The Sherburne County Board Tuesday approved a request by the zoning department to continue to monitor residential wells near the closed Vonco Landfill on Co. Rd. 14 in Big Lake Twp.
Testing by the Minnesota Pollution Control Agency (MPCA) in 2007 indicated high amounts of perfluorochemicals (PFCs) in groundwater at county landfills in Big Lake and Elk River.
After the MPCA report, the county hired Leggette, Brashears & Graham, Inc., (LBG) to conduct tests at 43 wells located at or near the Elk River Landfill, 15 wells at or near the VONCO I Landfill and 12 wells at the VONCO II Landfill. Tests conducted at landfills in Big Lake and Elk River between Aug. 2 and Aug. 5, 2010 found PFCs at varying levels at the landfill sites but not in any residential wells.
In 2012 the county board approved a four-year sampling program at six residential wells down-gradient of the Vonco landfill in Big Lake Twp.
Environmental specialist David Katzner said the results of that sampling identified no detections or visual trends that would suggest any contamination of the residential wells from the landfill.
“But two of the monitoring wells at the landfill continue to show impacts to the groundwater,” he said.
Katzner said county staff and the consultant are recommending continuing annual monitoring of the wells at 18864,18910, 18954 and 18976 180th Ave. NW and monitoring wells at 19029 and 19040 181st Ave. NW every other year.
The data after each sampling period will be evaluated.
The cost of sampling for 2016 is estimated at $3,209.
Vonco License
The board also approved a modified Solid Waste Facility License for Vonco II in Becker for the operation of a construction and demolition (C&D) landfill, industrial waste landfill, source separation compost facility, demolition waste processing facility and municipal solid waste transfer station.
It also includes a waiver authorizing locating a proposed leachate tank less than 200 feet from the property boundary.
Commissioner John Ri ebel was concerned about possible contamination from the landfill if the setback was reduced.
“They’re 100 feet closer to the road. What security do we have if all of a sudden it springs a leak?” he asked.
Katzner said the containment was a dual wall - a sheet of metal and a concrete barrier.
Since the license approved a municipal solid waste (MSW) transfer station, Commissioner Felix Schmiesing asked whether the landfill would be accepting MSW in the future.
Vonco president Ian Vagle, who was present at the meeting, said that wasn’t in the plans.
“We have no intent to convert that landfill into a MSW landfill,” he said. “Our intent is to focus on conversion technologies like anaerobic digestion, composting and C&D recycling.”
He said the facility currently takes in roll-off loads of waste that have to be separated. Instead of dumping the load and picking out the waste that is acceptable, the transfer station will allow them to sort the material, then store the MSW in containers before sending it to another facility.
