Government center construction: contractor reports contaminated soil removed, two-week delay, ~$111,000 remediation cost

BENTON COUNTY — Contegrity Group project manager Jim Ollman updated the Benton County Board on construction progress at the government center site and on a recent soil-remediation effort.

"We're in the midst of all the footings and foundations," Ollman told the board, saying crews were roughly 25% through that phase when they encountered contaminated soil near the center of the site. Tests identified number 1 and number 2 fuel oil, and Ollman said the contamination likely stemmed from a buried tank that once fed boilers at the former Foley School on the property.

Contractors removed roughly 1,500 tons of contaminated material and shipped it to a facility in Becker. "We only spent about half of that $200,000 that we allocated," Ollman said, explaining the final remediation tally was about $111,000, including removal, testing and storage costs. Third-party testers monitored truckloads and lab testing, he said.

Ollman told commissioners the excavation and removal cost and work caused approximately two weeks of schedule delay (Aug. 25–Sept. 4), which he called manageable for a project of this scale. He also reported minimal asbestos findings — a single sample associated with a pipe section that was removed and handled to MPCA standards.

Commissioners pressed whether earlier MPCA "clean bill of health" letters or prior soil borings should have detected the contamination. Ollman said he reviewed 2023 soil-boring reports and that the contamination likely fell between prior test locations: "They just missed it." County staff reminded the board that additional Phase I/II testing had been done before purchase.

Ollman said construction returned to footings and foundations work and that the contractor expected to resume steady progress if weather cooperated.

The board received the update; no formal action was required beyond acceptance of the report.