Environmental Protection Technology Series
CHARACTERIZATION AND IN-PLANT REDUCTION
OF WASTEWATER FROM HOG SLAUGHTERING
OPERATIONS
iai Environmental Kesearcn Laooratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagericy Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ENVIRONMENTAL PROTECTION TECH-
NOLOGY series. This series describes research performed to develop and dem-
onstrate instrumentation, equipment, and methodology to repair or prevent en-
vironmental degradation from point and non-point sources of pollution. This work
provides the new or improved technology required for the control and treatment
of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-097
May 1977
CHARACTERIZATION AND IN-PLANT REDUCTION
OF WASTEWATER FROM HOG SLAUGHTERING OPERATIONS
by
Paul M. Berthouex
University of Wisconsin-Madison
Madison, Wisconsin 52076
David L. Grothman and Donald 0. Dencker
Oscar Mayer & Co.
Madison, Wisconsin 53704
Lawrence J. P. Scully
Peat, Marwick, Mitchell & Co.
Washington, DC 20036
Grant No. 802833
Project Officer
Jack L. Witherow
Food and Wood Products Branch
Industrial Environmental Research Laboratory
Corvallis, Oregon 97330
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory-Cincinnati, U.S. Environmental Protection Agencyj and approved
for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorse-
ment or recommendation for use.
ii
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FOREWORD
When energy and material resources are extracted, processed, conver-
ted, and used the related pollutional impacts on our environment and
even on our health often require that new and increasingly more efficient
pollution control methods be used. The Industrial Environmental Research
Laboratory-Cincinnati (lERL-Ci) assists in developing and demonstrating new
and improved methodologies that will meet these needs both efficiently and
economically.
The report characterizes wastes generated by hog slaughtering opera-
tions and demonstrates in-plant reductions of wastewater 'volume and strength.
The information will enable managers and designers of hog slaughtering
plants to make major reductions in waste discharges. For further informa-
tion on the subject the Food and Wood Products Branch at the Corvallis
Field Station should be contacted.
David G. Stephan
Director
Industrial Environmental Research Laboratory
Cincinnati
ill
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ABSTRACT
The objective of this project was to characterize and quantify wastes
generated in a typical hog slaughtering operation both before and after
modifications were made to reduce wastewater volume and strength and to
increase by-product recovery. The research was carried out in the Oscar
Mayer plants at Madison, Wisconsin, in Beardstown, Illinois, and in Daven-
port, Iowa.
In the Madison plant, about two thirds of the flow and 80% of the
BODs were discharged during the production shift; the balance was from
cleanup. Total solids, suspended solids, volatile solids fractions, COD,
total Kjeldahl nitrogen, total organic carbon, and grease were also measured.
Each of these wastewater parameters was discharged in proportion to BOD5 .
The average work day for production was 7.79 hr, during which an aver-
age of 1.4 million pounds live weight of hogs were slaughtered (652,34-0
kg/day). The flow resulting from this operation was 520,000 gal/day (22.81
1/s), or 362.7 gal/1000 Ib live weight killed (LWK). The BODs load was
6,100 Ib/day (2769 kg/day), or 4.26 Ib BODs/1000 Ib LWK. This figure repre-
sents about 10% of the total flow from the Madison plant, which is a full-
range packinghouse, and about 25% to 30% of the total BOD load.
Process modifications were made that reduced the flow by 41%, the
by 63%, and the suspended solids by 63%. Some changes were costless, or
nearly so; the most expensive change cost $12,000. Most process modifica-
tions cost only a few hundred dollars. Every modification will pay for
itself within 1 or 2 years. Often the savings in water alone justifies a
modification, and savings in waste treatment and surcharges are a bonus.
Individual process modifications saved from $280 for simply turning off a
valve up to $129,000 for modifying the hasher washer to recover more scrap
for rendering. These are annual savings. The total present value of savings
due to all modifications (over 5 years at 10% interest) is more than a half
million dollars.
Details of the in-plant survey methods used, the data obtained, the pro-
cess modifications, and the economic analyses for each modification are given
in this report.
This report was submitted in fulfillment of Grant No. 802833 by the
University of Wisconsin and Oscar Mayer and Co. under the sponsorship of the
U.S. Environmental Protection Agency. The report covers the period 3/1/74
to 2/27/76, and work was completed as of 4/27/76.
iv
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CONTENTS
Foreword ..... ill
Abstract iv
Figures vi
Tables viii
Acknowledgments x
I Introduction 1
II Summary 4-
III Conclusions and Recommendations 7
IV Plant Descriptions 12
V Characterization of the Production Shift 36
VI Characterization of the Cleanup Shift 52
VII Characterization of the Total Hog Kill Floor Effluent 67
VIII Process Changes and Recharacterization 74
IX A Strategy for In-plant Reduction Studies 105
Appendices
A - Production Shift Data 112
B - Cleanup Shift Data \ » 121
C - Data for Total Day 130
D - Correlation of Parameters 139
E - Data Management 151
v
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FIGURES
Number Pa§e
1 Madison hog kill process flow sheet 13
2 Madison bleeding conveyor 1^
3 Madison scald tank I1*
4 Conveyor into dehairing machine 16
5 Madison kill rail between gambreling and rosin dipilator ... 17
6 Madison final carcass shower 19
7 Madison kill line at eyelid removal station 20
8 Madison kill line near brisket splitting station 21
9 Carcass splitting saw 22
10 Madison plant scraped fat catch trough 24
11 Madison scraped fat catch trough 24
12 Manual neck washer 25
13 Accumulation of fatty connective tissue on floor of manual
neck washing area 25
14 Heart tumble washer 26
15 Stomach slitter and tumble washer 27
16 Stomach scalder 27
17 Build-up of blood on platform at Beardstown bleeding area ... 29
18 Original chitterling washer sprays OQ
19 Beardstown chitterling washer 2Q
20 Madison kill floor drainage system
vl
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Number Page
21 Madison plant wastewater treatment flow diagram 34
22 Madison kill floor sampling points 39
23 Histogram showing length of the production shift 45
24 Histogram of pounds of live weight hogs killed per production
shift 46
25 Cleanup shift flow profile 57
26 Cleanup shift BOD,, concentration profile 61
o
27 Wastewater flow balance for the Madison production and
cleanup shifts 72
28 BOD,, mass balance for the Madison production and cleanup
shifts 73
29 Beardstown rail polisher automatic shut-off 83
30 Madison final carcass shower with old and new spray
configuration in parallel 85
31 Beardstown final carcass shower 86
32 Bridge and screen used after Madison final carcass shower to
keep meat scraps out of the 660 hog/hour kill line grease
drain 89
33 Tornado (brand) industrial vacuum cleaner with two inch wand
and floor gulper head 89
34 Madison eviscerating treadmill 91
35 Madison hasher washer with hasher blades removed 97
36 Chad automatic neck washer 103
37 Interior of neck washer showing position of spray
manifolds 103
38 Systems approach to industrial pollution control cost-
benefit analysis 108
vii
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TABLES
Number
1 Employment Statistics in 1974 2
2 Slaughter of Hogs in 1975 3
3 Cost of Changes and Savings Resulting From Changes 6
4 Flow Measurement and Wastewater Sampling Methods Using During
the Production Shift 44
5 Initial Characterization of the Hog Slaughtering Floor from
the Madison Plant Production Shift (Percent) 48
6 Initial Characterization of the Hog Slaughtering Floor from
the Madison Production Shift (lb/1000 Ib LWK) 49
7 Typical Cleanup Shift Flow Profile and Sample Total Flow
Calculation 58
8 Example of Pollution Load Calculation for the Cleanup Shift . . 60
9 Wastewater Flow and Pollution Load Characterization of the
Madison Cleanup Shift (Percent) 63
10 Wastewater Flow and Pollution Load Characterization of the
Madison Cleanup Shift (lb/1000 Ib LWK) 64
11 Wastewater Flow and Pollution Load Characterization of the
Combined Cleanup and Production Shifts (percent) 68
12 Initial Wastewater and Pollution Load Characterization of the
Combined Cleanup and Production Shifts (lb/1000 Ib LWK) . . 69
13 Summary of Changes in Pollution Load and Flow 75
14 Identification of Reduction by Sampling Point 76
15 Bleed Conveyor Wash Flow Reduction 70
16 Savings Due to Elmination of the Bleed Conveyor Wash During
Production . 79
viil
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Number Page
17 Dehairing Machine Reductions in Flow and Pollution Load-. ... 81
18 Annual Savings Due to Possible Dehairing Machine Changes ... 82
19 Carcass Shower Reductions in Flow 87
20 Annual Savings Due to Carcass Shower Reductions 87
21 Reductions in Flow and Pollution Load Due to Evisceration
Treadmill and Viscera Spray Changes: Segregation, Vacuum
Cleanup, and New Nozzles 93
22 Annual Savings Due to Evisceration Treadmill and Viscera
Spray Reductions of Table 21 94
23 Annual Savings Due to Use of Lockout Switch for Cleanup of
Evisceration Treadmill 95
24 Reduction in Production Shift Pollution Load Due to Removal
of Hasher Washer Blades 98
25 Annual Savings Due to Removing Hasher Washer Blades 99
26 Reductions in Production Shift Load Due to Installing the
Chad Neck Washer 101
27 Annual Savings Due to Installing the Chad Neck Washer .... 102
lx
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ACKNOWLEDGMENTS
This project was funded jointly by the U.S. Environmental Protection
Agency, Oscar Mayer & Co., Madison, Wisconsin, and the University of Wisconsin-
Madison .
James Kerrigen, AMEX International, Denver, Colorado, and formerly Associ-
ate Director of the Water Resources Center, University of Wisconsin-Madison,
was one of the initiators of this project.
Dr. John M. Harkin, Soil Science and Water Resources Center, University
of Wisconsin-Madison, established and supervised the laboratory support program
for the project. John Straughn worked as Laboratory Specialist throughout the
project.
The cooperation and assistance of many individuals in General Engineering
and the Production Departments of Oscar Mayer £ Co. are acknowledged.
Project administration and secretarial help was provided by the Water
Resources Center, University of Wisconsin-Madison.
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SECTION I
INTRODUCTION
The objective of this project was to characterize and quantify wastes
generated in a typical hog slaughtering operation both before and after
modifications were made to reduce wastewater volume and strength and to
increase by-product recovery.
One goal of this project was to see what could be reasonably accomplished
in a typical, large hog slaughtering operation without major alterations to
the plant, and with little or no hindrance to the productive output. This
need to reduce in-plant waste while maintaining the usual production rate
and quality required the cooperation of the operating personnel involved and
the backing of management. To this end, project personnel diligently kept
line supervision informed, and meetings were held to obtain the opinions
and recommendations of the people involved in any proposed change. A second
goal was to make the subsequent in-plant control easier and less costly.
Special attention was given to locations on the kill floor with greatest
potential for pollution load reduction through changes in work procedures,
equipment, and process redesign. Care was taken to insure that these changes
did not interfere with the rate of production, the quality of the product,
or the health and safety of the workers.
Until recently, almost all emphasis in handling meat industry wastewaters
was directed toward end-of-pipe treatment. However, it has been apparent
to those familiar with the industry that the potential exists for achieve-
ment of significant wasteload reductions through in-plant measures. These in-
plant measures can be designed into a new plant, but they present numerous
implementation problems in existing facilities.
MOTIVATION FOR THE STUDY
The enactment of the Federal Water Pollution Control Act Amendments of
1972 has provided added emphasis on in-plant measures as "Best Available
Technology Economically Available" required to be met by July 1, 1983. Ef-
fluent guidelines and standards promulgated by the U.S. Environmental Protec-
tion Agency envision extensive in-plant control of pollutional losses.
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The recently published Red Meat Industry Development Document (1) makes
reference to water control systems and procedures to reduce water use by
about 50%. Hog slaughtering operators should be interested in the results of
this study in that approximately 50% of their facilities are direct dischargers
to public waters, while most of the remainder are subject to the public facility
user charge and industrial cost recovery provisions of the 1972 Act (Public
Law 92-500).
The meat industry was identified in the 1972 Act as one of 27 industries
requiring standards of performance for new sources (Sec. 306). The listed
industries, including "meat product and rendering processing," have also been
covered by effluent guidelines and standards issued by the EPA. The FedeTal
Register, on February 28, 1974 published "Best Practicable Control Technology
Currently Available" (July 1, 1977) and "Best Available Technology Economi-
cally Available" (July 1, 1983) effluent requirements for the red meat
industry. These are the federal limits which are applicable to effluents from
existing hog slaughtering operations which are discharged to public waters.
Effluent requirements for discharge to Publicly Owned Treatment Works
(POTW) are not stringent, but the discharge is subject to Federally defined
user charge and industrial cost recovery provisions. POTW user charges are
escalating rapidly, and the industrial cost recovery requirement is spreading
so that it will be in effect at almost all POTW by 1983.
STATUS OF THE MEAT INDUSTRY
The meat industry is America's largest food industry and is included for
statistical purposes in the food products category classification. The 1974
employment data for comparison with the entire food industry and with all
manufacturing is shown in Table 1. in 1975, a nationwide shortage of hogs
resulted in the largest year-to-year dr©p in hog slaughter in 30 years. Pre-
liminary figures for 1975 hog slaughter are presented in Table 2.
TABLE 1. EMPLOYMENT STATISTICS IN 1974 (1)
% of all
Industry Total employees manufacturing
Meat packing (SIC2011) 170,200 0>9
Meat processing (SIC2013) 62,100 0<3
232,300 Ii2
All food 1,720,600 8-6
All manufacturing 20,016,000
100.0
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Table 2. SLAUGHTER OF HOGS IN 1975 (2)
Slaughtering site
Federal inspection
State inspection
Farm slaughter, est.
TOTAL
Head killed
64,927,700
3,762,000
810,000
69,499,700
% in 1974
84
80
80
1
The reduced supply of hogs adversely affected the industry as fixed costs
associated with slaughtering facility over-capacity eroded profitability and
highlighted the need for cost saving conservation measures. Much of the water
use within a plant is fixed since the water use per 1000/lb LWK increased
significantly during this time.
SUMMARY
The meat industry is large and comprises hog slaughtering plants of every
age and various descriptions. There is legal and economic pressure for all
plants to study in-plant reduction methods.
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SECTION II
SUMMARY
The quantity of wastewater issuing from the hog slaughtering floor and
the quantities of pollutants (BOD, COD, Kjeldahl nitrogen, suspended solids,
etc.) carried by this wastewater has been measured for both the production
shift and the cleanup shift. Several process modifications have been made
to reduce flow and the pollution load. The cost to make the changes ranged
from zero to $12,000; most cost only a few hundred dollars. Savings ran
from $280 annually for turning off a valve to $128,9M4 annually for modifying
the hasher-washer to recover more scrap for rendering while simultaneously
reducing the pollution load discharged. Even small and simple modifications
resulted in annual savings of several thousand dollars/yr. Often the savings
in water alone more than paid for the modification with savings due to pol-
lution load reduction being a tidy bonus. No installed change failed to
more than pay for itself. In-plant modifications are cost-effective, some-
times astonishingly so.
It is hoped that the results of this study will make plant management
more receptive to making modifications, even when this requires reordering
priorities for assignment of mechanics and plumbers to do the work.
The Madison plant processes beef in addition to hogs, processes the meat
into packaged products, manufactures spices and plastic packaging materials,
and incorporates some other operations. The hog slaughtering operation
represented about 520,000 gal./day wastewater flow (22.8 I/sec) and 6,100
BOD5 Ib/day (2,772 kg BOD5/day). This is about 10% of the flow and 25 to 30%
of the BOD from the entire Madison plant.
The changes described in the report reduce the flow to about 310,000
gal./day (1,173,350 I/day) and the BOD load to 2,250 Ib/day (1,023 kg/day).
This BOD reduction is a noticeable fraction of the total plant discharge.
The suspended solids discharge was reduced from 6,100 Ib/day to about 2 300
Ib/day (1,045 kg/day). '
Two-thirds of the flow was discharged during the production shift.
The three largest water users in Madison for production are the dehairing
machine, 70.3 gal./lOOO Ib LWK; the stomach washer, 48-5 gal./lOOO lb LWK-
and the process areas that contribute to sluice material to the hasher-washer
53.2 gal./lOOO lb LWK. '
BOD
of a
SOD load comes primarily from the hasher-washer, 2.707 lb/1000 lb LWK out
total for production and cleanup of 4.266 lb/1000 lb LWK. The stomach
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washer discharges 0.542 lb/1000 Ib LWK and the next largest contributors are
the dehairing.machine (0.661 lb/1000 Ib LWK) and the 330 hog/hr kill line
grease drain (0.215 lb/1000 Ib LWK). Eighty percent of the BOD was dis-
charged during the production shift.
The origin of these wastewaters and the data backing these summary fig-
ures are discussed in the report.
These summaries clearly identify the sources of gross pollution and lead
one to the process areas that must be modified. Table 3 lists the modifi-
cations made and the savings won. The flow was reduced by 4-1%; the BOD load
was reduced 63%; and other pollutants were reduced in proportion to BOD.
Many modifications required such a small investment that the first year sav-
ings paid for the installation. The net savings over a five-year period are
impressive. The present value of the sequence of savings less the initial
investment to make the change is listed as the net present value of savings.
The total net present value of savings, over 5 yr at 10% interest, exceeds
half a million dollars. This has impressed management with the enormous
benefit/cost ratio of in-plant changes and wastewater reduction steps will
be continued with enthusiasm.
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Table 3. COST OF CHANGES AND SAVINGS RESULTING FROM CHANGES
(All changes were made in Madison except where noted)
Problem Area
Bleed trough
Bleed trough clean-up
Bleed conveyor sprays
Hair chute - Davenport
Rail polisher shut off - Beardstown
Final carcass shower - Madison
Beardstown
Eyelids on Floor
Brisket splitting
Bone dust - carcass splitting
Viscera pan wash sprays
Viscera pan wash solenoid valves
Hasher-washer blade removal
Head washer
Neck washer
Cost of
change
$
$
$
$22
$
$
$
$
$ 2
$ 1
$
$
$17
0
3
0
,000
255
184
88
86
,377
,285
275
0
,000
Annual
savings
$ 40
$ 40
$ 260
$19,406
$ 624
$ 853
$ 2,080
$ 4,078
$ 2,907
$42,697
$96,244
$ 831
$30,000
$ 4,858
Notes
Increased by product recovery
value unknown
Pollution reduction
Increased byproduct recovery
Reduced labor
Reduced pollution & water
consumption
Chitterling washer - Beardstown
78
$ 5,070
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SECTION III
CONCLUSIONS AND RECOMMENDATIONS
Many older slaughtering operations were designed without consideration
of wastewater treatment costs and problems. Water was used extravagently;
water was drained indiscriminantly across floors where it contacted blood
clots and meat scraps, cleanup procedures habitually used vast amounts of
water and too little dry cleanup, and the cost of pollution control was
unknown or well hidden in overhead and utility costs. These older plants
can be modified, often rather easily and without great expense, to reduce
water use and lessen the amount of materials entering the drains as organic
pollution.
The economic motivation for in-plant modifications to reduce or
eliminate pollution have grown in recent years, and will grow even more
in the next few years. The impact of P.L. 92-500 and its associated
regulations for emission limits and industrial cost recovery where joint
treatment is used represent a huge potential cost to the meat industry.
There is no doubt that process modifications are an effective and economic
escape from this threatened cost for pollution control.
CONCLUSION
Many specific problems and solutions are discussed in the report in
Chapter 8. The magnitude of the wastewater flow and pollution load
reductions achieved and the net savings are reported there as well.
Broader conclusions are given here.
1. In the Madison plant the production shift discharged about two-
thirds of the flow and 80% of the BOD. Even after making production
shift modifications, while leaving the cleanup shift unchanged, the pro
duction shift would yield more wastewater (about 60% of the total) and
more BOD (about 90% of the total). Making changes in both shifts gave
the following result:
Flow .... 41% reduction to about 310,000 gal/day
BOD .... 63% reduction to about 2,250 Ib/day
SS .... 63% reduction to about 2,300 Ib/day.
After all changes, the cleanup shift represents about 25% of the flow,
9% of the BOD, and 17% of the suspended solids.
The opinion is often stated that the greatest target for reductions
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is the cleanup shift. The use of water for cleanup in the Madison plant
was not terribly wasteful when the project began; nevertheless, the
amount of water saved by making simple process modifications was 75,000
gal./day, a 56% reduction. This savings was due to process changes
and not due to retraining cleanup personnel or enforcing stricter pro-
cedures for using hoses and the like. Impressive as this value is,
shifting to dry conveyance of hair during the production shift represents
greater savings.
Implementing dry cleanup procedures prior to wet cleaning gave a
reduction in BOD load during the cleanup shift of 40%; the BOD load
dropped from 310 Ib/cleanup shift to slightly less than 200 Ib/shift.
There are savings worth thousands of dollars annually to be made on
the cleanup shift, even when the operation is initially reasonably effi-
cient. Unless, however, the cleanup is obviously wasteful and sloppy,
the greatest single improvements will be found on the production shift.
2. Dry conveyance of hair from the dehairing machine saves thousands
of dollars on water purchase and disposal. It also reduces the load
of suspended solids, BOD and other pollutants on the waste disposal
facility. In the Madison plant over $20,000 could be spent to modify
the dehairing machine to use dry conveyance and thousands of dollars
would still accrue as savings within 5 years. Dry conveyance is
used in many plants and the technology is well known..
3. Sluicing intestines, other viscera, and other scrap to rendering
is a water use that should be minimized. Usually it cannot be elimina-
ted and, therefore, some solid-liquid separation device may be needed
prior to rendering. The separated liquid will be very high in all
pollutants. It is the largest single source of pollution in the Madison
plant. Modifications of this solid liquid separation will be rewarded
handsomely by reduced waste treatment problems and increased rendering
income.
In Madison the solid-liquid separation device, called the hasher-washer,
first slashed the incoming intestines and other material with knives so
the contents could be washed out. The slots in the dewatering drum were
very large and gross amounts of solids spilled out with the water. Remov-
ing the knives so the intestines were sent to rendering intact can give
an annual net savings of about $130,000, in spite of a slight reduction
in the quality of the grease produced. Some plants have eliminated the
hasher-washer, which is clearly a major step toward pollution reduction.
Plants which have a hasher-washer should reevaluate immediately the need
for this unit and, if it must be retained, make some modifications.
4. Dumping the contents of the hog stomach creates a very heavy load
of suspended solids and other pollutants. Much of the contents are
soluble and any contact with water gives an immediate rise in the
soluble pollution load that must later be removed by expensive secondary
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treatment processes. Dry dumping of stomachs would save greatly on
water consumed and it would represent a major savings in pollution.
In plants which already use dry conveyance for hair and do not use
a hasher-washer, the stomach dumping and washing process may be
the largest single source of pollution. The importance of this
process has been clearly established. But a solution has not
been developed. Methods for dry cleaning the stomachs need to be
developed. Using smaller amounts of water for washing is a worth-
while objective, but this will not prevent the release of the potent
soluble stomach contents as pollutants.
5. Other than the three processes previously mentioned, the main
sources of pollution during the production shift are blood drippings
and clots, and meat scraps dropped on the floor. Some easily
installed and cheap remedies are screens around drains to hold back
scrap until it can be shoveled into a container, catch troughs under
the kill line to keep blood clots and scrap out of gutters and
prevent leaching of organic pollutants, and curbs to divert water
flow from floor areas which are covered with potential pollutants.
Changing the water use habits and physical drainage patterns to
eliminate water contact with meat tissue and bloody wastes is also
a great help. Dry pick up of material from the floor intermittantly
should be practiced. These remedies play a dual role. They reduce
the load of pollutants entering the drains and they increase the
amount of material that can be rendered.
6. There is good correlation between BOD and COD; either
measure could be used. Also, total Kjeldahl nitrogen is propor-
tional to BOD, COD, SS, and could be used as a surrogate measure
for screening studies. See Appendix D for details.
7. USDA regulations severely restrict the possibilities for
reusing water except for sluicing hair and material that goes to inedi-
ble rendering. If sluicing must be used for transport of material,
use recycled water and then reduce the volume of water to the minimum.
Better yet, eliminate sluicing whenever possible and use dry con-
veyance methods. This eliminates leaching of organics from meat
scraps and break up of blood clots.
8. The most difficult part of an in-plant wastewater reduction
program may be winning the cooperation of the management who must
approve the use of mechanics and other personnel to install the
changes. Obviously, production cannot be interrupted by slacking
on maintenance and process repairs, and mechanics are usually not
overabundant. The best hope of winning this cooperation is to show
estimated savings due to a particular change. In Chapter 9 a
strategy is outlined for making the in-plant survey and developing
a sequential program for attacking pollution problems and building
your account of benefits. These are simple steps that can bring
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attention getting benefits. The bulk of this report explains a very
complete and rather massive data collection program and the docu-
mentation of costs and benefits of changes. A project of this
magnitude is not required for a plant to begin reducing its pol-
lution load and saving money through increased byproduct recovery,
lower water bills, diminishing sewer surcharges, and fewer worries
over the rapidly approaching Federal datelines for implementing
stricter pretreatment and industrial cost sharing codes.
RECOMMENDATIONS FOR FURTHER STUDIES
The recommendation that Oscar Mayer S Co. continue implementation
of process modifications and exploration of in-plant conservation
measures has already been accepted by plant management. The estimated
savings from changes already installed stimulated this decision.
There are some specific problem areas that deserve attention on more
than a casual basis. These are identified as objectives for future
special studies.
1. Invention of a new method for dumping and cleaning stomachs
would be rewarding. Equipment manufacturers should be encouraged
to help solve this problem.
2. Skinning hogs is starting to be used in some plants in place of
scalding, dehairing, rosin dipping, singeing and manual shaving.
This will eliminate many points of water use and drastically change
the amount and nature of the pollution discharged from the pre-
butchering processes. The water use and pollution generation of
this growing technology should be characterized and conservation
methods should be developed and incorporated into the design of new
skinning operations.
