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Best Management Practices

for

Nitrogen and Phosphorus Control

in

Red Meat and Poultry Slaughter Plants

October 11, 2001 Partial Draft, prepared by J. Willis Sneed of HDR, Inc.

• I. Introduction
• II. Discussion of various slaughter plant types
• III. Description of production-related activities
• IV. Typical nitrogen and phosphorus levels
• V. Nitrogen and phosphorus sources
• VI. Best management practices for nitrogen and phosphorus control
• VII. BMP monitoring
• Appendix
• References

I. Introduction

This document is intended to provide guidance for plant and corporate personnel in voluntarily establishing Best Management Practices (BMP) to control nitrogen and phosphorus in the wastewater from red meat and poultry slaughter plants. These nutrient control practices solely address in-plant waste minimization practices and do not include wastewater pretreatment or treatment methods.

This is one part of a three-part set of documents. This part addressed BMP for the slaughter operations. The other two documents discuss BMP for cutting up the carcasses, further processing the meat, and rendering. Therefore it may be appropriate for some packing plants to use two or all three of these documents if they also cut up the carcasses, further process the meat, or render.

II. Discussion of various slaughter plant types

In the mid-1970s, the U.S. Environmental Protection Agency (EPA) divided red meat and slaughter plants into the following Segments and Subcategories:

• Simple Slaughterhouse
• Complex Slaughterhouse
• Low-Processing Packinghouse
• High-Processing Packinghouse

The plants were divided as follows

• Slaughterhouse. A plant that slaughters animals and has as its main product fresh meat as whole, half or quarter carcasses or smaller fresh meat cuts.
• Packinghouse. A plant that both slaughters and processes fresh meat to cured, smoked, canned, and other prepared meat products. Processed meat products are limited to: chopped beef, meat stew, canned meats, bacon, hams (boneless, picnic, water added), franks, wieners, bologna, hamburger, luncheon meat loaves, sausages.

Both slaughterhouses and packinghouses are further subdivided into two subcategories, depending on the amount of by-product processing. By-product operations include: rendering, paunch and viscera handling, blood processing, or hide or hair processing.

• Simple Slaughterhouse. A slaughterhouse that does very limited, if any, by-product processing; usually no more than two operations.
• Complex Slaughterhouse. A slaughterhouse that does extensive by-product processing; usually at least three operations.
• Low-Processing Packinghouse. A packinghouse that processed no more than the total animals killed at the plant and normally processing less than the total kill.
• High-Processing Packinghouse. A packinghouse that processed both animals slaughtered at the site and additional carcasses from outside sources.

The BMPs contained in this document are applicable to the slaughter portion of each of these plants. Many of these plants will also need to refer to BMPs for Further Processing Plants and BMPs for Rendering.

Although categorical limits were never promulgated for the poultry industry so no legal subcategorization exists in current regulations, in the mid-1970s, the U.S. Environmental Protection Agency (EPA) divided poultry plants into the following subcategories:

• Chickens
• Turkeys
• Fowl
• Ducks

These subcategories are obvious with the exception of the term "fowl", which are breeder-spent hens (heavy fowl), a few roosters, and laying hens (light fowl). From a wastewater perspective, the key difference is the presence of immature eggs in the hens, which can increases loadings from these birds.

More recently poultry plants are commonly split into the following three types of facilities:

• Slaughter/First Processing: A facility that simple slaughters birds and packages fresh and frozen whole birds and parts.
• Slaughter/Second processing: A facility that, in addition to performing the operations of first processing, also performs operations such as deboning, marinating, tumbling, IQF.
• Slaughter/Third Processing: A facility, which in addition to performing the operations of first and second processing, also produces a parfried or fully-cooked product. Parfried product is product that is not fully cooked. It is often done to "set" batter on a formed meat product.

The BMPs contained in this document are applicable to the slaughter portion of each of these plants. Second and Third Processing plants also need to refer to BMPs for Further Processing Plants.

