
31
LU
icn
ko
39^
5''3
1,33*
1,33«
_
?77
_
310
39
199
825
223
10
26J-
187
661*
801
480
_
1,224
315
51
(*
31
5?3
503
4,021

£,200
9,689

Manufacturing

11,278
11,278
2,331
2,666
4,997
7,092
11(6
14,042
21,280
1,800
1,800
_
287
_
1.02
Q
637
1,326
865
133
8,1(58
11,266
20,722
l(,107
13,983
_
708
1,062
2,51(0
o
955
1,097
1,21(5
25,697

0
87,100

Transportation,
& Ltilities
847
847
1(17
53
475
316
89
626
1,031
1(00
400
_
182
_
267
?88
797
1,5*
236
1(03
433
866
1,938
362
2,660
-
1(89
556
387
26
57
295
1*3
M75

200
11,300
Commercial
(Wholesale & Retail Trade;
Finance Insurance, ^ Seal

22,41(5
£2,1(1(5
18,582
1,61(6
20,228
8,071
91(0
2,303
ll,39l(
2,000
2,000
_
1,035
-
2,796
2,663
9,038
15,532
2,939
6,699
l,17l(
12,380
23,192
968
38,1(93
-
1,695
5,649
l(,OS3
190
881
730
519
56,208

2,001
153,000

Government

6,62l(
f'.telt
738
296
l,03l(
U,ll(6
161»
658
l(,968
900
900

716

528
852
2,556
"(,652
532
819
819
3,508
5,678
106
10,799

I,okk
1,960
177
60
1,921
298
179
16,5U1(

0
1(0,1(00

Total
Employment

11,228
1(1,228
22,081
1/97
a', 778
19,731.
1,379
18,103
39,216
f.1.38
6.1.38
.
2,1(J7
-
k,303
3,81(2
13,227
?3,869
"(,795
P., 06k
11,1 '.8
28,207
52, ?ll(
t,l(3'(
6t,'.15
-
5,160
9,539
7,238
282
3,51.5
7,9'(3
2,W9
109,31(5

1(,1(00
303,1(88

Employment
Excluding
8
Ul,19U
1(1, 194
22,068
^,666
26,734
19,625
1,339
17,709
38,673
5,100
5,100

2,220

3,993
3,803
13,028
23,01*
4,572
8,054
10,884
28,020
51,530
5,543
65,935

3,936
9,227
7,187
276
3,814
7,420
1,986
105,324

2,200
293,800

-------
70
QJ ,d T)
0
iH •
ft
d £

•H gj
-P CQ ft
S -p EH
g
stlUs


Is3'
3 d
o o
S -H
QJ -P
Pi
«N O
QJ -rH &
-P H W
tO fi d

^ ft EH
o
rH H
d d d
•H O JH
-P fc T) -P
•H QJ C U)
to a oj 2
o I -5
ft o c:
B U H
H
i d
•rl - CQ t> S
£H p Ti"^-»
O HH QJ OJ
ft QJ O C
Q) ££! fl) O
K « -P
 P lU tin
<; a
0) rH
ttf ,d H -p
rf -P -H QJ
[L, ft ft, QJ
< ° 0
tiD
d -H to
QJCD
^1*
H to
d d QJ
4-> QJ h
° ij °


QJ
•H
CQ
H
oi


to
S


11 1 1 VDrHrH VOCOCO* OJ


t-> H QJ QJ


rH >j^VOLT\H rHVl r<
OJ.d'dtijiJ rHHtiO hDtO D
NOS^O d t^o\dft M
OvH cOvHQPlrH E-i,d O
o sco Qft SEHQ QQPCD Q
rHrHHH rHH r-iHrHH rH
O CU O OJ

VO rH OJ O


H


0

j.
H




OJ VO f<^





O LTN LT\ O



O O CO O
8O LT\ O
OS- ON
O OJ VO N"1!


U
QJ -H OJ QJ QJ
-P H * -PIT) -P -P
•H ^3 W -H JH QJ -H -H

d 0) d x! H d d
o+p o+yfeo o
OJ

o
OJ -d- OJ -P

H

CO 1 CO -=*•
H OJ


CO tTN CO °
H r~l OJ rH


OH -*
IV OJ 1 -4"
H
O O

QJ
H -P
d -H
ft CD
'o QJ QJ H QJ
•H -P -P d -P
J CQ QJ CQ O ^ CQ
H > H CQ H H

-PW Gtfl HP W«
HO -H O n O
 dft
tO 4JtO S-P dcQ
O -H d -H C -H bD -H
Hft Sft RU rtQ
ft* ^ CQ ^
I J-





rH ^1
QJ QJ
W N
O O
n P
H H


d d













o o





o o



o o
-4t O
VO ON




D D
-P -P
•H -H
CD CD

S S




o


U"N O
H


OJ O
H OJ


O\ E^-

O LfN
H



QJ QJ
-P -P
•H -H
CD W CD
to
H d H
d Pn oj
ao o
CJ ft
O W QJ to
H* « 'OP
3 £
ir\ t i
H


H


!>i OJ
CO rl d
O O O
OJ H H
O




-4-








fO
OJ






K>



O
8_
LT\
t<~\
H

QJ
-p
•H
CD

g







I


d


d

vo
OJ




QJ
-p
•H
CD


H ft
d to
IS
I
t- ^ ^

^
QJ HO
d H +5
•H do

Q) tsO 1>3 JH ft
O 5-i VO d O
P P P H O O
OJ H H H H
0 0











O
CO


O
OJ





o o
CO OJ


o o
8 8_^
8^P
CXJ
H

-2
•rl
1 CD

O



f
>> CQ (0 0 ri

^ HO

-------


to
-p

o
U
-p

o
ft






















w
o
o

QJ
-p
a
















































H
G rH
rH -p O H •
-P o ^ • ro
O U rH -H O
EH (y O
PiO -I*

w
o
0

H
OJ
1
H -P O
d w -P • H
-P O HO
O O In O O
EH 0) O
Pi •!-
CO
H. -P
US 01 • rH
-P O H O
OOOO
H U +
X
-p
d) o d t— •
-P O ID *'--
-P •<-) OJ w —
ra P Pj KN
g ^ti
^3 ° •
OJ O ctj W
W &H h3 rH
o
O
•d OJ ,r!
OJ -H JP
-P c/j fn cJ


•H d d
-P 3 CD fn
[fl OJ
OJ u
D >H D



^ 'j &
K S rl
TJ T5 S
OJ D (U 0)
-P -P H ^i
O S O^o"

(U MO
K -P




0)
-p
•H
to



OJ
H







rH
H


o
H










CO




*-- '




^^
%2-





^






^_^
^














OJ





""^
^^,








o





-H- VD fA fO _HT
OJ OJ 1 KN V£) 1 1 1 £•—
I i 1 I
OJ rH OJ OJ O
-ce-


CO O O O O
LT\ J- O VO O
r*^\ KN rH O O
^ -, | ^ ^ III -V
OJ OJ 1 ON H 1 1 1 O
H KN OJ f*A
-w-



OJrH rHOJOJ OH.-H: rH
-69-

OVD OOO OOO O
VQfO OJVDOJ ^J-COOJ J-
rA[~— LfNOON IS- UPv O VO


H_t KNOJ OOJHCO
H rH H rH rH H


O OJ-OJVO OOOOO OO OO OOOOO OOOO OOOO OOOOO
VD J-OJU^H OJOOOOJ OO COOD -tfVD-4-O-H: VOVOVDCO OOJOOJ VOVOOJOJ-
i/N [-— ON rH CO VDVOCOONON LP\LTN VOVO <^KNLPvLr\rA rAHVDrH -S~VDCOcO fArHhfNLfNtA
VD wH ^X Si^S ^H ^^ H H RKN^^CO ^^^0 ^OJW^ f^roPH^R
H rH H

OOO OOO OOOd O O OOOO OOO OOO OOOO
Hfl- -«-


OJ OJ

H H
I
-^VOVQ VD rH VDCOCO OJ -^ I>-COOJOJ COCOVO D— VD J- COCOOJVD


H rH
rH fn OJ
d (U p, to

fnO 0)  d

THOpQEHd dO> rnO RoJ g >> E-HrnO
>J VH rH rHOJ d rH<3 Q
S G O ,£ 0 Q OVO
CO W H OJ


O OO O O OOOOOO OO OO OO O
o OGJ oj o OVDVD^J-O oo oo oo o
CO CO ON ON VO VD <-TN LPiOJOJ-^' -d--j- -3-OJ OJrii t^N
VD VDO O LfN u-NrHHVDVDr^N r^rfN rOrH H t^- t^-
-69-





OO O OOO OOO

VOVO VO VOVOVO VOVOVO
-w-



•HOJrH HOJHCOH H H Hi/N H
d*d d*ni*d d oj d* d
VO -PrH -P OJ 4^> nJ -pro, -pKN -P_H- 4J(0\ 40
OO OOO OOO O

O O CO OOO O O O
8O LTN OOO O O O
CO f- ONOO OOO
O OJ VD* fAccTu^ Cp'-^vo'
U"N KN [— KN O OJ LT\
rH rH H

O QJ
? U -P
CJ 0) W -H T1
UJ-HOJ CD i-i^ojcQ d-P -P Hy-p s^-pd
O -H -H QJ -H -H aJ -H OJ M >-p d-powaj »>-P
O-H f3H ^••-| bo-Hrnd-a cd -P-H ^-H
HO 3u gU FHWr-iflHCiJ wfi CO >CO
(S£5 ^gg 5^S

OJ
OJ

H










-H-

H


VO
LT\

H
LTN
CO


VD
LT\
H
Lf\
VD
VD





















O
OJ
VD"
H*





O
ITN
VD







OJ

CO
LTN

VO
CO
U<


rH
d
-P




-p
0
o
 ' 
-------
                                                                               TABLE 26
                                                           ESTIMATES OF SOUTJ WASTES BY BROAD CATEGORIES IN
                                                                       SAIffiA CIARA C01MTY, 1965


Palo Alto
Mountain View
Sunnyvale
Gilroy-Morgan Hill
Los Gat os
Los Altos
San Jose
Remainder of County
County Total
Population

66,847


35,545
22,950
151,225
163,200
33,325
3,091
874,595
Total
Excluding
Agriculture
.,1,194


38,673
5,100
23, OUt
51,530
105,524
'-,£•00
^93,799
Disposal 32ie

Mountain View Site

Sunnyvale City Disp. Site

Morgan Hill Disposal Site
San Martin Disposal Site
Furtado Ranch
Guadalupe Site
Pierce Ranch
<"
City ol Santa Clara Site
Edgewater Site
Woelfel Ranch
Wewby Island Site
Eastside Site
Storey Read Site
City of £an Jose
Singletor Road
Theur Ranch
Hessler Ranch
Collier Charcoal
Silviera Ranch
Carroll Ranch


Classi-
ficationa
^
P
c
P
C
c
P
c
s
P
P
P
c
c
c
c


Tons
Total Refuse
Received
(Excluding
Agr. Wastes)
50, ooo
32,600
2 1, 000
7^7*3
3/Uo
3,900
3,900
?,000
135,050
1,3*5
1C6, 000
24 , 000
57,000
114
156,000
3^,000
19, >00
5 {, 000
55,000
12, COO
1,211;
410
3,5f'0
-
8 '0,672

Ruboish &
Garbage
33,000
14,760
?5,365
2,730
?, i'3C
Commercial
& Industrial
Rubbish
12,500
l,u4D
49,893
1,092
1,1 rj


86,400
4,800
117,000
"
— -^

20,500
19,200
39,000
19,500
-
48 	
Cannery
Waste




1,365
1,100
114
1,215
6,460
410
3,560
-
14,224
Rib lie
Trash
I', 000
16, 400
27,000





Si',000
57,000
55,000
12,000
-
—32
Demolition
Waste
500




0,500 	


-


Disposal Service Area
Palo Alto
Mountain View
Sunnyvale
Gilroy-Morgan Hill
Los Gatos
Los Altos
San Jose
Remainder of County
County Total
aT
ym

Agricultural Manures"
(Dry)
255
2,920
59
18,532
1,505
941
4,099
7,237
35,548d

P - Public

Agricultural Prunings








75,000d

trash sites used by the general
Tons
Sewage Sludge
(Dry)








>,86oe

ublic and incidental hau

Junied Vehicles6








2^00f

ers only

Total Wastes








1,011,580


         Cannery waste data are for 19^5 which was an unusually short  season.

        cRows refer only to area In which waste is generated,  not to area in which they are disposed oi.

        T/he sources are the following reports:  California Department of Agriculture,  State Agriculture  Report,  19^5,  University of California AgJ
Extension Service of California Air Pollution Research, Progress Report;   Disposal of Agricultural Wastes in the  Bay Area,  July 19^6,  and Agriculti
Commissioner's Cropjtepprt, 1965, Santa Clara County.

        eThe source is the ABAC figure for the Bay Area, using population to determine  Santa Clara County's share.
•i cultural
o-al
         The source is the Department of Motor Vehicle reports showing age distribution of motor vehicles.   The number of junks was determined by
calculating the number of older vehicles that disappeared between 1964 and 1965 distributions.   This number of junks was multiplied by l.?5 tons

-------
serious lack of detail, the solid wastes totals were treated as a single dependent
variable in the regression study.  They were regressed against possible explanatory
variables such as population, employment in manufacturing,  employment in nonmanu-
facturing, land use in manufacturing, and land use in nonmanufacturing.  According
to the regression study, population is a significant variable, and it explains most
of the variation in the generation of solid waste.  Land in nonmanufacturing sectors
(service sectors) constitute the second important variable.  Since the number of
observations (seven) is very small and the number of variables almost outweigh the
degree of freedom, any further use of regression equations  in this case is not
applicable.

        The data use in the regression model are given in Table 27.  The regression
equations are given in Table 28.

        The regression models explain the variation in solid waste generated vis-a-
vis the independent variables — population, employment, and land use.  Such models
could also be used for developing projections of waste based on projections of
population, employment, and land use simply by using the projected values on the
right hand side of the structural equations.


DATA COLLECTION PLANS

        Information gained in the pilot study was used in formulating data collection
plans.  As is evident in the previous description and discussion, the data on solid
wastes must be collected in more detail than was possible in this study if they are
to be of use in establishing an analytical framework.  Moreover, data on other related
economic variables need to be collected and compiled for analysis through the use of
computers.  For the sake of convenience and as a means of organizing present and
future data needs, a detailed listing of data items was prepared in consultation
with the Computer Center of the University of California for eventual compilation.
The various data items to be collected and corresponding coding are described in
Appendix E.  The listing makes it possible to transfer raw  data to a punch card
system after careful editing.  With the data on punch cards, it is possible to con-
duct further analytical operations directly on the IBM computer.  This arrangement
will provide the necessary empirical base for analyzing the solid waste management
problems with respect to the objectives listed and discussed earlier.

-------
                                                   TABLE 27
                                      DATA USED FOR REGRESSION ANALYSIS
                                              SANTA CLARA COUNTY
Disposal Service
Area
Palo Alto
Mountain View
Sunnyvale
Gilroy-Morgan Hill
Los Gatos
Los Altos
San Jose
Solid Waste
Generated
(tons )
50,000
59,800
76,758
1J, 1+1*0
156,415
189,111*
3!*5,:iA5
Population
66,81*7
1*7,>*12
85,51*5
22,950
151,225
163,200
33!*,325
Employment,
Manufacturing
11,278
1*,997
21,280
1,800
1,326
20,722
25,697
Employment,
Kon -Manufacturing
29,916
21,737
17,593
3,300
21,718
30,808
77,627
Land Use,
t-fenufacturing
(acres )
362
175
798
115
52
806
1,1*27
Land Use,
Won -Manufacturing
(acres )
2,270
696
2,086
587
1,1*85
1,775
5,525
                                                    TABLE 28

                                   SANTA CLARA COUHTY WASTE GENERATION,  SUMMARY
                                          OF LINEAR REGRESSION RESULTS
Y:
Dependent
Variable
Waste
Generated,
tons
Step 1
Step 2
Constant Term

-7887.77051
-2061*8. (7905
Xi:
Population
Coefficient

1.06£i*0a
(0.0633't)b
1.0l*2l*0a
(0. 0661*3 }b
X2:
Employment ,
Manufacturing
Coefficient



*3:
Employment,
Non -Manufacturing
Coefficient



X4:
Land Use ,
Manufacturing
Coefficient



X5:
Land Use,
Non -Manufacturing
Coefficient


0.30379
(o.jotoj)6
T,£
R y.x

0.9825!*
0.98603
Significant t-ratio at 99 percent confidence.

Figures in parenthesis represent the standard error of the corresponding coefficient.

-------
                                 V.  PUBLIC HEALTH
INTRODUCTION

        As noted in a previous section (Figure 2, page 12) one of the four major
aspects to which research teams have directed attention during the period herein
reported (1966-67) is Public Health.  In the overall regional waste generation and
evaluation model (Figure 9, page 39) which describes the study, Public Health
appears as one of the important subsystems, imposing constraints specifically upon
such other subsystems as Land Use and Technology and directly upon the final Waste
Collection and Disposal Model which describes the management scheme for any indi-
vidual regional situation.  Thus, within this conceptual framework it is necessary
to consider the nature of public health constraints with regard to several factors.

    1.  The extent to which they are qualitative or quantitative in nature.

    2.  The effect of qualitative constraints on the numerical values necessary
        to make the affected subsystem model functional and capable of resolu-
        tion.

    3-  The public health justification of assigning specific numerical values
        to its quantitative constraints.

        In simpler terms this means that on the basis of present knowledge, and the
results of definitive research, or by subjective reasoning based on judgment and
man's social objectives, the public health aspect of the study must yield numerical
limits on what waste management procedures may contribute to the air, water, and
land environments.
OBJECTIVES OF PUBLIC HEALTH RESEARCH

        The foregoing interrelationships between the public health model and other
models or subsystems depicted in Figure 9 makes possible a clear statement of the
objectives of the public health aspect of the study.  These include:

    1.  Evaluating the true relationship between solid wastes management
        procedures and health dangers to the public.

    2.  Reviewing critically all public health regulations relating to solid
        wastes management with particular reference to the source and validity
        of any numerical values imposed.

    3.  Advising all other research teams of the known or possible health
        implications of their alternate proposals for wastes management.

    k.  Considering the components of solid wastes and the environmental fate
        of each in wastes disposal, with particular reference to the  health and
        welfare of humans.

    5.  Conducting definitive research on such of the components of solid wastes
        which are judged likely to have a significant effect on  human health or
        welfare.

    6.  Evaluating the occupational hazards to workers in the solid wastes manage-
        ment field.

        Progress  toward each of these objectives is  herein reported.
                                         75

-------
RELATIONSHIP OF WASTES MANAGEMENT TO HEALTH

        Although it is at once evident that there is a public  health interest  in the
management of any material vhich may produce flies,  mosquitos,  rodents,  or other
vectors of disease, the role of public health in solid wastes  research is  not  so
obvious.  Good housekeeping in such matters as household handling of garbage,  use of
tight containers, frequent and tidy collection,  and  provision  of proper collection
vehicles controls the generation of vectors in the general environment where domestic
refuse is produced.  Landfill practices in refuse disposal eliminate insect and rodent
problems on any scale compared to the potential of refuse to produce them.  But here
again, good housekeeping minimizes dust, odors,  blow-about, and other aesthetically
objectionable factors.  Incineration of refuse as a  problem in itself tends to be
overwhelmed by the greater problem of air pollution  by other combustion processes.
Animal manures, with their vast potential to produce flies, require insect control
programs and physical removal from the immediate environment of people.   Demolition
debris is generally innocuous, as are tree and grass trimmings and junk.  Composting
is not yet commercially important, and hog feeding with garbage is a declining
practice.

        From such gross observations as the foregoing it might be concluded that the
major unsolved problems of solid wastes management are not those of public health,
and that a combination of vigilance and good housekeeping, together with concern
for the accident and other health hazards to refuse  handlers,  essentially defines
the area of public health concern in the problem. To an important degree such a
conclusion is valid at present.  However, for the immediate and longer range future
there are at least two factors which suggest a closer look at  the role of health
research in a solid wastes management research program.

    1.  The problem of solid wastes management is far from resolved, hence it
        may not be assumed that any resolution will  leave undisturbed any
        existing equilibrium between refuse management and health objectives.

    2.  Public health concern in the modern world transcends traditional
        concepts of vectors and nuisance.

        Each of these is worthy of further explanation.  Possible sources of health
problems may be found in both the changing content of refuse,  and in technological
possibilities of the future.  An analysis of these possibilities based on the
feasible methods of management outlined in Figure 1  (page 8) is summarized in Table 29.
In this table the solid wastes of an overall community are depicted as a "waste
stream" moving from the source to some "sink," which for the most part is the  land
resource.  In some of the five cases noted, a fraction of the  stream is split  off,
processed, and recycled to the industrial resource with residues returned to the
land or atmosphere.

        As indicated in Table 29 public health concern in solid wastes management
includes occupational health, public health per se,  and general affronts to the
senses of sight and smell commonly classed as nuisances.  However, there is reason
to consider public health in much broader terms.

        Within a broad sociological concept of public health there are myriad problems
associated with solid wastes.  Noise, odors, increased traffic, contention over owner-
ship of cans, requirements for household management  of wastes, littering of the
neighborhood, and similar factors add stress to life which is  not subject to the type
of definitive research which contributes to technological solutions to the problems
of wastes management.  Nevertheless, such qualitative considerations may exert a
profound effect on technology, land use, and the final collection and disposal models
of the system  (Figure 9), through simple refusal of  the public to accept answers
proposed by its engineers and other officials.  Examples of such constraints are to
be found in the San Francisco Bay area in the rebellion of citizens of the town of
Brisbane against the landfill operations of the city of San Francisco despite con-
tractual relations made by their officials and the long standing practice of

-------
                                     TABLE 29

               POSSIBLE HEALTH PROBLEMS IN SOLID WASTES MANAGEMENT
                                                                                 77
                 Method
    Nature of Possible Health Hazard
Case 1. Disposal to sink.
                 Source
                   B
                   CO
                   
-------
78
                               TABLE 29.   Continued.
Case 3- Indirect recycling.
                  Atmos.
                  (Air       Basic
                  Resource)  Resources

        Source
       Sink (land)
                          1, 2, 3, 4.  Same as Case 1.

                          5.  Public health hazard in products
                             discharged to atmosphere.

                          6.  Occupational hazard to workers in
                             processes such as rendering,
                             pyrolization, grinding of glass, etc.

                          7.  Occupational hazard to workers
                             utilizing processed material returned
                             to  resource.
Case 4. Change of state.
                       Atmosphere
                     (Air Resource)
          Source           >N
                          1,  2,  3, 4.   Same as  Case  1.

                          5.   Occupational hazard to workers  in
                              process  (principally incineration).

                          6.   Nuisance in process residues, e.g.,
                              fly-ash  dust.

                          7.   Public health hazard in process
                              discharge to atmosphere.

                          8.   Nuisance in process discharge to
                              atmosphere.
         Sink (land)
Case 5. Conversion.
      Source
  Atmos.
  (Air
  Resource) Land
            Resource

               /\
        •p
        w
        01
        (U
        -p
        10
                    Process
~,1.
             i—
             I
             I
1, 2,  3-  Same as Case 1.

k.  Occupational hazard in process
    (principally composting).

5.  Nuisance in process discharged to
    atmosphere, e.g., odors.

6.  Public health hazard to users of
    processed material, e.g. virus.

7.  Occupational hazard in handling
    processed material.
        V
      Sink (land)

-------
                                                                                 79
landfilling by the city.  Similarly,  public sentiment against  the  long accepted
practice of utilizing marginal areas  of the San Francisco Bay  for  refuse  landfills
threatens to terminate the practice without regard to alternatives.   Since  the  envi-
ronmental objectives of people are a  real factor in practical  solid  wastes  management
they must be considered by some group engaged in the study herein  reported;  and the
public health team was deemed to be the most logical choice.

        In the investigation herein reported, public health is interpreted  as
including virtually all aspects of solid wastes management in  which  man is  the
center of concern.  Thus if solid wastes adversely affect people physiologically
or psychologically, or make the environment less comfortable or less pleasant by
affronts to any of the five senses, it is interpreted as being of  public  health
concern.  Obviously, this interest in man is not confined exclusively to  the public
health model of Figure 9.  The land use, population, process technology,  and
economic models, and to a lesser degree other components of the regional  waste
generation and evaluation model (Figure 9), all involve the interactions  of environ-
ment and man as well as man's response to constraints.  This,  however, is fortunate
in that it insures a constant interplay between the several research teams  and
minimizes the problem of maintaining  coordination between them.

        Pursuant to objectives 1, 2,  and 3 (page 75), progess  has  thus been made
by the public health research team during the period reported.  Work along  these
lines, however, is a continuing activity subject to continual  refinement  as:

    1.  Studies by cooperating agencies (U. S. Public Health Service and  California
        State Health Department) and  by the technological teams provide greater
        detail concerning the amount  and nature of individual  components  of refuse.

    2.  Proposals for improved or new technology are generated by  the various
        research teams in this area.

    3.  Further review is made of the literature and of other  reports associating
        solid wastes with any aspect  of public health.

    U.  Public reaction to proposed solutions develops.


RELATION OF WASTES COMPONENTS TO HEALTH

        Objectives number k, 5, and 6 (page  75 ) of the public health research  team
relate to consideration and definitive research on the ways in which the  possible
public health hazards listed in Table 29 may affect the health or  welfare of the
public in general or of workers in the wastes management field. Two principal
avenues of investigation are evident.

    1.  A determination of the health significance of wastes component materials.

    2.  The environmental fate of fractions of refuse known or judged to  have
        significant health implications.

        A specific example of the first of these two might be  found  in the  discharge
of lead ions into the atmosphere as a result of burning automobile storage  battery
cases or salvaging of lead.  Since lead is known to be inimical to health,  it might
be suspected that a significant problem exists.  However, when the contribution of
lead through the use of leaded gasoline is considered, the added contribution from
wastes management schemes is almost certainly trivial on a macroenvironmental scale
either to an appreciable number of citizens or to salvage workers.  Nevertheless,
since the extent of this contribution is not know, investigative work may be in order.

        Examples of the second type of question exist perhaps  in the ultimate fate
of such materials as asbestos fibers,  beryllium,  radioisotopes,  microbes, viruses,
etc. in various waste disposal procedures in relation to human contact.   Emissions
from incinerator stacks, leaching from landfills, and fertilizers  from sewage sludge

-------
80
digestion or composting processes are among the avenues "by which materials of
signficance to public health might adversely affect man.

        Against such a rationale the public health research team initiated during
1966-67 investigations relating both to what materials and in what concentrations
they follow these various avenues.  As in the case of work directed to the first
three objectives (page 75 ) such investigations depend for their increasing pro-
ductivity upon the development of greater detailed knowledge of the components of
community-wide refuse, and to a lesser degree upon solutions to disposal problems
offered by the technological research teams.  Initial concern, however,  has been
directed to processes in common practice and to factors known to be produced from
refuse by these processes.  Results thus far obtained are laregly derived from the
literature.  They relate to the possible health effect on citizens or on workers
in the industry of agricultural and industrial wastes and of disposal methods.


Agricultural Wastes

        Little experience is reported with the disposal of agricultural wastes in
combination with other wastes of an urban-industrial-rural community.  As noted in
a previous section the rural sector has been generally expected to look after its
own wastes in a manner acceptable to its urban neighbor and then only as regards
the generation of odors, dust, flies, mosquitoes, and rodents.  Sharing the general
attitude of citizens toward waste materials, and having in addition a weaker economic
base for which to operate, agriculture has utilized only the most primitive methods
of disposal, i.e., burning, discharge to water, and disposal on the land surface
either by spreading or placing in open piles.  Therefore the potential of agricultural
wastes to produce health problems, rather than demonstrated effects, is the basis for
judgment.

        Of greatest concern in the agricultural wastes area is the production of
flies by animal manures which, although possibly only a nuisance, always constitutes
a danger to the public health.  In California, for example, a single installation
may fatten 3,000 to 6,000 steers per year or maintain 10,000 to 100,000 hens.  These
and close-in dairies are estimated to produce 20 million cubic yards of animal
manures annually at the zone of contact between California's urban and rural sectors.

        Other than manures, by far the biggest fraction of agricultural wastes are
crop residues which represent the normal type of photosynthetics produced by nature
and has little direct implication for the public health.

        Many of the agricultural wastes, however, especially those from highly
concentrated operations such as hen and egg production and feedlots, contain elements
which if allowed to leach into ground or surface waters might constitute a localized
concern to public health via water contamination.  Examples of these are As, Mn, and
Zn substances which are normally found in poultry manure.  The danger resulting from
runoff from feedlots is in the large amount of organic and ammonia-N content of the
runoff waters.  This nitrogen is oxidized to N03 in the soil and as such is responsible
for excessively high N03 levels in waters thus contaminated.  Another factor that may
be of public health concern is the practice of burning agricultural crop wastes.
The resulting air pollution may be of some public health significance in already
polluted areas.  Another waste associated with agricultural practice consists of
emptied pesticide containers.  Unless carefully disposed of, they pose a threat by
way of indiscriminate reuse for other purposes and by accessibility to children and
animals.
Industrial Wastes
        The research schedule of the study herein reported calls for the obtaining
of detailed data on the composition of industrial wastes in a pilot area of
California from other state and federal agencies supported by demostration grants
from the Public Health Service.  The data, which should be available late in 1967,

-------
                                                                                 8l
will then become the basis for an evaluation and possibly definitive research activity
by the University of California public health research team.  In the meantime,, this
team in 1966 made an independent survey of industrial operations in a selected region
in the Bay area, viz., Santa Clara County, as a part of an attempt to determine the
extent of any threat to public health to be found in wastes generated by these
industries.  Of 28 industrial operations active in the county, all but three generate
wastes which have metals, wood, and paper as components.  The wastes of all but four
have fibers, synthetic, plastic, and natural.  Almost half of the total industrial
waste output contains organic and inorganic chemicals of some sort:  petroleum, paint,
glass, ceramics, and minerals.  Inasmuch as at the time of this survey information
was unavailable as to the disposition of the wastes from these sources, no estimates
of the actual threat to the public health posed by these wastes could be made.  As
in the case of agricultural residues, municipal refuse disposal has not traditionally
been concerned with industrial wastes but has left to the industry the problem of
disposal.  Public regulation of waste disposal, however, has attempted to exclude
from landfills such materials as oils, solvents, and chemicals — not always with
success.  Most certainly there is a potential threat to the public health in many
chemicals which might reach the groundwater via discarding in sanitary landfills.


Methods of Disposal

        Because disposal technology is a key element in solid wastes management,
and no foreseeable technology can remove wastes from some combination of the air,
water, and land resources, the public health implications of wastes disposal are
worthy of very close scrutiny.  Moreover, where health hazards are a factor ways
must be found to preclude contact between man and the hazardous components of his
refuse.  Unfortunately the hazards of many fractions of refuse have not been explored.

        For example, the contribution of refuse incineration to air pollution has
generally been recognized, perhaps to an exaggerated degree when considered in re-
lation to the total air pollution coming from other sources of burning.  On the other
hand, concern has been expressed largely for the oxides of sulfur and nitrogen,
carbon monoxide, and visible particulates — residues which may not be the critical
discharges from burning of mixed solid wastes.  Thus that aspect of incineration
which is not so conspicuous and which is now being studied is the fate of some of
the more exotic materials in refuse and of the solid residues.  Similarly, the
superficial aspects of landfill have always received much attention, while less
obvious but perhaps more important aspects have only relatively recently become
a matter of concern.  Thus, appearance and odors associated with landfills are by
their nature conspicuous characteristics, whereas leaching and gas migration are
subsurface phenomena, and hence inconspicuous as far as the casual observer is
concerned.  Composting, while not commonly practiced at present, nevertheless merits
attention, since it is frequently advocated as the ideal disposal method, especially
from the standpoint of public health.  Despite the high temperatures and other con-
ditions unfavorable to pathogenic organisms, composting also has some characteristics
which may pose a health hazard.  Among these might be mentioned the presence of
pathogenic fungi.  From these examples it is evident that much research needs to be
done before the public health constraints on other elements of the waste generation
and evaluation model can be given realistic values.


        Incineration.  The by-products of incineration are a volatilized moiety and
a residue, both of which have implications for public health.  Analyses of the ef-
fluent gaseous material and leftover inert residue reveal that their composition
varies directly in relation to that which is fed into the incinerator.  Unfortunately,
until the present, studies concerned with the composition of solid waste material
introduced into municipal or other incinerators have been very few.

        Effluents generated by the burning of refuse can be broadly categorized as
inorganic and organic gases and particulate matter.  Although not all of the con-
stituents of the gaseous effluents have been identified or analyzed, the principal
inorganic compounds have been classified as H2S, S02, S203, nitrogen oxides,

-------
82
     CO, and C02.  Prominent organic constituents are aldehydes (formaldehyde and
acrolein), organic acids and esters, fats and fatty materials,  phenols,  and poly-
nuclear hydrocarbons.  Particulate matter consists of smoke,  soot,  fly-ash, grit,
and dirt.  An idea of the composition of the stack discharge  can be obtained from
a perusal of the data list in Table 30.

        Even prior to identification, the inorganic gases make  their presence evident
by minor irritant action on skin and mucous membranes or by their odor.   Oxides of
sulfur are highly irritating to the upper respiratory tract when inhaled,  and can
cause serious trouble in susceptible individuals.  As is to be  expected, the effluents
are clearly related to the sulfur content of the input to incinerators,  which is not
usually excessive.  Generally, however, the concentration of  S02 in the  stack gases
of incinerators is in trace quantities, not exceeding the range of 1 to  20 mg/,0.
Nitrogen oxides are insidous gases which may bring about long-term damage to the lung
and bronchial passages, even though they do not cause any immediate physiological
difficulties.  The compounds MU and (NH4)2S04 are of concern in areas of heavy pol-
lution.  They may be present in incinerator gases in concentrations ranging from 0.5
to 10.0 mg/,0.

        Carbon monoxide and dioxide make up the bulk of the remainder of the incinera-
tor gases of concern to public health.  Carbon monoxide is a  colorless and odorless
gas which readily combines with hemoglobin.  This latter reaction may bring about
asphyxiation because of interference with the circulatory transport of oxygen in an
individual.  Studies recently conducted at Stanford University  and at other research
centers indicate, however, that long before such a chemical asphyxiation supervenes,
behavioral changes such as mental confusion will be noted, electroencephalogram
patterns will be altered, etc.  These adverse reactions definitely indicate an inter-
ference with optimal human function caused by carbon monoxide toxicity.   Carbon
dioxide also can lead to serious ill effects if the concentration exceeds one percent
of ambient air.  The role of these regular by-products of incineration has not been
fully explored, probably because atmospheric dilution has prevented a buildup of
concentrations to levels detrimental to public health.  The more subtle  effects
certainly warrant more well-planned investigations; and, therefore, not  only their
immediate effects, but the concomitants of continuous, long-term inhalation in small
amounts need attention.

        The incineration of the organic matter in refuse results in the  generation
of a wide variety of effluent gases.  Although a satisfactory analysis of these
gaseous effluents of organic origin is yet to be made, certain  compounds suggest
themselves.  These are the aldehydes such as formaldehyde and acrolein,  both pungent
in odor and highly irritating to eyes and skin as well as to  the mucous  membranes.
Acrolein, which was even used as a poison gas in World War I, can be readily formed
by burning fats and oils.  The combustion of these latter substances also results in
the formation of various organic acids and esters.  Certain phenols and  phenolic
substances liberated during combustion can harm tissues if present in a  sufficiently
heavy coneentration.

        Another class of organic compounds significant in extent of disease trans-
mitting potential is that of the polynuclear hydrocarbons.  While it is  known that
a great many of these hydrocarbons are formed, their exact amounts are unknown at
present.  Many of them are known to be carcinogenic, and as such should  be carefully
assessed and monitored.

        The particulates, found in all kinds and sizes in incinerator stack discharges,
have physiologic and pathologic significance inasmuch as they are often  impregnated
with acids and are filtered out by lung tissue.  Upon lodging in the lungs, they can
lead to the development of a focal buildup.  All organic fractions of airborne
particles sampled from the atmosphere in U. S. cities have been shown to be capable
of producing local skin tumors in mice following subcutaneous infection.  Chronic
low level exposure seems to be more injurious than brief heavy exposure.

        A further deleterious development in the gaseous environment has to do with
interactions between the different gases at concentrations lower than those required

-------
p.

vfl
pq
ra
0)
-p

rj
O
•H
+3
S-i
id
PM
ra
•H
X
0
i
ra
ra
d
1?
o
•d




>2
£_|
0
M
(D
-p
03
O





o
_3- rA VO LA
H g




VO -* O CM O
CO O CO VO -4-
-3- O CM H
*\ *\
H rH


CJ 'd
VO H LTN
CM O OJ u3 d
OJ OJ d




rA CO LA t — rA
CM VO CM H H
rA CM



VQ rA OA CO VO
ON rA i — 1 o rA
rA OJ H




o
t— rA co vo
F— rA oS O rA
rA d OJ H





O ON LTN CM -3-
LA rA OJ LT\ fTN,
rH


H
03
•p
o
^ 03 rH
H -H oj
S-< 03 -P -H
O P< d £H
+J .H 0) -p
o3 CJ 'd ra fn
^t -rl -H ^i (1)
(D d ra fti rd
d P 
%
fi
•H
 M
•H
S
                          •d

-------
84
to cause any overt effect on health.   These are the  reactant mixtures  involved in
what is known as photochemical smog,  a type which is prevalent  in  Los  Angeles and
other heavily populated and industrialized areas. At their lower  levels  of concen-
tration, ozone and compounds of nitrogen formed through oxidation  results in eye and
nasal irritation; while at higher levels,  they bring about  serious derangement of
lung and cerebal function.  Although it is well established that the internal com-
bustion engine is the main source of hydrocarbons involved  in photochemical reactions,
not to be ignored is the contribution of gases from  inadequately burned refuse in
household and municipal incinerators, the extent of  which is as yet undetermined.
Some idea of the relative amounts from the two sources may  be gained from the data
listed in Table 31, in which are given estimates of  contaminants poured into air in
Los Angeles County; and from Table 32, in which the  data are given on  pollutants
discharged in the St. Louis area.

                                      TABLE 31

                          TONS OF CONTAMINANTS INTRODUCED
                    INTO LOS ANGELES COUNTY ATMOSPHERE, 1962 [44]
Source
Stationary
Total
Hydrocarbons
and Organic
Gases
4
740
Oxides of
Nitrogen
4
220
Oxides of
Sulfur
1
105
CO
4
235
Other
Inorgani c
Gases
n
5
Aerosols
4
5
In situations in which there is a recurrent photochemical smog situation,  undoubtedly
all incinerator operations could be a source of danger.

        Air pollution control codes adopted in many areas are not sufficiently based
on careful measurement or on up-to-date information as to the health effects of
combined exposures.  Synergism and augmentation through concatenation of mild ir-
ritants and photochemical reactions in the atmosphere need to be taken into account.
Additionally, the meteorological status very often determines what is allowable at
a single point of time.  Local codes, on the other hand, often are based on general
findings of maximum allowable concentrations of single chemical entities worked out
in a restricted occupational environment in which exposure is not continuous and
where it can be easily controlled.  Our present understanding of the mode of action
of environmental toxic compounds goes too far beyond such initial guide lines to
permit the assumption of a comfortable posture in regard to the air pollution
standards.

        Noncombustibles in refuse undergo oxidation to varying degrees during
incineration, depending upon furnace conditions.  Metallic oxides remain as residue
or are dissipated in the flue gas.  The residue that becomes mixed with the water
in the quenching operation poses a problem in disposal.  Among the metals which
have been identified in incinerator ash and which could pose a public health hazard
are:  Co, Pb, Zn, Cu, Cd, Fe, Cr, Mn, Ni, and As.  Arsenic is dangerous even in
trace amounts if allowed to leach into surface waters, since fish concentrate the
element in their tissue.  The concentrated inorganic fraction of the solid wastes
consists of soluble and insoluble salts of various heavy metals that can leach into
ground water, and thus lead to the development of brackishness and the accumulation
of other undesirable contaminants in the water.  Vaporized metallic oxides having
been expelled into the atmosphere eventually settle on the land where they are
introduced into living systems through inhalation and ingestion.  This has been
demonstrated to be the case with cadmium  [45, 46].  The concentration level of
which is significantly higher in urban areas than in nonurban nonindustrial environ-
ments.  A correlation has been established between a cadmium buildup in the kidney
tissue of higher mammals and an increased incidence in hypertension and heart disease.

-------
                                                                                           85
02
cd
cd
v_*f
FQ
CO

-------
At least one investigator in this country has  related the  steep increase  in  cardio-
vascular disorders with the deposition of cadmium and other  trace metals  in  organs
of the body [k^] .

        Investigators have found that  tissues  of wild rats living in  the  vicinity of
sewers and refuse  dumps generally have a much  higher lead  content than  those of rats
reared in the laboratory [4y].   Associated with this higher  lead content  is  a high
degree of incidence of nuclear  inclusions and  carcinomas in  the kidneys of the wild
rats.  Although it cannot be stated on the basis of the evidence on hand  that these
inclusions and carcinomas are caused solely by lead, there is  good reason for
believing that lead may be the  precipitating agent.  In their  paper,  Kilham  et al.
[kj] report that the wild rats  assayed in their study were continuously exposed to
dense smoke emanating from the  smoldering refuse in the dump in which the rats lived.
They surmised that the lead was oxidized and carried with  the  smoke.  The rats
inhaled the lead oxides along with smoke.  The authors surmise that the oxidized
lead came from the sizing in paper, from paint, solder, batteries, and  any other
waste which may have contained  lead in one form or another.

        Studies of incinerator  residue conducted at Drexel Institute  indicate the
existence of pockets of metallic residue buildup in the soil.   No explanation for
these buildups is  available at  present.  This  heavy metal  buildup and its public
health aspects is  an area for further  study and surveillance.

        Sanitary Landfill.  Despite its widespread application, the influence of
sanitary landfill on the surrounding environment was not investigated in  any great
depth until relatively recently.  In addition  to the usual financial  reason  for the
belated interest in the subject, there may have been the one stemming from man's
inborn "belief that burial accomplishes removal from the environment.  It  was only
with the intensification of the general concern for all phases of the environment
that the practice of landfill and its  relation to the environment began to come
under close scrutiny.  Aside from the  purely aesthetic, this influence  can be
exerted by way of leaching of substances to ground waters  or by migration of gases
from the disposal site.

        Leaching studies have shown that water moving through  an unsealed or improp-
erly located landfill will leach soluble salts and alkalies  from the  dump and transport
them to receiving waters.  Thus ground water in the immediate  vicinity  of a  landfill
site can become grossly polluted by continuous or intermittent contact  with  deposited
refuse.  In studies conducted in California by the State Water Pollution  Board [48,^9]
it was demonstrated that within a year after the initiation  of one operation, con-
tinuous leaching of one acre-foot of the fill  being investigated would  result in the
extraction of 1.5  tons of sodium and potassium, 1.0 ton of calcium and  magnesium,
0.91 ton of chloride, 0.23 ton  of sulfate, and 3-9 tons of bicarbonate.  The amount
and rates of extraction become  much slower with the passage  of time.

        In a pilot-scale study  involving simulated landfills,  Burchinal et_ al. [50]
found the concentrations of leachate to be those listed in Table 33.  The water-
holding capacity of the refuse  used in their study was 1.62  in./ft of refuse.
Burchinal et al. point out that although the concentration of  leachate  from  the
deeper fills was greater than that from the shallow fill,  the  maximum concentration
per foot of depth of fill for an equal amount  of refuse was  lower in  the  deeper fills.
Their assessment of the amount  of pollutants which would be  leached by  an equivalent
of 0.^5 in. of rainfall percolating through one acre-foot  of 2.5, 6.5,  and 10 ft
refuse beds is summarized in Table 3^.

        Burchinal e_t al. stress several considerations which seem to  be of special
importance to them as a result  of their investigations.  They  are:

    1.  The potential damage to underground reservoirs by  way  of increase in
        hardness,  in the concentration of iron, nitrogen,  and  sulfur  compounds,
        and in that of total dissolved solids.

-------
                                       TABLE 33
                  CONCENTRATION OF LEACHATE FROM SIMULATED LANDFILLS
                           CONTAINED IN CONCRETE CYLINDERS51
                                                                                   87

Item
BOD (5-day)(ing/jl)
Alk. (as Ca Ca03)(mg/^)
Na + K (mg/4)
Cl" (mg/£)
Total N (mg/-0
Total Solids (mg/Jj)
Cylinder Depth (ft)
4
14,760
10,630
1,634
951
613
21,140
8
26,940
16,200
3,963
2,000
1,384
49,000
12
33,360
20,850
5,109
2,310
2,508
59,000
                                       TABLE 34

          ESTIMATION OF POLLUTION FROM REFUSE BEDS OF VARIOUS DEPTHS DURING
                 PERCOLATION OF THE EQUIVALENT OF 45 in. of RAINFALL&

Item (tons )

BOD (5 -day)
Bicarbonates
Na+ + K+
Cl
S04
Total N
Refuse Bed Depth (ft)


2.5
17.2
12.8
29.9
1.04
0.68
0.83

6.5
14.4
9.7
22.6
0.83
0.44
0.78

10.0
12.3
8.0
19.6
0.8
0.28
0.78
          Reference [50]
    2.  A need to know more about dispersion phenomena which occur during the
        movement of pollutants.

    3.  The possibility of decrease in permeability.

    4.  The dilution effect of moving water on the concentration of leachates.

    5-  The dissolving of minerals and subsequent degradation of water quality
        brought about by moving a large amount of C02 through an aquifer.

        A partial answer to the problems posed by Burchinal et_ al. may be found in the
results of other studies in which drops in volatile solids after passage of leachate
through 30 ft of soil ranged from 63 to 89 percent, and that of total dissolved solids,
from 70 to 91 percent [51].  In another investigation in which the reduction in con-
centration of a wide range of ions and other materials brought about by passing through
50 ft of soil was determined, drops ranging from 51 percent of the Ca++ to 99 percent
of the COD were observed.  Incidentally, they observed a sharp reduction in threshold
odor, about 99-5 percent according to their scale.

        Burchinal et_ al. [50] also investigated the travel of the volatile organic
acids in studies with simulated landfills.  Of the acids, butyric and valeric were
the most signficant in terms of leachate concentration.  Caproic, valeric, and

-------
propionic acids were in much Lower concentrations.   Dissociated forms  of volatile
acids accounted for approximately 75 percent of the total anions in a  given leach
sampler.

        Microorganisms have been found in significant numbers in the leachate from
sanitary landfills.  From seepage from a fill in West Virginia.,  Burchinal et_ al.
[50] isolated representatives of nine genera of mesophilic aerobes, two of
hermophilic aerobes, two of anaerobes, four of actinomycetes, and 15 of fungi.
Eliasson [52] records findings of as high as 975 x  106 fungi  and 73 x  106 bacteria
per gram of dry fill after 9 "to 18 months and lower — but substantial  — numbers  in
some four-year old undisturbed fills.  (Eliasson's  findings deal with  the fill
material itself — not the leachate.)  The health significance of this  aspect is  that
if sucl? a rich flora can be found in the leachate from a fill,  pathogens buried  with
the garbage could also be transported out of the fill by way of leaching water.

        An important consideration concerned with public health has to do with the
emanation of gases from sanitary landfills.  These  gases represent a portion of  the
metabolic end products of the many types of microbiological organisms  found in the
decomposing material in a fill.  Gases identified and measured thus far are H2,  N2,
C02, CH4, and HaS [51] •  The composition of the gas produced in the landfill resembles
quite closely that produced in the digestion of raw sewage sludge.  Eliasson reports
the composition of gas produced in a four-year old  fill as being 28 percent C02,
56 percent CH4, 15 percent nitrogen, and 10 percent miscellaneous gases [53] . Gas
production is a long-time affair, inasmuch as it is produced as long as decomposition
takes place, and decomposition continues for many years after a fill has been completed.

        Extensive studies have been made on the discharge of C02 and CEU from a  fill
to the surrounding environment [51, 'yk] .  In one report it was estimated that CPU
was discharged into the soil surrounding the fill being studied at a rate of 1,4^0
Ib/air/yr, and that nine times this amount diffused into the air.  In  another report
it is stated that an equivalent of 25,700 Ib C02/yr entered the soil from a fill,
and that kQ times that amount diffused out to the atmosphere through the fill's  one-
foot silt cover.  In a determination of the rate of downward travel of the gas,  the
conclusion was reached that it would take 2 A yr for the C02 to reach  ground water
which was 190 ft beneath the fill.

        This brings up the importance of the ground water level with respect to  C02
travel.  The researchers noted that the C02 concentration built up rapidly at the
50-ft level, whereas it probably would take 15 yr to reach a concentration of 5  per-
cent at the 200-ft level.  The carry-away C02 at a  5 percent concentration in contact
with ground water in the fill would be on the order of 1,200 Ib C02/acre refuse/yr.

        Horizontal travel proceeded at 0.093 Ib/sq  ft/yr in one site and 0.259 Ib/
sq ft/yr in another site.  Attempts to prevent the  diffusion of gases  into the
surrounding soil by placing a polyethylene sheet between the fill boundary and the
surrounding soil met with only partial success.

        The reasons for the concern about gas production and travel are many. The
destructive potential of C02 once it enters the ground water level has been stated
in the section on leaching.  Hydrogen and H2S probably would not be of significance,
since the amount produced generally is negligible.   Methane is of importance primarily
because of its combustibility, and only secondarily because it is a "suffocating"  gas.
The high concentration of methane renders explosive the gas emanating from a fill  in
the presence of "normal" air.

        In view of the biodynamics of a landfill, i.e., long-term decomposition and
associated gas production, considerable caution is  to be recommended before completed
landfill sites are opened for human dwelling.  When any kind of construction is
completed over a landfill site, the immediate problem with gaseous diffusion is  that
of C02 which lasts for a few months.  This period is followed by one of methane  dif-
fusion which may persist for many years.  An example of the need for this caution
may be found in the report by First et_ al. [55].  They describe a survey made of a
housing development constructed on filled land.  In graveled spaces under the dwelling

-------
units, unsatisfactory conditions were found to exist with respect to air composition.
In  some cases, the atmosphere contained less than 10 percent Oa, as much as 6 percent
CO2, and 20 percent methane.

        Although blowers and fans may serve as remedial steps to dissipate gases
collected in basements and gas-proof floor slabs may be used in construction,
greater engineering ingenuity and more study are needed before completed landfills
can be used for anything other than as recreational grounds.

        When refuse handling practices in sanitary landfill areas are marked by
carelessness, vector breeding in unprecedented proportions becomes a distinct
possibility, and the way is paved for the spread of fly and insect-borne diseases.
This is particularly true during warm weather and in situations where refuse storage
at  the site of generation is unsatisfactory.  Having gained entry to refuse stored
in  inadequately covered garbage containers, flies lay eggs in enormous numbers.  The
latter are carried to the storage pit where slip-ups in effective compaction or
complete coverage with soil permits their full development and release.  Some idea
of  the number of the transported eggs can be gained from a consideration of results
obtained by Barnes and Black [56, 57].  They found that an average of 1,128 fly
larvae per can per week migrated from refuse cans to pupate before the combined
refuse was collected each week.  As many as 23,208 larvae had been counted from one
can during a single week.  House flies that develop in landfills can penetrate and
emerge through five feet of uncompacted cover or through nearly six inches of com-
pacted cover.

        Composting.  The public health implications of composting as a waste treat-
ment process wherein a great many potentially dangerous pathogens are rendered innoc-
uous or are killed, hinges largely on one critical factor, namely, the temperature
to  which the treated material is raised.  At present the consensus is that the
likelihood of the survival of any pathogens or of fly larvae and eggs becomes remote
when the duration of exposure to the critical temperature level is sustained over a
period of days and weeks.

        Much work concerned with the effect of temperature on pathogen survival has
been carried on in Germany [58-61] .  For example, Knoll [58] made observations on
the survival of the Salmonella groups typhi-murium, cairo, infantis, and paratyphi.
His procedure consisted in inserting cultures of the organisms in gelatin capsules,
placing the capsules in 100 grams of raw material contained in nylon bags, and
dispersing the bags with their contents throughout a pile of composting material.
After 50 days exposure to the temperatures prevailing in the pile, all of the
organisms had been killed.  In another study involving S_. paratyphi B and S_. typhi
[59;6o], he found that the certain destruction of Salmonella strains cannot be
assured in zones in which the temperature does not exceed 4-5 °C; whereas complete
decontamination can be attained within one day in zones in which the temperature
is  65°C.  Survival in terms of number and duration between these temperatures is a
function of increase in temperature.  Strauch [6l], using S. enteriditis,
Erysipelothrix rhusiopathiae, and the psittacosis virus, found that these organisms
are completely destroyed under similar conditions.  However, when he added Bacillus
antracis to the collection, he found that the latter were only killed when the
exposure period was three weeks or longer, temperature in excess of 55 °C, and the
moisture content 40 percent or higher.  He also reports that the kill-off of anthrax
is  assured if the temperature of the composting material does not rise above 55°C
during the first three days.  The reason is that anthrax spores will germinate if
the temperature is held at a point lower than 55°C.  The organism is readily killed
when in the ensuing vegetative stage.  The organism has been observed to survive as
long as 231 days in so-called "cold" composting processes, i.e., those in which the
temperature does not exceed 55°C.

        Elevated temperatures alone cannot entirely account for the reduction in
pathogen number observed in composting refuse.   An appreciable amount of kill
undoubtedly is due to the mutually antagonistic effects found in cultures consisting
of the wide variety of types of microorganisms  found in composting material.  The
existence of this phenomenon was demonstrated by Knoll [59,60] in his experiments

-------
concerned with the effect of high temperatures.   In a run,  following the procedure
described previously, he exposed one set of samples containing S.  paratyphi  B and
§.' ca:i-ro in a pile of composting material held at a constant temperature of  50°C,
and simply incubated a second sample at the same temperature.  In  both instances,
the moisture content was 50 percent.  S_. paratyphi were killed within two days and
S_. cairo within seven days in the sample placed in the compost pile; whereas S.
paratyphi survived eight days, and S_. cairo,  17 days in the incubator.  He further
demonstrated that the rapid kill-off in composting material probably is due  to
antibiotic effects in an experiment in which  he placed samples of  cultures of S.
paratyphi and S_. cairo in media containing an aqueous extract of composting  material,
and a second set of samples in media without  the extract.   The organisms were killed
off within 10 days in the media containing the extract, and on the other hand, they
survived for more than four weeks in the control medium.  Knoll's  conclusion is that
the compost process, biological "self-purification," compensates for temperature
inadequacies as far as pathogen kill is concerned.

        Apparently resistant forms of parasites are destroyed during the composting
process.  Scott [62] found that the eggs of Ascaris and the cysts  of Ehdamoeba
histolytica and Endamoeba coli were completely destroyed within three weeks  in
windrow composting.  In a more general statement, Scharff  [63] reports that  despite
a heavy concentration of Ascaris eggs and hookworm eggs in night soil used in his
experiments, he could find no trace of intestinal worm eggs after  the material had
been composting for three weeks.

        Although the public health aspects of composting seem favorable with respect
to pathogenic organisms, some doubt exists as to whether this also applies to patho-
genic fungi.  Characteristically, at some time during the  composting process fungi
became quite conspicuous because of their number.  Judging from past observations [2],
the greater part of the fungal population during this stage in a windrow operation
is in the outer layer of the compost pile.  The layer usually has  a temperature
within the range 4 5  to 55°C and generally is aerobic.  In fact, in addition to that
of temperature, the depth of the fungal layer seems to be  a function of the  degree
of aeration as adjudged by the porosity of the material.  The occurrence of  a fungal
stage usually is observed in mechanical compost processes,  although because  of the
brief retention time in the digester proper,  peak development of the fungal  popula-
tion is not reached until the composting material is windrowed for the "curing" or
"maturing" step.

        In their publication, McGauhey ejb al. [2] report isolating representatives
of the genera Streptomyces and Micromonospora in the actinomycetes, and of two
thermophilic fungi, Aspergillus fumigatus and Penicillium  dupontii.  Knoll [59]
lists in addition to those found by McGauhey et_ al., members of the groups Geotrichium,
Mueorinae, Sporotrichium, Trichoderma, Gliobotrys, Torula,  and Fhialophora.   The list
was lengthened by von Klopotek [6kjto include Cladosporium, Debaromyces kleockeri,
Candida parapsilosis, plus many others.  This long list includes some genera which
have species known or suspected as being pathogenic under  certain  circumstances to
human subjects.  The wide variety of the organisms indicates that  fungi readily
survive the composting process, although the extent of survival is a function of
the group's thermotolerance.  It also indicates the possibility that truly patho-
genic forms may survive, and hence the need for intensive  research in this direction.
Work along this line is being conducted by the research group at Johnson City,
Tennessee [65].

        Another important public health aspect of composting that  warrants attention
is concerned with the dispersal of certain minerals and chemicals  in the surrounding
environment.  Some of these may be released in such minute amounts as to constitute
no hazard; however, no safe conclusion can be made until more is known concerning
the composition (i.e., chemical) of the refuse subjected to composting.  A published
analysis of trace elements found in Dutch V.A.M. compost [66] indicates the  following
concentrations, expressed as percentage of the total dry weight of the refuse:
Cu 0.01-0.06$, Mn 0.002-0.03fo, Zn 0.007-0.023%,B 0.005-0.007$, Mo  ± 0.001, and Mg
(as MgO) 0.11-0.3^$-  Another important group of substances which  may be found in
compost or escape from the compost plant to the environment are the pesticides and

-------
herbicides .  The concentration of such compounds in certain types  of refuse may be
great enough to constitute a definite hazard.   Agricultural wastes undoubtedly would
be the greatest offenders in this regard.  The Berkeley laboratory of the  National
Canners'  Association presently is conducting a study of the stability of pesticide
residues  in composting agricultural wastes.


OCCUPATIONAL AND GENERAL HEALTH HAZARDS

        The possible health hazards suggested in Table 29 seem more numerous  in the
case of persons directly occupied in the business of collecting, transporting, and
disposing of wastes than of the public in general.  However, the health-related
factors noted in the preceding section as being associated with burning, landfill,
and composting have general implications since polluted air, contaminated  water,  and
infected land are the avenues along which pollutants move from environment to man.
On first analysis the hazards to the public which emanate from solid wastes disposal
do not seem to be particularly serious; and it may well be that further study will
support such a conclusion.  Nevertheless, such further study is advisable  because,
for example, the stack discharges from refuse incinerators have been analyzed
principally for the types of effluents known to derive from the burning of fuels  of
a more homogenous nature.  It therefore remains for definitive research to reveal
what hazards, if any, might be added by the presence of such materials as  plastics,
asbestos, cadmium, beryllium, pesticides, etc. not found in normal fuels but  likely
to appear in mixed refuse; and to determine whether such hazards have a macro-
environmental effect.

        Evidence of the occupational hazards associated with solid wastes  management
is both definitive and presumptive.  Most definitive studies have  been made on the
health of persons involved in the collection of refuse, or on the  incidence of in-
dustrial type accidents to workers involved in the disposal process.

        One of the most extensive studies relating municipal refuse collection to
occupational health hazards has been reported by Dr. Sliepcevich   [67]. The  study
involved the effects of work conditions on the health of the uniformed sanitation
men of New York City.  The long-term health effects on one 500-man group,  and the
current health level of another group of 8,528 men, were investigated.  The results
led to a number of significant conclusions.

    1. Arthritis may be classified as an occupational disease of  refuse collectors.

    2.  Cardiovascular diseases may be classified as occupational  diseases of
        refuse collectors inasmuch as the incidence of these diseases in the
        sanitation occupation exceeded all other groups of similar ages.

    3-  There is a positive relationship between the age of workers or years  of
        service and arthritis and cardiovascular diseases.

    4.  The prevalence of muscle and tendon diseases among sanitation men  is  very
        high, particularly muscle ailments affecting the back. These diseases
       may be classified as occupational for refuse collectors.

    5.  Skin diseases may be classified as occupational for the refuse collectors.
        Some interesting points made by Dr.  Sliepcevich include:

        a.  The amount of daily lifting done by a sanitation man equals lifting
            a 24- or 35-lb can to the top of the Empire State Building.

       b.  Lifting a 60-lb load requires 3-1/2 hp of energy (46 in lift
            of 60 Ib).

       c.  The work of sanitation men consists of a chain of sudden bursts,
            the intensity of which varies from medium hard to extremely hard.
            These strenuous exertions can be continued only because there  are

-------
92


            periods of recuperation when the worker  carries the empty can back
            to its resting place.

        d.  More consideration was  given to the mechanical devices than to the
            workers.  For example,  facilities  to maintain cleanliness were de-
            plorable in the men's locker rooms; whereas the collection trucks
            were kept cleaner than  the  men were able to keep themselves.  (This
            is changing — the more  modern scavengers and city service departments
            are urging cleanliness  of the crews —more for public relations.)

    6.  Hernia may be considered as an  occupational  disease for collectors.

    7«  Injuries to the hand are the most common injuries.

    8.  Older men tend to have less injuries than  the younger men.

    9-  The injury frequency rate decreases as the years of service increase.

   10.  Sanitation workers have an  extremely high  injury frequency rate, exceeding
        that of all other occupations previously studied except logging.  (N.B. —
        this in 1955-)

        There is need for similar studies of the occupational hazards associated
with disposal techniques such as landfilling and incineration.  Recent indications,
for example, are that aerosals may  present a health  hazard by transmitting disease
vectors to men engaged in grinding  refuse for  composting or in mixing sewage  sludge
with refuse for composting.

-------
                     VI.  TECHNOLOGY OF SOLID WASTES MANAGEMENT
INTRODUCTION

        Studies of the technology of solid wastes management have proceeded along
three main lines of approach:

    1.  Improvement of existing technology — incineration, composting,  landfill,
        and salvage.

    2.  Adaptation of existing processes to a wider spectrum of wastes  — anaerobic
        digestion with sewage sludge.

    3.  Application of known processes to the development of new technology — wet
        oxidation, biological fractionation.

        During the period herein reported, active research has been directed to six
of the seven aspects of solid wastes management listed in the three foregoing cate-
gories .  The seventh, landfill, is scheduled for experimental work later in the
program.  Both land surface and underwater fills are of concern.  The rationale
underlying the approach to each of the six aspects investigated is set  forth at the
appropriate place in each of the following sections.


INCINERATION

         Burning is one of the oldest methods of dealing with the organic fraction
of solid wastes.  As suggested in an earlier section (Figure 1, type 4), it repre-
sents the only important current method involving "change of state" as  the basic
principle of operation.  In its systematized application to municipal refuse it has
advanced through the years from simple open piles or pits to highly mechanized
engineered systems which at best are capable of reducing organic matter to a sterile
ash having some 10 percent of the original waste volume.  The remainder is discharged
to the atmosphere as gases and particulates.  In the most favorable geographical
situations and from the best designed and operated plants this discharge represents
a tolerable pollution of the atmosphere.  At its worst the process is capable of
creating objectionable air pollution producing nuisance from fly-ash, and leaving
a residue of 15 to 25 percent of the original volume of solid wastes.  For many
large communities, however, where the value of land for landfill operations is an
overriding economic factor, incineration (whether at its best or at its worst) is
widely practiced and may be expected to be used in the future.  This being the case,
it is important to consider the nature of problems to which research and development
should be directed.

        One of the most urgent unsolved problems is in the area of economics:  how to
meet increasing standards of air quality, aesthetics, and related considerations at
a cost the public is willing to pay.  While the addition of precipitators and water
sprays to remove particles, scrubbers to remove sulfur dioxide, chemical systems to
remove other gases, etc. are all scientifically feasible, they involve  great expense.
Carried to the ultimate they are illogical in that their purpose is to  change the
incinerator effluents back to the solid state again, converting air pollutants once
again to water and land pollutants, albeit in an altered form.

        A second area of unsatisfactorily resolved problems is technology.  A change
in nature of solid wastes, particularly in the content of plastics, as  well as an
increase in the scope of community wastes which might be incinerated suggest that
better mechanical systems are required.
                                        93

 8-229 O - TO - 8

-------
        Some of the problems of economics  and technology are  capable  of  resolution
only through plant-scale development and demonstration projects.   Others are amenable
to research techniques such as those hereinafter considered.


Concept and Rationale

        Several concepts underlie the research herein reported.   First is that
incinerators are capable of better performance than has been  the  past experience  in
many cases.  Public attitudes toward refuse,  as noted in a previous chapter, have
not been conducive to expenditures for wastes management.  Too frequently performance
has been sacrificed to minimize capital investment and operating  cost.   An already
marginal, or even poor, situation is then  further worsened by both an increase  in
the population generating refuse and in the per capita waste-generating  rate.
Consequently, incinerators operating at well in excess of 150 percent of design
capacity are by no means rare.

        Almost inherent in the operation of incinerators is the receipt  of some 80
percent or more of the incoming refuse in  approximately six hours. Therefore,  if
combustion is to be carried out continuously refuse storage is required  to smooth
out the flow to the furnace.  Storage, however, particularly  in the hotter months,
can present the problems associated with putrefying organic matter.   Ideally, then,
it would be desirable to convert the as-received refuse into  some form which would
not give rise to such storage problems.

        Accompanying the storage problem is that of heterogeneity of  the incoming
waste — a situation certain to worsen if a wider spectrum of  community wastes are
brought to the incinerator.  Efficient burning, constant furnace  temperature, and
utilization of waste heat all depend upon  a uniformity of fuel, as well  as control
of the rate of its injection into the furnace.

        Looking at industrial furnaces or  boilers, current technology seems to  be
quite capable of producing clean, efficient combustion of gaseous and liquid fuels.
Sulfur oxides removal now seems feasible by several routes.  Coal can be burned
quite efficiently in powdered coal systems, and the fly-ash removal can  be as
complete as public authorities demand.  If the refuse could be converted into a char
or coke, either of which is quite friable, powdered coal technology could be used
in refuse incineration.

        The combustion of solids necessarily involves surfaces where  the fuel and
the air must be brought into contact.  Also,  the time for the complete combustion
of a small object is less than that for one that is larger.  Therefore,  grate  speed in
a furnace could be increased, thus increasing the capacity, if a  uniformly-sized
feed were available.  With a nonuniform feed, either the grate speed  must be adjusted
to achieve complete burnup of the largest  objects or incomplete burning  must be
accepted.  Thus, investigation of size reduction methods for  the  refuse  might well
be warranted.
Objectives

        In accord with the foregoing rationale it is the specific objectives of the
research team concerned with the technology of incineration to explore the scientific
and technical feasibility of converting the organic fraction of solid wastes into a
storable solid or gaseous fuel of relatively uniform heating value prior to charging
it into a furnace, either with or without the production of marketable by-products.

        During the period herein reported investigative work has proceeded along
two lines:

    1.  Preliminary feasibility studies of refuse pretreatment.

    2.  Studies of pyrolysis as a specific method.

-------
                                                                                  95
Refuse Pretreatment Studies

        In this aspect of the work preliminary design studies were made of the
equipment and plant necessary to produce a fuel of nearly uniform heating value
and particle size from typical urban refuse and garbage.  Assuming currently used
collection systems and concepts of economics, the prospect of producing a rela-
tively homogeneous fuel which might be utilized over a period of time by a power-
generating furnace does not seem particularly bright.  Among the several problems
encountered were segregation, particle size reduction, and drying.

        The least costly and most efficient method of segregation is, of course,
at the source of waste generation.  This poses no problem in the case of animal
manures, agricultural residues, cannery wastes, and minor activities which involve
essentially only organic residues.  The construction industry, however, cannot
conceivably separate its wastes under any foreseeable concept of economics.  Dis-
mantling of buildings board by board, while possibly desirable from a resource
conservation viewpoint, is only feasible within the U. S. standard of living if
combined with publicly financed welfare and other manpower support programs.   This
would require a whole new political concept that may or may not come to pass in the
future.  Segregation at the source of waste production by the construction industry
itself is equally infeasible without public subsidy; and if such cost were to be
assumed by the public, segregation after collection would be far less costly than
segregation at the source.

        In the case of household refuse, segregation by the producer of wastes is
out of step with the whole trend of the U. S. culture of convenience and a national
economy based on consumption (i.e., discarding) of goods.  Furthermore, it is contrary
to the wishes of citizens and few public officials are anxious to try to impose house-
hold segregation of refuse upon an unwilling electorate.

        The possibility that salvage might be made to overcome the cost of segregating
refuse was given consideration, while a full discussion of the salvage problem is
reserved for a following chapter, it is evident that under present economic and social
concepts it is uneconomic on any large scale.  This results from high labor costs for
sorting and low market prices for many salvable commodities.  Obviously some degree
of segregation is needed, and is currently practiced, in incineration.  However, it
must be concluded that the greater degree of segregation which seems necessary for
the production of a homogenous fuel cannot be achieved without a change in current
practice and current concepts of economics.

        The point has been made in a previous section that the whole problem of
solid wastes management calls for a reassessment of both economic and technological
assumptions.  Applying such a prospect to the field of incineration, the question
of segregation of refuse becomes less dismal.  Papers, particularly kraft, because
of its volume appears to be amenable to a mechanized separation process.  Thus
salvage of paper might become a greater economic facet in segregation for incinera-
tion.  Separation of noncombustibles from organics may not be necessary if particle
size reduction is first accomplished.  Some incinerator operators feel that cans and
bottles help keep the fuel bed permeable to air.  Thus hammer mills, followed by
ballistic separators if necessary, become a feasible part of the refuse pretreatment
plant producing homogenous fuels.

        For demolition debris, float and sink methods have been suggested for separating
wood from heavier components.  No doubt, some rough initial size reduction would be
required, possibly by hammer mills.  For large objects such as utility poles  specialized
size reduction machinery is needed.  Among the units considered are guillotine-type
shears, chain saws,  and extremely heavy duty sawmill hogs.  The problem is,  of course,
complicated by the inevitable presence of tramp metals but the problem is certainly
not insurmountable if refuse pretreatment should become an accepted concept of incinera-
tion practice.

        Drying of wet refuse to make it less putrescible ani more storable appears to
be too costly to consider as a separate process.  However, the conventional drying

-------
96
grates in an incinerator furnace at present are obviously performing  this  function.
There is no reason why the dried refuse need go directly to  the  furnace  from  the
drying grates, routing it to storage where part of its  elevated  temperature is used
to preheat water for steam production as an incinerator by-product  is a  relatively
simple problem in mechanical engineering design.   As  for steam and  power production
by the incinerator, the fact that it has been considered inconsequential in the past
is not significant.  Lack of homogeneity of fuel and  limited freedom  to  supply fuel
as needed has been the principal drawback.  A shift of  objective from that of simple
refuse disposal to power production using fuel salvaged from refuse is the initial
step.  The second step involves an upgrading of economic concepts of  refuse manage-
ment to the level necessary to solve the problem.

        Inasmuch as the first of the foregoing steps  is feasible and  the second
inevitable, further investigative work on the nature  of equipment and plants  nec-
essary to pretreat refuse and burn it productively, as  well  as on the economics of
the system, seems clearly desirable.  Experimental work along these lines  is  planned
for later in the research program.  The first work contemplated  is  an investigation
of the effect of preliminary size reduction on incinerator capacity and  performance.
Ultimate plant-scale experiments are to be encouraged but are, of course,  beyond the
scope of the research program herein reported.


Fyrolysis Studies

        In the production of a relatively uniform fuel  from  organic refuse, the ideal
situation might be one in which preprocessing of organic matter  returns  important
fractions to the industrial resources of the nation and the  residue becomes a fuel for
incinerator furnaces.  Thus the method noted as "Indirect recycling"  (Figure  1,
type 6) would precede the "change of state" represented by incineration.  Such a
procedure would be doubly desirable because of its combination of resource conserva-
tion and economic wastes management.  Pyrolysis represents one method of achieving
this ideal situation and has hence been given attention by the research  team  interested
primarily in incineration.

        Pyrolysis or destructive distillation of most organic materials  results in
the formation of three classes of products:  l) a solid residue, or char,  composed
of elemental carbon and ash; 2) a condensable liquid  product, water plus mixed
organics; and 3) a gas of rather low heating value, but definitely  combustible.
Advantages of the process include the following:

    1.  The pyrolysis products should all (except for the water  and ash) be
        combustible as fuels with existing technology and minimal air pollution.

    2.  The pyrolysis products, if used as fuel,  should present  less  of  a
        storage problem than refuse or garbage.

    3-  The possibility exists for the recovery of saleable  by-products, as
        for example, acetic acid, methanol, and mixed solvents.

        The first stage of the investigative work was to prepare a  quantitative  flow
diagram, material balance, and energy balance.  This  work was based on information
from the technical literature on the composition of urban refuse, on  wood  and coking
coal destructive distillation, and on the fragmentary data available  on  the  pyrolysis
of specific materials  [ll,68-73J-  The flow diagram for the  visualized process  is
given in Figure 15-  Tables 35; 36 and 37 present the data used  on  the as-received
refuse, and the refuse after removal of some of the noncombustibles and  drying.
Table 38 summarizes the material balance, omitting any  estimate  of the  organic
fraction of the total  liquids, which apparently can vary from 2  to  nearly  8  percent.

        A large laboratory or small-scale pilot plant to check the  material and
energy balance, and to obtain operating data as well  as produce  samples  for  separa-
tion process evaluation, is now being designed.  This unit is to have an approximate
throughput of 40 Ib/hr of dried refuse.

-------
                                                     97
FIGURE 15.   MATERIAL  FLOW  OF  REFUSE   PYROLYSIS

-------
                               TABLE 35
               COMPOSITION AND ANALYSIS  OF A  COMPOSITE
                       MUNICIPAL REFUSE  (1966)S
    1  Corrug.  paper boxes                                    23.

    2  Newspaper                                              9.40

    3  Magazine paper                                         6.80

    h  Brown paper                                            5-57

    5  Mail                                                   2.75

    6  Paper food cartons                                      2.06

    7  Tissue paper                                           1.98

    8  Wax cartons                                            0.76

    9  Plastic  coated paper                                   0.76

   10  Vegetable food wastes                                   2.29

   11  Citrus rinds and seeds                                  1-53

   12  Meat scraps, cooked                                     2.29

   13  Fried fats                                             2.29

   14  Wood                                                   2.29

   15  Ripe tree leaves                                       2.29

   l6  Flower garden plants                                   1-53

   17  Lawn grass green                                       1-53

   18  Evergreen                                              1-53

   19  Plastics                                               0.76

   20  Rags                                                   0.76

   21  Leather  goods                                          0.38

   22  Rubber composition                                      0.38

   23  Paint and oils                                         0.76

   Qh  Vacuum cleaner catch                                   0.76

   25  Dirt                                                   1.53

   26  Metals                                                 6.85

   27  Glass, ceramics, ash                                   7-73

   28  Adjusted moisture                                      9-05
                                                            100.00

According to Kaiser, cf. Reference [ll].

-------
                  TABLE 36


       CHEMICAL ANALYSIS OP RAW REFUSE
                                                               99
Item
Moisture
Carbon
Hydrogen
Oxygen
Nitrogen
Sulfur
Ash and Metal
Total
Percentage
by Weight
20.00
29.83
3-99
25-69
O.JT
0.12
20.00
100.00
                   TABLE 37


 CHEMICAL ANALYSIS AFTER DRYING AND SEPARATION
(20$ MOISTURE AND 9$ ASH AND METAL ARE REMOVED)
Item
Hydrogen
Carbon
Oxygen
Nitrogen
Sulfur
Ash and Metal
Total
Percentage
by Weight
5-6
42.0
36.2
0.5
0.2
15-5
100.0

-------
100
                                     TABLE 38
                     SUMMARY OF  THE MATERIAL BALANCE CONCERNED
                      WITH THE PYROLYSIS  OF MUNICIPAL REFUSE
Item
Raw Refuse (analysis as in Table 35)
Separation of Inorganics
Drying
Analysis after drying (see Table 37)
Products from Pyrolysis
Charcoal
Liquids
Gas
Ash and Metal

Percentage
In
100
100
91







Out
100
91
71







Removed

9
20


11.25
40.8
7-95
11
100
COMPOSTING

        Of the possible processes for converting organic solid wastes to products
more readily utilized, composting has been given widest attention.  Although most
studies of the process have been directed to the production of a soil conditioner
marketable in agriculture, the possibility of simply reducing the volume of material
going into a landfill, or producing less "insult" to the land resource, has not been
overlooked.  Following studies by the University of California in the early 1950's
[2] which established the parameters of aerobic composting, various attempts were
made to apply the process to municipal refuse on a commercial basis.  Progress has,
however, been slow because orientation of agriculture to commercial chemical
fertilizers, and other related factors, has made marketing of the product all but
impossible on any appreciable scale.  Of particular significance is the fact that
investment in an uncertain process based on connecting a low-value raw material
owned by the public to another low-value material for which there is little immediate
demand is not economically attractive to private industry.  At the same time the
public is reluctant to make long-term commitments to pay private enterprise to accept
its wastes and is in no legal or political position itself to develop and operate a
commercial composting plant.

        Recognizing the possibility that the time lag between the production of
compost and agricultural demand for soil conditioner may encompass many years, the
United States Public Health Service demonstrated that compost made from municipal
refuse can be compacted in a landfill and so stored for use at some future time.
This, however, did not answer the question of who is to do the composting and at
what profit or loss to whom.  Consequently no application of the method has developed.
Other experiments in which disposal of the waste rather than sale of the compost
have been conducted on individual fractions of the solid wastes of a community.

-------
                                                                                 101
Control of  flies and other nuisances from animal manures has been demonstrated on
various occasions; typical were early pilot experiments at San Quentin prison [7^]
and the Davis campus of the University of California.  Solid wastes from fruit and
vegetable canneries have likewise been successfully composted by the National
Canners Association and the University [75]•


Concept and Rationale

        Essentially all of the composting experiments and experience in the U. S.
have involved some selected fraction of the organic wastes of a community and a
high degree of refinement of product.  That is, segregation, shredding, screening,
and other processing was applied to such fractions as organic municipal refuse to
produce a product suitable for soil conditioning whether or not it ended as an
agricultural soil or in a landfill.  In either case the absence of a financial
return from the product does not justify more than the minimum investment in
processing  necessary to reduce the volume of refuse and get rid of its attractive-
ness to insects and rodents.

        The underlying rationale of the research program herein reported is that it
might be possible to apply rough composting to such of the organic wastes of a
community as can economically be assembled — domestic refuse, animal manures,
demolition  debris, sewage sludge, agricultural residues — and so reduce the volume
and otherwise improve the suitability of the mixture for land filling.  Thus
conversion  by composting might become a step in the preparation of organic wastes
for land filling in which the reduction in land area needs and earlier use of the
filled area by reason of its greater initial stability would at least offset the
cost of composting.  If then at some later data a compelling need to add organics
to the soil should develop, the fill could be mined, compost screened out, and
fill volume again made available for refuse disposal.

        The rationale also encompasses the alternate possibility that in a particular
instance a  demand for compost for immediate use could be developed.  In this case it
is conceived that animal manures in the mixture might furnish the nitrogen needed in
composting  paper and other carbonaceous materials and so make rough composting
feasible where it has not been so in the past.  The idea would be to compost prior
to segregation with only a minimum of shredding.  Ultimately the partially composted
organic material might be screened out and left to mature in a pile.  The remainder
would be subjected to salvage operations prior to disposal by land filling.


Objectives

        The objectives of the experimental work are suggested by the concept
and rationale underlying the project.  Specifically they include exploration of:

    1.  The feasibility of assembling organic fractions of the overall solid
        wastes of a community which might complement each other in the
        composting process.

    2.  The minimum parameters of a composting process suited to:

        a.  Preparing refuse for landfill with a minimum volume and "insult"
            to the land.

        b.  Producing compost from mixed organic wastes at a minimum cost.