3. Without doubt there are many simple process modifications that
should be done and the decision making process is straightforward
because benefits so obviously exceed costs. After these easy steps
have been taken an industry should still want to reduce pollution
rather than treat it or discharge it. This would be a public
service and an economic reward to themselves in many cases. The
economics become harder to quantify and the in-plant modifications
become more extensive. Also, the uncertainties of future pollution
control standards and costs complicate the problem. Work needs to
be done to develop methodologies for determining the interaction
between in-plant reduction and waste treatment costs. The true
costs of waste treatment are often not known. The decision whether
10
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to invest in major process changes or in expanded waste treatment
facilities, or to go to joint treatment and pay surcharges is
becoming more important economically. These engineering questions
about treatment and cost allocations need to be answered.
11
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SECTION IV
PLANT DESCRIPTIONS
GENERAL PLANT COMPARISONS
The Oscar Mayer and Company plants at Madison (Wisconsin), Beardstown
(Illinois), and Davenport (Iowa) were studied. These three plants represent
a wide variety of process technology and physical plant donditons. The
Madison plant is old, crowded, and difficult to modify. The Beardstown plant
is new, more spacious, and uses different methods for bleeding, dehairing, and
intestine handling. The Davenport plant provides examples of some different
technology.
The Madison plant was built originally by the Farmer's Cooperative in 1917,
and was purchased by Oscar Mayer £ Co. in 1919. Since the original purchase,
the plant has expanded to over 1,000,000 ft2 (93,000 m2) of space devoted to
slaughtering up to 1,000 head of hogs and 50 head of cattle/hr, and
processing of ready-to-eat meats. The Madison facility also provides space
for spice and pharmaceutical subsidiaries, a power plant and a large modern
plastic package fabrication plant.
The Davenport plant was purchased in 1946 from Kohr's Packing Co. and
since then has been greatly expanded. The present plant combines a 750 head/hr
hog slaughtering facility along with an extensive ready to eat processed
meats plant.
Built in 1967 as a hog slaughtering facility capable of processing 750
hogs/hr, the Beardstown plant has since been increased in size by 40% to pro-
vide space for a ham canning operation.
HOG KILL-CARCASS HANDLING (MADISON)
The hogs are driven singly from the stockyards into a conveyorized carbon
dioxide (COa) gas immobilizer where they are anaesthetized (Figure 1). From
the immobilizer the hogs are arranged on an inclined steel slat conveyor which
has a blood tr.ough along one edge (Figure 2). The unconscious hogs are killed
by cutting the carotid arteries and jugular veins. The blood falls into the
collecting trough and is pumped to the blood recovery system. The total
bleeding time is 3.75 rain from the time the hogs are stuck until they are
dropped off the conveyor into the scald tank.
The raw blood from the blood collecting trough is piped to a steam coagu-
lator and then to a centrifuge where most of the coagulated solids are removed.
12
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Madison hog kill process flow sheet.
-------
Slotted
conveyor
over blood
trough
Figure 2. Madison bleeding conveyor.
Dunker
Figure 3. Madison scald tank (entry end)
-------
The solids are sent by conveyor to a blood drier where it is dried to 10%
moisture content for use as animal feed supplement. The liquid portion from
the centrifuge is sent to the concentrator where some of the water is removed
to produce a 60% protein material called tankage or liquid stick.
From the bleeding conveyor the hogs are dumped into a 140°F (60°C) scald
tank (Figure 3). The carcasses are moved through the scald tank by a combina-
tion of mechanical' "dunkers" and circulating hot water. Two hundred Ib
(90.9 kg) of lime is added to the 8,000 gal. (30,3 m3) scald tank as a scald
aid. The scald solution is maintained at 140°F by circulating it constantly
and injecting steam into the recirculating pipe. The average time of a
carcass in the scald tank is 5 min; however, because of the method of move-
ing the hogs through the tank, this time can .vary from 4 min to 5 1/2 min.
The hog carcass is picked out of the scald tank and conveyed into the de-
hairing machine by means of an inclined conveyor (Figure 4). The dehairing
machine itself is a two unit "Boss" dehairing machine. It consists of a
series of rotating steel tipped rubber scrapers which rotate the hog carcass
and scrape and pull off the scalded hair and toenails. A continuously recir-
culating heated spray showers the carcass in the dehairing machine to lubri-
cate it and to convey away the removed hair and toenails. The water sprays
in the final 6 ft (1.83 m) of the machine are potable Sold water sprays required
by USDA regulation. The hair and toenails removed from the carcass drop to a
screen where a chain with "flights" scrapes it to a hair discharge chute.
Water sprays at the hair discharge chute spray onto the hair and flushes it
down a pipe into the manure water sewage system. Approximately 200,000 gal./
day potable water is used to transport hair in this system. The almost
completely dehaired carcass is expelled from the dehairing machine onto a
steel slat conveyor. While on the conveyor the hind legs are slit and a steel
gambrel is inserted behind the achilles tendon and the hog is hung onto a
steel rail to the rosin dipilator (Figure 5).
In the dipilator the carcass is dipped into a molten rosin bath to be
coated with 300°F (149°C) rosin except for the last 10 in. (0.25 m) of' the
hind legs. The rosin coated carcass is transported by means of a "live" chain
through a rosin stripping cabinet where dry scrapers pull most of the rosin
and hair off. The rosin-hair scrapings are remelted and rosin is recirculated
back into the dipilator- There is some manual scraping of the rosin and then
the carcass goes through another cabinet with rubber flails which remove the
rest of the rosin. The second stripping cabinet has water sprays in it which
lubricate the carcass. These sprays strip off"and also carry away the fine
bits of rosin. After rosin stripping the carcass passes through an 8 ft
(2.44 m) long cabinet with open gas flames which singe off any hair not re-
moved by the rosin and dehairing machine.
The head polisher is a large, concave, vertically rotating brush which
brushes the head, neck and jowls of the carcasses to remove singed hair, rosin
and dried blood. A water spray directed onto the brush flushes material away. .
After the head polisher is the rail polisher. This is a 16 ft (4-88 m)
long cabinet with two motor driven shafts, on which are mounted rubber flails.
A water spray showers the carcass with 30 gal./min (1.89 1/s) of cold water to
lubricate the carcass and flush off singed hair and rosin loosened by the
15
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v - ; -
\ JT:-r
Figure 4. Conveyor into dehairing machine.
-------
Combination blood
and water drain
Figure 5. Madison kill rail between gambreling and rosin dipilator,
17
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rubber flails.
The final shaving and cleaning of the outside of the carcass is done manu-
ally. While a series of showers lightly lubricates the carcass, men use^
knives to scrape all surfaces of the carcass, remove toenails, and cut tissue
from between the toes. The shaved carcass goes through the final carcass
shower (Figure 6) where spray nozzles flush off loosened hair and scrapings.
Any hair or soil remaining on the carcass after this point must be removed by
excision.
The first step after the final carcass shower is removal of eyelids. The
eyelids along with a large patch of skin and fat around the eye are cut off
and discarded onto the floor (Figure 7). Periodically these scraps are swept
up and taken to inedible rendering.
The head of the carcass is then nearly removed by cutting through the skin,
neck muscles and between the first vertebra and the skull. The head is left
hanging to the carcass by a narrow strip of flesh along the lower jaw.
USDA inspectors expose the salivary glands in the head to check for
abscesses. The carcass is also checked for signs of dirt, hair or disease. An
unacceptable carcass is tagged for trimming or disposal.
Next the brisket is split; i.e., the carcass is opened from the lower end
of the sternum to the neck. Large quantities of blood clots and serum drop
onto the kill floor (Figure 8). The next butchering steps open the abdomen,
split the aitch bone, and free the urethra. The bladder, uterus (if present),
and urethra are removed and discarded into a chute which carries them through
the hasher-washer to an inedible cooker. The anus is cut around and freed
from the surrounding skin and connective tissue.
A man standing on a treadmill synchronized to move with the hog carcass
removes the viscera. All internal organs except the kidneys are removed and
dropped into a viscera pan. Blood clots from the chest cavity fall onto the
treadmill or onto the floor. The treadmill is continuously washed with cold
water and sanitized with 180°F (82°C) water. Viscera work-up is explained
later.
The carcass is split with a lubricated circular saw (Figure 9). Two or
three small strips of skin are left uncut to hold the carcass halves together.
Fat, blood, and bone dust from this operation drops to the floor and are
carried into the floor drain.
Skin and fat around the stick wound, remains of the aorta, and sperm cords
(of barrows) are removed and dropped onto the floor. Periodically these scraps
are swept up for inedible rendering.
The kidneys are exposed. Bruises and blemishes are trimmed from the car-
casses prior to final USDA inspection. Trimmed pieces are put into containers
or dropped onto the floor. They are later swept up for inedible rendering.
The kidneys are removed and sent to the offal department.
18
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Lower spray used only
when sows are being
washed.
Figure 6. Madison final carcass shower.
19
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Figure 7. Madison kill line at eyelid removal station.
20
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Blood Clots From Brisket Splitting
Combination Blood And Water Drain
Blood Gutter Under The Kill Rail
Note The Accumulation Of Blood
Clots In The Gutter
Figure 8. Madison kill line near brisket splitting station.
21
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Water Spray
Figure 9. Carcass splitting saw.
22
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The carcass and head pass through sprays which wash blood and stomach
contents from the head (Figure 10). After washing, the head is removed from
the carcass and skinned. The cheeks, jowls, scalp, tongue and other muscle
tissue are removed for use in processed meats. The skull is split and the
pituitary and hypothalamus glands are removed for sale to pharmacuetical
manufacturers. The skull and jaw are sent to inedible rendering.
The^USDA inspected carcass is marked with an indelible stamp. Leaf fat,
which lines the interior dorsal sides.of the carcass, is pulled out and sent
to. lard rendering. Hand scrapers are used to remove loose fat and tissue from
interior and cut surfaces of the carcass. The tissue removed is collected in
a trough, and pumped to lard rendering (Figure 11).
Hand operated neck washers are used to remove blood clots and fatty tissue
from the stick wound (Figures 12 and 13). Material washed from the wound falls
to the floor and is flushed down to the hasher-washer.
The carcass is weighed, sent to the cooler, and held for butchering the
next day.
VISCERA HANDLING (MADISON)
Viscera is removed from the carcass and dropped into a viscera pan mounted
on a conveyor. The viscera is examined by USDA inspectors for signs of dis-
ease. Viscera approved by the USDA inspectors goes to the work-up table; the
organs are separated and sent to the offal department for further handling.
Viscera condemned by the USDA inspectors is dumped into a chute to the hasher-
washer and from there to inedible rendering. The viscera pans are continuously
washed with cold water and sanitized with 180°F(82°C)/pUSDA rules. Hearts
are separated and slashed to:,expose clotted blood. The hearts are washed in
a tumble washer in cold running water for 3 to 5 min to remove the blood
(Figure 14). The clean hearts are laid on trays and chilled. Blood clots,
parasite spots and membranes are trimmed from the livers. The livers are
hung on a rack and chilled.
The small intestines are sluiced to the hasher-washer where they are cut
open, rinsed, and sent to inedible rendering. Some small intestines are
ground, preserved in barrels, and kept for heparin extraction. Stomachs are
slit, rinsed, and tumble washed (Figure 15). The mucosa is stripped from the
stomach wall and held for pharmaceutical purposes. The stomach is scalded
and then frozen for animal food (Figure 16). The pancreas is washed in a
small tumble washer and chilled.
The caul fat is hand stripped from the spleen, hand rinsed and then trans-
ported manually to lard rendering. When lungs are being saved for animal food
they are weighed, packed into boxes and frozen. When lungs are not being saved,
they go through the hasher-washer to inedible rendering. Spleens are rinsed
and frozen for animal food. When gall is being saved, the empty gall bladders
are dumped to inedible rendering. If gall is not being saved, the intact gall
bladder is sent through the hasher-washer to inedible rendering. The large
intestine (black gut) is sent through the hasher-washer where they are slashed,
23
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Figure 10. Madison head washing sprays.
Figure 11. Madison plant scraped fat catch trough.
-------
Knobbed
metal brush
Water supply
to washer
Figure 12. Manual neck washer,
Figure 13. Accumulation of fatty connective tissue on floor of
manual neck washing area.
-------
Figure 14. Heart tumble washer.
26
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Tumble
Washer
Sampling Hub
For Stomach
Slitter And
Washer
Figure 15. Stomach slitter and tumble washer,
Figure 16. Stomach scalder,
27
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rinsed, and sent to inedible rendering. When kidneys are being saved, ^
are boxed and frozen. When they are not being saved, they are sent to inedible
rendering.
HAIR SAVING OR DISPOSAL (MADISON)
Prior to 1975, from May through September the hair removed in the dehair-
ing machine was sluiced to the sewage pretreatment plant, and screened. The
hair and toenails were landfilled. From September through May hair and toe-
nails were sluiced from the dehairing machine to a. hair cleaning department;
the sluice water was removed by a shaker screen. The damp hair was washed in a
mild caustic solution and rinsed with warm potable water. The clean hair
and toenails were conveyed to a steam-heated mesh conveyor and dried. A vac-
uum pick-up transported the hair from the dryer to a baler (the heavier toenails
not picked up by the vacuum drop into a trash collector). The baled hair was
overwrapped with burlap and held for shipment. Since 1975 hair was no longer
saved.
DAVENPORT PLANT HOG KILL
The basic processes used at Davenport are the same as at Madison except
for minor differences in layout and water use. In the Davenport plant, hair
removed in the dehairing machine is dropped by chute to a truck body for land-
fill disposal or to hair saving during the proper season instead of being
sluiced to its destination. Davenport also uses catch pans with weirs in some
carcass washing steps to keep fatty tissue out of the drains.
BEARDSTOWN PLANT HOG KILL
In Beardstown hogs are electrically stunned instead of being gas anaethe-
tized as in Madison and Davenport. The hogs are then shackled, bled out over
a pit as shown in Figure 17. Blood from the pit is drained to the blood re-
covery system.
The shackled hogs are dragged through the scald tank. Because they are
dragged through rather than being free floating (as in Madison and Davenport)
the time they spend in the scald tank can be more closely controlled.
In Beardstown the large intestines of hogs are processed to make chitter-
lings. The large intestines are separated from the small intestines and con-
veyed to the chitterling wash area. The intestines are pulled apart from
their connective tissue, slid onto the chitterling washer rail, slit open and
flushed with potable water in the washer (Figures 18 and 19). The chitterlings
are then chilled, packed in plastic cartons and frozen for sale.
Beardstown uses water recycled from the 'grease flotation tank in the sewage
treatment plant to sluice the hair and toenails from the dehairing machine back
to the shaker screens in the sewage treatment plant. Beardstown does not use
28
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Figure 17. Build-up of blood on platform at Beardstown
bleeding area.
-------
.
*
*
Figure 18. Original chitterling washer sprays.
New type sprays
Bucket conveyor
Figure 19. Beardstown chitterling washer.
30
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a rosin dipilator for hair removal.
WATER SUPPLY
The Madison plant has three wells and is starting up a fourth one. The
average flow of the three wells is 5,000,000 gaVday (219 I/sec). Water
is pumped from the wells to a central reservoir. Water is constantly pumped
from^the reservoir and used as ammonia condenser cooling water for the ammonia
refrigeration units and returned to the reservoir. Water from the reservoir
is pumped throughout the plant for use. The Madison plant also purchases
2,000,000 gal/day (87.6. I/sec) of water from the City of Madison. Most
of the city water is used for the production of processed meats and little is
used on the kill floor except in drinking fountains. The total water use in
the kill floor is not metered directly; it is not possible to isolate water
supply lines to the kill floor. Some water on the kill floor is used more
than once. The water used to wash the viscera pans, the treadmill, and the
viscera work-up table is also used to sluice condemned viscera and intestines
to the hasher-washer.
The Davenport plant has four wells on the plant property which supplies
most of the water for the plant. Some water is purchased from the city as
necessary to maintain the reservoir level, and some city water is piped directly
into the plant for use in processed meats manufacturing. The well water is
pumped through the ammonia condensers before going into the reservoir for use
in the plant. Some water is drawn from the reservoir through the ammonia de-
superheater and into a hot well to use as pre-heated water for the plant hot
water system.
The total water supply for Beardstown comes from three wells on the prop-
erty which pump an average of 1,420,000 gal. (5,375,268 liters) of water per
manufacturing day.
WASTEWATER HANDLING SYSTEMS
Madison
The Madison plant has segregated wastewater collection systems. Sanitary
wastes from plants and office toilets are discharged directly to the Madison
Metropolitan Sewage Treatment Plant. Cooling water from plastic extruders
with drains and roof drains empty directly into the city storm sewers which
discharge into the Yahara River-
There are four drainage systems from the kill floor of the Madison plant.
These are shown in Figure 20. They are the blood collection system, the
hasher-washer drain, the grease water drains, and the manure water drainage
system. Where large quantities of blood drip from the carcass there are dual
drain openings in the gutters. One opening goes to the blood collection system;
the other is the entry to the grease water system. During production, blood is
collected in the blood recovery system whenever this can be accomplished with-
out having the blood diluted by water from adjacent areas. When blood is being
31
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CX>
IO
HASHER WASHER CHUTE
^ BLOOD DRAIN
GREASEWATER DRAIN
MANURE WATER DRAIN
» CENTER LINE-KILL CHAIN
N
rcrr
^,' SCALES
4.»* **! ~^^fc * 1IZEIEI1 ' |j 1 -J- -i i ' jL_J__J__i_iLJi_J
L/«I..Xj5..«TJ>W.. .......~..' VISCERA { .
SHAVERS
Figure 20. Madison kill floor drainage system.
-------
collected for^recovery, the grease water system is plugged. During cleanup,
the blood drains are closed and the adjacent grease water drains are opened.
The blood collection serves primarily the bleeding conveyor area, but also
the drain gutters under the kill chain.
The manure water drainage system collects water from the stockyards, the
stomach dumper, the dehairing machine, hair wash, and the scald tank. The
wastes go to a pretreatment plant (Figure 21) where the large solids are re-
moved by a shaker screen and are disposed of in landfill. The wastewater then
goes into a settling tank where the heavy solids settle out and are pumped to
a sludge holding tank. The liquid wastes are metered and joined with the
grease water effluent and is piped to the treatment plant. The hasher-washer
drains are merely greasewater drains used to carry heavy solids. This system
is used to transport condemned viscera, unused intestines, pizzles, piggy
bags, and bungs to the hasher-washer using wash water from the viscera pan
washer and other places. At the hasher-washer the intestines are slashed into
pieces and the contents are flushed out by passage of the transport water over
and through the chopped up viscera. The solids from the hasher-washer are
sent to inedible rendering and the effluent goes into the plant greasewater
drainage system.
The grease water system contains the effluent from all of the plant floor
drains both from the manufacturing and slaughtering parts of the plant. It
also contains the effluent from the hasher-washer in the inedible rendering
department. Waste water from the kill floor goes to a catch basin where fatty
material is floated off and sent to inedible rendering. The effluent from the
catch basin is pumped to the pretreatment plant into a dissolved air flota-
tion tank where more solids are removed for inedible rendering. The effluent
from the dissolved air flotation tank joins the effluent from the manure water
settling tanks and is pumped across a rotating arm trickling filter, an inter-
mediate clarifier, a fixed bed trickling filter, a final clarifier (Figure 21)
and then to Madison Metropolitan Sewage District's Treatment Plant. The sludge
from the clarifiers is pumped to a sludge holding tank and then through a
vacuum filter. The solids from the vacuum filter are disposed of in landfill.
Davenport
The Davenport plant also has four wastewater drainage systems. The clear
water drainage and the sanitary sewers are combined and go directly to the
City of Davenport Sewage Treatment Plant. Kill floor drainage in Davenport
is the same as in Madison. The manure drains collect water from the stomach
washer, stockyard drains, dehairing machine and scald tank as in Madison.
The effluent from these drains is treated by a "Roto-Strainer" where the solids
are removed for landfill disposal. The effluent from the "Roto-Strainer" is
sent to the City Sewage Treatment Plant.
Grease drains collect wastewater from slaughtering and manufacturing plus
water from the hasher-washer. These effluents are treated by a pair of "Roto-
Strainers" where most of the solids are removed and sent to inedible rendering.
The "Roto-Strainer" effluent goes to dissolved air flotation tank. The skim-
mings from the dissolved air flotation tank are pumped to inedible rendering
33
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U)
INEDI8LE WET
RENDERING TANKS (3)
NOTES
FLOTATION RECWXE PUMPS NOT SHOWN
KEYS
MANURE CONTAINING WASTEWATER
GREASE SKIMMINGS
COMBINED WASTEHATER
CREASE CONTAINING WASTEHATER
I SOLIDS
Figure 21. Madison plant wastewater treatment flow diagram.
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and the bottom solids are pumped across the manure water "Roto-Strainer." The
effluent from the dissolved air flotation tank is sent to the city sewage
treatment plant.
Beardstown
The Beardstown plant has four wastewater drainage systems. Sanitary wastes
from plant and office toilets drain to a wet well. From the wet well the
effluent is pumped to an anaerobic lagoon. Clear water wastes from the roof
and yard drains are allowed to run off onto the yards into the soil. The kill
floor drainage for Beardstown is also the same except there are no blood drains
anywhere except in the bleed area. In Beardstown where the hogs are shackled
and stuck, they bleed out better and there is very little blood which falls to
the floor as compared to Madison and Davenport.
Manure containing wastewater from the stomach slitter and stockyards drains
to a wet well. From the wet well the effluent is pumped across a shaker screen.
The solids from the shaker screen are sent to landfill, the effluent drains to
a settling tank. The sludge from the settling tank is pumped to a sludge hold-
ing tank and to a vacuum filter. The solids from the vacuum filter are dis-
posed of in landfill. The effluent from the settling tank is pumped to the
same wet well as the sanitary effluent and is pumped to an anaerobic lagoon.
The hair containing effluent from the dehairing machine flows across a shaker
screen where the solids are removed for landfill disposal, the liquid flows
into the same wet well as the sanitary wastes and is pumped to an anaerobic
lagoon.
Grease containing wastewater from the plant floor drains flow to a wet
well in the sewage treatment plant. From the wet well the effluent is pumped
to a dissolved air flotation tank. The flotation grease from the tank is
sent to inedible rendering. A part of the water in the flotation tank is
pumped back to the plant to use for transporting hair from the dehairing
machine and the rest goes to a wet well from which it is pumped to an anaero-
bic lagoon. From the anaerobic lagoon, the effluent flows into an aerated
intermediate lagoon and then into a final aerobic lagoon before discharging
into the Illinois River.
SUMMARY
This description of the three slaughtering plants was most detailed for
the Madison plant because most of the process sampling was done there. Sampl-
ing was done in Beardstown only on processes that used different technology
or on processes that do not exist in Madison (i.e., chitterlings). The Daven-
port plant was characterized by comparison with Madison or Beardstown.
The arrangement of the Madison kill floor and the wastewater collection
system are important to remember through Chapters V to VIII. The sampling
procedures and characterization in several instances were constrained by this
physical arrangement. In Chapter VIII additional photographs and data that
show rearrangements of processes pictured in this chapter and the savings
achieved are also presented.
35
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SECTION V
CHARACTERIZATION OF THE PRODUCTION SHIFT
INTRODUCTION
The normal water use and wastewater production of the killing and produc-
tion shift and the cleanup shift have been characterized. This chapter deals
with the production shift. The next chapter deals with water use and charac-
terization during cleanup. The location of the sampling stations, the labor-
atory procedures, and the general methods used for sampling and flow measure-
ments were the same for both the production and the cleanup shift. Minor
changes from these general procedures or specific details about a particular
sampling location will be pointed out in the text.
LABORATORY METHODS
All laboratory analyses were done in accordance with standard accepted
procedures according to standard methods and EPA instructions for chemical
analysis (3). Twice during the project unknowns from the EPA were analyzed
as a check on the accuracy of the procedures being used and the procedures
were shown to be acceptable. Here only a few special points are mentioned.
Many of the samples contained blood. Some of the samples are known to be
contaminated primarily with blood and, therefore, precautions were taken to
be sure that an acclimated bacterial seed was used in BOD tests. A bacterial
seed colony was established in the laboratory. This colony was fed blood
periodically so that the organism would be certain to be acclimated. All BOD's
were seeded with this bacterial culture. COD's were run on all samples as well
as BOD's and for most samples the total organic carbon was run as well. These
three measurements, TOC, BOD, and COD, provide a check on each other and the
consistency of variations, one parameter with another, gives additional con-
fidence in the quality of the data which has been used to characterize the
system. Likewise, complete analyses on solid residues was done. The other
most useful parameter seems to be total Kjeldahl nitrogen.
Correlation of one parameter with the others will be discussed later. The
important point here is that increases in one parameter generally were associ-
ated with increases in the others; thus, strengthening one's confidence in the
quality of the data and of the skill of the laboratory analyst.
WASTEWATER FLOW MEASUREMENT
The accurate measurement of wastewater flow is an important step in the
-------
characterization project. In a few processes the effluent was known to be
equal to the influent and it was possible to monitor the influent with totali-
zing water meters. In other situations direct metering of the water supply
was not possible; the effluent was not equal to the influent because of spil-
lage and splashing; the plumbing to the process was so complex and would re-
quire so many water meters that this was not practicable; or there was inter-
mittent water use with hoses and off-on operations. In these instances a
tracer dilution method-was used (the tracer was lithium chloride). Or the
time required to fill a container of known volume was measured and the flow
rate was calculated.
The procedure of timing the filling of known volume was used for hoses
and other intermittent flows. These estimated flow rates were used in com-
bination with observed normal duration of use of hoses and other devices to
estimate total volume contributors of wastewater.
