Koochiching County moves to close Big Falls demolition landfill, cites potential MPCA rule costs

Koochiching County environmental staff told the Board of Commissioners on May 26 that closing the Big Falls demolition landfill now would likely save the county substantial future expense if the Minnesota Pollution Control Agency (MPCA) promulgates new demolition and construction debris rules.

The environmental services director (staff) said the proposed rules would require day‑one groundwater monitoring including PFAS sampling, final cover using geosynthetics or compacted clay, leachate collection, gas monitoring and long‑term post‑closure care. "The amount of waste and revenue we receive at that location doesn't justify that extra expense," the director said, noting current annual tonnage at the site is small and revenue from the site is limited.

Engineers provided a range of cost estimates for closing the site under the new regulatory expectations: an initial estimate of roughly $250,000 for basic closure work, with "you’re talking about a million maybe" if additional infrastructure or a new cell were necessary, the director said. Staff also noted the county lacks monitoring wells at the site and that MPCA notice requirements (including a 60‑day notice posted on site) must be met prior to closure.

The board approved moving forward with closure procedures and directed staff to prepare bid documents for closure work. Separately, the board approved a $10,000 change order to extend the existing Tetra Tech contract to include bid‑document preparation and additional engineering support for the Big Falls closure (vote 5–0).

Staff said the county plans to allow most of the 2026 season for contractors to remove material before an anticipated closure near the end of August and will work with contractors and the highway department to mitigate hauling costs. Next steps include preparing bid packages, posting required MPCA notices and soliciting bids for closure work.