        During the period herein reported no experimental work was undertaken.
Research activity was confined to two facets:

    1.  Compiling references on the subject of composting and incorporating it
        in the project's retrieval system.

-------
102
    2.  Making an on-the-site study of solid wastes  management  in Germany,  with
        particular reference to the utilization of organics  in  agriculture•

        Only the first of these two activities  was supported by project  funds.   The
second was made by Dr. S. A. Hart,  one of the project  investigators  under other
support for sabbatical leave from the University of  California.
West German Studies
        Inasmuch as experimental work on composting was  scheduled for  the  second
year of project activity in order to make possible the background study abroad,  the
project has produced more in the realm of ideas  and concepts  than concrete data
directly applicable to U. S. conditions.  Of particular  interest  is  the contrast in
attitude of farmers in West Germany and the United States  in  relation  to the  use of
compost and other organic refuse on agricultural soil.  West  Germany has today 56
million people living on 94,500 square miles. With about  25  percent of the U. S.
population and 3.2 percent of the land area of the U.  S.,  West  Germany produces
78 percent of its food supply.  The average size of farm is but 24 acres,  hence
productivity must be high.  One factor in this productivity is  intense use of barn-
yard manure, compost, and other organics, and German agricultural science  has found
[76] that maintaining a high and constantly replenished  soil  organic content  is  one
of the keys to continued high productivity.  Thus the incentive exists for the farmer
to route his agricultural residues back to the land and  hence to  prevent their be-
coming a part of the overall wastes management problems  of the  community.

        The situation in the United States today is, of  course, vastly different.
We have plenty of prime agricultural land and are easily able to  produce an
abundance of food.  Organic content of the soil  does not have to  be  husbanded,
although it seems desirable to do so in the western U. S.  Thus the  economic
pressure for compost production from solid wastes does not arise  in  the U. S. from
agriculture.  In fact, the economics of U. S. agriculture  tends to increase the
volume of solid wastes which agriculture does not want in  any form.

        Nevertheless a significant lesson may be drawn from the German experience —
i.e., it is possible to use the land and its ability to  assimilate organic matter
as a way of disposing of some of our solid wastes.  While  this  is a  relatively new
approach to refuse management it does imply that if compost can be produced at an
acceptable cost, agricultural land might be used instead of a landfill for its dis-
posal.  In this case the economics of refuse disposal rather  than the  economics  of
agricultural fertilization would become the controlling  factor.  Possibly  the farmer
might be paid for accepting compost rather than  asked to purchase it.

        Concerning the technology of composting  several  things  can be  learned from
the West German experience.  Eight plants erected since  World War II continue in
operation [j6] to the present.  None have been shut down.  The  general characteristics
of each are indicated in Table 39-  It is notable that all are  in or near  the wine-
growing areas of Germany.  Further, seven of the eight include  sewage  sludge  in  their
input.

        Extensive research on the survival of pathogens  in the  composting  process has
been conducted.  The results show that there is  a minimum  time-temperature condition
required for pathogen kill.  In windrow composting this  was observed to be 18 to 21
days at temperatures consistently above 55°C. At lower temperatures  some pathogens
lived 251 days.  In the Dano drum 5 days were required — or  3 days,  plus 4 additional
days in windrow storage.  At Heidelberg, where the refuse  is  ground  before putting it
in the Multi-Bakter Turns, pathogens were killed within  24 hours. These results
seem to be directly usable under U. S. conditions.

        From observations in West Germany, Dr. Hart draws  several conclusions which
have pertinence to project work planned for the  future at  the University of
California:

-------
                                                                      103
       TABLE 39




GERMAN COMPOSTING PLANTS

City and
Plant Ovner

Baden-Baden

City



Bad
Kreuznach

Private,
Farmers
Organization


Blauteurm

Private,
Cement
Manufacturer


Duisterg-
Huckingen

City



Heidelberg

City





Sctweinfurt

City





St . Georgen
{near Freiburg)

City



Stuttgart -
Mohrigen

City


Pop.
Served

56,000





1*5,000







20,000






120, 000






30,000







85,000







lit, 000






75,000





Oper-
ation
Begun
1955





1958







195U






1956






1955,
1962,
see
disc .




1963







1963






1959





Sludge
Accepted?

yes





yes







yes






yes






yes







yes







yes






not
nov




Process

Windrow
composting of
unground
refuse


Dano drum
without
pre -grinding





Windrow
composting of
ground refuse




Dano drum
without
pre -grinding




Multi-Bakter
Turn , with
pre -ground
refuse




Caspar i -Erik -
kolare, with
pre -ground
refuse




Windrow
composting of
pre -ground
refuse



Windrow
composting of
pre -ground
refuse

Wet Cost to City
per metric ton of
raw waste accepted
Compost Selling Price
1J.10 DM

10-12 DM/met ton



10 DM

10 DM/met ton to
Assoc . members




Estimate at 2 DM,
seems low

Set at lU-50 DM/
cubic meter for
quarry reclamation

5-20 DM, presently
good salvage income

9-20 DM/met ton



Estimated at 5-7 DM

13 DM/cu meter to
wholesaler who
distributes



9-10 DM

17-20 DM/met ton





33-50 DM, high due
to small size and
complete disposal
by composting

13.50 DM/met ton

7-20 DM

5 DM/met ton, with
only a portion
sold

Description of Operation

Magnetic iron removal plus hand separation, refuse
mixed with sludge, and piled for 3-5 months without
turning. An air-duct system for aerating the piles
has not "been effective. Finished compost is ground
and sieved. Noncompostable residues burned if
possible, and "buried.
Magnetic iron removal, then unground refuse and
sludge put in Dano drum for 3~^ days. Partially
rotted compost is sieved, and piled in windrows
without further turning. Oct-Dec disposal on grape
land. Noncomposted sieve residue is buried on the
site, thus raising the elevation of the storage
area. Successful operation, mostly due to the
demand for the compost.
Plant was erected to produce compost to reclaim sand
and gravel quarries. Hand separation of refuse
possible but not always done, DorrOliver rasp, then
ground in hammer-mill, sludge added and windrowed.
Three turnings. Finished compost used "as -is,"
mostly for quarry reclamation. Small incinerator
for bulky noncompostables.
Refuse from only part of Duisberg is processed.
Magnetic and hand separation, then unground refuse
and sewage sludge into Dano drum for 3-day deten-
tion. Discharge sieved. Sieve residues to
landfill. City is planning an incinerator.
Compost plant does not run continuously due to
odors from Dano drum.
Refuse and sewage from 30,000 (personal estimate,
city estimates 60,000) of area's 160,000 residents
composted. Magnetic and hand separation, Dorr-
Oliver rasp, sewage sludge added, and mix goes to
Multi-Bakcer Turn- 3-day detention (mechanism
runs only 8 hours per day). Discharge sieved and
ballistically separated, ready for immediate sale.
Residues are landfilled.
85,000 of the 120,000 residents of the area served.
Magnetic separation, Dorr-Oliver rasp, ballistic
separation, then the ground refuse plus sewage
sludge is pressed into "briquettes. Stored three
weeks on pallets in a warehouse where composting
occurs. Removed and stored outside until ground
and sold. Incinerator then landfilling for residues
not composted.
Smallest plant, but accepts total solid wastes from
2 communities and makes everything into compost .
Magnetic and hand salvage, noncompostables burned
and the ash returned to refuse which is ground and
mixed with sewage sludge. Piled for 5 months, with
3 turnings. Not in continuous operation although
equipment is large enough.
Only a part of the Stuttgart solid waste is made
into compost, rest goes to landfill (with some
incineration first). Magnetic and hand separation,
then rasp-sieved and ballistically separated.
Placed in windrows } 2 turnings in 3 months' time.

-------
104
    1.  Sewage sludge disposal is  an important  factor  in  the  reasoning behind
        composting.   Sewage sludge disposal has generally been  a  difficult  part
        of the water treatment process  of Germany;  and part of  the burden for  the
        management of the sludge seems  to have  been turned over to workers  in  the
        solid waste field.  Composting  is an efficient and effective method of
        sludge disposal.

    2.  Health and sanitation problems  should not be a serious  obstacle  to  compost
        use.  Careful scientific studies  on pathogen inactivation have been con-
        ducted in Germany, and both the results and the techniques of study are
        appropriate to the U. S.  Safe  compost  can  be  produced.

    3-  The various composting processes  produce equivalent quality compost at
        apparently equivalent cost.  The  quality of the compost and the  cost of
        producing it is more a function of the  amount  of  "cleaning up" of the
        material than of  the nature of  the raw  material or the  method of composting.
        The grinding, sieving, and separation can be done either  before  or  after
        composting,  but the higher quality compost  is  produced  with some final
        sieving and separation.  It also  appears that  there will  be no great new
        economies due to  new processes, although mechanical processes do save  space
        over windrow composting.  A high  quality compost  contains less inert or
        objectionable material (glass shards, plastic, and ash) than poor quality
        compost, and can  more economically be transported greater distances.  The
        economics of quality improvement  and transport logistics  has not been
        worked out but certainly should be done.

    k.  Compost has its greatest market on luxury crops.  The discussion and the
        data in Table 39  indicate  that  most of  the  compost is produced in the  wine-
        growing region of Germany  and is  used on the vineyards.   It is significant
        that compost presently seems to have value  only on the  luxury crops, and
        not basic agricultural soils and  crops. There are exceptions of course, such
        as Blaubeurin, where reclamation  of quarryland is the prime use. But  finding
        an appropriate and expanded market for  compost will be  a  most significant
        factor for future success  of any  composting plant.

    5.  Research is needed on compost utilization.   Most  people — laymen and
        professionals together — wish that the  composting situation were more
        favorable.  It is not, but this does not mean  that composting or composting
        research should be abandoned.  In addition  to  using compost for  luxury
        crops and land reclamation, composting  is appropriate for sludge acceptance,
        for reduction of  the volume of  waste going  into a landfill, and  perhaps
        other reasons.  (Organic material as a  container  for  poisonous material
        such as pesticides is a possibility and should be investigated.)
LANDFILL

        As noted in a preceding section,  no experiments  on the  technology of land-
fills was conducted during the period herein reported.

        Extensive studies [3]  of landfill previously made  by the investigators,
together with well established practice carefully analyzed on a continuing basis
by numerous cities and by such organizations as the Los  Angeles County Sanitation
Districts, have effectively removed the technology of landfill  from the list of
areas in which research is likely to make spectacular contributions to solutions
to the problem of solid wastes management.  One exception  to this generalization
is undersea landfilling and it is this facet of the subject to  which technological
studies may be directed in the future.

        Lack of research on the technology of landfills  does not mean, however,
that the sanitary landfill was ignored during the report period.  As noted in a
previous section, the land is  considered the most important, and in many areas the
only, sink capable of accepting all fractions of solid wastes;  and landfilling is

-------
                                                                                  105
the technique of such acceptance.  Considerable study was directed to the nature and
fate of various fractions of refuse going into sanitary landfills in the context of
their public health significance.

        A great deal of attention was directed to the economics of landfills  and to
the interrelationship between landfill and land use planning within a community.
Results of this aspect of the landfill studies are incorporated in this  report  in
the sections on Public Health and Planning where continuing attention is being  directed
to the method.
SALVAGE

        Diversion of fractions of the overall waste material from the wastes  stream
to the basic and natural resources of the nation is one example of the method called
"Direct Recycling" (Figure 1, type 5)-  More commonly it is known by the name of
"Salvage."  The term, however, has been used rather loosely in practice to include
both residues, such as metal scrap which was recycled within an industry itself and
hence never a part of the "wastes stream," and materials and objects which are
segregated from mixed refuse and returned to the resource.   In this latter category
are such items as rags, bottles, paper, nonferrous metals,  metal cans, etc. which
are destined for the landfill unless sorted out and reclaimed.  A distinction must
therefore be made between "reduction at source" and "direct recycling," (Figure 1
type 1 and type 5)> because of both technological and economic considerations, when
approaching the subject of salvage from a research viewpoint.

        In the broader sense, including both reclaiming and recycling, salvage forms
the basis of an enterprise estimated to range from 5 to 7 billion dollars annually
in the United States.  It is, in fact, an essential part of the economy in that were
it not for the reuse of scrap materials there would be insufficient raw materials
to meet the need of our basic industries.
Concept and Rationale

        Several fundamental concepts underlie the study herein reported.   To begin
with, it is recognized that in spite of the magnitude and importance of the  "salvage"
business in the U. S., the so-called solid wastes management problem has  assumed
critical proportions.  Consequently, of present activities under the title of  salvage,
it can only be said that without them the problem would be worse.  What must now be
considered is the way in which the present wastes stream can be reduced by direct
recycling to the basic resources.  Further, the concept of salvage or reclamation
from this stream must be resources or conservation oriented, rather than  simply cost
or profit oriented.  Again the social objectives of man must be combined  with  his
desire to be rid of unwanted residues and an appropriate concept of economics  must
be applied.

        Within the rationale of conservation it seems logical to assume that wastes
are simply the residue of resource use, and as such they represent "resources  for
which we have not yet found a use."  While so extreme a view may not be practical
it does lead to the concept that the ideal solution to the solid wastes management
problem is one which results in the maximum reduction in the generation of wastes by
way of reuse or recycling, and the disposition of the irreducible residue in a manner
devised to enhance or conserve the value of the final disposal site.

        Another concept underlying the study is that direct recycling is  most  readily
carried out in situations in which the waste is relatively homogenous and high in
value.  These conditions prevail most frequently in commercial and industrial  opera-
tions.  On the other hand, when salvable material is mixed with garbage and  other
refuse, its reclamation is difficult because the main control of salvage  and reclama-
tion is economics.  As a result, salvage in municipal operations is relatively limited
and sporadic in occurrence in place and time.  This difficult fraction cannot  be
ignored, however, because it does represent a sizable portion of our wastes  (or
resources ).

-------
106


        An advantage to be gained in making salvage an integral part of a waste
management system would "be the establishment of a dependable and continuous supply
of raw materials, the lack of which is a problem for some industrial salvage opera-
tions.  However, this continuity of supply would make it necessary to keep processing
and salvaging operations active and base economics on something other than current
marketing conditions.

        Another important consideration with respect to the supply of those components
which cannot be utilized in full is the need to develop new markets for them or, more
appropriately, reprocess them via an indirect recycling procedure (Figure 1, type 6)
to produce a raw material for some other industry.


Objectives

        Pursuant to the general rationale set forth above, study was directed to a
determination of those qualities or conditions in the socio-economic environment
which limit or prevent the orderly return of fractions of the waste to the basic
resources of the nation.  Subsequently, the objective is to develop a framework for
a  broad recycling scheme which can be enlarged or modified to fit in with techno-
logical developments or changes in local circumstances.


The Investigation

        Investigative work herein reported involved a search for imformation from
three major sources:

    1.  The literature;

    2.  Scientists whose background gives them an expertise with respect
        to certain components of the wastes;

    3-  Processors and salvors who deal directly with the components.

        Information obtained from the processors by way of interviews reflect the
practical realities of salvage.  The operators interviewed are presently engaged
in recycling those commodities which by reason of cost (including negative cost)
can make the enterprise economically justifiable.  Through the interviews, the
nature of many of the conditions which mitigate against reuse were ascertained.
These conditions constitute the specific problems which must be solved by research
or pilot-plant studies under present economic assumptions.  They may be materially
altered if the operation is conducted as a public enterprise, simply because some
social benefits which accompany the operation may be great enough to compensate
for any economic deficit.

        Specific studies were made of such fractions of solid wastes as metals, paper,
glass, rubber, plastics, and rags, with the following principal findings.


        Metals.  Because of their high value and ready market, the salvage of scrap
metals other than tin cans and abandoned automobiles is fairly complete, not only
with respect to industrial wastes but also to domestic wastes.  Consequently the
problem of the disposition of scrap metals resolves itself to one of handling the
tin cans and the abandoned automobiles.

        "Tin" Cans:  Tin cans are salvaged in California and in other states for
use in the recovery of copper from tailings and low-grade ores in copper smelting
operations in Montana, Arizona, and Nevada.  According to C. C. Sexton [78]^ a
private salvor who was interviewed on the subject, the salvage of cans from dumps
takes place in three steps:  sorting, burning, and shredding.  The cans are burned
to de-tin them, and are shredded to compact them for shipment.  Cans salvaged from
incinerators naturally require no further burning.  They are removed from the ashes
by a magnetic sorter, are screened, and finally shredded for shipment.

-------
                                                                                  107
        At the copper mines, the cans, along with light-gauge sheet metal and scrap
from de-tinning operations, are used in the extraction of copper.   In the process
an acid solution is percolated through tailings or low-grade ore to dissolve and
remove the copper.  The acid-copper solution is collected and is then pumped into
large tanks filled with shredded light-gauge iron.  The iron replaces the copper in
the solution, and the copper is precipitated in the form of pure copper nodules.
It is readily collected in this form.  According to Mr. Sexton,  the demand for
shredded light-gauge iron by the copper industry is steadily increasing and is in
competition with that of other users.  Thus to help meet its needs, a major copper
mining company developed a process for making a low-grade sponge iron from slag.
However, its application is not proving very successful because  of the high production
cost and the need for a certain amount of light-gauge iron in addition to the "sponge"
iron.  Apparently not all of the copper is removed by the sponge iron, consequently
it is necessary to use the light-gauge iron to precipitate that  copper remaining in
solution.

        Uncertainty exists as to whether or not the copper extraction industry could
serve as a market for the entire output of can salvage if the salvage operation were
extended throughout the United States.  Consequently, other uses should be sought  for
salvaged cans.  One such use might be in the tertiary treatment  of sewage.  The cans
would be converted to ferric or ferrous chloride by processing in a chlorine solution.
The chlorides would then be used as coagulants in precipitating  colloids from the
treated sewage.  This method was tried in the 1930's in the secondary treatment of
sewage,  (it was later superseded by biological methods.)

        Abandoned Automobiles:  Salvage of abandoned automobiles was the subject of
an interview with Mr. M. Seiden [79l, a private metal salvor whose operational base
is in Los Angeles.  Mr. Seiden is of the opinion that the problem of the abandoned
automobile is one of economics and that it is more of a problem  in suburban and
rural areas.  When an automobile is abandoned in a city, it usually is impounded by
the police department and hauled away to storage.  After due process of the law (held
for 30 days in California) it is auctioned off to junk dealers.   Generally, the cash
return is insufficient for defraying the handling and storage costs.  In effect,
therefore, the city subsidizes a part of the cost of disposing of the abandoned
automobile and recycling it back into the manufacturing cycle.

        Various schemes for financing the collection costs have  been tried.  For
example, the state of Pennsylvania appropriated 4-5 million dollars for use in
removing abandoned autos.  The project was abandoned after it was  found that more
than 2,000,000 abandoned cars would have to be handled — a number which would permit
the expenditure of only $2.00 per car.  The actual cost per car  was from $15 to $20.
Sweden is more progressive in its approach.  A part of the purchase price of new
cars is retained by the government for future use in paying for  the disposal of the
car at the end of its useful life.

        Once the liabilities in junking an abondoned car are cleared and the car is
sold to a junk dealer, the next problem is to transport it to a  fragment!zer.   The
cost of transporting an abandoned automobile in Bozeman, Montana,  for example,  to
the nearest fragmentizer may be as much as three times its scrap value.  As far as
the processor is concerned, he must be adjacent to steel making  or ship loading
facilities to make his operation financially successful.

        The abondoned automobile ceases to be a solid wastes problem once it is in the
hands of the processor.  The development of the modern fragmentizer has made it pos-
sible to process the junked car into high-grade scrap suitable for steel making.
However, chrome plated parts and copper wire represent a nuisance  in auto reclamation,
as does the burning of upholstery, etc. in areas where air pollution is a factor.

        Status of the Scrap Metal Industry:  The market for scrap  has been on the
decline in recent years because of the use of less scrap per ton of steel produced.
The reduction in need is the result of modern technological developments.   Another
reason for the decline in demand is the competitive challenge of the cost of scrap
as a raw material.

-------
108
        One of the troublesome problems in salvaging automobiles  is  the quantity of
wastes that is generated in processing it.  From 20 percent to 25 percent of the
total weight of the junked automobile is in the form of unusable  material such as
glass, rubber, plastic, and dirt.  This material must be disposed of,  a need which
in itself creates a waste disposal problem for the industry.  An  example of the
magnitude the problem can attain in a large-scale operation is that  of the Proler-
Nhu plant in Los Angeles which produces some 200 tons per day of  unusable material
that must be disposed of off the site.  At present it is disposed of by landfill.

        To meet the challenge occasioned by technology,  by rising costs, and the
requirements for higher quality scrap, the Luria Company has developed new methods
for processing what would normally be low-grade scrap into high-quality material.
This is done by passing the material (used automobiles,  refrigerators,  stoves,  etc.)
through a fragmentizer, which removes the 17 percent to 20 percent nonferrous
component of the material.  The processing is completed by an electromagnetic
separation of the ferrous material.  Nonferrous metals are recovered by a flotation
process (as yet in the developmental stage).

        A factor that has stimulated the scrap business in recent years is the
increased foreign demand for U. S. scrap.  For example,  Japan is  a major customer
for scrap.  It obtains 95 percent of its needs from the United States.   The market
also has been stimulated by the war in Viet Nam.

        Nonferrous Metals:  According to Mr. Learner (president of the Learner Company)
nonferrous scrap can be profitably segregated by hand and bundled for  shipment to
secondary users or refiners [8o].  Hand segregation is economically  feasible because
of the high market value of nonferrous metals.  Examples of current  prices are as
follows:  aluminum scrap, $0.10 to $0.12/lb; copper scrap, $0.30  to  $0.^0/lb; brass
scrap, $0.25 to $0.40/lb.  (iron scrap sells for about $0.01/lb.)

        In summary, it may be stated that the scrap metal industry in  the United
States is a healthy one.  Using the dollar volume as an index, it is one of the ten
leading industries in the United States.  The industry is interested in research on
ways to upgrade scrap in order to widen its application in steel  and other manu-
facturing industries.


        Paper.  Paper probably is the component of domestic and commercial refuse
that may have the greatest salvage potential.  Certainly it is the largest individual
component in terms of weight and volume, constituting 4-5 percent  of  the municipal
solid waste generated each year.  If segregated and satisfactorily processed for
reuse, it would have the greatest potential market value.  Indeed, in  1966, an
estimated 10 million tons of paperstock were recycled and became  raw material for
a wide range of new products.  The benefits accruing to a community  as a result of
salvaging this sizable portion of the total refuse has been well  summarized by
Russell I8l]:

    1.  Reduction of the waste disposal problem;

    2.  The employment opportunities provided by the collection system;

    3.  Provision of approximately 25 percent of the raw material for  one of the
        nation's greatest industries — paper and paperboard;

    k.  Conservation, in that trees are not cut because of availability of fiber
        from wastepaper;

    5.  Fund-raising opportunities for charitable groups.

        Classification:  In industrial salvage, paper is segregated  into grades
established according to a method of classification based on waste paper standards
adopted by the Waste Paper Institute, a division of the U. S. National Association
of Waste Materials Dealers [82].  Although the classification is  reviewed and revised

-------
                                                                                 109
from time to time, the general basis on which the gradation is made remains un-
changed.  This basis is the extent to which a given waste paper is a source of
paper fiber which can be used in the production of a paper with a high Mullen index
(strength), is amenable to refining, and possesses a high brightness index.  In
general, the top grades of salvaged waste paper are those which consist wholly of
unprinted white paper manufactured from bleached chemical pulps free of contamina-
tion by foreign material.  Comprising the lowest grades are the unsorted mixtures
of papers of a variety of qualities, as well as those which may contain material
not of use in paper making.  Strong, clean papers (even though colored) command
a high price because of their strength-giving qualities.  Examples of this type
are tinted sulfite papers and unbleached sulfate papers.

        In one classification, the salvaged paper is divided into three groups
according to volume of the source and use to which the paper may be applied:

    1.  Mixed waste paper and coarse paper material;

    2.  Paper whose fiber composition is mostly of bleached chemical pulps;

    3-  Clean, fresh wastepaper.

        Group 1--Paper belonging to Group 1 is sorted into a number of grades as
determined by composition and degree of cleanliness.  In this class are old fiber
containers and boxboard, old wrapping paper, paper bags, newspapers, and other
coarse paper.  Paper of this class is used in making paperboards on multicylinder
machines.  In the manufacture of high-grade paperboard, better grades of paper are
used, such as newspapers, old kraft paper, unprinted waste book paper, and fresh
chemical pulps.

        Group 2--Examples of paper in this grouping are printed books, magazines,
and other waste papers.  These papers are de-inked by a combination of mechanical
and chemical treatment.  Once de-inked, the processed paper fiber is suitable for
use as a supplement in the production of new pulp for use in the manufacture of
book, magazine, and other high-grade paper.

        Group 3--The clean, fresh waste paper which makes up Group 3 can be directly
used in paper mills for the manufacture of similar papers or serve as a supplement
to new pulp.  This type of waste paper can be used without pretreatment other than
that required'to reduce it to a sludge or slurry.  The reduction is accomplished
with the use of specially designed machines.  Examples of sources and applications
for this type of paper are:  clean waste ledger paper for the manufacture of writing
paper; paper waste from binderies and magazine publishers for the manufacture of
book paper; and clean wrappings and bag paper for the manufacture of coarse paper.

        Problem Waste Paper:  Wet strength and plastic coated papers are difficult
to reclaim.  In fact the recovery of wet strength paper probably would be a
questionable venture inasmuch as a large part of it cannot be properly pulped and
is lost with the trash that is removed from the pulper for disposal [83].  On the
other hand, apparently economically feasible methods have been developed for re-
covering plastic coated paper.  The paper in plastic coated cartons is being
successfully salvaged in a local (Antioch, California) paper plant which processes
the material along with other waste papers and some virgin pulp for use in the
manufacture of printed boxboard and cardboard.  Some appreciation of the amount of
plastic (polyethylene) involved may be gained from the fact that about 15 Ib of the
material is used to coat 3,000 sq ft of paper surface.  In the salvage operation,
chemicals (usually wetting agents) are added in the pulping stage to loosen the
plastic coating.  Approximately 87 percent of the paper fibers are recovered in
the operation.  The polyethylene film becomes a problem only when it chances to
become shredded into small pieces.  The problem arises from the difficulty involved
in removing the pieces from the slurry.

        Contamination:   According to local processors, the presence of contaminants
in waste paper constitutes their biggest problem.  The gamut of contaminants includes

  388-229 O - 70 - 9

-------
110
waxes, tars, latex, plastics, plastic foams, metals,  and resins.   Contamination with
wax, tar, latex, or any other coating material can bring about the ruin of an entire
batch, since this material forms a coating on the paper which interfers with the
adherence of glue to the corrugating medium.  Tramp metals can damage the paper-
making machines, and plastics can plug up screens. Plastic foams are broken into
small pieces in the pulper.   These pieces can plug up screens or  become embedded in
the paper and are difficult  to remove.  Even though contaminated  material may be
used in some applications without fear of damage, the fact remains that contamina-
tion does severely limit the use of potentially salvable sources  of paper fiber to
lower applications in which  the presence of contaminants is less  critical.  An
example would be the use of  a contaminated high-grade waste paper in the manufacture
of roofing felt instead of in the production of high-grade paper  for which it would
otherwise be suited.  Of course, an added economic penalty resulting from the
presence of contaminants is  the expense involved in removing and  disposing of them.

        Collection and Marketing:  The chief sources  of waste paper are office
buildings, large retail outlets, transportation terminals, and apartment "buildings
in the larger cities.  In the smaller cities it is collected by various local
agencies.  The small junk dealer and street pickers make some small contribution to
the collection process, but  only under certain economic conditions peculiar to the
area in which the collecting is done.  The collected  waste paper  next is passed
through the hands of dealers, who have facilities for grading it  into well-defined
classes.  The classified paper is then compacted, according to grade of paper, into
bales ranging from 500 to 1500 Ib in weight.

        As is to be expected, the activities of organizations responsible for the
flow of domestic paper to the waste paper packers are directly influenced by the
market for the paper.  A heavy demand for waste paper begets a high degree of activity
among the dealers in waste paper.  The degree of acceptability of the various grades
of paper also is a function  of the market.  When the  demand is brisk and the supply
is ample, grades of paper acceptable to the waste paper consuming mills tend to be
on the high side.  The reverse is true when the demand continues  brisk and the supply
is short.  An indication of  the monetary value of waste paper used in boxboard manu-
facture when the demand is heavy and the supply is normal is given by prices listed
in Table 40.
                                     TABLE hO

                             PRICES PAID FOB STOCKTON
                             FOR PAPERMAKENG STOCK?'13
Item
No. 2 Corrugated Bulk or Filler
No. 1 Corrugated Bulk or Filler
Box Mill Cuttings
Polyethylene Coated
Unbleached Kraft Side Rolls
Bleached Kraft Side Rolls
Bleached Kraft Pulp
Bleached Sulfite Pulp
Baled Newsprint
Price/ton
($)
29
lt-1
17
85
111
130
1*4-2
28
                           aApril 1967.

                            Private communication 7 April 1967
                   from Mr. B. Streaker,  Technical Superinten-
                   dent, Fiberboard Plant,  Stockton, California.

-------
                                                                                 Ill
        Glass.  The addition of a certain amount of salvaged glass (cullet) to basic
raw materials has long been practiced in the glass-making industry.   The reasons for
the practice are economic and technical in nature.  With respect to  the former, the
use of cullet extends the supply of basic material, and to the latter,  it favorably
affects the processing and the quality of glass.  One effect is an increase in the
melting rate of the glass mix; which in turn makes possible an increase in production
rate, a reduction in size and complexity of furnace, and in certain  types of glass
making, the production of a better quality glass than could be done  without cullet.
Another effect is the promotion of homogeneity in the molten glass,  and thereby,
an imporovement in quality of the finished product.  The amount of cullet used in
a given operation depends upon the type of glass to be produced.  The amount may be
as low as 10 percent of the basic raw material to as high as 60 percent.

        The only exception to the general use of cullet is in the manufacture of
certain glass products which have very critical specifications with  respect to
strength, light transmission, or other specific characteristics.

        Sources:  More than half of the cullet that is recovered and utilized in
glass making comes from scrap dealers who collect and sort the material as a part
of their scavenging activities; and from bottlers and others who either use or pack
glass containers.  Examples of members of the latter group are breweries, dairies,
food packers, and drug and cosmetic producers.  Except for the cullet generated and
reused as "home scrap" by the manufacturer himself, the remainder of the cullet comes
from manufacturers, such as sash, door, and window manufacturers; mirror makers; and
others who use glass in the production of their products.

        Composition:  From 60 percent to 80 percent of the glass found in domestic
wastes is in the form of bottles of various types, ranging from small pill bottles
to gallon-sized wine containers.  From 10 percent to 30 percent is composed of
broken window panes.  Glass from these sources is made up of "lime glass."  A sizable
fraction of the remaining glass is made up of discarded "TV" tubes,  fluorescent
lamps, and cut glass.  Glass used in the manufacture of these items  is  "flint glass."

        In the raw state, cullet is stockpiled chiefly according to  color grade, viz.,
flint, amber, emerald green, light green, and opal.  The flint cullet is separated
into three classes — lime, lead, and borax.  Flint glass of the lead variety comes
mainly from "TV" tubes and similar products, from cut glass, high luster tableware,
etc.  Lime cullet comes mostly from food, beverage, and drug containers; while borax
cullet is obtained from heat resistant wares such as pyrex.

        Processing:  In some cases, processing begins at the dealer's plant as a part
of the sorting operation.  When cullet arrives at his plant, it is fed on an endless
belt for sorting.  Here glass is removed and stored according to color and nature of
the glass, and foreign materials such as paper, rags, and metals are removed.  As
the cullet leaves the belt, it is discharged into a crusher in which it is reduced to
one-half inch to one-inch pieces.  The crushed cullet is then moved  to another sorting
belt where foreign matter left from the preceding step is removed.  Paper labels and
other nonferrous contaminants are removed by hand; while the ferrous materials are
separated by means of a magnet.  In the next step, the cullet is washed to remove
all remaining foreign matter.  Suitable chemicals are added to the wash water.  After
being de-watered, the cullet is passed over a final conveyor belt for a last checking
before it is stored or is packed for shipping.

        Further processing is required for cullet which is to be used for the match
and abrasive industry.  The additional steps are passing the crushed cullet through
rotary dryer and recrushing the material to the consistency of a fine powder by
passing it through a roll mill.  The powder is classified by means of an air-flow
cyclone separator to a particle size equivalent to 200-mesh.  The glass flour is
bagged — usually in 100 Ib portions.

        An important function of the processing step is the removal  of contaminants.
For example, the presence of tramp metal in the cullet can result in damage to the
furnaces in the form of erosion of the brick lining.  In fact, the limestone supplier

-------
112

must use Iron blasting caps in his quarrying operation in order to eliminate the
possibility of any copper finding its way into the quarried limestone.   Copper is
an especially troublesome contaminant because it melts and settles to the bottom
of the furnace thereby ruining the refractory brick liner.  In addition to the
danger of damaging the furnace, other requirements dictate the careful removal of
contaminants.  An important requirement is that of maintaining desired color
characteristics or pigmentation, especially in applications in which color is the
critical item.  For instance, iron and copper impart a certain tint to the glass.
Therefore, if a colorless glass is desired, care would have to be taken to remove
these substances, even though present in only small amounts.  Colored cullet would
have the same effect as would metals, and hence would have to be removed when color-
less glass is desired.  Some glass itself may be regarded as a contaminant in the
manufacture of special types of glass .  For instance, admixtures of flint glass
would be undesirable, and hence equal to contamination, in the manufacture of lime
glass.

        Special Applications — Containers:  Very little cullet is produced in the
manufacture of containers both because the selection rate is high and because no
cullet is produced as a part of each article.  Because of this fact and because of
the characteristics imparted by cullet to the mix, it is necessary to bring in
cullet from outside sources.

        One source is in the salvage of glass found in domestic refuse.  However,
certain difficulties must be met before this class can be used.  A problem arises
from the fact that color considerations are important in the manufacture of con-
tainers .  Another problem is the heterogeneity of the supply of glass obtained from
domestic refuse since the composition of bottle glass varies from factory to
factory.  If flat glass is used, its composition also varies.  The presence of
laboratory and technical glass further complicate the situation.  Nevertheless, if
the entire mass of salvaged glass could be made into a homogeneous mixture by suit-
able pulverizing and mixing, and contaminants could be removed, the material could
be compounded for reuse in the manufacture of amber or green glass containers.

        Special Applications — Fiber glass:  The fiber glass industry has often been
mentioned as a potential large consumer of scrap glass, probably because to the un-
initiated the manufacture of fiber glass would seem to be an operation with a minimum
of critical requirements.  To explore this potential, an interview was  arranged with
a local fiber glass manufacturer.  It was learned that the supply of basic raw
materials presently is augmented by "home" scrap cullet.  The mixing operation is
engineered to produce a homogeneous molten mass of glass having a known, uniform
viscosity.  These characteristics are essential, since the viscous liquid glass must
be passed through very minute orifices (diameters of 0.00025 to 0.0005  in.).  The
extruded glass rods are then transferred to a high energy field, in which are
produced the minute glass fibers that make up the product fiber glass.   Any foreign
material not liquified in the furnace will plug the orifices.  Moreover, at tempera-
tures higher than 2000°F, tramp iron forms an amalgam with the platinum in which the
orifices are drilled.  Once this has happened, the orifices are no longer suitable
for the extrusion process.

        From this brief description of the manufacture of fiber glass,  it can be
readily seen that many difficulties would be encountered were salvaged glass used
as a raw material.  The elimination of contaminants, especially tramp metal and dirt,
would be essential.  Removing these two types of contaminant would be a costly and
arduous task, especially if the glass is salvaged from unsegregated refuse.  As
stated previously, tramp metals would ruin the orifices.  Dirt causes "seeding,"
carryover, and "dusting."  The term "seeding" refers to the formation of a bubble in
the finished glass around a particle of dirt.  "Dusting" refers to the carryover of
dirt and other foreign material into the furnace regenerators.  The carryover material
clogs and coats the refractory bricks and thereby effects a reduction in the capacity
of the latter to store and to release heat.  The presence of colored glass would not
constitute a problem, since the basic fibers come out white.  In fact,  it is dif-
ficult to produce colored fiber glass.
         Mr. Bill Webber, Process Control Engineer and Glass Technologists, Owens
 Corning  Fiberglas, Santa Clara, Calif., 20 February 196?•

-------
                                                                                  113
        In summary, it can be stated that at present in the manufacture of fiber
glass it would be difficult to use scrap glass salvaged from domestic refuse because:

    1.  The contaminants found in the scrap glass would be difficult to remove
        to the extent required to meet the high quality standards of the mix used
        in fiber glass making.

    2.  The necessary precision of viscosity control would be difficult to
        maintain because of the random mixture of various types of glass and the
        corresponding variation in chemical composition of the scrap glass.

    3-  Because the low cost of the basic raw materials used in fiber glass
        manufacture, the potential savings to be derived from substituting
        salvaged scrap glass would not be great enough to offset the cost of
        processing the scrap to the degree needed to make it suitable.

    k.  The fiber glass industry is a relatively low mass user of glass, and
        hence its consumption of glass scrap would be correspondingly limited.

        Economics:  The problem to be solved in the economic phase of glass salvage
rests mainly in trying to offset the cost of transportation, accomplish a fairly
complex processing and contaminant removal operation, and obtain some small profit
in view of the low cost of basic raw materials used in glass manufacture.  The
basic costs range from $10 to $15/ton.  Thus, it becomes apparent that technical
factors exert a greater influence on the use of glass scrap than do economic con-
siderations .
        Rubber.

        Sources:  Discarded automobile tires constitute the major source of scrap
rubber.  An idea of the magnitude of the contribution from old tires may be gained
from the fact that in 1962 approximately 360,000 tons of rubber, about l6 percent
of the total rubber consumption, came from discarded tires.  In addition to the
scrap rubber generated in the rubber goods factories (some of which are recycled
into the plants' production system), the remaining rubber scrap is obtained from
articles which have outlived their original usefulness.  Examples of such items are
hot water bottles, rubber gloves, surgical wear, golf balls, etc.  Large volumes of
specialty scraps in the form of rejects, cuttings, and mold flushings are available
from the manufacturers of various rubber products.  Scrap rubber separated in
automobile processing is not suitable for reclaiming because of excessive contamina-
tion, especially with metals.  (E.g., Prolerization process.)

        Collection and Processing:  Both natural and synthetic rubbers are collected
and processed together since no distinction is made between the two with respect to
scrap.  Thus, the original fears of an increase in complexity of the scrap rubber
handling because of the advent of synthetic rubber failed to materialize.

        Specialty scraps are collected from the producers by scrap rubber dealers,
usually under regular service contracts.  The dealers prepare the scrapped rubber
for shipment to the various rubber reclamation plants which are located around the
country.  Scrap rubber originating in homes, garages, and farms is gathered by
collectors and peddlers who sell their accumulated rubber stock to local or regional
waste material dealers in lots ranging from 100 to 500 Ib.  The dealers send the
material to reclamation plants.

        At the reclamation plant, the collected scrap rubber is graded into one of
the following categories:  l) whole, modified whole, and nonstaining tires;  2) "peeling"
reclaims; 3) synthetic reclaims and butyl tube neoprene; 4) specialties;  5) natural
rubber reclaims (red and black).  The reclaimed rubber,  which can be revulcanized,
is ground,subjected to chemical treatment, and is then processed into rubber sheets
to be marketed for use in the manufacture of new rubber articles.

-------
        Uses:  One of the obvious economic advantages  to be gained  from the  use  of
reclaimed rubber is by way of the reduction in the amount of crude  rubber  needed in
the production of new goods.  In fact,  the availability and suitability of reclaimed
rubber for use in the rubber goods industry has been largely instrumental  in keeping
down excessive and sustained price rises in the cost of crude rubber.   Some  examples
of the replacement of crude rubber by reclaimed rubber are as follows:   Each 20-lb
tire contains the equivalent of 6 Ib of crude rubber.   Approximately 60 percent  of
the reprocessed rubber is used in the manufacture of new tires.  A  100-lb  lot of
inner tubes replaces approximately 65 Ib of crude rubber;  while  the rubber in 100 Ib
of discarded hot water bottles can be used to replace  57 Ib of crude rubber.   Finally,
from 2 to 5 It of reclaimed rubber are used in the manufacture of each  new tire.
Other uses for reprocessed rubber are found in the manufacture of automobile floor
mats, windshield mounting strips, rubber hose, rubber  inner soles,  heels,  motor
mounts, and various molded and extruded items.

        Many advantages of a technological nature accompanying the  use  of  reclaimed
rubber in the manufacture of new rubber goods.  Reclaimed rubber can be mechanically
masticated more rapidly than can crude or most synthetic rubbers, and is well
adapted to the absorption of fillers.  Because of these characteristics, mixing  time
is shortened, and consequently a saving in time and power is accomplished.  Reclaimed
rubber may also be extruded and calendered into sheets and embedded in  fabrics more
rapidly than raw rubber.  Vulcanization is completed more quickly and shrinkage  is
less than occurs with raw rubber.  Because it contains filler, reclaimed vulcanized
rubber is less thermoplastic and more firm than natural rubber.  Reclaimed rubber
is uniform in quality and can be easily modified to meet a wide  variety of require-
ment s.

        Processing the Discarded Tire:   A tire is about 80 percent  rubber  and 20
percent fiber in its composition.  The fiber consists  of nylon,  rayon,  or  cotton.
It is salvaged and sold for specialty uses,  as for example to the oil drilling
industry for use in preventing loss of oil drilling muds.   Another  use  is  in the
fabrication of light-weight concrete structures.  Here it serves to retard the "set"
and to retain moisture, therefore helping to improve the "cure"  and reduce shrinkage,
and thereby increasing the tensile strength of the concrete.  The bead  wire  in tires
cannot be economically salvaged since it is  coated with rubber,  which must be burned
off before the wire can be used.

        A relatively recent difficulty encountered in  the use of reclaimed tire  rubber
in the manufacture of new tires is in the form of government regulations.  Tires for
government vehicles must be manufactured according to  government specifications.
These explicity exclude the use of reclaimed rubber.

        Economics:  The economics of rubber salvage, especially  of  tires,  varies
according to locale.  The Midwest Rubber Company's St. Louis facility   pays  $l^/ton
FOB processor's yard for waste rubber.   An area having a radius  of  600  miles is
combed for raw materials to meet the company's commitments.  On  the other  hand,  the
price paid in the Los Angeles market is $7-50/ton FOB processor's yard. The difference
in price is due to the heavy demand in the former area and lighter  demand  in the latter.
The freight charge for shipping used tires from San Francisco to Los Angeles is  $9-50/
ton.  Some tire companies are actually paying the $4.00 (split between  the freight
and the broker's commission) just to get rid of their  waste tires.


        Plastics.  To arrive at a true evaluation of the practical  and  economic
feasibility of salvaging plastics, especially from mixed wastes, it is  necessary
to consider the physical and chemical nature of the material, as well as the dif-
ferences between the various types, since these characteristics  determine  the method
of processing to be used in salvage and the utilization of the salvaged material.
In general, plastics fall into one of two main groups  — thermoplasts and thermosets.
         Interview with Mr. C. E. Hart,  Plant Manager of the Midwest  Rubber
Reclaiming Company in Paramount,  California,  Ik March 196?•

-------
                                                                                 115
Thermoplasts, or thermoplastic materials, may be repeatedly formed by the application
of heat and pressure.  Thermosets, or thermosetting materials,,  lose this ability to
be repeatedly reformed; instead, upon being subjected to heat and pressure are con-
verted into hard, rigid solids.  An intermediate product may be formed by "vulcanizing"
or "wiring" thermoplastic material.  The state of this type of product may range from
"rubbery" or "elastic" to a rigidity comparable to that of thermosets.  The majority
of household plastics are made from thermoplastic materials.  The thermoplast may be
likened to a super-cooled liquid rather than a true solid.  Structural characteristics
of the thermoplasts range from amorphous (polystyrenes) to the completely crystalline.
The majority of the thermoplasts fall somewhere between these extremes.  In general
they tend to distort under their own weight at temperatures from 150° to 250°F.   The
permissible temperature maximum is lower at high stresses.

        Because of their molecular structure (cross-Ir'nked network with molecular
chains bonded to one another at the points of interse ition), thermosets are dif-
ficult to deform either by heat or by chemical solver; ;s.  The maximum temperature
at which thermosets will retain the properties pertailing to their use ranges from
300° to k50°F at continuous exposure.  The upper limi: at which they can withstand
even mild stress is ^50°F-

        Uses:  As is the case with the utilization of salvaged materials by any
industry, a distinction must be made between industrial and "inhouse" salvage and
salvage from refuse.  Plastics discarded as rejects, triflings, etc. during the
course of the fabrication of plastic articles generally are clean and ready for
reuse with a minimum of processing, and limitations on the range of their applica-
tions are not great.  On the other hand, plastics from mixed wastes, especially
domestic refuse, are contaminated, heterogeneous in composition, and generally
limited as to reuse.

        Because of the economic and technical difficulties involved, no significant
amount of salvaging of plastics from mixed refuse has been practiced.  If the con-
taminants could be removed and the plastics could be separated at least with respect
to thermoplasts and thermosets, then the reclaimed plastic could be put to much the
same use as corresponding industrial salvage.

        In mixed wastes, thermoplasts are intermingled with thermosets.  The two
types cannot be used as a mixture because the properties of either type renders
its mode of processing incompatible with that of the other.  Articles composed of
thermoplasts can be remelted, reworked, and formed into articles different from
their original forms.  On the other hand, articles of thermosets cannot be so
treated.

        Inhouse thermoplastic wastes are readily recovered and often after due
sorting and reworking reused in the plant in which they were produced.  Those which
are not reused in the plant are used for noncritical applications by other manufac-
turers.  Scrap from injection molding is in the form of "sprues" and "gates," short
moldings, rejects, and "nozzle lumps."  The last named items have the lowest value
as scrap.  Fabrication by vacuum forming results in the production of large quantities
of scrap in the way of trimmings discarded in the finishing operations.  The machine
prunings, which are generated in the extrusion process, have little value.  Film,
both rejected and scrapped new film, is becoming an increasingly important source of
raw material.  A considerable amount of old film scrap is obtained from the salvage
of polyethylene film, bags, and containers.

        Uses for reclaimed thermosetic plastics are limited.  Laminated stock may be
ground and used for filler, compounded for fertilizer, and some may be reused for
brake and clutch linings.  In the fabricating plant, scrap, powder spillings, or
overflow from the preform presses are collected and combined with ground excess  and
reject preforms of the similar material and then are reused in noncritical applica-
tions.  Recently work has been done on the use of salvaged plastic in reinforced con-
crete [8*4-].  The addition of plastic (8% to 16$ wt. of cement) introduces
a large number of potential variables such as effects on hydration rate, adhesion,
elastic properties, workability, air entrainment, and chemical reactions.  However,

-------
116
the reported research was done with the use of uncontaminated plastics,  and hence  it
is difficult at this time to estimate the future use  of reclaimed plastics  in this
application.

        Processing and Marketing:   Substandard virgin materials  are produced in con-
siderable quantity.  Since they cannot be sold in the originally intended market,
they can be classified as reclaimable wastes.   The material is marketed  at  a reduced
price —usually on a contract basis, to approved processors.   The latter blend,
compound, or color the material according to the needs for its intended  use.

        Plastic reclaimed from selected industrial salvage is cleaned and freed from
contaminants.  It is purchased by dealers from plastic fabricators.  The dealer has
the material ground, melted, screened, blended,  and pelletized.   Color may  be added
as needed.

        Salvaging plastic from domestic wastes poses  quite a problem technically
because of the heterogeneity of the wastes. A possible method would be  to  separate
the thermoplastic materials from the thermosetting by melting out the former.  A
difficulty to be overcome, however, is that even melted,  the plastic will not flow.
Hence some means would have to be sought for removing the viscous mass.   The use of
steam, hot air, or vacuum might serve the purpose. Another method would involve the
use of solvents to dissolve specific polymers.  The polymers could be recovered from
the solution.  Unwanted chemical constituents  could then be leached or eluted from
the material, leaving the purified salvaged plastic.   Short-chain polymers  might
be recovered from thermosetting plastics by pyrolytic distillation.

        Conclusions:  At present,  the prospects of the extensive use of  salvaged
plastics in the plastic industry seems to be rather dim.   Factors contributing to
this less than favorable outlook are as follows:

    1.  Low Selling Price of the New Plastic Material:  New plastic stock is sold
        for 10 to 20 cents per pound, a price  which leaves very  little margin for
        expenditures on salvaging.  The margin is materially reduced by  the fact
        that the reclaimed material must be sold at three to four cents  per pound
        less than is the fresh stock.  Moreover the market is more limited,  since
        the range for possible uses is narrowed considerably. For example,
        cleaned and baled discarded plastic milk containers sell for only three to
        four cents per pound.

    2.  Public Health Aspects:  Public health  agencies forbid the use of waste
        plastic, or even of reprocessed rejected food containers,  in the packaging
        of food products.

    3.  Need for Complete Segregation of Types of Plastics:   Plastics which are
        not compatible in molecular structure  cannot  be mixed in the fabrication
        of plastic products.  Incompatible plastics will not adhere to each other
        and consequently the fabrication of products  becomes impossible.

    4.  Need to Limit Salvage to Plastics Having a Broad Application:  Salvors
        must limit their salvaging activities  in plastics to those types that
        have a broad range of application.  Those having a limited application
        are difficult to sell, and at the same time expensive to store.

    5-  Constant Supply:  A limiting condition to the plastic salvaging  industry
        is the need for maintaining a steady supply of raw materials. This is the
        case because the dealer must be able to guarantee a steady supply of raw
        material to his customers.


        Rags.  Rags are salvaged by industrial salvors for use in the manufacture
of fine writing paper and roofing paper.  Generally,  rags used in the manufacture
of fine writing paper are obtained directly from textile or garment factories at
which cuttings and scrap ends of cloth are collected  as by-products.

-------
                                                                                 117
        Rags salvaged from refuse are of little or no use to the paper industry as
such because they are a conglomeration of natural and synthetic fibers, and usually
contaminated.  At present synthetic fibers are not used in the paper making industry,
and contaminants must be removed before nonsynthetic rag fibers can be used.  Removal
of the synthetic fiber and decontamination would require processing so extensive as
to make economically unfeasible the use of rags collected from municipal refuse.  If
the use should become feasible, a possible method of recovery would be by a process
in which the cotton and wool portion of the mixed rags would be dissolved out by
means of chemical reagents.


        Summary and Conclusions.  At present, most of the salvaged materials used
in the fabrication of new products consist of manufacturing rejects and of wastes
generated in the production of certain products.  Such materials are relatively
uniform in nature and free of contaminants.  Hence, they can be reused with a mini-
mum of preparation.

        The use of material salvaged from mixed or municipal refuse is declining
because of economic and technical difficulties in processing them for reuse.  The
material almost invariably requires extensive sorting, cleansing, and processing,
before it can be used in most applications.  The cost of such preparations often
exceeds that of new raw material.

        If the prime generator of municipal wastes, the householder, could be
persuaded to segregate his wastes at his home, the problems of sorting and decon-
tamination would be substantially reduced because most of the contamination comes
from the contact with contaminants in common receptacles.  However, in view of less
than full cooperation from all householders means of sorting other than separation
at the point of origin should be sought.  A mechanical separator could be installed at
some central point of collection.  To be economically and technically feasible,
however, such a separator would have to be more sophisticated in design than the
present conveyor belt-blower-vacuum systems presently available.

        Even with the availability of a sufficiently sophisticated separation device,
the problems involved in the use of salvage from domestic refuse would not be com-
pletely solved since there would remain those of decontamination and, where necessary,
the separation from one another of materials having completely different chemical
structures but possessing physical characteristics so similar as to make physical
separation almost impossible.  Simple washing (flotation, spraying, etc.) may suffice
as a means of decontamination in most cases.  However, some types of contamination
are such that drastic chemical treatment would be required.  With the development of
effective and at the same time of economical systems of decontamination, even the
complex systems might prove feasible.  However, the basic raw material to be replaced
or extended must have a high cost to justify the use of chemicals or any complex
physical process in decontamination.  The problem of sorting physically similar but
chemically dissimilar materials is one which will require much research.  Separation
could be done chemically, but the economic problem would still remain.

        A final difficulty is the one of converting the sorted and decontaminated
waste to a form easy to handle and ready to use by the consumer.  Generally, the
consumer has only the equipment needed to manufacture his product and is not in a
position to convert raw wastes to the form in which he can use it.  Obviously the
conversion must be done at a cost that would make the reclaimed product competitive
with the basic raw material.

        Probably the best approach to the economical salvage and subsequent reuse of
suitable wastes would be the development of a sophisticated processing system in
which a variety of valuable materials could be reclaimed.  With such an approach,
necessary reductions in the volume of solid waste materials could be achieved,  and
at the same time the lowering of expenses which would result from shared processing
costs would make the salvaged raw materials a more economically attractive source of
supply.

-------
                   VII.  ANAEROBIC DIGESTION WITH SEWAGE SLUDGE
INTRODUCTION
        For many years anaerobic digestion has proven to be a highly satisfactory
process for treating the settleable fraction of sewage.   During those years it also
has become well known that other organic materials can be equally well stablized by
anaerobic digestion; and in fact, a sizable portion of the domestic garbage output
is so treated in a dual disposal system — garbage and sewage.  However,  no signifi-
cant attempt has ever been made to expand the dual disposal system to include
organic components of refuse other than garbage, such as for example, wood and paper.
In dual disposal, as it is generally practiced, the garbage is introduced into the
sewers by way of the home garbage grinder.  In most of the new subdivisions,  all of
the homes are equipped with garbage grinders, and as a result the garbage of entire
communities is treated in their sewage treatment plants.  In a few communities,  the
garbage either is ground up at central grinding stations and water transported or
is introduced at the treatment plant itself and then treated with liquid wastes.
The application of the central grinder, dual disposal, is by no means a recent
development.  In fact, Babbitt [85] states that as early as 1885, dual disposal of
garbage and sewage was being practiced at Southampton, England.  Hazeltine [86]
describes a central grinding station which was functioning in 1923 at Lebanon,
Pennsylvania.  In a paper published in l^kl, Taylor [8?] reported that the city of
Goshen, England was using with satisfactory results a system in which ground garbage
was introduced into the treatment system at the sewage treatment plant.   A similar
operation at Richmond, Indiana has been reported more recently by Ross [88],

        Prior to the development of a reliable home grinder, studies were concerned
primarily with the effects of ground garbage on the digestion process itself.  Among
the early studies are those of Babbitt [85,89], Kratz [90], Bloodgood [91], and
Carpenter et_ al. [92].  Their work was confined mostly to laboratory studies  on the
technical feasibility of digesting garbage solids along with sewage solids.  Along
with the development of inexpensive and reliable home garbage disposal units  in the
late 19^0's and early 1950's, and the concomitant increase in their usage, came a
number of studies on the effect of garbage on sewage treatment.  Investigations by
Cohn [93],  Ross [88], and Ross and Tolman [9^] were aimed at determining the  extent
of increase in loading rates and gross effects on sewage treatment efficiency, as
well as studying the specific effects on the course of digestion and gas production
as the amount of garbage in sewage increased.

        Their findings with respect to garbage quantity are particularly significant
and applicable to an increased load of any kind (i.e., any organic solid waste).
Simpson [95] reports that there is an increase of 0.5 lb of solids per capita per
day and a flow increase of 3 gpd/cap.  He states that a 56"-5 percent increase in
raw sludge necessitates 50 percent greater digester capacity and results in increased
gas production and a stronger supernatant.  Greater problems with scum and grease
result and more frequent pumping of raw sludge is required.  Cohn [93] reports an
increase of approximately 15 percent to 30 percent in BOD loading.  He asserts that
there is no significant effect on rate and extent of volatile solids destruction or
on gas composition and amount of gas produced per gram of volatile matter.  Wylie
[96] recommends stage digestion as a means of obtaining a supernatant low enough in
solids to permit its return to the plant influent.  According to Hazeltine [86]  the
digestion of garbage alone produces acid conditions, but ratios of 1.5 to 3 parts
garbage to 1 part sludge gives good results.

        It is not surprising that little work has been done on determining the
maximum garbage to sludge ratio.  Investigations to date have been rightly con-
cerned with per capita garbage to sludge ratios.  However, from the standpoint of
solid wastes disposal, it may prove more feasible to dispose of these wastes  in
one treatment plant from an area served by several sewage treatment plants.
                                       118

-------
                                                                                119


It thus becomes important to know what sewage sludge fraction of the total solids
loading is necessary to maintain good digestion conditions.


CONCEPTS AND RATIONALE

        The basic rationale by which studies of anaerobic digestion of the organic
fraction of solid wastes are justified may be outlined as follows:

        First, an appreciable and increasing fraction of househould garbage is
presently routed to the municipal sewers and is successfully degraded along with
other sewage solids by presently-functioning treatment processes.  Further, of  all
methods of handling some fraction of solid wastes, the sewage treatment processes
have been most thoroughly investigated and exploited technologically.  The pos-
sibility must therefore be entertained that by relatively inexpensive modification
and expansion of sewage treatment plants they might be made  to handle a large
fraction of the organic wastes of a community — e.g., paper, animal manures,  and
tree and grass trimmings, as well as the entire output of garbage.   If such should
prove to be the case, reduction of organic matter by anaerobic digestion to a
stable humus suitable for soil conditioning or acceptable in a landfill with minimum
volume and minimum insult to the land might be one of the feasible  alternatives in
solid wastes management.

        Obviously if the process is to be practical, collection of  organic wastes
at the treatment plant must also be feasible and environmentally acceptable.  In
this matter the underlying rationale is that the sewage treatment plant as a waste
treatment environment is already accepted and the surface transport of wastes to
it would not entail problems different than those of any other central disposal
plant such as an incinerator.  Furthermore, the possibility  exists  that present
trunk sewers might be utilized to transport shredded refuse  to the  treatment  plant
or underwater fill during the night hours of low sewage flow.  The  research plan
calls for investigation of this aspect at a later date, but  the certainty that
organic wastes can be delivered to the treatment site justifies first attention
to the potential of the treatment process such as herein reported.


OBJECTIVES

        The objectives of the work reported herein and currently under way are
to:  l) determine the range of the ratios of green garbage to raw sewage sludge
within which garbage can be effectively stabilized in conventional  anaerobic
digestion; and 2) ascertain the effect of loading techniques in maximizing this
ratio.

        As a part of the research needed to attain these objectives, an initial
study was made in which unmixed (except during feeding) digester cultures were
shock loaded with garbage.  Currently, experiments are being conducted with the
use of mixed and unmixed cultures to determine the extent to which  the garbage-
to-sludge ratio can be increased without adversely affecting stabilization in
cultures acclimated to receiving heavy dosages of green garbage. As the research
progresses, studies will be initiated which will be concerned with  determining
the feasibility of digesting refuse other than garbage — such as paper, wood chips,
sawdust, tree trimmings, grass clippings, and animal manures.  In these studies
loading criteria in terms.of gross composition and chemical  composition will  be
evaluated relative to amount and combination of these waste  materials.

        In keeping with the rationale of the study, the feasibility of grinding to
sewers and utilizing water transport to treatment plants will be investigated.   In
addition, consideration will be given to the effect of such  treatment on the  quality
of the residual water and on the relation of the condition of the transported
material to its final disposition.  Eventually the research  plans call for an in-
vestigation of the undersea discharge either of shredded raw refuse or of stabilized
material, and for experiments concerned with the dispersion  of shredded refuse  in
water and determining the depth at which submerged material  will remain submerged.

-------
120
THE INVESTIGATION


Development of Equipment and Procedures

        Included with the principal activities of the  investigation during the  period
covered by this report were preparation of the materials;  adaptation of analytical
methods to special experimental needs;  and construction,  installation,  and necessary
modification of the apparatus to be used in the study.   In particular,  many equipment
modifications were required in the development of suitable mixing  devices  for the
digesters.  Among the problems encountered were overheating of incubators  by internal
motors, off-center drifting of stirring bars when the  Mag Mix  type of stirrer was
used, and providing equal rates of agitation to all of the test digesters.

        To make a relatively simple interpretation of  the results,  a uniform supply
of raw material, green garbage, was provided by collecting an  amount of the material
sufficiently large to last throughout the experimental runs, and by preparing the
material(in the manner described below) for indefinite storage without  deterioration.

        Preparation of Raw Materials.  Approximately 150 lb of vegetable trimmings
were collected from a local supermarket.  The waste consisted  predominantly of  lettuce
leaves, a sizable amount of cabbage, and smaller quantities of parsley,  onion,  and
other vegetable trimmings.  It was processed for storage with  the  use of the facilities
of the Western Regional Laboratory of the U. S. Department of  Agriculture  (Albany,
Calif.).  In the processing the material was finely chopped, steam blanched for 1.5
min, and dehydrated for 1.5 hr at l60°F, 3.0 hr at lUo°F,  and  16.0 hr at 100°F  until
it was reduced to less than 1 percent moisture content.  The steam blanching served
to deactivate enzyme systems — a standard procedure in the preparation  of  frozen and
dehydrated foods.  The dehydrated material was then ground to  a fine powder in  a
hammermill and the powder was stored in polyethylene bags.

        As a result of the dehydration process, the initial 150 lb  of wet garbage was
transformed into 8.5 lb of dried material.  Probably 90 percent of the  loss was in
the form of moisture, while most of the remainder vas  in the form  of the unrecoverable
material which adhered to the drying screens.  The dried material  contained 77-8 per-
cent volatile matter, 3-04 percent total nitrogen, 5^-7 percent total carbon, and
0.25 percent carbonate-carton.  Its carbon-to-nitrogen ratio of 18:1 was somewhat
greater than that of primary sludge, which varies from 10-18:1.

        Sewage Sludge.  Seed digester sludge was obtained from the Stege Sanitary
District Sewage Treatment Plant (El Cerrito, Calif.).   Usually a quantity  of
primary sludge, sufficiently large to last from two to three weeks of experimenta-
tion, was collected (from the Stege plant) and prepared at one time.  The  sludge was
prepared by homogenizing it in a Waring blender for 30 sec. It was adjusted to the
desired volatile solids concentration with the addition of a suitable amount of tap
water.  The blended material was stored at 2°C until used.

        Digester Units and Ancillary Equipment.  One-gallon glass  jugs  served as
digesters in those experiments in which mixing was not required.  Each jug was
provided with a gas outlet line which was passed through a holed rubber stopper and
on to a collection vessel.

        Four especially designed digesters were equipped with  stirring devices.
These units, one of which is schematically sketched in Figure  l6,  were  constructed
of Lucite, were cylindrical in shape, and had a depressed center well 3 in. in
diameter.  A 2-1/2 in. long magnetic stirring bar was  placed in each well.  The
arrangement of well and bar was intended as a means of preventing  off-center drift
of the stirring bar.  As stated earlier, this drift of the bar is  a recurring problem
when a material as viscous as sewage sludge is mixed.   As is shown in Figure 17, the
stirring system consisted of a mandrel-pulley arrangement powered  by an electric
motor  (one-eighth horsepower, d.c.) equipped with a speed controller (Minarik).
To prevent a buildup of heat in the incubator, the motor was installed outside  the
incubator and was connected by a flexible drive shaft  to the master ball-bearing

-------
                                                                              121
I
o:
o
                                                                                 [5
                                                                                 <0
                                                                                 UJ
                                                                                 o
                                                                                 Q
                                                                                 UJ
                                                                                  Q.
                                                                                  X
                                                                                  UJ
                                                                                  UJ
                                                                                  tr

-------
122
                                                                                         I-



                                                                                         1


                                                                                         UJ
                                                                                         o

                                                                                         Ul
                                                                                         o

                                                                                         CD
                                                                                         z
                                                                                         en
                                                                                         UJ



                                                                                         CD

                                                                                         u.

-------
                                                                              123
      FIGURE 18.   INCUBATOR  CONTAINING   FOUR   DIGESTERS

mandrel located inside  the incubator.  Each of the four drive-mandrels had a 2-1/2
in. magnetic stirring "bar attached to it, and each mandrel shaft was positioned
directly below the  center well of a digester unit.  Thus,  agitation of all four
digester units could be controlled and maintained at equal rates.  A general view
of the digester arrangement in one of the two incubators in which the digesters
were maintained is  shown in Figure 18.
        Gas Lines  and Collectors.  The four Lucite digesters were equipped with
stainless steel lines(1/8 in. in diameter) to eliminate  gas diffusion and to
reduce wall action as the gas moved from the digesters  to the collectors.  Rubber
tubing served as gas  lines for the 1-gal glass jug digesters.

        Two types  of  gas collectors, shown in Figures 19  and 20 were employed.
In Figure 19 the liquid displacement type is shown. It consisted of a 5-gal glass
carboy containing  red-dyed 2 percent HaSCU solution.  The acid solution was used
to prevent the absorption of the C02 by the liquid. Gas  entered the liquid dis-
placement collector through a glass tube which extended to within 2 in. of the
carboy bottom and  forced liquid to be discharged through  a bottom outlet.  Daily

-------
12k
                                       OUTLET
       FIGURE 19.  LIQUID   DISPLACEMENT  GAS  COLLECTOR

-------
                                                               125
   GAS INLET
                        GAS  OUTLET
                                                COUNTER
WEIGHT
         FIGURE 20.    INVERTED   TUBE  GAS  COLLECTOR
18-229 O - 70 - 10

-------
126
gas production corresponded to the volume of liquid discharged into 9-liter re-
ceiving carboys.

        Eight gas collectors of the inverted tube type also were employed (see
Figure 20).  Each of these consisted of an inverted cylinder telescoped into a
larger cylinder containing acid-dye solution.  Counter weights relieved back
pressure as gas filled the center tube and volumes were read directly from wall
calibrations.  A general view of the gas collection arrangement near the large
incubator is shown in Figure 21.


Analyses

        Total and Volatile Solids.  In determining the total solids content of the
sludge, 25-ml aliquots of the material were placed in tared evaporating dishes.
The samples were then  evaporated to dryness on a steam bath, placed in a 150 °C oven
for 1 hr, and subsequently were cooled and weighed.  The volatile solids content
was then determined by igniting the dried sample for 1 hr in a muffle furnace at
600°C.  The calculation of percent volatile solids destruction is as follows:


                         _       V in x V out
                         D = r—:	,-—	—T x 100
                             V in - (V in x V out)

in which D is the percentage of volatile solids destruction and V is the volatile
solids concentration.   Weighing accuracy was to the nearest mg on a Mettler balance.


        Volatile Acids.  The column partition chromatography method described in
Standard Methods L9TJ~was used in making total volatile acid determinations.


        Gas Analysis.   Sludge digester gas was analyzed for CH*, C02, N2, and 02  by
the gas chromatographic method as presented in Standard Methods [97].  A model
A-90-P3 Varial Aerograph equipped with a gas-solid adsorption column and a thermal
conductivity detector was used to analyze the gas samples,  which were injected with
a stream of helium carrier gas.


        Alkalinity.  Alkalinity was measured by titrating 20-ml aliquots of digester
supernatant with 0.02 NH2S04 to the proper pH.  This value was determined for a given
sample type by plotting a pH/acid addition curve and estimating the midpoint of the
HC03 neutralization section.  Sample type varied in accordance with the garbage-to-
sludge ratio of the feed, and midpoint values ranged from pH 4.08 to pH ^.65.


EXPERIMENTAL PROCEDURES AND RESULTS

        Pursuant to the previously stated objectives, the first phase of the
investigation was concerned with determining the effects of shock loading on the
performance of digester cultures which are not routinely mixed and determining
the general range of loadings that would be permissible under such conditions.
This phase of the study was continued for 6l days, or the equivalent of two of the
detention periods that were applied.  Cultures which survived the treatment were
then fed increasingly large dosages of the green garbage to determine the maximum
ratio of garbage-to-sludge at which the digestion process may proceed at an ac-
ceptable rate.  This portion of the investigation is still in progress, as is a
similar study involving the use of mixed cultures which are presently being
acclimated to receiving large dosages of garbage.

        As mentioned previously, the practical implication of determining a maximum
ratio rather than only a per capita ratio is that in large metropolitan areas it
might be more expedient to discharge a disproportionate quantity of the garbage from

-------
                                                      12?
FIGURE 21.  GENERAL VIEW  OF GAS  COLLECTING  APPARATUS

-------
128
a given area into one plant.   Accordingly in reporting the  study,  indicated loadings
are expressed not only in terms of per capita ratio but also  as  double  and quadruple
per capita ratios.


Procedure — Specific

        To obtain five digesters which would be reasonably  similar in performance,
ten laboratory units were set up in the following manner:   Three liters of digesting
sludge obtained from the Stege Treatment Plant were placed  in each of 10 one-gallon
jugs.  Each digester then received 100 ml of primary  sludge each day over a period
of two weeks.  During that time the performance of the digesters was evaluated in
terms of pH and gas production.

        At the end of the two-week period,  five of the more promising digesters
were selected and the following experimental conditions were  imposed upon them:

    1.  The temperature of the digesters was maintained at  37 °C  (±1°C).
        Digester 1 served as  the control and continued to receive 100 ml
        primary sludge daily.

    2.  The composition of the feed to digester 2 was based on the equivalent
        of a per capita ratio of 1.68 parts green garbage to  1 part of  sludge.
        This ratio is based on results of a study made by Hazeltine [86] in
        which he found the daily per capita production to be  0.13 lb volatile
        solids of green garbage and 0.08 lb volatile  solids of primary  sludge.
        On a percentage basis this mixture would be 62 percent garbage.

    3.  Digester 3 received a loading in which the garbage  content was  equal
        to double the per capita ratio or 3.24:1.  In this  case  76.5 percent
        of the dosage was in the form of garbage.

    4.  Digester 4 was fed garbage at a rate which was quadruple the per capita
        ratio at 6.5:lj that  is, 86.7 percent of feed was green  garbage.

    5•  Digester 5 received a loading that consisted  entirely of green  garbage.

        Despite the differences in the proportions of garbage to sludge, the
volatile solid loadings to all of the units were identical, viz.,  3-68  grams per
100 ml.  Individual batches of primary sludge feed were adjusted to this concentra-
tion in order to maintain constant loading throughout the run.  Thus, the feed
composition and quantity of each component delivered  to the units daily was as
listed in Table 4l.

                                     TABLE kl

                              DAILY FEED COMPOSITION

Digester
1
2
3
k
5
Garbage
% of
3.68 g
0
62.0
76-5
86.7
100.0
Vol. Solids
(g)
0
2.28
2.81
3.19
3.68
Total Sol.
/Vol. Sol., e]
\ 0.778 /
0
2.93
3.62
4.10
4.72
Primary Sludge
*
100.0
38.0
23-5
13-3
0
ml
100.0
38.0
23.5
13.3
0

H20
(ml)
0
62.0
76.5
86.7
100.0

-------
                                                                                 129

        Based on this schedule of feeding the theoretical  detention  time was  30 days
and the volatile solids loading per day was 0.077 lb/cu ft of digester  capacity.

        No attempt was made to acclimate the units to garbage,  and the  doses  described
in Table 4l were administered from the first day.  The green garbage was weighed  and
then rehydrated several hours before being fed to the units.  When this was not done
the relatively light dehydrate tended to float to the surface of the digesters.   As
a precautionary measure the refrigerated primary sludge was warmed to room tempera-
ture before feeding time to avoid severe temperature changes in the  digester  sludge.

        Digester performance was evaluated by measurements of pH,  gas production,
gas composition, and total and volatile solids reduction.   Frequent  determinations
were also made of total volatile acids and alkalinity.


Results

        Volatile Acids.  The relation of garbage loading to volatile acid  production
in the five digesters is indicated by the differences between the slopes of the
curves shown in Figure 22, in which the volatile acid production in  each of the di-
gesters is plotted as a function of time.  As the curves indicate, acid production
was highest in digesters 4 and 5, digesters which received the heaviest loadings  of
garbage.  On the other hand, acid production was lowest in digester  1 — the one which
received no garbage.  The phenomenon of increased acid production accompanying an
increase in garbage loading reflects the disproportionate  carbohydrate  content of the
garbage as compared to that of sewage sludge.  The carbon  to nitrogen  (C:N) ratio of
sewage sludge varies from 10-18:1 [86]; whereas the range  for vegetables is from
14-27:1 [98].  According to an analysis made of the material used in the experiment,
it had a C:N ratio of 18.1:1.  In the digestion of a feed  consisting solely of
garbage, as was the case with digester 5> the breakdown of carbohydrates to C02
H2, alcohols, and fatty acids favors the acid producing bacteria,  probably due, in
part, to their short generation time.  Consequently, acid  was produced  more rapidly
than the more slowly growing methane organisms could utilize them.

        Judging from the cessation of gas production, the  cultures in units h and 5
failed to survive longer than two weeks, i.e., after the acid level  reached a con-
centration of hOOO mg/,0.  The acid content of those units  which survived never
exceeded 1550 mg/,0, and judging from the methane production, it never was  high
enough to appreciably inhibit CH4 production.


        Gas Product!on.  The rate of gas production as a function of time  and garbage
loading is shown by the curves in Figure 2J.  According to the figure,  within a few
days after the initiation of the feeding program gas production declined drastically
in units k and 5> the units receiving the heaviest loadings of garbage. The  sharp
drop in gas production in units 2 and 3 from the 5th to the 10th days after starting
is indicative of an initial shock response.  Unlike digesters k and  5>  the cultures
in digesters 2 and 3 began to recover rapidly after the 10th day and later stabilized
at rates approximately 10 percent lower than that of the control (digester l).  All
units showed a sharp drop in gas production between days 27 and Ul.  Possibly some
toxic substance was present in the batch of sludge used as feed at the  time.  The
cultures recovered when a new batch of sludge was substituted.

        One of the more important indices of digestion efficiency is the relation
of gas production to volatile solids destruction.  The relation is expressed  as the
ratio of cubic feet of gas produced per pound of volatile  solids destroyed.   Changes
in the ratio (i.e., index) as a function of time and garbage loading are shown in
Figure 24.  The figure shows the great differences between the efficiencies of units
1, 2, and 3 and those of units k and 5-  Within one week after the beginning  of
feeding, gas production in units k and 5 fell from an initial volume of 13-1^ cu  ft/lb
volatile matter to 8 cu ft/lb and continued to decline until it ranged  from 0 to
1.8 cu ft/lb.  Gas production in unit 3 per pound of volatile matter destroyed
declined to a low of 8 cu ft/lb (9th day after starting) but then recovered fairly
rapidly, although not quite to the level attained in units 1 and 2.

-------
130
                                                                                                   cn
                                                                                                   DC
                                                                                                   LU

                                                                                                   CO
                                                                                                   LU
                                                                                              UJ
                                                                                              2
                                                                                                   g
                                                                                                   O
                                                                                                   ^
                                                                                                   Q
                                                                                                   O

LU


g





g

LU
                                                                                                    GO
                                                                                                    o:
                                                                                                    LU
                                                                                                    LU
                                                                                                    or
                                                                                                    o
                                                                                                    t
                                                                                                    LU
                                                                                                    <\J
                                                                                                    eg
                                   01130V  SV  SQIOV   3nilvnOA

-------
                                          131
                                               O


                                               8
                                               a:
                                               CL
                                               CO
                                               o
                                               2

                                               Q
                                               LU
                                           »   O
                                           o   <
                                          •o   00


                                          s   5
                                          I   o
                                               a:
                                               CD

                                              LU
                                              OJ
Aop/y
SV9

-------
152
                                                                                                 LU
                                                                                                 O
                                                                                                 (T
                                                                                                 e
                                                                                                 OC
                                                                                                 UJ
                                                                                                 O.
                                                                                                 (0
                                                                                                 UJ
                                                                                                 O
                                                                                                 UJ
                                                                                                 CO
                                                                                                 OC
                                                                                                 <
                                                                                                 O
                                                                                                 UJ
                                                                                                 UJ
                                                                                                 DC.
                                                                                                 U.
                                                                                                 O
                                                                                                 UJ
                                                                                                 OJ

                                                                                                 UJ
                                                                                                 a:
                                                                                                 o
                                                                                                 o
                                                                                                 u_
                                       'Q3AOJJ1S30  SQI10S   31I1V10A
                                        U  no   '  NOIlOnOOad   SV9

-------
                                                                                133
        The level of gas production per pound of volatile matter destroyed, which
was regained in units 1, 2, and 3 after the initial drop, was comparable to that
characteristic of normal municipal digesters.  Bloodgood [99] reports an average
value of 12.1 cu ft/lb for five different treatment plants.  Griffiths [lOO] lists
values ranging from 9 to 24 cu ft/lb.  However, in the experiment those digesters
fed garbage apparently were less efficient in the production of gas than was the
control, which received no garbage (unit l).  Thus, gas production per pound of
volatile matter destroyed in unit 2 averaged only 86 percent that in the control;
and that in unit 3 was only 76 percent of that in the control.  These findings are
consistent with those reported by Straub [lOl], who observed decreases of 20 per-
cent, 25 percent, and 40 percent in units fed cabbage, carrots, and potatoes,
respectively.
        Gas Composition.  The leakage of air into the digester gas was detected and
determined by nitrogen and oxygen measurements.  Results obtained in making these
measurements are listed in Table 42.  Obviously, some air leaked into the collectors
and the plenum of the digesters, since the 02 concentration of the gas as measured
ranged from 1 percent to 6.8 percent, and no 02 is produced in anaerobic digestion.
However, as techniques were improved, leakage was reduced and the 02 concentration
was lowered to about 1 percent.  Using 02 concentration as a guideline, about 4
percent of nitrogen measured in the gas can be attributed to air leakage and the
remainder to the digestion processes.

                                     TABLE 42

                   NITROGEN AND OXYGEN CONTENT OF DIGESTER GAS

Day

8
13
20
27
49
55
Volume, %
Unit 1
N2
11.6
9-6
8.1
8.1
9-9
9-0
02
3.0
2.4
1.8
1.6
1.1
1.1
Unit 2
N2
15-5
15-7
17-7
11.2
10.3
8.4
02
3.2
2.5
3.1
2.3
1.2
1.0
Unit 3
N2
13.4
16.4
12.6
11.9
10.3
8.3
02
2.4
2.8
2.1
2.3
1.2
0.9
Unit 4
N2
17.2
18.7
34.6
43.9


02
3-8
3.6
6.5
7.2


Unit 5
N2
21.2
18.7
28.8
31.0


02
4.4
3-5
6.2
6.8


        The effect of garbage loading on methane and C02 production is shown by the
curves in Figures 25 and 26, respectively, in which methane and C02 production is
plotted as a function of garbage loading and time.   As the differences in the slopes
of the curves in Figure 25 indicate, methane production decreased with increase in
garbage loading.  Conversely C02 production was enhanced by increase in garbage
loading.  These results are consistent with the volatile acid observations.


        Alkalinity.  Closely associated with digestion control is the alkalinity or
buffering potential of the system.  The buffering capacity may come from two sources:

    1.  Alkalinity contained in the carriage water.
    2.  Ammonium bicarbonate from the normal digestion process  which may be
        represented by the following equation:

-------
134
                                                                             UJ
                                                                                  2
                                                                                  O
                                                                                   cr
                                                                                  o

                                                                                  o
                                                                                  o
                                                                                   <
                                                                                  o

                                                                                  o
                                                                                  z
                                                                                  Q
                                                                                  <
                                                                                  O
                                                                                  S
                                                                                  CD
                                                                                  o:
                                                                                   LU
                                                                                   cr» co
                                                                                   .  3
                                                                                   o
                                                                                      CO
                                                                                   LJ  O
                                                                                  in
                                                                                  OJ
                     %  ' NOIlVyiN30NOO  3NVH13W

-------
                                                               a:
                                                               UJ

                                                               te
                                                               UJ
                                                                    135
                                                               o

                                                               z
                                                               g




                                                               z
                                                               UJ
                                                               u


                                                               o


                                                               UJ
                                                               9
                                                               X
                                                               g
                                                               Q
                                                               o
                                                               CO
                                                               cc
                                                               <
                                                               o
% ' NOU.VH1N30NOO   30IXOIQ N08HVO
                                                               Q


                                                               §
                                                               UJ
                                                               O
                                                               <
                                                               CD
                                                               CC
                                                               UJ
                                                               UJ
                                                               CC
                                                               o
                                                               o
                                                               UJ
                                                               u.
                                                               u.
                                                               UJ
CD
(NJ


UJ
CC
                                                               e?

