Benton County staff recommends denial of Coffin Butte landfill expansion after finding gaps in noise, odor and site plans

Benton County Planning Commission members heard the staff presentation and extensive commissioner questions April 29, 2025, on LU-24-027, an application by Republic Services (property owner Valley Landfills) to expand the Coffin Butte Landfill and to add employee and maintenance buildings, revised access roads, relocated leachate infrastructure, an outbound scale and other improvements.

The staff report recommended denial. Planning Director Petra Sheets told the commission that, based on the applicant’s materials and third‑party consultant reviews, "the noise and odor analysis and evidence provided by the applicant does not sufficiently demonstrate that the proposal will not seriously interfere with uses on adjacent properties or the character of the area. Therefore, staff recommends denial of this application." The commission recessed the hearing and scheduled additional sessions to allow more evidence and updated staff materials.

The project area described in the application includes multiple tax lots totaling several hundred acres of landfill property and adjacent lands. Staff and the applicant described the sizes of key tax lots in the application: tax lot 801 (~89 acres), tax lot 1101 (~4 acres), tax lot 1107 (~59 acres), tax lot 1108 (~29 acres) and tax lot 1200 (~82 acres). The proposal would add an approximately 1,800‑square‑foot employee building, a new maintenance/shop area and modifications to access roads and leachate handling; the application notes an elevation change of roughly 60 to 160 feet across the site. The applicant reported an extensive pre‑application review that began in mid‑2024 and a completed application submitted Jan. 15, 2025.

Why it matters: commissioners and staff said the expansion would extend the landfill’s operational life and raise recurring issues — noise, odor, groundwater/leachate, PFAS and traffic — that affect neighboring residents, Adair Village and other downstream users. Staff noted they had received roughly 185–190 public submissions by April 29 (roughly 3,000 pages in total) with the vast majority…