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Agricultural and Animal Wastes

Agricultural waste management is both economically important and also environmentally necessary. The reuse of animal wastes reduces the cost of hauling the material away and substitutes for the cost of a commercial fertilizer. Agricultural waste management consists of nutrient management at a given farm and site-specific waste management. The agricultural waste that is not used immediately should be stored in a building or in holding ponds away from bodies of water. Other strategies include avoiding over-application of waste to land; avoiding waste application before or after heavy rain; excluding livestock from sensitive areas; minimizing runoff and erosion of fields; and confining the waste from cattle to a given area.

Agricultural wastes from farms and feedlots which can degrade water quality and cause aesthetic problems may be solid waste or hazardous waste, or a combination of both. It is estimated that over 1 billion tons of agricultural wastes are produced annually. Besides this, domestic animals produce over 1.5 billion tons of fecal material and over 600 million tons of liquid waste yearly. (See endnote 3.) The GRACE Communications Foundation using US Department of Agriculture data estimates that there are over 335 million tons of dry matter waste, after water has been removed, coming from farms and that animal feeding operations create each year about 100 times more manure than the amount of human sewage sludge processed in sewage treatment plants. (See endnote 4.) Feeding 800,000 pigs can create one and a half times as much sanitary waste as the City of Philadelphia on a yearly basis. (See endnote 6.) These wastes may make the water unfit for drinking by humans and animals and help destroy aquatic life. Nitrates can enter surface bodies of water and seep into the groundwater from agricultural waste runoff and fertilizers used on the land.

Agricultural and animal wastes consist of the residues from crops, residues from processing of foods, decomposing vegetables and fruits, animal feed, animal urine, feces, bedding, dead animals, etc. These wastes come from crops, orchards, vineyards, dairies, feedlots, farms, etc. And then of course there is available a substantial amount of hazardous waste including used oil, pesticides, herbicides, etc., which will be discussed later in this chapter.

Animal feeding operations as well as concentrated animal feeding operations are increasing in size, although the numbers of them have decreased, and producing considerably more waste material which may contaminate the air, land, and ground and surface water. These wastes if used in proper quantities would be an excellent source of nutrients for plants, but also contain pathogens, heavy metals, antibiotics, and hormones. Reactive nitrogen as a nitrate or ammonium stresses water quality. Hormones are the most potent endocrine-disrupting chemicals that can impact ecosystems and human beings. Pathogens may contaminate all environmental media and food and lead to outbreaks of disease in humans. Antibiotics may create in humans a serious problem of dealing with antibiotic-resistant organisms. Other environmental problems include odors and providing food and harborage for insects and rodents. (See endnotes 5, 6.)

Groundwater and surface water may be contaminated through runoff from applying manure to the land as well as leaching from that which has been applied and from leaks or breaks in the manure storage units. Veterinary antibiotics have been found in well water from areas where manure has been spread. The rate of application and prevailing weather conditions are highly significant in the potential for the spread of microorganisms to food and water. Pathogenic organisms and substantial amounts of nitrates have been found in both groundwater and surface water.

Air quality in close proximity to industrial farms has been found to be poor and at times hazardous. Gases from the decomposition of the manure and particulate matter from feed and feathers (in poultry processing areas) are present in the air. There is a volatilization of ammonia from the manure when it is applied to the land at application and the production of nitrogen oxide when the nitrogen applied to the land undergoes nitrification and then denitrification. Children are most susceptible to the problem of breathing in these gases. Also present is methane, which is not a health risk but is highly flammable and is a greenhouse gas contributing to global warming, as well as hydrogen sulfide which comes from anaerobic bacterial decomposition of organic matter.

Odors are one of the most common complaints of citizens living near these industrial farms. The odors are a mix of ammonia and hydrogen sulfide as well as other volatile and semi-volatile organic compounds. The anaerobic reaction leading to many of the odors occurs when the manure is stored in pits or lagoons for long periods of time.

Where there is manure, there will be various types of flies, mosquitoes, and also rodents looking for food that has not been digested but is still in the manure. This can create substantial insect and rodent problems and also lead to outbreaks of disease.

Pathogens that may be found in animal manure include Bacillus anthracis, causing anthrax; Escherichia coli, certain strains of which will cause diarrhea; Leptospira pomona, causing leptospirosis resulting in abdominal pain, muscle pain, vomiting, and fever; Listeria monocytogenes, causing listerosis resulting in fever, nausea, vomiting, and diarrhea; Salmonella species, causing salmonellosis resulting in abdominal pain, diarrhea, nausea, and fever; Clostridium tetani, causing tetanus resulting in violent muscle spasms, difficulty in breathing, and lockjaw; Histoplasma capsu- latum, causing histoplasmosis resulting in fever, muscle ache, joint pain, and stiffness: Microsporum and Trichophyton, causing ringworm resulting in itching and a rash; Giardia lamblia, causing giardiasis resulting in diarrhea, abdominal pain, vomiting, and fever; and Cryptosporidium species, causing cryptosporidiosis resulting in diarrhea, dehydration, and weakness. All these organisms may lead to serious outbreaks of food- and waterborne diseases.

