Food Industry

 h Water and Wastewater Usage

 h SIC Code Segmentation

 h Defining Load using BOD5 and COD

 h Food Processing

 h Can Cooker Products

 h Regulations

 h World Food Market










Water and Wastewater Usage

Traditionally, the food-processing industry has been a large water user. Water is used as an ingredient, an initial and intermediate cleaning source, an efficient transportation conveyor of raw materials, and the principal agent used in sanitizing plant machinery and areas. Although water use will always be a part of the food-processing industry, it has become the principal target for pollution prevention, source reduction practices.

In food processing plants, water is used for many purposes. Its use starts with conditioning raw materials, such as soaking, cleaning, blanching, and chilling. It continues with cooling, sanitizing, steam generation for sterilization, power and process heating, and finally, direct 'in-process' use. The water classification categories used in the food and beverage industries are: general purpose, process, cooling and boiler feed.

Sanitary conditions have always been a concern for food products created in the manufacturing process. Disinfection through chlorination has been the quickest means of disinfecting wastewater. Disinfection has come under criticism due to chlorination byproducts and toxicity concerns that residual chlorine pose to aquatic life. The two principal means of disinfecting wastewater without using chlorination are ozone disinfection or UV disinfection. Ozonation works on the same principle as chlorination but leaves no residual in the treated wastewater and does not produce the magnitude of disinfection byproducts that chlorination produces. UV disinfection is even more environmentally friendly than ozone but requires more space and cleaner wastewater to be effective. Both technologies require high capital and operating costs.

General Purpose Water
This water includes all water used in washing and sanitizing raw materials, processing equipment, plant facility and ancillary equipment. It is used in the largest amounts and it should be potable, clear, colorless, and free of contaminants that affect taste or odor. In-plant chlorination is usually the only treatment required.

The main advantage of in-plant chlorination of general purpose water is the reduction of microbial number on raw materials, prepared products, and on equipment surfaces in the plant. There is no action as important to food and beverage processing as control of microorganisms.

Chlorinated water is often used for direct rinse of raw material or prepared products. When this is done, precautions must be taken to ensure that the flavor of the finished product has not been adversely affected

Process Water
Water used for cooking or added directly to the product must be potable and must be of sufficient quality not to degrade product quality. This includes being free of dissolved minerals that make water excessively hard or affect taste.

Most of the product in beverage production consists of process water, so treatment to achieve taste objectives is especially important. Often, treatment beyond that required to meet safe drinking water standards is essential for consistent high quality.

Treatment processes used in bottled water often include softening, reverse osmosis, and deionization. Many other beverages would require similar treatment.

Hard water contains minerals the can affect the texture of the raw materials to be processed, such as certain vegetables. Iron, manganese or sulfate can have an undesirable affect on the taste of the product.

Water softening might be required to prevent the formation of deposits on the surfaces of equipment, and canning and bottling materials. The type of food process determines specific quality requirements of the water beyond being potable.

Prior to its use in food processing, water must be microbiologically safe (free of bacteria, virus, protozoa cysts, and worms). Methods to remove suspended matter greatly reduce microorganisms, but terminal disinfection provides an essential added barrier.

The methods used for terminal disinfection include chemical, thermal, radiation, and ultrasonic treatment or cell disruption. Chemical treatment with chlorine or chlorine derivatives is the least expensive and most common process.

Cooling Water
Cooling water not in contact with food products or sealed containers does not have to be potable or meet the requirements of process water. The removal of staining minerals and odors is not as important. However, preventing the accumulation of scale in pipes and equipment is important, especially when cooling water is recycled.

The most efficient processing systems include recycling circuits to reduce cooling water waste, thus reducing processing costs. Potable water, even from public supplies, often has to receive additional treatment such as softening to avoid scale and deposits to be suitable for cooling.

Boiler Feed Water
Boiler feed water requires the removal of hardness. This may be the only treatment process applied to the water. If this water is not in contact with food, it does not have to be potable. Boiler feed water for high pressure boilers requires the removal of all dissolved solids or demineralization. Almost all potable water must have minerals removed through additional treatment to be suitable for boiler feed.

Not only can microorganisms produce color and odor in water, but if they are introduced into the production process, they can contaminate the equipment and finished product. Process contamination could damage and spoil foodstuffs. If pathogenic bacteria is introduced in the contamination, food poisoning could occur.





SIC Code Segmentation: Food




SIC Code Title No. of Facilities High Low Average MGD Total MGD CFM MGD
2011 Meat Packing Plants 18 3.6 0.2 2.09 37.6 511802 92.12
2015 Poultry Slaughtering & Processing 22 1.5 0.02 0.82 18.08 40143 7.23
2021 Creamery Butter 1 0.5 0.5 0.5 0.5   0
2022 Natural, Processed & Imitation Cheese 1 0.5 0.5 0.5 0.5 156099 28.1
2023 Dry, Condensed, & Evaporated Dairy Products 2 0.5 0.5 0.5 1 414251 74.57
2026 Fluid Milk 3 2.3 1.75 2.03 6.08 60862 10.96
2033 Canned Fruits, Vegetables, Preserves, Jams 10 0.4 0.1 0.2 2 967762 174.2
2035 Pickled Fruits & Vegetables 2 0.4 0.4 0.4 0.8 172581 31.06
2037 Frozen Fruits, Fruit Juices & Vegetables 11 1.8 0.34 1.13 12.46 222338 40.02
2046 Wet Corn Milling 7 15.62 0.01 4.2 29.37 6470710 1164.73
2047 Dog & Cat Food 3 26.11 0.43 9.35 28.04 67353 12.12
2048 Prepared Feeds 2 0.02 0.02 0.02 0.04 202573 36.46
2061 Cane Sugar Except Refining 8 20.19 0.05 9.4 75.2 9493007 1708.74
2062 Cane Sugar Refining 5 15.09 0.3 7.7 38.48 3834346 690.18
2063 Beet Sugar 18 10 1.02 5.93 106.74 4962272 893.21
2066 Chocolate & Cocoa Products 2 0.5 0.5 0.5 1 40000 7.2
2067 Chewing Gum 1 0.08 0.08 0.08 0.08 150000 27
2068 Salted & Roasted Nuts & Seeds 1 0.5 0.5 0.5 1   0
2075 Soybean Oil Mills 3 0.03 0.03 0.03 0.09 4194572 755.02
2076 Vegetable Oil Mills 1 0.5 0.5 0.5 0.5 138160 24.87
2077 Animal & Marine Fats & Oils 13 5.2 0.45 2.32 30.11 411605 74.09
2082 Malt Beverages 5 5.2 5.2 5.2 26 2802115 504.38
2083 Malt 1 1 1 1 1 153296 27.59
2085 Distilled and Blended Liquors 7 8 0.12 2.54 17.76 1100510 198.09
2091 Canned and Cured Fish & Seafoods 12 4.32 0.52 2.14 25.73 20275 3.65
2092 Prepared Fresh or Frozen Fish & Seafoods 17 0.5 0.5 0.5 8.5 13290 2.39