III. Description of production-related activities

[pending]

IV. Typical nitrogen and phosphorus levels

In the 1974, the Environmental Protection Agency (EPA) published a Development Documents for Red Meat Processing. Included within that document are tables showing waste characteristics for each slaughter plant subcategory. Table I shows data for total Kjeldahl nitrogen (TKN) from that Development Document.

TABLE I
RED MEAT SLAUGHTER PLANT EFFLUENT TKN LEVELS
FROM 1974 DEVELOPMENT DOCUMENT

In the 1975, a similar Development Documents for Poultry was published. That document included tables showing waste characteristics for effluent from each slaughter plant subcategory. Table II shows data for the various forms of nitrogen from the Development Document.

TABLE II
POULTRY SLAUGHTER PLANT EFFLUENT NITROGEN LEVELS
FROM 1975 DEVELOPMENT DOCUMENT

* Live Weight Killed

Table III shows effluent phosphorus levels for both Red Meat and Poultry slaughter plants.

TABLE III
SLAUGHTER PLANT TOTAL PHOSPHORUS LEVELS
FROM 1970s DEVELOPMENT DOCUMENTS

* Live Weight Killed

All data in Table Nos. I-III represents plant effluents after physical pretreatment, i.e. no chemically-enhanced pretreatment. However pretreatment facilities were generally less extensive in the early 1970s than is presently typical.

V. Nitrogen and phosphorus sources

A. Nitrogen

Total nitrogen is comprised of TKN, nitrate nitrogen and nitrite nitrogen. TKN is the combination of organic nitrogen and ammonia nitrogen. Table II shows that essentially all of the nitrogen in poultry slaughter plant effluents is in the form of TKN, with very little nitrate or nitrite nitrogen present. Although no effluent nitrate or nitrite data is presented in Table I for Red Meat slaughter plants, nitrate and nitrites are similarly low for these effluents as well. By far the major source of nitrogen is from the protein in the meat particles and blood in the wastewater from slaughter plants. Protein contains about 16 percent organic nitrogen. Other sources of nitrogen are the manure and partially-digested feeds from stomachs and gizzards and intestines, as well as urine. Fat contains no nitrogen, nor is any contained in carbohydrates such as sugars, starches and cellulose. The primary source of the small amount of carbohydrates in packing plant wastewater is from the animal feeds.

As protein is utilized by both aerobic and anaerobic saprophytic bacteria, organic nitrogen is broken down to ammonia. The longer the meat particles and blood are in contact with wastewater, the more the organic nitrogen will be converted to ammonia nitrogen. This is significant because organic nitrogen can be removed from the wastewater by physical pretreatment; such as fine screening, settling or flotation; but ammonia cannot because it is in solution. The longer feeds have been inside the animals, the more the proteins within the feeds will have been broken down into ammonia. All the organic nitrogen in urine has been broken down to urea, CO(NH2)2. Although ammonia is often used in the refrigeration systems at packing plants, it is not a significant source of nitrogen in the wastewater.

B. Phosphorus

A significant source of phosphorus in packing plant wastewater is also the proteins in the meat particles and blood. Lean meat contains approximately two percent (verify) organic phosphorus. Carbohydrates and fat contain small amounts of phosphorus. The manure and partially-digested feeds from stomachs and gizzards and intestines contribute to phosphorus in packing plant wastewaters. Since the general phosphorus contents in poultry plants shown in Table III were determined in the early 1970s, the use of trisodium phosphate (TSP) as a microbial agent to wash the animals has become common in poultry plants and, occasionally, in pork plants. This use of TSP can cause an appreciable increase in the phosphorus content of the wastewater from these plants. If phosphate-bearing detergents are used for cleaning, these can be a source of phosphorus in the wastewater. Boiler-water additives only contribute minor amounts of phosphorus in the wastewater.

VI. Best management practices for nitrogen and phosphorus control

The following is a list of items for consideration when establishing best management practices nitrogen and phosphorus control at slaughter plants. This list should not be considered as all-inclusive, nor are all of these methodologies necessarily appropriate for every plant. This list should be viewed as a starting point for establishing BMPs specific to each facility.

