ELG-11
                                      Developrnsnt Document for
                                    Effluent Limitations Guidelines
                                    and Stendards of Performanca
                                                for the
                                        Meat Packing  Industry
                                            Prepared for the

                               Usuited States Envifonmen'ai Protection Agency
                                    under Contract Nyivjber 68-01-0593
                                              June 19?3
                                              G.E. Erickson
                                               J.P. Pilney
                                              R.J. Reid, P.E.
                                   S  RESEARCH AND DEVELOPMENT INSTITUTE
                              3100 TWIRTV-E^MT^ AV6NUE  SCUTH • MINNEAPOLIS. MINNESOTA

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                             REVIEW NOTICE


This document presents conclusions and recommendations of a study
conducted for the Effluent Guidelines Division, United States
Environmental Protection Agency, in support of proposed regulations
providing effluent limitations guidelines and new source standards
for the meat packing industry.

The conclusions and recommendations of this document may be subject
to subsequent revisions during the document review process, and as
•Vf!   ,'/h! proposed Evelines for effluent limitations as contained
within this document may be superceded by revisions prior to final
promulgation of the regulations in the Federal Register on or before
October 18, 1973, as required by the Federal Water Pollution Control
Act Amendments of 1972 (P.L. 92-500).
                                 ii

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                                  ABSTRACT
                            flndinBs of an extensive  study of  the  meat
 of devlonf n           rownental Protection  Agency  for the purpose
 of developing -effluent limitations  guidelines,  Federal standards  of
 performance  and pretreatment  standards for  the industry,  to  implement
not include
                                                                    and
                                       S meat» but  do n°  slaughtering, and
                             °Ut  °ff  the  Slte °f the Packi^ Pla^  were
                                        forth f°r the
                   n         the application of the "Best Practicable
EconomllvAch   C^rently Available", and the "Best Available Technology
Economically Achievable", which must be achieved by existing point sourcef



The »ro»o!S    S?' f°Cesses' operating methods, or other alternatives.
                                                    treatment
added to the  Q7              flocculant Addition, and a final sand filter
                                 iii

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                        ipMri
                        y 11 j-iii it A i-j"*  'i
                              CONTENTS
Section                                                         Page

 i.      CONCLUSIONS	     l
 II.     RECOMMENDATIONS	  3
III.     INTRODUCTION	'	     5
            Purpose and Authority.  .........  	     5
            Summary of Methods Used for Development of
            the Effluent Limitations Guidelines and
            Standards of Performance	'	     6
            General Description of the Industry	     7
            Process Description	 •     9
            Manufacturing Processes	    12
               Stockyards and Pens	    12
               Slaughtering. ...'....	    12
               Blood Processing. .	    15
               Viscera  Handling. ....... 	    15
               Cutting	 .    16
               Meat Processing	    16
               Rendering	    17
            Materials Recovery 	 .........    18
            Production Classification. .  .  	  .....    19
            Anticipated Industry Growth	 .    19
IV.      INDUSTRY CATEGORIZATION	    21
            Categorization  . .  . ,  ,	 .    21
            Rationale for Categorization 	    21
               Wastewater Characteristics and
               Treatability	   22
               Final Products	    22
               Primary Manufacturing Processes 	 ....   25
               Secondary Manufacturing Processes  ........   25
               Raw Materials	   27
               Size, Age, and Location	 .   27

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                          CONTENTS  (Continued)


Section                                                            Page

 V       WATER USE AND WASTE CHARACTERIZATION 	    29

             Wastewater Characteristics  	    29

                Raw Waste Characteristi.cs	    29
                Slaughterhouses 	    30
                Packinghouses 	  ............    32
                Discussion of Raw Wastes	    35

             Process Flow Diagrams	    38

             Water Use - Wasteload  Relationships	    43

             Sources of Wastewater.	    45

                Animal Pens ...................    45
                Slaughtering	    45
                Meat Processing	    46
                Secondary Manufacturing  Processes ........    47
                Cutting	    48
                Clean-Up	    49

 VI      SELECTION OF POLLUTANT PARAMETERS	    51

             Selected Parameters	    51

             Rationale for Selection of  Identified Parameters .  .    51

                5-Day Biochemical Oxygen Demand 	    51
                Chemical Oxygen Demand	    52
                Suspended Solids.  .	    52
                Dissolved Solids.  . .	    53
                Ammonia Nitrogen	    53
                Kjeldahl Nitrogen  	    54
                Nitrates and Nitrites 	    54
                Phosphorus.	    54
                Chlorides	    55

 VII     CONTROL AND TREATMENT TECHNOLOGY	    57

             Summary.  .	    57

             In-Plant Control Techniques	    57

                Pen Wastes. .	    59
                Blood Handling	    59
                Paunch	    59
                Viscera Handling	    59
                Troughs	  .    60
                Rendering	    60
                                   vi

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                          CONTENTS (Continued)


Section                                                            Page

 VII     CONTROL AND TREATMENT TECHNOLOGY (Continued)

                Hide Processing	    61
                Scald Tank	    61
                Pickle and Curing Solutions 	    61
                Water Conservation Practices	  .    61
                Clean-Up Operations 	    62

             In-Plant Primary Treatment 	    63

                Flow Equalization	,	    63
                Screens	    63
                Catch Basins	    65
                Dissolved Air Flotation 	    66

             Secondary Wastewater Treatment Systems 	    71
                Anaerobic Processes 	    71
                Aerated Lagoons . . ;  .	    74
                Aerobic Lagoons 	    75
                Activated Sludge	  .    76
                Trickling Filter	    79
                Rotating Biological Contactor .  .	    80
                Performance of Various Secondary
                Treatment Systems 	  	    82

             Tertiary and Advanced Treatment	    84

                Chemical Precipitation of Phosphorus	    84
                Sand Filter	    85
                Microscreen-Microstrainer 	    88
                Nitrification-Denitrification 	    89
                Ammonia Stripping ..... 	  ....    92
                Spray/Flood Irrigation. 	    94
                Ion Exchange	  .    96
                Carbon Adsorption	    99
                Reverse Osmosis	101
                Electrodialysis 	   102

 VIII    COST, ENERGY, AND NON-WATER QUALITY ASPECTS	105

             Summary.	  .   105

             "Typical" Plant. .......	107

             Waste Treatment Systems.	108

             Treatment and Control Costs. .•	112

                In-Plant Control Costs	112
                Secondary and Tertiary Treatment Costs	113
                                  vii

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                          CONTENTS (Continued)

Section                                                            Page
 VIII    COST, ENERGY, AND NON-WATER QUALITY ASPECTS (Continued)
                Investment Costs Assumptions	113
                Annual Costs Assumptions	«...   116
             Energy Requirements	117
             Non-Water Pollution by Waste Treatment Systems .  .  .   118
                Solid Wastes	118
                Air Pollution	119
                Noise	120
 IX     • EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
         OF THE BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY
         AVAILABLE— EFFLUENT LIMITATIONS GUIDELINES	121
             Introduction 	   121
             Effluent Reduction Attainable Through The Application
             of Best Pollution Control Technology Currently
             Available	122
             Identification of Best Pollution Control Technology
             Currently Available	122
             Rationale for the Selection of Best Pollution
             Control Technology Currently Available 	   125
                Age and Size of Equipment and Facilities	125
                Total Cost of Application in Relation to
                Effluent Reduction Benefits 	   125
                Engineering Aspects of Control Technique
                Applications	126
                Process Changes	126
                Non-Water Quality Environmental Impact	126
 X      EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
         OF THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY
         ACHIEVABLE—EFFLUENT LIMITATIONS GUIDELINES	127
              Introduction  .......  	 .....  127
              Effluent Reduction Attainable Through Application
              of the Best Available Technology Economically
              Achievable	128
              Identification of  the Best  Available Technology
              Economically Achievable	....'..  128
                                  viii

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                          CONTENTS (Continued)
Section
 x
                                                                  Page
        EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION
        OF THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY
        ACHIEVABLE—EFFLUENT LIMITATIONS GUIDELINES
        (Continued)

            Rationale for Selection of the Best Available
            Technology Economically Achievable 	   132
               Age and Size of Equipment and Facilities	132
               Total Cost of Application in Relation to
               Effluent Reduction Benefits 	   133
               Engineering Aspects of Control Technique
               Application	•	133
               Process Changes 	   133
               Non-Water Quality Impact	   134

XI      NEW SOURCE PERFORMANCE STANDARDS	135

            Introduction 	   135
            Effluent Reduction Attainable for New Sources. .  .  .   135
            Identification of New Source Control Technology.  .  .   136

            Pretreatment Requirements	137

XII     ACKNOWLEDGMENTS	139

XIII    REFERENCES	   141

XIV     GLOSSARY	145
                                    ix

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                                FIGURES


Number                                                             Page

   1     Process Flow in a Packing Plant	    10

   2     Process Flow for Simple Slaughterhouse 	    11

   3     Waste Flow Diagram for a Packinghouse	    13


   4     Categorization of Meat Packing  Plants	    23

   5     Operating and Wastewater Flow Chart for Simple
         and Complex Slaughterhouses	    31

   6     Operating and Wastewater Flow Chart for Low- and
         High-Processing Packinghouses	34

   7     Typical Wastewater Treatment System Without
         Dissolved Air Flotation	4	39

   8     Typical Wastewater Treatment System Including
         Dissolved Air Flotation	40

   9     Separate Treatment of Grease-Bearing, Nongrease-
         Bearing and Manure-Bearing Wastewaters 	   42

  10     Effect of Water Use on Wasteload for Individual
         Plants	44

  11     Suggested Meat Packing Industry Waste Reduction
         Program	58

  12     Dissolved Air Flotation	68

  13     Process Alternatives for Dissolved Air Flotation ....   69

  14     Anaerobic Contact Process	73

  15     Activated Sludge Process 	 	   77

  16     Chemical Precipitation 	   85

  17     Sand Filter System	86

  18     Microscreen/Microstrainer	88

  19     Nitrification/Denitrification	90

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                          FIGURES (Continued)




Number



 20     Ammonia Stripping	



 21     Spray/Flood Irrigation System.  ...




 22     Ion Exchange 	



 23     Carbon Adsorption	



 24     Reverse Osmosis	



 25     Electrodialysis	
                                93



                                95



                                97



                               100



                               102



                               103
xi

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                                TABLES


Number                                                           Page

  1     Commercial Slaughter in 48 States	    8

  2     Summary of Plant and Raw Waste  Characteristics
        for Simple Slaughterhouses 	    33

  3     Summary of Plant and Raw Waste  Characteristics
        for Complex Slaughterhouses	    33

  4     Summary of Plant and Raw Waste  Characteristics
        for Low-Processing Packinghouses 	    36

  5     Summary of Plant and Raw Waste  Characteristics
        for High-Processing Packinghouses	    _„

  6     Performance of Various Secondary Treatment
        Systems	    83

  7     Average Total Waste Treatment Investment Costs  per
        Plant to Achieve a Given Level  of  Effluent Quality .  .  .  105

  8     Estimated Total Investment Cost to the Industry to
        Achieve a Given Level of Effluent  Quality from
        Present Level of Treatment	106

  9 '    Total Increase in Annual Cost of Waste Treatment ....  106

 10     Waste Treatment Systems, Their Use and Effectiveness  .  .  109

 11     In-Plant Control Equipment Cost Estimates	112

 12     Secondary Waste Treatment System Costs 	 ...  114

 13     Advanced Waste Treatment System Costs	115

 14     Recommended Effluent Limit Guidelines for
        July 1, 1977	123

 15     Adjustments for Exceptions in Plant Subcategories. .  .  .  124

 16     Recommended Effluent Limit Guidelines for July 1,
        1983	129

 17     Adjustments for Exceptions in All Plant Subcategories—
        1983	130
                                  xii

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                              SECTION I

                             CONCLUSIONS

                                NOTICE

                This document is a preliminary  draft.   It has
                not been formally released by EPA  and should
                nott at this stage, be construed to represent
                Agency policy.  It is being circulated for
                comment on its technical  accuracy  and policy
                implications,

A conclusion of this study is  that  the meat packing industry comprises
four subcategories:

           Simple  Slaughterhouses
           Complex Slaughterhouses
           Low-Processing Packinghouses
           High-Processing Packinghouses

The major  criterion for the  establishment of the  categories was  the
5-day  Diochemical oxygen demand (BOD5) in  the  plant wastewater.   Other
criteria were  the primary products produced and the secondary  (by-product)
processes  used.   Information relating to other pollutants  and  the effects
of such parameters as  age and location of plants,  kind of  animal, and
treatability of  wastes all lent support  to the categorization  selected.

The wastes from all subcategories are amenable to biological treatment
processes, and no materials harmful to municipal  waste treatment processes
were  found.

Discharge limits that represent the average of the best  treatment systems
in the industry for the four subcategories are being met by about 25
percent of the plants for which data are available; these limits are
recommended for 1977.  The same limits are recommended for new sources.
 It is estimated that the costs of achieving these limits by all plants
within the industry is less than $53 million.   These costs would increase
 the capital investment in the Industry by about three percent and would
 equal about 20 percent of the industry's 1971  capital investment.

 For 1983, effluent limits were determined as the best achievable in  the
 industry  for  5-day biochemical oxygen demand (BOD5) and suspended solids.
 Limits for Kjeldahl nitrogen,  ammonia,  nitrites  and nitrates, and phosphorus
 were  established on the basis of  transfer of technology from  other industries
 or of newly developing technology.   It   is also concluded,that,  where suit-
 able  and  adequate land is  available, land disposal is a more  economical  option.
                      NOTICE: Thcs* aio urasuve recommendations based upon information in this
                      report and are subject to change bnsed U| en Comments received and further
                      review  by EPA.

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It. is  estimated  that the  costs above those  for 1977  for achieving the
1983 limits by all plants within  the industry  are  less than  $107 million.
These  costs would further increase  the capital investment in  the industry
by about six percent, and would equal about 44 percent of the industry's
1971 capital investment.
              NOTICE: These are tcnljn.e recommondations based upon information In this
              report and are subject to change based upon tfimrnents received and further
              review by EPA.

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                                SECTION II

                              RECOMMENDATIONS

Guideline recommendations  for discharge to navigable waters for
July 1, 1977, are based  on the characteristics of well operated
secondary treatment  plants.   The guidelines for 5-day biochemical
oxygen demand (BOD5)   range,  for example, from 0.08 kg/1000 live weight
killed (LWK) for simple  slaughterhouses to 0.24 kg/1000 kg LWK for  an
average high-processing  packinghouse.  Other major parameters  that  are
limited are suspended solids  and grease.  Total Kjeldahl nitrogen,
ammonia, phosphorus,  and nitrite-nitrate are also included.

Recommended New Source Standards are the same as the 1977 guidelines.

Guidelines recommended for 1983 are considerably more stringent.   For
example, BOD5 limits range from 0.03 kg/1000 kg LWK for  simple slaughter-
houses to 0.09  kg/1000 kg LWK for an average high-processing  packing-
house.  Limits  are  also placed on the other parameters mentioned above,
with particular attention to the ammonia discharge.  The suspended
solids range  from 0.05 to 0.12 kg/1000 kg LWK; grease is below the
limits of detection by standard analytical methods; and  total Kjeldahl
nitrogen, ammonia,  nitrogen, phosphorus, and nitrite-nitrate  are limited
by the concentrations achievable by  the  technology rather than by a
relation  to  the production level.  In cases where  suitable  and adequate
land is available, land disposal  (no  discharge) will be a practical
option.
               ...... '£• These are tentative recommendations based upon ii f tms.un in this
               rep.it and are subject to change based upon comments retu.cu 
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                             SECTION III

                             INTRODUCTION


                         PURPOSE AND AUTHORITY

Section 301(b) of the Federal Water Pollution Control Act Amendments of
1972 (the Act) requires the achievement by not later than July 1, 1977,
of effluent limitations for point sources, other than publicly owned
treatment works, which are based on the application of the best
practicable control technology currently available as defined by the
Administrator pursuant to Section 304(b) of the Act.  Section 304(b)
also requires the achievement by not later than July 1," 1983, of
effluent limitations for point sources, other than publicly owned
treatment works, which are based on the application of the best available
technology economically achievable which will result in reasonable further
progress toward the national goal of eliminating the discharge of all
pollutants, as determined in accordance with regulations issued by the
Administrator pursuant to Section 304(b) of the Act.  Section 306 of
the Act requires the achievement by new sources of a Federal standard
of performance providing for the control of the discharge of pollutants
which reflects the greatest degree of effluent reduction which the
Administrator determines to be achievable through the application of
the best available demonstrated control technology, processes, operating
methods, or other alternatives, including, where practicable, a standard
permitting no discharge of pollutants.

Section 304(b) of the Act requires the Administrator to publish within
one year of enactment of the Act, regulations providing guidelines for
effluent limitations setting forth the degree of effluent reduction
attainable through the application of the best practicable control
technology currently available and the degree of effluent reduction
attainable through the application of the best control measures and
practices achievable including treatment techniques, process and pro-
cedure innovations, operation methods and other alternatives.  The
regulations proposed herein set forth effluent limitations guidelines
pursuant to Section 304(b) of the Act for the meat packing plant sub-
category within the meat products source category.

Section 306 of the Act requires the Administrator, within one year
after a category of sources is included in a list published pursuant
to Section 306(b)(l)(A) of the Act, to propose regulations establish-
ing Federal standards of performances for new sources within such
categories.  The Administrator published in the Federal Register of
January 16, 1973 (38 F.R. 1624), a list of 27 source categories.
Publication of the list constituted announcement of the Administrator's
intention of establishing, under Section 306, standards of performance
applicable to new sources for the meat packing plant subcategory within
the meat products source category, which was included in the list
published January 16, 1973.

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         SUMMARY OF METHODS USED FOR DEVELOPMENT OF THE EFFLUENT
           LIMITATIONS GUIDELINES AND STANDARDS OF PERFORMANCE
The effluent limitations guidelines and standards of performance proposed
herein were developed in the following manner.   The point source category
was first studied for the purpose of determining whether separate limitations
and standards are appropriate for different segments within a point source
category.  This analysis included a determination of whether differences
in raw material used, product produced, manufacturing process employed,
age, size, wastewater constituents, and other factors require development
of separate effluent limitations and standards  for different segments
of the point source category.  The raw waste characteristics for each segment
were then identified.  This included an analysis of (1) the-source and volume
of water used in the process employed and the sources of waste and wastewaters
in the plant; and (2) the constituents (including thermal) of all waste
waters including toxic constituents and other constituents which result
in taste, odor, and color in water or aquatic organisms.  The constituents
of wastewaters which should be subject to effluent limitations guidelines
and standards of performance were identified.

The full range of control and treatment technologies existing within
each category was identified.  This included identification of each
distinct control and treatment technology, including an identification in
terms of the amount of constituents (including thermal) and the chemical,
physical, and biological characteristics of pollutants, of the effluent
level resulting from the application of each of the treatment and control
technologies.  The problems, limitations and reliability of each treatment
and control technology and the required implementation time was also
identified.  In addition, the nonwater quality environmental impact,
such as the effects of the application of such technologies upon other
pollution problems, including air, solid waste, noise and radiation
were also identified.  The energy requirements of each of the control
and treatment technologies was identified as well as the cost of the
application of such technologies.

The information, as outlined above, was then evaluated in order to determine
what levels of technology constituted the "best practicable control
technology currently available", "best available technology economically
achievable" and the "best available demonstrated control technology,
processesi operating methods, or other alternatives".  In identifying
such technologies, various factors were considered.  These included
the total cost of application of technology in relation to the effluent
reduction benefits to be achieved from such application, the age of
equipment and facilities involved, the process employed, the engineering
aspects of the application of various types of control techniques process
changes, nonwater quality environmental impact (including energy require-
ments) and other factors.

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The data for identification and analyses were derived from a number of
sources.  These sources included Refuse Act Permit Program data,  EPA
research information;  data and information from North Star files  and
reports; a voluntary questionnaire issued through the American Meat
Institue (AMI), the National Independent Meat Packers Association
(NIMPA), and Western States Meat Packers Association (WSMPA); qualified
technical consultation; and on-site visits and interviews at several
exemplary meat packing plants and slaughterhouses in various areas of the
United States.  All references used in developing the guidelines  for
effluent limitations and standards of performance for new sources re-
ported herein are included in Section XIII of this document.


                   GENERALDESCRIPTION 0F,THE^INDUSTRY

Meat packing plants carry out the slaughtering and processing of  cattle,
calves, hogs, and sheep for the preparation of meat products and  by-
products from these animals.  The plants in this industry range from
plants that carry out only one operation, such as slaughtering, to full-
line plants that not only slaughter, but also carry out processing to
varying degrees (manufacturing of meat products such as sausages,
cured hams, smoked products, etc).  The amount of processing varies
considerably, because some process only a portion of their kill,  while
others process not only their kill, but also the kill from other plants.
Most full-line plants  (packinghouses) and many slaughterhouses also
render by-products; edible and inedible by-products are rendered from
edible scraps and trimmings and from inedible materials, respectively.

Reportedly, there were 5991 meat slaughtering plants in these 48 con-
tiguous states and Hawaii on March 1, 1973.1 Of these, 1364 were federally
inspected.  The industry produced about 37 billion pounds of fresh,
canned, cured, smoked, and frozen meat products per year.  Perhaps 85
percent of the plants in the industry are small plants, for which waste
load data are almost universally unavailable.  The remaining 15 percent
of the plants account for by far the largest part—probably over 90
percent—of the production, and thus, of the waste load.  In 1966,
about 70 percent of all wastewater in the meat packing industry went
to municipal systems; at that time it was projected that, by 1972,
80 percent would be discharged to municipal systems.  It was estimated
in 1962 that 65 percent of the waste from small plants discharged to
municipal systems;2 the figure is undoubtedly higher today.

While the industry is  spread over much of the country, the states of
Nebraska and Iowa led  the nation in beef slaughter with nearly 4.7
million head each in 1972.1 Between them, these two states accounted
for over 26 percent of the beef production in the nation.  The other
states making up the first ten in beef slaughter, each with over one
million head, are Texas, California, Kansas, Colorado, Minnesota,
Illinois, Wisconsin, and Ohio.

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                                        If
Iowa led in hog slaughter by a wide margin, slaughtering nearly 21
million animals in 1971 for nearly 25 percent of the national produc-
tion.  The second state, Illinois, slaughtered about 6.3 million; the
rest of the first ten include, in order, Minnesota, Pennsylvania, Ohio,
Michigan, Indiana, Wisconsin, Virginia, and Tennessee.

Colorado, California, and Texas led in sheep and lambs, with about 1.8,
1.7, and 1.5 million head, respectively.  New York led in calves with
0.64 million head, followed by New Jersey with 0.28, Pennsylvania with
0.25, and Wisconsin with 0.23 million.

The total live weight of livestock slaughtered was about three percent
lower in 1972 than in 1971, with only beef showing a small increase.
Table 1 lists the 1971 and 1972 slaughter in terms of liveweight killed
(LWK).  Beef, with nearly 63 percent, and hogs, with over 34 percent,
account for about 97 percent of the total slaughter.

Wastewaters from slaughtering of animals, and the processing of meat,
and the associated facilities and operation (stock yards, rendering,
and feed manufacturing) contain organic matter (including grease),
suspended solids, and inorganic materials such as phosphates and salts.
These materials enter the waste stream as blood, meat and fat, meat
extracts, paunch contents, bedding, manure, curing and pickling solu-
tions, and caustic or alkaline detergents.
         Table 1.  Commercial Slaughter in 48 States

Beef
Hogs
Calves
Sheep & lambs
TOTAL
Live Wei
Killc
(millic
of pound
1971
36,588
22,535
919
1,111
61,153
-ght
sd
ms
Is)
1972
37,126
20,249
767
1,081
59,223
Percent
of Total
in 1972
62.7
34.2
1.3
1.8
100.0
Percent
Change
Since
1971
+1.5
-10.1
-16.6
- 2.7
- 3.2
Source:  Livestock Slaughter, Current Simnary, 1972.l
                                    8

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                                       f
                         PROCESS DESCRIPTION

A general flowsheet of a typical full-line packing plant, or "packing-
house", is shown in Figure 1.  Such a plant is a "packinghouse" rather
than a "slaughterhouse" by virtue of the "processing" step.   As a packing-
house, it may process a wide range and volume of products.  For example,
it may process no more than its own carcasses; that is, only what it
kills, or even less.  Such a packinghouse is termed "low processing".
On the other hand, a packinghouse may bring in carcasses from other
plants and process much more than it kills.  Such a packinghouse is
termed "high processing".  Less complete plants would operate on appro-
priate parts of the flowsheet of Figure 1.  For example, primary processes
through cooling of carcasses are typical of all slaughterhouses, or
abattoirs.  The secondary processes of blood processing, hide processing,
and rendering may or may not be carried out in the slaughterhouse.  Most
pork plants include processing to some extent; many beef plants, however,
are only abattoirs.  A slaughterhouse may have all of the operations of
a packinghouse, except for the processing, cutting and deboning steps, as
noted in Figure 1.  Such a slaughterhouse, based on high waste load from
secondary processes, would be termed a "complex" slaughterhouse.  A slaughter-
house may also be extremely simple; the simplest kind, with no secondary
processing, is shown in Figure 2.  If the plant has relatively few secondary
processes, and those processes are of a type that give a low waste load,  the
plant is termed a "simple" slaughterhouse.

The meat packing operations begin at the point at which animals arrive
at the plant and carry through the shipping of the product to the whole-
sale trade (or sometimes directly to the retailer).  In the case of very
small operations, the product may go directly to the consumer.  All
processes and handling methods and their management are considered part
of the plant system.  These include not only the processes directed
toward the production of food products, but also those involved in re-
covery of materials of value for by-product manufacture, such as animal
feed ingredients.  The latter processes, indicated as secondary processes
in Figure 1, include those recovery steps such as screening and gravity
separation for proteinaceous solids and grease, and also serve to
reduce the plant waste load.  Hence, processes often considered primary
waste treatment are actually part of the plant system, even though their
effectiveness will have a large bearing on the plant's raw waste load.
For the purposes of this study, "primary" waste treatment refers to
these in-plant control measures.

The number of processes carried out and the way in which they are
carried out varies from plant to plant, and has an effect upon the
effluent treatment requirements.  It is convenient to discuss them in
terms of the processes listed at the top of page 12.

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    o

    fe
1
D>

I
8.
                                            1
                Processes
    Primary        I      Secondary
             Animals
             Livestock
               Pens
              Killing
Hide Removal
           Hog Dehairing
 Eviscerating
  Trimming
   Cooling
              Cutting
             Deboning
           Processing
               Grinding
               Curing
               Pickling
               Smoking
               Cooking
               Canning
                          Blood Processing
Hide Processing
                            Hair Recovery
                                     Viscera Handling
                                 I
                               Inedible
                             Rendering
                               .Edible
                             Rendering
        Pro cess Effluent
                                                             Products
                           Dried Blood
^Hi

H,
Hides

Hog Hair
                                                              -» Edible Offal
                         -> Carcasses
                         •> By-Products

                         ->Cut Meat
                            Lard
                            Edible tallow
                                                     >Meat Products
        Source:   Industrial  Waste  Study  of the Meat Product  Industry3


                  Figure 1.   Process Flow in a Packing Plant
                                         10

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               s
        Animals
            x
        Livestock

          Pens
          Killing
       Hide Removal

      Hog  Dehairing
        Eviscerating

         Trimming
          Cooling
     to
-> Outside
  Processing
Carcasses
Figure 2.  Process Flow for Simple Slaughterhouse
                     11

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                        MANUFACTURING  PROCESSES

Meat packing processes include:

     1.   Animal stockyards or pens
     2.   Slaughtering, which in turn, includes:
               Killing
               Blood processing
               Viscera handling and offal washing
               Hide processing
     3.   Cutting
     4.   Meat processing
     5.   Rendering
               Edible
               Inedible
     6.   Materials recovery (primary separation)

As indicated in a general waste flow diagram for a packinghouse, Figure 3,
all of these processes contribute to the raw waste load except the ma-
terials recovery or primary separation step; this removes material that
would  otherwise be lost to the sewer.


                         Stockyards and Pens

In most meat packing plants, animals are held in holding pens for less
than one day.  The animals are usually watered but not fed while waiting
their  turn for slaughter.  The pens are often covered for protection from
the elements, and sometimes are enclosed.  In winter in northern climates,
they may be heated enough to minimize condensation.  A small volume of
wastewater results from periodic washdown and from runoff; this enters the
sewer  downstream of any materials recovery processes.
                             .Slaughtering

The slaughtering of animals  includes the killing  (stunning, sticking—
cutting the jugular vein, bleeding) and hide removal for cattle, calves,
and sheep, and scalding and  dehairing for hogs; eviscerating; washing of
the carcasses; and cooling.  In the present context blood, viscera, and
hide processing are included as subprocesses.  Not all plants carry out
all operations; for example, some only follow a narrower definition by
shipping out blood, hides, and viscera for processing elsewhere.

Animals taken from the pens  are immobilized upon  entering the kill area
by chemical, mechanical or electrical means.  Cattle are usually stunned
by a blow  to the brain.  A steel pin driven by a  powder charge  or by air
pressure delivers the blow.  Hogs are immobilized by an electric shock
from electrodes placed on the head and back, or by running them through
a tunnel where  they breath a carbon-dioxide atmosphere.  The latter is
                                   12

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      Waste
Solid    I   Liquid
          Processes
Primary      !     Secondary
                      Animals
I
\
fsolid
1 Com)
| Lan
< 	 .--
r-*
, i Ma
* "1 Tr
L__,
««
«- —
Waste j
lasting '
dFIII |
" "Is
1
L
It
*• — i
nure I
Lp_jf— -
1^
k- -
Q."
u 	
< 	
K- "— —
. k--
1
r— '
i 	
k 	
Secondary '
Treatment r*~
	 r 	 1
\i/
Livestock
Pens

Killing


Blood Processing
J

Hide Removal
Hog Dehairing



Hide Processing
Hair Piecovery
„ r J- , '

Eviscerating
Trimming
	
Cooling
	
Cutting
Deboning

Processing
Grinding
Curing
Pickling
Smoking
Cooking
Canning
	

	 : 	


Viscora Handling
-JJ

Inedible
Rendering
-i
Edible
Rendering
i
Recovery
System
        Final Effluent
Figure 3.   Waste Flow Diagram for a Packinghouse.
                         13

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becoming rare.  Stunned cattle are suspended by their hind legs from an
overhead rail for sticking and bleeding.  Immobilized hogs are hung over
a bleeding trough or are placed on a conveyor with their heads hanging
over the bleeding trough.  When they are stuck, the blood drains into the
trough for collection.  During bleeding, the conveyor carrying the animal
moves slowly over the trough or gutter that catches the blood so it can be
collected for blood processing.  Sheep, lambs, and calves are generally  -
handled like cattle.  Some blood spills or splashes outside the collecting
area, especially as the carcasses are conveyed to the next operation.  Also,
clean-up operations wash considerable blood into the sewer.

Following bleeding, the hides are removed from the cattle, usually by
mechanical means.  Before pulling, the hide is separated (by conventional
or air-driven, hand-operated knives) sufficiently for fastening to the
hide puller.  Air knives are gaining favor because a skinner can be
trained to use them very quickly and there is less chance of damaging
the hide.  The most common hide puller pulls the hide "up"; i.e.t from
the neck to the tail, after the head is removed.  A newer puller pulls
downward, over the head.  A traveling cage places the operator at the
proper level for skinning and attaching the puller.  Very small plants
skin by hand.  Some blood and tissue falls to the floor from this operation,
or blood even splashes on walls.  Much is collected, but some reaches the
sewer, particularly during clean-up.

The hogs are usually not skinned, but are passed through a scalding tank
of water at about 130°F, then dehaired.  The dehairing machine is a
rotating drum containing rubber fins.  As the hog passes through the
drum, the rubber fins abrade off the hair and water constantly flowing
through the machine carries the hair to screens for recovery.  In small
plants, dehairing is often a hand operation.  The hair is sometimes
baled and sold for such uses as the manufacture of natural bristle brushes,
and for furniture stuffing.  Occasionally, it is hydrolyzed for animal
feed.  Often it is disposed of as solid waste.  Following dehairing, hog
carcasses are singed for final hair removal, and sprayed with water to
cool and wash.  They are inspected and trimmed to remove any remaining
hair or other flaws.  Scald water and dehairing and wash water contain hair,
soil, and manure.  The final carcass washwater is relatively clean.  All
are discharged to the sewer.

A trend appears to be developing for skinning hogs, much like cattle.
This eliminates the scalding and dehairing.

Next, the carcass is opened by hand knives and the animal is eviscerated.
The heart,  liver, tongue(cattle),  and kidneys are removed from the
viscera and washed;  these are sold as edible meat or are used in meat
products.  Lungs may be sold for pet food.  The balance of the viscera is
channeled to the viscera handling subprocess.  The carcass is also trimmed
and inspected.  Scrap trimmings go to rendering for edible or inedible
by-products.   Blood and tissue from the evisceration find their way directly
to the sewer and are washed into the sewer during clean-up.

-------
The carcasses, cut in half for beef and sheep, and left whole for hogs
and calves, are hung in a cooler  where they stay at least 24 hours.
Materials recovered during clean-up, particularly by dry clean-up pro-
cedures, go to inedible rendering, either on- or off-site.


                           Blood Processing

Handling and processing of the blood is usually a part of the slaughter-
house operation.  However, in some cases, the blood may be shipped out of
a plant for processing elsewhere.  The blood may be heated to coagulate
the albumin; then the albumin and fibrin are separated from the blood
water and forwarded for further processing such as pharmaceutical prep-
arations.  The blood water or serum remaining after coagulation may be
evaporated for animal feed, or it may be sewered.  In most cases, the
whole blood is sent directly to blood dryers and used for animal feed.
In small plants it is occasionally sewered.


