PB-236  543
A STUDY OF  PNEUMATIC SOLID WASTE  COLLECTION SYSTEMS
AS EMPLOYED IN HOSPITALS
ROSS HOFMANN,  ASSOCIATES
PREPARED  FOR
ENVIRONMENTAL PROTECTION AGENCY


1974
                             DISTRIBUTED BY:
                             National Technical Information Service
                             U. S. DEPARTMENT  OF  COMMERCE

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BIBLIOGRAPHIC DATA
SHEET
  lii Ir and Sulu ulc
1. Report No.

       EPAZ*i3Q/SW- 7tic
PB   236   543
        l\ Study of PNEUMATIC  SOLID VIASTE COLLECTION  SYSTEMS
        As Employed  in Hospitals
                                               5-.Report Date
                                                       1974
                                               6,
 Autliorfs )
     Ross Hofmann,  Associates
                                               8< Performing Organization Kept.
                                                 No.
 Performing Organization Name and Address
     Ross Hofmann,  Associates
     2908 Salzedo
     Coral Gables,  Florida  33134
                                               10. Project/Task/Work Unit No.
                                               11. Contract /Grant No.
                                                    EPA-68-03-0300
12. Sponsoring Organization Name and Address
     U. S. Environmental  Protection Agency
     Office of  Solid Waste Management  Programs
     Washington,  D.  C,  20460
                                                13. Type of Report & Period
                                                  Covered

                                                    Final
                                                14.
15. Supplementary Notes
16. Abstracts
  This report  summarizes a study that  assesses the technical  and  economic feasibility
  of pneumatically transporting hospital  solid waste.  Three  hosnitals employing
  pneumatic  collection systems were  surveyed.  Variations  in  systems design and
  utilization  were investigated and  reported upon.  Cost  information was accumulated
  and analyzed for each hospital.  Operational, oerformance and environmental analyses
  were performed for all systens involved.  This report should be helpful to hospitals
  already  employing pneumatic systems  from the standpoint  of  ootimizing operating
  procedures and should be further helpful for new installations  from a design
  standpoint.
17. Key Words and Document Analysis. 17o. Descriptors


  * Pneumatic  Conveyors, * Hospital  Solid Wastes, * Hand  Cart Systems
17b. Identifiers,Open-Ended Terms


  Storage-Collection of Waste, Hospital  Solid Wastes, Vacuum Collection Systens
17c. COSATI Field/Croup
18. Availability Statement
19. Security f lass (This
Report)
UNCLASSIFIED
20. Security Class (This
Page
UNCLASSIFIED

|2I. No. of Pages
I --» -»
USCOMM-DC 14952-P72

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              A STUDY OF PNEUMATIC SOLID WASTE COLLECTION SYSTEMS

                           AS EMPLOYED IN HOSPITALS
              'This final report  (SW-?5c) describes  uork perfcrr.ed
for the Federal solid vacte -nanacenent  r.r>oacans  under contrast ;1o,  68-03-0300
                            to ROSS  HOFMANN, ASSOC.
               md is reproduced a,?-  received fror, the contractor
                      U.S. ENVIRONMENTAL PROTECTION  AGENCY

                                        1974

                                         i a.

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This report as submitted*by the grantee or contractor has not been
technically reviewed by the U.S. Environmental Protection Agency  (EPA).
Publication does not signify that the contents necessarily reflect the
v4ews and policies of- EPA». nor does mention of cor™iercial products
constitute endorsement or recommendation for use by the U.S. Government

An environmental protection publication (SW-75c) in the solid waste
management series.
                                 n

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                             FOREWORD
     The problen of solid waste nanagerent in hosoitals has been
and continues to be of major concern to hosnital administrators.
The nature of the waste requires that snecial consideration be given
to handling, processing, and disposal.  The oast increase in the use
of disposables in place of reusables has increased ner patient solid
waste generation levels to new highs.  The cost of hosnital solid waste
management adds to other already high hospital systems costs.  In
light of these problems, careful consideration is being given to
devising systems which are effective from both a cost and an environ-
mental point of view.

     This report examines pneumatic transoort of solid wastes, a
method which appears to offer both environmental and economic benefit
when properly utilized.  It is the purpose of this rerort to discuss
the state of the art of pneumatic trarsnort of hospital solid waste
and to make broad  recommendations to  improve systems use and desinn.

     Although,  there have been some editorial revisions, this publication
is essentially  as  delivered from the  contractor.

     Harvey W.  Rogers,  of the  Systems  Management Division of OSWMP,
served  as project  officer for  this  contract  effort.
                                  --ARSEM  J.  DARNAY
                                    Deputy .Assistant Administrator
                                    Solid  Waste  Manaaement

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                                    INDEX
     Sunmary of Findings
     Introduction                                                          1

i.   Solid Waste Management in Hospitals                                   4
          The Size bf the Hospital Community                               5
          The Impact of Disposables                                        -J
          Quantities of Hospital Waste                                     9
          Environmental Problems from Hospital Wastes                      11
               Infectious Wastes                                           H
               Hazardous Wastes                                            16
               Plastics                                                    IB
          Hospital Waste Management Patterns                               21
          Personnel Utilization                                            22
          The Use of Containers in Waste  Handling                          23
          The Elements of  the  Solid Waste System                          24
          Automation and ffechattiiSation  in Waste  Management                25

2..    Architectural Design  Influences  on Transport  Systems                 28
          Planning Solid Waste transport  Systems                          28
          The Vertical  Chute-Pneumatic  Tube System for Solid
            Waste Transport                                                ?2
          Sizing the System                                               33
                Vertical Chutes                                            33
                Loading  Station?                                           34
          Chute Loading Rooms                                              36
          Fan  Room                                                        >7
          Control  Center                                                  37
          Collector  Boxes                                                  38

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2.   Architectural Design Influences on Transport Systems (Cont.)
          Structural Strengths for Installing Equipment                   39
          General Considerations                                          39

3.   Design and Construction Considerations for Pneumatic
      Transport Systems                                                   41
          Single Tube Full Vacuum Systems                                 41
          Multiple Loading Full Vacuum Systems                            44
          Double Tube Full Vacuum Systems                                 45
          Gravity Chutes to Vacuum Systems                                47
          Sizing of the Chutes and Tube                                   51
          Strength of the Chutes and Tube                                 54
          Fire Dampers                                                    59
          Tube and Chute Hanging Methods                                  61
          System Coatings and Abrasion                                    61
          Diverter Valves                                                 62
          Collector Boxes                                                 63
          The  Fan Room                                                    66
          Filters                                                         67
          Sound Attenuators                                               68
          Relief Valves                                                   69
          Feed Air                                                        69
          Compressed Air  System                                          70
          Roof Air  Inlets and Dampers                                     70
          Sprinkler Systems                                               71
          Loading Stations                                                71
          Clean Out Ports                                                 72
          Control Systems                                                 73
          Supervisory Panels  and  Alarm Systems                           74
          Cycling Times  in Pneumatic Systems                             75

 4.    Final  Reduction and  Off-Site Removal                                 78
          Volume Reduction                                                79
                                       11  c-

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£.   Final Reduction and Off-Site Removal (Cent.)
          Cleanliness in the Central Waste Collection Room                80
          Compactors                                                      81
          Dry Grinders, Mills, and Hoggs                                  84
          Incineration                                                    85
          Off-Site Hauling Vehicles                                       93
          Sanitary Landfills                                              94
          Salvage, Recycling, and Resource Recovery                       95

§.   Description of the Survey Hospitals                                  98
          St. Mary's Hospital, Duluth, Minnesota                          98
          Veterans Administration Hospital,  San Diego, California         104
          Martin Luther King, Jr. Hospital,  Los Angeles,  California       110

£.   Quantities and Types of Hospital  Solid  Waste                         115
          Total Waste Generated by the Survey Hospitals                   115
          Ratios of Waste to Hospital  Population  Segments and
           Utilization                                                    116
          Types of Waste Transported by Band Cart                         120
          Generation Points and Quantities  of Waste  Transported
           by Cart                                                        126
          Comparisons of System Utilization
           Cart Hauling Versus Pneumatic  Transport                       130
          Quantities of Waste Transported by Pneumatic  Tube              132
               The Sizing of Unit Loads                                   132
               Daily Quantities Transported                               133
               Floor Compactors                                           135
               Chute Loading Hours and Volumes                           135
               The Interfacing of Soiled  Laundry  and Waste in
                 the Pneumatic System                                      142
               Waste Generation Points and Volumes                       144

 7.   Operational and Performance Analysis                                147

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 8.    Codes  and  Regulations                                                154

 9.    Environmental  Testing                                                161
          Sound Level  Readings                                            161
          Odor  Detection                                                 174
          The Problems Created  by Aerosols                               177
          Housekeeping Practices                                         178
          Bacteriological Testing                                        180

10.    Economics  of Hospital Waste Management                              192
           Capital Costs of the  Transport System                          192
           Capital Costs of Interfaced Equipment                          193
           Operating Costs of the Pneumatic System                        194
           Operating Costs of Interfaced Systems                          194
           Division of Fixed Costs Between Waste and Laundry
            Transport                                                     195
           Cost Analyses                                                  196
                St. Mary's Hospital                                       196
                Veterans Administration Hospital                          208
                Martin Luther King, Jr. Hospital                          220

11.   Economic  Feasibility of Pneumatic Solid Waste Transport
       Systems                                                            233

12.   System  Ratings and Comparative Analysis                             241

      Appendix

      Glossary  of Terms
                                         IV

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                              SUJWARY OF FINDINGS

     1.  In an effort to reduce operating coats and improve efficiency in the
         transportation of solid waste, over 160 American hospitals have in-
       , or contracted for, pneumatic tube transport systems.  Approximately
3fltOs additional hospitals axe currently investigating the possible advantages
0$ totalling such a system.
     Z.  In the majority of such installations, the basic designing of the
sysJ&CKt  has been performed by system vendors, as  to type of  system to be
used* number of stations, length of run, speed of  operation,  full-vacuum or
gpsviifcyrto-vacuum, single or multiple bag loading, mechanical and electrical
eleven t-s, safety devices, structural strengths, and location  of  components;
retche?' than by independent, professional consultants with in-depth experience
in such systems.
     3v  Iti very few cases-have detailed feasibility studies  been performed
on a* professional level before- the decision  has been made to  install  such
          As a result, the true*-economic savings,  or the additional operating
       have be«n unknown by the hospital administration until as long as  two
      after the systems have been  in operation.
     4»  The capital costs of?such installed systems have increased considera-
    over the past 10 years with- some of the  current installations  amounting  to
over, $750,000.
     5~,  The installed systems are not being used  to the  full extent  practi-
cable* by many hospitals and much of the solid waste is being  hand  carted
aceund the pneumatic transport system.  With under-utilization,  the potential
operational savings are seriously  reduced.
     6*  Due to this under-utilization of  the systems  in  the  hospitals sur-
veyed.in this study, none were-saving enough labor expense  to recapture the
capital investment  in  the  system;  However,  if  utilization  is increased to the
lew*tSireocmmended  in  this  report, the  investment  could be  recaptured on a
          basis by  labor savings  in each  of  the three  hospitals, when compared.
                                       -I-

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to costs  of  hand hauling all wastes by the more conventional cart method.
     7.   The reasons for under-utilization are many and varied:
         a.   System mechanical failures and high maintenance factors.
         b.   Limitations in the size of tube diameter and system power, and
             the consequent size of load the system will handle.
         c.   Management decisions in individual hospitals that certain items
             will not be transported through the system (such as metal cans,
             glass bottles, and potentially infectious materials) for fear of
             breakage, noise, contamination, or damage to the system.
         d.  Feelings on the part of management that hand carting of waste
             materials can be done more efficiently, due to the generating
             points of the materials versus the configuration and loading
             stations of the pneumatic  system.
         e.  The preference  of  management  for hand  cart waste collection
             methods  in many areas  as  a more  efficient method for clearing
             the floors.
         f.  The hours  of  operation permitted the  pneumatic system.
      8.  Maintenance  costs for such systems have proven  to  be high, due to  a
 combination of design and  construction weaknesses  and  overloading or  improper
 loading  of  the system by operating personnel.
      9.  The efficiency and speed of operation of  the  pneumatic transport
 system varies  extensively  between the designs of  the various vendors.   The
 gravity-to-vacuum, heavy-wall, multiple bag systems, while more expensive  to
 purchase and install, are  superior from a design and construction viewpoint;
 operate  more efficiently;  handle far larger loads  per  hour; and have the  low-
 est operating  costs.   The  weakest and most inefficient systems  are  the thin
 wall, single bag, full-vacuum systems; particularly where a single  tube and
 suction  fan handles both solid waste and soiled laundry.
     10.   Virtually all such transport systems are designed to accept waste
 in a bagged condition.  Bag breakage or ripping presents a serious  problem
 during transport, due in many instances to poor system design or construction.
 With all but the heavy-wall, gravity-to-vacuum systems, loose waste presents
 operational problems.  Bagging of all waste has proven expensive.  As
                                      -II-

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                plastic bags are normally used, the increasing scarcity of these
          may present operational problems in the future.
         From the environmental aspects, all such pneumatic systems are an
            over the straight gravity chutes, or hand hauling methods, for
transporting solid waste.  Mien the collector boxes at the end of the trans-
     &$>£ Hne are cloee-conneeted to attrition mills or compactors, the
              benefits are further increased.
         The major environment a}, weaknesses in the pneumatic tube systems,
         they are operating properly, involve the collector boxes at the end
   the tube, the fan rooms, and the filtration of the effluent air  from the
       With bagged waste and the speed of bag travel, the vacuum tubes appear
£g be relatively self-cleaning,
    4.3,  The sound levels of the systems while in operation are relatively low
and do not appear to be annoying to patients.  Odor  levels are not  objection-
       The limited bacteriological  testing  that has been performed did not
       pathogens of any significant level.  The  systems appear safe to use
         operator viewpoint.  Fire  safety codes are satisfied.
       .  User  acceptance varied considerably between hospitals in view of
            and maintenance problems  experienced.  Amounts of waste trans-
       by  the  pneumatic system  ranged from a  low of  25.1%  to  38.8%  to 60.3%
       the  three hospitals, with the balance of  the waste hand cart  trans-

          It is possible  to both modify and expand all three  of  the  systems
         particularly  in  the  collection system  at the end  of  the  line,  or  if
           wings are constructed.
                                      -Ill-

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                                 INTRODUCTION

     In June 1973,  Ross Hofmann,  Associates was employed by the Environmental
Protection Agency to study solid  waste management practices in hospitals.
Particular emphasis was to be placed on pneumatic transport systems for the
moving of solid waste through a hospital complex.  Three hospitals were se-
lected for in-depth study of their pneumatic transport systems:  St. Mary's
Hospital in Duluth, Minnesota; Martin Luther King, Jr. Hospital in Los Angeles,
California; and the Veterans Administration Hospital in San Diego, California.
     The following report was a result of the Consultant's work.  It has been
divided into two main  sections.  The first section covers the principal fac-
tors involving solid waste management in hospitals.  It describes the magni-
tude of hospital solid waste  and the environmental effects from it; the various
management methods that  are used;  and  the problems that are encountered as a
result of both internal  and external  constraints.  It  describes in detail the
equipment that is  used in hospitals for pneumatic transport systems and  for
systems of  final reduction and off-site removal  of solid waste.   This material
is  covered  in Chapters 1 through A and sets  the  background for  any  study of
solid waste management and transport  within  a  general  hospital.
     The  second  section, covered by Chapters 5 through 12, concentrates  pri-
marily on the three  hospitals that were surveyed and the problems they have
encountered with  the use of  pneumatic solid  waste transport  systems.   It anal-
yzes  the  hospitals,  their architecture, the  systems  they employ,  the  loads of
waste  they  must  handle;  and  it analyzes the  performance of  their  systems,
ranging  from  costs to environmental affects.   The conclusion of this  section
rates  and compares the systems  the three  survey hospitals  are using.
      The delivery of health  care has  now  become the  largest  retail industry  in
America.   Hospital operating costs account for approximately one-third of  this
enormous expenditure.   Labor payrolls account  for almost 65  percent of total
hospital expenses, and hospitals are  turning increasingly  to methods  for labor
 reduction,  including automation  and mechanization.   In the management and
                                       -1-

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     fo'll 6i hospital solid waste, mechanization  is  a fairly recent deveiop-
    ,* w'ijth' pneumatic tube ay£tefis  the  method that has attracted the most in-
tffttL
         principle of a pneumatic tube systeia for the transmission of solid
        16 over 50 years old.  The use of large diameter tubes  (over 14 in,
        aiameter) for this p^rp'bse dates back to  1941, and the  designs involve
       iuliy pneumatic or gikvitjf trarfsfer in vertical chutes,  combined with
      fi'neumatic trinsier ih hdfiztinta'l aiid rising runs.  In all cases, a  suc-
     fHnciple rattier than a prilling (at blowing) principle has been used.
         first sUch  syitfcias Will werfe installed  in hospitals  in the United
       werfe an outgrowth of Syfeteins originally developed for  moving linens  in
            laundries.  Only iihetis, not  solid waste,  were moved pneumatically
           in hospitals.  The fir^fc such  system for handling solid waste  in  a
           tai was not installed until the midsixties. While  many  advances  for
           tube transfer have bfeen designed  in Europe, only  one such  system,
         originally  in Sweden  for use in solid waste  collection, has  been in-
         in U.S. hospitals  to  date.
      M  Is usually  thfe casb with  system  designs  that  have  been developed for
     Hild  and adapted to  ariothet  fleld^  the conversion of  large diameter pneu-
Mllfc lube systems  from  laundry  and  industrial use  into  a structure and oper-
         brgariization as  cotaplek  as a modern U.S. hospital  has presented innum-
       problems:   to the  engineers and  architects,  the manufacturers, and the
         personnel.   The  economic feasibility of many systems  that have been
           or  contracted  for hais  not  yet  been proven.   Users of certain instal-
         have  registered  serious  complaints with the authors of this Report as
 to ^£1 technical merits  of such systems.
          quantity oE such systems installed to date  in hospitals ie still
        , but  Is  growing.   Sixty-otte  are claimed by ECI Air-Flyte Corporation,
      Ifc  additional 68 on order;  23 In total installed and on order by Trans-
     iy^Vems;  eight by Envirogehlcs Company; two by American  Sterilizer Company;
     feii by other firms.   It is felt that an in-depth study,  under the sponsor-
 l&lp1 Bf  the United States Government, will greatly contribute  to further know-
       1bf these systems in View of the limited research published to date.
                                       -2-

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     In the Report that follows, we have analyzed hospital solid waste manage-
ment and pneumatic transport systems from several viewpoints and with separate
disciplines.  At first glance, these separate evaluations may appear to over-
lap, or even duplicate each other.  We believe that this is not the case, and
that each evaluation interfaces with the next one in a logical progression, and
that the data assembled by one discipline or phase is essential to the next.
     Each of the three pneumatic solid waste transport systems studied handles
both solid waste and soiled laundry.  Therefore, there is of necessity an in-
teraction between these two types of materials in the complete system, when a
common tube is utilized for both materials, and a possible interaction when
separate tubes and a common suction fan are used.  Although many of the details
of  laundry  removal were not studied, since this effort was intended to address
only solid  waste management practices in hospitals, the  interaction and impact
of  the linen removal  system on  the  solid waste removal system was analyzed,
evaluated,  and  the results  included in  this Report.
     With  continually  rising  operational costs in hospitals, coupled with  the
increasingly serious  environmental  problems  in solid waste management, consid-
erable interest  in the results  of the study have been expressed  to  the research
team by  hospital  personnel  in various parts  of  the  country,  by  governmental
agencies,  and by the  vendors  of solid waste management  equipment.   It  is hoped
that the data given in the  Report will  prove  useful  in  assisting hospitals in
solving  these problems,  as  well as  indicating some  of  the areas  in  which fur-
ther in-depth research may  produce  beneficial results  and guide lines.
     To  obtain  the background data  covered in the  first  four chapters  of this
report,  over  100 medium to  large size hospitals  have been researched by  the
survey  team,  in addition to the three  institutions  that  are described  in depth.
We  would like  to express our  appreciation  to the  administration and staffs of
all the  hospitals who cooperated so completely in the investigations of  their
solid  waste management systems, and to  the Project  Director and Staff  Engineers
of  the Office  of Solid Waste  Management Programs,  U.S.  Environmental Protection
Agency,  whose  constructive  criticism and guidance  was invaluable in the  prep-
aration of this Report.

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                   -SOLID WASTE MANAGEMENT IN HOSPITALS
     Over the past 20 years, various surveys have been conducted and articles
Jiaye been published on the amount and types of solid waste being generated by
hij|fp4.tals.  Unfortunately, a review of this material, which is quite limitedf
indicates a certain amount of disagreement among the researchers as to the
magnitude of the problem.  There is not a firm consensus of opinion as to the
amount of solid waste generated by hospitals, which departments generate how
much, and the make-up of the waste.  Most surveys have measured the solid
WfSte in terms of weight, in pounds.  The measurements have been limited
usually to the total weights generated by a relatively few hospitals.  The
u*ual procedure has been, then, to divide the patient census  of the hospital
i-ntp the total weight of waste recorded and to arrive at a figure  of "X"
pounds "per patient day" as the critical  factor  in  solid waste analysis.  The
cube pr volume of the waste, which is equally  important  in designing solid
waste management systems, does not seem to have  been  recorded in most  surveys.
     It is for this reason, probably, that  figures  have  varied considerably
between hospitals.  Solid waste is generated by  people,  by  the activities in
which people are engaged, and is affected by the size and  complexity of  the
building in which the activities take place.   "People,"  in a hospital  setting,
includes much more  than  patients.  It must  include  all  the staff  and  all the
visitors.  Hospitals do  not staff  on  an  identical basis.   The ratio of staff
£o patients varies  as much  as 50 percent  between hospitals,  depending  on the
work patterns  and  the  level of efficiency.
     Hospitals do not  perform identical work  loads  per patient.   One may have
the bulk of its  cases  as minimal  care.   Another  may be engaged in very sophis-
ticated  and intensive  care.   Another  may have  heavy teaching and/or research
Activities  and large  research laboratories and animal quarters.   Another may
have  thousands of  outpatient  and  emergency visits annually.   One may be crowd-
                                       -4-

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ed with visitors,  another extremely light in this respect.
     Hospitals with identical patient census figures vary somewhat in size and
architectural layout.  Theoretically, this should not affect the solid waste
load generated if  waste comes strictly from "people activities."  For some
reason (that may be from attitudes on the part of staff and visitors), archi-
tectural design affects the waste generated to some degree.
                     THE SIZE OF THE HOSPITAL COMMUNITY

     In attempting  to assess the impact on  the United  States  of  the solid waste
 load generated by all hospitals, a  review of the  industry  as  a whole,  and its
 work load,  reveals  some  interesting facts.  Hospitals  represent  a major  sector
 of  the  so-called "health care"  industry.   By 1973,  it  is estimated  that  Ameri-
 can health  care  expenditures had risen to  $94.1 billion, surpassing education
 as  the  largest  service  industry.   Hospital care  costs  have reached  $36.2
 billion.    Sales by  manufacturers  to the health care industry are estimated  to
 be  $3  billion.2
      However, the sheer quantity  of acute  medical care, rated by average num-
 ber of  inpatients staying in hospitals, has not  changed substantially in the
 past  20 years,  as can be seen from a review of the statistics published by the
 American Hospital Association.   The number of  hospitals has increased 7 percent.
 A.H.A.  registered hospitals in 1955 numbered 6,596; a high point of 7,172 was
                                                         3
 reached in 1967; and by 1972 this  had declined to 7,061.
      The number of available beds actually has declined.  With 1,604,000 in
 1955,  by 1965 this had increased to 1,704,000, and dropped to 1,550,000 by
 1972.4
      Average daily patient census has fallen as well.  In 1955 it was calcu-
 lated to be 1,363,000, rising to 1,430,000 in 1963, and falling by 1972 to
 1,209,000, the lowest since the late  1940's.  Hospital personnel looking after
 these fewer patients has more than doubled over  this  period, rising from
 1,301,000  in 1955  to 2,671,000 by  1972.5
      A similar rise has been seen  in  the number  of admissions, a statistic
                                       -5-

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that has had a direct connection to cleaning rooms of waste to prepare for new
patients, and to the number of patients and visitors going through the system,
In 1955, 21,073,000 patients were admitted to hospitals.  The figure shows a
regular increase each year, with 33,265,000 patients admitted annually for
1972.  A similar increase in activity is seen in annual number of outpatient
visits, which have Increased from 99,382,000 in 1962 to 219,182,000 by 1972.
     It has been estimated that since 1954 the total solid waste load of all
hospitals combined has increased 350 percent in the United States.  Admissions
have increased only 57 percent; outpatient visits  by 120 percent; and staff by
105 percent.  Other factors obviously have increased the solid waste output.
     Moft administrators feel that  the bulk of the increase has come from  the
quantity and type of care rendered.  When  inflation is  removed as a contribut-
ing factor, this would appear to be the  case.  Care and treatment of hospital
patients has become more complex;  the number of procedures, injections,  I.  V.'Sj
treatments, and medications given  the average  patient has  risen geometrically  in
20 y«*ir».  Each procedure leaves a  residue of  solid waste  to  be disposed of.
                            THE IMPACT OF DISPOSABLES

      Probably the  greatest effect on the solid waste load generated by hospi-
 tals comes from the use of paper, foil,  glass, and plastic "disposable" pro-
 ducts,  as against  reprocessing items for further use.   Disposables range in
 nodical items from syringes and hypodermic needles, to surgical dressings and
 complete operating room patient drapes,  to entire bedside sets of basins, cupss
 and pans.  They include the containers for entire meals when the dietary de-
 partment has switched to "convenience" foods.  And they include tremendous
 quantities of paper containers from vending machines that hospitals have in-
 stailed in snack bars.  They include the millions of plastic bags used in a
 year fco line waste baskets and trash cans and to transport waste.  All of these
 iteas: are designed to be used once and thrown away.
      Not only do the products add enormously to the warehousing and solid waste
 problems; all of them are packaged in further quantities of plastic and paper,
                                       -b-

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and the packaging has become much more elaborate as each year passes,  in order
to increase the eye appeal and saleability of the product.   It is currently
estimated that the packaging of the disposable products adds a solid waste load
that exceeds that of the products themselves.
     The phenomenon of packaged disposables is an outgrowth of consumer mer-
chandising of the thousands of items we buy in drug stores, super markets, and
variety stores.  The theory was originally sold to hospitals by a few large
hospital supply dealers on the basis that they would save the hospital process-
ing labor and therefore operating cost.  The hospitals, always pressed for capi-
tal funds to purchase processing equipment, and able to obtain operating dollars
by raising rates to patients and third party reimbursers, welcomed the dispos-
ables with open arms.  Unfortunately, it now has been discovered that, after
approximately 18 years of  intensive merchandising of these products, many hos-
pitals actually have experienced a net increase  in personnel due to the number
of staff needed to  store,  issue, and  inventory  the disposables.
     The trend toward disposable versions  of hospital products started with
those  items  that were the  most difficult  to  clean, package,  sterilize,  and
maintain in  a reusable version;  while at  the  same  time  offering  possibilities
of an  extremely  low cost  throw-away  substitute.  The first  items were hypoder-
mic needles,  syringes,  and tubing  of  various  types.  These  products were  fol-
lowed  quickly by  "sharps"  (cutting blades),  laboratory  petri  dishes and slides,
patient bedside utensils,  food service settings,  I.V.  and  topical  solution
administration sets,  surgical  and  examining  gloves, surgical trays and  sets
for O.R. and the  floors,  surgical  drapes  and clothing,  and even  bed sheets.
     From  1973 figures  that are based on  reports to the Department of  Commerce
and published by  trade  magazines for  the  surgical  and  hospital supply  industry,
the enormous production of disposable medical and  surgical supplies in the
United States can  be seen.  The dollar totals are  based on manufacturers'
selling prices.   The cost  to the consumer would be approximately double these
figures (Table 1).
      In addition to the items made from plastics,  textiles, glass, and metal
by the hospital  supply  manufacturers, there  are the millions of  bottles of  ir-
rigating and intravenous solutions in glass  or plastic, as well  as the
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packaged "unit dose" medications, supplied by the pharmaceutical manufacturers,
in plastic, paper, and foil, which are purchased weekly by the hospitals,
     The average disposable product is relatively low priced.  To give an idea
odE the enormous volume of solid waste they have created, we find that the annual
.sale of disposable products to hospitals has increased by approximately $700
                    Q
million in 18 years.   If we convert this huge annual dollar purchase into
pounds and cubic volume, we find that by 1973, disposables had more than
doubled the solid waste load in American hospitals.

                                    TABLE 1
                         HEDICAL AND SURGICAL  SUPPLIES

   Disposable Product                 1973  Sales  Volume  at Manufacturing  Level
            needles,  disposable                    $ 80,400,000
flypodermic needles,  "reusable"                       7,100,000
 Syringes, plastic                                   37,500,000
 Syriages, other                                     51,300,000
 Dressings, bandages                                 76,600,000
 Adhesive plaster and self-adhering bandages        158,300,000
 Surgical and medical gauze                           8,900,000
 Cotton balls and cotton wool                        30,500,000
 Sponges, pads, other dressings                     104,200,000
 Sutures                                            136,300,000
 Transfusion and blood donor supplies                85,000,000
     Another factor that has added to the solid waste load, to a lesser extent,
concerns the information systems that have mushroomed in hospitals.  Use of
paper in all shades and colors, often with disposable interleafed carbons, ft
simple requisitions, to photocopies of memos, letters, and reports, to compute:
print-outs, has grown by almost 500 percent in hospitals since 1950.
                                                                              om
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                          QUANTITIES OF HOSPITAL WASTE

     Many statements  have been made concerning the abnormally large quantity
of solid wastes that  hospitals generate compared to other institutions,  to
office and commercial buildings,  and to residential complexes.  A hospital is
a community in itself; with a total population made up of patients, staff, and
visitors.  Hence, comparisons should be made between the hospital as a com-
munity, and a residential complex of similar size, to determine how valid has
been the criticism that the hospital generates a far larger waste quantity
than does a residential community of equal size.
     The 1968 National Survey of Community Solid Waste Practices determined
that residential complexes generate approximately  3.0 pounds, or 0.53 cubic
feet, of waste daily  per  capita occupancy  (or resident).  It has been estima-
ted  that the average  density of this raw waste  is  170 pounds per cubic yard, or
6.3  pounds per cubic  foot.   (Compared  with  the  average of hospital raw waste,
as we  shall  see  from  figures  given later,  this  is  extremely  dense.)  This
waste  includes yard  cuttings  and  trash, as  well as all waste generated indoors.
      It  has  also been estimated that between 1968  and 1974,  residential waste
has  increased  approximately  4  percent  per  year.   If this holds,  then currently
residences are generating an average of 3.7 pounds per  resident.   This would
be made  up of  yard cuttings  and outside waste amounting  to  0.8  pounds and a
balance  from building interiors of 2.9 pounds.   The interior waste, which
would  be comparable  to that  generated  by  a hospital in  this current study,
can  be defined,  using the classifications issued by the American Public  Works
Association  (APWA),  as "garbage"  and "rubbish or mixed  refuse."  The make-up
would be 0.5 pounds  of "garbage"  (waste generated in the preparation,  cooking,
 and  serving  of food)  and 2.4 pounds of "rubbish or mixed refuse" (paper,  card-
 board, cartons;  wood, boxes,  excelsior; plastics; rags,  cloth,  bedding;
 leather; rubber; metals, tin cans, foil;  dirt and dust;  glass,  bottles;  stones,
 brick, ceramic,  crockery; and other mineral products).
      When we refer  to "solid waste" in hospitals in the present study,  we mean
 exactly that.   Studies have been made  in  this field in which "soiled  reusables"
 (such as soiled laundry, soiled utensils  and dishes, or soiled patient items
                                       -9-

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from bedpans to treatment equipment) were included in the total waste.  We do
not believe an item can be classified as "waste" that will be cleaned, and
possibly sanitized or sterilized, and then reissued for further use.  "Waste,"
for the purpose of this study, is material that will no longer be used, but
will be  discarded,  presumably moved off-site, and presumably will be destroyed
(or at least drastically modified in a recycling process).  The definition of
"soiid" is that it has insufficient liquid content to be free flowing at room
temperature.
     The exact quantity of solid wastes being generated by  tine 7,061 A.H.A.
registered hospitals  in 1974 has been a matter of considerable discussion and
disagreement among researchers.  Surveys have been limited  in any study to less
than a dozen hospitals.  Different  surveys have included or omitted various
materials in their definition of "hospital solid waste" and most comparisons
have been of the  "apples  to orangas" type.
     The research team that performed the present  study has reviewed,  to  the
best of our knowledge, virtually every  article  that  has been published in tech-
nical journals on this subject over the past  ten years and  has reviewed copies
of  several studies, both  published  and  unpublished,  that have been performed
by  governmental agencies, hospital  personnel,  independent researchers, and
other consulting  groups.
     From this material,  we can  at  least  state  that  the  general  consensus of
opinion  is  that during the last  20  years  hospital  solid  waste  has  experienced
over a  threefold  increase.  Various surveys  that  have been  made  would indicate.
that in  1950 hospitals generated approximately  three pounds of  solid  waste
per day  for each  of  the  1,253,000  inpatients  being cared for,  or a total  of
3,740,000 pounds  per day.   Continuing  research over the  years  on the  growth
of the  hospital  solid waste  load would indicate that the current figure  is
over 10.0 pounds  of  solid waste  for each of  the 1,209,000 inpatients.  A total
current waste  load  of 12,000,000 pounds for  all of America's hospitals appears
 to be  a reasonable  figure from the  information that is available.
      Viewing  hospitals as a community, consisting of inpatients, outpatients,
 staff,  and visitors, the permanent  24-hour population in 1974, exclusive of
visitors,  would total 4,600,000 people.  This would mean that the hospital in-
                                       -10-

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dustry is generating over 2.6 pounds of solid waste for each member of the
hospital community.   This is not too far from the current estimate of 2.9
pounds per resident  for interior waste from other communities.
                  ENVIRONMENTAL PROBLEMS FROM HOSPITAL WASTES

INFECTIOUS WASTES

     Solid wastes generated by hospitals are not in exactly the same category
as those generated by homes or other dwelling units.  While the total of hos-
pital solid waste appears to be only in the neighborhood of 6,000 tons per
day, and therefore less than 2 percent of the total solid waste load of the
nation, from a biological hazard viewpoint, hospital wastes contain a certain
amount of materials not normally found in other  institutional or home wastes.
     In any discussion of biological hazards,  the words  "concentration" and
"dilution" immediately arise.  The  spread of disease among humans is caused
by contact between the human system and the various bacteria or viruses that
are  inimicable  to the system.  This contact may  be by direct touch or through
the  air, the water, or the  soil.  If the bacteria or viruses are diluted  in a
large field, the chances of entering and affecting  the  human host are consider-
ably lessened.   If they are both virulent and  concentrated,  the chances for
spread of disease are strengthened.
     Some investigators have stated that the  type and concentration  of bac-
teria and viruses found in  hospital solid waste  are  little  different  from that
found in the wastes generated  from  dwelling units,  offices,  factories, and
other institutions of this  country. Other researchers  have  given a  completely
opposite view and stated that hospital  wastes  may be  potentially dangerous to  the
environment due to their  "infectious"  content.   Unfortunately,  the very few
surveys  that have been made (our own  included)  are  inconclusive.  Up  to  the
present, no large-scale surveys have been made—either  "in-house" or  off-site
at  landfills—to prove or disprove  the biological hazards of  hospital wastes.
      Theoretically,  the difference  between  the biological hazards of waste
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generated in hospitals, with their population of "sick" people,  and the waste
generated by dwelling units and other buildings that are occupied basically by
'Veil" people, lies in the concentration factor.  A proportion of the waste
materials generated by hospitals in the treatment of patients has been exposed
directly or indirectly to various bacteria in a fairly concentrated form.  From
2 to 8 percent of hospital wastes consist of such materials as:   dressings for
wounds, incisions, and burns; plaster casts; infectious laboratory samples;
bacteriological cultures and media; pathological specimens; animal remains and
biological specimens; body fluids and secretions, blood, urine, feces, and
tissues; needles and syringes; disposable treatment devices in plastic, metal.
aa4 glass; "sharps"; newborn, pediatric, and geriatric diapers; and various
contaminated disposable containers.
     Idhile such materials may represent only a  small percent of the. total hos-
pital waste load, it it known from observation  of waste handling practices
that these potentially infectious  items are not completely isolated from all
other wastes in the hospital system.  At some point, there is a reasonable
possibility that these "infectious" wastes  can  be intermixed with other wastes.
     Ihe leading generation points for known infectious wastes are the surgical
       , the clinical and research  laboratories, the research animal quarters,
    autopsy suite and pathology  laboratory, and the renal  dialysis department.
4s ttese wastes come from specific departments  or sources, segregation of  in-
C&ctious waste is possible by handling all  wastes from these particular  areas
as infectious.  Another known generation point  is any  care and treatment area
or room for a known  infectious  case—inpatient, outpatient,  or emergency.
Hany hospitals have  switched  to  the  use  of  almost complete disposable  care and
treatment devices for  such known cases.  The waste  load has  risen  accordingly.
     Infectious hepatitis  appears  to be  a  possibility  in  the waste from  a  renal
dlalysis department.   Hence,  all waste  from this  area  is  regarded  as  suspect.
la view of  the highly  infectious nature  of  this particular virus,  it  is  sug-
gested that any materials  used  in dialysis  and  around  known  hepatitis  cases be
handled with  extreme care.   One suggestion made is  that if wastes  from known
casfes  of hepatitis  (or other  highly  infectious  bacteria or viruses)  are  being
transported,  that  they be  moved in a virtually  "unbreakable  or  unrippable"
                                      -12-

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bagging system.   Further, that "needle sticking" of the waste handlers be
absolutely prevented by the methods used.  The expense of the containers
should be secondary.
     The major problems in isolating possibly "infectious" wastes arise from
the general patient care and treatment areas, both inpatient and outpatient,
where large numbers of patients are being cared for by nursing personnel and
diagnosis is often incomplete at the time.  It is in these areas that infec-
tion level of most waste is usually unknown.
     It is the conclusion of the research team that conducted the present
study of hospital wastes, that too many  hospitals are attempting to classify
their wastes into categories that may not be  logical—such as "definitely in-
fectious," "potentially  infectious," or  "safe,"   It is  our feeling that all
solid waste should  be  handled with good  management practices, regardless of
generation source,  both  with  in-house  and off-site methods and  systems.  By
standardizing  on well  thought  out  and  efficient  waste handling  methods, pro-
perly  supervised and executed,  for all wastes,  not  only will financial  advan-
tages  be achieved,  but breaks in waste handling systems and  resultant cross
 contamination should be greatly reduced.
      External  constraints have made  the  segregation of  solid wastes  extremely
difficult,  and hospitals have occasionally  gone to extreme methods  to solve
 these  constraints.   Burning known infectious material,  along with the poten-
 tially infectious,  in on-site incinerators, was a common practice until a few
 years  ago.   Today,  with much more  rigid air pollution codes and, in general,
 rather poor  incinerator installations that  are incapable of handling the large
 volumes of plastic used for disposables, hospitals have reduced the practice
 of bulk burning.  An exception is the pathological waste, required to be in-
 cinerated by local regulation in most communities.
      The majority of hospitals have turned to compacting their solid wastes
 to reduce hauling costs and contracting to have them hauled to a landfill or
 municipal incinerator.  However, the nation  is rapidly running out of sanitary
 landfill areas.  Further, many such landfills are increasingly reluctant to
 accept hospital wastes  for various reasons,  ranging from potential effect on
 ground water, to dangers to personnel from the aerosols such waste may create.
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     In certain instances, hospitals have attempted to use gennicidal sprays
on a large scale in connection with their compaction of waste.  In general,
this has proven to be impractical due to the difficulty of penetration of the
chemicals through the waste mass.
     At least one major health department has objected to hospitals transport-
ing wastes through city streets no matter how "sealed" the vehicle may be, or
what precautions are taken, and this has put further constraint on the use of
landfills  or municipal burning.
     ttt one  community, hospitals have attempted to solve the problem by vet
grinding of  solid waste and flowing it into the sewer system.  This procedure
may df may not be practical.  The opening of the waste grinder has been limiteu
to ttd more than 9 in. by 6 in. to prevent overloading or overuse.  This has
iliVdlved considerable manual handling of the material, to the point of sorting
and f»te-crushing to fit the opening.  The practice may involve risks to hos-
pital personnel, plus potentially high labor cost to the hospitals.  Grinding
hafl also proven to have problems in maintenance of equipment, plus problems in
flotation and sedimentation.  With the sewer systems designed basically to
4£€6^t food  wastes, and with hospital waste consisting of as much as 80 per-
cent in paper and plastic, external constraints have developed on the part of
the Sewer and sanitary departments, who  are worried as to the effect on their
Systems should this practice spread.
     A« a last resort, faced with these  various external and  internal con-
Stfaints, some hospitals have turned  to  investigating the possibilities of
Sterilizing  their wastes  froth potentially  infectious areas, before centrally
collecting them and moving them  off-site.  Conventional steam and ethylene
dftide gas autoclaves and  industrial retorts have been used; bactericidal  and
spbricidal sprays have been tested.   In  addition, experiments have been con-
dueted on sterilizing encapsulated waste within the plastic waste bags by
ethylene oxide or formaldehyde pellets.  Sterilization of waste has proven  to
tie expensive, due to the  difficulty in automating such a system compared  to
incineration, and has done nothing  to reduce  the total volume of waste for
which the hospital must pay off-site  hauling  costs.  Further, because of  the
labor, equipment, and supply costs  involved,  it has been  limited to waste from
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known infectious cases and has offered no guarantee that the remaining wastes
are "safe" to handle.
     The consulting team in researching this present study was unable to locate
much in definitive data from other surveys as to exactly what tests have been
done on determining how "infectious" and how "hazardous" hospital waste actu-
ally is, day in and day out, across the board, and what actual effects this
has had on the environment and human health.  The bulk of the judgements that
have been made in this connection have been based on the source of the waste
and the conclusion that, if the waste came in contact with known organisms at
the source, it was capable of retaining and transmitting these organisms.
     Considering the number of hospitals and the number of patients being
treated in the United States, surprisingly few studies have been conducted as
to "how infectious" are these infectious wastes; and what type of bacteria are
present in what levels.  Some university hospital studies have shown patho-
genic organisms present in the wastes, particularly if an organic substrate  is
present.  Significant counts were made of coliforms, fecal streptococci,
staphylococci, Candida albicans, and Pseudomonas.  Bacillus organisms  are most
noticeable, particularly staphylococci and streptococci.  With the amount of
paper and cotton  cloth in  the waste, it  is known that  the mix is ideal for
transmission  of viruses, with a potential transmission time duration  as  long
as  5  to 8 days.   However,  the studies have been  on such  a  small scale as to
not  be  useful when the conclusions  are extended  to all hospitals.
      A literature review  conducted  by a  commercial firm under an H.E.W.
contract  and  completed  in 1967, entitled "Solid  Waste/Disease Relationships,"
did an extremely  thorough survey  of the  research conducted to that year. A
 total of  755  references were analyzed, but  the  conclusions could  only point
 out suspected disease pathways  through  solid waste systems.   Opinion was ex-
 pressed repeatedly as to  the direct transmission effects between  waste and
 disease,  but, as  the  researchers  for this report found,  few solid facts were
 presented or conclusive proofs  offered.
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HAZARDOUS HASTES

     Several researchers have stated that all hospital wastes should be regard-
ed 4d "hazardous" when they are Intermingled in a central collection point, in
a campactor, or at a landfill.  Infectious wastes are obviously hazardous in
view of potential effects on handlers and the environment.  However, in this
Section the term hazardous is used to denote wastes generated from hazardous
materials:  from any element, compound, or combination thereof, that is flam-
mable* corrosive, detonable, toxic, radioactive, an oxidizer, or is highly
tftactive; and that in the process of handling, storing, processing, packaging,
or transporting, may have detrimental effects upon personnel, equipment, or
the environment.
     tn the total waste load of a hospital,  the quantity  of such materials is
Stall—normally less than 2 percent of the volume.  However, all such material
requires special handling in transporting and disposal and hence can be one of
thfe ttbst expensive elements of in-hospital waste processing.
     Radioactive materials are probably  the  best controlled of  the hazardous
frolpital wastes.  They may be in the form of radioactive  liquids, containers,
and disposable materials, animal carcasses,  or tissues.   Handling techniques
vary between hospitals and with the radioactive substance.  The most common
Method with liquids  of relatively low  level  output is  to  dump  the waste into
the Sewer system.  Another method is to  store both liquid and  solid wastes  in
fc Secure area in containers with foot  operated lids, allow the  radioactivity
to decay, then hand  carry the -waste through  and out of the building.  Other
hospitals move the radioactive substances directly to  the incinerator and
burn them.  Often this can result in high radioactivity  in the ash; with some
institutions storing ash  for as much as  three months to  permit radioactive
      before burial.  Other hospitals  transport such wastes  in sealed con-
         through  the  institution and bury it; in selected locations  of their
tfffo; In municipal disposal sites; or ship it to one of the national disposal
Bittts.   The decay of radioactivity  then  takes place away from the hospital.
     Chemical wastes form the bulk  of  the remaining hazardous wastes, with
Certain medicines and pharmaceutical products making up  the  remainder.   These
                                      -16-

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may be in liquid,  powder, or solid form.  The range of chemicals, solvents,
and heavy metals is wide for potential effect on human beings, as well as on
the hospital equipment and structure.  They include strong acids and caustics
of a highly corrosive nature; solvents in a wide range used from the labora-
tory to the maintenance department; compounds of mercury, arsenic, and cyanide,
all highly poisonous.  As much of the material is used in laboratory work and
research activities in larger hospitals, as well as part of the workings of
patient care and analytical apparatus, it becomes fairly wide spread through
the institution.  In many cases, it is in liquid form and the disposal method
for a high percentage is into the sewer system.  Recent OSHA regulations pro-
hibit this practice for  some chemicals.  Some heavy metals, such as mercury,
are subject in many hospitals to a reclamation program with varying degrees
of success.  Other liquid items generated in  large quantities, such as certain
solvents and acids, are  transported  in  special canisters and  then disposed of
off-site, either buried, put into  special wells  or landfills,  or shipped  to
reclamation centers.

