EPA 625-3-73-001
Ill-
Pollution
Abatement
Upgrading Poultry-Processing
Facilities to Reduce Pollution
EPAlechndogy Transfer Seminar Publication
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IN-PROCESS POLLUTION ABATEMENT
Upgrading Existing
Poultry-Processing Facilities
to Reduce Pollution
ENVIRONMENTAL PROTECTION AGENCY* Technology Transfer
July 1973
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ACKNOWLEDGMENTS
This seminar publication contains materials prepared for the
U.S. Environmental Protection Agency Technology Transfer Program
and presented at industrial pollution-control seminars for the
poultry-processing industry.
Part I was prepared by Richard H. Jones, Ph.D., P.E., John D.
Crane, and T. A. Bursztynsky, P.E., of Environmental Engineering,
Inc., Gainesville, Fla.
Part II was prepared by John A. Macon, Research Associate,
Department of Economics, North Carolina State University, Raleigh,
N.C. Information included in part II was developed through a project
jointly sponsored by the Environmental Protection Agency, the Gold
Kist Poultry Company, and North Carolina State University. Funds
were provided under Research, Development, and Demonstration
Grant Project No. EGV 12060.
Part III was prepared by J. E. Turner, D.V.M., U.S. Department
of Agriculture, Atlanta, Ga.
NOTICE
The mention of trade names or commercial products in this publication is
for illustration purposes, and does not constitute endorsement or recommenda-
tion for use by the U.S. Environmental Protection Agency.
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CONTENTS
Page
Part I. Poultry-Processing Water Management 1
Introduction 1
Definitions 3
Poultry Processing 4
Water Management and Wastewater Control 6
Summary of Recommendations 11
Future Efforts 14
References 15
Part II. The Gold Kist Case Study 17
Introduction 17
The Study 17
Process and Equipment Changes 19
Summary of Results 21
Part III. Water Supply in Official Poultry Plants 27
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BLANK
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Part I
POULTRY-PROCESSING WATER MANAGEMENT
INTRODUCTION
The poultry-processing industry is characterized by vertical integration from hatchery through
feed mill, processing, and disposal of product on contract. The overwhelming mass of production is
in 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 in 1950, 6.9
billion pounds in 1960, 9 billion pounds in 1965, and 10.8 billion pounds in 1971.l These figures
represent 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 considered 18.8
pounds per bird. In 1970 the percentages of federally inspected 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 1970.2
The South Atlantic region is composed of Delaware, Maryland, Virginia, 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 percent of mature chicken pro-
duction, and 32.8 percent of turkey production.
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 proc-
essed 50 million pounds or more.
The large size and concentration of the poultry-processing industry become particularly important
in view of the industry's 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 during processing and also in carrying
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 disrupted biota in receiving
streams. Waste discharged to a sewage-treatment system provides a substantial loading in terms of
population equivalent, escaping grease, feathers, and offal. These constituents hamper treatment
processes and are subject to substantial sewer-use surcharges by municipalities.
A survey in 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 treat-
ment, and 6 percent had no waste treatment whatsoever. The reduction of water use in the poultry-
processing operations and the water reaching the final effluent will thus be a benefit to processors,
municipal waste-treatment facilities, and the general public whose environment is affected.
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Many communities are faced with having to provide advanced waste treatment to comply with
Federal and State regulations. Individual industrial plants discharging directly to a water course are
also coming under more stringent controls. In the General Session of this Seminar, the Environ-
mental Protection Agency (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 indi-
rect 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 treat-
ment at the present time, there is a rapidly growing trend among municipalities to make industry
pay for its share of waste treatment. As regulations force municipal plants to improve their waste-
water 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 (biochemical oxygen demand) and suspended
solids in the waste stream. Additional concentrations of BOD and suspended solids have been
charged at rates of $25 to $80 per 1,000 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 gallons, the U.S. Department of Agriculture (USDA) has pre-
dicted a cost of municipal waste treatment to poultry processors at $4.6 million.1 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 solids to wastewater
streams stand to have increased sewer surcharges and concomitantly increased processing costs.
Total treatment costs were estimated for anaerobic-aerobic lagoon systems and extended aeration
systems. Private waste treatment by lagooning could cost the processor from 2.2 cents to 0.8 cent
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 require investment,
operating, and maintenance costs of 11 cents to 4 cents per 100 pounds live weight for hydrauli-
cally unmanaged and managed plants, respectively. Careful and diligent in-plant water-use reduction
by the poultry processor may save him substantial quantities of money by allowing smaller waste-
treatment systems than those calculated here for "typical" poultry-proccessing plants in 1970. At a
normal sewer charge of 25 cents per 1,000 gallons of waste, a water-use charge of 25 cents per
1,000 gallons of water supplied, and a sewer surcharge of $50 per 1,000 pounds of BOD over 300
mg/1 in concentration discharged, a typical 100,000-broilers-per-day, 7-days-per-week poultry proc-
essor 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 modern-
ization and improved processing using flowaway systems. It will remain for the industry to assess
the costs of process changes to either "dry" or recirculating systems and compare them against legit-
imate wastewater treatment charges. In the event of borderline decisions, 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, wasteful water-use practices have been common through-
out 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.
