Nirates seep into local private water wells
Nitrates seeping underground can be a problem when they reach the public water supply, as previously reported with the Verndale public works system. However, the risk of high nitrate levels in drinking water also exists in private wells far outside city limits, where the water isn’t tested regularly.
A 2011 test conducted jointly between the Minnesota Department of Agriculture (MDA) and the Wadena Soil and Water Conservation District (SWCD) found that more than eight percent of the 72 privately-owned wells sampled in Wadena County contained nitrate levels at 10 milligrams per liter or higher. That means they’ve reached the Minnesota Department of Health (MDH) drinking water standard. After that standard is exceeded, the risk of “blue baby syndrome”, which has been known to be fatal in some cases, becomes a concern.
The disease has that name because it primarily threatens infants younger than six months of age. Michael Convery, a hydrologist with MDH’s Well Management Section said that since babies have not yet developed enough helpful stomach acid that would ward off nitrate exposure, they are especially prone to the disease’s effects. After being exposed to high nitrate levels for an extended period of time, the victim’s hemoglobin may fail to deliver oxygen through the bloodstream, in a process similar to the effects of cyanide poisoning. The baby’s skin will turn blue as the symptoms set in.
Convery said the syndrome was rampant in the Midwest until the late 1940s, when doctors made the connection between the disease and nitrates in the drinking water. The last documented case in Minnesota was in 1980, where a one-month-old baby from Chippewa County had been drinking water from a well that was tested at 110 milligrams per liter.
Anne Oldakowski of Wadena’s SWCD said that wells in the bottom and top geographical thirds of the county are more likely to have a case of nitrate contamination because their aquifers, or natural underground chambers filled with water, are especially vulnerable to seepage. Sandy soil around the aquifers leaves them relatively unprotected compared to those that are surrounded by rock or clay, like in the middle band of the county.
“Anything that’s applied within that sand has a higher chance of actually concentrating and infesting the groundwater,” Oldakowski said. “The sands are sensitive.”
Oldakowski also said wells that are shallower, such as sand point wells, were more likely to be contaminated than deeper wells.
She said there were a number of possible sources for nitrate pollution, but since everything takes place underground, it’s difficult to pinpoint exactly where the contamination is coming from in any particular case.
“The road salt that they put on the highway to de-ice, that’s a contaminant,” Oldakowski said. “Fertilizer, any pesticides, septic systems… it could be yours, you don’t know until you test your water and find that it’s high, and then you need to start digging into ‘What are some potential causes around us?’”
Nitrates are also hidden by the fact that people can’t taste, see or smell them, according to the MDH website. Convery said the tasteless nature of nitrates means families may unknowingly drink contaminated water for decades if they don’t test their well.
“As long as the well is working right, and the water tastes fine, (people) often don’t think about testing the water quality,” he said. “It still amazes me to this day – and I’ve been doing this for 30-plus years – how many people have never tested their well.”
Oldakowski said those concerned they may have high nitrates in their well can bring water samples to the Wadena SWCD office for testing. Samples should be kept cold and measure about a cup. To take a sample, run cold water through the tap for about five minutes before collecting. For more information on sampling, contact SWCD at 218-631-3195, extension 4. For more information on the adverse health effects of nitrates, visit MDH’s website at www.health.state.mn.us and search “nitrates”.