                                    TABLE 2
         COMMON  TOXIC  CHEMICALS  REQUIRING SPECIAL HANDLING  IN  HOSPITALS
 Boric  acid
 Hydrochloric acid
 Nitric acid
 Orthophosphoric acid
 Phosphoric acid
 Potassium hydroxide
 Sodium hydroxide
 Sulfosalicylic acid
 Sulfuric acid
Trichloroacetic acid
Benzene
Carbon disulfide
Carbon tetrachloride
Chloroform
Copper sulfate
Iodine crystals
Mercury
Phenol
Potassium dichrornate
Potassium permanganate
Silver nitrate
Sodium dichrornate
Sodium floride
Toluene
Xylene
Zinc chloride
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PLASTICS

     In the total make-up of hospital wastes, plastics of all types account
for 11 to 20 percent of the total cube and from 5 to 12 percent of the total
weight, depending on the hospital's supply practices in purchasing disposables
There are over 100 different uses of plastics in a hospital that relies heavil
on disposables; and probably as many as 700 different formulations supplied
attong these.  The soft plastics are used for packaging; drainage and intra-
venous tubing; containers; sheeting; waste bags; examining gloves; tape; surg-
ical dressings and drapes; bed fabrics and clothing; masks.  Hard plastics are
us«4 for bedside utensils; bottles; surgical and food trays; syringes; ash
tt&ys; containers; dishes  and tableware; heart, lung, and dialysis machine
fatt6.  Various foams—mostly polyurethane and styrene—are used for heat-
resisting  cups and packaging materials.  Among hospital wastes, plastics create,
unique disposal problems.
     During incineration,  plastics  give off  the most heat of any major classi-
flfeation in the waste,  some exceeding  20,000 BTU per pound.  This  substantial
liftfct can create breakdown  of  incinerator linings.   In addition, the particular
emissions  are considerable if flash burning  occurs; as  in the  case of syringes
 (kndwn as  "syringe puff").  Flash burning  can make  it difficult to control  the
burning rate, which  is  essential  in order  to ensure that on  a  regular basis
combustion contaminants  remain at or below 0.1  grains of particulates per
cubic  foot of gas  calculated  to  12  percent of  C02  at  standard  conditions.
     It will  be noted  that polyethylene  is one  of  the plastics that  under  com-
bustion generates  an extremely high BTU  output.   It is  one  of  the  most widely
used plastic  materials,  accounting  for 30  percent  of  total  production.   All of
 the plastics  will  burn at  350 F  to  450 F,  but  to be incinerated in a smokeless
 and nearly contamination-free fashion, the combustion temperatures must  be
 1,800  F  to 2,000  F for many  common  formulations.   In  many  conventional  incin-
erators,  the  introduction  of  plastics  to combustion chambers that are not  pre-
 heated has merely  melted the  plastic,  clogged the  grates,  and deposited molteu
puddles  which burn erratically  and  even explosively.
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                                   TABLE 3
                           INCINERATION  OF PLASTICS
Type of Plastic
Poly vinyl chloride
Polyure thane
Polystyrene foam
Polypropylene
Polyethylene
Nylon
Vinyl
Acrylic
Heat of Combustion
cal/gram BTU/lb
7,040
9,050
7,040
10,100
11,064
8,050
8,050
7,040
13,700
17,600
13,700
19,600
21,600
15,700
15,700
13,700
Specific Heat
cal/°C/gram
0.35
0.45
0.35
0.50
0.55
0.40
0.40
0.35
     Destruction of certain plastics by burning releases corrosive chemicals
into the exhaust gases.  Polyvinyl chloride when burned gives off hydrogen
chloride gas, which is toxic to humans.  In a post-incinerator scrubber this
forms hydrochloric acid and the effluent water must be neutralized.  Addition-
ally, the polyvinyl chlorides have a corrosive effect on incinerator grates
and other metals as well as incinerator firewalls.  Iron smokestacks will
collapse after continued large scale burning of many plastics, since the re-
sultant gas penetrates and eats the iron in an action similar to etching.
     Plastics are not biodegradable in the same manner as animal and vegetable
substances.  One of the prime reasons for their popularity is that they are
durable and offer long-lasting protection.  If taken to a sanitary landfill,
their life can be many years.  None of the plastics commonly used in hospitals
are broken down in the short run by weak acids or weak alkalines of the type
which might be encountered in a landfill; they are extremely resistant to
attack by bacteria and fungi.  While not immune to ultraviolet in sunlight,
the attack is slow and affects only the surface of the plastic.  Some of the
plastics—notably polystyrene—have poor weatherability, but none of them de-
grade completely.  There is a form of advantage in this to the landfill.
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Since virtually all plastics are essentially nonbiodegradable materials,  they
d<> not contribute to the pollution of ground water or evolution of gases.
     They may, however, in certain physical forms, introduce special problems
in landfills because they are difficult to compact efficiently, due to their
resiliency, with ordinary equipment such as tractors, drag-lines, or steel-
wheeled compactors.  Plastic films, sheets, and bags tend to become entangled
in the treads, wheels, and radiators of spreading and compacting equipment.
     Because plastics are not readily biodegradable, composting has no effect
on them.  If plastic wastes are introduced into sewage treatment systems s  they
create problems.  Sewage treatment plants are designed to handle basically
biodegradable animal and vegetable products.  Not only are many sewer systems
already overtaxed, but also waste water is often reclaimed and reused and thr
danger of chemical contamination could be present.
     From the above remarks, it is apparent that the advantages of plastics
to hospitals for the fabrication of disposables and for packaging may be self-
defeating.  Each year during the past 10 years, the purchase of plastics by
hospitals has increased at a rate of approximately 20 percent, in each case
replacing an item made of paper, glass, metal, rubber, or a textile made £rom
animal or vegetable fibers.  In most cases, the plastic use has been in high
volume, as  it represents a disposable item that replaces a reusable item.
     Long before the current energy crisis affected the production of plastics,
many hospitals decided that they had reached  the point of no return in the
purchase of plastics.  With the current converting of hospitals  to reusable
items, the  ever-rising plastic purchase curve may commence to  level off, or
actually decline.  Recent surveys by the  study  team have shown that several
large hospitals feel that the most successful way they can combat  their present
solid waste problems is to greatly reduce purchasing of disposables.  In order
to reduce labor costs, at least 70 large  hospitals have spent  large sums on
automating  and mechanizing their processing departments, such  as Pharmacy,
Central Sterile Supply, Medical Records,  and  Dietary, and embarked on a seriour
return to reprocessing reusables manufactured from glass, metal,  and  other
            materials.
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                      HOSPITAL WASTE MANAGEMENT PATTERNS

     The management  of  solid waste in  hospitals has greatly improved during
the past 20 years.   It  has also become much more expensive in personnel,  sup-
plies, and equipment that are used.
     Any visitor to  a hospital quickly learns that he is viewing a complicated
and interrelated set of work procedures in which peaks and valleys are very
evident.  A hospital is a structured environment which (though many patients
may not like to admit it) is designed to give efficiency to the medical and
surgical care being rendered.  There are early and mid-morning peaks in work
loads ranging from giving patients baths, to readying them for medical and
surgical procedures, to tidying nursing floors so that they give an uncluttered
appearance to the patients and their visitors.  Other peaks of activity are
created by the  serving of meals,  given to most of the patients at their bed-
sides.  There are also slack periods during  which,  in nursing wings, nothing
appears  to be happening  except  the updating  of patient charts at the nursing
station.
      The  ancillary  and support  departments  are  operated   for  the benefit  of
the medical  team as well as  the inpatients  and  outpatients.   Surgeries have
their peak periods  during the morning  and  early  afternoon hours.  The labora-
tory and  radiology  find  that the bulk  of  their  work takes place during certain
hours of  the day, based  on the  time  samples are collected or  pictures made,  in
order to  provide physicians  and surgeons  with diagnostic data within the  time
frame they have set.   The kitchen and  the  food pantries  on the  floors  are
obviously tied  in to meals,  with hospital  cafeterias often serving  twice  as
many people  at  a sitting as there are  inpatients in the hospital.   Central
 sterile supply, the receiving department,  and the warehouses must fit  the
 routine of supply management in the institution, with peak times  for breaking
 open cartons and issuing supplies and materials to the floors.
      This routine of peaks and valleys has a definite effect on the way  solid
 waste is managed in the  average hospital.   As mentioned, activity connected
 with the diagnosis, care, and treatment of patients involves people and  it
 involves supplies,  and these in turn generate solid waste in peaks and valleys
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throughout the 24 hour day over which all hospitals operate.   In most  hospitals
successful waste management means concentrating on the peaks  to eliminate them
as rapidly as is practical.
                             PERSONNEL UTILIZATION

     There appear to be two basic approaches in utilizing personnel for waste
pick up and transport.
     The first  is known as "random" collection, in which a large number of the
total staff each devote a percentage of  their time to handling waste.  For
instance, during the day shift,  the maids and porters from the housekeeping
department clear waste from baskets in patients rooms, outpatient clinics, and
from public areas.  Assisting  them may be the  nurse  aides who will also move
waste;  along  with technicians  in the laboratory,  pharmacy, radiology, inhalatio-a
therapy, and  central supply department;  clerks and typists in  the offices; and
maintenance,  engineering, supply, and laundry workers.  Most of  this personnel
is  not  on  duty  during the evening shifts. During  night hours waste pick-up is
performed  mainly by nurses aides from patient  rooms  and  the Emergency clinics.
      In each  case  the amount of  handling of  waste by an  individual is relatively
limited;  consisting mainly of  emptying baskets or other  containers,  normally  in
a bagged condition, and  carrying the  bags to a nearby collection room on  the
floor,  or  depositing  the bags  in the  nearest vertical chute.
      The total  hours used by all this  staff  added together become quite sub-
stantial,  even  though  the individual  increments  are  in minutes.   As  a  result  of
ti«e and methods  studies, many hospitals have switched partially or  totally
 from the random collection  system;  and  have  set  up one or more specialized
voste handlers  to cover  the entire  building.
      On a "structured" system the maids  and  porters and  possibly  nurse aides
may clear and bag waste  from patient waste baskets and  carry the bagged waste
 a distance of 50 to 70 feet to a nearby collection room, such as a soiled
utility room on a nursing floor, or a chute room, where they will leave it for
piefc-up by specialized handler(s).   The special waste handlers, from the  house-
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keeping,or materials management department, will then pick up the bags and
transport them vertically by chute or cart.  Normally these handlers will also
make "sweeps" of the building and clear all containers from support and ancil-
lary areas and from all offices, public areas, and corridors.  This is now the
most common labor method used by hospitals.
     Some hospitals have taken the system one step further and only the spec-
ialized handlers are permitted to remove and bag waste from any container or
area of the hospital.
     Time and cost studies have revealed that such specialization reduces the
overall labor cost considerably and gives management a much tighter control
over waste handling practices.  If abnormal peaks develop in any area they can
be handled quickly and as part of an entire,  integrated system.
                    THE USE OF CONTAINERS LN WASTE HANDLING

      During  the past  20  years,  hospitals  have  become  sensitive to  accusations
 that  their environment is  "germ laden"  because of  the sick patients  and the
 potential "carriers"  among the  staff who  are handling these patients.   The out-
 breaks  of staphylococcus in many hospitals  a few years ago clearly revealed
 the contact  problems  that  a hospital must face.  More limited, less  known, and
 much  more deadly,  have been problems with other bacteria and viruses,  such as
 infectious hepatitis.
      While American hospitals have installed the heaviest quantities of steril-
 izers to be  found  anywhere in the world,  in order to rapidly kill bacteria
 present on supplies,  material,  and equipment,  they have also learned that
 "sterile filth is  no  more desirable than unsterile filth."  To maintain a pro-
 perly controlled environment in a hospital, constant cleaning of almost every-
 thing is essential.
      With  research into  aerosols and the effect of airborne contamination in
 hospitals, administrators have  learned that open, overflowing waste baskets
 and trash  cans  cannot  be permitted in a "clean" environment.  It has been
 determined  that solid waste in a hospital should be contained or encapsulated
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almost as quickly as it is generated and, secondly, that it should be removed
as rapidly as possible from the nursing and support areas packaged in a bag
durable enough to withstand transport.  The number of waste baskets and trash
containers has increased each year, with the galvanized metal container (with
the lid missing) giving way to synthetic, rust-proof  rubber created by Industrie
designers and with a lid that locks in place.
     The number of plastic bags to line  these containers has increased to the
point where they are used almost universally in hospitals, adding to the increast
of plastic in the waste stream.   The bags are capable of sealing, self tying,
or closing with twist wire bends, to provide a spill-proof, leak-proof contain-
erization when transporting waste through the building.  Only a few years ago
the few that were used were usually of flimsy, clear plastic.  Today such bags
are available in a host of sizes, thicknesses, construction, and  colors.  Red
bags are available for infectious waste;  yellow for  glass and metal cans; tan
or clear to line waste baskets; black, white, or  brown  to hold other bags dur-
ing, transport; laminated bags or plain,  straight  sides  or gusseted, with mil
thicknesses from 1.5  to 10; even anti-static bags for use in surgeries.
                     THE ELEMENTS OF THE SOLID WASTE SYSTEM

      Solid waste management in a hospital  is a "stepped system."  A series of
 operations follow in logical order,  one step at a time.
      The first  step is to  contain the waste intially,  as it is generated,  where
 it ±& generated.  This normally involves discarding it into a nearby waste
 basket or trash can, which  is usually lined with a plastic bag.
      The second step is normally the initial horizontal transport of the bagged
 waste* from the  waste container to the initial collection point.  This may be
 one of several  locations.   For example, the waste may be moved to a chute room
 or soiled utility room. Or it may be placed directly into a gravity chute and
 dropped to a collection room in the basement or first level.  Or it may be
 picked up by a  hauling cart and taken horizontally to an elevator, vertically
 to a lower level, and then horizontally to an intermediate collection area in
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the basement,  or taken all the way to a final and central collection point.
Or it may mean placing it in a pneumatic tube system for delivery to a central
collection point.
     The waste may be processed in some manner before it reaches the final and
central collection point.  It may be compacted on the floors before transport
through the building.  It may even be sterilized.
     The third step is to move the waste from all the initial and intermediate
collection points to a final and central collection point in the building or
in an adjacent service building.
     As the fourth step, all the assembled waste from all parts of the complex
is usually processed in some manner.  This may mean merely dumping it into an
open hauling vehicle for off-site removal.  More commonly it means compacting
it in special equipment  so  that volume  reduction is obtained.   Or it may be
incinerated.  Or it may  be  shredded, pulverized, or milled.
     The  fifth  step  is to haul it off  site,  bagged, or  as raw  loose waste, or
compacted,  or ground,  or milled,  or in the  form  of  ash  residue.
                AUTOMATION  AND MECHANIZATION IN WASTE MANAGEMENT

      The  majority of hospitals transport  solid waste within the building by
 hand methods,  either hand  carrying it in  bags, or moving it by a pushed or
 pulled  cart.   These methods have been used in virtually the same manner since
 the first hospitals were formed.
      While many hospitals  have gravity chutes to transport waste vertically,
 hand methods  must be used  to carry or push the waste to the chute loading sta-
 tions;  and hand methods or carts must be  used to carry the waste from the col-
 lection room  at the bottom of the chute to some central collection point.
 Gravity trash chutes have  created fire hazards in some hospitals.  In the past
 few years, new fire codes, requiring better construction specifications, fire
 walls,  and sprinkler systems, have obsoleted many existing chutes.
      Many more hospitals have purchased mechanized volume reduction equipment
 than have purchased mechanization for waste transportation.
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     The first volume reduction equipment were the incinerators that virtually
every hospital had installed by the 1920*s.  During the 1950's, wet grinders
for garbage were installed in kitchens, serving the dual function of volume
reduction as well as transport to the sewer line.  During the past 10 years,
as hauling costs have mounted, compactors have been purchased by over 40 per-
cent of the hospitals, ranging in size from home-type units for installation
on nursing floors and in ancillary departments, to heavy duty machines coupled
to 40 cubic yard off-site waste hauling vehicles.
     The most recent additions in mechanical equipment for volume reduction
have been the shredders, attrition mills, hoggs, and dry grinders that a few
hospitals have installed.  These, like compactors, range from small, portable
units for shredding office paper, to 3 ton per hour attrition mills installed
at the central collection point and connected either to a compactor or an in-
cinerator.
     Less than 200 of the 7,000 hospitals in the United States have automated
and mechanized the transportation of solid waste.  Among these institutions a
variety of methods are being used:  including wet grinding or pulping; carry-
ing in tote boxes on vertical and horizontal conveyors, or in dumb waiters;
the use of automated carts, either controlled by electric circuits on the floor
6r suspended  from overhead rails; the use of combination systems, with auto-
mation of the vertical movement  (ranging from gravity  chutes to  automatic ele-
vators) tied  in with hand or  cart movement for horizontal transportation in
fctte lower levels.
     A survey of over 100 hospitals  that have already  installed  or are purchas-
ing various types of automated  transport systems for solid waste reveals that
the installed cost ranges from  $100,000  to over  $1,000,000 for  the equipment
and space utilized.  Only a small number of  these  institutions  have  employed
cfte services  of professional  consultants and engineers, knowledgeable in solid
wafete management, and with  in-depth  experience  in  the  design and feasibility
of these  expensive systems.   In very  few cases were  intensive  feasibility
studies made  of the volume of waste  by specific  generation points before the
systfems were  designed.   The location of  sending  stations,  the  routing of the
syWtem, and the design  specifications  were usually done by a  system  manufacture
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and incorporated into the construction drawings by the architect.
     Hospitals for the first time are studying in great depth the economic
feasibility of such automation and mechanization.  These studies are revealing
that some of the directions that have been taken in the past have not resulted
in operational savings.  Caught in the squeeze between shrinking capital dol-
lars for equipment and pressures to reduce operating costs, hospitals are
learning the importance of feasibility studies, done professionally and done
in depth, before embarking on expensive programs of automation.
     With the external constraints and pressures on hospitals from local com-
munities with regard to the off-site removal ot waste, combined with the inter-
nal pressures, hospitals are also looking at another aspect of solid waste man-
agement; namely the possibility of drastically reducing the generation of waste
in the first place.  This involves their entire philosophy of operation.  It
particularly involves  decisions concerning the purchase and use  of disposables
versus reprocessing medical and surgical supplies.  Some hospitals that, up  to
two years  ago, were heavy users of disposables have made abrupt  changes in this
direction.  There  are  instances where  the purchases of  these  items have been
reduced  by as much as  50 percent  and replaced  by  reprocessed  reusables.  The
effect on  the total  solid waste  load has  been  dramatic, in some  cases  cutting
the total  cube  by  as much as  65  percent.  A  subsidiary  effect has been a con-
siderable  reduction  in operating  budget,  as  these same  hospitals are learning
                                                                             9
that intelligent,  mechanized  reprocessing is now also economically  feasible.

                                   REFERENCES
1.  The  1973 A.H.A.  Guide  to  the  Health  Care Field.
2.  Hospital  Industries  Association  Reports, 1973.
3.  The  1973  A.H.A.  Guide  to  the  Health  Care Field.
4.   Ibid.
5.   Ibid.
6.   Ibid.
7.  Ross Hofmann,  Associates,  unpublished  surveys,  1954,  1967, 1973.
8.  Hofmann,  R.  E.,  Automation of hospital  Sterile Processing, 3rd  ed.,
       Coral Gables,  Ross Hofmann, Associates,  publishers,  1972.  176  pp.
9.   Ibid.
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                    2- ARCHITECTURAL DESIGN INFLUENCES
     A modern hospital is probably the most complex institutional structure
that has been designed in the Twentieth Century.  The interrelationships be-
tween patient areas, both inpatient and ambulatory, and the ancillary and sup-
port departments run into the thousands.  What is done in one function or area
of the complex affects directly or indirectly dozens of other areas and func-
tions.  In the field of solid waste management, these complications are seen in
every study performed in the past 20 years.
     The architectural and engineering design of a hospital is always a com-
promise.  There are over 100 major, support systems involved, of which solid
waste management, movement, disposal, and removal is only one.  Within spaces
that have often been likened to the "interior of a submarine," several support
systems, often designed by several different disciplines, must fight for
entrance and egress, routes, support lines from interfacing systems, and sheer
space.  The maze of pipes, wires, ducts, chases, etc., is thus a compromise and
it is compromised still further by the installing trades and change orders
during construction.
                    PLANNING SOLIff WASTE TRANSPORT SYSTEMS

     No hospital has yet been designed where the solid waste management system,
whether it be pneumatic tube or other method, takes precedence over all else
and thus has been able to obtain ^  perfection in layout."  Being a compromise,
to fit with other systems into the structure, there are obviously built-in
weaknesses in the system layout when superimposed on an architectural design.
     Too often, a study of such systems reveals chat the mechanical components
are operating satisfactorily, ant4 the human elements in operation and mainte-
nance are doing exactly what they #re supposed tc do, yet the system is "weak"
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in one or more aspects of performance,  due entirely to the architectural lay-
out having compromised the system to too great a degree.
     The installed systems usually do not operate at 100  percent efficiency
unless they are planned on facts that are carefully assembled and then they
are programmed to meet these facts.  Good system design and layout cannot be
"ivory towered."  Architectural planning must move from being isolated at the
drawing board to being married with industrial and management engineering.
Before lines are drawn, and the fixed route, chutes, stations and collectors
are positioned, what each must perform should be determined in detail, based
on firm projections of the amount of waste (and laundry)  that will be genera-
ted by each and every department and section of the hospital that must be ser-
viced.  Volume-use-time relationships must be established through a typical
industrial engineering approach.
     With an existing hospital, these facts are readily obtainable by the use
of standard survey and statistical  techniques in which all quantities,
sources,  and  types of  the waste being generated are carefully recorded.   For
new construction, projections have  to be  made based on figures  obtained  from
hospitals of  similar  size, with similar  programs,  and in  a similar zone  of
service.   In  both cases,  operating  projections  for at least  ten years must be
made  so  that  the  systems are neither over- nor  under-sized.
      The  parameters that  must be  developed before  any systems can be planned
and designed  are  the  following:
      1.   What  materials,  defined  as waste, must  be managed,  and what is  their
make-up  from  a variety of standards—e.g.  combustible or  non-combustible;
"contaminated" or "safe," biological,  infectious,  hazardous,  radioactive, tox-
ic, or explosive; grindable or  non-grindable  (such as food wastes);  dissolva-
ble,  or able  to be slurried into  a  sewage system or wet pulping system;  patho-
logical and  surgical,  human and animal  parts,  and tissues; material  make-up
 (paper,  plastic,  wood, metal,  glass,  ceramic,  and textile).
      2.   What segregation,  if  any,  of  waste will  be maintained, to  separate
the "problem" wastes  from the  so-called "safe"  or general waste, and how prac-
tical is segregation,  as well  as  alternate methods of handling  the  segregated
wastes.
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     3.  From whence will each type of waste be initially generated,
     4.  In what quantities (both weights and volumes), at each generation
point, and at what times of day (peaks, valleys, and averages) will such waste
be generated, by type.
     5.  From what points in the building, by what routes, to what points
(interim as well as final) will all the different solid wastes have to be
collected, packaged, moved, stored, collected again, reduced, and ultimately
removed to some off-site location.
     6.  Due to either internal or external constrains, what time limitations
nay apply.
     7.  What safety regulations or limitations must or should be followed in
handling and packaging these wastes for transportation within and away from
the building.
     Solid waste management is a "stepped system," and each step must lead
logically to and be interfaced with the next step, so the result is one con-
tinuous flowing system without false breaks.  To convert  this to a hospital
setting, it  is essential that the  following steps be studied, analyzed, and
evaluated before the  architectural design can be finalized:
     1.  How the waste will be initially deposited by the person or device
generating it, and in what type of container  (e.g. lined wastebasket or gar-
bage can, closed or unclosed, mobile  cart, or cloth bag), and in what location
     2,  How the waste will be transported from this  point, over what route,
over what period of time,  at  what  time, by whom, in what  type of container,
and by what method  (cart or hand  carried),  to  a waste chute or other removal
method.
     3.  What temporary  storage and/or processing will occur  between initial
generation points and the  transporting of  the  waste  (e.g. use of soiled utili-
ty rooms, floor storage  rooms, corridor storage, autoclaving  or melting,
floor  compacting, grinding, double bagging  or  special packaging, and/or  label
ing, etc.);  what volumes and  types will be  involved,  and  over what  time ele~
meats.
     4.  What  transporting problems  and times  may be  involved.   This includes
waiting  times for access  to elevators and  waste chutes and  the  routes  that
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must be followed, to remove from the floor to a central collecting point.
     5.  If the waste is unloaded into an intermediate location, it must then
be moved once more, either manually by cart, or by one of a number of available
automated methods, to a central and final collection and/or reduction point.
     6.  From the central collection room, the waste may be transported into
the final storage or reduction area.  This can be located in a trash room in-
side the lower levels of the building; in & separate trash building; on, or
adjacent to, the loading dock, incinerator room, or compactor area.  Or some
automation may occur, feeding directly into a hogg or grinder, then via a surge
tank into an incinerator or compactor, or directly into a compactor and/or  in-
cinerator.  Space  for the various equipment items must be carefully planned.
     7.  Finally,  there must be determined what volume reduction will occur
in  each  step of  the  system "in  the  house,"  and how this affects the spaces
planned  for waste  storage.
     Solid wastes  and  their removal interface with the handling of the  returns
of  soiled  reusables  for  reprocessing,  such  as patient bedside utensils,  medi-
cal-surgical reusable  equipment and supplies, eating and  drinking tableware
and utensils,  and both surgical and patient linens.   Studies  and  analyses must
clearly  define these interfaces and how  they affect  and  interact  with the solid
waste  management.
      Solid waste removal also interfaces and may  affect  clean material  delivery
and storage.   Most hospital material consultants  have for years preached the
dangers  of  cross-contamination and the desirability  of  "clean"  and "dirty"  sep-
aration.  This is basically a management engineering problem.   The architectu-
 ral design will obviously affect the problem and  potential solutions tremen-
 dously.   Some  areas, such as  surgical suites and  laboratories,  are often
 designed with  "clean"  and "dirty" corridors that  establish a positive material
 flow to greatly reduce the problem.  Other areas, such as kitchens,  attempt to
 direct flow by equipment placement.  Other areas, which are major solid waste
 generators,  such as patient  care and treatment departments, attempt to control
 the problem solely by personnel management and the introduction of "clean"
 and "soiled" utility rooms.   However, the corridors, patient bedrooms, and
 treatment rooms are simultaneously used for the transportation of both soiled
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and clean items.  Cross-contamination is a real possibility.
      THE VERTICAL CHUTE--PNEUHATIC TUBE SYSTEM FOR SOLID WASTE TRANSPORT

     The principle of pneumatic waste transport systems is a simple one, vexy
similar to a large size vacuum cleaner, combined with a fixture that high-rise
buildings have had for many years—the gravity drop, vertical trash chute.
     To implement the system, one or more vertical waste chutes are installed
in the hospital, with openings installed in them on each floor being serviced,
These openings are the "loading stations" of the system.  They receive solid
waste, normally contained  in plastic bags sized to fit the diameter of the
chute.  The loading  stations are similar in appearance to those in standard
gravity chutes.  In  one system they are almost identical to these, as modified
gravity chutes are used for the vertical drop.  In other systems they are
sophisticated by the inclusion of a hopper that has an outer door for the use
of the operator in loading the waste, and an inner door that opens on a timed
cycle to permit the  bag to drop into the chute.
     At the bottom of the  chute is a connection to a tube of identical diameter
that pneumatically carries the waste horizontally through the hospital and
finally deposits it  in a box or tank known as a "collector."  On a timed basic
that is part of the  total  transport cycle, doors open in the base of the col-
lector and drop the  waste, by gravity, onto or into whatever is the next step
in the process—a compactor, a cart, a dry grinder, a truck, or a trash room
floor.
     There are  two basic system designs.  One uses a gravity chute and  the
bagged waste drops down onto a plate or slide valve at  the bottom.  This plate
cycles on a timed basis, opening  to  let the waste fall  into a horizontal  tube
and an air stream that carries it  to the collector box.  This is known  as a
gravity to vacuum system.  The other system uses a vacuum or air stream to pull
Che bag the entire route,  from  the  loading station  in the vertical chute  to  the
collector box.  This is known as  a  full vacuum system.
     Both systems use large fans  to pull the waste  through  the system,  with  the
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transport air allowed to enter the system at the opposite end to the fan.  It
is the velocity of the suction air stream that sets the speed at which the
waste moves through the system.  When the waste drops into the collector box,
the suction air continues through a port in the box, and by more tubing, tra-
vels to the suction fan, and through it by an exhaust duct to the atmosphere.
                              SIZING THE SYSTEM
VERTICAL CHUTES
     Based on chute  loading surveys and time studies,  it is obvious that select-
 ing the proper number of  loading stations  and  the proper location  for each is
 not simple.  We  are  dealing with a system  of vertical  chutes  that  are connected
 horizontally, at the bottom usually.   While it is possible  to lead the  flow  of
 material  downward other  than by a straight vertical  drop, it  complicates the
 installation of  the  system and  increases  the expense.
      If  the  areas to be  serviced are  laid  out  identically and are  stacked
 exactly  one  above the other in  a high-rise structure,  the installation  of  a
 straight  vertical chute  is relatively simple.   It can  go straight  up  through
 the middle of the heaviest activity,  floor after floor.  The  loading  stations
 will  be  stacked  above each other on each  floor for  deposits into the  chute.
      With this situation there  is still some  flexibility of architectural  de-
 sign  on  each floor,  as we are dealing with a  round  chute.   It can be  loaded
 from  different directions on each floor,  such  as loading second floor from
 the north side of the chute, third  floor  from  the south side, fourth  floor
 from  the west side,  and  so on.  Hence, location and entrance into chute rooms
 can differ somewhat  in  the floor plans when  stacking floors in an architectural
 design.
      However, if in  stacking, architecturally, one  floor  above the other,  it
 is decided  that  the  location of the  chute loading stations  will change hori-
 zontally from floor  to  floor,  the design  becomes complicated.  If on  second
! floor the chute  loading  station is  to be  next  to the nursing station, and on
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the third floor this is still desired but the nursing station has been moved
fifty feet to the west of the second floor location, and on fourth floor
twenty feet to the east, we need a vertical connector between the three that
must travel fifty feet horizontally on one floor and twenty feet on the other
J.H order to link up.  With a full vacuum system, this is possible, providing
there is ceiling space for the  tube.  With a gravity drop system, it is out
of the question.
     J$ is obvious that, architecturally, the lower the height of the building
o* the less vertical drops required, the easier it is to design a system; the
were important the horizontal rune become.  However, as few one and two story
hospitals are being constructed today, the designers have to worry about the
Vertical stacking problems.
        STATIONS
     TO reduce  the  number of vertical  chutes and loading stations to a minlmu; ,
       ra should do «xtreaely  detailed analyses of the entire waste load of
    building and then "zone"  the  entire  complex, locating the vertical chutes
and loading stations on a coapromise basis-.  It would be impractical to have
% chut.e loading  station exactly where every small sub-section generating  solio
vjaftte. would like one.   A rule of  thumb is used that is based on walking time
tp, load the chute.   An area radiating out from the chute station between  70
anjt 1QQ feet is  considered ideal  to be serviced by the particular station.
      To date, zoning on this  basis has left something to be desired in any
dftfj.gn we have studied.   The  simplest way to check this is to run a one-week
sj^vey, recording every bag that  is deposited in every chute.  A review of  ch
chapter on volumes of waste generated shows that 90 percent of the total  vol-
ufle in any hospital is deposited  in under 50 percent of the chute loading
stations.  This  raises the question as to whether the remaining 50 percent  of
t^, chute loading stations were worth the expense of installing.  How much
did this virtually unused 50  percent of  the stations cost?  How many years  of
extra walking labor time to haul  this 10 percent of the total waste to the
other 50 percent of the stations  would be involved before the extra stations
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pay for themselves?
     Hence, in zoning a system, walking distance to the chute station must be
factored mathematically with volume of waste generated within each zone, before
a decision can be made whether a particular station should be installed.  This,
in turn, means virtually designing the operational procedures for waste col-
lection before the system is designed.
     Some basic facts are known in any hospital as to where the greatest vol-
umes of solid waste are generated and over what periods of time during the day
and what the make-up is.
     On the basis of weight, as can be seen from the chapter on volumes and
types of hospital waste generated, from 10 percent to 20 percent cannot be
deposited easily in a pneumatic chute and tube system as they are currently
constructed.  The  size of the waste pieces defeats the ability to load into
the chute.  Typical examples are  large cardboard cartons, construction materi-
als, crating and packing materials, iron pipe, large metal drums, etc.  If
these  items end up on the floors  of the hospital,  they will have to be hand
trucked to the central collection point.  Certain  other items, either liquid
or solid,  should not be loaded  because of their hazardous nature; such as
highly corrosive,  explosive, inflammable, or  radioactive materials.  These
may be 1/2 percent of the total waste.  Other items possibly should not be
sent through the chutes, unless they  are packaged  in  spill-proof, unbreakable
containers; such as highly  infectious fomites, laboratory samples, and patho-
logical specimens.  These may be  as much as 4 percent  of  the total load.
     The  remaining 75 percent  to  90 percent of the total waste generated by
the hospital could be transported by  the chute system and the generation
points, times, and material make-up are known for  all  hospitals  in a general
way.   Past studies have shown  that 80 percent of  the  total  is generated by
20 percent of the  departments,  with surgery,  dietary,  nursing stations, mater-
nity,  laboratories, and the computer  department leading  the way.  This  overall
data can  be refined  in an existing hospital or projected with comparative
studies for a new  hospital.
     From this, a  grid can  be made for each floor  on  a zoned basis, as we have
described, and the vertical chutes and desired loading stations  overlaid on
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the architectural plan.  Hopefully, with a building in the design stage, the
architect and owner will agree to permit the vertical risers to be placed in
the proper locations,  With an existing building, the placement will depend
on finding a clear vertical route or shaft (duct shaft, elevator shaft, etc,}
even to the point of placing it external to the building, because there is an
way to put it through internally.
                             CHUTE LOADING ROOKS

     It  is essential  for the owner to  realize that the architect must enclose
the vertical  chute  in a fire-rated shaft.  With its installation, a chimney
has been added  to the building  that  could spread a fire in the lower part of
the building  upwards. This take* up space and must be allowed for.  The
latest  thinking is  that the chute loading room and the chute should be a com-
plete,  fire-rated envelope, with the chute rooms sprinkled, because of the
possibility of  storing trash  in them while waiting to load a chute.
     this raises the  question of how large a chute loading area should be.
Until a few years ago, when gravity  trash and laundry chutes were  installed
the Loading doors could be in an open  corridor or an open alcove.  Modern cod
prohibit this and call for a  room in which to load the chutes, and normally
with a  fire-rated door.   With a gravity to vacuum system, there should be no
delay in loading the  chutes,  ffee chute loading room should be only large
enough  to:  comfortably carry the wAfte bags into the room; comfortably
maneuver the  cart or  other conveyance  being used to carry the bags; and  allow
the room door to open and close wijjjbout getting in the way of loading or cart
maneuvering.
     With a full vacuum single  bag system, as will be seen, there  is often
waiting time  to load  the  chutes. Aides, nurses, maids, and porters may  refvu-r
to wait; also such  delays a«e expensive in labor wasted.  Administration at
the same time wants the patient routes, nursing stations, support areas,  and
corridors clear of  waste  and  soiled laundry and wants to prevent cross-
csftfcamination between the soiled and clean supplies.  The dilemma  arises—

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where to temporarily store the waste and laundry until it can go down the
chute.  And secondly, what quantity will be involved at any point in time.
While admittedly temporarily storing waste bags and laundry bags in the chute
room is not good practice, it is better than storing them in the adjacent hall-
ways.  With a full vacuum system, that cycles slowly and accepts only one bag
at a time, in peak periods some such storage will be necessary.  The rule of
thumb that has developed is to allow enough floor space in the chute room to
hold a cart capable  of holding 12 bags.  This means a chute room at least
45 square feet in size.
                                    FAN ROOM

      The main architectural requirements  are sufficient  space  to hold  and be
 able  to easily maintain the installed equipment;  sufficient  strength of  floor
 to  hold the heavy fan and motor without  transmitting vibration into the  sur-
 rounding area; sufficiently thick walls  to prevent transmission of sound out-
 side  the room; adequate space and air flow to keep the room  and its equipment
 cool; proper location in the complex so  that the  effluent air  from the fan
 can be exhausted without affecting the environment.
      There is no fixed rule as to where  the room  should be located in  the
 complex as long as the above criteria are met.  In general,  fan rooms  are
 installed on a roof area or on ground level.
                                 CONTROL CENTER

      Architecturally, the optimum location for this area is in the general
 location of other control engineering centers in the hospital.  In the vici-
 nity of the Engineer's office is the probable location.
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                               COLLECTOR BOXES

     A major weakness in many hospitals is that they have too  small  an area
for a loading dock and receiving section.  With a pneumatic  tube  system,  this
area must be large enough to fulfill its function.
     If the hospital has an in-house laundry, the soiled laundry  collector
box frill be installed in the soiled section of the laundry and should have a
receiving and sorting area under it of at least 120 square feet.
     If the laundry is remote from the hospital, the most protection from
theft and the least labor in handling at the end of the line,  is  to  construct
a truck well, with a protective and locked fence around it and load  an open-
top truck or trailer at this location.  The linen collector  would be placed
above the open trailer.  Hence, at least 15 feet total head  height would be
required from base of well to top of collector.
     The trash collector should be placed where it can be most directly fed
into the collection and reduction equipment that will be used.  This also
infers providing  sufficient vertical height and floor space  to accommodate
all the necessary equipment.  This also  infers that the location is  easily
available to hauling trucks for removal  of loose or compacted waste  or
Incinerator ashes.  This can be an area  adjacent to the hospital loading dock.
a separate dock area, or in a separate service building.
     If the collector is to discharge directly into a compactor-hauling bin
asenbly, a minimum of 14 feet head height and a minimum floor area of 12  ft
by IS ft is required for the compactor,  plus space  for the placement of the
receiving-hauling bin.
     If the collector is to discharge into an attrition mill or hogg, with
a cyclone-surge tank-filter assembly, the vertical  space required is up to
21 ft.  Often, the hogg is recessed  into an  8  ft  deep pit to reduce  floor
level height problems as well as  reduce  noise  transmission.  Floor  space  to
provide proper maintenance room for  this entire  arrangement is a minimum  of
20 ft by 30 ft.   To  this must be  added  the space required for a  compactor
and hauling bin or an  incinerator following  the  surge  tank.   Hence,  in
total, 1,500 to 1,650 square  feet of space say be required.
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                STRUCTURAL STRENGTHS FOR INSTALLING EQUIPMENT

     The heaviest equipment is at the end of the line with items such as com-
pactors, hoggs and attrition mills, surge tanks, and incincerators.  Equally
heavy, per square foot of floor space, are the heavy motors in the fan room.
Next are the collector boxes, many of which are suspended from ceiling beams.
All floor and ceiling loads should be calculated carefully to ensure there is
sufficient structural support.
     The chief architectural problem is to eliminate vibration, either within
the tube system, or being transmitted as sound or noticeable structural vibra-
tions.  In the chapter on construction analysis, the importance of vibration
isolation has been stressed.   The  importance of rigidly and  strongly anchoring
the pneumatic tube to the  structure has  also been  shown.   This  infers concrete
or other dense material  capable  of holding  the  mounting system.
                             GENERAL CONSIDERATIONS

      When an analysis is performed of the total waste removal problem of a
 hospital, it is seen that a pneumatic chute and tube system does not solve all
 removal problems.   Items that are too large for the chutes, or for one reason
 or another are considered too "hazardous" to send down the chutes, will still
 be transported manually from generation points to the central collection area.
      Whether the material is bagged and sent down the chutes or is hand hauled
 in a cart of some type to the ground level, the importance of avoiding cross
 flows and cross-contamination between the transportation of solid waste and
 the transportation of soiled reusables for reprocessing and the transportation
 of clean supplies cannot be overstressed.  This appears to be one of the major
 archiectural weaknesses discovered when an analysis  is made of solid waste
; management in hospitals.  The use of service corridors and service elevators
 for the movement of supplies and of  solid wastes  appears to have  been installed
 in too few hospitals.  Such corridors and elevators  should not be available
 to patients and the general public,  and should have  limited use for the move-
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ment of staff.  Too often, we see an elevator or a main corridor being used
simultaneously for the  transportation of a cart loaded with bags of solid
waste, a patient being  moved on a stretcher, several of the hospital staff?
from nurses  to porters, and a sprinkling of visitors.  It would appaar that
more attention should be given in the designing of hospitals for clear
separation of traffic flows, to avoid this situation.  Further, conditions of
this type usually  create much extra waiting time in both the movement of
supplies and the  transportation of solid waste, increasing the operational
costs  to the hospital.   This is particularly true when service elevators,
reserved exclusively  for supply movement, have not been included in a high-
rise structure.
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                 3 DESIGN AND CONSTRUCTION CONSIDERATIONS
     The purpose for which pneumatic tube systems are used in hospitals is to
transport safely and free of cross contamination, without plugging, or failure
to move, loads of solid waste and soiled laundry.  As it is possible for a
transporting bag to break or spill in transit, this infers also the ability to
transport loose particles of solid waste and loose textile items.  These facts
set certain limits and define certain standards for any such system.
     It is impossible to study the existing systems with respect to the move-
ment of solid waste only, as in many cases both soiled laundry and solid waste
are transported in the same vertical chutes and pneumatic tubes.  In other
cases, they are in separate chutes and tubes but controlled by a common suction
fan.  The transporting of laundry affects the transporting of waste, and vice
versa.
     A review of these systems that have been installed in hospitals reveals
a wide variation in design and construction standards, despite the fact that
all such installations are supposed to perform almost identical tasks.  A
detailed analysis indicates that these variations  in approach arose from the
fact that the owners, the specifiers (architects,  engineers, and consultants).
and the vendors attempted in many cases  to reduce  the capital cost of  the in-
stalled system, despite a potential for  serious effects on operating costs
during the first ten years of use.
                        SINGLE TUBE FULL VACUUM  SYSTEMS

     The first pneumatic transport design used in  a hospital was a single  tube
system, to carry both solid waste and soiled laundry,  and with a single fan at
the end of the line to create the suction to carry the load through  the system.
This fan runs during the period of the day  the system  operates.  There are
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separate loading stations throughout the complex for solid waste and for soil;
laundry.  These are normally in the same "soiled" collection room, and are ad-
jacent to each other, leading into a common vertical riser or chute.  When a
chute loading door is opened it exposes a sloped hopper, or loading station
with an iniier door leading to the vertical chute.  The operator places a sin-
gle bag of waste, ot of  soiled laundry, in the indicated (waste or laundry)
hopper and closes the outer door,  fie  then presses a button or turns a switch
to activate the movement.
     This creates a sequence of events.  A roof damper opens to allow air to
be sucked through the vertical chute involved and through to the exhauster
fan.  All other chute roof dampers remain closed.  A damper over a continuous
operating fan is raised, allowing the  fan to suck in this air; or alternative
ly the suction fan starts up.  After proper air flow is established itr tb« sj
tern, the inner door of  the loading hopper opens by a compressed air cylinder
allowing the bag of waste or laundry to drop into the vertical chute and In.t^
the suction of the ait  stream.  Depending on whether the waste or laundry se-
quence has been activated by the operator, at some point in the system a
"aiverter" valve swings into the proper position to shunt the bag into the
proper collector box at the end of the line—either waste or soiled laundry,
After a timed delay to  ensure the bag  has dropped into the chute, the innax-
dbor of the station closes.
     The bag travels the tube system and drops into the collector box.  The
effluent air stream that provides the  suction continues out of a port in  Hz*.
box and travels by more tube to the fan; it continues through the fan and  ic.
exhausted to atmosphere. At this point the dampers all close.  Based upon  ?
prefigured time cycle,  doors Bpeti in the bottom of the collector box  and  dro
the bag out of it by gravity otito the  floor, a cart, or whatever else is  de-
signed into the system  beneath  the box.  The system is then ready to  start;
over again and accept its next  bag.   In short, all such systems work  on  the
same principle as a vacuum  cleaner.  They are Called "full vacuum"  syr,terns,
the vacuum is pulled on the vertical  risers, or  chutes, as well as  on all  lh
horizontal tubing, creating a  suction  throughout every part of  the  system.
     Such a "single tube" system obviously can create problems.   Originally,
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some had only one loading door at each station with two activating switches to
push—one marked "trash" and one marked "laundry."  If the operator pushed the
wrong switch, the diverter valve had no way of. knowing this.  Waste wound up
with soiled laundry and vice versa.  To prevent this, separate loading doors
and hoppers were used—one for waste and one for laundry—each still leading
into the common vertical chute, the separation being purely psychological.
     However, human mistakes still could occur.  Or, mechanical and electrical
problems could develop, in which the diverters could be faulfy and not divert
as scheduled:  again resulting in misdirected loads.
     Another problem with "single tube" systems is that a bag of waste could
break or spill in transit.  When followed by a bag of laundry, particles of
waste often ended up in the soiled laundry, the most common being broken glass.
     It was also discovered that such single tube, full vacuum systems were
rather slow.  They were designed to carry a single bag in the system at a time,
with a total cycle time, from  the placing of the bag in the chute loading hop-
per to dropping out of the collector, as high as 40 seconds.  This meant that
less than  two bags per minute  could go  through the system.  The standard "push
button" design ensures that the inner door of the loading hopper provides a
positive seal or closure between the "soiled" chute room  (and the loading hop-
per) and the vertical-horizontal pneumatic system.  The inner door leading to
the chute  must be closed completely before the outer door of the loading hopper
can be opened.  This is accomplished by an electric or air-operated lock on
the outer  door.  The purpose is to ensure that the system operates on "one bag
at a time."  Also that it does not draw air in from the chute room and hence
change the basic balance of the vacuum pull for which it was designed.  Such
systems often have as many as  50 or more loading stations (divided between
waste and  laundry) and they cycle normally on a "first come-first served"
basis, with relays activating  the stations from a simple memory circuit.
     Let us assume that, during the morning service peak, seven people decide
to use the system, in various  parts of  the hospital, at the same time; and
that each  has up to five bags  of laundry and three of waste to get rid of on
this particular trip.  Let us  assume further that all seven operators load
their first bag (waste or laundry) about the same time into the particular
                                      -43-

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cfrate Station they are using.  Each also pushes his activating switch.   The
system cycles on a "priority load" basis through relays in the control  panel.
Each operator must wait until the system has cleared and the signal light on
Ms dder shows his first bag has been transported, so that he can load  in his
Second bag, and so on for each successive bag.  He waits his turn in line as
the System cycles between stations.  For each bag, he may be second in  line
or seventh.
     Assuming a total of eight bags for each operator and seven stations being
loaded simultaneously, this is a total of 56 bags being put into the system at
a pteftk period.  Assuming each bag takes as little as 30 seconds to travel its
complete route, only two per minute can be transported in total.  Hence, an
operator could be waiting by his chute station for as long as 28 minutes until
he could get rid of his last bag.  Obviously, this is an unsatisfactory situ-
ation, as all seven people loading the chute would be in virtually this same
position and approximately 7 x 28, or 196 minutes (over 3-1/4 manhours) of
expensive labor would be used aerely in waiting time to load only 56 bags into
vertical chutes.
                      MULTIPLE LOADING FULL VACUUM SYSTEMS

     To  avoid  this problem of nolding people at chute loading doors while  they
     thieir  turn will come quickly,  certain busy hospitals asked for a change
ifc  thfe loading sequence and  cycling.   They requested that the principle of one
%ag at a time  in the system  be eliminated.  They insisted that the tube system
%fe  capable  of  hauling,  in a  single  pull, a train of up to twelve bags at once.
In  a full vacuum system,  this was called a "key-lock" method.  Instead of
          the "go" button, the operator turned a key to activate the switch.
     overrode  the system's normal cycling.  As long as the key was "on," the
iiitter door  remained open, as did the  fan damper and roof damper.  In short,
the Vacuum  remained on  and pulled as  many bags as the operator could drop  in,
tftfle tffter another,  or that the collector box at the end of the line would  hold,
To hold  a succession of bags, the collector must be of larger size than for a
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single bag system.   When the key was turned the other way, the collector box
doors would open and drop the whole load of bags it held at the end of the line.
Then the entire operation could be repeated at the same chute station or at a
different station.
     A difficulty in this is that only one operator can use the system at one
time.  When he is loading his door, all other doors lock closed automatically
to avoid overloading the system with too many bags.  Hence, it is normal for
such a system to be used only by special operators, who travel from station to
station and load out all the bags of waste  (and laundry)  that various other
hospital personnel have deposited adjacent  to  the  chute station.  At  least
there  is the labor advantage of only one  individual  engaged in waiting  time,
and  that time  is reduced by at  least 75%  through multiple loading.
      Further, this loading  process has  certain hazards.  The operator  is over-
riding a  full  vacuum system.   Both  inner  and  outer doors  of the  loading hopper
remain open.   While air to create  the  vacuum  is being sucked  from the roof  vent
at the top of  the vertical chute,  it  is also  being sucked by  the fan  from the
open chute loading door.   We have observed enough vacuum force to pull open
 the heavy door of  the chute room itself and to require the operator to hold
 open the outer door of the chute station with the full weight of his  body.   A
 positive "open position" latch appears to be a necessity.
      Another problem of the single chute system lies in the fact that it is
 used to carry completely dissimilar objects in a common tube.  Laundry is nor-
 mally sent through the system in cloth bags, packed rather full and weighing
 from 5 to 20 pounds each.  Waste is usually in plastic bags with loaded weights
 of from 2 to 12 pounds.  Yet the same tube and the same  suction force or air
 velocity is required to carry this wide divergence in load in a single tube
 system.
                         DOUBLE TUBE FULL VACUUM  SYSTEMS

      Due to the problems described in  the  single tube  full vacuum system, de-
  signers decided to sophisticate  the construction of  such systems, though it
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               Single Tub*  Stotion
                                                   Double Tube Station
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                                                      These drawings show the
                                                 various configurations  used in
                                                 loading the stations  of the
                                                 full vacuum systems.  With a
                                                 single tube station that ac-
                                                 cepta both solid waste  and
                                                 soiled laundry, many  different
                                                 configurations  can be used to
                                                 enter the loading  hopper into
                                                 the vertical  chute.   Close
                                                 proximity of  waste and  laundry
                                                 loading doors,  despite  clear
                                                 markings for  the material to
                                                 be loaded, allows  room  for
                                                 loading error by  operators.
FIGURE 1.  TYPICAL  FULL  VACUUM PNEUMATIC TUBE STATIONS  FOR SOLID WASTF
                                  LAUNDRY
                                      -46-

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would increase the capital cost.
     The first approach was to utilize separate tubes for waste and for laun-
dry.  Obviously, this would permit totally different construction specifica-
tions for each tube.  At first a common fan was used to pull the air for both
tubes and a common return air line led from the collector boxes to the fan.
This still meant the systems had to cycle in the same manner as the single
tube system, as the fans and the logic were not designed to operate both the
waste and laundry systems simultaneously or independently.  The latest systems
are entirely independent and separate, each with its own fan, so that loading
of either system does not affect the  other.  The double tube system utilizes
either  the push button, one bag at a  time method,  or the key-lock method for
multiple loads.
                        GRAVITY CHUTES TO VACUUM SYSTEMS

      It was also apparent that pneumatic tube systems for moving solid waste
 and/or soiled laundry have certain operational problems that must be solved in
 providing a satisfactory design.
      The first problem already mentioned is the speed of removal of the solid
 waste or soiled laundry from the floor.  The second problem is whether this
 has to be done by special personnel trained to load the chutes, or whether any-
 one, from janitor to nurse, can handle the task, and on a completely random
 basis; by merely coming up to any chute door, opening it, and depositing in the
 proper chute ("trash" or "laundry") as many bags at a time and at any time as
 is desired.  Thirdly, to be economically feasible the system must move at least
 95% of the total waste cube and weights safely and without any cross-contamina-
 tion problems.  There cannot be all sorts of exceptions as to the type of
 waste that cannot be sent through the system for fear of damage to either the
 system or the environment and thus must be hand-carried around the system.
      A cursory examination of the "old fashioned" gravity chutes show they meet
 all the  loading criteria we have mentioned.  Anyone  can load  them at any time
 and as fast and as much as desired.  And further, the  loading can be in bags
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OE as completely loose  items.  The only limitation on the load descending the
chute is that is is small enough, or secure enough, not to lodge in the verti-
cal chute.  If it meets these  requirements, gravity does the work and the
load dumps out at the bottom.  The mess often created at the bottom is another
consideration altogether.   It  is off the upper floors of the building.
     0»e of the systems studied takes  advantage of this thinking.  The verti-
cal chutes are simply  the "old fashioned"  gravity chutes with separate chutes
for aolid waste and laundry.   The chute doors and loading ramps inside them
ate similar to those  found  in  other gravity chutes.  Some additional features
have teen added.  On  the waste chutes, the loading door is slightly smaller
than on  the laundry chute.   Normally,  a rubber baffle is placed at the outer
circumference  of  the  vertical  waste  chute, at the end of the sloped loading
hopper,  to prevent  any solid waste  that may be descending from the floors
above  from flying into a chute station when it is being loaded.  Further, a
fan downstream in the system creates  a slight negative pressure  through  the
chute  at all  times  by pulling 200 to  300  CFM of  air.  This prevents contami-
nated  air from entering the loading station when the chute door  is opened.
     At  the bottom of each vertical chute is a heavy steel plate termed  a
"slide valve."  The solid waste or the laundry falls down  the chute and  lands
OB this  plate, collecting vertically in the  chute.  On a predetermined time
cycle  (every  few minutes) through the action of  a pneumatic  cylinder,  the
plates slide,  or swing open,  through the  chute wall, one at  a time, and  drop
thft load each is holding into a short transition section below  them.   They
then swing  shut and the vertical chute is momentarily  empty.
     The chamber below the valve curves at the  bottom  into a horizontal  tube
of the same  diameter on the downstream side;  an inlet  air  line  of  like dia-
meter  enters  on the upstream  side.  When  the slide valve dumps  its load down,
the suction fan pulls  the inlet air against the load,  carries it into the hori-
zontal tube  and the suction air flow, to  the collection terminal at the end of
 the  system.
      Discharge of the  chute load is quite rapid (10 to 15 seconds).  In the
cycling, one chute at  a time  is discharged, starting at the downstream end,
 timed  so that as one valve  closes, the next valve opens, until the whole cycle
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(for all chutes)  has been completed.  Loads from two to three chutes may si-
multaneously travel in the tube to the collection terminal, if the cycling is
programmed in this fashion to expedite movement.  Normally the cycling is fig-
ured so that chutes are emptied when the storage load has reached a cubic yard.
As the cycling can be pre-programmed by a time clock, the waste cycle and the
laundry cycle do not have to be the same.  For example, in peak periods the
laundry chutes could be emptied twice as many times as the trash chutes.
     It will be noted that this is entirely different from the "key-lock,"
full vacuum system described earlier.  While the vacuum suction is pulling the
waste or the laundry through the system, there  is no vacuum being pulled on
the vertical chute is a gravity-vacuum system.  It  remains a gravity chute,
but with a negative pressure in it.
     Such a system is not problem-free.  A bag  can  break when it hits  the
slide valve after the vertical drop.  Further,  it can contain glass, other
breakable objects,  and  liquids.  Thus,  the vacuum pull  of  such systems is de-
signed  so that  it can move  loose objects,  such  as broken  glass; or  it  can move
a "plug"  such  as a single bag  or a train of  several bags.   Observations have
been made of as  many as 20  heavy  laundry bags being moved simultaneously in
this system.   The surfaces  of  the  slide valves  are  the main environmental haz-
ard.   They  must  be kept clean  on  a regular basis.   This aspect  is  discussed in
a later section.
      These  are "double tube" systems.  With separate vertical chutes for waste
 and laundry,  the vacuum, or pneumatic,  horizontal  tubes are also  separate and
usually constructed to entirely  different specifications.  Normally, the vacuum
 is supplied by a single fan for  both the waste  and laundry lines,  on the theory
 that the system has enough storage capacity at  the bottom of each gravity chute
 to permit a cycling sequence to  take place over a period of several minutes
 without slowing down chute loading.  A diverter valve switches the fan suction
 to the system (waste or laundry)  being serviced in a particular cycle.  A but-
 terfly valve opens to let in inlet air.  The exhauster fan starts and when full
 flow is reached the discharge valves open in sequence.
      Such a system has much larger loads going through it at one time than the
 other systems described, in order to clear the deposits from the bottom of
                                        -49-

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           Discharge Valve
          Open —,  |— Closed
             VIEW
    Loading
    Door —
                        Chute from
                       • Floor  Abovt
                                                    Cover Lock
                                                    Finished Floor
FLOP*  MOUNTED CHARGING STATION
                                             Pneumatic
                                            Transport Tube
                      ELEVATION
FIGURE 2.  GRAVITY-PNEUMATIC TRANSPORT  jYSTEM SHOWING  CHUTE STORAGE AND
                                   DISCHARGE  VALVE
                                         -50-

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several gravity chutes during a complete cycle.   Hence, the collectors at the
end of the line are quite large, usually 3 cubic yards minimum, in order to
hold these volumes.  The system is fast, with a capability of transporting
and collecting 24 cubic yards of waste or linen in one hour, in medium duty
operation; or as much as 10 cubic yards in an 8 minute cycle in a heavy duty
operation (the equivalent of 75 fully packed laundry bags of 3.6 cubic feet
each).
                        SIZING OF THE CHUTES AND TUBE