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The USD A is very strict in its observance of process-water quality standards. Great variations
in water use and reuse are generally not permitted at this time. Therefore, discussion will be pre-
sented on water-reuse methods that are permitted by the USD A, methods that are not presently
permitted but that 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 other classes of poultry; and further processing before retail
marketing. Many plants engage in canning, freezing, and processing into specialty items. The princi-
pal concern of this seminar session will be the processing of poultry through evisceration to the
chilling step.
DEFINITIONS
Common parameters of wastewater quality which are referred to in this session include:
• Biochemical oxygen demand (BOD)—A measure of the potential of a wastewater to utilize
oxygen while experiencing microbial degradation; a semiquantitative measure of the organic
content of a waste. BOD5—The standard test conducted over a 5-day period.
• Chemical oxygen demand (COD)—A measure of the potential of a wastewater to utilize
oxygen while experiencing chemical oxidation; a semiquantitative measure of the organic
content of a waste. It does not necessarily correlate with the BOD test.
• Coagulation—The process of reducing the repelling forces between colloidal particles in
order that they may combine into larger particles that are more easily settled.
• Colloidal 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.
• Dissolved oxygen (DO)—Uncombined oxygen in solution in a liquid. A minimum of 4 or 5
parts per million (ppm) DO is necessary for the survival of fish in streams, and a minimum
of 1 or 2 ppm is necessary to avoid odors in wastewater.
• Nutrient—A substance that promotes cellular growth in organisms. Compounds of nitrogen
and phosphorus are of concern in wastewaters due to their encouragement of overenrich-
ment of water bodies.
• Slug—A high concentration of a substance in a wastewater stream, usually beginning and
ending abruptly and of short duration. Slugs cause problems in wastewater-treatment facil-
ities by disrupting biological or chemical activities, and in receiving streams by causing
drastic DO reductions.
• 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 filtra-
tion.
• Total solids—A measure of both suspended and dissolved solids.
• Volatile solids—Organic solids which are combustible at 600° C.
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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 in what is a relatively simple procedure of slaughtering and
cleaning poultry for marketing. Live poultry are unloaded at the processing plant and taken to a
killing station where jugular veins are cut while the poultry are suspended from a conveyor chain. A
bleeding area is reserved to confine blood from the carcasses. The birds are then scalded with hot
water to loosen their feathers. Feathers are removed mechanically and manually. Residual hairs and
feathers are singed off with a flame or by wax stripping, and the birds are surface washed. The
washed birds are eviscerated manually and washed internally and again externally. The carcasses are
then chilled or frozen, packaged, and shipped to a market. Figure 1-1 provides a brief flow sketch of
this process.
Receiving Area
It may be stated generally for the industry that the receiving area is no longer used for
extended holding of live poultry. Stays of several hours may be necessary in order to smooth out
fluctuations in delivery; however, feeding and fattening up of chickens is 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.
Killing of the poultry is 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 in 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 indicated by the 100,000 mg/1 BOD concentration in blood.
Defeathering
After bleeding, the feathers on the carcasses are loosened by scalding with hot water of
approximately 130° to 140° F. In most plants the birds are immersed in a tank of hot water, but a
spray system is used by some processors. Water in the tank is 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 is usually by mechanical action. In a few of the smaller
plants birds are removed from the conveyor and placed in 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 continuously to remove feathers, and the birds are subject to a final body
spray. The more common method of feather removal, however, is to let the birds on the conveyor
line pass between rotating spools containing rubber fingers that beat and pull feathers off the
bodies. Continuous streams of water then wash the feathers to a central collection facility. Consid-
erable amounts of water are lost through this procedure, and equipment washdown at the end of
this processing period adds further pollution loads.
Pinfeathers remaining after defeathering 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.
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Potoble water
Empty |
coops i
1
— Truck-boi
ne coops
a. Receiving area
b. Killing station
d. Scalding
e. Defeathering
g. Whole bird
washing
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X
— •• c. Blood recovery — ~ *J
II X
\y t
Blood '
{Feather flow away f. Feather ,
*" recovery *"j
1 | Feathers x
L _. .__ I
, 1
h. Evisceration
i. Final washing
k. Chilling
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1. Grading, weighing,
packing
Oftal Now away _^ j gffal | i
| recovery "•
. ,. , ¥
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- -1 Offal x
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lx
Refrigerated
delivery trucks
Product
Byproduct
>- Potoble water
— "*• Process water
— X-»- Waste water
Figure 1-1. Flowchart of poultry-processing plant.2
m. Final waste water
collection and control
Sewer
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A gas flame is used to singe hair and odd pinfeathers on the carcasses. The "plucked" birds are
then washed with an external fine spray.
Evisceration
Evisceration takes place in an area separate or enclosed from the remainder of the plant to
prevent contamination of the poultry. The legs of the surface-cleaned birds are separated and the
carcasses are resuspended on the conveyor belt to allow easier access to the stomach cavities. Heads
may also be severed during this process. Manual operations remove all the inner organs and separate
edible portions, such as hearts and livers, from inedible organs. Flowaway systems continuously
flush offal to the wastewater system with relatively large quantities of water. Spray washes clean the
insides of the birds prior to USDA inspection.
Gizzard cleaning is a distinct subprocess of the evisceration step in which gizzards are separated
from the bulk of the viscera, opened, and cleaned of food, sand, and gravel. Similarly, other recover-
able 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 they account for less than 5 percent of total produc-
tion.