The lithium chloride dilution technique involves the injection of a con-
centration of lithium chloride solution at a known and uniform rate into the
wastewater flow. Samples of the lithium/wastewater mixture are collected
downstream after the lithium has become mixed uniformly with the wastewater.
Lithium is an excellent tracer for this purpose because it does not adsorb;
it can be detected by atomic absorption in very low concentrations. There is
no hazard associated with its use in the food industry? nevertheless, care was
taken to see that no lithium contamination of the food product could occur.
The wastewater flow rate is calculated from the ratio by which the lithium has
been diluted. This calculation is very simple because the volume of lithium
solution injected is extremely small in comparison with the wastewater flow,
so that the total flow is not essentially unchanged.
WASTEWATER SAMPLING METHODS
Collection of representative wastewater samples was difficult in many
instances due to the heterogeneous nature of the waste and physical restric-
tions of the existing processes and of the existing sewer system.
At some locations it was known that the flow would be constant during the
production shift. Often even in these locations grab samples were taken and
later were mathematically composited. This gave information about variability
within the process and additional information regarding correlation of one
strength parameter with another-
In several cases it was not certain that the flow was constant during the
day. Some drains that collected flow from several processes were sampled and
some of those processes had intermittent water use, intermittent cleanup opera-
tions, and other variations in water use that precluded compositing samples.
In these locations, either numerous grab samples were used or composites were
prepared over a short time period of 10 to 30 min. These grab samples
could be used with flow information compiled over the time of study to make
estimates of total pollutant discharge and to check assumptions regarding
patterns of water use and of wastewater pollution.
37
-------
Collection of samples was automated when possible by using an ISCO sam-
pler- This device collects 500 ml portions of wastewater at a frequency which
can be set as short as every 15 min. The sample volume is deposited in an
individual plastic bottle (or a clean glass bottle when grease was to be analy-
zed). Automatic sampling was feasible only in locations where the wastewater
was free of large and heavy suspended solids. Where heavy solids, hair or
other clogging materials were evident, samples were collected manually in a
small bucket. A number of these would be collected over a short time period,
and composited in a large bucket which was thoroughly mixed. The composite
sample sent to the laboratory was a portion of the well mixed contents,
Matching the sampling method to the particular sampling location was very
important. Care was taken to obtain representative samples. Whenever an
automatic sample was used, special precautions were observed to avoid clogging
of the perforated head on the suction tube and to avoid clogging of the tube
itself.
WASTEWATER SAMPLING STATIONS
Whenever possible, sampling points were chosen which would isolate the
flows from specific pieces of equipment or from specific processes. This was
not entirely possible and the flows and characterization of some processes are
combined with others. Sampling points located on the kill floor or one floor
below are shown on the Madison kill floor drain plan (Figure 22). Other drains
not shown are located in the hair saving area or in the variety meats department.
Bleed Area Floor Drain
This drain receives drainage from the floor around the bleeding conveyor
and from the conveyor cleanup. During production, there is no flow in this
drain.
Bleed Conveyor Blood Drain
The blood trough runs along the inclined bleeding conveyor and collects
the blood and channels it into a blood pump on the floor below where it is
pumped to the blood drying system. During production there is no wastewater
flow in this drain.
Bleed Conveyor Wash Drain
Spray nozzles continuously rinsed the blood from the bleeding conveyor
during production and the first part of cleanup. These sprays were the total
waste flow for this drain. Discharge was drained into the plant greasewater
drainage system. The drain was sampled from the end of the drain pipe before
it discharged into the floor drain. The flow rate was estimated by collecting
a timed sample in a calibrated vessel.
Scald Tank
There is no flow through the scald tank during production. The tank is
38
-------
CO
KEY
HASHER WASHER CHUTE
BLOOD DRAIN
GREASEWATER DRAIN
MANURE WATER DRAIN
CENTER LINE - KILL CHAIN
N
rcrr
±_ , SCALES
SHAVERS
?£V_ jS ,f
' '""" " *!.""
\
Figure 22. Madison kill floor sampling points.
-------
filled in the morning, and makeup water is provided by the steam which^is in-
jected to heat the tank. The volume of the tank is known. The pollution load
from the scald tank was estimated from samples of the tank contents taken dur-
ing the day. The scald tank is emptied into a manure drain^during cleanup.
The dehairing machine cleanup waste goes into this same drain.
Dehair Floor Drain
The waste discharge into this drain changes from season to season. In
summer, hair is not saved and the dehair floor drain collects the total pro-
duction and cleanup effluent from the dehairing machine. This includes dehair-
ing machine overflow and removed hair and toenails, plus the drainage and clean-
up of the scald tank. When hair is being saved the drain collects only over-
flow from the dehairing machine during production. This drain discharges into
the manure wastewater system.
The flows into the dehair floor drain were estimated by placing water
meters on every source of water contributing to the drain. The meters were
read before and after production each day to obtain flow data both for pro-
duction and cleanup.
Wastewater samples from this drain were obtained in three different ways:
(1) Grab sampling by inserting a hand dipper into a clean-out pipe in the drain,
(2) Automatic sampling with air operated sampler placed in the drain pipe three
floors below the dehairing machine. The sampler is comprised of an automatic
electric timer, a solenoid valve controlling an air line, and a 2 in.. -rmbbBr
lined "squeeze valve." When air pressure is maintained on the valve, the rub-
ber lining of the valve is closed. When the timer is tripped, the air is
exhausted and the valve opens allowing flow through the valve into a collection
bucket. The advantages of this sampler is that it allows taking samples which
contain heavy solids without the danger of solids blocking the valve and keep-
ing it from closing, (3) Automatic sampling with an ISCO Sampler through a
clean-out pipe in the drain. The strainer on the end of the ISCO was covered
with a screen to prevent heavy solids from plugging the intake hose, and the
strainer was inserted into the drain pipe so that the suction hose was con-
stantly flooded. The sampler was set to take individual samples every 15
min during production and cleanup. Methods (1) and (2) were used nearly
all the time during production. Method (3) was operable during cleanup.
Rosin Stripper Drain
The rosin stripper drain collects flow from the carcass sprays in the
rosin stripping area. Most of the rosin is stripped dry from the carcass.
The residual rosin is hardened by a cold water shower, loosened by beating the
carcass with rubber paddles ^ and rinsed off by cold water sprays. There is
no flow in this drain during cleanup. The effluent from this shower during
production goes into the plant greasewater drainage system.
Samples were obtained manually from the drain trap in the shower at various
times during production. Flow data from this drain was obtained by the lithium
dilution method.
-------
Rail Polisher Drain
The rail polisher drain collects only .water from the rail polisher and
empties into the plant greasewater drainage system. Characterization samples
were taken by placing the suction end of the I SCO Sampler in the drain trap
in the floor to take individual samples at one-half hour intervals during the
production shift.
Flow rates were obtained with a totalizing water meter on the water
supply by taking readings at the beginning and end of the production shift.
660 Grease Drain
This drain was sampled through a clean-out port in the drainpipe located
on the floor below. The drain collects wastewater from the final carcass
shower, lavatories, sprays, and floor drains in the immediate area. This drain
empties into the plant greasewater drainage system.
Samples were obtained through the clean-out port in the drainpipe auto-
matically with an ISCO Sampler. Samples were taken both during production and
cleanup.
Flow was obtained by the lithium dilution method. The ISCO Sampler was
used to collect the lithium samples from the drainpipe clean-out port at 15
min intervals.
Carcass Shower Drain
The carcass shower drain flowed into the 660 grease drain. This drain was
sampled separately, however, at the drain trap. There was no flow from this
source during cleanup. Samples were taken at the entry of the wastewater into
the floor drain at different intervals during production. Flow rates were
obtained by direct metering of the water supply to the shower. The water meter
was read before and after production to determine the flow rates for production
and cleanup.
Center Grease Drain
The total flow in this grease drain was from three floor drains. When the
330 kill line was not operating there was no flow in this drain during pro-
duction. When the 330 kill line was running, the total flow from the final
carcass shower went into this drain. Samples were obtained through a clean-
out port in the drainpipe on the floor below at various intervals during pro-
uction and cleanup. Flow rates for this drain were obtained by the lithium
dilution method.
330 Grease Drain
This drain received floor drainage from more than one-half of the kill floor
and includes floor drains and lavatories, as well as the head washer. This
drain flowed into the plant greasewater drainage system. Samples were obtained
-------
through a clean-out pipe on the floor below. Sampling was done both with the
ISCO Automatic Sampler and by manually taking grab samples at various times
during the production and cleanup shifts. Flow data were obtained by the lith-
ium dilution method.
Head Washer
The head-washing sprays remove blood and stomach ejecta from the head be-
fore it is removed from the carcass. The effluent from this washer flows into
the 330 grease drain. This drain was sampled as a part of the 330 grease
drain using an ISCO Sampler through a clean-out in the drainpipe. The flow
rate from the head washer was obtained by taking a timed sample of the spray
nozzles in the washer in a calibrated container.
Stomach Washer
All flow from the stomach slitter-dumper and tumble washer went into a
drain hub on the kill floor and from the hub into the manure wastewater system.
Samples were taken by using a dipper to reach down into the hub. This gave a
composite of flows from all parts of the stomach washer. Ten to twelve dips
were made from the hub to fill a sample container to insure that the sample
was representative of the flow.
Flow data was obtained by the lithium dilution method. Lithium stock
solution was dripped into the collecting funnel under the slitter-dumper and
the samples were taken in the drainage hub. Several dippers of the effluent
were composited to insure that the sample was representative. An off-shift
simulation was performed to determine which of the units contributed'the
majority of the wastewater.
Hasher-Washer Drain
This drain collected wastewater from the viscera pan washers, the evis-
cerating conveyor washers, the viscera work-up table, and the stick wound
washing. Water is used to sluice condemned viscera, large and small intestines,
the bung, and other inedible parts to the hasher-washer- At the hasher-washer
blades slash open the intestines and the transport water carries- the intes-
tinal contents, blood clots, and small pieces of fatty tissue through holes
in the dewatering drum into a shallow curbed tank. This effluent goes into
the plant greasewater drainage system. Solids retained in the perforated drum
go to inedible rendering.
Samples were taken by placing open containers under the dewatering drum
and allowing them to fill over a 2 to 3 min interval. Some samples were
also taken using a wide scoop shovel to pick up the effluent from the shallow
tank bottom. Several scoops were used to fill each sample container. Samples
were taken at various intervals during both production and cleanup shifts,
To determine flow on the production shift, special off-shift simulation
studies were made at night after the plant was completely shut down. Lithium
was injected into the sewer which collected the flow, and the flow was
-------
estimated by the lithium dilution method. It was possible also to identify
the volumes of hot and cold water used in this same way. The results are pre-
sented in detail in the characterization section.
Neck Washer
The neck washer drain collected flow from the machines which are used to
wash blood clots from the neck of the carcass. This flow went into the hasher-
washer drain and from there into the plant greasewater drainage system. Manual
grab samples were taken at the floor drain. Flows were estimated with the
bucket and stop watch method. The total flow in this drain was the combined
flow of two or three of these machines, depending on the kill rate.
Summary of Sampling Methods
Table 4 summarizes the flow measurement and sampling methods used at each
station during the production shift.
WASTEWATER CHARACTERIZATION
Production of pork was quite variable over the period of study. Therefore,
it was necessary to make the characterization on the basis of an average pro-
duction day. Production records have been summarized in Figure 23, which shows
the length of the operating day, and in Figure 24, which shows the distribution
of live hog weight killed per day. The two humps in the length of the produc-
tion day result from infrequent periods of extremely high production. The
normal work day was defined as the average value, that is 7.79 hr. During a
work day of this average duration, the hog production varied between 600 hogs
/hr and nearly 1000 hogs/hr. When the number of hogs processed reached about
700, the operation on the kill floor changed dramatically because a second kill
line was opened. The rated capacity of the two lines are 660 hogs/hr and 330
hogs/hr. The average production shift was defined on the basis of one line,
the larger of the two, being used with a kill of 1,438,135 Ib/day (652,340
kg/day).
This average shift was used to estimate total wastewater use and total
pollutant discharge on an average day as follows. An average flow rate for
the process or sampling station of interest was identified. The flow rate was
constant throughout the production period regardless of the number of hogs
processed with two exceptions; the hasher-washer drain and the neck washer.
The flow for the average production shift was calculated from the average flow
rate during the 7.79 hr/shift.
For example, the value for the bleed conveyor wash was calculated using
the average flow rate of 5.71 gal./min: 2668 gal./shift = (7.79 hr/shift)
x (60 min/hr) x (5.71 gal./min) = 10,100 I/shift.
The flow rate expressed as gal./lOOO Ibs live weight killed, shown as _
(LWK) is simply the flow for the average production shift divided by the weight
of hogs killed on an average production shift. For example, the value for the
43
-------
Table
FLOW MEASUREMENT AND WASTEWATER SAMPLING METHODS USED DURING THE PRODUCTION SHIFT
Sampling location
Sampling method
Flow measurement
Bleed floor drain
Bleed area floor drain
Bleed conveyor wash
Scald tank
Dehair floor drain
Railpolisher
Carcass shower
Hasher-washer drain
Stomach washer
Neck washer
Head washer
660 grease drain
Center grease drain
330 grease drain
No discharge
No discharge
Automated grab3
Manual short-term composite*3
Automated
Automated grab
Automated grab
Manual short-term composite
Manual short-term composite
Manual short-term composite
Manual short-term composite
Automated grab
Automated grab
Automated grab
No discharge
No discharge
Time known volume
No flowc
Totalizing flow meters in
water supply lines
Totalizing flow meter
Totalizing flow meter
Lithium dilution
Lithium dilution
Time known volume
Time known volume
Lithium dilution
Lithium dilution
Lithium dilution
aISCO automated sampler
^Five to six grabs composited over 5 to 10 minutes.
C0ne inch diameter rubber bladder valve with compressed air supply controlled by a solenoid.
^Samples were from the scald tank which is dumped during cleanup.
-------
AVERAGE = 7.79 HOUR OF KILL
III
II
1
1
II
III
1
II
II
II
II
III
II
III
w
m
m
w
i
w
m
w
w
m
w
Illl
m
m
m
HU
nu
m
m
m
m
m
tw
w
ii
m
m
m
m
m
m
HI
i
i
ii
ii
+HI
tfH
Illl
W
m
m
6.0 6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6 7.8 8.O 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6 9.8
TIME IN HOURS
1.0
Figure 23. Histogram showing length of production shift.
-------
AVERAGE = 1,438,135 POUNDS OF LIVE WEIGHT KILL PER DAY
II
700
tHi
1H4
lit
tHl
III
ItH
TtH
m
TOO.
I
III!
INI
Illl
MM
1H4.
TtH
tfU
tHt
tHi
tH4
1tH-
TH4-
TH4
II
m
HH
tw.
1*44.
TtH
ttu
II
tw-
W4-
tm
tm
t«i
Wi
HU
ttH
H44-
ThH
II
Wi
m
rt44
II
1 // II III
800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900"
THOUSAND POUNDS OF LIVE WEIGHT KILL PER DAY
Figure 24-. Histogram of pounds of live weight hogs killed per production shift.
-------
bleed conveyor wash was calculated as:
2668 gal/shift
lb LWK
1438.135 1000 lb LWK/shift
See Table 6. In Standard International units this is 15.9 1/1000 kg LWK.
The pollutant loads are calculated in similar fashion. In most cases there
is no clear relationship of concentration with the number of hogs being pro-
cessed. This point will be discussed more carefully in connection with specific
processes later. The data at each sampling location was analyzed to identify
either the average concentration during the day or the actual kilograms of
pollutant discharged during the day. These numbers are consistent with the flow
per production shift used, that is, the average flow multiplied by the average
concentration gives the mass discharged during an average production shift.
For example, the bleed conveyor wash BOD load is: 20.5 lb BOD/shift =
(920 mg BOD/1) x (2668 gal./shift) x(3,78 1/gal.) x (2.2 lb/ kg) xdo'6 kg/mg).
Also 20.5 lb BOD/shift * 2.2 lb /kg = 9.3 kg BOD/shift.
The ratio of BOD to live weight of hogs killed is calculated using the average
weight of hogs killed on an average production shift. For the blood conveyor
wash the calculation was 20.5 lb BOD/1438.135 1000 lb LWK = 0.014 lb BOD/1000
lb LWK. This is a mass per mass ratio and the numerical value is the same for
pounds or kilograms, i.e., 0.014 lb BOD/1000 lb LWK = 0.014 kg BOD/1000 kg LWK.
This value is shown in Table 6.
DISCUSSION
The production shift discharge is 350,700 gal. of wastewater (1,327,540 1)
which is 244 gal./lOOO lb of LWK (2032 1/1000 kg LWK). To be consistant with
industry tradition, to simplify the data presentation, and to focus on the
major pollution areas, the flows and loads from the various sample points are
presented as a percentage of the totals in Table 5. Table 6 summarizes the
results as mass/1000 mass units LWK. Table 6 is a summary of the detailed
data tables presented in Appendix A.
The objective of the characterization study was to pinpoint processes and
drainage points that were the main contributors to the pollution problems.
Table 5 will be discussed point-by-point to explain the relative role of the
various sample points in the overall pollution problem on the production shift.
Bleed Area
There was insignificant discharge from the bleed area floor drain during
the production shift. This location will receive greater attention^in Chapter
VI in the cleanup discussion. Bleed conveyor blood drain sample point had no
discharge during the production shift. It also will be discussed in the cleanup
chapter. The flow from the bleed conveyor wash drain is constant during the
47
-------
Table 5. INITIAL CHAKOERIZKnCN OF THE HOG SLAUGHTERING FTJOOR FOR THE MRDISON PUNT PHCXWCTICM SHUT
(percent)
4="
CO
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer drain
Hasher washer drain
Neck washer
Total %
Gal/shift
Liters/shift
Gal/1000 Ib LWK
Liters/1000 kg LWK
Lbs/shift
Kg/shift
Lbs/1000 Ib LWK
Kg/1000 kg LWK
Flow
Total
solids
Total Volatile
volatile Suspended suspended
solids solids solids
Total
Kjeldahl
Grease nitrogen
BOD
COD
No flow
No flow
0
28
3
3
9
(8
5
6
(1
19
21
(3
100
350700
1327400
244
2035
.8
.8
.6
.6
.0
.2)
.9
.7
.8)
.9
.8
.5)
0.5
16.6
0.7
0.9
1.9
(1.3)
1.2
5.8
-
13.3
59.0
(13.9)
100
10600
4800
7.4
7.4
0.
15.
0.
0.
1.
(0.
1.
3.
-
14.
63.
(16.
100
-
-
-
8400
3800
5.
5.
5
0
5
7
2
7)
3
0
0
9
9)
-
-
-
8
8
0.1
17.0
0.1
0.2
0.6
(0.1)
0.9
2.2
-
17.5
61.4
(12.0)
100
5500
2500
3.8
3.8
0.1
18.1
0.1
0.3
0.6
(0.1)
0.9
2.5
-
18.9
58.5
(13.8)
100
4600
2100
3.2
3.2
0.1
3.4
-
0.1
0.2
-
0.1
1.4
-
27.3
67.4
(28.5)
100
7656
3472
5.32
5.32
0.8
24.4
0.4
0.8
3.5
(1.5)
8.4
10.4
-
7.6
43.5
(4.6)
100
-
770
350
0.5
0.5
0.4
13.2
0.2
0.5
1.0
(0.2)
0.6
4.2
-
13.3
66.8
(8.9)
100
'~~
5800
2640
4.0
4.0
0.4
12.8
0.2
0.4
0.8
(0.3)
3.3
3.0
-
12.7
66.4
(9.5)
100
~"
14700
6700
10.2
10.2
Values in parentheses are a subset of the proceeding values and are not included in the total.
-------
Table 6. INITIAL WRSTEWRTER MO POLLUTION LOAD CHARACTERIZATION OF THE PRCDUCTION SHUT
(gal./lOOO Ib LNK and lb/1000 Ib UK)
F
tO
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower3
Center grease drain
"330" grease drain
Head washer*3
Stomach washer drain
Hasher washer drain
Neck washer °
Total gallons/1000 Ibs LWK
Total pounds/1000 Ibs LWK
Flow
-
1.9
70.3
8.6
8.9
21.9
(20.1)
14.3
16.4
(4.5)
48.5
53.2
(8.6)
244.0
Total
solids
-
0.036
1.225
0.054
0.069
0.136
(0.092)
0.088
0.430
0.981
4.340
(1.020)
7.36
Total
volatile
Solids
-
0.030
0.875
0.028
0.040
0.070
(0.039)
0.077
0.175
0.817
3.730
(0.980)
5.84
Suspended
solids
-
0.004
0.649
0.005
0.009
0.021
(0.004)
0.033
0.086
0.6.71
2.346
(0.472)
3.828
Total
suspended
solids
0
0
0
0
0
(0
0
0
0
1
(0
3
-
.003
.580
.004
.008
.018
.004)
.029
.080
.606
.880
.440)
.208
Grease
-
0.002
0.180
0
0.005
0.012
-
0.008
0.074
1.454
3.590
(1.580)
5.325
Total
Kjeldahl
nitrogen
-
0.004
0.131
0.002
0.005
0.019
(0.008)
0.045
0.056
0.041
0.230
(0.020)
0.533
0
0
0
0
(0
0
0
0
2
(0
4
BOD
-
.014
.536
.009
.020
.037
.010)
.025
.169
.537
.700
.360)
.047
COD
-
0.036
1.308
0.023
0.045
0.080
(0.030)
0.337
0.308
1.300
6.800
(0.900)
10.237
aCarcass shower is included in 660 grease drain totals.
bHead washer is included in 330 grease drain totals.
°Neck washer is included in hasher-washer drain totals.
-------
production shift and is only 0.8%. This indicated that extensive efforts
to reduce or eliminate this flovr could prove uneconomical.
Dehair and Scald Tank
During the production shift there is no discharge from the scald tank;
discharge during cleanup is considered in the next chapter. The dehair floor
drain is the largest single flow contributor during the production shift.
This drain constitutes 28.8% of the total production flow. This discharge
point obviously should receive a great deal of attention in the reduction and
change portion of the study. The pollution loadings are also a major percentage
of the total load from the production shift. The drain contributes 16.6% of
the total solids during the production shift, and 24,4% of the total Kjeldahl
nitrogen. The BOD and COD contributions from the drain are also a significant
percentage of the total. Chapter VIII discusses the types of changes that can
be made to the dehairing machine operation to reduce the high flow and pollution
contributions.
Although the rosin stripper is responsible for 3.6% of the production flow,
it produces only 0.7% of the total solids of the production shift. This piece
of equipment uses 8.6 gal./lOOO Ib LWK, but this water is used mainly for lubri-
cation and hardening in the rosin stripper and does not receive large concen-
trations of solids or BOD before it enters the drain.
The railpolisher is responsible for 3.6% of the flow, 0.9% of the total
solids, and 0.5% of the BOD during the production shift. The water is mainly
used for lubricating the hogs and does not receive high concentrations of solids
and BOD before entering the drainage system.
Grease Drains and Carcass Shower
The 660 grease drain, which includes the carcass shower, contributes 9% of
the flow, but only 1% of the BOD from the production shift. The majority of
the flow comes from the carcass shower.
*cC
Efforts should be directed toward volume reduction with attention being
given to carcass cleaning. The center grease drain has flow only when both
slaughter lines are running and the main contribution is a second carcass shower.
This drain produces 5.9% of the production flow, but only 0.6% of the production
BOD. This drain is similar to the 660 grease drain and offers the same poten-
tial for reduction.
The 330 grease drain and head washer contributed 6.7% of the flow on the
production shift. This is 16.4 gal./lOOO Ib LWK, of which 4.5 gal./lOOO Ib
LWK are from the head washer. This drain differs from the 660 grease drain and
the center grease drain in that it also has significant concentrations of solids,
nitrogen, and BOD. This grease drain covers almost two-thirds of the kill floor
and during production, receives organic solids from the carcass splitting area and
the evisceration treadmill area. This drain is responsible for 10.4% of the total
Kjeldahl nitrogen and, thus, any attempts to reduce nitrogen--should include
attention to this drain.
50
-------
Stomach Washer
The stomach washer drain contributed 19,9% of the flow, 13.3% of the total
solids, 13.3% of the BOD, but only 7.6% of the total Kjeldahl nitrogen of the
production shift. This indicated that the large volumes of water are coming in
direct contact with organic solids. These organic solids are undigested food
that contain a low nitrogen content. A large percentage of the total solids
are suspended solids and almost all of the suspended solids were volatile.
This suggested changes that could prove valuable for this particular piece
of equipment.
Hasher-Washer Drain
Although the hasher-washer drain contributed 21.8% of the flow of the
production shift, it contributed 59% of the total solids and 66.8% of the BOD.
This drain was by far the largest contributor to the pollution load of the
production shift; it contributed more pounds of BOD per production shift than
all of the others combined. Therefore, any successful reduction of the pol-
lution load from this drain will be a significant reduction in total load
from the production shift.
CONCLUSION
This wastewater characterization of the production shift has identified
those areas and proc'esses that are the largest contributors to the flow and
pollution load. The hasher-washer is the main polluter, followed by the de-
hairing machine.
51
-------
SECTION VI
CHARACTERIZATION OF THE CLEANUP SHIFT
INTRODUCTION
General Cleanup Procedures
The main cleanup shift begins immediately after the production shift, and
lasts approximately 6 hr- There are two mid-shift cleanups and a more complete
cleanup during the lunch break. These partial cleanups were characterized as
part of the pollution load from the production shift. The majority of the
pollution load from the cleanup shift is discharged within the first hour.
The most important production related influence would be the operation of two
kill lines, thus requiring two sets of evisceration equipment to be cleaned
and adding the general floor area around the second kill line to the normal
load.
Cleanup Equipment and Timing
The basic tool used for cleanup was the high pressure hose (60 - 80 psi).
