The Minnesota Pollution Control Agency continues to investigate contaminated soil that may be polluting Luverne's drinking water.
St. Paul geologists with the environmental firm, DPRA, are in town this week boring several holes in and around the Jubilee Foods parking lot.
The work is underway to uncover three of four existing monitoring wells which had been paved over when the new store went up this summer.
Also, several additional monitoring wells were drilled on and around the Jubilee lot to find the outer edges of the contamination "plume," according to geologist Donovan Hannu.
"We just need to determine whether or not it is moving in the direction of the city drinking water," Hannu said.
He said the additional periphery wells are part of the MPCA standard guidelines for investigating contaminated sites. They will be tested periodically to measure movement of the spill, if any.
DPRA geologist Brandon Flaada, who was taking samples in Luverne Tuesday, said the soil under the parking lot was heavily contaminated, but he said a sample taken that day east of the parking appeared to be clean. It will be lab tested for the presence of trichlorethylene (TCE) and other chemicals.
The Luverne Economic Development Authority, as a one-time owner of the property, is participating in a "voluntary investigation and cleanup" program with the MPCA, in addition to Jubilee Foods and former property owners.
Contaminated soil under the pavement was identified over a year ago as a likely source of TCE and petroleum-related chemicals found in four of Luverne's 16 municipal wells.
Only trace levels of the pollutants turned up in the water and levels were well below safe drinking standards. But TCE has been linked to cancer in humans exposed to the chemical over a period of 30 years.
Also, TCE is considered a "volatile organic compound" which tends to travel easily through soil to water.
"There is a potential risk here, and weÕre evaluating the level of that risk," said MPCA hydrogeologist David Scheer. "Your wells in that town are very shallow, and when thereÕs a contaminant in the ground water, we take it seriously."
The MPCA tested several properties in Luverne last year to find the source, and the former A.R. Wood property (what is now the Jubilee lot) was found to be contaminated with TCE.
TCE is used for degreasing metal, which is consistent with some of the activities reportedly having occurred on the property.
According to Scheer, the site is still under investigation to determine how serious the contamination is and if it's moving toward city wells.
It's too early to say what kind of cleanup measures, if any, will need to be taken.
The existing monitoring wells were in place when ground work was underway on the Jubilee lot. Because the well caps weren't at the proper elevation at the time the lot was paved, they were paved over, with the understanding that they would later need to be uncovered.
The one exposed monitoring well, located toward the northeast corner of the lot, is surrounded by a square concrete slab that slopes upward slightly in the center. The other wells will be finished similarly.
DPRS was hired by the responsible property owners as part of the VIC program.
If cleanup is necessary, it is unclear who would be responsible for the costs and what those costs would amount to.