Rising nitrate level in Verndale water draws scrutiny
Rising nitrate levels from water samples taken at a well in the Verndale city park have given officials there cause for concern.
Although the nitrates are still within state safety thresholds, the trend of levels going higher over the years has reached the point where the city feels corrective action is needed. The latest tests, conducted in February, showed the nitrate level at 8.6 milligrams per liter, with the Minnesota Department of Health’s legal limit at 10.4 milligrams per liter, said Matt Uselman, Verndale public works manager. In the last year, nitrates went up 1.4 milligrams per liter, he said.
“They’ve gone up gradually over the years, and now they’re getting up to where we’re going to have to do something about it,” Uselman said. “There’s still time now, but we’re going to have to do something about it...”
Possible sources for the nitrate buildup include manure from farms near the city, leaking septic systems and fertilizer use on lawns within the city, Uselman said. For years, the city has implemented a Wellhead Protection Plan in order to protect against nitrates seeping into the natural aquifer from which it draws water. However, the plan is focused on raising awareness of nitrate contamination rather than directly stopping actions that may lead to higher nitrate levels in the aquifer, Uselman said.
“We can’t prevent anybody from causing nitrates, we can only help educate people…” he said.
Aaron Meyer, a sourcewater protection specialist with the Minnesota Rural Water Association, helped create the Wellhead Protection Plan for Verndale. He agreed that it was more about education than enforcement.
“There are mechanisms to do enforcement, but we’ve never done that in Minnesota,” he said.
Uselman didn’t know of any specific anti-pollution ordinances guarding against nitrates. However, even if there were such an ordinance, Uselman said, it would be ineffective outside city limits where pollutants can still reach the aquifer.
Meyer said the health issues caused by high nitrates primarily affect infants six months old and younger. Babies exposed to excessive nitrates may begin to suffer from “blue baby syndrome”, where nitrates contaminating the blood compete with naturally occurring hemoglobin, thereby causing suffocation and death in extreme cases.
“It basically prevents oxygen from being carried in the bloodstream in infants,” he said.
Meyer, Uselman and Verndale Mayor Raye Ludovissie all agreed that the city’s upcoming sewer replacement project would go a long way toward alleviating the nitrate problem. Ludovissie said the project, slated to begin in 2014, would help eliminate the possibility of nitrates leaking from the city’s own sewer pipes.
“I’m confident that that would help out a lot,” Ludovissie said.