Hosing is preceded by a broom and shovel dry cleanup. The major accumulation
of solids should be shoveled into containers for inedible processing rather
than being pushed and washed down the sewer drains. It was often difficult
to enforce good drycleaning procedures, but they are an essential part of
any well-organized pollution reduction program. A vacuum technique was
implemented on this project to increase the amount of dry cleaning on the mid-
shift and final cleanups. This idea will be discussed with Bother changes in
Section VIII.
Several pieces of equipment are cleaned by turning on internal water sprays
to full capacity while personnel are performing other cleanup procedures. In
particular, the viscera pans, treadmill, and stomach washer were cleaned with
this technique. The first 30 min of rinsing washed the majority of the con-
taminates off the equipment, but the water was often left running at full
capacity for 3 to 4 hr. This waste of potable water accomplished little
additional cleaning, and was quantified in this study.
During the cleanup shift the blood recovery drains are plugged and all
wastes enter the greasewater drains. The stick-and-bleed area was the largest
contributor of blood pollution on the cleanup shift. Dry cleaning of this area
has been suggested-, but it has not been carried out consistently. Dry clean-
ing with high pressure air was studied at the Beardstown Plant in an attempt
to increase the amqmnt of blood recovered and to minimize the addition of the
pollution load. However, OSHA regulations prohibit using the high pressures
(above 30 psi) required to be effective.
52
-------
WASTEWATER FLOW MEASUREMENTS
Quantification of the flows on the cleanup shift and establishment of cor-
relations between flows and concentrations of pollutants were difficult. The
flow measurement techniques used were meters, bucket-and-stopwatch, and lithium
chloride dilution techniques. Meters were used whenever possible and readings
were taken before and after the cleanup shift. As in the production shift many
areas were not suitable for metering due to plumbing complexities and cost and
time constraints. Flow measurement in the grease drains was difficult due to
high flow variability (at times the flow approached zero). This made it dif-
ficult to use the lithium chloride technique which depends on sufficient
quantities of water to insure adequate mixing and dilution.
WASTEWATER SAMPLING METHODS
The cleanup shift offered sampling problems similar to those of the pro-
duction shift. The low flow problem was partially solved by having an ISCO
sampler pump continuously collect a volume of water over a 15 min period in
a single large container. This container was mixed and a 500 ml sample was
taken.
Sampling the cleanup period was also complicated by the large flush that
occurs during the first 30 to 60 min. Adequate sampling during this initial
period is critical for correct estimation of the pollution load. The heavy
load carried by this first flush can clog the automatic sampler. In many
cases only grab sampling was used. Often manual sampling was used to comp-
liment the automatic sampler during the first flush. During the first flush,
the sampling frequency was usually 6 to 12 samples/hr. Sampling problems
encountered at particular stations will be discussed in detail in the waste-
water sampling station section.
WASTEWATER SAMPLING STATIONS
Sampling points in the production section are shown on the kill floor plan
(Figure 22 in Section V). The nature of the cleanup operation tended to elimi-
nate a process-by-process breakdown of the pollution load. The discharges from
the various pieces of equipment during cleanup were difficult to trace, but pro-
cesses were isolated for characterization on the cleanup shift whenever
possible.
Bleed Area Floor Drain
During cleanup the bleed area floor drain collects waste from the stick-
and-bleed conveyor area and discharges into the plant grease drain system.
The first flush was very high in BOD and TKN due to blood spills from the pro-
duction shift. Manual sampling of this drain was required. Sample frequency
was increased during the first hour to insure accurate representation of the
first flush which is approximately 80% of the total pollution load from the
cleanup shift.
53
-------
Flow into this drain during cleanup was from cleanup hoses used on the
bleed conveyor and the general stick-and-bleed area. The total flow was esti-
mated by timing the use of each hose and multiplying by the flow rate of the
hose. The flow rate of the hose was determined by the bucket-and-stop-watch
technique. The total hose flow was split between this drain and the bleed
conveyor blood drain.
Bleed Conveyor Blood Drain
During the cleanup shift the bleed conveyor blood drain collected water
used to clean the bleed trough and discharges into the plant grease drain system.
Dry cleaning of the blood trough before hosing can increase the amount of blood
recovered and reduce the pollution load. When blood recovery was ended this
drain was switched from the blood recovery system to the grease drainage system,
The first flush was still very high in blood and solids. Flow was estimated
based on the cleanup hose flow in the bleed area that entered the blood drain.
Frequent grab samples were collected as the waste bypassed the blood recovery
pump and entered the grease drainage system.
Bleed Conveyor Wash Drain
During the cleanup shift the bleed-conveyor-wash drain collected water
from the rinse nozzle on the bleed conveyor and discharged into the plant
grease water drainage system. The drain was sampled just below the conveyor
with the ISCO automatic sampler. The .flow rate was constant from the spray
nozzles during cleanup and was measured with the bucket-and-stopwatch technique.
Dehair Floor Drain and Scald Tank
During the cleanup shift the dehair floor drain collected wastewater from
the dehairing machine and the scald tank and discharged this waste into the
manure wastewater system. This drain was sampled as described in the pro-
duction section. Due to the hair clogging problem, manual sampling was
necessary. The flow meters on the dehairing machine were read before and
after cleanup. To this was added the volume of the scald tank water (8*000
gallons) which entered the dehair drain.
Rosin Stripper Shower
During cleanup the rosin stripper spray was shut off. A negligible amount
of water was used to clean the rosin stripper.
Railpolisher Drain
The railpolisher spray should not be on during cleanup. Nevertheless, some
cleanup personnel did turn on the railpolisher sprays during cleanup. This
wasted thousands of gallons of water and did not improve the quality of the
cleanup. Proper cleanup, using only a hose, should result in a negligible
total flow from this drain during cleanup.
-------
The 660 Grease Drain
During the cleanup shift the 660 grease drain collected wastewater from
the south end of the kill floor and from the 660 line carcass shower. Several
lavatories, sprays, and floor drains on the south end of the kill floor dis-
charge into the 660 grease drain system. This drain was sampled with the
automatic sampler through a clean-out port one floor below the kill floor,
The flow was measured using the lithium chloride technique,
Carcass Shower Drain
During the cleanup shift the carcass shower drain collected water used to
clean several areas and discharges the water into the 660 grease drain. Since
the carcass shower itself was not on during cleanup the only flow is from clean-
up hoses.
Center Grease Drain
During the cleanup shift the center grease drain collected water used to
clean the 330 carcass shower and surrounding area. This drain was sampled by
pumping continuously with an automatic sampler to make up 15 min composite
samples. The lithium chloride technique was used to measure flow. The flow
and load samples were collected through a clean-out port on the floor below.
The flow in this' drain for the cleanup shift was negligible during the samp-
ling program.
330 Grease Drain
Normally production used only the 660 hog/hr line. During the cleanup
shift the 330 grease drain collected water from the north half of the kill
floor and discharged this flow into the plant greasewater system. These
flows are a total of the hose discharges used to clean the equipment on this
end of the kill floor. When the 330 hog/hr kill line has been used, more
flow is measured due to the cleaning of the additional pieces of equipment.
This drain was sampled both automatically and manually through a clean-out
port from the floor below. The flow was measured with the lithium chloride
technique. There were periods of no flow to this drain.
Head Washer
The head washer did not operate during cleanup. Any wastewater from cleaning
the equipment is included in the 330 grease drain.
Stomach Washer Drain
During the cleanup shift the stomach washer drain collected water used to
clean the stomach washer and slitter-dumper. This discharges into the manure
wastewater system. Some of the water used to clean the tumble washer spills
onto the floor and enters the 660 grease drain. This drain was sampled by the
same manual dip technique described for the production shift. Flow measurement
was by the lithium chloride technique as described for the production shift.
55
-------
Hasher-Washer Drain
During the cleanup shift, the hasher-washer drain collected water used to
clean the viscera pans, the evisceration treadmill, and the neck washing area.
The first flush from this cleanup operation was very high in blood and fatty
solids. Dry cleaning must precede hosing to reduce blood and solids entering
this drain. This drain was sampled from one floor below at the hasher-washer.
Samples were collected as described in the production section, and the flow
was measured using the lithium chloride technique.
Neck Washer Drain
During cleanup, the neck washer drain collected water used to clean the neck
washing area and discharged into the hasher-washer drain. This wastewater was
included in the hasher-washer drain cleanup total.
WASTEWATER CHARACTERIZATION
Characterization of the cleanup shift was complicated by the variability
of discharges, both flow and concentration. The first flush at each sampling
point represented the majority of waste for the entire cleanup shift. After
the first high concentration flush, the cleanup waters generally had very low
concentrations with varying flows.
The total load of pollutants for the cleanup shift was not dependent on
the production rate except when the second kill line was used. Approximately
the same volumes of water are used to clean the equipment independent of the
duration of production or the rate of production. The flow and concentration
values were based on the flow measurement and sampling techniques described in
the previous chapters. Due to the high variability, the total cleanup shift
flow for a particular sample point was found by summing the discharges over
several short-time periods (AT). The total flow is:
= (AT, min) * (Avg floWj gpm)
This value was then converted to gal./lOOO Ib LWK by dividing by the pounds of
hogs killed on the average day:
gal. _ _ gal . /shift _
1000 Ib LWK ~ 1138.135 (1000 Ib LWK/shift)
For example, the 330 grease drain has the cleanup shift, flow profile shown
graphically in Figure 25 and tabulated in Table 7. Summing the incremental
flow valves gives the 330 grease drain discharge of 16,405 gallons of waste-
water per cleanup shift. This was converted to gal./lOOO Ib LWK as follows:
»*
56
Shift)
-------
_L
CLEAN-UP SHIFT
FLOW PROFILE
SAMPLE POINT! 330 GREASE DRAIN
J.
J_
60 120 180 240 300
TIME OF CLEAN-UP SHIFTS, minutes
360
Figure 25. Cleanup shift flow profile (330 hog/hr grease drain)
57
-------
TABLE 7.
TYPICAL CLEAN-UP SHIFT FLOW PROFILE AND SAMPLE
TOTAL FLOW CALCULATION
Sample Point: 330 Grease 'Drain
Min.
start
0
10
30
50
60
105
120
170
190
200
215
230
245
275
290
320
335
350
365
380
, from
of cleanup Time
- 10
- 30
- 50
- 60
- 105
- 120
- 170
- 190
- 200
- 215
- 230
- 245
- 275
- 290
- 320
- 335
- 350
- 365
- 380
- 410
2:40 -
2:50 -
3:10 -
3:30 -
3:40 -
4:25 -
4:40 -
5:30 -
5:50 -
6:00 -
6:15 -
6:30 -
6:45 -
7:15 -
7:30 -
8:00 -
8:15 -
8:30 -
8:45 -
9:00 -
2:50 PM
3:10
3:30
3:40
4:25
4:40
5:30
5:50
6:00
6:15
6:30 .
6:45
7:15
7:30
8:00
8:15
8:30
8:45
9:00
9;:.30
AT
(Min.)
10
20
20
10
45
15
50
20
10
15
15
15
30
15
30
15
15
15
15
30
GPM
25
59
31
24
67
63
63
43
55
20
20
15
52
19
27
57
29
23
12
10
Sum of
total
gallons
250
1180
620
240
3015
945
3150
860
550
300
300
225
1560
285
810
855
435
345
180
300
16,405
58
-------
This value is shown in Table 10. In Appendix B, the complete cleanup shift
data tables are shown also in SI units;
16,405 gal. /shift x 3.78 1/gal. = 62,000 I/shift and
_ 62,000 I/shift nc n
652.340
-------
TABLE 8
EXAMPLE OF POLLUTANT LOAD CALCULATION FOR
THE CLEAN-UP SHIFT
Sample Point: 330 Grease Drain
AT
(Min.)
10
20
20
10
45
15
50
20
10
15
15
15
30
15
30
15
15
15
15
30
BOD
mg/1
1112
2318
960
392
399
102
331
968
857
66
132
275
178
3
3
29
61
125
83
58
GPM
flow
25
59
31
24
67
63
63
43
55
20
20
15
52
19
27
57
29
23
12
10
Constant
8 . 34/106
8. 34/10
8.34/10
8.34/10
8 . 34/10
8.34/10
8.34/10
8 . 34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
8.34/10
_
=
s
a
=
s
=
s
-
s
=
=
=
=
=
=
=
s
s
s
Total
pounds
or BOD
2.318
22.81
4.96
.78
10.03
.80
8.96
6.94
3.93
.16
.33
.51
2.360
.001
.02
.206
.206
.35
.12
.145
67.7
60
-------
2000
1000-
500
SAMPLE POINT : 330 GREASE DRAIN
100
v 50
o»
E
Q
O
ffi
60 120 180 240 300 360
TIME OF CLEAN-UP SHIFT, minutes
Figure 26. Cleanup shift BOD,, concentration profile.
61
-------
DATA SUMMARY
The variability of the samples collected on the cleanup shift was due to
the unpredictable nature of the first flush and the difficulty in analyzing
samples with very high solids and BOD values. Large numbers of samples were
taken, when possible, to increase the statistic validity of the data. Data
was collected on many different days with various cleanup crews to obtain
some idea of the inherent variability of the cleanup shift. If data was col-
lected on several days, an average of the days flow and pollutant loads was
used to produce the value, in Table 10.
As previously mentioned, to be consistant with industry notation, to
simplify the data presentation, and to focus on the major pollution areas,
the cleanup flow and pollutant loads from the various sample points are pre-
sented as a percentage of the cleanup total in Table 9, and per 1000 Ib LWK
in Table 10. Since the objective of the characterization study was to pin-
point processes and drainage points that were the main contributors to the
pollution problem, Table 9 will be discussed point-by-point to explain the
selective role of the various sample points in the overall pollution problems
on the cleanup shift.
Bleed Area Floor Drain
The bleed area floor drain contributes 1.6% of the flow, 0.9% of the total
solids, 7.5% of the BOD and 16.0% of the total Kjeldahl nitrogen of the cleanup
shift. This indicates a higher than average concentration of Kjeldahl nitrogen.
This is due to raw blood being washed down this drain during the cleanup shift.
Cleanup personnel used large volumes of water to move the blood to the floor
drain. This was necessary because the drain was confined so the cleanup man
had no access to dry clean the surrounding floor. Improvements are needed.
Bleed Conveyor Blood Drain
The bleed conveyor blood drain contributed only 0.7% of the flow, 0.4% of
the total solids, 2.1% of the BOD, and 3.6% of the total Kjeldahl nitrogen of
the cleanup shift. This was a small volume of water with a high level of nitro-
gen. The blood that did not go to the recycle system ends up in the blood
drain. Due to the construction, clots of blood built up on the trough, and hand
cleaning was necessary. The levels of nitrogen can be reduced by manual
cleaning techniques.
Bleed Conveyor Wash Drain
The bleed conveyor wash drain was constantly flowing during the cleanup
shift. The 5.71 gpm (mean value) of flow rinses the bleed chain and produces
a high concentration of nitrogen due to the blood. The total flow from this
drain was only 1.3% of the total cleanup flow and received minor attention
during the cleanup modification stage.
Dehair Floor Drain and Scald Tank
The scald tank is drained into the dehair floor drain for the first hour
62
-------
Table 9. VftSTEWKTER FLOW AND PCLLOTAWT LOAD CHRRftCTERIZATICN OF THE MADISON CLEMWP SHUT
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper shower
Rail polisher drain
"660" grease drain
Carcass shower
Central grease drain
"330* grease drain
+ head washer
Stomach washer drain
Hasher washer drain
Total %
Gallons/shift
Liters/shift
Gallons/1000 Ibs LWK
Liters/1000 kg LWK
Pounds/shift
Kilograms/shift
Pounds/1000 Ibs LWK
Kilograms/1000 kg LWK
Flow
1.6
0.7
1.3
55.6
(4.2)d
_a
_b
7.3
_a
_c
9.6
3.0
20.9
100%
170760
646370
118.7
990.6
""
Total
solids
0.9
0.4
0.6
15.2
(6.5,
-
3.7
-
75.4
0.6
3.2
100%
4765
2161
3.31
3.31
Total
volatile
solids
4.8
2.4
1.6
55.2
(22.5)
_
6.9
-
18.9
2.3
8.0
100%
677.8
307.8
0.472
0.472
Suspended
solids
2.0
0.9
0.6
56.7
(24.4)
-
4.4
-
26.4
1.5
7.5
100%
626.5
284.2
0.435
0.435
Volatile
suspended
solids
3.2
1.3
0.5
60.9
(21.4)
-
4.4
-
21.6
2.4
5.9
100%
__
349.4
158.5
0.243
0.243
Grease
9.4
1.2
0.3
21.4
(9.2)
10.0
-
45.2
6.8
5.7
100%
__
146.3
66.3
0.102
0.102
Total
Kjeldahl
nitrogen
16.0
3.6
1.9
62.4
(58.6)
_
8.2
-
3.0
0.5
4.4
100%
__
36.4
16.5
0.026
0.026
BOD- 5
7.5
2.1
0.4
57.2
(26.9)
6.5
-
20.9
2.3
3.1
100%
__
_ _
314.4
142.7
0.219
0.219
COD
4.9
2.2
i.o
66.2
(27.7)
-
7.9
-
12.1
2.0
3.8
100%
__
_
3
820.6
371.6
0.569
0.569
Included in "660" grease drain total.
"Should have negligible flow during cleanup shift.
CNO flow unless 330 kill live is cleaned.
e>Live weight kill.
-------
Table 10. INITIAL WASTEWATER FLOW AND POLLUTION LOAD CHARACTERIZATION OF THE CLEANUP SHIFT
(gal./lOOO Ib LWK and lb/1000 Ib LWK)
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald Tank
Rosin stripper shower
Rail polisher drain
"660" grease drain
Carcass shower a
Center grease drain
"330" grease drain
Head washer
Stomach washer drain
Hasher washer drain
Neck washer c
Total flow gallons/1000 Ib LWK
Total Ib of pollutant/1000 Ib LWK
Flow
1.9
0.8
1.5
66.0
(5.6)
-
-
8.7
-
-
11.4
-
3.6
24.8
_
118.7
Total
solids
0.
0.
0.
0.
(0.
-
-
0.
-
-
2.
-
0.
0.
_
3.
031
015
019
504
216)
124
498
019
105
315
Total
volatile
solids
0.023
0.011
0.008
0.260
(0.106)
-
-
0.032
-
-
0.089
-
0.011
0.038
-
0.472
Suspended
solids
0.
0.
0.
0.
(0.
-
-
0.
-
-
0.
-
0.
0.
-
0-
009
004
002
242
106
019
115
006
033
435
Total
suspended
solids
0.008
0.003
0.001
0.148
(0.052)
-
-
0.011
-
-
0.052
-
0.006
0,14
-
0.243
Grease
0.009
0.001
0.001
0.022
(0.009)
-
-
0.010
-
-
0.046
-
0.007
0.006
-
0.102
Total
Kjeldahl
nitrogen BOD-5
0.004
0.001
0.0005
0.016
(0.015)
-
-
0.002
-
-
0.001
-
0.0001
0.001
-
0.256
0.016
0.005
0.001
0.125
(0.059)
-
-
0.014
-
-
0.046
-
0.005
0.007
-
0.219
COD
0.028
0.013
0.005
0.377
(0.158)
-
-
0.045
-
-
0.069
-
0.011
0.021
_
0.569
^Carcass shower is included in 660 grease drain totals.
bHead washer is included in 330 grease drain totals.
cNeck washer is included in hasher-washer drain totals.
-------
of the cleanup shift. The scald tank alone constitutes 4.2% of the flow, 58.6%
of the total Kjeldahl nitrogen, and 26.9% of the BOD of the cleanup shift.
This indicates that the 8,000 gal. (30,280 1) of wastewater in the scald tank
had an unusually high concentration of total Kjeldahl nitrogen and should
receive attention for potential modification since nitrogen has become a press-
ing pollution problem.
The combined dehair floor drain and scald tank discharges accounted for
55.6% of the flow and 57.2% of the BOD of the cleanup shift. This drain de-
mands immediate attention to reduce both the total flow and the concentrations
of pollutants that enter this drain during the cleanup shift.
660 Grease Drain and Carcass Shower
The 660 grease drain located on the south end of the kill floor received
flow from the cleanup of the carcass shower area, the railpolisher area, and
the gambreling area. The area is splashed with blood and small solids.
Large volumes of water are used to clean this area because dry cleanup is dif-
ficult and time consuming. This drain is responsible for 7.3% of the total
flow on the cleanup shift. This flow was not highly concentrated with pollutants,
but it did contribute 6.5% of the BOD, 3.7% of the total solids, and 8.2% of
the nitrogen of the cleanup shift.
330 Grease Drain
The 330 grease drain receives flow from two-thirds of the north end of the
kill floor. Solids loads are high during the cleanup shift. Cleanup waters
from the carcass splitting and treadmill areas enter the 330 grease drain.
This drain accounted for 75.4% of cleanup total solids and low nitrogen content,
but only contributed 20.9% of the BOD of the cleanup shift. The extremely high
total solids load should be reduced. Several cleanup men work in this area and
it is hard to identify the sources of all the water that are contributing
to the pollution load.
Stomach Washer Drain
The tumble washer was cleaned by running circulating water through it.
After the initial flush the concentration of pollutants was low. The inter-
nal water jets run for 0.5 to 3 hr. Cleanup of this equipment used only 3.0%
of the water on the cleanup shift and 2.3% of the BOD.
Hasher Washer Drains and Neck Washer
The hasher washer drain contributed 20.9% of the flow, but only 3.1% of
the BOD of the cleanup shift. This was due to the cleanup technique presently
used which allowed all of the treadmill and viscera-pan sprays to run during
the cleanup shift. This drain was the single largest contributor during^the
production shift and is a major contributor on the cleanup shift. Modifica-
tion must be made in this area.
65
-------
CONCLUSIONS
Predicting the total load from the kill floor cleanup for an average day
requires a careful examination of the inherent variability due to the processes
and personnel. The amount and quality of dry cleaning performed prior to hosing
greatly affects the total quantity of pollution anticipated. A thorough dry
cleaning program is very expensive due to high labor cost. Foremen insist
that workers do not push the solids and blood down the drain, but this is hard
to enforce.
This chapter has identified the dehair floor drain and the 330 grease drain
as the high polluting areas on the cleanup shift. The previous chapter also
identified these areas as high polluting areas on the production shift.
66
-------
SECTION VII
.CHARACTERIZATION OF THE TOTAL HOG-KILL
FLOOR EFFLUENT
INTRODUCTION
This chapter presents the characterization of the combined hog-kill floor
effluent from the production shift and the cleanup shift. This characteriza-
tion consists of a summary of the data presented in Chapters V and VI. Certain
sampling points such as the bleed area floor drain have no discharge during
the production shift and therefore the total waste load from that sample point
will be the same as the cleanup waste load. Each sample point's contribution
is given in Table 11 as a percent of the total for each parameter measured.
This is meant to pinpoint on a relative basis the major polluting areas of the
kill floor and to minimize confusion with regard to units. A second table,
Table 12, gives gal./lOOO Ib LWK and Ibs of pollutant/1000 Ib LWK. The com-
plete data set is included in Appendix C.
WASTE WATER CHARACTERIZATION
The total flow and waste load summary will be discussed by sample point.
Bleed Area Floor Drain
The bleed area floor drain was not a major pollution contributor. This
drain produced less than 0.7% of any pollutant observed. However, the poten-
tial by-product value of the blood which enters this drain is high and it should
be kept out of this drain and put into the recovery system.
Bleed Conveyor Blood Drain
The bleed conveyor blood drain also was not a major pollutant contributor,
producing only 0.2% of the total flow and less than 0.2% of any of the pollu-
tants studied. As with the bleed area floor drain the value of^the blood as
a by-product makes imporoved recovery worthy of attention at this sample point.
Bleed Conveyor Wash Drain
This drain produced 0.9% of the total flow and 0.9% of the total Kjel-
dahl nitrogen, but less than 0.6% of any of the other pollutants. Efforts
should be made to reduce the amount of water used for cleaning. At Davenport
they have stopped washing the conveyor.
67
-------
Table 11. INITIAL WASTEWATER FLOW AND POLLUTION LOAD CHARACTERIZATION OF THE COMBINED CLEANUP AND PRODUCTION SHIFTS
(percent)
Sample point
Bleed area floor
drain
Bleed conveyor
blood drain
Bleed conveyor
wash drain
Dehair floor drain
Scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower3
Center grease drain
: "330" grease drain
oo Head washer^
Stomach washer drain
Hasher washer drain
Neck washer0
Total %
Gal/shift
Liters/shift
Gal/1000 Ib LWK
Liters/1000 kg LWK
Lb/shift
Kg/shift
Lb/1000 Ib LWK
Kg/1000 kg LWK
Flow
Or
.5
0.2
0.9
37.6
(1.5)
2.4
2.5
8.4
-
3.9
7.7
14.4
21.4
-
100
521480
1973318
362.7
3025.7
Total
solids
0.3
0.1
0.5
16.2
-
0.5
0.7
2.4
-
0.8
27.4
9.4
41.7
-
100
15345
6962.3
10.674
10.674
Total
volatile
solids
0.4
0.2
0.6
18.0
-
0.4
0.6
1.6
-
1.2
4.2
13.1
59.7
-
100
9084
4117.9
6.314
6.314
Suspended
solids
0.2
0.1
0.1
21.0
_
0.1
0.2
1.0
(0.1)
0.8
4.7
15.9
55.9
(0.1)
100
6125.7
2778.3
4.259
4.259
Volatile
suspended
solids
0
0
0
21
0
0
0
0
3
17
54
100
4956
.2
.1
.1
.1
_
.1
.2
.8
_
.9
.8
.7
.8
-
2247.9
3.451
3.451
Grease
0.2
0.02
0.03
3.7
(0.17)
0.1
0.4
_
0.1
2.2
27.0
66.3
-
100
7802
3537.8
5.427
5.427
Total
Kjeldahl
nitrogen
0
0
0
26
0
0
3
8
10
7
41
100
808
366,
0,
.7
.2
.9
.1
.4
.8
.7
_
.0
.1
.3
.8
BOD
0.4
0.1
0.4
15.5
0.2
0.5
1.2
0.6
5.0
12.7
63.4
100
COD
0.3
0.1
0.4
15.6
0.2
0.4
1.2
3.1
3.5
12.1
63.1.
