Worrisome levels of nitrate in drinking water for 7 million Americans

Seven million Americans who live in small cities and towns have worrisome levels of nitrates in their drinking water — below the federal limit of 10 milligrams per liter, but high enough to be associated with cancer in some studies, said an Environmental Working Group official. Craig Cox, head of EWG’s Midwest office, said 1,683 communities had nitrate levels above 5 milligrams per liter and, when plotted on a map, they “crazily lined up with intensive agriculture.”

Farm use of nitrogen fertilizer is regarded as a frequent source of nitrates in groundwater. Soils also shed nitrates naturally. Urban runoff and septic systems also are sources.

“Nitrates are the tip of the iceberg” for agricultural runoff that affects drinking water, said Cox during a panel discussion at the Society of Environmental Journalists meeting in Pittsburgh. “The voluntary (USDA stewardship) programs have proven inadequate to get on top of the water quality problems … We really think it is time for some mandatory measures.”

At present, farmers are required to practice soil and water stewardship to qualify for crop subsidies and premium subsidies for crop insurance. A coalition of two dozen farm, wildlife, environmental and conservation groups, including EWG, has called for the 2018 farm bill to broaden the so-called conservation compliance rule and for larger funding of USDA’s soil, water and wildlife programs.

“How do we feel about mandatory versus voluntary? Farmers know that voluntary programs work,” said Bev Paul of the American Soybean Association, a farm group. From the beginning, participation in USDA conservation programs has been voluntary. It’s a matter of human nature, said Paul, for people to be more enthusiastic about a project of their choice rather than being ordered to participate.

Some 24 million acres are enrolled in the long-term Conservation Reserve and 80 million acres are enrolled in the Conservation Stewardship Program, which defrays the cost for operators to adopt “practices” to improve soil health, reduce runoff or control erosion.

Lawmakers have been wary, too, of pressing action on private land when it is difficult to show the impact of individual action. Agriculture is generally exempt from clean water laws because it is not a “point source,” such as a smokestack or a sewer outlet. Two years ago, the Des Moines Water Works, in Iowa, unsuccessfully sued drainage districts in three farm counties in hopes of making them pay for the cost of removing nitrates from drinking water.

Ferd Hoefner of the National Sustainable Agriculture Coalition said Congress should direct USDA to check more often whether farmers are curbing erosion and nutrient runoff. Indiana, Iowa and Nebraska are the most active states in checking conservation compliance while other states barely stir on enforcement, he said. The 2018 farm bill ought to require all states to check 5 percent of farms each year, said Hoefner.

The EWG recently released an analysis of water quality data, including the presence of nitrates. Cox said the 1,683 communities with nitrate levels from 5-10 milligrams per liter showed up most often in states such as California, Kansas and Texas, where agriculture is a major industry.