How America’s Dairyland Is Polluted by Factory Farms


The slogan on Wisconsin’s license plate—“America’s Dairyland”—celebrates the state’s number one agricultural activity and iconic status as a milk and cheese producer. What it doesn’t reveal is how dramatically the dairy industry in Wisconsin and in other parts of the U.S. has been changing, or the environmental concerns those changes pose. 

While milk carton imagery pictures bucolic, small farms, more than 50 percent of U.S. milk is now produced by just three percent of the country’s dairies—those with more than 1,000 cows, according to the U.S. Department of Agriculture (USDA). The very largest U.S. dairies now have 15,000 or more cows. 

More than half of U.S. milk is produced by three percent of dairies.

Photo courtesy of Shutterstock

With this increased concentration of milking cows comes a corresponding concentration of manure production. And what happens to this manure is at the heart of the pollution issues surrounding the dairy industry. 

In Wisconsin, several dairy operations are now facing opposition to plans to expand their herds. Porous karst soils in the parts of Wisconsin where a significant portion of dairy expansion is occurring present some unique environmental issues. Run-off from dairy farms and other agricultural activities has seeped into aquifers and elevated levels of nitrogen, in some instances to unsafe concentrations; in one recent case, the Wisconsin Department of Justice levied a $65,000 fine against a dairy operation for contaminating groundwater. 

Neighbors of Kinnard Farms dairy, located in the Kewaunee County town of Lincoln—an area of karst soils—are now in court challenging the state’s approval of a permit that would allow the dairy to expand its herd from 4,000 to more than 6,000 milking cows. About 50 percent of the town’s private wells currently have water that exceeds bacteria or nitrate safety standards. Residents opposing the State Department of Natural Resources (DNR) permit contend that it lacks sufficient information about how the dairy will manage the tens of millions of gallons of liquid manure its cows will produce. 

U.S. farm consolidation is nothing new, but recent changes in the dairy industry are transforming the business in ways that are increasingly worrisome to regulators, residents and environmental groups. Wisconsin embodies this consolidation trend. DNR figures show the number of Wisconsin dairy farms with more than 500 cows grew by about 150 percent in the past decade. At the same time, the overall number of dairy farms dropped by about one-third, just as they have nationwide. The number of U.S. dairy operations with 2,000 or more cows has grown faster than those of any other size as milk production has increased about 20 percent. 

According to the U.S. Environmental Protection Agency (EPA) a 2,000-cow dairy generates more than 240,000 pounds of manure daily or nearly 90 million pounds a year. The USDA estimates that the manure from 200 milking cows produces as much nitrogen as sewage from a community of 5,000 to 10,000 people. 

This year and last, Wisconsin has fined several dairy operations for manure spills and manure runoff. According to an analysis by the Milwaukie Journal Sentinel, in 2013 a record number of manure spills—more than 1 million gallons worth—were recorded in Wisconsin. The newspaper reported that from 2007 to 2013, the state experienced an average of 15 manure spills annually from dairy farms. Roughly one-third of those spills came from large Concentrated Animal Feeding Operations (CAFO). 

“Wisconsin,” says Clean Wisconsin staff attorney Elizabeth Wheeler, “has a nitrate problem.” 

Wisconsin is hardly alone in grappling with this problem. Similar pollution issues—primarily from spills related to manure storage—have been cropping up across the country. Some recent cases include: 

  • In February, in Michigan’s Allegan County, a stormwater system failure at a dairy with a 1-million-gallon manure lagoon spilled manure into nearby waterways, creating a visible plume five miles long. 
  • In Yakima, WA, the Community Association for Restoration of the Environment and the Center for Food Safety allege in an ongoing lawsuit now in federal court that manure spreading by five large dairies has caused nitrate and other contamination of groundwater and violates the federal Resource Conservation and Recovery Act (RCRA). The plaintiffs contend that the way the manure is being applied is the equivalent of dumping solid waste, an activity covered by RCRA that has not previously been applied to manure spreading. The dairies filed a motion this month to dismiss the charges.
  •  In Canton, MN, a wall on an above-ground manure storage tank broke last April, spilling roughly 1 million gallons of manure.

In one of the larger cases of manure pollution in recent years, an estimated 15 million gallons of manure, water, and other matter spilled in 2010 into a slough that drains into the Snohomish River in Washington state, when a berm on a dairy farm’s manure lagoon failed. 

Erin Fitzgerald, senior vice president for sustainability at the Innovation Center for U.S. Dairy, a trade group, says a dairy’s size does not determine how well its environmental impacts are managed. William Matthews, Oregon Department of Agriculture CAFO program manager, concurs. “There are stellar operators of all sizes,” he says. 

Fitzgerald’s organization stresses the need for nutrient and water quality management plans tailored for each operation, and says dairy is “one of the most regulated and inspected industries in agriculture.” She also touts the industry’s voluntary commitment to “best practices” and improving its environmental footprint, including its 2008 commitment to reduce greenhouse gas emissions 25 percent. 

Milking cows, explains the EPA, produce more manure than beef cattle and the Holsteins that dominate the U.S. dairy industry produce almost twice as much manure as Jerseys. Cows that give more milk per cow also produce more manure and per-cow milk production has almost doubled since the 1970s. 

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