100
6133.6 15548.7
.7
.559
0.559
2782.5
4.266.
4.266
7052.3
10.833
10.833
aCarcass shower is included in 660 grease drain totals.
bHead washer is included in 330 grease drain totals.
°Neck washer is included in hasher-washer drain totals.
-------
Table 12. INITIAL l-JASTENKTER AND POLLUTION LOAD CHARACTERIZATION OF THE COMBINED CLEANUP AND PRODUCTION SHIFTS
(gal./lOOO Ib LWK and lb/1000 Ib LWK}
*o
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower a
Center grease drain
"330" grease drain
Head washer b
Stomach washer drain
Hasher washer drain
Neck washer c
Total gallons/1000 Ib LWK
Total lbs/1000 Ib LWK
Flow
1
3
136
8
8
30
( 20
14
27
52
78
362
.9
.8
.4
.3
-
.9
.6
.1)
.3
.8
.1
.0
-
.7
Total
solids
.031
.015
.055
1.729
-
.054
.069
.260
( .092)
.088
2.928
1.000
4.445
-
10.674
Total
volatile
solids
.023
.011
.038
1.135
-
.028
.040
.102
( .039)
.077
.264
.828
3.768
-
6.314
Volatile
Suspended suspended
solids solids
.009
.004
.006
.896'
-
.005
.009
.040
( .004)
.033
.201
.677
2.379
-
4.259
.008
.003
.004
.728
-
.004
.008
.029
( .004)
.029
.132
.612
1.894
-
3.451
Grease
.003
.001
.003
.202
-
.005
.022
( ' .)
.008
.120
1.461
3.596
-
5.427
Total
Kjeldahl
nitrogen'
.004
.001
.005
.147
-
.002
.005 1
.021
( .008)H
.045
.057
.041
.231 2
-
.559 4
BOD
.016
.005
.015
.661
-
.009
.020
.051
COD
.027
.013
.042
1.685
-
.023
.045
.125
.010)( .030)
.025
.215
.542
.707
-
.377
.360
1.315
6.821
_
.266 10.833
aCarcass shower is included in 660 grease drain totals.
t>Head washer is included in 330 grease drain totals.
washer is included in hasher-washer drain totals.
-------
Dehair Floor Drain and Scald Tank
The dehair floor drain was the largest contributor to the total flow of
the kill floor; it accounts for 37.6% of the water used during the full day.
The dehairing operation should receive a great deal of attention for water
volume reduction. This sample point also accounts for 26,1% of the total
Kjeldahl nitrogen and 15.5% of the BOD; it is the second largest contributor
of these pollutants. Several changes can be made to reduce both the flow and
waste load generated, as discussed in the next chapter,
Rosin Stripper
The rosin stripper contributes less than 1% of any of the pollutants, but
it does account for 2.4% of the total flow. New nozzles and piping should be
installed to reduce this flow during the production shift.
Railpolisher Drain
The railpolisher was very similar to the rosin stripper in flow and waste
loads. The railpolisher contributed little of the total BOD and COD, but
about 2.5%of ^the total flow. As with the rosin stripper flow reduction, is the
main problem to focus on for this sample point.
660 Grease Drain and Carcass Shower
The 660 grease drain was the fourth largest source of wastewater. The
majority of the flow is produced on the production shift by the carcass
shower. The carcass shower flow was 20.1 gal/1000 Ib LWK out of the total
of 30.6 gal./lOOO Ib LWK in the 660 grease drain (Table 12). However, the car-
cass shower was dilute; it was not responsible for the pollutant waste load.
The pollution came from the other process areas drained by the 660 grease
drain. The BOD contribution was only 1.2% of the total; Kjeldahl nitrogen is
3.7% of the total.
Center Grease Drain
The center grease drain contributed 3.9% of the total flow and 8.0% of
the total Kjeldahl nitrogen. This may be due to blood rinsed off the carcass
in the carcass shower.
330 Grease Drain
The 330 grease drain was the fifth largest contributor to the total flow.
It is the second largest contributor to total solids because of the large
amount of solids washed down this drain during the cleanup shift. Thus, solids
elimination was the main problem to focus on for this sample point.
Stomach Washer Drain
The stomach washer drain was a major contributor; it produced 14-.1% of the
waste water flow and 27% of the grease load. The large grease load was due
70
-------
to the fatty tissue from the outside of the stomach lining which was removed
in the tumble washer. This drain is also the third largest producer of BOD
and COD and suspended solids. This sample point needs both flow and load
reduction.
Hasher-Washer Drain
The hasher-washer drain was the obvious villain of the kill floor. It
alone accounts for 63% of the total BOD and COD, 56% of the suspended solids,
and 21.5% of the total flow. Cleanup at this point would be a major reduction
in the total wastewater load from the kill floor. The neck washer flowed
into this drain and contributed a significant proportion of grease and other
pollutants to the overall hasher washer total.
IDENTIFICATION OF MAJOR POLLUTANT SOURCES
The preceding discussion points out that the hasher-swasher drain, the
dehair floor drain, and the stomach washer were the three major sources of pol-
lution from the kill floor. This identification was the main objective of the
characterization study. Data in Chapters V, VI, and VII also identifies the
shift and the production areas that produced the largest quantities of pol-
lution.
Figure 27 is a flow summary by shifts and by sample point. It can
be seen that the production shift is responsible for 244 gal./lOOO Ib LWK for
a total of 362.7 gal./lOOO Ib LWK.
Figure 28 shows the sources of total BOD load by shift and process area.
The production shift contributed 4.0 Ib BOD/1000 Ib LWK and the cleanup shift
contributed only 0.2 lb/1000 Ib LWK. The pattern for total Kjeldahl nitrogen
and other pollutants follows the same pattern. Correlations of parameters
shown in Appendix D support this statement. Also, Tables 11 and 12 bear this out.
Modifications to reduce pollution should be made during the production
shift. The most critical areas are the hasher-washer, the stomach washer and
the dehairing. These three production shift sources represent nearly ninety
percent of the BOD load. This does not mean that cleanup and process modifica-
tions in other areas should be scorned but it does show dramatically how
initial characterization guides later efforts in the most important directions.
Maximizing money saved per dollar spent on modification will be accomplished
by giving most effort to the large pollution sources. After they are removed
or reduced a series of smaller conservation steps will remain.
71
-------
ro
BLEED AREA
«
o
o
£'
i
i
«
X
i
i
DC
O
1
8
SCALD
i
o
S
PRODUCTION FLOW
gallons/ 1000 IbLWK 0.0 0.0 1.9
CLEAN UP FLOW . - . -
nalloni/inoO IbLWK ' ' 8 ' °
DEHAIRING
s
g
1
U.
|
s
70.3
66.0
CARCASS
PREPARATION
tc
STRIPPER C
z
S
|
K
i
S
ae
X
I
SS SHOWER
MAIN KILL FLOOR AREA
i
1
*
3
|
* GREASE t
IU
x
u
i
IU
ae
3
ae
i
s
o
IH WASHER
s
I WASHER
1
2 i
u;
5
<
i
8.6 8.9 21.9 14.3 16.4 45.5 53.2
0.0 0.0 8.7 0 II .4 3.6 24.8
PRODUCTION FLOW 244.0
CLEAN UP FLOW 1187
TOTAL FLOW
got Ions /lOOOIblWK 1.9
3.4
136.3
8.6 8.9
3O.6 14.3 27.8
52.1
78.0
COMBINED FLOW 362.7
gallant /lOOOIbLWK
Figure 27. Wastewater flow balance for the Madison production and cleanup shifts.
-------
OJ
BLEED AREA
S
o
_i
z
a
a
X
ae
5
K
g
I
SCALD
S
a
s
PRODUCTION BOD LOAD
ID/1000 IbLWK 0000 0000 00|4
CLEAN UP BOD LOAD
Ib/ 1000 IbLWK O.OI6 0.005 0.001
TOTAL BOD LOAD 0 016 0.005 O.OIS
Ib/IOOO IbLWK
DE HAIRING
X
i
S
X
S
2
5
i
u
s
u
3
S
X
i 1
s g
111 *
x -
ae
1
|
S
5
0.009 0.020 0.037 0.025 O.I69 0.537 2.700 ^O^Vib^OJo'lbLWK*0
0.000 0.001 0.014 O.OOO 0.046 0.005 0.007 CLEAN-UP BOD LOAD
0.009 0.020 0.051 O.O25 0.215 0.542 2.7O7 COMBINED BOD LOAD
4 266 ID/WOO IbLWK
Figure 28. BOD,, mass balance for the Madison production and cleanup shifts.
-------
SECTION VIII
PROCESS CHANGES AND RECHARACTERIZATION
INTRODUCTION
The initial characterization of wastewaters and visual plant inspec-
tion indicated the areas which produced the greatest amounts of pollutants
and which used the largest volumes of water. This -information guided
redesign and process changes. In a few cases one of the plants was using
water in a particular process more efficiently than the others and this
plant could be used as an example.
Implementation of desirable changes was not always simple or pos-
sible. Fearing delays could cost dearly in terms of lost labor and loss
of production, management was reluctant to test some ideas. Even when
changes were made, many delays were experienced in installation of equip-
ment and process redesign features due to a shortage of trained mechani-
cal personnel available for this project. Because it was not possible
to test all changes that were thought to be desirable, in this chapter
not only are the actual changes that were tested presented and discussed,
but also tests which should have been made and changes which are clearly
worthwhile are presented. Tables 13 and 14 are a summary.
CHANGES IN THE STICK AND BLEED AREA
Problem: Most of the blood which is washed down the bleed area
floor drain during cleanup originates as a production shift problem.
The two sources of blood entering this drain are drippings from the
chain or bleed conveyor and blood overflowing the bleeding trough.
The overflows are intermittant and rather infrequent overflows occur
when heavy blood clots collect along the bleeding trough. When these
clots become too thick and heavy, they suddenly break free and 100 to
150 Ib (45 to 70 kg) of blood pours down the trough and overtaxes the
capacity of the receiving piping which should carry the blood from the
trough into the blood recovery system.
-------
Table 13. SUMMARY OF CHANGES IN POLLUTION LOAD AND FLOW
Production shift
Item
Original condition
Reduction
Percent reduction
Net -after change
Flow
gal/ shift
350,700
116,802
33%
233i«98
BOD
Ibs/shift
5,820
3,757
65%
2,063
SS
Ibs/shift
5,500
3,600
65%
1,900
Cleanup shift
Flow
gal/shift
170,800
95,660
56%
75,140
BOD
Ib/shift
310
124
40%
196
SS
Ib/shift
625
243
39%
382
Production & Cleanup
Flow
gal/day
521,500
212,462
41%
309,038
BOD
Ibs/day
6,130
3,881
63%
2,249
SS
Ibs/day
6,125
3,843
63%
2,282
-------
Table 14. IDENTIFICATION OF REDUCTION BY SAMPLE POINT
Production Shift
Sampling point
Bleed area floor drain
Bleed conveyor bl drain
Bleed conveyor washer drain
Dehair floor drain
Scald tank
Rosin stripper
Rail polisher drain
660 grease drain
Carcass shower
Center grease drain
Head washer
Stomach washer drain
Hasher washer drain
a. Blades out
b. a + curb * vacuum
c. a + b + new nozzle
for cleanup
Neck washer
Net reduction
Flow
gal/ shift
0
0
2,668
50,000
(0)
0
6,400
8,753
(8,753)*
6,520
(6,520)
0
42,461
(0)
(39,427)
(0)
(3.034)
116,802
BOD
Ib/shift
0
0
0
382
(0)
0
-
0
(0)
0
(0)
0
3,375
(2,948)
(170)
(0)
(257)
3,757
SS
Ib/shift
0
0
0
461
(0)
0
-
0
(0)
0
(0)
0
3,139
(2,906)
(-148)
(0)
(381)
3,600
Cleanup shift
Flow
gal/shift
0
0
0
60,000
(0)
0
-
0
(0)
0
(0)
0
35,660
(0)
(0)
(35,660)
(0)
95,660
BOD
Ib/shift
5
5
0
124
(0)
0
-
0
(0)
0
(0)
0
0
(0)
(0)
(0)
_iPJL
124
SS
Ib/shift
0
0
0
243
(0)
0
-
0
(0)
0
(0)
0
0
(0)
(0)
(0)
IPJL
243
Production & cleanup
Flow
gal/ shift
0
0
2,668
110,000
(0)
0
6,400
8,753
(8,753)
6,520
(6,520)
0
78,121
(0)
(39,427)
(35,660)
(3.034)
212,462
BOD
Ib/shift
5
5
0
506
(0)
0
0
0
(0)
0
(0)
0
3,375
(2,948)
(170)
(0)
(257)
3,881
SS
Ib/shift
0
0
0
704
(0)
0
0
0
(0)
0
(0)
0
3.287
(2,906)
(0)
(0)
(381)
3,991
Values in parenthesis are a subset of the above value and are not included in the total.
-------
Solution; A change in technique solved this problem. The man who
sticks the hogs now positions every 30th or M-Oth hog so that one front
leg drags along the trough as the hog is conveyed into the scald tank.
This prevented collection of large clots, eliminated the overflow prob-
lem, and reduced by about 80% the amount of blood reaching the bleed area
floor drain. The residual 20% of the blood that used to enter the bleed
area floor drain originates as drippage from the chain, washing of knives
and hands, etc., and is not considered recoverable. The result of this
change in technique is that 25 Ib (11.3 kg) of blood now enters the blood
recovery system instead of entering the wastewater system. This is
equivalent to about 5 Ib (2.3 kg) of BOD, as shown below.
25 Ibs blood x i * 3'78 J = 11.3 liters blood
11.31 x 200 g BOD x _!_ kg. =
2. 27 kg BOD x 2.2 Ibs =
Problem: After the last hog was killed for the day, six sprays along
and above the bleed trough were started to wash some of the blood from
the troughs to the blood recovery system. The first sluice of water
went to the blood recovery system; after this short initial sluice, drain-
age was diverted from the blood recovery system to the bleed conveyor
floor drain. The first sluicing removed only about 50 to 60% of the
blood in the trough and this blood, obviously, was diluted as it entered
the blood recovery system. This is inefficient. Another inefficiency
associated with this practice is that the remaining 50% of the blood
was washed into the bleed conveyor blood drain during the cleanup shift.
Solution: A squeegee with an offset handle was made to remove blood
from the blood trough into the blood recovery system without using the
initial sluice of water. This dry cleaning procedure increased the
amount of blood recovered from 50% of that on the trough as cleanup
began to 80 to 90% of the blood that was on the trough at the start of
cleanup. This is an increase of 25 Ib (11.3 kg) of blood and represents
5 Ib (2.3 kg) of BOD removed from the wastewater system. Not only is
more blood recovered by this method, but the cost of recovering the
blood is reduced because the water added to cleanup does not have to
be handled and heated in the blood recovery process. The only blood
from the bleeding trough, then, that does not go to blood recovery _ is
blood which is inaccessible because it is beneath surfaces or in pipes
where the squeegee cannot reach.
77
-------
Problem: During production the bleed conveyor was sprayed with cold
water to wash blood off the slotted side of the conveyor. This was to
prevent the conveyor becoming coated with dried blood that would be dif-
ficult to clean off. The water used in these sprays was 2,668 gallons
(10,100 1) per typical production shift.
Solution: Tests showed that eliminating these water sprays did not
make cleanup of the chain more difficult. The sprays are now used only
one or two hr/day and this is during the cleanup shift. These sprays
are not operated during the production shift. This saves 2,668 gal. of
water/day, and $260/yr (Tables 15 and 16). There is no reduction in
pollution loading by elimination of these sprays since the blood which
has been washed off by the sprays now drips off onto the floor under the
bleeding conveyor or this blood is washed off during the cleanup shift.
This blood is not recoverable.
PROCESS CHANGES FOR SCALD TANK
Problem: The scald tank in Madison holds 8,000 gal. of water. This
tank is filled once a day and make-up is not used other than condensed
steam which has been injected for heating. The contents of the scald
tank are dumped during the cleanup shift. This represents 85 Ib of BOD
(38.6 kg), 152 Ib of suspended solids (69.1 kg) and 13 Ib of grease
(5.9 kg).
Solution: No changes were made in the scald system. The water
consumption cannot be reduced and the amount of pollutants cannot be
reduced unless the technology is changed. The only way to eliminate
the source of pollution would be to skin hog carcasses rather than scald
and dehair them. The technology for hog skinning has been developed,
but data is not available to allow a comparison of the water use and
pollution load from a skinning operation with the load from the processes
replaced in a typical slaughtering plant.
PROCESS CHANGES FOR DEHAIRING
Problem: In Madison, during production 50,000 gal. (190,000 1) of
potable water are used solely to transport removed hair and toenails
from the dehairing machine to the sewage treatment plant and 60,000 gal.
(227,000 1) of water are used during cleanup to dislodge hair from the
machine and sluice it away. The reason for increased water use during
cleanup is that hair drops out of the machine in large matted bunches
and, unless large amounts of water are used for sluicing, these bunches
plug the dehair floor drain.
78
-------
Table 15. BLEED CONVEYOR WASH FLOW REDUCTION
Item
Before change
Production
Cleanup
Total
After change
Production
Cleanup
Total
Net reduction
Gallon/ shift
2,668
2,140
4,810
0
2.140
2,140
2,668
Gallon/1000 Ib LWK
1.855
1.488
3.343
0
1.488
1.488
1.855
Table 16. SAVINGS DUE TO ELIMINATION OF THE BLEED CONVEYOR WASH
_ DURING PRODUCTION _ - -
(Based on 250 work days/yr. and a water cost of $0.39/1000 gal)
Net flow reduction - 667,000 gal/yr.
Total annual savings » $260.13
Present value of savings - $985.00
(5 years @ 10%)
79
-------
The cost of this large volume of water is approximately $10,725/yr in
Madison*. An additional cost of $8,681 is due to pollution load. Over 5 years
at 10% interest this capitalizes to $73,561+ which could be invested in process
modification. This cost is based on an estimate of 110,000 gal. of water used
primarily to transport hair to the sewage treatment plant where the water must
be removed so the hair can be hauled to land disposal, and reduced BOD and
suspended solids surcharge.
Solution: One possibility with current technology is to reduce the amount
of water used to convey hair away from the machine. Oscar Mayer plants use
different methods for conveying away hair; other slaughtering plants visited
during the course of this study provided additional comparison. Neither the
Beardstown or Davenport plants have this extravagent use of hair sluice water.
In Davenport hair and toenails are scraped out of the dehairing machine onto
a chute which directs the hair into a dump truck. At Beardstown hair is trans-
ported from the dehairing machine to the sewage treatment plant by reclaimed
sewage, actually effluent from the grease floatation tank which is recycled to
the dehairing machine. Other plants which were visited used conveyors to
transport the hair from the dehairing machine to a truck for hauling to land-
fill >disposal. If dry conveyance of hair is not possible, u§e recycled water
in minimal amounts for sluicing. See Tables 17 and 18 for estimated savings
from using dry conveyance in Madison.
One way to eliminate this source of pollution is to change the carcass
handling and skin hogs rather than remove the hair- This technology exists,
but there is no data on which to make a direct comparison. Obviously, skinning
will substitute a new kind of pollution for that discharged from the scald tank
in the dehairing machine. One speculates that this change would be beneficial
and data should be compiled to make this comparison in some future study.
CHANGES FOR THE RAIL POLISHER
Problem: Water use in the rail polisher in all plants is too high, princi-
pally because cleanup personnel leave the sprays on during cleanup shift. This
water serves no useful purpose.
Solution: One solution is better training and supervision of cleanup per-
sonnel. This is not always easy to accomplish, so a mechanical solution was
developed and tested. The test was made at the Beardstown plant where an
automatic switch was installed which turns off the water when the last hog has
gone through the rail polisher. A steel push bar is depressed by the hog trol-
ley to activate a solenoid valve on the water supply to the rail polisher.
*This cost is estimated using the current cost of 15C/1000 gal. for cold
potable water, a sewer charge based on the volume of wastewater entering
the Madison Sewage System of 24C/1000 gal. and 250 working days/yr. All
cost for water and sewage disposal reported in this chapter will use this
basis for calculation unless a specific notation is made otherwise.
80
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Table 17. DEHAIRING MACHINE REDUCTIONS IN FLOW AND POLLUTION LOAD
(gal/1000 IbLWK or lb/1000 IbLWK)
Before change
Item
Flow
Total
solids
Susp.
solids
Grease
TKN
BOD
COD
Prod.
70.29
1.225
0.649
0.180
0.131
0.536
1.308
Cleanup
65.96
0.504
0.247
0.022
0.016
0.125
0.377
a
Total
136.75
1.729
0.896
0.202
0.147
0.661
1.685
After change
Prod.
35.52
0.619
0.328
0.091
0.066
0.270
0.660
Cleanup
24.25
0.159
0.078
0.007
0.005
0.039
O.li9
Total
59.77
0.779
0.406
0.098
0.071
0.309
0.779
Net Reduction
76.48b
0.950b
0.490
0.104
0.075
0.352
0.906
aThe change is to replace sluicing of hair from the dehairing machine with dry conveyance.
^Multiply by 1437.5 to get gal./day or Ib/day.
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TABLE 18. ANNUAL SAVINGS DUE TO POSSIBLE DEHAIRING MACHINE CHANGE3
(based on 250 work days/year)
Item Amount
Flow savings:
110,000 gal/day - 27,500,000 gal/yr @ $0.39/1000 gal. . . $10,825/yr
BOD surcharge savings:
506 Ib/day = 126,500 Ib/yr @ $0.319/ib $ 4,035/yr
SS surcharge savings:
704 Ib/day - 176,000 Ib/yr @ $0.0264/lb $ 4.646/yr
Total Annual Savings $19,406/yr
Present value of savings:
5 years @ 10% $73,564
Estimated cost of installing dry conveyance system $22,000
Estimated net present value of savings $51,564
aThe cost of water is $0.15/1000 gal for cold potable water
plus $0.24/1000 gal for wastewater surcharge. The BOD and
SS surcharge are the 1975 Madison rates.
82
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Micro switch
Actuating arm pivot
Switch actuating arm
Kill rail
i Ti
Figure 29. Beardstown rail polisher automatic shut-off.
83
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If there are not any hogs going through, the water supply is automatically
shut off. The shut-off mechanism is shown in Figure 29, There is a bypass
piping and valving around the solenoid for use in case of malfunction. To dis-
courage improper use of this bypass, the hand operated valve is inaccessible-.
without a ladder. Different switching, perhaps light rays and photo-
receptor tubes, could be used to shut off the water between the passage of
individual hogs. The savings from this sophisticated system would be at most
1/2 of the total water use during the production shift, or 12,800 gal./day
(48,453 1). The more reasonable target is to eliminate wastage during the
cleanup shift which is 1,640 ,gal. (6,208 1) every hour these sprays are left on,
and this unnecessary use of water had been running several hr/day. The cost of
the automated shut off was $255.00. The estimated annual savings in water use
is 1,600,000 gal. (6,400 gal./day x 250 day/yr) or $624.00.
PROCESS CHANGES FOR CARCASS SHOWER
Problem: The problem is excessive water use. The final carcass shower
contributes 60 gpm (3.78 1/s) into the 660 grease drain. This is the primary
source of wastewater entering that drain.
Solution: Different kinds and configurations of nozzles were tried to
reduce the volume of water required to clean the hog carcasses. In Madison a
series of 6 Veejet nozzles (Spraying Systems Co.) were installed to spray the
top of the carcass to sluice off loosened soil (Figure 30). These nozzles did
a good job of removing dirt from the carcass and reduced the water use from
60 to 43 gpm (3.78 to 2.7 1/s). Unfortunately, these nozzles created a fine
spray mist that carried out of the shower enclosure so that the nozzle arrange-
ment is now being modified.Tables 19 and 20 list savings.
In Beardstown, where a rosin depilator is not used, the dirt on the carcass
is not so difficult to remove as in Madison. Here it was found that two shower
nozzles which spray the feet and hams plus two one-half inch whirl jet nozzles
which spray the sides of the carcass are sufficient (Figure 31). Using these
nozzles has decreased water use in the carcass shower from 60 to 30 gal./min.
The savings would be slightly greater than given in Table 20 for Madison.
CHANGES IN CARCASS WORK-UP AREA
The carcass work-up area is defined as that part of the kill floor after
the final carcass shower where the carcass is being trimmed, cut and split.
In this section the focus is on water, meat and fat scraps, and blood that
falls onto the floor under and around the kill chain. Pollution is eliminated
by properly handling these scraps and drippings.
Problem: Eyelids, which are removed from the carcass right after the car-
cass shower, were dropped onto the floor- Despite periodic dry pick-up many
of these meat scraps were washed into the grease drain by water originating in
the carcass shower. (In the Madison plant this load was characterized as part
of the 660 grease drain).
84
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New sprays
Old style sprays
Figure 30. Madison final carcass shower showing old and new spray
configuration in parallel.
85
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Shower nozzles
Plugge* "test" nozzles
Spraying Systems Co.
1/2" Whirljet nozzle
detail of
nozzle
Figure 31. Beardstown final carcass shower
86
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TABLE 19. CARCASS SHOWER REDUCTIONS IN FLOW
Item Before change After change Net reduction
Production 28,852 20,098 8,753
Cleanup 0 Q Q
Total 28,852 20,098 8,753 gal/daya
a6.086 gal/1000 Ib LWK.
