Clover Valley soil cleanup underway
More than 471 tons of soil has been excavated from the site of the former Clover Valley General Store the past week in what the Minnesota Pollution Control Agency is calling one of it's "more extensive" clean-ups of old petroleum storage tank sites.
Project manager Laura Hysjulien said the MPCA was made aware of contamination of groundwater at the store site in 2000. It took 10 years to navigate through ownership of the old store site and then a determination that the state would need to pay for and execute the clean-up.
The site is at the intersection of Knife River and Home-stead roads in Duluth Township.
"That's a lot of soil," Hysjulien said of the project going on this spring. The MPCA can usually let soil repair itself from gasoline and diesel leaks but the four tanks at the store "saturated" the soil. The MPCA determined that excavation was necessary because of bedrock in the area along with sensitive water areas like wetlands. "There were places for (the contamination) to go," she said.
Hysjulien said fuel got into the groundwater at the site but monitoring over the years has shown no signs of the fuel reaching private wells, wetlands, or streams in the area. The MPCA is installing two water table monitors at the site once the cleanup is finished. Hysjulien said she expects her agency to "close out" the site in a year, meaning it will show no more risk to the environment.
The Clover Valley General Store had four tanks. Gas was held in two 1,000-gallon tanks and one 500-gallon tank. Diesel was held in one 500-gallon tank.
Ownership changes and hardships for those owners meant the state had to take over the cleanup, Hysjulien said. The state can often apply costs to owners but the agency first concentrates on the environmental impact, she said. It was decided to ahead with the project without owner cooperation.
The total cost of the clean-up will be about $225,000, Hysjulien said. It includes the complete investigation, which included drilling numerous holes and testing the soil and groundwater around the site.
"We have tested private drinking wells and done tests to see if vapors have entered homes," Hysjulien said.
The costs include the removal, transport, and disposing of the soil. The excavation crew is also driving water away from the dig site and that water has to go through a water treatment system before discharge, Hysjulien said.
"I know people are happy to see this addressed," Hys-julien said.