Defining Load Using BOD5 and COD

Chemical oxygen demand (COD) and biochemical oxygen demand (BOD5) are common measurements used to determine water quality. They measure the strength of the waste stream by measuring the oxygen required to stabilize the wastes. Most of the waste from milk processing plants are organic compounds, primarily most product. As these substances degrade, they consume some of the oxygen dissolved in the water. The amount of oxygen used is thus a good indicator of the amount of organic waste present. The BOD5 and COD values for three dairy products are shown in Figure IV-1. The values indicate the amount of oxygen (in milligrams per liter of product) needed to oxidize or stabilize these products when they appear in wastewater.

Figure IV-1: BOD5 and COD Values of Pure Dairy Products


BOD5 (mg/l)

COD (mg/l)






Ice Cream (10% fat)




Whey (acid)




COD and BOD5 are important to the food processing industry because they can be used to indicate lost product and wasteful practices. High BOD5 and COD levels indicate increased amounts of product lost to the waste stream. Measurements at various process locations can help locate sources of waste.

Relating COD to BOD5
At any point in a particular food processing operation, the relationship between BOD5 and COD is fairly consistent. However, the ratio's of these two measures varies widely with the type of product (Figure IV-2).

Figure IV-2: Typical Values of BOD5 and COD for Different Food Plant Wastewater

Type of Processor

BOD5 (mg/l)

COD (mg/l)


Bakery products




Dairy processing




Jams and jellies




Meat packing




Meat specialties




Poultry processor




COD values are always greater than BOD5 values because of the nature of the measurement procedure. With the dichromate refluxing procedure used to measure COD, almost all organic compounds are oxidized. With the BOD5 measurement procedure, some of these compounds do not fully oxidize, making the oxygen demand lower. The BOD5 value may be much lower than the COD value when a substantial amount of biologically resistant organic matter is present. In addition, a few chemical interferences – primarily from chlorides, certain nitrogen compounds and other substances that could interfere with bacterial growth can affect the test results.







Food Processing

Food-processing wastewater can be characterized as nontoxic, because it contains few hazardous and persistent compounds such as those regulated under the U.S. Environmental Protection Agency’s (EPA’s) Toxic Release Inventory (TRI) listing. With the exception of some toxic cleaning products, wastewater from food-processing facilities is organic and can be treated by conventional biological technologies. Part of the problem with the food-processing industry’s use and discharge of large amounts of water is that it is located in rural areas in which the water treatment systems (i.e., potable and wastewater systems) are designed to serve small populations. As a result, one medium-sized plant can have a major effect on local water supply and surface water quality. Large food-processing plants will typically use more than 1,000,000 gallons of potable water per day.

The five-day biochemical oxygen demand (BOD5) value is used as a gauge to measure the level of treatment needed to discharge a wastewater safely to a receiving water. The BOD for all food-processing wastewater is relatively high compared to other industries. A high BOD level indicates that a wastewater contains elevated amounts of dissolved and/or suspended solids, minerals, and organic nutrients containing nitrogen and phosphorus. Each one of these constituents represents a particular contaminant of concern when discharging a wastewater.

Publicly owned treatment works (POTW) that receive food-processing wastewater with BOD5 values greater than 250 to 300 mg/L typically will add an additional surcharge for treatment. Any company is subject to fines by either the state and/or federal environmental enforcement agency when they are discharging to a receiving water and exceeding their permitted BOD5 discharge level. In the past, wastewater disposal costs were a minor operating expense. In today’s climate, due to increased enforcement of discharge regulations and escalating POTW surcharges, many food-processing facilities are taking steps to either reduce, recycle (or renovate), and/or treat their wastewaters before they discharge them.

Another contaminant of food-processing wastewaters, particularly from meat-, poultry-, and seafood-processing facilities, is pathogenic organisms. Wastewaters with high pathogenic levels must be disinfected prior to discharge. Typically, chlorine (free or combined) is used to disinfect these wastewaters. Ozone, ultraviolet (UV) radiation, and other nontraditional disinfection processes are gaining acceptance due to stricter regulations on the amount of residual chlorine levels in discharged wastewaters.

The pH of a wastewater is of paramount importance to a receiving stream and POTW. Biological microorganisms, used in wastewater treatment, are sensitive to extreme fluctuations in pH. Companies that are found to be the responsible polluter are fined and/or ordered to shut down operations until their pH level meets acceptable values. Wastewater discharge values that range from 5 to 9 on the pH logarithmic scale are usually acceptable. Low pH values are more damaging to a receiving stream and POTW biological treatment process.

The food-processing industry utilizes water to meet its individual day-to-day needs. Fifty percent of the water used in the fruit and vegetable sector is for washing and rinsing. The meat processing sector has minimum requirements set by the United States Department of Agriculture (USDA) on the amount of water required to clean poultry products. Water is the primary ingredient in products for the beverage and fermentation sector, and dairies utilize water as the standard cleaning agent for process machinery.

