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Best Management Practices

for

Nitrogen and Phosphorus Control

in

Further Processing Plants

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

• I. Introduction
• II. Discussion of further processing 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) for to control nitrogen and phosphorus in the wastewater from red meat and poultry further processing 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 these documents. This part addressed BMP for cutting up the carcasses and further processing the meat. The other two documents discuss BMP for slaughter and rendering operations. Therefore it may be appropriate for some plants to use two or all three of these documents if they also slaughter or render.

II. Discussion of further processing plant types

In the mid-1970s, the U.S. Environmental Protection Agency (EPA) further processing plants into the following Subcategories:

• Meat Cutter
• Small Processor
• Sausage and Luncheon Meat Processor
• Ham Processor
• Meat Canner
• Poultry Further Processor

Each of these categories is briefly described as follows:

• Meat Cutter. A processor that produces only meat cuts as a finished product. Manual labor is used to break, trim, and cut the carcasses or large meat parts into smaller parts including single-portion sized meat cuts. In a beef plant this would be called fabrication or a "fab floor", while it would be called a "cut floor" in a pork plant.
• Small Processor. A small processor may produce a wide range of products, but in small quantities, 6000 lb/day finished product (FP) the early 1970s. Most of these plants prepared fresh meat cuts with fresh sausage being the second most frequent product. A few plants produced hams or wieners, usually in addition to the meat cuts and sausage.
• Sausage and Luncheon Meat Processor. This subcategory tends to be quite similar to the small processor, but with less emphasis on fresh meat cuts and a slightly expanded product mix and substantially higher production rates.
• Ham Processor. These are large plants that produce hams as their only product and plants that produce hams and any combination of other products, particularly cured products including bacon.
• Meat Canner. These are also large plants that produce canned meat products. Some plants only produce canned products, while others produce a full line of processed meat products.
• Poultry Further Processors. These plants prepare finished poultry products primarily from chicken, fowl and turkey. Fowl include a few roosters, but mostly hens used in meat bird and table egg production. Cooking is involved in all further processing plants, as defined in the Poultry Development Document. These plants remove specific pars of the birds, such as wings, legs or breasts, and then remove the remaining meat from the skeletal structure of the birds. Cooking may precede or follow this cutting operation. The meat is used in large pieces or reduced in size in special equipment. Various ingredients are mixed with the poultry meat and the numerous types of finished products are formed, breaded and battered, parfried or cooked, packaged, and usually frozen. (Parfried product is product that is not fully cooked. This is often done to "set" batter on a formed meat product.)

These subcategories are not all-inclusive and many plants may not fit precisely into any of these categories. To characterize these plants it may be necessary to blend two or possibly more subcategories together.

III. Description of production-related activities

[pending]

IV. Typical nitrogen and phosphorus levels

In the mid-1970s, the Environmental Protection Agency (EPA) published Development Documents for both Red Meat Processing and Poultry. Included within both of those documents are tables showing waste characteristics for each subcategory within these industries. Table I shows data for total Kjeldahl nitrogen (TKN) from those Development Documents.

TABLE I
FURTHER PROCESSING PLANT EFFLUENT NITROGEN LEVELS

FROM 1970s DEVELOPMENT DOCUMENTS

* Finished Product

Table II shows effluent phosphorus levels for further processing plants.

TABLE II
FURTHER PROCESSING PLANT TOTAL PHOSPHORUS LEVELS
FROM 1970s DEVELOPMENT DOCUMENTS

* Finished Product

All data in Table Nos. I-II 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 I shows that essentially all of the nitrogen in further processing plant effluents is in the form of TKN, with very little nitrate or nitrite nitrogen present. By far the major source of nitrogen is from the protein in the meat particles and blood in the wastewater from further processing plants. Protein contains about 16 percent organic nitrogen. Fat contains no nitrogen, nor is any contained in carbohydrates such as sugars, starches and cellulose. The primary source of carbohydrates in further processing plant wastewater is from curing and flavoring additives.

Since the general nitrogen contents in further processing plant effluents shown in Table I were determined in the early 1970s, tumbling or massaging of product has become common in further processing operations. This results in the release of protein from the product and discharge of these proteins in the wastewater. Unfortunately these salt-soluble proteins are not removed in wastewater pretreatment devices.

