RUSHMORE -- Water samples were collected from a privately-owned gravel pit Thursday to determine how much contamination exists following a manure spill discovered Wednesday morning in Little Rock Township.
"The spill is contained," said Nobles County Environmental Services Director Wayne Smith, who had been out at the site by 6:30 a.m. Thursday to check on things after a night of rainfall.
"We put up a clean water diversion to prevent any water from coming into contact with the manure, and they put a berm on the downhill side," he said. "We were fortunate we had got there before very much (manure) went into the water."
Smith said the farmers involved are "embarrassed this happened," and have been cooperating with the cleanup and investigation.
"They've done everything we've asked them to do, to berm it up and pick up the (manure) that slid down the hill," Smith said. "They've taken the steps they've needed to."
The water samples, which were taken at the request of the Minnesota Pollution Control Agency, will be sent away for analysis, and Smith didn't know how long it would take before that information would be available.
Nobles County Attorney Kathleen Kusz said the investigation into the stockpiled manure and subsequent runoff continues, and potential prosecution has not yet been determined.
Minnesota regulations regarding manure stockpiles are adhered to by Nobles County, and Smith said the county has additional, stricter regulations in some areas of the law.
Law specifically states that manure cannot be stockpiled in rock quarries or gravel pits, and while this particular pile of cattle manure wasn't within the confines of the gravel pit, it was only six feet from it, Smith said.
Manure stockpiles are required to be set back at least 300 feet from a road or open water body.
"Fortunately, this was caught before a lot got in the water," Kusz said, adding that the results of the water samples taken Thursday will determine how the contamination in the gravel pit is cleaned up. "The higher the dilution and the farther (the spill) is from the aquifer, the better things will be."
Department of Natural Resources Area Hydrologist Tom Kresko, after getting updates on the situation Thursday morning, said the manure spill was contained to the gravel pit and has not overflowed to any of the other waterways. The Little Rock River flows through Section 25 of Little Rock Township, and Kresko said there is a "hydraulic connection" -- water connecting the gravel pit and the stream.
"As long as they are mitigating and trying to contain (the spill), it doesn't appear it will overflow," Kresko said. "The sand between the gravel pit and the creek will do a good job of keeping the solids from entering the creek."
The concern is that if any manure would contaminate the Little Rock River, it would impact not just the federally-endangered Topeka Shiner minnow, but 10 to 15 other species of minnows and fish in the river.
"We'll keep an eye on that to see if there is any mortality," Kresko said. "The Topeka Shiner (presence) is something that may result in a long-term analysis."
As for the public health impact, Kresko said he did not see any drinking water risk as a result of the manure spill -- thanks in large part to the early discovery of the runoff.
The last manure spills in Nobles County date back about 15 years, Smith said, adding that one was in Section 7 of Little Rock Township, and the other was in Section 31 of Larkin Township.
Daily Globe Reporter Julie Buntjer may be reached at 376-7330.