-------
136
              r  0  H  H  S    digestion
             (OrganicVtter) 	=>^COg + HgO + m, + CH4  + H2S
                                                  ^V	

                                               NH4HC03


According to Coulter [102], the ammonium "bicarbonate remains in solution and con-
tributes to the alkalinity of the substrate.

        The cultures in units 2 and 3 had consistently higher concentrations of
alkalinity than did the control, despite having less carriage water and  a lower
protein content.  This is shown by the relation between the curves in Figure 27,
in which the alkalinity of the various cultures is plotted as a function of time.
This phenomenon must be interpreted then as indicative of an increase in digest-
ibility resulting from the addition of garbage to sewage.  Corroborative evidence
may be drawn from the work of Garber [lOj] and Rudolfs and Setter  [ic4]  who have
independently reported that increased ammonium bicarbonate production has been
associated with thermophilic rather than mesophilic digestion due  to more complete
breakdown of proteins.

        The cultures in units k and 5 were deficient in alkalinity probably as a
result of neutralization by the high concentrations of volatile acids.


        Hydrogen Ion Concentration (pH).  The pH level of the cultures in units 1,
2, and 3 remained within the range of 7-0 to 7.5 with few exceptions, as is shown
by the curves in Figure 28 in which the pH levels of the various digesters are
plotted as a function of time.  The pH levels of units k and 5 continued to drop
sharply soon after feeding was initiated, and continued to do so until a low of
5.2 was reached on the 28th day.  By this time the digesters ceased functioning
for practical purposes.

        The correlation between pH level and rate of gas production was  quite
evident in this experiment.  When the pH of a digester was above 7-25, gas pro-
duction generally was increased.  On the other hand, a drop in pH level  was
accompanied by an even sharper drop in gas production.  The pH levels in digesters
2 and 3 are also in keeping with the high levels of alkalinity prevailing in them.


        Reduction in Volatile Solids.  According to the data listed in Table 43,  in
which are presented values for the percent volatile solids reduction in  the various
digesters, from 65 percent to 80 percent of incoming volatile solids was destroyed.
The difference between the average values for units 2 and 3 and that of  unit 1 is
too slight to be significant.  In our experiments, evidence for an increase in rate
of digestion in units 2 and 3, such as was observed by Bloodgood [91] to take place
when garbage was digested with sludge over that of sludge alone, is to be found more
in the increased alkalinities in the two digesters, than in their insignificantly
higher percentage of volatile solids destruction.


Discussion and Conclusions
        Results  obtained thus far demonstrate that anaerobic cultures can adjust to
 shock loadings of garbage provided that the garbage content of the feed (garbage-
 sludge mixture)  is not in excess of 76.5 percent of the total feed.  Although those
 cultures which received a feed of which the garbage fraction was 76.5 percent or less
 of the input did survive, their efficiency dropped ko percent during the first week
 after the  initiation of the experimental run.  It was only after the bacterial
 population became acclimated or a new one was developed, that the cultures resumed
 functioning at an efficiency comparable to that of the control.  The point of
 minimum efficiency occurred on the tenth day, and there was every indication that

-------
                                                                                                     137
o
I
                            O

                        0  g
                                                                                         IS

                                                                                         $  8
                                                                                                     in
                                                                                                     >%
                                                                                                     o
                                                                                                    UJ

                                                                                                    5
                                                                                                          CO
                                                                                                          oc


                                                                                                          8
                                                                                                          UJ
                                                                                                          o
                                                                                                          Q
                                                                                                         o

                                                                                                         >-
                                                   O

                                                   UJ

                                                   8
                                                   00
                                                   a:
                                                   <
                                                   o
                                                                                                         UJ
                                                                                                         GC
                                                                                                         UJ
                                                                                                         UJ
                                                                                                         tr
o

8
o

8
                                          SV

-------
138
                                                                                                   o
                                                                                                   (D
                                                                                               _  o
                                                                                                       O
                                                                                                       •o
                                                                                                             CO
                                                                                                             tr
                                                                                                             LU

                                                                                                             en
                                                                                                             LU
                                                                                                             CD
                                                                                                             Q
                                                                                                             Q.
LU


1
oc
                                                                                                             LU
                                                                                                             CC
                                                                                                             O
                                                                                                             Li-
                                                                                                             Li.
                                                                                                             LU
                                                                                                             Cti
                                                                                                             OJ

                                                                                                             UJ
                                                                                                             tr

-------
                                                     139
         TABLE 43




VOIATILE SOLIDS REDUCTION
Day
1
6
7
8
9
12
13
14
15
16
19
20
21
22
23
26
2?
43
47
50
54
57
61
Avg.
Volume , %
Unit 1
79-0
78.4
78.2
77-8
77-2
78.8
71-7
70.5
72.3
72.3
72.2
72.5
72.2
70.4
71.2
71.8
69.9
70.1
70.3
80.1
79-0
80.5
70.9
74.2
Unit 2
79-0
78.9
78.8
78.3
78.3
77-8
72.6
71-5
72.9
73.1
73-7
73-2
72.2
72.9
72.2
73.4
70.5
68.3
69.1
79-9
79-1
77-3
79-1
74.9
Unit 3
79-5
78.2
78.2
77-7
78.2
77-7
72.4
71-5
72.5
72.2
73.2
68.3
72.3
72.4
72.4
72.2
71-3
69.1
66.8
79-2
76.8
80.5
76.9
74.3
Unit 4
78.9
78.9
78.8
78.3
77-9
77.3
72.2
71.0
71.3
71.0
69.9
68.2
68.5
67-5
67.4
65.9







72.7
Unit 5
79-5
78.8
78.4
78.2
76.2
77.8
72.3
71-7
71.6
70.4
69.3
69.9
67.8
67.6
66.6
65.8







72.6

-------
the culture in unit 3 (fed 76.5$ garbage)  was  near the  critical  limit of  survival.
Its pH had dropped to 6.8 which is considered  the minimum level  at which  methane
bacteria regeneration can proceed without  inhibition.   It might  then be concluded
that under conditions of shock loading,  in which no  attempt  is made to acclimate
the digester cultures, the maximum quantity of garbage  acceptable is about  75 per-
cent of the total input.  This is equivalent to about 3 parts of garbage  to 1 part
of primary sludge, or double the present per capita  ratio.

        Other specific conclusions concerning  the effects of green garbage  on the
digestion process which may be drawn from  the  results obtained in the study are as
follows:  (Estimations of percent reduction, changes in composition, etc. are based
on results obtained with the control.)

    1.  There was a marked increase in  organic acid  content  resulting from  the
        breakdown of carbohydrates to fatty acids.

    2.  Gas production was reduced by 10 percent in  units receiving 62 percent
        to 76.5 percent garbage.

    3.  The efficiency of digestion in  terms of cubic feet of gas produced  per
        pound of volatile solids destroyed was reduced  by 14 percent for  unit 2
        (fed 62$ garbage) and 24 percent for unit 3-

    4.  Gas composition was significantly  altered —  7 percent less methane  and
        7 percent more C02 — which is what one would expect  on the basis  of the
        increase in organic acids.  A favorable environment  for  acid-C02
        producers was created by the predominance of carbohydrates in the sub-
        stituted material, i.e., green  garbage for primary sludge.

    5.  The buffering capacity of digesters was increased by garbage feeding,
        as is indicated by 50 percent increases in alkalinity of the test
        units.  Alkalinity increases have  been cited in the  literature  [103,
        104] as indicative of a more complete  breakdown of proteins.  On  the
        basis of the literature, therefore, it may be assumed that because  the
        two garbage-fed digesters had a higher alkalinity than did the  control,
        the digestibility of a garbage-sludge  mixture was greater than that of
        sludge alone.

    6.  The pH of units receiving garbage  rose from  7.2 to 1.^,  reflecting  the
        increased alkalinity.

    7.  Destruction of volatile solids  was slightly  greater  in the test units
        than in the control, which is indicative of  greater  digestibility.


Future Work

        Experiments planned for the future will be concerned with:  l)  determining
the upper permissible limit of garbage  loading to fully acclimated digesters; and
2) evaluating the potential of the anaerobic digestion  process in coping  with
garbage containing waste paper.  Work on the first section already is in  progress.
Following the experiment described in the  preceding  sections, the surviving units,
now thoroughly acclimated to receiving large dosages of garbage, were and are being
fed increasingly large dosages of garbage.  One of the  digesters is receiving a
dosage having a 4:1 garbage-to-sludge ratio, without any apparent detriment to its
activities.  A second one is being even more heavily loaded  without ill effect;
the garbage-to-sludge ratio of its feed is 5:1- Inasmuch as these two  digesters
have been operating efficiently during  the two weeks preceding this writing, the
garbage loading will probably be appreciably higher  before the digesters  fail.

        The work involved in the second phase  of the future  work is considered to be
of a paramount importance because it will  be concerned  with  the  disposal  of paper,
a material which constitutes 60 percent of the municipal solid wastes.  Plans include

-------
                                                                                  141
studies in which digesters will be fed varying quantities of paper, and combinations
of paper with other wastes.  Parallel studies involving the use of pure cellulose
will be conducted to define the kinetics of cellulose digestion.
  388-229 O - 70 - 11

-------
                      VIII.  WET OXIDATION OF ORGANIC WASTES
INTRODUCTION

        Experimental work directed to the application of wet oxidation to solid
wastes is based on the general concept of indirect recycling depicted in Figure 1.
Under this concept certain fractions of solid wastes are subjected to special pro-
cessing to produce raw materials which may then be utilized by existing or new
industries for the production of consumer goods.  Ideally,  of course, the concept
should apply to all fractions of the solid wastes generated by a community.
Practically, however, only certain fractions can be economically reclaimed.

        The idea that wet oxidation might be a technologically feasible wastes
reclamation process derives from success in applying it to  the oxidation of organic
matter in liquids and from encouraging experiments in fractionating wood to produce
industrial chemicals in liquid form with a residual pulp which might be used in
gypsum board, formed packaging, or other low cost specialty items.  It was reasoned
that a process which will work on wood should be easily adaptable to paper and
perhaps to the whole spectrum of organic wastes found in community refuse, including
manures, tree trimmings, grass clippings and sewage sludge,  as well as demolished
lumber and waste paper.  Nevertheless, if it could be applied to nothing more than
waste paper the process would be an important new method of solid wastes management.
Obviously, materials cannot be expected to be eternally recycled into the basic raw
material pool.  The solid fractions would themselves eventually become wastes, but
if they were recycled, say two or three times, the net result would be both a net
reduction in the volume of solid wastes routed to sinks or  incinerators and a con-
servation of natural resources.

        Pursuant to the foregoing general concept and specific rationale, a research
team was assigned to a systematic experimental study of the application of wet
oxidation in the technology of solid wastes management.


DESCRIPTION OF THE PROCESS

        Wet chemical oxidation involves the combination of  molecular oxygen or of
atmospheric oxygen with organic material in an aqueous suspension or solution under
superatmospheric pressures and at elevated temperatures. As such the process has
been utilized for the disposal of water-borne Industrial and municipal wastes with
a consequent production of thermal energy.  The energy may  be recovered as steam
or electricity.

        Extensive reviews of the basic principles of the process have been given by
Zimtnermann  [105,106] and Teletzke [107]•  In theory any aqueously dispersed organic
material can be oxidized if sufficient energy is supplied to the reaction or if in
terms of the Zimmermann process, there is sufficient pressure and temperature.  The
critical difference "between this process and conventional combustion lies in the
much lower temperature at which the wet oxidation reaction  occurs.

        Typical equipment required for this process (shown  in Figure 29) includes:
a reactor, air compressor, heat exchangers, effluent pumps, and a gas expansion
engine.  An effluent containing organic waste material is pressurized, mixed with
compressed air, and preheated in heat exchangers by heat recovered from reactor
products.  At about 200°C the effluent-air mixture reacts spontaneously and is
introduced into the reactor.  Reactor temperature can vary  from 1^0°C to the
critical temperature of water (372°c); however, normal reactor conditions are 220-
320°C and 1000-2200 psig.  Reactor products pass through the first heat exchanger
to preheat the incoming effluent-air mixture, and are separated into a gas and
liquid phase.  The gases — steam, carbon dioxide, and nitrogen — are expanded to

-------
o
Ul
Q.
O
UJ
O
CO
CO
UJ
o
o
cc
Q.
g
Ul


CO

§
8
<  t
    z
u  <
5  uj




CO  N






CM





O

-------
provide power for the air compressor and in some instances  to generate  electrical
power; the'liquid phase is used to preheat incoming effluent.

        The extent of oxidation achieved by this process,  expressed in  terms of the
chemical oxygen demand* (COD) of the effluent,  is primarily-determined  by the tem-
perature reached in the reaction.  At a given temperature  a definite amount  of COD
is removed.  This reduction is independent of the quantity of air in excess  of the
stoichiometric amount required.  COD reduction  is very low around 100°C,  increases
sharply between 150-225°C,and is almost complete at 350°C.   Also,  at low tempera-
tures, several hours are required to attain the COD reduction,  and this reduction
is at a lower level of oxidation.  At temperatures of 250°C and above the reductions
are attained in minutes.

        Pressure indirectly determines the relationships between the other reaction
variables and under a given set of conditions,  the extent  of oxidation.  At  a given
temperature, the total pressure in the system must be sufficiently high to avoid
excessive water loss.  Oxidation proceeds smoothly only if water is present, and
usually stops if it is not.  At a given temperature and pressure,  the air input is
limited by the effluent concentration, i.e., by the amount  of water that will be
removed from the system.  The extent of oxidation of such  an effluent is determined
by its heating value expressed in terms of the  amount of air required.


Historical

        Almost without exception, wet oxidation as it is currently being utilized is
based on a process developed by Zimmermann in the early 1950's.  However, the basic
reaction involved, that of oxidizing aqueous suspensions or solutions of organic
material with oxygen under superatmospheric pressures at elevated temperatures, and
its application to organic waste materials extends back over fifty years to  the work
of Strehlenert and others.

        Strehlenert [108,109] developed a process for the  recovery of carbonaceous
solids (sulfite coal) from spent sulfite pulping liquors by heating unneutralized
spent liquor in the presence of air or oxygen under 20 atmospheres pressure  at 200-
210°C.  Initially, free and chemically bound sulfite was oxidized to sulfate and
then, as the cation supply was depleted, to sulfuric acid  which caused  the ligno-
sulfonic acids to condense and precipitate from solution.   This process was  extensively
modified by Strehlenert [110-11^-1 to improve the yields and properties  of the recovered
solids.  Although given plant-scale trials in 1916 [115] and 1918 [ll6],  it  was never
utilized commercially.

        Henglein and Stauf [117] patented a process in 1927 for the removal  of organic
impurities from aqueous solutions of metal salts by treating the solutions with oxygen
under pressures greater than 1 atmosphere and at temperatures above 130°C.

        Bergstrom and Cederquist [ll8] developed a similar process in 1937 for the
removal of organic substances from spent kraft  pulping liquors by heating the liquors
with oxidizing agents such as air or oxygen-containing gases at elevated temperatures
under superatmospheric pressures.  Later Cederquist [119]  noted that many organic
waste materials, particularly lignocellulosic materials such as spent sulfite pulping
liquor solids and peat, were completely oxidized to carbon dioxide, water, and low
molecular weight organic acids, mainly acetic acid, at temperatures of  190-225°C.
Technically useful reactions, particularly for  the recovery of carbonaceous  solids,
occurred at lower temperatures and at somewhat  less than complete oxidation.  Sewage
sludge was only partially oxidized at 225°C but the residue left by the reaction was
easily filtered and de-watered. Cederquist [120] also found that the low molecular
weight acids formed in the reactions of spent sulfite or kraft pulping  liquors were
extremely difficult to oxidize even at temperatures of 290°-295°C.  Catalysts such
as CuMn (Cr264)2 allowed complete oxidation of  these acids in both liquors at 26o°C.
         Chemical oxygen demand determined by standard dichromate reflux method.

-------
Entrained organic material could be oxidized by adding molecular oxygen to the steam-
gas mixture and passing it over this same catalyst at 300 C.

        In 195^; Cederquist [121,122] patented a process for the recovery of heating
values in spent sulfite pulping liquor solids by oxidizing the liquor with air or
oxygen, preferably in the presence of catalysts such as Cu, Fe, or V oxides, under
25-200 atmospheres pressure at l80-300°C until the solids precipitated from solution.
The heat evolved by the reaction was utilized to maintain the process; the carbo-
naceous solids were burned separately as fuel.  This process was modified [123]  to
allow conversion of sulfide and sulfite in the liquor to sulfate prior to addition
of a catalyst, and was extended [124,125] to include other lignocellulosic materials
such as wood, sawdust, lignite, and peat.

         Salveson et al. [126] developed a process in 19^-8 for producing vanillin
from alkaline spent sulfite pulping liquor by treating the liquor with air or
oxygen under autogenic pressure at l40-170°C.  Shoeffel [127] patented a modifica-
tion of this process which involved heating the alkaline spent liquor under 1500
psi pressure at 200°C.  These processes were the bases for the process patented by
Zimmermann[l28,129] for the oxidation of organic waste material in industrial and
municipal effluents. The Zimmermann process involved treating effluents such as
spent sulfite and kraft pulping liquors, Masonite liquor, cheese plant whey, sewage
sludge, or water-fuel oil dispersions with an oxygen-containing gas under 1500 psi
pressure at 250-330°C.  Under these conditions the process was self-sustaining and
allowed the recovery of up to 95 percent of the heating value of the organic
material.  Thermal energy in excess of that required to maintain the process could
be converted into steam and electricity.  Recently Earle et al. [130] patented a
modification of the Zimmermann process.  The modification involves sewage sludge
by heating the sludge with air under superatmospheric pressures at 100-225°C.  The
treated sludge has a faster settling rate and a reduced oxygen demand.

        Krysinskii and Gorchakova [lj5l] patented a process in 1955 for the removal
of organic substances from industrial effluents by treating the effluents with air
or oxygen at elevated temperatures under pressures greater than 75 atmospheres,  and
preferably under alkaline conditions.

        Schmalenbach et_ al. [132] developed a process in 1959 for "the purification
of industrial effluents, particularly those from ammonia-producing coke or gas
plants, by oxidizing the effluents with an excess of oxygen under superatmospheric
pressures at elevated temperatures.  Insoluble material was separated by deposition
at elevated pressure and temperature before the oxidation reaction.


Pilot- and Large-Scale Applications

        There are a great many variations on the type and arrangement of equipment
and on the conditions of oxidation depending upon the effluent involved and the
particular disposal requirements.  In the pulp and paper industry the Zimmermann
process has been applied to the treatment of spent pulping liquors for chemical or
energy recovery and stream pollution abatement.  The first commercial-scale trial
of this process was made in 195^-1955 by the Hammermill Paper Company at Erie, Perm.
for the disposal of pollution-causing organic material in spent sodium sulfite
semichemical pulping liquor from their 30 ton/day Neutracel process [133-135J-  A
throughput of 50,000 gallons per day (gpd) of full strength spent liquor was
oxidized in a series of three 3-ft x 30-ft reactors at 26o°C under 800 psi pressure.
Reactor products were separated and sent through heat exchangers to recover their
heat.  No steam or power production was attempted.

        The average chemical and physical properties of the spent liquor before and
after oxidation are shown in Table kk.   Water loss due to evaporation during the
process, some 60 percent of the original spent liquor volume, is reflected in the
values of oxidized liquor properties contrasted on "as is" and spent liquor bases.
Oxidation efficiency was 92 percent in terms of oxygen demand reduction or 88 percent
in terms of heat content reduction.  Residual biological oxygen demand (BOD) in the

-------
146
                                     TABLE hk

           AVERAGE CHEMICAL AMD PHYSICAL PROPERTIES OF SPENT NEUTRACEL8
                      LIQUOR  BEFORE AND AFTER  OXIDATION
Properties
PH
Specific gravity
(at 80°F)
Oxygen demand0
Total sodium
Total sulfur
Sulfate sulfur as S
Acetic acid
Heat of combustion
Spent Neutracel
Liquor
8.7
1.061
91-5 s/£
17-6 s/£
11.0 s/£
-
16.7 s/Jt
6000 btu/gal
Oxidized Liquor
'As Is1 Basis
k.9
1.117
18.8 g/£
^3-8 s/l
26.3 &/*
22.1 &/&
25-3 B/£
1800 btu/gal
Spent Liquor
Basisb
-
-
7-5 g/J
17-6 s/t
10-5 *Jt
8-9 g/4
10.2 s/£
720 btu/gal
             A sodium sulfite semichemical pulping process.

             Values corrected for water evaporated assuming  no  loss
        of sodium.
            0
             Based on potassium iodate  oxidation-
oxidized liquor, due almost entirely to sodium acetate,  presented no pollution
problem since the liquor was ultimately recycled into the Neutracel process.   The
inorganic pulping chemical, sodium,  sulfite,  present in the oxidized liquor as
sodium sulfate, was recovered by treating the liquor with lime and sulfur dioxide;
the basic reactions are shown below:
                    CaS03 + S02 + H20  ->  Ca(HS03)2

                    Na2S04 + Ca(HS03)2 -»  2NaHS03 + CaS04

                    2NaHS03 + Ca(OH)2  ->  Na2S03 + CaS03 + 2H20 .
This regenerated the sodium sulfite pulping liquor,  leaving calcium sulfate as a
waste by-product.  Preliminary results of the recovery process indicated that 80-
90 percent of the sodium sulfate was converted to sodium sulfite;  however,  conversions
in excess of 90 percent were thought possible.

        Although the Hammermill Paper Company considered the wet oxidation process to
be technically successful they did have some reservations related to large-scale
sulfur and energy recovery.  The Zimmermann process  was not used for spent liquor
treatment when the Neutracel process expanded into a new 100 tons/day mill in 1956.
Cost data related to the construction and operation  of the trial wet oxidation plant
were never published.

-------
        Zimmermann and Diddams [lj6] later indicated that the wet oxidation process
was successfully applied on a pilot-scale to magnesium-., calcium-, and ammonium-
base spent liquor; to semichemical acid, neutral, and alkaline sodium sulfite spent
liquor; to sodium-base liquor; and to kraft liquor.  Inorganic chemical recovery
systems for several of these liquors, including an alternate to the system used
with the Neutracel process, were also developed.

        In 1956 the Borregaard Paper Company decided to build a wet oxidation plant
based on the Zimmermann process to recover the heat in the spent liquor from a 500
tons/day calcium-base sulfite pulp mill in Sarpsborg, Norway.  Related studies [137-
139] indicated that this process was 50-60 percent more efficient than the conventional
evaporation-incineration method for the production of steam; and in addition, that a
wet oxidation plant would cost $2.5 million whereas the cost for a comparable
evaporation-incineration plant would be $3-8 million.  Power requirements would be
higher for the wet oxidation process.  However, they could be met with the use of
external sources or with energy recovered from the process.

        In the installation [105], the spent liquor is first fermented to produce
alcohol and then passed to the wet oxidation process at 105°C.  Two 6-ft x 60-ft
reactors operate in parallel at 310°-315°C under 2250 psig pressure.  Reactor
products move into a separator where the liquid phase is collected and discarded,
and the steam and gases pass through reboilers for the production of 20-150 psig
process steam and about 650 psig steam for a steam turbine.  The noncondensable
gases are passed through a gas turbine, and the power produced by the steam and
gas turbines is used for air compression.

        The wet oxidation plant has been in operation since early 1961, but the
Borregaard Paper Company has not given out any performance or operation cost data
to date.  The process was to furnish 236,000 pounds per hour (pph) of process steam
(6.2 tons of steam per ton of pulp), which represents a saving of about $1 million
a year in fuel oil.

        Additional applications have been evaluated and their implementation con-
sidered in several countries, such as Japan [l4o] and West Germany [1^1,1^2].

        In the treatment of municipal wastes, wet oxidation has been utilized for
the elimination of health hazards and nuisance conditions related to sewage sludge
disposal, and for the economical reduction of the volume of this waste.  The residue
from such an application, almost without regard to extent of oxidation, is bio-
logically stable, sterile, and can be compacted.  These are characteristics which
tend to simplify subsequent disposal [l43J•  Wet oxidation currently is being
utilized for the disposal of one hundred to two hundred tons per day of municipal
sewage solids in five cities in the United States.

        The first application of the wet oxidation process to municipal wastes was
in a pilot-scale study at the West-Southwest plant of the Metropolitan Sanitary
District of Chicago, 111. during parts of 1957 and 1958 [106,107,1^-1^6].  The
plant was designed to treat 2 tons/day (dry basis) of sewage sludge, and was
operated with various combinations of primary and activated sludges at 26o°C under
1200 psig pressure.

        Average performance data for the pilot operation are shown in Table k-5.
These data indicate, as expected, that the extent of sludge degradation is a
function of temperature and does not vary appreciably with changes in sludge con-
centration.  Under the oxidation conditions employed, COD reduction was about 80
percent and volatile solids reduction approximately 89 percent.  The process
effluent, characterized in Table h6} was found to have a relatively high ammonia,
volatile acid, and BOD content, and would require some treatment prior to disposal.
The effluent, as discharged from the reactor, was sterile, and the settled ash
biologically stable.  An analysis of the gases exhausted from the process indicated
they were mainly nitrogen and carbon dioxide, 82.8 percent and 13-9 percent (by
volume), respectively.  The hydrocarbon content was very low, less than 0.02 percent
(by volume), and no air pollution problem was anticipated.

-------
                                                      TABLE  45

                AVERAGE PERFORMANCE  OF PILOT -SCALE  SEWAGE SLUDGE WET  OXIDATION  STUDIES  [lOb,  145,  146]
Location
West-Southwest Plant,
Chicago, 111.

Salvo Chemical Co. ,
Rothschild, Wise.
Volatile
Solids
Cone .
Range
%
2.00-2.99
3.00-3.99
4 . 00-4 . 99
1.91-2.25
1-73-1.95
Pres.
psig
1220
1208
1209
1525
1820
Temp.
°C
255
26k
265
274
277
Influent
Total
Solids
1>
4.09
5.21
6.1*2
3.29
3.1.8
Volatile
Solids
$
2.61
3.1*3
1*.33
2.16
2.31
COD
s/t
50.8
63.lt
75.4
W.5
49.8
Effluent
Total
Solids
*
1 1(6
1.59
2.05
l.llt
0.92
Volatile
Solids
*
0.299
0.356
0.1(36
0.2l(
0 IT
COD
alt
10.2
13.2
16.6
9.3
8.1
Reduction
Total
Solids
%
6k. 3
69.5
68.1
65. it
73.6
Volatile
Solids
$
88.5
89.6
89.9
88.6
92. it
COD
*
79.9
79.2
78.0
79-3
85.1
 A subsidary of Sterling Drug,  Inc.
                                                       TABLE It6

                 AVERAGE CHEMICAL CHARACTERISTICS OF PROCESS EFFLUENT FROM PILOT-SCALE SEWAGE LIQUOR
                                    SLUDGE WET OXIDATION STUDIESa [106,  lit 5,  146]


Location

West-Southwest Plant,
Chicago, 111.

Salvo Chemical Co. ,
Rothschild, Wise.
Volatile

Cone.
Range
%
2. 00-2. 99
3.00-3-99
4 . 00-4 . 99
1.91-2.25
1.73-1.95
Reactor Effluent


HH3-H
mg/i
1370
1625
1640
1410
1490

Org . -N
mg/^
368
425
548
__
--
Volatile
Acids as
Acetic
rag/I
3200
3480
3980
3930
3820

pH
--
—
—
6.1
6.3

BOD
mg/t
5420
7030
8460
	
-

COD
mg/1
10200
13200
16600
9306
8100
Settled
Effluent


BOD
mg/^
4890
6410
7110
__
--

COD
mgA«
8300
9800
11600
7800
1030
Effluent Ash

Volume
Settled
in 1 hr
ml/J!
98
105
116
	
-

Content
ml/I
--
—
—
108
--

BOD
mg/i
530
620
1350
__
--

COD
mg/,2
1900
3400
5000
1550
967
aOxidation conditions for the locations and volatile solids concentration ranges shown here are given in Table

 A subsidary of Sterling Drug, Inc.
                                                       TABLE U7

            SUMMARY OF TYFTCAL OPERATING CONDITIONS FOR EXISTING SEWAGE SLUDGE WET OXIDATIOII PLANTS [lO?]
Plant Description
Location
West-Southwest Plant,
Chicago, 111.





Wheeling, W. Va.







Wausau, Wise .




South Milwaukee,
Wise.



Blind Brook Plant,
Rye, N. Y.


Characteristics
k oxidn. units
1 - 12,500 lew
power recovery
air compressors
( I/unit)
360 Ib/min
2250 hp
1 oxidn. unit
air compressor
37-5 Ib/min
225 hp




1 oxidn. unit
air compressor
23.4 Ib/min
150 hp

1 oxidn. unit
air compressor
5.0 Ib/min
40 hp

1 oxidn. unit
air compressor
7.0 Ib/min
40 hp
Initial
Operation
Date
December
1961





August
1961






October
I960



October
1961



April
1963


Typical Performance
Sludge
Characteristics
Raw primary-
activated
3$ solids
35$ ash
40 g/t COD


Raw primary
7.5$ solids
45$ ash
70 g/t COD
Raw primary
4.4$ solids
3056 ash
52 g/t COD
Primary
digested
8.5$ solids
5656 ash
62 g/t COD
primary raw
and digested
7.7$ solids
46$ ash
60 g/t COD
Raw primary
5.6$ solids
30$ ash
60 g/l COD
Solids
Through-
put,
tpd
55/unit






8



3



5-7




2.5




1.4



COD
Reduction
$
75/unit






60



72



75




40




65



Insol.
Organ! cs
Removal
$
90






90



97



92




70




90+



Pres.
psig
1750






1140



1650



1650




485




700



Max.
Temp.
°C
275






260



275



220




220




240



Power
Requirements
Total: 2,000
kw/unit
Net : 5 , 600
k»/unit
(with 4 units
on line) and
power recov.
Total: 200 kw



Total: 160 kw



Total: 160 kw




Total: 37.5 kw




Total: 37.5 kw




-------
                                                                                 149


        In a subsequent pilot-scale study [106,146] by the Salvo Chemical Co..,
Rothschild, Wise, (a subsidiary of Sterling Drug, Inc. which developed the Zimmermann
process), higher rates of oxidation were attained at elevated temperatures and pres-
sures without appreciable change in COD and volatile solids reduction.  The plant had
approximately half the capacity of the Chicago pilot operation and was run at 255°-
285°C under pressures of 1500 or l800 psig.

        The reductions in COD and volatile solids at 1500 psig, shown in Table 45,
were in the same range as those at 1200 psig; however, the sludge feed rate was
higher.  At 1800 psig these reductions, also shown in Table 45, were slightly larger
and the feed rate was doubled.  The process effluent from these operations, charac-
terized in Table 46, was similar in ammonia and volatile acid content to that obtained
at 1200 psig in the Chicago pilot study; the liquid effluent and ash COD contents were
lower than those of the 1200 psig process.

        As a result of these pilot studies the Metropolitan Sanitary District of
Chicago, in 1959^ contracted for the construction of four 50 tons/day (dry basis)
wet oxidation units to treat some 20 percent of the sewage sludge from that area
[106,107,146].  The plant was to provide ultimate disposal for sludge which was then
being lagooned or sold as a low-grade fertilizer.  Each unit consisted of a 7-ft x
62-ft reactor, six heat exchangers, four air compressors, and eight high-pressure
pumps, and was designed to oxidize sludge of 3 percent concentration at 320°C under
1800 psig pressure.  One turbogenerator was utilized for simultaneous power recovery
from all four units.  The plant was constructed at the West-Southwest Works of the
Sanitary District and has been operating on a continuous basis since late 1961.
Typical operating results are shown in Table 47.

        The combined construction costs for this plant, itemized in Table 48, were
almost $17 million, or $84 thousand per ton per day [l4l].  Operating costs for
the first l6-l8 months, also shown in Table 48, were $9-45 per ton (dry basis) of
sludge treated; the combined capital and operating costs were $18.65 Per ton (dry
basis).  A comparable, conventional disposal plant would have cost $25 million to
build, and the resulting sludge treatment — digestion followed by disposal as
fertilizer — about $35 per ton (dry basis).

        Other wet oxidation plants have been built and are in operation in Wausau,
Wise.; Wheeling, W. Va.; South Milwaukee, Wise.; and Rye, N. Y.  A summary of the
characteristics and typical operating results are also shown in Table 47-  Actually
the Wausau plant, put into operation in 19^0, was the first commercial application
of wet oxidation to sewage sludge disposal in the United States [l47].  This plant
was designed for almost complete oxidation of 3 tons/day (dry basis) of sludge,
and was equipped with an expansion engine to recover mechanical energy from the
process.  No construction or operating cost data are available for this operation.

        The Wheeling and South Milwaukee plants were started the following year
and displayed a marked contrast in size and operating conditions.  The Wheeling
plant, designed to treat 5-6 tons/day (dry basis) of sewage sludge, attains about
90 percent removal of organic material at 26o°C under 1200 psig pressure [l48].
Under these conditions, the process operating costs, itemized in Table 49, are
$19.97 per ton (dry basis).  Installation costs for the wet oxidation unit were
almost $300,000.  The South Milwaukee plant, in contrast, was designed to oxidize
1 ton/day (dry basis) of sludge at 220°C under 525 psig pressure, and to reduce the
amount of insoluble organic material by 70-80 percent [l49l•  No operating costs
are available for this plant, but the wet oxidation unit, exclusive of buildings and
other supplementary items, cost approximately $80,000.
        The most recent wet oxidation plant, the Blind Brook plant at Rye,  N.  Y.,
was built in lieu of a digestion-filtration-incineration process at a savings  in
combined construction costs of over $400,000 [150].   This plant, designed to treat
1 ton/day (dry basis) of sludge, operates at 238°C under 750 psi pressure.   Insoluble
organic material reduction averaged 84.2 percent during the first year's operation.
Estimated capital costs for two 1-ton/day units are  almost $300,000 or $14.20  per
ton (annual dry tonnage basis).  Operating costs for such an operation,  based  on the

-------
150
                          TABLE 1+8

UNIT COSTS FOR THE WEST-SOUTHWEST WET OXIDATION PLANT OF THE
 METROPOLITAN SANITARY DISTRICT OF CHICAGO, ILLINOIS51
                                                                  51 [l4l]
Item
Capital Costs
Wet Oxidation Installation
Maintenance Facility
Plant Foundation
Steel Framework, etc .
Electric Utilities
Sludge Concentration Installations
Miscellaneous Items

Operating Costs, per month
Labor
Lubricants and Chemicals
Replacement Parts
Steam

Operating Costs, per ton (dry basis)
Combined Capital and Operating Costs,
per ton (dry basis)
Item Costs

$11,870,000
808,000
598,000
398,000
2,325,000
974,000
54,000
$16,829,000

$31,800
9,600
2,000
14,000
$57,4oo
$9.1+5
$18.65
Percent of
Total Costs

70.5
4.8
2.4
2.4
13.8
5-8
0.3
100.0

55.5
16.5
3.5
24.5
100.0


                  aCosts are based upon a continuous, 200 tpd (dry basis) sewage
          sludge disposal operation as of October 1963.

                   No breakdown of capital costs on a per ton basis was given.
                                        TABLE 1+9

                         UNIT COSTS FOR THE WET OXIDATION PLANT
                           AT WHEELING, WEST VIRGINIA3- [l48]
                                    Item
                                                           Item Costs
                    Capital Costs

                      Wet Oxidation Installation

                    Operating Costs, per ton  (dry basis)

                      Labor (l man during operation)
                      Electricity
                      Chemcals
                      Start-up Fuel
                      Maintenance
                                               $284,000
                                                  $6.91
                                                   6.11
                                                   4.13
                                                   1.65
                                                   1.17
                                                 $19-97
                            Costs are based upon an intermittent 7-35 "tpd
                   (dry basis) sewage sludge disposal operation which operates
                   10 days per month, as of January 1965•   Ho combined capital
                   and operating costs per ton data were provided.

-------
                                      TABLE 50

                    UNIT COSTS FOR THE BLIND BROOK WET OXIDATION
                             PLANT AT RYE, NEW YORK51 [150]
                                                                                151
                              Item
Item Costs
            Capital Costs

              Allocated Capital for Wet Oxidation
              Installation

              Debt Service (jO-yr bonds at 3$)
                Amortization per year

                Average Interest per year

                Average Annual Capital Cost

              Annual Capital Cost, per ton (dry basis)


            Operating Costs, per day

              Power (1,^80 kw)
              Chemicals

                Soda Ash

                Caustic Soda

              Water (2,250 cu ft)

              Labor (6 hrs)


            Operating Costs, per ton (dry basis)

            Combined Capital and Operating Costs,
            per ton (dry basis)
$263,000
$  8,800
   i+,000

$ 12,800
$     1^.20
      3^.00


       8.00
       1.00
       9.00
      15-00
      67.00

      26.80

      41.00
                 Costs are based upon a proposed 2.5 tpd (dry basis)  sewage
            sludge disposal operation as of August 1965.   The existing  plant
            has a design capacity of 1 tpd (dry basis).
existing 1-ton/day unit and itemized in Table 50,  would be $26.80 per ton  (dry basis),
and combined capital and operating costs $4l.OO per ton (dry basis).
RECENT RESEARCH

        As the preceding discussion indicates,  in the past wet oxidation usually was
applied to dilute aqueous dispersions of organic waste materials  primarily with  a
particular disposal or recovery objective in mind.  Under conditions  of complete
oxidation, this material (or materials) was degraded to inert gases and water,
allowing recovery only of thermal and mechanical energy, and of inorganic  chemicals.
Under conditions of partial oxidation, it was converted to a more convenient  form

-------
152
for physical disposal or utilization as fuel.   The recovery of organic chemicals for
their chemical value under either of the preceding conditions was largely neglected,
and the question of their potential left unanswered.

        The trend of research  on wet oxidation now is toward the recovery of the
organic chemicals for their chemical value as  well as with the range of applications
of the system.  Of importance in this regard is the work of Grangaard [151,152]  who
investigated the production of organic acids - primarily acetic,  formic, and oxalic -
resulting from the degradation of ligneous waste materials, and from pulping wood
with application of molecular oxygen under superatmospheric pressures and at elevated
temperatures.  Waste materials, such as spent  pulping liquors or  sawdust, are
oxidized in aqueous alkali or "buffer solution  at 100°-225°C under 500-1000 psi oxygen
pressure.  Yields of different acids can "be optimized under appropriate pH conditions,
and combined yields can amount to about 80 percent of the material (dry basis) used.
Simultaneous pulping and production of organic acids is carried out in a slightly
alkaline, aqueous buffer solution under lower  oxygen pressures and temperatures.  The
acids formed are similar to those in the preceding process, albeit in somewhat lower
yields.  Grangaard later noted [153] that such acids, produced from the spent liquor
of a 100-ton/day sulfite pulp mill, had a potential annual market value of about
$^.25 million, as shown in Table 51> which approaches the value of the pulp.  In
addition, applied to the 1960 production of sulfite and sulfate pulps in the United
States, approximately 17-4 million tons, the potential production volume of these
acids,also shown in Table 51> far exceeds the  current domestic production.

        Merriman et_ al. [15^-^155^ a"t the University of California Forest Products
Laboratory studied the formation of similar organic acids in the  reaction of molecular
oxygen with wood in aqueous acidic, neutral, or alkaline buffer solution at 150°-
l65°C under 100 psia oxygen pressure.  Low molecular weight acids — mainly formic,
acetic, oxalic, succinic, and glycolic — were  formed as major products in all re-
actions; however, the yields of these acids varied significantly with pH.  Under
alkaline conditions total yield was highest —  amounting to approximately 3^ percent
of the wood (dry basis) used.  Under neutral and acidic conditions total yields
reached about 12 percent and 9 percent, respectively.  The cellulosic fraction of
the wood was preferentially attacked under acidic conditions.

        Recently, Brink et_ a!L. [156], using analytical techniques developed at this
laboratory in the above study and in a related study by Bicho et_ al. [l57>158]>
compared organic degradation products from alkaline nitrobenzene, molecular oxygen,
and nitric acid oxidations of wood.  These reactions were carried out in an aqueous
medium under autogenic pressures or elevated oxygen pressure, and at temperatures
ranging from 80° to l80°C.  The oxidants involved are somewhat similar in oxidizing
potential under the conditions employed.  Low  molecular weight organic acids were
formed in all reactions, particularly in the nitrobenzene and molecular oxygen
reactions under alkaline conditions.  Aromatic acids and, to a lesser degree, aromatic
aldehydes and ketones were also formed in these reactions.  Total yields of these
compounds ranged from approximately 10 percent of the wood (dry basis) used, for
molecular oxygen and nitrobenzene reactions under alkaline conditions, to k percent
for molecular oxygen and nitric acid reactions under acidic conditions.


APPLICATION TO SOLID WASTES

        In the preceding discussion evidence in the form of examples and research
results was presented, which demonstrates that the process of wet oxidation can be
used effectively on organic materials, especially the highly carbonaceous forms, to
recover potentially usable by-products and thermal energy.  Moreover, the end
product is in a form that is compact with no handling or disposal problems.  In
addition to demonstrations of technical feasibility, the process has been applied
on a sufficiently large scale to simulate the  economics of full-scale equipment and
operation.  Although heretofore the pilot- and full-production plants were constructed
for specific applications, the type of equipment and processing would not change
enough from one application to another to materially affect the overall costs.

-------
                                                                                                                                                     153
a








C(_,
O
H^
cd £H
•H +3
•P CB
d pi
CD *d
0 H
PH
ft
rH rH

C
.jj








•d
ft
-P
O
O H
H H
•H
ft
H H
•H PL,
d CD
OJ -P
-P -rl
pi
rH W

d
d

i
•r
C
e
O
•H
-P '-^
CO d CQ
D o a
E -H O
O -P -H
R O rH
Pi rH
•P Ti -H
d o S
CD Jn •— -
?H PH
^H O
Pi rH
O




f>3' — *•
^H CO
-P £3
CQ O
pi *H
d H
H -H
S
ft-C-
H
CD
H
cd to
!> k
cd
-p H
0 H
2 O
o

PH


i
^
>^
O >j
•H "-• —
-P f
O rH

•d
o
i
H
J
i!





t— O K^, LTS OH
. . • . 1 ••III 1
^1- J- H LTA O O
VD H CVI CO Ch
D-










OOOOOOOOJ-
O OOOCO OVDCQO\
OOOOCVIJ-t^VDCh
CO OOVOHr^KACO
VD H CO -d- H
VD VD VD CXI
*S *N
H H
OOOCXI LTAOOLTA
OO-3-KA I^VDVDVO
O L^ VD CO fP ON -^" 1^ VO rO

J-HVOON ON O 00 ON
COOKNf— [OtCOOrH
ro LT\ [>- H hTN
r-T r-T






8OOOOOOOO O
OOOOOOOO O
ooooooooo o
OOcOvoco^vocOC— ^
OOCXIVOJ-VDHCXIJ- VO

K~\ ON ON H H


o o o
O O -rt -H -H d
•H -H -H -H d M -H -H O O O
-p £ i — I -P o cd cu o o ^H d
CD M cd o * — I R i — 1 o cd ~P . ^
^^cS^lrli^rH^g





VD

^J-
t—
ON










H
H
CXI
fO\
CVI
•\

CXI
ro\
CO

O
LT\
CXI
_J






O
O
O
cv?
t—

£- —
CVI





                                                                                                                             -p
                                                                                                                             cd
                                                                                                                             -p
                                                                                                                             w

                                                                                                                             CO
                                                                                                                             CD
                                                                                                                             -p
                                                                                                                             •H
                                                                                                                             d
                                                                                                                             CD

                                                                                                                             -p
                                                                                                                             CO
                                                                                                                             ft
                                                                                                                             H
                                                                                                                             CD

                                                                                                                             cd

                                                                                                                             H

                                                                                                                             CQ

                                                                                                                             •d
                                                                                                                             d
                                                                                                                             cd

                                                                                                                             CD
                                                                                                                             -p
                                                                                                                             •H
                                                                                                                             d  -p
                                                                                                                             CD  cd
                                                                                                                             CQ  S
                                                                                                                             ni  -H
                                                                                                                             m  x
                                                                                                                            cd    o
                                                                                                                                 f-i
                                                                                                                                 ft
                                                                                                                                 ft
                                                                                                                                 cd
                                                                                                                                          -p
                                                                                                                                          CO
                                                                                                                                          CD
H

-------
        Because of these two facts,  viz.,  demonstrated evidence  of the  feasibility
of the process and the availability of information regarding full-scale plants,  an
investigation of the potential of wet oxidation in the treatment of solid wastes
is warranted.  The extent of this potential is quite great  inasmuch as  organic
materials constitute the greater part of the total volume of refuse.  Admittedly,
not all or even the major portion of the organics  would be  amenable to  processing
by wet oxidation.  Nevertheless, the amount in the form of  paper,  which according
to present evidence could be satisfactorily processed, is large  enough  to result in
a substantial reduction in the size of the waste stream if  it were so treated.

        However, the extent of information concerning the process  and the amount of
experience with it is not great enough to permit its application to the treatment  of
solid wastes without a previous intensive investigation. In applications to date,
wet oxidation has been applied to the disposal of organic waste  materials under
conditions of degradation approaching incineration at one extreme  and biological
oxidation or digestion at the other.  As stated earlier, the recovery of organic
chemicals for their chemical value under either of these conditions has been
generally neglected, and the question of their potential has accordingly been left
unanswered.

        Nevertheless the overall promise of the wet oxidation process as currently
utilized, and the potential of the process for the production of organic chemicals,
particularly acids, as indicated by related studies, justifies the assumption that
the process should be applicable to organic solid wastes.


OBJECTIVES OF STUDY

        The overall objective of the studies on wet oxidation herein reported is to
adapt the process to the conversion of organic solid wastes materials to products  of
commercial utility.  Ultimately the research should lead to the  making  of correla-
tions between material and energy balances and energy balances and reaction conditions
which will lead to the development of the process  designs needed for the realization
of the general objective.  Initial specific objectives,  with which this report is
concerned are to:

    1.  Provide an insight into the wet oxidation process itself.

    2.  Make possible a ready contrast of this wet chemical process with the more
        prevalent biological and chemical processes for solid wastes disposal.

    3-  Indicate the experimental approach to be taken in subsequent phases of
        the study.

Objectives 1 and 2 have been completed and reported in the  preceding text.  Objec-
tive 3 is discussed in the succeeding sections.


THE INVESTIGATION

        During the period covered by this report investigative work was mainly
preparatory in nature.  An extensive literature review related to the development
and application of wet oxidation was carried out and is summarily presented in the
INTRODUCTION to this section.  Pertinent questions raised by this  review were
considered in the formulation of the experimental plans which are described below.
The plans are extensions of earlier work by D. L. Brink on  the basic oxidation
reaction and of more recent related studies at this laboratory.   Although no experi-
mental runs were made, work was done on the modification of analytical  techniques
for application in the study, especially of those related to the determination of
aromatic compounds.

-------
                                                                                155
 Program and Methodology

        The experimental portion of this study has been divided into three phases
 which are to be approached sequentially.  Work concerned with phases 1 and 2 will
 be done at least in part during the initial two years of the research program;
 phase 3, which is dependent on the results obtained in the preceding phases, will
 be undertaken during the proposed extended period of this program.

        Phase 1:  Determination of Basic Reaction Relationships.

        Equipment:  The initial stage of this phase, which is now in progress, is
 being devoted to modification of existing equipment and to the design and fabrica-
 tion of additional equipment for the wet oxidation process.  When the modification
 and installation have been completed, laboratory-scale reactions will be carried
 out in a 1.5 cu ft steam-jacketed reaction vessel which is augmented by an external
 circulation system consisting of a liquor pump, heat exchanger, and flowmeter, and
 by an auxiliary vessel for injection or collection of reaction liquors.  This entire
 system will have a maximum design working pressure of ^50 psig steam at ^50 °F
 (237°C), and all metallic surfaces of the equipment which will be in contact with
 the reaction have been and are being fabricated from type 3l6 stainless steel.
 Automatic, programmed temperature control will be provided by a cam-operated,
 pneumatic recorder-controller which operates a valve at the high-pressure steam
 inlet.  The reaction system is and will be further augmented by an integrated
 instrumentation complex for monitoring and recording various reaction parameters
 such as pH, temperature, pressure, redox potential, and liquor flow rate.

        The wet oxidation process employed in this phase of the study, and probably
 the next one as well, will be a batch operation, a schematic diagram of which is
 shown in Figure 30.  A more detailed description of the reaction-instrumentation
 system is given in a paper presented at the 20th Alkaline Pulping Conference in
 1966 [159]•  In operation, a charge of a given waste material, dispersed in a
 minimal amount of water, will be added to the reaction vessel and rapidly brought
 to reaction temperature by applying steam to the jacket of the vessel and injecting
 additional preheated water into the reaction mixture.  Air will be supplied to the
 reaction at a predetermined rate and pressure from a high-pressure storage-regulation
 system.  Overall pressure in the reaction system will be maintained by a pneumatically
 controlled back-pressure valve.   Mechanical agitation of the reaction mixture and
 dispersion of air in it will be accomplished with a dual-turbine agitator.  Steam,
 volatile reaction products, and spent air will be expanded to atmospheric pressure
 and passed through an aqueous sodium bicarbonate scrubber to remove organic acids
 and condensable vapors.  The remaining gases will be measured volumetrically with
 a wet test meter, analyzed periodically by gas-solid chromatography (GSC), and
 vented to the atmosphere.  At the end of the reaction period, the reaction will be
 quenched by removing steam from the jacket of the vessel and injecting cold water
 into the reaction mixture.  The residual waste material will be collected and sub-
 sequently analyzed by standard techniques.

        To accomodate the proposed wet oxidation process,  several modifications and
additions have to be made to existing equipment.  An l8-in. extension to the reaction
vessel has been designed and is presently under construction to provide a disengage-
ment zone above the reaction mixture and to allow top entrance for the agitator.  A
 side entrance has also been provided in this extension and its application is dis-
 cussed later.  The agitator will be flange-mounted on this extension and has been
 designed to produce a downward flow of material in the reaction vessel.  It will
consist of two 5-in. diameter turbines,  each having four blades pitched at a ^5°
angle,  mounted on an 1-1/U in.  diameter shaft which passes through a balanced, double
mechanical seal mounted on the face.   Power will be transmitted to the agitator
 shaft  from a 2-1/2 hp electric motor through a pulley-gear train assembly which is
also mounted on the flange.  Shaft speeds will be varied by changing the pulley ratio
in this latter assembly.

        Air required for the reaction will be provided by an integrated compressor-
drier,  storage,  and pressure regulator system which has been designed for this

-------
156
                                       cr
                                   .  i_ UJ

                                   ill
                                                      I
                                                      cr

                                                      I
en
            CO
            <
            CD
en
CO
UJ
                                                                     X
                                                                     o
                                                                     UJ
                                                                     i
                                                                     CO
                                                                     o
                                                                     a.
                                                                     o
                                                                     UJ
                                                                     I
                                                                     o

                                                                     5


                                                                     o

                                                                     |

                                                                     UJ

                                                                     o
                                                                     CO
                                                                     UJ
                                                                     cc

                                                                     o

-------
                                                                                157
application and is shown diagrammatically in Figure 31•  This system will also
contain electro-pneumatic shutoff and fail-safe controls and mechanical pressure
relief devices to avoid exceeding the design working pressure limits of the air and
reaction systems.  Air under standard conditions will be compressed to pressures up
to 3000 psig at k cu ft per minute (cfm), physically separated from excess water and
oil, chemically dried, and stored in two 3000 cu in. and one 1300 cu in. spherical
receivers.  These air receivers can be simultaneously or individually utilized
through a manifold arrangement of pressure regulators.

        The back pressure valve noted in the above discussion will be installed at
an outlet on the reaction vessel extension, and will be controlled by an existing
pressure indicator-recorder-controller in the instrumentation complex.

        Procedure:  Upon completion of the equipment modification, wet oxidation
reactions will be carried out with wood chips or unbleached kraft pulp, or both,
to establish basic reaction relationships and to correlate the results of these
reactions with those from earlier studies at this laboratory.  Reaction parameters
to be considered will include:  time, temperature, pressure, liquid-to-solids ratio,
and agitation.  Reaction time, i.e., time at temperature, will probably be limited
to periods of four hours or less depending on temperature.  Temperature, in turn,
will be varied from l60° to 220°C at 20°C intervals.  It is anticipated that at
temperatures below l60°C the rates of reaction will not be practicable, and at those
above 220°C the saturated steam pressure will preclude appreciable air input.
Pressure will be considered in terms of total pressure and oxygen partial pressure.
Overall reaction pressure will be maintained at an arbitrary l6o psig above saturated
steam pressure in the reaction.  Influent oxygen partial pressure under these con-
ditions will be about UO psig; average oxygen partial pressure in the reaction
system, however, will be somewhat lower and will be controlled by the rates of air
input and oxygen consumption.  Solids content in the reaction mixture will be varied
over a wide range to determine both practicable and technically utilizable values.
Finally, agitation will be considered in terms of mechanical action and air disper-
sion.  Agitator shaft speeds will be varied from about 2^0 to 1200 rpm in 200 rpm
increments; the lower shaft velocity limit will be determined by the settling rate
of the solids suspended in the reaction mixture.  Turbine geometry will be changed
from pitched to straight or curved blades, and possibly from a turbine itself to a
hollow shaft-impeller assembly.

        Reactions involving any of these parameters, individually or in combination,
will be followed primarily by oxygen consumption and carbon dioxide-carbon monoxide
formation as determined by pressure-volume relationships and GSC data.  Additional
supplementary analyses may be applied to the reaction mixture and volatile reaction
products as required by experimental contingencies.  Based upon the results of these
reactions a standard reaction will be established and applied to various organic
waste materials in phase 2.  This standard reaction may not be optimum for the
production of organic chemicals;  however, it will serve as a reference for comparison
of these materials.


        Phase 2:  Oxidation of Organic Solid Waste Materials.  In this phase will
be applied the experimental techniques and results developed and obtained in phase 1
to the treatment of additional organic waste materials such as paper, agricultural
residues, sewage sludge, food processing residues, and combination of these and other
materials.  The organic chemical production potential of these materials will be
determined.  No immediate, additional equipment requirements are anticipated for this
application.  Material balances will be established by standard analytical techniques.
Chromatographic-spectrophotometric techniques developed in earlier studies or in
response to the needs of this study will be used to characterize the organic reaction
products.

        Further reactions under conditions specific for the production of a given
organic chemical or group of chemicals will be carried out in the later stages of
this phase.  This application may require a pressurized inlet system, which would be
mounted on the side entrance of the reaction vessel extension, to allow periodic

  388-229 O - 70 - 12

-------
158
                                                                                CD
                                                                                tf)
                                                                                UJ
                                                                                O
                                                                                O
                                                                                or
                                                                                Q_
                                                                                X
                                                                                O
                                                                                u^


                                                                                g
                                                                                O
                                                                                UJ
                                                                                LJ
                                                                                O
                                                                                UJ
                                                                                UJ
                                                                                cr

                                                                                S2
                                                                                u.

-------
                                                                                159
introduction of waste material into the reaction vessel during the reaction.   Organic
chemical production potentials and material and energy balances determined at  this
stage will provide the basis for process design development in phase 3-  Additional
experimental work related to a particular process will be performed in that phase.


        Phase 3:  Process Design.  In this phase the results of the preceding  phases
will "be assimilated in the development of possible process designs for the production,
isolation, and utilization of organic chemicals from wet oxidation of solid waste
materials.  Processes involving production and isolation of these chemicals probably
will be considered as one process or as a series of integrated processes.   Utilization
processes, such as acid hydrolysis of specific carbohydrate waste materials, will be
dependent upon the results of the above processes, and will be developed in the  later
stages of this phase.  Extensive equipment requirements related to the individual
processes are anticipated for this development phase.  Economic analyses of each
process design or combination of designs will be provided to indicate expected costs
or cost-profit ratios.


        Progress in Eqjpment Modification.  Most of the equipment modifications
discussed earlier are beyond the design stage and are in varying stages of construc-
tion.  Imbrication of the reaction vessel extension is well under way and  should be
completed by the middle of June.  Work on the agitator assembly is progressing as
various components are received and the assembly should be operational in  late
summer 19^7.  Lastly, the high-pressure air supply system, which is the most extensive
of all the modification activities, is also near completion.  The various  subassem-
blies, electrical controls, and air transfer lines will shortly be joined  together
into an integrated system.  With the possible exception of a few back-ordered  com-
ponents this system should be completed in the latter part of July.  Upon  completion
of the various modifications the overall reaction system will be subjected to  a  number
of trial reactions and then applied to the experimental aspects of phase 1.


DISCUSSION

        The approach taken in this research, namely of producing organic chemicals
from waste materials, implies several considerations which have not as yet been
discussed.  Usually, the wet oxidation process is applied to dilute aqueous dis-
persions of organic wastes which neither technically nor economically would be
practicable to treat by other means.  Taking a reclamation rather than a disposal
viewpoint toward such applications may remove many of the restraints currently
applied to the process.  In a reclamation or utilization approach all organic  wastes,
regardless of form or condition, are considered to be technically suited to the
process and the use of them would be economically justified in terms of chemical
production.

        The wet oxidation process involves hydrolysis and pyrolysis as well as
oxidation.  As such, this process initially degrades waste materials to simpler
organic compounds and then to carbon dioxide and water.  This intermediate level
of degradation is of primary concern in this study because it dictates both the
quality and quantity of organic chemical production, and the design of the process.
The utilization of waste materials in a complementary manner would allow control
of the organic content and concentration of the reaction mixture.  Such control
coupled with appropriate reaction conditions provides the basis for chemical produc-
tion.  This would be of particular significance in the case of an abundant organic
waste material such as paper, which comprises some ho percent to 65 percent of the
total solid wastes, and which could be converted to organic acids by this  process.

        Additional considerations are the much lower temperature and pressure
requirements of a utilization-oriented process as contrasted to those for  a disposal
process .  These modified reaction conditions would have a marked effect on equipment
design criteria, and all other factors notwithstanding, would lower subsequent con-
struction costs.

-------
l6o
        More immediately,,  in terms of these considerations,  existing  pulping equip-
ment and related instrumentation at this laboratory can be adapted to the  experimental
requirements of this study.  Most of the requisite modifications  to the  equipment  have
been designed and, to a large degree, fabricated.


FUTURE WORK

        As indicated earlier, the study will progress from a planning-experimental
stage to an active experimental stage within the next few months.  Most  of the
experimental requirements for phase 1 and most of phase 2 have been met  (or soon
will be), although some additional requirements are anticipated.   Further  modifica-
tions may be dictated by experimental contingencies.  For example,  the proposed
GSC technique for analysis of reaction gases may not be applicable to experiments
involving short reaction times.  Such experiments  would require modification of this
technique or application of fast-scan mass spectrometry, or both.  A  similar situation
would prevail for any equipment component which did not perform as expected.

        The conversion of the reaction system from batch to continuous operation in
the later stages of phase 2 will require the design and fabrication of additional
equipment.  This will include the pressured inlet  system discussed previously and  a
high-pressure pump for intermittent removal of aqueous reaction products.   Additional
insulation of the overall system may be needed to insure accurate heat loss-gain
data for energy balance calculations.  A small high-pressure reaction vessel may also
be required to supplement experimental results noted under lower  temperature-pressure
conditions.  Extensive equipment requirements related to various  process designs are
anticipated in phase J.  Specific needs are difficult to predict  in this instance
because of their reliance on the results of the preceding phases.

-------
                  IX.  BIOLOGICAL FRACIIONAIION OF ORGANIC WASTES
INTRODUCTION

        Biological fractionation of the organic content of solid wastes  is  another
possible process of indirect recycling of materials from the wastes stream  to the
basic resources of the nation.  It differs in concept from anaerobic digestion in
that by-products of elevated economic value are produced, whereas digestion is in-
tended to reduce volume and yield a residue which may be disposed of to  the land
with mimimum insult to that resource.  Biological fractionation also produces a
usable solid residue.   In regard both to intermediate products and to usable residue
it parallels wet oxidation, the difference being that in one case the oxidation or
fractionation is biochemical, in the other it is physiochemical.

        The general rationale underlying the experimental work on biological frac-
tionation is the same  as that described in the preceding section on wet  oxidation.
Similarly, the research plan calls for initial experiments with the paper fraction
of solid wastes, extending to other mixed organic wastes if the work with paper
produces satisfactory results.  Reasons for considering the process worth investigating
are to be found both in a general knowledge of the role of celluloytic microbes in  the
decomposition of dead plant material in nature, and in the fact that a large number of
microorganisms have been demonstrated as being cellulose degraders.  For example,
Siu [l6o] and Gascoigne [l6l] list several hundred of such species.  However, the
organisms vary widely with respect to cellulolytic activity, necessary environmental
conditions, types of metabolic products, etc.  The problem is to find those most
efficient and amenable to economical engineered systems.


WASTE TREATMFJW ORGANISMS

        A survey of the literature has shown a number of groups of the organisms to
be especially promising for waste treatment applications.  Among them are the cattle
and sheep rumen microorganisms, cellulolytic clostridia species, and some of the
fungi imperfect!.


Rumen Bacteria

        The mixed microbial population of the rumen consists of bacteria and protozoa.
The protozoa probably  have only a minor role in the decomposition of cellulose. Rumen
microorganisms are strict anaerobes.  In vitro studies consistently give relatively
rapid decompostion rates.  Halliwell [162] reports the decompostion of nearly 90 per-
cent of a cellulosic powder substrate within ^8 hours in a batch culture in which
by-products were not removed.  Stranks [163] observed a decompostion of  83  percent
of the cellulose in a  filter paper substrate within 72 hr.  In his experiment, end
products were removed  by ion exchange and dialysis.  Stranks noted also  that the
decomposition rates were much lower in experiments in which no provision was made
for removal of the end products.  Rumen microorganisms are more difficult to culture
successfully because of their fairly specific environmental requirements.  Until
rather recently, rumen liquor had to be used as a part of the substrate. However,
Quinn [l64] has shown  that it is possible to grow rumen microorganisms in continuous
culture on a chemically defined medium.


Clostridia and Related Forms

        Several varieties of thermophilic cellulose decomposing bacteria have been
isolated from the soil with the use of cellulose as the sole carbon source.
                                       161

-------
162

Extensive work has been done "by Enebo [165] in the isolation of such organisms, on
the determination of their fermentation rates and their metabolic products.  In his
working with C_. thermocellulosium he observed that fermentation rates were higher
in cultures having other bacteria in addition to C_. thermocellulosium than in pure
cultures of the organism.  According to Enebo, the slower rate in the pure culture
was due to the accumulation of reducing sugars such as glucose.  In a mixed culture
glucose is used by other microorganisms as rapidly as it is produced.

        In Table 52 (from Enebo [165]) is shown the distribution of fermentation
products by a pure culture of C. thermocellulosium and by a mixed culture containing
C. thermocellulosium, C. thermobutyricum, and B. thermolacticus.
                                     TABLE 52

                      DISTRIBUTION OF FERMENTATION PRODUCTS
                        BY HIRE AND BY MIXED CULTURES [165]
Item
Incubation time (days)
Portion of cellulose fermented ($)
Acid production (g/g of cellulose )
Ethanol
Formic acid
Acetic acid
Butyric acid
Lactic acid
Reducing substances
(as glucose)
Pure Culture
10
40.1

0.160
O.OjU
0.191
0.0
0.4J1

0.117
Mixed Culture
6
100

0.150
0.017
0.290
O.JOO
0.048

--
        Clostridium thermocellulosium.

        C. thermocellulosium, C. thermobutyricum,  and B.  thermolacticus,
        The thermophilic cellulose decomposers seem to degrade cellulose fairly
rapidly, although not quite as rapidly as do the rumen microorganisms.   Because
the former only function at elevated temperatures (55°-65°C),  systems in which
they are used are penalized economically because of the cost of maintaining the
higher temperature.  However, a compensation rests in the fact that the higher
temperatures reduce the chances of contamination by unwanted bacteria,  since the
number of thermophiles is small.
Fungi Imperfecti

        Because of its cellulose decomposing capacity,  Mycothecium  verrucaria QM 460
probably would be one of the more effective of the members of the fungi imperfect!
in the treatment of solid wastes.  Among the earlier workers who recognized its
superior cellulose decomposing potential were Siu [l6o] and Reese and Levinson [l66J.
Using loss in tensile strength of cotton duck as a measure, Reese and Levinson found
that of all the fungi tested, M. verrucaria vas the most active.  They observed that
the loss was 100 percent when M. verrucaria was used.  Although a great deal of work
has been done on the investigation of the cellulose decomposing capacity of Mycothecium,

-------
                                                                                163
most of it was done with the use of cell-free preparations of cellulase which had
been synthesized "by the organism.  In an investigation on the action of a cell-free
enzyme extract from the fungus, Saunders et_ al. [167] found that 16 percent of the
cellulose in a preparation of ground filter paper was decomposed within 5 days
(temperature at ^0°C).


APPLICATION TO SOLID WASTES

        Reports in the literature amply prove that groups of bacteria exist in
nature which can rapidly decompose cellulose under conditions that have been defined
and hence can be incorporated into practical processes, among which could be one
for waste treatment.  Such a process would yield only a minimum amount of offensive
gases (which could be easily controlled), and the amount of solid residue from the
cellulosic fractions would be quite small.  The strong possibility exists that
useful products can be obtained with the process in operation and that these could
prove important in offsetting the cost of the treatment operations.  Enough is
known about the metabolic processes of the cellulose decomposers to enable the
predicting of metabolic products under given conditions.  These products include
certain substances such as glucose and organic acids (e.g., butyric, succinic,
propionic, acetic, and formic).

        Any biological process that centers on the decomposition of cellulose to
usable and/or stable end products is especially valuable in modern waste treatment,
since as was shown in this section, cellulose constitutes such a large fraction of
the total output of refuse.  The stabilization and recovery can be done in a manner
that meets two important criteria for good waste treatment:  l) the wastes under-
going treatment do not reappear in other forms of waste (air, water, or terrestrial
pollution);and, 2) useful substances are being produced, i.e., the converted wastes
are recycled as resources.

        The fact that microbial decomposition of cellulose is a natural ecological
process, lends a good prospect of success to any technique involving the use of
microbes to recycle the carbon in wastes.  A major part of the problem of waste
disposal stems from the fact that man interferes with ecological equilibrium by
generating more wastes than can be decomposed by natural means.  Since man has and
is interfering with the equilibrium of nature, it seems logical that a powerful
means of combating the waste problem would be to attempt to restore the equilibrium.
Therefore, in the long run, a process to decompose cellulose microbially would be
highly feasible, since it would restore normal ecological succession instead of
creating an imbalance of another type, i.e., produce an environmental pollutant.

        Although much information is available about the identity and the activities
of cellulose decomposers, many questions remain unanswered; and in addition,  little
or nothing is known about the systematic use of the organisms in waste treatment.
In terms of the cellulolytic activities of the microorganisms, most of the work done
thus far has been with the use of cell-free enzyme extracts and with soluble forms
of cellulose such as carboxymethyl cellulose.  While helpful, information gained in
such studies is not sufficiently extensive for use in setting up a waste treatment
process.  High cellulolytic activity on soluble derivatives is not in general a
reliable indication of a microbe's ability to attack nonsoluble cellulose.  Therefore,
in the present study only those microorganisms which have shown a relatively high
rate of decomposing nonsoluble cellulose have been chosen for study.

        In addition to the need for additional fundamental information on the biology
of the cellulolytic microorganisms, ways must be found for applying this information,
once it has been gained, and other available information to the design of a practical
and economically feasible treatment system in which useful products can be recovered.

-------
164
OBJECTIVES OF STUDY

        The general or long-term objective  of this  phase  of the  overall  research  on
waste management is the development of a pilot plant  in which microorganisms  can  be
utilized continuously to decompose the cellulosic  fraction  of solid vastes.   To
attain this objective it will be necessary  to:   l)  determine the feasibility  of the
recovery and utilization of decomposition products; and 2)  develop methods with
which product recovery can be made an integral part of the  process in  order that  the
fermentation products can be recycled into  the economy as resources.

        The immediate and specific aims of  the research are:

    1.  Determination of the optimum range  of key  environmental  factors.

    2.  Identification and determination of the quantity  and rate of production
        of decomposition products.

    3.  Evaluation of the effect of the heterogeneity of  the nature of refuse
        and of the raicrobial population in  the refuse.

    4.  Determination of the potential utilization of the fermentation
        products.


THE INVESTIGATION

        The investigation has thus far consisted in surveying the literature  on
cellulose decomposers; in making a preliminary run to arrive at  culture  handling
procedures; and finally, in developing a methodology  for  carrying out  the principal
investigation.

        In the initial phases of the investigation a  preliminary study was made of
the isolation and maintenance of cultures of cellulose decomposers.  Cultures were
started as enrichments from soil.  The initial enrichments  demonstrated  a fairly
high degree of cellulolytic activity.  However, the activity seemed to decline after
several transfers.  The cultures also seemed to be adversely affected  by agitation.
The reasons for both of these inhibitory effects will be  sought  in future research.

        Experimental work planned for the investigation in  the immediate future
is concerned with selecting microorganisms  and determining  the type of culture
to be used.  Only those microbes capable of decomposing nonsoluble cellulose  will
be used in the study.  At the start, those  groups  considered in  the literature
as being very active cellulose decomposers  will be used,  viz., rumen bacteria,
C_. thermocellulosium and related species, and M. verrularia. As the investigation
progresses, screening studies will be made  to select  those  organisms best suited
to meet the conditions expected to be encountered  in  waste  treatment.  Two criteria
will be applied in making a selection, viz., rate  of  attack on cellulose and  the
economic value of the fermentation products.

        Pure and mixed cultures will be used.  If  a defined culture should prove
necessary, techniques and costs of the sterilization  of the paper fraction of solid
wastes will be made.  When mixed cultures are used, certain naturally  occurring or
artificially constituted mixtures will be used. Use  of mixed  cultures has *a
potentially valuable aspect.  If the noncellulolytic  species present in  the
culture are able to utilize the cellulose hydrolysis  products  (mainly  glucose and
cellubiose), they may in fact enhance the rate of  cellulose decomposition by
preventing a buildup of these products, which would otherwise  inhibit  the action
of the cellulolytic microbes.

        Assuming that no difference exists  between the fermentation rates of  mixed
and of pure cultures, several advantages and disadvantages  can be ascribed to each
mode of operation.  If a pure culture is used, the feed would have to  be sterilized
to assure maintenance of a pure culture.  The cost of sterilization would have to

-------
                                                                                165
be considered in determining the economic feasibility of the  system.   If  a mixed
culture is used sterilization would not be necessary but using  a mixed culture  opens
the possibility of the symbiants becoming the predominant organisms if any impurity
in the cellulose waste could be used as a carbon source by these organisms.   Should
this occur, cellulose fermentation might cease completely.

        The batch type of culture will be used in the initial stages  of the  research.
This type will be used in determining the optimum ranges of the environmental con-
ditions, in identifying decomposition products and ascertaining their quantities and
rates of production, in evaluating the effects of the heterogeneity of the refuse
and of the competition of other microorganisms present in the refuse  on the  rate of
decomposition, and finally in determining the extent of the potential utilization
of the fermentation products.  Environmental factors to be studied are nutrition,
cell density, aeration rate (for aerobes), temperature, and pH.

        The batch cultures will be followed by small-scale continuous cultures, each
grown in a chemostat-type apparatus.  Factors investigated in the  "batch-type"  runs
will be again studied in the experiments with the continuous  cultures. Additional
experimentation with the continuous cultivation will be concerned  with the new
variables of nutrient and cellulose feed rates as well as with methods and rates of
product removal.

        An important aspect of the experiments with continuous  cultures will be the
continuous removal of end products from the culture.  A method of  removal which ap-
pears promising is the combination of dialysis and ion-exchange techniques suggested
by Stranks Ll63J.  In Stranks'  apparatus a dialyzing sac is suspended in  the fer-
menter and an ion-exchange resin (Amberlite IRA-400) was placed inside the sac  to
take up the end products of fermentation as they passed through the dialysis membrane.
An alternate method of removal would involve the use of a molecular sieve.

        The greater part of the product analyses will be carried out  with the use
of a gas chromatograph (Aerograph 1520).  The rate of cellulose decomposition will
be measured by successive gravimetric determinations of the residual  cellulose  in
the medium.  The determination will be carried by means of a  technique developed by
Reese [l68] .  The principal problem involved in making gravimetric determinations
is the minimizing of the amount of cell material filtered together with the  cel-
lulose.  The structural characteristics of the mycelium aggravates this problem
when fungi are the microorganisms being studied.  Treatment with alkali serves  to
reduce the error somewhat, but it does not entirely eliminate it.

        When the most promising organisms have been selected  and the  environmental
and other conditions have been evaluated and determined, the  information  thus gained
will be used in the design and construction of a pilot plant  for the  continuous
fermentation of cellulose.  The design of the plant will include provisions  for pH
and temperature control, as well as the continuous removal of decomposition  products.


SUMMARY

        After the literature was reviewed two groups of strictly anaerobic bacteria
and a member of the fungi imperfect! were selected as the most  promising  of  the
microorganisms with respect to cellulose decomposition under  the conditions  to  be
met in the treatment of solid wastes.

        In preliminary experiments it was found that, though  very  active  in  their
cellulolytic activity when first isolated, cellulose exhibited a tendency to diminish
this activity upon being subjected to repeated subculturing.  Agitating the  cultures
was found to exert an inhibiting effect on the growth of organisms.

        The following program of research activity involves the conduct of the
research in three successive steps:

-------
166
    1.  With the use of batch cultures

        (a) determine the optimum levels  for the  various  key  environmental
            factors;

        (b) evaluate the effects,  adverse or otherwise, of the peculiar
            nature of refuse and the presence of  other organisms  on the
            activities of the cellulose decomposers;

        (c) develop methods for removing  the end  products.

    2.  With the use of continuous cultures, again seek information on the  items
        listed for the batch culture and  in addition, determine the effect  of
        nutrient and cellulose feed rates and methods and rates of product  removal,

    3.  Using information gained in steps 1 and 2,  design, construct, and operate
        a pilot-scale plant for the continuous fermentation of cellulose.

-------
                                     PART IV


                                    X.   SUMMARY
INTRODUCTION

        Progress is reported for the first year of a program of research entitled
"Comprehensive Studies of Solid Wastes Management."  A consideration of such
factors as the structure of modern communities; the impingement of the urban,
suburban, industrial, and agricultural sectors of the community;  the fragmentation
of jurisdictions concerned with solid wastes problems; the social and aesthetic
goals of man; attitudes of citizens and public officials in relation to economics,
resource conservation, etc.; and the realities of technology and the indestructibility
of wastes lead to the fundamental precept that solid wastes must be managed on a
community-wide basis.  Thus it is made evident that such disciplines as planning,,
engineering, public administration, law, demography, political science, public health,
geography, economics, and sociology must develop a common understanding and work in
harmony in solving the problem of solid wastes management.  To this end the research
program involves both studies of management techniques and the education of individuals
from the several participating disciplines through research participation in a co-
ordinated program.

        The problem of solid wastes management is defined both in terms of magnitude
and scope of concern.  In relation to the former it is shown that the wastes produced
by man's use of resources has grown from some 2 Ib/person/day to the order of 6  to
8 Ib/person/day.  Part of this growth results from increasing opulence of Americans
and a spendthrift attitude.  Part of it is from the growth of his scope of concern
from that of municipal refuse to include as well such fractions as agricultural
residues, animal manures, demolition debris, food processing residues, sewage sludge,
industrial wastes, and old automobiles and junk.  It is pointed out that a large
fraction, perhaps 50 percent, of this total must inevitably be consigned either  to
the land or to the ocean, unless acceptable ways are found to recycle such residues
to the basic resources of the nation.

        A chart is presented to show that there are but seven possible types of
waste disposal systems for dealing with all or with selected fractions of the
overall solid wastes.  These are:

    1.  Reduction at source — e.g., reducing the amount of material discarded
        as wastes.

    2.  Diversion at source — e.g., discharging to water or piling on land by
        the waste producer.

    3.  Disposal to land or ocean sink — e.g., sanitary land fill,  ocean
        dumping, or undersea filling.

    ^.  Change of state — e.g.,  incineration.

    5.  Direct recycling to resource — e.g., salvage.

    6.  Indirect recycling to resource — e.g., pyrolization,  chemical or
        biological oxidation,  rendering,  reprocessing, animal feeding.

    ?•  Conversion — e.g.,  composting,  digestion.
                                       16?

-------
168
NATURE OF RESEARCH PROGRAM

        To approach the problems of solid wastes  management  a research  program was
developed having the following major objectives.

    1.  To bring the competence of people in the  wide  variety of disciplines
        involved in planning,  financing,  and administering a community  into
        effective combination  with that of engineers and environmental  health
        specialists in seeking solutions to problems in solid wastes  management
        which are technically  sound, economically feasible,  and politically and
        socially acceptable.

    2.  To bring the techniques of modern operations research to bear upon the
        organizational problems of managing solid wastes on  an area-wide  or
        community-wide basis;  and on the physical and  logistic problems of
        collecting, transporting, and disposing of wastes.

    3.  To seek through experiments and other research techniques improvements
        in conventional methods of wastes disposal and the development  of new
        procedures for reclaiming or recycling fractions of  the refuse  mass.

    4.  To identify and seek answers to problems  involving man's health and
        well being that may be associated with solid wastes  and related to his
        use of land, water, and air resources.

    5.  To develop, through participation in research,  greater understanding and
        knowledge on the part  of engineers, planners,  administrators, economists,
        public health specialists, and others who are  confronted with the problem
        of solid wastes management in the course  of their professional  service to
        the modern urban-industrial-agricultural  community.

    6.  To insure, through close coordination and effective  communication with
        public and private agencies, the pertinence of research to real problems
        and the prompt availability of the results of  research to professional
        practitioners.

        Pursuant to these objectives and under a  grant from  the U. S. Public Health
Service a research group was organized.  It consisted  of University  faculty members
and graduate students, assisted by professional specialists, from the departments
of City Planning, Operations Research, Sanitary Engineering, Public  Health,
Mechanical Engineering, Forestry, Chemical Engineering, Agricultural Engineering,
Economics, and Civil Engineering.  All faculty participants  in this  group, together
with the project coordinator,  formed a coordinating board which met  biweekly with
all participants in the program to give direction and  coordination to the program
activities.

        The research plan that followed and herein reported  included two  phases.
The first, in which all participants functioned as a  single  investigative unit,
albeit with assigned individual tasks, involved Data  Collection and  Evaluation.
The specific activities of the group during Phase I included the following:

    1.  Collection and evaluation of published information on the technology and
        management of solid wastes.

    2.  Establishment of an information retrieval system.

    3.  Interviews and discussions with officials and operating personnel
        of public and private  agencies concerned  with  solid  wastes manage-
        ment in the San Francisco Bay and Los Angeles  areas.

    k.  Collection and evaluation of data on the  composition and amount of the
        various fractions which in combination constitute the overall solid
        wastes of a community.

-------
                                                                                 169
    5.  Definition and coordination of discrete areas of research to "be undertaken
        in Phase II "by the individual research teams.

        Following completion of certain aspects of Phase I, and as rapidly as proved
feasible, the research group was broken into a number of research teams for Phase II
of the program.  This phase involved Definitive Research in four major areas of
closely coordinated research and made use of nine research teams.