                          Viscera Handling

The beef paunches may be handled either wet or dry.  For wet handling,
the contents of the paunches, 50 to 70 pounds of partially digested feed
("paunch manure") are washed out with water and passed over a screen.
The separated solids go to solid waste handling.  The liquor passing
through the screen is generally scx/ered.  In dry handling, paunches are
dumped on a screen and the solids are sent either to a dryer or to a truck
for removal from the plant.  In some plants, the entire paunch contents
are sewered; solids are later removed at the sewage treatment plant.
A newer practice is to send the entire contents to processing or to haul
out for disposal elsewhere.  The paunch is then washed thoroughly if it
is to be used for edible products.  Hog stomach contents are normally
wet processed.

The intestines may be sent directly to rendering or they may be hashed
and washed and then sent to rendering.  Often, the beef paunches and hog
stomachs and the intestines are washed and saved for edible products.
For example, it is common practice to bleach the paunches for marketing
as tripe, and to recover hog casings and chitterlings (large intestines
of hogs).  Occasionally, paunches and stomachs are given only a brief
washing and are sold for food for mink or pet food.  Stomachs may be
routed, unopened, directly to an inedible dryer.  Hog intestines still
find some market as sausage casings and for surgical sutures.  Any viscera
washing or cleaning operation results in the contents of stomachs, intestines,
etc, as well as a considerable amount of grease being discharged to the sewer.
                                    15

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                            jjide Processing

Hides may be processed wet or dry.  Wet processing involves hide demanur-
ing, washing, and defleshing, followed by a brine cure in a brine vat or
raceway.  The cure time may be as short as 12 hours.  In dry curing, the
washed, defleshed hides are packed with salt and stacked in the curing
room.  Often hides are only washed and hauled to other plants or to
tanneries for defleshing and curing; sometimes they are hauled without
even washing.  Washing may be done by batches in a rotating screen or in
a tumbler similar to a large concrete mixer.  Defleshing is usually done
by passing the hide through rotating scraper knives.  In very small plants
both may be done by hand.  Some effort is being made toward transferring
some of the tannery operations to the slaughtering plant; this allows
better recovery and ensuing wastes to be channeled into animal feed.  On
the other hand, some specialty plants have come into being that take the
green, unwashed hides from the slaughtering operation and deflesh, clean,
and cure them as an intermediate step before they go to the tannery.  Hide
processing leads to significant loads of blood, tissue, and dirt being
sewered.  The curing operation contributes salt (sodium chloride) to
the wastewater.
                                Cutting

Although meat cutting may be considered part of the "processing operation",
it is often carried out in a separate part of the building, or may be
carried out in plants that do no further processing.  The latter is
particularly true in the case of beef plants.  In the cutting area, the
carcasses are cut for direct marketing of smaller sections or Individual
cuts, or for further processing in the processing operations.  Trimmings
from this operation that do not go to products such as sausages and
canned meats go to rendering of edible fats and tallows.  Inedible
materials are rendered for inedible fats and solids.  There is always
some material that reaches the floor, and a considerable amount that
adheres to saw blades or conveyer systems, including meat, bone dust,
fat tissues and blood that can be recovered  for inedible rendering.
Much of this, however, is washed to the sewer during clean-up.


                            Meat Processing

The edible portion resulting from slaughtering and cutting may be processed
in a variety of ways.  These include the manufacture of many varieties
of sausages, hams, bacon, canned meats, pickled meats, hamburger, portional
cuts, etc.  Obviously, the processing of edible products is complex and
varies from plant to plant.  Some beef cuts are delivered to curing rooms
for preparation of corned beef.  Hog carcasses are cut up and hams, sides,
and shoulders are generally sent to curing.  Some loins may be deboned
and cured for such products as Canadian bacon.  (Most loins are packaged
without curing for the retail market.)
                                    16

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The curing operation involves injecting a salt and sugar solution into the
meat, usually with a multineedle injection machine.  Some curing.is done
by soaking in cure solution.  Smoking is done in smokehouses at elevated
temperatures.  Smoked flavors are also obtained by soaking in or injecting
a solution containing "liquid smoke".  Spills from cooking equipment,
excess cure solution spilled during injection, and materials washed into
the sewer during clean-up all contribute to the waste load.

The processing operations may be carried out either in packing plants or
in separate plants that do processing only.  The "meat packing" industry
concerns only the processing associated with packing plants.


                               Rendering

Rendering separates fats and water from tissue.  Two types of rendering,
wet or dry, may be used for either edible or inedible products.  A type
of dry rendering process called "low temperature" rendering is coming into
common use, particularly for edible rendering.  Edible trimmings from the
cutting operations that do not go into products such as sausages and canned
meats go to rendering for preparation of edible fats and tallows.  The
inedible processing is carried out in an area in the packing plant separate
from the processing of edible products.  Inedible products find use mainly
in animal feed.

The materials to be rendered are normally passed through a grinder.  For
inedible rendering, this includes bones, offal (usually without
cleaning), condemned animals, etc.  From there it is fed to a continuous
rendering operation, or to a blow tank that can be pressurized periodically
to feed batch cookers.  Economics usually dictate the type of process
used.

Wet rendering is usually carried out in pressure tanks with 40 to 60 psi
steam added directly.  The fat phase is separated from the water phase
after cooking.  The solids in the water phase are screened out, leaving
what is called tankwater.  Tankwater is frequently evaporated to a thick
material, rich in protein, known as stick, which is added to animal feeds.

Dry rendering is carried out either in vessels that are open to atmo-
spheric pressure or are closed and under a vacuum.  The material is cooked
until all of the free moisture in the tissue is driven off.  The liberated
fat is then screened to remove the solid proteinaceous residue.  Dry
rendering can be either a batch or continuous operation, depending upon
the equipment used.  Batch operations arc conducted in moderate-sized
agitated vessels; continuous operations are conducted in either agitated
vessels that are long enough to provide sufficient retention time to
evaporate the water, or in multistage evaporators.   Dry batch rendering
is the moat widely used rendering process.
                                   17

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Low temperature rendering is a fairly recent development used primarily
to produce edible products.  In this process, the material to be rendered
is first finely ground.  The mass is then heated to just above the melting
point of the fat.  Centrifugation is used to remove the non-fatty material,
and the fat is further clarified in a second centrifuge.  The water phase
may be further treated in other types of equipment for grease and solids
recovery.

Spills from cooking equipment, collection tanks, and discharges from
equipment washdown further contribute to total waste discharges.  However,
rendering operations serve to recover a number of materials, (e.g.,
grease, fats, offal tissue) which might otherwise dramatically increase
total plant waste loads.  Moreover, since material such as grease that is
less readily biodegradable is reduced in raw waste discharges, subsequent
efficiencies in biological waste treatment are enhanced.


                           MATERIALS  RECOVERY

The wastewater from the plant, excluding only the wastewater from the hold-
ing pens and, perhaps, paunch screening, usually runs through catch basins,
grease traps, or flotation units.  The primary purpose of these systems is
usually the recovery of grease, which is sent to inedible rendering.  The
very important function of removal of pollutants is also served.  Grease
recovery most often has been the controlling factor, so the systems may
be considered part of the manufacturing operation rather than a stage in
pollution abatement.  However, if the catch basin or grease trap is not
adequate to meet the final effluent requirement, it may be necessary to
further remove grease by an air flotation unit, with or without the
addition of chemicals.  This unit can be considered primary treatment
because its main function is for pollution abatement rather than product
recovery.

The most common method of solids recovery employs a catch basin.  Solids
settle to the bottom and are removed continously or periodically; grease
floats to the top and is scraped off, often continuously.  For effective
recovery, these units usually have greater than a 20-minute detention
time and are designed to minimize turbulence.

The best grease recovery is accomplished by employing dissolved air flota-
tion in a tank.  The tanks are usually large enough to retain the liquid
for twenty minutes to one hour.  Air is injected into a portion of the
effluent, pressurized, and recycled, or is injected into the wastewater
before it enters the tank.  The liquid is pressurized to "supersaturate" it
with air.  The liquid then enters the tank where air bubbles coming out of
solution rise to the surface, carrying grease particles with them.  The
grease is removed by skimmers.  While the tanks are not designed for the
most effective removal of settleable solids, some solids settle to the
bottom and are scraped into a pit and pumped out.  In some cases, flotation
is added to other recovery systems for the primary purpose of pollution
abatement.
                                   18

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In addition to recovery systems above, some plants also recover part of
the settleable solids before the waste streams enter the grease removal
system by employing self-cleaning screens, either static, vibrating, or
rotating.  The solids that are recovered from these, as well as the solids
recovered from the catch basins are returned to the plant's rendering system.


                       PRODUCTION CLASSIFICATION
The U.S. Bureau of Census, Standard Industrial Classification Manual1*
classifies the meat products industry under Standard Industrial Classifica-
tion (SIC) group code number 201 (Major Group 20).  Meat packing plants
are classified as Industry No. 2011, which is defined.as:

          "Establishments primarily engaged in the slaughtering,
          for their own account or on a contract basis for the
          trade of cattle, hogs, sheep, lambs, and calves for
          meat to be sold or to be used on the same premises in
          canning and curing, and in making sausage, lard, and
          other products."

     Abattoirs  on own account or for the trade; except nonfood
          animals
     Bacon, slab and sliced, mitso*
     Beef, mitsc
     Blood meal
     Canned meats, except baby foods, mitso
     Cured meats, mitso
     Lamb, mitso
     Lard, mitso
     Meat extracts, mitso
     Meat, mitso
     Meat packing plants
     Mutton, mitso
     Pork, mitso
     Sausages, mitso
     Slaughtering plants: except nonfood animals
     Variety meats (fresh edible organs), mitso
     Veal, mitso

*mitso - made in the same establishment as the basic materials.


                     ANTICIPATED  INDUSTRY  GROWTH

Shipments of meat slaughtering and meat processing plants in 1972 was
$23.8 billion and is expected to rise by about six percent to about $25.3
billion in 1973.  The U.S. Industrial Outlook:: 197S5  estimates that this
annual growth rate of six percent per year will he substained through 1980
for American producers.

                                    19

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Factors that should contribute to growth can be distinguished from those
that act to restrain this growth.

A growing population and rising family incomes will continue to maintain
consumer demand for meat products.  Historically, as incomes of American
families have grown, they have substituted higher priced food products
such as meats for the bread and potatoes in their diets.  Demand for beef,
in particular, has continued to grow on a per capita basis as well as in
total; for example, in 1972 the typical American consumed 115 pounds of
beef, which was two pounds more than in 1971.  In addition, larger
quantities of portion-controlled meats are being processed in response
to institutional demands by fast-food outlets, hotels, restaurants, and
other institutions.

Several factors serve to restrain potential growth of the American meat
industry, including higher meat prices, removal of import quotas, and the
availability of synthetic substitutes.  Two factors in higher meat prices
may be the sharply reduced hog and calf slaughter in 1972, for an overall
decrease of more than three percent from 1971.  Supplies must increase
sharply during the remainder of the decade to achieve the projected
growth rates.  Although firms in the industry have installed new plants
and equipment, the resulting increased efficiency has been more than
offset by higher costs for labor, livestock, packaging materials, and
transportation—costs that have been passed on to consumers in the form
of higher retail prices.  On June 26, 1972, the U.S. eliminated all
quantitative restrictions on meat imports to try to curb rising meat
prices and to help meet the increased demand for beef; this effort was
not completely successful, as indicated by the drastic price increases
during the rest of the year.

Finally, synthetic meat substitutes, such as protein derivatives from
soy beans, have been introduced into consumer markets.  Although of minor
importance in 1973, these substitutes may reduce growth in meat
slaughtering and meat processing by 1980 if meat prices remain high and
widespread consumer acceptance of the substitutes is achieved.
                                    20

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                                          spaa
                               SECTION IV

                        INDUSTRY CATEGORIZATION


                             CATEGORIZATION

In developing effluent limitations guidelines and standards of perfor-
mance for the meat packing industry, a judgment was made as to whether
limitations and standards are appropriate for different segments (sub-
categories) within the industry.  To identify any such subcategories,
the following factors were considered:

          Wastewater characteristics and treatability
          Final products
          Primary manufacturing processes
          Secondary manufacturing processes
          Raw materials
          Size, age, and location of production facilities.

After considering all of these factors, it was concluded that the meat
packing industry consists of two major groups:  slaughterhouses and
packinghouses.

          A slaughterhouse is a plant that slaughters animals and has
          as its main product fresh meat, usually carcasses broken
          down no smaller than quarters.

          A packinghouse is a plant that both slaughters and processes
          fresh meat to cured, smoked, canned, and other prepared meat
          products.

Each of the above groups was further subdivided into two, giving a
total of four subcategories:

     I.   Simple Slaughterhouse—is defined as a slaughterhouse that
          does a very limited amount of processing of by-products
          (i.e.,secondary processing).  Usually, no more than two
          secondary processes, such as rendering, paunch and viscera
          handling, blood processing, or hide or hair processing are
          carried out.

    II.   Complex Slaughterhouse—is defined as a slaughterhouse that
          does extensive processing of by-products (i.e.,secondary
          processing).  It usually carries out at least three of the
          secondary processes listed above.


                                  21

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    III.  Low-Processing Packinghouse—is defined as a packinghouse
          that normally processes less than the total animals killed
          at the site, but may process up to the total killed.

     IV.  High-Processing Packinghouse'—is defined as a packinghouse
          that processes both the total kill at the site and additional
          carcasses from outside sources.

The differences between the four subcategories and the relationships
between them is shown schematically in Figure 4.  The simplest plant is
a Simple Slaughterhouse,and it does little secondary (by-product)
processing.  By adding substantial secondary processing, the plant
becomes a Complex Slaughterhouse.  By adding a meat processing operation,
but processing less than produced in the plant as fresh meat, (pro-
cessing less than the plant kills), the plant becomes a Lou Processing
Packinghouse.  When the plant processes more than it kills (e.g.,
brings in carcasses from outside in addition to processing its own),
it becomes a High Processing Packinghouse.


                      RATIONALE FOR CATEGORIZATION

              Wastewater Characteristics and Treatabllity

Industrial practices within the meat packing industry are diverse and
produce variable waste loads.  It is possible to develop a rational
division of the industry, however, on the basis of factors which
group plants with similar raw waste characteristics.  The wastewater
characteristic used in categorizing the industry is five-day bio-
chemical oxygen demand (8005) in units per 1000 units live weight
killed: kg BOD5/1000 kg LWK (Ib BOD5/1000 LWK).  BOD5 provides the
best measure of plant operation and treatment effectiveness among
the parameters measured, and more data are available than for all
other parameters except suspended solids.  Suspended solids data
serve to substantiate the conclusions developed from BOD5 in categor-
izing the industry.

The major plant waste load is organic and biodegradable: BOD5, which
is a measure of biodegradability, is the best measure of the load
entering the waste stream from the plant.  Furthermore, because second-
ary waste treatment is a biological process, BOD5 also provides a use-
ful measure of the treatability of the waste and the effectiveness
of the treatment process.  Chemical oxygen demand (COD) measures
total organic content and some inorganic content:.  COD is a good
indicator of change, but does not relate directly to biodegradation,
and thus does not indicate the demand on a biological treatment process
or on a stream.
                                 22

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                                         Meat Packing Industry
                          r
                                                   1
                    Slaughterhouses
              1
                          1
        Subcategory  I

            SIMPLE
      SLAUGHTERHOUSE
to
              i
           Slaughter
          Operations
Low-Level
Secondary
Processing
                           1
                     Subcategory Z

                       COMPLEX
                   SLAUGHTERHOUSE
                           1
                       Slaughter
                       Operations
 Intensive
Secondary
Processing
                                                           Packinghouses
                                1
                         Subcategory  3

                        LOW-PROCESSING
                         PACKIMGHOUSE
                            Slaughter
                            Operations
                                                                J_
                                                             intensive
                                                            Secondary
                                                            Processing
                                                            Low-Level
                                                          Processed Maat
                                                            Products
                                                            Production
  Subcafetpry  4

HIGH-PROCESSING
  PACKINGHOUSE
     Slaughter
    Operations
     Intensive
    Secondary
    Processing
                                                                                      _L
                                                                        Additions!
                                                                       Carcasses and
                                                                         Meat-Cut
                                                                        Purchases
                                                                                   Intensive
                                                                                   Processed
                                                                                 Meat Products
                                                                                   Production
                          Figure 4.  Categorization of Meat Packing Plants

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 As developed in  more  detail  in  Section  V,  specific  differences  exist
 in the BOD5  load for  raw wastes for  four distinct groupings  of  meat
 products  operations.  As defined above, these  groupings  (by  plant
 type)  are substantiated  as subcategories on  the basis  of waste  load.

 A number  of  additional parameters were  also  considered.  Among  these
 were nitrites and nitrates,  Kjeldahl nitrogen, ammonia,  total dissolved
 solids, and  phosphorus.  In  each case,  data  were insufficient to just-
 ify categorizing on the  basis of the specified parameters; on the
 other  hand,  the  data  on  these parameters helped to  verify judgments
 based  upon BOD5.

 Judging from secondary waste treatment  effectiveness and finaj.
 effluent  limits,  wastewaters from all plants contain the same consti-
 tuents and are amenable  to the  same  kinds  of biological  treatment
 concepts.  It was anticipated that geographical location, and hence
 climate,  might affect the treatability  of  the waste to some  degree.
 Climate has  occasionally influenced  the kind of secondary waste treat-
 ment used, but has not had an influence on the ultimate  treatability
 of the waste or  the treatment effectiveness, given  careful operation
 and maintenance.
                              Final  Products
 The  final products of a meat  packing plant  provide  further  support  for
 the  selected  subcategorization.   Final products relate directly to
 processes employed, as discussed  below.  A  plant  that processes meat
 to products such  as canned, smoked, and  cured meats is significantly
 different from  a  plant that does  no processing.   Thus, there  is a
 clear  distinction between  a packinghouse—a plant that both slaughters
 and  processes—and a slaughterhouse.

 Because  of product differences, a further division  of packinghouses
.is justified; some plants  process no more than they kill, and others
 process  far more  by bringing  in additional  carcasses and meat cuts
 from other plants.  Therefore, packinghouses divide into two  subcat-
 egories,  depending on the  amount  of final product that they produce.

           .Low-Processing Packinghouse—has  a ratio  of weight  of pro-
           cessed  products  to  live weight killed less than 0.4.  This
           numerical designation actually approximates the ratio of
           weight  of processed products to live weight, when the entire
           carcass is processed (i.e., forty percent of the  weight of
           a live  animal ultimately is processed into final  products).
           In  practice, these  plants have an average ratio not of 0.4,
           but about 0.14.  This low ratio indicates that low  process-
           ing plants process  only about  a third of  their kill.
                                 24

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          High-Processing Packinghouse—has a ratio of weight of pro-
          cessed products to live weight killed greater than 0.4.  From
          the earlier definition, such a plant must bring in carcasses
          from outside sources for processing.  For these type of
          plants the average ratio is about 0.65—high processing
          plants process about one-third more carcasses than are
          killed at the site.

The inedible by-products of a meat packing plant (i.e., tallow, dried
blood, tankage, dried solids) also affect categorization.  However,
the methods of by-product manufacture vary greatly, and the effect
of recovered by-products upon categorization is discussed in "Second-
ary Manufacturing Processes".

                    Primary Manufacturing Processes

The primary manufacturing processes include the storage and slaught-
ering of animals and the dressing (evisceration), cutting, and pro-
cessing of carcasses.  As diagrammed in Section III, Figure 1, there
is a distinct difference between the types and amounts of primary
processes in various plants.    Together with final products, this
factor enhances the logic of the chosen subcategories.


                   Secondary Manufacturing Processes

Secondary manufacturing processes are those by-product operations for
the handling, recovery, and processing of blood, trimmings, and inedible
offal.  This includes paunch and viscera handling, hide processing,
hair recovery and processing, and edible and inedible rendering.
Secondary processes used interrelate with both the final products and
waste characteristics; however, the kind of manufacturing process is
more relevant than the specific by-product.  The process by which a
by-product is made determines the waste load.  Thus, It is the nature
of the secondary processes rather than by-products themselves which
define the categories.  Unfortunately, there are a number of secondary
manufacturing processes that can be used within each by-product area.
Furthermore, there is no typical or usual combination of secondary
manufacturing processes in the industry.  Therefore, some other means
of grouping plants by secondary manufacturing processes is required.

Computer analysis, literature, and experience suggested that empirical
weighting factors (relative contributions to waste loads) assigned to
each secondary processing technique would permit a further analysis of
the slaughterhouse subcategory wherein the types and amounts of second-
ary processes prove critical.
                                  25

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Therefore, waste loads In terms of kg BOD5/1000 kg LWK (Ib BOD5/1000
Ib LWK) were estimated for each secondary process that contributes
materially to the raw waste load.  Estimates were made from discus-
sions with consultants, data obtained in this study, and from the
experience of the investigators.  As summarized in the subcategory,
definitions and waste characteristics section above, the waste load
factors are most important relative to each other rather than as ab-
solute waste load values.  The factors applied to the secondary
processes were:

          Process                               Factor

     Paunch handling:
          wet dumping                            1.0

     Blood processing:
          Steam coagulated and screened,
          with blood water sewered               1.2
          Whole blood dried                      0.3

     Rendering (edible or inedible)
          Wet and low temperature,
          sewering water                         2.0
          Dry                                    0.5

     Hide Processing
          Defleshing, washing, curing            1.5

     Hair processing
          Hydrolyzing                            1.0
          Washing                                °'7

     Viscera Handling
          Casing saving, hashing and washing,
          or stomach and chitterling washing     0.6
          Tripe processing                       0.4

The waste load factors for the secondary processes were summed for
each slaughterhouse.  The sum of the waste load factors divided the
slaughterhouse sample into two distinct clusters, one group of
slaughterhouses with totals below  4.0 and the other above^4.0
The plants with totals below 4.0 were relatively simple; i.e.t they
had few  secondary processes and  those processes tended to be the  types
that were low waste  load contributors.  These "simple" slaughterhouses
had relatively low total waste  loads.  The plants with waste load
factors  above 4.0 were much more complex; i.e., they had many secondary
processes.  These "complex" slaughterhouses had distinctly
higher waste loads.
                                  26

-------
The waste load factors serve an. additional purpose.  Occasionally,
a slaughterhouse in one of the subcategories carries out an unusually
high amount of secondary processing.  An example is a complex slaughter-
house that processes hides from several other plants.  Its raw waste
load is unusually high.  However, when a waste load of 1.5 kg BODs/lOOO
kg LWK (1.5 Ib BOD5/1000 Ib LWK, or about 1.5 Ib BOD per hide processed)
is taken into account for the extra hides processed, the waste load for
the plant leads to logical assignment of this plant to its proper
subcategory.
Raw materials characteristics help to substantiate the above categor-
ization.  The raw materials include live animals (cattle, hogs, sheep,
lambs, and calves), water, chemicals, and fuel.  Although different
kinds of animals vary greatly in size and require some different pro-
cessing techniques, these effects are best handled by incorporation
into other factors.  For example, weight variations are accounted
for by normalizing (dividing) waste parameter values by the daily
live weight killed; this gives a waste load per unit of raw material
independent of the kind of animal.  The effects on waste load of
differences in the plant processes that are dependent on the kind of
animal are not significant.

A definite relationship was found between raw waste load and water
use, both in individual plants and in the four subcategories.  Var-
iations in water flow between subcategories are caused by different
process requirements.  Highly varying water use in plants within the
same subcategory are the result of varying operating practices.

Chemicals used in packing plants  (i.e., preservatives, cure, pickle,
and detergents) do not serve as a basis for categorization.  Differences
in waste loads caused by chemicals are the result of different operating
practices.
Fuels are usually natural gas or fuel oil.
categorization .
                                            They have no effect on
                        Size. Age, and Location

Size, age, and location are not meaningful factors for categorization
of the  industry.  Neither  the information from this study, nor that
from previous studies , reveals any discernible relationship between
plant size and effluent quality or other basis for categorizing.
Both high and low quality  raw wastes were found at both ends of the
plant size spectrum within the industry.  Other factors perhaps related
to plant size, such as degree of by-product recovery, are discussed
elsewhere .
                                 27

-------
Age as a factor for categorization might be expected to be at least
amenable to quantitative identification and interpretation, but
unfortunately age does not even achieve that degree of usefulness.
The red meat industry is a relatively old industry, and some old plants
incorporate early operating ideas and practices.  Some plants, on the
other hand, are very new and incorporate the latest operating ideas
and practices.  Nevertheless, most older plants have been updated by
changes in plant processes and plant structure.  Therefore, to say
that a plant was built 50 years ago and is 50 years old is not par-
ticularly meaningful in terms of interpreting in-plant practices.  In
addition, no consistent pattern between plant age and raw waste
characteristics was found.

Examination of the raw waste characteristics relative to plant loca-
tion reveals no apparent relationship or pattern.  The effect of manure
and mud-coated animals processed in the winter by northern plants
is not as significant as other factors.  The type of animal handled,
which is sometimes influenced by location, does not seem to affect
the waste load either.
                                  28

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                               SECTION V

                  WATER USE AND WASTE CHARACTERIZATION

                       WASTEHATER CHARACTERISTICS

Water is a raw material in the meat packing industry that is used
to cleanse products and to remove and convey unwanted material.
The principal operations and processes in meat packing plants where
wastewater originates are:

     •    Animal holding pens

     •    Slaughtering

     •    Cutting

     •    Heat processing

     •    Secondary manufacturing (by-product operations)
          including both edible and inedible rendering

     •    Clean-up

Wastewaters from slaughterhouses and packinghouses contain organic
matter'(including grease), suspended solids, and inorganic materials
such as phosphates, nitrates, nitrites, and salt.  These materials
enter the waste stream as blood, meat and fatty tissue, meat extracts,
paunch contents, bedding, manure, hair, dirt, condenser water, losses
from edible and inedible rendering, curing and pickling solutions,
preservatives, and caustic or alkaline detergents.

                       Raw Waste Characteristics
The raw wasteload from all four subcategories of the meat packing industry
discussed in the following paragraphs includes the effects of in-plant
materials recovery (primary waste treatment).

The parameters used to characterize the raw effluent were the flow,
BODs, suspended solids (SS), grease, chlorides, phosphorus, and Kjeldahl
nitrogen.  As discussed in Section VI, BODs is considered to be, in
general, the best available measure of the wasteload.  Parameters used
to characterize the size of the operations were the kill (live weight)
and amount of processed meat products produced.  All values of waste
parameters are expressed as kg/1000 kg LWK, which has the same numerical
                                 29

-------
value when expressed in lb/1000 Ib LWK.  In some cases, treated effluents
are so dilute that concentration becomes limiting.  In these cases,
concentration is mg/1.  Kill and amount of processed meat products are
expressed in thousands of kg.

The data used to compute the values presented in Tables 2 through 5
were obtained through questionnaires distributed to their members by
the three major trade associations—the American Meat Institute, the
National Independent Meat Packers Association, and the Western States
Meat Packers Association; through data provided directly by the
companies; and through data obtained from state pollution control agencies
and the Environmental Protection Agency.  Some information on the kill
and amount of processed products was obtained from the U.S. Department
of Agriculture.  Sufficient information was collected on 85 identifiable
plants to allow the plants to be categorized and the data to be included
in characterization of the raw waste.  The information found in the
open literature was not detailed enough to be included.

A summary of data including averages, standard deviations, ranges, and
number of observations (plants) is presented in the following sections
for each of the four subcategories of the industry.  The four sub-
categories are:

     1)   Simple Slaughterhouse

     2)   Complex Slaughterhouse

     3)   Low-processing Packinghouse

     4)   High-processing Packinghouse

A detailed description of the subcategories was presented in Chapter IV.


                            Slaughterhouses

A typical flow diagram illustrating the sources of wastewaters in both
simple and complex slaughterhouses is shown in Figure 5.  It should be
noted that a simple slaughterhouse normally conducts very few of the
by-product operations (secondary processes) listed in Figure 5, whereas
a complex slaughterhouse conducts most or all of them.  Occasionally
slaughterhouses may not have wastewaters from some of the operations
shown, depending upon individual plant circumstances.  For example,
some slaughterhouses have dry animal pen clean-up with no discharge of
wastewater, some have little or no cutting, and others may have a
separate sewer for sanitary waste.
                                 30

-------
    Animal Pens
   Slaughtering
       Kill
   Hide Removal
   Evisceration
      Paunch
  Scalding  & Hair
      Removal
      Cutting
Sanitary Facilities
By-Product Operations
       Blood
                    Ancillary Operations
                    (except hair & hides)
Raw Uastewater
   from
Slaughterhouse
    Figure 5.  Operating and Wastewater Flow Chart
                for  Simple and Complex Slaughterhouses
                              31

-------
The flow diagrams include both beef and hog operations.  As noted in
Section IV, no distinction, was made in subcategories for the type of
animal.  It is recognized, however, that in some small plants there
will be more significant differences in pollution wasteloads depending
on the animal type.  These cases, however, are still within the waste-
loads cited for the subcategory.
Simple Slaughterhouses

Table 2 summarizes the plant and raw waste characteristics for a simple
slaughterhouse.  The table shows that 24 of the 85 plants analyzed were
simple slaughterhouses ( about one-half were beef and the others divided
between hogs and mixed kill) and that the BODg wasteload covers a
range from 1.5 to 14.3 kg/1000 kg LWK (same value in lb/1000 Ib LWK).
Defining small plants as those with a LWK of less than 43,130 kg
(95,000 Ibs), and medium plants as those with a LUK between 43,130 kg
and 344,132 kg (758,000 Ib), it can be stated that only small and
medium plants were included.  In fact, two are small and twenty-two
are medium.


Complex Slaughterhouses^

Table 3 summarizes the plant and raw waste characteristics for complex
slaughterhouses.  Nineteen of the 85 plants analyzed were complex slaugher-
houses (11 were beef; 6, hogs; and 2, mixed).  Defining a large plant
as one with a LWK of greater than 344,132 kg (758,000 Ib), and a med-
ium plant as in the paragraph above, the kill data of Table 3 shows all
complex slaughterhouses included are either medium or large.  Actually
about one-third were large.


                             Packinghouses

A typical flow diagram illustrating the sources of wastewaters in both
low- and high-processing packinghouses is shown in Figure 6.  As defined
in Section IV, the main difference between a low- and high-processing
packinghouse is the amount of processed products relative to kill,
i.e.t less than 0.4 for a low- and greater than 0.4 for a high-processing
plant.  As a result, the wasteload contribution from processing is less
for a low-processing packinghouse.  A comparison of Figures 5 and 6
shows that a packinghouse has the same basic processes and operations
contributing to the wasteload as a slaughterhouse, with the addition of
the meat processing for the packinghouse.  Another difference is that
the degree and amount of cutting is much greater for a packinghouse.  In
some cases, unfinished products may be shipped from one plant to another
for processing, resulting in more products produced at a plant than
live weight killed.


                                   32

-------
                 Table 2.   Summary of Plant and Raw Waste Characteristics for Simple Slaughterhouses
CO
u>


Base
(Number of Plants)
Average
Standard Deviation
Range , low-high

Flow
1/1000 kg
LWK
(24)
5,328
3,644
1,334-
14,641

Kill
1000 kg /day
(24)
220
135
18.5-
552.

BOD5
kg/1000 kg
LWK
(24)
6.0
3.0
1.5-
14.3

Suspended
Solids
kg/1000 kg
LWK
(22)
5.6
3.1
0.6-
12.9

Grease
kg/ 1000 kg
LWK
(12)
2.1
2.2
0.24-
7.0
Kj eldahl
Nitrogen
as N
kg/1000 kg
LWK
(5)
0.68
0.46
0.23-
1.36

Chlorides
as Cl
kg/1000 kg
LWK
(3)
2.6
2.7
0.01-
5.4
Total
Phosphorus
as P
kg/1000 kg
LWK
(5)
0.05
0.03
0. 014-
0.086
               Table 3.   Summary of Plant and Saw Waste  Characteristics for  Complex Slaughterhouses


Base
(Number of Plants)
Average
Standard Deviation
Range, low-high

Flow
1/1000 kg
LWK
(19)
7,379
2,718
3,627-
.12,507

Kill
1000 kg /day
(19)
595
356
154-
1498

BOD5
kg/1000 kg
LWK
(19)
10.9
4.5
5.4
18.8

Suspended
Solids
ks/1000 kg
LWK
(16)
9.6
4.1
2.8-
20.5

Grease
kg/1000 kg
LWK
(11)
5.9
5.7
0.7-
16.8
Kj eldahl
Nitrogen
as N
kg/1000 kg
• LWK
(12)
0.84
0.66
0.13-
2.1

Chlorides
as Cl .
kg/1000 kg
•LWK
(6)
2.8
2.7
0.81-
7.9
Total
Phosphorus
as P
kg/1000 kg
LWK
(5)
0.33
0.49
0.05-
1.2

-------

                              37551











Ai

Slaughtering





S

6


Kill

Hide Removal

Evisceration j
Paunch |

Scalding & Hair
Removal
Cutting


- -i
--!
-*L
icillary Operations
Laundry
Facilities
Boiler
Slowdown
i
Manure
Trap

	 *


Screening





~n


anitary Facilities








y-Product Operations

Blood
131 Aots _


Hair
Tripe ]

Rendering

Casing
Saving





(except hair

^
	 f
\
\ i



Materials
\
/
Recovery
X
Processing
f Grinding
Curing
Pickling
t

- , . * . Smoking
& hides)
Cooking
Canning
Slicing
Packaging
                                                    from
                                                  Packinghouse
Figure 6.  Operating  and Wastewater Flow Chart
           for Low- and High-Processing Packinghouses
                       34

-------
 Low-Processing  Packinghouses

 Table 4  summarizes  the plant and raw waste characteristics for
 low-processing  packinghouses. Twenty-three of the 85 plants analyzed
 were low-processing packinghouses.  The average ratio of processed pro-
 ducts to kill in  these 23 plants is 0.14, with a standard deviation of
 0.09.  The low-processing packinghouses included in the analyses have a
 ratio of processed products to LWK well below the value of 0.4 used to
 distinquish between low- and high-processing plants.  Using the above
 definitions of  plant size, the kill data shows that all the packinghouses
 in the sample are medium or large in size.


