More well monitoring needed
Clintonville still coping with contamination
By Bert Lehman
The Wisconsin DNR is requiring the city of Clintonville to conduct more well monitoring in an area where an underground fuel tank was discovered during the 2017 Main Street reconstruction project.
City Administrator Sharon Eveland updated the Finance Committee at its Aug. 12 meeting about the additional monitoring.
“We hired TRC to do some of the testing,” Eveland said. “We had to do a change order, we had some issues with getting what we needed out of the ground.”
When this information was sent to the Wisconsin DNR, the city of Clintonville was informed it needed to do more, Eveland said.
“It’s a little further spread out than we had thought,” Eveland said.
Extent of contamination
According to a June 3 email from Stephen Sellwood, PG, senior hydrogeologist for TRC, to the Wisconsin DNR, a 400-500-gallon tank, probably for gasoline, was discovered and removed from the Highway 22 right-of-way in 2017. At the same time, roughly 44 tons of petroleum-contaminated soil was “landfilled.”
Soil borings and soil samples that were collected defined the extent of the soil contamination.
“There are no direct contact exceedances in the upper four feet. Groundwater pathway exceedances in soil are limited to a small area in the vicinity of the tank,” Sellwood stated in the email.
He also said in the email that three monitoring wells were installed and have been sampled three times to assess groundwater quality and flow direction.
“The tank has not been active for many decades, so this is a very old petroleum release, meaning the plume is certainly stable,” Sellwood stated in the email. “In addition, the removal of the tank and approximately 44 tons of contaminated soil have decreased the source area mass.
Additional testing required
Eveland told the Finance Committee that TRC requested a change order to perform the additional testing required by the DNR. TRC would process all the paperwork and submit for closure in 2020.
She added that some funds for the testing have already been budgeted. All the funds needed to cover the cost of the additional testing is included the city’s Capital Improvement Plan (CIP).
“There’s not going to be any additional expenditures of funds this year,” Eveland said.
Committee member Jim Supanich asked Eveland about the probability that the DNR would close this issue next year.
“We had anticipated the DNR approving it this go around,” Eveland said.
She added that it is her understanding that if the additional testing yields the same results, the DNR should approve closing the matter.
“They just want to test further out than they originally had planned,” Eveland said. “As long as what comes out is not contaminated then we should be good to go to close.”
The committee recommended to Clintonville City Council that it approve change order No. 4 for additional site investigation by TRC for an additional cost of $11,721. The council approved the recommendation at its meeting the following night.