INPLANT WATER MANAGEMENT
TO MEET NEW ENVIRONMENTAL REQUIREMENTS:
POULTRY PROCESSING FACILITIES
PREPARED FOR
ENVIRONMENTAL PROTECTION AGENCY
TECHNOLOGY TRANSFER PROGRAM
DESIGN SEMINAR
FOR
INDUSTRIAL POLLUTION CONTROL
Little Rock, Arkansas
January 16, 17, 18, 1973
ENVIRONMENTAL ENGINEERING, INC.
Gainesville, Florida
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UPGRADING EXISTING
POULTRY PROCESSING FACILITIES
TO MEET NEU ENVIRONMENTAL REQUIREMENTS:
INPLANT WATER MANAGEMENT
Prepared for
ENVIRONMENTAL PROTECTION AGENCY
TECHNOLOGY TRANSFER PROGRAM
DESIGN SEMINAR
FOR
INDUSTRIAL POLLUTION CONTROL
Little Rock, Arkansas
January 16, 17, and 18, 1973
ENVIRONMENTAL ENGINEERING, INC,
Gainesville, Florida
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TABLE OF CONTENTS
Page
I. POULTRY PROCESSING WATER MANAGEMENT 1-1
Introduction 1-2
Definitions 1-8
Poultry Processing 1-10
Water Flows and Management 1-16
Summary of Recommendations 1-29
Future Efforts 1-31
References 1-32
XI. THE GOLD KIST CASE STUDY 2-1
Introduction 2-2
The Study . 2-3 .
Process and Equipment Changes 2-6
Summary of Results 2-12
III. WATER SUPPLY IN OFFICIAL POULTRY PLANTS 3-1
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POULTRY PROCESSING WATER MANAGEMENT
By
Richard H. Jones, Ph.D., P.E.
John D. Crane
and
T. A. BursztynsKy, P.E.
Environmental Engineering, Inc.
2324 Southwest 34th St.
Gainesville, Florida 32601
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INTRODUCTION
The poultry processing Industry 1s characterized by vertical
Integration from hatchery through feed mill, processing, and disposal of
product on contract basis. The overwhelming mass of production 1s 1n
broilers, turkeys, and mature chickens. The rise of poultry production
reflects the general growth of the consumptive market with 3.8 billion
pounds of broilers and chickens produced 1n 1950, 6.9 billion pounds in
1960, 9 billion pounds In 1965, and 10.8 billion pounds in 1971(1). This
represents a substantial number of birds at a 1971 average live weight
of 3.7 pounds per bird. Turkey production in 1950, 1960, 1965, and
1971 was 0.8 billion pounds, 1.5 billion pounds, 1.9 billion pounds, and
2.3 billion pounds, respectively. Average turkey live weight may be con-
sidered 18.8 pounds per bird. In 1970 the percentages of Federally in-
spected poultry slaughter by product class were broilers at 77.7 percent,
mature chickens at 6.3 percent, turkeys at 15.3 percent, and other poultry
at 0.7 percent. The plants under Federal Inspection slaughtered over
90 percent of the U.S. Poultry production in 1970^.
The South Atlantic region 1s composed of Delaware, Maryland, Vir-
ginia, West Virginia, North Carolina, South Carolina, Georgia, and
Florida. The South Central region Includes Kentucky, Tennessee, Alabama.
Mississippi, Arkansas, Louisiana, Oklahoma, and Texas. These two regions
In 1970 accounted for 86.8 percent of total broiler production, 48.1 per-
cent of mature chicken production, and 32.8 percent of turkey production.
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There are approximately 402 Federally Inspected slaughtering
plants In the United States, Of these, there are approximately 218
plants in the South Atlantic and South Central Regions. In these two
regions, 9 percent of the plants slaughtered less than 10 million
pounds of live weight In 1970, 58 percent processed between 10 and 50
million pounds per plant in 1970, and 33 percent processed 50 million
pounds or more.
The large size and concentration of the poultry processing in-
dustry becomes particularly important in view of its waste generation.
In poultry processing, feathers, blood, dirt, and viscera are removed
from a product that must be made acceptable for human consumption.
Large quantities of water are consumed In both washing and cleaning the
poultry in processing and also to carry away large amounts of waste to
screening and ultimate disposal. The highly organic nature of the waste
may cause bacterial blooms, depressed oxygen levels, and severely dis-
rupted biota in receiving streams. Waste discharged to a sewage treat-
ment system provides a substantial loading in terms of population equi-
valent, escaping grease, feathers, and offal. These constituents hamper
treatment processes and are subject to substantial sewer use surcharges
by municipalities.
A survey 1n 1970 of Federally inspected slaughtering operations
indicated that 29 percent of the plants had some degree of private waste
treatment, 65 percent had final municipal waste treatment, and 6 percent
had no waste treatment whatsoever. The reduction of water usage in the
poultry processing operations and the water reaching the final effluent
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will thus be a benefit to processors, municipal waste treatment facil-
ities and the general public whose environment 1s affected.
Many communities are faced with having to provide advanced waste
treatment to comply with Federal and State regulations. Individual in-
dustrial plants discharging directly to a water course are also coming
under more stringent controls. In the General Session of this Seminar,
the EPA has presented some of its plans for permitting wastewater dis-
charges. It has been Indicated that all poultry processors will eventually
come under direct or Indirect pressure to reduce their wastewater flows
and strengths. Either wastewater characteristics will be directly regulated
or those processors using municipal facilities will experience substantial
sewer surcharges.
While a considerable number of plants are being charged minimal
rates for their waste treatment at the present time, there 1s a rapidly
growing trend among municipalities to make Industry pay for its share of
waste treatment. As regulations force municipal plants to improve their
wastewater effluent qualities at greater treatment costs, the costs will
be passed on to those industries discharging a significant amount of waste
to the system. Normal sewer charges to industry are based on flow rate
and allow up to 250 or 300 mg/1 of BOD and suspended solids in the waste
stream. Additional concentrations of BOD and suspended solIds have been
charged at rates of $25 to $80 per thousand pounds of each. The result of
these factors is an increased incentive for wastewater reduction.
Based on a sewer charge of 25 cents per 1,000 gallons, typical
water use and waste discharges, and a wastewater flow of 18.4 billion
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gallons, USDA has predicted a cost of municipal waste treatment to poultry
processors at $4.6 million.^ ' The live weight slaughter at the plants
surveyed by the USDA was 8.4 billion pounds with a calculated sewer charge
of 5.5 cents per 100 pounds of live poultry. Inefficient plants losing
excessive sol Ids to wastewater streams stand to have Increased sewer sur-
charges and concomltantly Increased processing costs. Total treatment
costs were estimated for anaerobic-aerobic lagoon systems and extended
aeration systems. Private waste treatment by lagoon1ng could cost the
processor from 2.2 cents to 0.8 cents per 100 pounds live weight for poorly
to properly controlled plants, respectively. Extended aeration plants,
which provide a higher degree of treatment with less land area, would re-
quire Investment, operating, and maintenance costs of 11.0 cents to 4.0
cents per 100 pounds live weight for hydraullcally unmanaged and managed
plants; respectively. Careful and diligent 1n-plant water use reduction by
the poultry processor may save him substantial quantities of money by allow-
ing smaller waste treatment systems than those calculated here for "typical"
poultry processing plants In 1970. At a normal sewer charge of $0.25 per
1,000 gallons of waste, a water use charge of $0.25 per 1,000 gallons of
water supplied, and a sewer surcharge of $50 per 1,000 Ib of BOD discharged
over 300 mg/1 1n concentration, a typical 100,000 broilers per day, seven
days per week, poultry processor with poor water and waste management may
pay a monthly bill of over $20,000. With proper water management this bill
can be reduced by approximately 50 percent.
Reduction of flows need not be completely at odds with the trend
of Industry toward modernization and Improved processing using flowaway
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systems. It will remain for the Industry to assess the costs of process
changes to either "dry" or recirculating systems and compare them against
legitimate wastewater treatment charges. In the event of borderline de-
cisions, a processor should be aware that wastewater quality restrictions
«
imposed by states and municipalities will become more stringent in the
future and the most economical method to meet those restrictions is often
by in-plant process modifications and water management.