     After years of experimentation in hospitals, it has been determined that
 there are optimum handling sizes for bags of both solid waste and soiled laun-
 dry.  The laundry comes from  two main sources:   the patient bed linen and
 surgical or treatment  linen from O.B., O.R., and ancillary areas such as
 O.P.D., E.R.,  Radiology,  I.C.U., Recovery,  etc.  The solid waste comes  from a
 wider variety  of  sources,  ranging  from waste baskets in patient rooms,  offices,
 and  support departments;  disposable drapes  in  O.K.; animal bedding  in research
 facilities; cartons,  packing  and crating material,  generated  from incoming
 supplies and equipment;  solution bottles found in  certain treatment areas;
 snack bar, cafeteria,  and kitchen  containers,  paper, cans, and bottles.
      Is  there  a maximum and minimum weight  and cube of these  items, when bag-
 ged  for ease of handling,  as  well  as  an  ideal  or optimum size load? Apparently
 there is, and  several  factors enter  into the  determination.
      The first factor is convenience  of  deposit at the initial  stage of waste
 generation.  Over the  years a variety of sizes of  waste baskets  and trash  con-
 tainers have developed in hospitals.   They  are designed to be of  the proper
 cube to hold in an uncompressed form  the amount of waste generated  during  a
 fixed period  (8,  16,  or 24 hours)  in  the area they serve:  patients' room, of-
 fice, public hall,  snack bar, laboratory,  utility room,  etc.   Secondly, they
 are designed  to be loaded gently and  by  gravity, so that contamination of  the
 surrounding  area by aerosols, or contamination to the  people doing  the loading,
 is kept  to  a minimum,  without shoving and stuffing, without spillages  outside
                                       -51-

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the container.
     With the advent of disposable plastic bags, hospitals started buying
these in large quantities to line their waste containers.  The theory was that
this further reduced aerosols and waste handling.  Once  the container was fill-
ed, or partially so, the entire bag  load  could  be  removed and taken away in a
closed condition for disposal.  This brought  in another  consideration for siz-
ing containers.  These bags used for liners had to hold  a convenient amount in
both weight and cube that one individual  could  easily lift out and carry to
•one place for disposal.
     Obviously, there  should be direct engineering relationships between the
diameter of the tubes  in  any pneumatic solid  waste movement system, and the
suction power  of  the air  stream, versus the  size or  cube of containers and
loaded waste  bags,  and the  weight  of an average bag, and the number of bags
that Bust be  moved  at  one time.  Too often we have discovered the  two sets of
considerations appear  to  have  little connection with each other  in the systems
that have been installed.
     Under  the National Fire  Prevention Association's Code,  Section 82, grav-
ity waste chutes  in a  hospital  must be 24 in. in diameter  in order to  take the
bulk of  the waste sent down them.   This will be discussed  further  in  the sec-
tion on  codes and regulations.   Pneumatic systems in hospitals have not been
constructed  to this size, as it was felt they would be too  expensive  to in-
stall.   The bulk  of the pneumatic transport system chutes  and tubes  are  16 in.
in diameter,  some are  18 in.  in diameter, a few are 20 in.  in diameter.  The
NfPA  Code  states that 16 in. should be "a minimum."
     How does this compare with the size of waste loads that are generated and
the waste  container liners in use in  the various hospital departments?
     On  an  average, waste baskets in patient rooms  and  in offices measure  11
in. to  14  in.  in  diameter by 13 in.  to 17 in.  deep.   The average flat dimen-
sions of the  liner bags are 22 in. wide by 22  in. long.  Bulk trash containers
vairy considerably in size, depending  on  the  location  being serviced.   The
largest  are  found in public areas,  animal research  quarters when bedding is

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up to 36 in.  wide by 52 in. long in flat dimension, fitting into these bulk
containers as large as 22 in. diameter by 24 in. high.
     If the pneumatic chutes and tube system are to be used to remove solid
waste from all sections of the hospital, the containers and bag liners must
be sized to match the tubes.  For such an expensive, automated system to be
self liquidating and economically feasible in labor saving cost, it must carry
at least 95 percent of the total solid waste generated.  This is discussed in
depth in the section on economics.
     The containers and bag liners used  for initially depositing the solid
waste cannot be larger than will go in the chutes.  It is both a bad sanita-
tion practice and wasteful of labor to have to  break down by hand  into  smaller
bags the waste collected  in the initial  deposit containers so they will fit
the chutes.  Alternatively, the chutes and tube system should be capable of
moving groups of smaller  bags such as  are  found in half-filled waste baskets,
or these can be placed in a larger "chute  transport" bag.   If  there  is  such  a
thing as an "average" trash chute bag,  it  would be a plastic bag,  34  in. long
by 24 in. wide  (flat), which  stuffed  full  and  tied would be  approximately
15 in. in diameter by 25  in.  long, and weigh,  leaded,  4  to  14  Ib,  depending  on
the make-up of  this waste.
     Hence, there  is a minimum  size  of chute  and tube  that  should  be installed
and a maximum size of waste  container and  bag that should be used, if  the  hos-
pital is  to have a complete  system from start to finish.  It is  now generally
agreed that pneumatic tubes  should be at least 18 in.  diameter for optimum
 loading of bagged waste,  and that  16 in. diameter is  on the borderline as  a
minimum size.
     Laundry is  generated in different bulk and weight than waste; usually in
 larger unit quantities,  and for  this reason- alone it is most difficult to use
 the  same  chute  and  tube  to carry both laundry and waste successfully.   Laundry
 from patients'  rooms  breaks down satisfactorily into a bundle for a complete
 bed  change, along  with  towels and gowns, for two patients.   This weighs on an
 average  8.5  Ib  dry and  up to 10.0 Ib damp, and it fills a flat cloth bag 32 in.
 long by  23 in.  wide,  ending up as a bagged load 15 in. in diameter by 26 in.
 long.   Other  typical  patient linen loads (gowns, towels, sheets) weigh 5.0 to
                                       -53-

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15, Q Ib in such a bag.  O.K. linen and treatment  linen from single  procedures
4f mu.ch larger in bulk and weight, with the "average"  size bagged bundle 17 in.
i$ diameter by 30 in. long, weighing up to 20 Ib  in damp  condition.  For this
$Qis4b^y contaminated laundry,  a large hamper bag with flat dimensions of
2'7> IBU wide by 38 in. long keeps the "stuffing,"  and possible spread of aero-
    ,,. Sp a. minimum.   It  la thus seen that the pneumatic laundry tubes are more
          if  they ace slightly larger  than the  trash tubes.  The preferred
     SOB maximum efficiency  is 20 in.  in diameter.
                          STRENGTH OF CHUTES AND TUBE

      Having determined the ideal diameter of the tube for the system, along
      themaximum weight to be moved in horizontal runs and upward slopes, it
 is-tfcen necessary to determine-the suction or air flow required to pull the
 hfcayiejst' permissible load over'the planned distance of the system, at the
 S9$£d.
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light 20 gauge sheet metal and were usually square rather than round in cross
section, for ease of fabrication.  The tubes were hung from ceilings or slabs
by threaded bolts, usually into concrete.
     This light sheet metal can create problems when a pneumatic system is
used under heavy loads.  The major problem is collapsing of the tube or fit-
tings when excess vacuum is pulled on them.  The chief cause of such excess
vacuum is the plugging of a tube by bags getting lodged at some point and the
fan continuing to pull against the plug.  From the figures given previously,
it can be seen that on the full vacuum,  single bag systems the heaviest weight
to be pulled in a 16 in. chute could be  a 15 Ib bag of uncompacted waste, or a
laundry bag weighing 18 Ib.   In  an 18 in. chute, the weights could increase to
17.5 and 20 Ib respectively as the bag diameters are increased from 15 in. to
17 in.  In a key-lock multiple loading system, with 12 bags in a train,  the
average total weight being pulled could  amount  to  108 pounds of waste  and 180
pounds of laundry in a 16 in. system  and up  to  140 pounds  of waste and 220
pounds of laundry in an 18 in. system, based on  average weights transported.
     These figures  indicate  that over a  7  year  period,  averaging 6 hours use
per  day, the fatigue point of the  metal would be reached  if 20  gauge  steel
were used in a 16"  diameter  single bag  system.   With  a  multiple bag  system,
16"  diameter,  this  fatigue point would apply to 18 gauge.   In  an  18" diameter
system,  the same  condition would apply to  16 gauge and  14 gauge  steel respec-
tively.
     To  give  some engineering figures on vacuum being pulled in these systems
and  speed of  air  travel,  we  find that air  travel speeds range from 50 feet
per  second  to  100 feet per  second at the maximum with 80 feet per second proba-
bly  an  average.   The  lowest  air speed permissible to move a medium sized
waste bag has  been  calculated at 15 feet per second.   To convert these to
vacuum,  we  find  that  while many of the fans can pull 9 in. Hg, the average
 system  operates  around 5 in. Hg,with fan cut offs at around 6 in. Hg.  It has
 been calculated  a bag would move and the system could clear at as low as 1.0
 PSIg.
      This has led to three developments in  installing such systems.  First,
 maximum vacuum pressure for the system  is established by  the engineers or
                                        -55-

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   20.
*
u
3
III
O
o
(A
hi
|
Comparing  the  three commonly used
tube diameters with (1) potential
wall thicknesses  (metal gauge) and
(2) potential  vacuum or pressure
that can occur in pneumatic trans-
port,  the  accompanying curves in-
dicate  that  to withstand the aver-
age maximum  4.4 P.S.I, system
pressure,  a  20" tube should be
constructed  of 13 ga. metal or
heavier;  18" tube of 14 ga. or
heavier;  and 16" tube of 15 ga.
metal  or  heavier.
                                          PS.I. AVERAGE MAX
                                            FAN  CAPACITY
                       ,-f 24 PS I AVERAGE
                        *) FAN OPERATING
                          PRESSURE.
                                                   20" D1A
                       18" OIA.
              I        2       3456789       10
                                     VACUUM IN PS I
      FIGURE 3.
      AU.OWABLE VACUUM FOR  VARIOUS DIAMETERS AIJO WALL THICKNESSES OF PNEUMATIC TUBES
                                   SUPPORTED EVERY 8'
                                        -56-

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consultants and, after installation, the entire system is tested against this
by artifically plugging the inlet air.  All elements must pass this test before
the system is accepted.  Secondly, relief valves are being placed at the end
of the system immediately before the fan.  When vacuum reaches a predetermined
danger point, the valve opens to atmosphere to avoid both fan motor damage and
collapsing of tubes.  Thirdly, specifiers have begun calling for much heavier
tube and fittings than 18 gauge steel and this entails quite different fabri-
cating and coupling methods.  The calculations given in  curves in Fig. 3 show
engineering requirements that must be met.
     Mild steel can be lock-formed to manufacture  a tube in 18 gauge thickness,
and, with heavy equipment,  even in 16 gauge thickness.   Heavier tube walls than
this are normally seamless  welded.
     The gravity-pneumatic  systems use  up  to  1/4"  wall  thickness  in seamless
pipe or tube  for pneumatically  transporting waste, and with round cross sec-
tion fittings in wall  thicknesses up  to 3/8 in.   However, as  the  vertical
chutes in the gravity-pneumatic systems do not have  a vacuum  pulled on  them,
they can be built of much  lighter metal than  the tube at the  base that  trans-
ports the waste under  vacuum.   Normally,  the  chutes  are  built to  the  same
strength specifications  found in  other  top-grade gravity waste chutes  (14  or
16  gauge).
     As the  fittings  (elbows,  Y's,  tees)  appear  to be  the most subject  to
abrasion in waste movement, it is now common practice that they be specified
at  least- one  metal  gauge heavier  than the straight lengths  of tube,  and always
in  round cross  section to provide smooth air flow.
     The heavier wall  welded tube requires entirely different coupling  methods.
The original  Swedish  designs for heavy-wall tube  called for butt welding each
length  to  the next.   This proved tc be far too expensive.  Further,  weld
flashes inside the  tube were very difficult to grind smooth.   Unless this was
done,  bag  ripping  could result.
      It must always be borne in mind that the most successful pneumatic systems
 have the most even and smooth inside surfaces to  provide excellent air flow
without  turbulence and complete absence of bag tearing.  In this respect,
 they are  no different from small pneumatic message tubes.  This means that
                                        -57-

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     A  rather wide range of methods
 is  used to join together or couple
 the straight and curved tube sec-
 tions.   These include, for the light-
 er  gauge tubes, formed flanges with
 bolt holes held together by as many
 as  15 bolts, with gaskets between to
 ensure air-tight seals; flanges that
 ate covered on the exterior by a
 clamp ring to provide for rapid as-
 sembly and disassembly; and various
 support strapping devices.
      For the heavier wall tubing and
 fittings, the thickness of  the tube
 permits machining or  chamfering  the
 edges of the metal and welding the
 two sections  together.   In  addition,
 external sleeves  can  be  cemented or
 welded on to  the  tube to  increase
 the rigidity  of the joint.  Ball and
 docket methods have also been used,
 combined with welding.
      The smoothness and concentricity
 of  the joins  are  absolutely essential
 to  avoid bags ripping in transit.   It
 is  extremely  important  that inspec-
 tors be present during installation
 to  see alignments are made properly.
 I.-FLANGE AND BOLT COUPLING METHOD-FOR
  TUBING 16 GA. AND LIGHTER

yaaKKiga-rafftyj
k
4)


m
i

K*™«™™^
(
2-CLAMP COUPLING METHOD-FOR TUBING IS
  GA. AND LIGHTER
                        Si««v» Waitle*
                         Or Glued
 Air F
s- SLEEVE COUPLING METHOD-FOR HEAVY
  WALL TUBE
                        Wold
4-BELL AND SOCKET COUPLING METHOD-FOR
  HEAVY WALL TUBE UP TO  >/*"
FIGURE 4.   COUPLING METHODS USED IN PNEUMATIC TUBE SYSTEMS
                                      -58-

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when two tubes, or a tube to a  fitting, are joined,  the alignment must be as
perfect as possible.  Slip joins  that  are externally welded, or bell and socket
chamfered joins, provide this type  of  alignment  in all seamless welded tubing
that is 14 gauge and heavier in thickness.
     Despite the fact that these  are pneumatic systems with  a powerful vacuum
in force in the tube, the designers are extremely cautious when it  comes to
raising waste vertically.  This is  based on experience in the sort  of items
found loose in these waste systems  (such as a 4-ft   length of steel pipe).
They prefer to rise vertically  in slopes not  exceeding 30°,  with  clean-out
ports at the bottom of  such  risers  for the removal of overweight  solid objects
that may be put in the  system.
                                  FIRE DAMPERS

     One part  of  the  tube system still presents a problem.   Codes require
 fusible link fire dampers wherever the tube penetrates a fire wall.   This
 means  an actual gap exists in the smooth tube wall.  At this point,  a turbu-
 lence  is always created in the air stream which instantaneously balloons out
 the  transport  bag or  tends to hurl loose waste particles in the opening.  It
 is essential that such dampers be well constructed, with no sharp corners in
 the  interior surfaces, and that the fusible link and damper holding device in
.no way projects into  the interior of the tube in a way that could rip a waste
* bag.   An inspection of these devices reveals that much further thought should
 be devoted to  their design and construction.  Too often the latches have
 broken from vibration and closed the fire damper, causing serious plugging of
 the  system.
     The concern  for spread of a fire is not from a fire starting within the
 pneumatic  system, but rather one starting in a room and spreading through a
 fire wall. The  fire could melt thin wall tubing and pass through the fire
 wall,  melting  further tubing on the other side and hence spreading to adjoining
 areas.  If this  is the logic, it would appear more desirable to place the
 fusible  link  on  the exterior of the tube and a much heavier metal and a
                                       -59-

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                      Wall
                                                               Tub*
                    Fusible  Link
                    Promt
                    Tub*
                                                                 Handle To Pull Back
                                                                  Heavy Plato Fire Damper
                                                                  Spring To Keep Tension
                                                                  And Pull Down When Link
                                                                  Melts
                                                                Sweep Button Switch  To
                                                                Indicate Damper Has Closed
FIGURE  5.    FIRE  DAMPLR DESIGN
                                        ELEVATION
                                             -60-

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different guillotine door device than currently used.  The drawing in Fig. 5
is a suggested approach that appears practical.  It has the further advantage
of permitting reopening and fastening the door from the tube exterior.
                        TUBE AND CHUTE HANGING METHODS

     Another extremely inportant aspect of installing such tube systems is the
method of hanging or fastening the assembled tubing and fittings to the build-
ing structure.  For years, arguments existed on small message tube systems as
to whether the lines should remain flexible and move as the carriers traveled
through or whether they should be mounted rigidly.
     On the large diameter (16 in. and up) pneumatic waste and laundry tube
systems, there is no argument.  With potential weights of over 18 Ib in a
single laundry bag, traveling at up to 4800 ft per minute, the consensus is
that the tubing must be held rigidly to reduce noise level and prevent fatigue
at all joins.  Tube hangers must be of sufficient strength to prevent shearing
from metal fatigue and well fastened into solid concrete  in such a manner  that
they cannot vibrate loose; and installed as frequently as one every four feet
of tube length.
     Chutes and loading hoppers also must be mounted rigidly and supported at
each floor level to the building structure  to  avoid  fatigue from the "bounce"
effect of a heavy load tumbling downward.   This also applies to collectors
and diverter valves.
                          SYSTEM COATINGS AND ABRASION

     Three  types  of  considerations are involved in coating the tubes and
 fittings used.  First,  there must be moisture protection for the tubing if
 it  is buried below ground and subject to water attack.  While stainless steel,
 rust-proof  tubing has been used in these areas, it is limited to the lighter
 metals of down  to 16 gauge and is quite expensive.  A more common method is to
                                       -61-

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wrap or coat mild steel tube for corrosion protection in accordance with AWWA
specifications.
     The second consideration concerns sound deadening of exposed pipe and
fittings.  Various materials such as fiber glass or magnesia are used to wrap
the pipe after installation, in thicknesses up  to  2 in. and densities up to
3 Ib.
     Thirdly, the interior surfaces of mild steel  tubing are often  coated
with galvaneal or epoxy paint to ensure a rust  proof lining, particularly
with laundry  tubes.
     Abrasion of  the  tube has been discussed at considerable length by  the
designers  of  these  solid waste systems, both in the United States and in
Europe.  A mixed  bag  of waste can easily contain as high as  25%  glass which
is  subject to breakage, and  total waste from a  hospital can  contain as high as
10% abrasive  material—glass, metal, etc.   In Sweden, abrasion tests on tube
elbows,  of a radius three  times  the  tube diameter, measured  tube wall erosion
as  high  as 1/64 in. per year.  To  combat  this,  the  latest designs request  radii
in  bends of as much as five  times the  tube  diameter  (which cuts the erosion
figure in half);  with a minimum of  three  times.  If  the  1/64 in. or .0156 in.
of  erosion per year holds  true,  20  gauge sheet  steel  is  only .0368  in.  thick,
and hence could  wear through in slightly over  two years  at the erosion  point.
Fourteen gauge at .078 in. would last five  years,  and 8  gauge  would last  11
years.
      Several light gauge systems carrying  trash have been  installed in the
U.S.  and do not appear to show wear this  drastic.   However,  conservative  en-
gineering indicates that 14 gauge metal is  preferred as  a  minimum for tube
elbows and that, wherever the architectural considerations permit,  radii  be
 five  times the diameter of the tube and never  less than three times the
diameter.
                                 DIVERTER VALVES
      Single tube systems that handle both solid waste and laundry must have
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diverter valves to direct either the waste or the laundry to the proper col-
lector box at the end of the line.  These have been a source of problems in
this system design.  If the operating relay hangs up, the valve may not swing
into proper position.  This also applies if the air cylinder operating the
valve malfunctions.  Further, the valve must swing shut completely to avoid
line leakage and particles of trash getting into soiled laundry.  The valve
interior that shifts to divert  the load must be designed and constructed so
that loose paper or linen cannot jam it at the edge, or lodge on it and
prevent it from closing tightly.
     The latest designs in such valves appear to be much more efficient.   In-
stead of a plate swinging over  within  the  tube to direct the flow, an entire
inner tube swings  over, ensuring a complete continuation of the tube system.
A recent test, in  which  the older style plate-type diverter was replaced by
the tube type, showed  a considerable increase in vacuum pull in the system,
indicating the increased efficiency of the new  style valve  and  lack of  line
leakage.
                                COLLECTOR BOXES

     As described  earlier,  the bagged or loose solid waste and laundry is
 carried to  a  collector box, hopper or tank at the end of the transport tube
 line,  and the air  stream continues through a port in the box to the suction
 fan.   The material being transported hits the interior of the box at full
 speed, usually entering into it at a speed of 80 ft per second or 4,800 ft
 per minute.   This  is approximately 55 miles per hour.  When a bag of laundry
 weighs as much as  18 Ib, or when a bag of waste contains heavy glass or
 •etal, the  shock to a square box is fairly substantial.  Further, every at-
 tempt  is made to keep the effluent air, exiting the box to the  fan, as free
 as possible from lint, liquids and debris.  Screens protect the outlet port
 for this purpose and they,  in turn, must be protected from either being damaged
 by the blows  from bags entering the box, or from flying debris clogging them.
      At  the bottom of the box are doors that open at the end of the transport
                                       -63-

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cycle to let the solid waste and laundry drop by gravity into a container,
compactor, cart, etc. below.  The rubber gaskets on the doors, providing an
air seal, are a major maintenance item.  Examination of maintenance records
has revealed that the hinges used on collector box doors were a weak point
subject to frequent shearing.  It would appear that heavier duty and continous
hinges should be used.
     Hie first  collector boxes were not sophisticated in design and were
originally used only for laundry.  They were ruggedly constructed of heavy
plate and normally accepted a single bag at a time.  As solid waste systems
became more common, it was seen  that a collector box that worked well  for
laundry did not necessarily serve solid waste as well.  One of the main prob-
lems in waste was bag breakage and glass breakage when hitting the collector.
Secondly, there is a tremendous  variation  in weight between the various ele-
ments in  the waste,  ranging  from light paper or plastic films to heavy metal,
glass or wood.  This makes  the separation  process difficult between the drop"
out of  the waste  and the discharge of  clean effluent air  to the fan without
clogging  the debris  screen  with  "fines," or  lighter particles of paper and
plastic  in  the  waste.
     As  a result,  the  designers  turned to  principles used  in  industry  and
introduced  either cyclone inertial separators,  or widened  discharge  tubes  in
the  collector boxes.   With  the  cyclone separator design,  the  box  has  a cylin-
drical  top  and  conical bottom.   The  cyclone designs used  as waste  collectors
at the  end  of  the pneumatic tube systems work  slightly  differently from
standard  industrial  cyclones.
     The  waste  enters  at  a  tangent,  whirls around  the  circumference  at the
top  and works its way inward and  down at  a  reduced  velocity.   The  downward
notion  of the  air drives  the trash,  including  fines,  to the bottom of  the
cylinder.   Here it is  received  into  a middle section  by pneumatically opera-
ting doors.   On a timed cycle it is  dropped  out of  this by a  second set  of
pneumatic doors into a compactor bin or other  receiver below the collector.
The  effluent  air leaves through a flared tube  at the  top of the cylinder with
a much  wider  opening than that  in which the  air stream entered the collector.
This has the  effect  of reducing the  escape velocity in proportion to the
                                       -64-

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                                                             Flared Outlet To Reduce Air
                                                             Velocity
                                                                                   Electrical Conn.
                                                                                  For Control Circuit
Air Cylinder
                     '---£
Collector  Doors
        >\!
        \*
Air Cylinder t
        A"
Air Sealing Gasket
                                                                                     Collector
                                                                                       Doors
                                                                             Air Cock

                                                                         —  Continuous Hinge
       CYCLONE  TYPE BAGGED OR LOOSE WASTE

      COLLECTOR FOR LARGE VOLUME OR MULTIPLE

                  LOADING SYSTEMS


FIGURE  6.  TYPICAL  DESIGNS OF SOLID UASTE  COLLECTOR BOXES
                                                        BOX TYPE BA6SED WASTE COLLECTOR

                                                        FOR SMALL VOLUME. SINGLE  BAG SYSTEMS
                                          -65-

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ratio of the two openings.
     Other collectors employ a physical separation of the effluent air from
the fines and light waste, that could be either carried through in the escape
air to the fan, or could clog the exit screens.  The most common principle is
to greatly enlarge the exit opening in relation to the size of the entering
air stream, reducing exit air velocity to allow the lighter waste to descend
by gravity instead of continuing with the exit air.
     Mathematically this can be illustrated as follows.  Assuming the diameter
of the inlet or transporting pipe to be 18 in., this is 1.77 square feet  of
area.  It has been determined that a good air exit rate to avoid screen clog-
ging is  4 ft per second.  This is at l/20th the rate at which  the solid waste
air stream enters  the collector when it is traveling at 80 ft  per second.
Therefore, to achieve the reduced velocity, the air would have to escape
through  a flared tube in  the side of the collector that is 20  times the cross
section  of the  inlet pipe  (1.77 square feet), or 35 square feet, which even-
tually would taper down  to  the regular tube size of 18 in. for return to  the
fan.  To avoid  most light particles being caught in the effluent air stream
and clogging its protective screen, it is probable that the exit port would
have to  be twice this size,  reducing air flow  to 2 ft per second.
     The present boxes  and  cyclone type collectors are a compromise in  thic
direction.  Drop-out of  the trash by gravity is quite gentle and  the amount
of light material  clogging  the debris screens  has been drastically  reduced.
Automatic compressed air blow-down systems are being added to  keep  the
screens  free of the remaining debris.
                                 THE FAN BOOM

      From a design and construction viewpoint,  the fan room and all its
 equipment is one of the most critical aspects of the system.  It is essential
 that the room be adequately ventilated and that the temperature not exceed
 80 F during operation, in order to protect the electrical equipment installed
 in the area.  Despite sound attenuation, the noise of the fans and the air
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exhaust is substantial and potentially dangerous to the human ear.  The entire
room should be constructed of dense enough walls, floor, and ceiling to prevent
sound transmission.  Doors must be large enough for equipment removal in case
of replacement and should be sound gasketed.
     Two types of fans are in general use:  the enclosed, positive displace-
ment, centrifugal, turbine type exhauster, operating at relatively close tol-
erances, and the much more open, loose tolerance, typical materials handling
type or exhaust fan.  Motors in ranges from 100 to 250 HP are used to drive
these fans.  Adequate transformers and feeder lines are essential to eliminate
voltage drop with these large motors.
     Regardless of the type fan, they are heavy and, when running at full
speed under load, create a considerable vibration.  It is standard practice to
mount the fan and motor assembly on vibration isolator pads, inertia blocks,
spring type isolation bases, etc.  It is essential that there be  sufficient
size and mass to fulfill the purpose intended.
     Maintenance of the fan and motor has some special features to it.   In
many installations, the fan bushing has been attached to the motor shaft by
heat expanding the shaft for positive union.  Cases are reported  where  it has
been almost impossible to separate these at the site and, in order to perform
motor maintenance, the entire motor-fan assembly has to be  removed.  For motor
maintenance it is important that the room be designed to facilitate  such re-
moval .
                                    FILTERS

     While the positive  displacement  fans are more efficient than the more
open materials handling  fans,  due to  close  tolerances the blades must be  pro-
tected from waste particles  being carried through them.   It  is good practice
to place a 2 micron  bag  or roll filter ahead of the fan  to protect the  blades
from such airborne contaminants.   This has  the further advantage of cleaning
the exhaust air, before  it reaches the fan, of most micro-organisms and thus
protecting the environment from the fan exhaust.   The filter must be exceed-
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ingly well constructed, capable of resisting the maximum vacuum created by the
fan.   Also, it adds considerably to the air resistance, even in its clean
state (as much as 7 in. water), resulting in the fan having to be sized large
enough to compensate for this.
      With the more open tolerance exhauster fans, some manufacturers claim
fife-filters are not required to protect the blades.  This may be a risky claim
Where pre-filters are not installed, many maintenance men have discovered lint
and waste materials adhering to the fan blades to the point where the fan, re-
volting at over 3,400 RPM, was thrown out of balance.  In one hospital, the
motot base mounting bolts sheared and the base of the housing cracked from
the excessive vibration.  It is strongly recommended that pre-filters be
installed ahead of the fan to catch both fine particles and heavier debris
that may be in the air stream.  They must be easily removable for maintenance
and strong enough to stand both the air pull and debris in the air.  The same
requirements of 2 micron filtration should exist for these more "open" fans as
in the positive displacement fan.  This filtration for environmental protection
could be  incorporated  in the debris filter ahead of the fan or in a second,
bacterial  filter on the fan exhaust side.
                               SOUND ATTENUATORS

      The large,  heavy-duty exhauster fans and motors are obviously  not  noise-
less when operating.  An extremely large volume of air  is being  exhausted
outside  the  fan  room.  A good  rule in designing such systems  is  to ensure  that
a sound  attenuator  of adequate design and construction  is installed  after  the
fan so as to achieve a total noise level of  less  than 60 decibels on the "3"
scale when measured at the exterior walls of  the  building housing the fan
assembly.  The higher the octave band, the lower  the maximum  decibel rating
should be, in order to prevent annoyance to  patients, staff,  and visitors.
the following gives the  allowable maximum noise levels  suggested for various
octave bands.
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               OCTAVE BAND                        MAXIMUM LEVEL
           (cycles per second)                       (decibels)
                  37-75                                 67
                  75-150                                62
                 150-300                                54
                 300-600                                47
                 600-1200                               41
                1200-2400                               35
                2400-4800                               29
                4800-9600                               27
                                RELIEF VALVES

     An integral part of the fan assembly and tube system should be a relief
valve placed in the tube before the fan.  The purpose of this is to avoid
either fan and motor damage; or tube  collapse  (if the lighter sheet metal
tubing is being used) when for some reason the system plugs and creates a
vacuum higher than the maximum operating design.  Such a valve is normally
connected by a tube to the outside air and when  the maximum is reached it
opens and the fan pulls this air.  Alternatively, a switch can activate to
shut down the exhauster fan in case of too much  vacuum being pulled.
                                   FEED AIR

     It can be seen  from  the  previous discussion that  the  air  feeding  the
 system, whether from roof dampers in a full  vacuum system, or  from basement
 level tubes in a  gravity  to vacuum system, should be dry and clean.  In  ex-
 treme northern climates during winter this has occasionally created problems
 when the inlet air drawn  through roof dampers is as cold as -30 F.  and is
 entering a building  with  temperatures of  70  F.  Moisture and condensation may
 become  a problem  with the rapid rise in temperature and in severe cases  may
                                        -b9-

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require pre-heating of the air.
                            COMPRESSED  AIR SYSTEM

      Host of the moving parts in the system are activated by  rapidly moving
compressed air cylinders.  This applies to roof and fan dampers,  inner  chute
doors, collector box doors, diverter valves, and slide valves.   It  is essential
that the compressed air be filtered and lubricated and that  all  lines and
valves be made of rust-proof material.  The usual pressure in  this  system  is
125 p.s.i.
      This usually requires a separate air compressor used exclusively  for the
pneumatic tube system.  In many installations, it has been seen  that the
systems manufacturer under-calculated the total CFM of air required and the
size of the  compressor, with the result that the action of air valves was
•lover than  necessary.  Other design factors that have been  discovered  is  that
all air cylinders should have individual oilers.  Lov points in  the compressed
air liaes should have bleed-offs to drain out  any collected  moisture.   In
northern climates with  protracted periods of below zero temperatures, air
dryers should be  installed  in the line, effective up to -60  F, to prevent  the
air freezing exposed cylinders such as in roof dampers.
                          ROOF AIR INLETS  AND DAMPERS

       On the full vacuum system,  the inlet  air is obtained from double blade
 gooseneck shaped vents installed  at the top of the vertical chutes through
 the roof and projecting above the roof level approximately 48 in.  The dampers
 in tills are activated by compressed air for opening and closing.
       In the gravity-pneumatic systems, the vents appear similar in design and
 have a weather-tight vent relief  terminal cap.  They also contain a barometric
 daaper to maintain 1/4" negative  pressure in the vent and a fusible link in
 the top door in case of chute fire.
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                              SPRINKLER SYSTEMS

      From actual  observation of tests with gasoline-soaked rags that were
ignited  and thrown into a full vacuum system, it appears highly doubtful that
the tube system will support open combustion.  However, a small smoldering
fire could possibly continue inside a bag of trash.  For this to lead to a
fire in  the system, there would have to be a plug or a system shut-down, as
on the average the burning material would be dropping cut of the waste col-
lector in 40 seconds, much less remain in the vertical chute.  With a gravity
to pneumatic system, the situation is different and there can be storage on
top of the slide valves at the chute bottom  for a prolonged time period.
      Half inch sprinkler head stations are  usually installed in both types
of systems at the station below the roof  line  in the vertical chute and at
every other floor, or every floor, descending  to the lowest.  In addition,
occasionally sprinkler heads are  installed in  the  trash  collector boxes.
Sprinklers are normally fusible link activated.
                               LOADING  STATIONS

      The loading stations  are normally faced with a stainless steel panel
 from floor to ceiling.  There is  usually a maintenance door as well as the
 chute loading door.  These  must be U.L. Class "B" labeled, rated at 1-1/2
 hours at 250 F.  Station  doors are either stainless steel or aluminized steel
 and are normally side-hinged and  self-closing.  Bottom-hinged foot pedal
 operated doors are used on  the waste chutes of gravity to vacuum systems.
 Regardless of the hinge system, bottom hinged doors can present problems in
 that personnel may rest a heavy bag on an opened door and spring it.  The
 majority of these chute doors have a 36 in. height from the floor.  Some of the
 gravity-pneumatic chute doors  are as low as 24 in. from the floor to the
 loading sill.  The buck material  is usually stainless steel to ensure cleaning
 ease of the door frames.
      Maintenance door fasteners, in most systems, are merely a series of
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screws, attaching a maintenance panel to the buck.  It is felt that for pre-
ventive maintenance this is a poor method and should be replaced with a hinged
panel and a lock and key to open it, or some other quick opening, tamper-proof
method.
      Signal lights are normally positioned in the wall panel, always a red
"In Use" light, to warn prospective users that, either the door is locked, or
the inner hopper door is open and unavailable.  Alarm lights or buzzers are
rarely placed at the chute doors.  A central maintenance location is preferred.
However, there should be an "Out of Order" flashing light at each station to
warn the operators of a shut down, whether due to maintenance work or a
breakdown.
      Most  important, prominently displayed over each loading door is an
identification sign such as "Trash" or "Solid Waste"; "Linen" or "Soiled
Laundry."   It is essential that  these signs be distinctive and boldly lettered.
In cone hospitals, instruction signs or plates are placed over or adjacent to
the loading doors.
                                CLEAN OUT PORTS

       We  would like to report  that plugs never occur  in  pneumatic  transport
 systems,  but  unfortunately this is not  the  case.  Virtually  all  such  tubes
 get plugged with linen and trash  from time  to time, for  a  variety  of  reasons,
 ranging from  operator carelessness in using the  system,  to mechanical-electrical
 malfunctions.   In single bag systems, plugging is usually  caused by operators
 attempting to override the system and force multiple  bags  through  simultaneous-
 ly.  There are two types of plugs experienced.   The first  is self-clearing,
 when the  removal of a bag or two  and the applying of  full  fan vacuum  will allow
 the plug  to free itself.  The  second is more serious:  the entire  plugged load
 aust be removed by hand ("fished") from a  clean-out port,  or a chute  station,
 or a collector at the end of the  line.  With 500 feet of horizontal tubing,
 this could take time.
       This explains the necessity for clean-out  ports in horizontal tubing,  or

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where horizontal runs transfer to upward risers.  To have to remove sections
of tube to clear a plug is an extremely expensive job for the maintenance de-
partment .
    When installing clean-out ports, it is essential that they be constructed
in such a way as to not weaken the  tube wall; that  the interior tube surface
be completely smooth and free of projections where  it joins the clean-out
port; and that each port be large enough to permit  the removal of a full bag
of solid waste or laundry.
                                CONTROL SYSTEMS

    The heart of  the electrical operation of all pneumatic  waste and laundry
 transport systems is the  central control panel.   This monitors all  loading
 stations and supplies  the logic, through a succession of relays and breakers,
 that  sequences  the opening and closing of all pneumatic cylinders and valves,
 which in turn control  the routing of air (and hence material)  through the
 system.  It cycles the stations and provides the memory circuits for determin-
 ing the order of  priority for such cycling (either pre-programmed or first
 come-first served).  It reads the pressures and vacuums in the entire system
 and protects it from damage due to excessive build-up by supplying "fail safe"
 shut  down actions.
    A master switch controls power to the control panel and through it the
 entire system.   In addition, there are usually separate switches to turn the
 exhauster  fan on  and off and to run it manually or in automatic sequence.
 There is usually  a high pressure safety switch which activates automatically
    a  sensor when  vacuum exceeds allowable limits.  This throws open the
 relief valve  and/or shuts down  the exhauster  fan.  Before  the system can be
 returned  to normal operation,  this switch has to be reset  after the cause of
 excessive  pressure has been corrected.
     Various  types of memory systems have been designed  into such a  control
 panel and  each  year the electric designers have made  these more sophisticated,
 up to the  point where mini-computers  are now  being considered.  As  the systems
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get more complicated by building them with increased number of stations? the
aeed for speed and accuracy in the circuitry increases.  The bulk of the full
vacuum systems have memory systems constructed with stepping relays to  activate
the station unloading.  Originally, these were quite simple.  Whoever pressed
ttoe first station button sent his signal to the first activating relay.  The
second button pushed sent its signal to the next relay, where it was held until
the first sequence was completely cleared; and so on through a potential of 50
or acre stations.  Activation had to take place by throwing or pushing  switches
at the station doors.
    As we have seen earlier, with the gravity-pneumatic systems this is not
the case.  Adjustable time clocks run the system by determining when the valve,:
should open  and  they open and discharge into the air stream in a predetermined
sequence, whether  they contain a waste load or not.
    As  the  full  vacuum systems have been installed more recently,  they  have
leaned  in this direction and cycled in a predetermined  fashion.  However, only
the  loaded  stations operate.  They usually cycle one chute at a time in se-
quence,  such as  all the  loaded laundry stations for the entire system,  then
all  the  loaded waste  stations.  One problem that has been noticed  is  that  if
the  opening  of  the station  inner doors start at the bottom and work up  to  the
top  in  a  given  chute,  the  inner door must close on  time and  completely  to  pre-
vent  a  bag  from the one  above  it catching on it and creating  a jam.  Sequencing
from the  top down  has proven desirable.
                      SUPERVISORY PANELS AND ALARM SYSTEMS

     From rather simple and crude beginnings, during the past five years the
 supervisory panels have improved considerably.   They now show the complete
 schematic of the system and the exact status, at a point in time, of all major
 elements, by means of small lights superimposed on the schematic plan.
     One of the hospitals studied constructed its own panel, complete to the
 point where the approximate location of a plug in the system can be identified
 iastantaneously.
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      In the complex supervisory panels, alarms are included, either in the
form of flashing lights or buzzers, or both.  The panels monitor items such
as incomplete cycles, loading hopper doors not closed, collector box doors not
closed, diverter valves open, roof dampers open, low or high pressures in the
air flow, high temperatures in fan exhaust, slide or butterfly valves not
opening or closing, dust filters loading up and exerting too much air resist-
ance, etc.
      The monitoring of supervisory panels and the resetting of switches,
relays, timers, etc. in the control panel is the function of the Maintenance
and Engineering Department.  It is therefore essential that these elements
of the system be installed where they can be reached easily by maintenance
personnel or are under their constant and convenient surveillance.  Too often
architects and mechanical engineers designing  the structure are inclined to
"bury" such panels.
                      CYCLING TIMES  IN  PNEUMATIC  SYSTEMS

      The time that it takes a pneumatic  system to perform a  complete  cycle
depends on several factors:  the  design of  the system,  whether  full vacuum
or gravity to vacuum; whether it  is  a single or multiple  bag  loading design;
the speed of travel of the material  as  determined by a  combination of  the
suction force and the weight being transported; the length of total run  from
the collectors to the station farthest  away from  each collector;  and the
pauses or delays built into the  control panel by  the manufacturer for  sequenc-
ing the various components  in order to  be sure that valves, doors and  dampers
have  time to open and close without jamming the material  being  transported.
      It should be realized that cycling  is on a  "constant" time, not  a
"variable," in the design of virtually all single bag full vacuum and  all
gravity to vacuum systems.  What this means is that the time is fixed  by the
manufacturer, regardless of the  length of run.  If a bag  can be transported
in 10 seconds from the station  nearest the colledtor to the end of the line,
and it takes 50 seconds  to  transport a bag from the station farthest away
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from (the collector, then the system is timed for all cycles at 50 seconds
in order to achieve simplicity in the control system.  With a key-lock,
multiple bag system, overriding the normal time cycle of a single bag pro-
cedure, the operator has control over the length of the cycle, as he manipu-
lates the station door switch.
      In a full vacuum system, timing of the length of run starts when the bag
drops out of the loading hopper into the vertical chute.  With full vacuum,
and in typical hospital height buildings, the bags do not descend the chute
that much faster than in a straight gravity condition.  Assuming a ten-story
building with basement loading stations and with floor-to-floor heights
averaging 13.5 feet, the total vertical drop might be 141 feet.  In a gravity
drop, a bag would  take at least 2.5 seconds to cover this distance, assuming
it could fall freely.  Under an air pull that gives a travel speed of 80 feet
per second, it would take 1.75 seconds.
      Horizontal speed at a theoretical 80  feet per second would be 3 seconds
for 240 feet, up to 12 seconds for 960 feet.  The 80 feet per second is rarely
maintained over  the full run due to line losses, resistances, and slippages,
so it is normal  to add 25 percent to  these  times.
      The balance  of the time in the  cycle  is used up in activating the various
components.  These segments of time must be added to the travel  time in order
to arrive  at the total cycle  time.  In the  average full vacuum system, they
are as  follows:

                                              Seconds
      Opening of air  inlet  damper                 1
      Opening of fan  damper                      1
      Allowing  air to  achieve transport
        speed                                     2
      Opening of inner hopper door and
        bag  dropping                              2
       Shifting  of  diverter  valve                  1
      Closing of inner hopper door                1
      Closing of all  dampers  in  sequence
        after allowing for  travel  time            3
      Opening of collector  doors  to  allow
        bag  to  fall out                           2
      Closing of collector  doors  to  per-
        mit  recycling                            2
      Total  sequencing time                     15
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Hence, it can be seen that the sequencing of the system components can require
as long as, or longer than, the travel time of the material.  Timing of most
full vacuum system substantiates this.  An "average" total cycle takes approxi-
mately 30 seconds.
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                     FINAL REDUCTION AND OFF-SITE REMOVAL
     The care and precision of in-house transport of solid waste directly
affects the health and safety of the staff, patients, and visitors in a hos-
pital and equally affects the operating budget of the institution.  The most
serious effect on the environment and on the health of the community starts
at the "end of the line," after the loose or bagged waste has been transported
from the floors to some central location, such as the loading dock of the
hospital, and must be removed off-site, with or without further treatment.
     Management of hospital solid waste must be viewed as a total problem
that consists of a series of steps in a complicated system.  It starts with
the disposing  of a waste product in a trash basket or container in a patient
room or support area, and is not solved until the residue waste (loose, com-
pacted, ground, dumped to sewer, or incinerated) is safety treated in some
location remote from the hospital, such as landfill  or sewage treatment plant,
All hospitals are subject to various external constraints, designed to inter-
face with satisfactory in-house final treatment and reduction methods; and
these must be compatible with safe off-site removal that ensures satisfactory
public health and environmental conditions.  A subsidiary consideration is
that these final treatment and removal procedures also must be economically
feasible:  operating costs must be kept to a minimum.
     As can be seen from the chapter that analyzes the make-up of hospital
waste, 40 percent is potentially "hazardous."  It consists of fomites capable
of transmitting pathogenic organisms; pathological specimens; material from
known communicable disease cases; disposables that are hazardous  in nature
from a secondary use viewpoint  (plastic items, syringes, needles, and sharps);
potentially infectious material due  to contact with wounds, burns, or used  in
treatment of patients' surgical incisions; potentially infectious clinical  and
research laboratory wastes; human or animal fluids,  secretions, tissues,  and
feces, and the disposable containers that hold these; toxic, flammable,
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corrosive, explosive, and radioactive substances that have detrimental effects
on people, equipment, and property; and the solid waste that in the process of
assembly and removal may either become contaminated by such known infectious
and hazardous wastes and hence become infectious or hazardous itself; or is
originally infectious or hazardous to a degree not clearly established.
     The in-house final collection and treatment systems must consist of
adequately designed and installed equipment and carefully managed operational
practices, that completely avoid transmission and contamination problems
among the hospital personnel.  These systems must also ensure that the waste
is satisfactorily treated, reduced, packaged, and containerized so that it
can be moved to the off-site point of final disposition, safely and completely.
     With waste loads skyrocketing and exceeding 11 pounds per patient day in
many urban hospitals, the sheer volume to  be managed, and the time and expense
to manage it, is too often encouraging "short cuts."  The cry of "get it away
from patient, staff, and visitor areas and down  to  the dock  and away from  the
hospital" is heard daily.  In  the process, safety measures can be  ignored.
The hospital staff,  the  community health,  and the environment can  all  suffer
accordingly.
     Not only is hospital waste environmentally  hazardous  in varying degrees,
it is proving more expensive  to handle as  each  year passes.  As can  be seen
from the  chapter on  the  economics  of  hospital solid waste management,  the  ex-
pense is mounting at every step  in the process,  from original pick-up,  through
in-house  transportation,  through  final  collection,  reduction,  and  treatment,
to off-site  removal.
                                VOLUME REDUCTION

      When a bag of solid waste drops out of a collector at the end of a pneu-
 matic tube line, or is dumped into a hauler's trash truck by hand, it is
 immediately apparent that in the total volume there is about 20 percent
 material and 80 percent air; that mechanical compression or compaction could
 give up to a 5 to 1, or 80 percent reduction in volume by simply squeezing
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out all the air and leaving the material.  As off-site hauling contracts are
based directly and indirectly on the volume of waste being hauled, as well as
the weight, compaction or other volume reduction techniques reduce hauling
costs.
     A second examination of the original waste reveals that it is in all
sorts of shapes and sizes, from flimsy paper and plastic sheets, through heavy
cardboard and crating material, to strong containers made out of glass and
sheet metal.  And all of it is capable of being reduced to fairly uniform
particle size by feeding it through the proper type of attrition mill or
"hogg."  It is discovered that, if it is decided to transport the ground
waste to another area on-site, now that it is in a more or less uniform size
particle, it lends itself to various materials handling techniques that would
not accept the unground material.  It can be handled and transported pneu-
matically in sealed, small diameter tubes; or mechanically in screw conveyors
that are completely encased to avoid atmospheric contamination by the moving
waste.  If the ground waste is compacted at some point, it is discovered that
a further volume reduction can be obtained, against compacting the unground
waste.
     A third examination of the total hospital waste delivered to the final
in-house collection point reveals that 92 percent of the bulk is  combustible
under proper conditions, and after combustion the ash  residue is  quite small.
                CLEANLINESS  IN THE CENTRAL WASTE  COLLECTION ROOM

     From  an  examination  of the  solid waste  central collection points  in
dozens of  hospitals,  it can be stated categorically that  such an area  can  be
as free of litter,  as free  of odor,  as  free  of cross-contamination as  is the
lobby of the  building.  In  fact, the environmental  standards  between the two
areas in a hospital—public lobby  and central waste collection area—could b<;
the same,  with proper foresight.   To achieve this at the  end  of  the line,
design standards for  equipment and the  placement and interfacing of mechanical
items are  extremely important.   Equally important are the rules  for loading
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the equipment,  and the managerial supervision over the people doing the loading
in those instances where it is hand fed.
     Cleanliness, lack of spillage, and freedom from odor can be achieved
through sensible, well thought-out, and designed mechanization; and they can
be achieved through rigid control over the actions of all personnel entering
the area and hand loading solid waste into collection and/or reduction devices.
Both tight mechanical control and human control are essential.
     Design and construction of solid waste collection and reduction rooms
absolutely must follow certain rules if environmental problems are to be
avoided.  The most important rule is that once waste reaches this point it
should no longer be exposed to atmosphere, except in the case of a mechanical
breakdown enforcing a divergence from the standard system.  At all times, it
should be in tightly covered bins,  containers, conveyors, or machinery so that
it does not spread throughout the room  or the surrounding area.  Most institu-
tions have not paid enough attention to these points.   In the hot summer
months, odors from decomposing wastes are noticeable;  loose waste spillages
or "float" and liquid spillages can be  seen.
                                   COMPACTORS

     Stationary  compactors  for the end of the line are designed to reduce  the
 volume of waste  that  must be hauled off-site and thus reduce hauling costs.
 With the proper  container or sealed mobile bin doing the hauling,  the result
 is  an environmentally safer trip, hopefully with no spillages or leaks along
 the way.  A  final  advantage is that in the process of compaction much of the
 waste is destroyed, or at  least so mixed with other waste that it is difficult
 to  salvage it  for  secondary use, and thus create health hazards.
     By 1972,  over 20 manufacturers were merchandising over 150 different
 models of stationary  compactors that can be installed in the central waste
 collection terminals  of hospitals.  The rate of compaction varies from 2  to 1
 to  5 to 1 depending on the  design, the size of the compaction bin, and the
 strength of  the  unit.  The  designs differ considerably, ranging from units
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with a high receiving volume and quick action that give only a modest amount
of compaction, to units with extremely high compaction rates but much slower
cycling time.
     Sizing of the compactor depends on two direct considerations:  the total
quantity  (cube) of waste being generated and the frequency on which it is
desired to haul the compacted material off-site.  The indirect consideration
is the architectural space in which the compactor and hauling bin must be
installed.  In virtually all hospital installations the compactor is station-
ary.  It  is close-coupled to a closed steel container.  The compactor contains
a ram or  similar device that forces the waste into the container, reducing the
bulk as it compresses the waste.  When the container is full with compacted
waste* it is  connected to a truck or tractor and hauled away.
     Compactor containers used in hospitals are fairly large, on an average
ranging from  20 to 40 cubic yards in size.  They are also not the easiest
mobile bins  to maneuver.  As hauling contractors also charge for the  time re-
quired to pick up and drop off these vehicles,  the location and ease  of access-
is  important.
     In sizing a compactor and mating hauling container,  it is obviously  essen-
tial to know  the cube of waste being generated  each day and to determine  the
practical reduction given by compaction.   Hauling contractors charge  on a trip
basis; the  fewer the trips, the  less the  cost to  the hospital.  Hospitals
thus attempt  to use the  largest  compactor and container  for  the waste generatec
weekly, and  balance  this against the storage problems  the waste  can create.
OB* limit to size  of vehicle is  the  parking  space available.  Another limit  is
the amount  of odor and possible  environmental contamination the  stored waste
can create.   Out  of  all  these  considerations,  the hospital  will  size its  com-
pactor and  container,  for hauling weekly, or twice or  three times a week.
     The  National  Solid  Wastes Management Association,  Washington,  D.C.,  gives
a rating  to over  135  different models  of  compactors  on a set of  13 key para-
meters.   The base  size rating  defines  the charging  capacity of  the compactor,
measuring the theoretical  volume moved by the  ram in a single stroke.  The
clear  top opening, length  by width,  indicates  the largest objects that will
fall freely from top to bottom of the  charging  chamber.   The ram stroke is
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the maximum linear displacement or forward stroke of the ram.  The penetration
of the ram into the waste container provides the uniformity of compaction and
it clears the discharge opening of the container prior to decoupling from the
compactor.
     The speed at which the compactor moves materials into the hauling con-
tainer is the "cycle time," measured in seconds.  The theoretical upper limit
of compactor output based on 100 percent utilization is the "machine volume
displacement per hour," measured in cubic yards per hour.  Compaction capa-
bility is measured in terms of pounds force per square inch on the ram face at
stated actuator forces, such as hydraulic pressure.
     Another important measurement is the discharge opening which defines the
minimum dimensions for the opening of the mating container.
     When a compactor is interfaced with a pneumatic tube waste transport sys-
tem, an efficient and environmentally acceptable design can be achieved.
     At the bottom of the pneumatic tube collection hopper there must be suf-
ficient head height, along with length and width to allow the bagged or loose
waste to drop out into the compactor receiving  chamber without bridging.  Waste
arriving in the final collection room varies  tremendously in density once it
escapes from a bagged condition.  The major problem is "float—fine particles
and light weight pieces of plastic and paper, all  of which may have become
contaminated by contact with other waste.  A  second problem  is liquids in the
waste that can spill out of the transport path.  The connection between  the
pneumatic system collector box and the compactor  receiver  chamber must be dust
and liquid tight, so that when waste drops out  of  the  collector none can es-
cape.  Further, the connection between this receiver chamber of the compactor
and the hauling bin must be equally  tight so  that  no waste escapes during the
stroking of  the ram.  There is simply no  reason why waste  should be spilled,
or  float, in such mechanized systems.  If  it  does, it  is  the result of poor
engineering or poor construction.
      The  space alloted for  installing a  compactor  should  allow for properly
servicing the  equipment.  When installed  indoors  or  in a  protected area, pro-
per cleaning facilities  should be  provided  such as hose  and  steam  cleaner out-
lets, gutters, and  floor drains.   Also,  fire  protection  devices  such as
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sprinkler systems, extinguishers, or injection nozzles for chute fed units
should be provided.
                        DRY GRINDERS, MILLS, AND HOGGS