Chilling
Chilling of the carcasses to prevent bacterial decomposition is the final process associated with
wastewater flows and immediately precedes freezing or icing of the meat and subsequent shipment
to market. Large processing operations use countercurrent 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 is 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 is used as
makeup water in the first tank. Fresh ice 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 in batch tubs of
ice and water. Chilled birds are drained on a conveyor line and then sized, graded, and packaged.
Freezing of carcasses is a slowly growing innovation that has found greatest application with
turkeys, ducks, and exotic fowl. The freezing occurs after packaging but produces no inherent
wastewater. Consumer demands are causing the old process of shipping poultry in ice to change to
packing with dry ice. This has little effect on wastewater flow.
Although poultry meat is sold principally through retail food stores, about 25 percent of
broiler output is sold to institutional firms. Broilers are usually sold in chilled, ice-packed form;
turkeys are most often sold frozen; and mature chickens are usually further processed. Further
processing accounted for about 13 percent of poultry slaughter in 1970.2
WATER MANAGEMENT AND WASTEWATER CONTROL
The poor-quality processing plant in 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 standpoint. In a
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typical, poor water-management situation, hoses are kept running when not in use, excessive
amounts of water are used, and poorly designed water-supply systems permit little if any control
over pressures 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-use concept can nevertheless be applied to almost every area of almost every
plant. Some of the more general reduction techniques for the main subprocesses in a poultry plant
are discussed in the sections that follow.
Receiving Area
Live storage of chickens in a battery room may become a temporary 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 pounds per 1,000 birds per day.3-4 As a compar-
ison, chicken-manure production on farms is normally on the order of 240 pounds per 1,000
chickens per day. Water quantities resulting from a daily wetwash of the receiving area will vary
greatly among different plants and even in the same plant on different days. The wetwash may con-
tain detergents and cleaning agents in 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 pounds 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 process-
ing-line demands. Cleaning techniques using high-pressure sprays, as opposed to low-pressure, high-
volume flows, will significantly reduce cleaning-water demands. There is doubt at this time as to
whether the use of cleaning detergents provides 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 pounds of BOD
in recoverable blood. In a poorly operated plant the blood will wash to the sewer, and during post-
processing cleanup will be contained in the washwater.
Collection of blood may reduce the processing plant's sewage strength by 35 to 50 percent.
This is roughly equivalent to 17 to 18 pounds of BOD per 1,000 chickens. Since the poultry are
bled while they hang from a moving conveyor, the blood may be collected in a tunnel or a walled
area. In a high-walled 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 spurting 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 con-
gealed 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 that required for cleaning an enclosed tunnel of
limited dimensions.
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 is lost blood and increased wasteload. Stunning of the birds at slaughter will reduce such move-
ment, allow greater blood recovery, and reduce wastewater BOD load.
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Recovered blood may in some cases be sold to a local rendering plant and the profit used to
offset pollution-control costs. In other instances it 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 wasteload reduction.
Scalding
The scalding operation which loosens poultry body feathers also provides a first wash to the
carcasses. The spent scalding water will contain blood, dirt, feathers, manure, and dissolved fats and
greases. The scalding tank is 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 before defeathering provides an opportune process for conservation of
water. Scald-water temperatures between 128° and 145° F inhibit the growth of common bacteria,
and the water is 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 proc-
essed. Screened chiller overflow water that has been applied to relatively clean, washed carcasses 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 feedwater.
Defeathering
Defeathering under poor water-management techniques is performed mechanically with con-
tinuous streams of water washing away the feathers and washing the carcasses. While this is per-
formed in many new and modern 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 that 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/1.5 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.5 This water use was 11
percent of the total water supply to the plant. Additional in-plant water reuse for the feather flow-
away flume raised the total water use 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 washwater and
flume water. Feathers may be removed by screening operations of the washwater, but they have a
high tendency to foul screens and cause polluted-water overflow. Screened water from defeathering
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, N.C.
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Evisceration
The evisceration process consumes large quantities of fresh water in cleaning of the carcasses,
in viscera flowaway flumes, and in worker cleanup supplies. Wastewater from evisceration will con-
tain high BOD's, suspended solids and grit, greases, blood, and bacteria from the intestinal tracts.
Large volumes of water used to flush the offal would tend to dilute the BOD concentration, but the
total pounds of BOD produced 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 percent of the fresh-water
supply.5 >6
Gizzard cleaning is a distinct subprocess of evisceration and, according to USDA regulations,
presently requires potable water, as does evisceration. Gizzard-cleaning water is 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 in this process, it is still equiv-
alent to 12.2 pounds per 1,000 broilers.
Evisceration adds a large quantity of wastewater with a substantial amount of BOD to the
plant effluent. During evisceration, workers' hands are in contact with recoverable viscera, offal, and
bacterial pollutants. Constant supplies of fresh water are used to wash workers' hands and recover-
able 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 it inadvisable to reuse offal-flume water
in any process in which it can contact poultry products; however, in noncontact processes such as
feather fluming it may be possible to reuse even this water. Gizzard-cleaning water is similar in
nature to the eviscerating-trough water and should be treated similarly. Lung-vacuum pump effluent
is low in 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 gallon 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 washwater, used to wash both the inside and the outside of the carcasses, should
normally be the freshest water possible and washing must be conducted with potable water, accord-
ing to the USDA. This washwater may possibly be reused in another subprocess 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 is 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 mg/1.5 The overall water demand for
chillers is approximately three-quarters of a gallon per chicken. USDA requirements are one-half
gallon of water use per chicken. BOD production in a body chiller is on the order of 7.4 pounds per
1,000 birds.