Water management techniques also promise to provide the greatest
reduction in wastewater flows. The operators of poultry processing plants
often do not know how much water they are using, where they are using it,
when they are using it, and, in some cases, why they are using it. Water,
traditionally a resource of great convenience and minor cost, has not
occupied the attention of either managers or workers. As a result, waste-
ful water use practices have been common throughout the industry. It will
not be possible at this time to demonstrate a cure-all technique that will
eliminate water use problems, rather it will be shown where water misuse
can be prevented or corrected.
The USDA is very strict in its observance of process water quality
standards. Great variations in water use and reuse are generally not per-
mitted at this time. Therefore, discussion will be presented on water
reuse methods that are permitted by the USDA, methods that are not pre-
sently permitted but which with further study may some day be allowed, and
also methods that may never be allowed.
Poultry processing plants perform the functions of slaughtering
and evisceration; cutting up of broilers, turkeys, mature chickens, and
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other classes of poultry; and further processing prior to retail mar-
keting. Many plants engage in canning, freezing, and processing Into
specialty Items. The principle concern of this seminar session will
be the processing of poultry through evisceration to the chilling step.
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DEFINITIONS
Common parameters of wastewater quality which will be referred
to 1n this session Include:
(1) Biochemical Oxygen Demand - BOD - A measure of the poten-
tial of a wastewater to utilize oxygen while experiencing
microblal degradation; a semi-quantitative measure of the
organic content of a waste. BOD5 - The standard test
conducted over a five day period.
(2) Chemical Oxygen Demand - COD - A measure of the potential
of a wastewater to utilize oxygen while experiencing
chemical oxidation; a semi-quantitative measure of the
organic content of a waste. It does not necessarily cor-
relate with the BOD test.
(3) Coagulation - The process of reducing the repelling forces
between collodial particles in order that they may combine
Into larger particles that are more easily settled.
(4) Collodial Particles - Finely divided solids which will
not settle due to gravity alone but which may be removed
from a wastewater by coagulation, filtration, or biological
action.
(5) Dissolved Oxygen - D.O. - Uncombined oxygen 1n solution in
a liquid. A minimum of four or five parts per million (ppm)
D.O. 1s necessary for the survival of fish in streams and
a minimum of one or two ppm is necessary to avoid odors in
wastewater.
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(6) Nutrient - A substance that promotes cellular growth 1n
organisms. Compounds of nitrogen and phosphorus are of
concern 1n wastewaters due to their encouragement of over-
enrichment of water bodies.
(7) Slug - A high concentration of a substance In a wastewater
stream; usually beginning and ending abruptly and of short
duration. Slugs cause problems 1n wastewater treatment
facilities by disrupting biological or chemical activities,
and in receiving streams by causing drastic D.O. reductions.
(8) Suspended Solids - Those Inorganic and organic particles
which exist in suspension in a liquid and which may be
partially removed by gravity settling and completely removed
by filtration.
(9) Total Solids - A measure of both suspended and dissolved
solids.
(10) Volatile Sol Ids - Organic solids which are combustible at
600 degrees centigrade.
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POULTRY PROCESSING
All poultry processing plants have the same basic processing
flow stream. This flow stream has evolved as the best way to proceed
1n what 1s a relatively simple procedure of slaughtering and cleaning
.x
poultry for marketing. Live poultry 1s unloaded at the processing
plant and taken to a killing station where jugular veins are cut while
the poultry 1s suspended from a conveyor chain. A bleeding area 1s
reserved to confine blood from the carcass. The bird 1s then scalded
with hot water to loosen Us feathers. Feathers are removed mechanically
and manually. Residual hairs and feathers are singed off with a flame or
by wax stripping, and the bird Is surface washed. The washed bird 1s
eviscerated manually and washed Internally and again externally. The
carcass Is then chilled or frozen, packaged, and shipped to a market.
Figure 1 provides a brief flow sketch of this process.
Receiving Area
It may be generally stated for the Industry that the receiving
area 1s no longer used for extended holding of live poultry. Stays of
several hours may be necessary 1n order to smooth out fluctuations 1n
delivery; however, feeding, and fattening up of chickens 1s Infrequently
practiced in the battery room. Nevertheless, the birds will leave manure
deposits In the holding area. These deposits are a source of BOD, bacteria,
and solids, and are flushed Into the sewer system when the floors, cages,
and walls of the holding area are washed.
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Potable water
i— — —Truck-borne coops
Empty |
coopi | 1
L—
.
a. Receiving area
1
b. Killing station
1
d. Scalding
J
e. Dclealhering
g. Whole bird
washing
1
X
* I
Blood x
n *
r ! 1
H Feather flow away f. Feather _,
•* ~* "~ "" "~ """ recovery ""*]
1 1 ' TT ' *
II & \
. _J | Feathers x
L 1
-~l|
h. Evisceration
1
i. Final washing
I
k. Chilling
I
1. Grading, weighing,
packing
1
Refrigerated
delivery trucks
Ottal tlow away ^ j Qffal | _j
f "* recovery "*1
„,. *
i 4- 1
. J Offal ?
1
X
-"-*- ^~" ~"H
X
X
J
1
m. Final waste water
_ . . collection and control
• Product
i ^ Byproduct 1
» Potable water *
~~ •*• Process water \
—X-~ Waste water $«w«r
FIGURE 1. FLOW CHART OF POULTRY PROCESSING PLANT*
*Taken from reference 2
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Killing of the poultry 1s usually done when the birds are hanging
by their feet from a moving conveyor. The jugular veins are cut and there
is considerable spillage and splattering of blood as the carcasses drain.
In an old plant, the bleeding would be partially or entirely confined 1n
a special room from which the blood would be washed directly to the sewer.
The degree of the pollutant load resulting from such discharge is in-
dicated by the 100,000 mg/1 BOD concentration 1n blood.
Defeathering
After bleeding, the feathers on the carcass are loosened by
scalding with hot water of approximately 130°F to 140°F. In most plants
the bird 1s immersed in a tank of hot water, but a spray system 1s used by
some processors. Water In the tank 1s kept warm and replenished by the
addition of hot water at the rate of one quarter gallon per bird. The
overflow from the tank and also the tank drainings at cleanup contain
blood, dirt, and feathers, which pass Into the wastewater system. Deposits
of dirt and organic matter become concentrated in the bottom of the tank
and are discharged during daily cleaning.
Feather removal from the carcasses 1s usually by mechanical action.
In a few of the smaller plants birds are removed from the conveyor and
placed 1n rotating drums which strip the feathers from the carcasses. The
birds must then be manually rehung on the conveyor. Wash water may be
sprayed in the.drums on a continued basis to remove feathers, and the birds
are subject to a final body spray. The more common method of feather re-
moval, however, is to let the bird on the conveyor line pass between
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rotating spools containing rubber fingers which beat and pull feathers
off the body. Continuous streams of water then wash the feathers
to a central collection facility. Considerable amounts of water are
lost through this procedure and equipment washdown at the end of this
processing period adds further pollution loads.
P1n feathers remaining after defeatherlng may be removed by
costly manual labor or by wax stripping. In the latter method, some
wax will escape to the wastewater system when the wax Is hardened by a
cooling spray. Wax stripping Is usually employed with fatty birds such
as ducks which may be damaged by singeing.
A gas flame 1s used to singe hair and odd pin feathers on the
carcass. The "plucked" bird 1s then washed with an external fine spray.
Evisceration
Evisceration takes place 1n a separate or enclosed area from the
remainder of the plant to prevent contamination of the poultry. The sur-
face cleaned birds are separated from their legs and resuspended on the
conveyor belt to allow easier access to the stomach cavity. Heads may
also be severed during this process. Manual operations remove all the
Inner organs and separate edible portions such as hearts, livers, etc.
from Inedible organs. Flow away systems continuously flush offal to the
wastewater system with relatively large quantities of water. Spray washes
clean the inside of the bird prior to USDA inspection.
Gizzard cleaning is a distinct sub-process of the evisceration
step in which gizzards are separated from the bulk of the viscera, opened,
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and cleaned of food, sand, and gravel. Similarly, other recoverable organs
must be separated and cleaned.
Birds to be cut up for parts such as legs, wings, and breasts are
processed at this time. New York dressed poultry are not eviscerated,
but this accounts for less than 5 percent of total production.
