Nitrate Pollution: Are Farmers At Fault?

State officials in Idaho stepped out recently to defend farmers from claims that they are a significant source of nitrate pollution in groundwater.

"While some are quick to blame agriculture, it’s not the only source of nitrates in groundwater, said Irene Nautch, Idaho State Department of Environmental Quality drinking water protection coordinator in Twin Falls," MagicValley.com reported.

“We don’t get very far by pointing fingers,” Nautch said, per the report.

One thing isn't in dispute: Idaho has a nitrate problem.

"A recently released DEQ report shows 16 percent — or 691 — of water samples taken from 4,244 wells across Idaho exceed the 10.0 ppm threshold for federal health standards," the report said.

Farmers are not the only cause, officials said.

"Cow manure, produced in hundreds of dairies and feedlots in Idaho and spread on nearby fields, is often blamed for high nitrate levels. But manure is not the cause of nitrate in groundwater, said Marv Patten, dairy bureau chief for the state Department of Agriculture," the report said.

What else might be to blame?

"Much remains to be learned about the complex route nitrogen follows in and out of the soil system. Biological processes and climatic conditions along with the physical and chemical properties of a soil influence the route that ends with harmful nitrates in groundwater," the report said.

Idaho relies heavily on groundwater. According to the Idaho Department of Environmental Quality, "Groundwater supplies 95 percent of the water used in Idaho households and provides drinking water to more than 200 Idaho cities and towns. Although the quality of ground water in Idaho is generally good, ground water quality monitoring shows that in specific areas of the state, Idaho's ground water has been significantly degraded."

How are nitrates removed from drinking water? According to the EPA, "The following treatment methods have proven to be effective for removing nitrate to below 10 mg/L or 10 ppm: ion exchange, reverse osmosis, electrodialysis."

Check out Water Online's Nutrient Removal Solution Center.