 High-Processing Packinghouses

 Table 5  summarizes the plant and raw waste characteristics of high-
 processing packinghouses.  Nineteen of the 85 plants analyzed were high-
 processing packinghouses.  The range of data for the 19 plants is
 large for all wasteload parameters.  The range of 0.4 to 2.14 for the
 ratio of processed products to LWK suggests that much of the wasteload
 variation caused by the wide variation in processing, relative to
 kill.  Plant size as measured by kill ranges from small to large;
 two plants were small, 11 medium, and 6 large.


                        Discussion of Raw l-fastes

 The data in Tables 2 through 5 cover  a wastewater flow range of 1334
 to 20,261 1/1000 kg LWK (160 to 2427 gal/1000 Ib LWK); a wasteload
 range of 1.5 to 30.5 kg BOD5/1000 kg LWK (1.5 to 30.5 lb/1000 Ib LWK);
 and a kill range of 18.5 to 1498 thousand kg LWK/day (40 to 3300
 thousand Ib/day).  A comparison of the data from Tables 2 and 3 for
 simple and complex slaughterhouses shows that the averages of all the
waste parameters are higher for a complex plant.  This was expected
 because, by the method of categorization of slaughterhouses, complex
 slaughterhouses  conducted more secondary (by-product) processes.  In
 addition, the daily LWK for a complex slaughterhouse is notably larger,
 about 2.7 times based on averages.

 The data listed in Tables 4 and 5 for low- and high-processing packing-
houses show  that high-processing plants have much higher average values
 for all waste parameters on a LWK basis.

 Some variations in wastewater flow and strength within any one of the
 four subcategories can be attributed to differences in the amount and
 types of operations beyond slaughtering, such as by-product and prepared
meat processing, and the effectiveness of material recovery in primary
 In-plant treatment.  However, the major causes of flow and wasteload
variations are variations in water use and in housekeeping practices.


                                  35

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Table 4.  Summary of plant and Raw Waste Characteristics
          for Low-processing Packinghouses
Base
[Kunber of Plants)
Average
Standard Deviation
Range, low-high
Flow
1/1000 kg
LWK
(23)
7.842
4,019
2,018-
17,000
Kill
1000 kg/day
(23)
435
309
89-
1,394
BOD5
kg/1000 kg
LWK
(20)
8.1
4.fi
2.3-
18.4
Suspended
Solids
kg/1000 kg
LWK
(22)
5.9
4.0
0.6-
13.9
Grease
kg/ 1000 kg
LWK
(15)
3.0
2.1
0.8-
7.7
Kjeldahl
Nitrogen
as !i
kg/ 1000 kg
LWK
(6)
0.53
0.44
0.04-
1.3
Chlorides
as 01
kg/1000 kg
LWK
(5)
3.6
2.7
0.5-
4.9
Total
Phosphorus
as P
kg/1000 kg
LWK
w
0.13
0.16
0,03-
0.43
Processed
Products
1000 kg/day
(23)
54
52
3.0-
244.
Ratio of
Processed
Products
to Kill
(23)
0.14
0.09
0.016-
0.362
 Tqable 5.   Summary  of Plan^  and Raw Waste Characteristics
            for  High-Processing  Packinghouses
Base
('Juraber of Plants)
Average
Standard Deviation
Range of low-high
Flow
1/1000 kg
LWK
(19)
12.514
4,894
5,444-
20,261
Kill
1000 kg/day
(19)
350
356
8.8-
1,233.
BODS
kg/1000 kg
LWK
(19)
16.1
6.1
6.2-
30.5
Suspended
Solids
kg/1000 kg
LWK
(14)
10.5
6.3
1.7-
22.5
Grease
kg/1000 kg
LWK
(10)
9.0
8.3
2.8-
27.0
Kjeldahl
Nitrogen
as ,1
kg/1000 kg
LWK
(3)
1.3
0.92
0.65-
2.7
Chlorides
as Cl
kg/ 1000 kg
LWK
(7)
15.6'
11.3
0.8-
36.7
Total
Phosphorus
as P
kg/ 1000 kg
LWK
(3)
0.38
0.22
0.2-
0.63
Processed
Products
1000 kg/day
(19)
191
166
4.5-
631.
Ratio of
Processed
Products
to Kill
(19)
0.65
0.39
0.40-
2.14

-------
Excess water use removes body fluids and tissues from products and
conveys them into the wastewater.  The effect of wastewater flow on
wasteload is discussed in more detail later in this Section.

In all four subcategories , a correlation analysis of the data revealed
that the raw BODs wasteload correlates very well with suspended solids,
with grease, and with Kjeldahl nitrogen on a LWK basis.  This means that
an increase (decrease) in one parameter will account for a certain
predictable increase  (decrease) in another of the parameters.
The effect of plant size (kill) on wasteload as measured by
each category was assessed by a regression analysis.  The results
showed that larger plants tend to have slightly higher pollutional
wasteloads.  This trend is not caused by differences in processing.
Rather, it results from some of the plants operating at ever increasing
throughput, often beyond the LWK for which the plant was designed.
Under these circumstances, housekeeping and water management practices
tend to become careless.  Often waste management personnel do not have
the authority to enforce or change plant practices.  Line speed-up
overloads fixed operations such as inedible rendering and blood handling.

Only four small plants were included in the analysis; two were simple
slaughterhouses and two were high-processing packinghouses.  Three of
the four were substantially below the average BODs wasteload for their
subcategory, suggesting that small plants can meet effluent limits of
larger plants.  The only other information available on small plants is
that of Macon and Cote.5  Accurate waste data were obtained on ten
small packinghouses in 1961.  Because there was. insufficient information
on these plants to subcategorize them as low- or high-processing
packinghouses, and the plants were not identified, the results were
not used in determining wasteloads for the various subcategories.
Those plants that practiced blood recovery had BODs wasteloads
between 2.7 and 8.3 kg/1000 kg LWK; the other plants which sewered
blood had considerably higher waste loads.  Although some of the
data did not include the waste load from clean-up, Macon determined
that the clean-up could add from 0.35 to 3.0 kg BOD5/1000 kg LWK.
These results indicate that the waste load from small packinghouses
not sewering blood are slightly less than those from larger packing-
houses. This further substantiates that standards set for medium and
large plants can be met, without special hardship, by a small plant,
if the small plant is properly equipped for blood disposal, paunch
handling, and similar high waste-related operations.
                                   37

-------
Data in Tables 2 through 5 shows that chlorides and phosphorus values
are less frequently measured than are values for the other parameters.
From the data reported, however, chlorides and phosphorus are dependent
on in-plant operations and housekeeping practices.  For example,
large amounts of chlorides contained in pickling solutions and used
in the processing of ham, bacon, and other cured products ultimately
end up in the wastewaters.  This explains the unusually hip,h chloride
values for high-processing packinghouses, i.e., four to six times the
values for the other subcategories, where relatively large amounts
of products are cured.

Very little useful information on other waste parameters such as Kjeldahl
nitrogen, nitrites, nitrates, ammonia, and total dissolved solids were
reported by the 85 plants whose data were summarized by subcategory in
this chapter.  However, some information on these parameters was obtained
from other sources7 and from field verification studies conducted
during this program.  Typical ranges arc given below for these waste
parameters.  It should be noted that the values for dissolved solids
in the wastewater are also affected by the dissolved solids content of
the plant water supply.

          titrates and Nitrites as //, mg/1               0.01 - 0.85

          Kjeldahl nitrogen, mg/1                          50 - 300

          Ammonia as N, mg/1                                7-50

          Total dissolved solids, mg/1                   500  - 25,000
                         PROCESS FLOW DIAGRAMS
The most typical flow arrangement used in the meat packing industry is
shown schematically in Figure 7.  The system is used in about 70 percent
of the plants studied.  The figure shows that most of the wastewater
flows through a recovery system which consists of screening followed by
a catch basin.  Frequently, the only waste streams to by-pass this system
are the pen washing, sanitary wastes, hog scalding and dehairing waste-
waters, and hide-processing wastewaters.  Pen washing normally pass
through a manure trap and then are mixed with the other wastewaters
before entering further treatment for discharge to a watercourse or a
municipal sewer.  Only non-contaminated water, such as cooling water,
completely by-passes treatment: they usually discharge directly to a
stream.  In plants in which barometric condensers are used, the water
can become contaminated.  Most of this water is sent to further treat-
ment.

The second most frequently used wastewater arrangement is shown
schematically in Figure 8.  In this flow arrangement, several low grease-
bearing streams by-pass the screen and catch basin.  This permits an

                                   38

-------
                  Domestic Uses
  Slaughtering
     Kill
  Hide Removal
[  Evisceration
    Paunch
 Scalding & Hairj
    Removal
   Cutting
(may follow
 catch basins)
                               Wet Well
                                          Catch

/// 1
*

                                       Screens
                                    Sanitary
3y-Product Operations

Blood






Tripe

Rendering
Casing
Saving
^
^
J
t ^
^
Facilities
1

(except hair & hides)
^"
                    Secondary Treatment
                      (Industrial or
                         Hunicina
      Figure 7.   Typical Wastewater  Treatment  System
                   Without Dissolved Air Flotation
                             39

-------
 Slaughtering
 Hide Removal
 Evisceration
                         (may follow
                          catch basins)
  Dissolved
  Air
  Flotation
Scalding & Hair
    Removal
 By-Product Operations
                                Laundry &
                                Sanitary
                                Wastes
Receiving
Body of
Water
   Figure  8.   Typical Wastewater Treatment  System
               Including Dissolved Air Flotation
                            40

-------
increase in the detention time of the grease-bearing stream in a grease
recovery system because the system can now handle a lower wastewater
flow.  Low-grease-bearing wastewaters normally originate from the pens,
some secondary (by-product) processing, and sanitary wastes.  This
arrangement is commonly used when dissolved air flotation is included
in primary treatment.  A portion of the effluent from the flotation
unit is recycled to a pressurization tank where air is added for
flotation.

Several modifications of the flow arrangement shown in Figure 8 are
used by the industry.  Some plants add chemicals to the waste stream
via a mixing tank just prior to the flotation unit.  This usually
increases grease and solid recovery but it also may increase the moisture
content of the skimmings to 85 to 95 percent, making the handling of
skimmings more difficult. Other plants may have two dissolved air
flotation units in series.  Chemicals are usually added to the waste
stream entering the second unit.  Skimmings from the first unit are
almost always rendered while those from the second unit, which contain
chemicals, may be landfilled.  A few plants add chemicals to both
units to achieve a high wasteload reduction.  Chemicals may reduce
the rendering efficiency or produce a finished grease that is unaccept-
able on the market.

A third flow arrangement, which has been installed in a few recently
built plants, is shown in Figure 9.  The purpose of this arrangement
is to segregate waste streams according to the type of treatment to
be applied.  In the scheme shown, the streams are divided into low and
high grease-bearing streams, and manure-bearing streams.  For example,
floor drains located on the kill floor after the carcass is opened,
are connected to the high grease-bearing streams; hide processing
wastewater is directed to the manure-bearing streams.  Segregation
into the three ma.ior waste streams permits optimum design of each
catch basin and flotation unit for recovery and waste load reduction,
with minimum investment in equipment.  A more detailed list of the
segregated stream contents is given by Johnson.8

Although there are a number of operations where wastewater could
be reused or recycled, the industry is generally recycling or reusing
only non-contaminated cooling water, as illustrated in Figures 7, 8,
and 9.  One minor exception is reuse of lagoon water as cooling water.
                                  41

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ro
                                                                                                           Manure-BearinR
                                                                                                           Wastewaters
Greases-Searing        Non-Crease-Bearing
Wastewaters          Wastewaters
                                                                                                                      •Solids
                                                                                          To Secondary Treatment
                                                              To Separate Severs or
                                                              Receiving Body of Water
                             Figure  9.   Separate Treatment  of Grease-Bearing,  Nongrease-Bearing
                                           and Manure-Bearing  Wastewaters

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                  WATER USE - HASTELOAD RELATIONSHIPS

Increased water use causes increased pollutional wasteload in the
meat packing industry.  This was verified by regression and correlation
analyses of individual plant data  over long periods (up to two years),
and also on the data for each of the four subcategories.  For example,
multiple regression analysis of the data relating BOD5 wasteload to
kill and flow revealed that a variation of one standard deviation would
change the predicted BOD 5 for a simple slaughterhouse,  by 1.0 kg/1000
kg LWK (1.0 lb/1000 Ib LWK) ; it would change the predicted load for a
complex slaughterhouse by 2.8 kg/1000 LWK (2.8 lb/1000 Ib LWK).  Another
regression analysis between BODs and flow on a LWK bases showed that
one standard deviation in flow changed the predicted BOD5 by 5.6 and
5.3 kg/1000 kg LWK (5.6 and 5.3 lb/1000 Ib LWK) for low- and high-
processing packinghouses, respectively.

Figure '10 shows the average and range of the results of separate
regression analysis on the flow-wasteload data from each of eleven
plants.  This figure clearly illustrates that water use strongly
affects the pollutional wasteload.  For example, the figures show that
a 20 percent reduction in water use would, on the average, result in a
BOD5 reduction of 3.5 kg/1000 kg LWK (3.5 lb/1000 Ib LWK).

Further evidence for the dependence of pollutional wasteload on water
flow is that, in three of the four subcategories, the plant with the
lowest wasteload also had the lowest water use.  In the fourth sub-
category, the plant with the lowest wasteload had the second lowest
water use.

Low water use, and consequently low pollutional wasteload, requires
good water management practices.  For example, two simple slaughter-
houses practice very good water use practices.  The plants both had
wasteloads of about 2 kg/1000 kg LWK (2 lb/1000 Ib LWK); their waste-
water flows ranged from 1333 to 2415 1/1000 kg LWK (166 to 290 gal/1000
Ib LWK).  One plant was an old beef slaughterhouse; the other, a new
hog slaughterhouse.  This outstanding performance was achieved in a
subcategory for which the flox*s ranged to 21,000 1/1000 kg LWK
( 1750 gal/1000 Ib LWK), and for which the BOD5 loading ranged to
over 14 kg/1000 kg LWK (14 lb/1000 Ib LWK).
                                   43

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   15-
 o>
_*:

O
O
O
X
 en
O
O
m
   10-
    5H
                                        r

                                       I
                                        I
          Range
 Average  for
Individual  Plants
Gal/1000 Ibs LWK
500 1000
0 2000 4000
1 1 — I
6000 8000 10,000
                        Liters/1000 kg LWK
         Figure 10.  Effect of Water Use on Wasteload
                    for Individual Plants

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                         SOURCES OF WASTEHATER

                              Aplmal
Although pen wastes only contain an estimated 0.25 kg of BODs/1000 kg
LWK,9 the wastes are high in nutrients.10  Frequently, the solid wastes
are removed by dry cleaning, followed by little or no washdown.  If
the pens are washed down, a manure trap is frequently used to recover
solids rather than letting then enter a treatment system.

Another wastewater source in the pens is the watering troughs.  Each
trough may discharge 8 1/min (2.1 gal/min) or more.  With perhaps
50 or more pens in a large plant, the water source becomes significant.
The total waste from the pens, however, is a minor contributor to
the waste load.
                              Slaughtering

The slaughtering operation is the largest source of wasteload in a
meat packing plant, and blood is the major contributor.  Blood is
rich in BODs, chlorides and nitrogen.  It has an ultimate BODg of
405,000 mg/1 and a BOD5 between 150,000 to 200,000 mg/1.11
Cattle contain up to 50 pounds of blood per animal, and typically only
35 pounds of the blood are recovered in the sticking and bleeding
area.  The remaining 15 pounds of blood are probably lost, and this
represents a wasteload of 2.25 to 3.0 kg BOD5/1000 kg LWK (2.25 to
3 lb/1000 Ib LWK).  Total loss of the blood represents a potential
BOD5 wasteload of 7.5 to 15 kg/1000 kg LWK (7.5 to 15 lb/1000 Ib LWK).
Because very few meat plants practice blood control outside of the
bleeding area, the typical BODs load from blood losses in the slaughter-
ing operation is estimated to be 3 kg/1000 kg LWK.  In beef plants, much
of this loss probably occurs during hide removal, and particularly
from the use of the automatic "down" hide puller.

Beef paunch or rumen contents is another major source of waste load.
Paunch manure, which contains partially digested feed material, has a
BOD5 of 50,000 mg/1.12   At an average paunch weight of 50 pounds
per head, dumping of the entire contents can contribute 2.5 kg/1000 kg
LWK.  However, the common practices are to either screen the paunch
contents, washing the solids on the screen (wet dumping), or to dump on
a screen to recover the solids, allowing only the "juice" to run to the
sewer (dry dumping).  Because 60 to 80 percent of the BODs in the paunch
is water soluble, wet dumping of the paunch represents a BODs loss of about
1.5 kg/1000 kg LWK.  If dry dumping is practiced, the pollutional waste-
load is much less than this.  When none of the paunch is sewered but is
processed or hauled out of the plant for land disposal, paunch handling
does not contribute to the wasteload.  Cooking of the rumen or paunch
in a hot alkaline solution (tripe processing) will also add to the waste-
load, particularly to the grease load.  The strong alkalinity,of these
wastewaters may also make grease recovery more difficult.

                                  45

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                                       it
The hog scald tank and dehairing machine are other sources of pollution.
The overflow from a hog scald tank is usually about 84 1/1000 kg LWK
(10 gal/1000 Ib LWK) at a BODs concentration of about 3000 mg/1.  This
could represent a BODs loss of about 0.25 kg/1000 kg LWK.  Continuous
overflow of water from the dehairing machine is estimated to contribute
a maximum BODs load of 0.4 kg/1000 kg LWK.

Other sources of waste from the slaughtering of animals and dressing
of carcasses is from carcass washing, viscera and offal processing,
and from stomach and peck flushing.

The offal operations such as chitterling washing and casing saving
can contribute substantially to the pollution load.  If the slime
waste from the casing saving is not sewered, its pollutional wasteload
would be greatly reduced.

The highest source of water use in slaughtering is from the washing of
carcasses; an extreme example was 2915 1/tnin (350 gal/min).  Flushing
the manure from chitterling and viscera, or conveyer sterilizing, and
the tripe "umbrella" washer are other high water use operations.


                            Meat Processing

The major pollutants from meat processing are meat extracts, meat
and fatty tissue, and curing and pickling solutions. Loss of these
solutions can be the major contributor to the waste load from processing.
The results of a recent study showed that only 25 percent of the
curing brine remained in the product.11  The rest of the brine
is lost to the sewer.  This source of chlorides, plus others such as
from hide curing and the use of salt on the floors to reduce slipperiness,
explains why some packinghouse wastes have high chlorides.  A content
of 1000 mg/1 of chlorides is not uncommon in the effluent from a
packinghouse.  Another constituent of the cure is dextrose; it has a BODs
equivalent of 2/3 kg/kg (Ib/lb).  Consequently, packinghouses with a
sizeable curing facility will have high BOD5 waste unless the wastes
from curing are segregated or recycled.  In one plant over 2000 pounds
of dextrose was lost daily.13  The pollution load from meat and fatty
tissue can be substantially reduced by dry clean-up prior to washdown.
The water use in meat processing should be primarily limited to clean-
up operations and for product washing, and cooling, and cooking.
                                  46

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                   Secondary Manufacturing Processes

Secondary manufacturing processes, as described in Section IV, are
those by-product operations within the industry for the handling,
recovery, and processing of blood, trimmings, and inedible offal.  This
includes paunch and viscera handling, hide processing, hair recovery and
processing, and edible and inedible rendering.  Those viscera and offal
operations that occur on the slaughtering floor, such as paunch handling
and tripe processing, were considered under slaughtering.

The hashing and washing of viscera, often performed prior to rendering,
produces a strong waste load with a BOD5 value of about 70,000 mg/1.1*
The waste conservation trend in the past few years has been toward not
hashing and washing prior to rendering, but sending the uncleaned vis-
cera directly to rendering.  In one plant, removal of the hasher and
washer reduced the BOD5 to the x*aste treatment plant by 910 kg (2000
pounds) per day, with an attendant increase in the rendered animal
feed production.

Efficient recovery of hog hair is now practiced widely within the industry,
although the market for this by-product has been reduced in recent
years.  Very few plants hydrolyze hog hair, but rather wash and bale
for sale or disposes of it directly to land fill.   The waste load from
the recovery and washing of the hair is estimated to contribute less
than 0.7 kg/1000 kg LWK.

Hide curing operations are becoming increasingly involved at meat
packing plants.  Just a few years ago many plants were shipping hides
green or in salt pack. Today, however, many beef slaughter operations
include hide curing in tanks, vats, or raceways.  The hides, prior to
being soaked in brine, are washed and defleshed.  These washings, which
are sewered, contain blood, dirt, manure, and flesh.  In most defleshing
operations the bulk of the tissue is recovered.  In addition to these
wastes, soaking the hide in the brine results in a net overflow of
approximtely 7.7 liters (2 gallons) of brine solution per hide.  In a
few plants the brine in the raceway is dumped weekly, whereas in others
it is dumped yearly or whenever the solids build up to a point where
they interfere with the hide curing operation.  The life of the brine
can be extended by pumping the recycled brine over a vibrating or static
screen.  The waste load from the overflow and washings in a typical
hide curing operation, where the hide curing wastes are not frequently
dumped, is about 1.5 kg/1000 kg LWK for BOD5 and about 4 kg/1000 kg LWK
for salt.
                                  47

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Blood processing may be either wet or dry.  Continuous dryers, which
are quite common, use a jacketed vessel with rotating blades to prevent
burn-on; this process results in low losses to the sewer (estimated to
contribute about 0.3 kg BODs/1000 kg LWK). Continuous ring dryers are
sometimes used:  they produce a relatively small amount of blood water
that, in some small plants, is discharged to the sewer.  The old
technique of steam sparging the blood to coagulate it is still frequently
used.  The coagulated blood is separated from the blood water by
screening.  The blood water has a BODs of about 30,000 rag/1.11  It is often
sewered, contributing a waste load of about 1.3 kg/1000 kg LWK.  This
loss can be eliminated by evaporating the blood water, either by itself
or by combining it with other materials in conventional inedible dry
rendering operations.

Wet rendering and low temperature rendering are potentially large
sources of pollution.  Tank water from wet rendering can have a
value of 25,000 to 45,000 mg/1, and the water centrifuged from low
temperature rendering can have a BOD5 of 30,000 to 40,000 mg/1.  It
is estimated that sewering of either of the waste streams produces a
waste load of 2 kg BODs/1000 kg LWK.  These waste loads can be eliminated
by evaporation or combining with other materials used in dry inedible
rendering.  Triple-effect vacuum evaporators are often used to concen-
trate the "tankwater" from the wet rendering operation.  The wasteload
from wet rendering is primarily caused by overflow or foaming into
the barometric leg of these evaporators and discharge to the sewer or,
sometimes directly to a stream.  From dry rendering the pollution comes
from the condensing vapors, from spillage, and from clean-up operations.
A recent study10  revealed that a typical dryer used 454 to 492
1/min (120 to 130 gal/min) of water for condensing vapors, and that the
effluent contained 118 mg/1 of BODs and 27 mg/1 grease.  The estimated
wasteload from dry rendering is 0.5 kg/1000 kg LWK.

                                Cutting
The main pollutants from cutting operations are meat and fat scraps
from trimming, and bone dust from sawing operations.  Most of these
pollutants enter the waste stream during clean-up operations.  These
wastes can be reduced by removing the majority of them by dry clean-up
prior to washdown, and also by some form of grease trap in the cutting
area.  The collected material can be used directly in rendering.
Bone dust is a large source of phosphorus and, when mixed with water,
does not settle out readily; thus it is difficult to recover, and should
be captured in a box under the saw.
                                   48

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Macon6 found that clean-up contributes between 0.3 and 3 kg BOD5/1000
kg LWK in small packinghouses.  Data collected by the Iowa Department
of Environmental Quality showed that anywhere from 27 to 56 percent of
the total BODs waste load is contained in the clean-up wastewaters.
The clean-up operation thus is a major contributor to the waste load.
It also leads to a significant loss of recoverable by-products.
Detergents used in clean-up can adversely affect the efficiency of
grease recovery in the plant catch basin.

The techniques and procedures used during clean-up can greatly influence
the water use in a plant and the total pollutional waste load.  For
example, dry cleaning of floors prior to wash down to remove scraps
and dry squeegeeing the blood from the bleed area into the blood sewer
are first steps.  A light wash down, again draining to the blood sewer,
before the normal washdown definitely decreases the pollution load
from clean-up.
                                   49

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                              SECTION VI

                  SELECTION OF POLLUTANT PARAMETERS


                         SELECTED PARAMETERS

Based on a review of the Corps of Engineers Permit Applications from the
meat packing plants, previous studies on wastewaters from meat packing
plants, 3>^5  industry data, questionnaire data, published reports,11*
and data obtained frora sampling plant wastewatero during this study, the
following chemical, physical, and biological constituents constitute
pollutants as defined in the Act.

          BOD 5 (5 day, 20°C biochemical oxygen demand)
          COD (chemical oxygen demand)
          Suspended solids
          Dissolved solids
          Grease
          Ammonia nitrogen
          Kjeldahl nitrogen
          Nitrates and nitrites
          Phosphorus
          Chloride

On the basis of all evidence reviewed, there do not exist any purely
hazardous or toxic pollutants (such as heavy metals or pesticides) in
the waste discharged frora the meat processing plants.
           RATIONALE FOR SELECTION OF IDENTIFIED PARAMETERS

                 5-Day Biochemical  Oxygen Demand (BODg)

This parameter is an important measure of the oxygen consumed by micro-
organisms in the aerobic decomposition of the wastes at 20°C over a
five-day period.  More simply, it is an  indirect measure of the bio-
degradability of the organic pollutants  in the waste.  BODs can be related
to the depletion of oxygen in a receiving stream or to the requirements
for waste treatment.  Values of BOD5 range from 300 to 3800 mg/1 in
the raw waste, although typical values range from 900  to 1500 me/1.

If the BODs level of  the final effluent  of a meat packing plant into a
receiving body is too high, it will reduce the dissolved oxygen level
in that stream to below a level that will sustain most fish life; i.e.j
below about 4 mg/1.  Many states currently restrict the BODs of effluents
                                   51

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                                m> n ff^f3
                                        :3
                                     "U


to below 20 mg/1 if the stream is small in comparison with the flow of
the effluent.  A limitation of 200 to 300 mg/1 of BOD5 is often applied
for discharge to municipal sewer, and surcharge rates often apply if
the BOD5 is above the designated limit.

A 20-day biochemical oxygen demand (BOD2Q),  sometimes called "ultimate"
BOD, is usually a better measure of the waste load than BODg.   However,
the test for BOD20 requires 20 days to run.  so it is an impractical
measure for most purposes.


                       Chemical  Oxygen Demand (COD)

COD is yet another measure of oxygen demand.  It measures the amount of
organic and some inorganic pollutants under a carefully controlled direct
chemical oxidation by a dichromate-sulfuric acid reagent.  COD is a much
more rapid measure of oxygen demand than BOD5, and is potentially very
useful.  However, it does not have the same significance, and at the
present time cannot be substituted for BODs because CODtBODs ratios vary
with the types of wastes.

COD provides a rapid determination of the waste strength.  Its measure-
ment will indicate a serious plant or treatment malfunction long before
the BOD5 can be run.  A given plant or waste treatment system usually
has a relatively narrow range of COD:BODs ratios, if the waste character-
istics are fairly constant, so experience permits a judgment to be made
concerning plant operation from COD values.  In the industry, COD
ranges from about 1.5 to 5 times the BOD5; the ratio may be to the low
end of the range for raw wastes, and near the high end following secondary
treatment when the readily degraded material has been reduced to very
low levels.
                            Suspended Solids

This parameter measures the suspended material that can be removed from
the wastewaters by laboratory filtration, but does not include coarse
or floating matter than can be screened or settled out readily.  Sus-
pended solids are a visual and easily determined measure of pollution
and also a measure of the material that may settle in tranquil or slow-
moving streams.  Suspended solids in the waste from meat packing plants
correlate quite well with BODs.  A high level of suspended solids is
an indication of high BODs.  Generally, suspended solids range from
one-third to three-fourths of the BOD5 values in the raw waste.  Sus-
pended solids are also a measure of the effectiveness of solid removal
systems such as clarifiers and fine screens.
                                   52

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                             Dissolved  Solids

The dissolved solids in the wastewater  are mainly inorganic salts, and
the salt present in the largest amount  is sodium chloride (described
below).   Loadings of dissolved solids thus vary to a large extent with
the amount of sodium chloride entering  the waste stream.   Frequently
dissolved solids in the final effluent  amount to about 500 mg/1;
however, values of 1500 or more are not uncommon.  The dissolved
solids are particularly important in that they are relatively
unaffected by biological treatment processes.  Therefore, unless  re-
moved, they will accumulate on recycle  or reuse of water  within a
plant.  Further, the dissolved solids at discharge concentrations may
be harmful to vegetation and preclude various irrigation  processes.


                                .Grease

Grease,  also called oil and grease, or  hexane solubles, is a major
pollutant in the raw waste stream of meat packing plants.  The source
of grease is primarily from carcass dressing, washing, trimming,  viscera
handling, rendering and clean-up operations.  Grease forms unsightly
films on the water, interferes with aquatic life, clogs sewers, disturbs
biological processes in sewage treatment plants, and can  also become a
fire hazard.  The loading of grease in  the raw waste load varies  widely,
from 0.25 to 27 kg/1000 kg LWK (0.25 to 27 lb/1000 Ib LWK).  This would
correspond to an average concentration of about 650 tng/1.  Effluent
limitations of grease into receiving waters may be as low as 10 mg/1
and into sewer systems, typically 100 mg/1.  Grease may be harmful to
municipal treatment facilities and to trickling filters.


                             Ammonia Nitrogen

Ammonia nitrogen in raw waste is just one of many forms of nitrogen in
a waste stream.  Anaerobic decomposition of protein, which contains
organic nitrogen, leads to the formation of ammonia.  Thus, anaerobic
lagoons or digesters produce high levels of ammonia.  Also, septic
(anaerobic) conditions within the plant in traps, basins, etc., may
lead to ammonia in the wastewater.  Another source of ammonia can be
leakage in ammonia refrigeration systems; such systems are still fairly
common in meat packing plants.

Ammonia is oxidized by bacteria in a process called "nitrification" to
nitrites.and nitrates.  This may occur in an aerobic treatment process
and in a stream.  Thus, ammonia will deplete the oxygen supply in a
stream; its oxidation products are recognized nutrients for aquatic growth
and for some toxic qualities  (see below).  Also, free ammonia in a stream
is known to be harmful to fish.
                                  53

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A typical concentration in the raw waste load is about 10 to 40 mg/1;
however, after treatment in an anaerobic secondary system, the con-
centrations of ammonia can reach as high as 100 to 200 iog/1.  Ammonia
is limited in drinking water to 0.05 to 0.1 mg/1.11*  In some cases a
stream standard is less than 2 mg/1.


                            Kjeldahl Nitrogen

This parameter measures the amount of ammonia and organic nitrogen; when
used in conjunction with the ammonia nitrogen, the organic nitrogen can
be determined by the difference.  Under septic conditions, organic nitrogen
decomposes to form ammonia.  Kjeldahl nitrogen is a good indicator of
the crude protein in the effluent and, hence, of the value of material
being lost in the wastewater.  The protein content is usually taken as
6.25 times the organic nitrogen.  The sources of Kjeldahl nitrogen are
basically the same as for ammonia nitrogen, above, except for the re-
frigeration system.  The raw waste loading of Kjeldahl nitrogen is
extremely variable and highly affected by blood losses.  Typical loadings
range from 0.04 to 6.76 kg/1000 Ib LWK (0.04 to 6.76 lb/1000 Ib LWK),
and concentrations range from about 4 to 750 mg/1.  Typical raw waste
concentrations of Kjeldahl nitrogen are between 50 and 100 mg/1.  Kjeldahl
nitrogen has not been a common parameter for regulation and is a much
more useful parameter for raw waste than for final effluent.


                          Nitrates  and Nitrites

Nitrates and nitrites, normally reported as N, are the result of oxida-
tion of ammonia and of organic nitrogen.  They may also enter the waste
stream from use in the plant as preservatives.  Nitrates are important
in the water supply used for human or livestock consumption, because high
nitrate concentrations can lead to  toxicity  (methmoglobinemia or "blue
babies",nitrate poisoning and death in young cattle).  From investigation
of this toxicity, nitrates as // should not exceed 20 mg/1 in water
supplies,16 although the U.S. Public Health Service recommends a limit
of 10 mg/1.16  Nitrates are essential nutrients for algae and other
aquatic plant life.