Chilling
Chilling of the carcasses to prevent bacterial decomposition 1s
the final process associated with wastewater flows and Immediately pre-
ceeds freezing or icelng of the meat and subsequent shipment to market.
Large processing operations use counter current chilling. Specific details
of the operation are government controlled. The first chill tank will lower
carcass temperature to about 65°F. Regulations specify that overflow from
continuous chillers must equal at least one half gallon per frying chicken.
The meat 1s subsequently dipped In second and third chilling tanks which
achieve an ultimate carcass temperature of 34°F. The overflow from the
second and third tanks 1s used as make-up water 1n the first tank. Fresh
1ce and/or chilled water must be added to the second and third tanks In
adequate quantity to keep all sections reasonably clear and In continuous
overflow. Old and small plants, which do not use continuous flow and chilling,
cool the meat 1n batch tubs of ice and water. Chilled birds are drained on
a conveyor line and then sized, graded, and packaged.
Freezing of carcasses 1s a new and slowly growing Innovation that
has found greatest applications with turkeys, ducks, and exotic fowl. The
freezing occurs after packaging but produces no inherent wastewater.
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Consumer demands are causing the old process of shipping poultry In
Ice to change to packing with dry 1ce. This has little effect on waste-
water flow.
Although poultry meat 1s sold principally through retail food
stores, about 25 percent of broiler output 1s sold to Institutional
firms. Broilers are usually sold 1n chilled, Ice-packed forms; turkeys
are most often sold frozen; and mature chickens are usually further pro-
cessed. Further processing accounted for about 13 percent of poultry
slaughter 1n 1970*2).
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WATER MANAGEMENT AND WASTENATER CONTROL
The poor quality processing plant 1n terms of water management
must be distinguished from the poor quality plant as measured In terms
of product. The best, most modern processing plant turning out an
excellent poultry product may be the worst plant from a pollution stand-
point. In a typical poor water management situation, hoses are kept
running when not 1n use, excessive amounts of water are used, and poorly
designed water supply systems permit little if any control over pres-
sures and rates of flow. In general water is used Indiscriminately and
the basic philosophy seems to be that the more water used the better
the job.
A reduced water usage concept can nevertheless be applied to
almost every area of almost every plant. Some of the more general reduc-
tion techniques are discussed below for the main sub-processes in a
poultry plant.
Receiving Area
^—^— "- " " \
Live storage of chickens in a battery room may become a tempor-
ary necessity in even the most modern processing plant. Studies of the
production in this room of wastes from manure and feathers have indicated
BOD values exceeding 30 Ib per 1,000 birds per day.^3'4^ As a comparison,
chicken manure production on farms is normally on the order of 240 Ib per
1,000 chickens per day. Water quantities resulting from a daily wet wash
of the receiving area will vary greatly among different plants and even
in the same plant on different days. The wet wash may contain detergents
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and cleaning agents 1n addition to the poultry waste. Dry cleaning of the
battery room with shovels, scrapers, or brooms can remove most of the
deposits to a dry disposal container. A final wash of the battery room
will then require less water and will contain significantly less pollutants.
One study measured the reduction of BOD by dry cleaning operations to 5 Ib
per 1,000 chickens per day. This figure may be even further reduced by a
rapid turnover of birds in the holding area, accomplished by scheduling
staggered deliveries of poultry to coincide with processing line demands.
Cleaning techniques using high pressure sprays, as opposed to low pressure-
high volume flows, will significantly reduce cleaning water demands. There
is at this time doubt as to whether the use of cleaning detergents pro-
vides more or less pollution than the manure and feather contents of the
waste.
Killing and Bleeding
Blood drained from freshly killed carcasses constitutes an extremely
high pollution potential and, as a result, in exceedingly fewer plants is
it allowed to wash to the sewer directly. Chicken blood has an approximate
BOD of 92,000 mg/1 and 1,000 chickens may drain 17.4 Ib of BOD in recoverable
blood. In a poorly operated plant the blood will wash to the sewer and
during post processing clean-up will be contained in the wash water.
Collection of blood may reduce the processing plants sewage strength
by 35 to 50 percent. This is roughly equivalent to 17 to 18 Ib of BOD per
1,000 chickens. Since poultry is bled while it hangs from a moving conveyor,
the blood may be collected in a tunnel or a walled area. In a high walled
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tunnel, for example, the blood may be almost completely recovered and
drained Into receptacles spaced at regular Intervals. A section of the
killing room enclosed by a wall high enough to catch most of the spurt-
Ing blood would provide a contained collection area. In most cases
such an area would be cleaned of blood at periodic Intervals after the
blood has partially congealed to a slurry and can be shoveled or scooped.
In this case, final cleanup of the floors and walls of the bleeding area
would require more water than for an enclosed tunnel of limited dimen-
sions.
Body movement of the slaughtered poultry may splatter blood on the
conveyor, out of the bleeding area, and onto the feathers of adjoining
birds where It can be washed off In the scalders. This 1s lost blood
and Increased wasteload. Stunning of the birds at slaughter will reduce
such movement, allow greater blood recovery, and reduce wastewater BOD
load.
Recovered blood may In some cases be sold to a local rendering
plant and the profit used to offset pollution control costs. In other In-
stances 1t may be necessary to give the blood away In exchange for Its
removal from the premises, or to even pay for Its removal. In any event,
efficient blood recovery practices provide the single most effective step
of waste load reduction.
Scalding
The scalding operation which loosens poultry body feathers also
provides a first wash to the carcass. The spent scalding water will contain
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blood, dirt, feathers, manure, and dissolved fats and greases. The
scalding tank 1s continuously replenished with fresh water at the rate of
one quarter gallon of water per bird. The BOD of scalder water has been
measured as high as 1,182 mg/1, with suspended solids of 682 mg/1, and a
grease content of 350 mg/1.
Scalding of the poultry prior to defeatherlng provides an oppor-
tune process for conservation of water. Scald water temperatures between
128°F and 145°F Inhibit the growth of common bacteria and the water 1s
applied as an Initial wash to the dirty poultry. For these reasons scald
water need not be fresh water; however, the USDA requires an overflow of
one quarter gallon per chicken processed. Screened chiller overflow water
which has been applied to a relatively clean, washed carcass, has twice
the overflow rate of the scald water. Chiller water has fewer pollutants
than spent scald water and would, therefore, appear to be an Ideal makeup
water for the scald tanks. Chiller overflow water from the first contact
tank has been substantially warmed by residual body heat from the carcasses
and will not differ greatly in temperature from cold water supply lines.
The use of a simple heat exchanger between chiller feed to the heating tanks
and scalder water overflow can reduce the fuel needed to heat the scalder
feed water.
Defeathering
Defeatherlng under poor water management techniques 1s performed
mechanically with continuous streams of water washing away the feathers
and washing the carcass. While this 1s performed in many new and modern
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plants for expediency of cleaning, it represents a step backward in
pollution technology due to the high volume of water involved in the
feather flushing. Defeathering water will contain blood and dirt
which exert a BOD while the feathers themselves, although they are
somewhat resistant to the Standard BOD analysis, may create a BOD in
the feather flume of nearly 600 mg/r . Furthermore, feathers in the
wastewater stream have a considerable nuisance value by clogging the
mechanical recovery screens treating the wastewater flow.
The fresh water supply for mechanical feather removal has been
measured to be 1.4 gallons per bird, inclusive of the final outside body
wash and periodic area cleanup . This water use was 11 percent of
the total water supply to the plant. Additional in-plant water reuse
for the feather flowaway flume raised the total water usage for the
defeathering process to 2.8 gallons per bird, which was also the waste
discharge for the defeathering process.
Defeathering operations have been shown to carry a pollution
potential in wash and flume water. Feathers may be removed by screening
operations of the wash water, but they have a high tendency to foul
screens and cause polluted water overflow. Screened water from de-
feathering operations may be reused in the feather flume trough since
there is no direct contact with the final poultry product. Reuse of
feather flume water in the feather flume instead of another location would
prevent mixing of stray feathers with other types of possibly recoverable
products. Chiller water has been used in the feather flume at the Gold
Kist facility in Durham, North Carolina.
