compressed farm sanctuary inside chicken cafo

Thousands of chickens inside a factory farm building

Factory farms are designed to produce meat, eggs, and milk as quickly and cheaply as possible. As farms become increasingly specialized and larger, more and more animals are being raised on factory farms. These large, industrial-scale farms are also known as “animal factories” or “animal feeding operations.”

Factory farms are characterized by:

  • Confinement for at least 45 days out of the year, usually within buildings
  • No access to naturally growing vegetation during confinement
  • Health and growth is achieved with high doses of antibiotics and hormones
  • Very little space between individuals and limited mobility
  • Animals stand in or directly above their excrement.
credit: Steve Veysey

Dairy cows inside a factory farm

Some factory farms are called confined animal feeding operations (CAFOs). CAFOs have a certain number of animals and a potential to pollute nearby waterways (see

The Problem: Water Pollution Risks

The animals housed in factory farms produce millions of tons of manure and urine each year. For example, dairy cows produce approximately 6 gallons of milk a day, and 18 gallons of manure! Animal waste is temporarily stored in pits, tanks, or lagoons and is then spread onto nearby agricultural fields as fertilizer. But when factory farms do not manage animal waste properly, streams, lakes, and groundwater can be contaminated. Water pollution from factory farms is a common, significant, and largely ignored problem.

credit: Diane Baldwin, Neuse Riverkeeeper Foundation

A large factory farm with barns containing thousands of hogs. Waste is stored in the rectangular lagoons and later applied onto nearby agricultural fields (credit: Diane Baldwin, Neuse Riverkeeper Foundation)

Animal waste contains nitrogen and phosphorus as well as pharmaceutical products and pathogens such as Escherichia coli and Cryptosporidium. When enough of these substances enter water, harm can occur. The effects of this pollution on streams and lakes include loss of oxygen, harmful algal blooms, and fish kills. Human recreationalists may be at risk of illness if ingestion or submersion occurs. Drinking water supplies contaminated with animal waste can be unsafe or even deadly to people and livestock.

Some factory farms are required to develop and follow a management plan that ensures proper storage and disposal of waste products. However, waterways become contaminated when:

  • Waste is deliberately or accidentally discharged into a waterway
  • Waste is spilled during transportation
  • Animals have access to or are kept adjacent to waterways
  • Rain or snow carries waste downhill from where animals are kept
  • Rain or snow carries waste downhill from where manure is applied to agricultural fields
  • Manure is applied to fields that are directly adjacent to waterways
  • Flooding inundates factory farms.

The Solution: Public Participation

For more information and  how you can help, check out these pages:

Water & Farming Priorities

Sustainable Agriculture

Food production and conservation can go hand-in-hand.

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