Mono County approves $5.8 million bid authorization to complete Benton Crossing landfill final cover

The Mono County Board of Supervisors unanimously approved actions to authorize bidding and contract steps for the Benton Crossing Landfill final-cover project, a measure county staff said will reduce environmental liability and bring the site into compliance with methane and groundwater monitoring requirements.

Public Works staff described the project as the next phase after an intermediate cover and said the scope includes a dual-layer liner system, 21 inches of soil cover, methane venting and a wood-chip surface layer. The project manager told supervisors that completing the final cover now avoids higher costs tied to potential future tariffs on liner materials and limits future liabilities; staff estimated the county’s liability would be reduced by roughly $7.5 million upon completion.

The item included five recommended actions and a fiscal-impact figure cited in the staff report. County staff said the procurement and site-preparation work is already under way and that the period to complete final cover and associated infrastructure will be simpler if the county can avoid demobilization and site re-clearing costs.

County officials also explained operational details: the liner system contains a primary barrier to stop water infiltration and a secondary layer to transport water horizontally to collection points; methane venting and monitoring equipment will be installed as part of final work. Public Works noted that wood chips to finish the surface can be moved from county stockpiles at other sites to reduce additional expense.

A motion to approve the five recommended actions passed unanimously. Supervisors and staff thanked project managers and county engineers for pushing the project forward and called out project staff for extended hours to prepare necessary materials.

No member of the public registered comment during the board vote; staff said the county will move ahead with bid advertising and contract award steps consistent with the board’s authorization.