     The latest development in solid waste handling and reduction at the hos-
pital central collection point is to lead directly from the chute collector
box into an attrition mill or dry grinder, capable of reducing all waste into
a standard particle size.  This device must be selected to meet the require-
ments of handling a tremendous variety of material equally well:  paper, card-
board, sheet metal and cans, glass bottles, wood products ranging from pencil
size to heavy crating, plastic film and injection- or vacuum-molded plastic
shapes, metal wire, rubber, textiles, animal and vegetable products.  The mini
mun capacity should be 6,000 pounds an hour regardless of hospital size,
     The oversizing of the grinder is to ensure that it is powerful enough to
reduce any waste item being fed into it.  All waste should be reduced to a
particle size of from 3/4 in. to 2 in. diameter for ease of handling and mix-
ing after reduction.
     As in the  case of the compactor loading compartment, the pneumatic chute
collection box  should load into the receiving chamber of the grinder, or mill,
by a dust and water tight, heavy, steel plate transition section, designed in
a way that there is no possibility of bridging.  There should be  a flexible
connection at this point to positively prevent  any  transfer of  vibration from
the mill to  the collector box, as well as  the building structure.
     The throat openings  of such mills are sized to the capacity of  the grind
ing or milling  "teeth" or banners to prevent overloading.  The  opening  of  a
3 ton per hour  unit is approximately 3.9  square feet, which is  comparable  to
the area of  a 20  in. diameter tube or chute.
     After grinding and  reduction, the waste is normally  transferred  to a
holding and  mixing tank.  This can be done mechanically  in a  completely en-
closed screw conveyor, or  it can be  transferred by  a materials  handling fan
pneumatically in  an 8  in.  to 12  in.  diameter tube,  and dropped  into  the
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holding tank through a cyclone that removes the excess air.  This method also
must involve a completely enclosed system from the attrition mill to the hold-
ing tank.   When transferring ground waste pneumatically, the effluent air from
the cyclone should pass through a 2 micron bag or roll filter to prevent con-
tamination of the air outside the area.
     The final step in the reduction is to compact the waste from the holding
or surge tank; or to incinerate it.  The holding tank must be of a design and
construction that prevents bridging and, as stated, be completely enclosed.
Normally,  to provide a safety factor as well as a good mix of the waste par-
ticles, the holding tank should be large enough to hold a 48 hour supply of
the hospital total waste.  It can be sophisticated, with level sensors to pro-
vide maximum and minimum cut-offs in volume.
     Whether incineration or compaction is the final  step, the holding tank
should have a "live bottom" of slowly moving screws.   This has the advantage
of mixing the waste into a fairly even mass.   It ensures a homogeneous mix-
ture of materials.  It is also the most efficient method for moving  the waste
out of the holding tank and by completely  enclosed  screw conveyor into a com-
pactor or an automatically fed incinerator.
                                  INCINERATION

     The ultimate disposal  of  hospital solid waste has an environmental affect
 on the air, the water,  or the  land—discharge of gases and solids from incin-
 erators into  the atmosphere, discharge of garbage grinders into sewers, dis-
 charge of solids into  land  fills.  In recent years, the use of incinerators in
 hospitals, because  of  discharge of pollutant matter into the air, has been un-
 popular as the pollution regulations have become more stringent.  To combat
 this, incinerator designs have greatly improved, from the single-chamber,
 smoke-belching,  "black boxes"  of the 1930's, to the multi-chamber units of the
 1970's; with  auxiliary burners, controlled overfire and underfire air, auto-
 matic feeding devices,  and  flue g4s scrubbers.  However, certain communities,
 who  have studied  the make-up of solid wastes in hospitals, witn their heavy
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load of plastics, are worried as to whether the present advanced state of tech--
no logy in incinerator design can yet meet the emission requirements, day after
day.
     It is generally agreed that a properly designed and operated multiple-
chamber hospital incinerator with 700 F to 1,000 F in the primary and up to
2,000 F in the secondary, and with proper retention rates and complete com-
bustion, will sterilize the most infectious and heat resistant organisms found
in the waste.  Emission of bacteria, viruses, or spores into the atmosphere
will not be a problem.  However, burning must be complete.
     Entrained particulates and some gaseous elements are the major  air pollu-
tants emitted from the burning of solid wastes in incinerators.
     The principal gaseous emissions from incineration are carbon dioxide,
nitrogen, oxygen, and water vapor, none of which can be classified  as air pol-
lutants.  However, trace gases in the emissions can cause some air  pollution
due to  their odor; their effect on plants, animals, and property; or their
interaction with components in the outside air to form undesirable  secondary
components.  Chemical substances in this  category are sulfur oxides, nitrogen
oxides, carbon monoxide, hydrogen chloride, aldehydes, organic acids, ammonia.
and hydrocarbons.  Criteria exist in certain critical areas on nitrogen oxidejr
and total hydrocarbons,  and most areas place limits on permissible  sulfur  oxid-
emission.  Except for the  odor-causing elements, the  remaining trace gaseous
emissions are not of particular concern  in air pollution  control.
     The particulates,  or  solids, suspended or entrained  in the  gas being
emitted are  of more  serious concern as air polluters.   Specific,  quantitative
emission  limits  of  gas-suspended particulates have been written  into all  air
pollution codes.  The codes may be  expressed  in  various ways,  such  as:
<1) total weight of  suspended particulate per unit volume of exhaust gases;
(2) total weight of  suspended particulate per unit weight of exhaust gases;
(3) total weight of  suspended particulate emitted per unit weight of solid
waste  charged.
     To obtain a standard  of  reference  of the  condition of  the gas, and thus
to prevent  an incinerator  operator  from  avoiding compliance with emission
codes  by  diluting  emitted  gases with  air or  water  vapor,  almost  all codes
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require correction of the emission limits to a specific reference condition.
The most commonly used units for emission values are (1) pounds of suspended
solids per thousand pounds of dry flue gas, corrected to 50 percent excess
air, and (2) grains of suspended solids per standard cubic foot (29.92 in. Hg
and 70 F) of dry flue gas» corrected to 12 percent carbon dioxide.  These con-
ditions are approximately equivalent for municipal waste incineration.
     By 1966, the consensus of opinion was that emission limits should not ex-
ceed 0.2 grain  of  particulate matter per standard cubic foot of dry flue gas
corrected to 12 percent CO, in incinerators burning 200 pounds or more of waste
per hour (the usual size found in hospitals); and not to exceed 0.3 grain in
incinerators burning less than 200 pounds per hour.  The members of the Incin-
erator Institute of America adopted these standards in 1968 and guaranteed to
meet them.
     Many municipal and state codes also have established restrictions on the
opacity of the emissions.  These are based on the Ringelman chart.   A visual
observation is made of the stack "plume" with the Ringelman chart or scale.
This is a series of reference grids of black lines on white that, when proper-
ly positioned, appear as shades of gray  to the  observer.  The use of the  chart
takes a trained technician to achieve consistent visual evaluations.  Host
codes require that:   (1) the normal, continuous plume quality not exceed  Rin-
gelman No. 1; (2) for short periods, not exceeding  3  to 5 minutes,  plume  qual-
ity not exceed Ringelman No. 2.
     To control emissions of suspended particulate matter in  the  effluent gases
from an incinerator is not a simple matter.  The  first  requirement  is an  effi-
cient design of the incinerator itself to  ensure  that the waste  is  properly
and completely burned in the primary chamber and  that the gases  are retained
for a sufficient time period in a  secondary  chamber  to  burn  the  particulate
natter still further.  Many designs add  mechanical  devices  to remove the  par-
ticulates from  the gas.  The first of  these were  settling  chambers.  Starting
around 1957, some units  incorporated wetted  baffle-spray  systems  with screens
and baffles  and water sprays.  Other units incorporated cyclone  separators.
More efficient  than  the  wet baffle and  spray  systems have  been the  wet  scrub-
bers.   In these, the  entrained particulates  must  combine  with the water  itself
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rather than water flushed impaction surfaces.  The particulates collide with
water droplets to effect capture.  The particles and the water droplets then
form larger droplets that are collected.  The efficiency of well-designed
scrubbers is as high as 94 to 96 percent.  A problem is that certain chemicals
in the gas, when in contact with water, form corrosive substances, such as
hydrogen chloride forming hydrochloric acid.
     Other methods used to trap particulates are electrostatic precipitators
and fabric filters of fiberglas, asbestos, or high-temperature synthetics.
     W.P.A. has suggested that there should be no more than 0.08 grain of par-
ticulate matter per standard cubic foot of dry flue gases, corrected to 12
percent C0» (against the present standard of 0.2 grain per cubic foot).  This
is the equivalent of 1.6 pounds of particulates per ton of solid waste burned
and means that particulate removal would have to be 95 to 98 percent efficient,
     Estimating, in 1973, the solid waste generated at 10.2 pounds average  for
1,200,000 patients per day, this is 6,165 tons of hospital waste per day for
the United States.  If all this waste were incinerated, it would amount to 4,9
tons of particulate emission into  the  atmosphere per day for the whole country;
if the 0.08 grain standard were consistently met.  As all solid waste burning
of every type, from all sources, in the United States generates less than 4
percent of the estimated particulate matter  discharged into the atmosphere,
this 4.9 tons appears a rather infinitesimal amount.
     In 1968, the Incinerator Institute  of America published their  Incineratoi
Standards.  Stating that the "basis for  satisfactory  incinerator  operation  is
the proper analysis of  the waste to be destroyed, and  the selection  of  the  best
equipment to destroy  that particular waste," they classified mixtures  of  waste
•ost commonly encountered  as "Types 0 through 6."  They  then  classified  incin-
erators by capacity and type of  waste  they  are capable of burning as "Class 1
 through VII."
     Many hospitals have  stated  that reading these  incinerator standards  and
waste  classifications does not  seem  to solve their  problems.   Most hospitals
 require  incinerators  with burning  rates from 500 to 1,500 pounds  per hour and
 capable  of handling  solid wastes as  are typically  generated by hospitals.   Whr
 they  ask  of  the  manufacturers  and  consultants is specific data on the inciner-"
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tor that should be installed to achieve desirable emission rates.  The Incine-
rator Standards leave this matter literally up in the air as far as typical
high volume plastic and paper content is concerned.
     The question to be answered is whether hospital-operated incinerators can
consistently meet an emission rate as low as 0.08 grains per cubic foot.  The
experience in Los Angeles with locally constructed incinerators burning hospi-
tal wastes with large plastic content has shown  that to consistently maintain
0.3 grains per cubic foot was difficult with the loading and mixing methods
they used, despite the fact that the  Incincerator Institute guarantees to
meet 0.2 grains for this type unit.
     With automatic feeding of the incinerator on what amounts  to  a "B.T.U.
demand" basis, burning can be controlled very accurately.  With a  waste  that
is well mixed, both as to particle size and  as to content  (paper,  plastic,
wood, textiles, etc.) a fairly even-burning  fuel is  injected  into  the primary
chamber, load  after load.  This  solves most  of the  stack emission  problems
that have occurred in the past and assists  in meeting  all  present  air pollu-
tion standards during burning.   This  assumes that  the  incinerator  is  of  a
modern  design  with proper temperatures  and  holding times  in both the  primary
and secondary  chambers.   Several recent  tests,  on a continuing basis,  reveal
that a  system  of  automatic  grinding,  mixing, holding,  and feeding of  typical
hospital solid waste into a properly designed incinerator can consistently
achieve emissions lower  than 0.1 grains  of  particulate matter per cubic foot
of gas.  A  few such  systems,  as  the  forerunners  of several more, are  going on
 line in 1973 and  will  provide the nation with test data on a continuing basis.
 They are  tied  into pneumatic tube delivery systems and are completely auto-
 Bated.
     There  is  a definite trade-off of environmental effects, between the emis-
 sions  of  properly managed incineration,  and the effects of hauling and dumping
 the raw hospital  wastes in landfills.   In the balance there appears to be far
 less environmental hazard in the route of properly managed incineration.
      Incineration obviously has definite advantages in handling hospital
 wastes.  With  incineration, the original waste  is sterilized completely, both
 with regard to the solids and to the gases.  The material hauled off-site does
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not create known problems to either the environment or to the public health of
the community.  It is reduced in volume by 90 percent or more, resulting in lev
hauling costs of the ashes.  Further, after such reduction only a small portio-
of the original total is placed in land fill, thus extending the useful life
of these valuable sites that are becoming increasingly scarce in our urban
areas.
     With properly designed and controlled plants the volume reduction in
municipal incineration is estimated to be from 80 to 90 percent.  It is also
estimated that 98 to 99 percent, by weight, of the combustible materials can
be converted to carbon dioxide and water vapor.  Total weight reduction of the
waste  (with the non-combustible solids, such as glass included) is commonly
75 to  80 percent when it is converted to a dry residue with all the water
content evaporated.  Compaction of this residue results in further volume re-
duction, so that the compacted remains may be as low as 4 to 10 percent of the
original volume.
     The reduction in weight and volume of hospital waste by incineration is
even more impressive than with municipal waste, due to the far higher per-
centage of completely combustible paper and plastic products in the hospital
output.  The make-up of the volume or cube of hospital waste is approximately
the following:
           Paper and cardboard                          60.OX
           Plastics                                     21.0%
           Rubber and gums, natural  and synthetic        0.5%
           Textiles, cotton and synthetic                7.5%
           Animal products                               0.5%
           Wood products                                 1.5%
           Food products                                 1.0%
           Glass, metal and incombustible                8.0%
      In short, 92 percent  of the total  is  combustible.  Further,  the  density
of most hospital waste is  lighter than  municipal waste.  The  latter has been
estimated  to weigh  from 5  to 6.3 pounds per  cubic  foot as  against hospital
waste  in an uncompacted or raw  form  weighing  from  2.5  to 4 pounds per cubic
foot,  due  to  the higher quantity of  loosely packed and light materials  in  the
total  bulk make-up.
     Weight reduction during incineration  of  the hospital  waste is  greater
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than with municipal waste, due to the higher percentage of combustibles and
is estimated at 85 to 90 percent.  Thus a 2,000 pound lot of hospital uncom-
pacted waste measuring approximately 22.5 cubic yards would end up as an ash
residue that would weigh approximately 260 pounds.  Even more dramatic is the
reduction in volume, which is estimated to run as high as 99 percent against
the original uncompacted raw waste cube.  It is estimated that incinerator
residue has a land fill compacted density of 2,700 pounds per cubic yard.
Hence the 260 pounds of ash residue would occupy only .097 cubic yards or
approximately .44 percent of the original volume.
     In connection with incineration, we have a situation with hospitals that
should be resolved.  Virtually all state and local health codes insist that
hospitals maintain a pathological incinerator for the burning and destruction
of such specimens.  Such units in general do not meet emission standards and
hence are endangering the environment, although admittedly the emission
volume is quite small in the normal operation of destroying  the limited number
of pathological specimens that are generated.
     Where problems are created  is in  the case of hospitals  being forced to
destroy by incineration their other contaminated materials,  consisting of
large volumes of plastic and paper and other non-pathological matter.  In
many communities,  this has occurred because  the  local governments have refused
to permit such contaminated material being hauled to a  landfill  due  to  a  fear
of affecting the ground water, or for  other  public  health reasons.
     Too often we  see hospitals  that are placed  in  this  position  burning these
large volumes of such contaminated waste  in  their pathological  incinerator,
a device that was  never designed for  this purpose.   The  air  emissions then
become extremely serious  and an  environmental  problem.   It would  appear
more practical to  ensure  that  this  is  not done;  by  insisting that such hospi-
tals install environmentally acceptable  incinerators of  modern  design capable
of both pathological and  general waste burning,  and with systems  of feeding
these  that  guarantee the  desired results.
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                          OFF-SITE HAULING VEHICLES

     The open waste hauling truck or bin, until a few years ago, was the basic
nethod used for off-site removal.  It is generally accepted that if such an
open body is used for off-site hauling of only construction and crating ma-
terials, such as generated at the loading and receiving dock, that the effects
on the environment are not too serious.  This assumes a well constructed
vehicle with strong sides that is not overloaded.  If this same vehicle is used
to haul off-site the general solid waste of the hospital, either hand-loaded
into it or received from pneumatic transport tubes, this is not acceptable.
Too often have we seen such vehicles traveling city streets with red plastic
bag loads of hospital waste signifying infectious materials.
     A closed off-site hauling vehicle has been studied from several aspects
as to its effects on the environment in hauling hospital wastes.  As seen
from the section on compactors,  it is the normal type of trailer used for
hauling compacted wastes.  Despite the fact that closed vehicles of this type
have been seen to leak fluids during a haul to a land fill, the Center  for
Disease Control states that there has been no documented report of  infectious
diseases associated with such hauling.   Further, it would appear that closed
vehicles of this type can be constructed that do not leak.
     Waste hauling costs in most metropolitan areas have risen  as much  as
200 percent in the last 15 years.  In cities of  100,000  to  200,000, the price
for hauling a 20 to 25 cubic yard compacted load runs from  $43  to  $48,  and
a 35 to 40 cubic yard compacted  load  runs  from $46  to $55.   The cost  of amor-
tizing  the compactor and the hauling bin must be added  to  these figures.  This
Beans that hospitals in these smaller  communities, with  an  average  census of
350 patients, are paying from $7,000  to  $12,500  per year for  the hauling of
their solid waste.  In large Eastern  cities,  the fees are  approximately double
this amount.
     Obviously every effort  should be made to  reduce  the volume and weight
of  solid waste  the hospital  is  forced to haul, by  the use  of compactors,
 attrition  mills,  incinerators,  and  similar devices on a self-liquidating
 investment basis.
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                              SANITARY LANDFILLS

     At present, somewhere in the neighborhood of 80 percent of all hospital
waste is hauled to a landfill in an untreated form, with at least 40 percent
of the hospitals having first compacted the raw product.  Aside from the fact
that landfill sites are becoming in increasingly short supply, there is con-
siderable concern as to the effectiveness of the sanitary landfill operation
in destroying these wastes so that they do not become a health hazard after
burying.
     Landfills are accepted by hospitals in much the same manner as they are
by other members of the general community.  The same attitude applies to the
hauling contractors who pick up the solid waste.  It usually comes as a shock
to investigators surveying hospital solid waste management practices that the
hospital personnel, from top administration to middle management, have only a
vague idea as to who or what is hauling the waste off-site; where it is being
taken; and exactly how it is being handled after it arrives at its destination
     It is essential that all hospitals know where their solid wastes are
being hauled off-site; what  type of landfill is being used and how it is being
managed.  While the hospital has no legal jurisdiction  over the landfill, it
has a moral responsibility to the community to know the type of site to which
its contract hauler is transporting the solid waste generated by the institu-
tion.
     E.P.A. has published guidelines  and recommendations for landfill manage-
ment for several years.  The latest are published in the Federal Register for
April 27, 1973.  In proposed rules for landfill management, paragraph 204.201:,
"Solid Wastes Excluded,"  E.P.A. recommends that, "Using information supplied
by the waste generator/owner, the responsible agency, the disposal site owner/
operator and designer  shall  jointly determine specific  wastes  to be excluded
and shall identify them in the  plans.  The generation/owner of excluded wastes
and the responsible agency shall jointly determine an alternative method of
disposal for excluded wastes.   The criteria used  to determine  whether a waste
is unacceptable shall  include the hydrogeology  of  the site, the chemical and
biological  characteristics of the waste, and  the  safety of personnel."
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                   SALVAGE, RECYCLING, AND RESOURCE RECOVERY

     Studying the habits of hospitals in solid waste disposal indicates that
the salvage and recycling practices are used less in hospitals than with in-
dustrial plants or homes.  There are several apparent reasons for this.  The
most valuable salvage items are metal scrap of known purity, both ferrous and
non-ferrous.  Hospitals generate a fairly small amount of metals.  A known
major waste item that is easily separated from the waste stream would be glass
bottles and containers.  However, glass has an extremely Low recycling rate:
only 4.7 percent of the glass produced uses purchased scrap for its make-up.
     The amount of worn-out textiles sold by hospitals to salvage operations
is difficult to pin down.  It is known that clean, uncontaminated, patient and
surgical textiles are generated in fairly large quantities by hospitals.  How-
ever, recycling of textiles has been declining and the market for the hospital
product consequently falling.  Disposable textile products that are mixed in
the solid waste stream are universally destroyed along with  the other waste.
     Paper and plastics from hospitals have a very low recycling rate.  Little
effort seems to be spent on salvaging corrugated board,  flat board cartons,
office and computer paper, newspapers, books and magazines,  and packaging
paper, despite the fact that paper and cardboard make up 60  percent or  better
of the total solid waste.  Most hospitals seem to feel that  the  expense of
segregating  this  part  of  the waste,  even  though  clean and  uncontaminated, is
much more  than they can  realize  from sale  to  salvage dealers.
     Plastics generated  as waste  in  hospitals are  the same type  as  generated
by homes,  stores,  and  other  institutions.   Sale  as  salvage,  with present  tech-
nology for recycling,  is not practical,  due  to the  tremendous number  of dif-
ferent chemical  formulations used.   This  makes it  impossible to  sort  these
into like  formulations after use;  without  such sorting  little practical use
can be made  of the product.
     The net result  of the above  considerations  is  that  hospitals  and the com-
munity  are left  by and large with most  of the solid waste  that was generated.
Very few saleable materials  are diverted from the  waste stream.  The  only
potential  resource recovery  is to use the waste  as  energy; to possibly convert
                                       -95-

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it to a fuel under a method that will at least recapture the cost of burning
it, and hopefully at least part of the cost of collecting, transporting,  and
processing it.
     It has been discovered that municipal solid waste is a clean fuel from
the point of view of environmental pollution.  Several European municipal
plants, over the past years, plus a few in Canada and the United States
recently, have used solid waste as a fuel in special boilers for steam genera-
tion.  Hospital solid waste mixtures, as seen in the section on incineration,
have a relatively high B.T.U. output, and if ground, or milled, and mixed,
have a fairly consistent B.T.U. output.  Further, the moisture content is
much lower  than in municipal waste and also much more consistent, thus reduc-
ing a major problem in using solid waste as an efficient fuel.
     Hospitals are also heavy users of steam for heating and sterilization.
A few are now investigating the potential of capturing the heat generated
during  their  in-house incineration and putting it to use.  The systems are
still in the  experimental  phase and it  is not known how successful  the econo-
mics will prove  to be.  the technology would be similar to that used in cer-
tain municipal incinerator plants, and  in some industrial operations, but on
a ouch  smaller scale.
     What is  yet  to be determined is whether the waste generated by even  the
largest  hospitals  (500 beds and over)  is sufficient to operate an economically
feasible waste heat recovery system.
     In  municipal plants,  successful waste  heat recovery  systems appear to
involve  a 24-hour-a-day operation and  a  relatively  constant burning of waste
during  this period.  Hospital  incinerators  usually  do not operate over 12
hours, and  normally for far shorter periods.   Hence the technology  of heat
storage  must  be quite different  from that  of municipal systems.  To date,
experimentation in hospitals has  concentrated  on  piping superheated water
or other fluids from the incinerator to  remote  storage and heat exchangers,
rather than the direct production of steam  at  the incinerator  or an adjacent
boiler.
     It  would appear that  further engineering  and economic  research on the  use
of waste heat recovery systems in hospitals would be worthwhile  and might
                                       -96-

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offer a definite economic return for the design effort expended.
     The solution to using the heat of the gases from hospital incinerators for
waste heat recovery, as pointed out above, must follow a slightly different
technical direction than with municipal waste.  There are three main reasons
for this:
     (a)  While both municipal and hospital wastes are relatively "clean"
          fuels, hospital waste has a higher plastic content.  This means
          that the incinerator used must be capable of handling plastics in
          quantity.  Also it means that the effluent gases are more corro-
          sive from hospital waste and hence the waste heat recovery boiler
          linings, diverter valves, and tubes must be constructed of ma-
          terials that will not corrode quickly from the gas.
     (b)  Hospital waste  in medium sized  institutions rarely is burned at
          rates greater than 1,500 pounds per hour and the average is closer
          to 1,000 pounds per hour.   Burning  times rarely exceed 12 hours
          per day and  the average  is  closer to  6 hours per day.
      (c)  Due to the limited total quantity of  waste  and short burning hours,
          either waste heat storage systems must be developed  (such as hot
          water  storage  in tanks), or the waste heat  must be used  first  as
          an auxiliary to the main steam  supply and for  limited  use.
                                       -97-

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                    5-DESCRIPTION OF THE SURVEY HOSPITALS

     To determine the feasibility of pneumatic waste transport systems  in hos-
pitals, three institutions were selected that would give a good cross section
of medium sized hospitals, their solid waste management practices,  as well as
types of pneumatic equipment currently in use.  The institutions selected were
the Veterans Administration Hospital, San Diego, California; Martin Luther
King Hospital, Los Angeles, California; and St. Mary's Hospital, Duluth,
Minnesota.
                      ST. MARY'S HOSPITAL, DULUTH, MINN.

     St. Mary's Hospital, owned and operated by the Benedictine Sisters Benev-
olent Association, is a 495-bed acute general hospital.  During the past year.,
the average rate of occupancy has been 79.8 percent on an active 419 register-
ed beds for adults and children, giving a daily census of 335 patients.
     During the survey period, the admissions per day were 42 and the dis-
charges 44, with an average length of stay for each patient of 7.5 days.
     There were 44 outpatient visits and 48 emergency visits to the hospital
per day.
     The total hospital staff, on a full-time equivalent basis, was 1,033,
giving a total hospital population (inpatient, outpatient, staff) of 1,460 daily
     The ancillary and support activities can be seen from the following sta-
tistics of activity during the survey period for daily averages:
          Meals served ... 1,743
          Laboratory tests for both inpatients and outpatients ... 1,085
          Operating Room procedures for inpatients and outpatients ... 31
          Radiology procedures for inpatients and outpatients ... 198
          Pounds of laundry handled per day ... 6,841
     The building complex consists of 518,853 total square feet, of which
                                       -98-

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451,530 is maintained by the housekeeping department.  The oasic design con-
sists of a West Wing that is ten stories high, a Center Wing that is ten
stories high,  an East Wing that is seven stories high, a North Wing that is
connected to the Center Wing by a corridor and is five stories high, and a
Service Building housing the laundry, boiler plant, and waste collection room,
connected to the North Wing, and having a total height of three stories.
     The pneumatic trasn and linen system was designed by the vendor and in-
stalled in two phases.  The first phase, covering the East and Center Wings,
was completed in October of 1969 for a cost of $109,357.  The second phase of
the system was installed complete in January of 1971 at an additional cost of
$73,800.  The two phases resulted in a complete system for the hospital cotnr-
prising 41 load stations, of which 20 are for linen and 21 are for waste,
with three vertical pairs of chutes  (one for waste and one for linen), one for
the West Wing, one for the Center Wing, and one for the East Wing.
     The system that is used is a full-vacuum 16 in. diameter tube with 20
gauge wall system, with separate loading doors and separate chutes for waste
and laundry, and operates on the "single bag" method with no multiple loading
of bags.  The chute loading stations are located in chute rooms.
     As can be seen from the statistics in the next chapter, approximately
38.8 percent by weight and 67.4 percent by volume of the total waste of the
hospital is sent through the pneumatic system.  The balance of the items, that
are either too bulky, or consist of  glass and metal cans, are removed by cart
by the housekeeping department during regular "sweeps" of the building over
a 17 hour period each day.  The pneumatic waste system operates from 5:00 A.M.
to 10:00 P.M.  The cart removal of waste operates during the same time period,
plus additional hauling during the night hours from public lobbies and the
Qnergency Room.
                                      -99-

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PENTHOUSE » HOOP
                                                                                         EXHAUST TO ATMOSPHERE
                                                                                           (NO *ILTER IS  L^SED I
                                                                                                   r
                                                                                                      AERO ACUSTiC SOUND »TTE"tUATO*
                                                                                 L'NEN COLLECTORS
                                                                                     BUTTERFLY FAS CAMPER
                                                                                        AIR ACTIVATED
                     so
                          '< BASE
                                                                                                  CE-L'NG H'JXt
                                                                     ItCC-IP

                                                                   0   LIHEN STATION
       FIGURE  8
    ST MARY'S  HOSPITAL
      Ouluth-Mmnesoio
                                                                 	 AIR RETURN I
                                                                 	LINEN LINE
                                                                   	 TtUSH LINE
PNEUMATIC TUBE  SYSTEM  F
  SCUD WASTE ft LAUNDRY
                                                              -100-

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Loading the single bag, full vacuum
system at St. Mary's Hospital.
                                     During peak periods in
                                     busy nursing wings
                                     single bag systems
                                     rarely can keep up
                                     with the speed waste
                                     is  generated, as seen
                                     by  the above view of
                                     typical chute roonu
r^p"
l_besl
!Reproduced (rom
                        available copy.
                                                        Lower left:  these
                                                        nylon mesh bags
                                                        virtually eliminate
                                                        bag breakage and hence
                                                        environmental problems
                                                        in this system.
                                     -101-

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                              * Above:  Views of the
                                box type soiled
                                laundry and solid
                                waste collectors
                                at the  end of the
                              ^ line at St. Mary's
                              ^Hospital.  The waste
                              * must be hand carted
                               .
                              v from the waste
                                collector to the
                               • compactor located in
                                .the Service Building
                                court yard.
Reproduced from
best available copy.
           -102-

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Above:  The Engineering Department of
St.  Mary's designed and installed a
unique monitoring panel to determine
the status of any loading station.

Right:  Typical tubing rising from the
basement into the Service Building.
                                                   -
Left:  The fan room
equipment is unsophis-
ticated and quite
lightly constructed in
this system, using an
open type materials
handling fan and a
simple exhaust duct
type sound attenuator.
High level vacuum
protection is obtained
by a gate valve before
the  fan.
                        Reproduced from
                        best available copy.
                                      -103-

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           VETERANS ADMINISTRATION HOSPITAL,  SAN DIEGO,  CALIFORNIA

     The Veterans Administration Hospital, located in La Jolla, a suburb of
San Diego, California, is owned and operated by the Veterans Administration
of the United States Government.  It is a 811-bed general hospital which, dur-
ing the past year, has experienced an average rate of occupancy of 59.0 per-
cent on an active 646 registered beds, giving an average daily patient census
of 400.
     During the survey period, the number of admissions per day was 29.4 and
the discharges were 30.3, with an average length of stay for each patient of
11.5 days.  There were 199 outpatient visits per day.  Emergency visits, as
found in community hospitals, do not occur.
     The total hospital staff, on a full-time equivalent basis, consisted of
1,605 people daily, giving a total hospital population (inpatients, outpatient*
and staff) average of 2,204 daily.
     The various support activities of this hospital can be seen from the fol-
lowing daily average statistics gathered during the survey period:
     Meals served  . . . 2,380
     Laboratory tests, in- and outpatient  . .  . 4,936
     Radiology procedures .  .  . 165
     Operating Room procedures  ... 24
     Pounds of laundry .  . . 136,848
     The hospital has 677,700 gross square feet of enclosed area, consisting  or
the penthouse, six floors, a basement, and a mechanical room above  the pent-
house.  Above the first floor,  the building is  laid out as a cross, with North
East, South and West wings intersecting in the  center, with a  loading dock  at
the far end of the North wing.  The cost of construction was approximately
$35,250,000.
     The pneumatic trash  and  linen system was  installed in November 1971,  at
a cost of  $350,000.   It is a  full-vacuum,  single  tube system,  for moving both
waste and  laundry. The tube  is  16 in.  in diameter with 20 gauge wall, and  ther
are a  total of 54  load stations—27 for waste  and 27 for laundry.   The  system
is key-lock operated  and  permits one  operator  to  deposit 10  to 12 bags  of
                                      -104-

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laundry  and  up  to  12  bags of waste on a continuous loading basis, one station
at a time.
     As  can  be  seen from the statistics in the next chapter, approximately
25.1 percent by weight and 35.A percent by volume of the total waste of the
hospital is  sent through the pneumatic system.  The balance of the items are
either too bulky,  or consist of glass and metal cans, or are deemed infectious
or hazardous.  They are removed by cart using an average of 31 cart trips per
day.  The pneumatic waste system operates from 6:00 A.M. to 3:30 P.M.
                                       -105-

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                                                                              •t:fiviiw —1
                                                                                            L- .u»r«
«'
*l *
                              FIGURE  9
VETERANS ADMINiSTRATrOM nQSPiTAl
   Son Diego    California

     SOl 10 WASTE * LAUNDRY

                                                                                          T»«S" B i
                                                                                          T»ASH
                                                                                          I.INCN LINE
                                                 -10ft-

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The Veterans Administration Hospital
is noted for its excellent housekeeping
practices.
Above:   Special color coded and labeled
containers  with distinctively colored
plastic bag liners for the glass and
metal waste.
Top:  The loading hopper
of a typical waste chute.
                                                 Reproduced Irom
                                                 best available copy.
                                                      Left:   This  collection of
                                                      bags  of solid waste was
                                                      assembled to determine the
                                                      speed of loading in this
                                                      multiple bag system.  The
                                                      28 bags in the pile were
                                                      dispatched in under two
                                                      minutes.
                                    -107-

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The Veterans Administration Hospital
utilizes a single tube system.  Above
is the Diverter Valve Box designed to
divert waste or laundry to the proper
collector.
Above right:  The control panel of this system consists of a  series  of  stepping
relays to activate the various roof dampers,  inner chute  doors,  diverter valve,
collector box doors, etc.   The entire  system  requires  several miles  of  wiring,
making the  electrical hook-up one of the most costly elements in the installation.
                                                           Left:  The fan room is
                                                           located in a penthouse
                                                           atop the hospital.  The
                                                           fan has an excellent
                                                           vibration dampener base.
                                                           The RollomatU- filter to
                                                           protect the fan can be
                                                           seen at the rear, with
                                                           the high vacuum relief
                                                           system to the right of
                                                           the fan motor.

Reproduced
best available copy.
                                     -108-

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          At  the  Veterans Administration Hospital two
          totally different styles of collectors are
          used.   Top right is the square, box type,
          laundry collector dropping into the soiled
          laundry receiving section.
Reproduced from
best available copy.
                              Top left and lower  left:
                              The cyclone collector
                              used for waste  is designed
                              to receive rapid and
                              continuous loading.  Note
                              that most bags  are  ripped
                              by the  time they emerge
                              I  I ,uii I In- .Ml ill' t i'l .  Tilt'
                              entrance to the compactor
                              is not  close coupled  to
                              the collector  and  presents
                              serious aerosol possibil-
                              ities with broken  bags.
            -109-

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             MARTIN LUTHER KING HOSPITAL, LOS ANGELES, CALIFORNIA

     Martin Luther King Hospital, owned and operated by Los Angeles County,
is a 394-bed general hospital.  During the past year, the average rate of
occupancy has been 64.4 percent on an active 320 registered beds for adults
and children, giving a daily census of 206 patients, including bassinets.
     During the survey period, the admissions per day were 28 and the dis-
charges were 38, with an average length of stay of 7.7 days.
     The hospital operates a large outpatient department, averaging 360 visitf:
daily, and an equally large emergency service, averaging 218 visits daily.
     The total hospital staff, on a full-time equivalent basis, was 2,200
people daily.
     The ancillary and support activities can be seen from the following
statistics of activities during the survey period for daily averages.
     Meals served .  . . 1,519
     Laboratory tests for both inpatients and outpatients  . .  . 4,341
     Major surgical  procedures ... 6
     Minor surgical  procedures ... 9
     Radiology procedures for inpatients and outpatients  .  .  . 157
     Pounds of laundry handled per day  . .  . 9,524
     The building complex consists of 551,251 square feet  and  includes  six
floors plus a basement.  It was constructed  for a total cost of $23,540,000.
The pneumatic waste  and laundry system was  installed in March  1972.  The sys-
tem is a gravity to  vacuum  type, utilizing  14 gauge  20 in.  diameter  gravity
chutes and 20 in. vacuum tubes of heavy  wall pipe, operating on a key-lock,
multiple bag principle.  The  use of gravity  chutes means  there is no limit
on the number of bags that  can be loaded by  a single operator.  There  are
43 loading stations  total,  of which 19  are  for  laundry only and 24  are for
waste only.  The system includes four vertical  tubes for  laundry  and four
for waste.   The cost of  the installation was $425,000.   The system operates
on a  24  hour day basis.  Approximately  60  percent by weight and  85  percent
by volume  of the  total  solid waste  is  transported by the  system.
                                        -110-

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                                                                                VfMflCAL
                                                                "'""    fc>.     /  CO"""

                                                                  V^N-/"""1'"
••43- JT4T.OK

. • «t ' •« . •<
                                                            FIUUKE  10

                                                      MARTIN LUTHER KING HOSPITAL
                                                          Los Angeles Cot.fomio
                                      -111-
PNEUMATIC TUBE SYSTEM FOR
   SOLID WASTE a LAUNDRY

-------

             UKWHQMBR!
                 SBOfNt
         MARTIN LUTHER KING
The photograph above shows the  different
configurations used for the  loading
hoppers of the Laundry and Waste chutes.
The administration constantly reminds
the personnel against overloading  the
chutes or transporting breakables.
                     Reproduced from
                        available copy.
For basement and first level
loading stations, independent
of the 6-story high vertical
chutes, hydraulic operated
hoppers, as shown above, are
used.
                                               (Left)  View of a typical si
                                               valve, separating the vertical
                                               gravity chute from the pneumatic
                                               horizontal tube system.
                                     -112-

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All equipment items in the Martin Luther
King system are constructed ruggedly.
Top right:  The soiled laundry collector
is virtually a room in itself.  Note the
heavy reinforced plate construction.
Top left:  The compactor bin is located
in an air conditioned storage room and
large enough to hold a five-day waste
supply.
Lower left:  The compactor is close-
coupled to the concrete and steel waste
collector bin.

-------
Three views of the Mechanical-Fan room
at Martin Luther King, showing the ex-
cellent quality of the equipment.
Top left:  The alternating exhaust fans,
Top right:  The 2 micron bag filter in-
stalled to prevent fan damage and envi-
ronmental problems.  Lower left:  The
control and monitoring panel.

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              e,-QUANTITIES AND TYPES OF HOSPITAL SOLID WASTE

     To  determine the quantities of waste generated by hospitals, numerous
surveys  were  made during the present study, with in-depth analyses of the
three pilot hospitals.  The figures were compared with those the researchers
had obtained  from other hospital solid waste studies.  The surveys approached
the analyses  from several directions.  These included  weighing and measuring
each individual  bag transported through the pneumatic tube system, together
with all waste hand-hauled by cart, over a complete  24 hour period for seven
days in a row.  Breakdowns were obtained for each hour of the day, each day
of the week,  by each generating point in the building.  Analysis was made of
the types of waste generated from  all points.  Total figures were checked
against totals revealed in the central collection area.
                TOTAL WASTE GENERATED  BY  THE  SURVEY  HOSPITALS

     The three pilot institutions  represent a fair cross  section  of American
hospitals, with a census  from 190  to 400, a  total population of staff  and
patients from 920 to 2,000, and  outpatient-emergency visits  from  90  to 580 per
day.  Each was quite different in  type of patient and medical delivery program,
ranging from the "typical"  community hospital of a medium sized city,  to  an
urban area hospital with  county ownership, to a hospital  with research and
teaching programs.  However,  it should be pointed out that three  hospitals
are  too small a sample  to be  representative  of the American hospital  system
for  the purpose of establishing hospital waste loads on a broad basis.
     Other surveys performed  by the consultant  reveal that, currently, hospi-
tal  waste loads based on  total hospital population (patients plus staff)  vary
as much as 60 percent.  As  may be expected,  the more sophisticated the health
delivery and research,  and  the larger the metropolitan area in which the
                                       -115-

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hospital is located,  the larger the waste load.  This should not be surprising
when one considers  that a major metropolitan daily newspaper weighs as much
as 1.5 Ib, which, if  brought into the hospital by and for every member of the
total population  (staff and patients) plus a percentage of visitors, would
have the affect of  almost doubling the hospital waste load.
     Waste from food  preparation and from scrapings of plates from the cafe-
terias and snack bars was disposed of through kitchen garbage grinders into
the sewer system in all three hospitals.  Thus it does not appear in the waste
delivered at the central collection point to be hauled off-site.  As it was
impossible to weigh all such food waste without disrupting kitchen activities,
sampling techniques were used.
     From this it is estimated that in a combination of food preparation and
in plate food scraping before dishwashing, an average of 0.21 Ib of such waste
per meal served was generated between the three pilot hospitals.
     No "outside yard" or construction wastes were included in the total waste
figures unless they were taken to the central collection point and hauled off-
site with the waste generated in the building.  This applies to lawn cuttings.
In the only construction observed during the survey period, the general  con-
tractor removed his own waste.
     In the survey  of the wastes at the three pilot hospitals, detailed  anal-
yses were made of the total weights and cubes generated by the material  trans-
ported from the floors to the central collection point.  These cover a period
of seven consecutive  days and all three shifts for each 24 hour day.  The sur-
veys were conducted during July, August, and September of 1973.
        RATIOS OF WASTE TO HOSPITAL POPULATION  SEGMENTS  AND  UTILIZATION

     When hospital wastes are compared  on  the basis  of  combining  inpatient  cen-
 sus with outpatient  visits and  total  staff (total  full  time  equivalent of a
 24 hour population); and reviewed  along with  the activities  of  the  ancillary
 departments  that  are large waste producers; then direct  comparisons can  be  made
 between hospitals;  and between  hospitals and  other segments  of  the  economy.
                                       -116-

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     Other surveys of hospitals in major metropolitan areas indicate that 10.0
to 10.4 Ib per occupied bed appears valid for many hospitals.2  The average of
11.3 Ib per occupied bed in the current study is high.  The average of 9.2 Ib
per occupied bed obtained by totaling St. Mary's and the Veterans Administra-
tion Hospitals is a fairly representative figure.  When Martin Luther King is
added,  with its heavy outpatient and E.R. load and the extremely large staff
of 2,200 people handling only 183 occupied beds, the amount of waste per bed
becomes biased.
     The importance of factoring waste against the "full time population" of
the hospital can be seen from a review of the statistics in Table 4.  Figuring
the waste generated against the total population of the hospital more clearly
shows the valid differences between institutions regardless of scope of work
or staffing patterns used.
     "Full time population" of a hospital is a term that is not well understood
by many people.  First, it consists of the average daily inpatient census,
rather  than the total bed complement that is available.  Average daily inpat-
ient census varies considerably between hospitals  (anywhere from 45 percent to
95 percent of the total available beds).  Secondly, it includes the ambulatory
patients that each day visit the outpatient clinics and emergency service.
Each patient is recorded as a single "visit" in  the total population, even
though  he may be treated in more than one clinic.  Thirdly, the population in-
cludes  the "full time equivalent" staff of the hospital, both paid and non-paid
or volunteer.  This staff varies by shift and drops off on weekends.  First
shift,  from 8:00 A.M. to 4:00 P.M., may have two or three times the staff of
the 4:00 P.M. to midnight and the midnight to 8:00 A.M.  "Full time" equiva-
lent becomes a weighted average of the staff population of the three shifts.
     Each person in the total population is a contributor to the waste load.
The contribution of each person varies with his  or her activities and the hours
present in the hospital.  As the staff is the largest single block in the total
population, and as the staff varies considerably with the three shifts, as do
outpatient visits, the waste varies similarly by shift and between weekdays
and weekends, often as much as over 50 percent.
                                      -117-

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                    TABLE 4
              RATIOS OF SOLID WASTE
TO HOSPITAL POPULATIONS. ACTIVITIES & FLOOR SPACE
ITEM
Average Total Waste per Day:
Founds
Cubic Feet
Total Number of Available Beds
Average Occupancy Rate During Period
Average Number of Occupied Beds
Quantity of Waste Per Occupied Bed:
Pounds
Cubic Feet
Average Daily:
Discharges
Outpatient Visits
E.R. Visits
Laboratory Tests
Radiology Procedures
Meals Served
Avg. No. Full Time Equivalent Staff
Total Hospital 24 Hour Population
(Inpatients, Outpatients, Staff)
Quantity of Waste Per Unit of Full
Time Population:
Pounds
Cubic Feet
Total Gross Floor Space, Sq. Ft.
Quantity of Waste Per 100 Sq. Ft.:
Pounds
Cubic Feet
SI. MARY'S
HOSPITAL

2273
567
419
79.8%
335

6.8
1.7

44
44
48
1085
198
1743
1033

1460


1.6
0.39
451,530

0.50
0.12
V.A.
HOSPITAL

4445
1575
646
61.9%
400

11.1
3.9

30
199
0
4936
165
2381
1605

2204


2.0
0.71
677,700

0.65
0.23
MARTIN
LUTHER
KING
HOSPITAL

3678
1188
320
64.4%
183

20.1
6.5

28
360
218
4341
227
1318
2200

2961


1.24
0.40
551,520

0.67
0.22
                       -118-

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                                   TABLE 5
                         SOLID WASTE GENERATED DURING
                24  HOUR PERIOD AVERAGED FOR 7 CONSECUTIVE DAYS
ITEM
Bagged Waste Transported By P/N Tube:
Pounds
Cube
Avg. No. of Bags in 24 Hours
Avg. Weight, Lbs/per Cubic Foot
Bagged Waste, Cartons, Boxes, Etc.
Transported By Hand Cart:
Pounds
Cube
Avg. No. of Cart Trips, 24 Hours
Avg. Weight, Lbs/per Cubic Foot
Total Waste Transported
Pounds
Cube
Avg. Weight, Lbs/per Cubic Foot
ST. MARY'S
HOSPITAL

882
382
147
2.3


1391
185
15
7.5

2273
567
4.0
V.A.
HOSPITAL

1115
557
316
2.0


3330
1018
57
3.3

4445
1575
2.8
MARTIN
LUTHER
KING
HOSPITAL

2218
1008
528
2.2


1460
180
16
8.1

3678
1188
3.1
     From these figures, it can be seen that, of the total waste generated in
the. hospitals, as much as 75 percent by weight  is hand carried through the
building.  In general, this represents the heavy items in the total waste
load and consists of crating materials, bottles, metal, heavy cartons, and
other items too large to fit the chutes.  The figures reveal that this ma-
terial has a density per cubic foot of up to three times the waste sent down
the chutes and therefore occupies as low as 30  percent of the total cube for
the waste from the entire building.
                                      -119-

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                  TYPES OF WASTE TRANSPORTED  B\  HAND  CART

     With the installation of a pneumatic tube waste transport system, the
question is raised as to why wastes would be manually transported, and what
the make-up and quantities might be.  In the three hospitals studied, the
wastes that are carted to the central collection point covered a wider variety
and larger quantity than might be expected.
SHIPPING CARTONS, WOODEN BOXES, AND CRATING MATERIAL

     Virtually all cardboard outer shipping containers and boxes of 100 pound
test or heavier corrugated board were found to be too large to enter the
chute.  These range from I.V. bottle and baby formula cartons, to shipping
boxes for medical and surgical supplies, Pharmaceuticals, chemicals, X-ray
film, EOF paper, and general stores.
     The Receiving and Warehouse Departments were the largest producers of
this waste material, as might be expected.  In addition, large numbers of
complete cartons of supplies were sent  into various support and ancillary
departments  (such as dietary, main kitchen, laboratory, central sterile sup-
ply, radiology, and pharmacy) and this added to the waste load from disposing
of the empty cartons.  Nursing stations usually received supplies broken down
into smaller units and had few outer cartons.  It would seem that this could
be accomplished in the other departments to some degree.
     Wooden boxes appear in the kitchen in smaller quantities each year, as
they are replaced by corrugated cartons.  Some additional wooden boxes are
hand hauled by maintenance and engineering for heavy items such as plumbing
supplies.  Wooden crating material rarely gets on to the floors of the three
hospitals studied.  When heavy equipment is received in this material, it is
usually broken down at the dock or in the receiving or warehouse areas.
     The quantities of cardboard shipping cartons hand-hauled on a single day
                                      -120-

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was substantial.  At the Veterans Administration Hospital, San Diego, it
amounted to 445 pieces, originating from the canteeen  (68), radiology (30),
laboratory (19), O.R.  (4), basement areas  (79), day shift for all departments
(113), and night shift for all departments  (132).  These empty cartons weigh
up to 2-1/2 pounds each.  Hence, this  is 1/3 of the total weight of hand
hauled waste.  The other two hospitals had  similar percentages in their total
waste.
     None of the hospitals had any mechanical  equipment installed in their
receiving area, warehouse, or support  departments that would modify such car-
tons and boxes so the  material could be bagged and transported by the pneu-
matic chute.  This would apply to virtually every hospital in the country.
The authors of this  study have for years examined various shredding, grinding,
and crushing devices produced for industrial operations to see if they could
be used for this purpose.  To date, none have  been found  that are small enough,
inexpensive enough,  and most important, quiet  operating to be practical to
install in the various floor work areas of  a hospital.  However, if  the central
waste collection area,  compactor, or  incinerator  are  a considerable  distance
from the warehouse or  receiving  section,  it might be  economically feasible  to
place a chute station  at  this point,  along with a heavy duty grinder or heavy
carton shredder with a bagging attachment.   It must be capable of handling  all
such material.
     In many commercial  operations,  shipping  cartons  are  cut up  with hand
knives to flatten them and expedite waste  removal.  This  also was not done  in
the hospitals studied.  Admittedly,  it must be done properly.  All  three hos-
pitals had experienced the phenomenon of  "box accordioning"  in  chutes,  in
which a flattened box  opens  in  transport  and  creates  a jam.   Breakdown,  to be
effective, must cut  the carton  into  pieces under 14"  by  14"  in  size.
 GLASS AND METAL  CONTAINERS

     The use  of  glass containers in hospitals appears to have declined in
 recent  years  and been replaced to a degree by plastics.  As an example, certain
                                       -121-

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blood is now contained in plastic bags, as well as some I.V.  fluids.   However,
glass bottles are still substantial, making up as much as 8 to 15 percent of
the total waste weight in hospitals.
     Two of the hospitals had experienced glass breakage in the pneumatic
tube system that could possibly create glass splinters in the soiled laundry,
or liquid problems if not emptied before transport.  Glass containers are
supposed to be dumped of all liquids before depositing in lined waste contain-
ers, but occasionally this has not been followed out by nursing and technical
personnel.  Both these hospitals felt that glass bottles and metal cans, even
though  bagged, created noise problems going through the tubes.  Aerosol cans
create  a special problem and are not sent through the tube system for fear of
explosion possibilities.
     For these reasons, both hospitals place all glass bottles and metal con-
tainers in  separate  and labeled waste receptacles with distinctive bag liners
in each soiled utility room or support department and cart-haul the bagged
glass  and metal  daily to  the central collection point.
     The third hospital,  using heavier wall tubing, as well  as separate trash
and  linen  tubes, has experienced  no problem with glass and metal  in the systems,
including  aerosol  cans.
 OVERSIZED BAG LOADS

      It was discovered that certain areas, such as O.R.,  canteen,  warehouse,
 and Central Sterile Supply, are heavy waste generators and use a  certain num-
 ber of waste containers, such as 30 gallon plastic garbage cans,  with  plastic
 bag liners too large to send down the pneumatic chutes.   Except for  the  cube
 of the load, there was nothing in the material that would create  problems in
 the system.  However, this resulted in these over-sized bags  of waste  being
 cart-hauled.  Recommendations were made to install smaller containers, or
 adaptors for the regular sized chute bags in the large containers, and send
 this material through the pneumatic system.
                                      -122-

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INFECTIOUS OR CONTAMINATED WASTE