Figure IV-3 shows typical rates of water use for various food-processing sectors. An abundant and inexpensive source of water is a requirement for success in the food-processing industry. This coincides with the same need for water resources in agricultural farmland activities.

Figure IV-3: Typical Rates for Water Use for Various Industries


Range of Flow gal/ton product

Fruits and Vegetables

   Green beans


   Peaches and pears


   Other fruits and vegetables


Food and Beverage





   Meat packing


   Milk products




Food processing can be divided into four major sectors:

Fruit and Vegetable Food-Processing Sector
American consumers enjoy one of the safest food supplies in the world. However, over the last several years, there has been an increase in reported outbreaks of foodborne illness associated with both domestic and imported fresh fruits and vegetables. In a January 1997 radio address, President Clinton announced a Food Safety Initiative to improve the safety of the nation's food supply

Water use in crop production involves numerous field operations including irrigation, applications of pesticides and fertilizers, and produce rinsing, cooling, washing, waxing, and transport. Water has the potential to be a direct source of contamination and a vehicle for spreading localized contamination in the field, facility, or transportation environments. Wherever water comes in contact with fresh produce, its source and quality dictate the potential for pathogen contamination. If pathogens survive on the produce, they may cause foodborne illness.

Water can be a carrier of certain microorganisms including pathogenic strains of Escherichia coli, Salmonella spp., Vibrio cholerae, Shigella spp., Cryptosporidium parvum, Giardia lamblia, Cyclospora cayetanensis, and the Norwalk and hepatitis A viruses. Even small amounts of contamination with some of these organisms can result in foodborne illness. Research has shown that the use of contaminated irrigation water can increase the frequency of pathogen isolation from harvested produce

The source of water, how and when it is used, and the characteristics of the crop influence the potential for water to contaminate produce. In general, the quality of water in direct contact with produce may need to be of better quality compared to uses where there is minimal water-to-produce contact. An example of this is that water quality needs may be higher for overhead spray irrigation where water is more likely to have significant, direct contact with the edible portion of the plant compared to drip irrigation which can avoid such contact for many crops. 

The primary steps in processing fruits and vegetables include:

Wastewater and solid wastes are the primary area of pollution control within the fruit and vegetable food-processing industry. Their wastewater is high in suspended solids, and organic sugars and starches and may contain residual pesticides. Solid wastes include organic materials from mechanical preparation processes, that is, rinds, seeds, and skins from raw materials. For the most part, solid waste that is not resold as animal feed is handled by conventional biological treatment or composting. The total amount of material generated is a function of the amount of raw material moved through a facility, for example, for a given weight of apples processed comes a set amount of peel and seed waste. 

Attempts to decrease solid waste streams have not been an area of great development for pollution prevention opportunities and clean technologies. Pretreatment opportunities intended to reduce the amount of raw materials lost to the waste stream have been an area of clean technology development. For the most part, the majority of clean technology advances and research have been in reducing the volume of wastewater generated in food-processing operations. 

Most fruit and vegetable processors use traditional biological means to treat their wastewater. Advancements in the degradation chemistries of pesticides have aided in reducing their quantities and toxicity in process wastewater. 

Washing fresh produce (also known as surface treatment) can reduce the overall potential for microbial food safety hazards. This is an important step since most microbial contamination is on the surface of fruits and vegetables. If pathogens are not removed, inactivated, or otherwise controlled, they can spread to surrounding produce, potentially contaminating a significant proportion of the produce

Sanitizers or antimicrobials in wash water and other processing water may be useful in reducing pathogens on the surface of produce and/or reducing pathogen build-up in water. The effectiveness of a sanitizer depends on its chemical and physical nature, treatment conditions (such as water temperature, pH, and contact time), resistance of pathogens, and the nature of the fruit or vegetable surface. Chlorine is a commonly used antimicrobial. Chlorine dioxide, trisodium phosphate, organic acids, and ozone have also been studied for use as antimicrobials in produce wash water. All chemical substances that contact food must be used in accordance with FDA and EPA regulations.

Meat, Poultry, and Seafood Sector
In the United States, there are more than 4,000 slaughter and processing plants for the meat, poultry, and seafood sector. These processing plants are, with the exception of seafood plants, located in isolated rural agricultural areas. Sections of the United States with adequate grain supplies and water resources are areas in which livestock-processing plants predominate. Over the past fifty years, facilities have consolidated to incorporate "total" processing capabilities. Rendering and processing have been combined into one facility

The primary steps in processing livestock include:

Meat, poultry, and seafood facilities offer a more difficult waste stream to treat. The killing and rendering processes create blood byproducts and waste streams, which are extremely high in BOD. These facilities are very prone to disease spread by pathogenic organisms carried and transmitted by livestock, poultry, and seafood. This segment of the food-processing industry is by far the most regulated and monitored. Inspectors for the Food and Drug Administration (FDA), USDA, EPA, and local health departments all keep a watchful eye on meat, poultry, and seafood facilities. 

Waste streams vary per facility, but they can be generalized into the following: process wastewaters; carcasses and skeleton waste; rejected or unsatisfactory animals; fats, oils, and greases (FOG); animal feces; blood; and eviscerated organs. The primary avenue for removal of solid waste has been its use in animal feed, cosmetics, and fertilizers. These solid wastes are high in protein and nitrogen content. They are excellent sources for recycled fish feed and pet food. Skeleton remains from meat processing are converted into bonemeal, which is an excellent source of phosphorus for fertilizers. FOG waste (typically from industrial fisheries) is used as a base raw material in the cosmetics industry.