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Evisceration
The evisceration process consumes large quantities of fresh water
in cleaning of the carcass, In viscera flowaway flumes, and In worker
cleanup supplies. Wastewater from evisceration will contain high BOD's,
suspended sol Ids and grit, greases, blood, and bacteria from the in-
testinal tracts. Large volumes of water used to flush the offal would
tend to dilute the BOD concentration, but the total pounds of BOD pro-
duced would remain unchanged. A typical example of eviscerating flume
water has a flow of 3.1 gallons of water per bird and a demand of 24 per-
cent of the fresh water supply^5'6'.
Gizzard cleaning 1s a distinct sub-process of evisceration and
presently requires potable water according to USDA regulations as does
evisceration water. Gizzard cleaning water 1s discharged to the viscera
flowaway flume for a combined water use of 6.1 gallons per bird and a BOD
of 230 mg/1. While the BOD appears low due to the high volumes of flushing
water 1n this process, it is still equivalent to 12.2 1b per 1,000 broilers.
Evisceration adds a large quantity of wastewater with a substan-
tial amount of BOD to the plant effluent. During evisceration, workers
hands are in contact with recoverable viscera, offal, and bacterial pol-
lutants. Constant supplies of fresh water are used to wash workers hands
and recoverable viscera, and to transport waste heads, feet, and offal
down a flume to a screening operation. The nature of the waste and Its
high bacterial content make 1t Inadvisable to reuse offal flume water in
any process in which it can contact poultry products; however, in non-
contact processes such as feather fTurning it may be possible to reuse even
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this water. Gizzard cleaning water 1s similar 1n nature to the evis-
cerating trough water and should be treated similarly. Lung vacuum
pump effluent 1s low 1n quantity and usually may be Incorporated with
the offal flowaway.
Wastewater from the final bird wash after evisceration will
contain grease, blood, and scraps of meat. This has been measured at
0.8 gallons of water per chicken and 440 mg/1 of BOD, but it will vary
depending on the type of mechanical spray head used.
Final bird wash water, used to wash both the Inside and the out-
side of the carcass, should normally be the freshest water possible and
must be conducted with potable water according to USDA. This wash water
may possibly be reused in another sub-process within the plant. All
bird washing processes may be improved by the use of special water spray
nozzles that minimize water use.
Chilling
Other than general plant cleanup, chilling of processed poultry
1s the final step associated with wastewater. Chillers are often separate
for giblets and carcasses. BOD concentrations of giblet chill water have
been measured as high as 2,357 mg/1, while the BOD concentrations of the
two stages in a body chiller have been measured to be 442 mg/1 and 320
(5)
mg/r '. The overall water demand for chillers is approximately three
quarters of a gallon per chicken. USDA requirements are one half gallon
of water usage per chicken. BOD production in a body chiller is on the
order of 7.4 Ib per 1,000 birds.
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Chiller water requirements are established by the USDA and little
can be done to reduce them. However, screened chiller water overflow
has a great potential for reuse elsewhere in the plant. Also, measure-
ment of water 1n the slush 1ce added to chillers should be credited
against minimum chiller requirements.
Dry Cleanup
The basic processes presented above have been constrained by the
limitation of using a flowaway system. Dry cleaning of feathers and dry
removal of waste offal have a large potential for reducing wastewater
flows and concentrations and were the processes In general use before
Industry conversion to "modern" flowaway systems. It Is understood that
flowaway systems have provided quicker and more economical automatic
processing In an age of rising labor and food costs, yet new regulations
on wastewater qualities may force processors to compare wastewater abate-
ment costs with the return to more labor intensive, in-house dry cleanup
systems.
Dry cleanup of feathers from defeathering operations may be
performed manually or automatically, brushing feathers to a dry collection
point where there 1s a limited storage before removal by a renderer. Vacuum
removal of feathers may be automated and similarly provide for a central
dry storage. Residual feathers clinging to the carcasses and to equipment
may be washed away with greatly reduced quantities of water and substan-
tially reduced feather screening facilities. The area of dry mechanical
feather collection has great potential for an enterprising equipment manu-
facturer.
1-23
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Dry removal of evisceration wastes will reduce wastewater con-
stituent concentrations and some water flowaway requirements. Studies
: '.'•4
have shown that If waste solids from evisceration are put directly into
containers at the table, effluent from evisceration would contain 6 to
(4)
8 Ib BOD per 1,000 chickens . This compares to a total evisceration-
and gizzard-flowaway BOD of 12.2 Ib. Finally, heads may be pulled and
dropped directly into containers with no water use whatsoever.
By-Product Recovery
Dry or wet recovered feathers may often be sold to rendering
facilities for processing as protenaceous animal feed. New agricultural
foam products for field application use poultry feathers as a raw material.
The products control insects, temperature, weeds, and humidity on the field.
Offal collection may also be economically attractive with a ren-
dering plant located in the area. Rendering plants and some farmers will
convert offal to animal feed or return it to the soil.
Recovered blood can at times be sold to rendering plants and
rendering plant delivery trucks can be equipped with blood holding tanks
to make pickup of the blood more economical and attractive to the renderer.
In 1972, blood, feathers, and offal were sold to renders 1n Florida at
the rate of $9 to $10 per 1,000 broilers processed.
In the 1970 survey performed by the USDA, it was found that 0.6
percent of processing plants did not salvage offal, 70.8 percent of the
plants sold offal to renderers, 1 percent gave offal to renderers, 26.6
percent rendered offal "in-house," and 1 percent dumped or burned collected
of far '. The same study revealed that blood was not salvaged by 14.2
1-24
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percent of the plants, sold to Tenderers by 54.6 percent, given away by
7 percent, rendered In-house by 22,4 percent, and dry disposed by 1.8
percent. Feathers were wasted by 0.4 percent of the plants, sold by
71.6 percent, given away by 0.8 percent, rendered In-house by 25.9 per-
cent, and burned or dumped by 1.3 percent.
Housekeeping
In-plant cleaning of equipment and housing 1s an Important source
of pollutants. When scald tanks are emptied at the end of a processing
period, for example, they contribute a heavy slug load of dirt, feathers,
blood, and grease. Little can be done to reduce the waste flow from this
cleaning. In other areas, floors and tables should be swept prior to
washing to remove gross sol Ids 1n dry form to storage containers where the
contents could be used for rendering. Floor drains and outlets should be
accessible to wastes only during final cleanup after sweeping. Screens
placed on the drains of non-flowaway plants will prevent gross organic
sol Ids from reaching the sewer system. Organic solids 1n flowaway plants
may be processed through the offal and feather recovery screens. Floor
washing and general sanitation 1s Imperative, but there 1s no reason to
provide large quantities of water to wash bulky sol Ids through drain lines.
Employee awareness of the cost of water use will result 1n Im-
proved housekeeping procedures. Letting water hoses run freely on the
floor between uses 1s wasteful and employees should be encourages to make
the effort to turn off the water. Placing control nozzles on the hoses will
facilitate this and will also help reduce water usage to the minimum nec-
essary to do a good job.
1-25
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Hater Supply and Treatment Equipment
Improved spray nozzle designs at the Gold K1st facility were
able to reduce fresh water usage In final bird washers by 60 percent,
In hand washers at evisceration from 285 gpm to 100 gpm, and 1n whole
bird washers from 45 gpm to 30 gpm. Mechanical Improvements 1n the
replacement of old free running hoses by a high pressure cleaning
system using foam cleansers reduced dally cleanup water from 112,000
gpd to 46.000 gpd. Even plants not contemplating process changes or
Internal reuse of water can noticeably reduce fresh water usage and
wastewater flow by the Installation of the best available spray heads
/
and cleaning equipment. Varying line pressures and water demands in dif-
ferent parts of the plant can make automatic or timed spray equipment non-
functional. Pressure control valves placed at strategic locations in the
plant can prevent such difficulties.
Screening is a vital process in the reuse of waste streams and
general reduction of poultry plant waste. Rotary drum screens along with
stationary flat screens have long been used for by-product recovery. The
newest trends are toward vibrating screens which operate at higher ef-
ficiencies and are not as subject to clogging and overflows. But in any
case, screening of feathers and offal should be done in separate channels
by separate screens to facilitate water reuse without cross contamination.