     The survey found the operational thinking to be entirely different between
the hospitals on the subject of handling infectious or contaminated material.
At Martin Luther King Hospital, with a completely closed system and heavy wall
tubing, it was felt that all infectious and contaminated material should go
through the pneumatic system as offering the  least possibility for cross con-
tamination and the spread of aerosols creating infection problems in the house.
     At the Veterans Administration Hospital, all such material, along with the
material from surgery, is not sent through the system but rather is bagged in
red plastic and hand carted to the incinerator room.  At this institution, each
surgery has a kick bucket with a  special non-static liner.  Waste generated is
placed in these and then double bagged  in a red  plastic outer bag.  It is then
transported in special aluminum carts that are sanitized after each trip.  The
V.A. is a heavy user of disposable surgical drapes which adds considerably to
this load.  The hospital has experienced considerable bag ripping in the tubes,
and is fearful of contaminating the soiled laundry with contaminated or infect-
ious waste.
     At St. Mary's Hospital, infectious and  contaminated  solid waste is sent
through the system, as their double bagging  system has  apparently prevented
bag breakage.
     The only  hospital with research  animal  quarters was  the Veterans  Administra-
tion.  All bedding generated in  cage  cleaning is regarded  as contaminated  and
is red bagged  and transported  by  cart.
     Other surveys in hospitals  have  stated  chat the material that  can be
definitely established as  infectious  and contaminated is  only in the neighbor-
hood of 4 percent of  the  total solid  waste  load.   In this  present  study,  the
researchers found that  this figure is low by at  least 50  percent.   The per-
centage clearly established by the V.A. San  Diego Hospital as infectious was
almost  exactly in line with the  other two  hospitals  in this present study.
It represents  10.7 percent of  the 3330 pounds of cart transported material at
San Diego.  Eight percent  of the total waste transported  by cart and  tube
generated  in  each of  the  three hospitals was clearly established as potentially
infectious.
                                      -123-

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HYPODERMIC NEEDLES AND SHARPS

     Probably the most dangerous item in a hospital as a potential cause of
spread of infections is a hypodermic needle.  With the introduction of dis-
posable needles plus the increase in injections in the past 15 years, the
number of needles generated as waste has increased at least twenty times.
With the increase in drug addiction in  the United States, hospitals have also
become sensitive to the use of their needles by drug users, particularly after
use in the hospital.  Hence, most institutions break needles after use.  The
theory is fine.  The equipment to accomplish it, on the nursing floors, is
not.  Most nursing  station needle breakers are flimsy, and a source of nursing
irritation.   The disposable "catch containers" are not satisfactory.
     Many examples  were  given  the survey team of broken needles and/or sharps
projecting through  the bags and  puncturing  the hands of waste handlers.  It
would  seem that all such items could be deposited  in the waste  in  inexpensive
metal  cans,  such  as a  taped soft drink can,  so  that  there  is no possibility
of injury to waste  handlers.
 PATHOLOGICAL WASTE

      The quantity is quite small, but as most state laws enforce destruction
 in pathological incinerators, it is hand carried, normally red bagged,  from
 operating rooms, autopsy suite, and animal quarters, and disposed of by burning.
 RADIOACTIVE WASTE

      This is subject to special regulations originally promulgated by the
 Atomic Energy Commission and is disposed of in special containers to special
 sites.  In a hospital, the total quantity is small.
                                      -124-

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AREAS AND HOURS NOT SERVICED BY THE CHUTE SYSTEM

     In two of the hospitals, it was determined that at certain time periods,
general waste should be hauled by  cart  instead of sent through the chute sys-
tem.  This thinking has been revealed in several other hospitals  studied by
the survey team.  The reasoning is that the  system  should be shut down during
the late evening hours  (for example, from 10:30 P.M. to 6:00 A.M.) in order to
ensure better control over the chute loading.  To reduce floor waste to a mini-
mum, at least one "sweep" is made  of the building during this period, particu-
larly in public lobbies and in the 24-hour Emergency Department.  At the Martin
Luther King Hospital, this is not  the case and the  chutes are available 24
hours a day.
     Certain areas are  not served  economically by  the  chute  system due to de-
sign, or architectural  omissions or weaknesses.  For example, time studies in
the V.A. Hospital revealed that, for  the  first  floor office  areas, at the end
of the business day less  labor  is  required  in collecting the waste if a cart
hauling system is used, emptying all waste baskets in  one sweep  and  taking an
entire cart load directly to  the compactor.
     It has also been pointed  out  that  this  applies to dock  and  receiving area
waste when  it is found  that,  even  though  small  enough  to  fit the chute  system,
due to the  close proximity of  the  compactor  less labor is used  if it is carted
directly to the collection room rather  than to  a chute station  that  would be
further away.
 DENSITY OF HAND CARTED WASTE

      The table on page 119 reveals that the hand-carted waste is much heavier
 per cubic foot (denser) than the waste transported in the pneumatic system.
 This would be expected, as the hand-carted waste consists of corrugated card-
 board and crating lumber, glass bottles, engineering supplies, maintenance
 materials and metal, in as much as 60 percent of its total; whereas the bagged
 waste transported by chute is over 90 percent paper, light cardboard, plastic,
 and cloth.
                                      -125-

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                  GENERATION POINTS AND QUANTITIES OF WASTE
                             TRANSPORTED BY CARTS

     There is not the consistency of quantity in transporting the type of
waste handled by cart as there is in sending bagged waste in the pneumatic
tube system.  This arises from the fact that the bagged waste has a direct
relationship to the number of people in the total population of the building.
The total waste handled by cart is more dependent on the activities of the
ancillary and support departments and particularly, the delivery of supplies
to the hospital and its departments due to the effect of the quantity of
shipping containers in the total load.
     As the Veterans Administration Hospital had the largest census, the most
complex ancillary and support procedures,and the heaviest waste load trans-
ported by cart, it reveals these points most clearly among the three hospitals.
Further, the statistics are comparable with other hospitals that use the cart
movement method for solid waste management.  The following breakdown of hand-
carted waste in a typical week shows  its make-up and the departments that
produce it.
DIETARY

      The  quantities  transported per  day were  fairly consistent.  They averaged
124 pounds  in  the morning;  166  pounds in the  afternoon; and  125 pounds  in  the
evening.  The  bulk of this  was  shipping cartons,  followed by tin cans,  some
bottles,  and  a few  wooden  boxes.
ENGINEERING
     Variations from day to  day  were extremely heavy.   The work  period was  a
                                     -126-

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five day week.   Variations arose from the assignment of work schedules.
                    DAY                          POUNDS
                  Monday                           250
                  Tuesday                           35
                  Wednesday                         50
                  Thursday                         140
                  Friday                           300
WAREHOUSE

     The waste consisted entirely of heavy cartons and wooden boxes and dif-
fered considerably from day to day over  the five day work period:
            DAY        NO. CARTONS     NO. WOOD BOXES       TOTAL WEIGHT LBS.
          Monday           184                0                    423
          Tuesday           89              140                   1048
          Wednesday        144                30                    554
          Thursday         214                50                    814
          Friday           171                0                    393
The day to day variations arise  from variations in receipts, as  well as issues,
to the floors.
 SURGERY

     The waste  load would  be expected to tie into the operating room procedure
 schedule, and this can be  seen from the following breakdown by weight over the
 five day work period:                          GLASS &              TOTAL
            DAY            CONTAMINATED       GENERAL      CARTONS      LBS.
          Monday                12              220           10         242
          Tuesday                8              268           10         286
          Wednesday              12              200           10         222
          Thursday                4              168           10         182
          Friday                 8              112            3         123
                                      -127-

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LABORATORY

     This department does both clinical and research work.  As can be seen
from the figures, it peaks toward the middle of the week and generates waste
over a seven day work period, with a weight breakdown by type as follows:
GLASS &
DAY CONTAMINATED METAL
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
16
4
28
44
36
12
—
36
120
90
90
72
72
—
GENERAL
96
180
186
30
40
88
—
TOTAL WE
CARTONS LBS .
50
18
21
38
18
28
21
198
322
325
202
166
200
21
 RADIOLOGY

      Compared to other  ancillary departments, this is not a heavy producer of
 solid waste,  and the weight load is fairly level over the five day work period:

DAY
Monday
Tuesday
Wednesday
Thursday
Friday

CONTAMINATED
0
0
0
0
3
GLASS &
METAL
88
72
94
88
64
TOTAL WE
GENERAL
48
48
40
40
48
CARTONS
44
8
28
14
6
LBS.
180
128
162
142
121
 CANTEEN

      Indicating a fairly consistent level of  activities,  the weights  of waste
 generated during the week days are similar from day  to day,  with a week-end
 decline:
                                      -128-

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            DAY     GLASS & METAL     GENERAL     CARTONS     TOTAL WEIGHT  LBS.
          Monday          60            103          94              257
          Tuesday        192             42          74              308
          Wednesday      336             24          22              382
          Thursday       288             26          68              382
          Friday         328             38          15              381
          Saturday         0            112           0              112
          Sunday          24             64          74              162

     With the exception of the warehouse, which generated an average of almost
650 pounds per day, and the canteen at over 280 pounds, the other support de-
partments were quite similar in load, with daily averages ranging from 150 to
slightly over 200 pounds.  The above departments added together represent
just under 50 percent of the solid waste transported by cart.  The remaining
solid wastes, moved by hand carts, come mainly from the outpatient clinics,
central sterile supply, nursing stations, laundry cartons, inhalation and
physical therapy, and various offices, as recapitulated in the following
figures of pounds produced each 24 hour period, and the breakdown by type:
CONTAM-
DAY INATED &
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
233
398
435
341
482
175
164
GLASS & METAL

NON-COMBUSTIBLE GENERAL
608
860
710
820
596
520
640
452
328
476
286
308
206
223

CARTONS
174
594
286
810
386
174
130
TOTAL
WEIGHT LBS.
1,467
2,180
1,907
2,257
1,772
1,075
1,157
   TOTAL     2,228           4,754         2,279      2,554         11,815
   LBS PER WEEK
   DAILY        318             679           326        365          1,688
   AVERAGE LBS
                                    -129-

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                      COMPARISONS OF SYSTEM UTILIZATION
                   CART-HAULING VERSUS PNEUMATIC TRANSPORT

     Each of the three hospitals has a slightly different philosophy on solid
waste management.  This involves the total hours of the day active removal and
transport shall take place; the hours during which the pneumatic system will
operate; how the waste shall be initially collected from each room and how it
snail be removed from the floor; the use of specialized personnel to cart-haul
or load chutes versus random removal or loading by general housekeeping maids
and nursing aides; the items and type of waste that will be deposited in the
chutes versus being hauled from the floors by cart.  All are supervisor edicts.
     These differences in management philosophies have a marked effect on the
utilization of the pneumatic transport system in each hospital.  The percent-
age of total waste transported by pneumatic tube, as against the percentage
hauled by cart,  differed substantially in each hospital.  The differences are
far greater than would be expected and result almost entirely from management
decisions as to  the amount and type of waste that will be permitted to be
transported by chute.  In each institution the chute wastes are of lighter
weight and  greater cube per pound than the cart transported wastes.  This ex-
plains the  higher percentages in cubic volume as against weight that are  trans-
ported by tube.
      When the weights of waste are  compared between the hospitals we have seen,
for example, that  the Veterans Administration generates a  total weight of 63
percent  more waste per inpatient than  St. Mary's  and  40 percent more  total
weight  for  its  24-hour population than  St. Mary's.  When  this  is  analyzed still
further, almost  th«  entire difference  arises  from the extreme  weight  at  the
Veterans Administration Hospital in the items  that must be transported by cart
rather  than sent through the pneumatic system.
      Partly this has to do with the hours during  which the pneumatic  system is
 in operation.   The details of this  are shown  later in this chapter.   Partly it
has to  do with the supply practices in each  hospital  and  the amount of heavy
waste or large bulky waste that is  permitted  to go onto  the floors  of  the
building and cannot  be transported, due to  size, by  the  pneumatic  tubes.
                                      -130-

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And partly it concerns decisions that certain items will, for one reason or
another, not be sent in the pneumatic system for fear of breakage, bag tear-
ing or other reasons.
     In surveying other hospitals  that have pneumatic systems, it would be
safe to state that almost all full vacuum systems that have been installed for
transporting waste to date are under-utilized and that too much material is
going around the systems by expensive hand carting methods.
     The figures in Table 6 give  the comparisons between the  three hospitals,
showing the percentage of material by weight and by  cubic foot that is trans-
ported in the pneumatic system as  against being transported by hand cart.

                                    TABLE 6
                 COMPARISONS AND UTILIZATION OF TUBE AND CARTS
ST. MARY'S
HOSPITAL
Avg 24 Hour Weight Transported
by Pneumatic Tube
Avg 24 Hour Weight Moved by Cart
Total Weight in Pounds
% of Total Weight Transported
by Tube
Avg 24 Hour Cube Transported by
Pneumatic Tube
Avg 24 Hour Cube Moved by Cart
Total Cubic Feet
% of Total Cube Transported
by Tube
882
1,391
2,273
38.8%
382
185
567
67.4%
V.A.
HOSPITAL
1,115
3,330
4,445
25 . 1%
557
1,018
1,575
35 . 4%
MARTIN LUTHER
KING HOSPITAL
2,218
1,460
3,678
60 . 3%
1,008
180
1,188
84 . 9%
      As seen in the chapter on economics, hand  carted waste is expensive
 material to transport, requiring  as  much  as  21  manhours per day to clear it
 from the floors and move  it to the  central collection point, for the hospitals
 in the present study.
                                       -131-

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               QUANTITIES OF WASTE TRANSPORTED BY PNEUMATIC  TUBE

     Seven consecutive 24-hour  surveys were conducted at each of  the hospitals
to analyze the waste transported  by  the pneumatic  system and to determine:
          Where the waste originated
          Of what it was comprised
          In what chute station it was discharged
          At what time of day  it  was discharged
          What were the weights and  cubes transported, by type of
               waste, time  of  day, and chute station
          What were the weights and  cubes of the individual loaded bags
     The surveys were conducted at all chute loading doors in the house simul-
taneously, with every bag recorded at every door before deposit into the chutes,
THE SIZING OF UNIT LOADS

     The comparisons between the three hospitals of quantities of waste trans-
ported by pneumatic tube must take into consideration the size of the tube and
hence the size of the transport bag used.
     Martin Luther King Hospital uses a gravity to vacuum system with a 20"
tube.  This permits the use of a bag as large as 29-1/2" wide by 35" long in
the flat; which could produce a fully loaded bag 19" diameter by 25" long,
holding A.I cubic feet of waste.
     Both the Veterans Administration Hospital, San Diego, and St. Mary's
Hospital, Duluth, use 16" diameter tubes; permitting the use of bags 23-1/2"
wide by 33" long in the flat, giving a fully loaded bag 15" diameter by 25"
long, holding 2.3 cubic feet.
     In view of the cost of transport bags and the waiting times involved in
a  full vacuum system, there is a need to load bags as full as practical with
regard to bulk or volume.  Weight will obviously vary, depending on the nature
of trash and its compaction in the bag.  Surveys reveal that "fully loaded"
15" by 25" bags will vary in total weight, from 3.5 pounds to over 13 pounds,
                                      -132-

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with the normal filling practices of housekeeping workers.  The "average"
weight of this size bag should be 6.0  to  7.2 pounds when loaded with hospital
chute trash, depending upon whether glass bottles and metal have been included.
The larger bags used in the gravity to vacuum  system will average 10.7 pounds
fully loaded, and up to 12.0 pounds average if all glass and metal is deposit-
ed in the chutes.
     A three mil thick plastic trash bag  will  easily support these weights of
waste in the cubes that are listed  above.  Further, it was discovered at St.
Mary's that such bags have a considerable amount  of stretch and could be con-
siderably overloaded as to cube  and still go through the system without tear-
ing or without plugging the system, as they "elongate" during  transport.
Measurements of a representative succession of bags showed the following dia-
meters and  lengths:
16"x29"
17"x24"
16"x25"
17"x29"
14"x29"
14"x22"
16"x24"
21"x26"
19"x28"
15"x27"
20"x27"
18"x29"
16"x29"
15"x27"
21"x25"
16"x25"
13"x26"
17"x27"
21"x29"
19"x30"
16"x26"
18"x24"
15"x24"
21"x28"
17"x26"
15"x27"
19"x27"
19"x26"
18"x25"
16"x23"
17"x23"

 DAJLi"  QUANTITIES TRANSPORTED

     The  figures reveal an important fact about pneumatic tube transport sys-
 tems.   Hospitals that have installed 16" diameter tubes show considerable dif-
 ferences  in the average cube and weight of the bags of waste that are trans-
 ported, while at the same time the density of the waste only varies from 10
 percent to 15 percent between such hospitals.  This is evident in studying
 the figures from the Veterans Administration Hospital and St. Mary's, with a
 difference of 44 percent in cube and 70 percent in weight for the average bag
 load between these hospitals and only 13 percent in waste density.
                                      -133-

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     The main reason in all hospitals studied appears to arise from experiences
with plugging and bag breakage when the tube system first starts in operation.
Each hospital experiments with the bagging methods used to avoid this.  One
hospital will reduce the loading of individual bags to ensure they are kept
rather small.  Another, such as St. Mary's, will lean toward double bagging in
extremely strong bags, even to the point of adding nylon mesh reusable bags
over these.  As a result, the loading of individual bags is increased as the
hospital finds the bags are standing up to transport.
     Surveying the total number of waste bags placed in the pneumatic system
in  the seven consecutive days that were studied, we find the following:
                                   TABLE 7
          DAILY QUANTITIES OF WASTE TRANSPORTED IN PNEUMATIC SYSTEM

DAY OF WEEK
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Weekly Total
Daily Average
Daily Average Cube
Average Bag Weight
Average Bag Cube
Average Weight of
Waste Transported
ST. MARY'S
HOSPITAL
BAGS { LBS .
|
148 | 902
155 j 942
165 j 973
146 1 949
154 919
138 j 801
123 j 689
1029 | 6175
147 j 882
382 cu ft
6.00 Ibs
2.6 cu ft
2.3 Ibs/
cu ft
V.
A.
HOSPITAL
BAGS
170
416
342
571
186
329
206
2210
316
557
LBS.
612
1513
1165
2070
651
1119
679
7809
1115
cu ft
3.53 Ibs
1.8
2.0

cu ft
Ibs/
cu ft
MARTIN LUTHER
KING HOSPITAL
BAGS LBS.
562 2360
522 2192
668 2806
521 2188
662 2780
281 1180
482 2024
3698 15,530
528 2218
1008 cu ft
4.20 Ibs
1.9 cu ft
2.2 Ibs/
cu ft
                                      -134-

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FLOOR COMPACTORS

     The survey team did an investigation  on  the use of household compactors
in the three hospitals and found  that  none were in use.  The theory of install-
ing these units by each chute station  is that they are inexpensive and will
pay for themselves in under four  years by  increasing the density and reducing
the bulk volume of waste sent through  the  system.  With the waste generated in
the nursing floors and support departments,  it has been discovered that one of
these units gives an average compaction rate  of approximately 4 to 1.   Pre-
sumably this would reduce the number of bags  by 4 to 1 and reduce chute loading
waiting time.  It would also increase  the  weight of each bag by at least four
times and would provide more uniform bag loading.
     Not enough hospitals have installed these small home compactors to date
to prove their economic feasibility.   However, it is knoxm that, as the cost
of bags used in these is approximately four  times the  cost of chute bags, no
savings would be obtained in this aspect.   Further, they represent one more
step in the process and would add extra labor for lining the chamber with the
compactor bag.  As against  this,  chute loading total  time would be reduced 75
percent in a full vacuum system  and a  much tougher  transport bag would be used.
With the exception of large cartons and boxes, cart hauled waste could also be
reduced by 75 percent in bulk.
     It would appear worthwhile  to study the pros and  cons  of  these units.
 CHUTE LOADING HOURS AND VOLUMES

     When  the figures for waste bags alone are studied, the hourly quantities
 placed  in  individual stations are not particularly large.  However, with the
 full vacuum systems of St. Mary's and the Veterans Administration, the sta-
 tions must be examined for the ability to handle trash and linen at virtually
 the same  time,  and the totals of both within a given hour must be recorded to
 show the volume ability of the system.
     At first glance it would appear that a full vacuum system,capable of
                                      -135-

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receiving only one bag at a time,is  quite limited in volume capacity.   St.
Mary's, with separate waste and linen tubes,  was able to put through the sys-
tem in the morning peak single hour  between 110 and 120 bags maximum,  of
waste and linen combined.
     The Veterans Administration,  using a multiple loading and single tube,-
full-vacuum system, and with a specialized operator doing the chute loading
for the entire hospital, was able to send as high as 232 combined laundry and
waste bags through in a single morning peak hour; or over twice what the
limits of the single bag transport system set, despite the use of a single tube,
     The housekeeping management practices do enter into this loading speed.
It will be seen that St. Mary's loads waste and linen bags into the system at
a relatively even rate from early morning until late evening, over a 17 hour
period.  The Veterans Administration, on the other hand, does the majority of
the station loading in 4 to 6 very high peak hours per day, in the mid-morning
and early afternoon.
     These patterns are created by the management system used in each hospi-
tal.   St. Mary's uses random loading, in which all maids and porters from
housekeeping that clear the rooms and hospital support departments, and all
nursing aides that handle the laundry on the various floors, also deposit bags
in each of the chutes as they generate them.  At  the Veterans Administration,
the housekeeping and nursing aide personnel merely  clear the areas, tie the
bags,  and take them to  the chute rooms for temporary storage.  One  operator
then goes from floor to floor,  four to  six  times per  day,  and puts the bags
down the chutes on a multiple loading basis.  Further,  at  the Veterans Admin-
istration Hospital, the  clearing period  from  patient rooms and support  activi-
ties is over a much shorter time period,  and  without the late afternoon and
early  evening hours found  in a  community hospital handling private  patients.
     Figures 11 through 16  show  the  loading of each chute station  in each  hos-
pital  over each hour of  the day that  the pneumatic transport  system is  in
operation.  These  surveys,  over seven consecutive days, reveal clearly  the
loading  patterns used  in each  hospital.   They also show the management  prac-
 tices  on  the  part  of housekeeping,  maids,  and aides in clearing  the floors;
and  they  reveal  the  ability of  each system to handle a given volume per hour
 from individual  stations.
                                       -136-

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                                 ST.  MARYS  HOSPITAL.

                               SEVEN  DAY CHUTE  LOADING
                           FIGURE  11.
5-6    6-7    7-8
 ~i—  —r
 8-9   9-10   10-
MORNING
11-12    12-1
2-3    3-4   4-5
 AFTERNOON
                                                                        5-6
                                     LOADING BY TIME OF DAY
            ~\—  —r
6-7    7-8    8-9   9-10
    EVENING
                                                                                  FIGURE 12
           -E  2-W  2-C  3-E  3-W  3-C  3-E  4-W  4-C  4-E  5-W  5-C  5-E  6-W  6-C  7-W  7-C  8-W  9-W 10-W
 I-W   I-C
                                   LOADING  BY CHUTE STATION


                                             -137-
                         LEGEND
                	 Monday   	Friday
                	Tuesday  	Saturday
                	Wednesday	Sunday
                	 Thursday

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                            VETERANS  ADMINISTRATION  HOSPITAL
                                SEVEN DAY CHUTE  LOADING
                                                                           FIGURE 13
110.
"00 .
 80 .
                                                                     LEGEND
                                                              	 Mondoy     ._._ Friday
                                                                 Tuesday    _„_ Saturday
                                                           	Wednesday  	Sunday
                                                                 Thursday
  0 .
I-W  I-E  2N  2-W  2-S  2-E  3-N  3-W  3-S  3-E
                                                    4-W  4S  4-E  5-N  5S   5-E  6N   6-W  6-S  6-E
                                    LOADING BV CHUTE STATION

                                           -138-

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5-6
                        VETERANS ADMINISTRATION HOSPITAL

                            SEVEN  DAY  CHUTE LOADING
                                                                  FIGURE 14
                                                                  LEGEND
                                                          ....Monday     	Friday
                                                             Tuesday    	Saturday
                                                       	Wednesday   .  —Sunday
                                                             Thursday
7-8
 8-9   9-10
MORNING
                          10-11   11-12  12-1
                                 2
  2-3   3-4
AFTERNOON
                                                           4-5
                                                      5-6   6-7
7-8   8-9
EVENING
                                                                                     9-10
                               LOADING  BY TIME OF DAY

                                      -139-

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200
                              MARTIN  LUTHER KING  HOSPITAL

                                  SEVEN  DAY CHUTE  LOADING
                                                                              FIGURE  15
 180.
 160 .
 I 40 .


 130.
 100-
  80.
  20
                                                                        LEGEND
                                                                .... Monday     	 —Friday
                                                             	Tuesday    	Saturday
                                                             	Wednesday   .  	Sunday
                                                             	Thursday
A-l  A2  C-2  C-3  B-A  Bl  S-I-I WA-I S-I-2 \rV-C2 WB-2 WA2 SI3 WC-3
                                                              W63 S14 WC4 W6-4 WA4 SI5 WO5 WB5 WAS
                                      LOADING  BY CHUTE STATION

                                               -140-

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14 0
I00_
 80.
60.
 40_
20_
                            MARTIN  LUTHER  KING  HOSPITAL

                                SEVEN  DAY  CHUTE LOADING
                           FIGURE  16
                                                               Mondoy
                                                               Tuesday    _
                                                               Wednesday
                                                               Thursday
                        — Friday
                        — Saturday
                        	Sunday
                   8-9  9-10
                   MORNING
 2-3   3-4   4-5
AFTERNOON
6-7   7-8   8-9  9-10
     EVENING
                                  LOADING BY TIME OF DAY

                                          -141-

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THE INTERFACING OF SOILED LAUNDRY AND WASTE IN THE PNEUMATIC SYSTEM

     No hospital has installed a pneumatic tube transport system for waste
alone.  In each case soiled laundry is moved along with the waste, either in
the same tube, or in separate tubes, usually with a common fan.  Studies of
the loading figures in hospitals such as St. Mary's and the Veterans Adminis-
tration always reveal that the quantities of laundry transported in the system
exceed the waste, in cube, in pounds, and in number of bags sent per hour.
Further, the movement of laundry always takes precedence over  the movement of
waste,  Only when two entirely separate systems are installed  (as in the case
of Martin Luther King) can waste removal be completely independent of laundry.
      In St. Mary's and the Veterans Administration, using the  full vacuum sys-
tem dependent on a single fan and,  in the case of the V.A., restricted  to a
single tube, the waste management is highly influenced by the  removal of laun-
dry.  When laundry must be transported, the system is not available for waste
transport.  The figures in Table 8  show how important this influence can be.
                                       -142-

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                                                     TABLE 8
                      DAILY QUANTITIES OF WASTE AND LAUNDRY TRANSPORTED BY PNEUMATIC SYSTEM
                                                            NUMBER OF BAGS


Day of Week
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Totals
Daily Average
Percent of Total
Avg.per Operating Hour
ST. MARY'S
HOSPITAL
Waste
148
155
165
146
154
138
123
1029
147
20%
8
Laundry i Total
695
685
648
i
604
561
! 448
! 438
i 4079
1 	
! 583
i
j 80%
843
840
813
750
715
586
561
5108
730

! 34 42
V.A.
HOSPITAL
Waste
406
342
571
186
329
206
170
2210
316
46%
80
	 1
Laundry
336
414
506
323
368
261
395
2603
372
54%
80
1 	
Total
742
756
1077
509
697
467
565
4813
688

96
	
MARTIN LUTHER KING
HOSPITAL
Waste | Laundry, Total
j j 	 _
562
522
668
521
662
281
482
3698
528
56%
29
344
337
726
354
532
213
406
i 	 1
2912
416
44%
23
906
859
1394
875
1194
494
888
6610
944

52
UJ

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WASTE GENERATION POINTS AND VOLUMES
     From what has been described  in the preceding  sections, we have seen that
it is virtually impossible to plan a pneumatic transport system and locate the
stations throughout the hospital so that they are loaded equally.  Some depart-
ments and nursing floors and wings generate much more waste than others.  The
science in designing the layout of such a system is to attempt to place the
stations so that the load is somewhat equalized and that each and every station
can be proven to be worth the expenditure involved in installing it.
     Table 9 gives an indication of the equality or inequality of loading of
the individual stations with a combination of waste and laundry bags in each
hospital.
                                   TABLE 9
                   UTILIZATION OF CHUTE LOADING STATIONS

Hospital

St. Mary's

Veterans
Administration
Martin Luther
King
Total No. of
Stations

Waste — 22
Laundry — 19
Waste— 27
Laundry — 27
Waste — 24
Laundry — 19
No. of
50% of

8
5
6
5
6
6
Stations Used for Sending
Bags 80% of Bags

13
9
11
9
11
10
     The pneumatic system was laid out quite differently by the designer in
each of the three hospitals with regard to the departments and stations that
are to be serviced by a given chute station.  Hence, direct comparisons are
difficult to make between the hospitals as to the efficiency of the location
of the individual stations, particularly with regard to the ancillary and sup-
port departments.  This is heightened by the different concepts in each of the
three institutions concerning what should be hand-carted, versus what should
be transported by the pneumatic system.
                                     -144-

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     Examined individually, the  three hospitals  show the following
patterns in a seven day week  for each station, rated in descending
the volume of waste bags  each station handles.
STATION
Dietary
Intensive Care, P.A.R.,
Floor Dietary, Nursing
O.B., GYN., Nursery,
Floor Dietary, Nursing
C.C.U., Nursing, Floor
Dietary
Med-Surg Nursing
Obstetrics
Med-Surg Nursing
Floor Dietary, Nursing
E.R., X-ray
Floor Dietary, Formula
Room, Nursing
 STATION
 Nursing
 Nursing
 Nursing
 Nursing
 Outpatient Clinics
 Nursing
 Nursing
 Nursing
 Nursing
 Intensive Care,
 Nursing
 Nursing
 Nursing
NO. OF
 BAGS
 111
ST. MARY'S
      STATION
  94

  93

  67
  63
  58
  54
  51
  50

  49
      Med-Surg Nursing
      Surgery
      Med-Surg Nursing
      Med-Surg Nursing
      Med-Surg Nursing
      Floor Dietary, Nursing
      Offices
      E.R., X-ray
      Offices
      Central Sterile Supply
      Main Lobby
      Laboratory
                            VETERANS ADMINISTRATION
 NO.  OF
  BAGS
  259
  208
  207
  167
  155
  149
  147
  141
  130

  117
   97
   96
      STATION
      Nursing
      Offices
      Med.  Illus.,
      Card io-Pulmonary
      Nursing
      Animal Research O.R.
      and Lab
      Animal Research Lab
      Nursing
      Animal Research Lab
      Animal Quarters
       Surgery  N
       Surgery  S
       Central  Sterile Supply
                                           loading
                                           order of
NO. OF
 BAGS
  46
  43
  40
  37
  37
  35
  32
  25
  20
  17
  10
    2
 NO.  OF
  BAGS
   89
   73

   59
   55

   32
   17
   10
    2
    0
    0
    0
    0
                                       -145-

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                        NO.  OF
STATION                  BAGS
Pediatrics, Segment I,
5th Floor                485
Nursing, Wing C,
4th Floor                328
Nursing, Wing A,
3rd Floor                296
Orthopedics, X-Ray,
Segment I, 1st Floor     295
Offices, Wing A,
1st Floor                290
Nursing, Wing B,
4th Floor                279
Obstetrics, Segment I,
2nd Floor                230
O.K. & Labs,
Segment I, 3rd Floor     227
Nursing, Wing B,
3rd Floor                208
Nursing, Wing C,
2nd Floor                205
Nursing, Wing A,
4th Floor                178
Clinics, Segment I,
4th Floor                161
MARTIN LUTHER KING

         STATION
         Nursing, Wing A,
         2nd Floor
         Trash Room, C-2
         Nursing, Wing C,
         3rd Floor
         Nursing, Wing B,
         2nd Floor
         Autopsy, Offices,
         Basement A
         Kitchen, A-2
         Central Sterile
         Supply, C-3
         Kitchen, Offices,
         B-l
         Nursing, Wing B,
         5th Floor
         Not Used, Wing  C,
         5th Floor
         Not Used, Wing  A,
         5th Floor
         Laundry, A-l
NO. OF
 BAGS

 139
 118

  89

  69

  45
  27

  20

   5

   4

   0

   0
   0
 1  Ross  Rofmann, Associates,  Solid Waste  Surveys  of 43 Hospitals,  1970-1971,
    unpublished.
 2  Ibid.
 3  Brewer,  J.  B.,  A Case History, in  Proceedings,  A.H.A.  Institute on Hospi-
    tal Solid Waste Management,  Chicago, May  18-20, 1972.
                                     -146-

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                   7-OPERATIONAL AND PERFORMANCE ANALYSIS

     To analyze the operation and performance of a pneumatic transport system
the most revealing documents are the daily maintenance reports made by the
hospital engineering staff.  All three hospitals in this study keep excellent
maintenance records and these were made available to the survey team covering
the period from the first day of operation through November, 1973.  In the
case of Martin Luther King, this period was 23 months; 20 months for Veterans
Administration; and 47 months for St. Mary's.
     These records recorded every malfunction in each system, whether from
mechanical failure or from misuse by operating personnel.
     Of the three systems studied, the one at Martin Luther King General Hos-
pital had the highest installed cost at $425,000.  It also had the largest
total length of tubing, with over 1,400 ft for waste alone.  Comparable fig-
ures for the other two hospitals were $350,000 system installed cost at Vet-
erans Administration Hospital, with a total of 1,894 ft of tubing used for
both laundry and waste; and $193,000 system installed cost at St. Mary's, with
a total of 1,700 ft of tubing for waste and linen combined.
     The Martin Luther King installation has 20 in. diameter tubes of 3/16 in.
wall thickness in the horizontal tubes and a combination of 14 and 10 gauge
metal in the vertical chutes.  It is a gravity to vacuum system.  The other
two systems both use smaller diameter tubes of lighter metal—16 in. diameter
and 20 gauge metal—and are full pneumatic systems with loading hoppers.
     The maintenance practices of the three hospitals differ slightly, and
comparisons in maintenance hours used per year must be made very carefully to
ensure that the hospitals, and therefore, their systems, are being compared on
an identical basis.
     In analyzing the maintenance of any system, if detailed records are kept
by the engineering department, it will be seen that maintenance hours are re-
corded under three different classifications.  The first involves corrective
                                    -147-

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maintenance, and fro® the point of  view of  determining the efficiency of any
system and analyzing its operation  and performance, it is the "corrective"
hours that must be expended that reveal most clearly the problems involved
with the system.  Any efficient engineering department carries on a preventive
maintenance program, which is used  on a constant daily, weekly, or monthly
basis to catch trouble before it occurs and prevent breakdowns in any of the
operating parts of the system.  In  two of the hospitals  (Martin Luther King
and the Veterans Administration) a  considerable number of maintenance hours
are being used each year under a classification that is not "corrective" main-
tenance and is something less than  "preventive" maintenance.  We have termed
this "routine" inspection of the system by the maintenance department.  This
comes about because a full man, or  part of a man, is assigned full time to
the system, to be on call during normal working hours  to handle any problems
that arise with  the system.  He is  not assigned any other duties for these
particular hours and, therefore, his time can only be  charged against maintain-
ing the system.  Presumably, he is not sitting in an office during these hours
but, instead, is out walking the hospital and determining, on a constant basis,
that the  system  is operating properly.
     Table  10 shows the  actual hours recorded from  the beginning by  each hos-
pital for maintaining their pneumatic  transport  system,  adjusted to  a  twelve
month average.

                                   TABLE 10
                       AVERAGE ANNUAL  MAINTENANCE  HOURS
                            Corrective    Preventive    Inspection
 St. Mary's                     424            284           none
Veterans  Administration        454            	813  	
Martin  Luther King             171            240           441

      The  above  figures  clearly reveal  that  the  least amount of corrective main-
 tenance was performed  on the heavy wall system at  Martin Luther King.   The
 bulk of this was devoted to making changes  in certain architectural areas that
 interfaced with the system, with such changes chargeable to the system.  The
                                     -148-

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corrective maintenance time at St. Mary's and the Veterans Administration is
almost identical on an annual basis.  As can be seen from the following ac-
count, in the case of St. Mary's  it was used to repair damage to the system
caused by excessive vacuum or vibration and the effects on either the tubing
and fittings or the mounting hangars; while in the case of the Veterans Admin-
istration, it was devoted to basic modifications and replacement of components
of the system, such as collectors and diverters.  Due to the assignment of
personnel on a full time basis at the Veterans Administration, in order to
keep the system running, it was virtually impossible to divide the "non-
corrective" work between preventive hours and inspection hours.
     The most serious operational problems in the Martin Luther King installa-
tion were revealed shortly after  the hospital started up the system and they
cannot  be blamed on the system vendor, but rather on architectural designs of
surrounding areas.
     Laundry was to be collected  at  the end of  the tube line in a plastered
room with a closed door.  It was  discovered that plastered walls lacked the
strength to withstand the vacuum  pulled by the  system.  A large steel room was
built within the linen collection room  to act as a collector and solve the
problem.
     The original valve  rooms were not  vented and again the plaster walls would
not stand the vacuum pulled  through  the slide valves.  Vented doors have been
placed in all such rooms.
     The waste bin under the vendor's  collector was  supplied by the general
contractor, not the system vendor, and  was constructed with sloping sides which
tend to bridge, slowing  the  drop  to  the compactor at times.
     Materials used in maintenance have been  door locks, air valves, and var-
ious filters in the system.  The  filters  alone  account  for  68 percent of all
materials used for maintenance.
     The Veterans Administration  Hospital appears  to have had  the most drastic
changes in  the basic design  and  construction  of the  system, as  a  result of  main-
tenance experience showing weaknesses  in  operation  and  performance.  This might
be expected as it is a  single  tube system,  attempting to  transport both waste
and laundry in the same  tube,  with great  variations  in  bag  weights and cubes
                                     -149-

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between the two products,  as well as potential interferences of one with the
other.
     Shut downs of as long as 30 days occurred during the first 16 months of
operation while sections of the system were rebuilt.
     At Veterans Administration Hospital,  other than, the normal replacement of
filters, the most prevalent problem has been with diverter valves and the at-
tendant waste and laundry plug-ups which result when these valves malfunction.
New diverter valves were installed which are more positive in action and there-
fore not as prone to jam.   Also, a new cyclone collector was installed above
the compactor which reduces bag breakage and plug-ups, and problems with the
travel timers were rectified.
     In addition to plug-ups attributable to problems with the diverter valves,
Veterans Administration Hospital also experienced many instances of lighter
bags overtaking heavier bags in the tubes, which also causes plugs.  Over the
18 month period covered by the maintenance records in our possession, there
were a total from all causes of 62 instances of trouble with the tubes plug-
ging, some involving as many as 100 bags of linen.  Of these,  35 were cases of
linen blockages, 20 were cases if waste bag plugs, and 7 were  not  identified
as to cause.  It should be pointed out that the average blockage requires two
men seven hours to clear.
     The system operating procedures were  changed  from single  bag  loading  (as
is used at St. Mary's) to a keylock multiple bag loading.  A single operator
per shift was then placed in charge of all  chute loading  throughout the  build-
ing.  Under the new operating  procedures,  to  avoid the cycling of  the diverter
valves as much as possible, all  linen  is  supposed  to  be  moved  from all  floors
in the hospital first, starting  at  the  top floor and  working down. Following
this, the system is shifted to waste  transport  and all waste is  removed,  from
the top floor down.  This reduces wear  on the diverter valves  and  tends  to  re-
duce  jams.
      The downtime of this system is more  frequent  on  the weekend (usually four
or five  times)  than during  the week.   It  is felt  that this is  related  to more
efficient operational control  of  the  system during the week.
      An examination of  the maintenance  records  of  St. Mary's Hospital  reveals
                                     -150-

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that most of the trouble with the pneumatic system involves laundry blockages
and waste bag plugs.  This has resulted in tubes and air lines collapsing,  and
therefore  requiring replacement; as well as seams rupturing, which require
riveting or strengthening.  Over the 2.16 year period covered by the mainten-
ance records in our possession, there have been a total of 297 instances of
trouble with the tubes plugging.  Of these, 142 were cases of laundry blockage,
68 were cases of waste bag plugs, and 87 were not identified as to the cause.
There were also 14 occasions when either a tube collapsed or a seam split to
the point of requiring riveting.  In general, St. Mary's has solved all prob-
lems of tube plugging and bag breakage by the use of nylon transport bags.
However, it is obvious that the 20  gauge metal in the bends and tube of the
system is on the light side for trouble-free operation.  Further,  St. Mary's
feels that single bag loading is unnecessarily time consuming for  a hospital
of this size, resulting  in expensive labor waiting to load chute stations.
     All three of the pilot systems studied are equipped with fusible link
fire dampers, as required.  There was no indication that a fire had actually
occurred in the systems.  However,  these fire dampers have been a  cause of bag
ripping and occasional plugs of the system.
     None of the systems appear to  have experienced serious  shut-downs  from
electrical or hydraulic  line problems.  St. Mary's has  experienced some freez-
ing weather problems  in  roof dampers which were  corrected  by  air drying units
being installed.
     The three systems have  entirely different  exhauster  fan-filter arrange-
ments as well as design  of  the  dampers  or  valves  ahead  of  the fan  to  protect
the system in case  of high vacuum from  a  plug in  the  system.   The  most  sophis-
ticated and best working is  at  Martin Luther  King.   Fan protection has  been
100 percent with the  bag filter installed  ahead of  the  fan.   No  tube  damage
from plugging has occurred.  At Veterans  Administration,  a rollomatic filter
is installed ahead  of  the fan  and appears  to  operate  efficiently.   Initially
there was no relief valve ahead of  the fan at the V.A.  and when excess  vacuum
was drawn as the result  of  a plug,  fan  noise  and vibration was considerable.
This has been corrected  by  installing a quick acting relief system.
     These  two  systems  offer a good comparison between the two types  of pre-fan
                                    -151-

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2 micron filters.   Both the bag  and  the rollomatic filters operate efficiently.
However, changing the bag filters  appears  to involve considerable maintenance
labor.
     St. Mary's also had a fan  relief valve  installed ahead of the fan, after
the installation was made.  It  is  less sophisticated than the other two and
does not appear to work as efficiently.  There is no filter ahead of the fan
and the lack of it has resulted  in fan damage from lint and dust adhering to
the fan blades.  At one point,  the fan became so unbalanced that the vibration
cracked the motor base.  It appears  that a pre-fan filter is a necessity.
     Both the Veterans Administration and Martin Luther King discharge directly
from the collector to the compactor  receiving bin.  The slight additional cost
for direct discharge appears to  greatly improve the operation from a sanitary
viewpoint.  When the time to cart  haul from the collector to the compactor and
hand load the compactor (St. Mary's) is factored, it would appear that enough
labor could be saved in approximately two and a half years to amortize a direct
loading arrangement.
     The time required to clear  a  pneumatic transport system of a plug (either
laundry or waste bags) differs  considerably between the three hospitals.  The
surveys that were conducted reveal the absolute necessity of clean-out ports
located strategically throughout the system, should plugging occur.  Unless
these are present, the normal procedure is to either "fish" the bags back to
the nearest loading station or,  alternatively, to physically remove a section
of horizontal tubing in the general  location of the plug  (if the location can
be determined), remove the bags, and reconnect the tube.  Obviously, this is
extremely time consuming for the maintenance department.  Clean-out ports do
not appear to be included in the original designs of pneumatic transport sys-
tems of the thin wall, full pneumatic type.  They are usually included in the
designs installed by Envirogenics utilizing gravity to vacuum and heavy wall
tubing, and normally they are strategically placed at locations where  the hori-
zontal  tubing commences a vertical rise.  ihis makes bag  removal fairly simple.
     All three systems have experienced plugging  from improper loading from
time to time and it would appear that  the principal management solution is to
carefully control the personnel using  the system.
                                    -152-

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     All have experienced some cross-over between waste ending up in the laun-
dry collector and laundry in the  compactor.   In the case of St. Mary's and
Martin Luther King, this is due 100 percent  to operator carelessness in loading
the chute doors, as these are double  tube systems.  In the case of the Veterans
Administration, it is felt that the problem  has been created by faulty opera-
tion of the diverter valve in the single  tube system.
     As pointed out in the chapter on Design and Construction, the single bag
systems are the most costly in labor  utilization, and a single tube, single bag
system uses the most labor in waiting time of any method.  The multiple bag,
double tube system is far less expensive  to  load; with the gravity chute to
vacuum tube, and random  loading,  the  least expensive from a labor viewpoint of
any method.  This is completely borne out in the  labor figures for the three
hospitals, as can be seen from the chapters  on  Economics.
     All three hospitals are  designed differently architecturally but all have
at least four vertical wings  to service,  involving  either horizontal walking
distances on each floor  to vertical  chutes  installed on a "zoned" basis, or
the necessity for at least  four vertical  risers.  The  result,  as  can be  seen
from the chute station utilization figures,  is  that a  relatively  small number
of stations carry the bulk  of  the load and  the  remaining  are  installed on a
convenience basis.  With the  multiple bag system installed  at two of  the hospi-
tals (Martin Luther King and  V.A.).  the floor pick-up  time,  and walking  time  to
the chute stations, far  exceeds  the  loading time.   At  St. Mary's, where  consid-
erable waiting  time is  involved  to load the single  bag stations,  pick-up and
walking  time  is  slightly  less than loading time.
                                     -153-

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                         0-CODES AND REGULATIONS

     Solid waste handling in hospitals  is  affected  by  a series  of  codes and
regulations.   As virtually all  construction  in  a hospital requires a building
permit, it involves,  normally,  submittal of  drawings  and specifications for
the proposed  construction and approval  of  the finished work by  regulatory
bodies.  This usually involves  a local  building department; the local and/or
state fire marshal   regulatory bodies, either  local  or state,  concerned with
the construction and  operation  of hospitals; and,  if  Federal Hill-Burton
money is involved, the approval and  inspection  of  the Hill-Burton agency and
its regional  office.
     Probably the most important aspect in such approvals, when solid waste
is involved,  concerns the fire  safety aspects.  National fire codes, as pub-
lished by the National Fire Protection  Association  (NFPA) are used as the
basis for approvals for rubbish handling facilities and incinerators by most
local and state jurisdictions.  The  latest codes  are  the 1972-1973 version.
Building  Construction  and Facilities  are covered  in Volume  4, with the
standards on incinerators and rubbish handling  covered in Standard 82.
     Sections 70 and  80 of  this Standard cover  rubbish or solid waste chutes
and systems.   Sections 10 and 30 cover  incinerators.
     It should be noted that NFPA,  in  their Standard, does not include design
criteria for  the purpose of reducing air pollution.  They state that for such
criteria the  authorities having jurisdiction should be consulted.
     The following paragraphs from Sections 70 and 80 directly apply to solid
waste management in hospitals,  the control of  system design, and the inspection
of the facilities by agencies  that are  guided by the NFPA codes.
     70.  Rubbish Chutes
          701.  General
               7011.   Rubbish  chutes are usually employed where there  is a
relatively large area on each  floor from which rubbish  is  collected.   This
makes a chute a convenience in  handling rubbish in many manufacturing  plants,
apartment houses, office buildings, and institutions.  The procedure is to
bring the collected rubbish from  each  floor to the opening in  the  chute.  The
                                     -134-

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chute then conveys the refuse to its disposition point.  A rubbish chute shall
serve no other purpose.
               7012.  There are three types of rubbish chute systems, each
with separate fire safety criteria.
                    a.  General Access Gravity Type Rubbish Chute.
                    b.  Limited Access Gravity Type Rubbish Chute.
                    c.  Pneumatic  Rubbish Chute.
               7013.  Definitions.
                    a.  General Access Gravity Type:  A rubbish chute of this
type is an enclosed vertical  passageway  in a building to a storage or compact-
ing room where the rubbish  is transferred by gravity only.  All occupants of
the building are free to use  the chute at any time.
                    b.  Limited Access Gravity Type:  A rubbish chute of this
type is an enclosed vertical  passageway  in a building to a storage or compact-
ing room where the rubbish  is transferred by gravity only.  Authorized person-
nel only may use this chute,  gaining entry by key  to a locked  chute  door.
                    c.  Pneumatic  Rubbish Chute:   A rubbish chute of this type
has limited access.   It may be  a vertical, horizontal, or  inclined enclosed
passageway and having sufficient mechanical applied airflow to convey refuse
without clogging to point of  disposition.
          702. Construction
               7021.  A steel or steel-jacketed  refractory  chute may  be  support-
ed at intervals by  the building structure,  in which case  expansion joints
shall be provided at  each support  level.  Other  kinds  of  chutes shall rest
upon a substantial  noncombustible  foundation  having a  fire-resistance rating
of at least  3 hours.
               7022.   Gravity chutes  should  be  constructed straight  and plumb
with no offsets whenever possible.  If  offsets  are required  they  shall  deviate
not more than 15° from the  vertical,  and shall  be properly  reinforced.  All
chute interiors shall be smooth and without  projections.
               7023.   The  size  of  a refuse  chute shall be in accordance with
the  following:
                     a.  Gravity Type Chutes:   The size of the chute  shall not
                                     -155-

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be less than 22-1/2 by 22-1/2 inches or 24 inches in diameter inside measure-
ment.
                    b.  Pneumatic Conveyor:   The size of the chute shall not
be less than 16 inches diameter,  inside measurement.
               7024.  Masonry rubbish chutes shall be constructed of clay or
shale brickwork not less than 8 in.  thick or of reinforced concrete not less
than 6 in. thick.  Such chutes shall be lined with firebrick (ASTL Type G, low
duty, or the equivalent) not less than 4-1/2 in. thick.
               7025.
                    a.  Metal rubbish chutes shall be made of stainless steel
or galvanized or aluminum-coated steel with no screws, rivets, or other pro-
jections on the interior surface of the chute.  Laps or joints shall be of a
design so that liquid will drain to the interior of the chute.  The steel shall
not be lighter than as indicated below:
                         1.  For chutes handling Type 2 or Type 3 wastes, or a
combination of both, the portion of a chute located not more than 6 stories
'below the roof of the building shall be made of steel not lighter than No. 18
gage and any other portion shall be made of steel not lighter than No. 16 gage.
                         2.  Chutes handling wastes other than Type 2 or Type 3
shall be made of steel not lighter than No. 14 gage.
                    b.  Metal chutes may be lined with  firebrick  (ASTM Type G,
low duty or the equivalent) not less than 2-1/2  inches  thick.  Unlined steel
chutes shall be equipped with automatic sprinklers  installed  in accordance with
NFPA Standard No. 13, Section 4310 and other  applicable provisions, and  the
outlet of the chute shall be equipped with  a  self-closing steel door held open
by a fusible link.
                    c.  Rubbish chutes may  be made  of  listed medium-heat  ap-
pliance chimney  sections approved for  this  use.
                    d.  Rubbish chutes, other than  masonry  chutes  conforming
to 7024 or  constructed of masonry walls having a fire  resistance  rating  not
less than specified below, shall be  enclosed  in all stories above  the  storage
or compacting room within a  continuous  enclosure constructed  of materials
which  are not combustible, such  as  masonry,  and extending from  the  ceiling  of
                                     -156-

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the storage or compacting room to or through the roof so as to retain the
integrity of the fire separation as required by applicable building code pro-
visions.   The walls of the enclosure or the walls of the masonry chute shall
have a fire resistance rating of not less than 1 hour if the building is less
than 4 stories in height and not less than 2 hours if the building is 4 or
more stories in height.  Any opening in the enclosing walls shall be equipped
with self-closing fire doors approved for Class B openings.
               7026.  A rubbish  chute shall extend  (full size) at least 4 ft.
above the roof of the building.  The chute shall be  open to the atmosphere.
          703.  Service Openings
               7031.  Service  openings  shall  be provided in accordance with
the following criteria:
                     a.  General  Access  Gravity  Chutes:  All service  openings
into a rubbish chute shall be  provided  with  a self-closing, self-latching,
bottom-hinged hopper-type  door approved for  Class  B openings  and  having  a
rating of not less  than  1  hour with "Temperature  rise:   30 min.-250° F max."
The door  frame  shall be  firmly built  into the chute and the design  and  in-
stallation  shall  be such  that  no part  of the frame or door will project  into
the chute.
                     b.   Limited Access and Pneumatic Chutes:   All service open-
 ings  into a rubbish chute shall be provided with self-closing, self-latching
doors  approved  for Class B openings and having a rating of not less than one
 hour  with "Temperature rise:  30 min.-250° F max."  The door  frame shall be
 firmly built into the chute and the design and installation shall be such that
 no part  of  the  frame or door will project into the  chute.
                7032.  The area  of each service opening shall be limited to
 one-third of the cross-sectional area of the chute.
                7033.  Every service opening  shall be enclosed in a room or
 compartment separated from other parts of the building by walls and floor and
 ceiling  assemblies having a fire-resistance  rating  of not less than 1 hour
 with openings to such room or compartment protected by approved fire doors
 suitable for Class  B openings.
            704.   Chute Terminal  Rooms or  Bins
                                      -157-

