Accidents Waiting to Happen: Factory Farms

In recent decades, agriculture in the U.S. has undergone a dramatic shift from small family farms to giant industrial operations. In 2022, there were 1.7 billion animals in factory farms in the U.S., a 47% increase since 2002. Factory farms produce tremendous amounts of waste, with large factory animal farms in the U.S. producing 20 times as much excrement as all the people in America as of 2012. This manure is often stored in large pits or lagoons – especially at industrial dairy or hog operations.

Manure lagoons put water at risk

Waste lagoons are prone to leaks and spills, as they are often uncovered, unlined and separated from waterways only by narrow embankments that can overflow or deteriorate. Spills can be highly damaging to the environment and wildlife. Manure contains high levels of nitrogen and phosphorus, which can cause algal blooms in lakes and ponds and destroy aquatic ecosystems. Waste can also contain dangerous pathogens, along with growth hormones used on livestock, antibiotics, manure and animal blood. People exposed to pathogens through water can become sick with intestinal illnesses or bacterial infections.

A hog waste lagoon in Georgia.Photo by Natural Resources Conservation Service Georgia | Public Domain

Lagoon spills are common

There is no comprehensive national data on manure spills, but available evidence indicates that spills happen regularly and can be extremely damaging.

• In Missouri, Smithfield Foods spilled 6 million gallons of waste from 2006 to 2021.
• In Washington state, three dairies are suspected of having contaminated nearby drinking water wells with nitrate in the Lower Yakima Valley, according to legal action filed by the U.S. EPA in June 2024.
• In Wisconsin, Department of Natural Resources data reveals that the state’s livestock operations spilled 8 million gallons of manure from 2009 to early 2015.
• In Illinois, a Chicago Tribune analysis found that “pollution incidents from hog confinements killed at least 492,000 fish from 2005 through 2014, nearly half of the 1 million fish killed in water pollution incidents statewide during that period,” and impaired 67 miles of the state’s rivers, creeks and waterways.

Manure lagoons are at a predictable risk during extreme weather. In North Carolina, hurricanes Floyd (1999), Matthew (2016) and Florence (2018) resulted in the failure of dozens of waste lagoons, contaminating waterways including the South River and tributaries of the Cape Fear, Neuse and Tar rivers. Following Hurricane Floyd, E. Coli and Clostridium perfringens bacteria remained at hazardous levels in water even after floodwaters had receded, indicating the potential for people exposed to the water to become ill.

Factory farm manure pollutes in other ways

Waste from industrial livestock operations can also spill into the environment when it is transported to fields via hoses and pipes. In May 2024, a mechanical failure in the manure transfer system, which transports the waste from a barn to a treatment facility, caused a spill in Monroe County, Wisconsin, and a mile-long fish kill.

When severe storms inundated North Carolina in 2016, the spread of fecal matter was not just from manure lagoons but also from “more than 140 feces-strewn swine and poultry barns” and “thousands of acres of manure-saturated fields.”

Threat spotlight: North Carolina’s waste lagoons put water at risk

In eastern North Carolina, pigs outnumber humans 30 to 1. A 2022 analysis of factory farms in North Carolina by the Environmental Working Group and Waterkeeper Alliance (EWG/Waterkeeper) revealed the threat that waste from those animals poses to water.

EWG/Waterkeeper’s analysis of satellite imagery in North Carolina found 7,352 factory farms in the state. The analysis found that 156 of those farms were within a 100-year floodplain, putting them at particular risk of flooding.

In recent years, tropical storms have caused manure leaks across North Carolina, but it doesn’t take a massive storm to put waterways at risk. In 2022, nearly a million gallons of hog waste, hog carcasses and food waste leaked from a failed hog waste digester in Wayne County, N.C., with tens of thousands of gallons of the waste reaching nearby wetlands.

Protect American waterways from damaging spills

The huge volume of manure generated by factory farms puts America’s streams and rivers at risk, but it doesn’t have to be that way. Policymakers have a number of options to protect our waterways from these accidents waiting to happen. Public officials should:

• Limit industrial livestock operations that pose severe threats to water. The best way to prevent toxic spills is to limit activities that create the potential for spills in the first place, including moratoria on new or expanded factory farms, especially in already-polluted watersheds.
• Require waste treatment permits. Just as we require water utilities to treat human sewage, existing factory farms should all have enforceable permits with requirements to process manure so it does not pose pollution threats to surrounding waters.
• Support sustainable alternatives to factory farms. Funding from the Farm Bill and other sources should be allocated to support small farms raising livestock on rotational pasture and other alternatives that do not generate huge volumes of manure that are inherently risky for our waterways and our health.
• Protect all waterways. Congress should restore Clean Water Act protections for all wetlands and streams, and in the meantime, state officials should ensure that all state waters are comprehensively protected from factory farms and other pollution sources.

To find out more

• For more resources on pollution from factory farms, visit the EPA’s website.
• To learn how family farmers and other local activists are opposing factory farm expansion, please visit the website of our allies at the Socially Responsible Agriculture Project.
• To understand how some Farm Bill programs are subsidizing factory farms, check out this update from the National Sustainable Agriculture Coalition.
• To get a sense of how much manure is produced by the supply chains of major meat and poultry companies, see our 2016 report on Corporate Agribusiness and the Fouling of America’s Waterways
• To learn more about toxic algae (which is fueled largely by agricultural pollution), see our explainer on the topic.
• To see how the slaughterhouses that receive livestock from factory farms are polluting our waterways, see our fact sheet on slaughterhouse pollution.

Frontier Group intern Hailey Seo contributed to this resource.