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Meat and Poultry Processing
The meat and poultry processing industries in the United States together make up a $75.6 billion per year industry. The U.S. Department of Commerce reported that the value of red meat shipments for 1988 totaled $46.8 billion. Most red meat processing plants are located in the Midwest; most poultry processing plants are in the Southeast and the Mid-Atlantic. Processing of prepared meats, including canned cooked products, luncheon meats, hot dogs, bacons, stews, and other ready-to-eat meat products, has expanded rapidly in recent years.
Waste and By-Products
Most waste products are recovered somehow by the industry. Blood, feathers, and bone usually are processed into a meal product for animal feed. Similarly, meat scraps unsuitable for processing into food products are sold or given to rendering facilities for processing into animal and pet foods. The ultimate characteristics of solid materials and wastewaters generated by these source areas in a plant and unrecovered for another use differ greatly and are affected by:
- animal size and type
- processing level
- conveyance means
- processing water use
- cleanup and housekeeping procedures
Water Usage
Water use for broiler processing typically ranges from 3.5 to 10.0 gal./bird; for turkeys, 11 to 23 gal./bird. Flow rates of 350 gal./animal have been reported for beef slaughtering plants. In one beef slaughtering operation, water use dropped from 458 to 187 gal/head after water conservation measures were adopted. Similar water use numbers appear in the examples in Figure 37.
| Figure 37. Typical Water Consumption for Beef, Turkey, and Broiler Processing |
| Animal type |
Water (gallon/animal) |
| Beef |
150-450 |
| Turkey |
11-23 |
| Broiler |
3.5-10 |
Water is used for chilling, scalding, can retorting, washing, cleaning, and waste conveying. For example, poultry processing uses approximately 3.5 to 7.0 gallons of water per bird of four-pound average weight. All broiler processing plants are required to have a scalder overflow rate of 0.25 gal./bird and a chiller overflow rate of 0.50 gal./bird. In many instances, this water is used in the plant for the transport of feathers and offal from the processing area. One researcher, studying a broiler processing plant, reported that processing accounted for 76 percent of the water use, with 13 percent used in cleanup and 12 percent used in downtime.
Beef processing water usage, primarily from carcass washing and process cleanup, has been reported in the range of 150 to 450 gallons per animal processed. As a general rule, meat processors use about one gallon of water per pound of processed hamburger meat.
Use and Minimization of Wastes
The amount of wastewater generated by the industries can be decreased largely through changes in cleanup practices. Water use can be minimized by means of commercially available high-pressure, restricted flow hoses, which can be fit with automatic shutoffs to prevent water loss during inactivity. Many materials can be handled mechanically. For example, flour and other dry material can be vacuumed from the floor and augers and conveyors can be used to transport scrap meat and viscera.
Chiller and scalder water is reused in most poultry processing plants for flushing water to remove offal and feathers. Reconditioning of chiller overflow through the use of filtration and ultraviolet irradiation has been recommended. Limits to use include the potential of bacterial contamination by coliforms or by Escherichia coli. Recycling is limited by the characteristics of the wastestream and by the potential for contamination of food products.
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