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               7041.   Rubbish  chutes  shall  terminate or discharge directly into
a room or bin separated from the  incinerator  room and from other parts of the
building by walls and floor  and ceiling assemblies having a fire-resistance
rating equal to that  specified for  the  chute.   Openings to such rooms or bins
shall be protected by approved self-closing or  automatic fire doors suitable
for Class B openings.
               7042.   Rubbish  chutes  other  than charging chutes covered in
Section 40 and combined chimney flue  and charging chute covered in Section 50
shall not discharge directly into an  incinerator.
          705.  Automatic Feeding or  Stoking  Systems
               7051.   Systems  for the automatic transfer of waste materials
from a rubbish-chute terminal  room  or bin to  an incinerator or other means of
automatic feeding or stoking  incinerators  shall not be installed unless special
permission of the authority  having  jurisdiction has been obtained.
               NOTE:   There  may be  situations where arrangements are made for
handling refuse mechanically and  automatic  stoking of incinerators which would
not introduce an unreasonable  hazard.  In such cases, the authority having
jurisdiction may permit such an arrangement,  taking into consideration the
whole layout, its relation to  the rest of the building, the presence or absence
of complete sprinkler protection, the continuity and competence of the personal
supervision attending the operation,  ventilation, access for fire fighting,  and
similar factors.  See also Standard for Installation of Blower and Exhaust Sys-
tems for Dust, Stock, and Vapor Removal, NFPA No. 91.
          706.  Automatic Sprinklers
               7061.  Automatic sprinklers, properly installed, provide a
reliable and effective means for  fire extinguishment and shall be installed  in
chute terminal rooms or bins.   A short length of hand hose connected  to a
suitable water supply should also be provided.   Fires of the nature  likely to
occur at chute terminals are generally difficult  to  control by ordinary means
due to the large amount of smoke evolved and consequent difficulty of  access
by the fire department.  Automatic extinguishment of such  fires  in the  incipient
stage is, therefore, of primary  importance.
                                    -158-

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     80.   Rubbish Handling
          803.   Rubbish Receptacles
               8035.  Wastebaskets and small containers for rubbish should  be
of noncombustible material.  Large quantities of rubbish shall be handled in
metal ash cans, drums, or similar containers.
               8037.  Approved waste cans and receptacles shall be provided
for oily waste and other materials requiring special handling.
               8038.  Barrels and similar containers for rubbish and ashes
shall be substantial, approved metal construction, maintained in good condi-
tion and provided with handles and a cover.  They  shall be provided with a
flange at the bottom  to provide  at least a  2-in. air space between the bottom
and the floor.  Containers and barrels shall be kept covered.
          804.  Bailing and Compacting
               8041.  The  location of rooms for  the collection and baling or
compacting of refuse  should be given careful consideration to avoid creating
an exposure hazard  to the  rest of the building.  Quick-burning fires of  the
flash variety are to  be expected where waste paper is handled in  large quanti-
ties.
               8042.  If  a rubbish room  or  bin  is  not provided, refuse shall
be stored in covered  metal cans  only.
               8043.  Rooms used for baling or  compacting  shall be  cut off
from  the rest  of  the  building by ceilings,  floors, and  walls,  the minimum
fire  resistance  of  which  is  2 hours, with door  openings protected by  fire
doors suitable for  Class  B openings.
               8044.  Automatic  sprinklers, properly  installed,  provide  a  re-
 liable  and effective  means for fire  extinguishment and  shall be  installed  in
 baling  and compacting rooms.   A short  length of hand  hose connected to a suit-
 able  water supply should  also be provided.   Fires  of  the nature  likely to
 occur in baling  and compacting rooms are generally difficult to  control  by
 ordinary means due  to the large amount of smoke evolved and consequent diffi-
 culty of access  by  the  fire  department.   Automatic extinguishment of  such  fires
 in the incipient stage is, therefore,  of primary  importance.
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     The foregoing discusses  national  codes  and  regulations and only those
pertaining to fire safety.
     In addition,  there are literally  hundreds of additional regulations per-
taining to waste handling in  hospitals,  promulgated in municipalities, counties,
and states, by various governmental boards and agencies covering the regulation
of health facilities and the  control of the  environment.  Health departments
have published regulations affecting both the in-house handling practices,
as well as off-site reaoval;  environmental control bodies have concentrated on
off-site handling practices.   All hospitals  should be aware of all such regu-
lations to ensure they are in compliance when they install methods for waste
management.
                                     -160-

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                         f\- ENVIRONMENTAL TESTING

     The hazardous nature of a large proportion of hospital solid waste and
possible environmental effects has been established through various studies
that have been performed over the past 15 years.  The effect on the hospital
environment of the use of a pneumatic system,  transporting encapsulated solid
waste, has not been completely documented in past studies.
     Environmental effects from  such a system  may be classified under three
general headings.  First the systems involve machinery;  in particular, fans
moving moderately heavy loads at high speed within closed metal tubes.  The
increased noise  (if any) that this creates  in  the hospital environment must be
measured.  Secondly, it has been established in other studies  that solid waste
contains many odor-causing components.   If  the encapsulating method is destroy-
ed in the system, or if housekeeping practices are unsatisfactory, possibilities
exist that an odor condition may develop.   Thirdly,  the  system consists of.
chutes opening onto nursing areas, closed  tubes,  and collector boxes  joined to
fans  that exit the air  from the  system.  With  possibilities of bag breakage
within the system, coupled with  a  lack  of  self-cleaning  and sanitizing devices,
bacterial contamination of  the hospital  environment  is  a possibility.  The
survey team conducted  tests within each of  the hospitals in  these three areas;
noise level readings were  taken; odor  readings were  registered;  and bacterial
counts made of both  the pneumatic  system and the  adjacent area.   In addition,
notations were made  of the presence  or  absence of dust  and litter (including
ruptured waste bags) along with  any  physically unsafe  or hazardous conditions,
including  any problems in transporting and disposing of chemical and  toxic wastes.
                              SOUND LEVEL READINGS

      In  an institutional setting such as a hospital there are many areas and
 many  times of day where "quiet" or a lack of sound is desired to assist in the
 recovery of patients, or simply to avoid interference with staff activities,
 such  as  conversations.
                                     -161-

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     Sound or "noise" is caused by a variation in atmospheric pressure.   It
may be sudden and extremely loud, such as gunfire.  It may be at a constant
                    s
level that a person "gets used to" and finally does not even notice.   It may
be, in either case, of a level and frequency that can be dangerous to the point
of causing a loss of hearing, suddenly or gradually.  Or it may be merely
annoying, such as a faucet dripping, or chalk squeaking against a blackboard,
and not have any permanent effect on the listener's hearing.
               100
                                DISTANCE--FE
             FIGURE 17.   CURVES SHOWING HOU. NOISE INTERFERES WITH
                         SPOKEN OR SHOUTED CONVERSATION

      Before we can evaluate the possible effects of sound on  hearing,  or  dis-
 comfort,  we must know three things about it:   (a) the sound pressure  level;
 (b)  the frequencies present in the sound, from low pitch to high;  and (c)  the
 duration of the sound at these frequencies and pressure levels.
                                     -162-

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     To measure sound pressure, an instrument known as a "sound level meter"
is used.   This is an electronic ear that converts sound into electrical signals
and displays them on a dial.  The levels are expressed in decibels (dB), an
arbitrary measuring unit, in a scale from 0 to 140.  The weakest sound that a
person with excellent hearing can detect in an extremely quiet location is
assigned the 0-dB value.  At 140-dB the threshold of pain is reached in hear-
ing.  In between are the levels found  in institutions, homes, offices, and
factories, ranging from 50- to 60-dB as a typical office noise level, to a
power lawn mower at around 100-dB, or  a riveting machine at 118-dB, which is
the discomfort level.
     Coupled with sound pressure  level is the  frequency or pitch of the sound.
This is measured in "hertz" -units.  The frequency has much to do with how loud
a sound appears to be to the ear.  The higher  the frequency, the more annoying
and the more physical effect on the human hearing.   The human ear  can  tolerate
more low frequency sound than high.
     Hence, the more sophisticated meters  for  measuring sound  levels have
built-in weighing networks  that permit responding to some  frequencies  more
than others, similar to  the  reaction  of  the  human ear.  Acoustical standards
have established three  such  networks  and  designated them  "A,"  "B," and "C."
Very low frequencies are severely suppressed or discriminated  against  in  the
"A" network  (as  the human  ear  would  do);  they  are moderately  discriminated
against in  the "B" network;  and  they  are  accepted  in the  "CM  network,  which
gives  a flat  response  across all  frequencies.
     if the sound  level being  measured is  higher on the "C"  network than  on
the "A,"  the  noise  source  is predominantly at  the  low frequencies (below  600
hertz), since  the  "A"  network discriminated against the low frequencies and
give a lower  dB  reading.   If the  readings on the sound level meter are pro-
gressively  higher,  going from "A" to  "B" to "C" networks,  then the predominant
portion of  the sound source is below  600 hertz in frequency.   If, on the  other
hand,  the readings  on all three networks are close together in dB, it indicates
 that  the  sound energy is of a higher  frequency (above 600 hertz).
                                     -163-

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                «  -5
                ui
                5  .to
                   -.5
                  -20
                  -25
                ui
                oc
                u
                oc -40
                   -49
            z
                 ^
                                    B AND C
20      SO    100  200    500   1000   ?POO
                FREQUENCY IN HERTZ
                                                            spoo  iopoo
                                                                       FIGURE 18
                 PREOUENCV RESPONSE FOR A.B.AND C NETWORKS WEIGHTING CHARACTERISTICS
     As stated,  sound levels and  frequencies present two problems in  a  hospital
complex:   they may be annoying  to patients, staff, and visitors; or they  may be
dangerous  to the level of damaging hearing.  To prevent hearing damage, Federal
regulations  under the Occupational Safety and Health Act  (OSHA) of 1970 set per-
missible noise limits to protect  the workers in any place of employment.
          TABLE 11
      PERMISSIBLE NOISE EXPOSURES
Duration, per
Day, Hours
8
6
4
3
2
1-1/2
1
1/2
1/4 or less
Sound Level in
dB(A), Slow Response
90
92
95
97
100
102
105
110
115









      When sound  levels  and  duration exceed those values given above, protection
against the effects  of  noise exposure must be provided  and a continuing, effec-
tive hearing conservation program must be administered.
                                       -164-

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     To determine how much sound the pneumatic transport systems generate in
each of the three survey hospitals, sound level readings were taken inside and
outside each chute loading room; inside and outside the rooms containing col-
lector boxes and compactors;  in  the mechanical rooms that contain the motors
and exhaust fans; and at the  exit side of the fan exhaust outside each building.
     The. instrument used in  this survey was a Type 2 Sound Level Meter meeting
Standard SI.4-1971 of the American National Standards  Institute  (ANSI).  It
was calibrated twice each day during  the  survey.  All  readings were taken with
the equipment operating and  waste bags going down the  chutes.
     The following tables present the reduced data obtained  during the survey.
The first  table  for each hospital contains  data  taken  within each chute  room,
3  to 5  feet from the hopper  loading door.  It  shows  the maximum, minimum, and
average dB readings on  all  three networks for  all loading stations on each
floor  of the  hospital.
     The second  table  for  each hospital contains maximum, minimum, and average
dB values  of  all three  networks for each vertical chute within the hospital,
covering all  floors  through which the chute passes.   Here it can be  seen that
the average dB values,  for all  three networks, for all three hospitals,  are
consistently  close together and vary within any one hospital by only a few
dB's.   There  is  a difference between hospitals, due to the different types of
 systems installed.
      The  third and fourth tables for each hospital present data in the same
 format as  the first and second  tables, but the readings were taken outside the
 chute rooms,  3 to 5 feet from the outside door of the chute room.
      The  average readings outside the rooms were consistently lower  than those
 inside, for all three hospitals.  The difference between inside and  outside
 average readings was more pronounced at  St. Mary's and Veterans Administration
 Hospitals than at Martin Luther King Hospital.  This  is  attributed to the fact
 that the gravity to vacuum  system at Martin Luther King, with its absence of
 vacuum noise at the loading hoppers, proved to  be a very quiet  system even
 inside the chute rooms.
      The method of taking sound readings also  indicated  that, regardless of
 the type  of  pneumatic  system,  there  was  virtually no  correlation between the
                                      -165-

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vertical distance a bag drops and the sound level produced.
     An examination of the first four tables for all hospitals will show peaks
and valleys among the data.  As an example, one can see that the highest A-
network noise level inside a chute room at Martin Luther King occurred at the
fourth floor in Wing A and was 72 dB(A).  This may be considered against an
average of 66 dB(A) for the entire fourth floor, or against 63 dB(A) for the
entire Wing A.  Peaks of this nature occurred in all the hospitals surveyed.
     Several elements contribute to these peaks.  Architectural considerations
creating acoustical differences can and do occur.  Different methods of hang-
ing the chutes also contribute.  An important contributing factor to sound
level variations was found to be the actual content of the waste bag going
down the chute.  Those that contained a large amount of hard plastic and cans
not only created a higher sound level but  in most cases could be heard going
all the way down the chute.
     It will be noted that the dB readings consistently increase as the meter
recorded sound from the A to the B to the  C networks.  This is a clear indica-
tion that  the sound caused by bags of waste traveling  through the system, both
vertically and horizontally, is predominantly in the  low  frequency  range
 (below 600 hertz) and is relatively  tolerable to the  human ear.  The sound
from each  bag is relatively sudden,  of  quite short  duration,  and with  little
continuing reverberation or echo effect.   Even  though  bags may be  transported
constantly over an 8-hour day,  the maximum readings are well below  OSHA  per-
missible noise exposure levels.
     On the other hand, as seen  from the  A-network,  the maximums  in the  corri-
dor are from 62 dB(A) to  71 dB(A), which  is  approaching  the "annoyance"  level
 for quiet  conversation or  a resting  patient.   Therefore,  physical  locations of
 chutes  and tubes should always  consider this.
                                     -166-

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TABLE 12
IL:-!**^!!.^ HOSPITAL
Load Station Sound Levol Analysis
Inside Ch-jte Rooms. 3'-5' t'roi loading KODPLT Door
All Stations
on Floor
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Averages
All Stations, Ea
Verc1c.il Chute
West Wing
Center Wing
East Wing
Averages


All Stations
on Floor
L.
2 .
3.
4.
5.
6.
7.
6.
9.
10.
/vet aw;
Al 1 Stations , f ;
\Vrtlr..l fh..t<
wos» wing
Centt. Wlnj',

Aver j r-t s
A-Netvork, dB(A)
Max.
78
77
73
72
70
74
72
70
71
70
73
Mir..
67
74
66
70
61
69
69
70
71
70
69
ch A- Network,
Max.
78
74
77
76
Min.
61
65
67
64
Load St?
Outside
Chute
A-Netvork
Max.
62
66
61
65
65
61
69
61
60
60
63
nch A-N
c- K:*x
69
65
65
	 6fc
. V.in
59
59
5S
63
59
59
65
61
60
60
60
Avg.
71
75
70
71
65
72
71
70
71
70
70
dB(A)
Avg .
71
69
71
70
B-Nrtwork,
Max.
79
ei
73
75
70
74
73
75
71
73
74
Mln.
70
74
6E
70
65
71
72
75
71
73
71
B-Network,
Max .
79
75
SI
78
ticns Sourd Leve
Poons^
, do (A)
Avg.
60
63
60
64
61
60
67
61
60
60
6,"
Min.
67
65
70
67
dB(E)
Avg.
74
77
71
73
67
73
73
75
71
73
72
dB(B)
Avf .
73
71
73
72
C-Network, dB(C)
Max.
82
85
75
76
75
76
76
75
72
74
76
Min.
77
77
72
73
68
74
74
75
72
74
73
C-Netwurk,
Max.
82
77
85
81
Min.
68
72
73
71
Avg.
80
80
73
75
72
75
75
75
72
74
75
dB(C)
_AvgL._
74
74
77
75
1 Analysis
3'-5' from Outside Tcor
B-Network,
Ma*.
67
68
62
65
62
65
66
61
59
61
r'-4
Min.
65
64
60
65
59
62
66
61
59
f 1
62
dB(B)
Avg.
66
66
61
65
61
64
66
61
59
61
63
• 'U.-1..-1- , i'i.'(A) B-N'etwork, difb)
•-.. ^!'.
59
r-9
1,1
Sy
.. 	 \v_fc_.
62
62
61
6:
M.ix.
67
63
67
.. PL
Min .
59
61
S^1
60
__._A".E.-_ . ._
63
64
63
	 63
C-Network,
Hax.
77
74
64
68
67
66
70
64
70
64
68
Win.
72
68
63
66
63
66
70
64
70
64
67
C-Network,
-*i*7;--
73
~,2
77
74_
Min.
64
64
63
f'4_
dB(C)
Avg.
74
70
64
67
65
66
70
64
70
64
67
dB(C)
__Avg.
68
65
69
	 67_
  -167-

-------
TABLE 13
MARTIN LU1HER K'.
SG HO
SPtTAI.




Load Station EOUM Level Analysis
Inside Chute Roocs, 3'-5" frc-n Loading Hopper Door
All Stations
on Floor
Basement
1.
2.
3-
4.
5.
Averages
A-Network, dB(AI
Max. Min. Avg.
63
70
62
66
72
64
66
63
63
58
58
62
64
61
All Stations, Each A-Xetwork
Vertical Chute Max. Kin
Segment 1
Wing A
Wing B
Wing C
Awe rages
70
72
68
64
69
62
59
58
58
59
63
65
60
62
66
64
63
• Avg.
65
63
62
61
63
Load Station Sound
Outside Chutrr R..OC:-, 3'-
All Stations
on Floor
Basement
1.
2.
3.
4.
5.
Averages
All Stations,
Vertical Cii.
Segment I
Wing A
Wing B
Win*; C
Averages
A-Netvoik
Max. Min
62
62
63
64
60
59
62
Kiicl. A-N
Jte Max
59
62
62
63
62
6:
58
57
58
58
53
59
. Yin
S3
57
58
59
56
, UBiA)
Avg.
62
61
60
bi
59
59
eO
1 *• L ' *• '
• -vg .
58
60
5V
67
tu
B-Network,
Max. Min.
63
72
64
69
68
67
67
63
63
63
59
64
66
63
B-Netvork,
Max. Min.
72
64
67
65
67
64
59
63
£3
62
dB(B)
Avg.
63
66
64
64
66
67
65
dB(B)
Av,,.
68
63
65
64
65
C-N'etwork,
Max. Kin.'
67
72
69
77
65
70
70
67
67
65
60
63
69
65
C-Network,
Max. Min.
77
67
71
69
71
64
60
65
63
63
dB(C)
Avg.
67
69
67
68
64
70
67
dB(C)
Avg,
70
65
68'
66
67
Lewi Analysis
5" from Outside I'cur
B-Ke
fc2
62
64
66
64
fcC
63
twoik,
Min.
62
56
58
60
57
59
59
Avg.
62
60
61
64
Cl
CO
61
P-Kotwr.rl , dl;OO
62
64
66
66
t-4
50
58
59
60
58
59
6J
62
64
6i
C-Setwork,
Max. Min.
64
64
67
69
68
65
66
64
57
64
61
64
64
62
C-Niilwork ,
Max. Kin.
67
68
69
66
67
57
61
64
64
62
dS(C)
Avg.
64
62
66
66
65
65
65
dr.(c)
Avg.
64
f4
65
66
65
  -168-

-------
TABLE 14
VETERANS
Inside
All Stations
on Floor
1.
2.
3.
4.
5.
6.
Averages
All Stations, Each
Veitical Chute
North Wing
West Wing
South Wing
East Wing
Averages
APftlNISTFATlON HOSPITAL
Load Station ?cunc
Chute Rt.cms, 3' -5' i
A-Network,
Max. Min.
76
89
85
81
79
78
82
73
80
78
75
70
70
74
A-Network,
Max. Min.
89
88
80
85
86
7t>
n
70
70
72
dB(A)
Avg.
75
85
83
77
73
74
78
do (A)
Avg.
81
79
75
76
78
le .'*.' J Analysis
t OKI Loading Hopper
B- Network.,
Max. Min.
76
81
87
87
82
80
83
B-Ket
Max.
87
81
80
87
84
75
72
75
76
75
77
75
work,
Min.
72
75
75
78
76
dB(B)
Avg.
77
78
80
80
78
79
79
dB(R)
Avg.
79
77
77
81
79
Load Static-.-, Sound Levi 1 Analysis
Outside Chute Koccs, 3'-5' free, Outside Do
All Stations
on Floor
1.
2.
3.
It.
5.
6.
Averages
All Stations, Each
Vortical Chutf
North Wing
West Wing
<;ou(h Wing
tat, i *tnf.
AvcrupeL
A-Netwerk ,
Max. Min.
n
65
72
68
69
68
70
A-N
Max
68
77
68
69
71
55
56
60
62
62
61
59
ot worV
''in
50
C2
60
5r>
58
dB(A)
Avg.
66
61
66
65
65
65
65
, dB'O
. AV4-
63
60
fc'.
S,
65
B-Network ,
Max. Min.
73
6fJ
76
77
75
70
74
B-Ke
Max.
76
7?
7^
11
75
60
62
63
69
63
69
64
t vork ,
run.
63
1°.
6J
6'J
64
dB(B)
Avg.
69
66
72
72
f.9
70
70
dB(E)
AVd.
68
72
68
70
70
Door

C-Netvork, dB(C)
Hax. Min. Avg.
84
90
90
85
83
87
87
82
87
86
79
76
79
82
C-N'etwork,
Max. Min.
90
90
88
90
90
or
79
82
76
76
78

C-Network.,
Max . Min .
79
78
79
74
76
76
77
69
71
69
72
71
71
71
C-Network,
K;ix. Min.
79
79
74
78
76
73
72
69
69
71
81
88
89
82
78
84
84
dB(C)
Avg.
84
85
83
85
84
dB(C)
Avg.
74
75
74
73
74
73
74
dB(C)
Avg.
75
75
71
74
74
   -169-

-------
     The fifth table for each hospital presents maximum, minimum, and average
data on each network, for the fan (or equipment rooms), the collector, and
the compactor areas.  Readings were taken in several locations within each room,
5 to 10 feet from the operating equipment.  The sixth table presents data for
the same pieces of equipment, with readings taken 10 feet from outside the
area with the equipment running.  As might be expected, all these areas are
noisy ones.  The fans used in these systems are high-horsepower fans which
create noise when running.  Collectors have metallic dampers which bang loudly
when they open and close.  The rams on all the compactors were noisy.  The
dB(A) readings in the fan rooms in all hospitals were at least 95 dB(A) average,
and at one hospital it was as high as 104 dB(A).  All of these are at a level
where noise  protection for workers is required by OSHA if workers must remain
in these areas for extended periods.  Even short, yet constant, periods of ex-
posure might be harmful to an individual worker over a period of months or
years.  A worker should not remain in the 95 dB(A) fan room in excess of four
hours in any day or the 104 dB(A) fan room in excess of one hour.
     The fan rooms of two of these hospitals were on or near the roof, where
they are not likely to annoy anyone.  Happily, this includes the noisiest one
at 104 dB(A)—which, incidentally, does not have a sound attenuator.  The fan
room for the third hospital  (Martin Luther King) is at ground level,  in a small
service building.  This service building  is located approximately 40  feet from
a brick wall at the edge of  the hospital  property and beyond which  is a resi-
dential area of small homes.  A series of readings was  taken at  this  wall, 40
feet from the fan attenuator.  The average readings at  this point were 76 dB(A),
77 dB(B), and 80 dB(C).  These readings are sufficiently high to be annoying
to some people.
     In general, the analysis  shows  that  Martin Luther  King Hospital, with its
gravity to vacuum system, has  the quietest system.  Veterans Administration
Hospital, with a full-vacuum single-tube  system with  diverter valves, was the
noisiest, while St. Mary's Hospital, with a small-tube  full-vacuum  and using
nylon mesh bags in  the chutes, was  in  the middle.   Because of  the consistent
increase  in  dB readings  from A-network to B-network  to  C-network in all hospi-
tals, it  is  concluded that most, but not  all,  of the  sound is of a  low fre-
                                    -170-

-------
quency variety which is not so annoying to most individuals.  The general dB
levels throughout patient areas of all three hospitals are considered to be
sufficiently low as to not cause annoyance, with the possible exception of
Veterans Administration Hospital, which may cause problems in some areas.  It
was observed at Martin Luther King Hospital that both the automatic cart
system and the tote box system were a higher noise  level source than the pneu-
matic tube system.

                                   TABLE  15
                         MARTIN LUTHER KING HOSPITAL
          SOUND LEVEL ANALYSIS  OF FANS,  COLLECTORS,  AND  COMPACTORS
                     INSIDE  ROOMS,  5'  -  10'  FROM EQUIPMENT

Equipment
Name
Fan
Collector
Compactor
A-Network, dB(A) B-Network, dB(B) C-Network, dB(C)
Max. Min. Avg. Max. Min. Avg. Max. Min. Avg.
95 94 95 96 95 96 100 98
103 94 98 98 93 96 101 94
103 94 98 98 93 96 101 94
99
97
97

                                    TABLE 16
                         MARTIN LUTHER KING HOSPITAL
           SOUND  LEVEL ANALYSIS OF FANS, COLLECTORS, AND COMPACTORS
                           OUTSIDE ROOMS, 10' AWAY

Equipment
Name
Fan
Collector
Compactor
Sound attenuator,
A-Network,
Max . Min .
86
72
72
89
70
68
68
73
dB(A)
Avg.
77
70
70
82
B-Network, dB(B)
Max. Min. Avg.
87
75
75
91
72
71
71
74
79
73
73
83
C-Network,
Max. Min.
89
84
84
95
76
75
75
79
dB(C)
Avg.
82
78
78
87
  ground  level
                                     -171-

-------
                                   TABLE 17
                             ST.  MARY'S HOSPITAL
           SOUND LEVEL ANALYSIS OF FANS, COLLECTORS, AND COMPACTORS
                     INSIDE ROOMS,  5'-10'  FROM EQUIPMENT

Equipment
Name
Fan
Collector
Compactor
A-Network,
Max. Min.
106
70
75
101
69
70
dB(A)
Avg,
104
70
72
B-Network,
Max. Min.
108
76
77
106
73
72
dB(B)
Avg.
107
74
75
C-Network,
Max. Min.
110
81
85
107
80
78
dB(C)
Avg.
108
80
82

                                   TAKLE 16
                             ST. MARY'S HOSPITAL
           SOUND LEVEL ANALYSIS  OF  FADS, COLLECTORS,  AND  COMPACTORS
                           OUTSIDE ROOMS,  10' AWAY
Equipment
Name
A-Network, 42
-------
                                    TABLE 19

                       VKTh'RAN-; ADMINISTRATION HOSPITAL
           SOUND  LEVEL ANALYSIS OF FANS, COLLECTORS, AND COMPACTORS

                      INSIDE ROOMS,  5'-10'  FROM EQUIPMENT
Equipment
Name
Fan
Collector
Compactor
A-Network, <1B(A) B-Network, dB(B) C-Network, dB(C)
Max. Min. Avg. Max. Min. Avg. Max. Min. Avg.
96 94 95 96 96 96 98 97 98
92 80 86 91 87 88 92 89 91
92 80 86 91 87 88 92 89 91
                                    TABLE 20

                       VETERANS ADMINISTRATION HOSPITAL

           SOUND LEVEL ANALYSIS OF FANS, COLLECTORS, AND COMPACTORS

                           OUTSIDE ROOMS,  10'  AWAY

Equipment
Name
Fan
Collector
Compactor
Sound attenuator,
on roof
A-Network,
Max.
95
81
81
73

Min.
94
77
77
73

dB(A)
Avg.
95*
78
78
73

B-Network,
Max.
101
81
81
84

Min.
99
78
78
84

dB(B)
Avg.
101*
79
79
85

C-Network,
Max .
103
84
84
91

Min.
101
79
79
91

dB(C)
Avg.
102*
81
81
91


* The  area  10'  outside the door to the fan room contains three air compressors,
  which  contributed to the overall sound pressure level and accounts for these
  average dB  readings outside the fan roorr being generally higher than the cor-
  responding  ones inside the fan room.
                                     -173-

-------
                                 ODOR  DETECTION

     Tbe solid waste generated  in hospitals  contains many items capable of pro-
 ving a variety of  odors.   Although all  three hospitals surveyed place their
solid waste into plastic bags prior  to depositing them in the pneumatic tube
system, there is a very real possibility  that some of these encapsulated items
mi^ht become free at some points  in  the system and create a noxious odor which
-culd be detectable  by, and annoying to,  patients or staff in the vicinity.
•Ml three of the hospitals in the survey  have experienced occasional problems
in the past with the plastic solid waste  bags breaking, ripping, or coming open
either while being loaded into  the chutes or at some point during their transit
 •f the system.  As examples, a  bag can break when it hits the slide valve in a
gravity to vacuum system; it can  break when it hits a diverter valve in a single
; ube system; it can  break when  it enters  the collector box at a speed of as much
 ~ 80 feet per second.   Further,  the bag can contain glass, other breakable ob-
jects, and liquids.   The management  practices in many hospitals do not permit
glass and liquids to be placed  into  the tube system.  Nevertheless, people con-
ti-.ue to do so occasionally. At  one of the hospitals in this study, the survey
;:;ia!» observed the face of a slide valve which was covered with dried blood,
f-eces, liquids, and  other wastes. This valve room ixad a moderate but definite
odor,
     For these reasons, the survey team,  using techniques developed in the past,
performed odor detection tests  in all  three hospitals.  These tests were carried
out at each chute loading station, inside and outside of the collector boxes,
adjacent to the compactors, in  trie fan rooms, and in the effluent air downstream

-------
          1 = No odor present
          - = Threshold, or just recognizable odor present
          3 = Slight odor present
          4 = Moderate odor present
          5 = Strong odor present
     In addition, while determining  the odor readings, the survey team made note
of the presence or absence of dust,  litter, ruptured waste bags, and any physi-
cal hazards directly attributable  to  the pneumatic systems.
     At Veterans Administration Hospital,  San Diego, odor detection readings
were taken at a total of 28  locations.  Of  these, no odor was present at 13
locations, or 46 percent of  the total  readings.  There were 9 locations, or 32
percent of the tctal, where  there  was  just  a recognizable odor present  (Code 2).
Four locations, or 14 percent of the  total, had  a slight odor present (Code 3).
Only one loading station (6W) had  a  rtadiug as high as Code 4 (moderate odor
present).  Strong odor  (Code 5) was  detected at  the collector box leading into
the compactor.  Overall, 93  percent  of all  locations  tested had only a  slight
odor, or less.
     At Martin Luther King Hospital,  Los Angeles, odor detection readings were
taken at a total of  36  locations.  Of  these, no  odor was present at 13  loca-
tions, or 36 percent of  the  total  readings.  There were  17  locations, or 47
percent of the total, where  there  was  a just recognizable odor  present  (Code 2).
One location, or 3 percent of  the  total, had a  slight odor  present  (Code 3).
This reading was taken  directly behind the compactor.  There were four  locations,
or 11 percent of the total readings,  which had  a moderate odor  present  (Code 4).
Only one of these Code  4 locations was inside  the hospital  proper and occurred
inside the chute loading room  on  the fourth floor in  Wing A.  This  location
also had the highest sound  level  reading of all  chute loading rooms inside
the hospital, but this  appeared to be a coincidence  since no correlation be-
tween sound level and odor  level  could be  determined  at  this loading room.
The remaining  locations with Code  4  odor  readings were  in  the effluent  air
downstream of  the sound attenuator and in  one  slide  valve room  (Room 50-57).
This is  the slide valve mentioned  in the  introduction to this section which
had wastes on  its face  caused  by  bag breakage.   The  Code 4  readings obtained
                                     -175-

-------
in the effluent air were  taken  at  locations  directly behind and under the sound
attenuator and at a spot  approximately  40  feet west of the attenuator.  This
latter location is close  to  a group  of  private homes, the residents of which
could be annoyed by this  Code 4 odor.   This  situation probably could be allevia-
ted by more frequent disinfectant  spraying of the compactor and dust filter.
     Strong odor (Code 5) was detected  at  the collector leading into the com-
pactor.  Overall, 86 percent of all  locations tested had only a slight odor,
or less.
     At St. Mary's Hospital, Duluth, odor  detection readings were taken at a
total of 30 locations. Of these,  no odor  was present at 14 locations, or 47
percent of the total readings.   There were 11 locations, or 37 percent of the
total, where there was a  just  recognizable odcr present (Code 2).  Three loca-
tions, or 10 percent of the  total  readings,  had a slight odor present  (Code 3) .
these occurred inside chute  loading  rooms  on the third floor of the West wing,
the fifth floor of the East  wing,  and the  ninth floor of the West wing.
     Moderate odor (Code  4)  was detected at the collector box, and strong odor
(Code 5) was detected at  the compactor.  Overall, 93 percent of all locations
tested had only a slight  odor,  or  less.
     Not all of the odors detected in the  three hospitals were necessarily
noxious, unpleasant, or annoying.   A few were caused by bars of soap  being
stored in the chute room, and  these  were subjectively judged by the survey
team to be actually pleasant odors.   Others were caused by such things  as
ether, various antiseptics,  and soiled linens, as well as  the components of
solid waste.
     Overall, because of the relatively low odor code readings obtained, it
is our opinion that none of the three hospitals surveyed have a significant
odor problem within the hospital itself that can be  attributed to  the pneu-
matic  solid waste transport system.   Most of the moderate  and strong,  un-
pleasant  type odors were associated with  the "end  of  the  line" equipment,
away  from areas occupied by patients and  staff.  The most  significant of these
was the situation described above at Martin  Luther King, where there  is a po-
tential of annoying occupants of nearby homes.
     Table 21 gives a summary of the occurrences of  various  odor  levels in
                                    -176-

-------
the three hospitals:
                                   TABLE  21
               SUMMARY OF OCCURRENCES OF  VARIOUS ODOR LEVELS
Odor
Code
1.
2.
3.
4.
5.
V.A.
HOSPITAL
No. of
Occurrences
13
9
4
1
]_**
% of
Total
46%
32%
14%
4%
4%
MARTIN LUTHER
KING HOSPITAL

No. of % of
Occurrences Total
13
17
1
4
1**
36%
47%
3%
11%
3%
ST. MARY'S
HOSPITAL
No. of
Occurrences
14
11
3
I*
1**

% of
Total
47%
37%
10%
3%
3%
Totals
28
100%
36
100%
30
100%
 * Trash collector box
** Compactor
                       THE  PROBLEMS CREATED bY  AEROSOLS

     In pneumatic tube systems,  whether it  is  a gravity  to  vacuum  system or a
full vacuum system,  there  is  a constant negative pressure  in the system when.
it is operating.  This assures that air is  always pulled from the  load sta-
tions toward the waste collector.   Therefore,  with these type systems, the
probleir. found in straight  gravity  chutes,  in which air in  the chute  contami-
nates the load stations, does not  exist if  the  system is functioning properly.
     As seen, since  basically the  tubes do  not  leak,  the major aerosol prob-
lems with these pneumatic  systems  appear to exist at  the end of the  line, prin-
cipally in two areas.  First, leakage generally occurs between the waste
collector and reduction  equipment, whether  this equipment  is an attrition mill,
a compactor, or an incinerator.   Second, problems can. occur in the fan-mechani-
cal room, where effluent air  from  the system, is exhausted into the ambient
                                     -177-

-------
atmosphere adjacent  to the hospital.   There  not  only are leakages around the
fan itself, the exit ducts, and  sound  attenuators,  but there are often filters,
with potentially high bacteriological  counts,  and which must be manually
changed and disposed of.

                           HOUSEKEEPING PRACTICES

     The methods used in each hospital to control the environmental conditions,
to keep the areas clean, and to  manage failures or weaknesses in the pneumatic
systems that cause bag breakage  and the spread of waste and possible contami-
nation, were observed by the survey team during each site visit.  As has been
stated repeatedly in this report, the  most automated system for  transporting
and collecting waste, is subject  to various weaknesses, caused by human error
or by mechanical, electrical, and design weaknesses affecting the equipment
and the safe encapsulation of every bag of waste.  Further, the  equipment
itself may provide unsafe working conditions by the manner in which it operates
 VETERANS ADMINISTRATION HOSPITAL

     One broken waste bag was observed at Veterans Administration  Hospital.
 This bag was lying on the floor of the laundry room,  directly under  the  linen
 collector.  The bag was completely ruptured and its contents spread  over an
 area of approximately 25 square feet.  Laundry workers  cleaned  up  the  mess
 (wearing gloves to do so) while the team was still present.  This  hospital,
 witn its single-tube system, frequently has cross-over  problems, with  laundry
 bags going to the compactor and waste bags going  to  the laundry.   While  the
 survey  team was in the laundry, the doors of the  linen  collector opened  six
 times but instead of laundry bags coming down, a  moderate amount of  loose
 trash,  paper, and dust floated out.  This was also swept up by  the laundry
 workers.
     No unsafe or hazardous conditions were seen.  There was no visible  dust
 inside  the hospital other than that coming  from  the  linen collector.  The
                                    -178-

-------
effluent air filter on the roof, howtsvcr, was approximately 30 percent covered
by a heavy layer of thick dust.  Ibis  restricts  air  flow and obviously affects
the efficiency of the pneumatic  system.   This was  immediately brought to the
attention of hospital management by  the  survey  team  so  that the filter could be
either cleaned or changed.
MARTIN LUTHER KING HOSPITAL

     No broken waste  bags  were  actually seen by the environmental  testing  team.
However, as mentioned previously,  bags containing unauthorized waste had
obviously broken  in  the  past on the. face of one slide valve.
     No unsafe or hazardous  conditions were found except in the slide  valve
rooms.  There arc two such valves  in each valve room, one for waste and one
for soiled  laundry.   The valves consist of heavy, 20 in. diameter  metal plates
which are automatically  controlled.  When they are activated they  swing rapid-
ly, and without warning, out of the chutes and into the small room.  Even though
there are signs posted in the valve rooms warning of this danger,  a person who
is unfamiliar with  the operation of these large automatic valves,  or even one
who is  familiar but  may  become careless because of this familiarity, could be
struck  and  seriously injured by the valve plates when  they swing out.   This
situation could be  alleviated by placing a wire mesh screen around the areas
 covered by  the valve plate when it swings out.   Such a  screen  should have a
 removable section so that maintenance  personnel  can periodically clean the
 valve  face.
 ST. MARY'S HOSPITAL

      No broken bags, litter, dust,  or  unsafe  conditions  attributable  to the
 pneumatic, solid waste  transport  system were  observed  anywhere  in  this hospital.
 St. Mary's had established  the practice of placing their plastic  solid waste
    ,s, several at a time,  inside  large, heavy  nylon mesh  bags prior  to depositing
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them in the chutes.   As  can  be  seen  from the  chapter on Economics,  these
nylon mesh bags are  a significant  item of expense,  amounting to 25  percent of
the average total direct costs  per year to operate  the pneumatic solid waste
transport system. Nevertheless,  the practice appears to have solved the prob-
lem of bag breakage  and  ripping,  and also appears to be a causative factor in
lower sound levels in the chutes.
                            BACTERIOLOGICAL TESTING

     Many researchers have considered  the fact that up to 15 percent of raw
hospital waste is potentially infectious,  and that from 2  to 8 percent of the
total, due to the nature of the waste products and their generation points,
has proven pathogenic organisms present in high concentrations, particularly
if an organic substrate is present.   Tests of waste samples have shown that
Bacillis organisms are most prevalent, particularly streptococci and staphylo-
cocci, with Staphylococcus aureus the predominant pathogen.  Significant
counts have been made of coliforms,  Candida albiens and Pseudomonas.  In addi-
tion, waste mixtures have high concentrations of paper and cotton textiles that
have proven ideal for the transmission of viruses.  Other researchers have
shown that Escherichia coli can contaminate hospital environments.  Of the many
fungi to be found in the environment, the systemic, or deep seated, mycoses
create the most problems for humans.  Many are airborne,  entering through the
respiratory tract, are found in hospital wastes, and can  create allergens in
hospital patients and staff.
     The recorded biologically hazardous nature of hospital wastes indicate
that the housekeeping practices used in collecting, transporting, centralizing,
reducing, and moving these materials off-site must be  excellent at all times.
If there are breaks in management technique,  the environment of patient and
ancillary areas will be contaminated, with a  good  possibility  of affecting the
patients and staff.
     In preparing the methodology for bacteriological  testing, the survey team
worked in close association with administrative, housekeeping, materials
                                    -180-

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management, and maintenance staffs of  the  three survey hospitals.  The labora-
tories were consulted as to the environmental testing performed in the past.
All three hospitals have excellent laboratory facilities and personnel and all
three institutions are knowledgeable on  both the  importance and the methods of
testing for bacteriological levels in  the  hospital environment to prevent the
spread of infections, bacteria, and viruses encountered in treating patients.
     In embarking on bacteriological testing of a solid wasge management
program, and the systems and  equipment that are used  in the program, it is
important to understand how hospitals  normally handle solid waste and exactly
what are the main purposes of such  testing.
     As has been pointed out  repeatedly in this Report, well-managed hospitals
follow certain  definite procedures  in  handling waste:
     1.  Whether "infectious" or  not,  the waste products  are.  deposited
         into some  sort of container that is  lined  with  some  sort of
         removable  bag.
     2.  This deposit  is made at the point of  waste generation and  nor-
         mally  as  rapidly  as  the waste is generated.
     3.  The deposit  is  normally made with a  "gentle" motion—a gravity
         drop  into the open bag—by nurses, aides,  technicians,  doctors,
         etc.,  and without stuffing, shoving,  and forcing the waste into
         the bag.   This  prevents the waste from  being "stirred up"  and
         hence inhibits  the  spread of aerosols in the area of the waste
         container.
      4.  When  the bag holding the waste  is reasonably full, it is re-
         moved from the waste container and normally is tied or sealed
          immediately to prevent  spillage  of the  waste and/or the further
          spread of aerosols.
      5.   The encapsulated waste  is  then  removed  from the generation area,
          to the central collection point  in the  building, and eventually,
          in either a reduced or  a whole  form, off-site.
      In short, the bagged waste  collection systems used by most hospitals
 appear to have been well  thought out  and capable of  preventing contamination
 of the hospital environment  by  the  waste;  assuming the personnel follow each
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procedure properly and bags  of  a  proper  construction are always used.   Ob-
viously the bags must be  completely  sealed  and  must be water- and air-proof
to prevent any leaching of  the  encapsulated waste onto the surfaces with
which the bags come in contact  during  the process.
     All three of the survey hospitals were extremely conscious of the potential
environmental effects to  the institution from solid waste.  All used the pro-
cedures of encapsulating  it  in  containers (waste baskets, trash bins,  etc.)
lined with plastic bags at  the  immediate point  of generation, of not over-
loading such containers and bags, and  of carefully tying or sealing the bags
before removing them from the containers to commence transporting them.  All
impressed upon the nurse  aide,  housekeeping, and materials management personnel
the importance of these procedures and the  potential hazards of a torn, ripped,
or punctured bag during the collection and  transport process; including the
fact that bags could contain disposable  needles and sharps that could puncture
the sides or bottoms and  cut or puncture the handler.  In all observations made
by the survey team, handling personnel always picked up the bags by the tied
top and maneuvered them in this position.  Literally  hundreds of such bags of
waste were followed by the survey team during the initial collection process
in which they were picked up from a waste container.  At  that stage, various
transport methods were used.  Most bags were deposited in a cart and then
either moved to a chute room and transported by the pneumatic tube method,
or the cartload was moved from the floor by hand.  Alternatively the bag was
hand carried from the initial deposit  container to the chute room and  sent
through the pneumatic system, or it was carried either directly or via a
soiled utility room to a nearby hand cart for movement off the floor.
     Environmental testing in connection with such a system has one main
purpose:  to determine whether any breaks are occurring in the system; as  the
result of human error; or of weaknesses in  the bags, and  the bagging and
sealing methods; or from the waste content  itself  (such as sharp objects
puncturing the bags and allowing waste  to escape) ; or  from the equipment  used
in transporting and reducing the waste.
     Carts are used to transport waste  tc chute rooms, and in  some hospitals
from the  collector boxes to the  compactor,  incinerator, or other  reduction
                                    -1S2-

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and off-site hauling equipment.  Carts are also used to transport certain
wastes from the floors that do not go through the pneumatic system.  Hence
the surfaces of the carts should be  tested to determine their bacterial levels.
     In the case of a pneumatic tube transport system, the configuration of the
equipment indicates where breaks in  the  technique could occur.  There are six
main components that should be tested.   First, the  chute rooms are recipients
of waste bags, and it should be determined whether  the bacterial levels of the
floors and walls of these rooms differ  from  the nearby rooms and corridors.
Secondly, the chute loading stations have  the waste bags dropped into them;
the doors, sills, and loading  hoppers should be tested.  The vertical chutes
and pneumatic tubes that carry the bagged  waste and the collector boxes at the
end of the line will probably  have the  highest counts  in view of the possibili-
ties of bag breakage in  transit.  The effluent air  from the collector boxes
goes to the fan room where, if there are filters, bacteria can be  trapped, or
can escape to the outside atmosphere,  through  the  sound attenuator, possibly
allowing some contamination to escape  into the  fan  room itself,  or remain
within the equipment.
     As the purpose of  the present  study was to determine  the effect of  the
pneumatic tube system on the  improvement of  environmental  conditions,
bacteriological testing  was limited  to  this  system.
     The survey team believed  that  the  bacterial  levels of  the waste itself
have been sufficiently  documented  by other researchers.   It  is apparent  that
such levels will, be found  in  the  waste  from any  hospital  that  is tested  and
will also be  found  in  the hospital  compactors  as  the  result  of rupturing the
waste  bags during compaction.
     While no torn  bags  or  loose  waste  were observed,  the  chute  rooms  and
chute  loading station,  as well as the  hand carts,  were tested in all  three
hospitals for bacterial contamination;  to determine whether  the  levels in  and
around this equipment  exceeded the  levels of the adjacent  areas  with  their
normal "people  and  material  traffic."   For a point of comparison,  all  the
hospitals  involved  make routine  checks on the floors and walls of the  nursing
units  and  ancillary departments.
      As  transport  through the pneumatic tube system was the next step  in the
                                     -183-

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operation for from 35 percent  to  85  percent of the volume of the waste in each
hospital, and as visual inspection bad revealed considerable bag breakage when
the bags dropped from the collector  boxes at the end of the line, bacterial
levels were then recorded within  the tube and within the collector box at each
hospital, as well as in the room  holding the collector box (and the compactor).
     As it was observed that the  majority of bags were torn by the action of
the compactor, it was obvious  that readings would be quite high within this
unit if bacteria were present  in  the waste.  No readings were taken of the
interior surfaces of the compactor.   Concentration was instead on the area out-
side the collector box and compactor to determine leakage and the efficiency
of the linkage between these two  units.
     To record the quality of  the transport air, readings were taken of the
filters adjacent to the exhaust fans and within the sound attenuator or exhaust
duct after the fan, as well as within each of the fan rooms.
     An interesting  sidelight, in embarking on a program of bacteriological
testing of a pneumatic transport  system is the firm conviction on the part of
many of the staff that, despite all  they have observed in the way of careful
methods used in waste handling, the  results from testing of the pneumatic
system will be colonies that are  "T.N.T.C."   (too numerous to count).  This is
a general psychological reaction  to  solid waste.  Experienced waste handlers
know they are dealing with a dangerous substance that has the capacity to
sicken or even kill its handlers.  It is also a reaction to the tube system
and to a degree a lack of trust in its efficiency to safely transport encapsu-
lated bags of waste.  Too many handlers have  observed ruptured bags emerge
from the collector boxes.  Maintenance crews  are particularly convinced  that
the elements of the pneumatic system present  one of the most dangerous environ-
ments with which they must work.   Instances were given the research team of
maintenance men developing skin rashes and other afflictions that they
claimed resulted from working on the pneumatic system.  Unfortunately it was
impossible to verify any connection from the available records.
     To properly evaluate the efficiency of a pneumatic tube waste management
system and in encapsulating solid waste, two  types  of readings were required.
     1.  Surface sampling—Swab and RODAC  samples from the surface areas of
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the equipment,  such as the hand carts for moving the waste; and the sills,
frames,  doors,  tubes, collector boxes, filters, and fan room equipment of the
pneumatic tube  system.
     2.   Air sampling—To record the spread of aerosols in the chute loading
rooms,  the collector-compactor rooms, and the fan equipment rooms.
     As  the greatest activity occurred in each hospital between 8:00 a.m. and
3:00 p.m., samples were collected during this peak period.  They were taken
to the  laboratory immediately after collection and the interval between sampling
and analysis did not exceed three to four hours.
     Tryptose Glucose Yeast Agar  (DIFCO)  (Standard Methods Agar) was used as a
general  plating medium for enumeration of bacterial populations and an indicator
of the  general  level of contamination.
     Tellurite Glycine Agar (BBL) vas used  for the quantitative detection of
coagulose-positive staphylococci.   Selective  inhibition is attained by means
of lithium chloride, tellurite and  glycine; pathogenic coagulose-positive
cocci form black colonies on  the  surface within  24 to 48  hours which  can be
counted easily.
     MacConkey Agar  (BBL) was used  for  the  detection of Escnenchia coli; a
bile salt mixture is used for  inhibitions  of  gram-positive organisms.
     Cooke Rose  Bengal Agar  (DIFCO)  was  used  as  a  selective  nedium for the
isolation of fungi;  selectivity  is  obtained by  the dye, rose bengal,  and two
antibiotics, penicillin and streptomycin.
     For  sampling, a one  percent  peptone phosphate buffer solution was used
as a dilution  fluid  to preserve  microbes.
     The  principal specific bacteria for which  samples  were  taken and cultures
made were Staphylococcus  aureus,  Streptococcus  faecalis,  Pseudomonas  aeruginosa.
Bacillus  subtllis, and Escherichia  coli.  In addition,  effort was made  to
determine the  incidence of  saprophytic bacteria in general and of fungi  on  the
equipment and  the waste management  areas.
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VETERANS ADMINISTRATION HOSPITAL

     The personnel of the Veterans Administration- Hospital are acutely aware
of the potentially deleterious effects upon the hospital environment from the
hospital's solid wastes.  All levels of hospital administration—from top
management, through department director level, through section head level, and
in the various  laboratories—are actively int«res£ed in whether contamination
from solid waste is affecting patients, staff, or visitors.  In particular,
they are interested in whether the pneumatic solid; waste transport system is
or is not contributing to surface or air contamination.  Equally, they are
interested in whether this pneumatic system is superior to the system of hand
hauling solid waste with respect to the spread of bacteriological contamina-
tion.
     Certain staff personnel of this hc.spit.al have been accustomed to routine-
ly performing periodic bacteriological testing to determine the level of con-
tamination at various points in the hospital.  Recent manpower shortages in
the laboratories, however, have limited their capabilities to perform as many
of these tests  as they would like.  Despite laboratory manpower shortages,
the testing program was welcomed and given complete cooperation by the hospi-
tal administrative staff.
     Microorganisms of particular interest were staphylococcus aureus,
pseudomonas aeruginosa, and  klebsiella.  Information on other bacteria which
might be present was also desired, even though these bacteria might be non-
pathogenic.
     The survey team felt that a minimum of one half of the chute loading
stations should be tested in order to assure a reliable and representative
testing of the  system.  These should be those receiving the highest use fac-
tor.  The following stations were selected:
                    IE                2E                5E
                    2S                4S                6S
                    3N                4N                5N
                                      3W
     Test samples were also  taken inside one half of the trash carts and one
                                    -186-

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half of the soiled linen carts; in the trash and linen collectors; inside
the incinerator room; inside the compactor room; in the compactor loading
hopper; in the fan room; and adjacent to the effluent air filter.
     The results have not uncovered the presence of any pathogenic fomites
or air contamination inside  the hospital attributable to the pneumatic tube
system.  Non-pathogenic organisms  likewise have not been uncovered to a
significant level.
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MARTIN LUTHER KING HOSPITAL