Antibiotics are usually used in animal feed in the United States. They help reduce the chance for infection and reduce the need for animals to fight off bacteria. Because animals are now being so closely confined in the industrial farms, the chance for infection spreading has increased substantially. There is serious concern that these antibiotics are carried over in the food supply and are making the antibiotics taken by humans far less efficient and also creating a potential for allergic responses.

Best Practices in Disposal of Agricultural and Animal Wastes (See endnotes 7, 8, 9; Chapter 2, “Air

Quality (Outdoor [Ambient] and Indoor)”; and Chapter 14, “Water Quality and Water Pollution”)

An agricultural waste management program includes the areas of production, collection, storage,

treatment, transfer, and utilization. The Best Practices listed below will fall into these categories.

Along with the variation in the amount of production at different seasons of the year, there will

be a variation in the amount of waste which is produced.

  • • Project the amount and type of waste for disposal on a daily, weekly, monthly, and annual basis in order to determine how best to set up a waste management program.
  • • Reduce contaminated runoff from open holding areas, which contributes a large amount of the waste and pathogens coming from livestock operations. This can be accomplished by limiting the size of the open holding area, putting a roof over part of it, and installing gutters and water diversions away from the waste. Also reduce heavy rainfall from coming across the surface of the contaminated areas by installing necessary drainage from the area.
  • • Prevent heavy rainfall from flowing into bodies of water from areas where manure is being stored or spread by use of diversion ditches, catch basins, and vegetative filter strips which remove sediment, nutrients, and bacteria. Apply the water from the catch basins to the land.
  • • Place permanent stockpiles of manure on a concrete pad or clay base with at least 2 feet of separation between the base of the manure and the seasonal high-water table.
  • • Place fences around access to streams, rivers, lakes, or ponds to prevent livestock from entering these areas and contaminating them.
  • • Establish maintenance programs to correct leaking water facilities and clean up spilled feed.
  • • Provide a written record of the type, consistency, volume, location, and timing of waste which has been produced in order to determine if this can be reduced and how quickly it can be removed in an effective manner.
  • • Collect all waste on a regular basis as quickly as possible from the point of origin and remove it to the point of collection and disposal.
  • • Provide proper leak-proof facilities for storage of wastes which will allow management to distribute it in an appropriate manner based on weather conditions and the availability of resources to carry out the work.
  • • Transport the waste as a solid, liquid, or slurry in a manner which will not contaminate environmental media.
  • • Recycle all reusable waste products as a source of energy, bedding, animal feed, mulch, or plant nutrients as feasible.
  • • Since cattle and sheep are the largest source of methane emissions from human activity and because their normal digestive process produces methane, supplement the animals’ diet with urea which increases their ability to digest their food and thereby reduces gas production by 25-75%.
  • • Utilize the AgSTAR program to develop various biogas systems and recovery technologies at concentrated animal feeding operations.
  • • Federal agencies should use a regional approach to the development of nutrient water quality criteria, establish the regional criteria, and provide technical guidance documents to individuals and groups on how to protect various bodies of surface water and groundwater supplies in particular areas, as well as provide technical assistance where needed.
  • • Dispose of animal carcasses to prevent transmission of livestock disease and protect the environment through rendering, burial, incineration, and composting.
  • • Use appropriate vaccinations to prevent illness. Remove sick or stressed animals from the rest of the animals and also quickly clean up their wastes, including all manure, and dispose of it properly.
  • • Use organic acids in feed for animals where appropriate to reduce levels of certain microorganisms.
  • • Use anaerobic lagoons in southern climates and deep pits in northern climates for temporary storage and treatment of manure by means of anaerobic processes, especially to destroy bacteria.
  • • Use, where appropriate, composting of animal manure and livestock carcasses while maintaining a temperature of 150°F to destroy most pathogens. The compost must be turned and mixed on a regular basis so that the correct amount of carbon and nitrogen will be available to the microorganisms to substantially reduce the material and change its nature.
  • • Use, where appropriate, aeration techniques such as large shallow, under 5 feet deep, storage containers where oxygen can naturally reach the bacteria to reduce the material and change its nature. Mechanical aeration may be used by pumping air into the storage containers.
  • • Use lime stabilization of the animal waste to reduce odor and pathogens before applying to the land. Chlorine stabilization does not work well because of the large amount of organics and the chemical reactions between chlorine and the organic matter which may produce toxic and carcinogenic byproducts. Ozone is safe but also does not work well.
 
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