This report is part of a project on drinking water contamination in the United States produced by the Carnegie-Knight News21 program.
CASCO, Wis. – Lynda Cochart did not realize her water was contaminated with coliform bacteria until she contracted MRSA, an antibiotic-resistant skin infection. She believed it came from the water in her well in Casco, Wisconsin. “There’s no other way I could have gotten it,” she said.
A year later, U.S. Department of Agriculture microbiologist Mark Borchardt tested her well while testing others in Kewaunee County. He found total coliform bacteria at levels too dangerous to drink. Cochart lives between two dairy farms with over 1,000 cows each. None of the bacteria Borchardt found came from human feces, she said, so the methicillin-resistant Staphylococcus aureus most likely came from cow manure. Borchardt told her to immediately stop drinking the water.
“He said, ‘What I found in your well is what I expect to find in a Third World country,’” Cochart recalled. When she told him she still needed to shower with that water, Borchardt advised, “Then keep your eyes closed and your mouth shut.”
In California’s San Joaquin Valley, which grows nearly one-quarter of the nation’s food, fertilizer and manure spread on farms’ fields and orchards have contributed to unsafe nitrate levels in drinking water sources. The News21 analysis of Environmental Protection Agency records of community water systems shows 491 instances of unsafe nitrate amounts in many of the region’s 663 community water systems over the past 10 years.
Many farmworkers who live in these communities still have to pay for the contaminated water coming from the faucet, as well as buying bottled water to drink. But the farmers who employ them don’t agree with their concerns.
“They say, ‘Why are you complaining? You have jobs? We are giving you jobs. You eat because of us,’ ” said Irma Medellin, who works with Latino farmworkers in Tulare County to clean up the drinking water. “They contaminate our water, and we, the poor, are paying for water as if we were rich. And we are not rich. But we are paying the price of contaminated water.”
The News21 analysis shows that the drinking water of millions of Americans living in or near farming communities across the country is contaminated by dangerous amounts of nitrates and coliform bacteria from fertilizer and manure widely used in agriculture. Community water systems serving over 2 million people across the country were cited for excessive nitrate levels.
While the 5,050 nitrate violations can largely be traced back to agricultural activity, the 22,971 total coliform violations could be from either human or animal feces. However, in heavily farmed areas, much of the coliform bacteria can be attributed to manure.
Those records don’t cover the millions of private wells that many Americans use, which are left vulnerable to pollution of shallow groundwater in agricultural areas.
A 2012 University of California, Davis, study attributed high nitrate levels in the San Joaquin Valley groundwater to crop and animal agriculture activities based on an analysis of land use and the amount of nitrogen entering the water. Farmers’ heavy use of fertilizers and manure on their crops account for most of the nitrate found in the studied area.
An Iowa Geological Survey researcher found in 2004 that row crops, such as corn, cotton and soybeans, contributed the most to high nitrate levels in Iowa’s rivers. In 2007, U.S. Geological Survey researchers found that Iowa was one of nine Midwestern farming states that contributed over 75 percent of the nitrates that flow from the Mississippi River into the Gulf of Mexico. And a 2010 study by researchers from the University of Illinois and Cornell University found that the biggest contributors of excessive nitrate to the Mississippi River were in the Midwestern corn belt.