      This hospital also has a  staff extremely  conscious of the potential en-
vironmental effects to  the institution of solid waste.  Here again, the sur-
vey team found  from personal discussions that all echelons from top manage-
ment down to working  staff were aware of the hazards that might arise from
the problems of solid waste disposal.  Although this attitude was generally
held in all areas, it was particularly noticeable among the microbiology lab-
oratory staff.
     The hospital routinely and regularly conducts their own microbiological
testing throughout the  institution.  This routine testing, done by the hospi-
tal staff, has  normally been undertaken to  determine the general level of
airborne cross-contamination  that  might be  present inside the hospital.  The
staff expressed great interest  to  the survey team, however, in conducting
tests to determine whether or not  any contamination which might be present
could be attributed to  the pneumatic solid  waste transport system, and how
the hand hauled cart  system might  compare to this.
     The microorganisms of particular interest  were staphylococcus aureus,
pseudomonias aeruginosa,  and  klebsiella.  Information on other bacteria pres-
ent was also sought.
     The team  felt that a minimum  of one half the chute loading stations
should be included in the survey in order to assure a representative sample.
The following  stations  were selected:
     Segment I, 1st floor    Wing A, 1st floor    Wing B, 3rd floor
     Segment I, 2nd floor    Wing A, 2nd floor    Wing B, 4th floor
     Segment I, 3rd floor    Wing A, 3rd floor    Wing C, 2nd floor
     Segment I, 5th floor                          Wing C, 4th floor
     Test samples were  also  to  be  taken  inside  one half of the trash carts and
one half the soiled linen carts; in the  trash and linen collectors; inside the
incinerator  room; inside  the  compactor room; in the compactor loading hopper;
in the fan and  filter room; and adjacent to the effluent air filter.
     The results have not uncovered the  presence of any pathogens  such as
staph aureas or pseudomonas anywhere  in  the hospital that might be attributable
                                     -188-

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to the pneumatic tube system.  Traces of Id. eb si el la., however, were found on
the laundry floor.  There were fewer than five colonies, which is not con-
sidered a significant concentration.  Klebsiella is an organism which in con-
centrations of approximately 40 colonies or above can cause throat and nose
infections, intestinal infections,  sepsis in the bloodstream, and meningitis.
     Several non-pathogens were identified.  These  included staphylocoecus
epidermis, diphtheroids.  and  bacillus subtilis.  The face of all slide valves,
both trash and linen, and the  floor near the compactor, had colonies of these
non-pathogens, which were too  numerous  to count.  None  of  these were consid-
ered significant, being  non-pathogens.
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ST. MARY'S HOSPITAL

     This hospital is also acutely aware of the need for excellent housekeep-
ing and of the potentially dangerous effects upon the hospital environment
that could be attributed to the handling of solid waste.  It was found, after
conducting several personal interviews, that top management was interested
not only in good housekeeping practices but also in whether contamination from
solid waste was affecting patients, staff, or visitors.  There was interest
in whether either the pneumatic tube system or the hand hauled waste system
could contribute to surface or air contamination in the hospital.  Extensive
laboratory testing in the past did not appear to have been carried out fre-
quently on a regular basis on these particular elements.
     Here again, the microorganisms of particular interest were staphylococcus
aureus, pseudomonas aeruginosa, and klebsiella.  Information on other bacteria
present was also desired, even though they might be non-pathogens.
     The following chute loading stations were selected for testing:
                    3 East            4 Center          2 West
                    4 East            5 Center          4 West
                    5 East            6 Center          8 West
                                      7 Center
     Test samples were  also taken inside one half the trash and linen carts;
in the trash and linen  collectors; inside the incinerator room; in the com-
pactor loading hopper;  and adjacent to the effluent air ducts.
     No pathogenic bacteria were identified in any of the locations.  Non-
pathogenic bacteria such as staphylococcus epidermis and diphtheroids and
bacillus subtilis were  identified.  The highest colony count of any of these
non-pathogens was 13, which occurred in trash chute 2 West.
                                     -190-

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                    REPORT OF BACTERIOLOGICAL TESTING
ST. MARY'S HOSPITAL

AREA TAKEN FROM
Trash chute/ L-C
Trash chute/1-W
Trash chute/3-E
Trash chute/2-E
Trash chute/3-C
Trash chute/3-W
Trash chute/2-W
Trash chute/0. R.
Trash chute/5-E
Trash cart /incinerator room
Trash hopper/incinerator room
Linen hopper/laundry
Trash car t /incinerator room
Trash hopper /incinerator room
Linen hopper/laundry
Linen chute/2-W
Linen chute/3-E
Linen chute/3-W
Trash cart /incinerator room
Trash hopper/incinerator room
Trash cart/ incinerator room
Trash hopper /incinerator room
Linen hopper /laundry


Methodology: Swab samples streaked on
staphylococcus aureus and on MacConkey'

C -
1 -
0 -
0 -
0 -
1 -
13 -
0 -
0 -
5 -
0 -
0 -
0 -
0 -
0 -
0 -
1 -
1 -
0 -
0 -
0 -
0 -
0 -
0 -
C -
s -
p -

TYPE OF
S - P SWAB SAMPLE
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
0-0
Colonies
Staph aureus
Fseudomonas
nidnnitol salt agar for
s agar
for pseudomonas
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
wet
wet
wet
wet
wet


detection of
All were in-
cubated at 37°C. for 48 hours.
                                    -191-

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                 10-ECONOMICS OF HOSPITAL WASTE MANAGEMENT

     The transporting and reduction of  hospital solid  waste has become  increas-
ingly costly during the past fifteen years as  the  volume  of waste has  increased
along with hourly cost of the labor and supplies  that  must manage it.   With
labor representing as high as 80 percent of the average hospital's  operating
budget, every effort is made to conserve wages.   Automation and mechanization,
by the installing of methods such as pneumatic transport  systems, has  been one
approach hospitals have used.
     Most hospitals are now approaching capital expenditures  on the basis that
they must save enough labor for such capital outlays to be  self-liquidating in
under a ten year period.  In the case of solid waste transport systems this is
an extremely difficult goal to achieve  due to  a variety of  factors, ranging
from high capital installed costs, to cost of  supplies, maintenance, power and
utility requirements, to the feasibility of using the  automated system to the
maximum degree for the waste that must  be transported  as  against  hand cart or
other methods.
                     CAPITAL COSTS OF THE TRANSPORT S\STEM

     In evaluating the costs of an automated installation such as a solid waste
pneumatic transport system, the amount of space taken up in the building by all
the components of the system and the value of the space, coupled with the in-
stalled price of the equipment, and the installed cost of all utilities that
are necessary for the operation of the system, are the principal factors.  Based
on the original construction records these costs were obtained from the archi-
tect for  each of the three pilot study hospitals.  Space required for waste
handling  external  to the pneumatic tube system, yet exclusively devoted to this
purpose also must  be included, such as chute  loading rooms, waste storage areas,
compactor and  incinerator  areas.   To  this must be added the cost of the money
for purchasing  the space and equipment;  the  interest on investment that will be
incurred  over  the  expected life  of the system.   In developing costs,  the  space
used and  the pneumatic system  were capitalized  as an  investment over  a  twenty
year period.
                                     -1*2-

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     It is extremely difficult to obtain completely accurate figures in the
capital cost between the equipment itself and the labor required to install it.
A reasonable rule of thumb appears to be that, in the final installed price,
installation labor represents approximately 60 percent of the total.
                     CAPITAL COSTS OF  INTERFACED  EQUIPMENT

     In a complete analysis  of a  solid waste pneumatic transport system it is
Important to also investigate the costs of all other equipment that interfaces
with the tube system.   These items fall into two general classifications.
(1) Accessory equipment that is necessary to ensure the successful operation of
the transport system:   such  as carts  to move the waste to the chute doors and
away from the final  collector; or conveyors or other devices that will move
waste from remote points to  provide a mechanical interface with the pneumatic
system; and reduction  equipment such  as floor compactors and shredders or grind-
ers to ensure waste  will fit into the chutes-  (2)  General waste handling equip-
ment that is independent of  the transport system but provides further efficiency
in solving the  overall problem:   such as compactors, attrition mills, inciner-
ators and gas scrubbers, trucks,  scales, lifts,  balers, conveyors, and off-site
hauling vehicles and containers.   Finally,  for  the waste that is not handled by
the pneumatic transport system  there  are the capital costs of elevators and
other similar  items, a portion of  which  are  used  for  the transport  of waste at
various times of the day.
     In the three  pilot hospitals, equipment on  the  floors that  interfaced with
the pneumatic system were hand  carts  which  were  used  to haul waste to chute
loading rooms and  also to move  bulky  waste  from the  floors to the  central col-
lection point.   All  of the hospitals  had  reduction equipment installed  (com-
pactor and incinerator) after  the final collector  of  the pneumatic system.
All of the hospitals were high  rise structures  and used  elevators.  In  develop-
 ing waste  management costs such equipment  was  not  capitalized,  as  it  can be
purchased  separately from the structure.   A straight line depreciation  method
was used,  extending over the expected equipment life.
                                      -193-

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                   OPERATING COSTS OF THE PNEUMATIC SYSTEM

     The principal operating cost  is labor.  The  first  element is for materials
handling:  the hours required to haul waste from  the various points of generation
to the chute loading doors; depositing waste in the chutes (including waiting
times); moving waste from the collector at the end  of  the line to reduction units
such as compactor or incinerator.   The second element  is labor for maintenance,
both corrective and preventive.  The third element  is  slightly different, yet
similar, to maintenance; namely housekeeping labor  required to keep the system
and its interfacing areas clean and presentable.  The  fourth element is the cost
of training all labor elements in the operation of  the  system as well as direct-
ly managing the people who  are actually doing the work.   To these direct labor
costs must be added the fringe benefits and other labor overhead elements.
     The second heaviest operating cost involves  the supplies in which waste is
stored  and transported, namely the various disposable  bags and closures.  Thirdly
are  the costs of utilities,  such  as power to run  the system.
                      OPERATING COSTS OF INTERFACED SYSTEMS

     As  seen from the preceding  chapters, the pneumatic system handles only a
percentage  of the total waste of  each institution.  The balance is hand-hauled
by  cart  to  the central collection point.  The labor for this has been separated
from the labor used for the pneumatic system.
     The next major element in this group is that labor required to load and
maintain the reduction equipment  at the end of the line, such as compactor and
incinerator, and to ensure that the housekeeping of this equipment, and the
area in  which it is installed, is satisfactory.
     The additional supplies for  the interfaced  equipment consist primarily of
the bags required to contain the hand-hauled waste and the cleaning materials
required for the reduction areas.
     The utility costs of power for the compactor and incinerator, gas and oil
for the  latter are the next item to be included. The final cost at the end of
                                     -194-

-------
the line is the contract for hauling the waste off-site to the landfill.   (This
applied at each of the three hospitals.)
     A final item that must be included in determining the total waste manage-
ment costs for an institution is the cost of all the storage containers through-
out the floors of the building, ranging from waste baskets to 44 gallon contain-
ers, amortized over their expected life.
          DIVISION OF FIXED COSTS BETWEEN  WASTE  AND LAUNDRY TRANSPORT

     It could be  argued that  the  entire fixed charges of installed equipment
and space costs,  maintenance  labor, and utility costs for a pneumatic system
could be charged  against either  waste or  laundry transport, on the basis that
any hospital could elect to remove either product from using the system at
some point in time.   (A review of all hospitals with pneumatic systems has re-
vealed that this  has happened in a few cases due to management decisions.)
     However, when the systems were originally  installed for transporting both
products, as in the  case of the  three hospitals in the present study, it is
more logical to divide these  fixed system costs between waste and  laundry trans-
port.  This approach has been used in this  chapter and the following one to
determine the economic feasibility cf a pneumatic transport system.  The basis
for the calculation  is the number of bags of each product  (rather  than weight
or cube)  that travel the system, as  individual  bag loads more closely repre-
sent the  true use factor of such a system.
     Tables 22  through 45 analyze all the  foregoing cost factors  for  each of
the three hospitals  studied and  compare financially  the systems  each is using.
                                     -195-

-------
                                   TABLE 22
                                COST ANALYSIS
                          ST. MARY'S HOSPITAL, DULUTH
                    PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
CAPITAL COSTS
Building Costs
         Total         Total      Cost/
     Construction     Square     Square
         Costs         Feet       FcjQt
                                                 Total     Cost/
                                                 Cubic     Cubic
                                                  Feet     Foot
           $24,386,090     518,853     $47.00   7,902,910   $3.09
   1. Area Costs
           Laundry collector
           Waste collector
           Fan room
           Control panel
           Load stations (chute
            rooms), total
                Totals
Square Feet
      576
      216
      265
      150

    1,008
    2,215
                                          Value e $47.00
                                             $ 27,072
                                               10,152
                                               12,455
                                                7,050

                                               47,376
                                             $104,105
                                                                     Total
              $104,105
   2.  Volume Costs
                        Length. Ft.   Volame ;jg
           Linen, waste
            & air tubes    1.700
                Totals     1,700
                                     2,363
Value 6 $3.09

   $7,302
   $7,302     $   7,302
   3.  Cost of Pneumatic System - Equj^aent and Installation
                                                               $193,157
      TOTAL CAPITAL INVESTMENT FOR SPACE AND
      TOTAL CAPITAL COST PER YEAR. 7%  INTEREST. 20-^EAR LIFE

-------
                                   IABL£ 23
                                 COST ANALYSIS

                          ST.  MARY'S HOSPITAL, DULUTH

                    PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
DIRECT COSTS
  1. Labor
     Haul to and
      load chutes
Avg. Rate
w/Fringes
     Move to and load
      compactor
     Maintenance,
      corrective and
      preventive
  $2.66
   2.86
   4.95
          Total Labor Costs
 Avg.
Hrs./
Month
 441
  74
 Avg.
 Cost/     Hrs./     Cost/
 Month     Year     Year
$1,173    5,292   $14,077
   212
             292
888     2,540
            708
        3,505
                 Total
                Dollars
                      $1,677     6,888    $20,122    $20,122
2.
Bags to Transport Waste
Black plastic
Nylon mesh
Total Supplies Cost
No./
ttonth
7,000
4,410*
Cost/
Month
$ 400
873
$1,273
No./
Year
84,000
52,900
Cost/
Year
$ 4,800
10,476
$15,276
                                                                      $15,276
  3. Total Utilities (Power S, Control)
     TOTAL DIRECT  COSTS
                       Cost/Month

                           $510
                           Cost/Year

                            $6,121    $ 6,121
                                                  $41,519
 * These  are  reusable  transport bags in which the plastic  waste bags  are

  placed to  prevent breakage or bag ripping.   Each nylon bag  is used  for one
  transport, then emptied,  laundered,  and re-issued.   Total average inventory

  is  approximately 600.   Average life  is 200  uses.  Cost for  each use:  to
  purchase,  fill, handle, dump, launder, store,  and re-issue  = $0.198 each  per  day.
                                    -197-

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                                   TABLE 24
                                COST AK&LYSIS
                         SI. MARY'S HOSPITAL* DULUTH
                   PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
SUMMARY OF ANNUAL COSTS
          CAPITAL COSTS AMORTIZED;                          $36,548

          DIRECT OPERATING COSTS;
               Labor                   $20,122
               Transport Bags           15,276
               Utilities                 6,121
                    Total                                   $41,519

          INDIRECT OPERATING COSTS:
               Downtime                                     $    255

          TOTAL  COST  PER YEAR;                              $78,322

          TOTAL  COST  PER MONTH:                             $  6,527

          DEDUCTION Of FIXED  CHARGES PER YEAR
            ASSIGNED TO LAUNDRY TRANSPORT  (80%);
                Capital Costs           $29,238
                Utilities Costs            4,897
                Maintenance Costs         2?804
                     Total Deductions                        $36,939

           NET COST PER YEAR FOR WASTE TRANSPORT:             $41,383

           NET COST PER MONTH FOR WASTE TRANSPORT:           $ 3,449
                                      -1S8-

-------
                      COST ANALYSIS

               ST. MARY'S HOSPITAL. DULUTH

         PNEUMATIC SOLID WASTE TRANSPORT SYSTEM

                       (Continued)
Total Pounds Transported per Month:

Total Cost per Pound
     of Solid Waste Transported:
 26,733


$     0.13
Total Cubic Feet Transported per Month;

Total Cost per Cubic Foot
     of  Solid Waste Transported:
 11,578


$     0.30
Total Bags  Transported per Month:

Total Cost  per  Bag
     of  Solid Waste  Transported:
  4,456


$     0.77
                            -199-

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                                   TABLE 25
                         ST . MARY ' S HOSniAL*

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
Labor
               Cost/Hr.
Hrs./Mo.  Cost/fete.   Hgs./Yr.  Cost/Yr.
                                Totals
Pick up bags,
 load cart, walk
 to elevator     $2.93

Elevator time,
 including wait-
 ing, loading,
  311
$  911    3,732     $10,935
and unloading 2.93
Walk from ele-
vator & unload 2.93
Total Labor Costs
Ba^s to Receive and Transport
No . /Month
Beige plastic 20,000
Clear plastic 10,000
Red plastic 1,600
Clear kick bucket 1,600
Clear poly 5,000
Total Supplies Cost
68

10
389 $1
Waste
Cost/Month
$ 240
345
84
53
286
$1,008
199 816

29 120
,139 4,668

No. /Year
240,000
120,000
19,200
19,200
60,000

2,391

352
$13,678

Cost /Year
$ 2,880
4,140
1,008
639
3,432
$12,099
                                                                      $13,678
                                                                      $12,099
Utilities
Elevator power
 25UP x 0.746 x $0.015
 x 4.5 hrs./day x 7 x 4.33
                                        Cost/Month
                 §38
                            Cost/Year
                    $456
$   456

-------
                                COST ANALYSIS

                         ST. MARY'S HOSPITAL, DULUTH

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM

                                 (Continued)
Depreciation of Equipment
Elevator,
 @ $60,000, 25-year life,
 used 20% of the time

Waste baskets, trash containers
 @ $3.50,  5-year life

Carts,
 2 & $200, 10-year life,

     Total Depreciation Costs
                                        Cost/Month
            Cost/Year
$


40
73
3
$ 480
880
40
$116
$1,400
$ 1,400
                                     -201-

-------
                                   TABLE 26
                                COST ANALYSIS
                         St. MARY'S HOSPITAL, JPULUTH
                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
SUMMAJLV OF ANNUAL COSTS
               Labor                                        $13,678
               Transport Bags                                12,099
               Utilities                                        45b
               Depreciation                                   1,400
          TOTAL COST PgR YEAR;                              $27,633
          TOTAL COST PER MONTH;                              $ 2,303
          Total Pounds Transported per Month:                42,161
               Cost per Found
                of Solid Waste Transported:                  $     0.06
          Total Cubic Feet Transported per Month:             5,607
               Cost per Cubic Foot
                of Solid Waste Transported:                  $     0.41
          Total Cart Trips per Month:                           455
               Cost per Cart Load of Solid Waste:           $     5
               Cost per Bag Equivalent:                     $     0.32

-------
TABLE 27
COST ANALYSIS
ST. MARY'S HOSPITAL, DULUTH
END OF LINE SOLID
Avg.
Avg. Rate Hrs./
Labor w/Fringes Month
Load incinerator $2.93 30
Incinerator ash
removal 2.93 38
Clean compactor
and bin (none - done
Clean compactor
and incinerator
areas 2.93 20
Maintenance ,
compactor and
iticinerator 2.93 12
Total Labor Costs 100
Off-Site Hauling
2 times per week ^ $44
Cleaning
Total Hauling Costs
Amortization of Space
Incinerator room, 20-year life,
162 sq. ft. @ §47
Loading dock, 20-year life
Total Amortization Costs
Depreciation of Equipment
Incinerator, 10-year life
Compactor, 10-year life
Total Depreciation Costs
WASTE HANDLING
Avg.
Cost/ Hrs./
Month Year
$ 88 360
111 456
by contractor)
59 240
35 144
$293 1,200
$381
15
$396
$ 76
$ 76
$152
$283
42
$325
Cost/
Year
$1,055
1,336
703
422
$3,516
$4,572
176
$4,748
$ 914
914
$1,828
$3,400
509
$3,909
Total
Dollars
$ 3,516
$ 4,748
$ 1,828
$ 3,909
  -203-

-------
                                COST ANALYSIS
                         ST. MARY'S HOSPITAL, DULUTH
                       END OF LINE SOLID WASTE HANDLING
                                 (Continued)
Utilities
Incinerator
Compact or
     total Utilities Costs
Avg.
Cost/
Month
_ _ 1
$  12
Cost/      Total
 Year     Dollars
$  132
$  144    $   144
                                    -204-

-------
                                   TABLE 28
                                COST ANALYSIS
                         ST. MARY'S HOSPITAL, DULUTH
                       END OF LINE SOLID WASTE HANDLING
SUMMARY OF ANNUAL COSTS
          Labor                                             $  3,516
          Off-Site Hauling                                    4,748
          Space                                               1,828
          Equipment                                           3,909
          Utilities                                             144
     TOTAL COST PER YEAR                                    $14,145
     TOTAL COST PER MONTH                                   $ 1,179
     Total Incoming Pounds Handled per Month:                68,894
          Cost per Incoming Pound Handled:                  $     0.02

     Total Incoming Cubic Feet Handled per Month:            17,185
          Cost per Incoming Cubic Foot Handled:             $     0.07

     Total Bags and Bag  Equivalents Handled per Month:       11,736
          Cost per Bag and Equivalent:                      $     0.10
                                     -205-

-------
                             TABLE 29
                           COST ANALYSIS
                    ST. MARY'S HOSeiTAL, BULtJTH
            SUMMARY OF TOTAL HOSPITAL SOLID WASffe COSTS

                                                       Per Annum
1.   Labor;
          Pneumatic System        $20»122
          Hand Hauled System       13,678
          End of Line System        3^516
               Total              $37,316
          Less Laundry % of
          P/N Maintenance (80%)     2,804
               Net Labor Cost                          $34,512

2.   Transport Bags;
          Pneumatic System        $15,276
          Hand Hauled System       12,099
               Total Transport Bag Cost                $27,375

3.   Capital Costs:
          P/N System & Space      $36,548
          End of Line Space          1»B28
               Total              $38,376
          Less Laundry % of
          P/N Capital (80%)         29^238
               Net Capital Cost                        $  9,138

4.   Depreciation of Equipment;
          Hand Hauled System      $ 1,400
          End of Line System        3,909
               Total Depreciation                      $  5,309

5.   Off-Site Hauling Contract^                        $  4,748
                                -206-

-------
                           COST ANALYSIS
                    ST. MARY'S HOSPITAL, DULUTH
            SUMMARY OF TOTAL HOSPITAL SOLID WASTE COSTS
                            (Continued)

                                                       Per Annum
6.   Utilities:
          Pneumatic System        $ 6,121
          Hand Hauled  System          456
          End of Line  System          144
               Total              $ 6,721
          Less Laundry % of
          P/N Utilities  (80%)       4,897
               Net Utilities Cost                      $ 1,824

7.   Indirect Costs -  Downtime of P/N System;          $   255
TOTAL NET COST PER YEAR;                               $83,161
TOTAL NET COST PER MONTH :                              $ 6,930
Total Pounds Disposed  per Month:                        68,894
     Net Cost  per  Pound Disposed:                      $     0.10
Total Cubic Feet Disposed per Month:                    17,185
     Net Cost  per  Cubic Foot Disposed:                 $     0.40
Total Bags and Bag Equivalents  per  Month:               11,736
     Net Cost  per  Bag  and Equivalent:                  $     0.59

Percent of Total Net Cost Attributable  to  Pneumatic  System: 58%
Percent of Total Net Cost Attributable  to  Hand  Hauling:     42%
                                -207-

-------
                                  TABLE 30
                                COST ANALYSIS
                 VETERANS ADMINISTRATION HOSPITAL. SAN DIEGO
                    PNEUMATIC SOLID WASTE  TRANSPORT SYSTEM
CAPITAL COSTS
     Building Costs
Total
Construction
Costs
Total
Square
Feet
Cost/
Square
Foot
Total
Cubic
Feel
Cost/
Cubic
Foot
           $35,250,000     677,700     $52.01  14,645,165   $2.41

  1. Area Costs
                               Square Feet     Value (g $52.01        Total
          Laundry collector           63          $  3,277
          Waste collector
           & compactor               578            30,062
          Fan room                   465            24,185
          Control panel              156             8,114
          Load stations (chute
           rooms), total           3.238           168,408
               Totals'             4,500          $234,046          $234,046

  2. Volume Costs
                       Length. Ft.   Volume @ 16"D   Value @  $2.41
          Linen & waste
           tube            1,303           1,818           $4,381
          Air tube          591            825            1.988
               Totals     1,894           2,643           $6,369     $  6,369

  3. Cost of Pneumatic  System -  Equipment and  Installation          $350,000
      TOTAL CAPITAL INVESTMENT FOR SPACE AMD SYSTQ1
      TOTAL CAPITAL COST PER YEAR. 7% INTEREST, 20-YEAR LIFE
                                    -208-

-------
                                   TABLE 31
                                 COST ANALYSIS
                  VETERANS  ADMINISTRATION HOSPITAL. SAN DIEGO
                    PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
DIRECT COSTS
Avg. Rate
1 . Labor w/Fringes
Haul to chute
loading room $3.31
Load chutes 3.66
Load compactor
Maintenance,
corrective and
preventive 4.92
Total Labor Costs

2. Bags to Transport Waste
White plastic
Total Supplies Cost
Avg.
Hrs./
Month

319
143
(no cost -


38
500
No./
Month
9,700
Avg.
Cost/
Month

$1,056
523
automatic


187
$1,766
Cost/
Month
$237
$237
Hrs./
Year

3,828
1,716
loading)


454
5,998
No./
Year
116,400
Cost/
Year

$12,671
6,281



2,224
$21,186
Cost/
Year
$2,849
$2,849
Total
Dollars






$21,186

$ 2,849
  3. Total Utilities  (Power  &  Control)      Cost/Month     Cost/Year
                                               $560          $6,721    $ 6,721
     TOTAL DIRECT  COSTS
$30,756
                                     -209-

-------
                                   TABLE 32
                                COST
                 VETERANS ADMIKISTRAIIQK HOSE I'TAL. SAB DIEGO
                    PNEUMATIC SOLID WA&EE TRANSPORT SISIBd
SUMMARY OF ANNUAL COSTS
          CAPITAL COSTS AMORTIZED:                           $ 70,850
          DIRECT OPERATING COSTS:
               Labor                   $21,186
               Transport Bags            2,849
               Utilities                 6,721
                    Total                                   $ 30,756

          INDIRECT OPERATING COSTS:
               Downtime                                     $  2,112
          TOTAL COST PER YEAR;                              $103,718
          TOTAL COST PER MONTH;                              $  8,643

          DEDUCTION OF FIXED CHARGES PER YEAR
           ASSIGNED TO LAUSDRY TRANSPORT (54%);
               Capital Costs           $38,259
               Utilities Costs           3,629
               Maintenance Costs         1,201
                    Total Deductions                        $ 43,089
          NET COST PER YEAR FOR WASTE TRANSPORT;             $ 60,629

          NET COST PER MONTH FOR WASTE TRANSPORT:            $   5,052
                                     -210-

-------
                      COST ANALYSIS
        VETERANS ADMIN 1STRAT ION  HOSPITAL, SAN DIEGO
          PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
                        (Continued)
Total Pounds Transported per Month:                33,796
Total Cost per Pound
     of Solid Waste Transported:                  $     0.15
Total Cubic Feet Transported per Month:            16,701
Total Cost per Cubic Foot
     of Solid Waste Transported:                  $     0.30
Total Bags Transported per Month:                   9,578
Total Cost per  Bag
     of  Solid Waste Transported:                  $     0.53
                           -211-

-------
Labor
                                   TABLE 33
                 VETERANS ADMINISTRATION HOSPITAL.  SAN QIEgQ

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
                 Coat/Hr.  Hrs./Mo.   Cost/Mo.   HTS./YT,   Cpst/Yr,
                                                                      Totals
flck up bags,
 lead cart, walk
 to elevator       $3.66      114       $417

Elevator time,
 Including wait-
 ing, loading,
 and unloading     3.66       24         88

Walk from ele-
                                                 1,368    $5,007
                                                   288     1,054
vator & unload 3.66
Total Labor Costs
Ba$6 to Receive and Transport
No. /Month
Clear waste liner 36,000
Small red 6,500
Large red 4,400
Swall yellow 1,000
Large yellow 1,000
Large vinyl 3,300
Surgery, non-static 620
5
143
Waste
Cost /Month
$ 803
339
394
38
57
248
46
18 	 60
$523 1,716
No. /Year
432,000
78,000
52,800
12,000
12,000
39,600
7,440
220
$6,281
Cost /Year
§ 9,b35
4,064
4,726
459
688
2,970
555
                                                                      $  6,281
     Total Supplies Costs
                               SL.925
$23,100
$23,100
Utilities
Elevator power,
 2SHP x 0.746 x $0.015
 K 12 hrs./day x 7 x 4.33
                                        Cost/Month
                                           §103
                                                       Cost/Year
$1,236
$ 1,236

-------
                                COST ANALYSIS

                 VETERANS ADMINISTRATION HOSPITAL.  SAN  DIEGO

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM

                                 (Continued)
Depreciation of Equipment
Elevator,
 @ $60,000, 25-year life,
 used 50% of the time

Carts,
 2 rubber @ $200
 2 O.K. aluminum @ $300
 10-year life

Waste baskets, trash containers
 @ $3.50, 5-year life

     Total Depreciation  Costs
Cost/Month



   $100


      3
      5



    211

   $319
                                                       Cost/Year
$1,200

    40
    60
 2.530
$3,830
$ 3,830
                                     -213-

-------
                                   TABLE 34
                                COST ANALYSIS
                 VETERASS ACTtlKlSTRATKffl HOSPIIA.L,  SAN DIEGO
                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
SUMMARY OF ANNUAL COSTS
               Labor                                        $  6,281
               Transport Bags                                 23,100
               Utilities                                       1,236
               Depreciation                                    3,830
          TOTAL COST PER YEAR;                               $ 34,447
          TOTAL COST PER MONTH:                              $  2,871
          Total Pounds Transported  pet  Month:                 100,932
               Cost per Pound
                of  Solid Waste  Transported:                  $      0.03
          Total Cubic Feet  Transported  per Month:              30,856
               Cost per Cubic Foot
                of  Solid Waste  Transported:                  $      0.09
          Total Cart Trips  per  Month:                             940
               Cost per Cart Load of Solid Waste:            $      3.05
               Cost per Bag Equivalent:                      $      0.19
                                    -214-

-------
                             TABLE  35
COST ANALYSIS
VETERANS ADMINISTRATION HOSPITAL, SAN DIEGO
END OF LINE SOL.
Avg.
Avg. Rate Hrs./
Labor w/ Fringes Month
Load incinerator $3.66 65
Incinerator ash
removal 3.66 40
Clean compactor
and bin 3.66 47
Clean compactor
and incinerator
areas 3.66 28
Maintenance ,
compactor and
incinerator 3.66 13
Total Labor Costs 193
Off -Site Hauling
3 tin>es per week. @ $80
Cleaning (Done in-house.
Total Hauling Costs
Amortization of Space
Incinerator room, 20-year life,
903 sq. ft. @ $52
Loading dock, 200 sq. ft. (.<• $52
Total Amortization Costs
Depreciation of Equipment
Incinerator, 10-year life
Compactor & 2 bins, 10-year life
ID WASTE HANDLING
Avg.
Cost/ Hrs./
Konth Year
?238 780

146 480

172 56-4


102 336


48 156
$706 2,316

$1,045
Included in labor,
$1,045


$470
104
$574

$595
58


Cost/
Year
$2,855

1,757

2,064


1,230


571
$8,477

$12,562
above . )
$12,562


$5,636
1,248
$6,884

$7,140
700


Total
Dollars











$ 8,477



$12,562




$ 6,884



Total Depreciation Costs
$653
$7,840
                                -215-

-------
                                GOS1 MAOSIS,
                 VETEBABS ADMIUI5TRATIQS HOSPITAL, SAE DIEGO
                       END OF LIKE SOLID, BASTE HANDJUSS.
                                 (Continued)
Utilities
Incinerator
Co«f>actor
     Total Utilities Costs
$20
Cost/
 Year
 $192
   48
 $240
                            Total
                           Dollars
240
                                     -216-

-------
                                   TABLE 36
                                COST ANALYSIS
                 VETERANS ADMINISTRATION HOSPITAL,  SAN DIEGO
                       END OF LINE SOLID WASTE HANDLING
SUMMARY OF ANNUAL COSTS
               Labor                                        $  8,477
               Off-Site Hauling                               12,562
               Space                                           6,884
               Equipment                                       7,840
               Utilities                                         240
          TOTAL COST PER YEAB                               $ 36,003
          TOTAL COST PER MONTH                              $  3,000
          Total  Incoming Pounds Handled per Month:           134,728
               Cost per Incoming Pound Handled:             $      0.02

          Total  Incoming Cubic Feet  Handled per Month:        47,557
               Cost per Incoming Cubic Foot Handled:        $      0.06

          Iota]  Bags  and Bag Equivalents  Handled  per Month:   24,618
               Cost per Bag  and Equivalent:                 $      0.12
                                     -217-

-------
                              TABLE 37
                           COST A8&LYS1S
            VETE&AKS AfiMlNlSTRATlgS HOSPITAL.  SAN DIEGO
            SUMMARY OF TOTAL HOSPITAL  SOLID WASTE COSTS
                                                       Per Annum
1.   Labor:
          Pneumatic System        $21,186
          Hand Hauled System        6,281
          End of Line System        8j477
               Total              $35,944
          Less Laundry % of
          P/N Maintenance (54£)     1,201
               Net Labor Cost                          $ 34,743

2.   Transport Bagst
          Pneumatic System        $ 2,849
          Hand Hauled System       23.100
               Total Transport Bag Cost                $ 25,949

3.   Capital Costs;
          P/N System & Space      $70,650
          End of Line Space         6,884
               Total              $77,734
          Less Laundry % of
          P/N Capita] (54%)        38»259
               Net Capital Cost                        $ 39,475

4    Depreciation of Equipment:
          Hand Hauled System      $ 3,830
          End of Line System        7,840
               Total Depreciation                      $ 11,670

5.   Off-Site Hauling Contract:                        $ 12,562

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                           CQS'i_ ANALYSIS
             VETERANS ADMINISTRATION HOSPITAL.  SAN DIEGO
             SUMMARY OF TOTAL HOSPITAL SOLID WASTE COSTS
                             (Continued)
6.   Utilities:
                                                       Per Annum
          Pneumatic System        $ 6,721
          Hand Hauled System        1,236
          End of Line System          240
               Total              $ 8,197
          Less Laundry % of
          P/N Utilities (54%)       3.629
               Net Utilities Cost                      $  4,568

7.   Indirect Costs - Downtime of P/N System:          $    255
TOTAL NET COST PER YEAR:                               $129,222
TOTAL NET COST  PER MONTH;                               $ 10,768
Total Pounds  Disposed  per  Month:                         134,728
     Net  Cost per  Pound  Disposed:                       $      0.08
Total Cubic  Feet Disposed  per Month:                      47,557
     Net  Ccst per  Cubic  Foot Disposed:                  $      0.23
Total Bags and Bag Equivalents:                           24,618
     Net  Cost per  Bag  and  Equivalent:                          0.44

Percent  of Total Net Cost  Attributable  tc Pneumatic System:   54%
Percent  of Total Net Cost  Attributable  to Hand Hauling:       46%
                                -219-

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                                TABLE 38
                              COST ANALYSIS
                 MARTIN LUTHER KING HOSPITAL.  LOS ANGELES
                  PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
      COSTS
            Costs
Total
Construction
Costs
Total
Square
feet
Cost/
Square
Foot
Total
Cubic
Feet
Cost/
Cubic
Foot
         $23,540,000
551,251     $42.70   5,952,520   $3.95
1. Area Costs
        Laundry collector
        Waste collector
        Filter, attenuator,
         and fan room
        Control panel
        Load stations (chute
         rooms), total
        Manholes
             Totals
Square Feet
728
255
1,195
150
1,846
268
4,442
Value € $42.70
$ 31,085
10,889
51,027
6,405
78,824
11,444
§189,675
                                                                   Total
                                         $189,675
2. Volume Costs
                           . Ft..   Volume (g 20"P   Value (3 $3.95
Horizontal
tubes , trash
Horizontal
tubes , linen
Air supply
piping
Vertical chutes
1,400
900
520
560
3,380
3,053
1,962
1,134
1,221
7,370
$12,059
7,750
4,479
4,823
$29,111
                                                                 $ 29,111
                                  ^220-

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                              COST ANALYSIS
                 MARTIN LUTHER KING HOSPITAL, LOS ANGELES
                  PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
                                (Continued)

3. Cost of Pneumatic System - Equipment and Installation          $425,000
   TOTAL CAPITAL INVESTMENT FOR SPACE AND SYSTEM
   TOTAL CAPITAL COST PER YEAR. 7% INTEREST, 20-YEAR LIFE
                                   -221-

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                                   TABLE 39
                                 COST AKlU-YSIS
                          LCTtffiR JKIKG HOSPITAL, LOS AfiGELES
PNEUMATIC SOLJD
                                          TRANSPORT SYSTEM
DIRECT COSTS
Avg. Rate
1. Labor y /fringes
Haul to chute
loading room
& load chutes $3.42
Load compactor
Maintenance,
corrective and
preventive 4.80
Total Labor Costa

2. Bags to Transport Waste
White plastic
Total Supplies Cost
3. Total Utilities (Powrer &

Avg.
Mrs./
Month
534
(no cost -


71
605
No./
Month
16,004
Control)
Awg.
Cost/
Month
•••••••••^^
$1,326
automatic


341
$2,167
Cost/
Month
$392
$392
Hrs . /
Year

6,408
leading)


852
7,2bO
No./
Year
Cost/
Year

$21,915



4,090
$26,005
Cost/
Year
Total
Dollars





$26,005


192,048 $4,700

Cost/Moath
$868

$4,700
Cost/Year
$10,416
$ 4,700
$10,416
     TOTAL DIRECT COSTS
                                                   $41,121
                                     -222-

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                           TABLE  40
                        COST ANALYSIS
           MARTIN LUTHER KING HOSPITAL.  LOS ANGELES
            PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
OF ANNUAL COSTS
  CAPITAL COSTS AMORTIZED;                          $ 77,254

  DIRECT OPERATING COSTS;
       Labor                   $2o,GG5
       Transport Ba&s            4,700
       Utilities                10,416
            Total                                   $ 41,121

  INDI32CT OPERATING COSTS:
       Downtime                                     $    821

  TOTAL COST PER YEAR:                              $119,196

  TOTAL COST PER MONTH;                             $  9,933

  DEDUCTION OF FIXED CHARGES PER YEAR
   ASSIGNED TO LAUNDRY TRANSPORT (44%);
       Capital Costs           $33,992
       Utilities Costs           4,583
       Maintenance Costs         1,800
            Total Deductions                        $ 40,375

  X::T COST PER YEAR FOX WASTE TRANSPORT:            $ 78,821

  ALT COST PER MONTH FOR  'WASTE TRANSPORT;           $  6,568
                              23-

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                      COST ANALYSIS
         MARTIN LUTHER KIKG HOSPITAL. LOS ANGELES
          PNEUMATIC SOLID WASTE TRANSPORT SYSTEM
                        (Continued)

Total Pounds Transported per Month:                67,228
Total Cost per Pound
     of Solid Waste Transported:                  $     0.10

Total Cubic Feet Transported per Month:            30,552
Total Cost per Cubic Foot
     of Solid Waste Transported:                  $     0.22

Total Bags Transported per Month:                  16,004
Total Cost per Bag
     of Solid Waste Transported:                  $     0.41
                          -224-

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                                   TABLE 41
                                COST ANALYSIS

                   MARTIN LUTHER KING HOSPITAL, LUS ANGELES

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
Labor
                 Cost/Hr.  llrs./Mo.  Cost/Mo.  Hrs./Yr.  Cost/Yr.
                                                   Totals
Pick up bags,
 load cart, walk
 to elevator

Elevator t ime,
 including wait-
 ing, loading,
$3.42
332
$1,135    3,984
$13,625
and unloading
Walk from ele-
vator & unload
Total Labor
Bags to Receive
Black plastic
Large clear
Waste liners
Red isolation
3.42
3.42
Costs
and Transport
No. /Month
7,000
15,000
20,000
1,600
73
11
416 $1
Waste
Cost/Month
$ 400
518
240
84
250 876
38 132
,423 4,992
No. /Year
84,000
180,000
240,000
19,200
2,996
451
$17,073
Cost /Year
$ 4,800
6,216
2,880
1,008
                                                                     $17,073
      Total Supplies Costs
             $1,242
                            $14,904
                               $14,904
 Utilities
                                          Cost/Month
                                      Cost/Year
 Elevator power,
  25HP x 0.746 x $0.015
  x 4.8 hrs./day x 7 x 4.33
                           $.41
                              $492
                                   492
                                      -225-

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                                COST ANALYSIS

                   MARTIN LUTHER KING HOSPITAL, LOS ANGELES

                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM

                                 (Continued)
Depreciation o£ Equipment
Elevator,
 @ $60,000, 25-year life,
 used 20Z of the time

Carts,
 8 § $200, 10-year life
Waste baskets,trash containers
 0 $3.50, 5-year life

     Total Depreciation Costs
Coat/Month



   $ 40

     13


    207

   $260
Cost/Year



  $  480

    160


   2,485

  $3,125     $ 3,125

-------
                                COST ANALYSIS
                   MARTIN LUTHER KING HOSPITAL,  LOS ANGELES
                   HAND HAULED SOLID WASTE TRANSPORT SYSTEM
SUMMARY OF ANNUAL COSTS
               Labor                                        $17,073
               Transport Bags                                14,904
               Utilities                                        492
               Depreciation                                   3,125
          TOTAL COST PER YEAR:                              $35,594
          TOTAL COST  PER MONTH:                             $ 2,966
          Total  Pounds  Transported  per Month:                44,253
               Cost  per Pound
                 of  Solid Waste  Transported:                  $     0.07
          Total  Cubic Feet  Transported per  Mcnth:              5,456
               Cost  per Cubic Foot
                 of  Solid Waste  Transported:                  $     0.54
          Total  Cart Trips  per  Month:                            485
               Cost  per Cart Load of Solid  Waste:            $     6.12
               Cost  per Bag Equivalent:                      $     0.38
                                     - ' "> 7—

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TABLE 43

COST ANALYSIS


MARTIN LUTHER KING HOSPITAL, LOS ANGELES
END OF

Avg. Rate
Labor w/Fringes
Load incinerator $3.42
Incinerator ash
removal 3 . 42
Clean compactor
and bin 3.42
Clean compactor
and incinerator
areas 3.42
Maintenance,
compactor and
incinerator 4.80
Total Labor Costs
Off-Site Hauling
Approximately
2 times per week @ $48
Cleaning
Total Hauling Costs
Amortization of Space
Incinerator pad, 20-year life
900 sq. ft. @ $15.50
Loading dock, 20-year life,
600 sq. ft. @ $18.00
Total Amortisation Casts
Pjgr eclat ion of Equipment
Incinerator , 10-year Life
Compactor, 10-year life
Total Depreciation Costs
LINE SOLID WASTE HANDLING
Avg. Avg_.
Hrs./ Cost/ Hrs./
Month Month Year
32 $109 384

«»0 137 480

4? 161 564


21 72 25:


13 62 156
153 $541 1,836


$411
(Included in labor above)
$411

»
$ 38

45
$103

$574
58
£632


Cost/
Year
$1,313

1 , 642

1,929


862


749
$6,492


$4,926

$4,926


$ 698

540
$1,238

$6,890
700
$7,590


Total
Dollars











$ 6,492




$ 4,926





$ 1,238



$ 7,590
  -228-

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                                COST ANALYSIS
                   MARTIN LUTHKR KING HOSPITAL, LOS ANGELES
                       END OF LINK SOLID WASTE HANDLING
                                 (Continued)
                                           Avg.
                                          Cost/              Cost/      Total
Utilities                                 Month              Year     Dollars
Incinerator                                 $16               $192
Compactor                                   	4_                 48
     Total Utilities Costs                  $20               $240     $   240
                                      -229-

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                                   TABLE 44
                                COST  ANALYSIS
                   MARTIN LUTHER KING HOSPITAL,  LOS ANGELES
                       END CF LINE  SOLID WASTE HANDLING
SUMMARY OF ANNUAL COSTS
               Labor                                        $  6,492
               Off-Site hauling                                4,926
               Space                                           1,238
               Equipment                                       7,590
               Utilities                                         240
          TOTAL COST PER YEAR                                $ 20,486
          TOTAL COST PER MONTH                              $  1,707
          Total Incoming Pounds  Handled  per  Month             111,480
               Cost per Incoming Pound  Handled:              $      0.02

          Total Incoming Cubic Feet  Handled  per  Month:         36,008
               Cost per Incoming Cubic  Feet  Handled:         $      0.05

          Total Bags and Bag Equivalents Handled per  Month:   23,763
               Cost per Bag and  Equivalent:                  $      0.07
                                     -230-

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                              TABLE 45
                           COST ANALYSIS
              MARTIN LUTHEK KING HOSPITAL. LOS ANGELES
            SUMMARY OF TOTAL HOSPITAL SOLID WASTE COSTS

                                                       Per Annum
1.   Labor:
          Pneumatic System        $26,005
          Hand Hauled System       17,073
          Find of Line System        6,492
               Total              $49,570
          Less Laundry % of
          P/N Maintenance  (44,")     1,800
               Net  Labor Cost                          $  47,770

2.   Transport bags:
          Pneumatic System         $ 4,700
           Hand Hauled  System        14,904
               Total Transport Bag  Cost                $  19,604

3.   Capital  Costs:
           P/N System & Space       $77,254
           End of Line  Space         1,238
                Total              $78,492
           Less Laundry % of
           P/N Capital  (44%)        33,992
                Net Capital Cost                        $ 44,500

4    Depreciation of Equipment:
           Hand Hauled System      $  3,125
           End of Line System         7,590
                Total Depreciation                      $ 10,715

 5.   Off-Site Hauling Contract:                        $  4,926
                                 -231-

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                           COST  ANALYSIS
              MARTIN LUTHER KING HOSPITAL,  LOS ANGELES
            SUMMARY OF TOTAL HOSPITAL SOLID WASTE COSTS
                            (Continued)
6.   Utilities:
                                                       Per Annum
          Pneumatic System        $10,416
          Hand Hauled System          49.2
          End of Line Systen          240
               Total              311,148
          Less Laundry % of
          P/N Utilities (44%)       4.583
               Net Utilities Cost                      $  6,565

7.   Indirect Costs - Downtime of P/N System;          $    821
TOTAL NET COST PER YfcAJR;                               $134,901
TOTAL NET COST PER MONTH:                              $  11,242
Total Pounds Disposed per Mouth                          111,480
     Net Cost per Pound Disposed:                       $      0.10
Total Cubic Feet Disposed per Month:                      36,008
     Net Cost per Cubic Foot Disposed:                  $      0.31
Total Bags and Bag Equivalents:                           23,763
     Net Cost per Bag and Equivalent:                   $      0.47

Percent of Total Net Cost Attributable to Pneumatic  System:   68%
Percent of Total Net Cost Attributable to Hand  Hauling:       32%
                               -232-

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                         !:- ECONOMIC FEASIBILITY OF
                   PNEUMATIC SOLID WASTE TRANSPORT SYSTEMS

     The term economic feasibility infers a comparison between available meth-
ods.  To be feasible, a system must save labor or money over alternative ways
of performing the same task; over a given time period the investment in the
system, combined with the direct and indirect operating costs, must be self
liquidating from the dollars that are saved.  while other systems are possible
(and are available) for solid waste transport, the basic comparison that should
first be made is against hand hauling, involving carts, hallways, and elevators
to move the waste, as this is the most common method used in hospitals.  The
basic determination must be made as t.o whether installation of the automated
system saves hand labor and to what degree.
     In reviewing the figures from  the previous chapters, it can be seen that
all  three hospitals transport waste by both  the pneumatic system and by hand
carts, and in varying proportions,  depending on their management system.   In
each hospital the hand hauled waste  is transported at a lower cost per pound
than the pneumatically transported  material.  The differences on a per cubic
foot or volume  basis are not as  clear cut,  varying from lower in cost  to higher
for  the carted  material.
     Comparisons of costs by weight  are  more valid than by  cube, as the bulk.
of  the hand  carted material consists  of  empty cartons with  extremely  large
bulk.  If  they  were slit or compressed on  the floors  to bring cube and weight
to  relatively the same ratio as  the pneumatically  transported wastes,  compari-
sons on a  cube  basis would be more  realistic.