• A. Blood Collection/Blood Handling
• B. Manure Management
• C. Inedible Material Management
• D. Cleaning Chemical Management
• E. Solids Removal
• F. Dry Cleanup
• G. Egg Harvesting from Hens
• H. Water Conservation
• I. Product Loss Prevention
• J. Pollution Prevention Team
• K. Environmental Awards Program

A. Blood Collection/Blood Handling:  Whole blood contains about 27,000 mg/l of organic nitrogen and 300-400 mg/l (verify) phosphorus.

• Maximize Blood Collection:

1. Ensure stunning devices are properly functioning to maximize rapid bleed-out of the animal.
2. Ensure the animals are properly stuck so they are thoroughly bled out before leaving the blood collection area.  In poultry plants, maintain sharp blades, and adjust blade cut depth on killers to ensure clean cuts that allow maximum bleed out.
3. Check that adequate hang time is available so that the carcass is only dripping an occasional drop of blood when it leaves the blood collection area. If necessary, provide drip pans past the blood trough to prevent blood accumulation on kill room floor. In poultry plants, strive for minimum bleed times of 45 seconds for broilers and light fowl, 60 seconds for heavy fowl, 90 seconds for turkey hens, and 120 seconds for turkey toms
4. The blood collection pit and blood troughs need to be wide enough to avoid blood splashing outside these collection devises. At corners where the animals may swing outward, it may be necessary to add splash shields to contain the blood. The blood collection system needs to be of sufficient size to hold the blood during extended shifts.
5. Dry clean blood troughs and drip pans with a squeegee, or other appropriate tool, during sanitation and, if necessary, between shifts.
6. Collect and transfer to rendering, the "first rinse" water from blood trough sanitation.
7. Where possible, avoid the use of grating and other materials and areas within the blood collection pit that pack full of blood that cannot be removed during dry cleanup.
8. Electrical stimulation of beef carcasses maximizes blood recovery from the carcasses where it can be collected. This same concept may be possible in other plants as well.

Impacts:

1. Minimizes the loss of blood to the wastewater, thereby reducing nitrogen, phosphorus and BOD in the wastewater. This is particularly important since blood is not removed in physical pretreatment devices like screens, clarifiers and flotation systems.
2. Maximizes the capture of valuable blood.

• Consider Saving Blood Plasma for Sale: Add citric acid to raw blood and centrifuge to separate out most of the plasma for sale to off-site drying operations.

Impacts:

1. Minimizes the discharge of blood plasma from blood processing/drying, thereby affecting nitrogen, phosphorus and BOD reductions.
2. The sale of plasma is profitable.

• Consider establishing a program of routine maintenance to reduce leaks and spills of whole blood or plasma.

1. Where possible, dry clean up blood spills.
2. Repair or replace pump and valve seals as required to minimize or eliminate leaks of whole blood or plasma.
3. Strive to continuously eliminate pipe and equipment blood/plasma leaks and spills.

Impacts:

1. Reduction in total P, nitrite and BOD in the wastewater.
2. Maximizes the capture of valuable blood and plasma.

B. Manure Management:   The nutrient content of animal manure and urine is quite high, as shown in Tables IV and V:

TABLE IV
NUTRIENT CONTENT OF RED MEAT MANURE AND URINE

 Total P in the wastewater from hog pens has been measured at 106 mg/l, which was 3.5 times higher than the total packing plant flow.

TABLE V
NUTRIENT CONTENT OF POULTRY MANURE

• Less manure is deposited in the livestock trailers and pens, cages, live holding sheds, live receiving areas and less partially-digested feeds are lost to the slaughter plant sewers from the paunch/stomach/gizzard and intestines if livestock or poultry are taken off feed before they are sent to slaughter.

Impacts:

1. Reduction of total P, TKN, BOD, and TSS in the wastewater.
2. Results in a minor reduction in feed costs.
3. Reduces potential product contamination with manure.

Comment:

1. This may not be feasible if the animals are hauled long distances.
2. This is particularly important in pork plants where there is a current trend to rest the hogs longer in the pens before slaughter.