TABLE 20. ANNUAL SAVINGS DUE TO CARCASS SHOWER REDUCTIONS
Item Amount
Flow savings:
8,753 gal/day = 2,188,250 gal/yr @ $0.39/1000 gal $853/yr
Present value of savings $3,233
5 years @ 10%
Cost of installing change $184
Estimated net present value of savings $3,048
87
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Solution: A combination bridge and screen (.Figure 32) was built to fit
across the drain and gutter to keep eyelids out of the drain. About 12 Ib of
this scrap formerly entered the drain. The amount of grease, BOD etc. is not
known, but there is no doubt that this simple change has reduced the pollution
load.
Problem: Trimmings, blood clots, and meat and bone dust from carcass
splitting littered the carcass work-up area. Mid-shift and final cleanup per-
sonnel often found it more convenient to flush this material into a drain ra-
ther than use dry cleanup methods. This caused a large periodic pollution
load and loses material for inedible rendering. Dry cleanup with a broom and
shovel, the normal procedure, is an effective procedure. A "Tornado" indus-
trial vacuum cleaner shown in Figure 33 was tried for dry cleanup. This
cleaner readily picked up blood, floor scraps, sawdust, and even whole kidneys,
and left the floor dry, but it was cumbersome and slow. Some congested areas
were not accessible. A man with a broom and shovel could do almost as well
in less time and with less interference to kill line operations. The vacuum
system could be used to good advantage in some places, particularly if instal-
led as a central system, thereby, eliminating the cart, electrical cords, and
movable tank.
Problem: When the hog brisket is split open and when viscera is removed
large clots of blood fall into the gutter beneath the kill rail. During mid-
shift cleanup and final cleanup these are often pushed down the chute leading
to the hasher-washer rather than being picked up for rendering. Sluicing to
the hasherwasher breaks up the clots and leaches substantial amounts of
soluble material.
Solution: The solution is dry cleanup. Training and supervision of person-
nel is vital. Vacuum cleaning would be effective in some places.
Problem: Blood clots near the viscera removal treadmill fall onto the
floor and are washed with water from lavatories, drinking fountains, and the
viscera removal treadmill sprays. This leaches soluble material and generates
a pollution load.
.Solution: More frequent dry pick up of clots would reduce the problem, but
not eliminate it. This is not a practical solution because of labor costs.
Elimination of the water sources was not a practical solution either. Segre-
gation of the water and the blood clots was practical. A curb was built around
the eviscerating treadmill to divert water and prevent it from contacting the
clots. Mid-shift dry pick up of these "protected clots" is part of the pollu-
tion reduction solution at this location.
The kill method of electrical stunning and hung bleeding used at Beards-
town produces more complete carcass bleed-out than the CO2 immobilization
prone bleeding method used in Madison. This reduces blood clots on the floor.
Problem: Bits of fatty tissue, abdominal aorta and skin from around the
stick wound are trimmed off and dropped into the gutter. Periodically these
were swept into the hasher-washer chute where the sluice water would leach
88
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Figure 32. Bridge and screen used after Madison final carcass shower
to keep meat scraps out of the 660 hog/hour kill line
grease drain.
Figure 33. Tornado brand industrial vacuum cleaner with two inch wand
and floor gulper head.
89
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soluble material. Because of labor standards and work efficiency it was not
practical to have the trimmer deposit the scraps into a barrel or other con-
tainer. The vacuum cleaner was too cumbersome to be efficient in this work
area.
Solution: Blood clots and trimmed tissue could be kept off the floor and
out of the drains by installing a stainless steel trough under the kill line.
Material could easily be collected dry for rendering; no water could contact
it and solublize organics. The kill rail is so low in the Madison plant that
such a trough could not be installed without having the heads or ears of sows
come into contact with it. This would not be allowable. Such a trough would
be useful in many plants where only butcher hogs are slaughtered or where the
kill rail is higher.
CHANGES IN VISCERA HANDLING
In this section we deal with changes on the evisceration treadmill and the
viscera pans. Some process changes in the area of the evisceration treadmill
were discussed previously. Those changes were in connection with material
which had fallen onto the floor around the viscera handling area.
Problem: There is a continual loading of blood and other material which is
washed off the eviscerating treadmill by water spray. These sprays used a total
of 15 gal./min, part of which is 180°F water which is used to sanitize the
treadmill and part of which is cold water spray to loosen blood and other matter.
The problem was to reduce the amount of water used for washing.
Solution: Experiments showed that cleaning with only 5 gal./min of water
was sufficient. The reduction in water use was accomplished by installing new
nozzles in the spray system. The nozzles from the Spraying Systems Company are
as follows: 1/8 K 4.0 nozzles on 6 in. center located 3 in. from the treadmill
for the cold .-water washer; 1/8 K'2.5 nozzles on 6 in. centers: located. 3 in. from
the treadmill for the hot water water sanitizing sprays.(Figure 34). The change
saved 4,670 gal. (17,676 1) of water/day on the treadmill alone which is $ 455.00
annually*. The cost of making the change was $63.00.
Problem: The greatest contributor of water to the hasherwasher drain in
the Madison plant is the viscera pan washer on both the 660 and 330 kill line.
The problem was to reduce the water required to wash and sanitize the viscera
pan. The washing procedure consisted of a cold water wash followed by a hot
water (180°F) sanitizing water spray, followed by a cold water rinse to cool
viscera pans. The cold water wash consisted of two 1 1/2 in. water pipes which
were perforated with 1/8 in, holes drilled 1 1/2 inches apart. One of these
spray pipes was located above the viscera pans and one was located below the pans.
Solution: The old spray system was replaced with new nozzles. The nozzles
were placed on 8 in. centers at a 6 in.distance from the viscera pan conveyor to
spray the backs of the pans and 6 nozzles spaced on 6 Ln, centers at a distance
*10 gpm (7.79 hr/day) (60 min/hr) (250 day/yr) ($0.39/1000 gpm) = $455.
90
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spray for
washing treadmill
segregating curb
Figure 34. Madison eviscerating treadmill.
91
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of 6 in from the pan to wash the insides of the pan. This nozzle change reduced
the water used to clean and sanitize the viscera pans from 115 to HO gal./min.
Tables 21 and 22 give an accounting of the pollution and monetary savings for
all the changes in the evisceration area; that is, the curb around the tread-
mill which segregates water and blood clots so blood clots can be cleaned up
dry, changes in the treadmill washing, and changes in the viscera pan washing.
These changes are shown in Figure 34. Tables 21 and 22 document the changes
and savings.
Problem: Excessive amounts of water were being used on the viscera pans
and the visceration treadmill during cleanup. The cleanup men would leave the
viscera pan and treadmill sprays on during most of the cleanup. After the first
thirty minutes, this accomplished no useful purpose.
Solution: Solenoid valves were installed on the 3 water lines which supply
the viscera pan sprays and treadmill sprays. These valves are controlled by
a locked timer box. During production the timer is set on manual operation and
the solenoid valves remain open. At the end of production the timer is set on
automatic and the control cabinet is locked. To use the sprays the cleanup
man must push a button on the control cabinet to activate the timer and open
the water supply valve. The timer automatically closes the solenoid valve
after 15 min. The sprays can be restarted by pushing the button again if more
water is needed, but they cannot be left running by inaction or carelessness.
This automated lockout would not be required if cleanup workers were properly
motivated toward good conservation practices and were well supervised. In
many plants the automation will be the practice which is certain and effective.
Table 23 documents the savings accomplished by using this automated valve during
cleanup shift.
CHANGES IN THE HASHER-WASHER
Several of the changes mentioned previously to collect scraps from the
floor and prevent leaching of soluble materials were designed to keep scraps
out of the hasher-washer drain. In this section we consider a major improv-
ment made in the hasher-washer itself.
Problem: The hasher-washer drain is the largest contributor of pollution
load from the kill floor. Intestines and great quantities of other solid
materials are sluiced into the hasher-washer from various parts of the kill
floor. Knives in the hasher-washer slash the intestines and this enables the
sluice water to flush out the intestinal contents. The objective is to have
fat and meat solids go to inedible rendering and to have wastewater go to the
wastewater treatment plant. The separation of solids and the liquid is very
inefficient. Large quantities of solids escape with the water through the
slots in the hasher-washer drum. The problem is to send less of the solid
material, which represents an extremely high load in terms of BOD solids,
grease, and other pollutants, to the wastewater treatment plant and to capture
these materials for rendering.
Solution: One solution would be to design a hasher-washer with smaller
slots that could recover a greater portion of the solid material. A similar
92
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Table 21. REDUCTIONS IN FLOW AND POLLUTION LOAD DUE TO
EVISCERATION TREADMILL AND VISCERA SPRAY CHANGES:
SEGREGATION, VACUUM CLEANUP, AND NEW NOZZLES
(gal/1000 Ib LWK or lb/1000 Ib LWK)
Item
Flow
TS
SS
Grease
TKN
BODc
COD
Before change
53.14
1.433
0.324
0.255
0.134
0.650
1.581
After change
25.70
0.883
0.320
0.213
0.062
0.529
0.953
Net reduction
27. la
0.5503
0.004
0.042
0.072
0.121
0.628
Multiply by 1437.5 to get gal/day or Ib/day
93
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TABLE 22. ANNUAL SAVINGS DUE TO EVISCERATION TREADMILL
AND VISCERA SPRAY REDUCTIONS OF TABLE 21
(Based on 250 work days/yr and costs of
$0.39/1000 gal, $0.0319/lb BOD5, and
$0.0264/lb SS)
Item Amount
Flow savings:
39,427 gal/day = 9,856,750 gal/yr $3,844/yr
BOD savings:
170 Ib/day - 4,250 Ib/yr $ 136/yr
Loss due to increased SS Negligible
Net annual savings $3,980
Present value of savings:
5 years @ 10% $15,087
Installation cost $ 2,377
Net present value of savings $12,710
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TABLE 23. ANNUAL SAVINGS DUE TO USE OF LOCKOUT SWITCH
FOR CLEANUP OF EVISCERATION TREADMILL8
Item Amount
Annual savings:
7,456,250 @ $0.39/1000 gal $ 2,907
Present value of savings:
5 years @ 10% . .. $11,019
Installation cost $ 1.285
Net present value of savings $ 9,734
change in BOD or SS; flow reduction - 29,825 gal/shift
= 7,456,250 gal/yr.
95
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solution would be to follow the existing hasher-washer with a second screen-
ing operation that would capture smaller particles. Neither of these alter-
natives was tested because a better solution existed. The chopping blades
were removed from the hasher-washer (Figure 35) so the unit functioned only
as a dewatering device. The large and small intestines and their contents
remain intact and are sent to inedible rendering. This increases the quan-
tity of meat scrap and material for rendering by an average of 8,500 Ib/day.
The present value for rendered meat scrap is $5.75/100 Ib; this 8,500 Ibs/
day is worth $488.75. This additional income is not the total savings asso-
ciated with the change because allowance must be made for savings in waste-
water treatment. Analysis of the meat scraps produced during the test period
did not indicate reduction in the quality, although the crude fiber content
of the meat scraps did increase from 1.5% to 1.7%.
The solids from the hasher-washer are rendered to produce grease and meat
scraps. During the test with the hasher-washer blades removed, there were
several customer complaints about the quality of the choice white grease.
Some of this grease had to be downgraded to A-white with the resultant loss
in the selling price of .50/100 weight. (Choice white grease is $14.75/100
weight, and A-white grease which is lower quality is $14.00/100 weight).
During the years 1971 through 1975 the Madison plant produced an average of
5,188,000 Ib of choice white grease/yr. If this total production were down-
graded to A-white, there would be a loss in income of $25,940/yr. This is
offset by the increase in meat scraps going to rendering which was estimated
as $488.75/day which over 250 working days/yr approximates $122,000. This
accounting is not exact. The extra cost of drying the additional meat scraps,
the savings in power and maintenance in not running the hasher, and savings
in wastewater treatment have not been included.
Removing the hasher-washer blades gave a substantial reduction in BOD
suspended solids, and other pollutants going to the wastewater treatment
facility. See Tables 24 and 25 for detailed pollution and cost data.
CHANGES IN THE STOMACH WASHER
Problem: Water is used to flush out the contents of the stomach. The
stomach contents represent a high pollution load. Even if the solids are
captured later and separated from the water, there has been significant pol-
lution load generated as soluble materials. This was shown by mixing a
portion of stomach contents with an equal volume of water and filtering this
mixture through a 20 mesh screen. The filtrate had a total solids content
of 41,000 ppm, total volatile solids 37,000 ppm, and BODsof 42,000 ppm. The
objective was to eliminate the leaching of pollutants from stomach contents
during washing and sluicing.
Solutions attempted: Attempts to reduce water use and pollution generation
in the stomach washer were unsuccessful. The results of our attempts are re-
ported, nevertheless, in hopes of stimulating a workable solution in the future.
Reducing the flow of water in either the stomach slitter-dumper or the stomach
tumble-washer led to the failure of these units to clean the stomachs adequately.
96
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Figure 35
Madison Hasher-Washer With Hasher Blades Removed.
97
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Table 24. REDUCTION IN PRODUCTION SHIFT POLLUTION LOAD
DUE TO REMOVAL OF HASHER WASHER BLADES
Item
Net reduction
Before change After change Ib/lOOOlbLWKIb/day
Flow No
BOD lb/1000 IbLWK 2.70
SS lb/1000 IbLWK 2.35
TS lb/1000 IbLWK 4.34
Grease lb/1000 IbLWK 2.83
TKN lb/1000 IbLWK .23
COD lb/1000 IbLWK 6.80
change
.6498
.324
1.433
.255
.134
1.581
2.050
2.020
2.907
2.625
0.096
5.219
2948
2906
4180
3775
138
7505
98
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TABLE 25. ANNUAL SAVINGS DUE TO REMOVING THE HASHER BLADES
(Based on 250 work days/yr and costs of $0.39/1000 gal,
$0.0319/lb BOD, and $0.0264/lb SS)
Item Amount
Flow savings None
BOD savings:
2948 Ib/shift = 737,250 Ib/yr $23,518/yr
SS savings:
2906 Ib/shift = 726,500 Ib/yr $19,179/yr
Total annual savings $42,697
Annual added value due to increased meat scrap:
8500 Ib/day = 2,125,000 Ib/yr @ $5.75 per CWT $122,187/yr
Annual loss due to downgrading grease quality $25,940
Annual net savings $128,944
Present value of savings
5 years (§10% $526,681
Cost of modification $ 275
Net present value of savings $526,406
99
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Tests were made to see if the stomachs could be slit, dumped, and flushed
as they are now with a screening to recover the solids immediately following
these other operations. The contents might be dried and fed to the hogs in
the stockyard. Analysis of the composite sample of the stomach contents of
85 hogs showed 81% moisture and l.H-9% protein. The filtration test (the fil-
trate characteristics of which were reported above in the problem definition
section) showed that the solids could be recovered on a screen and that the
filtered solids were 1.83% protein. So much material has been solubilized
that the reduction in the BODs load is probably not worth while. The screen-
ing might as well be done at the sewage treatment plant as is the present
practice. Dry removal and handling of the stomach contents would give a sub-
stantial pollution reduction if a method can be found to accomplish this
economically.
CHANGES IN HEAD AND NECK WASHING
Problem: The scouring action of the neck washer removes fatty tissues
from the neck and jowl area of the carcass and removes blood from the stick
wounds. Excessive amounts of water are used and there is a large pollution
load generated.
Solutions: An attempt was made to eliminate water use and the pollution
by using a vacuum device to remove blood clots from the neck. The vacuum,
however, was unable to remove the clots which were firmly embedded in the con-
nective tissues. It was necessary to use water to dissolve the blood clot in
combination with mechanical action to get the neck clean. A Chad neckwasher,
was installed in the Madison plant to replace the two or three men who pre-
viously washed the necks with manually operated scrubbers. The Chad neck
washer uses 20 gal./min of water at 800 psi pressure to scour blood and soil
from the neck. The method previously used consumed 26 gal./min. Figures 36
and 37 show the Chad neck washer. Tables 26 and 27 give an accounting of the
pollution and dollar saving due to installing the new Chad neck washer.
The sprays of the Chad washer spray most of the interior of the carcass
and the lower part of the neck as well as the neck itself. Because of this
it is believed that the Chad neck washer could be used to wash the head and
the interior of the carcass and the stick wound area of the neck. If this
proves true, the need for a head washer will be eliminated. This elimination
of the head washer would save 6,520 gal./day. This idea cannot be tested
without moving the neck washer from its present location to a place right
after the kidney removal station. This may be done in the future, but not
until the efficiency of the Chad washer has been fully proven.
.Problem: The head washing equipment contributes a major portion of the
flow and pollution load into the Madison plant's 330 grease drain. The USDA
has no specific requirements for a head washer. Its function is to remove
blood and stomach contents which have dripped onto the heads to make the heads
easier to handle in the trimming operation.
100
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Table 26. REDUCTIONS IN PRODUCTION SHIFT LOAD DUE TO INSTALLING THE CHAD NECK WASHER
o
M
Item
Flow
TS
SS
Grease
BOD
Before change
12,382
1.020
0.472
1.290
0.360
After change
9,348
0.321
0.207
0.104
0.181
Net Reduction
gal/1000 Ibs LWK lh/1000 Ib LWK
2.1098
0.699a
0.265
1.186
0.179
Multiply by 1437.5 to get gal/day or Ib/day*
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TABLE 27. ANNUAL SAVINGS DUE TO INSTALLING THE CHAD NECK WASHER
(Based on 250 work days/yr and costs .of $0.39/1000 gal,
$0.319/lb BOD, and $0.0264/lb SS)
Item Amount
Flow savings:
3034 gal/day = 758,500 gal/yr $ 295
BOD savings:
257 Ib/day - 64,250 Ib/yr $ 2,049
SS savings:
381 Ib/day = 95,250 Ib/yr $ 2.514
Total annual savings $ 4,858
Present value of savings
5 years @ 10% $132,132
Costs:
Equipment purchase $ 17,200
Equipment installation $ 450
$ 17,650
Net present value of savings $114,482
102
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Figure 36. Chad automatic neck washer.
Figure 37. Interior of Chad neck washer showing position of spray
manifolds.
103
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Solution: The flow was reduced from 6,520 gal./shift to 3,260 in the
head washer by removing three of the six spray nozzles and by decreasing the
flow to the three nozzles which remained. The cost savings in water are
approximately the same as those reported in Tables 26 and 27 for the neck
washer. It is believed that even these three nozzles could be eliminated by
relocating the Chad neck washer. In the Beardstown plant, a head washer step
is not used. This is because the carcasses bleed out more completely because
they are shackled and hung vertically after sticking and, therefore, very
little blood drips onto the head.
CHANGES IN CHITTERLING WASHING
Beardstown is the only Oscar Mayer Plant still saving chitterlings.
Problem: Excessive amounts of water were used to flush manure from the
chitterlings. Additional large amounts of water were being used to wash
workers hands. Most of the water was being discharged through eight shower
type spray nozzles located along the.chitterling machine.
Solution: The shower type nozzles were replaced with Spraying Systems
Company 3/8 in GG "full jet" nozzles. Meter readings indicate that the average
water use for the three chitterling washers has dropped from 112,500 gal./day
to 60,685 gal./day. The amount of each pollutant before the change is not
known exactly. It is believed that the pollutant load would not change. The
savings based on the flow alone at $0.39/1000 gal., is $5,061/yr.
SUMMARY
The list of solutions reviewed in this chapter represent a net present
value over five years (at 10% interest) of more than one-half million dollars.
It is remarkable how small process changes, made with little or no expense,
add up to savings of thousands of dollars annually. Reductions in water used
alone is a great savings, and there is the added benefit that decreasing the
water use always brought a reduction in BOD, suspended solids, and other pol-
lutants. Often there was increased by-product recovery, as well.
In-plant changes ranging in complexity from shutting off a valve to alter-
ing a piece of machinery radically are an economic boom. They can be done
quickly. They pay for themselves in a very short time, within a few weeks to
a year. They are the best route toward meeting effluent discharge standards.
This chapter has documented how worthwhile in-plant modifications can be.
The plant manager who makes searching for potential changes a habit will be
well rewarded.
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-------
SECTION IX
A STRATEGY FOR IN-PLANT REDUCTION STUDIES
INTRODUCTION
This study shows that even small process modification represent savings
of thousands of dollars over a few years. For example, a reduction of 10,000
gal. water/day is roughly $l,000/yr saved. Additional savings due to BOD and
suspended solids reductions is probably available, as well. This section out-
lines a strategy for making a plant survey to identify valuable process
modifications; first the gross problems and then the smaller problems. The
goal is to provide advice that can help an industry that must accomplish this
by itself without investing great amounts of time and money in data collection.
A research program such as described in this report is not required to bring
savings to small industries.
A SEQUENTIAL STUDY STRATEGY
The strategy, in rough outline, has three stages.
1. Make a walk-through survey during production and cleanup to identify
points of water use, gross spillage, and collections of blood and scrap on
the floor. This visual survey will identify gross problems and these are
the targets of first attack. Generate a list of possible solutions for each
problem site (such as broom and shovel pick up, install a catch trough, curb
an area to divert water, install an automatic shut off, etc.). If the cost
of a change is less, than $500, it will repay its cost many times over within
5 years. If the cost is higher, even several thousand dollars, it may well
be profitable. Make an estimate of the water use and pollution load using
data from this report and other meat packing literature to assess economic
viability. Often the change is profitable for the water savings alone;
estimates of BOD and other measures of pollution may not be needed to make
the decision. Remember, the purpose of the in-plant survey is to make
decisions and not to quantify everything with great precision and accuracy.
Install the changes that seem attractive on the basis of this first analysis.
2. The first step has been taken and data is needed to make decisions
on additional process modifications. The strategy now is to get decision
making information quickly and without a massive measurement program. Because
savings in water alone are so significant, flow measurements should be made.
The two techniques of greatest value are the bucket-and-stop-watch method,
and the lithium chloride dilution method. (We assume extensive water meter-
ing does not exist). Use the bucket for small accessible flows. Use the
105
-------
lithium dilution method for large flows and flows that are not accessible to
the bucket method. Addition of the lithium to the wastewater flow that is
to be quantified is simple. The only problem for most plants is getting the
diluted lithium concentration measured, because this is done best by atomic
absorption. The samples can be sent to a commercial laboratory or a govern-
ment or university laboratory for a reasonable price. Most meat packers
have the capability for measuring total Kjeldahl nitrogen. They may also
have the set-up to measure BOD, COD or suspended solids. Measure BOD if it
is convenient; if not, measure COD and measure suspended solids. If these
measurements are not possible, the Kjeldahl nitrogen measurement is a useful
surrogate for BOD and COD. Analyze at least two or three samples. The
relations given in this report can be used only as very crude prediction
equations in another plant. They may establish the magnitude of a pollution
problem well enough to show that a change is profitable. Again, the focus
is on decision making rather than precise quantification. It is granted that
some decisions are close ones that require careful, quantification and a com-
plete economic evaluation. But more, it seems from the outcome of this
research, are easily evaluated with a small amount of information.
3. Steps 1 and 2 have taken care of the easy decisions. To go farther
requires more complete data. This can be expensive, but the investment
should repay itself. Discovering one problem of sufficient magnitude may
pay for the entire sampling program and the cost of installing the change,
as well. And there are savings from steps 1 and 2 that can be allocated
fairly to paying for step 3, particularly because the analysis expense in the
first two steps has been reduced so drastically. In this step it is not
necessary to survey the entire plant at one time. A process by process or
area by area study can be done, and this would be guided by knowledge gained
in steps 1 and 2.
Water meters should be installed at critical locations. The plant should
make arrangements to have BOD(oz''"COD or organic carbon), suspended solids,
and Kjeldahl nitrogen measurements done "in house" or on contract. Sampling
ports and automated equipment should be catalogued and compared against the
survey requirements. Work to provide sampling access will be normally
necessary because the drain systems in most plants are complex. Carefully
work up the budget for the survey. The cost may run from a few hundred
dollars to do properly one process area to thousands to do the entire plant.
Do not be intimidated by a high cost, but do cull the program to conform to
a previously developed priority list.
An important pre-measurement step, too often overlooked, is generation
of the optimistic and pessimistic economic outcome of the study results.
To make these estimates you must know the cost of water and other plant
utilities, sewage treatment surcharges, the probable impact of industrial
cost sharing legislation in your community, likely and possible changes in
your required level of wastewater treatment, and the selling price of ren-
derings, grease, or other marketable materials that may be affected by
changes in the process. This same information is used later when the data
is in hand to refine the estimates.
106
-------
The in-plant survey undertaken will be similar in many respects to that
described in this report, although it may not cover the entire plant and the
data bank may not be so massive. The five steps that will be undertaken are:
-characterization of wastewater streams and processes,
-design of process modifications and economic evaluation,
-installation of attractive process changes,
-recharacterization to certify effectiveness of the change,
-updating the economic impact of the in-plant survey and wastewater
reduction program on plant finances.
THE COST-BENEFIT FACTOR
Sometimes the pollution control problem requires that rather massive
modification be considered. Management then insists upon a more orderly
and detailed evaluation. The cost of the modification is estimated
easily, but the total benefits are elusive. A special problem exists when
several alternate modifications, each being expensive and producing benefits,
are to be studied. Each alternative can be evaluated by a systematic approach
as outlined in Figure 38.
The industry may first realize it has a serious economic problem related
to pollution control through violation of an effluent standard, payment of
excessive surcharges to a municipality, or a shocking result from an industrial
cost recovery study. In each case the major question may become "Shall we
improve our treatment plant, make in-plant conservation efforts, or pay some-
one else to take our problem?" The division of investment between treatment
and in-plant changes is difficult only when the in-plant change represents
a drastic process modification. Even then it may be the wisest course.
Certainly, for simple modifications as documented in this report, the in-
plant change is a proven winner. A few thousand dollars invested in treatment
facilities does little and probably returns no profit. The same investment
inside to reduce the generation of wastewater can do a great deal. There
are, nevertheless, occasions when major projects need to be studied in detail.