               TABLE 46                CQS1  OF TRANSPORTING  WASTE



ITEM
Avg. pounds/day
$ cost per pound
Avg. cubic feet/day
$ cost per cu. ft.
ST. MARY'S
DULUTH
PNEUMATIC tlAND
TUBE CART ED
882 1,391
0.13 0.06
382 185
0.30 0.41
V . A . MART IN LUTHER KING
SAN DIEGO LOS ANGELES
PNEUMATIC HAND PNEUMATIC HAND
TUBE CARTED TUBE CARTED
1,115 3,330 2,218 1,460
0.15 0.03 0.10 0.07
557 1,018 1,008 180
0.30 0.09 0.22 0.54
                                       33-

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     Several factors contribute to the higher cost per pound for the waste
transported by the pneumatic systera.
     The first, and most obvious, is  the high net cost of the space occupied
and the installed price of the pneumatic system equipment and its necessary
utility lines.  With total installed  costs amortized from $36,548 to $77,254
per year, the annual use percentage devoted to solid waste transport amortizes
from $7,310 to $32,591 to $43,262 for the three hospitals.
     Secondly, while these are automated systems, they are not completely auto-
matic.  They require labor to load and, in one case, unload the system.  They
also require extensive labor for preventive and corrective maintenance.  These
labor factors require supervision and they involve other overhead, including
fringe benefits.
     Thirdly, each pneumatic system involves the cost of purchasing special
bags to transport the waste, and the  cost of utilities to supply power and run
control circuits.  Should they be "down" for maintenance work, they incur extra
costs to transport waste by other methods.
     Added  together, all these costs  directly attributable to the pneumatic
systems range from $41,383 to $60,629 to $78,821 per year for the three hospi-
tals.
     Figuring an average wage for a "typical" waste handler in a hospital at
$3.30 per hour, with fringes and overhead (or an average of $6,900 per year in
1973), the pneumatic system installed and operating annual costs for waste trans-
port alone  are the equivalent of the  wages  of from 6 to 8.7  to 11.4 full time
positions for manual waste handling in the three hospitals.   To these must be
added the costs of the proportion of  waste that is manually transported.
     To determine the legitimate economic feasibility of  the  three systems, it
is necessary to determine whether each can save what proportion of this labor
p«r year.
     The percent of total cost of solid waste transport attributable to the
pneumatic system varied from 54  to 68 percent, yet  the percent of  the  total
weight handled by the systems ranged from only 25 percent  to  a high of 60 per-
cent.  Assuming a hospital elects to use an automated pneumatic  transport sys-
tem, then it must do so to the point where virtually no waste is  transported
                                     -234-

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outside the system.  No hospital, no matter how large, can justify automation
(at the installed costs of the past five years) unless it is used to the maxi-
mum extent possible.
     All three survey hospitals had low utilization rates.  All felt that this
is caused by limitations in the system.  Basically this comes down to the load-
ing patterns and methods they had developed.  The reasons for these do not ap-
pear completely valid.
     Research by the survey team in other institutions with similar systems
has revealed that all waste of all types can be sent  through a pneumatic sys-
tem with virtually  no breakage problems, or plugging  of the system, if the
system is designed  and  installed correctly; if the unit loads are properly
assembled and sized; if the transport  bags are purchased  to adequate specifi-
cations.
     From a review  of the make-up of  the waste transported by hand, it is seen
that the bulk of it is  toe  large to enter the  pneumatic system.  This situation
applies  to a large  percentage  of the  over 75 hospitals  that have installed
pneumatic tubes  for waste  transport.   Very  few have  installed portable volume
reduction and compacting equipment on the floors  (ahead of the chute stations)
to eliminate this  problem.  There  appears no valid  reason for  this  situation
to continue.
     Assuming each  of  the  three  surveyed  hospitals  elected to  send  all its
wastes  through  the  pneumatic  system,  and  to  spend the necessary  additional
labor  or equipment  dollars  for floor  volume  reduction to  achieve this,  the
cost  figures  for transport  that  were  developed in the previous chapter would
be considerably reduced.
      The high  capital  cost  for space  and  the installed equipment would now  be
spread  over  four times  the  total weight of  waste  at V.A.  Hospital;  almost  three
times  at St. Mary's; and a 40 percent increase at Martin  Luther King.  This
would  obviously considerably  reduce  the cost per  pound from the  fixed charges.
Utility  costs  and  downtime  coats,  based on.  the way the systems are  operated,
would  remain  about the same as they  are for the  present  partial  utilization.
Maintenance  labor  would also  remain  as a  constant.   Operating  labor would  rise
at a  different  rate in each hospital, due to the  differences in  the systems and
                                      -235-

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chute loading methods.   Transport  bags  would rise virtually in proportion
to the added waste being transported  through the system.   The following figures
reveal these revised costs:
                                       ST.  MARY'S    V.A.       MARTIN
                                         DULUTH    SAN DIEGO  LUTHER KING
Lbs. total waste transported/month       68,894     134,728     111,480
     MONTHLY COSTS
Capital cost, net                           609       2,716       3,605
Labor, operating, and maintenance          2,828       1,831       2,381
Transport bags                            2,660         782         470
Utilities                                   102         258         486
Downtime                                     21         176          68
     TOTAL MONTHLY COSTS                  6,220       5,763       7,010
     COST PER POUND                        0.09        0.04        0.06

 It will be seen that these figures approach the per pound costs presently being
 incurred in each hospital for hand carting wastes.
     In addition, each of the three hospitals Is underloading  the waste  trans-
 port bags by almost 60 percent on a weight basis.  Further,  if the bags  were
 actually mechanically sized and compacted before chute loading, bag costs and
 chute  loading costs could be reduced by up to 75 percent in  two of the hospi-
 tals including amortizing the cost of the floor compactors.  These changes would
 mean monthly savings to the three hospitals and per pound transport costs as follows:
                                      NET SAVINGS  REVISED MONTHLY    TRANSPORT
                                       PER MONTH      COST,  NET	COST PER LB.
 St. Mary's  Hospital                      $1,993          $4,227         0.061
 Veterans Administration Hospital            701           5,062         0.037
 Martin Luther King Hospital                 654           6,356         0.057

 In the case of St. Mary's and the Veterans Administration,  these  figures are
 only slightly higher than their present  per  pound  costs  for  hand  carting wastes;
 in the case of Martin Luther King,  the figure is  lower.
      If  all the wastes had  to be hand transported, would the costs compare  to,
                                     -236-

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be lower, or exceed the costs attainable from using the pneumatic system to
the full extent?  The revised pneumatic system costs are the equivalent of
7.3 full time positions in St. Mary's, 8.8 at the Veterans Administration, and
10.4 at Martin Luther King.   Table  47 shows  costs  for  hand  hauling  all  waste.
     Reviewing all the generation points of waste at each of the three hospi-
tals; the. weights and volumes generated; the hours of  the day and frequency
that transport must take place to equal the efficiency of removal of the
pneumatic system; and the  equipment that must be used; the cost figures shown
on the  following page would result  from a complete hand transport system, using
hallways and elevators, in each  of  the three surveyed  hospitals.
     Once the basis for comparison  has been established in  this matter, it is
then possible to finally establish  the differences in  cost between  transport-
ing waste pneumatically and  transporting waste completely by hand.  These cost
differences are  then  true  monthly or  annual  savings as a result  of  installing
the pneumatic system.  Table 48 on page. 240 shows these differences  and  hence
savings, as a result  of  installing  a  pneumatic system  in each of  the three hos-
pitals, but with two  major differences from  the  way  the systems  are currently
I/eing  utilized.   The  first figures  show the  operating  costs and  savings of the
pneumatic  system utilized  to the full extent,  transporting  all waste in the
building with  none being hand hauled.  The second  group of  figures  shows  the
costs  reduced  even further and the  savings consequently  increased by loading
each  transport  bag to the fullest extent in  order  to reduce the  number of bags
and  hence  the  chute loading and waiting time labor,  as well as  the cost of
 transport  bags.
      Despite  these impressive annual  savings as a result  of full utilization
 of the chute  system,  only in the case of the second alternate method can a
 recapture  of  investment be obtained.   In the case of  St.  Mary's, the time
 period of  5-3/4 years shows that their system could be feasible from an econ-
 omic standpoint.  In the case of the V.A. Hospital and Martin Luther King,
 with payoffs as long as 49 and 58 years respectively, the time period to re-
 capture, the investment at 7 percent  interest is so extensive that  in all prob-
 ability the system would be worn out halfway through  the investment life.
      It should be noted that if no interest  were charged on the investment,
                                      -237-

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                                                     TABLE  47

                                               ECONOMIC FEASIBILITY

                                MONTHLY COST TO HAND HAUL ALL HOSPITAL  SOLID WASTE
                                                              ST. MARY'S
                                                               HOSPITAL
  V.A.
HOSPITAL
M. L. KING
 HOSPITAL

Avg. no. of cart trips (to equal floor clearing (§
hourly rate of present pneumatic system)
1. LABOR;
Empty waste containers, load carts, walk to
elevator, elevator time (including waiting),
walk to compactor, load compactor, return to
elevator, elevator time (including waiting),
walk to next pick-up point
2. BAGS TO RECEIVE AND TRANSPORT WASTE:
3. UTILITIES:
Elevator power, 25HP x 0.746 x $0.015
x hours used per month
4. DEPRECIATION OF EQUIPMENT:
Elevator @ $60,000, 25-year life,
x period used
Carts, 10-year life
Trash containers, 5-year life
Total costs per month
Number of pounds per month
Cost per pound

121
Hrs/Mo Cost/Mo
1,359 $4,340
Cost/Mo
$1,644
114
173
9
73
$6,358
68,894
0.09

170
Hrs/Mo Cost/Mo
1,355 $4,525
Co at /Mo
$2,162
188
258
24
211
$7,368
134,728
0.05

180
Hrs/Mo Cost/Mo
1,871 $6,225
Cost /Mo
$1,634
143
226
39
207
$8,474
111,480
0.08
N.
Ou
oo

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recapturing of investment could take place in under 20 years.   However,  in
today's money market it is felt that this is an unreasonable approach from an
accounting practice and that such capital investments should be amortized at
least at 7 percent interest, when the prime rate has risen to 10 percent.
     A review of amortization investment tables   reveals an interesting fact.
It clearly shows the upper limits of capital investment that can be made in
the equipment and the occupied space for automated systems in any hospital.
factored against varying amounts of savings per year.
     If savings of $26,000 per year are to be realized from the installation
of a system and a 7 percent interest rate is used for amortizing the equipment
and occupied space, the maximum capital investment  cannot exceed $270,000 if
the investment is to be recaptured within 20 years through savings.  If the
realized savings fall to $18,000 per year, the upper  limit on a capital in-
vestment,with 7 percent interest for the money, falls  to $170,000 if the in-
vestment is to be amortized within  this same 20 year  period.
     This  clearly indicates that not only do pneumatic waste handling systems
have to be utilized for both waste  and  laundry handling  (regardless of  the de-
sign of the system) but that they must  be utilized to the fullest, possible ex-
tent in order to save maximum  labor; and most  important that to be  economi-
cally  feasible the upper  limits  of  investment  in  equipment  and  space  are  much
lower  than hospitals have  been expending  in  installing such  systems.  Whether
the desired operational  results  can be  achieved under the inflationary  condi-
tions  of  1974 through  pneumatic  transport  systems costing much  less than those
that have  been installed  so far  remains to  be  seen.   Probably  increased vendor
competition,  better designs,  better hospital management  practices,  and  improved
system construction will achieve these  results during the coming  years.  It
would  appear  that  unless  these goals are achieved such systems  will be  one
more example  of  adding to increased hospital costs without  proven economic
feasibility.
                                      -239-

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                                                      TABLE 48
t-
o
ECONOMIC FEASIBILITY
OF THE PNEUMATIC TRANSPORT SYSTEMS

1.
2.
3.
4.
5.
6.
7.
8.

9.



Monthly costs with full utilization
of the pneumatic system
Revised monthly costs by maximum
reduction of bags transported
Monthly costs of hand transporting
total waste output
Monthly savings - line 1 over line 3
Annual savings - line 1 over line 3
Monthly savings - line 2 over line 3
Annual savings - 1 ine 2 over line 3
Revised proportion of capital system
investment for waste under full
utilization
Years to recapture waste use proportion
of amortized capital investment in the
pneumatic system; @ 7% interest.
through savings line 1 /line 3
through savings line 2 /line 3
ST. MARY'S
HOSPITAL
$6,220
4,227
6 , 358
138
1,656
2,131
25,572

118,780

infinity
5-3/4
V.A.
HOSPITAL
$5,763
5,062
7,368
1,605
19,200
2,306
27,672

419,195

infinity
49
M. L. KING
HOSPITAL
$7,010
6,356
8,474
1,464
17,568
2,118
25,416

392,709

infinity
58

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                 12 . SYSTEM RATINGS AND COMPARATIVE ANALYSES

     The principal automated systems to which a pneumatic tube transport system
may be compared are:
     1.)  Selective, vertical-horizortal conveyor systems with tote boxes moving
          the waste.
     2.)  Automated cart systems, either run from an overhead rail, or from a
          strip or guide in the flocr or adjacent baseboard.
     3.)  Wet pulping systems in which the waste is ground, mixed with water,
          and pumped through relatively small tubes to an extractor where ap-
          proximately 50 percent of the water Is removed.  The damp pulp residue
          is then  further handled.
     4.)  Grinding systems  (the typical home kitchen-type disposal) in which the
          waste  is ground and dumped directly into the sewer system from point
          of generation.  (These may be installed throughout all sections of the
          building, or merely zoned in  the  lower  levels and  the waste moved to
          the  zone receiver by manual  horizontal  methods combined,  [or not combined]
          with gravity chutes.)
     5.)  Other  pneumatic waste systems.  In  this study, all  three systems are of
          a different type:   (a)  full  vacuum,  single bag loading;  (b) full vacuum,
          multiple bag loading; and  (c) gravity  to vacuum,  multiple bag  loading.
     In addition,  comparisons must be  made  with  the more conventional or  "hand
 removal"  systems,  either hand movement by cart  for both  horizontal and vertical
 transfer, or the combinations of  hand  horizontal movement  on the floors  with
 gravity chutes handling the vertical movement,  coupled with hand movement at the
 bottom of  the  gravity chutes  to a  central collection point.
     Due  to  the  very few hospitals  that use automated methods other  than pneumatic
 tube systems,  it was determined  that,  the  comparative analyses in this study  should
 be limited  to:
     a.)   Comparisons and ratings  between  the three  types  of pneumatic  tube  sys-
           tems themselves,  and
     b.)   Comparisons between the pneumatic tube systems and the hand transport
                                     -241-

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systems that most (over 98 percent)  of  American hospitals employ.
     In a study of  this type,  the final desired result is to assist architects,
engineers, consultants, and users in selecting the "best" system for a partic-
ular project that may arise in the future.   In short, to develop guidelines
and "rate" such systems from several denominators.
     In the Technical and Economic Analysis,  we have identified many problems
in solid waste management in general, and in pneumatic transport systems in
particular.  These range from architectural,  design, mechanical, and opera- .
tioUal deficiencies of the structure and physical equipment, to human opera-
tional, maintenance, and training problems, through problems in cost justifi-
cation and economic feasibility.   We have identified many environmental prob-
lems that affect the health and safety of the hospital personnel and possibly
of the community.
     In most previous comparative ratings of solid waste management systems,
primary emphasis has been placed on economic considerations.  These ratings
usually compare systems based only upon how much the equipment costs to pur-
chase, install, operate, and maintain.  While economic considerations are  im-
portant to hospital administrations, particularly in these days of rising
costs, systems economics is only part of the picture.
     Equally important are the improved environmental factors to be attained
by both the hospital and the community.  The spread of aerosols, atmospheric
cross  contamination, and other pollution, are reduced or increased in varying
degrees by each different system.  Fire and other safety hazards are reduced
or increased depending on the equipment used and how  it operates.
     A major purpose for automating solid waste management  is to reduce  the
spread of infection, accidents, and illnesses, thus providing advantages  to
patients, staff, and visitors.  There are certain esthetic  advantages which
may  be attained by  reason of  improved sanitation  and  a reduction in the  number
of sometimes noisy  waste carts moving through  the corridors.  These consider-
ations must also be taken  into account  in rating  different  systems and  their
success  in achieving these goals, since  the higher  cost  to  achieve  them  may
the® be  justifiable.
      In  comparing  the  available  pneumatic  systems,  it is essential  to break

-------
down the comparable elements oi  importance to the following:
     Economics
          Total capital costs
          Total direct costs
          Total indirect costs
          Cost per pound transported
          Cost per cubic foot
           transported
          Cost per bag transported
     Technical Design
          Ease and safety of  loading
          Qualifications required di
           loading personnel
          Speed of loading  and
           clearing  floors
          Strength and size of
           chutes and  tubes
          Completeness and  interfacing
           of  components
Environmeiital Acceptability
     Sound levels
     Odor levels
     Bacterial contamination
     Housekeeping practices
User Acceptability
Safety
     Physical hazards
     Fire hazards
     Contamination hazards
Reliabilit>
     Machinery
     Personnel
Maintainability
     Corrective  maintenance
     Preventive  maintenance  and
       inspections
 Flexibility  for  Modification
 Potential for Expansion
      Comparisons between systems must  be based on both qualitative and  quanti-
 tative  factors.   Some are arrived at by value judgements and qualified  obser-
 vations;  some by value judgements of the results of interviews with hospital
 personnel;  some by hard engineering data and physical measurements.  Others
 are based on actual audits of labor expended, of equipment and other costs,
 and by  physical testing.
      The  pneumatic transport systems of the three survey hospitals were com-
 pared against one another on an element by element basis.  A combined numeri-
 cal and narrative rating was assigned each element.  Under this, a system was
 judged  "best," "next best," or "least best" for that element.  The "best" sys-
 tem element was assigned a rating of 3, the "next best" a rating of 2,  and the
 "least  best" a rating of 1.  For example, in the element of economics,  the
 system with the lowest cost per pcund to transport solid waste by pneumatic

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tube was rated 3, the system with the highest cost was rated 1, and the re-
maining system was rated 2.   In the event two or more systems were judged to
be equal, they were assigned the same rating number and then the next lower
number was omitted from the ratings.  For example, if systems A and B were
equally low in cost, they both would be given a rating of 3 and the remaining
system a rating of 1.  This same rationale was followed for the other elements
of importance.
     The matrix on the following pages presents the results of the solid waste
transport systems comparisons.
                                     -244-

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                                       PNEUMATIC SYSTEMS COMPARISON MATRIX
i
^
.t-

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          OF
  IMPORTANCE
        HOSPIT2AL
     MARTIN
     KING
       ST. MARY'S
        HOSPITAL
.TECHNICAL
DESIGN  (Cont.)
Qualifications
 required of
 loading
 personnel

Speed of
 loading and
 clearing
 floors
Strength and
 si/;e of
 chutes and
 tubes
Completeness
 and inter-
 facing of
 components
Training critical due to
operation of diverter
valves.  Uses special
personnel.
       Rating 1
Requires 462 hours per
month to clear floors
and load chutes.  Time
to clear floors far ex-
ceeds loading time.
1.66 minutes per cubic
foot to clear floors
and load.
       Hating 2

Chute aad tube diameter
16", 20-igauge metal.
This is borderline as a
minimum diameter and
wall thickness.

       Rating 1
System is enclosed and
complete with air gap at
compactor,  which dis-
charges directly into a
large bin for hauling.
Bin relatively accessible
for truck pick-up.
Value judgement rating 2
Systeir  capable  of  com-
plete random  loading
without operator train-
ing.
        Rating  3
Requires 534  hours per
month to clear  floors
and load chutes.  Time
to clear floors far ex-
ceeds loading time.
1.05 minutes per cubic
foot to clear floors
and load.
       Rating 3
Tube diameter 20", 14-
gauge in vertical grav-
ity chutes.  Horizontal
vacuum tubes 20" dia-
meter, 3/16" wall thick-
ness .
       .Rating 3

System is enclosed and
complete through compac-
tor, which discharges
directly into a large
bin for hauling.  Bin
easily accessible to
truck.
Value judgement rating 3
Minimal training mostly
concerned with type
waste authorized and
size of chute.
        Rating 2
Requires 441 hours per
month to clear floors
and load chutes.  Time
to clear floors slightly
less than loading time.
2.29 minutes per cubic
foot to clear floors
and load.
        Rating 1
Chute and tube diameter
Ib", 20-gauge metal.
This is border lint; as a
minimum diameter and
wall thickness.

        Rating 1
System is enclosed only
to collector, then hand
hauled outside to com-
pactor,  which is located
at an undersized loading
dock.

Value judgement  rating 1

-------
            ELEMENT OF
            IMPORTANCE
          V.A.
        HOSPITAL
      MARTIN LUTHER
      KING HOSPITAL
        ST.  MARY'S
         HOSPITAL
i
h.
          TECHNICAL
          DESIGN  (Cent.)

          Efficiency of
           fan & filter
           installation
          Et fic iency  uf
           control
           circultrv
Excellent design of posi-
tive displacement single
fan with well engineered
vibration pad.  2 micron
Rollomatic filter to pro-
tect fan and prevent es-
cape of organisms in the
exhaust air.  Well en-
gineered safety system
to prevent fan damage due
to high vacuum caused by
tube plugging.
       Rat ing 3

Control panel located in
interstitullar space and
difficult to reach quick-
ly in emergency.   No
trouble shooting  panel
in Engineer's office.
       Rating 1
 Excellent  design of  posi-
 tive  displacement dual
 fans  together  with aux-
 iliary  fan to  maintain
 negative pressure in
 chutes.  Cycling of  fans
 to ensure  maximum per-
 formance.   Well  engineer-
 ed vibration pads.   2
 micron  bag filter to pro-
 tect  fan and prevent es-
 cape  of organisms  in ex-
 haust air.  Well  engi-
 neered  safety  system to
 prevent high vacuum
        Rating  3

 Excellent  trouble  shoot-
 ing and control panel in-
 stalled in  fan room.
 However, no monitoring
panel in Chief Engineer's
office.
       Rating  3
 Fan  is open materials
 handling  type.  Vibration
 mounting  and  fan  to  motor
 coupling  is border line,
 No pre or post fan filter
 to protect either fan
 blades or the environ-
 ment.  High vacuum safety
 system is slow acting.
 Motor mount damage al-
 ready experienced due to
 fan blade imbalance.
        Rating 1

Vendor circuitry was over-
simplified.  Hospital en-
gineer developed and lo-
cated in main engineering
office an excellent con-
trol and monitoring panel.
        Rating 3
          Total  rating
           points
                                     21
                                      10

-------
            ELEMENT OF
            IMPORTANCE
                         V.A.
                       HOSPITAL
      MARTIN LUTHER
      KING  HOSPITAL
       ST. MARY'S
        HOSPITAL
i
I-J
ENVIRONMENTAL
ACCEPTABILITY
Sound levels    Predominantly low fre-
                quency sound.  Average
                maximums ranged from 68-
                77 dB(A) with overall
                average of 65 dB(A) in
                corridors.  Maximum aver-
                age sound in system was
                inside fan room at
                95 dBU).
                       Rating 1
Odor levels     Strongest odor at collec-
                tor.  One load station
                had Code 4 odor.   93£ of
                all locations had Code 3
                or leas.

                       Rating 2

Bacteriological No pathogenic bacteria
 contamination  were found inside the
                hospital.
                       Rating 3
         Housekeeping
          practices
                Many cross-over problems.
                Ruptured bags,  loose
                trash.
                         Value judgement rating 2
 Predominantly  low  fre-
 quency  sound.   Average
 maximums  ranged from  59-
 63 dB(A)  with  overall
 average of  60  dB(A) in
 corridors.   Maximum aver-
 age  sound in system was
 inside  collector/compactor
 rooc at 98  dB(A).
        Rating  3
 Strongest odor  at  collec-
 tor.  One load  station
 had  Code  4  odor.   86% of
 all  locations  had  Code 3
 oe less.  Cede  4 odor
 close to  private property,
        Rating  1

 Pathogens were  observed
 but  were  well  below dan-
 ger  level.
        Rating  3

 Bag  breakage on slide
 valve,  which had not  been
 properly  cleaned.  Evi-
dence of unauthorized and
unsanitary waste in
system.
Value judgement rating 2
Predominantly low  fre-
quency sound.  Average
ruaximums ranged from 60-
69 dB(A) with overall
average of 62 dB(A) in
corridors.  Maximum aver-
age sound in system was
inside fan room at
104 dB(A).
        Rating 2
Strongest odor at  com-
pactor.  No load station
had Code 4 odor.   93% of
all locations had  Code 3
or less.

        Rating 3
No hazardous bacteria
were found.

        Rating 3

No broken bags,  litter,
dust observed.   Bag
breakage solved  by use
of nylon bags.
                                                                      Value judgement rating 3
         Total rating
          points
                                                                                 11

-------
            ELEMENT  OF
            IMPORTANCE
                         V.A.
                       HOSPITAL
                                MARTIN  LUTHER
                                KING  HOSPITAL
        ST. MARY'S
         HOSPITAL
          USER
          ACCEPTABILITY
ro
-C-
Total rating
 points

SAFETY

Physical
 hazards
         Fire hazards
                25.1% of total waste
                moved by tube.  Trust-
                ability factor low.  Di-
                verter valve and person-
                nel problems cause laun-
                dry to go to compactor,
                waste to laundry room.
                Many of staff feel they
                are serving the system
                rather than the system
                serving thera.
                Value judgement rating 1
Hazardous condition in
key lock loading due to
vacuum pull on chute
door.  No unsafe or haz-
ardous conditions for
maintenance staff except
high noise level in fan
room.
Value judgement rating 1

Meets NFPA Code for tube
size.  Has fusible link
fire dampers but these
occasionally cause bag
ripping.   No indication
of fire in system.
                           60.3% of  total waste
                           moved by  tube.  Trust-
                           ability factor high.
                           Loading is relatively
                           easy and  fast, causes
                           few problems.  Staff
                           generally was pleased
                           with system.
 38.8% of  total waste
 moved by  tube.   Trust-
 ability factor medium.
 System slow,  requires
 much waiting  to  load.
 Many of staff feel  they
 could clear floors  faster
 by hand.   Some staff also
 feel tube  too small.
                                                    Value judgement rating 3   Value judgement rating 2
                                                    Possible hazardous con-
                                                    dition exists for main-
                                                    tenance staff in slide
                                                    valve rooms.  High noise
                                                    level in fan room.  No
                                                    unsafe consitions for
                                                    operating staff.
No unsafe or hazardous
conditions for operating
or maintenance staff ex-
cept high noise level in
fan room.
                                                    Value judgement rating 2   Value judgement rating 3
                         Value judgement rating 2
                                           Exceeds  NFPA Code for
                                           tube  size.   Has  fusible
                                           link  fire dampers but
                                           these occasionally cause
                                           bag ripping.   No indica-
                                           tion  of  fire in  system.
                                           No hopper in load chute
                                           might contribute to chute
                                           fires as could trash on
                                           slide valve.
                                           Value judgement  rating  3
Meets NFPA Code for tube
size.  Has fusible link
fire dampers but these
occasionally cause bag
ripping.  No indication
of fire in system.  Fan
room is marginal due to
lint conditions.
                                                      Value judgement  rating 1

-------
           ELEMENT  OF
           IMPORTANCE
         V.A.
       HOSPITAL
     MARTIN LUTHER
     KING HOSPITAL
       ST. MARY'S
        HOSPITAL
         SAFETY  (Cont.)
         Contamination
         hazards  to
         patients and
         staff
Only non-pathogenic fo-
mites were found inside
hospital.
                        Value judgement rating 3
Small colony of krebsi-
ella found on laundry
floor.  Not considered
hazardous to patients or
staff.
Value judgement rating 3
Only non-pathogenic  fo-
mites were found inside
hospital.
                                                      Value judgement rating 3
        Total rating
         points
        RELIABILITY

        Machinery
Ul
O
I
Shutdowns tor as long as
30 days occurred.  Many
problems with diverter
valves which required in-
stallation of new valves.
Original square  collec-
tor required replacement
to reduce bag breakage.
Travel timers required
replacement several times.
No serious problems with
electrical or hydraulic
systems.  Quick acting
relief valve ahead of fan
operates efficiently.
Highest amount of down-
time of all three systems
Waste bin under collec-
tor, not supplied by sys-
tem vendor, has sloping
sides which tend to
bridge and slow the drop
to the compactor.  Air
valves and loading chute
door locks have required
occasional replacement.
Filter ahead of fan most
sophisticated of all
three, giving 100% pro-
tection.  No serious
problems with electrical
or hydraulic systems.
Lowest amount of down-
time.
                        Value judgement rating 1   Value judgement rating 3
Originally had excessive
vacuum and vibration due
to bag plugs.  Caused
damage to tubes, fittings,
and mounting hangers.  Ex-
perienced tube collapses
and eeam ruptures.  20-
gauge metal in bends and
tube is on light side.
Lack of filter ahead of
fan has caused an un-
balanced condition and
vibration sufficient to
crack fan motor base.
Originally had freezing
weather problems with
roof dampers.  Corrected
by air drying units.  No
serious problems with
electrical or hydraulic
systems.   Relief valve
ahead of  fan least so-
phisticated  Relatively
low amount of downtime.
Value judgement rating 2

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            ELEMENTS OF
            IMPORTANCE
                         V.A.
                       HOSPITAL
      MARTIN  LUTHER
      KING  HOSPITAL
        ST. MARY'S
         HOSPITAL
          RELIABILITY  (Cent.)
          Personnel
                Has experienced plugging
                from improper loading.
                This should be easy to
                control since only desig-
                nated people load chutes.
                Has experienced cross-
                over problems but this is
                due mostly to faulty di-
                verters rather than per-
                sonnel.
                Value judgement rating 1
Has experienced  plugging
from  improper  loading.
This  should be easy  tc
control  since  only desig-
nated people load chutes.
Has experienced  cross-
over  problems  due 100% to
operator carelessness.
 Has  experienced  plugging
 from improper  loading.
 This is difficult  to  con-
 trol since many  people
 load chutes.   Has  experi-
 enced cross-over problems
 due  100% to operator
 carelessness.
                                                     Value judgement rating 3   Value judgement rating
i
r .j
Total rating
 points

MAINTAINABILITY

Corrective
 train tenance
                          Highest amount of  correc-
                          tive maintenance required
                          on this single tube sys-
                          tem (454 hours yearly
                          average).   Most of this
                          was devoted to replace-
                          ment of system components
                          such as collectors and
                          diverters  to decrease
                          number of  bags breaking
                          and system plug ups.
Least amount of correc-
tive maintenance required
on this heavy wall two-
tube system (171 hours
yearly average).  Bulk of
this was devoted to cor-
recting situations in
linen collector room and
valve rooms where vacuum
pulled plaster from
walls due to inadequate
venting.
                          Value  judgement  rating  1    Value  judgement  rating  3
Very close to highest
amount ot corrective main-
tenance required on this
light wall two-tube system
(424 hours yearly average).
Most of this devoted to
correcting damage to tubes,
fittings, and hangers
caused by high vacuum and
excessive vibration.  Most
problems due to plug ups
resulting in replacement
of collapsed tubes and
riveting ruptured seams.
Value judgement rating 2

-------
           ELEMENT OF
           IMPORTANCE
                         V.A.
                       HOSPITAL
     MARTIN LUTHEF
     KING HOSPITAL
        ST. MARY'S
         HOSPITAL
i
r _
         MAINTAINABILITY  (Cont.)
         Preventive
          maintenance
          and
          inspections
Total rating
 points
         FLEXIBILITY
         FOR
         MODIFICATION
                Devotes yearly average of
                813 total hours for pre-
                ventive maintenance and
                inspections combined.
                Part of a man's full time
                is assigned on call to
                continuously check system
                operation.  Most preven-
                tive maintenance devoted
                tc lubrication, clean and
                changing filters,  clean-
                ing compactor.
                VaJue judgement rating 1
Devotes yearly average of
240 hours to preventive
maintenance and 441 hours
to inspections, or 681
total hours to this cata-
gory.  Most preventive
maintenance spent on lub-
rication, cleaning fil-
ters, cleaning compactor.
Devotes  yearly average of
284 hours  for preventive
maintenance and none  tc
inspection of the  system.
Most preventive mainten-
ance spent on lubrication,
cleaning dust from fan
blades,  and cleaning  lint
screens.
                                                    Value judgement rating 3   Value judgement rating 2
                The prime modification
                here could be the addi-
                tion of automated "end
                of the line" equipment.
                Hospital is presently
                modifying its system to
                add a general purpose
                incinerator.
This system could be
modified for automated
"end of the line" equip-
ment.  Are currently
considering reduction
equipment to replace
compactor.
                         Value  judgement  rating 2   Value judgement  rating 3
This system should have a
direct loading arrangement
from the collector to the
compactor to avoid possi-
ble contamination prob-
lems and to save labor.
Because of hospital limit-
ed dock facilities, will
require additional struc-
tural changes.
Value judgement rating 1
         Total rating
          points

-------
  ELEMENT OF
  IMPORTANCE
         V.A.
       HOSPITAL
     MARTIN LUTHER
     KING HOSPITAL
       ST. MARY'S
        HOSPITAL
POTENTIAL FOR
EXPANSION
Total rating
 points
Not only must all expan-
sion piping be under a
vacuum to expand this
system, with much higher
fan and filter capacity,
but the electrics and
control system of a sin-
gle tube system are the
most complex of all
systems.
                Value judgement rating 1
A gravity to vacuum sys-
tem is basically simpler
to expand than others.
If a wing is added to the
hospital, a relatively
simple vertical chute
could be added in the new
wing with a single hori-
zontal tube under vacuum
running to it.  Addition-
al fan capacity would be
minimal.
Value judgement rating 3
To expand a full vacuum
system requires both ad-
ditional vertical chutes
and horizontal tubes, all
of which must be under a
vacuum, thus requiring
much larger fans and fil-
ters.  Further, the elec-
trics of this type system
are more complex than
gravity to vacuum.

Value judgement rating 2
TOTAL RATING
1'UINTS FOR
ALL ELEMENTS
                                     59

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     As stated at the beginning of this chapter, comparisons were made be-
tween the pneumatic tube systems and the more conventional hand transport sys-
tems used by most hospitals in the United States today.  The comparisons are
presented as a composite of the three pneumatic systems as compared to a com-
posite of three hand transport systems with the capability of hauling all
solid waste from the three hospitals.  Where the rating elements could be
quantified, they are presented as individual values for each system, and the
average value among all  the systems.  In the case of narrative rating elements,
the descriptions cover the essential features of all systems in the three hos-
pitals and the ratings are assigned on the basis of value judgements.
     In making this type comparison, different elements of importance must be
used than were used in comparisons between the three pneumatic systems, since
some elements are unique to pneumatic systems and are not applicable to hand
transport systems.  The comparable elements of importance for this portion of
the analysis were broken down to the following:
     Economics                              Interfacing of Components
          Total costs per month             Reliability
          Total costs per peund             Maintainability
           transported                      User Acceptability
          Total costs per cubic             Environmental Acceptability
           foot transported                 Safety
          Total costs per bag                    Sound levels
           transported                           Odor  levels
     Qualifications Required of                  Contamination
      Transport Personnel                        Housekeeping practices
     Speed of Clearing Floors
     Certain assumptions, based on observations, were made  in rating the  cost
elements.  First, a hand hauled cart will hold, on  the average, Ib bags of
waste.  The bags  to receive and transport waste were actually costed out.
The cost of utilities, and depreciation of elevators,  carts, and  trash con-
tainers were factored.  Labor  includes time to  empty waste  containers, load
carts, walk to elevator, elevator time  (including waiting), walk  to  compac-
tor, load  compactor, return to elevator, elevator time  (including waiting),
                                       1)4-

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and walk to next pick-up point.  The cost figures for the pneumatic systems
are based on net cost assigned to hauling waste only.  A rating system of 2
for "best" and 1 for "least" is used here in a comparable manner to the 3-
point system used in the comparisons between pneumatic systems.
     The matrix on the following pages presents the results of the comparisons
between the composite of the three pneumatic systems and the composite of the
three manual systems.
                                      -255-

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          ELEMENT OF IMPORTANCE
                          PNLUMAIIC VS. HAND SYSTEMS COMPARISON MATRIX

                                   PNEUMATIC SYSTEM                 HAND SYSTEM
i
ro
CT-
I
ECONOMICS

Total individual costs
  per month
Average value
Rating

Total individual costs
  per pound
Average value
Rating

Total individual costs
  per cubic foot
Average value
Rating

Total individual costs
  per bag
Average value
Rating
                                      $3,449 to $5,052 to $6,568
                                                $5,023
                                                   2
                                      $ 0.10 to $ 0.13 to $ 0.15
                                                $ 0.13
                                                    1
                                      $ 0.22 to $ 0.30 to $ 0.30
                                                $ 0.27
                                      $ 0.41 to $ U.53 to $ U.77
                                                * 0.57
                                                    1
$6,358 to $7,368 to $8,474
          $7,400
             1
$ 0.05 to $ 0.08 to $ 0.09
          $ 0.07
$ 0.16 to $ 0.24 to $ 0.37
          $ 0.26
              2
$ 0.30 to $ 0.36 to $ 0.54
          $ 0.40
        Total rating points

        QUALIFICATIONS REQUIRED
        OF TRANSPORT PERSONNEL
        Rating
                                                                                        7
                              Requires minimal training to
                              learn routine of making rounds
                              and unlocking chute door, or
                              randomly loading an unlocked
                              chute.
Requires considerable training
and experience to learn routine
and accomplish rounds efficiently
and without interference.
        SPEED OF LOADING AND
        CLEARING FLOORS
        Average value
        Rating
                              Waste bags can be cleared from
                              patient and ancillary areas much
                              faster than by cart.  Requires
                              441 hours to 462 hours to 534
                              hours per month to clear floors
                              and load chutes.

                                          479 hours
Carts are bulky yet handle per
hour much less waste in vertical
transport than chutes.  Requires
1,355 hours to 1,359 hours to 1,871
hours per month to clear floors,
haul to compactor, and return.
          1,528 hours
              1

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  ELEMENT OF IMPORTANCE
         PNEUMATIC SYSTEM
                                                                         HAND SYSTEM
INTERFACING OF
COMPONENTS
Rating
RELIABILITY
Hating
MAINTAINABILITY

Individual values
Average values

Rating
Systems are enclosed and complete
with an air gap at compactor, ex-
cept one which is complete to
compactor, then hand hauled to
compactor.
                 2
System is completely open to the
compactor, except that waste is
encapsulated in plastic bags.
All systems experience plugging
and shut downs, one system down
for as long as 30 days.  Lack of
fan air filter in one system has
caused dust build-up and vibra-
tions in fan sufficient to crack
motor mount.  20-gauge metal in
some tubes is borderline, con-
tributing to tube collapse.
                 1
Averages 171 hours to 424 hours
to 454 hours per year for correc-
tive maintenance.  Averages 284
hours to 681 hours to 813 hours
per year for preventive mainten-
ance and routine inspections.
One system has no routine inspec-
tions.
Corrective, 350 hours
Preventive and inspections, 593
                 1
Reliability affected only by
availability of personnel to
push carts and operation of one
elevator.
Requires cleaning of carts plus
routine inspections and main-
tenance of elevator at 150 hours
per year.
           150 hours
                2

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          ELEMENT OF  IMPORTANCE
         PNEUMATIC SYSTEM
          HAND SYSTEM
        USER ACCEPTABILITY
i
i ^
Iwf
ex
        Value judgement rating
        ENVIRONMENTAL
        ACCKI'TA^JLITY

        Sound levels
        Average values

        Rating

        Odor levels
        Value judgement rating

        Contamination
        Value judgement rating
Trustability factor is low for two
systems, relatively nigh fcr the
third.  Low factor due to slowness
of system in one case, requiring
much waiting time to load, and in
the other due to many cast-s of
waste and laundry nags crossing
over.  High factor due to easy and
fast loading,
                 1
Trustability factor medium  to
high since the system will  work
Esthetic value rating meciuin.
Creates tratfic problems and
noise in the corridors.
Average roaximums ranged from 63
dB(A) to 69 dB(A) to 77 dB(A) in
corridors outside chute loading
rooms.  Overall average value per
hospital ranged fruin 60 db(.A) to
62 dB(A) to b5 dB(A) in the corri-
dors outside chute  loading rooms.
Maximum level 70dB(A)
Average level o2 d!3(A)

Odor, if any, as measured in cor-
ridors, coming from chute loading
rooms, is low but when present is
persistent.
                 1
No dangerous contamination noted
inside hospitals attributable to
pneumatic systems.  The risk is
lower inside patient areas.
                 2
Averages 5-10 dB(A) above sound
of chute loading stations, meas-
ured in corridors.
Maximum level 77dti(A)
Average level o9 dB(A)
                1

Odor, i! any, coming from a
waste cart is transient.  (This
assumes all waste is transported
in tied or sealed bags.)
                2
The risk is higher due to exposed
conditions in carts and longer
contact of bags witii carts.

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  ELEMENT OF IMPORTANCE
          -NEUMA1IC
                                                                           HAND
ENVIRONMENTAL
ACCEPTABILITY
Housekeeping practices
Value judgement rating
Total rating points
SAFETY
Value judgement ratinp.
TOTAL kATlNi; FOINTS
FOR ALL ELEMENTS
Bag breakage and waste spread
vithiti pneumatic system is con-
fined.  Negative pressure leads
odory and contamination to fan
and filter.
              brec?ka&e in cart loading and
          within carts can spread aerosols
          through Hospital corridors.
          Theoretically carts should be
          cleaned after each trip if
          breakage or leakage occurs.
                          1
No hazardous or unsafe conditions
were found, except high noise
levels in all fan rooms and, in
or,e hospital, a physically haz-
ardous condition to n.aintenance
personnel in slidf valve roorc.
          Potential safety hazard to
          pedestrians and wheel chair
          patients in corridors and
          elevators.
                                                    21
COMPARISON RATING SUMMARY
PNEUMATIC VS. PNEUMATIC
V.A. M.L.KINC ST. MARY'S
HOSPITAL HOSPITAL HOSPITAL
PNEUMATIC VS.
PNEUMATIC
SYSTEM
HAND
HAND
SYSTEM
Overall total rating
 points
                59
41
                                                             21

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                SUMMARY OF SYSTEMS RATINGS AND COMPARISONS

     As stated earlier in this chapter,  the previous comparisons and ratings
were based on both quantitative and qualitative factors.  Some were.based on
audit of cost and labor figures, measurements and physical testing, and some
by value judgments based on qualified observations, past experience, and
interviews on site.  Based on this, it is our conclusion that, after comparing
and evaluating the three pneumatic systems with one another, the heavy-wall,
two-tube, gravity to vacuum system at Martin Luther Ring is the "best" system,
even though it is the most expensive.  The thin-wall, two-tube, full vacuum
systems at St. Mary's Hospital was judged to be "second best," when compared
and evaluated with the other penumatic systems.  The thin-wall, single-tube,
full varuuc system at Veterans Administration Hospital was judged "third best"
when compared and evaluated with the other pneumatic systems.
     The composite of the three pneumatic systems, compared to the composite
cf three hand systems, was judged slightly "better" overall, even though
they rated lower in the economic factors.  This is due primarily to the higher
ratings of the pneumatic systems in environmental factors and speed and clear-
ing cf floors.
     The pneumatic solid waste handling systerj at Martin Luther King Hospital
was significantly more expensive to install than the other two pneumatic
systems.  It thus appears that this is a case of higher installation cost
being justifiable in order to achieve other advantages and help meet the goals
of improving the internal environment of the institution.
                                     -260-

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           A  GLOSSARY  OF  TERMS APPLICABLE  TO SOLID  WASTE MANAGEMENT
                                      IN
                            HEALTH  CARE  FACILITIES

     AN DIAL ViASTE - Waste generated from animal care or use; including secre-
tions, tissue,  remains,  droppings,  bedding for cages (such as sawdust, etc.).
     BAGGING  -  The deposition of solid waste in a paper or plastic bag for
storage or transport.
     BIODEGRADABLE - Waste material which is capable of being broken down by
bacteria into basic elements.  Most organic waste,  such as food remains and
paper, is biodegradable.
     BIOLOGICAL WASTES - Waste contaminated with or made up of animal or plant
tissue, secretions, remains, droppings,  or other elements.
     CHARGE - The quantity of solid waste introduced into a furnace at one
time.
     CHEMICAL WASTES - Any cnemical or mixture cf chemicals which  require
special consideration for disposal.
     CLASSIFICATION - To arrange or sort waste materials  into uniform cate-
gories or classes.  Usually  implies accurate grading by organic,  inorganic,
size, weight, color, or  shape,  etc.
     COLLECTION - The act of removing solid waste  from a  storage  point.
      COLLECTION CENTER - A place or facility designed  to  accept waste materials
from individuals  or mechanical  devices  (such as  conveyors,  carts,  or  transport
tubes).   The term can also be used  to mean  a  central receiving  point  for waste
material  collected by a  government  cr private  agency.
      COMBUSTIBLES - Various  materials  in  the  waste  stream which are burnable.
 In general,  these are organic in nature:   paper, plastics,  wood,  and  food
wastes.
      COMPACTOR  -  Any  power  driven  mecnanicaj.  equipment designed to compress
 and thereby  reduce  the volume of waste materials.

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     CONTAINERIZE - The deposition of sclid waste into metal,  plastic,  or
other containers for storage or transport.
     CONTAMINATED WASTES - Waste which has  been soiled, stained, corrupted,  or
infected by contact, association, or use.
     DISINFECTION - Killing of infectious agents outside the body by chemical
or physical means directly applied.
     DISPOSABLE - A product intended for single or limited use before being
discarded.
     DISPOSAL - The orderly process of discarding useless or unwanted material.
     DUMP - An open land site where waste materials are burned, left to decom-
pose, rust, or simply  remain.   Ln most localities, dumps are being phased out
because of the problems which they cause,  such as water pollution, creation of
unsanitary conditions, and general unsightliness.  Some dumps are left burning
as waste  is accumulated.  This  practice does not lend  itself to control, and,
therefore, very  little of the waste  is actually  consumed by fire.  The burning
also generates obnoxious  smoke,  fumes, and ash particles.
     ECOLOGY - The  science  that deals with the interrelationships of organisms
and  their living  and non-living surroundings.
     ECOSYSTEM -  The interdependence  of organisms and  their surroundings.
     EMISSIONS  (GASEOUS)  -  Waste gases  released  into  the  atmosphere  as  the
product  of combustion.
     ENVIRONMENT -  The air,  the water,  and the earth,  sometimes called  the
biosphere.   Alternatively,  homes,  institutions,  and  other places  of  residence
or work.
     ENVIRONMENTAL SYSTEM - The interaction of an  organism or  group  of  organ-
 isms with its  natural  and tuanmade surroundings.
      FOMITE  -  Inanimate objects such as clothing,  dishes, toys, books,  that
may  be contaminated with infectious agents and serve in their transmission.
      FOOD WASTE - Animal and vegetable waste resulting from the handling,
 storage, sale,  preparation, cooking, and serving of food; commonly called
 garbage.
      GARBAGE - Waste materials which are likely to decompose or putrefy.  Usu-
 ally contain food wastes from a kitchen, restuarant, grocery store, slaughter
 house, or food processing plant.

                                  - /-I -II-

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     GRINDING -  The  mechanical  pulverization of solid waste.
     HAUL DISTANCE - (1)  The  distance,  a collection vehicle travels from its
last pickup stop to  the solid waste  transfer station, processing facility, or
sanitary landfill.   (2) The distance a vehicle travels from a solid waste
transfer station or  processing  facility to a point of final disposal.  (3) The
distance that cover  material  must be transported from an excavation or stock-
pile to the working  face of a sanitary landfill.
     HAUL TIME - The elapsed or cumulative time spent transporting solid waste
between two specific locations.
     HAZARDOUS WASTE - The waste from a hazardous material:  which is any ele-
ment, compound,  or combination thereof, that is flammable, corrosive, deton-
able, toxic, radioactive, an oxidizer, an etiological agent, or is highly re-
active, and that because of handling, storing, processing, packaging, or  trans-
porting may have detrimental effects upon operating  and emergency personnel,
equipment, the workplace, or the environment.  Waste which requires  special
handling to avoid illness or injury tc persons, or damage  to property.
     INCINERATION - The controlled process by  which  solid, liquid, or gaseous
combustible wastes are burned  and changed into gases and  the residue produced
contains little or no  combustible material.
     INCINERATOR - An  engineered apparatus  used to burn waste  substances  and
in  which all  the factors of  combustion—temperature,  retention time, turbu-
lence,  and combustion  air—can be controlled.
     INCINERATOR RATED CAPACITY  - The  number of tons of solid  waste  that  can
be  processed  at an  incinerator per  2A-hrur  period when  specified  criteria pre-
vail.  Alternatively,  the pounds per hour that can be burned.
     INFECTED PERSON - Infected  persons  include both individuals  with  manifest
disease and  those with inapparent infection.
      INFECTION  - The entry and development  or multiplication of an infectious
agent  in the  body of mar.  or  animal.   Infection is not  synonymous  with infec-
 tious  disease;  the  result  may  be inapparent cr manifest.   The  presence of liv-
 ing infectious  agents  on  exterior surfaces  of the body or upon articles of ap-
parel  or soiled articles   is not infection, but contamination of  such surfaces
 and articles.
                                   - -111-

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     INFECTIOUS AGENT - An organism, mainly microorganisms (bacterium,  proto-
zoan, spirochete, fungus, virus, rickettsia, bedsonia, or other) but including
helminths, capable of producing infection or infectious disease.
     INFECTIOUS DISEASE - A disease of man or animal resulting from an infection.
     INFECTIOUS WASTE - Waste originating from the diagnosis, care, or treatment
of a person or animal which has been, or may have been, exposed to a contagious
or infectious disease.
     INSTITy'ri_ONAL__WA_STE - Waste originating from educational, health care, re-
search, and similar institutions.
     ISOLATION WASTE - Waste originating from the diagnosis, care, or treatment
of a patient placed in isolation because o£ a known or suspected infectious
disease.
     JUNK - Unprocessed materials suitable  for reuse  or recycling.
     LABORATORY  WASTE - Waste generated through  the activities  of  the laboratory
which may be innocuous, hazardous,  or infectious, solids, or liquids.
     MANUAL SEPARATION - The separation of  waste materials by hand.  Sometimes
called hand picking, manual separation is  done in the home or office by keeping
garbage separate from newspapers, or  in a  recovery  plant  by  picking out large
cardboard or metal  objects.
     MANURE -  Primarily  the excreta of animals;  may contain  some  spilled  feed
or bedding.
     MEDICALLY CONTAMINATED WASTE - Waste  originating from activities  associated
with patient diagnosis,  care,  or treatment.  Also medical waste.
     MILLED REFUSE  -  Solid waste that has  been mechanically  reduced in size  by
 the  grinding,  or pulverizing,  or bannering action of  an  attrition mill,  "hogg,"
 or  dry grinder.
     MOISTURE  CONTENT (SOLID  WASTE) - The  weight loss (expressed in percent)
 when a sample  of solid waste  is dried to  a constant weight  at  a temperature  of
 100  C  to  105  C.
      OPEN BURKING - Uncontrolled burning of wastes  in the open or in an open
 dump.
      PATHOGEN - An organism  capable of  producing disease.

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     PATHOGENIC WASTE - Waste contaminated with an organism capable of produc-
ing disease.
     PATHOLOGICAL WASTE - Tissues,  parts, and organs of humans and animals.
     PNEUMATIC COLLECTION (SOLID WASTE) - A mechanical system for conveying
solid waste through transport pipes.   When the system is in operation, a vacuum
is developed and a high velocity air  stream is drawn through pipes.  Waste,
which is dropped into this moving air stream, is carried to a collection point.
     POLLUTION - The condition caused by the presence in the environment of
substances of such character and in such quantities that the quality of the
environment is impaired or rendered offensive to life.
     POLYVINYL CHLORIDE (PVC) - A common plastic material that releases hydro-
chloric acid when burned.
     PYROLYSIS - The chemical decomposition of a material by heat  in the ab-
sence of oxygen.
     RADIOACTIVE WASTE - Waste contaminated with a  substance which emits ion-
izing radiation.
     RECLAMATION - The restoration to  a  better or more  useful state, such  as
land reclamation by sanitary landfilling,  or  the obtaining  of useful materials
from solid waste.
     RECOVERY  - The process of obtaining materials  or  energy  resources  from
solid waste.   Synonyms:  Extraction, Reclamation,  Salvage.
     RECYCLING - The process by which  waste materials  are  transformed  into new
products  in such a manner  that the original products may lose  their  identity.
     REFUSE -  A generally  used term  for  solid waste materials.
     RESIDUE - Material  that  remains after gases,  liquids,  or solids  have  been
 removed.
     REUSE - The use  of  a  waste material or product more than once.   For ex-
 ample,  a  soft  drink  bottle is  reused when it is returned to the  bottling com-
 pany and  refilled.
     RUBBISH - A general tenu for  solid waste—excluding  food waste and ashes—
 taken  from residences, commercial  establishments,  and institutions.
      SALVAGE - The utilization  of  waste materials.

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     SANITARY LANDFILL - A site where solid waste is disposed using sanitary
landfilling techniques.
     SANITATION - The control of all the factors in man's physical environment
that exercise or can exercise a deleterious effect on his physical development,
health, and survival.
     SCRAP - Waste material which is usually segregated and suitable for re-
covery or reclamation.
     SEPARATION - The systematic division of solid waste into designated cate-
gories; e.g. removing glass containers, metal cans, etc. from general waste.
     SHREDDER - A mechanical device used to break up waste materials into small-
er pieces.  The pieces are usually in  the form of irregularly shaped strips.
     SOLID WASTE - Useless, unwanted,  or discarded material with  insufficient
liquid content to be  free flowing.
     SOLID WASTE DENSITY - The number  obtained by dividing the weight of solid
waste by  its volume.
     SOLID WASTE MANAGEMENT  -  The purposeful, systematic control  of the gener-
ation, storage,  collection,  transport, separation, processing, recycling, re-
covery, and  disposal of  solid  wastes.
     SOURCE  OF INFECTION - The thing,  person, object,  or substance from which
an  infectious agent  passes immediately to  a host.
     SPECIAL WASTE - Waste that requires  extraordinary management.
     STERILIZATION - The destruction,  by  chemical or physical means, of a
microorganism's  ability to reproduce;  to  render something  barren.
      STORAGE^ -  The  interim containment of solid waste, in  an approved manner,
after  generation and prior to ultimate disposal.
      SURGICAL AND AUTOPSY WASTE - Waste that includes tissue, limbs, organs,
placentas, and similar types of materials.
      TOXIC WASTE - Waste contaminated with any  substance which has the  capacity
 to produce personal  injury  or illness to man through ingestion,  inhalation, or
 absorption.
      TRANSFER STATION - A site at which solid waste is concentrated and then
 taken to a collection center of a processing facility.
      TRANSPORT - The movement of solid waste subsequent to collection.
                                  - p. -VI-

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     TRASH - (Same as Rubbish)  - A general term for solid waste—excluding
food waste and ashes—taken from residences, commercial establishments, and
institutions.
     VOLUME REDUCTION - To process waste materials so as to decrease the amount
of space the materials occupy.   Complete conventional incineration can reduce
volume by 90 percent while high temperature incineration achieves as much as
98 percent.  Compaction systems can also reduce volume by 50 to 80 percent.
     WASTE - The useless, unwanted, or discarded materials resulting from nor-
mal community activities, including solids, liquids, and gases.
     WASTE GENERATION - The act or process of producing solid waste,
     WASTE PROCESSING - An operation such as shredding, compaction, composting,
and incineration, in which the physical or chemical properties of wastes are
changed.
     WET PULPING - The mechanical size reduction of solid wastes that have been
wetted to soften the water absorbing constituents  (such as paper and cardboard).
                                   /9 -vii-

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