                               Phosphorus

Phosphorus, commonly reported as P, is a nutrient for aquatic plant  life
and can therefore cause eutrophication in water courses.  The threshold
concentration of phosphorus in receiving bodies that can  lead to
eutrophication is about 0.01 mg/1.  The primary source of phosphorus
in raw waste from meat packing plants are bones and detergents.  The
total phosphorus in the raw effluent ranges  from about 0.01 to 0.63
kg/1000 kg LWK  (0.01 to 0.63 lb/1000 Ib LWK), or a concentration range
of 15 to 50 mg/1.
                                   54

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                               Chlorides

Chlorides in concentrations of the order of 5000 mg/1 can be harmful to
people and other animal life.  High chloride concentrations in waters can
be troublesome for certain industrial uses and for reuse or recycling of
water.  The major sources of chlorides from meat packing plants are the
salt from animal tissues, hide curing operations, pickling and curing
solutions, cleaning chemicals, blowdown water, and that used to prevent
slipping on floors.  The concentrations in raw waste are extremely
variable from plant to plant, and are normally higher for plants killing
cattle and treating hides than they are for other plants.  The amount in
the waste is an indicator of the way in vMch certain processes are being
operated.  The range of chloride loadings in raw waste effluents is from
less than one to greater than 20 kg/1000 kg LWK  (20 lb/1000 Ib LWK).
Chloride loadings are unaffected by secondary treatment systems used by
the industry today, and once in the wastewaters  they are very costly to
remove.

Some other pollution parameters are of lesser significance.  Color is
related to waste strength, and is a visible indicator; it is useful only
for qualitative purposes.  Odor is only a problem in the wastewater in
anaerobic treatment systems.  A cover, usually of grease, will solve this;
in some areas construction of anaerobic lagoons  has been forbidden because
of the odor problems.  pH is of relatively minor importance.  The usual
pH for raw waste falls between 6.5 and 8; unusual processes such as hog
hair hydrolyzing may raise this slightly, but not enough to significantly
offset treatment effectiveness or effluent quality.
                                   55

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                          L^tlu/AiU
                              SECTION VII

                   CONTROL AND TREATMENT TECHNOLOGY


                                SUMMARY

The wasteload discharged from the meat packing  industry  to receiving
streams can be reduced to desired levels,  including  no discharge  of
pollutants, by conscientious wastewater management,  in-plant waste
controls, process revisions, and by the use of  primary,  secondary,
and tertiary wastewater treatment.  Figure 11 is a schematic of a
suggested waste reduction program for the  meat  packing industry to
achieve high removal of pollutants in subsequent treatment.

This section describes many of the techniques and technologies  that are
available or that are being developed to  achieve the various levels of
waste reduction.  In-plant control techniques and wastewater management
suggestions are described first.  Waste  treatment technology normally  •
employed as a primary treatment is then  described.  In the  case of  the
meat packing industry this "primary" treatment is a  materials recovery
process, and is considered as part of the  in-plant system,  although
many of these systems have been improved  for reducing pollutional levels.
The effluent from these processes is considered the  "raw waste".
Secondary treatment systems, which are employed in the treatment  of the
raw waste, are presented with a description of the process,  the specific
advantages and disadvantages of each system,and the  effectiveness on
specific wastewater contaminants found in packing plant  waste.  The
tertiary and advanced treatment systems  that are applicable to  the
waste from typical packing plants are described in the  last part  of
this section.  Some of these advanced treatment systems  have not  been
used in full scale on meat packing plant waste; therefore,  the  develop-
ment status, reliability, and potential problems are discussed  in
greater detail than for the primary and secondary treatment systems
which are in widespread use.


                      IN-PLANT  CONTROL TECHNIQUES

The wasteload from a meat packing plant is composed  of  a wastewater
stream containing the various pollutants described in Section VI.
The cost and effectiveness  of treatment of the waste stream will  vary
with the quantity of water  and  the wasteload.  In fact,  as indicated  in
Section V, the pollutional wasteload  increases as water  use increases.
In-plant control techniques will  reduce both water use and pollutional
wasteload.  The latter will be  reduced directly by minimizing  the entry
of solids  into  the wastewater stream  and indirectly by reducing water
use.

The in-plant  control  techniques described below have been used in
packing plants  or have been demonstrated as  technically feasible.
                                  57

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          Waste Reduction
            Techniques
  Waste
  Water
 Mgmt. &
 In-Plant
 Controls
00
         Waste Reduction
             Effect
  Water-
 Flow &
  Waste
  Load
Reduction
By-Product
 Recovery,
  Grease,
 & Coarse
  Solids
  Removal
            Point of
           Application
By-Product
 Recovery,
  Grease,
Sus.  Solids
  Removal
BOD, Sus.
 Solids,
 Grease
 Removal
to 98.5%
 Removal of
  Fine Sus.
Solids,  Salt,
 Phosphorus,
 Ammonia (as
 necessary)
 to 99.5%
                         Figure 11.  Suggested Meat Packing  Industry Waste Reduction Program

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                            1 t j "M '  •' '• : • ; i   ' i


                              Pen Wastes
The best livestock holding pens are covered and  dry cleaned  with only
occasional washdown.   Bedding material and manure are readily disposed
of on farm land as fertilizer.  A separate sewer and manure  pit are
provided for liquid wastes from the pens;  disposal is on land or to the
secondary treatment system.   Drinking water in the pens  is minimized
and based on need.  Watering troughs should have automatic level controls.


                            Blood Handling

In good practice, blood is not sewered.  Blood is almost totally contained
and collected in a blood collection system.  Water or steam  are not
necessary to operate such a system, and both should be avoided.17
After dry cleaning the floors and walls exposed to blood flows and
splashing, a first water wash, using a minimum amount of water, can be  .
drained into the blood collection system.ie   Bloodwater can be avoided
by installing a blood dryer.  If a plant handles bloodwater, it should
not be sewered, but can be rendered, evaporated, or mixed with paunch and
cooked to produce a feed material.1?    Blood collection by  a vacuum
system may be a feasible process if markets for edible blood develop.
Very limited amounts of edible blood are collected for pharmacuticals.
In general, improved blood collection methods need to be developed to
match the high production rate of American plants.


                                Paunch

The use of water in the initial dumping of paunch material or in pumping
it must be discontinued.  Dumping the entire paunch contents (including
the liquid) for disposal or treatment without sewering, followed by a
high pressure but minimal water rinse of  the paunch will minimize the
pollutional wasteload from this operation.  Consideration should also
be given  to vacuuming out the residual material instead of washing it
outs.  In each case the economics of recovery of the paunch and cost of
the resulting waste treatment should be examined and compared to direct
rendering of the paunch, as is.

Liquids screened from the paunch material should be collected and
evaporated or rendered, not wasted.  Plants that presently slurry the
paunch with water for pumping should either install a solids handling
pump, thus avoiding the need  for  a water, slurry, or devise an alternate
handling  technique; e.g., transporting the entire unopened paunch to
rendering.


                           Viscera Handling

The  inedible hashing and washing  operation should be eliminated;  there
is no competitive reason  to Justify  its continuation.   Inedible viscera


                                  59

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      i
     u   L
                                     uy

can be rendered without washing.   A good quality grease may be obtained
if the washings of edible viscera (i.e.* chitterlings)  are collected in
a catch basin in the immediate area before sewering.^     The grease
and solids wasteload from the viscera can be cominensurately reduced
through such by-product recovery techniques.  Caustic washings from
any viscera processing should be segregated before sewering to minimize
grease saponification and to avoid a high pH in the wastewater.


                                Troughs

Troughs have been installed under the killing floor carcass conveying
line to keep as much blood, trimmings, bone dust, and miscellaneous
pieces off the floor as possible.  The troughs have proven very
effective in collecting and containing solids, blood, etc., 'that under
ordinary circumstances would have ended up in the sewer.  Substantial
wasteload reductions are evident in the plants using these troughs.
Variations in animal size may be a problem; however, if large
variations are rare, some accomodation should be possible.  A squeegee
or scraper shaped to fit the trough is used in clean-up to move all
collected materials to the inedible rendering system.


                               Rendering

Both wet and dry rendering are used for edible, as well as inedible,
rendering processes; although the trend is toward dry rendering.  In
processing lard, low- or medium-temperature continuous  rendering systems
are common.  The water centrifuged from this process can be sold as
50 to 60 percent edible "stickwater" and thus should be evaporated and
not discharged to the sewer..

In dry rendering, sprays are commonly used to condense the vapors.  In
inedible dry rendering, catch-basin effluent can be reused as condenser
water.  In edible dry rendering, the vapors are commonly condensed with
fresh water.  A direct heat exchanger can be used to condense the
vapors without increasing wastewater volumes.

In wet rendering, the greases are drawn off the top of the tank, then the
water phase (tankwater) is removed.  This tankwater has a BODs ranging
from 22,000 mg/1 to as high as 45,000 mg/1 and suspended solids as high
as 2 percent.  Under no circumstances can this type of  waste be dis-
charged to the sewer.  It must be evaporated and the end product, commonly
called stick or stickwater, is then blended into, animal feed materials.
The tankwater may also be dried directly with inedible solids in a dry
rendering tank.  The bottom sludge from wet rendering is pressed for
recovery of residual grease, and the remaining solids (cracklings) are
used as edible product from edible rendering, and as animal feed
ingredient from inedible rendering.
60

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                                         B
Even df the tankwater is evaporated, pollution can occur.   Triple-effect
vacuum evaporation can readily foam over, further contaminating the
wastewater.
                            Hide Processing

An overflow of water from the hide curing vat or raceway occurs because
water is added to the curing solution and because hides dehydrate as they
take on salt.  This overflow could be contained and collected separately,
allowing a more intensive treatment, at a reasonable cost, to achieve a
higher quality effluent, especially in terms of salt concentrations.
It is especially important to dump the raceway infrequently—perhaps
only annually.  When dumped, it should be drained gradually, over a
period of 24 hours or more, to avoid an extreme shock load on the
treatment system.  The life of the solution can be extended by pumping
it over a static or vibrating screen.
                              Scald Tank

The hog scald  tank contains settled'solids and wastewater with a high
wasteload.  Collection, treatment,  and reuse of this water should be
considered.  Slow drainage of the tank will reduce any shock load on the
waste  treatment system and should be standard practice.  Provision should
be made for the removal of the solids through the bottom of the tank
to a truck for land disposal.


                      Pickle and Curing Solutions

These  solutions are high  in salt content  and, in many curing solutions,
high in sugar  content.  Salt is a difficult pollutant to remove and sugar
has a  very high BODs-  The operations involving injection or soaking
of meat products in these solutions should be equipped to collect all of
the solution presently wasted.  The collection pans and equipment should
be designed to permit reuse of these solutions. 7»18


                     Hater Conservation Practices

The following  practices and equipment should be employed to reduce  the
water  consumption  in plants with coincidental reduction of the
pollutional wasteload:*7,* 8

      1.   Replace  all drilled spray  pipe systems with spray nozzles
          designed  and located  to provide  a desired water spray
          pattern.

      2.   Replace  all washwater valves with squeeze- or press-to-
          open valves wherever  possible.   Foot-  or knee-operated


                                  61

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         valve control is useful where operator fatigue is a
         problem or where the operation requires the operator
         to work with both hands.

     3.  Install foot—pedal operated handwashing and drinking
         fountain water valves to eliminate constantly running
         water.

     4.  Install automatic control for sprays which need to
         operate only about 50 percent of the time.

     5.  Product chillers using cold water may be economically
         replaced by chillers using a cryogenic liquid such as
         nitrogen, thus reducing water consumption and perhaps
         improving product quality.

     6.  Water waste from the boiler (blowdown) is soft water and
         should be considered for use in clean-up or in the plant
         laundry.  Detergent use will be reduced as well as water
         conserved.

     7.  Plant clean-up as an operating procedure consumes a
         substantial quantity of water in most plants.  Reduced
         water use can be achieved with equipment such as high
         pressure water spray systems, steam and water mix
         spray systems,or automated clean-in-place (CIP) systems.
         Management control is particularly vital in clean-up
         operations if water is to be conserved and cleanliness
         standards are to be maintained.

     8.  Whenever possible, water should be reused in lower
         quality needs.  Examples include carcass washwater
         reused for hog dehairing, and lagoon water reused for
         cooling.  The general axiom is:  use the lowest quality
         of water satisfactory for the process.


                          C1ean-Up Operations

In addition to water conservation practices, other steps can also be
taken to reduce the wasteload from clean-up.  Floors and other surfaces
should be dry squeegeed or scraped wherever feasible, to keep a
maximum amount of solids and grease out of the wastewater.  Pull the
drain basket only after cleanup has been completed.  Use the minimum
of water and detergent, consistent with cleaning requirements.  Automate
cleaning of conveyors, piping and other equipment wherever possible.17*18
                                 62

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                      IN-PLANT PRIMARY TREATMENT
                           Flow Equalization

Equalization facilities consist of a holding tank and pumping equipment
designed to reduce the fluctuations of waste streams.  They can be
economically advantageous whether the industry is treating its own
wastes or discharging into a city sewer after some pretreatment.  The
equalizing tank will store wastewater either for recycle or reuse or
to feed the flow uniformly to treatment facilities throughout the 24-
hour day.  The tank is characterized by a varying flow into the tank and
a constant flow out.

The major advantages of equalization for the meat packer are that
treatment systems can be smaller, since they can be designed for the
24-hour average rather than the peak flows, and secondary waste treatment
systems operate much better when not subjected to shockloads or
variations in feed rate.
                                Screens

Since so much of the pollutional matter in meat wastes is originally
a solid (meat particles and fat) or sludge (manure solids), interception
of the waste material by various types of screens is a natural first
step.  To assure best operation for application to the plant wastewater
stream, a flow equalization facility should preceed it.

Unfortunately, when these pollutional materials enter the sewage flow
and are subjected to turbulence, pumping, and mechanical screening,
they break down and release soluble BODs to the flow, along with
colloidal and suspended and grease solids.  Waste treatment—that is,
the removal of soluble, colloidal and suspended organic matter—is
expensive.  It is far simpler and less expensive to keep the solids out
of the sewer entirely.

Static, vibrating, and rotary screens are the primary types used for this
step in the in-plant primary treatment.  Whenever feasible, pilot-scale
studies are warranted before selecting a screen, unless specific
operating data are available for the specific use intended, in the same
solids concentration range, and under the same operating conditions.


Static Screens

The primary function of a static screen is to remove "free" or trans-
porting fluids.  This can be accomplished in several ways and, in most
older concepts, only gravity drainage is involved.  A concavely curved
screen design using high velocity pressure-feeding was developed and
patented in the 1950's for mineral classification and has been adapted


                                 63

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to other uses in the process industries.   This design employs  bar
interference to the slurry which knives off  thin layers  of  the flow
over the curved surface.18

Beginning in 1969,  United States and foreign patents  were allowed  on
a three-slope static screen made of specially coined  curved wires.   This
concept used the Coanda or wall attachment phenomena  to  withdraw the
fluid from the under layer of a slurry which is stratified  by  controlled
velocity over the screen.  This method of operation has  been found to
be highly effective in handling slurries containing fatty or sticky
fibrous suspended matter. *8

The arrangement of transverse wires with unique singular curves in the
sense of flow provides a relatively non-clogging surface for dewatering
or screening.  The screens are precisely made in No.  316 stainless steel
and are extremely rugged.  Harder, wear-resisting stainless alloys may also
be used for special purposes.  Openings of 0.025 to 0.15 cm (0.010 to
0.060 inches) meet normal screening needs.18


Vibrating Screens

The effectiveness of a vibrating screen depends on a rapid motion.
Vibrating screens operate between 900 rpm and 1800 rpm;  the motion can
either be circular or straight line, varying  from 0.08 to 1.27  cm (1/32
to 1/2 inch) total travel.  The speed and motion are selected  by the
screen manufacturer for the particular application.

Of prime importance in the selection of a proper vibrating screen is
the application of the proper cloth.  The capacities on liquid vibrating
screens are based on the percent of open area of the cloth.  The cloth
is selected with the proper combination of strength of wire and percent
of open area.  If the waste solids to be handled are heavy and abrasive,
wire of a greater thickness and diameter should be used to assure long
life.  However, if the material is light or sticky in nature* the
durability of the screening surface may be the smallest consideration.
In such a case, a light wire may be necessary to provide an increased
percent of open area.


Rotary Screens

One type of barrel or rotary screen, driven by external rollers,
receives the wastewater  at one open end and discharges the solids at
the other open end.  The liquid passes outward through the screen
(usually stainless steel screen cloth or perforated metal) to a
receiving box and effluent sewer mounted below the screen.  The screen
in usually sprayed continuously by means of a line of external spray
nozzles.  The screen is  usually inclined towards the solids exit end.
This type is popular as  an offal screen but has not been used to any
great extent in secondary "polishing"—that is, in removing solids from
                                 64

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waste streams containing low solids concentrations.      (A screen of
this type has been developed for recycle of hide brining waters.)

Another rotary screen commonly used in the meat industry is driven
by an external pinion gear.  The raw flow is discharged into tha
interior of the screen below center, and solids are removed in a trough
and screw conveyor mounted lengthwise at the center line of the barrel.
The liquid exits outward through the screen into a box in which the
screen is partially submerged.  The screen is usually 40 x 40 mesh,
with 0.4 mm (1/64 inch) openings.  Perforated lift paddles mounted
lengthwise on the inside surface of the screen assist in lifting the
solids to the conveyor trough.  This type is also generally sprayed
externally to reduce blinding.  Grease clogging can be reduced by
coating the wire cloth with teflon.  Solids removals up to 82 percent
are reported.18
Applications

A broad range of applications exist for screens as the first stage of in-
plant primary treatment processes.  These include both the plant
wastewater and wastewater discharged from individual processes.  The
latter include paunch manure, hog stomach contents, hog hair recovery,
stickwater solids, hide washing operations, hide curing brine recycle,
and others.
                             Catch Basins
The catch basin for the separation of grease and solids from meat
packing wastewaters was originally developed to recover marketable
grease.  Since the primary object was grease recovery, all improvements
were centered on skimming.  Many catch basins were not equipped with
automatic bottom sludge removal equipment.  These basins could often be
completely drained to the sewer and were "sludged out" weekly or at
frequencies such that septic conditions would not cause the sludge to
rise.  Rising sludge was undesirable because it could affect the color
and reduce the market value of the grease.

In the past twenty years, with waste treatment gradually becoming an
added economic incentive, catch basin design has been improved in the
solids removal area as well.  In fact, the low market value of inedible
grease and tallow has reduced concern about quality of the skimmings,
and now the concern is shifting toward overall effluent quality improve-
ment.  Gravity grease recovery systems will remove 20 to 30 percent of
the BODs, 40 to 50 percent of the suspended solids and 50 to 60 percent
of the grease  (hexane solubles).18

The majority of the gravity grease recovery basins (catch basins) are
rectangular.  Flow rate is the most important criterion for design;
30 to 40 minutes detention time at one hour peak flow is a common


                                 65

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sizing factor.18    The use of  an equalizing  tank ahead  of  the  catch
basin obviously minimizes the size requirement  for the basin.   A
shallow basin—up to 1.8m (6 feet)—is  preferred.

A. "skimmer"  skims the grease and scum off  the top into collecting
troughs.   A  scraper moves the sludge at the bottom into  a. submerged
hopper from  which it can be pumped.   Both  skimmings and  sludge  go to
by-product recovery.

Usually two  identical catch basins,  with a common wall,  are desirable
so operation can continue if one is down for  maintenance or repair.
Both concrete and steel tanks are used.

Concrete tanks have the inherent advantages of  lower overall maintenance
and more permanence of structure.  However, some plants  prefer  to be
able to modify their operation for future expansion or alterations or
even relocation.

All-steel tanks have the advantage of being semiportable, more  easily
field-erected, and more easily modified than  concrete tanks. The all-
steel tanks, however, require additional maintenance as  a result  of
wear from abrasion.

A tank using all-steel walls and concrete bottom is probably the  best
compromise between the all-steel tank and the all-concrete tank.   The
advantages are the same as for steel; however,  the all-steel tank
requires a footing underneath the supporting  members, whereas,  the
concrete bottom forms the floor anu supporting footings  for the steel
wall tank.


                        Dissolved Ai r F1 otati on

This system is, by definition, a primary treatment system; thus the
effluent from a dissolved air flotation system is considered raw waste.
This system is normally used to remove fine suspended solids and is
particularly effective on grease in wastewaters from meat packing plants.
This is a relatively recent technology in  the meat industry; however,
it  is in fairly widespread use and increasing numbers of plants are
installing  these systems.

Dissolved air flotation appears  to be  the  single most effective device
that a meat packing plant can install  to reduce the pollutional wasteload
in  its wastewater  stream.  It is expected  that the use of dissolved air
flotation will  become  standard practice in the industry, especially as
a step in achieving  the 1977 or  1983 standards.
                                 66

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                              l.i UU 'ill:
Technical Description
Air flotation systems are used to remove any suspended material from
wastewater with a specific gravity close to that of water.   The dissolved
air system generates a supersaturated solution of wastewater and
compressed air by raising the pressure of the wastewater stream to that
of the compressed air, then mixing the two in a detention tank.  This
supersaturated mixture of air and wastewater flows to a large flotation
tank where the pressure is released, thereby generating numerous small
air bubbles which effect the flotation of the suspended organic material
by one of three mechanisms:  1) adhesion of the air bubbles to the
particles of matter; 2) trapping of the air bubbles in the floe structures
of suspended material as the bubbles rise; 3) adsorption of the air
bubbles as the floe structure is formed from the suspended organic
matter,19    In most cases, bottom sludge removal facilities are also
provided.

There are three process alternatives varying by the degree of wastewater
that is pressurized and into which the compressed air is mixed.  In the
total pressurization process, Figure 12, the entire wastewater stream is
raised to full pressure for compressed air injection.  In partial
pressurization, Figure 13, only a part of the wastewater stream is
raised to the pressure of the compressed air for subsequent mixing.
In the recycle pressurization process (Alternative B of  Figure 13),
treated effluent from the flotation tank is recycled and pressurized
for mixing with the compressed air and then, at the point of pressure .
release, is mixed with the influent wastewater.  Alternative A  (Figure 13)
shows a side-stream of influent entering the retention tank, thus reducing
the pumping required in the system shown in Figure 12.  Operating costs
may vary slightly, but performance should be essentially equal among
the alternatives.

Improved performance of the air flotation system is achieved by
coagulation of the suspended matter prior to treatment.  This  is done
by pH adjustment or the addition of coagulant chemicals, or both.  A
slow paddle mix will improve coagulation.  It has been suggested that
the proteinaceous matter in meat packing plant waste could be  removed
by reducing the wastewater to the isoelectric pH range of about 3.5.19
The protein material would be coagulated at that point and readily
removed as float from the top of the dissolved air unit.  This is not
being done in the meat industry in the United States at the present
time.

However, a somewhat comparable practice involving by-product recovery
is gaining acceptance.  In this system, segregated sewers are  required
along with two stages of air flotation treatment of the wastewaters.
A good quality grease product can be recovered from a grease-bearing
wastewater without the addition of chemicals in the first dissolved
air system.  The effluent from the first dissolved air unit is mixed
with effluent from the other waste streams in the plant and this is
fed to the second dissolved air unit which may or may not include
chemicals addition, as mentioned above.

                                 67

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                 Feed
00
                         Compressed
                             Air
Totol  Pressurizotion
       Process
                                                                          v
                                                                                  Treated
                                                                                  Effluent
                                                                              Float  to
                                                                               Disposal
                                                                       Sludge to
                                                                        Disposes!
                                 Figure 12.  Dissolved Air Flotation

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VO
                                                  Compressed
                                                      Air
                             Recycle  Pressurizotion
                                    Process
                                 (Alternative B)
Feed
Prir
Trea
from
nury
tment
T "I Tank
1 ^-^
1
i r 	
i
\t- . Flotc
| * - lai
i — ^(Retention j 	 i
V Tank /
1
1 Treated
	 ' 	 ^ httluen?
ition
ik ^
Float to
Disposal
Sludge to
Disposal
                    Compressed-
                       Air
Partial Pressurizotion
      Process
   (Alternative A)
                         Figure 13.  Process Alternatives for Dissolved Air Flotation

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One of the manufacturers of dissolved air flotation equipment indicated
a 60 percent suspended solids removal and 80 to 90 percent grease
removal without the addition of chemicals.  With the addition of 300 to
400 mg/1 of inorganic coagulants and a slow mix to coagulate the
organic matter, the manufacturer says that 90 percent or more of the
suspended solids can be removed and more than 90 percent of the
grease.20

North Star's staff observed the operation of several dissolved air
units during the verification sampling program and other plant visits.
One plant that was visited controlled the feed rate and pH of the
wastewater and achieved 90 to 95 percent removal of solids and grease.
Other plants had relatively good operating success, but some did not
achieve the results that should have been attainable.  It appeared that
they did not fully understand the process chemistry and were using
erroneous operating procedures.

The Alwatec process has been developed by a company in Oslo, Norway,
and uses a lignosulfonic acid precipitation and dissolved air flotation,
recovering a high protein product that is valuable as a feed.21
Nearly instantaneous -protein precipitation is achieved when high
protein-containing effluent, such as that from a meat packing plant,
is acidified to a pH between 3 and 4, and high molecular weight fully
sulphonated sodium lignosulphonate is added.  BODs reduction is reported
to range from 60 to 95 percent.  The effluent must be neutralized before
further treatment by the addition of milk of lime or some other
inexpensive alkali.   This  process  is being evaluated  on meat packing
waste in one plant in the United States at the present time.


Problems and Reliability

The reliability of the dissolved air flotation process and of the
equipment seems to be well established, although it is relatively new
technology for the meat packing industry.  As indicated above, it
appears that the use of the dissolved air system is not fully exploited
by some of the companies who have installed them for wastewater treat-
ment.  As in many other treatment systems, the problem seems to be limited
training of operators.and perhaps some disinterest on the part of
supervision and management in terms of the operating results expected
from the process.

The sludge and float taken from the dissolved air system can be
disposed of with the sludges obtained from secondary waste treatment
systems.  The addition of polyelectrolyte chemicals was reported to
create some problems for sludge dewatering; however, this may have been
the unique experience of one or two meat packing plants.  The
mechanical equipment involved in the dissolved air flotation system
is fairly simple, requiring standard maintenance attention for such
things as pumps and mechanical drives.
                                 70

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                                     -
                                  :'
                                   u
                SECONDARY HASTEWATER TREATMENT SYSTEMS

The secondary treatment methods commonly used for the treatment of meat
packing wastes after in-plant primary treatment (solids removal) are
the following biological systems; anaerobic processes, aerobic lagoons,
Variations of the activated sludge process, and high-rate trickling
filters.  Based on operational data from a pilot-plant system, the
rotating biological contactor shows potential as a secondary treatment
system.  Several of these systems are capable of providing 70 to 97
percent BODs reductions and 80 to 95 percent suspended solids reduction,
while combinations of these systems can achieve reductions greater
than 99 percent in BODs and grease, and greater than 97 percent in
suspended solids.

The selection of a secondary biological system for treatment of meat
packing wastes depends upon a number of important system characteristics.
Some of these are wastewater volume, equipment used, pollutant reduction
effectiveness required, reliability, consistency, and resulting secondary
pollution problems (e.g.3 sludge disposal and odor control).  The
characteristics and performance of each of the above mentioned secondary
treatment systems, and also for common combinations of them, are
described below.  Capital and operating costs are discussed in
Section VIII.  Since the treatment of wastes does not differ for the
four subcategories of the meat packing Industry (see Section IV),
no distinction by subcategory is made in the following discussion.


                          Anaerobic Processes
Elevated temperatures  (29° to 35°C or 85° to 95°F) and the high
concentrations of carbohydrates, fats, proteins, and nutrients typically
found in meat packing wastes make these wastes well suited to anaerobic
treatment.  Anaerobic or faculative microorganisms, which function in
the absence of dissolved oxygen, break down the organic wastes to
intermediates such as organic acids and alcohols.  Methane bacteria
then convert the intermediates primarily to carbon dioxide and methane.
Unfortunately, much of the organic nitrogen present in the influent
is converted to ammonia nitrogen.  Also, if sulfur compounds are
present  (such as from high  sulfated raw water—50 to 100 mg/1 sulfate)
hydrogen sulfide will be generated.  Anaerobic processes are economical
because they provide high overall removal of BODs and suspended solids
With no power cost  (other than pumping) and with low land requirements.
Two types  of anaerobic processes are used:  anaerobic lagoons and
anaerobic  contact systems.
Anaerobic  Lagoons

Anaerobic  lagoons are widely used  in the  industry as the first step in
secondary  treatment  or  as  pretreattaent prior  to discharge to a municipal
pystem,.  Reductions  of  up  to 97 percent in BODs and up to 95 percent in


                                 71

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                                   '!'•'
                              iii\\[r
                               ij i_ii.»
suspended solids can be achieved with the lagoons; 85 percent reduction
is common.  A usual arrangement is two anaerobic lagoons in parallel,
although  occasionally two are used in series.  These lagoons are
relatively deep (3 to 5 meters, or about 10 to 17 feet), low surface-area
systems with typical waste loadings of 240 to 320 kg BOD5/1000 cubic
meters (15 to 20 Ib BOD5/1000 cubic feet) and a detention time of
five to ten clays.  A thick scum layer of grease and paunch manure is
frequently allowed to accumulate on the surface of the lagoon to retard
heat loss, to ensure anaerobic conditions, and hopefully to retain
obnoxious odors.  Low pH and wind can adversely affect the scum layer.

Plastic covers of nylon-reinforced llypalon, polyviriyl chloride, and
styrofoam have been used on occasion in place of the scum layer; in fact
some states require this.  Properly installed covers provide a convenient
means for odor control and collection of methane gas.

Influent wastewater flow should be near, but not on, the bottom of the
lagoon.  In some installations, sludge is recycled to ensure adequate
anaerobic seed for the influent.  The effluent from the lagoon should
be located to prevent short-circuiting the flow and carry-over of the
Bcum layer.

Advantages-Disadvantages.  Advantages of an anaerobic lagoon system are
Initial low cost, ease of operation, and the ability to handle large
grease loads and shock waste loads, and yet continue to provide a
consistent quality effluent.22    Disadvantages of an anaerobic lagoon
are the hydrogen sulfide generated from sulfated waters and the typically
high ammonia concentrations in the effluent of 100 mg/1 or more.
Incidentally, if the  gases evolved are contained, it is possible to use
iron filings to remove sulfides.

Applications.  Anaerobic lagoons used as the first stage in secondary
treatment are usually followed by aerobic lagoons.  Placing a small,
mechanically aerated  lagoon between the anaerobic and aerobic lagoons
is becoming popular.  A number of plants are currently installing
extended  aeration units following the anaerobic lagoons to obtain
nitrification.  Anaerobic lagoons are not permitted in some states
or areas where the ground water is high or the soil conditions are
adverse  (e.g.3 too porous), or because of odor problems.


Anaerobic Contact System

The  anaerobic contact system requires far more equipment for operation
than  do  anaerobic lagoons,  and  consequently is not as commonly used.
The  equipment, as illustrated in Figure 14, consists of equalization
tanks, digesters with mixing equipment, air or vacuum gas  stripping
units, and  sedimentation tanks  (clarifiers).  Overall reduction of
90 to 97  percent in BODs and suspended solids is  achievable.
                                  72

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                   Equalizing Tank
        Plant
w     Effluent
                        A

                        > f
Sludge  Recycle
                               Heaters
                                           Anaerobic
                                           Digesters
          Gas
         Stripping
          Units
Sedimentation
    Tanks
                                           Effluent

                                   Figure 14.  Anaerobic Contact Process

-------
Equalized wastewater flow is introduced into a mixed digester where
anaerobic decomposition takes place at a temperature of about 33° to 350C
(90° to 95°F).  BOD5 loadings into the digester are between 2.4 and 3.2
kg/cubic meter (0.15 and 0.20 Ib/cubic foot), and the detention time is
between three and twelve hours.  After gas stripping, the digester
effluent is clarified and sludge is recycled at a rate of about one-
third the raw waste influent rate.  Sludge at the rate of about 2 percent
of the raw waste volume is removed from the system.''

Advantages-Pisadvantages.  Advantages of the anaerobic contact system
are high organic waste load reduction in a relatively short time;
production and collection of methane gas that can be used to maintain
a high temperature in the digester and also to provide auxiliary heat
and power; good effluent stability to grease and wasteload shocks;
and application in areas where anaerobic lagoons cannot be used because
of odor or soil conditions.  Disadvantages of anaerobic contactors are
higher initial and maintenance costs and some odors emitted from the
clarifiers.

Applications.  Anaerobic contact systems are restricted to use as the
first stage of secondary treatment and can be followed by the same
systems following anaerobic lagoons or trickling filter roughing
systems.

                            Aerated Lagoons

Aerated lagoons have been used successfully for many years in a limited
number of installations for treating  meat packing wastes.  However,
With recent tightening of effluent limitations and because of the
additional treatment aerated lagoons can provide, the number of
installations is increasing.

Aerated lagoons use either fixed mechanical turbine-type aerators,
floating propeller-type aerators, or a diffused air system for supplying
oxygen to the wastewater.  The lagoons usually are 2.4 to 4.6 m (8 to
15 feet) deep, and have a detention time of two to ten days.  BODs
reductions range from 40 to 60 percent with little ot no reduction in
suspended solids.  Because of this, aerated lagoons approach conditions
similar to extended aeration without sludge recycle (see below).


Advantages-Disadvantages

Advantages of this system are that it can rapidly add dissolved oxygen
(DO) to convert anaerobic wastewaters to an aerobic state; provide
additional BODs reduction; and require a relatively small amount of
land.  Disadvantages are the power requirements and that the aerated
lagoon, in itself, usually does not reduce BODs an^ suspended solids
adequately to be used as the final stage in a high performance
secondary system.
                                 74

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                                    n
                                    *;i
Applications

Aerated lagoons are usually the second stage of secondary treatment and
must be followed by an aerobic (shallow) lagoon to capture suspended
solids and to provide additional treatment.


          Aerobic Lagoons (also called Stabilization Lagoons)

Aerobic lagoons (or stabilization lagoons or oxidation ponds), are large
surface area, shallow lagoons, usually 1 to 2.3 m deep (3 to 8 feet),
loaded at a BOD5 rate of 20 to 50 pounds per acre.  Detention times
will vary from about one month to six or seven months; thus aerobic
lagoons require large areas of land.