Meat and fish processors must operate in a manner that protects human health and the environment while maintaining the highest food safety standards. If not minimized and properly managed, these operations can create enormous negative impacts on the environment. The primary environmental issues associated with meat and fish processing are water use, high-strength effluent discharge, and energy consumption. The meat and poultry processing industry (excluding rendering) uses an estimated 150 billion gallons of water annually. Although a portion of the water used by the industry is reused or recycled, most of the water becomes wastewater. Noise, odor and solid wastes are additional significant impacts that can detrimentally affect the environment if not adequately addressed.  

The amounts and types of wastes generated depend upon a variety of factors including: 

The information contained in this section includes environmental impacts for beef, pork, poultry and fish processing and associated rendering activities. The upstream processes of distribution and post-consumer packaging management are not covered. The manufacture of specialty meats and associated products are also not included in this topic hub. This sector focuses on activities that occur at a slaughterhouse and the related processes. The following table lists common wastes generated from specific processing areas. 

Meat & Seafood Processing Area Wastes

Process Area

Process Area Wastes 


Transportation, receiving and holding  

manure, hair, feathers, grit, mortalities


blood, fluids


feathers, skin, bone, hides, beaks



Trimming and evisceration

trim scrap, offal, paunch material


contaminated and rejected materials

Further Processing

meat scraps, cheeks, hides, feet, offal, bone and fat

Cooling and storage

contaminated ice, damaged product, off-spec inventory

Prepared foods

additives, oils, grease, sauces, damaged product

Fermented, smoked, pickled foods

spices, brines, sauces, spoiled materials, drippings




At-sea treatment

cuttings, bones, blood, off-spec product

Transport and marketing

off-spec, spoiled product

Receiving and thawing

Spoiled materials, thaw-water, melted ice

Butchering and processing, including canning

Off-cuts, viscera, bones, skins, suspended and dissolved solids, sauces, brines, fish oils other oils

Quarantine, storage and distribution

Off-spec. materials, spoiled materials, damaged cans

Meat Processing Water Consumption: Like many other food processing activities, the necessity for hygiene and quality control in meat processing results in high water usage and consequently high wastewater generation. Volumes of wastewater from meat processing are generally 80-95 percent of the total freshwater consumption (MRC, 1995). The United Nations Environmental Program, Cleaner Production Assessment in Meat Processing (2000), estimates a range of 1,100 to 4,400 gallons of water are used per live weight ton of slaughtered animal in the United States. Between 44-60 percent of water is consumed in the slaughter, evisceration and boning areas (MRC, 1995). The following table illustrates the breakdown of water consumption in beef and pork processing based on a study of Australian abattoirs. 

Water Consumption in Meat (Beef and Pork) Processing Operations

Meat Processing Activity

Percent of Usage

Stockyard washdowns and animal watering

7-22 percent

Slaughter, evisceration and boning

44-66 percent

Casings production

9-20 percent


8-38 percent

Domestic uses

2-5 percent


2 percent

Boiler losses

1-4 percent

Meat Research Corporation (MRC), 1995

In poultry processing plants, in addition to being used for carcass washing and cleaning, water is also consumed for hot water scalding of birds prior to defeathering; in water flumes for transporting feathers, heads, feet and viscera; and for chilling birds. As a result, poultry processing tends to be more water intensive on a per unit  production basis than red meat processing (Wardrop Engineering, 1998). Water consumption rates vary from 4,000 to 24,000 gallons per 1,000 birds processed (Hrudey, 1984). 

Meat Processing Wastewater Generation: Freshwater consumption has a major impact on the volume and pollutant load of the resulting wastewater. Wastewaters generally have high organic loads and are also high in oils and grease, salt, nitrogen and phosphorous. At red meat abattoirs, water is used primarily for washing carcasses during the various process stages and for cleaning at the end of each shift. Eighty to 95 percent of water used in abattoirs is discharged as effluent (MRC, 1985). 

The wastewater from a slaughterhouse typically contains blood, manure, hair, fat, feathers and bones and may be at high temperatures. Untreated effluent may be as high as 8,000 mg/L BOD with suspended solids at 800 mg/L or greater. The wastewater may also have pathogens, including Salmonella and Shigella bacteria, parasite eggs and amoebic cysts. Pesticide residues may be present from treatment of animals or their feed. Chloride levels may be very high (up to 77,000 mg/L) from curing and pickling processes. Cooking activities also greatly increase the fat and grease concentration in the effluent. 

Fish Processing Water Consumption: Most seafood processors have a high baseline water use for cleaning plant and equipment. Therefore, water use per unit product decreases rapidly as production volume increases. Major sources of wastewater include: fish storage and transport; cleaning, freezing and thawing; preparation of brines; equipment sprays; offal transport; cooling water;  steam generation; and equipment and floor cleaning. 

Water consumption in fish processing operations has traditionally been high to achieve effective sanitation. Industry literature indicates that water use varies widely throughout the sector, from one to four gallons per pound of product. Several factors affect water use, including: the type of product processed, the scale of the operation, the process used, and the level of water minimization in place (Environment Canada, 1994a). General cleaning contributes significantly to total water demand so smaller-scale sites tend to have significantly higher water use per unit of production. Reducing wastewater volumes tends to have a significant impact on reducing organic loads, as these strategies are typically associated with reduced product contact and better segregation of high-strength streams.

Fish Processing Wastewater Generation: Wastewater from seafood processing operations can be very high in BOD, oil and grease, and nitrogen content. Literature data for seafood processing operations shows a BOD production of two to145 pounds of BOD per ton of product (Environment Canada, 1994a). White fish filleting processes typically produce 25 to 75 pounds BOD for every ton of product (UNEP, 1998). BOD comes primarily from the butchering process and from general cleaning and nitrogen originates -- predominantly from blood in the wastewater stream (Environment Canada, 1994a). Thawing operations can also account for up to 50 percent of the wastewater generated. 

Rendering Wastewater Generation: Rendering, while it recovers raw materials for beneficial use, raises the production of high-strength wastewater. Similarly, other byproduct recovery such as offal collection and hide treatment increase wastewater generation. Conveyance by fluming, carcass cleaning and general cleaning and sanitation also create significant quantities of wastewater.