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, measurement of water in the slush ice added to chillers should be credited against
minimum chiller requirements.
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Dry Cleanup
The basic processes presented above have been constrained by the limitation of using a flow-
away system. Drycleaning 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 indus-
try's conversion to "modern" flowaway systems. It is understood that flowaway systems have pro-
vided 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 abatement
costs with the return to more labor-intensive, in-house dry cleanup systems.
Dry cleanup of feathers from defeathering operations, brushing feathers to a dry collection
point where there is a limited storage before removal by a renderer, may be performed manually or
automatically. 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 substantially reduced feather-screening facilities. The area of
dry, mechanical feather collection has great potential for an enterprising equipment manufacturer.
Dry removal of evisceration wastes will reduce wastewater constituent concentrations and
some water flowaway requirements. Studies have shown that if waste solids from evisceration were
put directly into containers at the table, effluent from evisceration would contain 6 to 8 pounds
BOD per 1,000 chickens.4 This compares to a total evisceration-and-gizzard-flowaway BOD of 12.2
pounds. Finally, heads may be pulled and dropped directly into container with no water use what-
soever.
Byproduct Recovery
Dry or wet recovered feathers may often be sold to rendering facilities for processing as pro-
teinaceous 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 rendering 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 Tenderers in Florida at
the rate of $9 to $10 per 1,000 broilers processed.
In the 1970 survey performed by the USD A, it was found that 0.6 percent of processing plants
did not salvage offal, 70.8 percent of the plants sold offal to Tenderers, 1 percent gave offal to
Tenderers, 26.6 percent rendered offal in-house, and 1 percent dumped or burned collected offal.1
The same study revealed that blood was not salvaged by 14.2 percent of the plants, sold to rend-
erers 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 percent, and burned or dumped by 1.3
percent.
Housekeeping
In-plant cleaning of equipment and housing is 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 solids in dry form
10
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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 nonflowaway plants will prevent gross organic solids from reaching the sewer system. Organic
solids in flowaway plants may be processed through the offal and feather recovery screens. Floor
washing and general sanitation is imperative, but there is no reason to provide large quantities of
water to wash bulky solids through drainlines.
Employee awareness of the cost of water use will result in improved housekeeping procedures.
Letting water hoses run freely on the floor between uses is wasteful, and employees should be
encouraged 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 necessary to do a good job.
Water Supply and Treatment Equipment
Improved spray nozzle designs at the Gold Kist facility were able to reduce fresh water use in
final bird washers by 60 percent, in hand washers at evisceration from 285 gpm to 100 gpm, and in
whole-bird washers from 45 gpm to 30 gpm. Mechanical improvements in the replacement of old
free-running hoses by a high-pressure cleaning system using foam cleansers reduced daily cleanup
water from 112,000 to 46,000 gallons per day. Even plants not contemplating process changes or
internal reuse of water can noticeably reduce fresh water use and wastewater flow by the installa-
tion of the best available spray heads and cleaning equipment. Varying line pressures and water
demands in different parts of the plant can make automatic or timed spray equipment nonfunc-
tional. 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 the general reduction of poultry-
plant waste. Rotary drum screens along with stationary flat screens have long been used for byprod-
uct recovery. The newest trends are toward vibrating screens which operate at higher efficiencies
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 USDA1 estimated total BOD and suspended solids production for
poultry-processing plants based on production figures and various sources for pollutant loads. The
various sources resulted in table 1-1, which lists a collection of coefficients for byproducts, water
use, and wasteloads to be applied to production figures. It must be noted that table 1-1 may be rea-
sonably accurate on quantities of byproduct, but the numerous variables of processing, such as
poultry type, water use, spray nozzle design, cleaning practices, and screening efficiencies, make
predictions on water use and wasteloads a gross estimate at best. Based on the values in table 1-1,
however, it was estimated 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 the investigators' experi-
ence, which indicates BOD's of 450 to 600 mg/1 and suspended solids of 300 to 400 mg/1.
SUMMARY OF RECOMMENDATIONS
The changes that may be made in each plant to reduce water use will depend upon the partic-
ular circumstances at that plant. A general list of steps for improved water management, which may
be used as a framework by each poultry processor for his own actions is presented:
11
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Table 1-1 .—Coefficients used in estimating byproducts, water use and wasteloads of
poultry-slaughtering plants
Variable
Unit
Value per 1,000
pounds1
Byproducts:
Blood:
Young chickens Pounds
Mature chickens do.
Turkeys do.
Other poultry do.
Offal:
Young chickens do.
Mature chickens do.
Turkeys do.
Other poultry do.
Feathers:
Young chickens do.
Mature chickens do.
Turkeys do.
Water use:
Young chickens Gallons
Mature chickens do.
Turkeys do.
Other poultry do.
Cut-up do.
Further processing do.
Wasteloads:
BOD:
Young chickens Pounds
Mature chickens do.
Turkeys do.
Other poultry do.
Suspended solids:
Young chickens do.
Mature chickens do.
Turkeys do.
Other poultry do.
Timespan of operation:2
Young chicken, mature chicken, and other poultry plants Days
Turkey plants do.
