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Home > Healthy Great Lakes, Healthy Michigan > Facts About CAFOs

Facts About CAFOs

What is a CAFO?
A CAFO, or Concentrated Animal Feeding Operation, is an industrial-sized livestock operation.

  • The quantity of urine and feces from even the smallest CAFO is equivalent to the urine and feces produced by 16,000 humans.
    Large CAFO in Lenawee County, visible are 4 barns and 3 pits.

    Photo : John Klein/Ed Steinman/Lighthawk

  • A CAFO can house anywhere from hundreds to millions of animals.
  • The animals in CAFOs are most often dairy cows, hogs, or chickens.
  • CAFO animals are confined at least 45 days or more per year in an area without vegetation.
  • CAFOs include open feedlots, as well as massive, windowless buildings where livestock are confined in boxes or stalls.
  • Other terms used to describe a CAFO: mega farm, animal factory, hog motels, poop factories, industrial farms.

Also see CAFO in the glossary.


What pollutants do CAFOs produce?
CAFOs produce huge amounts of animal sewage and other pollutants.
Brown liquid enters Lime Lk Drain, with plume clearly visible.
CAFO owners and operators spend millions of dollars on technologies that make it possible to produce massive quantities of milk, eggs, and meat, yet they resist investing in technologies and practices to properly treat the wastes that are by-products of this industry:  

  • The amount of urine and feces produced by the smallest CAFO is equivalent to the quantity of urine and feces produced by 16,000 humans.
  • CAFO waste is usually not treated to reduce disease-causing pathogens, nor to remove chemicals, pharmaceuticals, heavy metals, or other pollutants.
  • Over 168 gases are emitted from CAFO waste, including hazardous chemicals such as ammonia, hydrogen sulfide, and methane.
  • Airborne particulate matter is found near CAFOs and can carry disease-causing bacteria, fungus, or other pathogens.
  • Animals frequently die in CAFOs. Their carcasses, often in large numbers, must be dealt with.
  • Infestations of flies, rats, and other vermin are commonplace around CAFOs and therefore around CAFO neighbors.

Often you'll hear owners of CAFOs argue that the wastes produced by the livestock provide nutrients that help them offset the use of synthetic fertilizers. The sheer amount of wastes produced, however, often overwhelms the ability of the land and crops to absorb CAFO wastes.


Are there different kinds of CAFOs?

One type of CAFO houses livestock in buildings the animals seldom leave. Removing wastes from these buildings is a major challenge.

  • Dairy and hog CAFOs often use clean water to wash animal wastes and contaminants from the buildings into waste-storage structures or lagoons.
  • Poultry CAFOs use dry-waste systems. The waste falls from animal cages to the floor, where it is scraped out of the building periodically or collected on conveyer belts and moved to composting or storage sites.

Another type of CAFO is the feedlot, which keeps the animals outdoors in pens. Here the manure waste accumulates on the ground, often washing off into nearby ditches and streams.


What's in CAFO waste?
In addition to plant nutrients such as phosphorus and nitrogen, CAFO waste is likely to contain:
  • antibiotic-resistant bacteria
  • hormones
  • chemicals used in livestock care
  • milkhouse wastes
  • cleaning agents
  • ammonia and heavy metals
  • silage leachate
  • millions of gallons of water contaminated by all of the above.
CAFO waste is often stored untreated in gigantic anaerobic waste storage structures or pits for up to six months. After storage, it is spread on farm fields for disposal. This is where CAFO wastes often enters surface water.
Lime Lake is shown bright green with an algae bloom, downstream from drainn shown in photo above.
Nutrients in this CAFO waste can cause bright-green algae blooms in ditches, streams, and lakes. As these surface-water algae blooms die off, the oxygen in the water is depleted. What does this do? It can lead to fish kills. Additionally, drinking-water plants must remove these nutrients before water is fit for consumption.

Pathogens such as E.coli bacteria, cryptosporidium, and salmonella, all of which can cause sickness or death in humans and animals, may be present in CAFO wastes.


How do CAFOs pollute water?
Water pollution is possible at virtually any point in a CAFO's operation.
  • In the production area, spills, overflows, and tracking of wastes on tractor and truck tires can cause surface runoff of contaminants.
  • Stormwater that mixes with manure wastes, silage leachate, or milkhouse wastes can flow into drains.
  • Pipes or hoses carrying wastes can break or become unattached. Waste storage structures can overflow or burst.
  • Field tiles or catch basins can be installed that drain wastes directly into surface waters. 

Truck spraying manure onto white snow covered field in February 205.
It may take dozens of trips per day by semis or tanker trucks to dispose of CAFO waste. These trucks haul the wastes from the production area waste-storage structures to fields that are often many miles away.

One of the main sources of CAFO-caused pollution in Michigan comes from discharges of manure and other wastes through the soil into field drainage tiles, which carry the wastes directly into county drains and streams.

When CAFO wastes are applied to farm fields, water pollution can be caused by overapplication of wastes, direct runoff into surface waters, or by traveling through the ground- or catch basins into field tiles or drainage ditches that discharge directly into surface waters. Tests have shown that waste applied to the surface of a field can take a little as 45 minutes to reach the field tiles three to four feet below the surface.

Manure wastes are also sprayed from travel irrigators, trucks, tractors, or draglined. This waste can flow directly into surface waters due to wind, by direct discharge from running over a drain or waterway, or through malfuntions of the equipment.

Groundwater pollution can be caused by leaking waste storage structures, and improper or overapplication of wastes on fields. The use of injection systems for shooting wastes directly into the soil is encouraged as a method to keep odor from CAFO land application down, however there is significant concern that this could simply lead to quicker travel time through the soils into field drainage tiles. Some CAFO owners have converted field drainage tiles into de facto septic systems by plugging them with gate valves and other devices. These systems at best only delay the pollution and don't keep pollution from flowing to groundwater. They certainly don't remove pathogens. Groundwater is difficult to monitor, so the extent and source of contamination are often harder to pinpoint than surface water contamination.