Organic loads can vary considerably depending on whether the site incorporates a rendering operation. Rendering plants, where installed, are the largest single source of wastewater contamination. The wastewater from rendering (often referred to as stickwater) contains approximately 60 percent of the plant’s total COD output while being typically only 10 percent of the volume (MRC, 1995). As a general rule, red meat abattoirs with rendering will generate approximately 100 pounds COD/ton HSCW (hot standard carcass weight)*, whereas operations without rendering will generate only about 30 pounds COD/ton HSCW (MRC, 1998). 

Energy Consumption
Energy consumption depends upon the age and scale of the plant, level of automation, and range of products manufactured. Processes involving heating, such as cooking and canning, are very energy-intensive, whereas filleting requires less energy. Thermal energy, in the form of steam and hot water, is used for cleaning, heating water, sterilizing and for rendering.  Electricity is used for the operation of machinery and for refrigeration, ventilation, lighting and the production of compressed air. 

Like water consumption, the use of energy for refrigeration and sterilization is important for ensuring good quality meat and fish products.  Storage temperatures are often specified by regulation.  As well as depleting fossil fuel resources, the consumption of energy causes air pollution and greenhouse gas emissions, which have been linked to global warming. Typical ranges for energy use are 330 to 1330 kW per ton of hot standard carcass weight. Representative figures for ton of fish processed range from 65 to 87 kW for filleting, 150-190 kW for canning, and about 32 kW for fish meal and oil production. The following table provides a breakdown of electricity consumption at a meat processing facility.

Meat (Beef & Pork) Processing Energy Consumption

Meat Processing Activity

Percentage of Usage



Boiler Room






Compressed Air


Boning Room




Energy Authority of New South Wales, 1985

Air Emissions and Odor:

The U.S. EPA has identified air emissions from meat and fish processing and rendering operations in the following documents.

Process Sector

EPA Document

Meat Processing

AP-42, Fifth Edition, Volume I 
Chapter 9:  Food and Agricultural Industries,Introduction to Animal & Meat Products Preparation, 9.5.1 Meat Packing Plants

Fish Processing


Meat Rendering

AP-42, Fifth Edition, Volume I
Chapter 9:  Food and Agricultural Industries, Section 9.5.3, Meat Rendering Plants, Final Report

For meat processing, the above report did not quantify VOC (volatile organic compound), HAP (hazardous air pollutant), or PM (particulate matter) emissions; however, engineering judgment and comparison of similar processes in other industries may provide an estimation of the exact types of emissions expected from meat processing plants. Potential sources of PM are animal holding areas, feed storage, singeing operations and other heat sources (boilers). VOCs and HAPs may be generated from scalding tanks, animal holding areas, sanitizing operations, wastewater systems and heating sources. Control methods for VOCs and particulates include wet scrubbers, dry sorbants and cyclones. Air emission controls will vary from facility to facility and depend upon the nature of the emissions and the pollutant loading in the gas stream.

Although smoke and dust can be a problem in fish processing, the most objectionable emissions are odors.  Processing fish byproducts results in more of the odorous contaminants than cannery operations because of the greater state of decomposition of the materials processed. The fishmeal driers are the largest odor sources. Reduction cookers emit less offensive odors than meal driers; however, these emissions consist primarily of hydrogen sulfide and trimethylamine, which are not currently listed as HAPs.  Almost no particulate emissions result from reduction cookers. Fish cannery and reduction odors can be controlled with afterburners, chlorinator-scrubbers and condensers.  Drier dust can be captured using centrifugal collectors. 

VOCs are the primary air pollutants emitted from rendering operations, which have historically been an odor nuisance in residential areas located in close proximity to the facility. Emission controls are directed to odor control and elimination. Particulate matter is also emitted from grinding and screening of the solids (cracklings) and other operations such as blood and feather drying. Boiler incinerators are a common control technology for rendering emissions because the boilers can be used to generate steam for cooking and drying operations. Multistage wet scrubbers are the primary alternative to incinerators. These scrubbers can be used to remove particulate matter as well as odors from rendering waste streams.

Biological treatment systems, commonly used to treat abattoir effluent, are another common source of odors.  Insufficient capacity of treatment systems or shock-loadings to the system can upset the microbiological balance of the system, resulting in the release of hydrogen sulfide and other odorous compounds.

Solid Waste
For many food processing plants, a large fraction of the solid waste produced by the plant comes from the separation of the desired food constituents from undesired ones in the early stages of processing. In some cases, the materials are composted. Due to their potential to carry disease, animal-derived solid wastes are often regarded as industrial waste. The availability of suitable licensed waste disposal sites needs to be assessed. 

Other significant solid wastes include packaging materials such as waxed corrugated boxes, pallets, shrink wrap, strapping ties, drums and polystyrene. Packaging waste accounts for about one-third of municipal solid waste. Many of these products can be reused or recycled. Markets exist nationwide for most of these materials. 

The main purpose of refrigeration is to cool the meat after slaughter and to maintain it in a chilled state for shorter or longer storage periods and for cutting and further processing. For operations that use refrigeration systems based on chlorofluorocarbons (CFCs), the fugitive loss of CFCs to the atmosphere is an important environmental consideration, since these gases are recognized to be a cause of ozone depletion in the atmosphere.  For such operations, the replacement of CFC-based systems with non- or reduced-CFC systems is important.

If an abattoir is located close to residential areas or other noise-sensitive receptors, the noise generated from various items of equipment and the maneuvering of trucks delivering livestock and removing byproducts can cause a nuisance.  These potential problems should be taken into consideration when determining plant location.

Poultry processing plants contribute large biological oxygen demand (BOD) loads, as well as total suspended solids (TSS) and phosphorus to wastewater.