    1.  Operations Research

    2.  Planning and Economics

    3.  Public Health

    k.  Technology

        (a)  Incineration

        (b)  Composting

        (c)  Landfill (Public Health team)

        (d)  Salvage

        (e)  Anaerobic Digestion

        (f)  Wet Oxidation

        (g)  Biological Fractionation


RESEARCH ACTIVITIES AMD FINDINGS
Phase I

        In this aspect of the research more than 500 documents were assembled and
abstracted and incorporated in a manual (notched card) retrieval system.   A general
evaluation of those documents is reported.

        Orientation and informing of the research group was furthered by interviews
and discussions with public and private individuals responsible for managing solid
wastes in the San Francisco Bay and Los Angeles County areas of California.  Twelve
refuse disposal sites covering all degrees of landfill practice were visited and
studied.

        Specific studies of the composition and amounts of solid wastes generated in
a modern community were made.  Cooperative arrangements were made with the California
State Department of Public Health to furnish detailed data from its statewide and
Fresno city studies under PHS demonstration grants; and from the Food Machinery
Corporation which is collecting data on industrial wastes in Santa Clara County,
Calif, under a similar grant.

        The investigative team itself obtained data from a literature search,
personal interviews, case histories, and field studies in Santa Clara County and
the City of Berkeley.  From these, a general estimate of the quantity and composition
of areawide refuse was made and reported (Chapter II).  Specific estimates were also
made and reported on the basis of field studies and general information in Santa
Clara County.  In this case estimates, tabulated in the report, were made for
domestic wastes, industrial wastes, agricultural wastes, and animal manures.

        In the field study at Berkeley, municipal wastes were segregated and the
various components weighed for comparison with a similar study made at the same site

-------
170
in 1952.  From these data important conclusions  are  reported relative  to  the  change
in refuse composition with time.   (See Chapter II.)

        The final aspect of Phase I was the production  of a Regional Waste  Generation
and Evaluation Model ( see Figure 9j page 39.>  Chapter II) involving a  series  of sub-
models to which work of the various research teams could  be directed during Phase  II
in a coordinated manner and with  a common goal.


Phase II

        The research plan envisioned that within the first year  of study  Phase  I
would be completed and Phase II advanced to the  point that definitive  research
subprojects were well defined and evaluated both for pertinence  to the overall  solid
waste problem and for the prospect of positive results.   The work proceeded according
to plan and achievements exceeded the general expectation of the investigators.  As
might be expected, the data collection and evaluation aspects of Phase I  are  a  con-
tinuing aspect of research.  Likewise not all aspects of  Phase II were initiated at
the same time nor advanced at the same rate.  Specifically, such areas as operations
research and planning were involved in definitive research almost from the  beginning
of Phase I, others of the nine research teams began  work  at various appropriate stages
of the study.  All established well defined approaches  to definitive research repre-
senting necessary and coordinated aspects of the overall  waste generation model
developed in Phase I.  The report presents the nature and results of each definitive
research area during the report period (first year).


Operations Research

        The operations research team developed a mathematical model based on  the
conceptual model of Phase I and considered the ways  in  which its subsystems could
be applied in optimizing solid wastes management decisions and operating  procedures.
The work proceeded from the general concept that the broad interdisciplinary  problem
of effective management and operation of refuse  handling  systems is of the  type which
is within the traditional domain of operations research.   Details of the  mathematical
model by which to predict the wastes generated by a  community and to optimize the
collection, treatment, and disposal activities are presented in  the body  of the report.
Examples of application of such an evaluation model  are included in an appendix.


Planning and Economics

        Definitive research by the planning and  economics team proceeded  from the
general rationale that since some fraction of solid  wastes must  inevitably  remain
on the land, land-use planning for a community must  include some provision  for  that
fact.  Conversely, those responsible for the technical  and economic aspects of
wastes management must take into consideration the cultural realities  of  the  times.
Working closely with the operations research team the planning team therefore
directed attention to those aspects of wastes generation which relate  land  use  to
the nature and volume of refuse materials to be  managed.   The way in which  wastes
generated by a community derives from how many people use how much land for what
purposes was given major attention.  Using Santa Clara  County as a laboratory in
which to study wastes generation, rather than as a  case in point, four major  factors
were explored:

    1.  Location of disposal sites and definition of service areas.

    2.  Land use and employment.

    3.  Solid wastes generation.

    h.  Composition of solid wastes.

-------
                                                                                171

        A series of tables were developed which give an insight into waste genera-
tion.  Some of the data were then used for developing regression models to study
waste generation as a function of economic activity of a community.  These models
explain the variation in solid wastes generated in relation to such variables as
population, land use, employment, etc.  Of particular importance was the early
identification of the extent of detailed information which must come from the
cooperating agencies or from field studies by the research team itself in order
that the land-use model generate the inputs needed for the overall evaluation model
which is to produce an optimal plan of decisions and operations for management of
solid wastes.  Work toward generating such inputs is progressing in accord with a
sequence of objectives described in the body of the report.


Public Health

        In considering the public health aspects of solid wastes management it was
first concluded that public health concern should transcend the epidemiology of
disease in relation to wastes and include also such matters as nuisance and other
environmental constraints by which solid wastes may make human life less pleasant,
convenient, or healthy.  While experimental studies might not be directed to all
such sociological phases, meaningful inputs to the overall evaluation model call
for attention to several objectives of study.  These include:

    1.  Evaluating the true relationship between solid wastes management
        procedures and health dangers to the public.

    2.  Reviewing critically all public health regulations relating to
        solid wastes management with particular reference to the source and
        validity of any numerical values imposed.

    J.  Advising all other research teams of the known or possible health
        implications of their alternate proposals for wastes management.

    k.  Considering the components of solid wastes and the environmental
        fate of each in wastes disposal, with particular reference to the
        health and welfare of humans.

    5.  Conducting definitive research on such of the components of solid
        wastes which are judged likely to have a significant effect on human
        health or welfare.

    6.  Evaluating the occupational hazards to workers in the solid wastes
        management field.

        Work of the public health research team took two major directions:

    1.  A consideration of the health implications of the various individual
        materials occurring in refuse of all types within a community,  with
        particular reference to the fate of such materials during each method
        of disposal.

    2.  The conduct of experimental studies of those materials found to be
        released into the environment of humans by refuse management procedures
        which might be judged to have a significant potential hazard to human
        health.

        Results presented in the report concern largely the first of these two lines
of investigation.  The incineration,  composting,  and landfilling with domestic,
agricultural, industrial, and mixed wastes were analyzed with respect to their pol-
lutional effects on air,  land,  and water environments.  Such materials  as lead,
asbestos,  beryllium, and cadmium were reviewed in relation to the human contact  that
might result from solid wastes management.  In the future the public health research
team's attention will be  directed to experimental studies,  but it will  continue  to
serve as an advisory group to all other research teams proposing new technologies.

-------
172
Technology

        Studies of the technology of solid wastes management  proceeded  along  three
main lines of approach:

    1.  Improvement of existing technology - incineration,  composting,  landfill,
        and salvage.

    2,  Adaptation of existing processes to a wider spectrum  of wastes  — anaerobic
        digestion with sewage sludge.

    3.  Application of known processes to the development  of  new  technology — wet
        oxidation, biological fractionation.

        Progress is reported in relation to each of the several main  lines noted.

        Incineration — The study of incineration as a refuse  disposal project was
based on the rationale that the furnace should be managed  as  a  device for producing
useful power or steam rather than as a device for disposal of wastes.  Under  this
concept, solid wastes represent a fuel to be burned at such times and at such rates
as the product of the furnace demands, rather than  as a converter into  which  wastes
are dumped at varying rates during an eight-hour refuse collection day.  However,
to operate a furnace in such a manner, fuel must be amenable  to storage in an
acceptable condition and of relatively constant quality and uniformity.  The  incinera-
tion research team has, therefore, directed attention to preliminary  studies  of
refuse pretreatment problems such as segregation, particle-size reduction, and
drying, and to economical ways of resolving them.   The study  of these items led to
a consideration of pyrolysis as a means of pretreatment.  Accordingly,  a study  of
pyrolysis also was made.  This latter process might be expected to produce liquid
and gaseous fractions as well as a. solid combustible residue.  All are  usable as
fuels under existing technology and are capable of  being stored.   The possibility
also exists that some of the fractions, such as for example acetic acid, methanol,
and mixed solvents, might be more valuable as resource materials  than as fuel,  and
so enhance the economics of the process as well as  its conservation merits.   Con-
ceptual and pilot-plant design studies pursuant to  the concepts cited are being
pursued.

        Composting — No experimental work on composting was initiated during  the
period herein reported.  Nevertheless, it was given attention at  the  Phase I  level.
First, literature references on the subject were compiled  and incorporated in the
project's retrieval system.  The fate of various materials in refuse, particularly
biological agents of disease, was evaluated by the  public  health  team on the  basis
of reported observations.  Most important to the future of the  project  when it
entered Phase II was the study of composting plants and the use of compost in
agriculture in Germany.  This investigation was conducted  by  one  of the faculty
investigators of the project on sabbatical leave from the  University.  From this
study it is evident that the careful scientific studies of pathogen inactivation
made in Germany are applicable to U. S. conditions  and that a safe compost can  be
produced even with the inclusion of sewage sludge in the raw  material.   Agricultural
use abroad, however, is motivated by economic and other factors not characteristic
of U. S. agriculture.  Consequently, Phase II of the composting research, scheduled
to begin in the 1967-68 period, is to be based on the general rationale that  a  time
lag between production and use of compost must be envisioned.  Furthermore, it  must
be determined whether the process itself might be justified on  the basis of re-
duction and stabilization of organic matter prior to landfilling, with  a resultant
decrease in land area requirements and in "insult"  to the  land  resource. Finally,
it is noted that composting has been associated with the municipal refuse fraction
of solid wastes, or with individual special fractions, rather than with the entire
spectrum or organic wastes of a community.  Phase II will  therefore be  directed to
an exploration of:

-------
                                                                                 173
    1.  The feasibility of assembling organic fractions of the overall solid
        wastes of a community which might complement each other in the composting
        process.

    2.  The minimum parameters of a composting process suited to:

        (a)  Preparing refuse for landfill with a minimum volume and
             "insult" to the land.

        (b)  Producing compost from mixed organic wastes at a minimum cost.

        Landfill — Due to the extensive previous work on landfilling conducted by
the project investigators, and the wealth of practical experience with the method
in the U. S._, no definitive research on this aspect of refuse management was under-
taken during the period reported.  Phase I activities were concerned with the
economic, public health, and sociological problems of landfilling by the planning
and public health teams.  The model developed by the operations research team
requires consideration of the land use, transportation, and economic aspects of
landfill.  No productive results are expected to derive from specific attempts to
improve the technology of landfill, except possibly undersea filling.  Definitive
research on this aspect is considered for a future phase of the investigation.

        Salvage — Definitive research on salvage was developed around the concept
that the ideal solution to the solid wastes management problem is one which results
in the maximum reduction in the generation of wastes by way of reuse and recycling
of residues.  The reuse by industry of its own residues, which never appear in the
wastes stream that the community must manage, are not in fact a part of the manage-
ment problem.  Much of the 5 to 7 billion dollar activity of the "Salvage" industry
is therefore outside the area of immediate concern.  For purposes of study, salvage
is therefore related to the extracting of materials from the wastes stream for return
to the basic resources of the nation either with or without intermediate processing.

        During the period herein reported a search for information was directed to:

    1.  The literature.

    2.  Scientists whose background gives them an expertise with respect to
        certain components of the wastes.

    3-  Processors and salvors who deal directly with the components.

        Specific studies were made of such fractions of solid wastes as metals,
paper, glass, rubber, plastics, and rags, and principal findings are reported in
relation to source, marketing, use, economics, etc.  From the information presented
in the body of the report it is evident that the salvage material from mixed
municipal refuse is a declining practice. Moreover, simple economics is an inadequate
basis for salvage as a method of solid wastes management.  Objectives of resource
conservation, reduction in landfill areas, air pollution control and similar public
goals of refuse management must some day motivate the practice of salvage.

        Anaerobic Digestion — The well established anaerobic digestion of solids,
including household garbage, separated from municipal sewage might well be applied
to a broader spectrum of the organic wastes of a community.  An exploration of this
possibility through laboratory and pilot experiments was the objective of a definitive
research team beginning in November 1966.  While the end product of this process is
still a solid waste, it is greatly reduced in volume and, like compost,  might be
applied to agricultural land or placed in landfills with limited insult to the land
resource.   Other factors favorable to the process are that treatment plants are
already located at acceptable places in the community;  the process is one of the best
known methods of treating organic wastes;  and an underground transporation system
exists which might be made to deliver shredded organic  solid wastes during off hours.
  388-229 O - 70 - 13

-------
        Initial experiments were directed to the amount  of garbage  in  relation to
sewage sludge the system might handle.   Successful digestion with garbage  at  5 times
the amount of sewage sludge is reported with only a 14 percent  reduction in gas
production per pound of volatiles destroyed and a 7 percent reduction  in methane
production.  When acclimating of digesters preceded maximum loading, digesters fed
at 4:1 and 5:1 garbage-to-sludge ratios performed satisfactorily.

        Forthcoming experiments will involve the addition of such other  fractions  of
solid wastes as paper, animal manures,  grass clippings,  and tree trimmings.

        Wet Oxidation and Biological Fractionation — Two separate research teams
began investigative work on the fractionation of organic wastes by  chemical and
biological means.  In contrast with anaerobic digestion,  the objective of  the two
studies is to produce chemical byproducts of a liquid or gaseous nature  which are
valuable as raw industrial chemicals, plus a residue which might also  be utilized
in such applications as the production of gypsum board,  packing, etc.

        The wet oxidation is a modification of the Zimmermann process  but  involving
concentrated dispersions of solid organic wastes and temperature and pressure in the
200°C and kOO psia range, far below those used in the Zimmermann process.   Initial
experiments with wood residues have indicated that the process  is feasible.   The
pilot plant used in the initial experiments was rebuilt  during  the  period  reported
herein.  During the coming period, experiments will be initiated in which  waste
paper will be the raw material.  Successful application  of the  process to  waste
paper would in itself be a major contribution to the technology of  solid wastes
management.  However, if it does prove feasible with paper, then grass clippings,
sludges, tree trimmings, animal manures, and garbage will be incorporated  in  the
material to be processed and the experiments repeated.

        In a similar manner biological fractionation experiments are planned  for
paper and, subsequently, for mixed organic refuse.  The  research team  concerned with
this facet of the investigation completed a literature survey and has  designed
experiments for the second year of study.  In these experiments such bacteria as the
rumen bacteria, the Closteridia and mixed cultxires of cellulose fermenters, as well
as certain forms of the fungi imperfecti, will be studied in relation  to their ability
on a practical basis to produce amino acids or other valuable fractions  from  organic
wastes.


GENERAL SUMMARY OF PROGRESS

        During the first year of research the project completed Phase  I  (Data Col-
lection and Evaluation) of its objectives and began Phase II (Definitive Research)
in accord with plans.  Nine research teams in the four major areas  of  planning,
operations research, public health, and technology refined their objectives,  co-
ordinated their efforts, and engaged in definitive research on  systems essential
to the success of an Overall Wastes Generation and Evaluation Model.   By 1 June 1967
(end of first year) all had made progress — some producing experimental  data, others
in various stages of design of experiments, the details  of which are described in
the body of this report.

-------
                                      REFERENCES


 1.  Byron,  J.  H.  D.   "A multipurpose information retrieval system based on
         edge notched cards," Bioscience,  l6_:402, June  1966.

 2.  McGauhey,  P.  H.,  C. G.  Golueke,  and H.  B.  Gotaas.   Reclamation of Municipal
         Refuse by Composting, Tech.  Bull.  Wo.  9.  Berkeley:   Sanit.  Eng.  Research
         Lab.,  Univ.  of Calif.,  June  1953.

 3.  An Analysis of Refuse Collection and Sanitary Landfill Disposal,  Tech.  Bull.
         No. 8.Berkeley:Sanit.  Eng.  Research Lab.,  Univ.  of Calif.,  December 1952.

 4.  Municipal Incineration, Tech.  Bull. No. 5-  Berkeley:   Sanit. Eng.  Research Lab.,
         Univ.  of Calif., October 1951.

 5.  A Field Study of Performance of  Three Municipal Incinerators, Tech.  Bull.  No.  6.
         Berkeley:  Sanit. Eng.  Research Lab.,  Univ. of Calif.,  November 1951-

 6.  Ross,  W. E.  "Dual disposal of garbage and sewage  at Richmond, Indiana," Sew.
         & Ind. Wastes, 26:140,  January 1954.

 7.  International Research Group on  Refuse Disposal.   Information Bulletins.
         Published by Sekretariat:  Eidg.  Anstalt fur Wasserversorgung,
         Abwasserreinigung und Gewusserschutz,  Physikstrasse 5>  Zurich 7/44
         Switzerland,  1956-1964.

 8.  Wiley,  J.  S.  and G. W.  Pearce.  "A preliminary study of high rate composting,"
         Transactions, ASCE, 122:1009, October  1957-

 9.  Maier,  R.  P., E.  R. Williams,  and G.  F. Mallison.   "Composting studies, I.
         Composting municipal refuse  by the aeration bin process," Proc.  12th Ind.
         Waste Conf.,  Purdue U., Lafayette,  Ind. Eng. Bull.,42(3):590, 1958.

10.  Proceedings of the 1964 National Incinerator Conference.   Incineration  Comm.,
         Process Industries, Div. of  ASME,  New  York, 1964.

11.  Proceedings of the 1966 National Incinerator Conference.   Incineration  Comm.,
         Process Industries, Div. of  ASME,  New  York, 1966.

12.  Brown,  R.  M., ed. Political Processes in Environmental Management,  Monograph
         No. 4.  Natl. Sanit. Found., Ann Arbor, Mich.,  1966.

13-  Venezia, R. and G. Ozolins.  Interstate Air Pollution  Study.   II.   Air  Pollutant
         Emission Inventory.  USPHS Div. of Air Pollution,  R.  A. Taft  Sanit. Eng.
         Center, Cincinnati, Ohio,  May 1966.

l4.  Ingram, W. T. and H. K. Work.  Refuse Collection and Disposal Requirements for
         Contiguous Communities.  Tech.  Report  of a study sponsored by Paterson,
         Possaic,  and Clifton, N. J.  Res.  Div., NYU College of Eng., New York,
         New York, May 1961.

15•  Municipal Refuse Collection and  Disposal.   Office  for  Local Gov't.,  State  of
         New York, September 1964.

l6.  Refuse Disposal Plan for the Detroit  Region.  Detroit  Metropolitan Area Regional
         Planning Commission.  Detroit,  Michigan, January 1964.
                                         175

-------
176
IT-  In Situ Investigation of Gases Produced from Decomposing Refuse.   5th and Final
         Annual Report prepared for State of Calif.  Water Quality Board by Engineering-
         Science, Inc., Oakland,  Calif.,  November 1966.

18.  "Composition of municipal refuse and properties of  typical combined refuse"  in
         California Waste Management Study.   Report  to the State of Calif.  Dept.  of
         Public Health.Report No. 3056  (Final). Aerojet General Corp., Azusa,
         Calif., p. 11-27, August 1965.

19.  Rogus, C. A.  "Refuse quantities and characteristics" in Proc. of Nat'l.  Conf.
         on Solid Wastes Research.  APWAssoc.  Research  Found.,  p. 17,  December 1963.

20.  Nuss, G. R., A. J. Darnay, Jr., and  G.  M.  Ford. Environmental Pollution
         Control - A State-of-the-Art Review.  Final Report,  MRI Proj.  No.  2999-D.
         Midwest Research Inst.,  Kansas City, Mo., November 1966.

21.  Golueke, C. G.  "Dual disposal of garbage  and sewage sludge," Compost  Sci. 2_:8,
         February 1961.                                                        "~

22.  Kaiser, E.  General discussion of the paper "Characteristics of municipal
         refuse" (by John M. Bell) in Proc.  of  Nat'l. Conf. on Solid Wastes Research.
         APWAssoc. Research Found., p. 37,  December 1963.

23.  "Refuse quantities and characteristics" in Municipal Refuse Collection and
         Disposal.  Office for Local Government, New York State Executive Dept.,
         p. 6-10, 1961;.

24.  President's Science Advisory Committee  "Solid wastes — magnitude  of the
         problem" and "The sources of pollution" in  Restoring the Quality of Our
         Environment.  Report of the Environment Pollution Panel, President's
         Science Advisory Comm.,  pp. 10 and  1^5, respectively.  The Whitehouse,
         November 1965.

25.  Environmental Pollution, A Challenge to Science and Technology.   Report of the
         Subcommittee on Sci., Research,  and Dev. to the Comm. on Sci.  and Astronautics,
         U. S. House of Representatives,89th Congress.   Series S., U.  S. Government
         Printing Office., Washington, D. C., 1966.

26.  Bay Area Regional Planning Program Refuse  Disposal  Needs Study.   Supplemental
         Report.  Assoc. Bay Area Governmements, Berkeley, Calif., July 1965.

27.  Taiganides, E. P.  "Agricultural solid  wastes"  in Proc.  Nat'l. Conf.  on
         Solid Wastes Research, December  1963.

28.  Hart, S. A.  "Fowl fecal facts," World's Poultry Sci. Jour., 19:262,
         April 1963.

29.  Hart, S. A. and P. H. McGauhey.  "The management of wastes," Food Tech. l8_:30,
         April 1964.

30.  Moniz, F. J.  1965 County of Santa Clara Agricultural Crop Report.  County of
         Santa Clara Dept. of Agric., San Jose, Calif.,  14 March 1966.

31.  Waste Management and Control.  Report to Federal Council for Sci.  and Tech.,
         Nat'l. Acad. Sci. Nat'l. Research Council.  Publ. 1^00, 1966.

32.  200 Years of Agriculture in Santa Clara Co. 1777-1977.  Univ. of  Calif. Agric.
         Extension Service, San Jose, Calif., December 1963.

33.  Osterli, V. P., L. B. McWelly, and E. F. Darley. A Progress Report Relating
         to the Disposal of Agricultural  Wastes in the Bay Area.  Univ. of Calif.
         Agric. Extension Service and Statewide Air  Pollution Research Center,
         July 1966.

-------
                                                                                 177
34.  Young, A. et_ al_.  County Burning Surveys.  Univ. of Calif. Agric.  Extension
         Service7 Univ. of Calif., Davis, Calif., 1959-

35-  Stockmann, R. C.  Refuse Disposal Study for Sanitary Fill Co.  Wilsey, Ham,
         and Blair, 12 April 1966.

36.  Private communication from Bruce McArthur, Project Manager FMC Central Eng.
         Lab., FMC Systems Group, 15 November 1966.

37.  Standard Industrial Classification Manual.  Executive Office of the President,
         Bureau of the Budget, 1957-

38.  Solid Waste Disposal Demonstration Project.  1966 Systems Analysis Progress
         Report.  Prepared for the City of San Jose and the County of Santa Clara
         by FMC Machinery/Systems Group, Central Eng., Santa Clara, Calif.,
         15 February 1967.

39.  California Waste Management Study.  Aerojet-General Corporation, Report No.
         3056, August 1965.

40.  Bay Area Regional Planning Program Refuse Disposal Needs Study.  Association
         of Bay Area Governments,July 1965•

4l.  Lofting, E. M. and P. H. McGauhey.  Economic Evaluation of Water,  Part III,
         An Interindustry Analysis of the California Water Economy.  Berkeley:
         Sanit. Eng. Research Lab., Univ. of Calif., February 1966.

42.  Chenery, H. B. and P. G. Clark.  Interindustry Economics.  New York:  John Wiley
         and Sons, Inc., 1959-

43-  Standard Industrial Classification.  Executive Office of the President,
         Bureau of the Budget, 1957.

44.  Proceedings of the National Conference on Air Pollution.  U.S. Dept. HEW,
         Public Health Service, Div. of Air Pollution, Washington, D. C.,
         p. 120-125 and 387-389, 10-12 December 1962.

45.  Carroll, R. C.  "The relationship of cadmium in the air to cardiovascular
         disease death rates," Jour. Am. Med. Assoc., 198:177, March 1966.

46.  Gunn, S. A., T. C. Gould, and W. A. D. Anderson.  "Metals in pathology: II.
         In concerigenesis," The Bull. of Pathology, 8:68, March 1967.

47.  Kilham, L., R. J. Low, S. F. Conti, and F. D. Dallenbach.  "Intranuclear
         inclusions and neoplasms in the kidneys of wild rats," J. Nat. Cancer  Inst.,
         28:863,  November 1962.

48.  Report on the Investigation of Leaching of a Sanitary Landfill.  SWPCB Publ.
         No. 10.  State Water Pollution Control Board, Sacramento, Calif., 1954.

49.  Effect of Refuse Dump on Ground Water Quality.  SWPCB Publ. No. 24.  State
         Printing Office, Sacramento, Calif., 196!.

50.  Burchinal, J. C. and H.  A. Wilson.  Sanitary Landfill Investigation.  Progress
         Report,  Dept. of Civil Eng., Univ. of West Virginia,  July 1966.

51.  In-Situ Investigation of Movements of Gases Produced from Decomposing Refuse.
         4th Annual Report prepared for State of Calif. Water Quality Board by
         Engineering Sci., Inc.,  Arcadia,  Calif.,  November 1965.

52.  Eliasson,  R.   "Decomposition of landfills," Amer. Jour.  Public Health,  32:1029,
         September 1942.

-------
178
53-  Eliasson, R.  "Why you should avoid housing construction on refuse  landfills/'
         Eng. News Record,  138:756, 19^7.

54.  In-Situ Investigation of Movements of Gases Produced from Decomposing Refuse.
         5th and Final Report prepared for State Water Quality Board by  Engineering
         Sci., Inc.,  Arcadia, Calif.,  November 1966.

55-  First, M. W., F. J. Viles,  and S. Levin.   "Control of toxic and explosive
         hazards in buldings erected on landfills,"  Public Health Reports, 8l:4l9,
         May 1966.

56.  Black, R. J. and A. M. Barnes.  "Effect of earth cover on housefly  emergence,"
         Public Works, 89:91, February 1958.

57-  Black, R. J. and A. M. Barnes.  "Compacted cover prevents fly emergence at
         sanitary landfills, "Calif. Vector Views,  5_:2k, April 1958.

58.  Knoll, K. H.  Compost Preparation from the Hygienic Viewpoint.   Intern. Congress
         on Disposal and Utilization of Town Refuse.   Schevenlgen.   April 1959-

59-  Knoll, K. H.  The Influence of Various Composting Processes on  Non-Sporeforming
         Pathogenie~Bacteria.Intern. Research Group on Refuse Disposal.(English
         translation issued by U. S. Dept. HEW, Public Health Service.)   Information
         Bull. No. 19, p. 1, December 1963.

60.  Knoll, K. H.  "Public health and refuse disposal," Compost Sci.,  £:35, January  1961,

6l.  Strauch, D.  Requirements of Veterinary Hygiene  in the Removal  of Urban Refuse.
         Intern. Research Group on Refuse Disposal.(English translation issued by
         U. S. Dept.  HEW, Public Health Service.)  Information Bull. 20,  p. 37,
         1964.

62.  Scott, J. C.  Health Aspects of Composting with Night Soil.  WHO, Expt. Comm.
         on Envir. Sanit. 3rd Session, Geneva, July  1953-

63.  Scharff, J. W.  "Composting — The safe conversion of village refuse and night
         soil into a valuable manure," Jour. Malaya  Branch, Brit. Med. Assoc.,  |±:1,
         126, June 1940.

64.  Klopotek, A. von.  Mold Fungi and Refuse.  Intern. Research Group on Refuse
         Disposal.  (English translation issued by U. S. Dept. HEW,  Public Health
         Service.)  Information Bull. 19, p. 11, 1963.

65.  Wiley, John.  PHS, private communication, 9 August 1965.

66.  Gerretsen, F. C.  On the Content and Value of Trace Elements in Urban Refuse
         Compost.  Intern. Research Group on Refuse  Disposal.(English  translation
         issued by U- S. Dept. HEW, Public Health Service.)  Information Bull.  6,
         p. 1, 1959-

67.  Sliepcevlch, D. P. E.  "The effect of work conditions upon the  health of
         uniformed sanitation men of New York City."  Doctoral Dissertation
         presented to the Faculty of Springfield College.  Doctoral  Dissertation
         Series, Publ. No. 20,008.  University Microfilms, Inc., Ann Arbor,
         Michigan, 1955.

68.  German Patent, DAS 1 173 851.  Aufbereitung von Hausmu'll, 1964.

69.  German Patent, DAS 1 178 022.  Verfahren zum Trennen der Bestandteile eines
         Mischgutes, z.B. Mull.

70.  German Patent, DAS 1 178 38l.  Mullsortierung.

-------
                                                                                 179
71.  Herrmann, W.  Ueberblick uber die Aufbereitungsverfahren fiir Siedlungsabfalle.
         AkA Denkschrift, 1954.

72.  Nelson, W. G.  "Waste wood utilization by the Badger Stafford Process/'
         Ind. and Eng. Chem., 22:: 312, April 1930.

73.  Wise, L. E.  Wood Chemistry.  New York:  Reinhold Publ. Corp., 1952.

74.  Golueke, C. G.  Investigations of Manure Composting at San Quentin.  Unpublished
         Report.  Berkeley:  Sanit. Eng. Research Lab., Univ. of Calif., June 1954.

75-  Merier, W. A.  Composting Fruit and Vegetable Wastes.  Part I.  Investigation
         of Composting as a Means for Disposal of Fruit Wastes Solids.  Progress
         Report by Nat'l. Canners' Assoc. Research Found., Berkeley, Calif., May 1962.

76.  Hart, S, A.  Organics Utilization in German Agriculture:  Philosophy and Science.
         Report to USPHS, Office of Solid Wastes, 1st Interim Report, September 1966.

77•  Hart, S. A.  Solid Waste Management:  Private and Governmental Activity in
         Organics Utilization in Germany.Report to USPHS, Office of Solid Wastes,
         2nd Interim Report, January 1967.

78.  Sexton, C. C.  Interviewed on Ik March 1967 on the subject of the salvage of
         cans at Los Angeles.  Mr. Sexton is President-Manager of the Los Angeles
         By-Products Co., Los Angeles, Calif.

79-  Seiden, M.  Interviewed on 13 March 1967 on the subject of the salvage of
         abandoned automobiles.  Luria Brothers Corp., Los Angeles, Calif.

80.  Learner, P.  Private communication — Interview on 23 February 19&7-  Mr. Learner
         is President of the Learner Co., Oakland, Calif.

8l.  Russell, W. M.  "Advantages to the community of a progressive secondary material
         collection program," paper presented before the Technical Association of the
         Pulp and Paper Industry, New York, New York, 1966.

82.  Paper Stock Institute of America (Commodity Division of National Assoc. of
         Secondary Materials Industries., Inc.).  Paper Stock Standards and
         Practices.  Circular PS-66, Association Headquarters, 330 Madison Ave.,
         New York, New York, 1 January 1966.

83.  Streaker, W.  Private communication — Interview on 7 April 1967.  Mr. Streaker
         is Tech. Sup't. at Fibreboard's Stockton, Calif., boxboard plant.

84.  Wagner, H. B.  "Compressive strength of polymer-modified hydraulic cements,"
         Ind. and Eng. Chem.,5:l49,  February 1966.

85.  Babbitt, H. E.  "Disposal of garbage with sewage sludge," Sewage Works J.,
         6_:1103, December 1934.

86.  Hazeltine, T. R.  "Addition of garbage to sewage," Water and Sewage Works  J.,
         86:4, R151, January 1951.

87.  Taylor, H.  "Garbage grinding at Goshen," Eng.  News-Record,  127:441,  194l.

88.  Ross,  W. E.  "Dual disposal of garbage and sewage at Richmond,  Indiana,"
         Sewage and Ind. Wastes,  26:l4o, February 1954.

89.  Babbitt, H. E.   "The dosing of sewage tanks with ground garbage,"  Sewage
         Works J.,7;l6, January 1936.

90.  Keefer, C. E. and Herman Kratz.   "The quantity  of garbage that  can be digested
         with sewage sludge," Sewage Works J.,  6:250,  March 1934.

-------
 180
 91•   Bloodgood,  D.  "Digestion of garbage with sewage sludge,"  Sewage Works J.,  8:3,
          January 1936.                                                           ~

 92.   Carpenter,  Lewis,  Albert C. Rogel and Bernard Grabois.   "The disposal of
          garbage," Sewarage Works J.,  J:?28,  July 1936.

 93-   Cohn, Morris M.  "Effect of food wastes  on sewers and sewage treatment,"
          Sewage  Works J.,  l8_:477, May 1946.

 9k,   Ross, W. E. and S. F. Tolman.  "Garbage  grinding pays its  way," Public Works,
          p. 70,  May 1953.

 95-   Simpson, R. W.  "Effect of ground garbage on sewers and sewage treatment,"
          Wastes  Eng., £2:33, January 1952.

 96.   Wylie, G. F.  "A year's experience in digestion of sewage  and garbage solids,"
          Sewage  Works J.,  1£:760, August 1940.

 97-   Standard Methods for  the Examination of  Water and Waste Water.  12th ed.,
          Amer. Public Health Assn.,  American  Water Works Assn., Water Pollution
          Control Federation, New York, 1965.

 98.   Chat field.,  C. and G.  Adams.  Proximate Composition of American Food Materials.
          U. S. Dept. of Agric. Circular No. 549,  Washington, B.C., June 1940.

 99.   Bloodgood,  D. E.  "Sludge digestion," Water and Sewage  Works, 104:38,
          January 19^7-

100.   Griffiths,  J.  The Practice of Sludge Digestion.  Waste Treatment.  New York:
          Pergamon Press, 1960.

101.   Straub, C.  P.  "Digestion studies on pure vegetables,"  Sewage Works J., 15:658,
          July 1943.

102.   Coulter, R. G.  "Environment for anaerobic destruction of  organic material,"
          Public  Works,  5_:78> January 1953.

103.   Garber, W.  F.  "Plant-scale studies of thermophilic digestion at Los Angeles,"
          Sewage  and Ind. Wastes, 2(5:1202, October 1954.

104.   Rudolfs, W. and L. R. Setter.  "High and low temperature digestion experiments.
          III.  Effect of certain organic wastes," Sewage Works  J., £:549, June 1937-

105.   Zimmermann, F. J.  "New waste disposal process," Chem. Eng., 65_(17):117-22,  1958.

106.   Zimmermann, F. J.   "Wet air combustion," Ind. Water Wastes, 6_:102-6, April  1961.

107.   Teletzke, G. H.  "Wet air oxidation," Chem.  Eng. Progr., 60:33-8, January 1964.

108.   Strehlenert, R. W.  "Recovery of wood products in the sulfite waste," Svensk
          Kern. Tidskr.,  £2:78-87, 1913.

109.   Strehlenert, R. W.  Separating Organic and Inorganic Constituents of Waste
          Sulfite Liquor.  United States Patent 1,149,420, 10 August 1915.

110.   Strehlenert, R. W.  Decomposing Sulfite  Waste to Extract Organic and Inorganic
          Materials.  Norwegian Patents 28,641 and 28,655, H March 1918.

111.   Strehlenert, R. W.  Decomposing Sulfite  Cellulose Waste Lye.  Swedish Patent
          43,860, 3 April 1918";

112.   Strehlenert, R. W.  Treating Waste Liquor from Sulfite Cellulose Factories.
          Canadian Patent 190,864, 10 June 1919.

-------
                                                                                  181
113.  Strehlenert, R. W.  Production of Valuable Organic Substances from Sulfite
          Waste Liquor.  Canadian Patent 191,432, 8 July 1919-

114.  Strehlenert, R. W.  Recovering Values from Waste Sulfite Liquor.  United
          States Patents 1,384,219, 12 July 1921, and 1,361,506, 7 December 1921.

115.  Strehlenert, R. W.  "Sulfite coal/' Pulp Paper Mag. Can., 16:671, 1918.

Il6.  Strehlenert, R. W.  "Production of sulfite carbon at the Creaaker Cellulose
          Factory in Norway," Svensk Papperstid., 2_2;136, 1919-

117.  Henglein, F. A. and F. W. Stauf.  (To I. G. Farbenind, A.-G.)  Purification
          of Metal Salt Solutions.  German Patent 500,813, 22 July 1927.

118.  Bergstrom, H. 0. V. and K. N. Cederquist.  Treating Cellulose Waste Lyes .
          Swedish Patent 90,896, 23 November 1937-

119.  Cederquist, K. N.  "Wet combustion," Svensk Papperstid., 5_8_: 154-64, May 1955-

120.  Cederquist, K. N.  "Some remarks on wet combustion of cellulosic waste liquors,"
          Svensk Papperstid., 6l: 38-46, February 1958.

121.  Cederquist, K. N. (To Stora Kopparbergs Bergslags Aktiebolag)  Recovery of the
          Heat Content of the Organic Substances in Sulfite Waste Liquor.  Swedish
          Patent 143,765, 19 January 195*4-.

122.  Cederquist, K. N.  (To Stora Kopparbergs Bergslags Aktiebolag)  Removal of
          Dissolved or Dispersed Organic Material from Aqueous Solutions and
          Suspensions'!  United States Patent 2,773,026, 4 December 1956.

123.  Cederquist, K. N.  (To Stora Kopparbergs Bergslags Aktiebolag)  Wet Combustion
          of Water-Soluble Materials in Waste Liquors .  Swedish Patent 172,223,
          26 July I960.

124.  Cederquist, K. N.  (To Stora Kopparbergs Bergslags Aktiebolag)  Enriching
          Lignocellulosic Materials .  United States Patent 2,668,099, 2 February 1954.

125.  Cederquist, K. N.  (To Stora Kopparbergs Bergslags Aktiebolag)  Continuous
          Method of Burning Highly Hydrous Organic Materials.  United States Patent
          2,949,010, 16 August I960.

126.  Salveson, J. R., D. L. Brink, D. G. Diddams, and P. Owzarski .  (To Salvo
          Chemical Corp.)  Process for Making Vanillin.  United States Patent
          2,434,626, 13 January 1948.

127.  Schoeffel, E. W.  (To Salvo Chemical Corp.)  Vanillin from Sulfite Waste
          Liquor.  United States Patent 2,598,311, 27 May 1952.

128.  Zimmermann, F. J. (To Sterling Drug Inc.)  Destructive Oxidation of Organic
          Matter in Waste Water Disposal.  United States Patent 2,665,249,
          5 January 1954.

129.  Zimmermann, F. J. (To Sterling Drug Inc.)  Self -Sustaining Plameless Oxidation
          of Combustible Liquid Wastes.  United States Patent 2,824,058, 8 February
             ~
130.  Earle, J. S., E. W. Schoeffel, and F. J. Zimmermann.  (To Sterling Drug Inc.)
          Pressure Oxidation of Sewage Sludge.  Belgian Patent 667,038, l6 November
          196T

131.  Krysinskii, B. V. and E. V. Gorchakova.  Purification of Waste Waters .
          Russian Patent 101,199, 30 November 1955.

-------
182
132.  Schmalenbach, A., A. Karl,  and M. Schulz.  (To H.  Koppers G. m. b. H. and
          W. J. Boulin)  Purification of Waste Water.  German Patent 1,051,210,
          19 February 1959.

133-  "How Hammermill solved its  effluent problem," Pulp Paper, 30:98-99, May 1956.

134.  Jackson, D. T. and R. W. Brown.  "Oxidation of spent semichemical pulping
          liquors," Pulp Paper, 3£:69-72, February 1958.

135-  Brown, R. W., D. T. Jackson, and J. C. Tongren.  "Semi-chemical recovery,"
          Pulp Paper, 32=66-69, June 1959.

136.  Zimmermann, F. J. and D. G. Diddams.  "The Zimmermann process and its applica-
          tions in the pulp and paper industry," TAPPI,  43.:710-15, August 1960.

137-  Hanssen, L. J.  "Wet combustion of spent liquor from pulp manufacture,"
          Norsk Skogind., 8:454-65, December 1954.

138.  Brunes, B., J. Torsten, and S. E. Jonsson.  "What may become of wet combustion,"
          Svensk Papperstid., 58_:332-45, September 1955.

139-  Blikstad, F.  "Zimmermann process for the chemical pulp industry," Norsk
          Skogind., 10:172-80, May 1956.

140.  Ishii, R., H. Ito, and A. Honda.  "Sludge and industrial waste disposal by wet
          air combustion," Hakko Kogaku Zasshi, 4£: 62-69, February 1964.

l4l.  Lohmann, U. and A. Tilly.  "Wet combustion," Chem. Ing. Tech., 37_:913-l6,
          September 1965.

142.  Schoeffel, E. W. and N. Seegert.  "Wet air oxidation procedure and its
          utilization for industrial waste removal," Wasser Luft Betrieb., 10:541-45,
          August 1966.

143.  Hurwitz, E., G. H. Teletzke, and W. B. Gitchel.  "Wet air oxidation of sewage
          sludge," Water Sewage Works, 11£:298-305, August 1965.

144.  "Sludge disposal by wet oxidation," Wastes Eng.,30:25,44, January 1959-

145.  Twenty-Third Progress Report of the Committee on Sanitary Engineering Research
          of the Sanitary Engineering Division.  "Sludge treatment and disposal by
          the Zimmermann process," J. Sanit. Eng. Div. Am. Soc. Civil Eng., 8_5_(SA4):
          13-23, July 1959-

146.  Hurwitz, E. and W. A. Dundas,   "Wet oxidation of sewage sludge," J. Water
          Pollution Control Federation, 32:918-29, September 1960.

147.  Price, F. C.  "Process consumes sludge by flameless combustion," Chem. Eng.,
          6j_(24):80-2, 1960.

148.  McKinley, J. G.  "Wet air oxidation process," Water Works Wastes Eng., 2_:97-99,
          September 1965.

l49.  "Wet sludge burner now made for small cities," Eng. News-Record, l6_7_(22 ):40-4l,
          1961.

150.  Harding, J. C. and G. E. Griffin.  "Sludge disposal by wet air oxidation at a
          five MGD plant," J. Water Pollution Control Federation, 37:1134-41, August
          1965.

151.  Grangaard, D. H. and G. H. Saunders.  (To Kimberly-Clark Corp.)  Cellulosic
          Product.  Canadian Patent 6ll,503, 27 December 1960.

-------
                                                                                 183
152.  Grangaard,  D. H.   (To Kimberly-Clark Corp.)  Production of Organic Acids.
          Canadian Patent 6ll,507>  27 December 1960.

153.  Grangaard,  D. H.   "Decomposition of lignin. II.  Oxidation with gaseous  oxygen
          under alkaline conditions/' paper presented  to the Division of Cellulose,
          Wood, and Fiber Chemistry at the l44th Meeting of the American Chemical
          Society, 4 April 1963.

154.  Merriman, M. M.  "The reaction of oxygen and wood in buffered systems," M.S.
          Thesis, Univ. of Calif.,  Berkeley, January 1966.

155.  Merriman, M. M.,  H. Choulett, and D. L. Brink.   "Oxidative degradation  of
          wood.  I.  Analysis of products of oxygen oxidation by gas chromatography,"
          TAPPI,  4_9:34-39, January 1966.

156.  Brink, D. L., J.  G. Bicho, and M. M. Merriman.   "Oxidative degradation  of
          wood.  III.  A comparison of products by alkaline nitrobenzene,  molecular
          oxygen, and nitric acid oxidations," In Advances in Chemistry Series,
          No. 59, R. F. Gould, ed., Lignin Structure and Reactions,  Washington,  D.  C.,
          American Chemical Society, Ch. 13, p. 177-204, 1966.

157.  Bicho, J. G.  "Products of alkaline nitrobenzene oxidation by a methylation-
          gas chromatographic technique," M.S. Thesis, Univ. of Calif.,  Berkeley,
          June 1966.

158.  Bicho, J. G., E.  Zavarin, and D. L. Brink.  "Oxidative degradation of wood.
          II.  Products of alkaline nitrobenzene oxidation by a methylation-gas
          chromatographic technique," TAPPI, 4_£: 218-26, May 1966.

159.  Brink, D. L.  "A versatile laboratory system for studying pulping reactions,"
          paper presented before 20th Alk. Pulp. Conf., Richmond, Va., 14  September
          1966.

l6o.  Siu, S. G.  H.  Mierobial Decomposition of Cellulose.  New York:  Reinhold,
          1951.

l6l.  Gascoigne,  J. A.  and M. M. Gascoigne.  Biological Degradation of Cellulose.
          London:  Butterworths, 1960.

162.  Halliwell,  G.  "Cellulolysis by rumen micro-organisms," J. Gen. Microbiol.,
          17:153, February 1957.

163.  Stranks, D. W.  "Mierobial utilization of cellulose and wood," Can.  J.
          Microbiol., £:56, January 1956.

1.6k.  Quinn, L. Y.  "Continuous culture of rumen microorganisms in chemically
          defined medium," Appl. Microbiol., 10:580, November 1962.

165.  Enebo, L.  Studies in Cellulose Decompostion by  an Anaerobic Thermophilic
          Bacterium and Two Associated Non-Cellulolytic Species.  Stockholm,  1954.

166.  Reese, E. T. and H. S. Levinson.  "A comparative study of the  breakdown of
          cellulose by microorganisms," Physiol. Plant., 5.;345, 1952.

167.  Saunders, P. R.,  R. G.-H. Siu, and R. N. Genest.  "A cellulolytic  enzyme
          preparation from Mycotheeium verrucaria," J. Biol. Chem.,  174:697,  1948.

168.  Reese, E. T.  "On the effect of aeration and nutrition on cellulose  decomposi-
          tion by certain bacteria," J. Bacteriol., 53:389,  May 1947.

-------

-------
                                    APPENDIX A

               APPLICATION OF THE EVALUATION MODEL TO SPECIAL CASES


          To illustrate the broad application of the regional model, three examples
of optimization studies of management systems are simply outlined [391•

Expanded Existing System (Transfer Station)

          This is a specialization of the general regional model where the final
disposal sites are fixed and it is desired to test the feasibility of adding trans-
fer stations to aid in the collection operation.

Development System (Treatment Plant)

          Here the final disposal site-location is fixed and the possibility of
using solid-to-liquid treatment plants to reduce overall collection costs is con-
sidered.  If this conversion plant is stationary the familiar location-allocation
problem is similar to the Expanded Existing System.  An alternative idea is to have
mobile treatment plants.  These would take the form of a mobile grinding truck
capable of towing a special pickup lift truck.  The operator would set up over
a centrally located solid waste pickup point where the solid waste would be fluidized
and dumped into the sewer system.  There seems to be many interesting problems here.
Possibly our regional model could be used if plants located at each pickup point are
considered.  Obviously, in this case the need is to investigate secondary problems
similar to the traveling salesman to ascertain equivalent stationary plant costs.

Advanced System (Disposal Site)

          In this future system it is assumed that technology has advanced to the
extent that there exists some sort of automatic household collection device which
operates as follows.  The homeowner deposits solid waste into a wall inlet which is
collected in a container beneath or beside the home.  An underground conveyor belt
transports the waste out to and under the street and deposits it on a central under-
ground belt running beneath the center of the street.  A street conveyor transports
the waste to the nearest predetermined intersection or collection point and dumps
it into an underground container.  This underground container would be emptied
periodically by rubbish collection devices such as road or rail vehicles integrated
with the rapid transit system.  Most of the solid refuse would be transported to
automated gaseous-, liquid-, and solid-processing and separating plants where little
residue remains after processing.  The problem would be to find the optimal location-
allocation and size of the final disposal sites given the collection or pickup points.
This is just another specialization of the model.
                                        185

-------
                                   APPENDIX B

                   DESIGN OF TRANSFER STATION CHARACTERISTICS
Introduction

          Initially a single-period static model of transfer plant operation is
examined.  The refuse input profile may be taken as either stationary throughout
the period (year) or vary seasonally.  A one-period cost function is defined over
a decision vector representing the transfer station operational characteristics for
a fixed location.  This function is to be minimized over a vector of design variables
subject to city planning and budget constraints.  The optimal expansion of the
transfer station over time, is then considered as a stochastic multiperiod sequential
decision problem reflecting refuse growth and economic predictions.

Single-Period Static Model

          General Description:  In this section the operation of a transfer station
is formulated where its location-allocation and associated operational costs for
a single period are given.  The classifications and various combinations of transfer
station components are extremely numerous.  The following three main components,
however, seem to persist throughout all transfer station configurations.

     (i)  Waste collection trucks which comprise the input or arrival stream
          considered to emanate from an infinite reservoir.

    (ii)  Haul trucks which form a second arrival stream from a finite
          reservoir ("the fleet of haul trucks).

   (iii)  Transfer channels of various types, quantities, and service
          characteristics.

          The characteristics suggest the formulation of a transfer  station as
a queuing system.  Before embarking on a detailed description of this formulation
we make the distinction between two types of transfer stations—direct and indirect.

          Direct Transfer Station;  The basic attribute of a direct  transfer station
is the operation of transferring refuse from one or more collection  trucks directly
into a haul truck.  (Assume capacity of a haul truck = capacity of a collection
truck.)  As shown in Figure 32 when the disposal operation is considered along with
the transfer station operation we obtain a cyclic queuing situation  with a fixed
number of hauling trucks which possibly develop queues in front of each of two types
of service channels.  A waiting line of collection trucks may also evolve in front
of the collection-haul truck type of channel.

          Indirect Transfer Station:  An indirect transfer station is a facility
at which two types of transfer operations are performed on a "parcel" of refuse
before it is carried to the disposal area by a hauling truck.  The first type of
transfer, designated as a collection-storage type,  occurs between the incoming
collection truck and the refuse storage lot.  Parcels of refuse are  then transferred
from the storage lot to a hauling truck in a second type of operation.   Again when
the disposal operation is considered we obtain a cyclic queuing situation, but with
an additional service channel placed in series with the incoming stream of refuse
(cf.  Figure 33)'  An important quantity in this system is the queue  length (or
inventory) at the storage lot and possibly its waiting time.

          State Space:   Define the expanded state space of an indirect transfer
station as the three-dimensional space of vectors n representing the numbers of
items at each of the three service channels.
                                       186

-------
                                                                     18T
    LEGEND
•   COLLECTION  TRUCK
•   HAUL  TRUCK
 O   PARCEL  QUANTITY
     OF REFUSE
  COLLECTION TRUCK  STREAM
                                  r
                                ~i
 I
 I
                                          HAULING  TRUCK  CYCLE
 I TRANSFER
 | CHANNEL

-\	
                                                             TRANSFER  TO
                                                             DISPOSAL  AREA
  FIGURE 32.  DIRECT  TRANSFER  STATION  AND  DISPOSAL  STATION
                                        HAULING TRUCK  CYCLE


nn
	 KJLJ
COLLECTION
TRUCK
STREAM
TRANSFER
CHANNEL

1


STORAGE
LOT
INVENTORY
1
1

TRANSFER
CHANNEL
                                                              o
                                                            TRANSFER  TO
                                                            DISPOSAL AREA
FIGURE  33.  INDIRECT  TRANSFER  STATION   AND  DISPOSAL  STATION

-------
188
          Let n = (n , TL, n )
                    <~   11   to
where: n  = the number of collection trucks present at the collection-storage channel;
n,  = the number of haul trucks present at the storage-haul channel; and n  = the
quantity or number of parcels of refuse in the refuse storage lot or being loaded
into haul trucks.

          If K,  is assumed to represent the number of haul trucks in the fleet, then
K,  - n,  indicates the number of haul trucks in the final disposal system.  We may also
define queue limits of K , K, , K  as the maximum number of units in the respective
channel subsystems indicated by the subscripts.  These values reflect the limitations
on transfer facility capacity in terms of storage area, parking lot size, and hauling
truck fleet; thus they represent important design characteristics.

          For the direct transfer station we reduce the vector n to a two-dimensional
vector by setting n  and K  to zero and redefining n  as the number of collection
trucks present at a collection-haul type channel.  A further delineation is required
to adequately describe the state space.  It is assumed that the random variables
representing the elements of the random state vector only take on non-negative integer
values divisable by some common factor ("parcel").  This, of course, implies an
expansion of the number of elements in the domain of n as the degree of refinement
is increased.

          Number and Types of Transfer Channels:  The number of transfer channels of
a particular type represents the maximum possible number of simultaneous refuse opera-
tions of that type.  The following types of transfer channels are defined.

     (i)  Collection-Haul Channel (ch) -- A service facility in which the
          operation of transferring refuse from a collection truck(s) directly
          to a haul truck takes place.

    (ii)  Collection-Storage Channel (cs) — A transfer channel in which refuse
          is removed from a collection truck to the storage lot.

   (iii)  Storage-Haul Channel (sh) — A transfer channel in which refuse from
          the storage lot is loaded into a haul truck.

    (iv)  Haul-Disposal Channel (hd) — The channel in which refuse from the
          haul truck is unloaded into the final disposal area.

          Let M ,  represent the number of channels of type (ab).  The upper bound on
the number of transfer channels of a particular type should be consistent with the
systems capacity limits, i.e.,

                                 M ,  - min

                                 M   S K
                                  cs    c
          The range of variation of the M , 's from between zero and their respective
upper bounds, represents the design domain for these operational characteristics.

          Arrival Characteristics:  Most likely in a realistic situation the inter-
arrival time distributions of collection trucks will be non-stationary, i.e., will
reflect seasonal variations.  One possible approximation is to let the distribution
of arrivals be non-homogeneous Poisson distribution allowing the arrival rate A  (t)
to vary over time according to the time of day or year.  Additionally, one may consider
the quantity of refuse carried by the i"kh collection truck to be independent random
variables with a common distribution defined over some finite probability space.

-------
                                                                                   189


Thus,  a  compound  Poisson distribution may  be used  to  represent  the  total  amount  of
refuse arrivinh at the transfer  station over some  time interval.  The  accuracy of
this assumption,  however,  should be tested empirically.

          Service Characteristics:  The term service  characteristics denotes  the
service  time distributions  for the respective  channels and queue  disciplines.

     (i)  Queue Discipline:  Assume a "first in  first out" queue  discipline
          for all types of channels, although  in some cases the storage-
          haul truck transfer channel may  have a "last in first out" discipline.
          Since trucks may be carrying different loads, and therefore  may have
          different service times, initially a simplifying assumption  is  made.
          This assumption  is that the queue discipline takes no account of
          the difference between different truck load classes so  that  we  may
          now take the service times to be pooled  distributions by  using  the
          appropriate proportions.

     (ii)  Zero Service Time:  If the time  of transfer of refuse from the  col-
          lection truck(s)  to the haul trucks may  be  considered negligible
          the problem for  a direct transfer station is extremely  simplified.
          The state space  at this channel  may then be reduced to  a  single
          dimension where  either haul trucks or  collection trucks are
          queuing, but not  both.  (This is accomplished by defining the
          state space as having  positive as well as negative integers.)
          In the  indirect  transfer station case  the collection trucks  never
          queue while the  refuse level and haul  trucks may form non-
          simultaneous queues.   The disposal area  channels for both direct
          and indirect cases will represent total  haul truck round  trip time
          if the  unloading  service time is considered negligible.

    (iii)  Service Time As A Won  Negative Random  Variable:  A simplifying
          assumption until  further data is received is to let all channels
          except  the haul-disposal have exponential service time  distributions.
          The total service time of a haul truck is equal to its round trip
          time plus some unloading time at the disposal area.  This service
          time would most likely be some finite  time  with a random  error  term
          superimposed on  it.  This type of service could be represented  by
          an equivalent infinite channel system  with  common general distribu-
          tion (to allow passing of haul trucks).

          System  Interruptions;  For continuous  (2k hours per day)  operation it  may
be  appropriate to use steady state results to represent the systems operational
characteristics for the period (one year)  providing "convergence" is reached in  a
relatively short  time compared to the diration of  the period.

          For conventional  intermittent (8 hours on and 16 hours off per  day) opera-
tion, a steady state condition may never be reached.  One must then examine the
transient behavior of the system in order  to ascertain equivalent long term state
operational characteristics.  Of particular importance here is the  expected number of
collection trucks turned away, during the  "on time" of the system,  due to queue  limits.

          For the direct transfer station, the probability distribution of the number
of  collection trucks in the system at the  time of  shutdown is of interest; these
correspond to unserviced customers.   Of equal importance is the number of hauling
trucks  not at the channel at the time of shutdown, and the total expected time until
all return representing overtime costs.   The initial  conditions at  the start of  each
on time interval are considered to be identical  for each cycle.  That is, the system
is assumed to start each new cycle with zero,  (or  some finite probability distribution)
collection trucks queuing at the collection-haul channels.  The total fleet of K, haul
trucks  will also be waiting at these channel entrances.

          The situation is not so simple in the  case  of the indirect transfer station.
In addition to the operational features  described  for the direct transfer station we
are concerned with the initial and terminal "on period" (8 hr) inventory  level in the
   388-229 O - 70 - 14

-------
190
storage area.  The terminal waste storage level will depend on the terminal situation
of the previous day.  This markov property allows one to obtain a steady state solu-
tion  (assuming one exists) for the storage lot level once the single-step transition
probabilities are determined.

Optimization of Single-Period Transfer Station Design

          Let the one-period (annual) cost function of a transfer station in terms of
its design factors given arrival, service, and cost parameters be denoted by C(D,V,P).
The design vector D of a transfer station specifies various channel quantities, and
queue-limit capacities, and is represented as:

                          D = (Mch, Mcs, Msh, Kc, Ks, Kh).


Assume that Mhd, the number of disposal area channels, is given.  Also, for a direct
transfer station Ks, MCS, and Mg^ are all set to zero.  V is the vector of deprecia-
tion, operating, and penalty cost coefficients for the period (one year).  We may
define V as being composed of six cost elements, i.e.,

                           V = (V!, V2, V3, V4, V5)

where

     Vi = the annual depreciation cost coefficient of the transfer station
          facility including the hauling truck fleet.  This set of cost
          coefficients is some function of the design vector D and the actual
          location of the transfer station.

     ₯2 = Annual operating cost coefficient.  This cost is a function of the
          design vector D and the level of activity in say dollars per ton
          of refuse transferred.a

     V3 = Penalty cost coefficient of unit overflow of collection trucks.
          This cost is the difference between collection trucks serviced
          through a transfer channel and direct routing to the disposal area.

     V* = Penalty cost coefficient of collection trucks not serviced at the
          end of the operating phase (for intermittent operation only).

     Vs = Overtime operational penalty cost coefficient for haul trucks
          (for intermittent operation only).

The vector P represents the set of elements defining the arrival and service patterns
(based on a given location-allocation).

          The objective is to minimize the cost function over D, the set of admissible
designs D.  This set may be determined by budget limitations, present available land
at the given location, and/or other city planning constraints.  The optimal one-period
operational design characteristics of the transfer station is designated as D* and is
obtained when the cost function is minimized.  Thus

                              min C(D,V,P) = C(D*,V,P)

                              DeD

This minimization problem is most likely nonlinear and involves integer variables,
and additional research will be needed to develop solution techniques.
 This cost may be based on intermittent operation or continuous operation.

-------
                                                                                 191
Optimal Expansion Plan of a Transfer Station over N Periods (Dynamic Model)

          One immediately recognizes that the optimal transfer station design for
the static model need not remain optimal once the predicted growth of solid waste
generation and its impact on collection truck activity is considered.  Consequently,
one should examine the optimal design criteria over the future use of the station.
The decision variables now become the design characteristics of the transfer station
at each period.  For an W-period model the sequence of decision vectors (D*, D* ... D*)
denotes the optimal N-period expansion plan for the transfer station given the refuse
and cost profiles over the horizon.  It may be possible to use dynamic programming
to find the optimal expansion plan if the dimension of D is small.

Conclusion

          As may be seen from the general formulation of a transfer station, an
abundance of interesting queuing situations are suggested.  Unfortunately, not all
of these situations are amenable to direct analysis, and it is presumed that for
those situations that are not, either gross approximations must be made or simulation
attempted.  There are configurations, however, that do seem attractive for operations
research investigations.  These investigations appear in such areas as semi-markov
chains, nonlinear mathematical programming, dynamic programming, and queuing theory.
Moreover, analogous studies and research may be conducted for the optimal design of
waste treatment plants.

-------
APPENDIX C












QJ

T_|
d
03














-p
d
OJ

&
0
1 — 1
H






w
o
O -H
•H O -P
fi -H ra
ft a -H
Cd O M
fn d 0)
M 0 -P
O O 0
a w 03
0) M
P 08 03
.d
o


H
ra
o
Definition of Disp
Service Area

08

g
o
o
uo
d
•H
fn
p
-P
O
cd
P
§
S

1
•H
<^
w
0)
o
•H
0)
ra
o
o
i

o

"
 ^"^ ?H ra -H a H
H CM o O -p P cd
H — ' H — — ft'—" d ra o
03 cd w w p " — ' i
wed racd |>j'Ha3 do i
OCU O 0) -Ppd) OO 0) '-N
ftfn ftfn dfn-H -Pra
•H -H O O 0) O -P O
Pd) RD Oil K ra-H
  cdOt> cdo cdPn
-p -p -P M -p -P -P M -P M £H -P ^ -P
•H -H O 0) -H -H O a> O O 0) O O O 'H
rara Hra wra Enra EH — ra EH — EH o
    192

-------
                                                                                                   193
•d


I
•H
•P

O
O
CO
-p
EJ
O
O
Solid Wastes
Supervision
& Management
(Public Exp. )
H

-------
                    APPENDIX D


          Solid Wastes Management Project

Economics, Planning, and Operations Research Phase:

     A Questionnaire To Refuse Collectors and
  Disposal Site Operators for Analysis of Refuse
              Collection and Disposal
   Center for Planning and Development Research
        University of California, Berkeley
                        194

-------
                                                                                                                                                         195
 O
-P
 O
    >> a
                            <   CS  H
                                •d
                             M  eg  0)
                             cd  TJ  w
                             ^•~\t3
                             aj   ra
                             l>   M  C
                            <;  3  H
                               5? ft
                               ft0
                              •H  O
                               ^  -P
                              EH
                               O

                               0)  0)
                               N  fn
                              •H  U
                              CQ
                              >
                             aj  to
                             ft C  S
                             cd  o  o
                            O  EH
                                a
                                o
                                •H
                                -P
                                ft
                                •H
                                0)
                                o

-------
196




















































«•
ra
O


a
0
•H
-P
O
CD
H
H
O
O

.
H
1 — 1


-p
0)
a
a
•H
O'Ti
W 
W
O
0)
•a
CD
^
•rH (U
CD O
K K
ID t-l
a D

in 0
o
i — |
cd o
-p -P
O
EH
Tj 0
 0
H CD
• H
hfl O
> 0
"•

-------
                                                                                 197
                                               County	
                           III.   Disposal Site  Operations:
(l)  Name of the site:
          Owner:
          Operator:
(2)  Land area and cost of site:
          Total land area
acres; Cost of purchase:  $
          Starting date of operation:_
(3)  Acres of land filled to date:	
          Avg. depth of fill	
         ;  Acres remaining
   ft.  Acre-feet remaining
(h)  What is the service area from which solid refuse is  brought to the  disposal
     site:  Mark it on the county map.
(5)  Approximate estimate of refuse filled in the site during the past year  (1965)
          tons/week_
           tons/year
             yds/week
           acre ft/year
(6)  Breakdown of refuse by type:
               Category:
          Residential garbage	
                      rubbish
           Percent of total:
          Commercial (food wastes)
          Commercial (paper and allied)
          Industrial (manufacturing)
          Cannery and food processing
          Agricultural (farming) wastes
          Special wastes:   (Specify)

          Municipal waste:  (Sewage Treatment
                             Sludge)
               Total:
(7)   Disposal operation:
          Number of (full-time equivalent)  men
          employed at the  site
          Number & type  of equipment used
          Average lift height
          Cover material source (
                                (
          Total depth fill & cover
          Average density  of fill
                  100.0
                            (thickness)
                           _(lb/cu yd)

-------
198
(8)  Cost of disposal operation:                        (Obtain detail data and enter
                                                       total cost or per unit cost)
          Labor	

          Machinery	

          Material
(9)  Source of revenue to meet the cost of operation:   (Obtain detailed data
                                                       as available)
          Direct user charge 	

          Tax revenue             	

-------
                                    APPENDIX E

                               CODIFICATION OF DATA


Identification of Observations:

Each observation may be identified by:

      A.  County (58 such counties)
      B.  Disposal service area  (10-15 per county)
      C.  Some subcounty unit  such as
              census tract
              county census division  (group of census tracts)
              city (group of census tracts)

It will be necessary to aggregate the observations in any of the following manners:

          Sum of appropriate subcounty units = Disposal Service Area

          Sum of Disposal Service Areas = County

          Sum of counties = Region

      or  Sum of counties = State of California

For these purposes, the following code is suggested:

      A.  Two-digit county code
      B.  Two-digit disposal service area code
      C.  Three-digit subcounty area code:
              1-^99:  correspondingly numbered census tract
            501-599:  county census division within county
            901-999:  city within the county

The following examples are offered to illustrate the use of the identification
s cheme:

          02060^3:   Census tract #^3, D.S.A. #06, County #02.

          130^501:   County census division #501 (some census tracts grouped)
                    for D.S.A. #0k, County #13.

          130U901:   City #1, D.S.A. #04, County #13.

          0607000:   The sum of all observations for D.S.A. #07 in County #06.

Major Data Blocks:

The following major categories of data are required:

      A.  Demographic characteristics (no totals required)
      B.  Employment (totals required)
      C.  Land use  (totals required)
      D.  Solid waste (totals required)
                                         199

-------
200
The detailed data requirements within each of these blocks are presented below at
various levels of aggregation.

      A.  Demographic characteristics:

          1.  Population
          2.  Number of households
          3.  Average household size (population/number of households)
          k.  Total personal income
          5.  Average household income (total personal income/no. of households)
          6.  Per capita income (total personal income/population)

                                                                      Corresponding
                                                                         SIC Code
      B.  Employment, total

          1.  Agricultural employment, total

              a.  field crops
              b.  orchard crops
              c.  dairy
              d.  livestock
              e.  other agricultural employment

          2.  Mining and extractive employment, total                    13-1*4-

          3.  Manufacturing employment, total

              a.  food and kindred products employment, subtotal         20

                  (l) meat products                                      201
                  (2) dairy products                                     202
                  (3) canned and frozen foods                            203
                  (U) grain and bakery products                          20H-205
                  (5) other food processing employment

              b.  non-food manufacturing employment, subtotal

                  (l) tobacco products                                   21
                  (2) textile mill products                              22
                  (3) apparel and related products                       23
                  (U) lumber and wood products                           2k
                  (5) furniture and fixtures                             25
                  (6) paper and allied products                          26
                  (7) publishing and printing                            27
                  (8) chemical and allied products                       28
                  (9) petroleum and coal products                        29
                 (10) rubber and plastic products                        30
                 (ll) leather and leather products                       31
                 (12) stone, clay, and glass products                    32
                 (13) primary metal products                             33
                 (lU) fabricated metal products                          3^
                 (15) machinery, non-electrical                          35
                 (l6) electrical machinery                               36
                 (17) transportation equipment                           37
                 (l8) instruments and related products                   38
                 (19) ordnance                                           19
                 (20) misc. manufacturing employment                     39

-------
                                                                          201
    k.  Commercial and service industry employment, total

        a.  construction                                           15-17
        b.  transportation, communication and utilities            Ul-U9
        c.  wholesale trade                                        501-509
        d.  retail trade                                           52-59
        e.  finance, insurance, and real estate                    60-67
        f.  personal and business services                         70-89
        g.  government                                             90-99

C.  Land, total acres

    0.  Residential use, total acres

        a.  single family
        b.  multiple family
        c.  special and group residences

    1.  Agricultural use, total acres

        a.  field crops
        b.  orchard crops
        c.  dairy
        d.  livestock
        e.  other (including grazing and range land)

    2.  Extractive industry use, total acres

    3.  Manufacturing use, total acres

        a.  food and kindred products, subtotal acres

            (l) meat products
            (2) dairy products
            (3) canned and frozen goods
            (U) grain and bakery products
            (5) other food processing use

        b.  non-food manufacturing,  subtotal acres

            (l) tobacco products
            (2) textile mill products
            (3) apparel and related  products
            (h) lumber and wood products
            (5) furniture and fixtures
            (6) paper and allied products
            (7) publishing and printing
            (8) chemicals and allied products
            (9) petroleum and coal products
           (10) rubber and plastic products
           (ll) leather and leather  products
           (12) stone,  clay, and glass products
           (13) primary metal products
           (l^O fabricated metal products
           (15) machinery, non-electrical
           (16) electrical machinery
           (17) transportation equipment
           (l8) instruments and related products
           (19) ordnance
           (20) misc.  manufacturing  land use

-------
202
          k.  Commercial and service,  total acres

              a.  transportation,  communication and utilities,  total acres net
                  of street and roads
              b.  wholesale trade
              c.  retail trade
              d.  finance,  insurance and real estate
              e.  personal and business services
              f.  government (facilities)

          5.  Other uses, total acres

              a.  public open space
              b.  other public (military reservations,  etc.)
              c.  urban vacant
              d.  rural vacant
              e.  other misc. uses

      D.  Quantity of solid waste  (data to be collected by the  California State
                                   Public Health Department)

          1.  Quantity of solid waste  by source, total

              a.  households
              b.  agricultural industry
              c.  extractive industry
              d.  manufacturing industry, total

                  (l) food processing industry
                  (2) non-food manufacturing

              e.  commercial and service industry
              f.  municipal wastes, total

                  (l) sewage sludge
                  (2) street sweepings

          2.  Quantity of solid waste  by material, total

              a.  garbage
              b.  paper and cardboard
              c.  grass, brush and prunings
              d.  metals totals

                  (l) ferrous
                  (2) non-ferrous

              e.  glass and ceramics
              f.  plastics
              g.  demolition and construction wastes
              h.  ashes
              i.  sewage sludge

-------
   COMPREHENSIVE STUDIES




OF SOLID WASTE MANAGEMENT






      Second Annual Report

-------

-------
                                      PREFACE
NATURE AND SCOPE OF REPORT

        The report herein presented is of the nature of a progress report covering
the second year and the first two months of the third year of a comprehensive study
of solid wastes management made possible "by a Public Health Service Research Grant
No. UI-005^7-02 from the Environmental Control Administration —Bureau of Solid
Waste Management to The Regents of the University of California.

        The research plan on which the grant (originally, SW-00003) w&s based called
for two phases of investigative work.  The first phase involved the organizing of a
multidiscipline research group and its participation in a data-collecting and data-
evaluating activity.  During the second phase, the group was to be divided into
research teams and directed to a coordinated study of such aspects of the solid
wastes problem as planning, economics, operations research, public health, and
technology.  Phase I and the initial activity of Phase II was reported in the First
Annual Report [l] (SERL No. 6?-7 dated May 196?).

        The report herein presented is concerned with the progress of research by
teams devoted to Phase II of the study during the period June 196? to September 1968.


AUTHORSHIP CREDITS

        Authorship credit for individual chapters of the report is due the following
participants in the project.

        Planning - Dr. S. A. Rao

        Operations Research - H. Stern, A. Nigam, Professor C. R. Glassey

        Economics - R. Dawson, Dr. S. A. Hart, D. B- Chan, R. Rosenbluth,
                       Professor C. R. Wilke, J. Bicho, Dr. D. L. Brink,
                       P. K. Basu

        Anaerobic Digestion - S. A. Klein, D. B- Chan

        Composting - Dr. S. A. Hart, A. K. McFarland

        Wet Oxidation - J. Bicho, Dr. D. L. Brink

        Incineration-Pyrolysis - Dr. D. L. Brink
        Biological Fractionation - R. Rosenbluth, Professor C. R. Wilke
        Introduction
        Evaluation of Problem
        Public Health
        Summary
C. G. Golueke
P. H. McGauhey
ACKNOWLEDGMENTS

        The project staff is indebted to many individuals and agencies throughout
California and the nation for information and assistance during the report period.
Among those who have been particularly helpful are:

        Peter A. Rogers, California State Department of Health, Berkeley
        Bruce McArthur, Food Machinery Corp. (FMC), Santa Clara
        P. H. Savage, University of California, Berkeley
        J. J. vasconcelos, University of California, Berkeley
                                        iii
 8-229 O - 70 - 15

-------
        F. Stephanelli, President,  Sunset Scavenger  Co.,  San Francisco
        J. Moscone, President,  Golden Gate Scavenging Co.,  San Francisco

        Professors P. H. McGauhey,  I. R.  Tabershaw,  B-  D. Tebbens,  S. A. Hart, and
W. J. Kaufman acted in the capacity of faculty investigators for  the study.
                                         iv

-------
                                 TABLE OF CONTENTS
                                                                               Page
Chapter

    I.   Introduction ............................      1

            Need for Study  .........................      1

            Rationale of Study  .......................      1

            Objectives of Study .......................      1

            Organization for Study  .....................      2

            Nature and Scope of Study ....................      3

   II.   Reevaluation of the Problem  ....................      k

            Introduction  ................. .  ........      k

            Nature of the Problem ......................      k

               The Problem in 1966  .....................      k

               The Problem in 1968  .....................      5

                  Changes During the Period .................      5

                  Emerging Concepts .....................      6

                  The Number One Problem  ..................      6

                  Program Emphasis  .....................      7

                  Collection System Problems  ................      7

                  Public Health Problems  ..................     10

            Evaluation of the Research Program  ... ............     11

  III.   Planning ..............................     13

            Introduction  ..........................     13

               Rationale  ..........................     13

               Objectives of the Regional Solid Wastes
                 Generation Model ......................     l4
            The Investigation

-------
                           TABLE OF CONTENTS (Continued)

Chapter                                                                        Page

               Study Region	    ik

               Specification of Variables 	    15

               Definition of Functional Regions (Disposal
                 Service Areas) 	    15

               Location and Identification of Disposal Sites and
                 Functional Regions (DSA's) 	    16

               Development of Data on Solid Wastes Generation
                 and Related Variables   	    17

                  Solid Wastes Generation 	    17

                  Collection of Solid Wastes Data from
                    Disposal Site Operators 	    17

                  Estimation of Solid Wastes Quantities from
                    Sources of Wastes and Wastes Multipliers  	    18

                  Sources of Wastes	    18

                  Solid Wastes Multipliers  	    21

                  Residential Sources 	    21

                  Commercial, Nonmanufacturing, and Public
                    Agency Sources  	    21

                  Industrial Sources  	    26

                  Agricultural Sources   	    29

               Total Wastes  Generated Within the Region  	    31

               Employment	    31

               Population	    31

               Household (Residential) Income  	    38

               Land Use by DSA's	    38

               Results of the Solid Wastes Generation in the
                 Nine-County Bay Area	    38

               Public and Private Expenditures for Refuse
                 Removal and Disposal	    hi

   IV.   Operations Research in Solid Wastes   	    47

            Optimal Activity Locations	    4-7

            Determination of Optimal Wastes Flow Patterns  	    50

            Optimization of  Solid Wastes Treatment
              Plant Operation	    51

               Introduction  	    51


                                         vi

-------
                           TABLE OF CONTENTS (Continued)

Chapter                                                                        Page

               Dual Service Rate Treatment Facility with
                 Continuous Arrival of Wastes 	    52

                  General Description 	    52
                                                                                    i
                  Mathematical Formulation   	    52'

               Continuous-Rate Treatment Facility •with
                 Periodic Arrival of Wastes  	    52

                  General Description 	    52

                  Mathematical Formulation   	    53

                  Extensions	    55

    V.   Economics	    56

            Introduction   	    56

            Economics of Scale	    56

               Introduction 	    56

               Importance of Economics of Scale 	    57

               Analysis of Cost Data	    57

               Economics of Scale In Collection "by Truck	    59

               Incineration 	    59

               Transfer and Long-Haul Transport In
                 Road Vehicles   	    6l

               Landfill Utilization 	    62

               Discussion	    63

            Economics of the Low-Cost Biostabilization
              (Composting) System	=	    6j

               Background	    63

                  The Process	    63

                  Land Requirement	    63

                  Total Daily Production   	    64

               Costs  	    64

                  Hauling	    64

                  Refuse Grinding 	    64

                  Composting	    64

                  Field Spreading and Tilling	    65
                                        vii

-------
                           TABLE OF CONTENTS (Continued)

Chapter                                                                        Page

                  Land-Use Charges  	    65

                  Burial of Noncompostables 	    66

                  Summary of Costs	    66

               Comparison with Conventional Composting Methods  	    66

            Economics of the Anaerobic Digestion Process  	    67

               Introduction 	    67

               Assumptions	    67

               Amounts of Wastes to be Treated	    68

               Grinding	    68

               Digestion	    69

                  Volumes	    69

                  Digester Costs  	    69

                  Maintenance and Miscellaneous Costs 	    71

               Cash Value of Digester Gas	    72

                  Volume of Gas Produced	    72

                  Sale of the Gas	    73

               Summary of Costs	    73

               Discussion	    73

               Conclusions	    75

            Economics of Biofractionation  	    75

               Preliminary Cost Estimate of the Proposed Microbial
                 Cellulose Decomposition Process  	    75

               Description of the Process Design Basis  	    75

               General Process Description  	    76

               Cost Factors	    76

               Net Waste Treatment Costs   	    76

               Discussion of Process Economics  	    79

            Economics of Wet Oxidation	    79

               Introduction 	    79

               Process Evaluation 	    79
                                        viii

-------
                           TABLE OF CONTENTS (Continued)

Chapter                                                                        Pag

               Equipment Requirements 	    8l

               Costs	    8l

               Conclusion	    82

            Economics of Pyrolysis   	    82

               Introduction 	    82

               Proposed Design  	    82

               Discussion and Conclusions 	    82

   VI.   Public Health	    84

            Introduction  	    84

            Relation of Solids Wastes Management to Disease 	    84

            Role of Public Health in Solid Wastes Management  	    85

            Nature and Results of Investigation 	    86

               Procedure	    86

               Investigative Findings 	    87

               Discussion	   110

                  Research Needs  	   110

                  Future Work	   Ill

  VII.   Anaerobic Digestion	   112

            Introduction	   112

            Objectives	   112

            The Investigation	   112

               Introduction 	   112

               Development of Equipment and Procedures  	   113

                  Preparation of Raw Materials	   113

                  Analyses	   117

               Experimental Series I:  Addition of Green Garbage
                 to Acclimatized Sludge Digesters 	   117

                  Procedure	   Il8

                  Results	   118

                  Conclusions	   121
                                         ix

-------
                           TABLE OF CONTENTS (Continued)

Chapter                                                                        Page

               Experimental Series II :   Digestion of Paper Pulp .......   125

                  Procedure .........................   125

                  Results ..........................   125

                  Conclusions ........................   130

               Experimental Series III:  Digestion of Combined
                 Solid Wastes ........................   130

                  Procedure .........................   130

                  Results ..........................   13*1

                  Conclusions ........................   137

               Experimental Series IV:   Addition of Wood to
                 Digesters  .........................
                  Introduction  .......................

                  Procedure .........................

                  Results ..........................

                  Conclusions ........................

 VIII.   Composting .............................

            Introduction  ..........................

               Rationale  ..........................

               Low -Cost Biostabilization System ...............

               Objectives ..........................   150

            The Experiments .........................   150

               Experimental Setup  ......................   150

               Progress  ...........................   153

   IX.   Wet Oxidation   ...........................

            Introduction  ..........................