A few of the important considerations are given here.
The cost of organizing a study and implementing a proposed change must
be weighed against the benefits of lower water bills, reduced sewer charges,
reduced treatment costs, and increased by-product recovery. The cost/benefit
analysis must be considered for several years into the future. The uncer-
tainty of future labor, energy, raw water, and wastewater treatment costs
makes the analysis very difficult and requires careful judgment by the
industry.
The first step for the industry is to realize that a pollution problem
exists or that a savings can be made by reducing its total effluent load.
This realization may be the result of violation of an effluent constraint,
excessive user charges, or industrial cost sharing studies.
107
-------
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Once the industry decides to act, step two is a survey of "in house"
operations to pinpoint major problem areas and sources for potential
improvement. The most difficult decision facing the industry is selecting
the most cost-effective changes.
The third step requires the industry to make a detailed analysis of
the present or expected treatment and disposal costs (Ci). This is the basis
of comparison for the revised costs. One industry may operate a primary
and^secondary treatment facility and discharge the treated effluent into a
municipal sewage district interceptor. Other industries may have complete
on-site treatment. In all cases the present cost of disposal, the method
used for calculating that cost, and an estimate of future changes in those
costs should be understood. It is often difficult to estimate accurately
the "real" present treatment cost. This is due to the poor segregation of
all costs associated with wastewater treatment from general corporate costs.
Estimates of treatment costs often do not include administrative costs for
secretaries, engineers,processing plant managers, vice presidents, and other
personnel who spend a portion of their time with different aspects of the
pollution problem. The vice president of finance may spend a great deal of
time arranging financing for a treatment facility, and a public relations
manager may devote time and resources to keeping the public informed con-
cerning the company's pollution efforts. These costs and others are definitely
associated with pollution control and should be included when making a valid
cost/benefit analysis. If the pollution problems were eliminated, then
personnel could direct their efforts toward maximizing corporate profits.
The fourth step in this approach involves studying each proposed modi-
fication and estimating the pollution reduction and water conservation that
can be achieved. The reduced effluent load is used for calculating the
revised treatment cost, and the cost for installing and operating the modi-
fication. Also, any benefits due to reduced raw water volumes and by-product
recovery can be calculated.
If the net result is a savings, install the modification. If the new
cost is greater than the original cost, reject or re-examine the modification.
If an initial segregation modification is rejected, a more complete segregation
can be examined.
The viable modifications are compared and the ones with the best cost/
benefit analysis are chosen if they also satisfy the company's requirements
for space, base of operation, reliability, and other factors. The best
judgment of the industry must be used to select the modifications which will
achieve a least-cost, long-run solution to its pollution problem.
It is important to note that the treatment costs and by-product recovery
values are on an annual basis, while the cost for the modification is a one-
time cost. Present value analysis should be applied to account for the time
value of money. At times when industries are faced with tighter capital
markets, in-plant reduction can be a method for reducing treatment costs
with minor capital expenditures.
109
-------
SUMMARY
In-plant wastewater reduction studies offer significant savings to
industries. Studies should progress from a "first cut" to a complete indus-
trial survey unless the desired reductions are achieved. Industries must
decide if they should invest additional money in a wastewater treatment
plant or invest that money in more efficient process equipment.
110
-------
REFERENCES
I* Meat Facts, 1974 Edition, American Meat Institute, July,1974.
2. American Meat Institute, private correspondence, 1975.
3. U. S. Environmental Protection Agency, Methods for Chemical Analysis
of Water and Wastes, Office of Technology Transfer, Washington, D.C.,
1974.
Ill
-------
TABLE A-l
INITIAL
CHARACTERIZATION OF THE HOG SLAUGHTERING
(PRODUCTION SHIFT) FOR THE
Sample point
Gallons/
shift
Bleed area floor drain -
Bleed conveyor blood drain
Bleed conveyor wash drain 2668
Dehair floor drain imnQfi
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grr.ase drain
"330" grease drain
Head washer
Stomach washer drain
Hasher washer drain
Neck washer
12490
12797
31432
(28852)
20565
23533
(6520)
69694
76436
(12382)
FLOW SUMMARY
Liters/
shift
10100
382649
47275
48438
118972
(109207)
77840
89074
(24680)
263791
289313
(46867)
MADISON
PLANT
Gallons/
1000 Ib
1
70
8
8
21
(20
14
16
(4
48
53
LWK
.9
.3
.6
.9
.9
.1)
.3
.4
.5)
.5
.2
(8.6)
FLOOR
Liters/
1000 kg
15.
586.
72.
74.
182.
(167.
119.
136.
(37.
404.
443.
(71.
LWK
48
6
5
3
4
4)
3
6
8)
4
5
8)
Percent
of load
0.
28.
3.
3.
9.
(8.
5.
6.
(1.
19.
21.
(3.
8
8
6
6.
0
2)
9
7
8)
9
8
_5)
Tl
25
M
X
>
*
PRODUCTION SHIFT
>
> 1
M
a
a
M
CO
Total
350711
1327452
244
2035
100%
-------
TABLE A-2
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
TOTAL SOLIDS SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Central grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
-
2340
2090
750
930
750
(550)
750
3150
-
2430
9790
(14230)
Pounds/
shift
-
50
1760
77
99
195
(133)
127
618
-
1411
6242
(1470)
10579
Kilograms/
shift
-
23.6
799.0
35.1
45.0
88.4
(60.1)
57.6
280.6
640.9
2831.6
(666.5)
4801.8
Pounds
1000 lb LWK
-
0.036
1.225
0.054
0.069
0.136
(0.092)
0.088
0.430
-
0.981
4.34
(1.02)
7.36
Percent
of load
-
-
0.5
16.6
0.7
0.9
1.8
(1.3)
1.2
5.8
-
13.3
59.0
(13.9)
100%
-------
TABLE A-3
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
VOLATILE SUSPENDED SOLIDS SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
_
-
210
990
60
120
100
(20)
245
580
-
1500
4230
(6190)
Pounds/ Kilograms/
shift shift
_
-
4.7
835
5.9
12.2
26.1
(5.2)
42.1
114.6
-
871
2696
(639)
46X)7.6
_
-
2.1
379.0
2.7
5.5
11.8
(2.4)
19.1
52
-
395.0
1223.0
(289)
2090.2
Pounds
1000 Ib LWK
-
0.003
0.580
0.004
0.008
0.018
(0.004)
0.029
0.080
-
0.606
1.880
(0.440)
3.208
Percent
of load
-
0.1
18.1
0.1
0.3
0.6
(0.1)
0.9
2.5
-
18.9
58.5
(13.8)
100%
-------
VJ1
TABLE A-4
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
SUSPENDED SOLIDS SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
-
-
250
1100
65
120
120
(25)
275
630
-
1660
5290
(6590)
Pounds/ Kilograms/
shift shift
-
5.5
933.0
6.8
12.8
30.8
(6.0)
47.4
123.7
-
964.5
3374.9
(680)
5499.4
-
2.5
423.2
3.1
5.8
14.0
(2.7)
21.5
56.1
-
437.5
1530.8
(308)
2494.5
Pounds/
1000 Ib LWK
-
0.004
0.649
0.004
0.009
0.021
(0.004)
0.033
0.086
-
0.671
2.346
(0.472)
3.828
Percent
of load
-
-
0.1
17.0
0.1
0.2
0.6
(0.1)
0.9
2.2
-
17.5
61.4
(12.3)
100%
-------
J-1
a\
TABLE A-5
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
TOTAL VOLATILE SOLIDS SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
-
1940
1490
390
530
380
(230)
650
1280
-
2020
8420
(13700)
Pounds/ Kilograms/
shift shift
-
45
1260
41
57
100.1
(56.1)
111
251.3
-
1174
5364.4
(1415)
8403.8
-
19.5
570.3
18.5
25.8
45.4
(25.4)
50.4
113.9
-
532.7
2433.3
(642.)
3809.8
Pounds/
1000 Ib LWR
-
-
0.030
0.875
0.028
0.040
0.070
(0.039)
0.077
0.175
-
0.817
3.730
(0.980)
5.84
Percent
of load
-
-
0.5
15.0
0.5
0.7
1.2
(0.7)
1.3
3.0
-
14.0
63.9
(16.9)
100%
-------
TABLE A-6
INITIAL CHARACTERIZATION OP THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
GREASE SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
No flow
No flow
104.43
306
67
64
-
64
541
-
3600
8099
(21142)
Pounds/ Kilograms/ Pounds/
shift shift 1000 Ib LWK
-
2.3!
258.4
7.2
16.8
-
11.0
106.3
-
2092
5162
(2183.)
7656
-
1.01
117.2
Negligible
3.3
7.6
-
5.0
48.2
-
948.9
2341
(990.2)
3472.2
-
0.003
0.180
0.005
0.012
-
0.008
0.074
.
1.454
3.590
(1.518)
5.325
Percent
of load
-
0.1
3.4
0.1
0.2
-
0.1
1.4
-
27.3
67.4
(28.5)
100%
-------
H
TABLE A-7
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
KJELDAHL NITROGEN SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
-
270
220
30
62
105
(50)
380
410
-
100
530
(346)
Pounds/
shift
-
6.3
188.5
3.3
6.6
27.2
(11.5)
64.5
80.3
-
59.0
336.2
(35.7)
771.9
Kilograms/
shift
-
2.9
85.5
1.5
3.0
12.3
(5.2)
29.3
36.4
-
26.8
152.5
(16.2
350.2
Pounds/
1000 Ib LWK
-
-
0.004
0.131
0.002
0.005
0.019
(0.008)
0.045
0.056
-
0.041
0.23
(0.02)
0.533
Percent
of load
-
-
0.8
24.4
0.4
0.8
3.5
(1.5)
8.4
10.4
-
7.6
43.5
(4.6)
100%
-------
TABLE A-8
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
BOD-5 SUMMARY
Sample point
mg/1
Pounds/
shift
Kilograms/
shift
Pounds
1000 Ib LWK
Percent
of load
Bleed area floor drain -
Bleed conveyor blood drain - - - - -
Bleed conveyor wash drain 920
Dehair floor drain
+ scald tank
H Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
915
120
260
205
(60)
210
1240
-
1330
6090
(5010)
20.5
771.
12.6
28.2
53.8
(13.7)
35.7
242.6
-
772.5
3883.
(517.)
5819.9
9.3
349.9
5.7
12.8
24.4
(6.2)
16.2
110.1
-
350.4
1761.
(234.)
2639.6
0.014
0.536
0.009
0.020
0.037
(0.010)
0.025
0.169
-
0.537
2.70
(0.36)
4.047
0.4
13.2
0.2
0.5
1.0
(0.2)
0.6
4.2
-
13.3
66.8
(8.9)
100%
-------
ro
o
TABLE A-9
INITIAL CHARACTERIZATION OF THE HOG SLAUGHTERING FLOOR
(PRODUCTION SHIFT) FOR THE MADISON PLANT
COD SUMMARY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
+ scald tank
Rosin stripper
Rail polisher drain
"660" grease drain
Carcass shower
Center grease drain
"330" grease drain
Head washer
Stomach washer
Hasher washer drain
Neck washer
Total
mg/1
-
-
2360
2230
320
610
440
(200)
2830
2260
-
3220
15340
(13580)
Pounds/
shift
-
-
52.5
1882.
34.0
64.9
114.5
(48.2)
485.0
444.3
-
1871.0
9780.
(1402.)
14728.2
Kilograms/
shift
-
-
23.8
854.
15.3
29.4
51.9
(21.8)
219.8
201.5
-
849.
4436.
(635.)
6680.7
Pounds/
1000 Ib LWK
-
-
0.036
1.308
0.023
0.045
0.080
(0.03)
0.337
0.308
-
1.300
6.800
(0.90)
10.20
Percent
of load
-
-
0.4
12.8
0.2
0.4
0.8
(0.3)
3.3
3.0
-
12.7
66.4
(9.5)
100.
-------
TABLE B-l. WASTE WATER FLOW FROM THE MADISON PLANT CLEAN UP SHIFT
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
scald tank
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Gallons/
shift
2840.00
1150.00
2140.00
94880.00
(8000.00)
12540.00
-- , ;
16400.00
5150.00
35660.00
170760.00
Liters/
shift
10743.00
4360.00
8100.00
359120.00
(30280.00)
a
a
47470.00
a
a
62100.00
a
19490.00
134980.00
a
646370.00
Gallons/
shift
1.9
.8
1.5
66.0
(5.56)
8.7
11.4
3.6
24.8
118.7
Liters/
shift
16.5
6.7
12.4
550.2
(46.37)
72.8
95.2
29.9
206.9
990.6
Percent of
flow
1.6
.7
1.3
55.6
(4.7)
7.3
9.6
3.0
20.9
100.00%
'PENDIX B.
o
£
c
T)
CO
ac
M
3
O
g
No flow during the clean up shift.
-------
TABLE B-2. TOTAL SOLIDS FROM THE MADISON PLANT CLEAN UP SHIFT
ro
ro
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs /shift
44.4
21.6
27.8
724.2
(310.8)
a
a
177.7
a
b
3592.
a
27.2
150.3
a
4765.2
kg/shift
20.1
9.8
12.6
328.5
(140.9)
80.6
1629
12.3
68.2
2161.1
lb/1000
Ib LWK
.031
.015
.019
.504
(.216)
.124
2.498
.019
.105
3.315b
Percent
of load
0.90
0.40
0.60
15.2
(6.51)
3.7
75.4
0.6
3.2
100.00%
No flow during the clean up shift.
3lb/1000 IbLWK = kg 1000 LWK.
-------
TABLE B-3. TOTAL VOLATILE SOLIDS FROM THE MADISON PLANT CLEAN UP SHIFT
CO
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs /shift
32.8
16.2
11.0
374.
(152.7)
a
a
<+6.5
a
a
127. if
a
18.5
54.4
a
677.8
kg/shift
14.9
7.3
5.0
170.
(69.3)
21.1
57.8
7.0
24.7
307.8
lb/1000 IbLWK
.023
.011
.008
.26
(.106)
.032
.089
.011
.038
.472
Percent
of load
4.8
2.4
1.6
55.7
(22.5)
6.9
18.8
2.3
8.0
100.00%
3
No flow during the clean up shift.
-------
TABLE B-4. SUSPENDED SOLIDS FROM THE MADISON PLANT CLEAN UP SHIFT
N>
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Qrease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Nech washer
Total
Ibs /shift
12.7
5.7
3.5
355.2
(152.7)
a
a
27.8
a
a
165.4
a
9.2
47.0
a
626.5
kg/shift
5.8
2.6
1.6
161.1
(69.26)
12.6
75.0
4.2
21.3
284.2
lb/1000 IbLWK
.009
.004
.002
.247
(.106)
.019
.115
'
.006
.003
.435
Percent
of load
2.0
.9
.6
56.7
(24.40)
4.4
26.4
1.5
7.5
100.00%
flow during the clean up shift.
-------
TABLE B-5. VOLATILE SUSPENDED SOLIDS FROM THE MADISON PLANT CLEAN UP SHIFT
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs /shift
11.2
4.4
I-7
212.7
(76.06)
a
a
15.3
a
a
75.4
a
8.2
20.5
a
349.4
kg/shift
5.1
2.0
.8
96.5
(34.1)
6.9
34.2
3.7
9.3
158.5
lb/1000 IbLWK
.008
.003
.001
.148
(.052)
.011
.052
.006
.014
.243
Percent
of load
3.2
1,2
.5
60.9
(21.4)
4.4
21.6
2.3
5.9
100.00%
aNo flow during the clean up shift.
-------
TABLE B-6. GREASE SUMMARY FROM THE MADISON PLANT CLEAN UP SHIFT
to
o>
Sample point mg/1
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain 145.00
Carcass shower
Center grease drain
330 Grease drain 620.00
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ib/shift
13.6
1.9
.3
31.41 -
(13.4)
14.6
66.1
10.0
8.42
146.33
kg/shift
6.2
.8
.2
14.2
(6.1)
6.6
30.0
4.5
3.8
66.3
lb/1000
Ib LWK
.009
.001
.001
.002
(.009)
.010
.046
.007
.006
.102
kg/1000
Ib LWK
.009
.001
.001
s .002
(.009)
.010
.046
.007
.006
Percent
of load
9.4
1.2
.3
21.4
(9.2)
10.0
45.2
6.8
5.7
100.00%
-------
TABLE B-7. TOTAL KJELDAHL NITROGEN FROM THE MADISON PLANT CLEAN UP SHIFT
Sample point
Bleed area floor drain
Blfeed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
5.8
1.3
.7
22.7
(21.7)
a
a
3.0
a
a
1.1
a
.2
1.6
a
36.4
kg/ shift
2.6
.6
.3
10.3
(9.83)
1.4
.5
.1
.7
16.5
lb/1000 IbLWK
.004
.001
.0005
.016
(.015)
.002
.001
.0001
.001
.0256
Percent
of load
15.9
3.6
1.9
62.4
(58.6)
8.2
3.0
.6
4.4
100.00%
No flow during the clean up shift.
-------
TABLE B-8. BOD FROM THE MADISON PLANT CLEAN UP SHIFT
to
00
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
23.6
6.5
1.2
180.0
(84.9)
20.5
--
65.7
7.2
9.7
314. 4
kg/shift
10.7
3.0
.6
81.7
(38.5)
9.3
29.8
3.2
4.4
142.7
lb/1000 IbLWK
.016
.005
.001
.125
(.059)
.014
.046
.005
.007
.219
Percent
of load
7.5
2.1
0.4
57.2
(26.9)
6.5
20.9
2.3
3.1
100.00%
-------
TABLE B-9. COD FROM THE MADISON PLANT CLEAN UP SHIFT
to
<£>
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Ibs /shift
40.0
18.18
8.1
543.00
(228.6)
64.5
99.7
16.1
31.0
kg/shift
18.1
8.24
3.6
246.00
(103.7)
29.2
45.2
7.3
14.0
__
lb/1000 IbLWK
.0278
.01264
.0056
.377
(.158)
.045
.0693
.011
.021
__
Percent
of load
4.9
2.2
1.0
66.2
(27.7)
7.9
__
12.1
2.0
3.8
«._
Total
820.58
371.64
.5693
100.00%
-------
CO
o
TABLE C-l. WASTEWATER
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
FLOW FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
Gallons/
shift
2840
1150
4810
195980
(8000)
12490
12800
43970
28850
20560
39930
(6520)
74850
112100
(12380)
Liters/
shift
10740
4360
18200
741769
(30280)
47275
48440
166450
109200
77840
151174
(24680)
283280
424290
(46870)
Gallons/
1000 Ib LWK
1.9
.8
3.4
136.3
(5.56)
8.6
8.9
30.6
(20.1)
14.3
27.8
(4.5)
52.1
78.0
(8.6)
Liters/
1000 kg LWK
16.5
6.7
27.9
1136.8
(46.4)
72.5
74.3
255.2
(167.4)
119.3
231.8
(37.8)
434.3
650.4
(71.8)
Percent
of flow
0.5
0.2
0.9
37.6
(1.5)
2.4
2.5
8.4
(5.5)
3.9
7.7
(1.2)
14.4
21.5
(2.4)
APPENDIX C. D,
H
*>!
O
*J
O
i-3
f
5
hrl
EDUCTION
ti
g
tn
o
£
1
^
Total
521500
1973818
3025.7
3025.7
100.00
-------
TABLE C-2. TOTAL SOLIDS FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
45
22
78
2484
(310.8)
77
99
373
(133)
127
4210
a
1438
6392
(1470)
15345
kg/shift
20.1
9.8
36.2
1127.5
(140.9)
35.1
45
169
(60.1)
57.6
1910.0
653.2
2898.8
(666.5)
6962.3
lb/1000 Ib LWK
0.031
0.015
0.055
1.729
(0.216)
0.054
0.069
0.260
(0.092)
0.088
2.928
1.000
4.445
(1.02)
10.674b
Percent
of load
0.3
0.1
0.5
16.2
(2.0)
0.5
0.7
2.4
(0.9)
0.8
27.4
9.4
41.7
(9.6)
100.00%
The pollutant load from the head washer is included in the 330 grease drain.
3lb/1000 Ib LWK = kg/1000 kg LWK.
-------
TABLE C-3. TOTAL VOLATILE SOLIDS FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
N>
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
33
16
56
1634
(153)
41
57
147
(56.1)
111
379
a
1190
5420
(1415)
9084
kg/shift
14.9
7.3
24.5
740.3
(64.3)
18.5
25.8
66.5
(25.4)
50.4
171.7
540
2458
(642)
4117.9
lb/1000 Ib LWK
.023
.011
.038
1.135
(.106)
.028
.040
.102
(.039)
.077
.264
.828
3.68
.980
6.314b
Percent
of load
0.4
0.2
0.6
18.0
(1.7)
0.4
0.6
1.6
(.6)
1.2
4.2
13.1
59.7
(15.6)
100.00%
The pollutant load from the head washer is included in the 330 grease drain.
3lb/1000 Ib LWK = kg/1000 kg LWK.
-------
TABLE C-4. SUSPENDED SOLIDS FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
CO
CO
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
12.7
5.7
9.0
1288.0
(152.7)
6.8
12.8
58.6
(6.0)
47.4
289.1
a
973.7
3421.9
(680)
6125.7
kg/shift
5.8
2.6
4.1
584.0
(69.3)
3.1
5.8
26.6
(2.7)
21.5
131
441.7
1552.1
(380)
2778.3
lb/1000 Ib LWK
.009
.004
.006
.896
(.106)
.005
.009
.040
(.004)
.033
.201
.677
2.379
(.472)
4.259b
Percent
of load
0.2
0.1
0.1
21.0
(2.5)
0.1
0.2
1.0
(.10)
0.8
4.7
15.9
55.9
(.1)
100.00
The pollutant load from the head washer is included in the 330 grease drain.
3lb/1000 Ib LWK * kg/1000 kg LWK.
-------
TABLE C-5. VOLATILE SUSPENDED SOLIDS FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
11.2
4.4
6.4
1048
(76.1)
5.9
12.2
41.4
(5.2)
42.1
190.
a
879.
271.6
(639)
4956.6
kg/shift
5.1
2.0
2.9
475.
(34.1)
2.7
5.5
18.7
(2.4)
19.1
86.2
398.7
1232.
(289.)
2247.9
lb/1000 Ib LWK
.008
.003
.004
.728
(.052)
.004
.008
.029
(.004)
.029
.132
.612
1.894
(.440)
3.451b
Percent
of load
0.2
0.1
0.1
21.1
(1.5)
0.1
0.2
0.8
(0.1)
0.9
3.8
17.7
54.8
(12.8)
100.00
The pollutant load from the head washer is included in the 330 grease drain.
?lb/1000 Ib LWK = kg/1000 kg LWK.
-------
TABLE C-6. GREASE FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
CO
en
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs /shift
13.6
1.9
2.6
289.81
(13.4)
c
7.2
31.4
d
11.0
172.4
a
2102.0
5170.4
e
7802.01
kg/shift
6.2
.9
1.2
131.4
(6.1)
3.3
14.2
5.0
78.2
953.4
2344.1
3537. 8b
lb/1000 lb LWK
.009
.001
.003
.202
(.009)
.005
.022
.008
.120
1.461
3.596
5.427b
Percent
of load
0.2
0.1
0.1
3.7
(0.2)
0.1
0.4
0.1
2.2
26.9
66.3
100.00
The pollutant load from the head washer is included in the 330 grease drain.
bib/1000 lb LWK = kg/1000 kg LWK.
cThe rosin stripper has a negligible grease contribution.
^The carcass shower grease load is included in the 660 grease drain.
eThe neck washer grease is included in the hasher washer.
-------
TABLE C-7. TOTAL KJELDAHL NITROGEN FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
en
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs/shift
5.8
1.3
7.0
211.2
(21.7)
3.3
6.6
30.0
(11.5)
64.5
81.4
a
59.2
337.8
(35.7)
808.1
kg/shift
2.6
.6
3.2
95.8
(9.8)
1.5
3.0
13.7
(5.2)
29.3
36.9
26.9
153.2
.(16.2)
366.7
lb/1000 Ib LWK
.004
.001
.005
.147
'(.015)
.002
.005
.021
(.008)
.045
.057
.041
.231
(.021)
.559b
Percent
of load
0.7
0.2
0.9
26.1
(2.7)
0.4
0.8
3.7
(1.4)
8.00
10.1
7.3
41.8
(4.4)
100.00
aThe pollutant load from the head washer is included in the 330 grease drain.
blb/1000 Ib LWK = kg/1000 kg LWK.
-------
TABLE C-8.
BOD,. FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
o
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ibs /shift
23.6
6.5
21.7
951
(84.9)
12.6
28.2
74.3
13.71
35.7
308.3
a
779.7
3892.
(51.7)
6133.6
kg/shift
10.7
3.0
9.9
431.6
(38.5)
5.7
12.8
33.7
(6.2)
16.2
139.9
353.6
1765.4
(234)
2782.5
lb/1000 Ib LWK
.016
.005
.015
.661
(.059)
.009
.020
.051
(.010)
.025
.215
.542
2.707
(.360)
4.266b
Percent
of load
.4
.1
.4
15.5
(1.4)
.2
.5
1.2
(0.2)
.6
5.0
12.7
63.4
(8.4)
100.00
The pollutant load from the head washer is included in the 330 grease drain.
Dlb/1000 Ib LWK = kg/1000 kg LWK.
-------
TABLE C-9. COD FROM THE MADISON PLANT PRODUCTION AND CLEANUP SHIFTS
CO
GO
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Scald tank
Rosin stripper drain
Rail polisher drain
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Head washer drain
Stomach washer
Hasher washer drain
Neck washer
Total
Ubs /shift
40.
18.2
60.6
2425.
(228.6)
34.0
64.9
179.
(48.2)
485.
544.
a
1887.
9811.