Most of the wastewater loading in the poultry industry comes from the slaughtering process when the birds are bled, scalded with hot water, rinsed up to three times, gutted, and chilled with water. The need to both maintain high production and meet 1997 zero fecal contamination requirements set by the U.S. Department of Agriculture (USDA) makes using high volumes of water essential.

Wastewater Reduction Tips
Below are useful tips to keep poultry processing by-products from entering and contaminating the wastewater.

Measure for Success. Measure water flow throughout your facility. Flow meters can quickly indicate water overuse. This tool measures wastewater volumes to help you plan your pollution prevention tactics. Some meters on the market use circular chart recorders to measure water use in gallons per minute (gpm) over a 24-hour period. Fluctuations may indicate leaks, wasteful water use or inefficient equipment.

Install meters in high water use areas such as the chiller, scalder, wash cabinets, evaporators and condensers. Monitor overflow areas like the chiller and scalder. The USDA requires a water overflow of one gallon per bird for the chiller and 2 gallon per bird for the scalder. Regulate meters to avoid unnecessary overfilling. Because both the scalder and the chiller are large water users, monitoring the flow rate to avoid inefficient water use is important. Fix Leaks. Prevent water loss by finding and repairing all leaks in the facility. Make a checklist of all potential sources of leaks and conduct weekly inspections of equipment such as valves, tanks, hoses and nozzles.

Break and Shut-Off Time. Another source of water waste comes from leaving water running during breaks and shutdown times. Develop a water shut down checklist for all areas of the facility. This can help reduce water loss during breaks and shut down periods. Simple steps can be taken to reduce water loss during nonoperating times. Post signs that remind workers to shut off water throughout the facility before plant shut-down time. Hang a reminder sign after the last bird is placed on the production line before break.

Measure water flow rates during nonoperating periods to make sure water has been properly turned off and to discover leaks.

Nozzles and Spouts. Installing adjustable pressure/low-volume water nozzles can reduce the amount of water loading in your facility. Equipment such as handwashing spouts in the evisceration room and cleanup hoses can use these nozzles.

The USDA requires that all employees on the evisceration line wash their hands after handling each bird to prevent cross-contamination. Many handwashing spouts run constantly to accommodate both USDA requirements and the rapid pace of the production line. Using lower-volume water spouts can reduce water waste. Also, consider installing foot pedals on the handwashing units. These save water by having the water on only when needed. Install water saving devices such as water regulating valves or narrow pipe fittings in the handwashing unit pipes to reduce water flow.

Water Reuse. Consider reusing some of the water in your facility for melting ice and cleaning. Scalder water can be filtered and reused to melt ice left over from the chillers. This practice eliminates the need for fresh water for melting ice. The same process can be used for reusing water from the evisceration process for some first stage cleanings.

Keep Organic Materials Out of the Wastewater. Poultry by-products can be cleaned-up or moved-out without using water. Keeping by-products out of the water stream can reduce BOD and TSS loading in the wastewater.

Consider replacing water troughs with conveyors for moving organs from the evisceration line to the next process area. The USDA has no requirements on the amount of water used to clean the hearts, livers or gizzards.

Collect blood and liquids from the birds using troughs and curbs to direct their flow. Solid by-products, blood and other fluids can also be collected in holding tanks using a vacuum hopper system which does not require the use of water. These by-products can be shipped to rendering plants and converted to animal feed.

Use dry cleanup methods before using water. This can reduce the BOD and TSS loading to the effluent water stream. Some of the most effective dry cleanup methods include scraping fat and grease off conveyor belts; installing strainers along the evisceration line and other areas to keep poultry by-products off the floor; and sweeping, squeegeeing or shoveling materials off the floor before wet cleanup.

Table Toppers. Keep your employees informed of the plant’s energy and water costs. One option is to post a comparison of the current month’s water and sewer bills with that of last year’s utility bill for the same month on the tables in the break area or a central location in the facility. Consider mapping out the trends using charts and graphs that show the cost comparisons.

Non-Phosphorus Cleaners. Move to low/no phosphorus chemicals for clean-in-place (CIP) systems and other cleaning operations.

Case Histories

Owned by Hormel Foods and based in Willmar, MN, Jennie-O Foods is the world’s largest turkey producer. The company ships food products throughout the United States, as well as 14 foreign countries.

Jennie-O wanted to reduce water use and BOD, TSS and phosphorus loading into the wastewater for two of its plants in Minnesota. MnTAP funded a student intern at Jennie-O Foods to reduce water use and wastewater loading at the Jennie-O Foods plant in Melrose and the Heartland Foods plant in Marshall.

The intern began by documenting the improvements made earlier at West Central Turkeys, Inc., a Jennie-O facility located in Pelican Rapids.

West Central Turkeys, Inc. is a slaughter and processing plant. West Central produces processed turkey products such as turkey bacon and turkey roasts. It employs about 720 people. West Central has implemented many effective pollution prevention tactics that served as models for other facilities.

West Central developed a utility task force to help the plant reduce its use of energy and water. One goal was to involve all employees in lowering the utility costs. Employees in each department were assigned to help reduce monthly energy use. To reduce water use and effluent water loading, the task force started meeting weekly to review the volumes and cost of wastewater loading. They looked for inefficient water use and leaks, and installed meters to track water use. By monitoring cleanup water use alone, West Central was able to reduce its water use by 23,000 gallons a day.

The West Central staff started using water volume reduction tools such as narrower pipe fittings, low-volume spray nozzles, and foot pedals on hand washers in the evisceration line. They also started reusing water from evisceration for first stage washings of the turkey transfer trucks. This helped reduce the need for fresh water.

The most effective waste load reduction practice was keeping by-products out of the water stream. Employees started using dry cleanup methods to remove by-products before wet cleanup. Keeping by-products off the floor greatly reduced BOD and TSS loading into the effluent water stream.

The Melrose Jennie-O Foods plant is the largest turkey slaughtering plant in Minnesota. The facility is a whole bird packing plant that employs about 900 people and bags turkeys under 200 different name brands.