Tabulated Water Analyses
A report released by the USDA estimated total BOO and suspended
solids production for poultry processing plants based on production fig-
ures and various sources for pollutant loads. The various sources resulted
1-26
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in Table 1 which lists a collection of coefficients for by-products,
water use, and waste loads, to be applied to production figures. It
must be noted that Table 1 may be reasonably accurate on quantities of
by-product, but the numerous variables of processing, such as poultry
type, water usage, spray nozzle design, cleaning practices, and screen-
ing efficiencies, make predictions on water use and wasteloads a gross
estimate at best. Based on the values in Table 1, however, it was esti-
mated that a typical poultry processing plant releases wastewater with a
BOD of 448 mg/1 and suspended solids of 344 mg/1. This is in agreement
with our experience which indicates BOD's of 450 to 600 mg/1 and suspended
solids of 300 to 400 mg/1.
1-27
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TABLE 1
COEFFICIENTS USED IN ESTIMATING BY-PRODUCTS, WATER USE
AND WASTELOADS OF POULTRY SLAUGHTERING PLANTS
Variable
TJnTt
Value per 1,000
pounds I/
By-products:
Blood
Young chickens Pounds 70
Mature chickens do. 70
Turkeys do. 70
Other poultry do. 70
Offal
Young chickens do. 175
Mature chickens do. 170
Turkeys do. 125
Other poultry do. 140
Feathers
Young chickens do. 70
Mature chickens do. 70
Turkeys do. 70
Water Use: « IQR
Young chickens Gallons 2*173
Mature chickens do. i
Turkeys do.
Other poultry do.
Cut-up do. 50Q
Further processing do.
Wasteloads:
BOD--
Young chickens Pounds 8.2
Mature chickens do. 8.7
Turkeys do. 8.0
Other poultry do. 8.0
Suspended sol Ids-
Young chickens do. 6.3
Mature chickens do. 5.4
Turkeys do. 5.0
Other poultry do. 5.0
Time span of operation 2/:
Young chicken, mature chicken,
and other poultry plants... Days 234
Turkey plants do. 130
I/ Live weight except for cut-up and further processed coefficients which
are ready-to-cook weight.
21 These coefficients are based on a maximum of 260 operating days per year.
We assumed that the chicken and other poultry plants operated at 90 percent
capacity—0.90 x 260 = 234. Turkey plants were assumed to operate at 50
percent capacity—0.50 x 260 = 130.
Source: Environmental Protection Agency, Industrial Waste Study of the
Meat Products Industry, 1971; U.S. Department of Agriculture, Processing
Poultry By-products 1n Poultry Slaughtering Plants, Marketing Research
Report No. 181, 1957; and industry contacts.
1-28
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SUMMARY OF RECOMMENDATIONS
The changes that may be made 1n each plant to reduce water usage
will depend upon the particular circumstances at that plant. A general
11st of steps for Improved water management, which may be used as a
framework by each poultry processor for their own actions 1s presented:
1. Choose a person specifically responsible for water
management. This person should have reasonable
powers to make and enforce changes.
2. Determine where water 1s used and 1n what quantities.
3. Install flow meters and pressure gauges in major flow
areas.
4. Install water pressure regulators to prevent gross
line pressure variations. This will help prevent
occasional oversupply at unit points 1n the process.
5. Tackle each unit process to determine possible water
use reductions.
6. In receiving area* dry sweep wastes to receptacles
before washing floors.
7. In receiving area, replace open garden type hoses with
nozzles that given high velocity spray, reduced water
flow, and that may be turned off at point of application.
8. Cleaning with detergents and cleansers may further
reduce water usage and will certainly produce a more
hygienic area.
9. Stun carcasses electrically at slaughter to prevent
body movement and splattering of blood.
10. Confine bleeding to a tunnel or enclosed area where
blood for collection may easily be accomplished.
Recover the blood for rendering or farmland disposal
and do not let it into waste stream.
11. Use the minimum approved USDA quantities of water that
will maintain your temperature.
1-29
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12. Reuse screened chiller water as scalder feed water.
Consider simple heat exchange between scalder over-
flow water and scalder boiler feed water.
13. Pay attention to new developments 1n vacuum removal
of feathers 1n defeatherlng. Consider an application
of such a system when practical.
/
14. Screen feather flume water and reuse in the feather
flume.
15. Install spray nozzles on bird wash that will get the
job done with a minimum amount of water.
16. Place nozzles on hand washers and evisceration meat
washers that will clean adequately with minimum water
use. Body or foot control valves can supply water
only when It 1s needed for hand washers. Timed sprays
can wash evisceration sol Ids away with no wasteful water
use between bursts.
17. Measure the Ice-slush added to chiller water and
credit it against chiller water overflow requirements.
18. Keep all screens 1n perfect working order. A clogged
and overflowing screen costs the processor money.
19. Use dry cleanup 1n plant prior to "wet rinse" to
reduce water use. Collect dry solids in container
for disposal or rendering.
20. Consider Institution of dry removal of wastes, such as
on-site containers for heads.
21. Recover all possible by-products to Improve the economy
of in-plant water management.
22. Stimulate employee awareness of the expense and undesir-
ability of poor water management. Encourage employees
to be careful of their water use.
1-30
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FUTURE EFFORTS
The methods for reducing water usage as discussed 1n this report
are but a part of what can be accomplished toward recycling of water and
reducing fresh water demand. The ultimate goal for Industries, as en-
visioned by some people, Is total reuse of water or zero pollutant dis-
charge. Such an Ideal goal may never be realized, but pressure will be
brought to bear to approach 1t. Wastewater treatment will become more
expensive in the future and Incentives for In-house flow reductions will
substantially Increase.
Several water reuse schemes have been considered. These Include
total reuse of screened offal water 1n the evisceration flume, use of
screened whole bird wash water in the scalder on the premise that the bird
will contact water of that quality anyway, reuse of screened final wash
water 1n the gizzard machine, and reuse of chiller water in the final bird
wash. These schemes have not been approved by the USDA. They do, however,
have the potential of reducing water usage by 18 percent over that in an
uncontrolled plant. In time a detailed study will need to be conducted on
these methods, not only to verify their technical and economic practicality
but also to safeguard the public health.
1-31
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REFERENCES
1. U.S. Department of Agriculture, Statistical Reporting Service,
(April, January, 1972).
2. "The Poultry Processing Industry," Marketing Research Report
No. 965, Economic Research Service, U.S. Department
of Agriculture (June, 1972).
3. Porges, R., "Wastes From Poultry Dressing Establishments," Sewage
and Industrial Wastes. 22, 4, p. 531 (April, 1950).
4. "Wastes from the Poultry Processing Industry," Technical Report
W 62-3, U.S. Public Health Service, Department of Health,
Education & Welfare, 1962.
5. "Proceedings, Workshop on Poultry Processing Plant Water Utilization
and Waste Control," September 16, 1971, Greensboro, North
Carolina sponsored by North Carolina State University and
the University of North Carolina.
6. "The Cost of Clean Water," Vol. Ill, Industrial Waste Profiles,
Federal Water Pollution Control Administration, (September,
1967).
1-32
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THE GOLD KIST CASE STUDY
by
John A. Macon
Research Associate
Department of Economics
North Carolina State University
Raleigh, North Carolina
-------
INTRODUCTION
My presentation will focus on the impact of in-plant process
and equipment changes on water use and waste abatement in poultry pro-
cessing. An attempt will be made to: (1) present the results of a
research, development, and demonstration project conducted in the Gold
Kist plant at Durham, North Carolina; (2) interpret the usefulness of
these results for improving the operation of your plants.
A detailed study of opportunities for water and waste reduction
was made throughout the plant. There has been a 30 percent reduction
in water use (580,000 gallons versus 838,000 gallons) and a 65 percent
reduction in waste discharged to the city system (1,400 pounds versus
4,000 pounds of BOD), Blood from the killing room has been effectively
eliminated from plant effluent, and feathers in the plant effluent have
been controlled. Biological quality of the final product has been main-
tained.
The Water Quality Office, Environmental Protection Agency, and
Gold Kist supported the study on a 70-30 cost-sharing basis. North
Carolina State University provided technical and research requirements
including a biological evaluation of all phases. Effectiveness of the
project has been greatly enhanced by the full cooperation of the Poultry
Inspection Group at all levels.