• To the extent practical, dry clean livestock trailers, cages, pens, live holding sheds and live receiving areas before the initial hose down. Vacuums may be used to assist in this effort. This recovered material should then be land applied at agronomic rates, or landfilled if appropriate.

Impact: Reduction of total P, TKN, BOD, and TSS in the wastewater.

Comments: This is easier in beef plants and live poultry receiving and holding areas, than pork.

• Consider dry bedding cattle pens. The manure and bedding material should be land applied at agronomic rates.

Impact: Reduction of total P, TKN, BOD, and TSS in the wastewater.

• Investigate dry dumping beef paunch and hog stomachs and, to the extent possible, shake out beef pecks (omesum). This recovered material should then be land applied at agronomic rates.

Impact: Reduction of total P, TKN, BOD, and TSS in the wastewater.

Comments:

1. It is difficult to shake much manure out of the pecks.
2. Dry dumping beef paunches is far more common than dry
   dumping hog stomachs.

• Eliminate hashing and washing of intestines and render whole.

Impact: Reduction of total P, TKN, BOD, and TSS in the wastewater.

Comments: The cost of rendering manure in the intestines exceeds any value in the recovered product.

C. Inedible Material Management

• Red Meat: Try to eliminate the use of water to sluice meat scraps to inedible rendering or rendering trailers. This water must be drained from the raw materials before the inedible material is rendered. This leaches blood and other soluble materials out of the inedible material and sends them to the sewer. Alternatives to sluicing include screw and belt conveyors, ram-type and other solids-handling pumps, blow tanks and vacuum systems.

Impact:

1. Reduction of TKN, total P, BOD, TSS and fat, oil and grease (FOG) in the wastewater.
2. More recovery of inedible material for rendering.

• Poultry
  

1. Where practical, utilize vacuum system to transport lungs to inedible rendering or rendering trailers.
2. Consider usage, on a plant specific basis, of vacuum systems for hearts, giblets, paws and /or leaf fat.

Impact:

1. Reduction of TKN, total P, BOD, TSS and FOG in the wastewater.
2. More recovery of inedible material for rendering.

D. Cleaning Chemical Management: Consider switching to low-phosphorus or non-phosphorus cleaning compounds. Phosphorous-based cleaners can often be replaced with organic surfactants (butyoxyethanol) and caustic cleaners (NaOH or KOH).

Impact: This step alone reduced phosphorus in the effluent from a pork low-processing packinghouse by approximately 2 mg/l for a six percent reduction.

Comment:

1. Consider food safety concerns when evaluating a switch to a low-phosphorus or non-phosphorus product
2. Non-phosphate cleaning compounds may be less effective and more costly.
3. Caustic cleaners can harm aluminum and copper equipment.

E. Solids Removal: Improve in-plant practices to physically remove solids from wastewater.

• Red Meat Drain Management. Consider a two-tier screening system using the drain covers for coarse solids removal and drain basket screens with finer openings.

Impact:

1. Reduction of TKN, total P, BOD, TSS and FOG in the wastewater. Rapid removal of meat scraps and blood from the floors prevents the breakdown of organic nitrogen to the ammonia form, which cannot be removed through pretreatment.
2. More recovery of inedible material for rendering.

Comment:  This may not be practical where large amounts of solids would quickly plug the baskets and require constant attention. In other areas, occasional plugging may force more frequent cleaning of the drains and baskets. Removal of the baskets or emptying them into the open drain must be prohibited for this to be effective.

• Poultry Solids Removal. Investigate improving screenings practices to include both primary (coarse) and secondary (fine) screening.

Impacts:

1. Reduction of TKN, total P, BOD, TSS and FOG in the wastewater. Rapid removal of meat scraps and blood from the floors prevents the breakdown of organic nitrogen to the ammonia form, which cannot be removed through pretreatment.
2. More recovery of inedible material for rendering.