In addition to reducing its water use, the Melrose plant wanted to decrease the amount of water discharge. The MnTAP intern started addressing water loss by documenting leaks throughout the facility. He estimated that the plant wasted 876,500 gallons of water per year, costing approximately $2,638 annually. By eliminating leaks, the Melrose plant reduced wasted water and improved the efficiency of the water-using equipment. To make sure that all leaks were continuously addressed, the intern made a weekly checklist for leaks throughout the plant.

The Melrose facility also started using adjustable pressure/lower-volume hose nozzles on the evisceration line and for cleanup hoses. This flow reduction strategy has an estimated savings of more than $25,000 and more than eight million gallons a year. As another means of saving water, the plant also installed aerated nozzles, which mix air with the water, on all handwashing spouts on the evisceration line. The intern estimated savings of more than $10,000 and more than three million gallons of water per year.

The intern looked at water use during company break times and estimated that the Melrose facility could save more than eight million gallons of water a year by turning off the water. Employees posted signs in the high water use areas reminding workers to shut off the water before breaks and shutdown time.

Melrose also decreased the rate of the water going into the prechiller. The intern noted that the plant exceeded the USDA required one gallon overflow per bird by 0.63 gallons. He brought down the average overflow to 1.2 gallons per bird. This reduction has a projected annual savings of more than seven million gallons of water.

The plant’s salvage station was one source of water waste. This water station continuously pumped chlorine into the water stream to rinse and disinfect partially damaged birds that are cut up and salvaged. Water runs constantly to maintain a dilute amount of chlorine in the water. The intern incorporated an idea from Heartland Foods Company which involved installing a flow switch and surge pump to regulate the amount of chlorine in the water flow. With this system in place at Melrose, the chlorine pump runs only when the water at the product salvage station is running, reducing the amount of water and chlorine waste. Melrose estimates a yearly savings of more than one million gallons of water from this change.

By implementing the intern’s suggestions, the Melrose plant estimates a savings of about 31 million gallons of water with an annual savings of $93,700.

Heartland Foods Company slaughters, de-bones, and packages turkeys. Its main product is the whole bird. The plant employs approximately 500 people. Like Melrose, Heartland Foods’ main product is whole birds. A large volume of water is needed for daily production.

Heartland was interested in reducing its water use to help bring down utility costs and reduce the load on its pretreatment water system. The MnTAP intern also made suggestions that led to significant changes in this facility.

Heartland expanded on the intern’s ideas and installed five water flow meters along with a computer system to measure and track water flow. This helped them identify areas where they can reduce water use.

They installed a tank to recycle water for melting ice or cleaning. The tank is used to collect relatively clean water for reuse. Heartland estimates that it will quickly recoup the cost to install the tank by lowering water and sewer costs. The plant would also benefit from reducing its flow into Heartland’s water pretreatment system.

The intern also borrowed an idea from West Central and Melrose to post reminders to shut off the water throughout the facility. This simple solution also helped reduce their water waste.

With these changes, Heartland Foods reduced its water use from about nine gallons per bird to about six gallons per bird. They also estimate savings of more than 14 million gallons and $43,000 annually.

Beverage and Fermentation Sector
In the U.S., the soft-drink and brewery companies are controlled by a few large diversified corporations. Both markets have regionalized smaller companies, but for the most part four to five corporations control more than 70% of all sales.

The primary steps in processing beverages are

Wastewater and solid waste are the primary waste streams for the beverage and fermentation sector. Solid wastes result from spent grains and materials used in the fermentation process. Wastewater volume of "soft drink processes" is lower than in other food-processing sectors, but fermentation processes are higher in BOD and overall wastewater volume compared to other food-processing sectors.

Ozone technology has proven very useful in the beverage market since the earliest 20th century. Recent changes in legislature and industry guidelines have increased the need for ozone in the beverage industry in general. In bottled water plants, ozone can be used to disinfect product water to comply with International Bottled Water Association (IBWA) guidelines while leaving no residual taste or odor. At beverage plants, ozone can reduce or eliminate the need for chemical or high temperature disinfection processes during clean-in-place (CIP) cycles, reducing downtime and chemical costs. The effectiveness and cost benefits of ozone for these uses is proven in many locations throughout the world.

Ozone provides the following benefits to the beverage market:

Today, the world beer market amounts to some 35 billion gallons per year. About 5 percent of all beer produced in the U.S. these days comes from a new class of breweries called microbreweries. About 800 microbreweries in the U.S. account for about 300 million gallons of beer production each year. The central process that occurs during the production of beer, whether ale or lager, is the conversion of an aqueous solution of sugars extracted from cereals to an aqueous solution of ethanol. The sugar solution, known as wort, is a nutrient medium for yeast cells. During the fermentation process, the yeast cell population increases by feeding on the sugars. At the same time, the yeast excretes ethanol, carbon dioxide, and, in smaller amounts, other fermentation products. 

Four distinct processes are involved in beer production: malting, mashing, boiling, and fermenting. After fermentation, the yeast is separated by skimming, bottom cropping, or centrifugation. Many raw "green" beers, particularly lagers and North American ales, are then stored or aged in a tank for several weeks at low temperatures. This allows the flavor to mature and haze-forming proteins to precipitate out. The beer is finally clarified by filtration, carbonated, and packed into kegs, bottles, or cans. 

Solid-liquid separation occurs both upstream in the separation of the wort from the spent grain and removal of the hops after boiling, and also downstream to make bright, clarified beer. The development of crossflow filtration using ceramic membranes to clarify beer has been a major part of the Brewing Research Foundation International process innovation program in recent times. The conventional method for producing bright beers uses filter aids such as diatomaceous earth, also known as kieselguhr, to clarify beer. Some beers, such as traditional British ales, are not filtered at all. 

Tangential flow filtration (TFF) is a relatively new process for beer recovery from fermentation yeast and tank bottoms. The first production size plant was installed several years ago and many installations are now in successful operation.

