Benton County commissioners reverse approval, deny Coffin Butte landfill expansion after DEQ enforcement notice

Benton County’s Board of Commissioners on March 3, 2026 voted to reverse its Nov. 17, 2025 decision and deny a conditional use permit to expand the Coffin Butte landfill, concluding the applicant did not meet its burden of proof in the record.

The board adopted the 02/24/2026 staff report and the board’s findings and conclusions as its final decision. Chair Malone said the written findings were adopted on the date of the vote and the decision may be appealed to the Land Use Board of Appeals.

The staff report, presented by contract planner Jesse Winter of Winterbrook Planning, said a Department of Environmental Quality pre-enforcement notice (PEN) issued after the November hearings documented seven Class 1 violations related to monitoring, gas control and site operations. County-contracted reviewers at MFA found that key assumptions in the applicant’s odor model—most importantly that surface gas emissions were evenly distributed across the site—were not supported by the evidence and that significant portions of the landfill had not been surveyed. “We concluded the odor analysis and evidence provided by the applicant do not sufficiently demonstrate that the proposal will not seriously interfere with uses on adjacent properties, the character of the area, or the purpose of the forest conservation zone,” Winter said.

Commissioner Shepherd, who moved to adopt an order reversing the board’s prior approval and deny the permit, said staff’s analysis and the PEN undermine confidence in the applicant’s odor study and that resident testimony about repeated odor impacts also weighed heavily. “None of the new information in the record alleviated my concerns from the original application regarding impacts on adjacent properties,” Shepherd said.

Commissioner Wise said she gave greater weight to the DEQ letter and the county’s experts than to the applicant’s evidence, noting the PEN raised “serious and legitimate questions about the methodology and assumptions in Republic’s odor study.” Wise emphasized that her decision was based on the record and applicable criteria, not on personal feelings about participants in the proceeding.

The motion was seconded and carried; the chair declared the findings of fact and conclusions of law adopted and the hearing adjourned. The board noted that the written decision, adopted March 3, 2026, is final when the findings are entered and may be appealed to LUBA.

The board’s action overturns the prior approval for LU-24-027 and will halt the proposed expansion unless reversed on appeal.