               Rationale  ..........................   154

               Objectives ..........................   156

            Experimental Approach  ......................   156

               Phase I — Determination of Basic Reaction
                 Relationships  .......................   156

               Phase II - Oxidation of Organic Solid Wastes
                 Materials  .........................   l6l

-------
                           TABLE OF CONTENTS (Continued)




Chapter                                                                        Page




               Phase III — Process Design	   l6l




               Results   	   l6l




            Discussion	   l6j




            Future Prospects   	   169




    X.   Incineration — Pyrolysis  	   171




            Introduction  	   171




               Rationale  	   171




               Objectives	   172




            Basic Demonstration Unit Design	   172




            Progress During Past Year	   173




            Future Prospects   	   175




   XI.   Biological Fractionation of Organic Wastes  	   176




            Introduction  	   176




               Rationale  	   176




               Objectives	   177




            The Investigation	   177




               Organisms  	   177




               Description of the Process	   178




               Development of Equipment 	   180




               Experimental Work	   180




                  Optimization of Enzyme Production  	   180




                  Maintenance of Enzyme Activity   	   l8k




                  Recovery of Enzyme	   1.8k




                  Dense Culture Technique for Rapid Decomposition  	   1.8k




            Summary	   1.8k




  XII.   Summary	   186




            Introduction  	   186




            Research Activities and Findings  	   l87




               Planning	   187




               Operations Research  	   188





                                        xi

-------
                           TABLE OF CONTENTS (Continued)
Chapter
Page
               Economics	   189

                  Low-Cost Biostabilization (Composting) System 	   189

                  Anaerobic Digestion 	   189

                  Biofractionation  	   189

                  Wet Oxidation	   190

                  Incineration-Pyrolysis  	   190

               Public Health  	   190

               Technology	   191

                  Anaerobic Digestion 	   191

                  Composting	   192

                  Wet Oxidation	   192

                  Incineration-Pyrolysis  	   192

                  Biofractionation  	   192

APPENDICES

    A.   List of Disposal Sites	   193

    B-   Definition of Disposal Service Areas 	   196

    C.   Disposal Service Areas, Corresponding Disposal
           Sites, and Census Tract Boundaries 	   199

    D.   Solid Wastes Classifications by Point of Origin  	   216

    E.   Multipliers for Large and Small Firms  	   220

    F.   Population Data Sources	   22J

    G.   Land-Use Data	   226

    H-   Determination of Cellulose in Sewage 	   2J1

REFERENCES	   2kl
                                        xii

-------
                                  LIST  OF  TABLES
Table                                   Title
1.
2.

3-
4.
5-
6.

7-
8.
9-
10.
11.
12.
13-

14.

15-

16.

IT-
18.
19-

20.
21.
22.
23-


Conceptual Comparison of Utility and Natural Systems 	
Detailed Tabulation of Comparable Wastes Figures,
Population, Total and Average Per Capita Wastes 	
List of Wastes Sources 	

Employment by DSA and by Wastes Source 	
Multipliers for Nonmanufacturing Industry,
Commercial and Public Facilities 	
Industrial Multipliers 	
Multipliers for Vineyards and Orchards 	
Agricultural Source Units by DSA: 1966 	
Agricultural Wastes by DSA, by Source : 1966 	
Wastes Generation by DSA and by Wastes Source (tons per year) ....
Population by DSA 	
Solid Wastes Production in Terms of Disposal Service Area,
Source, Population, Households, and Employment 	
Examples of Combinations of Private and Public Collection
and Disposal Services 	
Privately Operated Disposal Sites : Revenues
and Expenditures 	
Publicly Operated Disposal Sites: Revenues

Cost Per Capita Per Year for Digesting Refuse 	
Cost Per Ton of Refuse or Garbage Digested 	
Estimated Materials Balance for Proposed Cellulose
Conversion System 	

Fixed Capital Estimate for Cellulose Conversion System .......
Manufacturing Costs for Cellulose Conversion System 	
Preliminary Economic Estimate for Pyrolys is -Combustion
System of Disposal of Solid Wastes for a 200-ton/day
Solid Wastes Capacity (Oven Dry Basis) 	
9

19
20
22
23

26
28
30
32
33
3^
37

39

42

44

45
74
74

77
77
78
78


83
                                       xiii

-------
                            LIST OF TABLES (Continued)

Table                                  Title                                   Page

 2k.    Public Health Evaluation of Domestic Wastes .............    89

 25.    Public Health Evaluation of Industrial Wastes ............    9^

 26-    Public Health Evaluation of Agricultural and Food
          Processing Wastes .........................   100

 27-    Public Health Evaluation of Commercial Wastes ............   104

 28.    Public Health Evaluation of Special Wastes  .............   108

 29.    Cellulose Content of Primary Sludge Feed During
          Paper Pulp Digestion Experimental Runs  ..............   126

 30.    Daily Input of Cellulose to Digesters ................   126

 31.    Cellulose Destruction in the Digesters (Paper Pulp) .........   127

 32.    Efficiency of Paper Pulp Digestion  .................   129

 33-    Percent Total Solids Reduction in Paper Pulp Digestion  .......   131

 3^-    Efficiency of Cellulose Reduction in Combined
          Wastes Digestion  .........................   139
 35-    Solids Reduction in Digesters Fed Monterey Pine Wood

 36-    Cellulose Decomposition in Digesters Fed Monterey Pine

 37-    Acid-Base Parameters in Wood-Fed Digesters

 38.    Gas Composition in Wood-Fed Digesters
 39-    Loading Rates for Shredded Refuse and Rough
          Compost on Experimental Plots ...................   153

 hO.    Typical Costs for Low -Temperature and Low -Pressure
           Wet Oxidation of Sewage Sludge ..................   155

 hi.    Summary of Wet Oxidation Reactions of White Fir Wood  ........   162

 k2.    Materials Balance for Wet Oxidation Reactions of
          White Fir Wood  ..........................   l6k

 ij-3 •    Oxygen Consumption and Carbon Dioxide -Carbon Monoxide
          Formation in Wet Oxidation Reactions of White Fir Wood  ......   166
 kk.    Disposal Sites in Alameda County  ..................

 k*y.    Disposal Sites in Contra Costa County ................   19^

 k6-    Disposal Sites in Marin County  ...................   194

 V?.    Disposal Sites in Napa County ....................   19^

 k-8.    Disposal Sites in San Francisco County  ...............   19^

 49 •    Disposal Sites in San Mateo County  .................   195
                                       xiv

-------
                            LIST OF TABLES (Continued)

Table                                  Title

 50.    Disposal Sites in Santa Clara County  	   195

 51.    Disposal Sites in Solano County 	   195

 52.    Disposal Sites in Sonoma County 	   195

 53-    List of Disposal Service Areas as Defined
          According to Census Tracts  	   197

 5^.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Alameda County 	   200

 55-    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Contra Costa County   	   200

 56.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Marin County 	   201

 57-    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Napa County  	   201

 58.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, San Francisco County  	   202

 59-    Disposal Service Areas, Corresponding Truck Routes,
          and Census Tract Boundaries, San Francisco County  	   203

 60.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, San Mateo County 	   20k

 6l.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Santa Clara County 	   205

 62.    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Solano County  	   206

 63•    Disposal Service Areas, Corresponding Disposal Sites,
          and Census Tract Boundaries, Sonoma County  	   207

 64.    Solid Wastes Classification by Point of Origin  	   217

 65-    Large-Firm Multipliers  	   221

 66.    Small-Firm Multipliers  	   222

 67-    Population Data Sources, Special Problems and
          Solutions by County	   224

 68.    Data Sources and Reference Period	   227

 69-    Comparison of Land-Use Data Code and Wastes Sources	   228

 70.    Land Use - BASS III:  1965	   229
                                       xv

-------
                                  LIST OF FIGURES


Figure                                 Title                                   Page

   1.   Realization for Period i	    53

   2.   Flow Diagram of a Generalized Continuous
          Wet Oxidation System  	    80
   3 •   Incubator with Controls for Stirring
          System and Temperature
   4.   Digester Units and Stirring System
          Within the Incubator  .......................   115

   5.   Digester Gas Collection Apparatus ..................   116

   6.   Efficiency of Green Garbage Digestion ................   119

   7-   Morphological Variety of Microorganisms Found in the
          Digester Culture Fed Entirely on Sewage Sludge  ..........   120

   8.   Morphological Variety of Microorganisms in the
          Digester Fed Entirely on Garbage  .................   120

   9.   Solids Reductive in Green Garbage Digestion .............   122

  10.   Effect of Green Garbage Loading on Digester
          Acid-Base Equilibria  .......................   123

  11.   Effect of Green Garbage Loading on Gas Composition  .........   124

  12.   Efficiency of Paper Digestion ....................   128

  13.   Effect of Paper Pulp Loading on Digester
          Acid-Base Equilibria  .......................   132

  l4.   Effect of Paper Pulp Loading on Gas Composition ...........   133

  15.   Efficiency of Combined Wastes Digestion ...............   135

  16.   Effect of Combined Wastes on Digester
          Acid-Base Equilibria  .......................   136

  17-   Solids Reduction in Combined Wastes Digestion ............   138

  18.   Gas Composition of Combined Wastes Digestion  ............

  19.   Gas Production of Wood -Fed Units  ..................

  20.   Efficiency of Wood Digestion  ....................

  21.   Small Refuse Shredding Facility Used to Prepare On -Campus
          Domestic Refuse for Composting or for Direct
          Application to the Experimental Plots ...............   151

  22.   Compost Drum, 5 ft Long by 6 ft Diameter, Batch Operation ......   151

-------
                           LIST OF FIGURES (Continued)

igure                                 Title                                   Page

 23.   Experimental Field Plots  ......................    152

 2k.   Close -Up of the Plot Receiving 200 ton/acre/year
         of Rough Compost  .........................    152

 25.   Schematic Diagram of Batch Wet Oxidation Process  ..........    157

 26.   Instrumentation Complex for Monitoring and
         Recording Reaction Parameters ...................    158

 27-   Reactor Extension and Agitator Drive in Assembled Form  .......    159

 28.   Air Compression and Storage System  .................    160

 29-   Total Carbon Distribution in Wet Oxidation Reactions  of
         White Fir Wood as a Function of Temperature
         and Air Input ...........................    165

 JO.   Oxygen Consumption and COa-CO Formation in Wet Oxidation
         Reactions of White Fir Wood as Functions of
         Temperature and Air Input .....................    167

 31.   Oxygen Consumption and COa-CO Formation per 100  g
         Solubilized Carbon in Wet Oxidation Reactions  of
         White Fir Wood as Functions of Temperature and
         Air Input .............................    168
 32.   Schematic of a Two-Stage Pyrolysis -Combustion Unit
 33-   Schematic Representation of a Continuous  Process  for the
         Production of Protein and Carbohydrate  from
         Cellulosic Waste Material .....................    179

 3^«   Schematic Diagram of Fermenter and Control System ..........    l8l

 35-   System of Three Culture Vessels ...................    l82

 36-   Control Panel for Culture Equipment .................    183

 37-   Alameda County DSA's  ........................    208

 38.   Contra Costa County DSA's ......................    209

 39-   Marin County DSA's  .........................    210

 kO.   San Francisco County DSA's  .....................    211

 kl.   San Mateo County DSA's  .......................    212

 k2.   Santa Clara County DSA's  ......................    213

 ^3.   Solano County DSA's .........................    2lk

 kk.   Sonoma and Kapa Counties DSA's  ...................    215
                                     xvi i

-------

-------
                                   I.   INTRODUCTION
  NEED FOR STUDY

          The need for comprehensive studies of solid wastes management that gave  rise
  to the investigation upon which this report is based derives  from man's  delay in
  defining his environmental goals until the problems of living with his wastes had
  reached critical proportions.   For a detailed evaluation of this  need the  reader is
  referred to the First Annual Report [l] on the investigation, in  which the authors
  set forth at some length the nature of the solid wastes problem;  its  basis in
  tradition, urbanization, affluence, and ignorance;  and the ways in which jurisdic-
  tional arrangements, economic  concepts, social attitudes,  and technology have
  delayed any satisfactory solution.  It is  particularly stressed in the report that
  citizens and public officials  have historically shown little  interest in investing
  money in solid wastes management; that unplanned and uncoordinated urban expansion
  has brought the urban, suburban, and rural sectors  of many communities into intimate
  contact; that solid wastes management has  become a  regional problem involving the
  whole spectrum of wastes produced by industrial, agricultural, and domestic utili-
  zation of resources and products rather than of domestic refuse alone; that our
  national economy depends to an important degree upon the generation of wastes; that
  the technology of production of consumer goods is not significantly concerned with
  their ultimate disposability,  while the technology  of disposal has not been related
  to the total wastes except in  the most primitive way; and that ignorance of the
  problem and of its feasible solutions persists at all levels  of society.


  RATIONALE OF STUDY

          The rationale of the study, as set forth in the First Annual  Report [l],
  involves three principal concepts.

      1.  That all wastes are destined to remain somewhere on the earth or in its
          atmosphere, hence the  general problem of research  is  to find  the optimum
          way to sequester wastes on the earth without interfering  with man's
          freedom to use the earth's resources.

      2.  That "wastes" are more properly defined as  residues of resource  use which
          result from the application of current technology under present  concepts
          of economics and social objectives.

      3-  That a program of research can simultaneously achieve many of the
          objectives of a needed educational program  while contributing to the
          solving of jurisdictional, planning,  economic,  operational, and
          technological problems of solid wastes management.

          The report then sets forth ten major specific concepts and illustrates
  graphically the seven ways in  which solid  wastes disposal  is  feasible.


  OBJECTIVES OF STUDY

          The general objective  of the study is to contribute significantly  through
  research,  and through the knowledge gained in research participation,  to an under-
  standing of the systems, /technological and human aspects of wastes  management
  involved in utilizing the earth's natural  resources  with a minimum degree  of
  degradation of the human environment.   Pursuant to  this  general goal,  the  research
  program is directed to several more specific  objectives, including:
3S8-229 O - 70 - 16

-------
    1.  To bring the competence of people in the wide variety of disciplines
        involved in planning, financing, and administering a community into
        effective combination with that of engineers and environmental
        health specialists in seeking solutions to problems in solid wastes
        management which are technically sound, economically feasible, and
        politically and socially acceptable.

    2.  To bring the techniques of modern operations research to bear upon
        the organizational problems of managing solid wastes on an area-
        wide or community-wide basis; and on the physical and logistic
        problems of collecting, transporting, and disposing of wastes.

    3-  To seek through experiments and other research techniques improve-
        ments in conventional methods of wastes disposal and the development
        of new procedures for reclaiming or recycling fractions of the
        refuse mass.

    b.  To identify and seek answers to problems involving man's health and
        well-being that may "be associated with solid wastes and related to
        his use of land, water, and air resources.

    5-  To develop, through participation in research, greater understanding
        and knowledge on the part of engineers, planners, administrators,
        economists, public health specialists, and others who are confronted
        with the problem of solid wastes management in the course of their
        professional service to the modern urban-industrial-agricultural
        community.

    6.  To insure, through close coordination and effective communication
        with public and private agencies, the pertinence of research to real
        problems and the prompt availability of the results of research to
        professional practitioners.


ORGANIZATION FOR STUDY

        The five faculty investigators noted in the Preface,  representing  the
Sanitary Engineering Research Laboratory of the College of Engineering and School
of Public Health on the Berkeley campus and the Department of Agricultural Engi-
neering of the Davis campus of the University of California,  were responsible  for
the overall management of the project.  In the conduct and coordination of the
research program, they were assisted by additional faculty members and professional
researchers who took responsibility for various specific aspects, including:

                   Professor C. R. Glassey, Operations Research
                   Dr. D. I- Brink, Forestry
                   Professor C- R- Wilke, Chemical Engineering
                   Professor P. B. Stewart, Mechanical Engineering
                   Dr. S. A. Rao,  Planning and Economics

        Dr. Clarence G. Golueke, Chief Biologist of the SERL staff,  served as
project coordinator, with assistance from Mr. S. A. Klein, Assistant Specialist  on
the project staff.  A total of 12 graduate students participated in the program;
five doing work on doctoral dissertations in economics, forestry, chemical engi-
neering, sanitary engineering, and operations research; two completing Masters'
theses in Planning and Operations Research.  As noted in the  First Annual  Report
[l], close cooperation with the California State Department of Public Health
afforded the project the benefits of its statewide survey of refuse management and
its federally-financed demonstration project at Fresno, California.   A similar
arrangement with the Public Health Service made available the results of a survey
of industrial solid wastes conducted by the Food Machinery Corporation under a
federal grant.

-------
NATURE AND SCOPE OF STUDY

        As described in the First Annual Report, the study reported herein is
directed to a number of related facets of solid wastes management conceived as
subsystems in a comprehensive wastes generation and evaluation model developed by
the project.  To this end, coordinated research teams with overlapping staff
personnel organized as noted in the preceding section are directed to specific
aspects of the problem, including:

    1.  Planning on a regional scale, both for the wastes-generating potential
        of alternate types of development and the land requirements of disposal
        of such wastes.

    2.  The operations research aspects of wastes management,  including the
        logistics of assembling wastes and moving them efficiently and economi-
        cally through an urban complex; and the nature of systems suited to
        regional or community-wide wastes management and disposal.

    5.  The economics of alternate planning, operating, and disposal schemes.

    k.  The possibilities of improving technology for disposing of all or
        selected fractions of the total solid wastes of a community, with
        special research emphasis on the processes of:

        a.  Anaerobic digestion

        b.  Wet oxidation

        c.  Biofractionation

        d.  Pyrolization-incineration

        e.  Composting

    5-  The public health implications of solid wastes management.

        Investigative work on each of these several aspects is included in the
scope of the study.

-------
                         II.  REEVALUATION OF THE PROBLEM
INTRODUCTION

        In order that any research program maintain its relevance to the problems
which originally justified its initiation, it is necessary to reevaluate both the
program and the problems themselves from time to time.  This is particularly true
in the solid wastes field where management of physical materials (wastes) is more
a matter of political accommodation, systems engineering,  logistics, economics,
and technology than of discovery of basic scientific facts.  This is not to say
that there is no place for fundamental research related to wastes disposal, but,
rather, that it should be clearly understood at the outset of any project just what
achievements will constitute its success; and the project  should be reviewed from
time to time for evidence of "drift."  Projects intended to yield practical results
are much more likely to drift off into exploration of scientific minutiae than are
narrowly-conceived scientific projects likely to produce practical solutions instead.
There is also the danger in the practical project that the point where economics
becomes limiting within an acceptable time span will pass  unnoticed unless the
investigator is particularly alert to this pitfall.

        But assuming that neither drift nor demonstrable economic infeasibility
befalls a well-managed project, the very fact that research moves slowly at best
imposes the risk that the project may continue to seek the answer to a question
long after the time when the question ceases to be considered worth the asking.
In the case of solid wastes, where progress toward solution of problems has been
glacier-like in its advance because of man's inability to  see the problem or his
disinclination to recognize it, there is little reason to  fear that the answer will
outrace the quest.  Nevertheless, the rapid rise of national concern for environ-
mental quality and the growing intensity of local alarm over refuse disposal
problems might render such a judgment invalid or generate  new problems of solid
wastes management which either overwhelm the old in importance or require resolution
before the old ones become again relevant.

        In this section of the report, attention is directed principally to a
reexamination of the status and nature of the solid wastes problem and to the
background for evaluation of the ongoing research program.


NATUEE OF THE PROBLEM


The Problem in 1966

        When the project herein reported was initiated in  1966, Public Health
Service activity in the field of solid wastes had just been given major status
under the Solid Waste Disposal Act — the common designation of the amendment to
the Clear Air Act signed into law by President Johnson in  October 1965-  As noted
in the preceding chapter (under Need for Study), the most  urgent problems of solid
wastes management at that time were the outgrowth of deficiencies in planning,
politics, economics, technology, and general public awareness.  Specifically,
essentially no plan for land use could be found in which the planning agency had
proposed to dedicate any land to solid wastes disposal.  There was a tendency to
consider land too valuable for refuse fills or composting activities if it could
conceivably be utilized profitably for any other purpose.

        Politically, each jurisdictional unit was organized to handle only its own
local affairs, which included the distasteful responsibility of getting rid of its
wastes.  Except in a few larger cities, this task was commonly given a minimum of

-------
concern; and under the then prevailing concept of land use,  the ancient idea of
disposal by exporting wastes beyond its own jurisdictional boundaries prevailed
in most communities.  Moreover, the economic feasibility of even this method was
viewed with a quite conservative attitude.

        In addition, traditional public concern was primarily for municipal refuse
disposal, with other producers of wastes expected to solve their own disposal
problems.  Technology involved land disposal by procedures ranging from open dumps
to sanitary landfills; incinerators of varying degrees of acceptability; and a
process of composting with a history of commercial failure.

        In 1966, a crisis in solid wastes disposal was already mounting as plastics
and other undegradable materials became more common; the nation increasingly
included aesthetics and quality of life in its environmental goals; and land once
considered worthless came to be highly valued for its resource potential and
ecological importance.


The Problem in 1968


        Changes During the Period.  During the period 1966 to 1968, the solid wastes
program of the federal government stepped up its activities until in the fiscal
year 1968 it conducted and supported some 15-5 million dollars of research,  train-
ing, and demonstration projects.  Simultaneously, numerous communities, under the
stress of unresolved local problems of solid wastes disposal and the hope of
possible federal assistance, took stock of their own unhappy situations.  Private
enterprise likewise began to take an eager interest in the way in which systems and
hardware might be involved in any resolution of the problem.  Many planning agencies
became aware of the land use planning deficiency in relation to solid wastes manage-
ment schemes.  And local governmental units became conscious of the need and the
pressure for regional jurisdictions to deal with solid wastes.

        All of the foregoing activity had some impact on the problems identified in
1966, and on bringing into sharp focus a number of related problems.  The effect in
resolving the solid wastes problem of 1966, however, was more apparent than real.
No new authority accrued to planning agencies in general.  Awareness of solid wastes
tended to add only one more aspect to plans which historically had no effect in law.
In any event, the information and data needed for predicting the solid wastes
generating potential of land dedicated to any use pattern remained elusive;  and
public sentiment and organized group pressure against landfills in many places
further constrained the possibilities.  The gross effect of all this was to make
the land-use planning problem more acute in 1968 than 1966.

        A similar situation developed in relation to jurisdictional arrangements.
Awareness of the need for regional solutions brought into play those forces  of
provincialism and local jealousy, as well as those questions of taxing power, which
must be reckoned with before effective action is to result,  thus compounding the
problem of regional solutions to solid wastes management problems.  Investigative
activity and awareness of jurisdictional and planning problems tended to bring into
focus the fundamental economic realities of the situation.  This, if anything,
tended to harden the concept that economics is the real roadblock to action, and
brought out clearly the near impossibility of finding reliable cost data on which
to make future projections.

        In the realm of technology, the two-year period of 1966-68 saw no profound
changes.  Research continued apace along a  number of lines and pursuant to a number
of ideas which might prove to have technical and economic possibilities for managing
or utilizing various fractions of the overall solid wastes mass.  A number of
significant demonstrations likewise got underway during the  period.  Promotional
activity, particularly in the realm of incineration, was greatly intensified.  Some
technological progress was, of course, made in the interval, but not enough to
render invalid in 1968 those problems of technology confronting the community, the

-------
researcher, or the engineering profession in 1966.   Very little,  if any,  progress
seems to have been made tovard a public realization that incineration is  not a
total answer to its problem of land disposal of solid wastes.

        Leaving to later paragraphs a discussion of effects on the relevance of the
project herein reported, it is here concluded that  awareness rather than  resolution
characterized the changes in the 1966 problems during the two  years which followed.
The period did, however, call attention to other facets  of solid wastes management
which, although not unobserved in 1966, will require greater attention in the years
immediately ahead.  To them we now turn attention.


        Emerging Concepts.   One of the most elusive facets of  the problem of solid
wastes is the shifting cultural attitudes which tend to  disorient the public to
rational solutions and to compound the already considerable task of education and
communication.  Solid wastes management is one of a growing number of aspects of
environmental control in which what people will support, or at least tolerate, may
be the deciding factor in determining the feasibility of otherwise possible solu-
tions.  One of the major causes of this phenomenon  is the changed environmental
goals which have emerged in recent years; particularly,  the shift in emphasis from
the control of "pollutants" in the environment to the maintenance of "quality of the
environment" or of air, water, and land resources.   Regardless of the desirability
of this new objective, it is based on idealistic and aesthetic considerations with
which no one can disagree,  and so makes it more difficult to overcome the stubborn
realities of dealing with unwanted residues.

        An outgrowth of the "resources quality" approach, or the corollary to it,
is the growing concept that considerations of ecological streams, preservation of
habitat, maintenance of natural environments, and similar factors, preclude the
dedication of much low-lying land to the purpose of wastes disposal, regardless of
alternatives.  This adds to an unwillingness to accept refuse  disposal as a benefi-
cial use of land and so contributes to the persistent pretense that some  process
such as incineration, composting, or digestion, which will degrade organic matter,
is an alternative to landfill, and so one of the oldest  and most stubborn problems
of solid wastes management is kept alive if not, indeed, worsened, no matter how
often or carefully it is explained that some 50 percent  of refuse must, and will,
come to rest on the land.

        Compounding the problem is a second emerging concept — the concept of
"environmental insult" or "land pollution."  Although this may seem a logical
extension of established concern for air pollution  and water pollution to the last,
(land), of the three basic resources (air, water, land), and has an easy  appeal to
the citizen, it poses a new problem in environmental control.   Specifically, solid
wastes differ from air and water pollutants because they generally have no tendency
to diffuse into the land resource.  The act of rejection of a  physical object which
converts it from a "resource material" to a "waste" involves its deposition on the
land.  There it remains essentially in its original concentration until someone picks
it up and transports it to another resting place more acceptable to man.   In contrast,
the "pollutant" rejected to the air or water is at  once  introduced into a natural
transport system where, by diffusion, it contaminates other sectors of the receiving
resource and is translated to other areas distant from its point of origin.  The
fundamental characteristic of air and water pollution makes possible a control
program based on regulation of permissible concentration in the resource.  A regula-
tory approach to the so-called "solid wastes," however,  is infeasible. Physical
"management" of the discarded object, including the provision of a transport system,
is required.  Although well known to engineers and scientists concerned with the
solid wastes program, the emerging popular idea of  "land pollution" introduces a
relatively new aspect to the problem of environmental control or of gaining public
support for some control measures.


        The Number One Problem.  Throughout the period covered by this report, and
especially during the year 1968, the project staff inquired of public officials,

-------
"What is the number one problem of solid wastes management?"  At the local level,
in smaller communities, the answer often ranged from finance to labor; but in all
large communities, where the problem of solid wastes management in the United
States is most urgent, the answer was, invariably — "Finding any location at which
to do whatever it is you need to do, whether it be a transfer station, an incin-
erator, a landfill, a processing plant, or even a transport route."  As noted in
the preceding sections, some of this attitude derives from emerging concepts of
environmental quality; some from historic inattention to solid wastes as a land
worthy of consideration.  Property value depreciation, noise and hazard of passing
trucks, and general dislike for "garbage," especially someone else's, are among the
identifiable reasons.  In some cases, citizens have lain down in the streets to
force rerouting of collection vehicles; and at least one city threatened to sue in
an attempt to prevent a refuse-laden train from passing through it on its way to a
distant disposal site.  Although the Los Angeles County Sanitation Districts have
done a remarkable job in gaining public acceptance of their we11-conceived and
executed landfills, many other communities are persuaded by the haphazard routines
permitted in their environs in the past that "sanitary landfill" is merely a
euphemism for "dump."  In any event, there seems little doubt that the number one
problem of solid wastes management in 1968 is the matter of site, or that this
problem is more acute in 1968 than in 1966.


        Program Emphasis.  Major inventories of solid wastes problems and facilities
conducted by the federal solid wastes program, the California State Department of
Public Health, and various localities have demonstrated that some 80 percent of the
cost of solid wastes management is in the collection and storage phases.  At the
same time, it was reported that most of the federal expenditure for research and
demonstration is directed to the problem of disposal.  This in 1968 introduced a
question concerning program emphasis which is of concern to the authors of this
report in their project evaluation.

        Explanation and justification of the priority of disposal is forthcoming
from public officials who note that rather than tolerate wastes indefinitely in the
streets the public will find some way to provide money needed to alleviate the
problem.  With money it is possible to employ men to pick up the refuse and to
purchase trucks on which to load it.  But to find any place in the environment where
the public will permit the trucks to be unloaded is an all but insoluble problem.
This is, of course, but another manifestation of The Number One Problem cited in the
previous section.  It does not,  however, evaluate the problem of collection ade-
quately for the objectives of this chapter.


        Collection System Problems.  Perhaps the problem of solid wastes management
which has assumed greatest proportions since 1966 is that of the collection system
and its associated on-site storage of wastes.  Logic suggests that if the cost of
solid wastes management is to be reduced or minimized as the cost of disposal
increases, a careful study should be made of that portion of the total system where
the most money is being spent.  In this aspect of the solid wastes problem, three
principal questions arise:

    1.  What is the problem of on-site storage?

    2.  What is the major item of cost in the collection system, and how can it
        be reduced?

    3-  What can be done with the system itself?

        In the discussion that follows, it is intended to identify the problems
rather than to suggest their ultimate solutions.

        Although householders find storage of refuse on their premises a bother or
perhaps a nuisance, the principal complaints come from hotel, high-rise apartment,
and other commercial building owners or managers.  The problem is that large volumes

-------
of refuse are a nuisance and an expense,  particularly in that storage ties up
building floor space which in some cases  is valued at several thousand dollars
per square foot.  The question, however,  is not so much how to provide and manage
on-site storage as how to develop a collection system that makes on-site storage
unnecessary.

        The major item of expense in the  collection system is reported to be labor.
More than any other utility or public service, refuse collection depends upon a
relatively large labor force.  Historically, this labor has been generally low-
priced, at least in comparison with that  of the building trades, for example.  In an
increasingly opulent society with a strong status concept attending man's function
in that society, some communities in 1968 reported difficulty in getting men to take
jobs on the sanitation force.  Others reported this to be no problem but, neverthe-
less, 1968 saw a growing tendency for public employees to form unions and to go on
strike without evident penalty of laws forbidding strikes by public servants.  In
such diverse cities as New York and Memphis, it was made evident by sanitation
workers that labor costs are destined to  increase rather than to decrease in the
coming years.  The problem then becomes one of finding a way to attract labor to
sanitation jobs; to provide pay and other incentives sufficient to keep men reason-
ably happy and productive, so that service is not interrupted; and, at the same time,
to keep the cost of refuse collection in  scale with that of other municipal services
in terms of output of product.

        Some individuals officially concerned with developing programs designed to
solve problems of urban deterioration envision public subsidy to put labor to work.
Refuse collection has been cited as a natural area for such a program because of its
traditional need for large numbers of laborers.  There is, however, growing reason
to doubt the validity of the sociological assumption underlying this proposal, and
to suggest that, as in the case of on-site storage, the problem is most likely to
become one of devising a collection system which does not depend upon large numbers
of men for its operation.

        The problems of the collection system, especially that of changing it to a
low-labor operation without on-site storage, are unique.  In fact, the collection
system as a system is without parallel in either municipal utilities or in nature.
This is true as regards such aspects as  l)  nature of inputs;  2)  input energy
potential;  j)  direction of flow;  k) continuity of function; and  5)  labor input
to volume output ratio-

        If municipal and natural systems, which involve either in concept or in
physical configuration a main trunk or stream branched into myriad small inlets or
outlets, are compared with the existing solid wastes collection system, the unique-
ness of the latter is at once evident. Furthermore, it takes on an aspect of
improbability which makes questionable its long-term survival.

        Table 1 summarizes some of the principal system characteristics worthy of
further comparison.

        From an examination of Table 1, it is evident that only sewers and telephone
systems and such natural systems as streams and growing plants function by incremental
inputs at multiple points as does the refuse collection system.  Water, gas, and
electrical systems function by applying pressure in the main trunk by means of
mechanical equipment rather than by hand  labor.

        Delivery systems tend to function as reverse collection systems, with a high
labor-to-output ratio.  The volume of commercial delivery systems is, however,
small, and the customer pays the cost in  his milk or merchandise bill.  In the case
of the U- S. mail delivery system, where  the labor input is also high, the system
is kept from failure only by a subsidy which spreads the cost to the general taxpayer
on a national scale.  By analogy with the mail delivery system, the refuse collection
system as now conceived may be expected to fail in the long run unless the labor-to-
output ratio is reduced, or, the fact of  excessive labor cost is recognized and
accepted by the public-

-------
-p
+3 pi
3 P.
ft -p
o d pi
•H H O
-P O
S|* |

5 "o
^>



+3 d
•H O
Pi -H
d CH -P
•H O 0
-p d
d 3
o PC,
o



d
o
•H
-p >
o CH o
CD O rH
Jn P^i
•H
P




63
S-i H
CD CO
d -H
pj 43
d
-P CD
a +3
ft O
d PL,
H





ra

"§
ft
d
H
CH
o

CD
-p
S










e
CD
•P
ra
ra











js
o
H

£j>
CD


T3
cd

ra
j^
d P
•H cd
-P -H
d S-t
o cd
0 >
ra
0 "S
'n
X ft
P CD
+3 ft
•H
d -P
•H H
cd ^
S3 S
1
43
d
•H
cd


d
•H

CD

ra
ra
£
PH
1
-P

S3
•H
cd
0
-p

•g
ft
d
•H

ra
w
cd






^f
ft
&
ra
S-|
CD
4-=
cd
rs






J5
O

&
CD


^
d
CO

[n
j3
§3
d ,£>
•H cd
-P -H
d ^
O CO
0 >
ra
5*
'n
^3 ft
3 CD
^ H
4^ ft
•H
5S
cd p1
S E
|
43
g
•H
cd


d
•H

CD

ra
ra
S
PH
1
-p

d
•H
cd
o
-P

-g
ft
•H

ra
ra
cd












ra
cd

o
i — |

r*S
rH
bQ
d
•H
id
CD
CD
O
X
H

•d
d
cd

w
3
d ,0
•H CO
4= -H
d SH
O erf
O F>
ra
o £
'n
X p
Pi CD
1-t H
-P ft
•H
d 43
•H r-i
cd P*
S3 B
|
43
d
•H
cd


d
•H

CD

CO
ra
CD
S-i
PM
1
-P

d
•H
crt
O
4J

-p
pi
ft
d
•H

ra
ra
cd
2





^
43
•H
CJ
•H
4^
CJ
CD
H




>3
H
i-l
C8
•H
-P
a
 co ra
•H -H 43
•P d -d pi
d -H ft
o co o d
O B -P -H
ra
"S •*
'n P
ft *-l
CD
0,5

-P S
H
j3 O
S -P

J>j
-p
•H
[>
cd

oD

K*>
r^

d
O
•H
ra
d
^


+3
cd

4=
ft 43
d Id
•H ?-i
o
ra p.
d o>
QJ H
E PI
OJ -H
^H -P
0 H
d pi
H S








CO
£_i
CD
*j
QJ
ra









.j
o
^
ra
o
d CD Pi
•H H d
,JD -H
cq erf -P
Pi -H d
0 SH 0
2 0 CJ
d i> ra ra
•H -H 43
-p d -d pi
d -H ft
o ed o d
0 S -P -H
CO
1 T
'n Pi
ft ^
CD
H d
ft -H

rH
jj O
S -P
-p
CO
TJ
CD ra
ra 43
O rj
ft-H
B o
•H p.

CD CD
b H
3 ft
ra -H
ra 43
CD i-l
^ Pi
CM B


•p
cd

4^
3 ra
ft 4^
d d
•H .H
o
ra p
d CD
CD H
B ft
CD -H
M -p
CJ H
d d
H B







CD
d
o
ft
CD
1 — 1
CD
^










1
1

T3
d

[n
P
d £>
•H cd
•P -H
d ^,
0 CO
0 >
ra
•g ^
'rl P
ft ^
CD "^
ft -S

H
p1 o
2 -p

J>3
-P
•H
[>
cd

t>D

r"i
Q

O
•H
ra
d
^


4^
CO

43
Pi CQ
ft 43
d d
•H .H
O
ra p
? 3
CD rH
S ft
CD 'H
?H 43
CJ rH
d d
H B



S
CO
B
•P

hO
d
•H
>
o
H











1
1

•d
d
cd

ra
jj
O CD
a H
d rd
•H cO
-P -H
1 £
ra
d •«
'rl H
ft ^
CD
H d
ft -H

•P K
H
^ O
S 43
|
S-,
43
c3
-H

g

d
•H

d
o
•H
ra
d
^


•P
cd

43
PS ra
ft 43
d d
•H .H
O
ra p,
S3
g p.
CD -H
M 43
0 rH
d pi
H B





CD
CD

EH
bfl
d
•H
>
6

0









•a
•H
K


Pi 0
O -H
Pi id
d o
•H -H
4^ ^
d CD
O ft
O
ra id
R cd
w
o •£,
'n
"H ft
3 jj
-P ft
•H
d -p
•H S
CO 0
g B
1
•P
a
•H
[ri


a
•H

QJ
§
ra
ra
a
PH
1
4=

d [>3
•H ^
S **
•H
O i-H
-P CD

-g ^
d S'B'
•H o CD
-P -P
ra ra ra
ra pi i>>
& O CO

CD


i — | ^
1) >» CD
R ^ !>
CD -H
rH > H
•H -H CD
CO i — 1 R
S CD
R H
* CD
W A! o
H In

& g(5









•a
•H
M


3 o
O -H
^ r^
d o
•H -H
-S M
d CD
O ft
CJ
ra TJ
R co
ra
•g ^
'rl P*
R ^
CD
H S3
ft -H
*H rrt
H
^ O
S -p

CO
-p
Tj (H
CD -H
ra H
O p,
ft w
B GU
•H rH
ft
CU -H
3 H
ra p!
ra g
CD
PM cd


43
cd

-P
ft M
"'H -H
o
ra p
43
d CD
CD H
g PI
CD -H
^ 43
O rH
d 3
H S
d
o
•H
4J
CJ
3
H
O
O
CD
ra
pi
CH
CD
K

-------
10
        Assuming the continuance of existing system characteristics, the problem of
labor reduction in solid wastes collection systems has limited prospects except,
perhaps, by the adoption of one-man vehicles, as is presently under study,  or by
some as yet unconceived alternative.  A study of the problem of labor,  however,
might well begin with a, comparison of labor costs for various municipal depart-
ments —  e.g., water, gas, electricity, sewerage, buildings, parks, etc. —to
establish definitely the comparative labor-to-output ratios of refuse management and
other public works activities.

        If a change in system concept rather than in simple labor investment is
assumed, the problem becomes one of finding a feasible alternative to the present
system.  Returning to Table 1 and considering alternatives, only the sewer  system
among the utilities involves incremental inputs at points of origin.  However,
since the points of origin of sewage and solid wastes are the same households, two
possibilities appear:  l)  discharge of solid wastes to the sever, or  2)  development
of a refuse collection system which in concept is analogous to the sewer system.
The first of these is already partially in practice as a result of widespread use of
household and restaurant garbage grinders.  The question of what greater fraction of
the total mass of refuse might  be ground to the sewer has not yet been fully answered,
but it is well known that an appreciable fraction of household wastes cannot be
disposed of via the sanitary sewer.  Thus, the second must be considered for some
fraction of refuse.

        The concept of a collection system in which inputs are made at multiple
points by the householder or other generator of wastes and transport results from
tension in the main trunk is rationally feasible if tension is imposed mechanically
rather than by gravity.  This type of a system is, of course, in limited use outside
the United States.  Problems yet to be resolved, however, include economics and the
range of solid wastes fractions that can be transported with low-pressure air as the
transporting medium.

        A collection system in  which air or water pressure rather than tension is
imposed is not a hopeful idea.   Attempts to develop a sewer system pressurized
at each household have failed for reasons obvious to anyone familiar with pumping
problems, although pressurized transport along a limited number of branches in a
main trunk sewer is a well-established practice.  In solid wastes management, it is
feasible also, but introduces the added problem of noise, dust, and site location
of grinding and pumping stations, and does not solve the problem of collection and
delivery to such input points.

        From the foregoing considerations, it may be concluded that, although there
is good reason to direct major attention to the problems of refuse disposal which
remain unsolved in 1968, very difficult problems persist in the collection  aspect
of solid wastes management.


        Public Health Problems.  The problems of public health associated with solid
wastes management fall into a special category in which potential rather than
immediately recognizable crisis is the distinguishing characteristic.  Three general
classes may be identified:

    1.  Problems which are reasonably well solved, but remain solved only by
        constant vigilance.

    2.  Problems which are unsolved, but are incapable of resolution independent
        of technological, political, and planning problems.

    J.  Problems which remain either unidentified or unevaluated in relation to
        other environmental hazards.

        Problems which might be included in the first category occur in every aspect
of solid wastes management from on-site storage to ultimate disposal.  They include
such matters as production of flies, mosquitos, and other insect vectors; harboring

-------
                                                                                  11
of rats and other rodents; nuisance of blow-about of paper and other refuse, of smoke
and odors from burning fills, and dust from transfer or disposal operations.  Such
problems are, of course, timeless.  They were recognized and attacked by health
department activities long before 1966 and may be expected to continue long after
1968.  The overall problem they impose on health agencies is that of eternal vigilance
and the exercise of authority to control them to an acceptable degree.  At no time
can they be eradicated completely; hence their potential to degrade both human health
and man's environment remains a characteristic of solid wastes quite as real as its
physical aspects.

        The second class of problems include both physical and psychological hazards.
Refuse collection is known to be one of the most hazardous of occupations because
men are required to lift and carry heavy loads in congested traffic situations, and
to perform duties in dust that may carry bacteria, viruses, or inorganic particles
which may have serious physiological effects.  More subtle and less understood
problems are involved in the close contact of humans and refuse in overcrowded urban
environments.  The effect on man's health is of constant nuisance and a degraded
environment is a problem of public health concern which, however difficult to
identify, cannot be resolved separately from other problems, some of which are
involved with solid wastes management.  Similarly, the occupational hazards of
physical injury can be minimized by public health activities, but the problem itself
can be resolved only as problems of collection and disposal are resolved with
reduction of physical hazards as one of the objectives of the resolution.  A similar
situation exists in the case of air pollutants resulting from incineration, and the
noise and congestion from the collection operation.  Little change in this type of
problem from the public health viewpoint has occurred in the past two years, hence
concern must continue into the future.

        Problems falling into either of the first two classes cited call for vigilance
and supervision on the part of health authorities.  Research, however, is more
directly concerned with vector control, occupational health, and occupational medicine
than with solid wastes management per se.

        The third category of problems involves both medical and solid wastes manage-
ment aspects.  First, it is necessary to find that hazards to health exist in a vast
spectrum of ever-changing products of industry which may appear in solid wastes.
Therefore, the problem is to determine whether such materials constitute a hazard to
workers who handle solid wastes, or may escape from the disposal process to become
a danger to the public health.  In case such hazards do indeed exist, the problem
then becomes one of evaluating the risk involved in comparison with other environmental
hazards; and, finally, of establishing values which constitute the limits of acceptable
risk and devising ways to reduce the risk to such limits.  Because the answer to such
questions depends upon the simultaneous advance of research in medical toxicology,
solid wastes management procedures,  and environmental interrelationships, the questions
persist in 1968 and may be expected to continue into the indefinite future.


EVALUATION OF THE RESEARCH PROGRAM

        The research herein reported was directed to the problems of solid wastes
management identified as valid in 1966.  Five areas of investigation — planning,
economics, operations research,  technology,  and public health — (see Chapter I,
Nature and Scope of Study) constituted the program.  Assuming as correct the judgment
of the authors that the problems of solid wastes management to which the research
was directed initially persisted throughout the second year of study, evaluation of
the program is appropriate along four lines:

    1.  Continued relevance to solid wastes problems

    2.  Relative scope of the program and the overall problem of solid wastes
        management

    3-  Progress toward program objectives and solutions to the problem

    k.  Economic feasibility of  various aspects of the program

-------
12
        On the basis of familiarity with the program,  and an evaluation of it against
the problems discussed in preceding paragraphs,  it is  the general conclusion of the
authors that the research effort remained relevant to  the problem of solid wastes
management throughout the period reported.  In Chapters III through XI which follow,
progress is reported on various aspects of the program and specific conclusions are
presented concerning relevance and scope.  In Chapter  V estimates of the economic
feasibility, particularly of technological aspects of  the program,  are presented.
These more detailed evaluations of the program are expected to furnish guidelines
for further work on the project, and perhaps suggest to other researchers some areas
to which investigative work might be directed.

-------
                                  Ill.  FLAMING
INTRODUCTION

        The long-term objectives of the planning team as set forth in the First
Annual Report  [l] of the project were as follows:

    1.  Development of structural models of wastes generation and obtaining the
        required data on solid wastes and other related variables with reference
        to a particular study region.

    2.  Exploration of the implications of changes in transportation and disposal
        technologies on solid wastes management and resources use in the study
        region.

        Pursuant to these objectives, the first year of study (1966-67) was directed
to a pilot study of wastes generation in Santa Clara County, California, in order
to give definite form and content to the research method and objectives.

        During the second year of study (1967-68), herein reported, investigative
work was directed to several aspects of the wastes management problem.  The objec-
tives and methods of approach were tested against the realities of the situation
and accordingly modified to suit the contingencies of research.  Inasmuch as the
development of some of the facets of the work hereinafter discussed are incomplete,
the analysis of them is necessarily carried on into the third year (1968-69) of the
project and hence the subject of a subsequent report.


Rationale
        The complexities which beset solid wastes management suggests heuristically
a need for regional or subregional approaches which can come to grips with the real
problem and can lead to long-lasting solutions that are both efficient and satisfac-
tory to the community at large.  Before a regional system for disposal of solid
wastes can be devised, however, it is necessary to have accurate information concerning
generation of the wastes, i.e., of the quantity, source, composition, distribution,
and variability of solid wastes.

        Solid wastes are inherently integrated into the total problem of air and
liquid wastes pollution.  The burning of solid wastes increases air pollution; the
use of garbage grinders increases the load on the liquid wastes disposal system.
On the other hand, measures undertaken to abate the air pollution problem or to
decrease the output of liquid wastes usually result in an increase in the quantity
of solid wastes that must be handled.  Thus, the generation of solid refuse not only
is a function of the existence of households and municipalities, it is a consequence
of all productive processes.  Business, industry, and agriculture all generate solid
wastes, and therefore the source should be identified under categories such as
"households," "type of commercial, industrial, or agricultural activities," or other
appropriate categories of generators of wastes.  For decisions regarding the
feasibility of disposal methods, composition of wastes must be further distinguished
by "type (garbage, rubbish, street refuse, etc.) and by physical and chemical proper-
ties (caloric value, nitrogen content, etc.).  In addition, the need exists for
estimating significant relationships that explain the amount and types of wastes
generated in a given region based on comparable data relating to wastes generation
and specific wastes generators.  In order to specify the various data requirements
in detail and to formulate the specific relationships to be estimated, it is necessary
to devise a model-building framework that is conceptually sound and at the same time
operationally feasible for a given region.  Also, since standards of solid wastes
management depend on criteria based on aesthetic values, public health, and economic

-------
efficiency, it is necessary that these constraints be effectively recognized within
the model.  With an awareness of such social and political aspects,  alternative
solutions to the problem can be developed with the aim of making it  possible to
select an optimization program.  Furthermore, the differences in the future economic
development of the region will have both qualitative and quantitative effects on the
amount and types of solid wastes that must be handled within the system in the
future.

        Thus, in recognizing and establishing a regional solid wastes management
system, it is imperative to formulate the initial data base with great clarity and
consistency so that the system is operationally feasible and subject to revision
whenever there is a structural change in the system.  The specification of the
relevant variables will be instrumental in discerning the regional differences in
solid wastes management systems and sets the stage for further analytical research
work.  The aggregation of variables should be governed both by theoretical necessity
and data availability.  After the variables in the system are stipulated,  the inter-
relationships between the amount of solid wastes generated and other concomitant
variables should be estimated through structural equations of the model framework.


Objectives of the Regional Solid
Wastes Generation Model

        There are two principal objectives of the regional solid wastes generation
model.  The first is to develop a comprehensive, factual basis for the quantitative
aspects of the regional wastes management system by giving due conside'ration to the
spatial and functional nature of the region.  The second is to use this factual base
as the primary source of data in analyzing and estimating future volumes of solid
wastes that would be handled within the system.

        The ultimate goal of the analysis is to provide any given region with
generalized methods of approach for arriving at a solution to the solid wastes
problems within its functional boundaries.  While it is possible to  develop a
theoretical framework with very little practical significance, the need today is
to incorporate many of the systems analysis techniques into a comprehensive model
that will give solutions capable of testing against the levels of data that are
presently available.  Traditional methods of recording data on amounts and types
of solid wastes generated by the scavenger companies thus far have precluded a
thorough analysis based on theoretical grounds.  By necessity, the method at present
should conform to the available body of data.  A systems analysis approach based on
existing data will facilitate a more thorough understanding of the solid wastes
management problem than heretofore possible, and will provide insights into the
various aspects of the problem which hitherto have been considered only on the
periphery.


THE INVESTIGATION
Study Region

        To test the validity of the regional model,  an area of presently fragmented
jurisdictions was chosen which encompasses most of the complexities  of the  wastes
management problem.  Because of its nature and proximity,  the nine-county
San Francisco Bay Area region was selected as the operational area.   The planned
approach is to collect and correlate data on the types and quantities of solid
wastes generated in the Bay Area, along with data on the wastes generators, and
attempt to explain the interrelationships among them for further study and  analysis.
     Alameda, Contra Costa, Marin, Napa,  San Francisco,  Santa Clara,  San Mateo,
Solano, and Sonoma counties.

-------
                                                                                  15
Specification of Variables

        Wastes generation is a consequence of a variety of economic, geographic,
and demographic factors, and each category of wastes may be associated with one or
more explanatory variables.  The major variables explaining wastes generation are
population, income, employment, and land use.  These and other less significant
variables can be used to develop cross-correlations that will identify their
relationships to the various categories of wastes and thereby facilitate effective
projections of solid wastes volume.

        In an ideal analytical model, every conceivable interrelationship between
sources and types of wastes, and the activities that might affect the generation
of the wastes, would be set forth and tested.  While cost constraints and data
limitations dictate that the actual dimensions of the model may be less than ideal,
the specification of relevant relationships should be as complete as possible.  A
particular case study may aggregate the relationships to data needs, but the
theoretical formulation should be available for a more detailed analysis as addi-
tional data on solid wastes are developed.

        According to the initial research plans as set forth in the First Annual
Report, five major sources of wastes were recognized, namely, household, commercial,
manufacturing, agricultural, and special.  The plan was to collect data on the total
amount of solid wastes generated by these major sources, and to relate the wastes
generation to corresponding explanatory variables such as population, income,
employment, and land use by type of manufacturing, commercial, or agricultural
activities within the study area.  Had data on solid wastes generation been available
by sources of wastes, a regression study of the relationships among the types of
wastes (as the dependent variable) and other explanatory variables would have been
carried out.  However, the data on solid wastes generation from the various sources
were not fully accounted for, even though special efforts were made to supplement
the data obtained from disposal site operators.  Because of the contingencies of
the research and of the operational characteristics of the San Francisco Bay Area
solid wastes study, the intended approach had to be modified.

        The present modified approach — somewhat less idealistic than the original —
consisted in developing the data needed on solid wastes generation from the source
units and wastes multipliers.  In so doing, the present method preempted the use of
regression analysis of wastes generation.  However, it calls for the recognition of
important explanatory variables for each of the types of wastes to be considered in
the study.

        As a result of this modification, the wastes sources have been recognized
in greater detail than was originally contemplated.  Each source of wastes is
measured by the size of the explanatory variables, e.g., residential wastes sources
by households or population, commercial and industrial wastes sources by employment,
agricultural wastes sources by acres of land used, number of trees per acre, and
number of animals per acre, etc.

        The various steps involved in developing solid wastes generation can be
briefly stated as follows:  l)  definition of functional boundaries,  2)  collection
of data on source units, and  j)  development of appropriate wastes multipliers by
type of economic activity.


Definition of Functional Regions
(Disposal Service Areas']

        To develop data on solid wastes and related variables on a uniform basis, it
was necessary to define a set of functional geographic units into which the study
region (the nine-county San Francisco Bay Area) could be divided.  Since this divi-
sion is instrumental in explaining the interrelationships between several variables,
it was desirable to choose the smallest geographic unit so that a large number of
independent observations could be developed for analysis.

-------
16


        The I960 Census tracts (boundaries) have been and are being used as primary
units in many empirical studies since they provide an initial data base for building
up various economic data such as population, employment,  and land use.  However,
while data on demographic and economic elements are available by Census tracts for
the recent period 1965-66, corresponding data on solid wastes generation are conspic-
uously absent for such small geographic units.   It would have been ideal if data on
solid wastes generation had also been available by Census tract, since such a
situation would have provided 750 or more observations for the present study.

        Inasmuch as the use of Census tracts as primary geographical/functional
units for wastes disposal was preempted by the  paucity of solid wastes data, larger
units consisting of groups of Census tracts (or parts thereof) were considered as
the primary functional boundaries for analysis.  Consequently, the available data on
explanatory variables such as population, employment, and land use had to be aggregated
spatially to correspond to the larger units defined as the primary functional bound-
aries .  These primary functional boundaries, designated in this study as "Disposal
Service Areas" (DSA's) form the basis for developing comparable data on all variables
for study and anlysis.  The DSA, as defined in  this study, transcends all political
boundaries (city or county) and establishes functional boundaries.  This definition
serves the purpose of establishing mathematical relations among wastes generation
and other variables.  The definition of an individual DSA is a nebulous one, as are
all functional boundaries, and therefore it must be brought up-to-date if and when
a change occurs in the nature of the function it represents.


Location and Identification of Disposal
Sites and Functional Regions (PSA's)

        Before actually delineating the functional boundaries (DSA's), it was neces-
sary to locate and identify each and every solid wastes disposal site that receives
wastes.  Using the information developed by the California State Department of Public
Health, a complete list of disposal sites was made and located on the county maps.
These are given in Tables k-h through 52 in Appendix A.

        Following the location of the disposal  sites, the next step was to define
the disposal service areas into which the study region could be divided for developing
the primary data.  The actual drawing of boundary lines for each DSA was done as
follows:  If a disposal site received wastes generated from one or more Census tracts
(or parts thereof), that region was defined as  a disposal service area.  In situations
in which two or more disposal sites receive wastes from two or more overlapping
boundaries, and it was impossible to split the  boundaries meaningfully, a single
disposal service area was defined to consist of that total area.  In other cases, the
Census tracts were split between different disposal service areas, since it was
possible to identify these parcels.  Thus, the  amount of wastes deposited in the
site (sites) is always made comparable to the wastes generators with reference to the
functional boundary (DSA) as the basis, thereby eliminating any arbitrary splicing
of boundaries.  For the purpose of this study it was possible to divide the study
region (nine-county San Francisco Bay Area) into k2 functional boundaries.  These
boundaries, as identified by the Census tract codes, are given in Table 53 in
Appendix B and in Figures 37 through ^5 in Appendix B-

        Problems encountered in defining disposal service areas for the nine Bay Area
counties generally stemmed from two primary sources.  The first source was the
multiple-county use of a particular disposal site.  This practice necessitated the
formation of "cross-county" DSA's.  The second  was the splitting of Census tracts to
correspond to collection boundaries when the scavenger company collection routes did
not coincide with Census tract boundaries.

        After a careful and detailed consultation with the California Department of
Public Health arid local city and county public  health agencies, a consistent set of
boundaries was established.  The locations are  shown in Appendix A; the allocation
of disposal sites by functional boundaries in Appendix B; and the detailed list of
Census tracts are given in Tables ^k through 6j in Appenxid C.  Once the

-------
                                                                                  17
functional boundaries were defined, a systematic approach to data collection was
required to maintain the standards of consistency, reliability, and comparability.
The approach was formulated after a considerable effort had been made to determine
the appropriate method of data retrieval given the constraints of time and costs.
Since very little time-series data on solid wastes were available on a comparative
basis, only spatial data on a cross section basis were incorporated into the model.


Development of Data on Solid Wastes
Generation and Related Variables


        Solid Wastes Generation.  The development of complete and consistent data  on
solid wastes generated in the study region by functional regions (DSA's) and type  of
wastes generating source is of prime consideration.  Data on wastes generation and
disposal are being collected by public health agencies through on-site interviews
with disposal site operators and with officials of the scavenger companies that
collect refuse in the region.  Although a mailed survey was conducted on a pilot
basis in one of the counties (Santa Clara, California) to determine data collection
procedure, it was later deemed appropriate to coordinate our own data collection
efforts with those of the California State Department of Public Health.  These
initial plans have been described in the First Annual Report [l]•  According to the
agreed-upon plan, the data on solid wastes generation by functional boundaries were
to be collected by the California Department of Public Health as part of their ongoing
studies and supplied to this project.


        Collection of Solid Wastes Data from Disposal Site Operators.  The actual
data collection procedures used by the California Public Health Department involved
a specific timetable for interviewing and surveying particular counties.  Accordingly,
the nine Bay Area counties were surveyed by the Public Health Department at different
times.*  The Santa Clara county survey was completed in April, surveys of Contra Costa
and Marin in May, and of Solano and San Mateo counties in June of 1967-  The survey
of Alameda was finished by the end of September 1967-  The variation in reference
periods, together with certain inherent data difficulties, gave rise to some incom-
parabilities which had to be reconciled before the data could be properly analyzed.

        Each of the operators of nearly 100 disposal sites within the Bay Area was
personally interviewed by the California Public Health group.  Usually estimates were
based on the characteristics of the collection vehicles, their routes, and the amounts
in the fill that could be ascertained.  The data were based upon the month-to-month
average daily amounts deposited at the individual sites during the year preceding
the survey, and were expressed in tons per day.  Since the dates of each county's
interviews varied, some noncomparability exists between the per day averages.  When
the actual amounts of wastes could not be obtained, close approximations were attempted
by the Public Health Department interviewers with the use of a variety of methods.
The methods included making a percentage estimate of the amounts of each category  of
wastes contained in each truckload, using as a basis information on known routes and
known load categories, percentages obtained in other surveys, and of estimating
percentages of wastes in the site, taking into consideration the average compaction
ratio for the site.

        Data on solid wastes received at the disposal sites were tabulated by the
California Public Health Department under ten major types, viz., garbage and rubbish,
bulky wastes, street refuse, food processing, industrial sewage solids, agricultural,
demolition, ashes, dead animals, and special.  Even though some indication was made
as to type of wastes received, no quantitative estimates were made by type, and only
the total wastes received at the sites were estimated.
    *
     The Health Department is collecting data from all the 58 counties in California
as part of their 3-year study of the State as a whole.
   388-229 O - 70 - 17

-------
18
        The survey brought to light the interesting fact that a considerable amount
of wastes does not find its way to the disposal sites.  Consequently,  the sum total
received collectively at all of the sites represents only a fraction of the total
quantity of wastes generated in the Bay Area.  Using the solid wastes  data as repre-
sented by the sum total received at the disposal sites,  one could infer that the
average daily per capita household wastes at the time the survey was made was around
5-3 pounds, varying from as low as 2 pounds to as high as 11 pounds.  A detailed
tabulation of comparable wastes figures, population, total and average per capita
wastes is given in Table 2 for each of the 42 functional boundaries defined in this
study.

        A thorough analysis of functionally comparable factors relating to the wastes
data in Table 2 proved to be practically impossible, because the amount of wastes
received at the disposal sites in the Bay Area represents only about 35 "to ^0 percent
of the total wastes generated in the area [2].  (The remainder, consisting of
commercial, industrial, and agricultural wastes, is disposed of elsewhere.)  Moreover,
the wastes received at the sites are not strictly residential, inasmuch as some
commercial, and possibly a slight amount of industrial,  wastes (such as food
processing) are included.  Of prime importance is the fact that the wastes generated
by the bulk of commercial, industrial, and agricultural sectors in the region were
omitted from the tabulation (Table 2), inasmuch as the wastes were not transported
to regular disposal sites.  Efforts are currently being made by the Health Department
to fill these deficiencies in the tabulation.

        The incompleteness inherent in data based solely on wastes received at
disposal sites made it necessary to develop methods for making estimates of the
total wastes generated by various sources before the analyses required by the present
study could be made.


        Estimation of Solid Wastes Quantities from Sources of Wastes and Wastes
Multipliers.  Data on solid wastes can be classified in different ways, using
different criteria for classification.  Essentially, they can be classified by
detailed sources, and by composition relating to a reference region which, in the
present case, is a functional region (DSA).  The major sources of solid wastes are
the residential, commercial, public agencies, industrial, and agricultural sectors
of the region.  These could be classified in further detail from the point of view
of studying the present rate of generation and future changes in quantities of wastes
corresponding to changes in the sources.  The composition of wastes can be classified
according to the physical or chemical properties of wastes from the transfer and
disposal point of view.  Composition could be broken down as follows:   bulky or
light, combustible or noncombustible, organic or inorganic, dry or wet basis, and,
finally, by proportions of the different items, e.g., paper, glass, wood, plastics,
ferrous and nonferrous metals, etc.  Judging from the existing literature, a
delineation of the full gamut of cross-classifications of wastes relating to a
particular region's wastes has rot been made as yet.  In the present study, the plan
calls for the definition of the sources of wastes in the required detail, and for
the estimation of the wastes quantities on an objective basis to describe the wastes
generation in the functional regions.  Other related information on composition is
to be gathered and applied to the basic wastes data on a .consistent and comparable
manner in future research work.  In this report, emphasis is placed on the detailed
development of sources and wastes generation.  During the third and subsequent years,
possible future changes in quantities and in composition will be examined in detail
while alternative transportation and disposal technologies will be considered for
feasibility.


        Sources of Wastes.  The principal sources of wastes (residential, commercial,
etc.) can be broken down further, depending upon the need, the nature  of the wastes
generation, and the composition characteristics.  In this study, the sources identi-
fied for purposes of estimating the wastes generation by each functional boundary
(DSA's) are listed in Table 3.  A detailed definition of these sources is given in
Appendix D.

-------
                                                                       19
                           TABLE 2

DETAILED TABULATION OF COMPARABLE WASTES FIGURES, POPULATION,
             TOTAL AND AVERAGE PER CAPITA. WASTES
Disposal Service Area
Code
01 01
02
03
Oil
05
06
02 01
02
03
03 01
02
Ok 00
05 01
02
03
04
05
06
07
08
09
10
11
12
05 oo
06 01
02
03
Ok
0? 01
02
03
Ok
05
06
07
08
08 01
02
09 01
02
03
Ok
Name
Berkeley
Oakland
Alameda
Fremont
Pleasanton
East Alameda County
West Contra Costa
Central Contra Costa
East Contra Costa
West Marin
East Marin
Napa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Ness
Potrero -Bayshore
Outer Mission
So. Frway-Mt Davidson
Lake Merced
Sunset
San Francisco
Daly City
South San Francisco
Pacifica
Central San Mateo
Palo Alto
Mountain View
Sunnyvale
Gilroy -Morgan Hill
Los Gatos
Los Altos
San Jose
Remainder of County
Vacaville
Fair fie Id
Healdsburg
Santa Rosa
Western Sonoma
South Sonoma
TOTAL ALL DSA's
Population

117,870
691,900
69,200
122,250
25,300
32,500
235,006
280, 530
60,340
10, 6l6
127,051
152,467
90,5^0
67, 100
93,295
28,260
52,815
63,025
43,570
45,800
83,000
58,075
29,620
92,400
747,500
65,000
105,100
4o, 500
303,320
68,593
51,178
84,703
24,201
174,684
180,450
344,775
3,091
29,491
65,104
17,690
82,810
8,765
78,375
4,400,360
Solid Wastes
tons/day
145
1,652
375
275
30
50
88l
432
215
9.63
190-37
183
*^v




lb/day
290,000
3,304,000
750,000
550,000
60,000
100,000
1,762,000
864,000
430,000
19,252
380,748
366,000





> Data Not Available





_x
2,699
89
395
60
710
175
170
256
36
370
570
1,005

78
127
63
181
47
l4o
11,609






5,398,000
178,000
790,000
120,000
1,420,000
350,000
34o,ooo
512,000
72,000
740,000
1,140,000
2,010,000

156,000
254,000
126,000
362,000
94,500
280,000
23,218,000
Ib/capita/day
2.46
4.78
10.84
4.50
2.37
3.08
7-50
3.08
7-13
l.8l
3.00
2.40












7.22
2.74
7.52
2.96
4.68
5-10
6.64
6.04
2.98
4.24
6.32
5.83

5.29
3-90
7-12
4.37
10.78
3-57
5.28

-------
20
                                      TABLE 3

                              LIST OF WASTES SOURCES
Source
No.
Description of the Source of Wastes6
            1.
              la
              Ib
            2.
            3-
            k.
            5-
            6.
            7.
              8a
              8b
              8c
              8d
              8e
              8f
              8g
              8h
              8i
              8J
              8k
            9-
           10.
           11.
           12.
           13.
           Ik.
           15-
           16.
           17-
           18.
           19-
           20.
           21.
           22.
           23.
           24.
           25.
           26.
           27.
           28.
           29.
           30.
           31.
Residential
   Single-Family Dwelling Units
   Multiple-Family Dwelling Units
Restaurants and Hotels
Institutions - Private (Schools and Colleges)
Public Offices and Facilities
Health Services (Private)
Commercial and Service Establishments (Private)
Construction and Demolition (Private and Public)
Agriculture
   Orchards and Vineyards
   Vegetables, Berries, and Seed Crops
   Field Crops
   Milk Cows
   Feedlot Cattle
   Hogs and Pigs
   Hens and Pullets
   Turkeys
   Other Poultry
   Cut Flowers (Nursery)
   Dead Animals
Extractive Industry (Mining)
Canning and Preserving
Other Food Processing
Tobacco Industry
Ordnance and Accessories
Textiles and Apparel
Lumber and Wood Products
Furniture and Fixtures
Paper and Allied
Printing, Publishing, and Allied
Chemicals and Allied
Petroleum Refining
Rubber and Plastic Products
Leather and Allied
Stone, Clay and Glass
Primary Metals
Fabricated Metal
Nonelectrical Machinery
Electrical Machinery
Transportation Equipment
Professional and Scientific Instruments
Miscellaneous Manufacturing
Nbnclassifiable Establishments
                  sources are described in detail in Table 65 in
            Appendix E.

-------
                                                                                  21
        Solid Wastes Multipliers.   Estimation of the amount of solid wastes generated
by various sources of wastes (Table 3) for each of the k2 disposal service areas
(functional boundaries defined in Appendix B) involved the following steps:

    1.  The wastes source units were measured either as number of units,  or by
        level of activity represented either by employment or land use.

    2.  For each source of wastes, wastes multipliers were developed from
        available ongoing research studies.  For example, results of solid
        wastes loading studies carried out in Santa Clara County, California,
        were utilized in developing the wastes multipliers.

    3.  Finally, the solid wastes generation was calculated as the product of
        the wastes multipliers and the level of source units developed in this
        section.

This approach had to be used because original and complete data on total  amounts of
solid wastes by functional boundaries could not be estimated for the study region
by any other method.

        Development of the wastes multipliers and wastes sources is discussed  under
the following categories:  residential, commercial, nonmanufacturing and  public
agencies, industrial, and agricultural sources of wastes.  The development of  wastes
multipliers for residential, commercial, nonmanufacturing and industrial  sources of
wastes was based on information collected through sample surveys conducted by  the
Food Machinery Corporation (FMC) in Santa Clara County (California) in 196? and  made
available to this research team.  In the case of agricultural sources of  wastes,
nearly all of the needed information was collected and analyzed by this research
team.  The detailed development of wastes multipliers is given below.


        Residential Sources (Source Numbers la and Ib in Appendix D).  Wastes
multipliers were developed for single-family dwelling units and multiple-family
dwelling units from a sample survey of households conducted by Food Machinery
Corporation (FMC) in Santa Clara County.  This sample included 359 single-family
and 7^ multiple-family dwelling units.  The wastes data were considered reasonably
complete and accurate.  The average quantity of rubbish from single-family dwelling
units was estimated at 2858 pounds (or 1.^3 tons) per dwelling unit per year.  This
includes both the amount collected by regular collection agency and the amount
hauled by the individual to the disposal site.  For the multiple-family dwelling
units, the average quantity was estimated at 1315 pounds (or 0.66 tons) per dwelling
unit per year.  It was assumed that the latter did not have any appreciable quantities
hauled by the individuals to the disposal sites.

        The number of single- and multiple-family dwelling units for 1966 was
obtained from the Bay Area Simulation Study conducted by the Center for Real Estate
and Urban Economics, University of California, for each of the k2 DSA's (Appendix
B).  The residential wastes figures were developed by multiplying the number of
units and the corresponding multipliers.  These are given in Table k.


        Commercial, Nonmanufacturing, and Public Agency Sources (Source Numbers  2
through 7 in Appendix D).These categories consist of a variety of sources, viz.,
shopping centers, hotels and restaurants, schools, hospitals, private and public
offices, and other allied sources  of wastes such as streets, parks, freeways,  etc.
The data on employment by these sources were developed on the basis of the data
furnished by the California Department of Employment (Management Analysis Section)
through the Association of Bay Area Governments.  The original data on employment
were available by Census tracts and SIC industry type.  These have been aggregated
to conform to the boundaries of the DSA's defined in this study (Appendix B)•  The
data on employment by DSA for each of the nonmanufacturing sources, sources 2  through
7, are given in Table 5 along with industrial sources.  The aggregation of employment
data for the above categories as developed in this study do not strictly  conform to

-------
22
                                        TABLE 4
                                  RESIDENTIAL WASTES
Disposal Service Area

Code


01 01
02
03
Ok
05
06
02 01
02
03
03 01
02
Ok 01
05 01
02
03
ok
05
06
07
08
09
10
11
12
06 01
02
03
ok
07 01
02
03
ok
05
06
07
08
08 01
02
09 01
02
03
04

Name


Berkeley
Oakland
A lame da
Fremont
Pleasanton
East Alameda County
West Contra Costa
Central Contra Costa
East Contra Costa
West Marin
East Marin
Napa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Ness
Potrero -Bayshore
Outer Mission
So. Frway-Mt. Davidson
Lake Merced
Sunset
Daly City
South San Francisco
Pacifica
Central San Mateo
Palo Alto
Mountain View
Sunnyvale
Gilroy -Morgan Hill
Los Gatos
Los Altos
San Jose
Remainder of County
Vacaville
Fairfield
Healdsburg
Santa Rosa
Western Sonoma
South Sonoma
TOTAL
Housing Inventory
Single -
Family
Units
1
20,9^9
15^,393
12,944
21,760
2,024
5,838
57,719
63,084
1^,996
3,636
27,530
40,190
13A95
3,629
2,034
2,215
1,619
7,541
2,21?
5,623
17,973
14,543
7,822
27,328
15,675
25,684
8,738
76,172
16,600
10,438
19,354
6,002
38,192
42,461
73,259
782
7,768
ll,88i
7,401
24,320
2,796
24,008
942,633
Multiple-
Family
Units
2
20,183
72,598
11,757
3,772
586
663
13,526
9,340
2,688
189
7,657
8,200
25,043
26,508
55,954
11,107
19,385
18,451
12,472
4,804
8,507
5,689
2,635
7,160
3,583
4,689
1,311
23,492
4,424
4,446
6,278
365
8,459
6,787
19,147
38
595
5,567
742
3,580
280
2,410
445,067
Wastes Generated (tons/yr)
Single -
Family
Units
3
29,938
220, 643
18,498
31,097
2,892
8,343
82,486
90,153
21,431
5,196
39,343
57,436
19,286
5,186
2,907
3,165
2,314
10,777
3,168
8,036
25,685
20,783
11,178
39,054
22,401
36,705
12,487
108,857
23,723
14,917
27,659
8,577
54,580
60,681
104,694
1,118
11,101
16,979
10,577
34,756
3,996
34,310
1,347,113
Multiple -
Family
Units
4
13,271
V7,737
7,731
2,480
385
436
8,894
6,142
1,767
124
5,035
5,392
16,467
17,430
36,793
7,303
12,747
12,132
8,201
3,159
5,59^
3,741
1,733
4,708
2,356
3,083
862
15,447
2,909
2,923
4,128
240
5,562
4,463
12,590
25
391
3,66i
488
2,354
184
1,585
292,653
Total
Wastes
All Units
5
43,209
268,380
26,229
33,577
3,277
8,779
91,380
96,295
23,198
5,320
44,378
62,828
35,753
22,6l6
39,700
10,468
15,061
22,909
11,369
11,195
31,279
24, 524
12,911
43,762
24,757
39,788
13,349
124,304
26,632
17,840
31,787
8,817
60, 142
65,144
117,284
1,143
11,492
20,64o
11,065
37,110
4,i8o
35,895
1,639,766
NOTE:  Columns 1 and 2:  Bay Area Simulation Study (BASS),  University of  California,
                            Center for Real Estate and Urban Economics
              Column 3:  Column 1 multiplied "by 1.42910 (see text)
              Column 4:  Column 2 multiplied "by 0.65755 (see text)
              Column 5:  Column 3 plus Column 4

-------
                                                         TABLE 5

                                         EMPLOYMENT BY DSA AMD BY WASTES SOURCE"
                                                                          23
DSA
1
01 01
02
05
ok
05
06
02 01
02
03
0} 01
02
Ok 01
05 01
02
03
o4
05
06
07
OS
09
10
Restaurants
and
Hotels
2,243
9,573
562
527
78
l81i
2,308
2,lll6
556
45
1,637
1,741
1,037
1,1(69
20,407
3,32|i
464
21'
1,270
327
1*52
222
11 241
12
1(90
06 01 • 501*
02
1,721
03 191
04 ! 5,153
07 01
1,358
02 713
33 1,380
oil ' 319
05
06
07
08
1, 526
1,74'
"(,608
22
08 01 lit
02
09 01
782
395
02 459
03
Oil
TOTAL
179
1,753
75,321
Institutions
Private
(Schools and
Colleges)
3
1(05
2,156
150
69
0
32
361
507
511
0
84o
1,222
1,269
632
567
1«3
137
93
468
Public
Offices
and
Facilities
4
23,656
33, 744
14,058
3,410
687
6,821
7,174
11,555
1,996
196
6,231*
17,708
10,461
7,934
14,794
14,315
2,634
1,770
3,374
'i3 \ 9,734
261
1,119
281* 2,01(3
119 3,153
278
81
183
8
795
9,095
151
26
21
1,874
1,302
4,708
861
13,235
3,378
Health
Services
(Private)
5
2,345
10,789
730
272
30
335
1,537
2,617
357
16
1,913
1,851
4,549
3,325
4,092
Commercial
and
Service
Establish-
ments
(Private)
6
15,405
127,192
4,735
6,730
892
2,102
24,100
21,677
4,983
150
16,738
11,190
9,641
9,123
108,121
194 66, 9^2
1,580
Construction
and
Demolition
(Public and
Private )
7
2,044
13,259
1,442
4,569
1,897
1,26,8
4,276
8,822
669
126
3,104
1,872
1,541
4,520
10,382
1,268
6,<'ll ' 1,005
584 2,701 1,027
707
13
1,126
49
274
365
271
679
61
4,128
3,379
19,688 689
11,173 357
4,802
3,450
4,189
6,886
5,593
31,619
1,193
48,044
19,062
1,835 : 297 8,731
5,813
630
172 1 4,004
798
685
0
6
151
39
39
lil
226
22,647
4,750
18,150
125
1,312
4,988
778
744
258
3,986
271,301
34l 10,056
290 2,033
1,432 I 10,563
1,610
4,053
0
51
828
254
36
176
1,779
59,295
13,288
46,566
1,147
2,776
6,090
4,038
1,504
1,085
14,691
720,320
309
1,335
120
104
1,687
2,865
1,223
8,528
3,382
1,819
2,831
391
3,981
3,257
6,418
0
549
955
4 10
390
164
3,095
107,950
Agriculture
8
152
1,301
123
2,516
519
1,109
194
I,o02
3,812
169
1,029
3,731
66
Extractive
Industry
9
0
873
0
145
232
0
174
131
30
0
Canning
and
Preserving
10
420
5,279
81
207
6
10
196
135
288
0
80 o
0
0
0 55
10 1 1
4i6
13
18
14
14
°4o f
-------
TABLE 5 (Continued)
DSA

01 01
02
03
01*
05
06
02 01
02
03
03 01
02
Ol* 01
05 01
02
03
04
05
06
07
08
09
10
11
12
06 01
02
03
ok
07 01
02
03
Oil
05
06
07
08
08 01
02
09 01
02
03
2l*
16,029
0
0
0
3,779
0
0
0
0
0
0
0
22,81*7
Textiles
and
Apparel
lit
2
1,11*7
0
33
0
153
52
It
0
0
111
1*86
36
13
2,500
2,759
139
0
1,780
51*3
89
7
0
8
13
235
1*
137
1
1
0
0
95
25
568
0
0
0
57
0
0
1*0
10,91*1
Lumber
and
Products
15
32
878
156
9
0
0
57
17
36
0
156
10
0
5
12
51
0
0
l*lt
128
0
0
0
i
it
63
0
271*
32
111
0
1
23
257
182
0
0
23
689
307
636
196
4,390
Furniture
and
Fixtures
16
207
1,168
22
279
1*1*
0
185
21*
0
0
26
32
1
6
836
346
77
0
405
568
33
0
0
20
0
309
0
1*36
0
69
9
1*0
ItO
346
117
0
0
0
2
1*
28
43
5,722
Paper
and
Allied
Products
17
Ml
2,696
187
661
0
0
47
3
2,815
0
17
28
0
0
295
797
0
0
223
54
0
0
0
0
0
1198
0
123
ll*6
0
30
33
268
638
500
0
0
0
0
0
0
0
10,1*70
Printing,
Publishing
and Allied
18
580
4,230
68
137
0
56
510
473
112
0
320
359
12
67
4,379
6,698
lt27
33
81*2
117
9
3
2
16
34
709
28
1,543
568
225
267
34
l4o
403
1,61*1
0
52
58
162
I*
26
101*
25,408
Chemicals
and
Allied
19
2,077
1,926
575
701*
0
0
1,709
970
1,093
0
0
15
2
3
770
726
3
0
121
139
23
5
0
0
0
1,089
0
858
67
30
145
72
10
188
686
0
0
0
3
0
27
8
llt,oW*
Petroleum
Refining
20
lit
1,61*8
0
30
0
0
4,120
l,74l
0
0
0
0
0
0
2,623
750
0
0
38
0
0
0
0
0
0
33
0
264
1
35
0
0
0
0
97
0
0
0
0
0
0
0
11,394
Rubber
and
Plastic
Products
21
134
827
11
0
0
0
47
10
287
0
55
12
0
0
1
113
0
0
l*lt
50
0
3
0
0
0
113
0
21.3
0
3
7
2
7
30
ltl*lt
0
0
0
0
0
7
0
2,450

-------
TABLE 5 (Continued)
DSA

01 01
02
05
Oil
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
Oil
05
06
07
08
09
10
11
12
06 01
02
03
01*
07 01
02
03
01*
05
06
07
08
08 01
02
09 01
02
03
04
TOTAL
Leather
and
Allied
22
85
101
0
0
0
0
192
0
0
0
0
132
0
0
1
95
0
0
5
184
0
0
0
1
0
85
0
2
0
0
0
3
0
0
0
0
0
0
0
0
0
159
1,043
Stone ,
Clay,
and
Glass
23
74
3,445
0
325
149
0
673
353
554
0
203
77
43
7
373
9k
0
0
355
130
2
0
0
0
"45
207
0
521
18
13
36
39
3
1,745
776
0
37
44
0
0
0
86
10,427
Primary
Metals
2k
564
3,576
0
1,247
0
0
224
517
3A95
0
125
632
0
0
844
187
0
0
193
289
0
0
0
0
0
1,464
0
269
10
0
0
0
4
474
284
0
0
0
8
7
0
24
14,137
Fabricated
Metals
25
1,069
7,538
750
492
0
135
1,814
26
345
0
53
82
2
0
373
2,438
2
0
483
3,002
114
136
0
16
17
1,607
0
1,067
25
51
186
18
31
811
1,382
0
4
325
146
30
0
108
24,678
Nonelec-
trical
Machinery
26
872
8,029
84
19
0
6
467
580
30
0
16
71*
4
0
330
1,233
10
2
827
505
0
7
0
0
0
547
0
1,675
84
558
239
117
141
346
5,089
0
0
118
57
4
6
138
22,214
Electrical
Machinery
27
226
2,259
0
159
0
0
255
76
0
5
700
13
3
0
53
603
6
0
137
254
14
0
0
3
0
617
1
9,329
8,399
5,808
it, 016
0
168
690
2,658
0
0
0
2
0
0
39
36,493
Transpor-
tation
Equipment
28
201
2,236
1,367
6,242
0
0
605
93
62
0
146
10
0
15
84
2,306
1
0
196
4o4
0
0
0
0
1
117
0
523
1,070
26
79
84
3
91
2,236
0
0
51
0
0
18
28
18,295
Professional
and
Scientific
Instruments
29
284
521
1
0
0
3
849
289
0
0
0
28
0
0
55
1A5
14
0
27
0
0
0
0
1
0
38
0
263
719
137
263
0
67
66
52
0
0
23
0
0
0
152
3,997
Miscella-
neous
Manuf ac -
turing
30
65
465
47
29
5
7
134
16
28
0
61
11
0
30
276
446
10
2
207
185
22
6
28
15
15
lJ.3
0
221
1
0
2
0
5
104
394
0
0
1
"0
48
0
10
3,082
None las -
sifiatle
Establish-
ments
31
50
173
0
4
0
1
39
52
2
0
87
26
12
21
153
25
6
3
23
6
3
3
3
5
9
19
2
88
168
36
14
3
21
21
119
0
0
30
0
39
0
33
1,299
Total
Employment

54,661
260,169
25,351
29,330
"t,553
12,248
53,278
55,401
22,744
707
33,876
45,468
28,896
27,237
175,381
110,906
13,688
6,448
35,461
31,088
9,021
7,409 ;
8,171
10,134
9,921
51,693
3,660
101,750
53,307
22,371
43,508
7,160
24,988
34,826
115,879
6,063
8,884
18,778
9,^
5,244
4,204
28,231
1,611,526

-------
 the  sources  for which  data  on wastes  generation were developed by the FMC in its
 Santa Clara  County study.   Only an  average multiplier could be arrived at in a
 number of these sources.  The average multipliers were  derived by dividing the
 total wastes by corresponding employment  in  Santa Clara County.  The multiplier
 was  estimated as 7620  pounds per  employee per year, and was applied to sources 2, 3.>
 4,  5, and 6  in Appendix D.  A separate  multiplier was developed for demolition
 and  construction (source  7) from  the  total wastes generated and the corresponding
 employment in that industry in Santa  Clara County.  The multiplier was estimated
 to be 82,504 pounds or 4l.25 tons per employee and  is applied for source 7 (in
 Appendix D).  This figure is considered somewhat high and will probably have to
 be revised downward when  the data from  the State's  studies become available.
 Detailed calculations  pertaining  to this  category are given in Table 6.
                                       TABLE  6

                     MULTIPLIERS FOR NOHMANUFACTURING  INDUSTRY,
                          COMMERCIAL AMD  PUBLIC FACILITIES


Waste Source


f
Commercial
and Public
Facilities
Demolition
and
Construction

.a
Annual
Wastes,
Volume
cu yd

1


3,9^6,928


2,115,717



Employment

2


184,153


22,079

Annual
Wastes,
Volume
per
Employee
cu yd
3


21.433


95- 824


. .a
Annua j_
Wastes,
1000 Ib

4


1,403,287.1


1,821,607.7


Annua 1
Wastes,
Ib per
Employee

5


7,620.22


82,504.08


Q
Annual
Wastes,
ton per
Employee

6


3.81011


41.25205

    aColumns 1 and 4:  Food Machinery Corporation (FMC) Santa Clara Study,  1967,
unpublished data

     Column 2:  Tabulation of data obtained from California  Department  of
Employment, San Francisco Office, Research and Statistics

    °Column 3:  Column I/Column 2

     Column 5:  Column 4/Column 2

    eColumn 6:  Column 5/2000
    -p
     This group includes all wholesale and retail trade,  transportation,  utilities
and other services, churches, shopping centers,  and all publicly-owned  facilities
         Industrial Sources (Sources 10 through 31 in Appendix D).   A survey of
 representative industrial firms was carried out by FMC in Santa Clara County for
 developing the industrial wastes multipliers.  A distinction was  made between firms
 (enterprises) and establishments representing actual location of economic activity.
 The Food Machinery Corporation developed wastes multipliers per establishment which
 were based on the wastes generated by establishments and the ratio between firms to
 establishments.  Consequently, the wastes multipliers developed by FMC relate only to
 the number of establishments, and no consideration is given to the size of the
 establishments.