70
70
70
70
175
170
125
140
70
70
70
2,198
2,173
1,700
2,100
500
500
8.2
8.7
8.0
8.0
6.3
5.4
5.0
5.0
234
130
^ Live weight except for cut-up and further processed coefficients which are ready-to-cook weight.
2These coefficients are based on a maximum of 260 operating days per year. It was 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.
Sources: Environmental Protection Agency, "Industrial Waste Study of the Meat Products Industry," 1971; U.S. Department of
Agriculture, "Processing Poultry Byproducts in Poultry Slaughtering Plants," Marketing Research Report No. 181,1957; and
industry contacts.
12
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• Choose a person specifically responsible for water management. This person should have
reasonable powers to make and enforce changes.
• Determine where water is used and in what quantities.
• Install flowmeters and pressure gages in major flow areas.
• Install water pressure regulators to prevent gross line pressure variations. This will help
prevent occasional oversupply at unit points in the process.
• Tackle each unit process to determine possible water-use reductions.
• In receiving area, dry-sweep wastes to receptacles before washing floors.
• In receiving area, replace open garden-type hoses with nozzles that give high-velocity spray
and reduced water flow and that may be turned off at point of application.
• Clean with detergents and cleansers to further reduce water use and to produce a more
hygienic area.
• Stun carcasses electrically at slaughter to prevent body movement and splattering of blood.
• Confine bleeding to a tunnel or enclosed area where blood collection may be easily accom-
plished. Recover the blood for rendering or farmland disposal and do not let it into waste stream.
• Use the minimum approved USDA quantities of water that will maintain your temperature.
• Reuse screened chiller water as scalder feed water. Consider simple heat exchange between
scalder overflow water and scalder-boiler feed water.
• Pay attention to new developments in vacuum removal of feathers in defeathering. Consider
an application of such a system when practical.
• Screen feather-flume water and reuse in the feather flume.
• Install spray nozzles on bird wash that will get the job done with a minimum amount of
water.
• 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 for hand washers only
when it is needed. Timed sprays can wash evisceration solids away with no wasteful water
use between bursts.
• Measure the ice slush added to chiller water and credit it against chiller water overflow
requirements.
• Keep all screens in perfect working order. A clogged and overflowing screen costs the
processor money.
• Use dry cleanup in plant prior to "wet rinse" to reduce water use. Collect dry solids in
containers for disposal or rendering.
• Consider institution of dry removal of wastes, such as onsite containers for
heads.
13
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• Recover all possible byproducts to improve the economy of in-plant water management.
• Stimulate employee awareness of the expense and undesirability of poor water management.
Encourage employees to be careful of their water use.
FUTURE EFFORTS
The methods for reducing water use as discussed in 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 envisioned by some people, is total reuse of water or zero pollutant discharge. Such an
ideal goal may never be realized, but pressure will be brought to bear to approach it. 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 in the evisceration flume, use of screened whole-bird washwater in the scalder on the premise
that the bird will contact water of that quality anyway, reuse of screened final washwater in 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 use 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.
14
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REFERENCES
iU.S. Department of Agriculture, Statistical Reporting Service, Apr. and Jan. 1972.
2 "The Poultry Processing Industry," Marketing Research Report No. 965, Economic Research
Service, Washington, D.C., U.S. Department of Agriculture, June 1972.
3R. Porges, "Wastes from Poultry Dressing Establishments," Sewage and Industrial Wastes,
vol. 22, No. 4, p. 531, Apr. 1950.
""I
I 4"Wastes from the Poultry Processing Industry," Technical Report W 62-3, U.S. Public Health
** Service, Department of Health, Education, and Welfare, 1962.
^Proceedings, Workshop on Poultry Processing Plant Water Utilization and Waste Control,
\ Sept. 16,1971, Greensboro, N.C., sponsored by North Carolina State University and the University
of North Carolina.
6"Industrial Waste Profiles," The Cost of Clean Water, vol. 3, Federal Water Pollution Control
Administration, Sept. 1967.
15
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THIS PAGE INTENTIONALLY
BLANK
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Part II
THE GOLD KIST CASE STUDY
INTRODUCTION
Part II will focus on the impact of in-plant process and equipment changes on water use and
waste abatement in poultry processing. An attempt will be made to
• Present the results of a research, development, and demonstration project conducted in the
Gold Kist plant at Durham, N.C.
• Interpret the usefulness of these results for improving the operation of other plants.
A detailed study of opportunities for water and waste reduction was made throughout the
Gold Kist 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
vs. 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 maintained.
The Office of Research and Monitoring, Environmental Protection Agency (EPA), and Gold
Kist supported the study on 70-30 cost-sharing terms. North Carolina State University (NCSU) pro-
vided technical and research requirements, including a biological evaluation of all phases. Effective-
ness of the project has been greatly enhanced by the full cooperation of the Poultry Inspection
Group at all levels.
THE STUDY
Since the trend of poultry production has seen a great increase over the past 2 decades and the
total production in the United States in 1970 was approximately 3 billion birds, the team began this
study with the realization that the cost of water and wastes could be very significant in poultry
processing. Although the unit costs are small, they are still significant. When only the sum of
approximately 7.3 cents per pound is available for live hauling, processing, selling, delivery, and
profit, and a cost of 0.1 to 1 cent per bird is added, the costs become very significant.