"Aerobic lagoons serve three main functions in waste reduction:

     •  Allow solids to settle out;

     •  Equalize and control flow;

     •  Permit stabilization of organic matter by aerobic and
        facultative microorganisms and also by algae.

Actually, if the pond is quite deep, 1.8 to 2.4 m (6 to 8 feet), so that
the wastewater near the bottom is void of dissolved oxygen, anaerobic
organisms may be present.  Therefore, settled solids can be decomposed
into inert and soluble organic matter by aerobic, anaerobic or
facultative organisms, depending upon the lagoon conditions.  The
soluble organic matter is also decomposed by microorganisms.  It is
essential to maintain aerobic conditions in at least the upper 6 to 12
inches in shallow lagoons since aerobic microorganisms cause the most
complete oxidation of organic matter.  Wind action assists in carrying
the upper layer of liquid (aerated by air-water interface and photosynthesis)
down into the deeper portions.  The anaerobic decomposition generally
occurring in the bottom converts solids to liquid organics which can
become nutrients for the aerobic organism in the upper zone.

Algae growth is common in aerobic lagoons; this currently is a drawback
when aerobic lagoons are used for final treatment.  Algae may escape into
the receiving waters, and algae added to receiving waters are considered
a  pollutant.  Algae in the lagoon, however, play an important role in
stabilization.  They use C0£, sulfates, nitrates, phosphates, water
and sunlight to synthesize their own organic cellular matter and give
off free oxygen.  The oxygen may then be used by other microorganisms for
their metabolic processes.  However, when  algae die they release their
organic matter in the lagoon, causing a secondary loading.  Ammonia
disappears without the appearance of an equivalent amount of nitrite
and nitrate in aerobic lagoons.  From this, and the fact that aerobic
lagoons tend to become anaerobic near the bottom, it appears that some
denitrification is occurring.
                                 75

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Ice and snow cover in winter reduces the overall effectiveness of
aerobic lagoons by reducing algae activity,  preventing mixing, and
preventing reaeration by wind action and diffusion.   This cover,  if
present for an extended period, can result in anaerobic conditions.
When there is no ice and snow cover on large aerobic lagoons,  high
winds can develop a strong wave action that can damage dikes.   Riprap,
segmented lagoons, and finger dikes are used to prevent wave damage.
Finger dikes, when arranged appropriately, also prevent short circuiting
of the wastewater through the lagoon.   Rodent and weed control, and
dike maintenance are all essential for good operation of the lagoons.


Advantages-Disadvantages

Advantages of aerobic lagoons are that they reduce suspended solids,
oxidize organic matter, permit flow control and wastewater storage.
Disadvantages are reduced effectiveness during winter months, the large
land are required, the algae growth problem, and odor problems for a
short time in spring, after the ice melts and before the lagoon becomes
aerobic again.


Applications

Aerobic lagoons usually are the last stage in secondary treatment and
frequently follow anaerobic or anaerobic-aerated lagoons.  Large
aerobic lagoons allow plants to store wastewaters from discharge during
periods of high flow in the receiving body of water or to store for
irrigation purposes during the summer.  These lagoons are particularly
popular in rural areas where land is available and relatively inexpensive.


                           Activated Sludge

The conventional activated sludge process is schematically shown in
Figure 15.  In this process recycled biologically active sludge or floe
is mixed in aerated tanks or basins with wastewaters.  The microorganisms
in the floe adsorb organic matter from  the wastes and convert it by
oxidation-enzyme systems to such stable products as carbon dioxide,
water, and sometimes nitrates  and sulfates.  The time required for
digestion depends on the type  of waste  and its concentration, but  the
average time  is six hours.  The floe, which  is a mixture of micro-
organisms  (bacteria, protozoa, and  filamentous types), food,  and slime
material, can assimilate organic matter rapidly when properly
activated; hence, the name activated sludge.

From  the aeration tank  the mixed sludge wastewaters, in which little
nitrification has taken place, are  discharged  to a sedimentation tank.
Here  the sludge settles out, producing  a  clear effluent, low  in BODs,
and a biologically active  sludge.   A portion of the settled sludge,
normally about 20 percent, is  recycled  to serve as an  inoculum and to


                                 76

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    Primary                           Secondary
Sedimentation                       Sedimentation
now
Waste
_/ \
•*\ J A ? Aeratio
n"T"m«ti ,.._,. \/
Tank ">(
T !
1 . [_Return Activated Sludge

I
! Waste
1 Sludge
J,
'
1
i
i
1
Waste 1
Sludge^
      Figure 15.  Activated Sludge Process
                                                     Effluent

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maintain a high mixed liquor suspended solids content.   Excess sludge
is removed (wasted) from the system, usually to thickeners and anaerobic
digestion, 01- to chemical treatment and dewatering by filtration or
centrifugation.

This conventional activated sludge process can reduce BODs and suspended
solids up to 95 percent.  However, because it cannot readily handle the
shock loads and widely varying flow common to meat packing wastewaters,
this particular version of activated sludge is not a commonly used process
for treating meat packing wastes.

Various modifications ofthe activated sludge process have been developed,
such as the tapered aeration, step aeration, contact stabilization, and
extended aeration.  Of these, extended aeration processes are being
used for treatment of meat packing wastes.


Extended Aeration

The extended aeration process is similar to the conventional activated
sludge process, except that the mixture of activated sludge and raw
materials is maintained in the aeration chamber for longer periods of
time.  The common detention time in extended aeration is one to three
days, rather than six hours.  During this prolonged contact between the
sludge and raw waste, there is ample time for the organic matter to be
adsorbed by the sludge and also for the organisms to metabolize the
organic matter which they have adsorbed.  This allows for a much greater
removal of organic matter.  In addition, the organisms undergo a
considerable amount of endogenous respiration, and therefore oxidize
much of the organic matter which has been built up into the protoplasm
of the organism.  Hence, in addition to high organic removals from the
wastewaters, up to 75 percent of the organic matter of the microorganisms
is decomposed into stable products and consequently less sludge will have
to be handled.

In extended aeration, as in the conventional activated sludge process, it
is necessary to have a final sedimentation tank.  Some of the solids
resulting from extended aeration are rather finely divided and therefore
settle slowly, requiring a longer period of settling.

The long detention time in the extended aeration tank makes it possible
for nitrification to occur.  In nitrification under aerobic conditions,
ammonia is converted to nitrites and nitrates by specific groups of
nitrifying bacteria.   For this to occur, it is necessary to have sludge
detention times in excess of ten days.22    This can be accomplished by
regulating the amounts of sludge recycled and wasted each day.  Oxygen
enriched gas could be used in place of air in the aeration tanks to
improve overall performance.  This would require that the aeration
tank be partitioned and covered, and that the air compressor and dispersion
system be replaced by a rotating sparger system, which costs less to
buy and operate.  When cocurrent, staged flow and recirculation of gas


                                  78

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back throxjgh the liquor is employed, between 90 and 95 percent oxygen
utilization is claimed.23    Although this modification of extended
aeration has not been used in treating meat packing wastes,  it is being
used successfully for treating other wastes.


Advantages and Disadvantages

The advantages of the extended aeration process are that it is stable
to shock loading and flow fluctuations because the incoming raw waste
load is diluted, by the liquid in the system,  to a much greater extent
than in conventional activated sludge.  Also,  because of the long
detention time, high BOD5 reductions can be obtained.  Other advantages
of the system are the elimination of sludge digestion equipment and the
capability to produce a nitrified effluent.  Disadvantages are that it
is difficult to remove most of the suspended solids from the mixed liquor
discharged from the aeration tank; large volume tanks or basins are
required to accommodate the long detention times; and operating costs
for aeration are high.


Applications

Because of the nitrification process, extended aeration systems are
being used following anaerobic lagoons to produce low BODs and low
ammonia-nitrogen effluents.  They are also being used as the first stage
of secondary treatment followed by polishing lagoons.


                           Trickling Filter

A trickling filter consists of a bed of rock or prefabricated plastic
filter media on the surface of which the microbial flora develops; a
rotary arm wastewater distribution system; and an under-drainage system.
The distribution arm uniformly distributes wastewater over the filter
media.  The microflora adsorbs, and eventually metabolizes the organic
matter in the liquid as it trickles down through the media.  When the
growth becomes fairly thick it begins to slough off the surface of
the media as large pieces of solids vihich are carried with the liquid
out through the under-drainage system.  Consequently, the trickling
filter must be followed by an appropriate sedimentation tank to remove
the solids.  To avoid clogging the trickling filter, the wastewater must
be pre-treated  (primary, in-plant treatment) to remove most solids and
grease.

The high-rate trickling filter is used in treating meat plant wastewaters
either as a roughing filter preceeding a conventional secondary treatment
such as activated sludge or as complete secondary treatment in several
stages.  Hydraulic loading for high rate trickling filters is generally
in the range of 93.5 to 187 million liters per hectare  (10 to 20 million
gallons per acre) per day.


                                 79

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In treating high organic wastes with trickling filters there is a
definite limit to BODs removal by a single stage.   Common practice has
been to use a multistage filter system.  The first stage filter can be
fed at a BOD5 rate of 0.016 to 0.024 kg/cubic meter of media (100 to
150 pounds/1000 cubic feet) and can result in 40 to 50 percent removal
of BODs.  If the second stage filter is the final filter to be used,
the loading should not exceed 0.4 kg BODs/cubic meter of media (25
pounds of BODs per 1000 cubic feet) of media.  However, since the raw
waste load of meat packing plants is relatively strong, this may mean
that the size of the second filter will be excessively large.  In this
case, it might be better to provide still a third stagey then loadings
can be higher in the second state—up to 0.8 to 1.2 kg BODs per cubic
meter of media (50 to 75 pounds of BOD5/1000 cubic feet of raedia).  The
loading to the third stage should be limited to 0.32 kg of BODs/cubic
meter of media (20 pounds/1000 cubic feet).  The overall removal of such
a system can be as high as 95 percent reduction in BODs.  When staging
of filters is used, it is desirable to provide a sedimentation tank for
each stage.  However, large rock or synthetic media can be used without
intermediate sedimentation.  Because of the size of second and third
stage filters and because of the number of sedimentation tanks that may
be required, this system is no longer generally used in the meat packing
industry.  Although single-stage filters alone result in considerably
less BODs reduction than staged trickling filter systems, they have found
use in the meat industry, particularly as a pretreatraent prior to some
type of activated sludge system.


Advantages and Disadvantages

Advantages of the roughing trickling filter are that it can smooth out
hydraulic and BODs loadings; provide some initial reduction in BODs
(40 to 50 percent); and the fact that it is not injured materially by
extended rest periods such as weekends.  However,  if there are long rest
periods it is desirable to recirculate the effluent of one of the settling
tanks through the filter to keep the floe moist.  Another advantage of
the roughing filter is its reliability with minimum care and attention.
A disadvantage of the trickling filter system in general is that it is
a costly installation, it may also be necessary to cover the filters in
winter to prevent freeze-up and the effluent concentration fluctuates
with changes in incoming wasteload.
                     Rotating Biological Contactor
Pirocess Description
    rotating biological contactor (RBC) consists of a series of closely
spaced flat parallel disks which are rotated while partially fcnmersed
In the wastewaters being treated.  A biological growth covering the
surface of the disk adsorbs dissolved organic matter present in the
                                80

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wastewater.  As the biomass on the disk builds up, excess slime is
sloughed off periodically and is removed in sedimentation tanks.  The
rotation of the disk carries a thin film of wastewater into the air
where it absorbs the oxygen necessary for the aerobic biological
activity of the biomass.  The disk rotation also promotes thorough
mixing and contact between the biomass and the wastewaters.  In many
ways the RBC system is a compact version of a trickling filter.  In
the trickling filter the wastewaters flow over the media and thus over
the microbial flora; in the RBC system, the..flora is passed through the
wastewater.

The system can be staged to enhance overall wastewater reduction.
Organisms on the disks selectively develop in each stage and are thus
particularly adapted to the composition of the waste in that stage.
The first couple of stages might be used for removal of dissolved
organic matter, while the latter stages might be adapted to nitrification
of ammonia.
Development Status

The RBC system was developed independently in Europe and the United
States about 1955 for the treatment of domestic waste, but found applica-
tion only in Europe.  Currently, there are an estimated 1000 domestic
installations in Europe.22    However, the use of the RBC for the
treatment of meat packing waste is relatively new.  The only operational
information available on its use on meat packing waste was obtained on
a pilot-scale system, although a large installation was recently
completed at the Iowa Beef Processors plant in Dakota City, Nebraska,
for the further treatment of meat packing waste effluents from an
anaerobic lagoon.  The pilot-plant studies were conducted with a four-
stage RBC system with four-foot diameter disks.  The system was treating
a portion of the effluent from the Austin, Minnesota, anaerobic contact
plant used to treat meat packing waste.  These results showed a BOD5
removal in excess of 50 percent with loadings less than 0.037 kg BODs
per square meter (0.0075 Ib BODs per square foot) of disk area, based
on an average BODs influent concentration of approximately 25 mg/1.
Data from Autotrol Corporation revealed ammonia removals of greater than
90 percent by nitrification in a multistage unit.  Four to eight stages
of disks with maximum hydraulic loadings of 61 liters per day per square
meter (1.5 gallons per day per square foot) of disk area are considered
normal for ammonia removal.
Advantages and Disadvantages

The major advantages of the RBC system are its relatively low installed
cost; the effect of staging to obtain both dissolved organic matter
reduction and removal of ammonia nitrogen by nitrification; and its good
resistance to hydraulic shock loads.  Disadvantages are that the system
should be housed, if located in cold climates, to maintain high removal

                                81

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efficiencies and to control odors.  Although this system has demonstrate
its durability and reliability when used on domestic wastes, it has not
yet been fully tested to treat meat packing plant wastes.
Uses

Rotating biological  contactors  could be used for the entire  aerobic
secondary system.  The number of stages required depend on the desired
degree of treatment  and  the  influent strength.  Typical applications
of the rotating biological contactor, however, may be  for polishing the
effluent from anaerobic  processes  and from roughing trickling filters
and as pretreatment  prior to discharging wastes to a municipal system.
A BODs reduction of  98 percent  is  achievable with a four-stage RBC.22
           Performance of Various Secondary Treatmervt Systems

Table 6 shows BOD5,  suspended solids  (SS), and grease removal
efficiencies for various secondary biological treatment systems used
to treat meat packing wastewaters.  Average values are presented  for
10 systems; exemplary values for 5 systems.  Exemplary values each repre-
sent one system (except for anaerobic plus aerobic lagoons, where they
represent  two systems) considered to be among the best for that kind of
system and whose values were actually verified in the field sampling
study conducted during this program.

The number of systems used to calculate average values, also shown in
Table 6, clearly shows that the anaerobic plus aerobic lagoons are
the most commonly used.  In fact this system was used by about 63
Percent of the plants included in the study that reported having
Secondary  systems  (see Section VIII).

The estimated value  of BOD5 shown for the anaerobic  lagoons plus
rotating biological  contactor is based upon pilot plant results and is
Considered to be conservative.

The values shown for the anaerobic lagoons plus extended aeration
are also estimated and are all below  th3 values calculated by using
average removal efficiencies for the  two  components  of the system
individually.  For example, if the BODs reduction for both the anaerobic
lagoon and extended  aeration were 90  percent  , the calculated efficiency
°f the two systems combined would be  99 percent.
                                  82

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                       ^If^nPT
                              u
          •  Table 6.  Performance of Various Secondary
                    Treatment Systems.
Secondary Treatment System
(number of systems used
to determine averages)
Anaerobic + Aerobic
lagoon (22)
Anaerobic + aerated +
Aerobic lagoon (3)
Anaerobic Contact Process +
Aerobic lagoon (1)
Extended Aeration +
Aerobic lagoon (1)
Anaerobic lagoon + Rotating
Biological contactor
Anaerobic lagoon + Extended
Aeration H- Aerobic lagoon
Anaerobic lagoon +
Trickling filter (1)
2-Stage Trickling filter (1)
Aerated + Aerobic
lagoon (1)
Anaerobic Contact (1)
Water Wasteload Reduction
Average Values
BOD 5

95.4

98.3

98.5

96.0

98. 5e

98e

97.5
95.5

99.4
96.9
SS

93.5

93.3

96.0

86.0

™

93e

94.0
95.0

94.5
97.1
Grease

95.3

98.5

99.0

98.0



98e

96.0
98.0

— —
95.8
Exemplary Values
BOD 5

98.9

99,5



96.0








99.4
96.9
SS •

96.6

97.5



86.0








94.5
97.1
Grease

98.9

99.2



98.0








—
95.8
e - estimated
                            83

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                    TERTIARY AND ADVANCED TREATMENT
                 Chemical Precipitation of Phosphorus

Phosphorus is an excellent nutrient for algae and thus can promote
heavy algae blooms.  As such it cannot be discharged into receiving
streams and its concentration should not be allowed to build up in a
recycle water stream.  However, the presence of phosphorus is
particularly useful in spray or flood irrigation systems as a nutrient
for plant growth.

The effectiveness of chemical precipitation, Figure 16, is well
established and has been verified in full scale during the North Star
verification sampling program.  One packing plant operates a dissolved
air flotation system as a chemical precipitation unit and achieves a
35 percent phosphorus removal to a concentration of less than 1 mg/1.


Technical Description

Phosphorus occurs in wastewater streams from packing plants primarily as
phosphate salts.  Phosphates can be precipitated with trivalent iron
and trivalent aluminum salts.  It can also be rapidly precipitated by the
addition of lime; however, the rate of removal is controlled by the
agglomeration of the precipitate colloids and by the settling rate of
the agglommerate. 19   Laboratory investigation and experience with
in-plant operations have substantially confirmed that phosphate removal
is dependent on pH and that this removal tends to be limited by the
solubility behavior of the three phosphate salts mentioned above.  The
optimum pH for the iron and aluminum precipitation occurs in the 4 to
6 range, whereas the calcium precipitation occurs in the alkaline side
at pH values above 9.5.

Since the removal of phosphorus is a two-step process involving
precipitation and then agglommeration, and both are sensitive to pH,
setting the pH level takes on added significance.  If a chemical other
than lime is used in the precipitation-coagulation process, two levels
of pH are required.  Precipitation occurs on the acid side and coagulation
is best carried out on the alkaline side.  The precipitate is removed by
sedimentation or by dissolved air flotation. 19

Polyelectrolytes are polymers that can be used as primary coagulants,
flocculation aids, filter aids or for sludge conditioning.  Phosphorus
removal may be enhanced by the use of such polyelectrolytes by producing
a better floe than might occur without such chemical addition. ***

The chemically precipitated sludge contains grease and organic matter
in addition to the phosphorus, if the system is used in primary treatment.
If it is used as a post-secondary treatment, the sludge volume will be
less and it will contain primarily phosphorus salts.  The sludge from
either treatment can be landfilled without difficulty.


                                84

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Primary
or
oCCOnGciry 	 P
Treatment
Effluent

PH
Ajustmant

v,
••>*

Alum or
Lime
Addition

X
J
Float
t
Air
Flotation
System

partial
	 	 	 s, Thrtinrv
— i Treated
Effluent-
                                                          V
                                                       Sludge
                                                          to
                                                       Disposal
                  Figure 16.  Chemical Precipitation
Development Status

This process is well-established and understood technically.  Although
its use on meat industry waste is very limited» it is gaining acceptance
as a primary waste treatment process.  Where it is in use, it is being
operated successfully if the process chemistry is understood and the
means to control the process are available.


Problems and Reliability

AS indicated above, the reliability of. this process is well established;
however, it is a chemical process and as such requires the appropriate
control and operating procedures.  The problems that can be encountered
in operating this process are those caused by a lack of understanding
or inadequate equipment.  Sludge disposal is not expected to be a problem.
The use of polyelectrolytes and their effect on the dewatering properties
of the sludge are open to some question at the present time.


                              Sand Filter

A slow sand filter is a specially prepared bed of sand or other mineral
fines on which doses of wastewater are intermittently applied and from
which effluent is removed by an under-drainage system, Figure 17j it
removes solids from the wastewater stream.  BOD5 removal occurs
primarily as a function of the degree of solids removal although some
biological action occurs in the top inch or two of sand.  Effluent
from the sand filter is of a high quality with BOD5 and suspended
solids concentrations of less than 10 mg/1. 2S   Although the performance
of a sand filter is well known and documented, It is not in common use
because it is not needed to reach current wastewater standards.
                                 85

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Primary or
Secondary
Treatment •
  Effluent
                                            Chlorination,
                                              Optional	
                                            for Odor Control
                                Surface nr Back
                                  Clean  °  Wash
                                  to Regenerate
                                                                ••Treated
                                                                 Effluent
                     Figure 17.   Sand Filter System
A rapid sand filter may operate under pressure in a closed vessel or may
be built in open concrete tanks.  It is primarily a water treatment
device and thus would be used as tertiary treatment, following secondary
treatment.  Mixed media filters are special versions of rapid sand
filters that permit deeper bed-penetration by gradation of particle .
sizes in the bed.  Up-flow filters are also special cases of rapid
filters.


Technical  Description

The slow sand filter removes solids primarily at the surface of the
filter.  The rapid sand filter is operated to allow a deeper penetration
of suspended solids into the sand bed and thereby achieve solids
removal through a greater cross-section of the bed.  The rate of
filtration of the rapid filter is up to 100 times that of the slow
filter.  Thus, the rapid filter requires substantially less area than
the slow filter; however, the cycle time averages about 24 hours in
comparison with cycles of up to 30 to 60 days for slow filter. 26   The
larger area required for the latter means a higher first cost.  For small
plants, the slow sand filter can be used as secondary treatment.  In
larger sizes, the labor in maintaining and cleaning the surface may
operate against its use.  The rapid sand filter on the other hand can
be used following secondary treatment, but would tend to clog quickly and
require frequent automatic backwashing if used as secondary treatment,
resulting in a high water use.  This washwater would also need
treatment if the rapid sand filter is used following conventional solids
removal.
                                86

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                                          y

 The rapid filters operate essentially  unattended with  pressure  loss
 controls  and  piping  installed  for  automatic  backwashing.  They  may be
 enclosed  in concrete structures  or in  steel  tanks.  2It

 Chlorination,  both before and  after.sand  filtering, particularly  in
 the use of rapid  filters, may  be desirable to minimize or eliminate
 potential odor problems  and  slimes that may  cause  clogging.

 Clean-up  of the rapid sand filter  requires backwashing the bed  of sand
 with a greater quantity  of water than  used for  the slow sand filter.
 Backwashing is an effective  clean-up procedure  and the only constraint is
 to  minimize the washwater required in  clean-up  as  this must be  disposed of
 In  some appropriate  manner other than  discharing it to a stream.


 Development Status

 The slow  sand  filter has been  in use for  50  years  and  more.  It has been
 particularly well suited to  small  cities  and isolated  treatment systems
 serving hotels, motels,  hospitals,  etc.,  where  treatment of low flow is
 required  and  land and sand are available.  Treatment in these applica-
 tions  has been a  sanitary or municipal-type  raw waste.  The Ohio
 Environmental  Protection Administration is a strong advocate of slow
 sand filters  as a secondary  treatment  for small meat plants, following
 some form of  settling or solids  removal.  As of early  1973, 16  sand filters
 had been  installed and 8 were  proposed and expected to be installed.
 All 24 of these installations  were on  waste  from packing plants. 27
 The land  requirements for a  slow sand  filter are not particularly
 significant in relation  to those required for lagooning purposes in
 pecondary treatment  processes.   However,  the quality and quantity of
 sand is important and may be a constraint in the use of sand filters in
 some local situations.   It should  also be recognized that this  process
 requires  hand  labor  for  raking the crust  that develops on the surface.
 Frequency of raking  may  be weekly  or monthly, depending upon the quality
 of  pretreatment and  the  gradation  of the  sand.
Problems and Reliability

The reliability of the slow sand filter seems to be well established
in its long term use as a municipal waste treatment system.  When the
sand filter is operated intermittently there should be little danger
of operating mishap with resultant discharge of untreated effluent or
poor quality effluent.  The need for bed cleaning becomes evident
with the reduction in quality of the effluent or in the increase cycle
time both of which are subject to monitoring and control.  Operation in
cold climates is possible as long as the appropriate adjustment in the
surface of the bed has been made to prevent blanking off of the bed
by freezing water.
                                 87

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The rapid sand filter has been used extensively in water treatment plants
and in municipal sewage treatment for tertiary treatment; thus its
use in tertiary treatment of secondary treated effluents from meat plants
appears to be a practical method of reducing BODs and suspended solids
to levels below those expected from conventional secondary treatment.


                       Microscreen-Microstrainer

A microstrainer is a filtering device that uses a fine mesh screen on
a partially submerged rotating drum to remove suspended solids and
thereby reduce the BODs associated with those solids, Figure 18.   The
microstrainer is used as a tertiary treatment following the removal
of most of the solids from the wastewater stream.  The suspended solids
and BOD5 can be reduced to 3 to 5 mg/1     in municipal systems.   There
are no'reports of their use in the tertiary treatment of meat plant
Wastes.
Technical Description

The microstrainer is a filtration device in which a stainless steel
tnicrofabric is used as the filtering medium.  The steel wire cloth is
mounted on the periphery of a drum which is rotated partially submerged
in the wastewater.  Backwash immediately follows the deposition of
solids on the fabric > and  in one  installation,  this is  followed by
ultraviolet light exposure to inhibit microbiological growth,19    The
backwash water containing the solids amounts to about 3 percent of the
wastewater stream and must be disposed of by recycling to the secondary
treatment system. 28   The drum is rotated at a minimum of 0.7 and up
to a maximum of 4.3 revolutions per minute.  9   The concentration and
percentage removal performance for microstrainers on suspended solids
and BODs appear to be approximately the same as for sand filters.
 Secondary
  Effluent
s

Micro-
Screen
>
t
Ba<
N,
ckwash
Clear
to
Screen/Strainer
Tertiary
                Figure 18.  Microscreen/Microstrainer
                                                         Effluent
                                88

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 Peyelopmant  Status
       there  is  general  information  available on the performance of
microstrainers  and  on tests  involving  the use of them, there appears
to be  only one  recorded installation of a microstrainer in use on
municipal waste;  the requirements for  effluent quality have not
necessitated such installation.  The economic comparisons betx^een sand
filters  and  microstrainers are inconclusive; the mechanical equipment
required for the  microstrainer may  be  a greater factor than the land
requirement  for the sand filter at  the present time.


Problems and Reliability

The test performance of  the microstrainer fairly well establishes the
reliability  of  the  device in its ability to remove suspended solids
and the  associated  BODs.  Operating and maintenance problems have not been
reported; this  is probably because, in large part, of the limited use
of the device in  full-scale application.  As a mechanical filtration device
requiring a  drive system, it would  have normal maintenance requirements
associated with that kind of mechanical equipment.   As a device based
on microopenings  in a fabric, it would be particularly intolerant to any
degree of grease  loading.


                     Nitrification-Denltrification

This two-step process of nitrification and denitrification, Figure 19,
is a system  to remove the nitrogen which appears as ammonia in treated
meat plant wastewaters,  and it is of primary importance for removal
of the ammonia generated in anaerobic secondary treatment systems.
Ammonia removal is  becoming more important "because of stream standards
being pet at levels as low as 1 to 2 mg/1.  7    Removal of ammonia is
Virtually complete, with the nitrogen gas as the end product.


Technical Description

The large quantities of organic matter in raw waste from meat packing
plants is frequently and effectively treated in anaerobic lagoons.  Much
of the nitrogen in  the organic matter,  present mainly as protein,  is
converted to ammonia in anaerobic systems or in localized anaerobic
environments.  The  following sets of equations indicate the nitrification
of the ammonia to nitrites and nitrates, followed by the subsequent
denitrification to nitrogen and nitrous oxide.  29   The responsible
organisms are indicated also.
                                89

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Secondary
Jreatrnsnt ^
Cttl 	 _i
Aeration
System
*v
1
* -*
Anaerobic
Pond
V,

Aeration
Cell
Tertiary
p Treated
C-*il.._«A
                         Carbon
                         Source,
                       e.g. Methanol

               Figure 19.  Nitrification/Dentrification
     Nitrification:
          2N0
                        -> N02  + H30+  (Nitrosomonas)
     2NO,
                              (Nitrobacter)
     Denitrification (using methanol as carbon source)
6H
5CH3OH
                                                    13
          Small amounts of N?0 and NO are also found
                                        (Facultative heterotrophs)
Nitrification does not occur to any great extent until most of the
carbonaceous material has been removed from the wastewater stream.  The
ammonia nitrification is carried out by aerating the effluent sufficiently
long to assure the conversion of all of the nitrogen in the raw effluent
to the nitrite-nitrate forms prior to the anaerobic denitrification
step.

The denitrification step, converting nitrates to nitrogen and nitrogen
oxides, takes place in the absence of oxygen.  It is thought to proceed
too slowly without the addition of a biodegradable carbon source such
as sugar, ethyl alcohol, acetic acid, or methanol.  Methanol is the
least expensive and performs satisfactorily.  Investigators working on
this process have found that a 30 percent excess of methanol over the
stoichiometric amount is required. 2If»31

In current waste treatment practice using anaerobic and aerobic
lagoons, ammonia nitrogen that disappears in the aerobic system does
not show up to a large extent as nitrites and nitrates.  Ammonia stripping
                                90

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                          ffv
is not likely to account for the loss.  It appears that denitrification
must actually be occurring in the bottom reaches of the aerobic lagoons,
where anaerobic conditions are probably approached.

Presuming total conversion of the ammonia to nitrites or nitrates, there
will be virtually no nitrogen remaining in the effluent from the
denitrification process.  Total nitrogen removal can be maintained at
90 percent over the range of operating temperatures; the rate increases
with temperature to an optimum value of approximately 30°C for most
aerobic waste systems.  Temperature increases beyond.gSO* result in a
decrease in the rate fcr the mesophilic organisms.

The wastewater is routed to a second aeration basin following de-
nitrification, where the nitrogen and nitrogen oxide are readily stripped
from the waste stream as eases.  The sludge from each stage is settled
and recycled to preserve the organisms required for each step in the
process.


Development Status

The specific nitrification-denitrification process has only been carried
out at the bench- and pilot-scale levels.  Gulp and Gulp 2^  suggest
that the "practicality of consistently maintaining the necessary
biological reactions and the related economics must be demonstrated on
a plant-scale before the potential of the process can be accurately
evaluated."  A pilot model of a three-stage system using this process
was reportedly developed at the Cincinnati Water Research Laboratory of
the EPA and is being built at Manassas, Virginia. 32    This work is
also reported to be experimental.  Thus, it can be concluded that this
process is as of yet unproven.  However, as mentioned above, observations
of treatment lagoons for meat packing plants gives some indication that
the suggested reactions are occurring in present systems.  Also,
Halvorson 33  reported that Pasveer is achieving success in denitrifica-
tion by carefully controlling the reaction rate in an oxidation ditch,
so that dissolved oxygen levels drop to zero just before the water is
reaerated by the next rotor.


Problems and Reliability

In view of the experimental status of this process, it would be premature
to speculate on the reliability or problems incumbent in a full-scale
operation.  It would appear that there would be not exceptional
maintenance or residual pollution problems associated with this process
in view of the mechanisms suggested for its implementation at this time.
                                91

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                           Ammonia Stripping

Ammonia stripping is a raodificationof the simple aeration process for
removing gases in water, Figure 20.  Following pH adjustment, the
wastewater is fed to a packed tower and allowed to flow down through
the tower with a countercurrent air stream introduced at the bottom of
the tower flowing upward to strip the ammonia.  Ammonia-nitrogen
removals of up to 98 percent and down to concentrations of less than 1
mg/1 have been achieved in experimental ammonia stripping towers.  2l*'
Technical Description

The pH of the wastewater from a secondary treatment system is adjusted
to between 11 and 12 and the wastewater is fed to a packed tower or
to a cooling tower type of stripping tower.  As pH is shifted above 9
the ammonia is present as the soluble gas in the wastewater stream
rather than as the ammonium ion.      Ammonia-nitrogen removal of
90 percent was achieved with countercurrent air flows between 1.8 and
2.2 cubic meters per liter (250 and 300 cubic feet per gallon) of
Wastewater in an experimental tower with hydraulic loadings between
100 and 125 liters per minute per square meter (2.5 and 3 gallons per.
minute per square foot) .      Ammonia removal was increased to 95 percent
with the air rate increased to 3 cubic meters per liter (400 cubic feet
per gallon) of wastewater and the hydraulic loading lowered to 85 liters
per minute per square meter (2 gallons per minute per square foot).  A
ffiaximum of 98 percent ammonia removal from a wastewater stream was
reported with the air rate at 5.9 cubic meters per liter (800 cubic
feet per gallon) and a hydraulic loading of 33 liters per minute
per square meter (0.8 gallons per minute per square foot).  The ammonia
concentration was reduced to less than one part per million at 98 percent
removal.  The high percentage removal of ammonia-nitrogen is achieved
only at a substantial cost in terms of air requirements and stripping
tower cross sectional area.

Because the system involves the stripping of ammonia from a water stream,
ambient air temperatures below 0°C  (32°F) present a problem; operation
in cold climates may require housing inside a building or heating of the
air prior to introducing it to the  stripping tower.  The residual
Pollution would be the ammonia stripped from the wastewater stream and
mixed with the air, which is vented to the atmosphere.  The maximum
concentration of ammonia in the air stream prior to mixing with the
ambient air would be about 10 milligrams per cubic meter, wj^ereas the
threshold for odor is about 35 milligrams per cubic meter.