F. Dry Cleanup:  A meat particle on the floor is probably at least four percent nitrogen.

a. Review the design of equipment to avoid creating difficulties with dry cleanup. For example, try to minimize numerous legs on equipment that inhibit use of a squeegee or shovel for dry cleanup.
b. Assign workers during the production shift(s), at breaks and lunch to dry cleanup materials from the floors for rendering.
c. Provide tools for dry cleanup, such as squeegees, shovels, dump carts, vacuums, etc. Adapt squeegees to fit within blood troughs.
d. Consider establishing and enforcing written standard operating procedures for dry cleanup, either at the end of the production shift or at the start of the sanitation shift.

Impacts:

1. Reduction of TKN, total P, BOD, TSS and FOG in the wastewater. Rapid removal of meat scraps and blood from the floors prevents the breakdown of organic nitrogen to the ammonia form, which cannot be removed through pretreatment.
2. More recovery of inedible material for rendering.

G. Egg Harvesting from Hens. Harvest eggs from hens before evisceration.

Impacts: Reduction of TKN, total P, and BOD in the wastewater from the
broken eggs.

Comments: Foaming caused by the egg whites (like a meringue) prevents
The use of dissolved air flotation (DAF) for pretreatment.

H. Water Conservation: Although there is no readily-apparent reason why water conservation would result in nitrogen and phosphorus reductions, the Development Documents for these industries all contain graphs showing that plants with lower water use per animal also had lower waste loads, on a total mass basis. Obviously less water is used, however, if a scrap of meat is picked up during dry cleaning than if it is hosed to a floor drain during sanitation, for example. This may also simply be an indication that better-run plants use less water and discharge less wastes versus poorer-managed plants in general.

• Use the appropriate pressure and volume of water for sanitation according to each application.

Impact: Reduced water requirements for sanitation.

• Consider installation of "electronic eyes" , foot valves or other devices on spray cabinets, carcass washers, eviscerating machines, chill tanks and other large water users to shut off the water when no animals are present.
  
• Evaluate installing water meters and monitoring potable water usage for: 1) each department within the plant, 2) each shift, and 3) individual machines that use large quantities of water, such as carcass washers, chitterling machines and stomach machines.

1. Monitoring water use on a day-to-day, month-to-month, and year-to-year basis can detect daily excursions, as well as long-term trends. Gradually increasing water use for an individual piece of equipment may indicate spray nozzle openings are slowly wearing larger. Significant water flow during idle shifts and weekends may indicate water leaks.
2. Consider establishing baseline quantities and holding each department manager responsible for water usage for his department. Reward usage under budgeted amounts and condemn usage over budgeted quantities.
3. Encourage competition for water reductions between shifts and between different departments

• Consider establishing a program to inspect all hose nozzles and equipment spray nozzles and measure flow rates, where possible, at least annually. Replace nozzles discharging excessive flow.

Impact: Less water usage; hence less pollutant discharge.

• Use push-to-open nozzles on hoses.

Impact: Reduced water requirements for sanitation.

I. Product Loss Prevention: Consider establishing procedures to monitor wastewater pollutant loadings (TKN, total P, BOD, TSS, and FOG).

• Monitoring pollutant loads on a shift-by-shift, week-to-week, month-to-month, and year-to-year basis will reveal daily excursions, as well as long-term trends.
• Consider establishing baseline quantities and holding each department manager responsible for loads from his department. Reward quantities under budgeted amounts and condemn discharge of excessive quantities.
• Encourage competition for waste reductions between shifts and between different departments.

Impacts:

1. Reduced loadings for wastewater treatment, hence reduced waste treatment costs.
2. Problem areas are identified and corrected.
3. Allows measurement of the impact of waste reduction projects within the plant.

J. Pollution Prevention Team: Investigate establishing teams to identify methods to reduce water usage and plant waste, set goals, and monitor progress.

Impacts:

1. Reduced water usage and waste loads.
2. Recognition for employee efforts.

K. Environmental Awards Program: Consider participating in an industry-sponsored awards program or establishing corporate sponsorship of awards to plants, departments or individuals for both water and waste reduction. Plants could compete for awards with winners recognized by the industry or company management with a trophy or plaque.

Impacts: Annual savings over a $1 million/year were attributed to these projects, plus energy reduction, by one red meat corporation.

VII. BMP monitoring

[remainder pending]

Appendix

References