2-2
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THE STUDY
One of the special features of this project was the joint
development of the project. The demonstration project, although
conceived by the University and EPA, was asked for and granted to the
Gold Kist organization. The actual tests were run at their Durham
plant. The Durham facility was managed by Mr. Byron Hawkins with Mr.
Lawrence Carter as the in-plant project director, and the project
became known as the Gold Kist Study. The North Carolina State Univer-
sity (NCSU) role, which Is very unusual in a research project of this
type, was Involved with Gold Kist In what we call a subcontract. We
had from the Department of Economics Dr. Crosswhite and myself, and
from the Food Science Department Mr. Roy Carawan, Dr. Marvin Speck
and Dr. Fred Tarver who gave unlimited assistance, and led to the Inter-
disciplinary research team.
Since the trend of poultry production has been a great Increase
over the past two decades, and the total production In the United States
In 1970 was approximately 3,000,000,000 birds, we began this study with
the realization that the cost of water and wastes could be very signi-
ficant in poultry processing. Although the unit costs are small, they
are still significant. When only approximately 7.3 cents per pound
exists for live hauling, processing, selling, delivery, and profit, and
you add a cost of 0.1 to 1 cent per bird, it becomes very significant.
We started developing the project with the belief that managers
in poultry processing would act providing they had the necessary knowledge.
2-3
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Me didn't believe that the supervisors and managers knew how much water
they were using. Me also didn't believe they knew how much wastes were
being discharged or where they were coming from.
Now, getting to the specific objectives of the project: (1)
to Install and/or modify the processing equipment itself. What could
we do in modifying the equipment that was in the plant to enable it to
use less water, to generate less wastes? (2) to evaluate the impact of
these changes. How much water reduction would a change make? How much
waste would one of our changes eliminate? (3) to determine the economic
implications of these changes. Could a poultry plant justify the expenses
of the process modification? In other words, would we save enough water
and would we eliminate enough wastes to justify spending the money to make
the changes? Not all of our changes panned out. We didn't expect them
to, and this is why we had the demonstration grant. If we had the answers
before we started, we wouldn't have to do the work.
Our basic plan of work was first to obtain bench mark infor-
mation. By bench mark information, we mean just how much water was used
in the plant. Where were the wastes coming from in the plant? This was
just to give us an overall feel for what was going on. The second thing
was to approach the technical developments in the plant Itself. These
were the process modifications or changes.
The applied systems analysis was done by Mr. Bob Ward a gradu-
ate student in the Biological and Agricultural Engineering Department.
The supporting biological work was done by Dr. Marvin Speck, Food Science
Department. Our reason for the biological work was that as we were making
2-4
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these water reductions and eliminating wastes, we had to assure ourselves
and the USDA that the wholesomeness of the birds was not affected. We
appreciate the cooperation of USDA In this project. They helped us In
deciphering regulations, analyzed our work, and helped keep us on an
even keel. Also, we appreciate all the cooperative work relations. There
were the employees of the Environmental Protection Agency; the state water
resource people, the Water Resources Research Institute and the university
staff.
The way we approached the bench mark data and the biological work
was to go to different points In the plant. We took each unit operation
In the plant and looked at it In Its entirety. For example, we took the
scalder exit; the chill entry and the pre-chiller, water samples to deter-
mine where the wastes are generated. Then we added these up for the total
waste stream of the plant. Also, we did the same thing for the biological
work.
Now if you wonder what this means just in North Carolina, in 1971,
we produced somewhat over 300 million birds. Using average water use figures,
this amounts to over 3.60 billion gallons of water that was used in North
Carolina last year for the processing of poultry. From two to ten million
pounds of BOD5 were discharged from the plants. You will notice I used a
wide range there. It all depends on whose figures you are using for what plant.
We do not have figures on most of the plants so I am averaging these myself.
But I would say somewhere in the two to ten range and this shows you the mag-
nitude of the problem. There is quite a lack of information in this area and
this is one of the problems and one of the reasons that we started the project.
2-5
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PROCESS AND EQUIPMENT CHANGES
Look at this project from the standpoint that we were primarily
using the plant as a "laboratory in action." We made mistakes; we pur-
chased materials that were not suitable for the job, but in making our
mistakes, we were able to say these mistakes led to success. It is
very hard to measure the quantity of goods going out of a plant, but water
was squirting out of so many places in this plant it seemed impossible
to measure all of the water going out. At the beginning the volume was
close to a million gallons a day.
Flow Measuring Devices
Measuring devices that we used were Parshall flumes, water meters,
V-notch weirs with automatic recorders for the large flows. With a bucket
and a stopwatch you can find out how much water is being discharged from
small sources.
Housed above our Parshall flumes were Thompson recorders that
recorded the total flow of the water. Measuring to get the original volumes
was one of the first things done throughout the plant. Me put in water
meters in just about every logical place to measure the daily volume of water.
We could then monitor what was happening in each individual process. Meters
were a very important part of our testing program.
The next thing was to find out if we could get the same results
twice. Let me say that you can take samples all day long only to find out
that if a worker comes in the next day and opens up the valves differently
than he did the day before, you are right back where you started. You don't
2-6
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know how much of what is passing through where. So the first thing we
learned to control the flow by regulation. Before we could ever get
a uniform pattern on waste generated in this plant, we had to get
regularity of processing or at least some uniformity of operation.
Blood Collection and Control
One of the first major equipment developments was one of the
most difficult of all. The high BOD, concentrated blood was being
scattered over everything in the blood tunnel. A stainless steel, sheet
metal trough container was fabricated. A series of electrical shocking
bars were used so the birds could be stilled by the shocking machine early
after being killed. The body and the feathers are now kept clean, the
blood is well contained in the trough; therefore, we are collecting not
only the worst pollutant in the plant but it is now a good by-product.
Sealder
Reuse of chiller water eliminated the use of fresh water for
scalder make up. Our primary objectives were to do two things: to reduce
wastes but at the same time minimize our water usage, and this was one
case in which we are minimizing the water. The scalder is a chamber used
to heat up the birds and wet them so that the feathers can be flailed
from the birds. In this case instead of using regular fresh water, we
Installed the recirculation pumping system to go back to the scalder. This
was a reuse of water and put the water from the chillers into the scalding
machine.
2-7
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DefGathering
Flow away flumes were redesigned to efficiently remove the
feathers from beneath the pickers with the use of less water. Water
for this purpose is now solely supplied from the screened eviscerating
line effluent.
Whole Bird Hashers
Small opening and higher efficiency spray nozzles were installed
in both washers. Regulations and control valves were also installed in
the water supply line of each bird washer.
Evisceration
a. Hand Mash Outlets — The largest volume users of water in
this plant are the little hand nozzles at each eviscerating station along
the evisceration line. Spray nozzles are used by the workers to both
cool and rinse their hands from bird to bird. When we first went to the
plant they were using shower heads just like the ones found in home
showers. Instead of washing their hands, the volume would be equal to
the amount for washing a whole human being. The shower type nozzles used
three and a half gallons per minute. Our last nozzles use about 0.4 gpm.
Water flow rates vary slightly from place to place and station
to station. However, with this drastic reduction in the amount of water
these operators today do just as good a job as when they were using three
and a half gallons of water per minute per nozzle.
Very Important is the pressure gauge regulating the flow out
of these nozzles. Here is what was happening to Durham prior to this study.
2-8
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The pressure going Into the plant might be the same but due to the
variable use of the water throughout the plant, the pressure would
bounce up and down like a rubber ball and would range anywhere from
about thirty-five to forty pounds up to eighty pounds or more. When
the pressure ran up high, these nozzles would fog, and wet you as if
you were going through a shower of rain. Before we could even use the
nozzles the water pressure had to be regulated to them.
Shown in our slide is a tickler nozzle. This nozzle has not
been approved by the USDA. A tickler type hose nozzle is like one you
would have seen at a service station that quits running when you drop
it down. We have found the total bacterial count on this nozzle was
very low, and we are going to pass the information to the USDA for their
evaluation hoping that some day this nozzle may become useful to you.