Development Status

The ammonia stripping process is  a well-established industrial practice
in the petroleum refinery industry.  The only significant difference
                                92

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                                    •  H'
                                    'UU
Secondary
Treatment
 Effluent
    pH
Adjustment
                                                                 Treated
                                                                 Effluent
                     Figure 20.  Ammonia Stripping
between petroleum refinery application and that on a meat packing
plant waste would probably be the comparatively small size of stripping
tower for the meat packing plant in. comparison to the refinery.  The
air  stripping of ammonia from secondary effluent is reported primarily
on an experimental basis in equipment that is 1.8 meters (6 feet) in
diameter with a packing depth of up to 7.3 meters (24 feet).  Two large
scale installations of ammonia stripping of lime treated wastewater
are  reported at South Tahoe, California, and Windhoek, South Africa.   >  •
The  South Tahoe ammonia stripper was rated at 14.2 M liters per day
(3.75 MGD) and was essentially constructed as a cooling tower structure
rather than as a cylindrical steel tower which might be used in smaller
sized plants.

Thus, although there is no reported u&e of ammonia stripping on meat
packing plant waste, the technology is well established and implementa-
tion, when standards require it, should be without difficulty.


Problems and Reliability

The  reliability of this process has been established by the petroleum
refinery uses of the process over many years.  Although the source of
the  ammonia may be different and there may be other contaminants in the
water stream, none of this should affect the established reliability of
this process.  The experience of other users of the process will have
pretty well identified potential problems.and, presumably, the solutions
for  these problems.  The maintenance requirements would be only those
normally associated with the mechanical equipment involved in pumping
the  wastewater to the top of the tower, where the feed is introduced to
the  tower, and in maintaining the air blowers.  The tower fill would
undoubtedly be designed for the kind of service involved in treating
a wastewater stream that has some potential for fouling.
                                 93

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                        Spray/Flood Irrigation

A no discharge level for meat packing waste can be achieved by the use
of spray or flood irrigation of relatively flat land, surrounded by
dikes which prevent run-off and upon which a cover crop of grass or other
vegetation is maintained.  Wastewater disposal is achieved by this
method to the level of no discharge.   Specific plant situations may
preclude the installation of irrigation systems;  however, where they
are feasible, serious consideration should be given to them.


Technical  Description

Wastes  are disposed of in  spray or flood  irrigation  systems by
distribution through piping  and spray nozzles over relatively flat
terrain or by  the  pumping  and disposal  through ridge and furrow irrigation
systems which  allow a certain level of  flooding on a given plot of
land, Figure 21.   Pretreatment for removal of solids is  adviseable  to
prevent plugging of the  spray nozzles,  or deposition in  the furrows of
a ridge-and-furrow system, or collection  of  solids on the surface,
which may  cause odor problems or  clog the soil.  Therefore, the BODs
would undoubtedly  have already been reduced  in the preliminary  treatment
in preparation for distribution through the  spray system.

In a flood irrigation system the  waste  loading in the effluent  would be
limited by the waste loading tolerance  of the particular crop being
grown on the land, or it  may  be limited  by the soil conditions or potential
for vermin or  odor problems.

Wastewater distributed in  either  manner percolates through the  soil and
 the  organic  matter in the  waste undergoes a  biological degradation.  The
liquid  in  the  waste stream is either stored  in the soil  or leached  to
a groundwater  aquifer and  discharges into the groundwater.  Approximately
10 percent of  the  waste  flow will be lost by evapotranspiration (the
loss due to  evaporation  to the atmosphere through the leaves  of
plants). 29

The  following  factors will affect the ability of  a particular land  area
to absorb  wastewater:  1)  character of  the soil,  2)  stratification  of
the  soil profile,  3) depth to groundwater, 4) initial moisture  content,
5) terrain and groundcover.  29

The  greatest concern in  the  use of irrigation as  a disposal system  is
the  total  dissolved solids content and  particularly  the  salt  content
of the  wastewater.  A maximum salt content of 0.15 percent is suggested
in Eckenfelder.  29  In  order to  achieve  this level  of salt content,
30 percent of  the  total  wastewater stream from a typical plant  was
determined to  require treatment in an ion exchange  system upstream  from
the  spray  irrigation system.

                                  94

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  Primary,
Secondary
    or
  Partial
 Tertiary
 Treatment
  Effluent
Holding
Basin
•v

Pumping
System


Application
Site
                                                            Grass or
                                                           Hay Crop
               Figure 21.  Spray/Flood Irrigation System
An application rate of 330 liters per minute per hectare (35 gallons
per minute per acre) has been recommended in determining the quantity
of land required for various plant sizes.  This amounts to almost  5 cm
(2 inches) of moisture per day and is relatively low in comparison with
application rates reported by Eckenfelder for various spray irrigation
systems.v     However, soils vary widely in their percolation properties
and experimental irrigation of a small area is recommended before  a
complete system, is built.

The economic benefit from spray irrigation is estimated on the basis of
raising one crop of grass hay per season with a yield of 13.4 metric
tons qf dry matter per hectare (six tons per acre) and valued at $22
per me.tric ton ($20 per ton).  These figures are conservative in terms
of the number of crops and the price to be expected from a grass hay
crop.  The supply and demand sensitivity as well as transportation
problems for moving the hay crop to a consumer all mitigate against
any more optimistic estimate of economic benefit.

Cold climate uses of spray irrigation may be subject to more constraints
and greater land requirements than plants operating in more temperate
climates.  However, a meat packer in Illinois reportedly operated  an
irrigation system successfully.  Eckenfelder also reports that wastes
have been successfully disposed of by spray irrigation from a number
of other industries. 29

North Star found in its survey that the plants located in the arid
regions of the southwest were most inclined to use spray or flood
irrigation systems.


Problems and Reliability

The long term reliability of spray or flood irrigation systems is  a
function of the ability of the soil to continue to accept the waste as
                                95

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                                   Ui

it is disposed of through the irrigation system, and thus reliability
remains somewhat open to question.   Problems in maintenance are primarily
in the control of the proper dissolved solids level and salinity content
of the wastewater stream and also in climatic limitations that may exist
or develop.   Many soils are improved by spray irrigation.


                             Ion Exchange

Ion exchange, as a tertiary waste treatment, is used as a deionization
process in which specific ionic species are removed from the wastewater
stream, Figure 22.  Ion exchange would be used to remove salt (sodium
chloride)  from waters.  Ion exchange resin systems have been developed
to remove specific ionic species, to achieve maximum regeneration
operating efficiency, and to achieve a desired effluent quality.  In
treating meat packing waste, the desired effluent quality is a total
wastewater salt concentration of 300 m&/l.  Ion exchange systen are
available that will remove up to 90 percent of the salt in a water
stream. 19   They can also be used to remove nitrogen.


Technical  Description

The deionization of water by means of ion exchange resin involves the use
of both cation and anion exchange resins In sequence or in combination
to remove an electrolyte such as salt.
           RS03H + NaCl %     v RSO-jNa + NCI

           R-OH + HCL	> R-C1 + «20

           where R represents the resin

The normal practice in deionization of water has been to make the first
Pass through a strong acid column, cation exchange resin, in which the
first reaction above occurs.  Effluent from the first column is passed
to a second column of anion exchange resin to remove the acid formed
in the first step, as indicated in the second reaction.  As indicated
in the two reactions, the sodium chloride ions have been removed as
ionic species.  A great variety of ion exchange resins have been
developed over the years for specific deionization objectives for
Various water quality conditions.

Wastewater treatment with ion exchange resins has been investigated
9nd attempted for over 40 years; however, recent process developments
in the treatment of secondary effluent have been 'particularly successful
in achieving high quality effluent at reasonable capital and operating
costs.  One such process is a modification of the Rohm and Haas, Desal
Process. 19  In this process a weak base ion exchange resin is
converted to the bicarbonate form and the secondary effluent is treated
ty the resin to convert  the inorganic salts.  After the first step,
the process includes a flocculation/aeration and precipitation  step to
                                96

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       Partial
      Tertiary
     Treatment
      Effluent
                              Ion
                          Exchange
                          Column (s)
                                                       Tertiary
                                                   ->  Treated
                                                       Effluent
Backwash £
 Regsnerant
   System
                      Figure 22.  Ion Exchange
remove organic matter;  however,  this  should  be unnecessary if the
sand filter and/or carbon adsorption  system  is used upstream of  the
ion exchange system.   The effluent  from the  first  ion  exchange column
is further treated by a weak cation resin  to reduce the  final dissolved
salt content to approximately five  mg/1.   The anion resin in this
process is regenerated with aqueous ammonia  and  the cation resin with
an aqueous sulfuric acid.  The resins did  not appear to  be susceptible
to fouling by the organic constituents of  the secondary  effluent used
in this experiment.

Other types of resins can be used for nitrate and  phosphate removal,
as well as color bodies, COD, and fine suspended matter.  Removal  of
these various constituents can range  from  75 percent to  97 percent,
depending on the constituent.

The cycle time on the ion exchange  unit will be  a  function of the  time
required to block or to take up the ion exchange sites available in the
resin contained in the system.  Blockage occurs  when the resin is
fouled by suspended matter and other  contaminants.  The  ion exchange
system,is ideally located at the end  of the  wastewater processing
scheme thus having the highest quality effluent  available as a feedwater.
The ion exchange system needed for  irrigation purposes (mentioned  earlier)
based on an assumed inlet salt concentration of  2000 mg/1, was required
to treat 30 percent of the wastewater stream. This inlet concentration
is fairly conservative, based on the  North Star  survey data.  Salt
concentration should be easily reduced to  1000 mg/1 and  less with  a
minimal effort at controlling salt  discharge into  the  wastewater.
                                97

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To achieve a recyclable water quality, it may be assumed that less than
500 mg/1 of total dissolved solids would have to be achieved.  Of the
total dissolved solids, 300 ppm of salt are assumed to be acceptable.
To achieve this final effluent quality, 95 percent of the wastewater
stream would be subjected to ion exchange treatment.

The residual pollution will be that resulting from regeneration of the
ion exchange bed.  The resin systems as indicated earlier, can be
tailored to the ion removal requirements and efficient use of regeneration
chemicals thus minimizing liquid wastes from the regeneration step.


Development Status

Ion exchange as a unit operation is well established and commonly used
in a wide range of applications in water treatment and water deionization.
Specific resin applications such as in wastewater treatment have not
been widespread up to the present time, as there has not been a need
for such a level of treatment.  However, process development and
experimental work have shown the capability of ion exchange systems to
achieve the levels of salt removal required for the suggested irrigation
and closed-loop water recycle systems examined in this report.

Part of the economic success of an ion exchange system in treating packing
plant waste will probably depend on a high quality effluent being
available as a feed material.  This again, can be provided by an upstream
treatment system including carbon adsorption or sand filtration to remove
a maximum of the particularly bothersome suspended organic material.
However, the affect of a lower quality feed would be primarily economic
because of shorter cycle times, rather than a reduction in the overall
effectiveness of the ion exchange system in removing a specific ionic
species such as salt.


problems and Reliability

Inasmuch as ion exchange is widely used, the reliability of  the concept
is well established.  The application of the technology in waste
treatment has not been tested and therefore the reliability in that
application has yet to be firmly established.  The problems associated
with ion exchange operations would primarily center on the quality of
the feed to the ion exchange system and its effect on the cycle time.
The operation and control of the deionization-regeneration cycle can
be totally automated, which would seem to be the desired approach.
                                98

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                                -I
                                   M~

                           Carbon Adsorption

Carbon adsorption is a unit operation in which activated carbon adsorbs
soluble and trace organic matter from wastewater streams,  Figure 23.
Either granular or powdered activated carbon can be used to remove up
to 98 percent of colloidal and dissolved organics measured as BODs and
COD in a wastewater stream. 31   The organic molecules which make up
the organic material attach themselves to the surface of the activated
carbon and are thereby removed.  Larger particles should be filtered
from the wastewater in treatment systems upstream from carbon adsorption
since the effectiveness of the latter will be substantially reduced by
gross particles  of organic matter.   Total organic carbon removal
efficiencies of about 50 to 55 percent have been reported for carbon
adsorbers and 45 to 50 percent removal of soluble organic carbon is
reported.     Carbon adsorption treatment of meat packing waste would
be required only if a closed loop water recycle system were to be
installed with a requisite low organic concentration,


Technical Description

Activated carbon in a granular or powdered form provides an active surface
for the attachment and resultant removal of organic molecules from
wastewater streams.  This is a surface adsorption phenomenon and is
not preferential for any particular molecule.  Thus, in addition to
trace organic matter, odors and color bodies will also be removed from
the wastewater stream by carbon adsorption.  The rate of adsorption is
controlled by the rate of diffusion of the organic molecules within
the capillary pores of the carbon particles.  This rate varies inversely
with the square of the particle diameter and increases with increasing
concentration of organic matter and with increasing temperature.  The
implication of the particle diameter-adsorption rate relationship is that
the smaller the carbon particle the larger the adsorption rate will be,
in any given system.  This factor is the basis for the interest in
powdered activated carbon in preference to granular carbon. 2

The granular carbon is effectively used in packed or expanded bed
adsorbers.  A number of processes have been experimentally attempted
to utilize powdered carbon in various process systems such as the
fluidized bed and carbon-effluent slurry systems.

Regeneration of the carbon is periodically required.  A standard
regeneration technique is incineration of the organic matter deposited
on the surface of the carbon.  It is economically important to
regenerate and recover the carbon and regeneration has been a serious
limitation to the use of powdered activated carbon up to the present
time.

Carbon adsoption will remove up to about 98 percent of the colloidal
and dissolved organic matter with resulting effluent COD's down to
12 mg/1  in any of  the various  physical systems devised for contacting
                                99

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 Partial Tertiary
    Treatment  -
     Effluent
Adsorption
  Column
   Tertiary
•> Treated
   Effluent
                                   Carbon
                             Regeneration and
                                   Storage
                     Figure 23.   Carbon Adsorption
activated, carbon and wastewater.   This is a finishing treatment for
wastewater intended to remove the trace organic material left after
standard secondary and partial tertiary treatment.   Essentially all  of
the gross organic particles must-be removed from the wastewater before
entering this treatment system.

The residual pollution associated with carbon adsorption will be that
due to regeneration and a properly operated low oxygen furnace achieving
complete combustion of the organic matter should present no pollution
problem for the surrounding air environment.


Development Status

Activated carbon treatment in water purification is common practice
and well established.  Several large scale pilot projects testing
carbon adsorption as a treatment of wastewaters are presently underway.
In addition carbon towers have been used for the removal of suspended
solids in a small number of municipal treatment systems requiring high
quality effluent.  The treatment has not been applied specifically
to meat packing plant effluent; however, at the point in a waste treatment
system where an activated carbon system would be used, there should  be
no significant difference between municipal waste and meat packing waste.
The effluent should be of high, quality.

The primary question demanding the attention of research investigators in
the use of this system is to find an economic method for the use of
activated carbon in powdered form rather than granular form.
                                100

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                                  n  n3
                                  ' J  !
E-^ra
                           •Vj''i\\l>

Problems and Reliabilities

Since this technology is well established in the water treatment industry»
it presumably can be operated with the proper type of feedstrcam on an
efficient and reliable basis.  While the treatment of wastewater for
this system is largely limited to large scale pilot projects, the
reliability and utility of such treatment should be clearly established
within a relatively short time, certainly before the need for equipment
to meet 1983 standards.

Operating and maintenance problems do not seem to be significant,
particularly if the quality of the feedwater is maintained by appropriate
upstream treatment systems.  Regeneration is no problem in the packed
and expanded bed systems and presumably can be worked out for powdered
carbon systems before the mid 1980's.


                           Reverse Osmosis

The reverse osmosis process uses semi-permeable membranes to remove
contaminants down to molecular size, Figure 24.  It is capable or
removing divalent ions at efficiencies of up to 98 percent and monovalent
ions and small organic molecules at 70 to 90 percent.      Total solids
concentrations between 25 mg/1 and 65 rag/1 have been obtained in reverse
osmosis effluent. 3tf   Reverse osmosis would not be needed for
applications other than a closed loop recycle water system.  The
application of reverse osmosis to date has been limited to capacities
no larger than 190,000 liters (50,000 gallons) per day, and current
operating costs are estimated to be $0.08 to $0.16/1000 liters ($0.30
to $0.60/1000 gallons). 24


Technical Description

Several different kinds of semipermeable membranes are available for use
in the reverse osmosis process.  Data are available on the use of
cellulose acetate membranes.  These and other semipermeable membranes
are more permeable to pure water than to dissolved salt and other ions
and molecules.  The process  operates by reversing the normal osmotic
process by increasing the pressure on the- side of the membrane
containing the contaminated water until pure water flows through the
membrane from the contaminated side to the pure water side.  Excellent
rejection or removal of essentially all contaminants in a wastewater
stream from a meat packing plant would be achieved through a reverse
osmosis system.  However,  the rate at which pure water would be produced
is still unacceptably low for economic application of this system.
Current development work is  aimed at improving the rate at which pure
water can be produced,while  retaining the high quality of the effluent.
                                101

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                              F^T^k  "U  cr
                              ffa A  i
                              -' '* /r\\ I
                                '  .'.!! .~  •
                                     il   U
Partial
Tertiary , v
Treatment
Effluent
Reverse
Osmosis
System
- - - - *Th

1
                                                            Full  Tertiary
                                                              Treated
                                                              Effluent
                                           Concentrated
                                              Brine  to
                                              Disposal
                      Figure 24.  Reverse Osmosis
Development Status
The application of reverse osmosis to the treatment of wastewater
streams has been confined to nsiperiments on domestic sewage on a small
scale.  As a waste treatment process, the.limited capacity of commercially
available units and the high Operating costs tend to limit the potential
applicability of reverse osmosis wastewater treatment in the near future.


Problems and Reliability

The reliability of reverse osmosis r.emains open to question until larger
pca.le and longer term experiments have been conducted on wastewater
treatment,  A very significant problem remains in the bacterial growth
tha,t ha9 been observed on reverse osmosis membranes which seriously
Deduces their operating efficiency.  Microbial growth has also been
observed in the support structure under the membranes.  Chlorine cannot
be used because the membranes which are presently available are damaged
by chlorination. 19
                            Electrodialysis

Electrodialysis is a process that uses an applied electric current to
separate ionic species in a solution, Figure 25.  Membranes allow
specific ions to pass from the wastewater stream on one side of the
Membrane to a highly concentrated solution of contaminants on the
other side of the membrane.  Electrodialysis is Used to remove dissolved
solids such as salt, which is of particular concern in meat industry
waste.  Single-pass removal efficiencies of^up to 40 percent of the
is the reported performance of the system.
31
                                102

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   Partial
  Tertiary .
 Treatment
   Effluent
Full  Tertiary
  Treated
  Efflusnt
                                           Concentrated
                                              Brine  to
                                              Disposal
                      Figure 25.   Electrodialysis
Technical Description

The electrodialysis process incorporates a number of chambers made
by alternating anionic and cationic membranes that are arranged between
two electrodes.  A brine solution is alternated with contaminated
wastewater solution in the chambers between the differing membranes.
Electric current is applied across the membrane chambers causing the
cations to move towards the cathode and the anions towards the anode.
However, after passing from the chambers containing the wastewater
into adjacent brine chambers, the ions can travel no further toward the
electrodes.  Their path is blocked by a membrane that is impermeable to
that particular ionic species.  In this manner, the wastewater stream
is depleted while the adjacent brine stream is enriched in the ions which
are to be removed.

Power costs limit the salinity of the effluent wastewater after treatment
in the electrodialysis system to approximately 300 to 500 mg/1 of salt.
This limitation is imposed because of the increase in electrical resistance
in the treated wastewater that would occur at lower concentrations of
(salt,

The residual pollution from an electrodialysis unit would be the brine
solution used and generated in the chambers jf the unit.  This brine
solution might be handled by a blowdown system which removes the quantity
of, s.alt added per unit of time,
Development Status

Electrodialysis is an old process snd3£n fairly widespread use for the
purpose of; desalting brackish water.      The treatment of wastewater
in electrodialysis systems has not been done except on an experimental
basis.  There is no reported application of the process on wastewater
                                103

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from the meat industry which tends to have a ffiirly substantial salt
content.  The potential utility of the process is therefore speculative
as to its use on wastewater, however, its widespread use in water
desalting suggests that, if the need arises for its application, it
is technically feasible to desalt wastewater in such a process.


Problems and Reliability

The reliability of the electrodialyais system in removing salt from
wastewaters is only speculative based on the use of the system in desalting
brackish waters.  It has demonstrated its reliability in the desalting
application.  The problems associated with using this process in
treating wastewater from meat packing plants is the substantial cost,
the necessity of brine disposal, and the bacterial growth which occurs
on the dialysis membranes. *9   Chlorine cannot be applied because it
damages the membranes.
                                 104

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                               SECTION VIII

              COST,  ENERGY,  AND NON-WATER QUALITY ASPECTS

                                 SUMMARY

The wastewater  from  meat  packing plants is amenable to treatment in
secondary and tertiary  waste treatment systems to achieve low levels
of pollutants in  the final effluent.   In-plant controls, by-product
recovery operations,  and  strict water management practices can be
highly effective  in  reducing the wasteload and wastewater flow from
any industry plant.   These water management practices will reduce the
requisite size  of secondary  and tertiary treatment systems and improve
their waste reduction effectiveness.

The waste treatment  investment for a  typical plant in each industry
subcategory is  listed in  Table 7 to achieve each of four levels of
treatment:
          Level 1 -  reduction of organics by the use of exemplary
                     secondary treatment systems.
          Level 2 -  in-plant controls plus partial tertiary treatment.
          Level 3 -  no  discharge via  land disposal by irrigation.
          Level 4 -  wastewater recycle.
Assuming that 70  percent  of  the industry plants discharge to municipal
sewers,^   the  total investment cost  was calculated for the industry
for the various effluent  treatment levels.  The total costs and per-
installed capacity costs  are reported in Table 8,  The Level 3 alterna-
tive results in no discharge and costs less than Level 2.  The critical
requirements for  irrigation  are sufficient land availability within
reasonable piping distance and a total salinity in the wastewater of
less than 1500 ppm or  0.15  percent.
                                    29
Total dissolved solids concen-
tration may also be  a  consideration,  depending on the type of soil.

          Table 7.   Average  Total Waste Treatment Investment Costs per
                     Plant  to Achieve  a Given Level of Effluent Quality.
Effluent
Quality
Level 1
Level 2
Level 3
Level 4
Simple
Slaughterhouse
$ 80,000
A 25, 000
268,000
733,000
Complex
Slaughterhouse
$ 139,000
665,000
487,000
1,315,000
Low-Processing
Packinghouse
$ 131,000
629,000
451,000
1,227,000
High-Processing
Packinghouse
$ 148,000
736,000
544,000
1,475,000
*Locker plants were not included in any subcategory, but were assumed to require an
 investment of $10,000 each to go to no discharge by 1977, which appears to be the
 most attractive choice other than municipal treatment.
                                105

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                 Table  8.   Estimated Total Investment Cost
                           to  the  Industry to Achieve a Given
                           Level of Effluent Quality from
                           Present Level of Treatment

Effluent
Quality
Level 1
Level 2
Level 3
Level 4

Total Industry
Investment,
($ millions)
52.8*
159.7
119.0
252.2
Investment
Cost per
.million kg LWK
per year
2,355
7,119
5,306
11,240
Investment
Cost per
million Ib LWK
per year,
1,069
3,232
2,409
5,103
*Includes $10,000 per plant for  2600 locker  plants,  totaling  $26 million,
        Table 9.  Total Increase in Annual Cost of Waste Treatment,
                  $/1000 kg ($/1000 Ib) LWK.
Effluent
Quality
Level 1
Level 2
Level 3
Level 4
Simple
Slaughterhouse
0.35
(0.16)
2.93
(1.33)
2.00
(0.91)
4. 74
(2.15)
Complex
Slaughterhouse
0.26
(0.12)
1.92
(0.87)
1.34
(0.61)
3.i7
(1.44)
Low-Processing
Packinghouse
0.33
(0.15)
2.44
(1.11)
1.74
(0.79)
4.30
(1.95)
High-Processing
Packinghouse
0.46
(0.21)
3.37
(1.53)
2.42
(1.10)
5.62
(2.55)
                                 106

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                           IpAfHT
                            hi,", {.".'! i,-1  i
The annual operating costs for  a  treatment system to achieve the
indicated effluent quality are  reported in Table 9.  The costs to
achieve Level 1 range from 12 to  21  cents per head of beef, depending
on the subcategory.  The costs  to achieve Level 2 vary from $0.90 to
$1.50 per head more than present  waste treatment costs.  Costs above
present for Level 3 are about two-thirds of those for Level 2, and
costs for Level 4 are nearly twice those for Level 2.

Energy consumption associated with wastewater treatment in the meat
industry is not a serious constraint, varying from 10 to 40 percent
of present power consumption.   The higher percentage is for the
smaller packing plants that consume  relatively small quantities of
electric energy at the present  time.

With the implementation of these  standards, land becomes the primary
waste sink instead of air and water.  The waste to be land filled
from packing plants can improve soils with nutrients and soil con-
ditioners contained in the waste.  Odor problems can be avoided or
eliminated in all treatment systems.
                            "TYPICAL" PLANT

The waste treatment systems  applicable to wastewater from the meat
packing industry can be used by  plants in all four subcategories of
the industry.  A hypothetical "typical" plant was constructed in each
subcategory as a basis for estimating investment and total annual
costs for the application of each waste treatment system within each
subcategory.  The costs were estimated, and, in addition, effluent
reduction, energy requirements,  and non-water quality aspects of the
treatment systems were determined.

The waste treatment systems  are  applied on the basis of the following
plant constructs for each subcategory:
                                107

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                             »rj
                                         sr?j
                           ..lyUUu
/  \  r
U UU  L

Kill, kg LWK/day
(Ib LWK/day)
Wastewater flow
liters /1000 kg LWK
(gals/ 1000 Ib LWK)
Raw waste, BOD^
kg/ 1000 kg LWK
(lb/1000 Ib LWK)
Processed meat
production
kg/day
(Ib/day)
Industry Subcategory
Simple
Slaughter-
house
220,000
(484,000)
5,328
(639)
6.0
(6.0)
0
Complex
Slaughter-
house
595,000
(1,310,000)
7,379
(885)
10.9
(10.9)
0
Low-
processing
Packing-
house
435,000
(900,000)
7,842
(941)
8.1
(8.1)
54,000
(119,000)
High-
processing
Packing-
house
350,000
(800,000)
12,514
(1,500)
16.1
(16.1)
191,000
(422,000)
                        WASTE TREATMENT  SYSTEMS

The waste treatment systems included in  this  report  as  appropriate
for use on meat packing plant wastewater streams  can be used by all
plants in the industry.  The treatment systems will  work, subject
to specific operating constraints or limitations.  However, the cost
of such treatment systems may be uneconomical or  beyond the economic
capability of some plants.

The waste treatment systems, their use,  and the minimum effluent
teduction associated with each are listed in  Table 10.

The dissolved air flotation system can be used upstream of any second-
ary treatment system.  When operated without  chemicals, the by-product
grease recovered in the floe skimmings has an economic  value estimated
at lie/kg (5c/lb).  The use of chemicals will increase  the quantity
of grease removed from the wastewater stream, but may reduce the value
of the grease because of the chemical contaminants.
                                108

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                           jmnir
                           •ilif'-V mp
                                  i • \ i j
             Table 10. Waste Treatment Systems, Their  Use
                       and Effectiveness
       Treatment
        System
     Use
   Effluent  Reduction
Dissolved air  flotation
(DAF)
DAF with pH control and
flocculants added
Anaerobic + aerobic
lagoons
Anaerobic + aerated +
aerobic lagoons
Anaerobic contact
process
Activated sludge

Extended aeration
Anaerobic lagoons  +
rotating biological
contactor
Chlorination


Sand filter,

Microstrainer

Electrodialysis
Ion exchange
Ammonia stripping

Carbon adsorption


Chemical precipitation

Reverse osmosis

Spray irrigation
Flood irrigation
Ponding and evaporation
Primary treatment
or by-product
recovery

Primary treatment
or by-product
recovery
Secondary treatment

Secondary treatment

Secondary treatment

Secondary treatment
Secondary treatment
Secondary treatment
Finish and
disinfection

Tertiary treatment  &
Secondary treatment
Tertiary treatment
Tertiary treatment
Tertiary treatment
Tertiary treatment
Tertiary treatment


Tertiary treatment

Tertiary treatment

Mo discharge
No discharge
No discharge
Grease,  60%  removal, to
  100 to 200 mg/1
BOD5, 30% removal
SS, 30%  removal
Grease,  95-99% removal,
BOD5, 90% removal
SS, 98%  removal
BOD , 95% removal

BOD5, to 99% removal
BOD5, 90-95% removal
BOD_, 90-95% removal
BOD , 95% removal
BOD5, 90-95% removal
BOD5, to 5-10 mg/1
SS, to 3-8 mg/1
BODc, to 10-20 mg/1
SS, to 10-15 mg/1
TDS, 90% removal
Salt, 90% removal

90-95% removal
BOD5, to 98% removal as
  colloidal & dissolved
  organic
Phosphorus, 85-95% removal
  to 0.5 mg/1 or less
Salt, to 5 mg/1
TDS, to 20 mg/1
Total
Total
Total
                                 109

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                                    rail
The secondary treatment systems are generally land intensive because of
the long retention time required in natural biological processes.
Mechanically assisted systems have reduced the land requirements but
increased the energy consumption and cost of equipment in achieving
comparable levels of waste reduction.  A final clarifier is included
at the end of all secondary systems.  Some of the tertiary systems are
interchangeable.  Any of them can be used at the end of any of the
secondary treatment systems to achieve a required effluent quality.
Chlorination is included if a disinfection treatment is required.

The most feasible system for no discharge at this time is flood or
spray irrigation, or, in some cases, evaporation from a shallow pond.
Closing the loop to a total water recycle or reuse system is technically
feasible, but costly.  The irrigation option does require large plots
of accessible land—roughly 2.7 hectares/million liters (25 acres/million
gallons) of wastewater per day; and limited concentrations of dissolved
solids.  More detailed descriptions of each treatment system and its
effectiveness are presented in Section Vll-Control and Treatment
Technology.

Of all the plants in the study sample that reported wastewater treatment,
55 percent indicated discharging raw waste to a municipal treatment
system.  Thirty-eight plants reported some on-site secondary treat-
ment.  Of the 38 plants, 63 percent used the anaerobic plus aerobic
lagoons system.  This system was used to treat large and small waste-
water streams alike, varying from 76,000 liters per day (0.2 MGD)
to 4.8 million liters per day (1.3 MGD).  The rest of the systems
listed as secondary treatment were used by  1, 2, or 3 plants each,
except the rotating biological contactor, which is now being evaluated
at full-scale at one site.

Dissolved air flotation is used as a primary treatment, either alone
or along with screens or a catch basin, by about 30 percent of the
plants in the sample.  About 5 percent use chemicals in the flota-
tion system.

Chlorination is a rare practice, according to the information col-
lected in the survey questionnaires; it appears to be used by about
5 percent of the plants.

Other than sand filters and spray irrigation, there is no reported
use of any of the advanced treatment systems.  Sand filters are used
for secondary treatment in Ohio instead of anaerobic lagoons,
which are discouraged by the Ohio Environmental Protection Administra-
tion.  The few spray irrigation systems are located in arid regions
of the Southwestern U.S.
                                 110

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Among the industry subcategorics, for which we have specific plant
information, slaughterhouses have almost twice as many air flotation
systems in use as do packinghouses.  Municipal treatment and the
anaerobic plus aerobic system for secondary treatment arc used by the
bulk of the industry.  A breakdown of the sample by subcategory is as
follows:
               Secondary Treatment by Each Subcategory, %

Municipal
treatment , %
Anaerobic +
aerobic
lagoons , %
Other, 7,
TOTAL
Simple
Slaughter-
house
56
33
11
100%
Complex
Slaughter-
house
29
65
6
100%
Low-
Processing
Packing-
house
70
11
19
100%
High-
Processing
Packing-
house
59
14
27
100%
North Star
Sample of
Industry
55
28
17
100%
This tabulation does not take into account the large number of small
plants in the industry.  Depending on the source of information, the
total number of plants in the industry varies from 4000 to 6000 and
the approximate percentage of small plants varies from 85 to 90 per-
cent.  However, these small plants account for only 10 percent or
less of the industry's output and, probably, a somewhat smaller pro-
portion of the total wastewater load.  Of the few small plants for
which data were available, about 50 percent reported discharging
wastewater into city sewers.  The remaining 50 percent used a wide
variety of secondary treatment systems.  Based on all of the available
information, it is estimated that 50 percent of the small plants use
municipal treatment facilities, a small percent probably dump raw
waste into local streams or use land disposal, and the remaining plants
treat their own waste.  Taken as single point sources of wastewater,
these small plants represent an unknown but a very small fraction
of the total wasteload on receiving streams.
                              •  Ill

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                                     f'i
                                     i "3
                      TREATMENT AND CONTROL COSTS

                         In-Pi ant Control  Costs

The cost of installation of in-plant controls is primarily a function
of the specific plant situation.  Building layout and construction
design will largely dictate what can be done, how, and at what cost in
regard to in-plant waste control techniques.  No in-plant control costs
were included in the cost estimates for Level 1 and 2 technologies,
although a dissolved air flotation system as primary treatment was
included in the Level 2 costs.  Rough approximations of the range of
costs for the in-plant controls requiring capital equipment are listed
in Table 11.