The team started developing the project with the belief that managers in poultry processing
would act, provided that they had the necessary knowledge. We did not believe that the supervisors
and managers knew how much water they were using. We also did not believe that they knew how
much wastes were being discharged or where they were coming from.
Now, getting to the specific objectives of the project:
• To install and/or modify the processing equipment itself. What could be done in modifying
the equipment in the plant to enable it to use less water, to generate less waste?
17
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• To evaluate the impact of these changes. How much water reduction would a change make?
How much waste would one of the changes eliminate?
• To determine the economic implications of these changes. Could a poultry plant justify the
expenses of the process modification? In other words, would enough water be saved and
would enough wastes be eliminated to justify spending the money to make the changes?
Not all of our changes panned out. We did not expect them to, and this was the reason for the
demonstration grant. If we had known the answers before starting, we would not have had to do the
work.
The basic plan of work was first to obtain benchmark information. Benchmark information
means just how much water was used in the plant. Where were the wastes coming from in the plant?
This information was just to give the team 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 modifica-
tions or changes.
The team approached the benchmark data and the biological work by going to different points
in the plant. We took each unit operation in the plant and looked at it in its entirety. For example,
we examined the scalder exit, the chill entry and the prechiller, and water samples to determine
where the wastes are generated. Then we added these up for the total waste stream of the plant. We
did the same thing for the biological work.
Now if one wonders 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 3.6 billion gallons of
water that was used in North Carolina last year for the processing of poultry. From 2 to 10 million
pounds of BOD5 were discharged from the plants. It will be noticed that a wide range was used
here. It all depends on whose figures are used for what plant. We do not have figures for most of the
plants, so an average has been made. The average would be somewhere in the range of 2 to 10
million, and this shows the magnitude 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.
PROCESS AND EQUIPMENT CHANGES
Look at this project from the standpoint that the team was using the plant primarily as a
"laboratory in action." We made mistakes; we purchased materials that were not suitable for the
job; but in making our mistakes, we were able to say that 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 used were Parshall flumes, watermeters, and V-notch weirs with automatic
recorders for the large flows. With a bucket and a stopwatch one can find out how much water is
being discharged from small sources.
Housed above the 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.
18
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Watermeters were installed in just about every logical place to measure the daily volume of water.
The team could then monitor what was happening in each individual process. Meters were a very
important part of the testing program.
The next thing was to find out if we could get the same results twice. Now, an investigator 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, the investigator is right back at the start. He does not know how much of what is
passing through where. So from the first, we learned to control the flow by regulation. Before we
could ever get a uniform pattern on waste generated in the plant we had to get regularity of proc-
essing, or at least some uniformity of operation.
Blood Collection and Control
The first major equipment development was one of the most difficult. 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 was used so that the birds
could be stilled by the shocking machine early after being killed. The bodies and the feathers were
thus kept clean and the blood was well contained in the trough; therefore, we were collecting not
only the worst pollutant in the plant, but it was now a good byproduct.
Scalder
Reuse of chiller water eliminated the use of fresh water for scalder makeup. Our primary
objectives were to do two things: to reduce wastes but at the same time to minimize water use, and
this was one case in which we were 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,
which reused water and put the water from the chillers into the scalding machine.
Defeathering
Flowaway flumes were redesigned to remove efficiently the feathers from beneath the pickers
with the use of less water. Water for this purpose was now solely supplied from the screened
eviscerating-line effluent.
Whole-Bird Washers
Small-opening and higher efficiency spray nozzles were installed in both washers. Regulation
and control valves were also installed in the water-supply line of each bird washer.
Evisceration
Hand-wash outlets. The largest volume users of water in the Gold Kist 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 enough for
washing their hands, the volume would be equal to the amount for washing a whole human being.
The shower-type nozzles used 3x/2 gpm. Our last nozzles use about 0.4 gpm.
19
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Waterflow rates vary slightly from place to place and station to station. With this drastic reduc-
tion in the amount of water, however, these operators today do just as good a job as when they
were using 3x/2 gallons of water per minute per nozzle.
Very important is the pressure gage regulating the flow out of these nozzles. Here is what was
happening in Durham before this study. 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 35 to 40 pounds up to 80 pounds or more.
When the pressure ran up high, these nozzles would fog and wet the users as if they were going
through a shower of rain. Before we could even use the nozzles the water pressure to them had to
be regulated.
We tried using a tickler nozzle. This nozzle has not been approved by the USDA. A tickler-type
hose nozzle is like one that may be seen at a service station; it stops running when it is dropped
down. We found that 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 plant operators. It does cut the water off completely. It will not run until the little bar is
pushed to one side. The nozzles are sold by local suppliers.
Side-pan wash. The team wanted to reduce further the amount of water used in the eviscera-
tion line. We found that each side pan has to be flushed with water to keep the slides clean while
the workers are working. If the regulating valve could be shown, it would be a timed unit. When the
water is on, it flows full force to flush the surface of the eviscerating pan properly, and then an elec-
tric timer cuts that water off immediately. It stays off a predetermined 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
reducing the amount of water used. Before, in trying to control the water, the flow had been re-
duced by merely cutting back on the amount of water flowing down the pan. Here, we felt that the
full force of the water was needed to clean the total surface of the pan, and yet it was not needed at
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 gages as described previously. By use of the quick-
opening shutoff 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 for chilling. To assure
this quantity the regulations require watermeters for verification. To cool the water in the chiller
and, subsequently, the birds, ice is 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 to measure
the slush ice is developed or engineered, the amount of water running into the chillers can be re-
duced 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 con-
siderable cost Gold Kist installed a CO2 snow system in their plant to replace this use of ice. This
20
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method replaced 15 pounds of ice per 65 pounds of product, or the equivalent of nearly 2 gallons
of water.