It does cut the water off completely. It will not run until you push
this little bar to one side. They are sold by your local supplier.
b. Side Pan Wash — Another thing we wanted to do along the
eviscerating line was to further reduce the amount of water. We found
that the pan on each side has to be flushed with water to keep the slides
clean while the workers are working. If I could show the regulating
valve, it would be a timed unit. When the water is on, it flows full
force to properly flush the surface of the eviscerating pan, and then an
electric timer cuts that water off immediately. It stays off a prede-
termined length of time, and then it is turned on again. We have found
that this sequence gives a very clean surface along the pan while re-
ducing the amount of water used. Before, in trying to control the water
2-9
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they had reduced the flow by merely cutting back on the amount of
water flowing down the pan. Here, we felt like it needed the full
force of the water to clean the total surface of the pan, and yet, we
did not need it every moment of the operating time.
Final Bird Washer
New high efficiency nozzles were installed in these process
units to improve the cleaning action while applying a smaller volume
of water per bird processed. Good regulation was obtained with the
control valves and water pressure gauges as described previously. By
use of the quick opening shut-off valve the employees will even turn
the water off during break periods, lunch, and downtime.
Chillers
By the USDA regulations one half gallon of water per bird is
required. To assure this quantity they require water meters for verifi-
cation. To cool the water in the chiller and subsequently the birds,
ice is being put into the chillers through a slush water system. This
plant gets no credit for the amount of water used against the amount
required. As soon as a device is developed or engineered to measure
the slush ice, we can reduce the amount of water running into the chil-
lers by the quantity that is flowing as slush ice.
Packing
In many plants ice is used on top of the product to keep it
cool during transportation. At a considerable cost Gold Kist installed
2-10
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a C02 snow system in their plant to replace this use of ice. This re-
placed 15 pounds of ice per 65 pounds of product or the equivalent of
nearly 2 gallons of water.
Plant Clean-up Water
Last but by no means the least was the sizeable volume of water
being used to clean all the processing equipment, building, and receiving
yard area. Several types of new chemical formulations were tried. Com-
bined high pressure spray equipment and chemicals were used in the final
selection to minimize the volume of water used, reduce the time for
cleaning, reduce the chemicals needed and reduce the overall cost for
the total clean-up operation.
Final Waste Mater Collection and Control
To further reduce the suspended solids and grease in the plant's
final wastewater effluent, a commercial air flotation and skimming mechanism
was purchased including the associated pumps, sumps, tanks, and by-product
holding chamber. Although this was not strictly an in-plant change the
additional by-products recovered increased yield and by-products income
while further reducing the waste surcharge cost. With both cost advantages
it has been economically feasible to install and operate this air flota-
tion system.
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SUMMARY OF RESULTS
Given 1n Table 1 1s the volume of water that was being used
for all purposes 1n the processing of approximately 70,000 birds per day.
This bench mark data indicates a usage of nearly 13 gallons of water
for each bird processed. It also identifies where the water was being
used in the plant at the beginning of the project.
Shown in Table 2 is the bench mark data relative to the waste
characteristics of selected wastewater flows throughout the plant. These
values are averaged over several weeks of testing.
The bench mark data presented some interesting points that can
be examined in Table 1. The total water consumption is about 840,000
gallons per day. The important point is that the eviscerating trough
itself accounted for appoximately 200,000 gallons of this 840,000 total.
This consisted of the hand-wash outlets and the side pan wash. The other
area with a tremendous amount of water use 1s the gizzard machine and
the gizzard splitters where there 1s 194,000 or almost 200,000 gpd so
the eviscerating trough and the gizzard operation consume almost 50 per-
cent of the total water used in the whole plant.
Another thing I would like to point out 1s for those of you associ-
ated with hoses, a hose used for ten minutes uses 340 gallons. One hose
used for one hour is 2,000 gallons of water. How many times in your
poultry plant do you see hoses just running? Realize that that is 2,000
gallons of water an hour going down the drain from that hose laying on
the floor. Also, why do you not have nozzles on the ends of the hoses?
2-12
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TABLE 1
Process
1. Killing Station
2. Scalder
3. Pickers
4. Feather Flume
5. Neck Scalders
6. Whole Bird Washers
7. Defeather Cleanup Hose
(1 @ 1 hr.)
8. "Hang-Back" Belt
9. Eviscerating Trough
a. Hand Wash Outlets
b. Side Pan Wash
10. Final Bird Wash
1 1 . Lung Vacuum Pump Ef f 1 .
12. Gizzard Machine
& Glblet Flumes
13. Evisc. Cleanup Hose
(2 @ 30 m1n. ea.)
14. Glblet Chiller
15. Neck Cutter
16. Chillers
17. Packing Ice
18. Bird Pickup
(10% In chillers)
19. Packing Cleanup Hoses
(3 @ 10 min. ea.)
Source
Fresh
Fresh
Fresh
Chiller Effluent
Re. Offal Water
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh & Ice
Fresh
Fresh & Ice
Ice
Fresh
Fresh
Flow
Rate
(gpm)
2.0
38.7
38.0
94.3
54.6
111.7
1.5
37.3
34.0
9.1
285.0
90.0
100.0
14.2
360.0
72.0
4.5
4.0
72.1
15 Ibs/box
—
102.0
Total
Vol ume
(gal)
1,080
20,898
20,520
50,922
--
__
810
20,142
2,040
5,460
153,900
48,600
54,000
7,668
194,400
2,040
2,430
2,160
38,934
6,111
8,640
1,020
20. By-Product Cleanup Hoses
(1 @ 10 min.)
Normal processing day runs
Water Meter Readings: a.
b.
Fresh
from 7:00 a.m. - 4:00
Processing (7:00 a.m.
Cleanup (4:00 p.m.
34.0
p.m.
- 4:00 p.m.)
- 7:00 a.m.)
Total
340
= 725,600 gpd
= 112,200 gpd
837,800 gpd
Undetermined Process Water: 850,000 - 837,800 = 12,200 gpd
Note: Cleanup hoses are used to rinse off equipment at break periods and
lunch during processing operation.
2-13
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TABLE 2
BENCHMARK DATA ON WATER AND WASTE
GOLD KIST PLANT
DURHAM, NORTH CAROLINA
DECEMBER, 1969
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Scalder Entry
Scalder Exit
Whole Bird Wash
Final Bird Wash
Glblet Chiller
Chiller I
Chiller II
Feather Flume
Eviscerating Flume
Plant Effluent
BOD
1,182
490
108
442
2,357
442
320
590
233
560
COD
2,080
986
243
662
3,959
692
435
1,078
514
722
Total
1,873
1,053
266
667
2,875
776
514
894
534
697
Solids
Dissolved
1,186
580
185
386
1,899
523
331
382
232
322
Suspended
687
473
81
281
976
253
183
512
302
375
Grease
350
200
150
580
1,320
800
250
120
430
150
Note: All values are in mg/1
-------
Why is this water wasted? Is an employee too lazy to go over and turn
1t off because in thirty minutes he Is going to want to use It again
so he leaves It running?
Getting Into the area of reduction and to summarize the
results — It may be Interesting for you to know a little something
about the City of Durham. This plant was consuming approximately 10
percent of fresh water production of the City. We reduced the water
from 838,000 gallons per day or something more than that to in the
neighborhood of 580,000 gallons per day. This total reduction is 30
percent or a little greater. The amount of 6005 coming out of the plant
In pounds was reduced from 4,000 pounds a day to 1,400 pounds. This is
approximately 65 percent reduction in wastes. The BOD of the effluent
at the present time has been reduced from 600 to 300; and with the
final air flotation system it has been reduced to 200 mg/1. Grease of
200 mg/1 was reduced to 90 mg/1 in the plant and further to 40 mg/1 by
use of the air flotation mechanisms.
The reductions in the various areas of the plant, are given in
Table 3. In the evisceration area the use of improved nozzles in the
final bird washer reduced the potable water consumption from 50 GPM to
30 GPM. That 1s quite a reduction in itself, just by changing the noz-
zles. The hand washers resulted in a change from 285 to 100 GPM.
Cycling of the side pan wash was originally about 90 GPM. Now
It has been reduced down to 30 GPM. Of course, this would depend on the
time period and effect of the cycling and other things, but this 1s on
one particular set of conditions.