          Table 11.   In-Plant Control Equipment Cost Estimates
Plant Area
Pen wastes

Blood handling

Paunch handling


Viscera handling
Troughs
Rendering
Hide processing
Hog Scald Tank
Pickle & Curing
solutions
Water Conservation
Water Conservation
Item
Roof on pens
Manure sewer
Curbing 4 collection
system
Blood dryer
Solids pumping
system
Liquid screening (•
collection equip-
ment
Localissed catch basin
	
Surface condensers
Tankwater evaporator
Overflow collection
& treatment
Water treatment &
reuse system
Solution collection,
treatment, reuse
system
Install spray nozzles
Press-to-open &
foot operated valves
Equipment Cost Range
$5000 - $10,000
$8 - $12/foot
$10,000 - $50,000
$30,000 - $50,000
$10,000 - $20,000
$5,000 - $10,000

$6,000 - $12,000
$5 - $10/foot
$15,000 - $20,000
$50,000 - $200,000
$5,000 - $20,000
$10,000 - $25,000
$10,000 - $30,000
$5,000 - $10,000
$10,000 - $20,000
                                 112  .

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                                 *
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Table 12.  Secondary Waste Treatment System Costs
           [.Investment, $1000; Annual Costs, 0/1000 kg LWK
           (e/1000 Ib LWK)]
Waste Treatment
System
Pre-treatment and
Finishing Systems
Dissolved Air Flotation,
pre-treatment
ChJ.orination,
finishing
Secondary Systems
Anaerobic + aerobic

Anaerobic + aerated +
aerobic
Aerated + aerobic

Anaerobic contact
process
Activated sludge
Anaerobic lagoon +
extended aeration
Anaerobic lagoon +
rotating biological
contactor
Simple
Slaughterhouse
Total
Investment


65
7.5

238.

318.

210

410

438
308
198
Annual
Cost


2.4
(1.1)
0.44
(0.2)

10.4
(4.7)
13.9
(6.3)
10.6
(4.8)
16.3
(7.4)
17.2
(7.8)
14.3
(6.5)
10.6
(4.8)
Complex
Slaughterhouse
Total
Investment


81
18.8
•
425.

564

432

520

1130
370
364
Annual
Cost


0.44
(0.2)
0.44
(0.2)

6.0
(2.7)
8.8
(4.0
7.5
(3.4)
7.3
(3.3)
14.3
(6.5)
8.6
(3.9)
6.6
(3.0)
Low-Processing
Pa ckingho use
Total
Investment


79
17.5

400.

531

398

500

1000
364
334
Annual
Cost


0.9
(0.4)
0.7
(0.3)

7.9
(3.6)
11.2
(5.1)
9.2
(4.2)
9.7
(4.4)
17.8
(8.1)
10.1
(4.6)
8.4
(3.8)
High-Processing
Packinghouse
Total
Investment


86
21.2

475

623

500

570

1375
373
375
Annual
Cost


0.7
(0.3)
0.9
(0.4)

10.4
(4.7)
15.0
(6.8)
12.8
(5.8)
12.6
(5.7)
27.1
(12.3)
13.2
(6.0)
10.6
(4.8)

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Table 13.  Advanced Waste Treatment System Costs
           .[Investment, $1000; Annual Costs, c/1000 kg LWK
           (C/1000 Ib LWK)]
Waste Treatment
System
Sand Filter

Microstrainer

Reverse osmosis

Electrodialysis

Ion exchange

Ammonia Stripping

Carbon adsorption

Chemical precipitation

Spray irrigation

Simple
Slaughterhouse
Total
Investment
140

' 105

640

275

57

75

238

65

91

Annual
Cost
6.0
(2.7)
6.6
C3.0)
28.4
(12.9)
33.8
(15.4)
4.4
(2.0)
5.3
(2.4)
13.2
(6.0)
8.8
(4.0)
4.2
(1.9)
Complex
Slaughterhouse
Total
Investment
195

146

1600

625

102

112.5

475

81

254

Annual
Cost
2.9
a. 3)
3.1
(1.4)
25.5
(11.6)
32.8
(14.9)
2.4
(1.1)
2.6
(1.2)
9.0
(4.1)
6.2
(2.8)
3.1
(1.4)
Low-Processing
Packinghouse
Total
Investment
188

140

1470

588

92

106

438

79

229

Annual
Cost
3.7
(1.7)
4.2
(1.9)
32.6
(14.8)
.41.8
(19.0)
3.1
(1.4)
3.5
(1.6)
11.4
(5.2)
7.7
(3.5)
4.0
(1.8)
High-Processing
Packinghouse
Total
Investment
215

161

1860

700

122

119

537

86

297

Annual
Cost
4.8
(2.2)
5.3
(2.4)
46.2
(21.0)
60.0
(27.3)
4.4
(2.0)
4.2
(1.9)
15.8
(7.2)
11.0
(5.0)
5.3
(2.4)

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                                       .3
The investment cost data were collected from the literature,  personal
plant visits, equipment manufacturers, engineering contractors, and
consultants.  These costs are "ball-park" type estimates implying an
accuracy of + 20 to 25 percent.  Rarely is it minus.  All costs are
reported in August 1971 dollars.  Percentage factors were added to the
basic system estimate for design and engineering (10%) and for con-
tingencies and omissions (15%).  Land costs were estimated to be
$1000 per acre ($2470 per hectare).

In addition to the variation in plant water flows and BODs loadings
and the inherent inaccuracy in cost estimating, one additional fac-
tor further limits the probability of obtaining precise cost estimates
for waste treatment systems.  This factor was reported by a number of
informed sources who indicated that municipal treatment systems will
cost up to 50 percent more than comparable industrial installations.
The literature usually makes no distinction between municipal and
industrial installation in reporting investment costs.


                        Annual Costs Assumptions

The components of annual costs include capital cost, depreciation,
operating and maintenance costs, and energy and power costs.   The cost
of capital is estimated to be ten percent of the investment cost for the
meat packing industry.  This cost should be a weighted average of the
cost of equity and of debt financing throughout the industry.  Neither
individual companies nor industry associations have a known figure
for this cost.  Presuming that target and realized return-on-investment
(ROI) or return-on-assets (ROA) figures incorporate some estimate of
capital cost plus an acceptable profit or return, industry and cor-
porate reports were used as a guide in selecting the 10 percent figure.
One sample of companies reported earnings at 7.1 percent of total
assets for 1971,36 a recent business periodical reported earnings
at 10.1 percent of invested capital,3' and general Industry sources
report corporate target ROI or ROA figures at 12 to 15 percent for
new ventures.  The ten percent figure is probably conservative and
thus tends to result in a high estimate of annual cost.
                                 116

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The depreciation component of annual cost was estimated on a straight-
line basis over the following lifetimes, with no salvage value:

     Land costs — not depreciated

     Cost of improvements for land intensive treatment — 25 years

     Simple treatment systems without complex process equipment;
     e.g., extended aeration, sand filter — 25 years

     Treatment systems requiring complex process equipment — 10 years

The operating and maintenance costs include the cost of one man-year
at $A.20/hr for each typical secondary treatment system plus 50 percent
for burden, supervision, etc.  One-half man-year was included in the
annual cost for each tertiary treatment plus the 50 percent burden, etc.
General and maintenance supplies, taxes, insurance, and miscellaneous
operating costs were estimated as 5 percent of the total investment
cost per year for process equipment based systems and 2.5 percent of
the total investment cost for land intensive waste treatment systems.
Specific chemicals use costs were added when such materials were
consumed in the waste treatment system.  By-product income, relative to
waste treatment was credited only in the dissolved air flotation system
for 160 mg/1 of grease recovered per day and sold at $0.05 per pound,
and in spray irrigation for 13,400 kg of dry matter (hay or grass)
per hectare at $22/100 kg (6 tons/acre at $20/ton) and one crop per
season.
                          ENERGY REQUIREMENTS

The estimated electrical energy consumption per plant based on 1967
Census of Manufactures38 data is as follows:

          Small plants — 0.72 million KWH per year

          Medium plants — 5.5 million KWH per year

          Large plants — 18.6 million KWH per year

The meat packing industry consumes relatively small quantities of
energy.  The waste treatment systems require power primarily for pumping
and aeration.  The aeration horsepower is a function of the wasteload
and that for pumping depends on wastewater flow rate.
                                117

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Power consumption for waste treatment varies from 0,8 to 3.4 million KWH
per year for various secondary treatment systems.  This consumption is
between 10 and 40 percent of that indicated above for 1973.  The larger
plants with greater power consumption would tend toward the smaller per-
centage.  The total additional power consumption to achieve Level 1 and
Level 2  does not appear to raise serious power supply or cost questions
for the meat packing industry.

Thermal energy costs roughly equal electrical energy costs for operations
within the industry.  Waste treatment systems impose no significant
addition to the thermal energy requirements of plants.  Wastewater can be
reused in cooling and condensing service if it is separated from the
process waters in non-barometric type condensers.  These heated waste-
waters improve the effectiveness of anaerobic ponds which are best main-
tained at 90°F or more.  Improved thermal efficiencies are coinciden-
tally achieved within a plant with this technique.

Wastewater treatment costs and effectiveness can be improved by the
use of energy and power conservation practices and techniques in each
plant.  The wasteload increases with increased water use.  Reduced water
use therefore reduces the wasteload, pumping costs, and heating costs,
the last of which can be further reduced by water reuse as suggested
previously.


             NON-HATER POLLUTION BY WASTE TREATMENT SYSTEMS

                              Solid Wastes

Solid wastes are the most significant non-water pollutants associated
with the waste treatment systems applicable to the meat packing industry.
Screening devices of various design and operating principles are used
primarily for removal of large-scale solids such as hair, paunch manure,
and hog stomach contents from wastewater.  These solids may have some
economic value as inedible rendering material, or they may be land-
filled or spread with other solid wastes.

The solids material, separated from the wastewater stream, that contain
organic and inorganic matter, including those added to aid solids
separation, is called sludge.  Typically, it contains 95 to 98 percent
water before dewatering or drying.  Both the primary and secondary
treatment systems generate some quantities of sludge; the quantity will
vary by the type of system and is roughly estimated as follows:
                               118

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                                       rpa^fp
 Treatment  System
Sludge Volume as Percent of raw
wastewater volume
Dissolved  air  flotation

Anaerobic  lagoon

Aerobic and aerated  lagoons

Activated  sludge

Extended aeration

Anaerobic  contact process

Rotating biological  contactor
Up to 10%

Sludge accumulation in these
lagoons is usually not sufficient
to require removal at any time.

10 - 15%

5 - 10%

approximately 2%

unknown
The raw sludge can be concentrated,.digested, dewatered, dried, incin-
erated, land-filled on-site, or spread in sludge holding ponds.  The
sludge from any of the treatment systems, except air flotation with
polyelectrolyte chemicals added, is amenable to any of these sludge
handling processes.

The sludge from air flotation with chemicals has proved difficult to
dewater.  A dewatered sludge is an acceptable land fill material.
Sludge from secondary treatment systems is normally ponded by the meat
industry plants on their own land or dewatered or digested sufficiently
for hauling and deposit in public land fills.  The final dried sludge
material can be safely used as an effective soil builder.  Prevention
of run-off is a critical factor in plant-site sludge holding ponds.
Costs of typical sludge handling techniques for each secondary treat-
ment system generating sufficient quantities of sludge to require
handling equipment are already included in the costs for these systems.
                             Air Pollution
Odors are the only significant air pollution problem associated with
waste treatment in the meat packing industry.  Malodorous conditions
usually occur in anaerobic waste treatment processes or localized
anaerobic environments within aerobic systems.  However, it is
generally agreed that anaerobic ponds will not create serious odor
problems unless the process water has a sulfate content; then it most
assuredly will.  Sulfate waters are definitely a localized condition
varying even from well to well within a specific plant.  In nothern
climates, however, the change in weather in the spring may be accom-
panied by a period of increased odor problems.
                                 119

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The anaerobic pond odor potential is somewhat unpredictable as evi-
denced by a few plants that have odor problems without sulfate waters.
In these cases a cover and collector of the off-gas from the pond
controls odor.  The off-gas is then burned in a flare.

The other potential odor generators in the waste treatment are tanks
and process equipment items for the anaerobic contact process that
normally generate methane.  However, with the process confined to a
specific piece of equipment it is relatively easy to confine and
control odors by collecting and burning the off-gases.  The high heat-
ing value of these gases makes it worthwhile and standard practice to
recover the heat for use in the waste treatment process.

Odors have been generated by some air flotation systems which are
normally housed in a building, thus localizing, but intensifying the
problem.  Minimizing the unnecessary holdup of any skimmings or
grease-containing solids has been suggested as a remedy.

Odors can best be controlled by elimination, at the source, in pre-
ference to treatment for odor control which remains largely unproven
at this time.
                                 Noise

The only material increase in noise within a packing plant caused by
waste treatment is that caused by the installation of an air flotation
system or aerated lagoons x^ith air blowers.   Large pumps and an air
compressor are part of an air flotation system.  The industry normally
houses such a system in a low-cost building; thus, the substantial
noise generated by an air flotation system is confined and perhaps
amplified by the installation practices.  All air compressors, air
blowers, and large pumps in use on intensively aerated treatment systems,
and other treatment systems as well, may produce noise levels in excess
of the Occupational Safety and Health Administration standards.  The
industry must consider these standards in solving its waste pollution
problems.
                                120

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                              SECTION IX

              EFFLUENT REDUCTION ATTAINABLE THROUGH THE
             APPLICATION OF THE BEST PRACTICABLE CONTROL
                    TECHNOLOGY CURRENTLY AVAILABLE
                   EFFLUENT LIMITATIONS GUIDELINES

                             INTRODUCTION

The effluent limitations which must be achieved July 1, 1977 are to
specify the degree of effluent reduction attainable through the appli-
cation of the Best Practicable Control Technology Currently Available.
Best Practicable Control Technology Currently Available is generally
based upon the average of the best existing performance by plants of
various sizes, ages, and unit processes within the industrial category
and/or subcategory.  This average is not based upon a broad range of
plants within the meat packing industry, but based upon performance
levels achieved by exemplary plants.

Consideration must also be given to:

     •    The total cost of application of technology in relation to
          the effluent reduction benefits to be achieved from such
          application;

     e    The size and age of equipment and facilities involved;

     • •   The processes employed;

     •    The engineering aspects of the application of various types
          of control techniques;

     •    Process changes;

     •    Non-water quality environmental impact (including energy
          requirements).

Also, Best Practicable Control Technology Currently Available emphasizes
treatment facilities at the end of a manufacturing process but includes
the control technologies within the process itself when the latter are
considered to be normal practice within an industry.

A further consideration is the degree of economic and engineering
reliability which must be established for the technology to be "currently
available."  As a result of demonstration projects, pilot plants and
general use, there must exist a high degree of confidence in the engineer-
ing and economic practicability of the technology at the time of start
of construction of installation of the control facilities.
                                121

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                              lilllJ UJ
       EFFLUENT REDUCTION ATTAINABLE THROUGH THE  APPLICATION OF
       "~BEST_POLLUTION CONTROL TECHNOLOGY  CURRENTLY  AVAILABLE

Based on the information contained  in  Sections  III  through VIII of
this report, a determination has been  made  that the quality of effluent
attainable through the application  of  the Best  Pollution Control Technology
Currently Available is as listed in Table 14.    Approximately 25 percent
of the plants with secondary treatment systems  for  which effluent qualities
were available are meeting these standards.

Exceptional cases may arise occasionally that require adjustment.  An
example is a plant that processes a large volume of hides or blood from
other plants in addition to its own.   Adjustments can be made to the
effluent guidelines on the basis of information contained in Sections IV,
V, and VII for BOD5, suspended solids, Kjeldahl nitrogen, and ammoniat
The adjustments for exceptions are  listed in Table  15.   It is assumed
that the grease, phosphorus, and nitrite-nitrate levels are unaffected.


               IDENTIFICATION OF BEST  POLLUTION CONTROL
                    TECHNOLOGY CURRENTLY AVAILABLE

Best Pollution Control Technology Currently Available for the meat packing
industry involves biological waste  treatment  following in-plant solids
and grease recovery steps.  To assure  that  treatment will successfully
achieve the limits specified, certain  in-plant  practices should be
followed.
     1.   Reduce water use by shutting off  water when not in use,
          practicing extensive dry  clean-up before washing, and
          exercising strict management control  over housekeeping and
          water use practices.  Water  use should be controlled at
          least to the following values:

   Class of Plant                   liters/1000  kg LWK    gal/1000 Ib LWK
     Simple slaughterhouse                5,416              650
     Complex slaughterhouse               7,497              900
     Low-processing packinghouse          8,333             1000
     High-Processing packinghouse*        12,495             1500

*This is for the average mix of  kill and processing of about 0.65 kg
processed meat products/kg LWK.

     2.   In-plant recovery  systems should  include, as a minimum, a
          gravity catch  basin with at least a SO^inute detention time,

     3.   Blood recovery should  be practiced extensively, with all
          major bleeding areas  curbed and with separate drains to
          blood collection tanks.   If blood is coagulated, blood
          water should be evaporated.
                                 122
NOTICE: Then ar« tentative recommenditlori* bated upon information in this
report and are subject lo chan|» based Ujwrl femrftofrt* received and further
review by ETA.

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                    Table 14.  Recommended Effluent Limit Guidelines for 1 July  1977




Plant
Subcategory
Simple
Slaughterhouse
Complex
Slaughterhouse
Low-Processing
Packinghouse
High-Pro cess ing
Packinghouset


BOD

kg/1000 kg
LWK
0.08
0.12
0.12
0.24


Suspended
Solids
kg/1000 kg
LWK
0.15
0.22
0.18
0.31



Grease*

mg/1
Trace
Trace
Trace
Trace
Total
Kj eldahl
Nitrogen
as N
kg/1000 kg
LWK
0.15
0.20
0.20
0.34


Ammonia
as N
kg/1000 kg
LWK
0.13
0.18
0.18
0.31


Phosphorus
as P
kg/ 1000 kg
LWK
0.05
0.07
0.07
0.11

Nitrite-
Nitrate
as N**
Eg/1

0.5
0.5
0.5
0.5
                                                                                                                a« -•.—. -w «M-|« .•
                                                                                                                  ,.,—s~ 4
                                                                                                                  a  y
 *The grease should neverrbe  greater than the  limit of sensitivity  for the analytical procedure  (5 mg/1).
**For waste treatment at this level, concentration becomes limiting.
 tThe values for BOD  and suspended solids are for average plants;  i.e.,  plants with weight ratios of
  processed meat products to  LWK of 0.65.  Adjustments can be made  for high-processing packinghouses
  at other  ratios according to the following equations:
       kg BOD5/1000 kg LWK =  0.21 + 0.23 (y -  0.4)

       kg SS/1000 kg LWK = 0.28 + 0.30 (y - 0.4)

          where y = kg processed meat products/kg  LWK.
                                                                  NOTJCt: These are tentative recommendations bzsc
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                                  • I ' !• '
                             Mi'  < !'• '• ' )
                            tLbimhitl
      Table 15.  Adjustments for Exceptions  in  Plant Subcategories

Processing hides from other
plants in addition to own:
Defleshing, washing,
curing
kg/1000 kg LWK* (~lb/hide)
Processing blood from other
plants in addition to own:
Steam coagulation and
screening, sewering
water
kg/1000 kg LWK*
Rendering material from
other plants in addition to
own:
Wet and low-temperature,
sewering water
kg/1000 kg LWK*
Dry
kg/1000 kg LWK*
BOD5




0.02





0.02





0.03

0.01
Suspended
Solids




0.04





0.04





0.06

0.02
Total
Kjeldahl
Nitrogen
as N




0.03





0.03





0.05

0.02
Ammonia
as N




0.03





0.03





0.05

0.02
*Live weight killed (LWK) represented by blood, viscera,  etc., brought
 in from outside.
                                124
                                          KOIKE ne» tn tertrtht itcottDendMbm. b»setf upon Information in this
                                          Kiwi M« me notes to &H& taut u^* n,mroew, rMe)w(, Md ,WM|
                                          mufeN a* am.

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     4.   Water from low temperature rendering should be  evaporated.

     5.   Barometric leg evaporators which  tend  to  foam,  such  as  for
          tankwater evaporation, should be  equipped with  foam  breakers
          and demisters.

     6.   Uncontaminated cooling water should not be discharged to
          the secondary waste treatment system,

The above in-plant practices, in addition to good housekeeping, can
readily produce a raw waste load below that cited as average in Section V.
With an average waste load, the following secondary treatment  systems
are able to meet the stated guidelines:
     1.   Anaerobic lagoon + aerated H- aerobic  (shallow)  lagoon
     2.   Anaerobic lagoon + extended aeration
     3.   Anaerobic contact process + aerobic  (shallow)  lagoons
     4.   Extended aeration + aerobic  (shallow)  lagoons
                       RATIONALE FOR THE SELECTION OF
           BEST  POLLUTION CONTROL TECHNOLOGY CURRENTLY AVAILABLE

                Age and Size of Equipment and Facilities

The industry has generally  modernized  its  plants as new methods that are
economically attractive  have been introduced.   No relationship between
age of plant and effectiveness  of its  pollution control was found.
Also, size is not  a significant factor, even though plants vary widely
in size.   Small plants are  not  mechanized  to the extent of the rest of
the industry; still they are able to achieve at least as effective
control as larger  plants.   This is partly  because the small-scale of
operation  permits  options for  simple paunch disposal, small low-cost
in-plant equipment, viscera disposal,  etc., that are not open to large
operations because of  the immense volume of materials concerned.
                       \

Total Cost of Application in Relation  to Effluent Reduction Benefits

Based on the information contained in  Section VIII of this report, the
industry as a whole would have to invest up to an estimated maximum of
$52.8 million to achieve the effluent  limitations described.  This
amounts to a cost  of about  $2,355 for  installed capacity of one million
kg  ($1,069 per  one million  Ib)  per year.  The cost increase
will amount to  about $0.345/1000 kg LWK ($0.157/1000 Ib LWK).  Based
on an estimated overall investment of  $1.7 billion, the maximum increase
in investment would be about  3 percent.  This also represents about
20 percent of  the  capital expenditures reported for 1971.db
                                •IOC                              , „—-,—-,—j.—,-

                                        1 MOTICf: These are tentative recommendations based upon Information to
                                         '""'* •"'' "i subject to change '   '

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All plants discharging to streams can  implement  the  Best Pollution
Control Technology Currently Available.   The  technology is not affected
by different processes used in  the plants.


          Engineering Aspects of Control Technique Applications

The specified level of technology is practicable because it is being
practiced by plants in all subcategories.   The level represents the
averages for 13 plants  (no less than two in any category).  Eight of the
plants are operating within this level,  and all 13 could readily reach
it.  The levels at several plants were verified during this study.
Further, several  treatment facilities  are currently under design that
will enable other plants  to meet the limits.


                            Process  Changes

No major in-plant changes will  be needed by most plants to meet the
limits specified. Many plants  will  need to improve their water conser-
vation practices  and housekeeping, both  responsive to good plant management
control.


                  Non-Water Quality Environmental  Impact

The major  impact  when  the option of  an activated sludge-type of process
is used  to achieve  the limits will  be the problem of sludge disposal.
Nearby land for  sludge disposal may be necessary—in some cases a sludge
digester (stabilizer)  may offer a solution.  Properly operated activated
sludge-type systems should permit well conditioned sludge to be placed
in small nearby  plots  for drying without great difficulty.

Another  problem  is  the odor that emits periodically from anaerobic
lagoons.   Covering  with a plastic sheet and burning the off-gas offers
a potential solution to this problem.   It is necessary  to avoid high-
sulfate  water supplies.   The odor problem can be avoided with all-
aerobic  systems.

It  is concluded  that no new kinds of  impacts will be introduced by
application of the best current technology.
                                 126  ,
NOTICE: These are lenuito «comm«K»,,,ons ba«d UBon ,„,  "I	
report ind ,rt *«bjecl to chan« b«.M        ^ 'nformilion In this
review * WA.        *   '" "^ *"nmen" »«*- •* talk*

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                               SECTION  X

       EFFLUENT REDUCTION ATTAINABLE THROUGH THE APPLICATION OF
       THE BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE —
                   EFFLUENT  LIMITATIONS  GUIDELINES

                              INTRODUCTION

The effluent limitations which must be achieved no later than July 1,1983
are not based on an average  of the best  performance within an industrial
category, but are determined by  identifying the very best control
and treatment technology employed by a specific point source within
the industrial category or subcategory,  or by one industry where it
is readily transferable to another.  A specific finding must be made
as to the availability of control measures and practices to eliminate
the discharge of pollutants, taking into account the cost of such
elimination.

Consideration must also be given to:

     •    The age of  the equipment and facilities involved;

     •    The process employed;

     •    The engineering aspects of the application of various types
          of control  techniques;

     •    Process changes;

     •    The cost of achieving  the effluent reduction resulting
          from application of the technology;

     •    Non-water quality  environmental impact (including energy
          requirements).

Also, Best Available  Technology  Economically Achievable emphasizes in-
process controls as well as  control or additional treatment techniques
employed at the end of  the production  process.

This level of technology considers  those plant processes and control
technologies which, at  the pilot plant,  semi-works, or other level,
have demonstrated both  technological performances and economic
viability at a level  sufficient  to  reasonably justify investing in
such facilities.   It  is  the  highest degree of control technology that
has been achieved or  has been demonstrated to be capable of being
designed for plant scale operation  up  to and including "no discharge"
                                 127
NOTICE: Thiie til tenlativl recommendations based upon' Information in this
report and ir« eubject to chine* based upon Amments received and further
revtew by EPA.

-------
          e and engineer!,*  feasibility.                 .
   rnrHr-^l risk with respect  to  performance and with respect
certfinty of lofts.  Therefore/some industrially sponsored develop-
ment work may be needed  prior to its application.


         FFFLUENT  PFnnrnnN  ATTAINABLE THROUGH APPLICATION OF
Based  on  the information contained in Sections  III through VII
of  this report, a determination has been made  that the quality of
effluent  Attainable through the application  of  the Best Available
Swhnnloav Economically Achievable is as listed in Table 16.  The
  ecnnology to achieve these goals is generally available, although
 it  may not have been applied as yet  to  a packing plant or on a
 full scale.

      M™,«I  cases may arise occasionally that  require adjustment in
Exceptional cases may ar          processing Of large quantities of
the guide li«p«J£ ^d blood) ?rom  other plants In addition to
materials (e.g., '^£m   be made  on  the basis of the information
 their own   A^^ments ca               BOD      ^^ solids>
 contained in Sectl°^ I*» ^ia    The adjustments for exceptions are
                      d°nT   thaJ phosphorus and nitrite-nitrate
should consider land disposal,
^ suitable land ls available,
that not only is  recommended
     usually be more economical
levels are unaffected.

                    j
It should be. pointed
and hence no disc har S
                           fh^i-
                           that
                              «*3
 than  the  system otherwise required
 The Best Available TectaOlof
 listed under the Best Pract lable
 Available.  In addition,
                                                   etreat»ent , such as
                                                        flocculation;
  following secondary treatment.
                                    128
                                           NOTICE: These at* tentative recommendations based upon information in this
                                           report «wJ art subject to chance based upon Comments received and lurthet
                                           review by EPA.

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                         Table 16.  Recommended Effluent Limit Guidelines for July 1, 1983
ro
vo



Plant
Sub category
Simple
Slaughterhouse
Complex
Slaughterhouse
Low-Processing
Packinghouse
High-Processing
Packinghouset

BOD

kg/1000 kg
LWK
0.03
0.04
0.04
0.08

Suspended
Solids
kg/1000 kg
LWK
0.05
0.07
0.06
0.10


Grease*

mg/1
Trace
Trace
Trace
Trace
Total
Kj eldahl
Nitrogen**

og /I
4
4
4
4

Ammonia
as 37**

mg/1
4
4
4
4

Phosphorus
as P**

mg/1
2
2
2
2
Nitrite-
Nitrate
as N**

mg/1
0.5
0.5
0.5
0.5
      *The grease should never be greater than the limit of sensitivity for the analytical procedures (5 mg/1).
     **For treatment of these components, concentration becomes limiting at these levels.
      tThe values for BODs and suspended solids are for average plants; -I.e., plants with a weight ratio of
       processed meat products to LWK of 0.65.  Adjustments can be made for high-processing packinghouses
       at other ratios according to the following equations:

            kg BOD5/1000 kg LWK « 0.07 + 0.08 (y - 0.4)

            kg SS/1000 kg LWK - 0.09 + 0.10 Cy - 0.4)

               where y = kg processed meat products/kg LWK.


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                                i I'.'1''] ;..\ HI
                               MM:  ! i<-\ i  3
                               '••"•"•'•"'  ii
                Table 17.  Adjustments for Exceptions  in All
                           Plant Subcategories - 1983
 Exception
 --•-     .——•

 Processing of  hides from other
 plants in addition to own:
    Defleshing, washing, curing
    kg/1000 kg  LWK* f> Ib/hide)

 Processing of blood from other
 plants in addition to own:
    Steam coagulation and
    screening, sewering blood
    water
    kg/1000  kg LWK*

 Rendering of  material  from other
 plants  in addition  to  own:
   Wet and low  temperature,
   sewering water
   kg/1000 kg LWK*
   Dry
   kg/1000 kg LWK*
 BOD,
 0.007
0.007
0.01
0.003
Suspended
 Solids
  0.013
 0.013
 0.02

 0.007
*Based on the LWK of the animals which were the
 source of the material.
                                 130
        NOTICE: These art tentative recommendations based upon Information in this
        report «nd ire lubject to (heHgg bsM Ubon Comment* received and further
        rivlew by ECA,

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                           m&M
In-plant  controls and modifications  are also required to achieve
the specified levels.  These include:

     •    Segregation of grease-bearing from nongrease-bearing waste
          streams ;

     e    Water control systems and  procedures to reduce water use
          to about 50 percent of that  listed in Section IX;

     •    Dumping of entire paunch contents for processing or outside
          disposal;

     c    Installation of shell-in-tube or comparable systems for
          heat exchangers and evaporators ;
•

e
          Provision for collection of excess pickle and cure solutions;

          Installation of dry rendering operations;

     •    General elimination of viscera washing operations;

     •    Design for extensive use of troughs under carcass conveying
          lines ;

     a    Instigation and continuous enforcement of meticulous dry
          clean-up and materials recovery  procedures.

To reduce the water use to the required levels, several changes in
normal plant operations may be required.  Push-to-open valves need
to be used wherever possible.  Spray nozzles can be redesigned for
lower water flow.  Automatic valves that close when the water is not
in use should be installed; examples are in carcass washers and for
washdown operations.  Automatic level control should be used in pen
watering troughs;.  Pens should be covered in areas where rain and
snow are significant; wood chips should be used for bedding and dry
clean-up procedures should be used.

Water reuse should be practiced, reusing water for lower quality
needs.  For example, carcass washing water can be reused for hog
dehairing and lagoon water can be reused for cooling waters (this
latter has the advantage of heating a lagoon for greater biological
activity) .


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                            L^' U Uy Uu
Dissolved solids can be minimized by changing  some  current  practices.   . .
Excess cure solutions should be  collected immediately  for reuse  or
treatment.  Concentrated brine overflow  from hide curing should  be
segregated for salt recovery, perhaps by evaporation.   Salt should
not be used on floors as an antislip material; other methods are
available to counteract this problem.  Reducing  carcass and head
washing water will reduce the body  fluids(and  thus  the salts)
washed into the sewer in this step.

If suitable land is available, land disposal is  the best technology;
it is no discharge.  Depending on the amount and type  of land,  the
above in-plant techniques and primary treatment, including  dissolved
air flotation with pH control, may  be adequate before  discharging
to the land.  On the other hand, a  secondary treatment system may
be required before disposal to soil.  Any of the systems mentioned
in Section IX, or even simpler ones, are suitable.  The potential
problem of dissolved solids in irrigation systems can  usually be avoided
by minimizing dissolved solids as described above;  in  some  cases a  part
of the stream may need to be treated by  ion exchange.

Technology is available for small plants for no  discharge  via the
irrigation or evaporation or other  land  disposal methods.   For  example,
a septic  tank can be used with a drainfield or large  cesspool.
Strict in-plant controls are readily managed  to  minimize  the raw
waste load.


                     RATIONALE  FOR  SELECTION OF THE
          BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE

               Age  and  Size of Equipment and  Facilities

Neither  size nor age are  found to  affect the  effectiveness of end-
of-process pollution control.  Although in-plant control can be managed
quite effectively  in older  plants,  some of  the technologies  required
for reducing  the raw waste  loads to the low levels that are  possible
are costly  to  install in  older plants.   For example,  rerouting of
sewers  to segregate waste streams  is both very difficult and costly.

Small plants,  for  the reasons discussed in Section IX, have  more
options  for waste  control than do large plants.  It is anticipated that
most  small  plants  will find land disposal the best choice.
                                132
NOTICE: HUM «n tentative iccummendations bated upon Information in this
iqwt Md are wtym to chance Used upon commenti received and further
revfcw by EM.

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                             "*A14 r^\ p \ CTJ3KT3I

                             11HM!j f)


               Total Cost of Application  in Relation to
                     Effluent Reduction Benefits

Based on information contained in Section VIII of this report, the
industry as a whole would have to invest  up to a maximum of $107
million above that required  to meet the 1977 standards.  This amounts
to a cost of about $4760 for installed capacity of one million kg
($2160 for one million pounds) per year.  The operating coat increase
will amount to about $2.10/1000 kg LWK ($0.96/1000 Ib LWK).  The
capital investment above that to meet the 1977 standards amounts to
about six percent of the total investment of the industry, estimated
at about $1.7 billion.  It also equals about 44 percent of the capital
investment reported for the  industry for  1971.

All plants discharging to streams can implement the Best Available
Technology Economically Achievable; the technology is not affect by
'different processes used in  the plants.