(1402)
15548.7
kg/shift
18.1
8.2
27.4
1100.
(103.7)
15.3
29.4
81.1
(21.8)
219.8
246.7
856.3
4450
(635)
7.052.3
lb/1000 Ib LWK
.027
.013
.042
1.685
(.158)
.023
.045
.125
(.030)
.377
.360
1.315
6.821
(.900)
10.833b
Percent
of load
.3
.1
.4
15.6
(1.5)
.2
.4
1.2
(0.3)
3.1
3.5
12.1
63.1
(9.0)
100.00
3The pollutant load from the head washer is included in the 330 grease drain.
blb/1000 Ib LWK = kg/1000 kg LWK.
-------
APPENDIX D. CORRELATION OF PARAMETERS
The cost of conducting a wastewater survey increases rapidly as more
pollution parameters are measured. It may fortunately happen that
one measure of pollution correlates strongly with another. Then the
survey could eliminate some measures without sacrificing information.
Linear correlations between parameters were examined to see if this
could be
-------
O
18
16
14
_ 12
o>
E
ro
'O
Q
O
CD
10
8
T
BOD = 1121 +0.35 COD
f = 0.82
1
I
I
_L
8000
16000
240OO
32000
40000
COD, mg/l
Figure D-l. Correlation of BOD-COD at hasher washer.
-------
o>
6
10
'O
o
§
18
16
14
12
10
8
1
BOD = 298 + 1.54 TOTAL CARBON
r *0.83
2000
4OOO 6000 80OO
TOTAL CARBON , mg/l
IOOOO
Figure D-2. Correlation of BOD-Total Carbon at -hasher washers.
-------
.p
to
If)
o
Q
O
00
18
16
14
12
10
8
6
4
2
0
T
- BOD*630 + 1.53 ORGANIC CARBON
r = 0.84
I
I
I
2000
4000
6000
ORGANIC CARBON,mg/l
I
8000
10,000
Figure D-3. Correlation of BOD-Organic Carbon at Hasher washer.
-------
O»
E
to
'O
o
O
CD
I8|
16
- 800=164540.86 SS
3000
6000
9000
12000
I5OOO
SUSPENDED SOLIDS, mg/l
Figure D-4. Correlation of BOD-Suspended Solids at hasher washer.
-------
18
o>
E
to
O
o
O
CD
16
14
12
10
8
6
4
2
0
-2
BODH404 + 14.6 TKN
200 400 600 800 1000
TOTAL KJELDAHL NITROGEN , mg/l
1200
Figure D-5. Correlation of BOD-TKN at hasher washer.
-------
measurement indicates both nitrogen and BOD and is, therefore an
attractive and efficient parameter for wastewater characterization
Meat industry wastes contain large amounts of proteinaceous matter
apparently, in concentrations that are a consistent proportion of '
the total organic matter measured as organic carbon or carbonaceous
oxygen demand. Table D-2 summarizes these relations. The three
stations having low correlations produced a few erratic data points
for which there is insufficient justification for total rejection.
This nitrogen measurement is very informative because from it one
can infer usable values for other parameters at most stations. Most
meat industries have the capability to measure TKN; they may not
be equipped to do the BOD, COD, or Total Carbon tests. The TKN
test, therefore, becomes a good screening tool for the first in-house
pollution survey.
Suspended solids is also a useful surrogate even though the
correlation is slightly less.
Table D-3 shows BOD prediction equations for the thirteen sampling
points in the Madison plant. The correlation for the center
grease drain is not significant. The correlation coefficients of
those relations that are significant are very high.
The two parameters of each equation are the slope and the intercept.
The value of the intercept depends on the strength of the waste at
a particular location while the slope depends on the nature of the
organics in the waste and their relative biodegradability. In four
cases the intercept is positive even though it is well known that
the COD of a waste is always greater than the BOD. This happens
because the intercept obtained by extrapolation is far beyond the
range of the actual data. The intercept is a fitting parameter
without any physical significance.
If the wastewater from each station contains the same proportion
of biodegradable organics to chemically oxidizable organics, the
slopes would all be the same (within some reasonable range). The
slopes for the bleed conveyor wash drain and the neck washer are
noticeably different than the others. The bleed conveyor wash
drain waste is very dilute and the pollutant is blood. The neck
wasSrTstewater contains substantial amounts of fatty tissue and
this may be the reason the BOD at this station represents a
greater fraction of the COD than at other stations.
-------
Table D-2. BOD-TKN CORRELATIONS
Sample point Relation
Bleed area floor 4rain BOD - 32 + 4.6 TKN 0.84 15
Bleed area blood drain BOD 188.4 + 4.2 TKN 0.97 12
Chain wash BOD » 0.67 + 1.8 TKN. 0.97 25
Dehair floor drain BOD - 37.6 + 4.28 TKN 0.86 44
Rosin stripper BOD 43 + 3.79 TKN 0.98 5
Rail polisher BOD 11.9 + 4.4 TKN 0.90 13
660 grease drain BOD - 179 + 0.258 TKN 0.49 41
Carcass shower a 18
Center grease drain BOD "38+0.45 TKN 0.85 11
330 grease drain a 24
Stomach washer a 11
Hasher washer BOD »-1404 + 14.6 TKN 0.85 24
Neck washer BOD - 2626 + 6.8 TKN 0.86 16
a
Insignificant correlation.
-------
Table D-3. CORRELATION VALUES BETWEEN PARAMETERS MONITORED DURING THE STUDY
Sample point
Bleed area floor drain
Bleed conveyor blood drain
Bleed conveyor wash drain
Dehair floor drain
Rosin stripper drain
Rail polisher drain
660 grease drain
Carcass shower
Center grease drain
330 grease drain
Stomach washer
Hasher washer drain
Neck washer
Prediction equation
BOD
BOD
BOD
BOD
BOD
BOD
BOD
- BOD
BOD
BOD
BOD
- -135 +0.53 COD
a
= 10 + 0.13 COD
= 109 + 0.32 COD
= -3.7 + 0.38 COD
» 40.6 + 0.36 COD
= -9.7 + 0.49 COD
- -10.4 + 2.29 COD
b
= -8.7 + 0.54 COD
= 85.1 + 0.38 COD
= 1121 +0.35 COD
= 2584 +0.17 COD
Correlation
coefficient
0.98
a
0.93
0.90
0.94
0.89
0.84
0.95
0.98
0.84
0.82
0.76
Sample
size
15
25
60
5
13
42
18
24
28
24
16
Significant
at 95% level?
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
yes
aData insufficient to do analysis.
Insignificant relation.
-------
Table D-4 shows other correlations that bear out conclusions already
drawn.
Another question that has been studied in cursory fashion is whether
or not the correlations change after a change has been made. If,
for example, meat scrap that once entered the drain is picked up dry,
does this alter the wastewater organic fractions enough to change
the slope of the regression equations? Table D-5 shows a few of
the hasher washer relations derived after a substantial change in the
process was made. The nature of the relation was maintained. The
correlation coefficient is higher, probably, because there was less
intermittent sluicing of heavy wastes into the drain. COD or TKN
still seem to be attractive surrogates for BOD.
Because so much of this project was directed toward thorough
characterization, it was considered better practice to collect data
on many parameters throughout the project rather than to try and
take advantage of correlations to alter the analytical program
early in the project. Now that the project is complete and the data
is at hand, it is clear that preliminary wastewater surveys in the
meat industry could be based firmly on total Kjeldahl nitrogen
measurements , supplemented with solids analysis and an occasional
COD. Major sources of pollution would be identified quickly and
reliably with minimum effort.
148
-------
Table D-4. BOD PREDICTIVE RELATIONS FOR THE MADISON PRODUCTION SHIFT INITIAL CHARACTERIZATION
(£>
Sample point
Bleed area floor drain
Bleed area blood drain
Chain wash
Dehair floor drain
Rosin stripper
Rail polisher
660 Grease drain
Carcass shower
Center grease drain
330 Grease drain
Stomach washer
Hasher washer
Neck washer
Total carbon
-319 +1.78 TCa
(0.99)b
c
-19.4 + 0.37 TC
(0.96)
c
d
-70.4 +1.19 TC
(0.94)
d
c
c
2.98 + 1.54 TC
(0.85)
c
Organic carbon
898 + 0.65 OC
(0.65)
c
8.5 + 0.41 OC
(0.95)
9.2 + 1.2 OC
(0.95)
d
12.6 + 1.19 OC
(0.94)
d
c
c
630 + 1.53 OC
(0.84)
c
Susp. solids
-56 + 2.79 SS
(0.82)
536 + 0.78 SS
(0.74)
22.8 + 0.24 SS
(0.80)
181 + 0.50 SS
(0.84)
15.8 + 1.60 SS
(0.79)
113 + 1.25 SS
(0.45)
c
-8.37 + 2.59 SS
(0.66)
c
283 + 1.51SS
(0.87)
407 + 0.55 SS
(0.75)
1645 + 0.86 SS
(0.71)
1084 + 0.59SS
(0.90)
TKN
32 + 4.6 TKN
(0.84)
338 + 3.5 TKN
(0.88)
0.67 + 1.8 TKN
(0.97
386 +2.6 TKN
(0.57)
-0.43 + 3.79 TKN
(0.98)
11.9 + 4.4 TKN
(0.90)
178 + 0.26 TKN
c
38 + 0.45 TKN
(0.85)
d
d
-1404 +14.6 TKN
(0.85)
2626 +6.8 TKN
(0.86)
N
15
19
25
60
5
13
42
18
11
24
28
24
16
: BOD - given relation.
Correlation coefficient.
5Insufficient data.
°Insignificant correlation.
-------
Table D-5. CORRELATION AT THE HASHER WASHER AFTER THE IMPROVEMENT
BOD =
BOD -
BOD =
BOD =
BOD =
Relation
433 +0.33 COD
507 +1.05 Total carbon
638 +1.05 Organic carbon
354 +1.87 Suspended solids
654 + 3.2306 TKH
r
0.95
0.908
0.908
0.89
0.95
n
11
11
11
11
11
150
-------
APPENDIX E. DATA MANAGEMENT FOR AN INDUSTRIAL WASTEWATER SURVEY
I INTRODUCTION
Accurate and efficient data handling and analysis is crucial to the
success of an industrial waste survey. If data is lost, or if data
is misrepresented, the resulting conclusions will be weak or
incorrect. The value of a well organized data handling system
increases in proportion to the size of the project and the amount of
data handling and analysis.
The data management program described here is not needed for small
surveys. It was necessary for this project because it involved
studies at three different production facilities. At the Madison
plant thirteen locations were sampled on both the production and
cleanup shifts, and each location was sampled on many different days.
Flows and concentration parameters had to be measured and recorded.
The pollution parameters routinely analyzed were:
.Total solids .Total Kjeldahl Nitrogen
.Total volatile solids .Organic Carbon
.Suspended solids .Total Carbon
.Volatile suspended solids .Biochemical Oxygen Demand
.Grease .Chemical Oxygen Demand
Fifteen people were involved in data collection, data processing,
and data analysis. Hundreds of bits of data needed to be processed
and each bit of data represented a sample that had to be collected
and analysed in the laboratory. Keeping track of the samples as
they were processed through the laboratory, and monitoring the data
as they went to the keypunch operator and then onto magnetic tape was
a major problem.
The overall data management scheme is diagrammed in Figure E-l. The
stepwise procedure included data collection, laboratory analysis,
data entry for computer logging, data storage, and data analysis.
The production shift data and the cleanup shift data had to be
analyzed differently so they will be discussed separately.
II DATA MANAGEMENT
2:
151
-------
PHASE ONE
Data Collection and Data Storage
PHASE TWO
Data Analysis-
Data
logged on
tape from
remote >-
terminal
Data
stored
in
matrix
format
production
shift data v
cleanup
Statistical
analysis
Calculate
pollution
loadings
Correlation
analysis
/
tn
ro
shift data
Conclusions are not clear -
order more samples for specific
sampling points or specific
pollution parameters
Figure E-l. Process flow sheet for data management and analysis.
-------
CHARACTERIZATION AilD REDUCTION
Date
01
CO
IH-PLAHT HOG PROCESSING UHI7S «,
OP THE JJEAT INDUSTRY. Sample Description: Plant Location
Process Area »
OSCAR MAYER & CO./W7-MSN Sample Point
EPA R802833-01
Sanple
ident .
Time
Solids (Residue)
TO
TVS
Analysis Comoletefl
SS
VSS
Grease
anpling
nalyst
Kill St
En
Nitrogen
TICI
WH.j-n
Remarks: Concentrations in milligrams per liter
Phosphorus
T.P.
S.OP-P
Diagram:
Alk.
pH
units
_______ Sup. _____
art
a
Carbon
Org.
Total
DOD
COD'
Rev 9/74
Figure E-2. Laboratory data form.
-------
accomplish this task. The individual collecting the sample filled
in the form consistant with the sample bottle labels, and marked
a check under the desired analyses. One sheet is used for each
sampling point and for each day of sampling.
The second step is laboratory analysis. The laboratory technician is
responsible for proper care of the samples after they have been
delivered to the laboratory and, obviously, for accurate analytical
measurements. When the analysis is complete, he checks the
"Analysis Completed" box in the bottom row of Figure E-2, and gives
the completed form to the project manager. Two copies are made of
the completed laboratory analysis sheet. One copy is retained in
the laboratory file, one copy goes to the project manager, and the
original is sent to the teletype terminal operator. It is essential
that the laboratory technician fill in the form completely and
legibly to avoid confusions during entry of the data onto the
computer tape.
A "Lab in Progress" form was developed to control the sample inventory.
This is shown as Figure E-3. It gives the project manager and the
laboratory technician a method for estimating the number of samples
in the laboratory and the length of time they have been there. It
was also useful in planning sampling schedules.
The terminal operator enters seventeen bits of data from each line
on the Laboratory Analysis Sheet. The seventeen data points entered
are: the time each sample was collected, and the following sixteen
columns of parameter values. The data analysis program is written
in free format to minimize the instruction for the terminal operator.
Plant location, date, processing area, and other geographic
information from the data transmissions sheets are logged as data and
eventually appear on the print out to facilitate clear and complete
identification of the data. The data is put onto magnetic tape. A
soft copy of the data on tape is given to the project manager who
checks it for errors. Decimal point errors are obvious on the
computer printout. Suspicious values also stand out and'these are
checked against the original data sheet. Samples are stored until
this check is made in case a "wet check" is desired. Once the data
file is error free, the data is transferred from the tape to cards.
Some users might prefer to manipulate the tape file but in our
case different computing facilities were used for different data
analysis jobs, and having the data as a card deck was very convenient.
To optimize the data entry and data handling, the data was collected
into groups or batches. The progress of each batch from laboratory
to computer file to carddeck in the project manager's hands was
monitored and controlled.
154
-------
Ol
Ol
FIGURE E-3
CHARACTERIZATION AND REDUCTION OF SPECIFIC WASTEWATERS FROM IN-PLANT HOG
PROCESSING UNITS OF THE MEAT INDUSTRY
Lab In-progress Inventory Sheet
Plant
Shift
Sample Point
"i DatG~Recfeved~iNo 7 of "SampTes i~ "Data sent tot
J ! L-.-Jianage£ i
I
Bleed _conveypr_washjJrarnr ~ ~" _Z_ L ~ _ H _ _"~Z
DeiTafr'Troor "cTrafn"" "~ ~i i i
Scard" "CanT? " _ _~ ~j ~ [ j
ITosfn""sTffpp"ef d"raTn f T~^"\ i
\
.
Grea£e _
Carcass shower
grease "drain ~~i i-=,7j~"7"3"-~y «"*£ 7"S"
" ~~~ "-Li 3*111 I~JL
rread~wasn"e"r ~d"raTn
ITasTTef "washer "drain
i
f
-2-7
-------
In addition to having the data stored as a card deck, a printed
display in matrix form was always prepared. This matrix was
identified with all details of time and location. These printouts
were used to convey data, and this matrix format was the basis for
subsequent data analyses. (See Table E-l)
III PRODUCTION SHIFT DATA ANALYSIS
Data analysis consisted of three steps: (1) statistical analysis,
(2) calculating pollution loads, and (3) correlation analysis with
graphical output.
Statistical analysis was used to summarize the concentration data
available at each sampling point. This was used to facilitate
interpretation and, later, to calculate pollution loads. The average
concentration of each pollutant at each sampling point for each
day is calculated. A sample of the output is shown as Table E-l.
The "grand mean" represents the arithmetic average and is considered
the best estimate of the average concentration. The "90% maximum
value" for each parameter and the standard deviation indicate the
spread and variability of the data. Sample points with a large
standard deviation have to be sampled more frequently than others to
obtain a precise estimate of the average.
The total pollution load calculation was discussed in Section 5 and
no lengthy comment is required here. In nearly all cases (days
and stations) the best estimate of the mass load of a pollutant
was the average concentration multiplied by the average flow rate.
This calculation was performed by the computer and the printout is
shown in Table E-2. Because of flow measurement problems at some
stations, there was not always an estimate of the flow for the day
on which samples were collected. Samples were collected on several
days at each station to minimize day to day variation that would
invalidate this approach. At a few stations the flow and wastewater
load was influenced by the start-up of a second kill line. At a
few stations the rate of killing (hogs per hour) seemed to change
concentrations. Day to day and within day variations were studied
to select the proper means of calculating the mass loads. The
stations where killing rate made it proper to adjust the calculations
were the Hasher Washer Drain and the Hair Wash Drain.
The method of calculation used in these cases is given below.
Calculate gallons/1000 IbLWK (from the daily flows and the
corresponding live weight kills.
156
-------
TABLE E-l
MADISON PLANT - PRODUCTION
RAILPOLISHER FLOOR DRAIN
CONCENTRATIONS IN MILLIGRAMS PER LITER
IEE Jl
_SS
fJ THiCS SOP-P AU< PH ORG-C TOT-C JOJ>5 COD
1D.O
10.3
11,0
11.3
12.3
1.0
1.3
2.0
1,0
1.1
1.4
2.0
2.1
942.0
908.0
835.0
1034.0
868.0
944.0
820.0
966.0
798.0
890.0
1082.0
932.0
1068.0
554.0
510.0
450.0
630.0
476.0
530.0
464.0
582.0
400.0
498.0
672.0
518.0
640.0
123.0
102.0
94.0
118.0
106.0
102.0
88.0
138.0
154.0
140.0
150.0
126.0
U6.0
127.0
101.0
94.0
115.0
103.0
98.0
82.0
132.0
142.0
128.0
140.0
112.0
108.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
60.4
60.9
50.7
78.5
57.4
62.4
48.1
64.0
40.8
63.0
80.2
65.9
78.9
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
o.o
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
205.0
187.0
177.0
235.0
175.0
190.0
150.0
207.0
163.0
207.0
297.0
233.0
295.0
280.0
260.0
250.0
310.0 -
250.0
205.0
223.0
277.0
86.0
127.0
215.0
150.0
213.0
254.0
255.0
201.0
280.0
230.0
254.0
186.0
292.0
196.5
270.0
394.0
280.0
346.0
536.
571.
496.
806.
505
en.
430.
611.
459.
591.
836.
592.
868.
GRAND
5.1 929.8 532.6 120.2 114.0 0.0 62.4 0.0 0.0 Q.O 0.0 0.0 0.0 209.3 218.9 264.5 608.
90 PERCENT PROBABILITY OF OCCURENCE = VALUE THAT THE POLLUTANT MILL BE LESS THAN 90 PERCENT OF THE TIME
11.4 1046.2 635.7 147.5 137.9 0.0 .77,7 0.0 0.0 0.0 0.0 0.0 0.0 267.8 301.8 339.4 791.
STANDARD DEVIATION
4.8 90.8 80.4 21.3 18.6 0.0 11.9 0.0 0.0 0.0 0.0 0.0 0.0 45.7 64.6 53.5 142.
STANDARD ERROR
1.3 25.2 22.3 5.9 5.2 0.0 3.3 0.0 0.0 0.0 0.0 0.0 0.0 12.7 17.9 16.2 39.
-------
TABLE E-2
PLANT - PRODUCTION
PAILPOLISHER FLOOR DRAW
CONCENTRATIONS IN MILLIGRAMS PER LITER
AVERAGE FLOW IN GALLONS PER SHIFT = 12797.40
AVERAGE FLOW IN GALLONS PER 1000 LB LWK - G.90
AVERAGE FLOW IN LITERS PER 1000 & LWK = 71.25
H
cn
00 AVERAGE FLOW IN LITERS PER SHIFT = 1033.15
IS M SS. i& GBS. m %N QR6-N TPHQS SOP-P M PJi ORS-C TQT-C MS COD
AVERAGE POUNDS OF POLLUTANT PER SHIFT
.55 99.24 56.85 J2.82 12,17 0.00 6.66 0.03 0.00 0.00 0.00 0.00 0.00 22.34 23.37 23.23 64.9
AVERAGE POUNDS OF POLLUTANT PER JOOO LB LWK
.000 .069 .040 .009 .008 0.000 .005 0.000 0.000 0.000 0.000 0.000 0.000 .016 .016 .020 .04
KILOGRAMS PERlOOOLWK=LBsPERlOOOLBLWK
AVERAGE KILOGRAMS OF POLLUTANT PER SHIFT
.25 45.02 25.79 5.82 5.52 0.00 3.02 0.00 0.00 0.00 0.00 0.00 0.00 10.13 10.60 12.81 29.4
-------
T P°llutant concentration to get Ib of pollutant/
JLbLWK
.Convert to international units
-liter/lOOOkgLWK
-Kg/1000 kgLWK
Correlation analysis was done simply by specifying which columns of
the data matrix should be worked with. For example, the BOD-COD
correlation could be done by calling column 16 and column 17 from
the matrix and entering them in the correlation subprogram. Samples
of the correlation analysis were given in Appendix D. Graphical
output was managed in the same way and sample graphs are also
included in Appendix D. The entire data analysis technique was
centered around the matrix display format. This format gave clear,
visual displays of data as it was obtained and it aided in pin-
pointing errors and problems.
IV CLEANUP SHIFT DATA ANALYSIS
The data management and analysis for the cleanup shift was
complicated by the flow measurement data problem. There is extreme
variability in flow during cleanup and most of the pollution load is
washed out as a "first flush" at the beginning of the cleanup shift.
An accurate estimate of both flow and concentration during the first
flush was needed. Cleanup hoses and other intermittant water use
devices could not be metered directly so the Lithium dilution method
was used. This created the need to handle many more samples for
lithium analysis along with samples for COD analysis, etc. The
inventory control method described before was used.
The data for flow and concentration was combined into estimates of
mass loading as illustrated in Section VI. The computer print out
that is the counterpart of the example in Section VI is similar to
Tables E-l and E-2.
V CONCLUSIONS
The costs of organizing the data management and analysis system were
amply rewarded. There was always easy access to the data and it
ra always obvious to the laboratory, terminal operat or «*p«J«*
wa&
-------
Due to the computerized data analysis system, the entire data file
was recalculated in three hours.
A well organized data management system repays the initial investment
in its creation with many benefits. The management system described
was developed during the early part of this project and was used with
great success for more than one year. Experience gained from this
will be valuable whenever a large sampling program is undertaken in
the future.
160
-------
REPORT NO.
EPA-600/2-77-097
T!£HBL?AJ-REPORT DATA
IDI '"^nimv.ML. rttrUK I
(Pease read Instructions on the reverie
3. RECIPIENT'S ACCESSIOf*NO,
TITLE AND SUBTITLE
CHARACTERIZATION AND IN-PLANT REDUCTION OF WASTEWATER
FROM HOG SLAUGHTERING OPERATIONS WAblhWATER
5. REPORT DATE
May 1977 issuing date
6. PERFORMING ORGANIZATION CODE
Paul M. Berthouex, David L. Grothman, Donald 0. Dencker
Lawrence J. P. Scully
8. PERFORMING ORGANIZATION REPORT NO.
University of Wisconsin - Madison, WI
Oscar Mayer g Co. - Madison, WI
Peat, Marwick, Mitchell £ Co. - Washington, DC
10. PROGRAM ELEMENT NO.
1BB610
11. CONTRACT/GRANT NO.
802833
12, SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory - Cin., OH
Office of Research and Development
U.S. Environmental Protection Aeency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Wastes generated were characterized and quantified in typical hog slaughtering
operations both before and after modifications were made to reduce wastewater volume
and strength and to increase by-product recovery. The research was carried out in the
Oscar Mayer plants at Madison, Wisconsin, Beardstown, Illinois, and Davenport, Iowa.
In the Madison plant, abut two thirds of the flow and 80% of the BODs were dis-
charged during the production shift; the balance was from cleanup. The average work d;
for production was 7.79 hr, during which the Live Weight Killed (LWK) averaged l.H
million pounds. The flow resulting from this operation was 520,000 gal/day or 362.7
gal/1000 Ib LWK. The BOD5 load was 6*100 Ib/day, or 4.26 Ib BOD5/1000 Ib LWK.
Process modifications reduced the flow by 41%, the BOD5 by 63%, and the suspended
solids by 63%. Most process modifications cost only a few hundred dollars; the most
expensive change cost $12,000. Every modification will pay for itself within 1 or 2
years. Often the savings in water alone justifies a -modification, and savings in wast<
treatment and surcharges are a bonus. Individual process modifications annually saved
from $280 for simply turning off^a valve up to $129,000 for modifying the hasher washei
to recover more scrap for rendering.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
Industrial Wastes, Industrial Water, Food
Processing, Blood, Greases, Hair, Swine
3. DISTRIBUTION STATEMENT
Release to Public
c. COSATI Field/Group
Meat Packing Wastes,
In-plant Control, Slaugh-
terhouse, Viscera
19. SECURITY CLASS (ThisKeport)
20. SECURITY CLASS (ThU page)
13B
EPA Form 2220-1 (9-73)
161
U.S. GOVERNMENT PRINTING OFFICE: 1977-757-056/WO* Region
NO. 5-1 1
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