2-15
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TABLE 3
WATER REDUCTION DEVELOPMENT ACTIVITIES
BY AREA OF THE PLANT
AND CHANGES IN FRESH WATER
no
Area of
Plant
Evisceration
Scalding and
defeathering
Cleanup
Activity
Use of Improved nozzles
Final bird washers
Hand Washers
Cycling of side pan wash
Rearrangement of glblet handling
Use of Improved nozzles In
whole bird washers
New design of feather flume for
reuse of offal flume waters
Use of chiller water in scalder
to replace fresh water
New high-pressure cleaning system
with foam
Reduction
From
50 gpm
285 gpm
90 gpm
360 gpm
45 gpm
94 gpm
40 gpm
112,000 gpd
In Fresh Water Use
To
30 gpm
100 gpm
30 gpm
320 gpm
30 gpm
0
0
46,000 gpd
-------
In the rearrangement 1n the giblet handling, we made a small
reduction there. Another area where we made an Impact was 1n the
eviscerating flume water, by changing the design of the feather flumes.
We eliminated the fresh water that was going Into these and eliminated
94 GPM. Previously they had some additional fresh water hoses stuck
1n the flumes trying to flush the feathers down because they weren't
moving properly. Multiplying this flow by sixty, you come up with a
figure of 6,000 GPH.
The dramatic reduction of water used 1n clean-up has been
caused by the Installation of new equipment coupled with good chemical
utilization.
Not to be overlooked 1s the reuse or multiple continued use
of process waters. The best example of this type application 1s the fresh
water first used In final chiller. Then It 1s pumped to the prechlller.
The collected effluent from the prechlller Is then skimmed and pumped
Into the scalder as make up water. As a scalder effluent the same water
discharges Into the feather flow away flume to assist 1n transporting
the feathers to the by-product recovery screens. Thus the water 1s
finally discharged 1n the plant's final drain.
This multiple use of water was responsible for most of the re-
duction of fresh water In the feather flume and 40 GPM as continued-used
chiller water.
Figure 1 depicts the total plant operation from the period of
setting up to March of 1971. The heavy line represents water used, and
2-17
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the dashed line waste discharged. The trend 1s down to just over eight
gallons per bird received. Waste discharge was up about .045 pounds of
BOD per bird, and now we are down to .025. These have been reduced
slightly as far as what goes Into the city system by the use of the air
flotation system.
Most of you who are 1n a city know when you buy water you are
charged for water and sewage. The water, sewer, and surcharge costs are
shown In Table 4. For those of you who have a surcharge, you will add
this additional cost. At the beginning of this project the water bill
was running $6,446 a month. Then after some changes were made, 1t was
running $5,382. You say that 1s not much different? Before that the
water and sewer costs went up by 20 percent and the surcharge was enacted.
If the changes had not been made 1n the plant, their water would have been
In excess of $11,000. The difference 1s more than $6,000. The surcharge
alone would have been about $3,600. The water and sewer charges would
have been over $8,000 per month.
2-18
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•o
-rt
00
-------
TABLE 4
WATER, SEWER, AND SURCHARGE COSTS
FOR SELECTED MONTHS
ro
ro
o
Item
Water
Sewer
Surcharge
July 1969
$ 3,069
3,377
~
Month
December 1970
$ 2,157
2,372
853
Total $ 6,446 $ 5,382
-------
ACKNOWLEDGMENTS
Information contained In this study was developed through a
jointly sponsored project by the:
Environmental Protection Agency
Gold K1st Poultry Company
North Carolina State University
Funds for the Research, Development, and Demonstration Grant
were provided under the Grant Project Number EGV 12060.
2-21
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WATER SUPPLY IN OFFICIAL POULTRY PLANTS
by
J. E. Turner, DVM
United States Department of Agriculture
Atlanta, Georgia
-------
WATER SUPPLY IN OFFICIAL POULTRY PLANTS
The amount of water per bird used 1n poultry processing In-
creased significantly during the middle and late 1950's when most poultry
plants remodeled for government Inspection and at the same time Installed
flowaway systems for moving organic waste and flumes or pumps for moving
giblets. Since that time, further mechanization such as continuous chil-
lers and gizzard machines has added still more to the demand for clean
water.
Section 381.50 of the Poultry Products Inspection Regulations
outlines the general requirements for water. More detailed references
may be found in the Poultry Inspector's Handbook and The Guidelines for
Implementation of Sanitary Requirements 1n Poultry Establishments. Some
of the provisions of Section 381.50 are as follows:
1. The water supply shall be ample, clean, and potable;
the pressure and facilities for distribution must
be adequate and protected against contamination and
pollution.
2. A water potability report issued under the authority
of the State Health Agency, certifying to the potability
of the water, must be provided.
3. Nonpotable water must be restricted to parts of the
plant where no poultry product 1s processed or other-
wise handled and then only for limited purposes such
as condensers not connected with potable water supply,
vapor lines serving inedible product rendering tanks
3-2
-------
and in sewer lines moving heavy sol Ids in sewage.
Nonpotable water shall not be permitted for wash-
Ing floors, areas or equipment, nor in broilers,
scalders, chill vats or ice making machines.
4. In all cases, nonpotable water lines shall be
clearly Identified and shall not be cross-con-
nected with potable water supply unless it 1s nec-
essary for fire protection. Any such connections
must have adequate breaks to assure against acci-
dental contamination and must be approved by local
authorities and the Administrator.
5. Any untested water supply In an official establish-
ment must be treated as a nonpotable supply.
In reviewing Section 381.50, it can be seen that the use of
nonpotable water is very restrictive. A good question then 1s -
where can water be reused?
Pages 4 and 5 of the Poultry Inspector's Handbook outline
areas and conditions under which water from chilling units, conden-
sers, and compressors may be reused. I might also add that while it
1s not mentioned in any of these references, recirculated water from
the refuse room 1s permitted in the drains to float feathers in the
picking room. This drain is then considered the same as a sewer
and any carcass that makes contact 1s condemned.
In permitting chilling water reuse, the Handbook may appear
to contradict Section 381.50. The Handbook is taken by USDA Inspectors
3-3
-------
as the official, working Interpretation of Section 381.50 and admin-
istratively 1s much easier to update or amend.
The Handbook provides that water from poultry chilling units
may be reused:
1. To aid In the movement of heavy solids 1n the
eviscerating trough, but not for flushing Inner
surfaces or side panels of the trough.
2. After removal of visible solids by screening for:
(a) Scalding tanks
(b) Flushing feathers from the picking machine
aprons
(c) Feather flowaway
(d) Washing down the floor in the picking *
room, or
(e) For hardening the wax In pinning operations.
Water from condensers or compressors may be used In any of the
locations stated above provided the system Is closed and there 1s a
vacuum break In the line to prevent back siphonage. It may also be
used for any other purpose in the plant where artificially heated water
is permitted provided it 1s covered by a potability certificate Issued
under authority of the State Health Agency.
If pumps or pipes are required to convey water Intended for
reuse from condensers, compressors, or chilling units, they must be
of the same type that can be readily dismantled as required for sani-
tizing.
Specific amounts of overflow water in giblet and carcass
chilling units are required, and the Handbook suggests a minimum amount
3-4
-------
of overflow from scalders. All other requirements regarding the amount
of water required are on an "adequate amount" or what 1s necessary basis.
Sanitary processing requires enough running water on goose-neck
washers to keep hands and hand tools rinsed, enough on bird washers to
thoroughly wash each carcass, and enough on equipment to keep contact
surfaces rinsed. In addition, some non-contact surfaces, such as the In-
side of troughs, must be continuously rinsed to prevent accumulation of
waste. There 1s, however, a difference 1n an adequate amount of water
and a wasteful amount. Many plants waste water — by running more than
1s required or necessary, or failure to cut It off when no longer needed,
or both. In many Instances, water can be saved by paying more attention
to plumbing.
Most plants now take advantage of melted Ice to count toward the
required overflow In the first chilling unit, but few that I know of have
made any attempt to utilize the overflow water from chillers. Perhaps
that 1s because It Is not generally needed In the areas where permitted.
Most plants do utilize some source of redrculated water to move feathers
to the refuse room.
3-5
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