The Wall Street Journal shines a light on increasing problem of agriculture's pollution of wells and public water systems

Wall Street Journal chart, from USDA and USGS data

"Farms, More Productive Than Ever, Are Poisoning Drinking Water in Rural America." That's the headline on a big story in The Wall Street Journal, with this subhead: "One in seven Americans drink from private wells, which are being polluted by contaminants from manure and fertilizer."

Both produce nitrates, which rose significantly in 21 percent of the regions where the U.S. Geological Survey "tested groundwater from 2002 through 2012, compared with the 13 prior years," Jesse Newman and Patrick McGroarty report. "The greatest increases were in agricultural areas. More recent sampling shows the pattern is continuing, at a potentially greater rate."

The reporters add, "More than 16 percent of groundwater from wells sampled between 2002 and 2012 topped the federal nitrate limit of 10 parts per million, versus 12 percent in the 1990s. The percentage above the limit fell slightly in the wells sampled after 2013 but remained elevated."

The story comes on the heels of a Minneapolis StarTribune package exploring agriculture-related water-quality issues in the Upper Midwest. “The worst-kept secret is how vulnerable private wells are to agricultural runoff,” David Cwiertny, director of the University of Iowa’s Center for Health Effects of Environmental Contamination, told the Journal.

The story also notes the problems for public water systems, which draw from streams and wells. "Runoff from fields is largely exempt from federal regulation," the reporters note. "Many water utilities in the Midwest are struggling to pay for flushing farm runoff from their systems, say scientists and utility managers."

The writers summarize, "Among factors producing contaminants: fewer, more-intensively worked farms, bigger cows and shifting crop mixes. Those factors have helped drive abundance in the U.S. farm economy. Corn and soybean harvests have hit records, as have pork, poultry and dairy production. Farmers and their supporters say America needs to balance environmental concerns with food security."