Plant Cleanup Water
Last, but by no means least, was the sizable volume of water being used to clean all the proc-
essing equipment, building, and receiving yard area. Several types of new chemical formulations
were tried. Combined 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 cleanup operation.
Final Wastewater 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, including the associated pumps, sumps, tanks,
and byproducts holding chamber, was purchased. Although this was not strictly an in-plant change,
the additional byproducts recovered increased yield and byproducts income while further reducing
the waste surcharge cost. With both cost advantages it has been economically feasible to install and
operate this air flotation system.
SUMMARY OF RESULTS
Table II-l gives the volume of water that was being used for all purposes in the processing of
approximately 70,000 birds per day. These benchmark data indicate a use of nearly 13 gallons of
water for each bird processed. They also identify where the water was being used in the plant at the
beginning of the project.
Table II-2 shows the benchmark data relative to the waste characteristics of selected waste-
water flows throughout the plant. These values are averaged over several weeks of testing.
The benchmark data presented some interesting points that can be examined in table II-l. The
total water consumption is about 840,000 gallons per day. The important point is that the eviscerat-
ing trough itself accounted for approximately 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 is the gizzard machine with the gizzard splitters where there are 194,000 or almost 200,000
gallons per day used, so the eviscerating trough and the gizzard operation consume almost 50 per-
cent of the total water used in the whole plant.
Another thing to be pointed out concerns hoses. A hose used for 10 minutes uses 340 gallons.
One hose used for 1 hour means 2,000 gallons of water. How many times in a poultry plant have
hoses been left just running? Note that 2,000 gallons of water an hour are going down the drain
from one hose lying on the floor. Also, why are there not nozzles on the ends of the hoses? Why is
this water wasted? Is an employee too lazy to turn off the hose because in 30 minutes he is going to
want to use it again, so he leaves it running?
To get into the area of reduction and to summarize the results—it may be of interest to know a
little something about the city of Durham. The Gold Kist plant was consuming approximately 10
percent of the fresh water production of the city. The team reduced the amount from 838,000
gallons per day, or something more than that, to in the neighborhood of 580,000 gallons per day.
21
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Table 11-1 .—Volume of water used in processing approximately 70,000 birds dailya
Process
Killing station
Scalder . .
Pickers
Feather flume .
Neck scalders
Whole bird washers
Defeather cleanup hose (1 at 1 hr)
"Hang-back" belt
Eviscerating trough:
Hand-wash outlets
Side-pan wash .
Final bird wash
Lung-vacuum pump effluent
Gizzard machine and giblet flumes
Eviscerating cleanup hose (2 at 30 min each) . .
Giblet chiller
Neck cutter ,
Chillers
Packing ice
Bird pickup (10% in chillers)
Packing cleanup hoses (3 at 10 min each)
Byproduct cleanup hoses (1 at 10 min)
Source
Fresh
Fresh
Fresh
Fresh
Chiller effluent
Recirculated offal water
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh
Fresh and ice
Fresh
Fresh and ice
Ice
Fresh
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
3 15.0
(2)
102.0
34.0
Total
volume,1
gal
1,080
20,898
20,520
50,922
(2)
(2)
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
340
aNormal processing day runs from 7:00 a.m. to 4:00 p.m.
1 Watermeter readings: processing (7:00 a.m.-4:00 p.m.) = 725,600 gpd; cleanup (4:00 p.m.-7:00 a.m.) = 112,200 gpd; total,
837 800 gpd. Undetermined process water: 850,000 - 837,800 = 12,200 gpd.
2Data not available.
^Unit of measure is pounds per box.
Note.—Cleanup hoses are used to rinse off equipment at break periods and lunch during processing operation.
This total reduction is 30 percent or a little greater. The amount in pounds of BOD5 coming out of
the plant was reduced from 4,000 pounds a day to 1,400 pounds. This is approximately a 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 in the
amount 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 II-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 is quite a reduction in itself, just by changing the nozzles. The hand
washers resulted in a change from 285 to 100 gpm.
Cycling of the side-pan wash originally used about 90 gpm. Now the amount has been reduced
to 30 gpm. Of course, this result would depend on the time period and effect of the cycling and
other things, but here it is based on one particular set of conditions.
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Table \\-2.-Benchmark data on water and waste at the Gold Kist plant in Durham, N.C.,
during December 1969
[Milligrams per liter]
Scalder entry . ....
Scalder exit
Whole bird wash
Final bird wash
Giblet chiller
Chiller I
Chiller II
Feather flume
Eviscerating flume
Plant effluent
BOD
1 182
490
108
442
2,357
442
320
590
233
560
POD
2080
986
243
662
3959
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
350
200
150
580
1,320
800
250
120
430
150
Table 11-3.—Water reduction development activities by area of the plant
and changes in fresh water
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 giblet 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 in fresh
water use
From
To
Gallons per minute1
50
285
90
360
45
94
40
1 112,000
30
100
30
320
30
0
0
1 46,000
Cleanup data given in gallons per day.