How do CAFOs pollute air?A hydrogen sulfide meter shows the gas present in this family's yard at 2 parts per million.
Air pollution from CAFOs can come through numerous methods. Some can cause bad odors, but others emit several dangerous gases as manure and biological materials break down in the absence of oxygen such as in the bottom of a manure pit.  Methane, ammonia, and hydrogen sulfide are some of the gases.  Exposure to hydrogen sulfide can cause neurological problems, including extreme anger, depression, and illness.  The image at right shows a family raising the American flag in their yard, while a hydrogen sulfide meter shows concentrations of the contaminant at 2 parts per million in October 2008.  The source CAFO can be seen beyond the pine tree.  Unfortunately, this home is also surrounded on three sides by fields often used by the CAFO for manure disposal.

Some of the sources of CAFO air pollution are:

  • Barns where the animals are housed  
The air pollution inside the buildings is potentially deadly to the animals and humans inside if the fans ever stop operating.  Normally the fans simply blow the contaminated air to the outside where it can pollute the whole community. Poultry operations blow ammonia and particulate matter, including feathers and chicken feces out of the buildings.
  • Waste storage structures
Hog operations often build the waste storage structure immediately beneath the area where the animals are kept, with slats in the floors to allow wastes to simply drop into the pit.
  • Handling of the wastes
The CAFO wastes stored in waste storage structures is not treated or aerated, often resulting in extreme off-gassing of pollutants such as hydrogen sulfide (H2S) when the wastes are transported and sprayed onto farm fields. 
  • Techniques used in land application
For example, once or twice each year many liquid waste CAFO systems will scrape the solids out of the bottom of the waste storage structures and spread these thick, fermented wastes onto farm fields, causing even worse air pollution.


How do CAFOs impact human health?
CAFOs may cause health effects to their neighbors from pollution damage to the air, land and water.

Over 168 gases are emitted from CAFO waste, including hazardous chemicals such as ammonia, hydrogen sulfide, and methane.

Hydrogen sulfide poisoning can cause irreversible brain damage, dizziness, headache, nausea, sore throats, sinusitis, burning eyes, and other illnesses.

When phosphorus and nitrogen are overapplied to fields, the nutrients can move through the soil into field tiles to surface water, or through soil to groundwater and drinking water.

Elevated levels of nitrates in drinking water can cause "blue baby syndrome", a potentially fatal blood disorder.


Are CAFOs sustainable?
  • CAFOs are resource-intensive and unsustainable.
  • CAFOs animal-raising practies are neither economically viable or sustainable.
  • CAFOs use large amounts of electricity for lighting, equipment, milkers, pumps, and irrigators.
  • CAFOs use fuel in tremendous quantities to run tractors, gas motors, and pumps, and to transport milk, waste, supplies, and chemicals.
  • CAFOs use millions of gallons of Michigan's clean fresh groundwater every day to dilute waste and to wash manure from milking parlors and CAFO barns.


Do CAFOs need taxpayer subsidies?

CAFOs can't survive without taxpayer subsidies. CAFOs receive many subsidies, such as milk price support guarantees, federal EQIP money through the Farm Bill, Development Right Agreements, tax abatements, grants, bonds, even economic development funds for roads.

These taxpayer supports not only encourage the growth of this industry, they undercut the ability of traditional livestock operations to compete with CAFOs. Without the subsidies, CAFOs would fail financially.


How are CAFOs regulated and permitted?
Federal laws establish minimum standards for the regulation of any activity that causes air pollution or water pollution. However, through aggressive lobbying by the promoters of CAFOs, federal laws for the environmental oversight of CAFOs are extremely weak.

Currently, the U.S. Environmental Protection Agency provides no regulation of air pollution problems from CAFOs. Under the Right-to-Know provisions of CERCLA 42 U.S.C. §11001 et seq. (1986).  Also known as Title III of the Superfund Amendments and Reauthorization Act (SARA), the Emergency Planning and Community Right-to-Know Act - otherwise known as EPCRA (pronounced EP-kra) - was enacted by Congress as the national legislation on community safety. This law is designed to help local communities protect public health, safety, and the environment from chemical hazards. CAFOs are required to report emissions of some pollutants, most notably ammonia. This requirement led to disclosure that the largest emitter of ammonia in the country is a dairy CAFO in Oregon.

The federal Clean Water Act does provide some regulation of CAFOs, although interpretations of the extent of those requirements are being litigated. State laws must be at least as restrictive as the federal law, but in Michigan and some other states it has required citizens to bring challenges to state's delegation under the Clean Water Act to force the agencies to implement the laws. Federal law requires that any CAFO which has had an illegal discharge into surface waters must obtain a National Pollutant Discharge Elimination System (NPDES) permit in order to continue operations. Several states (including Michigan) now require NPDES permits for all CAFOs, including new ones.

It is important to review the regulations in your state in order to understand what is allowed and not allowed. (View EPA links to state program websites.)

State and federal agricultural agencies often play a role in establishing voluntary standards that CAFOs and other livestock operations are expected to abide by. In some instances, the agricultural agencies will act as the gatekeeper for securing any enforcement actions by the state, particularly in the area of air pollution. In Michigan, for example, the Department of Agriculture is given the responsibility for investigating air pollution complaints from CAFOs, although they have no enforcement authority. Except in an emergency, the agriculture director must make a referral to the Department of Environmental Quality before any action can be taken by the environmental agency regarding those complaints.

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