-------
                                                                                  27
        On the basis of experience gained in the study reported herein, it became
evident that to arrive at meaningful multipliers, size as well as number of
establishments must be taken into consideration.  Another possible approach would
be the use of actual production of goods as a factor.  However, since employment
was the only variable on which data could be obtained in sufficient detail in the
nine-county Bay Area, it was used as the proxy variable representing the size of a
given industry.  Original survey data on wastes collected by FMC from the various
industries, and generously made available to the Planning and Economics team, were
used to develop multipliers by large and small firms, and by type of industry
(Standard Industrial Classification -SIC Code).  The method is briefly described
in the two following paragraphs.

        Data obtained from the FMC survey represented information gained from 32 of
the 36 large firms (100 or more employees per firm) interviewed by the organization.
(The total number of large firms located in Santa Clara was 102.)  The information
consisted of detailed data on wastes generation, seasonality, etc.  These data were
then used in conjunction with comparable data on employment of the firms sampled to
develop solid wastes multipliers by industry type.  The total wastes generation by
the canning and preserving industry (SIC 20) was ascertained by FMC by way of
personal interviews.  These data were divided by corresponding total employment in
the industry to arrive at the appropriate wastes multiplier.  The multipliers are
developed by SIC industry type (19 through 39)-  The calculations and multipliers
are presented in Table 65, Appendix E.

        The following comments concerning the lack of certain industry data in the
survey are in order:  multipliers for the canning and preserving (SIC 203), textile
(SIC 22), chemical and allied (SIC 28), petroleum (SIC 29), primary metal (SIC 33),
and instrument (SIC 38) industries were not available from the survey data.  The
extractive industry (mostly mining) were excluded, since usable information was not
available.  Petroleum refining (SIC 29) was not considered, inasmuch as the wastes
from this industry is mostly treated as liquid wastes, and its overall effect on
solid wastes generation is not appreciable (at least in the Bay Area).  With regard
to the majority of the other SIC groups for which data were lacking, some may be
considered as not being important in terms of the Bay Area as a whole.

        Only a fraction of the 1222 small industrial firms (less than 100 employees
per firm) surveyed by FMC returned the questionnaire.  These responses were made
available by the corporation to the research team.  Of the responses, nearly 122
questionnaires contained information which could be used in developing wastes
multipliers.  The data were tabulated by the research team in terms of average
weekly wastes output per small firm by SIC group.  A separate tabulation of employment
of small firms by SIC group was made with the intention of determining the average
size of employment comparable to the average weekly wastes.  These were used to
develop wastes multipliers for small industrial firms, as is indicated in Table 66,
Appendix E.

        The multipliers developed for large and small industrial firms were used to
develop average multipliers for the industry as a whole.  For each of the SIC groups,
the multipliers for the large and small firms were weighted by the corresponding
total employment in the county to arrive at an average.  These multipliers were
expressed in cubic yards per employee, and were converted to pounds and tons per
employee, using densities of wastes developed by FMC (unpublished data).  The various
stages of these calculations are given in Table 7-  Data on employment by industrial
wastes sources (cf. Table 5) were tabulated from the data furnished by the California
Department of Employment and made available to this study by the Association of Bay
Area Governments.

-------
28
                                                                   TABLE 7

                                                            INDUSTRIAL MULTIPLIERS
Standard Industrial
Classification

No.

19
205
20

21
22
25
24
25
26

27

28
29
50
31
32

33
34

35
36
37

38
39


Title

Ordnance and Accessories
Canning and Preserving
Other Food Processing
(Except 203)
Tobacco
Textiles
Apparel
Lumber and Wood Products
Furniture and Fixtures
Paper and Allied
Products
Printing, Publishing,
and Allied
Chemicals and Allied
Petroleum Refining
Rubber and Plastics
Leather
Stone, Clay, Glass,
and Concrete
Primary Metals
Fabricated Ifetal
Products
Nonelectrical Machinery
Electrical Machinery
Transportation
Equipment
Instruments
Miscellaneous
Manufacturing
Industries
Small Firms

Total8
Employment
1
h
-
920

-
-
98
455
385
570

1,744

701
k
173
-
960

h
1,259

2,838
2,337
557

825
317


^
Annual Waste
Volume per
Employee
(cu yd)
2
h
-
20.961

-
-
35-560
48.492
86.877
65.442

25.230

18.348
k
28.583
-
29.235

4.443
21.214

17.909
16.645
14. 31*8

8.943
5-946


Large Firms

Total"
Employment
3
29,499

4,306

-
-
625
217

1,555

1,923

937
k
653
-
1,696

-
1,304

9,805
37,8l4
4,185

926
149



Annual Waste0
Volume per
Employee
(cu yd)
4
4.476
8.977
8.720

-
-
2.077


57-440

7-252


k
18.854
-
5.260

-
13-206

11.401
7-333
24.580

HA
HA


Annual Waste : All Firms

Volume per
Employee
(cu yd)
5
4.476
8.977
10.875

-
-
6.601
48.492
86.877
45.022

15.802

18.348
k
20.892
-
15-926

-
17.140

12.862
7-875
23.378

8.943
10.495



Densities6
Ib/cu yd
6
294.4
1,240.0
885.8

-
-
159-3
894.5
464.0
557.0

1,671.0

895-0
k
148.2
-
2,601.5

-
785-5

650.5
756.5
290.5

562.9
4750



Pounds per
Employee
7
1,317-7
11,151.4
9,655.1

-
-
1,051.5
45,376.1
40,310.9
25,077-3

26,405.1

16,421.1
k
5,096.2
-
36,228.5

-
15,460.0

8,364.2
5,957-4
6,786.6

5,034.0
4,9870



Tons per6
Employee
8
0.65885
5.5657
4.81655

2.493651
0.52575J
0.52575
21.68805
20.15545
12.53865

15.20255

8.21075
X
1.54810
2.495651
18. 11425

6.7300 I
6-7JOO

4.18210
2.97870
3-39330

2.51700
2.493651


       aColumns 1 and 5 - Tabulated from data obtained from California  Department of Employment,  (Research end Statistics), San Francisco
   office

       bColumn 2 - From Column k of Table 66  (Appendix E)


       CColumn 4 - From Column J of Table 65  (Appendix E)

       ^Column 5 - The average multiplier (cu yd/employee)  for the  industry as a whole was obtained for each SIC as the weighted average
   of small and large firm multipliers (Columns 2 and *>}, using employment  (Columns 1 and j) as weights


       eColumn 6 - Unpublished data furnished by FMC Santa  Clara study, 196?


        Column 7 - Column 5 multiplied by Column 6


       Column 8 - Column 7 divided by 2,000


        Data not available

       1The multiplier for the SIC 59, Miscellaneous Manufacturing Industries, calculated as weighted average of all  industry
   multipliers available.  Thie multiplier is used wherever an industry had no data available, e.g.,  Tobacco (SIC 21), Leather
   (SIC 31).

       JSame as the multiplier for Apparel (SIC 23)


       ^Omitted from calculations


       •LSame as the multiplier for Fabricated Metals (SIC jM

-------
                                                                                  29
        Agricultural Sources (Source Number 8 — 8a through 8k).  As shown in Table 3>
the agricultural sources were classified as follows:

                      8a   Orchards and vineyards
                      8b   Vegetables, berries and seed crops
                      8c   Field crops
                      8d   Milk cows
                      8e   Feedlot cattle
                      8f   Hogs and pigs
                      8g   Hens and pullets
                      8h   Turkeys
                      8i   Other poultry
                      8j   Cut flowers (nursery)
                      8k   Dead animals

        Source units for orchards, vineyards,  vegetables,  seed crops,  field crops,
and cut flowers (8a, b, c, and j) generally were  measured  by acres, and the wastes
by pounds or tons per acre.  The acreage data were obtained from the County
Agricultural Commissioner's Report for 1966, and the  wastes multipliers were
obtained from a variety of sources.  Wastes generation was calculated for each crop
in the group before group totals were formed, since each crop has a different wastes
production rate.  Source units for milk cows, feedlot cattle, hogs and pigs, hens
and pullets (Sources 8d, e, f, and g) were measured by number of animals inventoried
for the year 1966.  These were obtained from the  County Agricultural Commissioner's
Report.  The wastes multipliers (manure expressed as  pounds per number of animals)
were obtained from available published sources.  The  source units were multiplied
by the wastes multipliers to obtain the total wastes  generated.  In the case of
turkeys and other poultry (Sources 8h and i), the source units were number of heads
produced during the year.  The data were obtained from the Agricultural Commissioner's
Report.  The wastes multipliers (expressed as pounds  per unit hatched) were obtained
from available published sources.  With respect to dead animals (Source 8k), the
wastes were developed separately for cattle, sheep, hogs,  and pigs, and poultry on
the basis of the source units, mortality rate, and average weight — utilizing in each
case separate multipliers and the corresponding units (inventories or production
during the year).

        The data used in estimating total agricultural wastes were obtained from a
number of sources.  Among them were consultation with the  appropriate agricultural
agent, with members of the University's Agricultural Extension at Berkeley and with
those of its agricultural engineering department  at Davis, and, finally, the literature
on the subject.  The judgment factor entered into these estimates to a greater degree
than in those of the other sources of wastes already discussed.

        The wastes multipliers for orchards and vineyards  were estimated for each
fruit and nut crop separately as pounds per acre-year by bearing and nonbearing type.
The multipliers were developed in two stages.  In the first stage, data on per-tree
wastes generation were obtained from FMC data [3] separately for bearing and non-
bearing types of trees.  (These data include pruning and attrition wastes, if any.)
Values for per-tree output were multiplied by those for the number of trees per acre
[^•,5], to arrive at a value for the amount of wastes  generated per acre by each type
of fruit or nut crop.  The multipliers are given in Table  8.

        The average of each of the wastes multipliers for  vegetable, berry, and nut
crops (8b) was used in arriving at wastes generation for this source group.  The
mushroom crop was treated separately, since its wastes generation is out of scale
with that of the other crops in this group, due to the need of disposing of large
amounts of bedding (straw and manure).  The multiplier for vegetables, berries, and
seed crops was estimated at 3-0 tons per acre per year [2]; and that for mushrooms,
2l8 tons per acre per year.  The latter is bacefl  upon a multiplier of 10 pounds per
square foot [3]•

-------
                                     TABLE 8

                     MULTIPLIERS FOR VINEYARDS AMD ORCHARDS
Source of Wastes
(Tree or Vine)
Apple
Apricot
Cherry
Peach
Pear
Plum
Prune
Olive
Fig
Persimmon
Orange
Walnut
Almond
Miscellaneous Fruits
and Nuts
Grape
Multiplier
( It/acre -yr)
Bearing
3,100
3,081*
2,853
2,934
6,084
4,080
1,083
3,118
3,117
3,117
3A17
1,010
642
3,117
3,224
Woribearing
250
750
625
720
1,620
760
592
-
-
-
-
255
-
753
1,209
        Generally, in planning for the disposal of agricultural wastes,  those
generated in the production of vegetables,  terries, and seeds  are  not  taken into
consideration, since generally they are not regarded as subject to public  disposal.
Inasmuch as the study reported herein is concerned with all aspects  of wastes
management, these wastes had to be taken into consideration.

        In arriving at an estimate of total wastes generated in the  production of
field crops (8c), an average multiplier of 1-5 tons per acre per year  [2]  was  used.
Field crops generally are not considered as significant wastes generators, since
they either are disc plowed into the soil or burned in the field.

        With respect to milk cows, feedlot cattle, and hogs and pigs,  land used for
range and pasture accounts for approximately three-quarters of the total acreage
devoted to agriculture in the nine Bay Area counties.  Generally,  wastes generated
on this land do not present a disposal problem, at least not for the present.

        To estimate the total manure produced by milk cows and feedlot cattle, the
number of cattle (inventory) was multiplied by the average wastes  multiplier,  13-21
tons per head per year [6].  The wastes multiplier used in arriving at a value for
pig and hog manure production was 1.28 tons per pig per year [6].

        The multipliers used in arriving at total wastes production for hens and
pullets (number from inventory) was 67-5 tons per 1000 head per year [7J;  for turkeys
(annual turkey production) 90 pounds per head per hatch-to-slaughter;  and for other
poultry (miscellaneous poultry and rabbits) 9 pounds per head-to-slaughter [7]•

-------
                                                                                  31
        Wastes generated in cut flower production have become a disposal problem,
since they no longer can be burned on site.  The multiplier used in arriving at
wastes production from this source was 25 tons per acre per year [8].

        Tonnage of dead animals was arrived at on the basis of one-half the average
weight of each class of animal (many of them die before reaching full growth) and
a mortality factor.  Farm animal mortality was estimated to be at the rate of
0-5 percent per month for large animals, and 1.0 percent for poultry [9]-  The
multiplier used for cattle, hogs, and pigs was 0.06 times one-half the average
weight per animal; for hens and pullets, 0.12 times one-half the average weight;
miscellaneous poultry, 0.03 times one-half the average weight; and for sheep,
0.06 times one-hall" the average weight.

        The various source units and data on acreage, and number of heads (invento-
ried and produced) pertinent to the year 1966 are listed in Table 9-  Values for
total wastes generated by each of the sources, 8a through 8k, are presented in
Table 10.
Total Wastes Generated Within the Region

        The amounts of solid wastes generated within each functional boundary were
estimated by multiplying the source units and the corresponding wastes multipliers
with respect to each of the wastes sources listed in Table 3-  Final and immediately
preceding calculations for wastes generation by residential sources are given in
Table k; by commercial nonmanufacturing, public agencies and by industrial sources,
in Table 11; and by agricultural sources, in Table 10.


Employment

        Data on employment were available at the highest level of detail as compared
to those for other variables evaluated in this investigation.  The primary data used
in the calculations were those tabulated by the California Department of Fjnployment
according to Census tract, and by detailed categories of enterprises commonly known
as the Standard Industrial Classification code (at the four-digit level).  Problems
involved in the use of the data had to do with time period, coverage, and uniformity.
The basic employment data were aggregated to conform to the definitions of wastes
sources as defined in Table 3 an<^ to correspond to the Census tract boundaries
defined for each of the functional boundaries (DSA's in Appendix c).  Final tabula-
tions of the available data on employment are given in Table 5-

        The aggregated data and the wastes multipliers developed in this study were
then used in developing complete and comparable data on solid wastes generation by
commercial and industrial sources in the study regions.


Population

        The plan for the evaluation of the variable "population" involved the
estimation of data on population on a comparable basis and as accurately as possible
for the k-2. functional regions defined in the present study.  The Census tract was
used as the primary source unit, and aggregations of Census tracts (or portions
thereof) were made to correspond to DSA boundaries.  The calendar year 1966 was made
the reference period for the population data so as to have them correspond to the
other data elements in the study.  The population tabulation is given in Table 12.

        In making the tabulation, the problems relating to reliability and accuracy
could not be completely and satisfactorily resolved.  Santa Clara County, in which
a special census was taken in April of 1966, was the only county in which an official
count was made since the I960 census.  Methods of estimation varied in the other
counties.  Sources of population data, methods (where known) of estimating population
numbers, the dates of the estimations, limitations of the data, and adjustments made
by the research team are described in Appendix F.

-------
                                                                 TABLE 9




                                                   ACBICULTURE SOURCE UHITS  BY DSAa:   1966
Disposal Service Area
Code
01 01
02
03
04
05
06
02 01
02
0?
03 01
02
04 01
05 01
02
03
01*
05
06
07
08
09
10
11
12
06 01
02
03
04
07 01
02
03
Olt
05
06
07
08
08 01
02
09 01
02
03
Oil

Name
Berkeley
Oakland
Alameda
Fremont
Pleasanton
East Alaroeda County
West Contra Costa
Central Contra Costa
East Contra Costa
West Mann
East Marin
Hapa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Ness
Potrero-Bayshore
Outer Mission
So. Frway-Mt- Davidson
Lake Merced
Sunset
Daly City
South San Francisco
Pacifica
Central San Mateo
Palo Alto
Mountain Vieu
Sunnyvale
Gilroy-Morgan Hill
Los Gates
Los Altos
San Jose
Ramainder of County
Vacavllle
Fairfield
Healdsburg
Santa Rosa
Western Sonoraa
South Sonoraa
Orchards
and
Vineyards
(acres)
0
563
0
1,548
1,152
1,584
0
2,158
18,957
0
55
19,142












0
0
0
56
0
0
0
16,288
10,208
4,158
3,388
20,324
9,527
6,780
27,803
2,391
2,169
7,071
Vegetables,
Berries and
Seed Crops
(acres)
0
5,6l4
0
3,724
1,862
1,755
0
369
12,073
16
k
0












530
0
0
3,005
0
0
0
5,858
1,674
837
837
7,531
8,699
5,799
144
143
48
144
Field
Crops
(acres)
0
0
0
2,946
3,172
16,540
0
3,738
33,«7
2,800
700
8,709












0
0
0
8,010
0
0
0
5,889
1,682
841
841
7,572
92,880
19,737
0
0
0
36,760
Milk
Covs
(head)
0
0
0
637
1,258
0
0
0
3,750
20,970
2,330
1,185












0
0
220
880
0
0
545
4,905
0
0
4,905
545
0
2,765
5,505
5,505
21,220
21,220
Feedlot
Cattle
(head)
0
277
0
648
0
0
0
0
25,000
3,735
415
1,325












0
0
0
0
0
0
0
5,377
0
0
0
0
0
15,675
1,000
1,000
4,000
4,000
Hogs
and
Pigs
(head)
0
0
0
5,295
883
2,647
0
590
5,310
270
30
0












3,548
0
0
187
0
0
0
115
0
0
1,035
0
67
1,283
290
1,160
290
1,160
Hens and
Pullets
(head)
3
0
0
52,230
156,690
52,250
0
3,015
27,136
23,140
12,460
296,911












0
0
0
1,425
0
0
0
706,800
0
0
0
176,700
173,250
19,250
0
696,200
0
1,044,300
Turkeys
(head)
0
o
0
~
0
0
0
0
0
0
0
127,959












0
0
0
0
0
0
0
0
0
0
0
0
80,280
8,920
0
222,400
0
333,600
Other
Poultry
(head)
0
0
0
Cut
Flowers
(acres)
0
125
0
2,607,380 53
7,822,140 ' 0
2,607,380 o
0 54
650
5,850
0
0
679,645












0
0
0
0
0
0
0
16, 240
0
0
0
4,060
902,838
100,315
0
6,4;6,84o
0
9,655,260
0
0
19
24
0












9
14
5
70
322
322
323
0
0
0
107
0
0
0
0
0
0
0
Dead
Animals
(head)
0
33,851
0
194,645
177,720
16,926
0
416
5,475
4,275
1,661
60,008












213
0
13
235
0
0
33
85,936
0
0
356
21,359
50,287
6,770
396
283,769
1,531
426,565
NINE-COUHT! TOTAL 155,082 58,664 246,454 97,925 62,452 24,160 3,441,737 773,159 30,838,598 1,1*7 1,372, Wo
aData tabulated directly from the original sources.   (Sec  text.)

-------
                                                     A(2*ICULTURAL WASTES BY DSA,  BY SOURCE^;  1966
                                                                    (tons per year)
                                                                                                                                                33
Disposal Service Area
Code
01 01
02
03
04
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
Olt
05
06
07
08
09
10
11
12
06 01
02
03
04
07 01
02
03
04
05
06
07
08
08 01
02
09 01
02
03
Oil

Name
Berkeley
OaKland
Alameda
Fremont
Pleasanton
East Alameda. County
West Contra Costa
Central Contra Costa
East Contra Costa
West Marin
East Marin
Hapa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Hess
Potrero-Bayshore
Outer Mission
So. Frway-Mt. Davidson
lake Merced
Sunset
Daly City
South San Francisco
Pacifies
Central San Mateo
Palo Alto
Mountain Viev
Sunnyvale
GiU-oy -Morgan Hill
Los Gatos
Los Altos
San Jose
Remainder of County
Vacaville
Fairfield
Hea Ids burg
Santa Rosa
Western Sonoma
South Sonoma
NINE-CODMY TOTAL
Orchards
and
Vineyards
8a
0
55>>
0
1,706
1,139
2,176
0
1,287
15,284
0
86
25,491












0
0
0
66
0
0
0
18,684
11,429
4,637
3,941
23,653
12,55"*
9,061
34,890
3,188
3,359
10,989
184,174
Vegetables,
Berries,
Seed Crops
8b
0
10,843
0
11,172
5,586
5,258
0
1,108
36,218
48
12
0












1,591
0
0
9,014
0
0
0
17,574
5,021
2,510
2,511
22,595
26,096
17,398
431
431
144
431
175,992
Field
Crops
8c
0
0
0
4,4l8
4,758
24,811
0
5,606
50,457
4,200
1,050
11,322












0
0
0
12,015
0
0
0
8,833
2,524
1,262
1,262
11,356
141,061
29,606
0
0
0
55,140
369,681
Milk Covs
8d
0
0
0
8,423
16,351
0
0
0
49,549
277,077
30,786
15,657












0
0
2,907
11,627
o
0
7,201
64,810
0
0
64,810
7,201
0
36,535
70,095
70,095
280,380
280,380
1,293,884
Feedlot
Cattle
8e
0
3,667
0
8,555
0
0
0
0
330,325
49,351
5,483
17, 507












0
0
0
0
0
0
0
71,046
0
0
0
0
0
207,113
13,213
13,213
52,852
52,852
825,177
Hogs
and
Pigs
8f
0
0
0
6,765
1,127
3,382
0
75"»
6,783
3l»5
38
0












|t,532
0
0
239
0
0
0
147
0
0
1,322
0
86
1,639
371
1,482
370
1,482
30,864
Hens
and
Pullets
8g
0
0
0
3,526
10, 577
3,525
0
204
1,831
1,562
84l
20, Oil












0
0
0
96
0
0
0
47,709
0
0
0
11,927
11,695
1,299
0
46,994
0
70,490
232,317
Turkeys
8h
0
0
0
0
0
0
0
0
0
0
0
5,758












0
0
0
0
0
0
0
0
0
0
0
0
3,613
401
0
10,008
0
15,012
34,792
Other
Poultry
81
0
0
0
6,556
19,669
6,556
0
3
26
0
0
3,058







Cut
Flowers
(Nursery)
Si
0
3,115
0
1,335
0
0
1,340
0
0
465
620
0












0
0
0
0
0
0
0
73
0
0
0
18
4,063
451
0
16,116
0
24,173
80,762




245
367
123
1,715
8,055
8,055
8,055
0
0
0
2,685
0
0
0
0
0
0
0
36,175
Dead
Animals
8k
0
58
0
334
305
29
0
21
1,026
564
100
157












66
0
19
80
0
0
15
479
0
0
220
46
20
970
217
217
868
868
6,679
Total
Agricul-
tural
Wastes
8
°i
18,237
0
52,790
59,512
45,737
l,34o
8,983
491,499
335,612
39,016
98,991












6,434
367
3,049
34,852
8,055
8,055
15,271
229,355
18,974
8,409
76,751
76,796
199,188
304,473
119,217
161,744
537,973
511,817
3,270,497
See text for estimation procedures
     388-229 O - 70 - 18

-------
                  TABLE 11

WASTES GENERATION BY DSA AND BY WASTES SOURCE
               (tons per year)
DSA
1
01 01
02
03
01*
05
06
02 01
02
03
03 01
02
Ol* 01
05 01
02
03
Ol*
05
06
07
08
09
10
11
12
06 01
02
03
01*
07 01
02
03
Ol*
05
06
07
08
08 01
02
09 01
02
03
01*
TOTAL
Restaurants
and Hotels
2
8,51*6
36,1*71*
2,11*1
2,008
297
701
8,791*
9,205
2,119
171
6,237
6,633
3,951
5,597
77,753
12,665
1,768
812
l*,839
l,2l*6
1,722
81*6
918
1,867
1,920
6,557
728
19,631*
5,17"*
2,717
5,258
1,215
5,8llt
6,652
17,557
81*
2,766
2,980
1,505
1,71*9
682
6,679
286,981
Institutions
Private
'Schools end
Colleges )
3
1,51*3
8,215
572
263
0
122
1,376
1,932
206
0
3,201
l*,656
It, 835
2,1*08
2,160
697
522
351*
1,783
161*
995
1,082
1*53
1,059
309
697
30
3,029
31*, 653
575
99
80
655
3,01*0
2,610
0
23
575
ll*9
ll*9
156
861
86,288
Public
Offices
and
Facilities
1*
90,132
128,568
53,563
12,992
2,618
25,989
27,331*
1*1*, 026
7,605
71*7
23,752
67,1*69
39,858
30,229
56,367
51*-, 51*2
10,036
6,71*1*
12,855
37,088
l*,26l*
7,781*
12,013
7,ii*o
l*,96l
17,938
3,281
50,1*27
12,871
6,992
22,11*8
2,1*00
15,256
18,098
69,153
1*76
!*,999
19,005
2,961*
2,835
983
15,187
1,033,689
Health
Services
(Private)
5
8,935
1*1,107
2,781
1,036
111*
1,276
5,856
9,971
1,360
61
7,289
7,053
17,332
12,669
15,591
739
6,020
2,225
2,691*
50
l*, 290
187
l,0l*l*
1,391
1,033
2,587
232
15,728
12,871*
1,132
1,299
1,105
5,1*56
6,131*
15,1*1*2
0
191*
3,155
892
137
671
6,778
225,920
Commercial
and
Service
Establish-
ments
(Private)
6
58,695
1*81*, 616
18,01*1
25,61*2
3,399
8,009
91,821*
82,592
18,986
572
63,771*
5)1,065
36,733
3U, 760
1*11,953
255,132
25,189
10,291
75,013
1*2,570
18,296
13,11*5
15,960
26,236
21,310
120,1*72
l*,5l*5
183,053
72,628
33,266
38,311*
7,71*6
1*0,21*6
50,629
177,1*22
l*,370
10,577
23,201*
15,385
5,730
it, 13"*
55,971*
2, 71*1*, 1*98
Construction
and
Demolition
(Public and
Private)
7
81*, 319
51*6,961
59,485
188,1*81
78,255
52,308
176,39"*
363,926
27,598
5,198
128,01*6
77,221*
63,570
186,1*59
1*28,279
52,308
1*1,1*58
1*2,366
28,1*23
ll*,727
12,71*7
1*6,821
l*,950
l*,290
77,81*3
118,187
50,1*51
351,797
139, 511*
75,037
116,785
16, 130
16U, 221*
13l*,358
261*, 756
0
22,61*7
39,396
16,913
16,088
6,765
127,675
4,1*53,159
Agriculture
8
0
18,237
0
52,790
59,512
1*5,737
1,31*0
8,983
1*91,1*99
333,612
39,016
98,991
0
0
0
0
0
0
0
0
0
0
0
0
6,368
367
3,030
3l*,937
8,055
8,055
15,271
229,355
18,971*
8,1*09
76,751
76,796
399,188
301*, 1*73
119,217
I6l,7«*
337,973
511,817
3,270,1*97
Extractive
Industry
9








I



o
s
«
K
O
*d
S
ffi
H
CO
CO
1-3
C
a


















Canning
and
Preserving
10
2,338
29,381
1*51
1,152
33
56
1,091
751
1,603
0
0
0
306
78
3,390
6,696
768
11
l*,625
3,91*1
852
0
56
6
0
1,013
0
779
1,809
501
l*,86l*
3,829
3,11*5
6,161
1*2,967
111
0
0
1,993
189
167
1,837
126,91*8

-------
TABLE  11 (Continued)
                                                                        35
USA

01 01
02
03
04
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
04
05
06
07
08
09
10
11
12
06 01
02
03
04
07 01
02
03
04
05
06
07
08
08 01
02
09 01
02
03
04
TOTAL
Other
Food
Processing
11
5,028
63,289
973
2,481
67
125
4,715
3,266
6,936
0
1,551
5,520
780
202
8,646
17,084
1,956
19
11,796
10,057
2,177
10
135
10
0
8,448
0
6,526
756
207
2,037
1,604
1,320
2,587
18,019
43
6,401
9,248
1,893
183
164
1,749
208,008
Tobacco
Industry
12
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
12
0
0
52
0
0
0
0
3
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
67
Ordnance
and
Accessories
13
0
0
0
0
0
0
0
11
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
0
0
0
22
1,027
938
10, 561
0
0
0
2,490
0
0
0
0
0
0
0
15,053
Textiles
and
Apparel
14
1
603
0
17
0
80
27
2
0
0
7
256
19
7
1,450
73
0
936
285
47
4
0
4
7
124
2
72
1
1
0
0
50
13
299
0
0
0
30
0
0
21
5,752
Lumber
and Wood
Products
15
694
19,042
3,383
195
0
0
1,236
369
781
0
3,383
217
0
109
260
1,106
0
0
954
2,776
0
0
0
22
87
1,366
0
5,943
694
2,407
0
22
499
5,574
3,947
0
0
499
14,943
6,658
13,794
4,251
95,211
Furniture
and
Fixtures
16
4,172
23,542
443
5,623
887
0
3,729
484
0
0
524
645
20
121
16,850
6,974
1,552
0
8,163
11,448
665
0
0
403
0
6,228
0
8,788
0
1,391
181
806
806
6,974
2,358
0
0
0
40
81
564
867
115,329
Paper
and
Allied
Products
17
5,153
33,804
2,345
8,288
0
0
589
38
35,296
0
213
351
0
0
3,699
9,993
0
2,796
677
0
0
0
0
0
6,244
0
1,542
1,831
0
376
4 14
3,360
8,002
6,269
0
0
0
0
0
0
0
131,280
Printing,
Publishing
and Allied
18
7,657
55,847
898
1,809
0
739
6,733
6,245
1,479
0
4,225
4,476
158
884
57,814
88,431
5,637
436
11,116
1,5*5
119
40
26
211
449
9,36i
370
20,371
7,499
2,971
3,525
449
1,848
5,321
21,665
0
422
766
2,139
53
343
1,373
335,450
Chemicals
and
Allied
19
17,062
15,814
4,721
5,780
0
0
14,032
7,964
8,974
0
0
123
16
16
6,322
5,961
25
0
994
I,l4i
189
4i
0
0
0
8,942
0
7,045
550
246
1,191
591
82
1,544
5,633
0
0
0
25
0
222
66
115,312
Petroleum
Refining
20











o
s
M

O
S3
O
S
*
M
CO
CO
1





















-------
36
                                                         TABLE 11 (Continued)
DSA

01 01
02
03
04
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
(A
05
06
07
08
09
10
11
12
06 01
02
•03
(A
07 01
02
03
04
05
06
07
08
08 01
02
09 01
02
03
(A
TOTAL
Rubber
and
Plastic
Products
21
207
l,28l
17
0
0
0
73
15
444
0
85
19
0
0
2
175
0
0
68
77
0
5
0
0
0
175
0
376
0
5
11
3
11
1*6
687
0
0
0
0
0
11
0
5,793
Leather
and
Allied
22
212
252
0
0
0
0
479
0
0
0
0
329
0
0
3
237
0
0
12
459
0
0
0
3
0
207
0
5
0
0
0
7
0
0
0
0
0
0
0
0
0
396
2,601
Stone,
Clay,
and
Glass
23
1,3*0
62,404
0
5,887
2,699
0
12,191
6,39*
10,035
0
3,677
1,395
779
127
6,757
1,703
0
0
6,431
2,355
36
0
0
0
815
3,750
0
9,438
326
235
652
706
54
31,609
14,057
0
670
797
0
0
0
1,558
188,877
Primary
Metals
24
3,796
24,066
0
8,392
0
0
1,508
3,479
21,502
0
841
4,253
0
0
5,680
1,259
0
0
1,299
1,945
0
0
0
0
0
9,853
0
1,810
67
0
0
0
27
3,190
1,911
0
0
0
54
47
0
162
95,141
Fabricated
Metals
25
7,194
50,731
5,047
3,311
0
909
12,208
175
2,322
0
357
552
13
0
2,510
16, 408
13
0
3,251
20,204
767
915
0
108
114
10,815
0
7,181
168
343
1,252
121
209
5,458
9,301
0
27
2,187
983
202
0
727
166,083
Nonelec-
trical
Machinery
26
3,647
33,578
352
79
0
25
1,953
2,426
125
0
67
309
17
0
1,380
5,157
42
8
3,459
2,112
0
29
0
0
0
2,288
0
7,005
351
2,334
999
489
590
1,447
21,283
0
0
493
238
17
25
577
92,901
Electrical
Machinery
27
673
6,729
0
474
0
0
760
226
0
15
2,085
39
9
0
158
1,796
18
0
408
757
42
0
0
9
0
1,858
3
27,788
25,018
17,300
11,962
0
501
2,055
7,917
0
0
0
6
0
0
116
108,702
Transpor-
tation '
Equipment
28
682
7,588
4,639
21,l8l
0
0
2,053
316
210
0
495
34
0
51
285
7,825
3
0
665
1,371
0
0
0
0
3
397
0
1,775
3,631
88
268
285
Professional
and
Scientific
Instruasnts
29
715
1,311
3
0
0
8
2,137
727
0
0
0
70
0
0
138
365
35
0
68
0
0
0
0
3
0
96
0
662
1,810
345
662
0
10 169
309
7,587
0
0
173
0
0
61
95
62,080
166
131
0
0
58
0
0
0
383
10,062
Miscella-
neous
Manufac-
turing
30
162
1,160
117
72
12
17
334
40
70
0
152
27
0
75
688
1,112
25
5
516
461
55
15
70
37
37
357
0
551
2
0
5
0
12
259
982
0
0
2
107
120
0
25
7,681
None las -
slfiablfi
31
1,247
4,314
0
99
0
25
973
1,297
50
0
2,169
648
299
524
3,815
623
149
75
574
150
75
75
75
125
224
474
50
2,194
4,189
898
349
75
524
524
2,967
0
0
748
0
973
0
823
32,393

-------
                   TABLE 12

              POPULATION BY DSA
                                                                37
Disposal Service Area
Code
01 01
02
03
04
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
04
05
06
07
08
09
10
11
12
06 01
02
03
04
07 01
02
03
04
05
06
07
08
08 01
02
09 01
02
03
04
Name
Berkeley
Oakland
A lame da
Fremont
Pleasanton
East Alameda County
West Contra Costa
Central Contra Costa
East Contra Costa
West Marin
East Marin
Napa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Ness
Potrero -Bayshore
Outer Mission
So. Frway-Mt. Davidson
Lake Merced
Sunset
Daly City
South San Francisco
Pacifica
Central San Mateo
Palo Alto
Mountain View
Sunnyvale
Gilroy-Morgan Hill
Los Gatos
Los Altos
San Jose
Remainder of County
Vacaville
Fairfield
Healdsburg
Santa Rosa
Western Sonoma
South Sonoma
NINE -COUNTY TOTAL
Population
1966
117,870
691,900
69,200
122,250
25,300
32,500
235,006
280,530
60, 340
10,616
127,051
152,467
90, 540
67,100
93,295
28,260
52,815
63,025
43,570
45,800
83,000
58,075
29,620
92,400
65,000
105,100
40,500
303,320
68,593
51,178
86,015
24,201
174,684
179,138
344,775
3,091
29,491
65,104
17,690
82,810
8,765
78,375
4,400,360
NOTE:  For data sources and method of estimation
          see Appendix F

-------
38


Household (Residential) Income

        Income is one of the variables used in explaining variation in wastes
generation.  The manner in which income level affects wastes generation is fairly
obvious and needs no stressing here.  Suffice it to say that wastes generation is
a function of extent to which a product is used, variety of products purchased,
and frequency of purchase of a particular product (and hence of discard); and these,
in turn, are functions of income.

        The primary source of income data was the 1960 Population and Housing census.
Among the other sources was the publication Sales Management, Survey of Buying
Power 1966 [10].  The difficulty in using both sources was the inability to estimate
corresponding figures for the 42 functional boundaries (DSA's) defined in this study.
Using the I960 census figures as a benchmark, the development of data to correspond
to 1965 would involve using population and/or employment data.  The Sales Management
figures would be heavily biased toward "big city incomes" and could not be used to
represent the average for the DSA.  Some comparisons were attempted between these
figures and those available from the 1966 census in Santa Clara County.  The
difficulty in estimating income for 1966 and the very nature of the method of
estimation precluded the use of income variable at the DSA level in the present
study.  Since employment, population, and land could be satisfactorily used in
estimating wastes data at the DSA level, the addition of the income variable, for
which data were less than satisfactory, would have served no useful purpose in the
study.  However, income data which are available in sufficient detail at the county
level will be used in later phases of the investigation.


Land Use by DSA's

        Land-use information can be used in two important ways.  Firstly, it can be
used to constitute one of the explanatory variables such as is done with agricultural
wastes in the present report.  Secondly, it also can be used in conjunction with
land-use planning for the region to suggest future locations of solid wastes disposal
sites as part of the overall regional management issues.  This latter aspect will
form an important subject for future research investigations.

        The research plan called for the use of data on land use (for 1965 or 1966)
to be obtained either from the Bay Area Transportation Studies or from the Bay Area
Simulation Studies (BASS).  The results from the latter were published recently and
were available for this study [11].  Agricultural land-use information was, however,
aggregated with vacant land and was not separately available.  Separate tabulations
of required agricultural land-use information were made by the planning and economics
research team with data obtained from the County Agricultural Commissioner's reports
by each of the functional boundaries (DSA's).  Information on industrial land avail-
able from the BASS studies is still under investigation.  However, an attempt was
made to tabulate the industrial land-use information from the BASS studies for use
in later phases of this study.  Data tabulated thus far are given in Appendix G-


Results of the Solid Wastes Generation
in the Nine-County Bay Area

        Important aspects and final tabulations of the results developed thus far
are described in Table 13-  Essentially, the table presents summary information on.
total solid wastes estimated for the nine-county Bay Area by major sources of wastes,
namely, residential, agricultural, commercial and nonmanufacturing, and manufacturing
(industrial) categories.  Corresponding figures on population and employment are
given for comparison.  The comparable data are summarized for each of the k2 func-
tional boundaries (DSA's) defined in this study.  The last column in the table gives
the totals for the entire study region.

-------
                                      SOLID WASTES PRODUCTION IN TERMS OF DISPOSAL SKBVICE AREA,
                                            SOURCE, POPULATION,  HOUSEHOLDS,  AND EMPLOYMENT
                                                                                                                                        39
Disposal Service Area

Code

01 01
02
03
04
05
06
02 01
02
03
03 01
02
04 01
05 01
02
03
04
05
06
07
08
09
10
11
12
06 01
02
03

04
07 01
02
03
04
05
06
07
08
08 01
02
09 01
02
03
04

Name

Berkeley
Oakland
Alameda
Fremont
Pleasanton
East Alameda County
West Contra Costa
Central Contra Costa
East Contra Costa
West Marin
East Marin
Napa County
Richmond
Marina -Pacific Heights
Central
South of Market
Western Addition
Twin Peaks -Buena Vista
South Van Hess
Potrero -Bayshore
Outer Mission
So. Frvay-Mt. Davidson
Lake Merced
Sunset
Daly City
South San Francisco
Pacifica

Central San Mateo
Palo Alto
Mountain View
Sunnyvale
Gilroy-Morean Hill
Los Gates
Los Altos
San Jose
Remainder of County
Vacaville
Falrfield
Healdsburg
Santa Rosa
Western Sonoma
South Sonoma
NINE-COUNTY TOTAL
Residential

Population
1
117,870
691,900
69,200
122,250
25,300
32,500
235,006
280,530
60,340
10,616
127,051
152,467
90,540
67, 100
93,295
28,260
52,815
63,025
43,570
45,800
83,000
58,075
29, 620
92,400
65,000
105,100
40,500

303,320
68,593
51,178
86,015
24,201
174,684
179,138
344,775
3,091
29,491
65,104
17,690
82,810
8,765
78,375
4,400,360

Household
Wastes
(tons)
2
43,209
268,380
26,229
33,577
3,277
3,779
91,380
96,295
23,198
5,320
44,378
62,828
35,753
22,616
39,700
10,468
15,061
22,909
11,369
11,195
31,279
24,524
12,911
43,762
24,757
39,788
13,349

124,504
26,652
17,840
31,787
8,817
60,142
65,144
117,284
1,143
11,492
20,640
11,065
37,110
4,180
35,895
1,639,766
Household
Wastes
Per Capita
(tons)
3
.36658
.38789
•37903
.27466
.12953
.27012
.38884
.34326
.38445
•50113
.34929
.41208
•39489
•33705
.42553
.37042
.28517
-36349
.26094
.24443
.37686
.42228
.43589
.47361
.38088
.37857
.32960

.40981
.58826
•34859
•36955
•36432
• 34429
.36365
•34018
•36978
.38968
.31703
.62549
.44813
.47690
•45799
•37264
Agricultural

Employ-
ment
4
152
1,301
123
2,516
519
1,109
194
1,602
3,812
169
1,029
3,731
66
10
4l6
13
18
14
13
87
34
54
4
4l
145
91
47

2,499
274
165
442
2,009
1,417
1,468
2,896
4,726
1,982
2,300
1,586
1,522
1,390
829
42,815

Wastes
(tons)
5
0
18,237
0
52,790
59, 512
!<5, 737
1,340
8,983
491,499
333,612
39,016
98,991
0
0
0
0
0
0
0
0
0
0
0
0
6,434
367
3,049

34,852
8,055
8,055
15,271
229,355
18,974
8,409
76,751
76,796
199, 188
304,473
119,217
161,744
337,973
511,817
3,270,497
Commercial, Nonmanu-
facturing and Public

Employ-
ment
6
46,098
196,713
21,677
15,577
3,584
10, 742
39,756
47, 594
8,615
533
30,466
38,584
28,498
27,003
158,363
86,246
12,431
6,388
26,196
21,647
8,069
7,183
8,096
9,997
9,638
41,775
3,537

79,883
59,654
13,546
20,447
3,684
21,678
25,449
80,480
1,294
5,420
13,794
5,894
3,172
1,903
25,530
1,256,834

Wastes
(tons)
7
252,170
1,245,941
136,583
230,422
84,683
88,405
311,578
511,652
57,874
6,749
232,299
217,100
166,279
272,122
992,103
376,083
84,993
62,792
125,607
95,845
42,314
69,865
35,338
41,983
107,376
Manufacturing
Industry

Employ-
ment
8
8,397
59,634
3,551
11,062
218
397
9,034
4,333
10,287
5
2,301
3,153
332
223
13,739
23,817
1,239
46
9,213
9,354
914

Wastes
(tons)
9
61,979
434,736
23,389
64,840
3,699
1,984
66,821
34,226
89,827
15
19,831
19,263
2,4l6
2,194
119,710
174,367
10,296
554
58,183
61,760
5,023
172 1,134
71
96
138
266,438 1 9,794
59,267 | 35
1
623,668
277,714
119,719
183,903
28,676
231,651
218,911
546,940
4,930
41,206
88,315
37,808
26,688
13,391
213,154
8,830,535
19, 100
13,349
8,625
22,619
1,467
1,865
7,879
32,368
29
1,402
2,593
1,920
515
812
1,861
297,959
362
948
1,736
71,976
425

109,873
49,729
30,210
38,895
9,401
13,217
8l,24o
170,470
154
7,520
Ik, 971
22,451
8,523
15,351
15,025
1,918,724
Total

Wastes
(tons)
10
357,358
1,967,294
186,201
381,629 !
151,171
144,905
471,119
651,156
662,398
545,696
335,524
398,182
204,448
296,932
1,151,513
560,918
110,350
86,255
195,159
168,800
78,616
95,523
48,611
86,693
140, 303
378,569
/6,090

892,697
362,150
175,824
269,856
276,249
323,984
373,704
911,445
83,023
259,406
428,599
190,541
234,065
370,895
775,891
15,659,522
Column 1       -  Table 12
Column 2       -  Table k
Column 5       -  Column 2 divided by Column 1
Columns k, 6,  -  Table 5
  and 8
Column 5       -  Table 10
Column 7       -  Table 11
Column 9       ~  Table 11
Column 10      -  Sum of Columns 2,  5,  7,  and 9

-------
4o
        Some of the highlights of the results are as follows:

    1.  Of the total wastes (15-66 million tons) generated in the nine-county
        Bay Area during 1966, nearly 56-4 percent came from commercial, non-
        manufacturing sources; nearly 21.0 percent from agricultural sources;
        about 12-3 percent from industrial sources; and about 10.4 percent
        from household sources.

    2.  Of the total residential (household) wastes (1.64 million tons), nearly
        83 percent of it came from single-family dwellings.  These wastes have
        a composition differing from that of the remaining 17 percent which
        came from multiple-family dwellings.  On the basis of a total population
        of 4.4 million, the household wastes accounted for about 2 pounds per day
        per capita.

    3-  Of the total 3-27 million tons of agricultural wastes, cattle manure
        constituted the largest amount —nearly l.J million tons.  All other
        livestock and poultry wastes, including dead animals,  accounted for
        approximately 1.24 million tons.  The remaining 0.73 million tons of
        agricultural wastes came from orchards, vegetables, and field crops.

    4.  The manufacturing (industrial) wastes, accounting for nearly 1.9
        million tons in the Bay Area, came from a variety of sources (see
        Table 11 for details).  Canning, preserving, and other food proces-
        sing accounted for nearly 0.33 million tons of wastes.  Printing,
        publishing, and allied sources generated 0-34 million tons.  The
        remaining wastes came from a variety of sources.

    5«  In terms of wastes generation, the major portion came from sources
        in the category of commercial, nonmanufacturing, including public
        offices.  This major source accounts for nearly 8.8 million tons of
        wastes.  It is well known that the greater portion of these wastes
        consists of paper, and that paper is the largest constituent of total
        wastes.

    6.  On the whole, if the total wastes (15.66 million tons) were related
        to the total population of the Bay Area (4.4 million), the per capita
        wastes generation per day in 1966 would have been around 19-5 pounds.
        This figure includes nearly 4.0 pounds of agricultural wastes (some-
        times omitted from calculations), 11.0 pounds from commercial
        nonmanufacturing wastes, approximately 2-5 pounds from industrial
        wastes, and about 2.0 pounds from household wastes.

        The above information can be used in a variety of ways.  A comparison of the
solid wastes data based on estimates made by disposal site operators (Table 2) with
those given in the summary table gives an indication of the amount and nature of
wastes that did not enter the regular disposal sites.  In fact, according to the
data in the summary table, of a total of 15-66 tons of wastes generated during the
year 1966, only about 4.24 million tons ended up in disposal sites.  The latter
figure is estimated on the basis of 11,609 tons per day (cf. Table 2).  This means
that only about 27-1 perce.it of the total wastes generated in the nine-county Bay
Area is disposed of in regularly operated disposal sites.  If agricultural wastes
are not taken into consideration, the wastes disposed of in sites accounts for
approximately 34.2 percent.

        The implication of the above figures is obvious with respect to the validity
of estimates of the life span of existing sites.  As more and more of the industrial
and agricultural wastes are directed to the disposal sites, the supply of disposal
site facilities could diminish at a rate much more rapid than heretofore, and thereby
create a near-crisis situation, unless meaningful alternative solutions are developed
beforehand.

        The present implications of the enormous quantities of wastes listed in Table
13, and, more importantly, their effect in the future on the resources of the region,

-------
constitute one of the more important issues to be considered in effective wastes
management.  Before these implications can be discerned, it is necessary to examine
a host of factors, of which the following warrant special consideration:

    1.  Physical and chemical properties of wastes by source of wastes;

    2.  Meaningful forecasts of the quantities of the individual constituents
        of the total wastes load, with a realistic appraisal of changes in
        composition;

    3-  Survey of existing transportation and disposal techniques;

    k.  Possible breakthrough in technology; and

    5-  Recognition of the need for regional management with its attendant
        influence on existing practices of solid wastes management.

These factors, in turn, would lead to others, such as private and public expenditures
by type of function, forecasts of increase in costs, incidence of costs on different
private and public bodies, and the broader questions of efficiency, equity, and
incentives for regional management•


Public and Private Expenditures for
Refuse Removal and Disposal

        An important element of the whole question of effective wastes management is
the expenditure on the various functions relating to wastes management incurred by
different segments of the community such as private households, industry, agriculture,
and those public agencies which either are in the business of wastes management or
which supervise activities pertaining to it.  Before embarking upon empirical research
on the subject, an essential step to be taken is the establishment of a detailed
accounting procedure by means of which it would be possible to determine true costs
(avoiding duplications and omissions) in terms of private and public expenditure by
type of function and by the individual segment which pays the bills.  The development
of such a procedure is one of the activities of the planning and economics team.
A report on the progress made thus far in this phase of the study is the subject
matter for this section.

        The collection, transfer, and disposal of solid wastes is handled by
scavenger companies, private commercial haulers, individual householders, and public
agencies.  Several different combinations of services are possible, ranging from
scavenger company operations (involving one or more companies) to part-private,
part-public operations, to all-public agency operations.  There are a large number
of scavenger companies, private collection companies, and private disposal site
owners operating under an even larger number of public jurisdictions in the nine-
county San Francisco Bay Area.  In addition to nine county governments, there are
ninety-one cities, thirty-five sanitary districts, nineteen county sanitation
districts, one garbage disposal district, and one sanitation and flood control
district empowered by law to collect and dispose of refuse.  In addition, some
fifteen sewer and sewer maintenance districts are empowered to provide for the
"collection, treatment, and disposal of sewage and industrial wastes."  While few
of these public bodies are actively engaged in direct collection and disposal
services, almost all incur some regulatory and administrative expense.

        In addition to the expenditures by the 171 local public bodies specifically
concerned with the problem of solid wastes disposal, there are the wastes disposal
expenditures associated with other special districts and various state and federal
facilities scattered about the region.  These range from local school districts,
which arrange for collection services from private companies in the same manner as
would any commercial operation, to the State Parks and large military installations
which dispose of all refuse on their own premises and operate their own collection
and disposal systems.  Additionally, many of the sanitary districts operate sewage

-------
disposal plants which produce sludge and sewage wastes that must be disposed of
elsewhere at public expense, either by another public agency or by a private
disposal company.

        According to the report Refuse Disposal Needs issued by the Association of
Bay Area Governments [12], from 90 to 95 percent of the people living in the Bay
Area in 1963 were provided with regular collection and disposal service.  The bulk
of this service was handled privately.  Of the eighty-two major refuse collection
companies in operation in July of 1963; only four were publicly operated, namely,
Berkeley, San Leandro, Dixon, and San Quentin Prison.  For the most part, the
private companies operate under exclusive franchises or contracts issued by counties,
cities, or sanitary districts.  A few collection companies operate without franchise
in the unincorporated areas.  Some of the cities issue a franchise for household
refuse only, and leave commercial pickups to open competition.  The greater number
of the disposal sites are privately owned and operated, although subject to public
regulation.  The publicly owned sites are in some cases used exclusively for publicly
collected refuse, in other cases by private companies, and in many cases directly by
individual citizens and enterprises.

        Accounting for total expenditures on wastes removal, handling, transfer,
disposal, and supervision by public bodies covers a wide range of activities.
Initially, for data collection purposes, collection, handling, and transportation
of refuse were treated as one function, and the operation of the disposal site as a
separate function.  The many different combinations of private and public agencies
providing these functions fall into three general categories.   Examples of the
combinations are given in Table l4.


                                     TABLE lit

  EXAMPLES OF COMBINATIONS OF PRIVATE AND PUBLIC COLLECTION AND DISPOSAL SERVICES
Cases
1. Scavenger Co. to Own Site
2. Scavenger Co. to Private
Site of Another Company
3- Scavenger Co. to Public Site
k. Public Agency to Private Site
5. Public Agency to Own Site
6. Public Agency to Public
Site of Another Agency
7. Commercial Haulers to
Private Company Site
8. Commercial Haulers to
Public Site
9. Self -Service to Private
Company Sites
10. Self-Service to Public Site
11. Commercial Haulers to Nonsite
12. Self-Service to Nonsite
Collection and
Transport Agent
Private Scavenger Co. A
Private Scavenger Co . A
Private Scavenger Co . A
Public Agency C
Public Agency C
Public Agency C
Commercial Haulers
Commercial Haulers
Self -Service
Self-Service
Commercial Haulers
Self-Service
Disposal Site Operation
Private Scavenger Co . A
Private Scavenger Co . B
Public Agency C
Private Company A
Public Agency C
Public Agency D
Private Company A
Public Agency C
Private Company A
Public Agency D
Not -to -Site
Not -to -Site

-------
        In the first category., wastes are picked up at the source as part of a
regular collection service and taken to a disposal site (rows 1-6 in Table ]A).
The source of the wastes may be a household,  a business,  an agricultural unit, or
a governmental office.  The collection service may be provided either privately
by a scavenger company or by a public agency.  The disposal site may be  privately
operated by the same company as the collection service or by a different one,  or
it may be publicly operated by the same jurisdiction as the collection service or
by a different public agency.  Thus, there are several different possible combina-
tions within this category.  Costs of the transportation and disposal functions  may
be determined as the sum of the revenues of the operators providing the  relevant
services.  Care must be taken, however, that the funds paid to the disposal site
operator by the collection company or operator are not counted twice in  estimating
costs, i.e., once as revenue of the disposal site, and once again as revenue of the
collection company or agency.  Similarly, in cases in which the collection and
transfer operation and/or the disposal operation are carried on by a public agency,
double counting of public expenditures should be avoided.  A distinction must  be
made between such expenditures by the public agency for administration,  management,
and supervisory functions, and these costs should be examined in detail.

        In the second category, wastes are transferred directly to a disposal site
by a private hauler or the consumer, i.e., by some party other than a scavenger
company or a public agency (Table l4, rows 7-10).  Disposal costs are inclusive
and may be obtained, but transportation costs must be estimated separately.

        In the third category, wastes are not handled by a scavenger company (or a
public agency), nor are they taken to a disposal site (Table lk} rows 11 and 12).
The wastes may be burned or buried on the premises, spread on agricultural land,
disposed of at sea, sold or otherwise reused, or disposed of by some other means.
In estimating expenditures in this category,  the amounts  of solid wastes and the
associated expenditure for transportation and disposal must be determined one  by
one.

        The three categories described above are listed in increasing order of
difficulty with respect to obtaining accurate data, and in decreasing order with
regard to reliability of the applied estimation procedures.  The selected data
collection system must be able to account for all expenditures made in the management
of solid wastes.  The expenditures may be measured in terms of either the revenues
collected by those providing the service, or by the expenditures made by the users.
Given a particular source of wastes, the wastes generated either will be collected
by a regular collection service (category l) or removed by the consumer  in some  other
way (categories 2 and 3)-  The expenditure incurred by the consumer in any of the
three categories is equal to the revenue of the party that provided the  service, and
thus can be accounted for by summing all such revenues.  In those instances in which
some of the producers of wastes also perform some of the  operations of collection
and disposal (termed "self-service units"), the value of those services  performed in
accomplishing the wastes disposal should be estimated.  This value or cost should
be added to that of the services supplied by the regular collection and  disposal
site operators so as to arrive at a true total cost for the entire region.

        Another question of interest in the study of the  expenditures involved in
wastes management is that of separating private and public expenditures  by type  of
function.  The fact that public wastes sources do not pay directly for their wastes
disposal operations does not mean that these operations do not cost anything.   These
operations are paid for indirectly by taxes (direct subsidy from the taxpayers to
the public agency involved) and by fees paid by private collection disposal companies
for indirect services.  Although the public collection agencies generally are
exempted from paying franchise and administrative fees and taxes, these  elements
should not be excluded when estimating the true costs of operations and  when making
comparisons with similar costs of operations by private agencies.  In other words,
in arriving at estimates and in making comparisons between private and public
operations, the items of costs should be made uniform by avoiding possible omissions
or double countings, as the case may be.  Some of the problems in arriving at
estimates are described schematically in Tables 15 and 16.

-------
kk
                                     TABLE 15

           PRIVATELY OPERATED DISPOSAL SITES:  REVENUES AND EXPENDITURES
           Sources of Revenue
            Expenditures
  1.  Disposal Fees from

      a.  private scavenger companies

      b.  public collection agencies

      c.  commercial haulers

  All three will have collected wastes
  from

      households

      businesses

      industry

      public agencies

  Their disposal fees will have already
  been counted in the revenues of the
  collectors — disposal fees listed
  here are thus a subcategory of total
  revenue-expenditure of operation.

      d.  self-service haulers who may
             be households, businesses,
             industry, agricultural
             units, or public agencies

  Their disposal fees have not been
  previously accounted for and are new
  items.


  2.  Additional Revenue from Sale of
      Refuse and Salvage Operations
  Note:  Private-source disposal fees
  may be lumped together, but public-
  source fees must be kept separate,
  and each source indicated to keep
  track of separate public agency
  expenditures.
Processing Costs

   equipment

   labor

   fill and cover material

   general administration and
      maintenance

   extra costs for salvage operations,
      if any


Land Costs
   Land could be:

      owned by site operator

      leased from another private
         party

      leased from public agency

      (could even be negative or zero
       cost if refuse is of high
       quality and valuable for fill)


Public Fees
   business license

   special disposal fees for health
      inspections, franchise privilege
Profit
   (to be recognized)

-------
                                   TABLE 16

         PUBLICLY OPERATED DISPOSAL SITES:  REVENUES AND EXPENDITURES
         Sources of Revenue
            Expenditures
1.  Disposal Fees from

    a.  private scavenger companies

    b.  public collection agencies
           (either accounting trans-
            fer if site operated by
            same agency as does
            collecting, or other
            public agency)

    c.  commercial haulers

These disposal fees will have already
been counted in calculating revenue
of collectors — disposal fees listed
here are thus a subcategory of total
revenue-expenditure of operation.

    d.  self-service haulers who may
           be households, businesses,
           agricultural units,
           industry, or public
           agencies (again, same or
           different)
2.  Salvage Fees from Sale of Refuse
3-  Subsidy (if operated at loss)
Note:  Private-source disposal fees
may be lumped together, but public -
source fees must be kept separate
and each source indicated to keep
track of separate agency expenditures.
Processing Costs

   equipment

   labor

   fill and cover material

   general administration and
      maintenance

   extra cost for salvage operation


Land Costs
   Land could be:

      already owned

      purchased for this purpose

      leased from private owner

      leased from other agency

      (land costs could be zero or
       even negative if refuse is of
       high quality and valuable for
       fill)


Additional Costs
   Site may operate at cost, or
      operate at deficit in which case
      additional revenue from taxes
      are necessary to balance
      account.

-------
        The public expenditures could be incurred at the local level by city,  county,
or special districts, or at higher levels by state and federal agencies.  The  nature
of the function could be simply that of a customer, collecting agency,  disposal
agency, self-service unit", supervisor or combination of these  functions.  The
procedures for collecting data on expenditures by functional lines  and  by type of
agency, private and public, (if public, at which level), should be  devised with
proper care and the avoidance of double counting.  Finally,  the expenditures should
be estimated at the functional boundary (DSA.) level.  Where  expenditures are not
readily divisible and cannot be determined along these lines,  e.g.,  county and state
road sanitation expenses, the data should be collected for the larger area and
appropriately apportioned among the USA's.  Following these  steps,  each governmental
body involved in any way with the collection, handling, treatment,  or disposal of
solid wastes should be listed.  These activities should be subdivided into appropriate
agencies as necessary, and the net expenditure by each governmental unit or depart-
ment recorded.  Use could be made of data on the gross revenues from collection,
transfer, or disposal obtained by private companies engaged  in systematic, regular
collection and disposal operations.

        Finally, those private companies engaged in occasional or special hauling
should be listed along with their gross revenues.  Row totals  thus  would be the sum
of all of the monies collected by any private company, or spent by any  governmental
body on all aspects of solid wastes management within the area, while column totals
would reveal the total money spent in each area by function.

        In the preceding discussion, a brief description was given of the difficulties
which may be encountered in any attempt at arriving at estimates of true and
comparable costs of solid wastes management by the different agencies.   Possible
approaches are presently under consideration, with the view  of making them operational
for the Bay Area, and thereby arrive at procedures which would be more  general in
application.  The first step in the research, therefore, will be an investigation
of the various ramifications with respect to a metropolitan  area within the Bay Area.

-------
                     IV.  OPERATIONS RESEARCH IN SOLID WASTES


        A comprehensive wastes generation model was described in Chapter III of the
First Annual Report [l] of the project.  During the second year of the study,
attention of the operations research group was focused on wastes collection, treat-
ment, and disposal.  A series of models was developed which deal with this general
topic at different levels in the wastes management structure and utilizing different
planning horizons.

        The subjects receiving special consideration were:

    1.  Optimal location of treatment plants and disposal sites.

    2.  Determination of the least cost flow pattern of wastes from origin, via
        existing transportation networks, to treatment plants and ultimately to
        disposal sites .

    3.  Optimal operating policies for treatment plants in the face of randomly
        varying wastes loads.

        The models are described in detail in separate reports [13,1^-1 of the project
and hence are herein described only briefly.


OPTIMAL ACTIVITY LOCATIONS

        The problem of optimal activity locations is one which is concerned with
locating a treatment plant or disposal site or group of sites to serve a certain
number of sources (wastes generators) in the most economical manner; in other words,
for a number of sources — given their location requirements and associated shipping
costs — to find the prescribed number of disposal sites, their locations and their
capacities.  This problem, as is apparent, is usually long term in outlook and the
planning horizon approximates 15 to 20 years.

        Stated mathematically the main problem reduces to :  Given a set of generation
points, n, their locations (xj_, yj_) i = 1, 2, ..., n  and their requirements wj_,
i = 1, 2, ..., n.   Find disposal sites (xj, yj), j = 1, 2, ..., m   and minimize
F(x,y) subject to

                                      n   m

                            F(x,y) =

                                     1=1 J=l

where
                          .  =  I x.  - x.   +  y.  - y.
                                              i    J
                      1 if generation point i is assigned to site j;
               ij   [0 otherwise.


        A general power k was considered in the distance (or cost) expression,
allowing treatment of all possible  cases where the power of cost is more than unity.
This problem lends itself to different solution procedures depending on the number
of disposal sites that are prescribed.

-------
1*8
        The single "free" site problem has been considered and solved in the
literature [15]-  It was not considered desirable here since the site thus chosen
may not be practical.  The single -site problem occurs when given a set of generation
points, their location requirements, and associated shipping costs, a single -site
location is required such that the sum of the total shipping cost from all generators
to this single -site be minimized.  A quadratic approximation search procedure was
developed that converged to an optimal-site location faster than other presently
known methods .  This search procedure is based both on the quadratic and the
Fibbonacci approximations which are used alternately until the directional vector
becomes very small or the distance between two successive site locations is negligible.

        The multiple -site problem arises when a prescribed number (greater than one)
of sites have to be located in order to serve a given set of generation points at a
minimum total transportation cost.  Two general assumptions were made:  l)  There
is no capacity restriction on the sources, and  2)  the unit transportation costs
are independent of the amount transported.  It should be borne in mind that complete
enumeration of all possible assignments of sources to destinations can always be
resorted to, but that the time and cost involved in doing so for any reasonably
large -size real-life problem would be prohibitive.  A branch and bound algorithm was
developed which results in the optimal activity location.  To express this mathe-
matically, let


              L = set of all locations, generation points and sites,  |L| = n
              S = set of sites, SCL,  |s| § m
              D = set of generation points, DCL,  |D  s n - m
              A = set of unassigned locations or where sites could
                     be located, ACL,  JA| S n
             S  = optimal set of sites, £>OCL, |SO| = m

             D  = optimal set of generation points, D CL,  D   = n - m


then
                          S H D n A = 

and

                                  S  U D  = L
                                   o    o


Then the  original problem can be rewritten in the following form:  Find a-j* and
min F(ai)  subject to   S  = m, where
                                    =  Z  Z
                                      j€L  ieS

 and

                                 CU = Vij

 Let min F(a. .)  *>e  Z(S),  then

-------
                            Z(S) = min  }   )  a..
                                        Z_!   Z_.   n-j
                                       j£L ieS
                                       mm c. .

                                   jeL ieS


and the problem thus is to find Z(S) subject to JSJ  = m.  The procedure developed to
achieve this objective is to construct the set by adding one location at a time.
After a number of iterations, the site set will equal (n-m) in which case a feasible
solution has been found that satisfies the main requirement.  In order to get the
optimal site (or generation point) set, the above procedure is repeated until Z(S)
is minimized.  Since the branch and bound algorithm thus developed reduces the
number of feasible site (or generation point)  sets to be constructed in order to
arrive at the optimal solution, great savings  are effected as far as time and number
of iterations are involved.  The details of this method are given in a report
prepared by the operations research group [l^]•  This solution procedure can be
easily modified to take care of another type of problem that usually arises; namely
one in which some disposal sites are already existing and are operational and only
a few additional ones are required.  This procedure, given the number of new sites
to be opened and where they_can be located, leads to the determination of their
exact optimal location.  A modification to include disposal site capacities can also
be incorporated easily.  This solution procedure can also be used to optimally locate
intermediate points (e.g., treatment plants, transfer stations) once the generation
points and disposal sites are given as fixed.   However, using it to simultaneously
locate disposal sites and intermediate points  will not result in an optimal solution.

        The application of the procedure described above to the Solid Wastes Manage-
ment Project is obvious.  In any given region there  are some existing wastes disposal
sites which are currently in operation, as well as other sites which may be potential
sites for the future when the existing ones will no  longer be available.  This
argument is valid for the sanitary landfill method of wastes disposal, for incinera-
tion, or for any method where future expansion may be required because of limitations
in the capacity of an existing facility.  The  algorithm then can be used to determine
where, out of all of the available potential sites,  the prescribed number of actual
disposal "plants" could be operated in such a  manner that the sum of the transporta-
tion costs would be at a minimum.  The cities,  or even smaller subdivisions, if the
size of the problem allows it, can be approximated to serve as wastes generation
points.  So far as the present "state of art"  of the procedure is concerned, the
actual number of disposal plants to be made operational at the potential sites is
left to the user of the program.  It is obvious that, as this number is increased,
the net transportation costs incurred for wastes disposal will not increase.  However,
in actual practice, there is a limited budget,  and only a given amount of money can
be used to acquire the site and get the plant  in operation.  Thus, a still more global
optimum can be obtained by considering the budget restraint.  Differing acquisition
costs, differing means of wastes disposal leading to a different "payoff" by the site
after its usage, as well as several qualitative features which simply cannot be
expressed mathematically, certainly add to the  complexities of finding a global
optimum.  For example, a landfill site in general has a short life, but then it may
be converted to a golf course, whereas an incineration site has a much longer life
but no payoff appeal.

        A computer program has been written and will be applied to an existing
problem.  The nine counties around the Bay Area were chosen as the test area for
the study.  This region contains 120 cities which served as wastes generation points
and 75 wastes disposal sites currently in operation.  Another 15 potential sites have
been identified by detailed discussions with the authorities concerned.  When
completed, the program will yield a complete timetable of how much wastes should be
disposed of at a given site from a particular  city each day; when a given -site will

  388-229 O - 70 - 19

-------
50
be completely used up; which of the potential sites should be made operational and
when; and when they should be closed, along with the total optimal operational costs
involved (transportation costs plus disposal costs only).


HETEBMINA.TION OF OPTIMAL WASTES
FLOW PATTERNS

        The principal objective of this aspect of the investigation was to develop
a general procedure for shipping wastes from generation points to disposal sites
via intermediate points, as required, at minimum costs, and within the limits of
transportation and activity capacities.  Since the pattern of wastes generation
remains essentially the same over short periods of time, the planning horizon
encountered here usually is of the order of four to six months.

        In the first phase of this investigation, the plan was to examine the
specific problem of transporting solid wastes only from communal transfer stations
via transfer vehicles.  The main characteristic of this type of transportation
problem is that the wastes must be shipped in aggregate amounts, such as in large
transfer vehicles, and that the aggregate flow not be too  small in relation to the
total flow leaving the source.  In addition, the possible  shipping routes from
source to sink are constrained for capacity, while the sinks are also capacitated,
limiting the aggregate flow into them.  Also, since it can be safely assumed that
a dump site will always be found to handle the inflow, the feasibility restriction
is  Z flows from transfer stations S 2 disposal capacities, which is the opposite
of a regular transshipment feasibility condition.  Mathematically, if an artifical
source o and sink s be added on, the problem is reduced to:
                   Minimize     c =

                                     ij
                  Subject to    )  f..  - f.
                                Z_i
                                j
                                   0 g f. .  g k. .


and

                                    f, ,  = n q,
where n is an integer and q^ is the aggregate flow at source i.  An algorithm was
developed, which with the proper use of heuristic schemes converges directly on an
optimal shipping schedule, and thus eliminates the need of linear programming theory
completely.  This algorithm provides a framework for partitioning the total problem
into subsets, and then guiding the search for a solution along certain of these
subsets until the optimal is reached.  Applied to the transportation problem, the
separation procedure (branching) systematically enumerates the feasible shipping
schedules, while the evaluation procedure (bounding) directs the search toward a
minimum cost solution.  In addition, a heuristic node ordering is utilized to
eliminate the examination of uninteresting activities and to facilitate convergence.

        In the second phase a model was made of the general problem of transporting
and treating all wastes generated in a typical community.  The system was then
optimized by developing and applying a parametric out-of-kilter linear programming
procedure.  While the system thus developed was in general a multicommodity network
flow problem because of the presence of solid, liquid, and gaseous wastes, the
consequent limitations were avoided by incorporating fixed-ratio flow dividers to

-------
                                                                                  51


segregate the commodities and to allow optimization by near-conventional methods.
The resulting network is as shown in Figure 1 (see page 53).   A few simplifying
assumptions were made.  These involved either the existence of at least one feasible
solution, or the fact that all the wastes generated could be  transported,  treated,
and sent to the final sink.  The activity costs were assumed to be linear, and the
lower bound on all the arcs to be zero.  The treatment plants were represented as
fixed-ratio flow separator nodes, with the ratio dependent on each specific plant
and fixed over the operation of that plant, but capable of varying from plant to
plant.  Similar nodal representations were developed for a typical transfer station,
solids treatment plant, liquid treatment plant, and the final disposal activity.
Mathematically, the problem was reduced to a typical network flow problem with the
exception of these fixed flow separator nodes.  An algorithm was developed to find
the optimal flow through this network.  This was done along the lines of the currently
popular out-of-kilter algorithm.  The flow-labeling rule and the potential change
rule which were developed, were quite akin to those already in use in the  out-of-kilter
algorithm.  This algorithm was developed in all its generalities to account for the
backtracking of flow, which is usually encountered in such cases.  The details of
the algorithm are given in a report prepared by the group [l^].


OPTIMIZATION OF SOLID WASTES
TREATMENT PLANT OPERATION


Introduction

        One of the generic components of any solid wastes disposal system — located
between the wastes collection activity and final disposal — is the treatment
facility.  Whether it be of the type that converts wastes into another form such as
ash or some valuable resource, that reduces its volume by compaction, or that
decomposes its components by separation, the operational structure of the  treatment
facility is the same.  Essentially, one has an arrival stream of raw wastes, a
processing or service operation with variable rates, and a storage operation.

        Superimposed on this system is a cost structure.  If the initial capital
cost is fixed, one may wish to examine the day-to-day variable costs in the interest
of economy.  These daily costs are usually directly proportional to the processing
or service rates of the facility.  Additionally, if the quantity of raw input wastes
temporarily exceeds the quantity of processed wastes, a storage operation  becomes
necessary.  Although, again considering capital costs fixed,  the daily cost of
storing solid wastes may be negligible, it is still in the interest of public health
to keep this quantity of stored wastes at a reasonable level.  In more concrete terms,
it is advisable to incur a low risk of the delay of any given particle of  wastes
beyond a specified holding or waiting time.

        The manager of a wastes treatment plant is now confronted with an  interesting
problem, namely:  considering the variation in the arrival stream, what service rate
policy he should employ to minimize expected processing costs at a given waiting
time risk level.  The key to the formulation and solution of this problem is to
consider an artificial holding or storage cost which is directly proportional to the
amount of unprocessed wastes in storage.  Once the sum of daily processing and
holding costs is minimized with respect to service rate, the  resulting waiting time
distribution may be related to the artificial holding cost, and optimization for a
given risk level may be achieved.  It is the first part of this problem that has
been currently investigated.  More specifically, the problem is:  given holding and
processing costs, find the service rate rule that minimizes the long-term expected
value of the cost rate or gain.  Two versions of this problem and their solutions
are discussed in the sections that follow.  Finally, some extensions to the proposed
model are preferred.

-------
Dual Service Rate Treatment Facility with
Continuous Arrival of Wastes [1]


        General Description.  In this version of the problem the treatment facility
has two constant processing rates having given operating costs.  The arrival of
wastes occurs in batches (e.g., truckloads of refuse).  Batch amounts have a general
(known) distribution and the interarrival times of batches are assumed to be
exponentially distributed.  Arrival amounts per batch are independent of each other
and of the interarrival times of trucks.  Both the arrival stream and processing
facility are continuously in operation.  It is assumed that the holding cost is
linear in the current inventory level of wastes.

        Assuming that the slower process rate exceeds the mean arrival rate of
wastes, a stationary control policy can be found which will minimize the long-run
average cost rate.  A procedure for optimally operating the facility involves a
single critical wastes inventory level above which the fast rate is used, and below
which the slower rate is employed.


        Mathematical Formulation.  The system may be characterized by an underlying
continuous parameter, continuous state stochastic process (X(t), 0 s t < »}, where
X(t) is the wastes inventory level at time t in tons.  There are two processing
rates c^ and a2 in tons per hours, with respective costs of r.j_ and r2 dollars per
hour all considered to be known constants.  The holding cost rate at time t is
assumed to be h-X(t) dollars per hour, and h is a specified constant.  The units
for h are in dollars per ton-hour-  It is assumed that as > ax, r2 > rx, and
ra 0]_ > r-|_ aa. The cost per ten at time t is (r^ + h-X(t))/a1 and (r2 + h-X(t))/aa
when rates 1 and 2 are used, respectively.

        Batches of material arrive singly in a Poisson process.  Let T be the inter-
arrival time with distribution function Frp(t) = Pr(T § t), and that Frp(t) = 1 - e~^,
for t g 0, where \ is the average arrival rate in batches per hour and E(T) = 1/X.
The amount of material in each batch is a continuous random variable and can be
specified by any general distribution.  Let V be the number of tons making up a batch
arrival with distribution function Fy(•)•  Let E(V) = l/£ be the expected number of
tons per batch-  The average arrival rate is \/| tons per hour.  Also, batch sizes
are independent of each other and of the interarrival times.  Assume that E(V2) < °°.

        If the same processor is always selected whenever a positive amount of
material is in inventory, then the process is essentially and M/G/1 queue.  Using
many well-known properties of M/G/1 queues, the stationary cost rate of the two-
processing-rate problem is derived assuming a single inventory level, Y*, is used
as a switchover criterion from rate 1 to rate 2 (Y policy).  The optimal rty  policy
is found in terms of a simple implicit formular for Y*-  It is proven that ty* ^s
optimal for all stationary policies.


Continuous-Rate Treatment Facility with
Periodic Arrival of Wastes  [13, JiT


        General Description.  In this version of the problem, the set of possible
deterministic processing rates is extended to a continuum.  It is assumed that the
processing cost may be approximated by a quadratic in this variable.  The arrival
stream is interrupted periodically.  The distribution of the cumulative quantity
of wastes arriving during the  "on" portion of each period  (equivalent to the eight-
hour day of a collection agency) is represented by its first two moments as an
approximation, thus allowing a distribution-free analysis.  During the  "off" portion
of the period (equivalent to the remaining l6 hours of a day), no raw wastes are
introduced into the system, although the processing facility is allowed to operate
for more efficient use of fixed capital  outlay.  The service rate is selected at the
start of the  "on" and  "off" portions of  each period.