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. Although ammonia is often used in the refrigeration systems at further processing plants, it is not a significant source of nitrogen in the wastewater.

B. Phosphorus.

A significant source of phosphorus in further processing 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. Pickle solutions, used to cure many meat products in further processing plants, contribute to phosphorus in packing plant wastewaters. 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

• A. Pickle/Spice/Marinate Management
• B. Cleaning Chemical Management
• C. Solids Removal
• D. Dry Cleanup
• E. Inedible Material Management
• F. Water Conservation
• G. Product Loss Prevention
• H. Pollution Prevention Team
• I. Environmental Awards Program

A. Pickle/Spice/Marinate Management: (Pickle is a solution of sugar, salt, lactates, phosphates, nitrites, etc. for bacon and ham curing. Marinate is a solution of sugar, salt, lactates, phosphates, nitrites, etc. for flavoring of poultry meat.)

• Evaluate improving batch preparation and process to maximize use in the product and minimize waste.

1. Use multiple smaller tanks, rather than fewer larger tanks to make up pickle solutions to minimize dumping large amounts of pickle or marinate when formulations change.
2. Collect, screen and reuse spent pickle or marinate from the injection or tumbler machines.
3. Bag product in plastic while horizontal to avoid runoff of pickle or marinate when product is hung vertically.

Impacts:

• Reduction in Total P, nitrite and BOD in the wastewater.
• Savings in pickle costs, which often costs over a dollar a gallon.

Comment: Physical pretreatment is ineffective in removing soluble pickle or marinate materials.

• Assess modification of production/cleaning schedules when switching product mixes to minimize dumping of pickle or marinate solution to the sewer.

Impacts:

1. Reduction in Total P, nitrite and BOD in the wastewater.
2. Savings in pickle or marinate costs, which often costs over a dollar a gallon.

Comment: Physical pretreatment is ineffective in removing soluble pickle or marinate materials.

• Consider establishing a program of routine maintenance to reduce leaks and spills of pickle or marinate solution or ingredients.

1. Where possible, dry clean up ingredients spilled during make up of pickle or marinate.
2. Repair or replace pump and valve seals as required to minimize or eliminate leaks of pickle or marinate.
3. Strive to continuously eliminate pipe and equipment pickle/marinate leaks and spills.

Impacts:

1. Reduction in Total P, nitrite and BOD in the wastewater.
2. Savings in pickle or marinate costs, which often costs over a dollar a gallon.

Comment: Physical pretreatment is ineffective in removing soluble pickle or marinate materials.

B. 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.

Comments:

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

C. Solids Removal: Evaluate improvements to screening 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.

Impacts:

1. Reduction of TKN, total P, BOD, TSS, and fat, oil and grease (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.

Comments:

1. Occasional plugging may force more frequent cleaning of the drains and baskets.
2. 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.

D. Dry Cleanup:

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) to dry cleanup materials from the floors for rendering.
c. Provide tools for dry cleanup, such as squeegees, shovels, dump carts, vacuums, etc.
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

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.

E. Inedible Material Management: Minimize the use of water to sluice meat scraps to inedible rendering trucks. This water must be drained from the raw materials before the inedible material is hauled away. 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 FOG in the wastewater.
2. More recovery of inedible material for rendering.

F. Water Conservation: Although there is no readily-apparent reason why water conservation would result in nitrogen and phosphorus reductions, the Development Documents all contain graphs showing that plants with lower water use per 1000 lb RM also had lower waste loads. 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 water meters and monitor potable water usage for: 1) each department within the plant, 2) each shift, and 3) individual machines that use large quantities of water.

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 of excessive quantities.
3. Encourage competition for water reductions between shifts and between different departments

• Evaluate 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.

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

• Monitor pollutant loads on a week-to-week, month-to-month, and year-to-year basis can 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.

H. 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.

I. 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: One corporation attributed annual savings over a $1 million/year to these projects, plus energy reduction.

VII. BMP monitoring

[pending]

Appendix

[pending]

References

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