Wisconsin state justice misses mark on how much waste produced by cows at factory farms

It’s no secret that factory farms produce a lot of waste. 

Also known as Concentrated Animal Feeding Operations, or CAFOs, the farms are home to thousands of animals at a time, ranging from cows to hogs to chickens. One of the most common complaints about the large-scale farms is the waste, which must be collected and disposed of in some way. 

It’s no surprise that a case involving the waste from factory farms made its way to the Wisconsin Supreme Court, though the written decision in the case raised an interesting question: Exactly how much waste does a CAFO produce? 

The court held that the state Department of Natural Resources has the ability to impose a maximum number of animals on factory farms and off-site groundwater monitoring conditions on factory farms. In writing the majority decision, Justice Jill Karofsky cited an evaluation by the U.S. Environmental Protection Agency, which stated that "a farm with 2,500 dairy cattle is similar in waste load to a city of 411,000 people." 

But in America’s Dairyland, we know our cows. And that number seems awfully high. 

Is it true that a dairy farm of 2,500 cows could really produce more waste than the population Madison, Racine and Oshkosh combined? 

Let’s check it out. 

If you look at the study referenced by Karofsky, "Risk Assessment Evaluation for Concentrated Animal Feeding Operations," it does indeed state that a farm of 2,500 animals produces as much waste as a city of 411,000. 

But, the paper was published in 2004, making it 17 years old. 

So we went in search of newer information. 

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A Dec. 6, 2019 report by the Milwaukee Journal Sentinel likened a herd of 1,000 cows to the city of Fond du Lac, which has 42,000 residents. So, by that measure, 2,500 cows would equal a city of about 105,000 --  much smaller than Karofsky wrote.

The article also noted the largest CAFO in the state, which boasts 6,000 cows, generates about as much manure and urine as 252,000 people, roughly the size of the city of Madison. So, at 2,500 cows, the comparison point would again be a city of about 105,000.

And studies by Cornell University animal science department professors Michael Van Amburgh and Karl Czymmek, published in 2017, showed that a herd of about 340 cows can produce the same amount of waste as 10,736 humans. 

That puts the amount of waste for a herd of 2,500 cows at about the same level as 79,000 humans, a smaller number, but one even further under the number cited in the state high court’s opinion.

In writing a recent decision for the state Supreme Court, Karofsky claimed a herd of 2,500 cows produces as much waste as a city of 411,000 people.

The statistic was part of a case that upheld the state DNR’s ability to consider the number of animals at factory farms and whether groundwater should be monitored offsite. 

That’s an awful lot of waste from a lot of cows. And a 17-year-old study included the figure.

But newer numbers suggest that while cows produce a lot of waste -- up to 17 gallons of it a day, per animal -- a farm of 2,500 cows isn’t producing the same amount of waste as 411,000 people. It’s more like 100,000 people.

We’re going to have to call bull on this claim. 

We rate this claim False.