23
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In the rearrangement in the giblet handling, the team made a small reduction. We made an
impact in 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 there had been some
additional fresh water hoses stuck in the flumes trying to flush down the feathers that were not
moving properly. Multiplying this flow by 60 gives a figure of 6,000 gal/hr.
The dramatic reduction of water used in cleanup has been caused by the installation of new
equipment coupled with good chemical utilization.
Not to be overlooked is the reuse or multiple continued use of process waters. The best exam-
ple of this type application is the fresh water first used in the final chiller. Next it is pumped to the
prechiller. The collected effluent from the prechiller is then skimmed and pumped into the scalder
as makeup water. As a scalder effluent, the same water discharges into the feather flowaway flume
to assist in transporting the feathers to the byproduct recovery screens. Thus the water is finally
discharged in the plant's final drain.
This multiple use of water was responsible for most of the reduction of fresh water in the
feather flume and for 40 gpm as continued-use chiller water.
Figure II-l depicts the total plant operation from the period of setting up to March of 1971.
The heavy line represents water used, and the dashed line, waste discharged. The trend is down to
just over 8 gallons per bird received. Waste discharge was up to about 0.045 pound of BOD per bird;
now it is down to 0.025 pound. This has been reduced slightly as far as what goes into the city
system by the use of the air flotation system.
Most of those who are in a city know that when they buy water they are charged for water and
sewage. The water, sewer, and surcharge costs are shown in table II-4. Those who have a surcharge
will add this additional cost. At the beginning of the Gold Kist project the water bill was running
$6,446 a month. Then, after some changes were made it was running $5,382. One can say that it is not
much different? Before that, the water and sewer costs went up by 20 percent, and the surcharge
o
I
•d
a
4J
£
13 r
12 -
u 11 -
10 -
Water Used
Vasts Discharged
,TL
.05
.04 &
.03
.02
JJ ASONDJFMAMJ JASONDJFM
Figure 11-1. Quantity of water and waste per bird. Gold Kist plant, Durham, N.C.
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Table 11-4.—Water, sewer, and surcharge costs for selected months
[Dollars]
Item
Water . .
Sewer . .
Surcharge . . .
Total
Month
July 1969
3,069
3,377
6,446
December 1970
2,157
2,372
853
5,382
was enacted. If the changes had not been made in the plant, the water bill would have been in
excess of $11,000. The difference is 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.
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Part III
WATER SUPPLY IN OFFICIAL POULTRY PLANTS*
The amount of water per bird used in poultry processing increased 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 chillers 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 require-
ments for water. More detailed references may be found in the Poultry Inspector's Handbook and
The Guidelines for Implementation of Sanitary Requirements in 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 distri-
bution 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 is
processed or otherwise handled and then only for limited purposes such as condensers not
connected with potable water supply, vapor lines serving inedible-product rendering
tanks, and in sewerlines moving heavy solids in sewage. Nonpotable water shall not be
permitted for washing floors, areas, or equipment, nor in boilers, scalders, chill vats, or
icemaking machines.
4. In all cases, nonpotable-water lines shall be clearly identified and shall not be cross-
connected with potable water supply unless it is necessary for fire protection. Any such
connections must have adequate breaks to assure against accidental contamination and
must be approved by local authorities and the administrator.
5. Any untested water supply in an official establishment 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 is-^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, condensers, and compressors may be reused. It might also be added that,
while it is not mentioned in any of these references, recirculated water from the refuse room is per-
mitted in the drains to float feathers in the picking room. These drains are then considered the same
as a sewer and any carcass that makes contact is condemned.
*Contributed by J. E. Turner, doctor of veterinary medicine, U.S. Department of Agriculture, Atlanta, Ga.
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In permitting chilling water reuse, the Handbook may appear to contradict section 381.50.
The Handbook is taken by U.S. Department of Agriculture inspectors as the official, working inte
pretation of section 381.50, and administratively is 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 in 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
e. Hardening the wax in pinning operations
Water from condensers or compressors may be used in any of the locations stated above pro-
vided the system is closed and there is a vacuum break in the line to prevent backsiphonage. It ma;
also be used for any other purpose in the plant where artificially heated water is permitted, pro-
vided that it is 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, com-
pressors, or chilling units, they must be of the same type that can be readily dismantled as requirei
for sanitizing.
Specific amounts of overflow water in giblet- and carcass-chilling units are required, and the
Handbook suggests a minimum amount of overflow from scalders. All other requirements regardin
the amount of water required are on an "adequate amount" or what-is-necessary basis.
Sanitary processing requires enough running water on gooseneck washers to keep hands and
hand tools rinsed, enough on bird washers to thoroughly wash each carcass, and enough on equip-
ment to keep contact surfaces rinsed. In addition, some noncontact surfaces, such as the insides oi
troughs, must be rinsed continuously to prevent accumulation of waste. There is, however, a diffei
ence between an adequate amount of water and a wasteful amount. Many plants waste water—by
running more than is required or necessary, or by failing 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 there appear to be few that have made any attempt to utilize the overflow
water from chillers. Perhaps that is because it is not generally needed in the areas where permitted,
Most plants do utilize some source of recirculated water to move feathers to the refuse room.
' U. S. GOVERNMENT PRINTING OFFICE : 1973—514-155/313
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U.S. ENVIRONMENTAL PROTECTION AGENCY • TECHNOLOGY TRANSFER
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