County hears plan to investigate petroleum release at old road shop, estimates about $64,433

Brandon Kingsbury, an environmental consultant with Tetra Tech, told Madison County commissioners that historical excavations at the old road shop left contamination behind and that a new investigation is needed to assess remaining soil and groundwater impacts.

Kingsbury said the firm developed a work plan calling for seven soil borings, five completed as monitoring wells and one additional boring to host a soil vapor probe to evaluate potential vapor intrusion near the old shop building. "This release is still outstanding in that there's probably a groundwater plume that's still associated with this," he said.

The consultant said one monitoring well from prior work had become unusable and that the new scope responds to a March work-plan request from the state environmental regulator. Kingsbury estimated total professional and field costs at about $64,433 and said the county competitively bid drilling, with Olympus Technical Services the low bidder at $9,000.

County staff and Kingsbury discussed payment and reimbursement. Kingsbury said the site is eligible for the Montana Petroleum Tank Release Compensation Board; the county would execute the contract with Tetra Tech, complete the work and then submit claims for reimbursement, which could occur after final invoicing and may be processed in 2027. He noted the county has a five-year window to submit claims.

Commissioners did not vote on the work plan in the session. Staff said the budget impact must be determined before formal action. The county asked staff to clarify financing and scheduling so the project can proceed if the board decides to fund the immediate work.

The county will consider the next steps in a future meeting once more budget detail and reimbursement timing are confirmed.