-------
        The total expected sum of processing and holding costs is minimized with
respect to the operating rate.  Holding costs are linear in the quantity of wastes
present at the end of each period.

        Preliminary results indicate that the optimal service rate is linear in
the wastes level at the start of each period, and piecewise linear in the quantity
of wastes present at the start of the "off" portion of each period.  The optimal
expected discounted rf^1 period cost is approximated as a quadratic in the wastes
level at the start of the n^ period.


        Mathematical Formulation.  The system may be characterized as a continuous
state, discrete parameter stochastic process {X^_; i = 1, 2, . ..}, in which Xj_
represents the amount of wastes in the system at the start of period i.  Each period
is of length T, and is further divided into two intervals, the "on" interval of
length Tx and the "off" interval of length T2.

        The dynamics of the system state may be understood by examining a realization
for a typical period.  Figure 1 is a realization for arbritrary period i.
              c
              o
              LU
              I-
              
-------
                            Y.-v.
                     •
                     1+1
        The single period cost is composed of a holding cost  charged at  the  end  of
the period and a processing cost charged during the  times when  the  inventory level
is positive.  The various cost parameters are defined below:

        a.  Holding costs:

               h = unit holding cost in dollars per  ton of wastes remaining
                     at the end of the  period.

            C,  .  = total holding cost in period i  in dollars.


                       0      ;      if  X.
        b.  Processing costs:

            r(u.)  = processing cost using rate  u^  charged  in  dollars per
                      hour during the  "on" interval.   This  is a  quadratic
                      convex function  in u^ with r(o)  = 0.

            r(v.)  = same as r(u.) but  for the  "off"  interval.


            C  .   = total processing cost in period  i  in dollars.
             P.!1
        c.  Total period costs :

            F.  (X. ,u. .,v. .,3) = total i^ period costs  in dollars  given the
                                period starts  in state  Xj_ with amounts  of
                                wastes S arriving during the period and
                                processing rates u^_ and Vj_ being used.
            F. (X.,u.,v.,S) = C,  .  + C  .   .
             i v  i' i  i       hji     p,i
            The optimal i*"1 period rates  u^  and v^   are  found by minimizing
              the above function with respect to the  nonnegative  variables
              and u.  and v..
            c. (x.,u., v.) =       {F.CX.^.^.^
            If C. (X. .,u. ,v. ,S) is approximated by a  quadratic  in Y.,  its
              expected value may be found in terms of the  first two moments
              of the distribution of S designated as E (S)  and E (S2),
              respectively.

-------
                                                                                  55
        The total expected cost incurred during n consecutive intervals may be
found by forming the appropriate recurrence relation and applying Bellman's [16]
principle of optimality.  The resulting optimal n period policy is denoted as a
sequence of rates, {u^, v.,_o; U2°, V2°; ... Uj_°, v-j_°, ... un°, vn°) .
        Extensions.   Work yet to "be undertaken in refining the model will be directed
to the following objectives:

    1.  Relate holding cost to waiting time distribution of wastes.

    2.  Include switchover costs in the cost structure.

    3-  Investigate  nonstationary arrival patterns (seasonality).

    ^•.  Include maximum storage and processing capacity for treatment facility.

    5-  Find optimal plant expansion for a given wastes growth profile.

-------
                                   V.   ECONOMICS
INTRODUCTION

        Studies of the economic aspects of solid wastes management during the report
period were concerned with three principal aspects :

    1.  The interrelationships of regional economics and the amount of solid
        wastes generated.

    2.  Economics of scale in solid wastes management.

    3-  Economic analysis of technologies under experimental study in the
        project.

        The first of these is an integral part of the planning study and is, there-
fore, discussed in Chapter III as one of the factors which govern the amount of
wastes generated, as well as a possible clue to the  wastes which might be expected
from any land area planned for a certain pattern of  development in the future.

        Progress along the second line is one of the subjects reported in this
chapter.  It concerns evaluation of economics of scale  on the basis of data from
existing installations.

        A report on the third aspect, likewise presented in this chapter, represents
the current efforts of the project's economists and  technologists to assess the
economic feasibility of ongoing technological studies at the present stage of their
progress.  Two objectives underlie this assessment:

    1.  An evaluation of the future feasibility of the  technologies of compost-
        ing, anaerobic digestion, biofractionation,  wet oxidation, and pyrolysis.

    2.  On the basis of item 1, either to judge the  advisability of continuing
        research effort along any given line, or to  anticipate the amount of
        work yet to be done before such a judgment is possible.


ECONOMICS OF SCALE


Introduction

        Although there are a number of compelling reasons — geographical, jurisdic-
tional, political, and technological — why a regional approach to solid wastes
management is logical and necessary, economic factors must weigh heavily in the
actual design of any regional system.  Particularly  important are cost data on the
unit processes in the collection-disposal sequence and the way in which economics
of scale might be utilized to advantage.  However, it is first necessary to determine
whether economics of scale do indeed exist in each of the several processes of wastes
management•

        The discussion which follows is of the nature of a progress report on work
by the planning and economics team in collecting and analyzing pertinent data.  With
respect to the overall mathematical Regional Wastes  Generation and Evaluation Model
described in the First Progress Report [l] the data  sought will serve as input
information in the development of the cost row vector representing collection
(transportation), treatment, and disposal work (R) in the model, and in arriving at
a minimum yearly cost of collecting, treating, and disposing of a set of wastes
                                         56

-------
                                                                                  57


(Z° in the model).  Since these two factors are essential considerations in the
optimization of a disposal program, data related to them serve as input information
in the development of the process technology- and of the wastes collection, treatment,
and disposal submodels.

        The specific approach in the economic aspect of the study is to gather and
analyze cost data for existing facilities in the real world.  Such an approach may
not necessarily answer all of the questions relevant to the planning problem, but
it does provide a systematic and rigorous framework for determining realistic cost
values which must be used in the evaluation of alternatives among wastes management
systems.  Moreover, because the data used in the analyses pertain to existing
facilities operating in the solid wastes industry, they have objective rather than
subjective origins.


Importance of Economics of Scale

        For purposes of the investigation, the term "economics of scale" is defined
as the lowering in average cost per unit of wastes processed which accompanies
increase in the level of operation (scale) of the plant.  Economics of scale is of
importance from the standpoint of planning, since one of the major advantages claimed
for the regional approach to solid wastes management is that with such an approach
large facilities can be used, with consequent superior performance and lower cost
than could be done under the present fragmented system.  Although there are formidable
problems of site and of delivery of wastes which may accompany large-scale disposal
undertakings, the first step is to determine the extent of the validity of the
foregoing assumption through observations of real situations.  It is the objective
of the research here reported to undertake this first step.


Analysis of Cost Data

        If cost data are to be analyzed to determine whether economies of scale exist
in the several processes involved in wastes management, consideration must be given
to an appropriate analytical method.  To this end the use of regression analysis was
proposed as appropriate.  In considering how the method might work,  the cost of
incineration is used as an example.  For such a purpose a cost range of $4 to $10
per ton was selected, inasmuch as it is based on a collection of data on a certain
number of incinerators.  Before starting the analysis, it is determined that the
data are comparable, lest the observed differences simply reflect random inclusions
and exclusions of categories of cost.

        In making the analysis, it is expected or hypothesized that there are some
factors which determine a systematic variation in costs.  If it is suspected that
average cost becomes lower as the capacity of the incinerator increases, the validity
of the supposition can be determined by matching cost per ton figures with the
capacity figures for each incinerator.  In the example, it is assumed that there are
10 incinerators and that the capacity ranges from *iOO to 1200 tons per day.  The
pairing for the 10 incinerators is depicted in the following scatter diagram:
    Average Cost    10
      ($/ton)
                                                I
                         400    600    800    1000    1200     Capacity
                                                              (tons/day)

-------
The general trend of the scatter does seem to be lower as capacity increases, but
the points do not fall on a straight line or curve.  A line, termed a "regression
line," may be fitted to the scatter by statistical methods.  The line has a general
formula for a straight line, namely, $/ton = ao + a-j^ (tons/day).  (For the sake of
simplicity, the points were fitted with a straight line.  Other functions would have
been appropriate.)  If it is supposed that the results of the statistical fitting
are aQ = 12 and &1 = -0.008, the formula becomes $/ton = $12 -0.008 (tons/day).
The formula allows for the calculation or prediction of average cost in dollars per
ton for any value of capacity expressed as tons per day within the cost range of $4
to $10 per ton.

        Predictions made on the basis of the formula given in the preceding para-
graph would not be fully accurate, since the points in the scatter diagram do not
all fall on the fitted line.  In determining the extent of the error in prediction,
reference is made to the following scatter diagram in which the fitted regression
line has been drawn:
     Average Cost    10
       ($/ton)
                           J	I
                           kOO    600    800    1000    1200      Capacity
                                                                (tons/day)
There is an error in the prediction for each incinerator, the extent of which is
measured by the vertical distance between the regression line and the points of
the scatter.  The regression line is fitted to minimize this error.  If, by
appropriate tests, the error is proven to be random, then the relation between
average cost and capacity has been established except for the unpredictable influence
of factors which contribute to the error.  If the scatter of points is close to the
regression line, the errors in prediction of average cost will be small.  A measure
of how well the line fits the scatter of data is available from the statistical
calculations made in the fitting.

        A systematic relation of the errors to the regression line (nonrandom
errors) is an indication that some factor, in addition to those plotted in the
scatter diagram, also systematically influences cost.  In the incinerator plant
example, the age of the facility undoubtedly is important.  Consequently, age is
taken into consideration and is expressed here as (1968-t), in which t is the year
during which the plant was constructed.  Another axis perpendicular to the two
already on the scatter diagram can be constructed for this variable, and the age of
each plant can then be matched with its average cost and capacity.  A regression
plane is fitted to this scatter of points.  Its general formula would be:
$/ton = a0 + &]_ (tons/day) + a2 (1968-t).  The estimated parameter, a2, will then
express the trend of cost per ton over time independently of the influence of
capacity-  The underlying cause of the trend may be inflation, or it could be
technological change.  In the planning problem it would be useful to project this
trend into the future to predict incinerator costs.

        Other variables may be added to the right-hand side of the cost function.
The mathematics of the statistical fitting is complex but rigorous.  The inter-
pretations of the estimated coefficients are substantially the same as for the
simpler two-variable equation.  Parallel tests of the resultant measures are in
existence.

-------
                                                                                  59
Economics of Scale In Collection by Truck

        In the determination of the existence and extent of the economies of scale
for collection by truck, the following regression equation will be used:


                                P = a  + a  N + aD
in which P is the basic monthly residential charge for service to households; N is
the population of the service area; and D is the distance from the center of the
collection area to the disposal area.

        To treat P (price charged to the household) as a cost, it is necessary to
assume the existence of a mechanism, either competition or regulation, through
which the price is held at a level close to that of the actual cost.  This level
should include a normal return on capital.  (An inquiry is being made into the
price -setting behavior of the individual sample members with the intention of
checking the assumption and, if need be, of tempering the conclusions of the
regression analysis.)  N is a proxy variable for the number of customers, inasmuch
as it may or may not be possible to obtain the number cared for by each collection
agency.  The variable D is included because it exerts a significant influence on
the cost of service.  Its inclusion will be of assistance in accounting for
variances which occur in prices of service.

        Data for the regression are available from approximately 73 collection
agencies in the nine San Francisco Bay Area counties for the year 196^.  At
present, monthly residential rates range from $0.75 to $2-50; populations of
communities served by the collectors, from hOO to 750,000; and hauling distances,
from 0.75 to 21 miles.

        If the hypothesis of economies of scale is valid as applied to collection
by trucks, the coefficient a-^ should be less than zero.  If this should prove to
be true, then the obvious conclusion would be that refuse collection agencies
should be enlarged to a degree at which the advantages of economies of scale could
be attained, other factors permitting.  The coefficient a2 would be greater than
zero, since it reflects the increase in costs which accompanies increase in distance
of haul.  Although unlike coefficient a-j^ in its significance in that it does not
have a policy implication, it would be useful for making calculations needed in the
planning procedure .

        In the regression equation formulated in this section, it should be noted
that the value for P is not solely that for the price of the collection service;
it also includes the cost of disposal.  If it is constant or is randomly distributed
for the sample, there will be no bias in the estimates of a1 and a2.  It does seem
likely that a systematic relation exists between size of collection agency and
disposal cost-  If this be true, it will bias the estimate of a1.  The existence of
such a relationship will be checked by way of an inquiry Into costs at landfills
utilized by the collection agencies and by results obtained in research on landfill
operating costs .
Incineration

        The scale of incineration to be considered in this section is that character-
istic of incineration on a municipal or regional basis.  A scale of this magnitude
was chosen because of its bearing on air pollution control.  It is only when
practiced on such a scale that satisfactory air pollution control can be carried on
within a cost range meriting consideration.  Unless equipped with expensive control
equipment, "teepee burners" and incinerators on the scale used in "backyard"
burning will necessarily be sources of severe air pollution.  Consequently, incinera-
tion of the magnitude characteristic of the latter types of units is not considered
in this investigation.

-------
60
        In the study reported herein,  the plan is to collect data on a sample of
incinerators with respect to initial capital costs and to operating costs incurred
over a period of one year.  Variations in the average costs as determined from the
collected data will be analyzed by the regression technique.  The cost per ton value
will be taken as equivalent to the long-run average cost in economic theory in which
all inputs are variable, and the cost  per ton is a minimum for the scale of operation.
In analyzing data pertaining to capital costs, a separation will be made between
cost of the land on which a plant is built and the other elements making up its
capital costs.  The separation is made because costs associated with the incinerator
plant itself are functions of plant size, whereas those concerned with land are
functions of the land value in the region in which the plant is built, and thus are
more or less independent of plant size.  Hence, the location should be analyzed
separately.

        The average cost for the year  of operation selected for study will be the
sum of two items:

    1.  The dollar equivalent in capital for the year, and

    2.  Operating and maintenance costs for the year in terms of dollars per
        ton.

Item 1 is obtained by dividing the capital costs of the plant and equipment
(excluding air pollution equipment) by the number of years in the life span of the
equipment.  An attempt will be made to separate costs associated with air pollution
control from those for incineration itself, so that the capital involved in the air
control equipment can be related to the efficiency of air pollution control equipment
and the scale of the incineration operation.

        Item 2 is obtained by dividing the total operating and maintenance costs
for the year by the number of tons of wastes incinerated (i.e., input of wastes
minus residue) during that time.

        In addition to the important question of economies of scale in incineration,
is the one of whether or not technical advances made in incineration practice have
contributed to a lowering of the per-ton cost of the process.  An approach to
answering the two questions can be made by use of the regression equation,


                            C = a0 + &1 S + a2 (1968-t)


in which C is the average cost in dollars per ton of wastes destroyed, as defined
previously; S is the number of tons of wastes destroyed during the year in question;
and (1968-t) is the age of the capital equipment.  If the coefficient a.j_ is negative,
economies of scale exist.  If a2 is positive, technical change is demonstrated to
have contributed to a reduction in the per-ton cost of incineration.  (All cost
elements will be deflated according to a price index so as to remove the effect of
inflation over time.)

        Inasmuch as they are in the process of being collected, data to be used in
the analysis of incineration costs have only been partially organized thus far.
At present, the collection of data on hand consists of information on various
categories of costs in varying amounts of detail for approximately 150 incinerators.
A goodly portion of the data cannot be utilized because of their doubtful reli-
ability, and many of them are inadequate as far as analysis is concerned.  Probably,
data can be obtained from a sample of from 30 to 50 incineration facilities
constructed since i960 which will be suitable for the study.

-------
                                                                                  61
Transfer and Long-Haul Transport
In Road Vehicles

        An activity which is coming into increasing use in solid wastes management
as landfill sites "become more distant from the wastes sources is the transfer of
refuse from the collection truck to a long-haul truck by way of appropriately
located transfer stations.  Generally; a collection vehicle is very costly to use
for the straight-haul portion of the wastes handling sequence,, since it has a
relatively small capacity and carries a crew of from two to four men.  The unit is
designed for performing an efficient job of collecting refuse in residential areas,
and as such is not geared to the efficient transfer of the wastes over long
distances.  On the other hand, the tractor-trailer rig, because of its large
capacity and need for only a one-man crew (the driver) can be used for long hauls
at a lower unit cost than would be the case with the collection truck.

        Although transfer-transport usually is associated with landfill disposal,
it can be used just as well in connection with other disposal or treatment systems.
Thus, transfer-transport may be an input between collection and any method of final
disposal in a wastes management system.

        The costs to be investigated with respect to transfer and long haul are the
capital costs of the transfer station (exclusive of land) and road vehicles, on the
costs of operating the facility and equipment.  Transfer stations vary quite broadly
in terms of components.  A common characteristic is an arrangement of ramps whereby
collection trucks can be unloaded and their contents transferred to road trailers.
The transfer station may include equipment for weighing, storing, and compacting
wastes.  The operation may or may not be housed.  Trailers used in the operation
are of the type especially designed for the bulk hauling of materials of low
densities.

        The regression equation to be used in the investigation of the average cost
function of the transfer—long haul operation is


                                          ^S + aaD


in which C is the average cost of transfer and haul in dollars per ton.  It is the
sum of the capital costs of the station and road equipment prorated for the year in
question and the total of the year's operating costs of the station, and the road
equipment divided by the number of tons handled during that time.  S is the number
of tons of wastes handled during the year.  D is the number of miles traveled during
the year by the road vehicles.

        Cost per ton is the dependent variable on the left side of the equation to
be estimated, rather than cost per ton-mile as is usually reported.  This specifica-
tion is made because the effects of variation in tons and miles on costs are presumed
to differ.  Separation of these effects could not be done by using a specification
of cost per ton-mile.

        If economies of scale are present, the coefficients a-L and a2 will be
negative.

        The data for this investigation as yet have not been fully organized.
Again, partial data have been obtained for a number of cases,  and a reference file
of approximately 40 transfer-transport operations has been obtained.  The extent
of the response to the questionnaire to be sent to these operations will determine
the final size of the sample.

-------
62
Landfill Utilization

        Although landfill as a method of wastes disposal may be the simplest from
the technological point of view, it does present rather substantial difficulties
in terms of economic analysis.  Any meaningful analysis will be somewhat limited
in the scope of its application, since much of the cost of the operation is related
to that concerned with the site of the operation.  By the very nature of the opera-
tion, three major items determine the per-ton cost of disposal by landfill.  They
are:  l)  cost of the site itself;  2)  the topography of the site; and  3)  "the
yearly input or scale at which the landfill is operated.  The first item or deter-
minant cannot be analyzed in a meaningful way on the basis of data from a survey
of existing sites, since the price of land is a specific which varies from region
to region.  For example, the knowledge that land values are high in the vicinity
of New York City has little application to planning for wastes disposal by landfill
in northern California.  Because of extreme variability, the use of information on
land values could only lead to trivial analysis, and therefore this quantitatively
important variable is left out of the analysis.

        Although the second variable, topography of the site, will be analyzed
statistically, the analysis will not be wholly satisfactory because of the qualita-
tive nature of the variable.  A casual inspection of data on tons of wastes per
acre at landfill sites gives one the impression that dry flatlands are at the low
end of the scale and canyons are at the high end.  The research plan calls for
quantifying the relation between tons per acre (density) and topography by regres-
sion analysis of density on an ordinal ranking of topography type assigned to each
landfill.  The ranking will be  l)  dry flatlands;  2)  tidelands; and  3)  canyons.
The ranking involves some judgment and the assignment of some ordinal value to
somewhat dissimilar elements.  As a result, the statistical technique will treat
the ordinal values as though they were cardinal values.  Useful information can
come out of the analysis, however.

        The equation to be estimated is


                                    D = a0 + &1 T


in which D and T are respectively, density and topography, as defined above.  The
estimated coefficient a1 will supply a quantitative measure of the change in
technological efficiency for receipt of solid wastes as topography changes.  The
variance of the estimate of a^^ is expected to be high because of the qualitative
nature of the variable.

        The final question is whether economies of scale exist for landfill operations
with respect to the elements of cost, exclusive of land costs.  These cost elements
are termed variable costs and include all site modifications, structures, equipment,
and operating costs.  Some of these elements of cost are long-lived, and, consequently,
a share of them must be assigned for the year of operation being studied.  This is
the same situation which exists for incineration and transfer-transport, and it will
be handled in the same way.

        To control the effect on cost of topography, each of the variables will be
subject to a separate regression analysis.  The equation to be estimated is


              C1 = a0 + a1 S     :    0 = 1, 2, 3 (topographical type)


in which C^ is the average cost; namely, the prorated capital costs for the year
plus the operating costs for that year divided by the year's input of wastes, S.
If economies of scale are present for variable costs, a1 will be negative.

-------
                                                                                  63
        The data for the regression analysis of the relation between density and
topographical type have been supplied by the Association of Bay Area Governments
and the California State Department of Public Health, Vector Control Division.
It consists of a tabulation of l)  the total area of each site;  2)  the unusable
area remaining;  3)  the depth of the fill; and  k)  an estimate of the weight of
refuse received per year.

        The data for operating costs will be obtained by way of a questionnaire
sent to a sample of approximately 15 public agencies in California that operate
about 50 sanitary landfills.  Those agencies were selected which maintain good
control over type of wastes received and which hold to high aesthetic and sanitary
standards of operation.  The sampling was restricted to facilities operating under
these high standards, because standards of this level will be the only ones permis-
sible in the management of wastes in the future.


Discussion

        Although the methodology herein described seems appropriate to the planning
and economics objectives of the study, it is not as yet clear whether sufficient
data from the real world can be assembled.  An analysis of such data resulting from
various national, regional, and local surveys indicates that generally the objectives
of the surveys are too broad for the scale of their budget.  The result is that the
detail needed for economic analysis, or even for classification of the wastes at
levels below general categories, is either not obtained or not reported.  Further
complications exist in the way cities keep their records.  Often it is impossible
to determine what fraction of the salaries of engineers, public works directors,
payroll and clerical staffs, etc., is applicable to one utility as against another,
even though data on the number of men employed in various phases of the solid wastes
management process are readily available.  Furthermore, there is no easy way of
comparing one incinerator, for example, with another in terms of efficiency of
operating personnel or of bringing the cost of incinerators built over a period of
years to some common basis.  Nevertheless, some data do exist and, as noted in
previous sections, may contribute significantly to the economic study under way.


ECONOMICS OF THE LOW-COST BIOSTABILIZATION
(COMPOSTING) SYSTEM


Background


        The Process.  The low-cost method of biostabilization considered in this
analysis is described in Chapter V of this report.  It involves three principal
processing steps:  grinding, composting, and incorporation of the material into the
soil-  The degree of processing applied in the composting step is intended to be
minimal.  In fact, as stated previously, a study is being made of the possibility
of omitting the composting step and of incorporating the material into the soil
directly after grinding without giving rise to any nuisances or environmental
hazards.
        Land Requirement.   Since an essential feature of the system involves  tilling
processed wastes into the  soil, land requirements are a major consideration in
making an analysis of the  economics of the system.

        The method probably would be most appropriate to a city of 25,000 to  250,000
people.  In the analysis which follows, a city of 100,000 people is assumed.   At
present levels the inhabitants of this city would produce about 3-0 pounds per capita
per day of domestic plus biodegradable commercial solid wastes.  The annual wastes

-------
production amenable to the low-cost compost system of management thus would be
100,000 people x   3!° ">   x
   '        e
capita -day   2000
                                          year
                                                          = 5^750
                                                              '
                                                                   year
        If refuse can be applied to the land at 200 tons per acre-year as now seems
feasible, the land requirement would be
51+750  2EL* 200
       year       acre -year
                                     = 276.5 acres, i.e.,  about 280 acres  .
        Total Daily Production.  Refuse is generally collected and disposed of
5 days per week, or 260 days per year, therefore the daily amount to be handled
would be
                 750 SS2S.+ 260
                '    year
                       worKing days    _  ,  n  ,         ,
                       	a	«•— = 204.2  tons  per day
                           year                  v     J
Typically, Mondays and Tuesdays are "heavy" days and the collection may be 200 tons
per day or more, with lighter loads during the latter part of the week.  Although
the operation probably should be designed to handle 250 tons per day,  the calcula-
tions given below are based upon the average, or 205 tons per working day.
Costs
        Hauling.   Although hauling generally is not considered in making an economic
analysis of a particular disposal method, attention is given to it in this analysis,
inasmuch as in practice the system would involve fairly long hauls.   It is quite
likely that the site would have to be some 15 to 20 miles from the city center.
Therefore, the first charge would be to refuse hauling, namely,
                    205
                        day
                             x 20 miles x
                                           $0.(
                                 ton-mile
                                          = $328.00
        Refuse Grinding.  Preliminary figures based on data obtained in refuse
grinding cost studies being conducted at the city of Madison, Wisconsin, under a
U. S. Public Health Service demonstration grant suggest that grinding for the
low-cost compost system may cost about $2.60 per ton.
                           205
                                       ton
                                   = $533-00
        Composting.  To produce a compost of a grade acceptable to agricultural or
nursery usage, an expenditure of $5-00 to $13-00 per ton of raw refuse is necessary.
The Metropolitan ₯aste Conversion composting plant at Gainesville, Florida, for
example, expects to perform salvage plus composting to make a top-quality compost
for $6-53 per ton of raw refuse.  The minimal composting-without-quality-upgrading
called for in the low-cost composting system will, hopefully, cost only $1-50 per ton.

-------
                                                                                  65


Thus, the cost of composting the refuse from the city of 100,000 would be:
                                        ton
        Field Spreading and Tilling.  The ground refuse or rough-quality compost
must be transported from the processing plant to the "disposal" area, spread out,
and tilled in.  If the processing plant is adjacent to the farm, two dump trucks
of 5-ton (25 cu yd) capacity could easily transport 205 tons 1/2 or 1 mile.  Such
dump trucks, with drivers, might cost


                            $75 per day each = $150.00  .


        The 205 tons per day will be put on at 200 tons per acre; therefore, 205
tons per day -=- 200 tons per acre = 1.0 acre will be "farmed" each day.  To distribute
the dump truck loads of refuse onto the land and till it in, a medium-sized (50 hp)
crawler tractor with dozer blade and plow will be required.  Although the actual
distribution and spreading should take only two or three hours per day, the daily
charge would approach that of full-time tractor rental, ($75 per day), so a $60 per
day charge is assumed.

        The acre that receives the 205 tons on one day will not be ready to accept
another 205 tons until the same day one year hence .  In the intervening year it will
probably be necessary to irrigate three times ($20 per acre -irrigation, for water
plus labor), plow or disc once to encourage biological breakdown ($15 per acre),
and fertilize to obtain a better nutrient balance (estimate 300 Ib nitrogen at
6^ per Ib = $18.00 plus application cost of $10 per acre).  The total cost of
irrigation and fertilization, therefore, would be $103 per acre.

        The total cost of the field spreading and tilling step, therefore, would be
$313-00.


        Land -Use Charges.  It would be hoped that the site of the facility, some
20 miles from the city center, would be on poor land obtained at minimal price.
However, it is likely that political pressures would drive the land cost quite high,
and consequently a land-use cost must be included.  Assuming $1000 per acre land
with a 20-year salvage value of $500 per acre instead of a normal appreciation to
$2000 per acre, it would mean a land -use charge of:


        (l.OO acre) ($1500 value loss) (capital recovery at 8$ — 20 years)
              + (1.00 acre) ($500 tied up) (8$ interest) = $188.00  .


        A private entrepreneur would have to pay property taxes on the land, while a
municipal operation would lose tax revenue by operating the garbage farm.  Thus, if
annual taxes are assumed to be 3$ °? "the $1000 land investment, the tax would be
                      (.03) (  $i°°0  ) x (LO acre) = $30.00
                      v    ' \  acre /   ^         i   •*;
        The total cost for land use, therefore,  would be $2l8.00.
   388-229 O - 70 - 20

-------
        Burial of Moncompostables.   Although the low-cost method of biostabilization
would be expected to care for the normal garbage and domestic refuse,  it probably
will be uneconomical to shred tires, bedsprings, tree stumps, overstuffed furniture,
concrete rubble, and similar materials.  These might average 5 percent of the 205
tons per day, or 11 tons per day.  The cost of hauling this to the inevitable burial
site, and burying it, might amount  to $4.00 per ton = $44.00.


        Summary of Costs.  Total costs, including actual composting:


          (328 + 533 + 308 + 313 + 218 + 44)      =  $1?44 per day


          Excluding the composting ($1744 - 308)  =  $1436 per day


          Cost per ton is $1744 per day
             -5- 205 tons per day                   =  $8.50 per ton raw refuse


          and $1265 per day
             -i- 205 tons per day                   =  $7-00 per ton raw refuse


          Cost per person-year = $1744 per day
             x 260 working days per year
             * 100,000 persons                    =  $4.53 per person-year

          $1436 per day
             x 260 working days per year
             -5- 100,000 persons                    =  $3-73 per person-year


Comparison with Conventional
Composting Methods

        These prices (of $7-00 per ton, or $8.50 per ton depending upon the need to
compost or not) seem very high.  They seem even higher when one quotes $1-50 per ton
for landfilling (without considering hauling), $6-52 per ton for composting as is
hoped for at Gainesville, Florida,  or the typically quoted $6.00 per ton for
incineration.  It is felt that the  hypothesized low-cost biostabilization figures
are on the very conservative side,  while the alternative method figures may not be
quite so conservative.  For example, in estimating land-use charges, it is assumed
that the land used in the operation will depreciate in monetary value  over the
years, whereas, judging from the present escalation in land values, the odds are
equally in favor of the land retaining its present monetary value or even acquiring
a higher value.  For instance, the  $1-50 per ton sanitary landfill cost is actually
attained in Los Angeles, but 8,000 to 10,000 tons per day are handled, and the
economy of scale is important.  Additionally, the transportation cost  of perhaps
$0.08 per ton-mile x 20 to 25 miles is not included.  Certainly, for comparison, a
hauling distance at least equal to that used in this analysis should be used.

        The Gainesville composting cost estimate of $6.52 per ton of raw refuse would
be more desirable than the costs given for the low-cost composting system.  In fact,
if Gainesville could sell the compost, the net cost per ton raw refuse would be
further reduced.  If the city could merely give the compost away, the  cost would be
the quoted $6-52 per ton.  But if the city cannot sell or give the compost away it
might have to bury it, and this would add to the cost-

        Likewise, the quoted figures for incineration are subject to enquiry regarding
plant amortization period, interest rate, and whether ash disposal costs are included.

        From the foregoing considerations it is concluded at this time that, even with
very conservative cost estimating,  low-cost composting appears to be comparable to
other wastes processing-discharge methods, and to be worth further consideration.

-------
                                                                                  67
ECONOMICS OF THE ANAEROBIC
DIGESTION PROCESS
Introduction

        The factors which determine the economic advantage or disadvantage in
utilizing conventional anaerobic digestion for the treatment ("disposal") of
organic solid wastes such as garbage, rubbish, and wastepaper are so dependent
on local conditions that no general conclusions can be reached which would be
valid for all circumstances.  However, judging from the experience of the many
municipalities in the U. S. which are practicing in varying degrees the dual
disposal of the sewage sludge and the garbage fraction of refuse, the process
apparently should be reasonable in cost.

        The economic analysis made herein includes the costs entailed in the
establishment of the central grinding stations needed in those operations in
which all of the organic refuse is to be digested, i.e., that fraction not
ordinarily ground into the sewer by way of the home garbage grinder.  In the
analysis, a complete breakdown of costs ascribed to each step in the process
(grinding, grit removal, digestion, etc.) is given for cities of small, inter-
mediate and large-sized populations.  The analysis is divided into two parts.
In the first part, treatment of all of the organic constituents of refuse is
considered; in the second part, the garbage fraction only.


Assumptions

        In making the analysis, the following assumptions are made:

    1.  Population

        City A     30,000 (small city)
        City B    300,000 (medium city)
        City C  1,000,000 (large city)

    2.  Domestic refuse to be treated (includes garbage):

        3-0 Ib per capita per day [IT]-

    3-  Garbage to be treated (includes a portion of wasted wrapping paper):

        O.ij-5 Ib per capita per day (15 percent of total domestic refuse [IT] •

    k.  The wastes have been collected and transported to the central grinding
        station.

    5.  The wastes are treated as follows:

        a.  The wastes are weighed and then dumped into a hopper.

        b.  A conveyer belt transports the wastes from the hopper to a primary
            grinder in which the packages are shredded and their contents exposed.

        c.  Another conveyer belt transfers the shredded material to a third belt
            which serves as a "sorting" belt.  Here salvageable items and over-
            sized material are removed.  A magnetic separator is used for
            removing ferrous materials.

        d.  The sorted wastes are then subjected to a secondary grinding.

        e.  A grit chamber receives the final ground garbage and a pump transports
            the grit-free ground wastes to an anaerobic digester.

        f.  Digested wastes are pumped to a drying bed.

-------
68
        g.  Dried digested vastes either are ready to be composted or to be
            combined with sorted refuse (other than the salvaged portion)
            for incineration or landfill.

    6.  A separate digester is required for handling the additional solids.


Amounts of Wastes to be Treated

        Total Domestic Refuse :

        3-0 Ib/capita/day x    30,000 =    90,000 Ib/day (    k$ tons) -City A
        3-0 Ib/capita/day x   300,000 =   900,000 Ib/day (   k-50 tons) -City B
        3-0 Ib/capita/day x 1,000,000 = 3,000,000 Ib/day ( 1,500 tons) -City C

        Garbage Only (15 percent of Refuse):

         13,500 Ib/day (6-75 tons) - City A
        135,000 Ib/day (67-5 tons) -City B
        450,000 Ib/day ( 225 tons) - City C


Grinding

        The data on grinding are based on those in a recent publication of the
American Public Works Association
        For a grinding plant of 300 tons per day capacity and which includes an
enclosed dumping area, primary and secondary grinders, conveyors, standby equipment,
air purification equipment, employees' facilities, etc., the plant building would
cost $300,000; and the plant equipment, $300,000.  Assuming a 30-year life span for
the building, construction costs would be $0.^0 per ton of wastes.  Assuming a
20-year life span for the equipment, operation and maintenace costs should be on
the order of $0.50 to $1.00 per ton.

        To accommodate the three population sizes used in the analysis,  an inter-
polation was made in determining the costs for each population size.  The
interpolation was based on information contained in the U. S. Public Health Service
publication No. 1229 [l8]; according to which, the ratio of costs per capita for
the construction of primary treatment and separate sludge digestion plants between
populations of 1000, 10,000, and 100,000 is on the order of U:2:l.  In the present
analysis, it is assumed that this ratio also holds true for the population sizes
30,000, 300,000, and 1,000,000.

        By proportion, the grinding costs for City A would be $3-00 per ton x 4 5 or
$135 per day, if all of the domestic refuse were ground.  If only the garbage is to
be treated, grinding costs would be $6.00 x 6.75 or $40.5 per day.  (it is assumed
that it would cost twice as much to grind garbage alone.)  The costs for City B
would be $1.60 per ton x *<-50 or $720 per day for the refuse; and $3-201 per ton
x 67-5 or $216 per day if only the garbage is ground.  The costs for City C would
be $0.80 per ton x 1500 or $1200 per day for refuse; and $1.60 x 225 or $360 per
day if only the garbage is ground.

        The grinding costs may be summarized as follows :

        City A   a.  $135/day  = $ ^9,.250/yr = $1.6^133/capita/yr
                 b.  $40.5/day = $ 14,800/yr = $0.^933 /capita/yr

        City B   a.  $720/day  = $262,500/yr = $0.87500/capita/yr
                 b.  $2l6/day  = $ 78,800/yr = $0.26267/capita/yr

        City C   a.  $1200/day = $438,000/yr = $0.43800/capita/yr

                 b.  $360/day  = $131,250/yr = $0.13125/capita/yr

-------
                                                                                  69
Digestion


        Volumes.  If the daily flow rate to the digester is assumed to be two
gallons per pound of refuse or garbage ground [II], then the following would
apply:

        City A:

             a.  If refuse is disposed of:

                 2 gal/lb x 90,000 lb/day = 180,000 gal/day = 0.18 mgd

             b.  If garbage only is treated:

                 2 gal/lb x 13,500 lb/day =  27,000 gal/day = 0.02? mgd

        City B:

             a.  If refuse is disposed of:

                 2 gal/lb x 900,000 lb/day = 1,800,000 gal/day = 1.8 mgd

             b.  If garbage only is treated:

                 2 gal/lb x 135,000 lb/day =  270,000 gal/day =0.27 mgd

        City C:

             a.  If refuse is disposed of:

                 2 gal/lb x 3,000,000 lb/day = 6,000,000 gal/day = 6.0 mgd

             b.  If garbage only is treated:

                 2 gal/lb x 450,000 lb/day = 900,000 gal/day =0.9 mgd


        Digester Costs.  According to the sludge handling cost curve for standard-
rate filtration developed by Logan et_al^ [19], "the construction cost would be
1/5 of the total cost, which includes chlorination, pumping, and administration
fees.  The same would be true for operation costs.  Using the cost curves by
Logan et_ al., the following calculation may be made if a construction life of 20
years and a capital interest of k percent are assumed:

        City A:

             a.  If refuse is disposed of:

                 Construction cost:

                 5 x $115,000/mgd x 0.18 mgd = $103,500
                 Operation cost:

                 5 x $5,000/mgd x 0.18 mgd = $^500/yr

-------
70
             "b.  If garbage only is treated:




                 Construction cost :




                 5 x $140, 000/mgd x 0.02? mgd = $18,925
                 Operation cost :



                 5 x $6500/mgd x 0.02T mgd = $877-5/yr
        City B:




             a.  If refuse is disposed of:




                 Construction cost :




                 5 x $85, 000/mgd x 1.8 mgd = $765,000
                 Operation cost :



                 5 x $3500/mgd x 1.8 mgd = $Jl,500/yr
             t>.  If garbage only is treated:




                 Construction cost :




                 5 x $105, 000/mgd x 0.27 mgd = $l4l,750
                 Operation cost :




                 5 x $^500/mgd x 0.27 mgd = $6075/yr

-------
                                                                                  71
        City C:

             a.  If refuse is disposed of:

                 Construction cost:

                 5 x $72,000/mgd x 6.0 mgd = $2,160,000
                 Operation cost :

                 5 x $3000/mgd x 6.0 mgd = $90,000/yr
             b.  If garbage only is disposed of:

                 Construction cost:

                 5 x $90,000/mgd x 0.90 mgd = $405,000


                              -, ,  ~ «], \2O
                 Operation cost :

                 5 x $3700/mgd x 0.90 mgd = $l6,650/yr


                                     - $0.0l665/capita/yr
        The summary of construction and operation costs of anaerobic digestion
facilities is as follows :

        City A    a.  $0-52750

                  b.  $0.09825

        City B    a.  $0.38^50

                  b.  $0.07200

        City C    a.  $0-32700

                  b.  $0.06100


        Maintenance and Miscellaneous Costs .   According to Logan et_ al_.  [19]>  costs
for maintenance and repairs, materials, supplies, and miscellaneous should average
$2000 per year per mgd plant capacity.  Based on this given data, the cost calculation
may be made as follows :

-------
72
        City A:

             a.  If refuse is disposed of:
                                x O.l8 ngd = $0.01200/capita/vr
             b.  If garbage only is treated:


                                   .027 mgd = $0.ool8o/capita/yr
        City B:

             a.  If refuse is treated:
                                   1.  n   = $0.01200/capita/yr
             b.  If garbage only is treated:


                                              $0 . Ol80/capita/yr
        City C:

             a.  If refuse is treated:
                                           - *0.1200/caPita/yr


             b.  If garbage only is treated:


                                   .o.O mgd = $0.ool8o/capita/yr
Cash Value of Digester Gas


        Volume of Gas Produced.  In conventional raw sevage sludge digestion, about
12-5 cu ft of gas are produced per pound of volatile solids destroyed.  The volatile
solids destruction is about 6j percent.  When garbage is digested, the gas produced
per pound of volatile solids introduced would be 7-9 cu ft per pound  [l].  Judging
from experience gained in the study reported herein, the amount of gas which would
be produced in the digestion of refuse would be one -half (5-95 lt> per cu ft) that
from the digestion of garbage alone .

        Assuming that the volatile solids content in garbage is 75 percent and in
refuse ^5 percent [1,17], and that the per capita production of refuse and of
garbage is 3-0 and 0.^-5 pounds per day, respectively, then the following calculations
are applicable :

        Gas Production:

             a.  If refuse is treated:

                        7-9 cu ft/lb VS x O.JO (VS content)
                                   x J.O x O.ij-5 = 5-33 cu ft/capita/day

-------
                                                                                   73
             b.  If garbage only is treated:


                            7-9 cu ft/lb VS
                                  x OA5 x 0.75 = 2.67 cu ft/capita/day


        Sale of the Gas.  The Pacific Gas and Electric Company sells gas for $0.08
per 100 cu ft.  Inasmuch as gas produced from the digestion of sewage sludge contains
an average of JO percent COs, an optimistic estimate of the sales price of the
digester gas would be about $0.05 Per 100 cu ft.  According to calculations based on
a sales price of $0.05 Per 100 cu ft, the sales value of the digester gas would be:


        a.  $0.05/100 cu ft x 5-33 (cu ft/capita/day) x 365 = $0.97l4-/capita/yr .

        b.  If garbage only were treated:


                 $0.05/100 cu ft x 2.67 x 365 = $0.487/capita/yr


Summary of Costs

        The costs involved in treating domestic refuse by way of conventional
anaerobic digestion are summarized in Table 17 and l8.


Discussion

        In studying the cost data given in the preceding paragraphs, certain of the
assumptions listed in the section "Assumptions" should be emphasized, namely:

        a.  The digester gas can be sold at the rate of $0.05 per 100 cu ft.

        b.  The refuse has been collected and transported to the grinding station.
            In other words, these costs are not included in the calculations.

        c.  No increase in primary treatment capacity would be required.

        The first of the above three assumptions led to the conclusion that the
cost of treatment could be offset by $0.50 to $1.00 per capita per year.  Although
the last three columns in Tables 17 and 18 indicate that a profit could be made by
digesting domestic refuse and selling the digester gas, it is unlikely that such a
highly favorable event would ever come to pass.  The cash values given for the gas
do not include the cost of processing, transporting, and metering the gas.  More
importantly, before a profit can be realized, a market must be found for the gas.
In areas where natural gas is in abundant supply,  this may be difficult to do.
However, in the long run, the day may come when all energy sources must be exploited
to their full potential.

        With respect to the second assumption, it should be kept in mind that these
costs would be incurred regardless of the method of treatment or disposal to be
given the refuse.  According to a report prepared by Ross [20], the cost of collection
in I960 in Richmond (population 50,000), Indiana,  was $11.30 per ton of garbage.

        The basis of the third assumption is the fact that the increase in flow rate
in the sewers needed to accommodate the refuse loading would only be on the order
of 6 percent.

        The digester volume required to treat a given amount of refuse solids is
much less than that required for an equal amount of sewage sludge.  The reason is
that it is possible to thicken the refuse "sludge" to 10 percent; whereas sewage

-------
74
                                     TABLE 17
                  COST PER CAPITA. PER YEAR FOR DIGESTING REFUSE'
                                                               ,a
Items
Grinding Process
Anaerobic Digestion
Maintenance and
Miscellaneous
Total Costs
Cash Value of
Digester Gas
Net Costs
City A
50,000
Population
Refuse
1.64133
0.52750
0.01200
2.18083
0-974
1.10683
Garbage
0.49333
0.09825
0.00180
0.59338
0.487
0.10638
City B
300,000
Population
Refuse
0.87500
0.38450
0.01200
1.27150
0.974
0.29750
Garbage
0.26267
0.07200
0.00180
0-33647
0.487
-0.15053
City C
1,000,000
Population
Refuse
0.43800
0.32700
0.01200
0.77700
0-974
-0.19700
Garbage
0.13125
0.06100
0.00180
0.19405
0.478
-0.28395
      Based on the value of the dollar in 1960
      F.O.B. the treatment plant
                                     TABLE 18
                    COST PER TON OF REFUSE OR  GARBAGE DIGESTED
Items
Total Costs
Cash Value of
Digester Gas
Net Costs
City A
30,000
Population
Refuse
4.00
1.78
2.22
Garbage
7-24
5-93
1-31
City B
300,000
Population
Refuse
2.32
1.78
0.54
Garbage
4.10
5-93
-1.83
City C
1,000,000
Population
Refuse
1.42
1.78
-0.36
Garbage
2.37
5-93
-3-56
           aBased on the  value  of  the  dollar  in  1960
           F.O.B. the treatment  plant

-------
                                                                                  75
sludge generally is pumped to the digester at a concentration of k to 6 percent.
Moreover, the concentration of a slurry of solid wastes is easily adjusted.  Sewage
sludge, on the other hand, generally has to be thickened by way of expensive
physical and chemical processes.  The calculations presented in this report are
based on the use of a 6 percent slurry.  According to Torpey and Melbinger [21],
however, the digester of slurries having concentrations higher than 6 percent would
give rise to no operational problems.  Loadings administered in the experiments
reported herein were made at slurry concentrations conventionally applied.  The
research plan calls for future research on the effect of loadings at higher solids
concentrations in the slurry.


Conclusions
        Although the various assumptions and estimates noted in the preceding
paragraphs may be of debatable accuracy, the indications are that digestion of
organic refuse with sewage sludge cannot be ruled out on economic grounds,  insofar
as the digestion process itself is concerned.  A complete economic analysis leading
to a judgment of what fraction of the overall organic wastes of a community could
be assembled and digested economically is, of course, beyond the scope of this
report.
ECONOMICS OF BIOFRACTIONATION


Preliminary Cost Estimate of the Proposed
Microbial Cellulose Decomposition Process

        In order to determine in a very general way the economic feasibility of a
process to convert paper wastes to protein and glucose, a cost estimate study was
made for the process diagrammed in Figure 33 (see Chapter XI).  The estimate is
based on data for decomposition and hydrolysis rates reported for S_._ myxococcoides
[21].  The cost estimate is very preliminary in nature, since the basic data are
few and many assumptions concerning process conditions, yields, and equipment
performance were necessary.  The following evaluation was developed according to a
method outlined by Newton and Aries [22].
Description of the Process Design Basis

        The raw material for the process is ground cellulesic wastes while the end
products are glucose and a mixture of single cell protein and an unhydrolyzed
cellulose.  The glucose can be used as an edible carbohydrate source and the
protein-cellulose mixture is envisioned as an animal feed or feed supplement.  The
latter possibility has not been demonstrated as yet.

        The plant size chosen for this study is based on a daily waste cellulose
feed of 10 tons.  The amount of products are estimated to be 5 tons of glucose and
5000 pounds of an animal feed supplement consisting of 50 percent single cell protein
and 50 percent partially degraded cellulose.  It is envisioned that a plant of this
type would be located within a short distance of the source of the waste material.
Costs for transportation, separation, and grinding of the cellulosic waste material
are not included.

        In the design, the following further assumptions are made:

    1.  The land necessary for the plant is already owned and available.

    2.  There is a market for the single cell protein-cellulose mixture as
        a feed supplement.

    3-  As a municipally owned and operated plant it is tax-exempt.

-------
76
    k.  The disposal of the waste cellulose should "be considered as a credit,
        although this is not taken into account in the cost estimation.


General Process Description

        The process consists of the following steps:

    1.  Feed preparation:  The ground cellulose waste is placed in a water
        suspension along with the necessary inorganic mineral nutrients.

    2.  Cellulose fermentation:  In this, one of the two main steps in the
        process, S. myxococcoides is grown in a continuous culture on a
        cellulose substrate.  It is during this step that the protein and
        cellulose enzyme solutions are produced.  On the basis of preliminary
        data, it was assumed that decomposition would be complete in five
        days.

    3-  Separation of enzyme solution:  In this step the cellulose enzyme
        solution is separated from the cell material and cellulose by means
        of centrifugation.

    4.  Cellulose hydrolysis:  This is the second main step of the process.
        The cellulose enzyme solution produced in the fermentation step
        comes in contact with a second feed stream of cellulose and a
        hydrolysis to glucose occurs.  Bacterial growth is prevented by
        the presence of toluene, an antiseptic.  Available data formed the
        basis for assuming that hydrolysis would be complete in 25 days

    5.  Separation of glucose solution:  Here the dissolved glucose is
        separated from the nonhydrolyzed cellulose.  This is accomplished
        by centrifugation.

    6.  Recovery of single-cell protein:  In this step, a bleed is taken
        from the stream recycling the cell material-cellulose mixture back
        to the fermenter.  This suspension is dried and then packaged for
        use as an animal feed supplement.

    7-  Glucose purification and recovery:  Finally, the glucose solution
        leaving the centrifuge is concentrated in an evaporator and
        crystallized.  The glucose crystals are then washed and dried.

        An estimated materials balance of the process is presented in Table 19-
Process water and substances present in small amounts are not considered.
Cost Factors
        The major equipment, size of the components and their costs, are given in
Table 20.  Items involved in arriving at an estimate of fixed capital are given in
Table 21.  Manufacturing costs are itemized in Table 22.
Wet Waste Treatment Cost

        Assuming a sales price of $0.1^ per pound for the glucose product and $0.05
per pound for the feed supplement, the net sales per day would be $1650.  The daily
net operating cost, therefore, would be $2065 — $1650, or $4l5 per day.  The cost
per pound of treated cellulose waste, therefore, would be $0.021 or $42 per ton.

-------
                           TABLE 19

           ESTIMATED MATERIALS BALANCE FOE PROPOSED
                  CELLULOSE CONVERSION SYSTEM
                    (Based on 20,000 Ib/day)
                                                                        77
Material
Cellulose
Nitrogen (as NaN03)
Oxygen (as air)
₯ater (for hydrolysis)
Feed Supplement
Glucose
Carbon Dioxide
Water (from cell respiration)
Total
Waste Cellulose
Input
Ib/day
20,000
300
6,700
1,100




28,100
Output
Ib/day




5,000
11, 100
8,000
4,000
28,100
                           TABLE 20

       MAJOR EQUIPMENT FOR CELLULOSE CONVERSION SYSTEM3
Equipment
Medium Preparation Vessel
Medium Sterilizer
Fermenter
Centrifuges (2)
Hydrolysis Vessel
Evaporator
Crystallizers (4)
Agitated Tank Washer
Drum Dryers (2)
Centrifugal Pumps (6)
Total
Size/Capacity
12,000 gal
12,000 gal/day
60,000 gal
20 in. diam
300,000 gal
8,400 gal/day
3,600 gal
3,600 gal
50 sq ft area
20 gal/min

Material
CS
CS
SS
SS
SS
CS
CS
SS
CS
SS

Cost
$ 14,500
14, 800
115,000
43,000
119,000
22, 500
30,000
14,800
28,400
3,000
$405,000
Paper to be treated, 10 tons/day

-------
78
                                     TABLE 21
                       FIXED CAPITAL ESTIMATE FOR CELLULOSE
                                 CONVERSION SYSTEM
            Purchased Equipment
            Installation
            Piping
            Instrumentation
            Insulation
            Electrical Auxiliaries
            Building
            Land and Improvements
            Utilities
                      Physical Plant Cost
            Engineering and Construction
                      Direct Plant Cost
            Contractors Fee
            Contingency
                      Fixed Capital
    405,000
    107,500
    155,000
     64,500
     34,000
     43,000
    215,000
     43,000
    107,500
  1,174,500
    300,000
  1,474,500
    150,000
$ 1,699,500
                                     TABLE 22
                         MANUFACTURING COSTS FOR CELLULOSE
                                 CONVERSION SYSTEM
            Raw Materials
            Labor
            Supervision
            Maintenance
            Plant Supplies
            Utilities
                      Direct Manufacturing Cost
            Payroll Overhead
            Laboratory
            Plant Overhead
            Packaging
                      Indirect Manufacturing Cost
            Depreciation
            Insurance
                      Fixed Manufacturing Cost
                      Manufacturing Cost

-------
                                                                                  79
Discussion of Process Economics

        It should be emphasized that the cost estimate made in this analysis is
based on rather extensive assumptions, some of which may be conservative.  On the
other hand, it does not include costs of separation and grinding, operations which
may add materially to the net cost.  However, if biofractionation is only a part
of an overall recovery program, then the two costs may be prorated among the various
recycling processes.  At any rate, the results of the analyses should be viewed
only as being on a rough order of magnitude.  A major cost factor is the large size
of the fermentation and hydrolysis vessels necessitated by the slow growth of the
organism and the slow rate of hydrolysis of the cellulose as reported in the
literature.  There is reason to believe that organisms and process conditions
leading to a considerable reduction in vessel size may be found in future study.
For example, Ghose [2*4-] very recently reported cellulose hydrolysis with Trichoderma
viride culture filtrates at rates approximately four times those assumed in the
present design.  Other process improvements may also be possible.  A very modest
reduction in the manufacturing costs dependent upon these rates could make the
process self-supporting.  Moreover, it is likely that the market value of glucose
and protein will increase considerably in the future.


ECONOMICS OF WET OXIDATION
Introduction

        The wet oxidation system as applied to solid wastes processing has been
described in the First Annual Report [l] and is treated again in Chapter IX of
this report.  The process under consideration in this analysis would be applied to
solid wastes in general with a disposal-organic chemical recovery objective in mind.
Equipment requirements and cost estimates are based on published data [25-27] for
the West-Southwest Wet Oxidation Plant of the Metropolitan Sanitary District of
Chicago, Illinois, corrected for scale and inflation-  Organic chemical production
potentials are based on the results obtained by D. L- Brink [28] with the reaction
of molecular oxygen and wood in an unbuffered aqueous system.


Process Evaluation

        For the purposes of this analysis, wastes material entering the wet oxidation
process will be considered equivalent to the solid wastes production (domestic and
some commercial) of a city of 40,000 people or 100 tons per day of material.  Such
wastes would undergo preliminary separation and size reduction before entering the
reactive phase of the process .  Recoverable metals of commercial utility would be
directed to salvage operations, while other metals and high-density materials would
be diverted to landfill operations.  The remaining material,  primarily organic
wastes, would be mixed with water-borne wastes, such as municipal and industrial
sewage, or aqueous effluent from the process, or both, and wet ground to 1/4-in. or
less particulate.  These operations —separation, diversion,  and size reduction —
would be done at the process site. • The subsequent treatment  given the wastes is
summarized in the flow diagram in Figure 2.

        The aqueously dispersed wastes, containing about 10 percent solids by weight,
will be pressurized, mixed with air, heated, and introduced into a two-stage reactor.
Reactor conditions will be 220" to 260CC and 500 to 1000 psi.  Effluent from the
first stage, a partial oxidation stage, would be separated centrifugally and the
aqueous phase directed to organic chemical recovery operations.  The residual solids
will be mixed with the stripped aqueous effluent from the chemical recovery operations
or aqueous effluent from the second stage and introduced into the second stage for
complete oxidation.  Effluent from the second stage would be  passed through heat
exchangers and separated from noncondensable gases.  These gases will be scrubbed
and expanded to recover power for air compression.  The residual solids will be
separated by vacuum filtration and directed to landfill operations.  The aqueous
filtrate will be returned to various stages of the process as indicated above.

-------
80
                                                                               z
                                                                               o
                                                                               a.
                                                                               UJ
                                                                               (O
                                                                               g

                                                                               O
                                                                                   (O
                                                                                   o

                                                                                   o
                                                                                   to

                                                                                   g

                                                                                   I>
                                                                                   O
                                                                            o
                                                                            X
                                                                            o
                                                                            £

                                                                            co
                                                                            :D
                                                                            o
                                                                            13
                                                                            Z
                                                                                                   O
                                                                                                   o

                                                                                                   o
                                                                                                   UJ
                                                                                                   o:
                                                                                                   UJ
                                                                                                   z
                                                                                                   UJ
                                                                                                   o
                    <
                    UJ
                    i
en
(T
UJ
o
Z
<
I
O
X
UJ
gc
<
                                                                                                   IT
                                                                                                   O
                                                                                                   O
                                                                                                    <\J

                                                                                                    UJ
                                                                                                    cr
                                                                                                    D
                                                                                                    O
                                 Z
                                 UJ

-------
                                                                                  8i
        The process as described would eliminate 90 percent or more of the organic
material in the wastes influent involved with sufficient thermal and mechanical
energy production to make the process self-sustaining.  In addition, about 50 percent
of the oxidized organic material would be recovered as discrete chemicals of
commercial utility.  On a weight basis, for every 100 tons of solid wastes processed,
about 10 tons would be returned for landfill, 4 5 tons converted to organic chemicals,
and 4-5 tons oxidized to carbon dioxide and water.


Equipment Requirements

        Specific equipment requirements for the preliminary separation and size
reduction of incoming wastes materials will not be listed because of the dependence
of these requirements on the composition of the solid wastes involved.  Similarly,
no requirements will be given for organic chemical recovery because recovery may
involve one or several operations such as distillation, extraction, precipitation,
crystallization, or vapor phase deposition.

        The wet oxidation process, per se, will be built around a stainless steel
lined reactor, k ft in diameter and ko ft high, designed to operate at 1000 psi and
260°C.  There will be 6 heat exchangers with a 3000-sq ft heating surface.  The
aqueously dispersed wastes will be pumped to the reactor by a high pressure pump
with a rated capacity of 180 gpm at a discharge pressure of 1000 psi.  This pump in
turn would be fed by a centrifugal sanitary pump.  Compressed air will be furnished
to the process by a 4-500-hp, multistage compressor with a rated free air displacement
of 9600 cfm at 1000 psi.  Exhaust gases from the process will be expanded through a
turbogenerator to produce 6250 kw-hr of power.  Reactor effluent will be filtered on
a l60-sq ft rotary belt vacuum filter.

        The pumps, compressor, vacuum filter, and automated process controls will be
housed in a 4000-sq ft building; the reactor, heat exchangers, and intermediate
storage facilities will not.  The whole process will cover about 7000 sq ft and may
be located on any urban or rural site with little or no pollution restraint.


Costs
        The proposed wet oxidation process, exclusive of preliminary separation and
size reduction and chemical recovery facilities, will cost about $3,820,000* to
build.  Of this amount, $2,860,000 would be for the purchase and erection of the
major equipment items of the process.  The remainder would be allocated to the
foundation, steel framework, maintenance facility, electric utilities, and other
items.  Calculated on a 25-year amortization period, this amounts to a $4.20 per ton
capital cost.  Operating costs for this process — labor, lubricants, chemicals,
replacement parts, and power -would amount to $^.58 per ton.  Combined capital and
operating costs would total $8.78 per ton.

        Costs related to preliminary separation and size reduction,  chemical
recovery, and disposal of wastes material diverted from the process  or residual
solids discharged from the process would have to be added to the above wet oxidation
cost.

        Part of the above costs, however, would be defrayed by salvaged metals and
recovered organic chemicals.  Assuming a chemical value of 6 to 10 cents per pound,
the annual organic chemical production of the wet oxidation process, some J2-8
million pounds, would have a gross value of 1-97 to 3.28 million dollars, or a
revenue value of 5^ to 90 dollars per ton of solid wastes processed.
     Wet oxidation costs calculated on a volume and weight of wastes  material
handled basis as one-fifth of that for the West-Southwest Wet Oxidation Plant and
corrected for a 3 percent per annum inflationary rise.
   388-229 O - 70 - 21

-------
Conclusion

        The process of wet oxidation cannot be ruled out at this time on the basis
of economics as a possible method of organic wastes  management,  even though
extensive study is yet to be made of the problems involved in scaling up from pilot
plant to prototype, segregating materials for processing,  and in determining the
full spectrum of organic wastes which can be processed.


ECONOMICS OF PYROLYSIS
Introduction
        Operating costs of incineration of solid wastes according to various
literature sources vary from $4.25 to $6.00 per ton-day,  assuming continuous
operation.  Capital costs vary from $10,000 to $15,000 per ton for a plant of
200 ton per day capacity, exclusive of land and advanced air pollution control
equipment.  The installation of the air pollution equipment to meet the demands
of modern regulations would materially increase the  plant costs.

        In estimating capital and operating costs for a pyrolysis-combustion
plant employing the principles outlined in this report and as represented in
Table 23, additional factors must be considered.  These include utilization of
pyrolysis gases in production of heat in a boiler operation and possible predrying
of certain types of solid organic wastes after comminution.


Proposed Design

        The basic design presented in Table 23 is envisaged as being embodied in
a solid wastes pyrolysis-combustion unit.  To pyrolyze 200 tons per day, two  first-
stage pyrolysis units would be required to feed into a single second-stage unit.
Solid wastes would be fed to the two first-stage units through an appropriate feed-
ing mechanism.  This mechanism would in turn be preceded by appropriate classification,
separation, and predrying, if needed, of the solid wastes.  Hence costs have  been
estimated under the conditions noted and are as presented in Table 2J•


Discussion and Conclusions
        Based upon these preliminary estimates,  the  capital costs  of a  200-ton per
day pyrolysis-combustion process with generation of  by-product steam and based on
continuous operation will be on the order of $9025 per ton-day of  solid wastes.
Operating costs, based upon 2k-hour continuous  operation including grinding of feed
material are on the order of $5-05 per ton.   The calculation of steam is based upon
a solids feed of 50 percent moisture.  (The  moisture content of municipal refuse
generally averages about 35 percent.)  On this  basis,  the value calculated for steam
produced is $5-00 per ton of refuse pyrolyzed.   Apparently, therefore,  the disposal
of organic solid wastes by this process,  assuming a  market for the steam or the
possibility of generating electricity, would defray  operating costs. Therefore,
depreciation of capital costs would be the only cost involved-  With an improvement
in earnings from steam generation, the process  can conceivably be  designed so  that
it would be self-supporting.

        In considering these estimates and the  apparently favorable economics  of  the
system, it should be kept in mind that the figures are very preliminary in nature
and that the system has not been tested with solid wastes as yet.   On the other hand,
the system has been successfully tried with kraft black liquor as  the feed. The
principal difference with respect to using solid wastes as a raw material, will be
the need to develop a suitable mechanism for charging or feeding the solid wastes
into the system.

-------
                                     TABLE 23                                     83
              PRELIMINARY ECONOMIC ESTIMATE FOR PYROLYSIS -COMBUSTION
                      SYSTEM OF DISPOSAL OF SOLID WASTES FOR
                        A 200 -TON/DAY SOLID WASTES CAPACITY
                                 (OVEN DRY BASIS)
                                                                     Installed Cost
                                                                          ($)
A.  PLANT COSTS:
       Two Carton -Steel Reactors (3 ft diam x 30 ft high)                10,000
       Two Furnaces for Above (complete with instrumentation)           400,000
       One Stationary Cylindrical Furnace ( 6 f t diam x 30 ft
          high; complete with instrumentation)
       One Multicyclone System                                           20,000
       One Waste -Heat Boiler (56,000 Ib/hr capacity)                    225,000
       One Scrubber                                                      l4,000
       Two Feed Systems for Stage 1 Reactors, plus Cyclone
          ~     ,      ,
          Separator, etc .
                      1.  Total Equipment Costs                       1,269,000
       Piping (20 percent of total purchasing cost
          excluding furnaces $469,000)                                  L ->>
       Instrumentation (15 percent of total purchasing                   „.  .._.
          cost excluding furnaces)                                         '
       Control Room                                                      25,000
                      2.  Cost of Physical Plant                      1,467,000
       Engineering (7 percent of physical plant cost)                   103,000
                      3.  Direct Plant Cost                           1,570,000
       Contingency (15 percent of direct plant cost)                    235,000
                      4.  Total Plant Cost                            1.805,000

B.  ANNUAL DIRECT OPERATING COSTSa :
       Eight Operators ($10,000 each including fringe                    H  nnn
          benefits)                                                      U0>000
       Supe rvi s ion                                                       1 5 , 000
       Maintenance (5 percent of physical plant cost)                    73>400
       Water and Electricity                                             15,000
       Insurance and Miscellaneous                                       30^000
                      5-  Total Annual Operating Costs                  213,400
                      6.  Direct Operating Cost/ton-day                       3.05
                          Grinding Costs/ton -day (200 tons                    p on
                             at $2.00/ton)
                          Total Operating Cost/ton-day                        5-05
       Earnings from Generation of Steam/ day '                            1,010
       Earnings from Generation of Steam/ton-day                              5-00
     'Continuous 24-hr/day, 7 days/week,  350 days/year operation
     By-product steam value at $0.75/1000 Ib
     Heat value of solid wastes feed assumed to be 5000 BTU/lb

-------
                                VI.   PUBLIC HEALTH
INTRODUCTION

        From a consideration of the nature of the problem of solid wastes management
summarized in Chapter II it seems evident that there are significant differences
between the planning, operations research, economic, and technological aspects of
the problem on the one hand, and the public health aspects on the other.   In fact,
it might be said that while lack of attention by land-use planners has created the
Number One problem of wastes management, long-time attention by public health
agencies has so contained the health problem that the unwary observer sometimes
questions whether such a problem exists at all.  This makes it necessary that careful
consideration be given to the nature and relative magnitude of research effort
appropriate to the public health aspect of the research program.

        A need for such evaluation became evident early in the study and was discussed
in some detail in the First Annual Report [l].  Although the research herein reported
represents a continuation of the work in progress at that time (1967), some furthei
analysis of the role of public health, both in solid wastes management and in research
in that field, seems basic to a full understanding of the progress reported.


RELATION OF SOLID WASTES
MANAGEMENT TO DISEASE

        Solid wastes management has traditionally been regarded as a problem in public
health, generally because of the belief that unless properly handled, wastes can
constitute a hazard in terms of the etiology of disease.  Possibly, the reason for
this automatic association of solid wastes with spread of disease dates back to the
preplumbing days when night soil was an important fraction of the total mass of solid
wastes which at various times in history and in various cultures has been permitted
to accumulate in the streets.

        Despite this long-term association of health hazard with solid wastes, it
would be hard to pin down specific instances in which an outbreak of disease can be
unequivocally related to solid wastes management practices.  For example, in a study
conducted by the Aerojet-General Corporation for the U. S. Public Health Service
[29], 1236 publications were read and abstracted without finding sufficient data to
permit a quantitative estimate of any solid wastes-disease relationship,  although
circumstantial and epidemiologic information was found which gave reason, for concluding
that such wastes do have a definite, if not a well defined, etiologic relationship.

        The failure to demonstrate a direct relationship between poor management of
wastes and spread of disease does not necessarily imply a lack of connection between
public health and solid wastes management.  It may be that the diseases thought of
in this context never really existed as environmental problems peculiar to solid
wastes, even though their solution may not have been possible unless the solid wastes
aspect was resolved.  For example, a poorly managed disposal site can serve as a
shelter, food supply, breeding place, or focal point for vectors which can transmit
disease, but good solid wastes management alone is by no means the only action neces-
sary to control such vectors.  However, if the vectors are effectively controlled,
the problems involved in that control with respect to solid wastes management cannot
be correlated with the diseases which the vectors are capable of transmitting, for
the simple reason in logic that eliminating a cause precludes a result.  Thus one
type of public health problem having relevance to wastes management may be said to
exist more as a threat than as a visible problem requiring definitive experimental
research.  It is this sort of problem which in Chapter II is called Type 1 and
described as being reasonably well solved, although remaining solved only at the
price of constant vigilance.
                                         8k

-------
        Solution of problems before they become identified to a significant degree
with solid wastes may not "be the only reason for the uncertain linkage between
wastes and disease.  It may be that the term "health" has been interpreted in too
narrow a sense, i.e., as freedom from disease and infirmity.  It may also be that
a lack of information exists because no study has been made in which the entire
gamut of wastes is considered.  Or it may be that primary concern has been for the
biologic agents of disease to the neglect of chemicals which either directly or
through decomposition products pose hazards to health.  Through the years, chances
have grown more remote for pathogenic biological agents to enter the environment by
way of solid wastes.   The same may not be said of chemicals.  There is a growing
literature on the subject of leaching from landfills, as well as on the pollution of
air resulting from incineration and on the toxic nature of various chemicals and
metals which are used in industry and hence may be presumed to find their way into
solid wastes.

        It might be concluded therefore that failure to find any convincing evidence
of the relation of solid wastes management to disease may mean that available infor-
mation relates only to the first of the three types of problems identified in Chapter
II.  Nevertheless the subject merits more consideration in relation to the role of
public health in environmental control of solid wastes, along with a similar
examination with respect to the other two types of problems cited in Chapter II,
i.e.,

        Type 2  Those which are as yet unresolved; and may not be solved apart
                from other solid wastes management problems.

        Type 3  Those which remain unevaluated in comparison with other more
                obvious environmental hazards, or are still unidentified as
                problems in public health.


ROLE OF PUBLIC HEALTH IN
SOLID WASTES MANAGEMENT

        Two distinct roles of public health specialists in solid wastes management
are identified in the First Annual Report of the project herein reported.   One of
these is regulatory;  the other investigative.  The regulatory role involves
participation in the establishment of appropriate legal ordinances and in a program
of surveillance of the entire solid wastes management activity in all of its phases
from on-site storage to disposal by whatever method.  It is by this activity that
health problems of the first type cited in Chapter II are kept under control.  On a
research team the presence of public health specialists having an awareness of the
requirements and underlying rationale of this regulatory activity serves to keep
other researchers alert to certain practical realities and constraints imposed by
health considerations.

        In his role as a researcher, the public health, or environmental health,
specialist functions  in a variety of ways.  Data on which regulatory criteria are
established and refined, particularly those related to vector control, have normally
come from research activities in which vectors rather than solid wastes per se_
motivated the investigation.  Thus it might be said that interest in the public
health aspect of solid wastes predated widespread attention to solid wastes management
problems In general and played an important role in identifying such problems and in
defining some of the  necessary objectives of a program of research directed to their
solution.

        As noted in Chapter II, the second type of public health problem is concerned
with occupational hazards and with psychological and sociological responses of people
to environmental conditions.  In this type of problem the public health researcher
often finds his interest broader than the solid wastes aspect of environmental
management.  Consequently he is likely to bring to the solid wastes research team
on which he serves, information from other investigative work in sociological and
related problems apart from the solid wastes study itself.

-------
        In relation to the third type of problem,  the public health researcher tends
to play the dual role of inventigator and interpreter.  Again as noted in Chapter II,
the fact of toxicity or health hazard of any specific material,  as well as information
on hhe concentration at which it is significant,  is a matter for medical and epide-
miological research which may proceed quite independent of solid wastes management
considerations.  Thus the public health specialist concerned with solid wastes
problems is likely to be called upon to assess the health significance of various
components of solid wastes during the management  routine, on the basis of knowledge
gained by himself and otherr- in a separate research context which may have broader
implications.  This doer, net r-.ean that the quest  for knowledge of the health
significance of individual fractions of solid wastes is not an appropriate aspect
of research on solid wastes management.  It does,  however, pose  the problem of which
of the vast spectrum of components of solid wastes, if any, should be investigated
in a solid wastes management program of limited budgetary support; and calls for
value judgments cf which components of refuse are  likely to prove significant and
which trivial in health consequence.


NATURE Am RESULTS OF INVESTIGATION

        The principal objective of the research herein reported was systematically
to screen data on the types and composition of solid wastes and on the processes
of disposal for the purpose of:


    1.  Identifying those fractions which might have public health implications.

    2o  Evaluating the public health significance  and environmental fate of the
        various fractions in relation to wastes processing or disposal.

    5-  Identifying those constituents of the solid waste stream which merit
        intensive study, as well as the point in  the management procedure where
        such study should begin.

    k.  Suggesting means of keeping those components shown to constitute a
        significant hazard from entering the environment in such a manner as
        to come in contact with man•

        A second responsibility undertaken by the  public health specialists on the
project was to evaluate, on a continuous basis, the proposals and findings of other
aspects of the project for public health implications which might be overlooked, or
which might generate new health-related problems.   This responsibility was generally
advisory and consultative in nature and concerned problems of the sort cited as
Type 1 and Type 2.  Wo findings of particular import resulted from this aspect of
the project.  Consequently the results herein reported derive from the screening
study.


Procedure
        A series of tables was prepared by a survey technique involving five major
steps as well as the exercise of value judgments of both qxialitative and quantitative
factors.  These steps were sequential in nature and included:

    1.  Classifying of wastes as to source (e.g., domestic, industrial, etc.).

    2.  Identifying of the individual components of each class (e.g., wood,
        iron, plastics, etc.).

    3.  Listing of the chemical nature of each component (e.g., cellulose,
        lignin, etc.) •

-------
                                                                                   87


     k.   Listing the  chemical nature  of  any breakdown  products  to which  each
         component might  be  converted in each of the several disposal  processes
         (i.e.,  incineration, landfill,  composting).

     5-   Assessing the  public health  significance of the  components  and  their
         breakdown products.

         In making the  evaluation necessary to Step 5,  three criteria  were utilized
 as  a basis for  value judgments:

     1.   Magnitude of the component in the  waste stream.

     2.   Likelihood of  a  given component entering man's environment.

     3-   The effect on  the public health of any given  component if released
         to the  environment.

         In applying  these criteria it was, of course,  recognized that magnitude is
 a relative term in the context of health significance.   Trace amounts of one class
 of  substance might have  a profound effect  on public health  were it  released to the
 environment, whereas large  amounts of other  types might  be  present  before they
 constitute a threat  to the  public health.  An example of the former is cadmium.
 Ingestion  of a  milligram or  two  per  kilogram of body weight  is sufficient to have
 dire effects on an individual.   On the  other hand, an appreciable amount of iron is
 needed to  constitute a hazard.   In either  case,  however, the significance of any
 substance  in any amount  in  solid wastes  is dependent upon it being  released to the
 environment under circumstances  which might  injure man,  either directly or through
 depletion  of his  crops or animal resources.   Inasmuch as both original substances
 and their  breakdown  products may be  involved and the  long-term significance of
 dangerous  materials  sequestered  in the  ground are speculative, a considerable degree
 of  subjective reasoning  enters into  an evaluation of the likelihood that any material
 will enter the  environment even  if it is present in the waste stream in significant
 amounts.   Obviously, an  insoluble material has  a far less chance of entering the
 environment than one that is highly  soluble.

         In assessing the  effect  on public health if a toxicant is released to the
 environment at  any stage  in  solid wastes management,  a choice has to be made between
 individual health  and  epidemiological significance.  For the purpose of this report
 the  criterion is adopted that if  a material  is harmless to the average individual's
 health (without attempting to define an  "average" individual) it is of little public
 health significance.   Conversely, if  it  is a hazard to an individual it is considered
 a public health hazard if released to man's environment.


 Investigative Findings

        The  results  of the investigative work herein reported are summarized in
 Tables 2k through  28 inclusive.    The sources used in arriving at the information
 presented  in the tables are  found in the References at the end of the  report.   In
 preparing these tables consideration was first given to the myriad ways  in which
 solid wastes might be classified.  For example, one might choose to adopt the
 traditional approach which identifies wastes in relation to environmental origin,
 e.g., domestic,  commercial,   industrial,  etc.   On the  other hand,  wastes  might  be
 classified according to their nature, e.g., metals,  plastics, wood,  etc.  In the
 first instance the material  itself (e.g., wood) must be reconsidered in  relation to
each origin.  In the second, the origin must be repeated in regard to  each material
 considered.

        When evaluating the  public health significance of individual materials in
wastes disposal processes the second approach would seem the most logical,  provided
all  community or regional wastes were combined in a single mass for disposal.
Although the rationale underlying the study herein reported is that a  regional
approach to solid wastes management is necessary, the  fact remains  that  public
 responsibility for wastes disposal is still oriented to domestic refuse  while  other

-------
wastes producers make various arrangements to dispose of their own wastes.  The
result is that so little is known concerning the nature and amount of wastes from
individual origins that research needs in some instances are first to identify ami
quantitate wastes materials before any public health evaluation based on degree of
hazard can be made.  For this reason environmental origin was adopted as the basis
of classification for Tables 24 through 28.

        The tables themselves must be considered in the nature of "work sheets" to
which data or value judgments may yet be added, but from which conclusions are herein
drawn relative to the health significance of various components of wastes and to
identifiable research needs.  See references [30-69] for the materials used in
compiling the tables.

        The overall nature of the tables may be explained by reference to Table 24.
In setting it up the authors first list the principal constituents of domestic
wastes that contribute a fraction of the class of material to be considered.  For
example, the general class of Metals includes such things as "cans," which are
essentially 100 percent metal, and "luggage," of which plastics, wood, or leather
may be the major component.  However, in relation to metals only the type and fate
of that fraction of the item is considered at this point in the table.  Therefore
"luggage" appears again in Column 1 of the table when other of its constituents is
the subject of consideration.

        In Column 2 of the table the "type" of material (e.g., kind of metal) is
listed.  In Columns J an<3- 4 the kind of conversion products which may appear in the
air, water, or land resource during or as a result of disposal processes are tabulated.
It is particularly important to note that the spectrum of products includes those that
are possible under some level of operation of the method cited.  For example, the
products of incineration may include those which can come from open burning as well
as those from proposed high temperature furnaces.  There is no attempt to argue the
point that the best operation or the most effective system presently technologically
possible will prevent some of these products from entering the environment.  Instead
it is recognized that in the real world these products do exist and sometimes follow
the pathways suggested; and that as long as such is possible, any attendant public
health hazard must be presumed to exist.

        In the column headed "Identified Public Health Significance" (Column 5) the
entries represent only the principal factors recognized by the project personnel at
the time the table was prepared.  It does not, unfortunately, represent the aggregate
knowledge of mankind concerning the health implications of the materials cited.

        In the final column of the table (Column 6), technological and medical, as
well as environmental health, research needs are indicated.  Furthermore, as discussed
in a subsequent section, consideration was given to the possibility that the research
need might concern the knowledge gaps at any point in the table, i.e., in any of the
Columns from 1 to  5-

        In Table 24 percentages of various classes of materials (e.g., metals,
7 percent of total domestic refuse) are included where such data are available.
These values represent information from some actual analyses but are not necessarily
the national average nor applicable to any individual community.  They do, however,
total to 100 percent and give some basis for judging the public health importance of
the conversion products of any particular major constituent of domestic refuse.  No
data are available on the percentage of each type of industrial wastes listed in
Table 25.  Such would be essentially meaningless in any individual case because
regional or local  patterns of industrial diversity are highly variable.  This lack
of data does, however, underscore the importance of studies leading to an estimate
of our national industrial wastes load and its environmental significance.  In
Tables 26, 27, and 28, available values are presented which give scale to the
magnitude of any associated health problems.

