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In 2003, the Iowa Chapter of the Sierra Club expanded its efforts to protect Iowa's rivers and streams from agricultural and urban water pollution. Our Environmental Public Education Campaign is working with activists across the state to empower local communities and hold polluters accountable. Find out more about Iowa’s water quality problems, and how you can be part of the solution.

Animal Factories

Iowa is home to approximately 8,000 animal feeding operations (AFOs).  More than 6,500 confinements raise close to 8.5 million animal units.  Concentrated Animal Feeding Operations (CAFOs) generally house pigs and chickens by the tightly packed thousands. In fact, nearly 7.4 million animal units of swine are raised in confinement And, as corporations build more confinement sheds and manure cesspools every year, we continue to lose our state’s sustainable family farmers - the true stewards of Iowa’s land. In fact, between 1995 and 2002 the number of hog producers in Iowa declined by 60% while the number of hogs produced increased by 10%. (USDA NASS)

Water Pollution

This concentration of animals concentrates their waste, which is mixed with water in enormous lagoons or pits, creating disposal problems and water and air pollution on a scale that would never have been possible in a traditional, diversified system. Manure that has been a tremendously valuable fertilizer since the dawn of agriculture has been transformed in the factory farm system into a hazardous waste product that CAFO operators can’t get rid of quickly enough.

Every year, the largest 5% of US livestock operations produce, in addition to 54% of all US livestock, 575 billion pounds of manure (USDA). When CAFO operators dispose of this liquefied manure on nearby fields, it often does far more than fertilize crops.

According to the EPA, hog, chicken and cattle waste from large animal factories has polluted 35,000 miles of rivers in 22 states and contaminated groundwater in 17 states. In Iowa, studies have shown that more than half of tested manure pits leak at rates above legal limits - and the legal limit allows some structures to pollute on the scale of millions of gallons per year (Wallinga, Institute for Agriculture and Trade Policy).

Manure lagoon breaks and spills are also common; illegal discharges of hog wastes from Iowa lagoons have killed hundreds of thousands of fish and destroyed the aquatic communities they live in, as well as contributing to the nutrient polluted “Dead Zone” downstream in the Gulf of Mexico.

Animal factories are threatening waters all across Iowa, including the groundwater that most Iowans drink. Yet, despite the fact that the federal Environmental Protection Agency (EPA) mandates it, the Iowa Department of Natural Resources (DNR) has yet to issue a single Clean Water Act permit to an Iowa CAFO. These facilities are “point sources” of water pollution, and should be regulated like other industrial polluters!

Check out the animal factories near you, and find out who owns and operates them, on the DNR’s web site at  You don't need a login name or password; just read the instructions and click "search" or "reports."

Then take a closer look at where AFOs are located:


Air Pollution

Animal factory air pollution is another problem that has been growing right along with the size of Iowa’s livestock confinements. Rural Iowans are increasingly plagued with health-threatening levels of ammonia, hydrogen sulfide, particulates and odors emitted from animal factory lagoons, confinement houses, and the fields manure is spread on.

Under tremendous public pressure, the DNR acted in 2003 to approve Air Quality Standards for ammonia and hydrogen sulfide from CAFOs based on a 2002 study by the University of Iowa and Iowa State University. ( The 2003 Iowa Legislature, however, threw the standards out. In 2004, the Department started again, and recommended a Health Effects Value for hydrogen sulfide of 15 parts per billion for a one-hour average exposure time. This value, as recommended by the Joint University Study, would be protective of public health and would have no adverse impact on the state’s family farmers. Aside from the fact that only large confinements would be at any risk of violating the standard and the fact that facilities would be permitted to exceed the standard 7 times annually, only the very largest animal factories in the state would even be monitored for emissions violations.

Despite all of this, businesses and agribusiness lobbies launched a fear-based campaign to generate family farmer opposition to the standard, claiming it would “drive agriculture out of Iowa” when in fact it would help do just the opposite. The hydrogen sulfide standard would be a small step towards leveling the playing field for sustainable farmers by holding corporate animal factories accountable for their impacts on the environment and their neighbors' quality of life.

The 2004 Iowa Legislature passed HF 2523, which would have made it illegal for the DNR to establish air quality standards that are any stricter than the federal government or to establish standards for airborne substances for which the federal government has not developed standards. This legislation would have allowed CAFOs to pollute our air with impunity. This would be in direct opposition to the CAFO legislation of 2002, which directed the Iowa DNR to develop meaningful air quality standards for CAFOs.

Then-Governor Tom Vilsack vetoed HF 2523.

In 2002, the Legislature required that the Iowa DNR to perform a study of the airborne pollutants emitted by animal feeding operations (AFOs), including hydrogen sulfide, ammonia, and odor. The odor measurements for the study were taken from 2003 through 2005.  The "Results of the Iowa DNR Animal Feeding Operations Odor Study" was published in 2006.


Antibiotic Resistance

Another growing concern about factory farming is the threat of antibiotic-resistant bacteria emerging as a result of antibiotic overuse in livestock confinements. Animal factories are responsible for an estimated 80% of total US antibiotics use, with the vast majority of that being fed to animals that are not sick. This routine or “sub-therapeutic” antibiotics use is necessary in huge animal factories simply to keep animals alive in stressful, unsanitary and crowded conditions, and also has been found to promote accelerated growth.

Unfortunately, most of the antibiotics misused in livestock production are identical or similar to those we rely on to treat human disease. And, while we require a prescription for antibiotics, confinement operators can buy antibiotics and antibiotic-laced feed with no such prescription, or for that matter, government information oversight or record keeping of any kind.

As a result, all major, interested medical authorities, including the American Medical Association, the World Health Association and the Centers for Disease Control and Prevention, agree that the agricultural abuse of medicines must stop if we are to protect their effectiveness in treating human illness.

To learn more about antibiotics use in agriculture, visit

To find sustainable meat producers and retailers near you, visit