Have You Thought About Animal Waste and Your Water? By Julie Peller, Ph.D.

Green Junction

In the United States, most meat comes from livestock raised in concentrated animal feeding operations (CAFOs). Defined by the EPA as “agricultural operations where animals are kept and raised in confined situations,” the term factory farm is also used to describe the conditions for over 99% of chickens and turkeys, over 98% of pigs, and 75% of cows. One of the major consequences of raising farm animals in confined conditions is the generation of massive amounts of manure. A 2024 study determined that the 21,000 factory farms in the United States produce over 1.6 million tons of manure each year, far greater than the amount of human sewage. The excrement includes antibiotics and their metabolites, nitrates, and even pesticides that originate from animal feed.

CAFO waste, often stored in large waste lagoons, can pollute waterways. Last month, multiple organizations filed a lawsuit against the Oregon Department of Environmental Quality. They argued that the state issued a new water quality permit that failed to adequately monitor and prevent CAFOs from illegally discharging waste into ground and surface water. To protect water, they contend that representative monitoring – adequate testing to detect the leakage of pollutants into ground and surface water from CAFOs – is necessary. 

Oregon’s state laws are tougher than laws in other states such as Indiana. Kim Ferraro, senior attorney at the Conservation Law Center in Bloomington, Indiana, has worked extensively on the problems associated with CAFOs and the weak regulations. She explains that “Waste lagoons leach into our waterways, and it’s perfectly legal under Indiana’s lax regulations.” The state of Indiana does not require National Pollutant Discharge Elimination System (NPDES) permits for CAFOs unless the facility has an ongoing, actual discharge into state waterways. These permits are important measures to ensure compliance with the Clean Water Act.  

The United States Geological Survey published the study “Impacts of waste from concentrated animal feeding operations on water quality” in 2007. Among their conclusions was “the generally accepted livestock waste management practices do not adequately or effectively protect water resources from contamination with excessive nutrients, microbial pathogens and pharmaceuticals present in the waste.” Unfortunately, laws to protect water from this pollution have not improved since the 2007 report.

Julie Peller, Ph.D., is an environmental chemist (Professor of Chemistry at Valparaiso University). She has been writing a weekly column, The Green Junction, for the past seven years and is helping to move the call of Laudato Si to action. Her research interests include advanced oxidation in aqueous solutions, water quality analyses, emerging contaminants, air quality analyses, challenges along the Lake Michigan shoreline (including Cladophora, water, and sediment contaminants), and student and citizen participation in environmental work.