Protecting well water

Keeping Rock County’s private well water safe to drink will be the focus next year under the state’s Targeted Township Nitrogen Testing Program.
Private well owners in seven Rock County townships can voluntarily have their wells analyzed for nitrate levels in a joint effort by the Minnesota Department of Agriculture (MDA) and the Rock County Land Management Office (LMO) in Luverne.
Townships involved in the program are Clinton, Luverne, Magnolia, Mound, Vienna, Rose Dell and Battle Plain.
“We (LMO) will help them in knowing where the private wells are at,” said Doug Bos, LMO’s assistant director and water plan coordinator. “It is strictly voluntary.”
Selection of the seven townships was based on land use and topography. Each township had greater than 30 percent of its land area with vulnerable geology and 20 percent of the land is used in row crop production.
The testing will be for nitrate-nitrogen (or nitrate) levels in well water. Potentially, 300 to 500 wells could be tested, Bos estimated.
Nitrate is a water-soluble compound made up of nitrogen and oxygen, according to the MDA. Nitrate occurs naturally in groundwater at levels typically in the range of 0 to 3 parts per million (ppm). Human activities such as sewage disposal, livestock production and crop fertilization can elevate the level of nitrate in groundwater.
The state’s drinking water standard for nitrate is 10 ppm. Above this level nitrate can have negative effects on human health, specifically infants younger than 6 months.
State officials have discovered that contamination above the drinking water standard more often occurs in sand, gravel or fractured rock aquifers.
Combined with heavy row crop agriculture, these aquifers are especially at risk.
“Our aquifers are fairly shallow,” Bos said. “We are talking wells that are 30 to 40 feet deep. We don’t have a lot of soil over the top of it.”
Beginning next year, homeowners in the identified townships will receive a water sampling kit in the mail. The homeowner collects a water sample and places the sample in a prepaid mailer to a certified lab. Results from individual wells are sent directly to the homeowner along with a letter explaining the results.
Program participants’ identities remain confidential.
The MDA will examine all the test results and prepare a final report for the county.
 
Targeted nitrogen testing is part of state’s plan
MDA officials are currently updating the department’s 1990 Nitrogen Fertilizer Management Plan. The plan is a blueprint for preventing and minimizing the impacts of nitrogen fertilizer on groundwater.
The Rock County LMO piloted a nitrogen management program in 2014 targeting producers who farm over highly vulnerable wellheads in the county.
The program encourages farmers to better manage their nitrogen application in those fields around the wellheads.
Last year five farmers (encompassing 510 acres of the possible 1,400 acres) changed how they applied nitrogen to the soil.
Nitrogen is a nutrient most often deficient in the state’s crop production and its use can result in substantial economic return for farmers, according to the Minnesota Extension Service.
When nitrogen inputs exceed crop needs, there is a possibility the excessive nitrate amounts may enter either ground or surface water.
Locally, a nitrogen management program pays farmers $20 per acre to try different nitrogen application practices. These practices include the use of side-dress applications, slow-release nitrogen products and/or cover crops to absorb the excess nitrogen.
The nitrogen management program continues to be a voluntary option for area farmers in 2016.