-------
            S  *  g  i
 ^ =   +1     <  TJ  o  s
                                                         j  o 3    oj  d  d
                                                         !  H «    J.  d  g
rH >*; 0) ^
   O Sj
oj -p 03
•P O
*H t-
                                         i X r
                                                                                        -
                                                                                        i m
                                                                                                                                 ^  OJ


                                                                                                                                  n]  O
                                                                                                 G C !
                                                                                                 CO > H
                                    S H j
                                                              ss
                         )  >, O  H -H +3 J
                                                                             rQ     H H  (D     OJ W rH

-------
90
                    la
                  i  fci
                  sg»
o +»  ~
H a  -d
.£ o>  d
                                                                              to -P

                                          oj  •• ••
                                          ^Sw
                         4)        (U W    H  o  O
                         -P   •     01.       ^  (J

                         o  S    -d ,Q    ,a     fj
                         H  H     0) H    ^ rH ^
                                                        Si^w
                                                        -pOCU

                                                           .-
                                                        f,-P,C
                                                        M> o H X ^    J
 J JB >" JU if    <
                                   '
                                   -— . X  IJ~i CM a\^— '--^ O    OJ
                                  a-eK—           -«f».— ' •-
                                  Ot<~\     ^--^ac\i   ij*.  -.    H
                                  PaDrHOOCO OJCO-^VDO &(U

                                  O    O          'rl    H              g]
                       itntrt     drfM    Pm

                       S) ft"C  M ri  hD O >, O  t-
                                                                                                                     O C
                                                                                                                        Oct     H  »    >(     ^
                                                                                                                      tdlr-H     Ulj    hp-^H-P
                                                                                                                                                                       r
                                                                                                                                                               u       COTJS
                                                                                                                                                               3       ft-H^f
                                                                                                                                                                                i
                                                                                                                                                                          HOcSn
                                                                                                                                                                          ft    a)
                                                                                                                                                                             -PJ2C
                                                                                                                                                                          UnC    fn

                                                                                                                                                                        j    ooo
                                                                                                                                                                          fjf^dd
                                                                                                                                                    u        ^
                                                                                                                                                    H       -p
                                                                                                                                                    -P       -P
                                                                                                                        H  o]  o  o  B       m
                                                                                                                     ^i  ra .c!  
-------
                                                                                                                                    91
M  PL,


SS3,
|55|
-d .p H  3
la ^

3 C ^



ill




  a) tu i     aj i
">-d H  n   en
a rH 3 O   0! I
s at M a   cc r
                 r-

               O 3
               f-ita
                      9 V  "'
                      I-ETU
                      a) O W ti
                      0) -   ••<
                      PiaJWOC
                      a) rH B   .rt
                      cj o   TH -p
                      ur-^cto
as

   S   £  8?  &
 i... d  .  -s T!  s
                                         S jo a41
                                             £3 01
                                           J3 "O iH

                                         H r-f -p H
                                         at aj 0) £
                                         -P 
                                         i  .
I


I





-p

1)  •
rd  -P

-P  tn
                                                       =      V<  >! P  '
                                                       >      co  H Gf d

                                                       )      ?E -P   O

                                                             „  a »5

                                                       i      S  S.S §
                                                       :      +3  tO rH
                                                       3  •       ill rH 0)
                                                       1 ti    g  >-i (D O
                                                       H OJ    O    S C

                                                       2 g    £ 5 * S
                                                           ai    II W
                                                           rH      C    '
                                         JH S C      ,0

                                         0) D H   •—-^

                                        r? ft Cb  1) CO p
                                                                                               -


                                                                                           Od
                                                                                           in"  S -d



                                                                                           a  S £
                                                                                           a  P. Q
                                                                                          -H  01 -P
                                                                                           O >, °
                                                                                             Cl

                                                                                          0) -P
                                                 h >, !>
                                                 o w ta « w
                                                                                             (MO   O O
                                                                                          ±   oj H =   (\l H
                                                                                          HJ H CO T5 CP W
                                                    10 $ '
                                                    r. C )
                                                    n) td i


                                                  E"S?
                                                                                                   _   _  _

                                                                                                   "s is is    oc

-------
i  c:
i  1Ssa
                9s

             HOO
               'OrH
 • H   5 «  p   a
 «>.H   g, p  D p -a


~ a   8m  "5).g *


-p        a  C o
 U  h   >> B    H -P
 0)  Q   £f    4) Vi o


 H      -H u  a 8> o
   P   +> U  d -H rl

 O *"*   fl) £  -r)
  S $ '(\j
  O R O
                    8f
                    -P rl
                    a) O
  HH   ^1"]


  Jl •-* 43   (U O fC
  S o) P.   en ft a
?
                a)
                                         i.S


                                         ?I
         ""8
   ^O   OiO    >>OOr-

   1- rl   p, h    A rl G J

   C -P   < P,   S & rl E
       ••> rH  I OJ O tt)  •

     rHHOO-tt)3a.tfl]
3-PO)+JajH)'d5
1uXatlUH)>H
J-nbCSpSo
H Du ffl O EH M OT ta
                                                            eg  •
                                                            d a o)



                                                            p ^^


                                                            0) 03 43
                                                                     P 0) H   -p  ;
                                                                  a« s
                                                                             ri     ,  H
                                                                                >, g] td

                                                                             •0  5 S H
                                                                             p      co
                                                                             cfl-drHj^
                                                                                0) o)
                                                                             -p  ti n 43
                                                                             000+3
                                                                                      U  d
                                                                                      e!  11
                                                                                      OJ
                                                                                      M  4^

                                                                                      HC
                                                                                      3  oj

                                                                                      G-P
                                                                                        I-
                                                            SH?
                                                         O § g
                                                        •P H ,Q
                                                           P. r.


                                                        !~s   ^|   «!

                                                        Ill   S    *; "
                                                         rn 01 o

                                                        £«S
                                        P B W
                                        H    o

                                        43 w "d
                                        o G p



                                          II

                                          £*
                                                          :|   „


                                                          ; 3 S
                                                            X SJ?

                                                            a) -P >O
                                                             0     C 0)  -P               R



                                                             !"u    IS,        1   -^ y    >
                                                             IS-HS'd^        rHrHD    al
                                                                        u    -
                                                                        H    3   to
                                                                        iH    )H   0)

-------
93

-------












s
a


H C

££
H iH
B"
$




>nve rs ion
^thod
0£

"d 'd
cd to
r-t W
T! ^
OJ O
^ g

O 4*
*5

« s
11
g g
w




























0)
i
cfl

w
13
1
to



1
LJ
w
Sr~ .
+;

3 ft

0.

*



.tary Landfill
L Composting
4-


to









d
o
+1
a
c
a
M







g.
?. CM








V
3 H
s





































i
• W OH H
V. S O C Cd H £ O r-H ° .a
"^.HO^^.^ ^ vi C 3 i" rH1
G rH 6) C >>-P
> H i-H p -d W (flCOSoJ-P^
O rH & p H c! -P 3 r-l UJ
a T3 -H 0> -^ 43 HEJ.H tn -P
a > rt -P "OP-PflJO
w a) O to O o In
-p 43 d -p Vi aEgjo^o
d w u o o oidft-Pr-f
i .n "§ ti d c. ^> "a rH H a! -H

O 03 Cd ft<3) H • -H $ ^ O •
H HflHM M-ptlJ'iJtj&M
t-. ^ .p H .d
MmE --a 'd a! 3 wp
-HrH Offl O >5 (UH
S3C Jl ft -P M 3 C
!>> CO--.4J to TZ)«H
81) « H "o (j -S-P § "^ -p P-flT

034^00 x h p-*o 3 ^ f-< Bl
rHO 0) ••- tn • Oh cdd) 5 EH ?^S
-P EO^C !)• 9J<0 ti ^Ji^Vi
ca 42 a. "•i.co ew ft * mo >i
fl>4J Ho-PC 0)rH(B CC "-I-P O-P -PCf-i
ftrH Ij^SCJ Oti-H .H £.3 "P^1 ^B0
s a s^s s HI «•§ fi s a? 5 as
rH OJ pA -* l^ VD t—
o p"1" ' c
O 3 g rH Cd H
-P rt O W- — • J-l O ft O O
a 0  ""a; PSo 9WS
QUOJ-P'-1 rHO'" -P01
t.lDC<- d C drH
.-P.I c ^jg K. .„ ^


oj SrH H cap. to o g
aiac1 30+^ . TJ -P
^^•EHal1 wS^ ^O-HK'

H OJ rA
_.

a-« rt 0)C ^! Ht.E.2 -H,O QrHP]
OM ES)o ow cdoTI -Pto 3rH(u
rt°? cfl-p rHH"0£dai TO * ftfln fo
H-pM Hg OC+>4^'Sl>i MflJ rHft,
•PP.T -P H ° S 0 S -H .S Cdfi- goJW
CC-- a ^ >-i -P 4> 3P mSO M OO1
^HjS H-^S S.'OrH^r^.H'-H ft.. " ltiHE§'H
V P^-L0 "** OrH^Fdt. S-P^l Pt-POO
^ c. ,A ^ >A
c
a -H • c H -o
S OJT)O to H -.rHC
3 tone o -p tJocd
C.JO< S h-lQCQ O PJ <
S -p o B
;3 | -H

^JiU-HHtiCOH OfiOi -P

SCC0145MP--P OHO) ?
OOOp-Hf-ig 0) CJ'H'-' „
-H-P-PtHCB^-p S End-OOJ C
tCOOft-PcO 11 K d M -P rl tri
^ooc«> ^ i^^ico S .3
_° 77"c\? -P "in" "c\T H tJU^^H u S
oo o ^1 || H^ gg S |
43 ° H ^

o > to S


























1


0
•i-.
»
3
3
g

1

1
1
1





























X
OJ

a
B3
^

-p
I-H
to
J


h

s
to
^
-p

c
K
ft
p
rH

-d
leachates to groun

rH
-^
M
1

H


g
f.
u
fll

1

•d
A:
1
CO
^


















0)
H

p

rH
*
^H
rH
a
d
^
o
43
co
to

a







s

1
d
1
r-
'c



s
i
rH
1
(a


•^
aj
g




s

a
g

u
s
M.
c.

^
1
rH
p
§

8

}
p

3



s
o
p
D1
•p
0)
M
•H
n





-p
a

f
ft

o
-p
o
rH
nJ

















I
ft
to
p


^
lj
a








I

—'
WASTES

$
5
p

0

i
s
o
43
n.





cO

e
1
s
s
D-i











-p
g


-

E? 15, 13-

CM tJ~\

F-i
° c?
to .* co
'C rH n d

££3 n
E -id O
•s!iH
B S -^ •
o - *
05 H °'T'<(fi
JJ CO O •*-* •-
ft ^ CO rH C
Cd
SKS ^3 S S ~ I
ifip'orH <£ ^ M "S S* o7 i "S* -^ oT w" to"
S S M1? ° «.3 ^ g °-S o> C ^ 5 In"0 XJ&.I 5
rHG)p3-^-.3C W"?.O S) H S.T^'d'd CO^'urHa

o)rHoiwco_a)^ g^^ H-'S"rH*'3i^w'^ow"§-P
- w •• cd w '-p rt "-"S"^ |S^-2i-I- -^'S.c'S ₯irS'prH''o^
i5lsjp| IS a~!l f!-l^?as'lt
£d-i>OOJ(D^lH OHp 3^0) PQ)rHHP-P-rlOtirHrH
'S-—' cO --- cl o cc t^rHwnit.rHp, e..oN

tn
rH T)
W rl O
r. ^ E §
O 0 fn
h tJ t. >H p3
Q) CO O 03 -p 3
P M O 43 S-i
So 0) &-P
w o -d s. H
-P H M 5 -H ^
in P Oj p Pn S
Eo
h
^j ib
1

-------
                                                                   95











1*-
r-l
|"^3
IH ' S
H ? i, £
^ 5 "' ^ "4

^ 03 -P C
OJ la ri cJ ••

1 j^^' o
 "
&; B
oT 1 -" [
g IH H
H ^ 0

-P 0) H O

id S-XI -^ o1 !
S ' 3 o PJ •
i E o w > X
~ _,"
l^|
e B g
O O
^ rH r^
a ££

' **l

J g -H
^ ^ 0
£• ^ 'a
-p S u


01

SH
^5
>j
-> r-H
R

-P •>
05 (H
•S & +
                      E ri

-------
96

-------
                                                                                                                                                                                                            97
                       ? qn       d) 4
                       --5O       w
                                   !  g S i
                                        n       B)          ^-,

                    ^ "S          w  o> !> >>    £       .c
                    to  3          gj T3 oj LI    o       b1"
                       •     •     C  a V< ft >i C       cu °

                       G -r< 0)     N  N H 0) B  N       CM
                      'rl    -P          03 H               O
                    uX-pro     "in  n3 -p    -PC       w+J


                      -P 03 §        id S -P 3
                       0)
                    r-H  > H
                            G    Q  H G
                                    r.
                                                           d|
                                                   D    fflO-P
                                                  -p       ^H
                                                                       >i M
                                                                       gj 3   "
                                                                       E o  ut
                                                                         Tf-P
                                                                       *. Li  £j
                    §D

                    C
                    3
                  So™->^
                 4Jr-IOW
                         —
c jj     a  $ H
cfl &  T3  O    O

01 M a  ta -H -H
Ll d  -H  0) rH
P -H  ^2  h  O >1
4^ &  e     w ,a
   Sw  O  nj
   •HO    rH -P
   G     C H a
CM H  4)  H  gj 0) r-
O In  f     C S r-

   tr-t  -P  W  S &)<£

   4J  "ffi^  ° § "E
-p a:  H  p  O is n
CO S  E  & -P E i-
                                                                                                                                                                      S  §5 '
                                                                                                                                                G-PS'dCid          E    cd    f-

                                                                                                                                               =H S G  a  >>.§       S -p  t?  - n\

                                                                                                                                                Li ri    HOC!)          60  G •-! G  +
    P. rH    H  O
                                                                    w
                                                           Ua-P

                                                            >
                                                                                               .  .     a)






                                                                                               i i     >  o    y
-
cdo-pti-,    &  .
i-H       Hq-i       tn

(J+J     M       rH+3
                                                                                                                                                           -i            i                 -            r
                                                                                                                                                       TJrH-pX     SoLi    0} "r4    *-o3    COX    0)
                                                                                                                                                       H3HO     03(0     ^3    rtrH    OJO    £J

                                                                                              !     Sn3    -pwnajOo    -PHO
                                                                                              i^,            HL.-PCO      j-^'0


                                                                                              ?^^i^    031-tHO    G    aJ-P
                                                                                                   cu  • ^
                                                                                                  -P  o  <
                                                                                                   ca -p  i
                                                            ^
                                                            OJ    &OO

                                                           S    •S'p.a.
                                                                                             O  -p IH  o +
                                                                                             s«H^
                    H    fa    c"o"      - o -H
                    BC       ajCOntltHX
                    §  a TJ    aci  o  * h  o
                    HaJd    O(DOO(L)H
                                           t
                 IHU    OrHOG    W^

                 4J(n     -H    rH    Oa)r
                 wa    BOB  •v.xwL.&
                 aj       a)     L-urHhO-
              HH       H    jj-H-H(UO
               aim       w    EHPHO
-------
98
                               g  S   £3
                               H -P      O
                              S-p  H 43 (H >H
                                O H
                             4) ,h -H lj   H
                             -P 03 H p, C P.
                             •d ^  W t) ^ -H
                              H   C w '
                             O 03 rH a) rd ,C
                             •P -P  n3   O -P
                               IJ -P  "• ,£! H
                             •d B  O >l£ Oj
                             3^ H1 SJj
                             a) o  c rt
                                 SH 3 H a>
                               W  to I [0 ^
                             illsII

                             I 1  1^3t
                                    sglsl
             !!
             li
                                    i
                                    8g
                             trj  - C
                             0) H D
                             P. rH J2
                             ft H 4J
                            < 3C '
                                     mty-pu)   dfdOS
                                     rdftlnai^HrHOoi)
                                     0) i*. Bj f- O   rH
                                     (D +J p,     bfl ft in T)

                                     O      "^O^rMoS
                                     waduH^iiH
                                     (U, cfl a) P.-P 3 P rn d
                                     a     >, (fl +j « a o
                                     fa Ul  ^4JtHrjr-i>Hr-
                                     d-Piq   (D 0} 0)   -PC
                                     ^gHfHa"HrHrH(rJ[
                                     OPOJ H'^P^liH-*-

                                     ^l«-e°ass^ =
                        0) O   Q) CfJ



                        BUN   oj

                        -P B ^ ^ S d
                        M     +3 +3 O

                        =H H 5 O 3 -P
                        O   rH +J -d 0]

                        M O 4J Oi H gj

                        w ^-^2 «i5

                        ^ i 'o -2 H a
                          H   p w H
                        1> * -P ,0 P
0)   Slr^   O 0) .H
H     p   P &, o
 1  p|S   JS  -*
el  S     o o c
O   Q  •*  (d 4) H
Si  §l|  5fe  -.
                                                                        nL
                                                                        oV~.
                                                                                                MCO     n
                                                                                                 T3    O

                                                                        qJhomtiJ  Hotd
                                                                        WfluoCU  OVid
                                      D      HI U  H S

                                   r      a05001

-------
                                                                                                99
      -P CH TJ d H T»
      U   D     D
      S to tfl -. w ii
        O S-H to O C
      =M -P CO Ai -P
      -P C ,1

      S !!  i
      R


      f^
      ^^^
      H §  U
      w  o ;
      -Q  ti -i
                *OO CJ TJ -3
                !  H -p 0 C '1  .
                ) -P M O 03 «: '
               So"
ia
!  U
             jU -rt    (DC
             P.      p. u
      51 u   "S §
      S  S   ^ p-
                                                   S (D
                                                   *"§
                                                   5"S
                                                   c & J
                                                   £«'i
                                 s   i
                                -»"   H
     s

II   B]
SI   S|
                                              I113

-------
100
'
!
,
p
'
0
05
"3 r
ss
4-1 CO
iterial and Conversion
to Disposal Method
EnvironnEntal Fate of ME
Products in Relation


c
5
)
;
3
3
i
! ^
s
fi
1
.
C 0.
1°
Sanitary landfill
and Composting
k
Incineration
5


>
3 rH
g








is i 1 a
c3 " g ;
O G h ttJ -P U
S4J +J 0) i (Q
,a d .2 a m a
g -p S u o S
01 O 3 rH ° ^ S
d "o &£* § & d
id In • .c E (d
0) 
20)38 3 "^ 3
r-t CVJ
rl
lH 0 (0 "C -P W
o) £ Ur-f a! c\j § u G 5
a « IH s 9 o o doj-S
01 M tt C "G C K ti M ° §
is| ^ | ssl f|^
°S^ C? S^fS al°
CJ-drH GO) ^HDlO H-Otl
G as a oO'H-pajtj-
•Htn • 3aj- dSjoi -H^U-H
3OOOJ Ci3(j -HOrH 8« -P
d^-Hh ^^° "^ At fl hp
rH > Oicjfflp
__r-*V, £HS' rlT+jC
-P-v OJ OfntO4J ^3fn*d
gOra-P -Pootra tajiK-H
I|||S tS^I 4! !S1
3 p 2d o -HWGft
O^""h QJOJ-U -pwnja
Hfljpjn Mobto toffio
W >O U dOQjSO H CVlCJ
oB-d- SnJ§S 2 u5, c
+J Cw -PjBCfn -d~^-H
s~"Ml s .. !« §*^ "^
^ oj Q & H ^i jn D >, g x
OrHgw WD-PrH ^'"-^ ^
lis+jj^ [£SC'H 5l o oi , w d
rH eg iA
W r7 0
Is |
Kl T3 W
Si "o ^ o"
r. tj ^ W
M o -d a •• v
HOC H H -p
^ r( - d ^ "ft
03-d P- d o
rH OJ
"~^ 0 rl -P H >H 1 ^4J -P U -H rH 1 J^ +> 0 1-t "^JC § ' ' -^ °^ "^ '^'~* H H Cd "^
^--3t,G P.- G.C S OJrOB'-MCL,OC i-HOJT3B-*^iP-ifJG *— - 3 a) -d ""''rf'. C 3 •> (U IT\ O
•»^. H 0) -H •* ED ^-— ^ aJ H . W 1 K OJ ' — --~- a ' rH W T B OJ -—*-». «>(*. rH " DO W C CM OS' — --— •• TO —< • rH M (Q S -^
^ S fl .,_ _
O +J O r-H ^3 -d [0 >P.
rHdJrH rH(0+) rHH r«^
~- 	 -P O ^^-P « l^. O rH ^~- 1
>ja. >• r-t -ep. cvj oj
-3- Tp,_* lf>1'?S- "^ V
^f CO ' O"l CT\>(*. O CV1 rH ^ •<
d'H'rH • r-t .--^J W-0 'S
rH--.— - O-" QJO^ffl +>-H H
Dp-" ? £*>•• O O
iH<(O 0)< -P
-------
                                                                                                                                      101
  H i)

 ! O -P
        C   "*H    O l> HH V
   < O  - C    O
 i £ S S,?
 I «as^
 i s s at
             o C  >i g j
            O 0)  ,Q E -I
         -,-d
        I g
  EIL a)   aj -
  X! C   -H ITS


  ttl 4J   «3 G
  .C rH   EH 1
nwae

WOOD, .
  fn  •   -PI)

  •S01   S 3
to^

O § -g   -rT^
+j   S    E C •
   •s "      01 M



o!   H   Xi -o &
x: dj w   -H -d o
                               •d x!   to •

                               ro E o S -t
                               4J  O 13 x! W C
                               C  h(t   a C C

                               o  e *H t 9J S
                                                   g^
                                                     a


                                                   si
  o a

  S "S
                                                                                          -P 1J •


                                                                                          H   "
                                                                                      o £J x: -P  o
                                                                                               C S
                                                                                             >  rl 01

                                                                                               cfl J3
                                                                                         r. •«
                                                                              §13
                                                                                  K
                                                                              D O
                                                                              se
                                                                                           -
ol o



•S CO  '
" '-        T3 bp

         "Xiib26o-p



    CM'   -pHJftoo"^"0



         s -a o a P-

    j.
U< M. "- H ^ '
                                                                                        C    U   H CO N lj

                                                                                        ;E?§   S^s^s

                                                                                        e§c   Sfi^SS
                                                                                                           O^

                                                                                                           lHl)
                                                                                                                    T ^ _ E
                                                                                                                        N

-------
102




vo









^





-»




1



W\








OJ








1-1












*SJ 3

13 fr
§5 S
§ p d ^
d o a) b
4> -d g
J3 d a 3
P a) -H
d w w O?
O 4) 4)
ro ;3 o a .
l> "o oj -P "a?
•H rt 43 M £
"o -P m o
3 10 ,0 4! ^j
S H. w $ *
^ OJ
£a Is ^s°.
^j MO] O 3 4t t> -d w
;&£§ £5 S £$£ «C ^g
, ,§ S ° "a c ^ S^^S pi 1 S* ^*







fc
s
a
ttl
0)
d
8
O
s





















a_u> "VHMoj "£ -g P ^ -a 3 3
ajmo m§S £ ° 41 -H -ri +3 .5 g
•Hid • 3>j3 d -H Ca-Ou
3 .CM Pl-iO CJ H .p t^ 3 41 H
d4)p41 V Lt •* ,£ O ttia)w O d > fl to d M -P airoOtj
rH cy w, _j
u to m
1 Id to & i: S M -^
H tj 4) ; ;• P -d d (J
•• O --H p f-l -ri-H ^
ri U 3 fl] 4) d D) IH O
s ."i i*1 «l -s
§§§•£ lic^j •""
•3 OH a g M H «) H
1*'.^ SS'S;:; S
fel^l &&•* 1
o §« - 2 ° S^ • -
-P Cw OM^
«j j £ t a d f° e
^CMH« asi"B-s $
.Qojmpi y O P *) 0 M.
SH H w C^-Hmgi
^lUO dp^vB ID
ijjflpj: .Psw^o V
M EH rH A EH a«-t P 0 CO

H OJ H-,
^
3rH- rf
51 t£ i ^
f^ 3»| |
« 1 -S 11 |
MO q rH •- 5
a " • t ° R. SJ H
t O i» 	 o w
^ P -H _-
^ BO M W 1 tH
rH S rH """"' P. d
^c?^ a ^S1* H" c "S 1
^a^cj'S: -S-"CO-P £1 8*
-— Ty o — -— HMO f, -
w id jl •*£- •" B *j j3 -d «-H
4) o5 P 0) ^^T; * ^ ^ «
O o)& OOJOO-HPi OP
3O -P 3 wCdj-P ••> W

i




5^-1 4) rH O >H rH 1
DL, CJ Pj ^ EH O 1
e
1
s

s „ ° •
S w P W3 m p
P.C Vi my uiin-HO
3 O gjtn r,
C ID E
fc, >• 0

d
o

•§
51
R
(B
O
rH
O

1
H

i
|
a
•a
i
S
1
r-
4)
> undwater : Se
&
d
J3
id
a

1-1
^
OJ
1

S

I
rH

1
*
«3
§
S
H
P 01 H
0) 4) JV-j

"^ S O rH
0 M -d d
*-t d « H
w "S S
-d M P. c
•p o -do
S^ d js
P. (0 P
-d -P rH S.
^ S 5 rH
g a > S
o. tc u -H
-H H CO S
OJ

p. r-t o (0
1 j| S •§ "d id ^
P*. a P-p VH ra O
to > fl o -H ^J
•d rH >, 41 O
G ,h P 4) -a ^-^
• a3 d X q (-1
• — ' -H d 41 a is w
« 3 -a S "t ^ §
Co" B oj
-P m d "^ "S ^
t> aj D a) 3 D t-, O M
O 4)0]HIdCJ-rtq
,0 C B l> O C t> J< 0)
n p.3p.ha>dg D
c^ ^
i
111 1
i ^ti i
.^r p s
™ ^ „- a 5
a |s| ^
jO -P j2 a) 4)
EH w tt S CO

OJ

rT
4J -d 41
PS >
M J3 O
1 3 S 1
V" -
§T« • "
!ti 1

-d "^ P 41
OJ

^c „ "Sx
o O q K\ f—
O\ l~t T3 	 	 rH

1^1^
S? IT".
O g ^" ** U~\
-P £• P O 4) (M

«







1

,O i-H

d
t)
'oj § 01
0) 3 *
n g dp
o3E!*p 3OTHPC4iaJp-'OP
O A dOca-HpdUOoJcd
II " "K:C'i'




















"?
«
i
6
H
S
g
•H
d
<_
to
i
t
























t5
p
1

I
r;

g
i
™
•d
c
«
I
-H

i undwater : Se<
S

3
a

rH


I
1
c?
a
M
a
-'<

.,
1

1
a
&,
-p

fi

1
K

&
1











^
^ I
1 -
1 1
OJ r«^,
B B
s-*. D 41
gj 4J +J
•^ cn w
OJ K>

O $
•3^ "S 1
i n H •
rH ^j ro rCN
•H M -P ^)
f d I- 4)
rH^T'P. S CO

OJ
































g
B
g
B







O i
-P
B


1
v 1
e
P M
H
C S
» S







•s
Jd q m ^
0 Vn r, *H
C^^S X
^ &s ss
V V -H (H 3
p5 co co tn &<













4:

R
a
u
o
d
A
rH

R
|
O?
-c
c

i
M
4)
a
H

lundwate r : Sei
g
t«
o
1
a

H

.
i

S,
1



4)

-------
                                                                                                        103
                    H ,   !
                  (  H> O (
                  >  EJ S- -
                 •o  SIH v,
                    S3  P H '
                 0)  C  © ffi '

                 EH ^  ? ,£ 1
0) °

IRIO,
   q|P
   iL.
   QJ ^ -p
   § ra H
O |-t M -P ^

^^^•as
^
      H ^ nj   o3
      n3 aj H   >
                                  ti ^ U
                                           o -
                                  a B ^ -a s   a
                                  H       "
                                                                             -
                                                                         O -P t
                                                                           ^ -P -P >j4*
                                                                           1 "i C W C

                                                                        	18=  g
                                                                        a cfl   c ti -p



                                                                        S S o fM H -p
                                                                        U .  J! 00 .
                                                               ' C 11 f
                                                               i.a^

                                                               ! * >> P
                                                                      O   3  -v -p co   Tl
                                                             E;w   Swwa     H


                                                             s3cn   CMwaictidh

                                                             d     G  W  h  ID E *•> 0)
                                                             wi w   ED  o      * M -a
                                                             H     H-p-flj-pljH

                                                              -~~      a) -p  nj rH a H
                                                             •--*^-   •-  a. a  S bo oj 4J


                                                             od^owl^ugg.
                                                                 D nJ CD

                                                                 "   K
                                                                 H 0) tn
                                                                   P O

-------
104

•c
4J
,c
rt

£
_t
a
%
S
Cf


4>
C
«c


5
1








e

il

o JU

5$
5 a
a) O
-P +J
4 §
Environmental Fate o
Products In Relat
£






u









*






a
1
„
If
o ir\

C P.
s».
i °
Oi
05





•H
•H U)

C -P
3 S^
E? o

S -o
d a
w ffl



Incineration
3
i
J 01


i>
j
3 rH
3
5






































CLfiANIN(
^
S
§
LAUHDRY












•a
iH







,


rt
CLOTH, j
slgnlfi -
%
Sr
sis
n-°


Ss
a,^
c^ ft,
rH

Q

ol

K\
E|
si
^~

v •
p-t CO
gg
*3
CO Q-

^

1. See Table 2lt, PAPER, CLOTH,
PLASTICS.
jj
c
1
I
I
c
p.
I

•g
id
„ 8

C.

S.1
d *
A 0.












ill
0 S ^H rH 4J
<°^I§C
U O W t4 S

o a -P m «

-p t> w d
° 5 o5!^
s o2S h«
S -9 (2 S -3 a

CM
4) O 1
H O «H • 3
•§ *°d

O S O £ ^
W "tf 4^ G
oil 3
sl I5

O - O 4J

H "^ S
r-l 4-1 B 0)
§ 3 2 "S

CU

2- Snail amounts of 502, C02, CO
and hydrocarbons from deter-
gents appear in stack gases.
( Item numbers in Columns 5 and
1 a
it S
S . A
-S .«
0) Hi -^ r.
Tl H rH 11
H >> HP
>^t ti 01 -H
rH a) m ••
J3 >H C u
tJ 11 (U O iH
d B +J +J
^S* S5
s^a "|
& -^ ° ^7 ^
^ tu o ^ w
P- *
1
Eh
S

«

1



I





























g
S

s

1
I
,_]
1
WHOLESALE AND BE













§1 ° fc-s
S.,4 >»"£ I
. S .H rH

a el *«s|
4j COl ° * d° f J

S fenl " ^ -H "S
w] "§ jj Jl
S SI n « S S
H Oi
•2 • „
'S Si 3 5
pelw £ V ° "S
In « 1 i ^
-.Q r5* ffi "" §


S-P 0) ^
m to o
rP O -p S P- P<
ra o «*=oj
5E ••
H 1

I).

3=t>-l

ccl&i
El
ft.lco|
^r£j|
CM cq
D 5
«H Pit
§B)
$§1

M

PH|CO| _C -P w M
V 51 S •• •» A
rH CM •rt rH M t
,Q rH CJ 4-,
* pi (fl H S P
4) S. d G
Pi pi O S "T3 • £ 41 O ja^-v-H o
Mat rP -PWiHO -rtOD +3W B -H
>P- «>»IH'P SMTJ S.S.™H ^
ajS M -rt^^S d • H rHrH -. v a
;6e r-i -pjtfrHj) -loot «l H 01 d • H
Er-HH -p O iH k
wSoa- co ? Q o

(0 h
s 3 S

Si S "a o
a j3 a) u
•HO a
g- r. M tD ^
% x3 -p a V

•H E o 3 C 5 10
nisir"0"
































fc

s
t>
e
Eo

CO
8
















0)

-H 5

S. +J
" £

r;
1
g]

^

w

o> 1
t?5 o
H





H
>y -p
a
A "S
+j

c M g a

•p i> -p R

H CM
OTl In «
0 rH 0, ^ - t\l
M at M) 0) C O -P
1 H s ^ I..S™ § e
JM g -H o  0)
™sl  +» l~t fl) Pi •» 43. rt
§o'owmo"-'H -p* -^^2 t!-^ w
o ^S «i o 3 -P&4? i>pip. 3
or^«'1J'.]i^'Hs & ^S^ o T! '£ P.
ajOp,Oaiw9j3rH wcE^ >-(g^i r-<
•p B a a v_* +j UCB !*> jj^w iiStB fl
rH r-f S & d
•H ~H H flj 0)
§ 3
rH tD
s s
J3 J- O
2 v o
,0


£ -p rH


^ a -n ^ -d
a) TH H a) H >j
S o o. a o G

-------
                                                                                                                                                                  105
                           W           O
                           •P       4J  c
                           g       j:
                           3    >>-P
                                    T   «
                           d    -H >  O
                3 0          u
      w     d ja    M    mows
      i-(     0)    H a)    Cr-4     B  S

      Q     .,
                                                 Q           att-i
                                            l          /—
                                        jH    HoJj U)    nj  C  -P
                                                                                                              H  CD  r-f n     M  U  d
                                                                                                                    h H     -H  §  Jj

                                                                                                              c  S  B.-5     d  o  S
                                                                                                              "^"     ^"
                                                                                                              •^CHa)    •PCaj     r*a>
                                                                                                             'p'-'-—-S    'd fl ^>     m  •&
                                                                                                             (HO.    o    rg°     MP

-------
106
cc      in ra 5
-2 •   TJ 4J V H
3lfi   «i e -e .9
          £S   S
                  1) d
                  C 4S
                3  o  .a
                0 -P  -P
                ^     r-4
                < T3  <&
                )  to a A +j  » •
                i  $ -H 3 a  a ai
                j  > +j p. •) -H a
                >    a  C -a 1-1
            Q|   -P as tn   u4-i     p y   B
          4>Q     tnW-d     O   ^"O*Hi-(
            «O   ^ 3^ D  >* M4J   -H H O
            *l   o a)  -P X) O           0)
                  •P   S3      0) O S O
            •v   rdw'3'didSi   *-* +* v a
          •ffil   hDUHh^aj   -g   ^ rH  M 0) ai   O I) S ^
          Col   S^wuS"tt   U3AD.C
                    w a -d

                i  S8|
     AS   3 3 ^ S -g S


SI  slal  d * M>a 1o (£

     •»S   hO'H'do^-i

"oj   ojSl  S"S
           i 43 •« p   w

           J a) -P O n 4)
                  O i-t O Si -H -H     83
                  •^ (t « jl -p S     «•*
                  U5SSS5 .   &i
                  al^!   -d i-l a 10   "-3
                  H o •-  Q
  ID   0^5.

+J Q S H 4^ -H

Sfleifi10

l^^is?
d -H o >   BJ

Vi U 41 ° "a -p
o to o o H a
  fl d -P i i)
u o 5   > a

•H -p "t S H Si
•d o g -p d d
3 d P< w -P a
-P EH Q a) O g
W 
                                                                   a t<  d T)  a w o
                                                                   3 p- S, cd  H :  p
                                                       i~H  r-l

                                                       •°  -2
                                                                              t ^a
                                                                              S -H o
                                                                                        -^   V I

                                                                                        III!
                                                                               |o"SI




                                                                               ,d o o j
                                                                               S en o i
                                                                                  H •- rj
                                                                                w>   >.•§. i
                                                                                0 "• (ft IB (
                                                                           t ^   ^ -e •? * '
                                                             84?
                               H •- aJ'~- (H (U
                               sjs .sal
                                                                            -
                                                                          «J ij
                                                                          So
                                                                   H   j
                                                                   Q    U

                                                                  I   &
                                                                                                                     &
                                                                                                                       v



                                                                                                                   col  o
                                                                                                                   CO   CJ
                                                                                                                         -.   .
                                                                                                                         Maj   -P -v
                                                                                                                 .        -pa   wa>^
                                                                                                               ^) ^—J^ d   D     o) 3  .
                                                                                                               H     O  ^rH C   iH d •-»

                                                                                                                                    "
                                                                                                                               PJ-H

                                                                                                                               •>!?>,
                                                                                                                     fl 3*
                                                                                                      H     ft)
                                                                                                      0-—   ft h 4J
                                                                                                      5^   „*!
                                                                                                      ^M   S t
                                                                                                      ^ d   rH S
                                                                                                      •) J3   -p v

                                                                                                      h   si

-------
                                                                                   107
»l
 -O (
•^ fe! (
°"A>
sr'

l\
  !§!!:
*
               Q1   1  -

              k   Jiis.
             IP   Sjl«
              •>«!   SSSfi
                   s,:
                   • S I
                   33 I
                   Saj
                   ss:
              o-lwl
               O

              
                                               -PO^H^I^O   4»«y-H
                                             U    CJ+iathO   H C  d
                                             dtjto-HH&rt     (dad.3
                                         joj      £ a a S.!p ^ 3 +5  0*1
                                         H    M»    b>igJt)-p(0  HH
                                     1 l!
                                        31 CJ
                                               H (3
                                               rH N
                                 11  gg
                                 a o    en
                                                i 0) a]
                                                I C N
                                        .  JS
                                               -PO  •
                                  •    IT
                                  s    II,
                                 S.H  S8
                                 "i  SB

                                 II  IS
                                                         .
                                      il
                                                       'ftg
                                      JI -. M    (-1  •   -PC'"



                                      d- 3l u> B  B -P o)   •H to
                                      \J SI >
                                  0 fl  S-;
                                  J 0)  *f -t
                                             «i

-------
108
                                           fl)  O
                                     w O,
                                    53

                                    I:
                                                                        8% S
                                                                    \SS
                                                                    1    ni
                                                                        SI
                                                                        i
                                                           Is]
                                                                       ) fll  *
                   !§•§

                   p fl a)
                   D a -p
                                                            id •D    ta 01
                                                            H C  ^ oJ  0)
                                                            h -^ £ ~~*

                                                            I -P H" a? w
                                                            ^ JH  ^ k -P E

                                                            cfl C  <    S §
                                                            flj H     -^ CJ
                                                            P. CJ  -.OR
                                                            ft d  QJ a o~
« CQ  S) >> b w Q
•-*   ^ fl  3 OJ P
•O ".  rt   43 05 Gl
   cy IH 4J  a
Ai O    5  S
O CO  W «) S  •

•P — -P a)  S.-P
M O  M S r-T 0)
   O  (U    O
C!   ,5 IH  & •- .
•H ••«  CO fll    ED
   t^j  aj H TJ d
^ o    s  5 o

w    t? S    "£ cal
& •*  a) r-i  w ai o
P- c -d o  a y oc
«3 N  H N  o p 9rl|
 >> - O > 1
^£i-S !
                                                                           SH O O
                                                                        rH 0) O rH -»
                                                                         -  " > (J  [
                                                                                                       J
                                                                                                                  I ^i  OJ C £>
                                                                                                                  J O  C O H (

-------
                                                                                                                          109
bi«a-pS^a*io
Cta3   -H t>, g Q rrj p.


"S  o -P   w 8)H -d H P.
D   -H 0) W D al a)
   to?og-pj^S)a3 >5

'S'g»gagS:Sc'?
   W 3 U  • -H        r

  -H   -p S-i 3  o cu O S
  -dXdJcflH-P-P-HC
   3CO)WococoMl

  -P3ritd,Sn3aJl)<
he

ve
health

generally

e of auto
Pu

me
^|fi

*"  H  D
ola
(H  ui
O  „  .

C  S  K

Igg
E.S  s

a«l3
•H,  n  m  '
cs o ic

tals particularly

tionable because
                         i  03 u

                         '5s,,
                           C ^ C_.

                           ^°l^

                          •°ft


                           »*
                           5.H
                           o «j  -.
                             w J-
facilit

See Tab

CLOTH,
pra

fac
See
o  w
S3
 '  H      wt
 1  o    o> <|
 :5    all

           HO        O -P    Cfl -p

           cdH-d   fHH^   ^Ht-


         cdfi    ^   £1 -i   O-i
         lU-rlrHfH   3HCHcc!   Hi
         >-HNi<3;o   ospHi-HCJO   oe
  0)  O 0) co





     affl O 3
     C r-t ^O
       ! £A
       IS g
                                                 h   &
                                          STf «      (
                                          3      O -J
                                          rH V( r( -P <
                                                       SI)  D
                                                       O  O
                                                          8O H
                                                          O  I
                                        da s
                                        •d o -P
                                        IIS
                                            CJ 4>  5 i-

                                          C C r.  O I

                                          O H 43  O I
         11 H •- -p cc

         -P H y 3   >d
         J3 CH O CO -d 01
         3"g x s .5 U
H -P        T) o a) !
,c oj      ro g    ,c i

o cu      £ o "S   -i



  2C O   Oi O O 01 !
  H^   W -P H ^ t.
                                                                               a^
                                                                               -H-P
                                        DBaiQ)            QC"-     3o
                                       -p • oj   Go 42            H^llcq     T3
                                       -PHX^f-iO            ^   cu-d   -^OC

                                        B " ••% (5   ^ly   \i?     H0'ocjo.pa.-H3'(
                                       ^OjCJH-   H   OJ      HHr.cdncfl   -POH






                                       ^ s S ^ i 11   ^      "t-g s ^ ^ -s ° •§f
                                       ^""gtg.^n £^i   SJ * > :: - 7c i
                                       oJ-d'-vOCRtQHHcQ
                                          0) C H -H D D 0-   --'
                                       -P^-rl 3Q)-PM(.
                                       S S &H 4? d a q
                                                   HhJoftK>6--'
                                                                                                   i
                                                                                                 ntC
                                                                                                 SCQ
                                                                                               -\lld
                                                                                              W-PU
                                                                              )Cca>lfH'MVl

-------
110

Discussion

        A detailed study of Tables 2k through 28 makes particularly evident the "work
sheet" aspect of the undertaking.  Some degree of inconsistency is unavoidable,
especially in connection with Columns 1 and 2.  For example, it is feasible to list
in Column 1 of Table 2h' the principal discarded objects which have some content of
metal, plastic, or wood, etc.  To make such a listing in Tables 25 and 27, however,
would require a tabulation of thousands of individual items produced by industry or
chemistry.  Consequently "Source" (Column l) in some tables is interpreted as types
of physical objects and in others as categories of material, sometimes resulting
from a particular process.  In relation to Column 2 of the tables the limitations of
the data can hardly escape the notice of specialists in individual industries.  For
example, the full spectrum of metals and compounds associated with paint and paint
manufacture, or of residues of the petro-chemical industry, certainly exceeds the
listing presented in the tables.  It is not so certain, however, that anyone can say
just which oxides of bivalent metals, or what less obvious compounds, would result
from burning the variety of possible wastes combinations under the several controlled
and uncontrolled conditions loosely classed as incineration.

        To a large degree the lack of quantitative data is due to the dearth of such
information in the literature and to the scale of effort which the project herein
reported could exert in any one aspect of the study.  This scarcity of information
should be somewhat reduced by the recently completed nationwide survey conducted by
the solid wastes program.  Fortunately, it is not necessary to complete the tables
in full detail to determine the course of action needed in research on the public
health aspects of solid wastes management.


        Research Weeds.  The foregoing limitations of the tables presented underscore
the need for two types of studies noted in Column 6 of the tables:

    1.  An accurate summary of the kind and amounts of individual materials or
        compounds, which occur in the wastes of each of a vast number of human
        activities, in terms of the unit of product produced.

    2.  A study of the nature and amount of conversion products resulting from
        wastes management processes, particularly incineration-

        Both of these, it will be noted, are not strictly public health research
concerns.  Instead they involve factors of technology, chemistry, process engineering,
and operation.  The results, however, would make necessary two types of health-related
investigations:

    1.  Medical evaluation of the health significance of some materials, and the
        level at which they are hazardous.

    2.  Environmental health studies of the possibility of exposure of man to
        significant concentrations of harmful materials resulting from solid
        wastes management practices; and of the measures necessary to preclude
        that possibility, with due regard to all other hazards of life.

        In some cases materials which occur in solid wastes have already been
demonstrated as toxic.  Thus, elements such as cadmium, lead, beryllium, and other
metals, although normally present only in trace amounts, should be thoroughly
followed from their entrance into the wastes stream until and including the time of
their final disposal.  The same should be done of other materials, which, in their
pristine state may be  innocuous enough, but when subjected to certain treatment
processes form toxic substances.  Plastics containing chlorine are a case in point.
When incinerated, such plastics are converted to volatile chlorine products highly
toxic in nature.

        A further review of the research needs cited in Column 6 of the tables leads
to several conclusions in relation to the role of public health research in solid
wastes management.

-------
                                                                                 Ill
    1.  Because disposal of the combined solid wastes of a community has not
        been undertaken except by landfill, which at best is monitored for
        surface evidence of nuisance and for vector control, a large research
        effort is needed to evaluate the nature and amounts of materials and
        conversion products which might result from community-wide solid
        wastes management.

    2.  Many of the components of wastes presently given limited attention by
        public agencies involved in solid wastes management are known to have
        health implications and are subject to public health control in other
        contexts.  Consequently it must be assumed that their presence in
        solid wastes is a matter of public health concern.

    3•  The urgent needs for research identified in the project herein reported
        would mostly not exist if health implications were ignored.   They do,
        however, involve a spectrum of scientific endeavor beyond that of the
        public health specialist, yet the results have little meaning without
        his interpretation.

    k.  In view of Items 1, 2, and J above, it is finally concluded that at
        the present time research teams on which environmental health specialists
        are prominent and active contributors are a particular need of solid
        wastes management research.  Later, the findings of such studies can be
        expected to identify specific areas for medical and other health-oriented
        studies per se_.


        Future Work.  Obviously the research needs cited represent a long-term
conclusive investigative effort, the results of which would fill out the gaps in
Tables 2k through 28, and perhaps correct any errors of fact to which these tables
are presently subject.  A more modest approach could also add to the usefulness of
the tables.  This would involve a restudy of the tables in the light of a recently
completed national survey of solid wastes by the solid wastes program of the
Department of Health, Education, and Welfare, together with a more intensive search
of the literature and other sources of specialized information concerning industrial
and commercial wastes production and products.

-------
                             VII.   ANAEROBIC DIGESTION
INTRODUCTION

        The application of anaerobic digestion to materials other than sewage sludge
alone is not a new concept in municipal wastes management.   Numerous  communities
have practiced some degree of dual disposal of garbage and sewage for many years as
a result of widespread use of the home garbage grinder.  This has resulted in a
significant reduction of the garbage fraction of domestic solid wastes without
disruption of the sewage treatment process.  The concept that other organic fractions
of the total refuse of a community might also be reduced in volume and stabilized in
this manner is, therefore, but one step beyond current practice.

        An integral and attractive aspect of this concept is the use  of hydraulic
transport.  Generally, existing sewer systems would be used with the  refuse being
ground into the sewers at points of origin or at central grinding stations.  Certain
materials such as metals, brick, and other high density inert materials would have
to be excluded, but the greater part of domestic, light commercial, and agricultural
wastes could be transported in this manner.  Experiments conducted by the Los Angeles
County Sanitation Districts demonstrated the efficacy of refuse transport in sewers.
The major difficulty encountered in the Los Angeles experiments resulted from the
fact that the sewage treatment plant was not designed to accept the added burden of
solids reaching it.  As one would expect, if refuse were to be transported by way of
sewers, existing treatment facilities would have to be expanded in terms of grit
removal chambers, primary sedimentation tanks, and increased digester capacity to
cope with the higher solids loading.


OBJECTIVES

        The studies of solid wastes disposal by anaerobic digestion reported herein
involved two major considerations:  l)  the efficiency of volume and weight reduction
achieved by the process, and  2)  the effect on the process of a given wastes
material, i.e., retardation of digester performance because of the presence of toxic
substances or through the promotion of unfavorable environmental conditions.  From
the standpoint of practicality of the method the toxicity consideration is of primary
importance, since facilitation of solid wastes transport is sufficient justification
for grinding to sewers, regardless of whether or not there is the added benefit of
solids reduction by the ensuing anaerobic digestion process.

        In large metropolitan areas served by several sewage treatment plants, it
might be expedient to discharge a disproportionate quantity of solid wastes to one
plant.  For this reason, experiments were designed to cover the broad range of
loading possibilities.


THE INVESTIGATION


Introduction

        The effect of a variety of solid wastes on digester performance has been
studied to date, including materials such as garbage and paper which are already
present to a degree in raw sewage sludge.  Here the purpose was to determine loading
limitations in terms of sludge-refuse ratio and solids concentration.  Other wastes
fractions not normal to sewage sludge also were studied during the period covered
by this report.  These included Monterey pine wood residues and chicken manure.
Wood was selected because it is a component of demolition rubble.  The manure was
                                        112

-------
                                                                                  113
combined with paper to investigate the possibility of constructing special digesters
intended solely for treating solid wastes, especially the vast quantities of animal
manures which are rapidly becoming an urban rather than an agricultural wastes
problem.  This state of affairs is an outgrowth of the trend toward industrialization
of meat., egg, and milk production in or near metropolitan centers.  Industrialization
involves the heavy concentration of animals in confined areas to maximize production
efficiency.  In egg production enterprises it is not uncommon for a hundred thousand
hens to be in one building, with each hen producing 0.2 pound per day of a highly
malodorous and unstable waste•

        Investigations by Hart [TO] have shown that while dairy manures are digested
poorly, chicken manure is readily amenable to the digestion process.  Since chicken
manure is a nitrogen-rich waste, the possibility of digesting it in combination with
a carbonaceous waste, paper pulp, was investigated.  Although chicken manure could
be treated in conventional sewage treatment plants, its high concentration of water-
soluble organics would divert much of the BOD to the liquid stream of the process.
Water quality considerations, therefore, dictate the desirability of charging the
wastes to a solid wastes digester.  Development of an adequate disposal method for
handling the paper and chicken manure fractions of solid wastes would go far toward
the alleviation of the total refuse treatment problem, since paper constitutes about
50 percent of domestic solid wastes, and chicken manure is one of the more offensive
materials to be treated.
Development of Equipment
and Procedures

        Several modifications were made in the apparatus described in the First
Annual Report.  The incubator shown in Figure 3 was equipped with new thermoregulator
(control shown in top center)-  Heavy-duty industrial magnets (4 in. by 1 in.) were
substituted for the small laboratory magnets attached to the mandrels of the mixing
system.  This substitution made it possible for the flat-bottom plastic "pigs" (l-gal
capcity) containing magnetic stirring bars to be used as effective reactors for
mixed-culture digestion (see Figure 4).  Mixing was controlled by a repeat-cycle
timer set for 1-5 minutes of operation out of each hour.  A battery of eight reactors
was set up, of which four were equipped for mixing.  The four units not equipped for
mixing were l-gal glass jugs.  Each reactor was connected by a stainless steel gas
line to an individual liquid displacement-type gas collector (see Figure 5), and
the four inverted tube gas collectors previously in use were discarded.  Advantages
gained by these changes included the elimination of gas diffusion through collection
tubing, increase in accuracy of gas volume measurements, and improved mixing in
reactors.


        Preparation of Raw Materials.  Materials were prepared in sufficient quantity
for an entire experiment and in a manner to facilitate constant loading at a desired
volatile solids strength.  Preparation of garbage and sewage sludge was as described
in the First Annual Report.

        The paper source was a bleachable grade of kraft paper pulp used in the
manufacture of brown wrapping paper, paper bags, etc.  This material, which was
supplied by Fibreboard, Inc., is representative of plain paper, i.e., paper not
containing newsprint or dye.  Moist paper pulp (3^-^ percent dry weight) was stored
at 2°C in polyethylene bags.  Its carbon concentration was h-^.6 percent (dry weight),
and its cellulose content, 99-8 percent (dry weight).

        Air-dried chicken manure obtained from a nearby egg-production ranch was
screened to remove feathers and rocks, and then ground to a fine powder in a Waring
blender.  The powder was packaged in polyethylene bags and stored at 2°C.   Chemical
and physical analyses of the manure gave the following results:
  388-229 O - 70 - 23

-------
FIGURE  3
INCUBATOR WITH  CONTROLS  FOR STIRRING
SYSTEM AND TEMPERATURE

-------
                                                       115
FIGURE  4
DIGESTER UNIT  AND STIRRING  SYSTEM WITHIN
THE INCUBATOR

-------
116
  FIGURE  5 .   DIGESTER  G-AS COLLECTION  APPARATUS

-------
                                                                                  117

                      N  (dry weight)                  =  3-2/o
                      C  (dry weight)                  = 23-4$
                      Moisture                        =  9.8%
                      Volatile Solids  (dry weight)    = 56.2/0
                      Inorganic Material  (dry weight) = ^3-8^

 The unusually high  inorganic content reported in the analysis was due to the presence
 of a  large quantity of soil in the manure .

        The Monterey pine wood was supplied "by the Forest Products Laboratory of the
 University of California Richmond Field Station.  Wood chips obtained from a young
 tree  (containing  little heartwood) were ground in a Wiley mill to a fine powder.
 The powder was  stored at room temperature.  Analyses of this material gave the
 following results :

                       N (dry weight)               =  0.
                       C (dry weight)               = 50.
                       Cellulose (dry weight)       = SO.
                       Volatile Solids (dry weight) = 99-
                       Moisture                     =  7-
        Analyses .  Total and volatile solids, volatile acids, and alkalinity were
measured as described in the First Annual Report.  However, the gas analysis
procedure was altered by normalizing the methane and C02 measurements to 100 percent,
and eliminating  Os and Na values.  This was done because tests demonstrated that
virtually all the air present in the collectors resulted from contamination during
feeding and was  not a product of digestion.  Furthermore, air was expelled from the
digesters within ten minutes after feeding, so interference with the digestion
process was negligible.

        For evaluating properly the fate of added paper and wood materials in the
digestion process, cellulose determination was considered to be of the most signifi-
cance .  Because  methods described in the literature proved to be unsuitable from
the standpoint of reliability when applied to raw and digested sludge, a major effort
was made to develop a method of cellulose analysis which would be accurate and
reasonably rapid.  To do this, a variety of test procedures was investigated until
a method capable of effecting over 95 percent recovery in the presence of both raw
and digested sludges was attained.  This procedure and the recovery tests are
described in Appendix H.  Tests indicated that more than 98 percent recovery was
achieved from raw sludge media when the added cellulose was in the form of small
pieces of paper  pulp.  Cellulose added in the form of finely divided powder could
not be recovered to the same extent.  In that case losses of 12 to 15 percent were
noted, and were  attributed to the centrif ugation step in the procedure .   However,
cellulose rarely would be expected to be present to an appreciable degree in the
form of minute particles either in normal sludge digesters or in "solid wastes"
digesters.  No problem was encountered in the recovery of cellulose added in any
form to digested sludge .

        The high degree of precision of the technique in determining the  background
cellulose content of digested sludge was indicated by a coefficient of variance (Cv)
of 2.91 percent.  In the recovery of added cellulose, the Cv was  found to be  7-0
percent.  For half -strength sewage sludge media,  the  background Cv was 1.6l percent.
Added paper pulp was recovered at a Cv of 3.63 percent.  For full-strength sludge the
background Cv was 3-53 percent in one test and 2.87 percent in another.   In the latter
test,  added cellulose powder was recovered at a Cv of 2.28 percent.


Experimental Series I :  Addition of Green
Garbage to Acclimatized Sludge Digesters

        The investigation of garbage digestion was pursued along two lines :  l)
determination of the maximum proportion of garbage that could be mixed with sewage
sludge and successfully digested; and  2)  determination of the maximum quantity of

-------
118
garbage in terms of total pounds of organic material (garbage and sludge) that could
be digested per cubic foot of digester capacity per day.  The first line of investi-
gation was further divided into two aspects — shock loading to digesters not
acclimated to large quantities of garbage, and gradual acclimatization of digesters
to this material.

        In the research reported in the First Annual Report, an experiment was
described in which green garbage was fed to unacclimated digesters.  It was found
that mixtures of up to 76-5 percent garbage and 23-5 percent sludge did not interfere
with normal digestion.  Richer mixtures than this caused failure within 11 days.


        Procedure.  Studies described in this report were performed with the use of
digester cultures which had survived the first year's experiments and which were
gradually acclimated to heavier dosages of garbage.  The proportion of garbage in
the feed was increased by increments over a two-week period to 80 percent in one
digester (Unit 2) and to 83.4 percent garbage in another (Unit 3)-  These values are
equivalent to garbage-sewage solids ratios of 4:1 and 5:1-  loading at these levels
proceeded for one month and was then increased to 90 percent garbage fed to Unit 2
and 100 percent garbage to Unit 3-  Total volatile solids loading to these digesters
and to the control (Unit 1 — fed 100 percent sewage sludge) was 0.077 pounds per
cubic foot of digester capacity per day.  This schedule was followed for 60 days.

        With the completion of the investigation of the relationship between ratio
of garbage to sludge on digester performance, the study was directed to the deter-
mination of the effect of increasing total loading (quantity).  The volatile solids
loading was increased incrementally over a three-week period, i.e., until the
loading was doubled (0.154 pounds per cubic foot of digester capacity).  The
proportion of garbage, however, was kept at the previous level.  These conditions
were maintained for the succeeding two months or two detention periods.  During this
period, a comparison was made between the effect of mixing and not mixing.

        The final step in this stage of the investigation was the making of an abrupt
shift from a dosage consisting entirely of garbage to one of raw sewage sludge at
the original loading of 0.077 pounds per cubic foot of digester volume per day.  This
step was carried out to determine the reaction of the digester cultures to a sudden
change in the nature of the material fed to it.


        Results.  The most notable result in the series of experiments was the
ability of acclimated digesters to accept high proportions of garbage up to and
including 100 percent garbage feed.  As is shown in Figure 6, the efficiency of
garbage digestion was almost as high as that of sludge digestion; i.e., l4 cubic
feet of gas produced per pound of garbage volatile solids destroyed, as compared to
15 cubic feet per pound of sewage sludge volatile solids.

        The garbage-fed digesters proved to be capable of handling greater loadings
of organic volatile solids than did the sludge-fed digesters.  Thus, by the time the
loading rate had been doubled, the garbage-fed digesters were continuing to perform
satisfactorily, whereas the sludge-fed digesters had failed.  At the rate at which
the loading was increased, about 20 percent each third day, the control (sludge-fed)
failed during the second week when the dosage had reached 14-0 percent that of the
initial loading.  At that time, the efficiency of the garbage-fed digesters had
declined somewhat, but soon thereafter it was back to the previous level.  The
digester receiving a dosage consisting of 90 percent garbage had an efficiency about
10 percent higher than that of the unit fed solely on sludge.  However, the efficien-
cies of the two became roughly about equal when both were mixed hourly (the 14-3
day of the  experiments).

        During this stage of the study, photomicrographs (Zeiss 1600 X) were made of
the cultures.  The morphological types found in the cultures are shown in Figures 7
(sludge-fed digester) and 8 (garbage-fed digester).  Judging from the  greater variety
of morphological types found in the garbage-fed cultures, the diversity of species
was greater in it than in the sludge-fed digester.  For example, the culture receiving

-------
                                                                        119
o
<
Q,
<
O

or
en
LU
3
O
V)

O
O
>
o
z

Q
<
O
!£  UJ
                                                            O

                                                            I-
                                                            (/)
                                                            LLl
       LU
       O
       <
       CD
       o:
       <
       o
                                                            LU
                                                         M  LU
                                                         2T  K
       o
       z
       LU

       o

       u_
       Lu
       LU


       <£>

       LU
       £T
       ID
       CD
        Q3AOaiS3Q SQHOS 3-lllVlOAqi  / SV9

-------
    120
  FIGURE  7
  MORPHOLOGICAL VARIETY OF MICROORGANISMS
  FOUND IN THE DIGESTER CULTURE FED ENTIRELY
  ON SEWAGE  SLUDGE
FIGURE  8
MORPHOLOGICAL VARIETY OF MICROORGANISMS
IN THE DIGESTER FED ENTIRELY ON GARBAGE

-------
                                                                                 121
garbage was characterized "by an abundance of filamentous spore-formers having long,
rod-shaped configurations.  None were to be found in the sludge-fed digester.  The
population observed in each field was related to amount of loading, in that units
receiving double the loading to the control (Units 2 and 3) had cell counts almost
precisely twice that of the control.

        Because of the apparent magnitude of the diversity of species in the garbage -
fed digesters, it would be likely that their populations would be sufficiently
flexible to cope with sudden changes in nature of and strength of dosage.  This
proved to be the case, in that the unit fed nothing but garbage (Unit 3) for 150 days
showed no unfavorable reaction when the dosage was suddenly switched to 100 percent
sludge on the 151st day and thereafter.

        According to the curves in Figure 9> i-n which are indicated total and volatile
solids reductions during the course of the experimental run, the rates of destruction
of solids were about the same in all three digesters, namely, about 65 percent
destruction of volatile solids, and 50 percent of the total solids.  These values
are comparable to field results for sludge digestion, and are indicative of a quite
satisfactory weight and volume reduction of the garbage solids.  The rate of reduction
in the control dropped only when its failure to function became imminent because of
overloading.  It also dropped when, toward the end of the run the rate of loading was
decreased abruptly.  However, instead of showing an immediate and matching decline,
the solids reduction was unusually great during the days directly following the drop
in dosage rate.  This phenomenon undoubtedly was due to the large residual bacterial
population remaining from the period of heaving loading.  Solids reduction became
"normal" after the population shrank to the size supported by the lower dosage.

        The ability to maintain a favorable acid-base equilibrium (Figure 10) probably
enabled the garbage-fed digesters to adjust without adverse effect to heavy loadings.
Initially, their alkalinities were almost double that of the control (5500 rag/2
compared to 3000 mg/£), thus indicating a much higher buffering capacity.  When the
organic loading was increased, volatile acid production rose significantly.  This
increase was readily buffered in the garbage digesters and was accompanied by a rise
in alkalinity to more than 9000 mg/£.  The net result was that the increased acid
concentration was more than offset, and in fact the pH level increased from 7-5 to
7-8.  No such response was observed in the control.  Instead, the pH level dropped
and the digester failed.  It is interesting to note that when the feed rate was
returned to its original level (0.077 pounds per cubic foot per day) on the iSo^h
day of the run, the acid-base equilibrium in the garbage-fed digester soon dropped
to its original level.  These data suggest that feeding large quantities of garbage
to anaerobic digesters would establish no irreversible condition.  This characteristic
would allow for flexible digester loading on a day-to-day "basis in terms of "both
proportion and quantity.

        The effect of green garbage loading on the composition of gas produced by
the digester is shown in Figure 11.  The normalized values indicate that the gas
from the control contained 65 percent methane and 35 percent C02.  The fuel value
of the garbage-fed digester gas was somewhat lower; its methane content was about
7 percent lower than that of the gas from the sludge-fed digester, and the COa
content was correspondingly higher.


        Conclusions.  On the basis of the results of the experiments, it may be
concluded that acclimated digesters may be fed 100 percent garbage and will perform
similarly to normal sludge digesters in terms of solids reduction.  Garbage digesters
are highly adaptable to varying proportions and quantities of feed, in fact more so
than are sludge digesters

-------
122
 o
 <
 a.
 <
 o

 a:
 UJ
 i-
 CO
 O

 _J

 O
 CO
   If
        o
        6
        it
        in
 CD
 roj

10 dt
CJ
       CO-
  z

  Q
  h-
  i^-
  o
  o
                  8
                            
-------
                                                                                 123
o

2

-------
   12U
to
o
O
(0
5
Q
<
O
       r-
       Is-
       O
       O  -
o
<
0.
<
o

1C
UJ
"'    O)
UJ    ro;
o    —h
-   ro°
Q   c\J|—

£   °oo -«-


3    ^_L
    rdO _ _
sh
o
       O
       o
                                O
                                •3-
                                        O
                                        PJ
o
00
o
r-
o
(D
                                                                                    o
                                                                                    co
                                                                                       10

                                                                                    o  o
                                                                                               O

                                                                                               O
                                                                                               z

                                                                                               Q
                                                                                               <
                                                                                               O
                                                                                               CO
                             ul  JJO

                             ±   UJ h-
                                                                                               \- o
                                                                                               o o
                                                                                               U-
                                                                                               UJ
                                                                                               o
                                                                                               u_
              %'30ixoia
                                                             % '3NVH13W

-------
                                                                                 125
Experimental Series II:  Digestion
of Paper Pulp


        Procedure.  The experiments on the digestion of paper pulp were designed to
test the digesters over a range of loadings sufficiently vide to establish the
maximum proportion which could be efficiently digested in combination with sewage
sludge.

        Four units were operated initially as "normal" sewage sludge digesters on
a theoretical detention period of 30 days.  At the end of the 30-day period,
feeding with pulp was  initiated.  The proportion of paper in the dosage was increased
incrementally over a three-week period until the following proportions were reached:


             Unit A (control) =  100$ sewage s ludge,  o$ paper pulp
             Unit B           =   50% sewage sludge, 50$ paper pulp
             Unit C           =   ^-0$ sewage sludge, 60$ paper pulp
             Unit D           = 31.8$ sewage sludge, 68.2$ paper pulp

This feeding program was followed for the remainder of the experiment — a period of
four months.


        Results.  Since, as previously noted, the paper pulp was essentially pure
cellulose, the best indicators of extent of digestion were those results pertaining
to destruction of cellulose.  The contribution of sewage sludge to the total cellulose
input was determined by taking weekly measurements of the cellulose content of the
sludge feed.  As shown in Table 29, the average cellulose content of the feed was
35-6 percent of the dry weight total solids.  Despite the need for using several
batches of sludge during the course of the experiment, the cellulose content remained
remarkably constant.   The respective amounts of cellulose contributed by the sludge
and by the paper pulp  in the daily feed are given in Table 30-

        The extent of  the destruction or degradation of the incoming cellulose and
the concentration of the residual cellulose in the digester sludge (g/100 m£) are
indicated by the data  in Table 31.  The results demonstrate conclusively that the
test digesters could use paper pulp as a substrate and digest it without any observable
adverse effects.  In digesters B (equal parts sludge and paper) and C (kO parts sludge
and 60 parts cellulose), destruction averaged more than 90 percent.  The residual
cellulose per total solids in the two units was only 17 to l8 percent, an amount
which was only very slightly higher than the 15 percent residual in the control.
Judging from these facts, the addition of sizable quantities of paper pulp would
have but little residual effect on the characteristics of anaerobic digester sludge.
Unit D (32 parts sludge to 68 parts pulp) ultimately failed for reasons which will
be discussed later.  However, prior to its failure, it was quite efficient in
breaking down the incoming cellulose.  The high rate of cellulose destruction
(80 percent) in Unit A, the control, indicates that normal sludge digesters are also
highly efficient in degrading cellulose.

        The extent of cellulose and volatile solids reduction, as well as amount of
gas produced per pound of volatile solids destroyed, are plotted in Figure 12.
According to that figure, volatile solids reduction in the digesters fed paper was
more extensive than that in the control, namely, an average of about 75 percent in
the former and 65 percent in the latter.  However, if efficiency were to be measured
in terms of gas production,  the control would be superior.  On the basis of gas
production per unit of volatile solids destroyed, gas production dropped as the
proportion of paper was increased.  According to Table 32, the average values were
15.1 cubic feet for Unit A (100 percent sludge), 12-9 cubic feet for Unit B (50
percent sludge — 50 percent paper), 12.1 cubic feet for Unit C (k-0 percent sludge —
60 percent paper), and 11.1 cubic feet for Unit D (32 percent sludge — 68 percent
paper).

-------
126
                                     TABLE 29

                  CELLULOSE CONTENT OF PRIMARY SLUDGE FEED DURING
                      PAPER PULP DIGESTION EXPERIMENTAL RUNS
Day
50
57
6k
71
78
85
92
99
106
113
120
Avg.
Influent Primary Sludge
Cellulose
g/100 m£
1.716
1.856
1.964
2.032
1.680
1.832
1.212
1.788
1.464
1.632
1.916
1-736
Cellulose/Total Solids
%
36-5
39-5
4i.9
42.2
33-1
40.1
23.2
39-2
30-5
35-4
32.0
35-8
                                     TABLE 30

                       DAILY INPUT OF CELLULOSE TO DIGESTERS
To
Unit
A
B
C
D
Cellulose Added, g
From Paper Pulp
0
1.735
2.082
2.369
From Sludge Feed
1.736
0.868
0.690
0-552
Total
1.736
2.603
2.772
2.921

-------
    «
    e
    ra
    n
NA     0

W  O
M  H ?H
PQ  EH cu
,
S
^ °J -* ^ , ,
CO LT\ J- Ol
CJ CO CM -d-
co OJ UA j-
VO C— LTN Q\
CO CO CO C—
LT\ l/N J- OJ
CO t~- -O\CO
CvJ i-HrHHHCOCvlrHrHHH
b-COCOOLr\Lr\CMONHCr\H
CO H^fN^OOr-IOCXJOH
co a\a\a\o\o\o^a\o^o\o\
CvJ C— O K^CVI-d-J- KAOArOCO
H CX1VD CTNVOVDJ- UAH UA-^-
h^CVIHHCVICMOlCVIaJCvJCvl
ooooooooooo
CO MD O\ Lf\ L— O -d" UAl/NVDi-H
C— C— J- _4- UAVD MAC— UAI^CO
HHrHi-Hi-IHCVIHHHiH
OA^t-J- t—t--V£) OJ OAVDJ- O
OAOAOrHOOcOOHONO
COCOOAC^OAOACOOAOACOOA
NAUDrHC— C\JJ-t~-COCOf— H
VD t — Lf^rH^-_^- O f^rHO-VD
cvJaJaJaJOJCvl^-O OCO OAOANAJ-
LlAKAM-\CYINAr^OjOJOJNANA
OOOOOOOOOOO
Otr—J-i— lcDL(AOJO>VDNAO
UALTNVOt— [— 00 OAOAO H OJ
H H H
H
6
KA
L^
j-
co
c~
.4-
-d-
0
H
CO
H
_*
H
0\
-^
VO
CV|
0
H
f~-
H
K\
O
OA
^t
UA
OJ
O
OJ
UA
H
H
H
CO
QA
OJ
K^
O
&
<,
                                                                                                                    127

-------
128
o     o
CTl     00
                     O
                     r--
in

00
O
cj
                                                                             8
                                                                             S
                                                  U)
                                                  >.
                                                     z
                                                     o

                                                     >-
                                                     CO
                                                     UJ
                                                     o
                                                                                    cr
                                                                                    UJ
                                                                                    Q.
                                                                                    b.
                                                                                    O
                                                                                    U
                                                                                    z
                                                                                    UJ

                                                                                    o

                                                                                    ul
                                                                                    u.
                                                                                    UJ
                                                                                    OJ
                                                                                    UJ
                                                                                    a:
                                                                                    Z)
       % '
                                NOI10nQ3d  S A
                             03X081530  'S'A
                                Ql  / SV9 i^ no

-------
                                                                                      129
                                        TABLE 32




                          EFFICIENCY  OF PAPER PULP DIGESTION
Day
4
11
15
18
22
25
29
32
36
39
43
46
50
53
57
60
64
67
71
7V
78
8l
85
88
92
95
99
102
106
109
113
116
120
Avg.
cu ft Gas Produced/Ib Volatile Solids Destroyed/ day
Unit A
100$ Sludge
15.1
15-1
14.6
15-8
19.0
15-6
16.0
16.2
14.8
15-8
15-2
15-2
15-3
14.2
15-8
17-0
16.3
16.0
15-7
15-2
13-9
14.1
14.1
14.2
13-6
15-6
14.6
15-1
Ik. 9
14. 7
14.2
11-9
12.6
15-1
Unit B
50$ Sludge -50$ Paper
13-1
12.0
10.8
11.0
11.9
11.8
12.4
12.5
12.4
13.8
15-5
14.7
14.0
13-9
12.8
12.1
14.6
14.4
12.9
12.8
12.1
12.2
11.8
11.6
15-3
15-7
12.8
14. 3
11-5
12.2
13-0
11.2
11-3
12.9
Unit C
40$ Sludge -60$ Paper
13-5
10.5
10.0
10.2
10.8
11-3
11.7
11.7
11-7
12.6
13-1
13-2
13-3
12.9
12.9
12-9
11.9
12.0
11.1
11.0
13-4
13-9
11.8
11.8
12.6
13-0
12.5
12.0
11-9
11-9
12.7
11.0
11.4
12.1
Unit D
32$ Sludge-68$ Paper
12-5
10.4
9.9
10.1
11.0
11.0
11.2
11.2
11.1
11.8
12.1
12.4
11.9
11-7
11.2
10.0
9-5
















11.1
388-229 O - 70 - 24

-------
130
        Data concerned with reduction in total solids are presented in Table 33.
According to the data, a weight reduction of almost 70 percent occurred in the
digesters which received paper.  Since the residual solids were shown by the cellu-
lose determinations to have been derived almost exclusively from the sludge portion
of the feed,, the digesters must have been very effective in accomplishing the
destruction of the paper portion of the feed.

        The relation between feed composition (i.e., sludge-to-paper ratio) is shown
by the slopes of the curves in Figure 13, in which is plotted change in alkalinity
that occurred during the course of the experiment.  The alkalinity in Unit D (32 parts
sludge to 68 parts paper) dropped very rapidly and when the level reached 800 mg/,0,
the culture failed.  Although the alkalinity in Unit C (ho parts sludge to 60 parts
paper) also dropped, it leveled off at 850 mg/£ and continued at that level without
any obvious inhibitory effect on the digester.  Judging from these results, the
ratio of ^0 parts sludge to 60 parts paper approximates the critical ratio.  However,
since the biological effects of this proportion of paper to sludge are due to the
C:N ratio (^5:l) resulting from such a mixture rather than to anything intrinsic to
the ingredients themselves; any increase in the nitrogen content of the sludge or
through some additive could result in a higher permissible proportion of paper to
sludge.

        The critical pH level associated with the safe operating level of alkalinity
of 800 mg/,0 (as carbonate) apparently was 6-5, inasmuch as Unit C functioned success-
fully during the latter half of the experimental period at a pH of 6.6 to 6-7-

        The effect of paper pulp loading on gas composition is shown by relative
positions of the curves in Figure l4.  As was observed in the experiments on garbage
loading, a shift took place from methane to COs production.  The normalized values
show that the gas from the digesters fed paper averaged 65 percent methane, approxi-
mately 5 percent less than that from the control-  No significant differences were
noted between the gas compositions of the three test units.


        Conclusions.  In terms of weight and volume reduction, the digestion of paper
pulp proved to be an effective means of disposing of that material, inasmuch as the
degradation of its cellulose content was as much as 90 percent.  Loading with respect
to paper should not become critical until the percentage of paper exceeds 60 percent,
i.e., until the resulting C:N ratio exceeds ^5:1.  Failure occurred in the experiments
when the paper-to-sludge ratio was 68 to 32, at which stage the C:N ratio of the
feed was 52:1.


Experimental Series III:  Digestion
of Combined Solid Wastes

        The effectiveness of combining different types of wastes materials and
digesting them in special "solid wastes digesters" was evaluated in experiments
involving the use of chicken manure and paper pulp.  The carbon-to-nitrogen ratio
was investigated over a broad range to determine the maximum quantity of paper
that could be disposed of with a limited amount of chicken manure.


        Procedure.  Three digesters were used in these experiments.  Three liters
of digesting sewage sludge, obtained from a nearby treatment plant, were placed in
each of the units to serve as starting cultures.  One digester, Unit 6, was made
to serve as a control-  It received 100 rn£ of sewage sludge daily.  The other two
digesters were gradually acclimated to receiving a feed having the proportions of
chicken manure and paper pulp suited to the needs of the experiment.  The period of
acclimatization lasted 16 days.  During the initial phase of the experiment
(ll8 days), the proportions were as follows:

-------
                                                                   131
                       TABLE 33




PERCENT TOTAL SOLIDS REDUCTION IN PAPER PULP DIGESTION
Unit A
087 100$ Sludge
1* !*7-5
11 1*8.1*
15 1*9.2
18 H.l
22 37-3
25 1*5-7
29 W.8
32 46.0
36 1*7-2
39 1*3-8
1*3 1*6-2
1*6 1*6.2
50 1*5.8
53 1*6.0
57 1*5-0
60 1*1.8
64 1*8.2
67 1*9-3
71 55-8
71* 57-6
78 56-3
8l 55-1*
85 55-^
88 55.0
92 1*5-5
95 1*1*. 8
99 1*1*. 8
102 1*3.2
106 1*5.0
109 1*5-6
113 1*8.5
116 61* . 5
120 61* . 1
Avg. 1*8.7
Unit B
50$ Sludge-50$ Paper
72.0
70.0
69-1
66.8
66.2
66.1*
65-1*
61*. 7
67-3
62.1*
59.1*
62.1*
61.5
61.7
61.7
65-1*
61.3
61-9
67-5
68.2
69.2
68.2
66.3
67-5
59-2
57-6
59-6
53-5
62.8
59.1*
61.3
75-1
71*- 6
61*. 7
Unit C
1*0$ Sludge-60$ Paper
75-2
75-2
75-0
71-9
71*. 3
71-0
69-5
70.0
71-9
66.2
66-9
66.1
63-7
65-9
66.2
65-9
65-7
65.2
70-6
71-3
70.0
67-6
69-8
69.8
62.2
60.5
61.6
61*. 3
63-1
63-1
62.0
75-1
73-9
68.2
Unit D
32$ Sludge-68$ Paper
79-2
79-7
78.1*
76.3
75-0
71*. 7
71*. 3
71*. 3
71*. 7
69-6
70.1
68.7
65-5
66.7
61*. 5
72.0
61*. 3
















72.2

-------
132
 o
 o
 m
 ro
O
O
O
ro
                                       \

o
o
             CO
o
o
o
C\J
o
o
IO
o
o
o
o  o
o  o
in  
-------
                                                                                  133
               '/A
^  OQ (J (7^

t  111
Z  Z Z Z
                 O
                 ro
                       O
                       CM
O
00
                                                       \\
O
to
                                                                           o
                                                                           CJ
                                                                           §
                                                                           o
                                                                           oo
                                                                         £
                                                                                   o
                                                                                   o.
                                                                                   (O
                                                                                   <
                                                                                   o
                                     z

                                     o

                                     o
                                     _J

                                     0.
                                                                           °  J   £
                                                                              2
                                                                           o
                                                                           in
                                                                           O
                                                                           «3-
                                                                           O
                                                                           fO
                                                                         o
                                                                         C\J
                                                                                   Q.
                                                                                   <
                                                                                   Q.
                                                                                   U

                                                                                   UJ
                                                                                   U.
                                                                                   U.
                                                                                   UJ
% ' 3QIXOIQ
                                                    % '3NVH13W
UJ
(C
D

O

-------
              .,        Chicken Manure        Paper Pulp
            UtlJ-T'             rl                   rl             C :
              7             50                  50

             12             30.7                69-3

            During the succeeding ^2 days the proportions were changed to:

              7             28.8                71.2           65:1

             12             27.2                72.8           70:1

            In the final phase (kk days) Unit 12 was fed:

             12             25-7                74.3           75:1

         Volatile solids loading remained at 0.077 pound per cubic foot digester
capacity per day throughout the course of the experiment.


         Results.  The efficiency and performance of all digesters during the initial
phase of the experiment was quite satisfactory.  This is indicated in Figure 15, in
which gas production is plotted in terms of volume per liter of culture and volume
per unit weight of volatile solids destroyed.  Generally, volume of gas production
in the control was 10 to 20 percent greater than that in the "solid wastes"
digesters, but the volume per pound of volatile matter destroyed was about the same.
These results indicate that although the volatile solids were destroyed at a slower
rate than those in the control, on a "per pound" "basis gas production was comparable
to that in the control.

         A similar trend was noted during the second phase (days 117 to 167) of the
run, during which time the carbon-to-nitrogen ratios were increased in Unit 7 to
65:!, and in Unit 12, to 70:1-  These results are surprising in view of the fact
that conventional sludge digesters generally fail at C:N ratios higher than 50:1.
The reason for absence of inhibition in the "solid wastes" digesters may have been
the resistance of the manure to decomposition, and the consequently gradual release
of carbon.  Thus, carbon may have been only slowly available for bacterial metabolism,
and as a result the effectual C:N ratio may have remained at a satisfactory level,
even though the absolute level was higher than that normally permissible.

         In the final phase of the run, in which the C:N in Unit 12 was increased to
75:1, volume of gas production and volume per pound of volatile matter destroyed
were adversely affected.  That the culture was not functioning properly at this
loading is apparent from Figure 15, but the magnitude of the difficulty is better
realized from the change in acid-base relationships involved.  As shown in Figure 16,
the volatile acids production soared to more than 2000 mg/,0 and the pH dropped to
6.0.  This condition, of course, was severe enough to cause digester failure.

         Although most of the parameters of digester performance would indicate that
Unit 12 was functioning properly when the C:N of its feed was 70:1, it is highly
uncertain that the condition would have persisted under a prolonged dosage at this
C:N level.  The alkalinity results cast a measure of doubt on the possibility of
the continued successful functioning of the experimental digesters operated at both
65:1 and 70:1, since their alkalinity concentrations continued to decrease throughout
the 50 days of the second experimental phase.  If the decline were to have continued
at this same rate in the two digesters, the critical level of 750 to 800 mg/J
alkalinity would have been reached after an additional three to four months of
operation.  However, it is more than likely that the two units would have stabilized,
as occurred in the experiments on paper digestion.  The alkalinity of the two units
was considerably above the lowest permissible level at the time the feeding program
was changed.

-------
                                                                                                135
o  o
ro  co
                            1      T

                                                                                       CSJ
                                                                                       O