Schenk Filterbau states that beer recovery from spent yeast with tangential flow filtration using ceramic membranes is part of the process technology of the today's modern brewery. Ceramic membranes made of highly pure alpha-aluminum oxide have proven to be the most suitable with respect to reliability, membrane life and beer quality. Cleaning with all detergents at high temperatures is possible with the exception of phosphoric acid. The modular design of the TFF-plant gives high flexibility to any brewery size and for later extension of the plant with increased investment cost.

The brewery process presents one of the biggest challenges possible to a microbiological control program. Microorganisms are responsible for both the production and the degradation of the product. Microbiological control is critical for production and filling equipment.

Process chemicals used in breweries include chemicals for:

Breweries use high volumes of fresh water. For every one barrel of beer produced, 10 barrels of water are used. Consequently, water treatment is critical. Many of the most critical problems brewery plant managers face are system inefficiencies that can cause process problems, downtime and poor product quality. Treatment of the boilers, cooling towers, water preparation, wastewater and the most important phase of the brewing operation, the pasteurization process, are necessary. Chemicals prevent microbial growth, scale, corrosion and "dome staining" or rust rings from forming on beer cans as they pass through the pasteurizing tunnel.

Breweries have numerous vessels that are used to pasteurize, heat and cool their products. Organic loading from broken containers and the warm temperature in these systems create ideal conditions for the growth of microorganisms and bio-film. Applying chlorine dioxide to obtain a residual between 0.5- and 1.0-ppm immediately controls free-floating (planktonic) microorganisms, and over 48 hours, will control attached (sessile) microorganisms. Typically a 5-ppm dosage, based upon the re-circulation rate, is more than enough to obtain these residual levels.

Dairy Sector
The dairy sector can be divided into two basic segments: fluid milk and processed milk products. U.S. dairy production is expected to remain fairly constant in the coming years. Production of fluid milk (with the exception of skim milk) and butter has steadily decreased over the past 10 years, while specialty items like yogurt and ice cream have forged ahead. The number of dairies within the United States has decreased due to consolidation, but the overall level of output has remained constant. 

All processed milk products, which include cheese, butter, ice cream, and yogurt, originate from fluid milk. The primary steps in processing are

A majority of the waste milk in dairy wastewaters comes from start-up and shut-down operations performed in the high-temperature, short-time (HTST) pasteurization process. This waste is pure milk raw material mixed with water. Another waste stream of the dairy sector is from equipment and tank-cleaning wastewaters. These waste streams contain waste milk and sanitary cleaners and are one of the principal waste constituents of dairy wastewater. Over time, milk waste degrades to form corrosive lactic and formic acids. Approximately 90% of a dairy’s wastewater load is milk.







Can Cooker Products

Water plays a role in most of the problems associated with metal food containers after processing. Whether steam, hot water or cold water, each can serve as the vehicle to transport undesirable substances. The mechanisms by which these chemically act is important to understand when designing an effective, comprehensive water treatment program.

There are unique demands placed upon water treatment chemistries by the stressful conditions of temperatures near the boiling point of water. Only high-heat stable formulations should be used in the "hot zones" of the thermal process. The cooling section requires the use of different inhibitors that are compatible with oxidizing biocides. These oxidizing biocides are used to prevent microbial contamination.







Various federal environmental regulations and statutes, such as the Federal Water Pollution Control Act or the Clean Water Act (CWA), Clean Air Act (CAA), Pollution Prevention Act (PPA), and Resource Conservation and Recovery Act (RCRA), have changed the way processing facilities handle food products and dispose of their waste. 

The CWA’s increasingly stringent regulations for discharging wastewater are the primary regulatory drivers for the food-processing industry. RCRA regulations typically apply only to solid waste disposal issues, and the Superfund’s Emergency Planning Community Right-to-Know Act (EPCRA) has had only minor impact on the hazardous material handling and waste generation practices of the food-processing industry. 

An increasingly viable option for companies is the "zero-discharge" system. Many food-processing facilities are looking to pretreatment options that can help reduce the amount of lost product. Once a part of the food product is lost to a waste stream, it represents a decrease in product utilization and an increase in treatment costs.







World Food Market

Many factors working in unison have helped the food-processing industry in the United States become a leader in the domestic and international marketplace. Abundant and productive agricultural sources, along with natural isolation, helped the industry thrive domestically. Competition during the nineteenth century from foreign rivals was minimal due to high transportation costs and continual European conflicts in the late 1800s and early 1900s. 

Inexpensive farmland, conducive climate conditions, European agricultural techniques, as well as modern technological advances were all important factors in promoting the supply-side economics of the U.S. agricultural system. The establishment and growth of a middle class in the United States helped create the demand side and economic competition for quality food products. Together, both supply and demand economic factors helped facilitate the success of the U.S. food-processing industry. 

Today, the principal global competition in the food-processing industry for the United States comes from Canada, Europe, and South America. The primary growth markets for U.S. products include Asia, Eastern Europe, and South America.

The United States is the largest consumer and producer of "processed" food products in the world. The U.S. food-manufacturing stage is dominated by large-scale, capital-intensive, highly diversified corporations. There are more than 17,000 food manufacturing facilities in the United States. The top 20 manufacturers combined gross more than the next 80 manufacturers and more than the next 101-500 manufacturers in total sales.

The U.S. food-processing industry accounts for approximately 26% of the food-processing output of the world. Food quality standards in the United States are recognized as some of the toughest in the world. The U.S. Environmental Protection Agency (EPA), Food and Drug Administration (FDA), and United States Department of Agriculture (USDA) enforcement agencies have helped ensure a high level of quality and safety for food products to the U.S. consumer. Because the United States is a world leader in food processing, it follows that many of the major technological innovations in the industry, including those in clean technologies and processes, occur in the United States. The term "clean technologies" is defined as "manufacturing processes or product technologies that reduce pollution or waste, energy use, or material use in comparison to the technologies that they replace."