        Engineering Aspects  of Control Technique Application

The specified level of technology is achievable.  It is presently
being met for BOD5 and suspended solids by at least one plant in each of
three of the industry subcategories.  Both medium and large plants
are included.  The limits are not being met, however, for ammonia,
Kjeldahl nitrogen, or phosphorus' newer technology is required for
these parameters.  Phosphorus is effectively removed by chemical
treatment in air flotation,  and by filtration of the final effluent
from the secondary treatment.  The greatest unknown is the nitrifi-
cation-denitrification step.  However, nitrification has been achieved
in pilot units and on a limited extent in plant operations.  Denitri-
fication has been explored successfully on laboratory and pilot scales.
Ammonia stripping may require pH adjustment and later neutralization;
it is a technology transferred from other industries.

Each of the identified technologies, except ammonia removal, is currently
being practiced in one or more packing plants.  They need to be combined,
however, to achieve the limits specified.

Technology for land disposal is being used by several plants in Texas;
it is being planned for a plant in Iowa.  Other industries, 0.g.3
potato processing, are using it extensively.  Secondary treatment
and large holding ponds may  be required in the North to permit land
disposal over only about one-half the year.  Application of technology
for greatly reduced water use will facilitate land disposal.


                           Process Changes

In-plant changes will be needed by most plants to meet the limits
specified.  These were outlined  in the "Identification of  the Best
Available Technology Economically Achievable", above.

                                133
                             KOUCE: These »i« lemitive recommendations based upon intormatipr) in this
                             ttpon trt lit ubjnt to ttHJW too* UK)* SBUHBSItt*
                             review by EPA.

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                              I 1
U'
                        Non-Hater Quality Impact

The major  Impact will be when  the option of  land  disposal is chosen.
There is a potential, but unknown, long-term effect on the soil  of
irrigation of packing plant wastes.  To date,  impacts have been
generally  obviated by careful  water application management.

Otherwise, the effects will essentially be those  described in  Section IX,
vrtiere it was concluded that no new kinds of  impacts will be introduced.
                                   134
    NOTICE: IteMMttatxkvtrewmmendstibni based iHMf ililferttMibri'in thi#
           M MOjM to CHUB* baced- Upon1 dDtitthbrit* re&tied' iritf' fUtthw

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                              SECTION XI

                   NEW SOURCE PERFORMANCE  STANDARDS


                              INTRODUCTION

The effluent limitations that must be achieved  by new sources are termed
performance standards.  The New  Source  Performance Standards apply to
any source for which construction starts after  the publication of the
proposed regulations for the  Standards.  The  Standards are determined
by adding to the consideration underlying  the identification of the Best
Practicable Control Technology Currently Available a determination of
what higher levels of pollution  control are available through the use of
improved production processes and/or treatment  techniques.  Tims, in
addition to considering the best in-plant  and end-of-process control
technology, New Source Performance Standards  are based on an analysis of
how the level of effluent may be reduced by changing the production process
itself.  Alternative processes,  operating  methods or other alternatives
are considered.  However, the end result of the analysis is to identify
effluent standards which reflect levels of control achievable through the
use of improved production processes  (as well as control technology),
rather than prescribing a particular type  of  process or technology which
must be employed.  A further  determination made is whether a standard
permitting no discharge of pollutants is practicable.

Consideration must also be given to:

     •    Operating methods;

     •    Batch, as opposed  to continuous, operations;

     •    Use of alternative  raw materials and  mixes of raw materials;

     •    Use of dry rather  than wet processes  (including substitution
          of recoverable solvents for water);

     »    Recovery of pollutants as by-products


              EFFLUENT  REDUCTION  ATTAINABLE FOR NEW SOURCES

The effluent  limitation  for  new  sources is the  same as that for the
Best Practicable Control Technology  Currently Available (see Section IX).
This limitation is readily achievable  in newly  constructed plants.
However, the  guidelines  for  the  Best Available  Technology Economically
Achievable should be kept  in mind;  it may  be  a practical approach to
design a plant which approaches  the  1983  guidelines.  Consideration should
also be given to  land  disposal,  which would be  no discharge; in many
cases this will be the most  attractive  and economical option.
                                135      I NOTICEt These ire tiirtJtive ttcommenfoliont touduptn JAfarcuUanu Wi
                                          ripen tnd in tubjtct to elunga bised upon rtmnHfltf received ind further
                                          nvliw by EPA.

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             IDENTIFICATION OF  NEU  SOURCE CONTROL TECHNOLOGY

The technology is the same as that  identified as the Best Practicable
Control Technology Currently Available (see Section IX).  However, certain
steps that will be necessary to meet  the 1983 guidelines should be
considered and, where possible, incorporated.  These include:

     o    In-Plant Controls

                Segregation of  grease-bearing streams from nongrease-
                bearing waste streams;

          -     Water control systems and procedures to reduce water
                use considerably  below those cited in Section IX;

                Dumping of entire paunch contents for processing or
                outside disposal;

          -     Installation of shell-in-tube or comparable systems for
                heat exchangers and evaporators;

                Provision for collection of excess cure solutions;

                Installation of dry rendering operations;

                General elimination of viscera washing operations;

                Design for extensive  use of troughs under carcass conveying
                lines;

                Installation of dissolved air flotation, with provision
                for a second unit to  be added later;

                Instigation and continuous enforcement of meticulous
                dry clean-up and  materials recovery procedures.

     o    End-of-Process Treatment

                Land disposal  (evaporation, irrigation) wherever possible;
                this should be  a  prime consideration;

                Sand filter or  microscreen for effluent secondary treatment;

                Solid waste drying, composting, upgrading of protein content.
                                136
NOTICE! These an teittattvi rttommendrttons based upon information In tnlt
Wpott ii*J ar« subject to eh»hj« based upon eomments receiwd rod lurth«
                                         review by EPA.

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                                    n
                                     l
                                        3
                        PRETREATMENT  REQUIREMENTS

No constituents of the effluent  discharge  from a plant within the meat
packing industry have been  found which  would interfere with, pass through,
or otherwise be incompatible with  a well designed and operated publicly
owned activated sludge or trickling filter wastewater treatment plant.
The effluent, however, should  have passed  through materials recovery
(primary treatment)  in the  plant to remove settleable solids and a large
part of the grease.  The concentration  of  pollutants acceptable to the
treatment plant is dependent on  the relative sizes of the treatment facility
and the packing plant, and  must  be established by the treatment facility.
It is possible that  grease  remaining  in the packing plant effluent will
cause difficulty in  the treatment  system;  trickling filters appear to be
particularly sensitive.  A  concentration of 100 mg/1 is often cited as a
limit, and this requires an effective air  flotation system in addition to
the usual catch basins.  If the  waste strength in terms of BOD5 must be
further reduced, various components of  secondary treatment systems can be
used—anaerobic contact, trickling filter, aerated lagoons, etc., as pre-
treatment.
                                137
NOTICEi ThenM Untalive .ecommenditien* fcueditpon i
i«port Md •« wbject to elwnw twiH «p»" emm** ««•**
review by EPA.

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                                                     I
                                                            f'^crsa
                                                            ! ^   ;
                                                            I !
                                                             .'3
                              SECTION XII

                             ACKNOWLEDGMENTS

This Program was directed by Dr. E.E. Erickson; Project Engineers were
Messrs John P. Pilney and Robert J. Reid.  Special assistance was
provided by North Star staff members: Mrs. Janet McMenamin, Messrs
R.h. Forester and A.J. Senechal, and Drs. L.W. Rust and L.L. Altpeter.

The contributions and advice of Mr. A.J. Steffen of Purdue University,
Mr. W.H. Miedaner of Globe Engineering, Mr. John Macon, and Dr. H.O.
Halverson are gratefully acknowledged.  Also, James and Paula Wells
of Bell, Galyardt, and Wells made invaluable contributions in
numerous telephone conversations.

Special thanks are due Mr. Jeffrey D. Denit, Effluent Guidelines Divi-
sion for his guidance in the direction of the program and for his invalu-
able help in carrying out all aspects of the research program.  Also,
Mr. Richard Watkins of the same office was most helpful.

The cooperation of the meat packing industry is greatly appreciated.
The American Meat Institute, the National Independent Meat Packers
Association and the Western States Meat Packers Association deserve
special mention, as do many companies that provided information and
cooperated in plant visits and sampling programs.

Various Regional EPA offices were most helpful in arranging for site
visits.  The plant data provided by Dr. Wm. Garner and Mr. Ron Wantock
of the Region'VII office in Kansas City were especially appreciated.

The help of Dr. Dwight Ballinger of EPA in Cincinnati in establishing
sampling and testing procedures used for the field verification studies
was also appreciated.

Various offices in the United States Department of Agriculture, espe-
cially the Meat and Poultry Inspection Division, and many state and
local agencies were also most helpful.  Among these, special mention
should go to the Iowa Water Quality Commission, the state of Ohio
Environmental Protection Administration, and the City and County of
Denver Water and Sanitation District.

Special thanks also go to Mr. Ross Frazier of the Minnesota
Department of Health for periodically running duplicate sets
of BOD5 analyses.
                                139

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                              P A F
                            SECTION XIII

                              REFERENCES

 1.  Livestock Slaughter,  Annual Summary  1972,, Statistical Reporting
     Service, U.S. Department of Agriculture,  Washington, April 1973.

 2.  The Cost of Clean Water, Industrial  Waste Profile No.  8,  Meat
     Products, U.S. Department of the Interior, Federal Water  Pollution
     Control Administration, U.S. Government Printing Office,  Washington.

 3.  Pilney, J.P., Halvorson, H.O. , and Erickson, E.E. , Industrial Waste
     Study of the Meat Products Industry, Environmental Protection
     Agency, Contract No.  68-01-0031.

" 4.  Standard Industrial Classification Manual,Executive Office of the
     President, Office of  Management and  Budget, U.S. Government
     Printing Office, Washington, 1972.

 5.  U.S.  Industrial Outlook, 1973, with Projections to 1980>]J.S.
     Department of Commerce, U.S. Government Printing Office,  Washington.

 6.  Macon, John A., Cote, Daniel N., Study of Meat Packing Wastes in
     North Carolina, Part  I, Industrial Extension Service, School of
     Engineering, North Carolina State College, Raleigh, August 1961.

 7.  Kerrigan, James E., Grandall,  Clifford J,, Rohlich, Gerard A.,
     The Significance of Wasteuaters from the Meat Industry as Related
     to the Problems of Eutrophication, American Meat Institute, Chicago,
     November 1970.

 8.  Industrial Wastewater Control:  Chemical Technology, Volume 2,
     C. Fred Gurnham, Ed., Academic Press, New York, 1965.

 9.  Wells, W. James, Jr., "How Plants Can Cut Rising Waste Treatment
     Expense", The National Provisioned  (July 4, 1970).

10.  Miedaner, W.H,, "In-Plant Waste Control", The National Provisioned.
     (August 19, 1972).

11.  Witherow, Jack L., Yin, S.C., and Farmer, David M., National Meat-
     packing Waste Management Research and Development Programt
     Environmental Protection Agency, Corvallis, Oregon, December 1972.

12.  Elimination of Water Pollution by Packinghouse Animal Paunch and
     Blood* Environmental Protection Agency, U.S. Government Printing
     Office, Washington, November 1971.

13.  Miedaner, W., "In-Plant Waste Water Control", presented at the
     University of Wisconsin, Department of Engineering Extension Course:
     Waste Water Treatment in the Meat Industry, April 17-18,  1972.


                                 141

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                            1M
14.  Basics of Pollution Control*  Gurnham & Associates,  prepared for
     Environmental Protection Agency Transfer Program, Kansas City,
     Mo., March 7-8, 1973, Chicago, Illinois.

15.  An Industrial Waste Guide to  the Meat Industry*  U.S.  Department of
     Health, Education, and Welfare, Washington, revised 1965.

16.  Public Health Service Drinking Water Standards*  Revised 1962*  U.S.
     Department of Health, Education and Welfare, U.S. Public Health
     Service Publication No. 956,  U.S. Government Printing Office,
     Washington, 1962.

17.  Miedaner, W.H., "In-Plant Waste Control", The National Provisioner.
     (August 19, 1972).

18.  Steffen, A.J., In-Plant Modifications to Reduce  Pollution and
     Pretreatment of Meat Packing  Wastewaters for Discharge to Municipal
     Systems* prepared for Environmental Protection Agency .Technology
     Transfer Program, Kansas City, Missouri, March 7-8, 1973.

19.  Water Quality Improvement by  Physical and Chemical  Processes*
     Earnest F. Gloyna and W. Wesley Eckenfelder, Jr.,  Eds., University
     of Texas Press, Austin, 1970.

20.  Telephone communication with  M. Hartman, Infilco Division, Westing-
     house, Richland, Virginia, May 1973.

21.  Rosen, G.D., "Profit from Effluent", Poultry Industry (April 1971).

22.  Upgrading Meat Packing Facilities to Reduce Pollution:  Waste
     Treatment Systems* Bell, Galyardt, Wells, prepared for Environmental
     Protection Agency Transfer Program,Kansas City,  Missouri, March 7-8,
     1973, Omaha.

23.  "Direct Oxygenation of Wastewater", Chemical Engineering, (November 29,
     1971.

24.  Gulp, Russell L., and Gulp, Gordon L., Advanced Wastewater Treatment*
     Van Nostrand Reinhold Company, New York, 1971.

25.  Babbitt, Harold E., and Baumann, E. Robert, Sewerage and Sewage
     Treatment* Eighth Ed., John Wiley & Sons, Inc., London, 1967.

26.  Fair, Gordon Maskew, Geyer, Jbhn Charles, and Okun, Daniel
     Alexander, Water and Wastewater Engineering:  Volume 2.  Water
   .  Purification and Wastewater Treatment and Disposal* John Wiley &
     Sons, Inc., New York, 1968.

27.  Personal communication, H.O.  Halvorson, 1973.
                               142

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                             MO)|M
28.   Fair,  Gordon Maskew, Geyer, John Charles,  and Okun, Daniel
     Alexander,  Voter and Wastewater Engineering:  Volume 1,  Water
     Supply and  Vastewater Removal, John Wiley  & Sons, Inc., New York,
     1966.

29.   Eckenfelder, W.Wesley, Jr., Industrial Water Pollution Control,
     McGraw-Hill Book Company, New York, 1966.

30.   Personal communication, C.E. Clapp, United States Department of
     Agriculture, Agricultural Research Service, Univesity of Minnesota,
     Minneapolis, May 1973.

31.   Eliassen, Rolf  and Tchobanoglous, George,  "Advanced Treatment
     Processes,  Chemical Engineering,  (October  14, 1968).

32,   Knowles, Chester L. , Jr., "Improving Biological  Processes",
     Chemical Engineering/Deskbook Issue  (April 27,  1970).

33.   Personal communication, H.O. Halvorson, May 1973.

34,   McGraw-Hill's  1972 Report on Business & the Environment,
     Fred C.  Price,  Steven Ross and Robert L. Davidson, Eds.,
     McGraw-Hill Publications Co., New York, 1972.

35.   Rickles, Robert N., Membranes, Technology and Economics, 196?,
     Noyes Development Corporation, Park Ridge, New  Jersey.

36.   Financial Facts About the Meat Packing Industry, 1971, American
     Meat Institute, Chicago, August  1972.

37.   "Survey of  Corporate Performance:  First Quarter 1973", Business
     Week, p. 97 (May 12, 1973).

38.   1967 Census of Manufactures,  Bureau of the Census, U.S. Department
     of Commerce,  U.S. Government  Printing Office, Washington,  1971.
                             .  143

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                             SECTION XIV

                               GLOSSARY

Abattoir;  A slaughterhouse.

"Act";  The Federal Water Pollution Control Act Amendments of 1972.

Activated Sludge Process:  Aerated basin in which wastewaters are
mixed with recycled biologically active sludge for periods of about
six hours.

Aerated^;  The introduction and intimate contacting of air and a
liquid by mechanical means such as stirring, spraying, or bubbling.

Aerobic;  Living or occurring only in the presence of dissolved or
molecular oxygen.

Algae;  Major group of lower plants, single and multi-celled,
usually aquatic and capable of synthesizing their foodstuff by
photosynthesis.

Ammonia Stripping;  Ammonia removal from a liquid, usually by intimate
contacting with an anmonia-free gas such as air.

Anaerobic;  Living or active only in the absence of free oxygen.

Bacteria;  Primitive plants, generally free of pigment, which
reproduce by dividing in one, two, or three planes.  They occur as
single cells, chains, filaments, well-oriented groups or amorphous
masses.  Most bacteria do not require light, but a limited number
are photosynthetic and draw upon light for energy.  Most bacteria
are heterotrophic  (utilize organic matter for energy and for
growth materials), but a few are autotrophic and derive their bodily
needs from inorganic materials.

Bedding;  Material, usually organic, which is placed on the floor
surface of livestock buidlings for animal comfort and to absorb
urine and other liquids, and thus promote cleanliness in the building.

Biological'Oxidation;  The process whereby, through the activity of
living organisms in an aerobic environment, organic matter is
converted to more  biologically stable matter.

Biological Stabilization;  Reduction in  the net energy level, of
organic matter as  a result of the metabolic activity of organisms>
so  that  further biodegradation is very slow.
                             .   145

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                                •,  /"Iff
                            ^U'ULf iiU   L
Biological Treatment:  Organic waste treatment in which bacteria
and/or biochemical action are intensified under controlled conditions.

Blood Water (Serum):  Liquid remaining after coagulation of the blood.

Blowdown;  A discharge of water from a system to prevent a buildup
of dissolved solids in a boiler.

BODfi;  A measure of the oxygen consumption by aerobic organisms
over a 5 day test period at 20°C.  It is an indirect measure of
the concentration of biologically degradable material present in
organic wastes contained in a waste stream.

Capacity-Cost Relat ionship:  The variation of investment cost for
equipment or a total plant as a function of its size or capacity.

Capacity-Ratio Exponent (n) ;  In capacity-cost relationships, cost
usually increases at a slower rate than capacity.  The ratio of
capacities of two different size systems (C. and C.) is therefore
raised to an exponential power  (n) in estimating investment cost
at one capacity,given the cost at a different, capacity; e.g.t

(W" (cost of Ca) "Cost of cr
Carbon Adsorption!  The separation of small waste particles and
molecular species, including color and odor contaminants, by attach-
ment to the surface and open pore structure of carbon granules or
powder.  The carbon is usually "activated", or made more reactive
by treatment and processing.

Category and Subcategory! Divisions of a particular industry which
possess different traits that affect raw wastewater quality.

Chemical Precipitation; A waste treatment process whereby substances
dissolved in the wastewater stream are rendered insoluble and form
.a solid phase that settles out or can be removed by flotation
techniques.

Chitterling;  Large intestine of hogs.

Clarification;  Process of removing undissolved materials from a
liquid.  Specifically, removal of solids either by settling or
filtration.

Clarifier;  A settling basin for separating settlable solids from
wastewater.

Cm:  Centimeter.
                                146 .

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                                 f!
Coagulant;  A material, which, when added to liquid wastes or water,
creates a reaction which forms insoluble floe particles that adsorb
and precipitate colloidal and suspended solids.   The floe particles
can be removed by sedimentation.   Among the most common chemical
coagulants used in sewage treatment are ferric sulfate and alum.

COD-Chemical Oxygen Demand;   An indirect measure of the biochemical
load imposed on the oxygen resource of a body of water when
organic wastes are introduced into the water.  A chemical test  is
used to determine COD of wastewater.

gomposting;  Present-day composting is the aerobic, thermophilic
decomposition of organic wastes to a relatively stable humus.  The
resulting humus may contain up to 25% dead or living organisms  and is
subject to further, slower decay but should be sufficiently stable
not to reheat or cause odor or fly problems.  In composting, mixing
and aeration are provided to maintain aerobic conditions.  The
decomposition is done by aerobic organisms, primarily thermophilic
bacteria, actinomycetes and fungi.  Heat generated provides the
higher temperatures the microorganisms require.

Contamination; A general term signifying the introduction into  water
of microorganisms, chemical, organic, or inorganic wastes, or sewage,
which renders the water unfit for its intended use.

Cracklings;  The crisp solid residue left after the fat has been
separated from the fibrous tissue in rendering lard or tallow.

Cur ing '•  A process, method, or treatment involving aging, seasoning,
washing, drying, injecting, heating, smoking or otherwise treating a
product, especially meat, to preserve, perfect, or ready it for use.

Denitrification;  The process involving the facultative conversion
by anaerobic Bacteria of nitrates into nitrogen and nitrogen oxides.

Digestion;  Though"aerobic" digestion is used, the term digestion
commonly refers to the anaerobic breakdown of organic matter in water
solution or suspension into simpler or more biologically stable
compounds or both.  Organic matter may be decomposed to soluble
organic acids or alcohols, and subsequently converted to such gases
as methane and carbon dioxide.  Complete destruction of organic solid
materials by bacterial action alone is never accomplished.
                                 147

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D i_s so ly ed Air F lot a t ion ;   A process involving the compression of  air
and liquid, mixing to super-saturation,  and releasing  the pressure to
generate large numbers of minute air bubbles.   As the  bubbles rise to
the surface of the water, they carry with them small particles that
they contact.  The process is particularly effective for grease removal.

Dissolved Oxygen;   The oxygen dissolved  in sewage, water, or other
liquid, usually expressed as milligrams  per liter or as percent of
saturation.

Effluent:  Liquid which flows from a containing space  or process  unit.

Electrodialysis;  A physical separation  process which  uses membranes
and applied voltages to separate ionic species from water.

Eutrophication!  Applies to lake or pond - becoming rich in dissolved
nutrients, with seasonal oxygen deficiencies.

Evapotranspiration:  Loss of water from  the soil, both by evaporation
and by transpiration from the plants growing thereon.

Extended Aeration;  A form of the activated sludge process except
that the retention time of wastewaters is one to three days.

Facultative Bacteria;  Bacteria which can exist and reproduce under
either aerobic or anaerobic conditions.

Facultative Decomposition;  Decomposition of organic matter by
facultative microorganisms.

Feed;  A material which flows into a containing space  or process  unit.

Filtration;  The process of passing a liquid through a porous medium
for the removal of suspended material by a physical straining action.

Floe;  A mass formed by the aggregation  of a number of fine suspended
particles.

Flocculation;  The process of forming larger masses from a large
number of finer suspended particles.

Floe Skjtmmings;  The flocculent mass formed on a quieted liquid
surface and removed for use, treatment, or disposal.

Full-Line Plant;  A packinghouse  that slaughters and produces a
substantial quantity of processed meat products.
                                148

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                            fr^.Fr^ H H
                            •fi!!%\  '.
Green Hides;  Animal hides that may have been washed and trimmed,
but have not been treated, cured, or processed in any manner.

Hydrolyzlng;  The reaction involving the decomposition of organic
materials by interaction with water in the presence of acids or
alkalies.  Hog hair and feathers, for example, are hydrolyzed to
a proteinacous product that has some feed value.

Influent;  A liquid which flows into a containing space or process unit.

Ion Exchange;  A reversible chemical reaction between a solid and a
liquid by means of which ions may be interchanged between the two.
It is in common use in water softening and water deionizing.

Kj>;  Kilogram or 1000 grams, metric unit of weight.

Kjeldahl Nitrogen!  A measure of the total amount of nitrogen in the
ammonia and organic forms in wastewater.

KWH:  Kilowatt-hours, a measure of total electrical energy consumption.

Lagoon!  An all-inclusive term commonly given to a water impoundment
in which organic wastes are stored or stabilized or both.

Locker Plant;  Very small meat packing plant that slaughters
animals and may produce processed meat products, it stores meat in
frozen form for its customers.

LWK;  Live weight killed, a measure of production in a meat packing
plant, commonly expressed in thousands of kilograms or pounds per day.

M:  Meter, metric unit of length.

Mm:  Millimeter - 0.001 meter.

Mj»/I;  Milligrams per liter; approximately equals parts per million;
a term used to indicate concentration of materials in water.

MGD or MGPD;  Million gallons per day.

Microstrainer/microscreen!  A mechanical filter consisting of a
cylindrical  surface of metal filter fabric with openings of 20-60
micrometers  in size.

Municipal Treatment;  A city or community-owned waste treatment plant
for municipal and, possibly,  industrial waste treatment.
                                149

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New Source;  Any building, .structure, facility, or installation from
which there is or may be a discharge of pollutants and whose con-
struction is commenced after the publication of the proposed
regulations.

Nitrate, Nitrite;  Chemical compounds that include the NO-" (nitrate)
and N02"~ (nitrite) ions.  They are composed of nitrogen and oxygen,
are nutrients for growth of algae and other plant life, and contribute
to eutrophication.

Nitrification;  The process of oxidizing ammonia by bacteria into
nitrites and nitrates.

No Discharge;  No discharge of effluents to a water course.  A
system of land disposal with no run-off or total recycle of the
wastewater may be used to achieve it.

Non-Water Qua1i ty;  Thermal, air, noise and all other environmental
parameters except water.

Offal;  The parts of a butchered animal removed in eviscerating and
trimming that may be used as edible products or in production of
inedible by-products.

Off-Gas;  The gaseous products of a process that are collected for
use or more typically vented directly, or through a flare, into
the atmosphere.

Organic Content;  Synonymous with volatile solids except for small
traces of some inorganic materials such as calcium carbonate which
will lose weight at temperatures used in determining volatile solids.

Oxidation Lagpon;  Synonymous with aerobic or aerated lagoon.

Oxidation Pond;  Synonymous with aerobic lagoon.

Packinghouse;  Meat packing plant that slaughters animals and also
produces manufactured meat products such as weiners, sausage, canned
meats, cured products, etc.

Paunch;  The first stomach, or rumen of cattle, calves, and sheep.
The contents are sometimes included in the term.

Paunch manure;  Contents of the paunch.

Pens  (Holding Pens);  The area or building for holding live animals
at meat packing plants prior to slaughter.
                                150

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                                    r\ n
Percolation;  The movement of water through the soil profile.

pH;  A measure of the relative acidity or alkalinity of water.   A
pH of 7.0 indicates a neutral condition.   A greater pH indicates
alkalinity and a lower pH indicates acidity.   A one unit change in
pH indicates a ten fold change in the concentration of hydrogen
ion.

Pickle SplutJon:  A water solution that may contain salt, sugar,
curing or pickling agents, preservatives, and other chemicals.   It
is used for injection or soaking of meat  to prepare finished meat
products.
                                                          -»*
Pollutant;  A substance which taints, fouls,  or otherwise r.enders
impure or unclean the recipient system.

Pollution;  The presence of pollutants in a system sufficient  to
degrade the quality of the system.

Polishing;  Final treatment stage before  discharge of effluent to a
water course, carried out in a shallow, aerobic lagoon or pond,
mainly to remove fine suspended solids that settle very slowly.
Some aerobic microbiological activity also occurs.

Polyelectrolyte Chemicals:  High molecular weight substances which
dissociate into ions when in solution; the ions either being bound
to the molecular structure or free to diffuse throughout the solvent,
depending on the sign of the ionic charge and the type of electrolyte.
They are often used as flocculating agents in wastewater treatment,
particularly along with dissolved air flotation.

Ponding;  A waste treatment technique involving the actual holdup of
all wastewaters in a confined space with evaporation and percolation
the primary mechanisms operating to dispose of the water.

Ppm;  Parts per million, a measure of concentration, expressed
currently as mg/1.

Pretreatment;  Wastewater treatment located on the plant site  and
upstream from the discharge to a municipal treatment system.

Primary Waste Treatment;  In-plant by-product recovery and wastewater
treatment involving physical separation and recovery devices such as
catch basins, screens,and dissolved air flotation.

Processing;  Manufacture of sausages, hams, canned meats, smoked meat
products, etc., from fresh meat cuts or ground meats.
                               151

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Process Water;  All water that comes into direct contact with the
raw materials, intermediate products, final products,  by-products,
or contaminated waters and air.

Raceway;  Circular shaped vat containing brine, agitated by a
paddle wheel and used for brine curing of hides.

Raw Waste;  The wastewater effluent from the in-plant  primary waste
treatment system.

Recycle;  The return of a quantity of effluent from a  specific unit
or process to the feed stream of that same unit.  This would also
apply to return of treated plant wastewater for several plant uses.

Rendering;  Separation of fats and water from tissue by heat or
physical energy.

Return—on-Assets (ROA):  A measure of potential or realized profit  as
a percent of the total assets  (or fixed assets) used to generate
the profit.

Return-on-Inyestment  (ROI);  A measure of potential or realized profit
as a percentage of the investment required to generate the profit.

Reuse:  Water reuse,  the subsequent use of water following an
earlier use without restoring it to the original quality.

Reverse Osmosis;  The physical separation of substances from a
water stream by reversal of the normal osmotic process; i-.e,t high
pressure, forcing water through a semi-permeable membrane to the
pure water side leaving behind more concentrated waste streams.

Riprap;  A foundation or sustaining wall usually of stones and brush,
so placed on an embankment or a lagoon to prevent erosion.

Rotating Biological Contractor;  A waste treatment device involving
closely spaced light-weight disks which are rotated through the
wastewater allowing aerobic microflora to accumulate on each disk
and thereby achieving a reduction in the waste content.

Rumen;  The large first compartment of the stomach of  a ruminant;
see paunch.

Sand Filter;  A filter device  incorporating a bed of sand that,
depending on design,  can be used in secondary or tertiary waste
treatment.
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Secondary Processes;  Edible and Inedible rendering and the processing
of blood, viscera, hide, and hair.

S ed intent a t ion Tank;  A tank or basin in which a liquid (water, sewage,
liquid manure) containing settleable suspended solids is retained
for a sufficient time so part of the suspended solids settle out by
gravity.  The time interval that the liquid is retained in the tank
is called "detention period".  In sewage treatment, the detention
period is short enough to avoid putrefaction.

Secondary Treatment;  The waste treatment following primary in-
plant treatment, typically involving biological waste reduction
systems.

Semipermeable Membrane;   A thin sheet-like structure which permits
the passage of solvent but is impermeable to dissolved substances.

Settling Tank;  Synonymous with "Sedimentation Tank".

Sewage;  Water after it has been fouled by various uses.  From the
standpoint of source it may be a combination of the liquid or water-
carried wastes from residences, business buildings, and institutions,
together with those from industrial and agricultural establishments,
and with such groundwater, surface water, and storm water as may be
present.

Shock Load;  A quantity of waste water or pollutant that greatly
exceeds the normal discharged into a treatment system, usually
occuring over a limited period of time.

Slaughterhpuse;  Meat packing plant that slaughters animals to produce
fresh meats.  It does not produce manufactured meat products such as
weiners, sausage, canned meats, etc.

Sludge;  The accumulated settled solids deposited from sewage or other
wastes, raw or treated, in tanks or basins, and containing more or
less water to form a semi-liquid mass.

Slurry;  A solids-water mixture, with sufficient water content to
impart fluid handling characteristics to the mixture.

Stick or Stickwater;  The concentrated (thick) liquid product from
evaporating the tankwater from rendering operations.   It is added
to solids and may be further dried for feed ingredients.
                                153

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Stoichiometric Amount;  The amount of a substance Involved in a
specific chemical reaction,either as a reactant or as a reaction
product.

gSj  Suspended solids; solids that either float on the surface of,
or are in suspension, in water; and which are largely removable by
laboratory filtering as in the analytical determinate of SS content
of wastewater.

Surface Water;  The waters of the United States including the
territorial seas.

Tankwater;  The water phase resulting from rendering processes,
usually applied to wet rendering.

Tertiary Waste Treatment;  Waste treatment systems used to treat
secondary treatment effluent and typically using physical-chemical
technologies to effect waste reduction.  Synonymous with "Advanced
Waste Treatment".

Total Dissolved Solids (TDS):  The solids content of wastewater that
is soluble and is measured as total solids content minus the
suspended solids.

Tripe;  The edible product prepared from the walls of the paunch or
rumen.

Viscera:  All internal organs of an animal that are located in the
great cavity of the trunk proper.

Zero Discharge;  The discharge of no pollutants in the wastewater
stream of a plant that is discharging into a receiving body of water.
                                154 .

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                                               \\lrd
                                                         ,
d
                                         CONVERSIONS
Multiply (English Units)
English Unit
acre
acre-feet
British Thermal Unit
British Thermal Unit/pound
cubic feet/minute
cubic feet/second
cubic feet
cubic feet
cubic inches
degree Fahrenheit
feet
gallon
gallon/minute
horsepower
Inches
inches of mercury
pounds
million gallons/day
mile
pound/square inch (gauge)
square feet
square inches
tons (short)
yard

Abbreviation
ac
ac ft
BTU
BTU/lb
cfm
cfs
cu ft
cu ft
cu in
°F
ft
gal
gpm
hp
in
in Hg
Ib
mgd
mi
pslg (0.
sq ft
sq in
t
y
by
Conversion
0.405
1233.5
0.252
0.555
0.028
1.7
0.028
28.32
16.39
0.555CF-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
06805 pslg -hi)*
0.0929
6.452
0.907
0.9144

Abbreviation
ha
cu m
kg cal
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
a tin
kg
cu m/day
km
atm
sq m
sq cm
kkg
m
                                                                        To Obtain  (Metric Units)

                                                                              Metric Unit
                                                                        hectares
                                                                        cubic meters
                                                                        kilogram-calories
                                                                        kilogram  calories/kilogram
                                                                        cubic meters/minute
                                                                        cubic meters/minute
                                                                        cubic meters
                                                                        liters
                                                                        cubic centimeters
                                                                        degree Centigrade
                                                                        meters
                                                                        liters
                                                                        liters/second
                                                                        kilowatts
                                                                        centimeters
                                                                        atmospheres
                                                                        kilograms
                                                                        cubic meters/day
                                                                        kilometer
                                                                        atmospheres (absolute)
                                                                        square meters
                                                                        square centimeters
                                                                        metric tons (1000 kilograms)
                                                                        meters
^Actual conversion, not a multiplier
                                           155

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