The Yolo County Planning Commission on Tuesday heard staff and applicant presentations and public comment on CEMEX’s proposed amendment to its Cache Creek mining and reclamation permits but did not take final action after staff said the item was not properly noticed as a public hearing.

The commission received a detailed staff report from contract planner Heidi Chudin and a presentation from CEMEX representatives explaining a request to extend the existing permits through 2047, increase the total excavation tonnage and modify reclamation plans. Chudin and the applicant emphasized that the meeting was a public information and public-comment session only; the commission was asked to refrain from making a decision and the matter is scheduled for a properly noticed public hearing on Nov. 13.

Why it matters: The operation at issue is one of Yolo County’s long-standing aggregate producers and the amendment would change the timetable and footprint for mining and reclamation on roughly a 1,900-acre site near Madison. The proposal affects local land use, habitat restoration plans, trail and road easements intended as “net gains” for the county parkway and raises continuing concerns about methylmercury in off-channel pits that have drawn repeated public comment and scientific study.

Most of the meeting focused on technical changes CEMEX seeks and on mercury monitoring. Staff said the application would: extend the permit 20 years (through 2047); raise the total excavable tonnage by about 21.4 million tons to match the longer term; change the county’s assumed maximum simultaneously disturbed acreage from 126 acres to a dynamic range of roughly 167–285 acres to reflect concurrent mining and reclamation; shift processing and settling-pond areas on site; eliminate Phase 7 (no footprint west of I‑505); and amend the development agreement to add or refine net-gain dedications, including a roughly 12‑acre Millsap connector property and a Creekside Trail easement.

Staff said the proposed changes would be incorporated in an updated engineering and reclamation plan and subject to revised conditions and mitigation measures in a Subsequent Environmental Impact Report (SEIR). Chudin told the commission staff recommends certification of the SEIR and that the county would ask the Board of Supervisors to certify CEQA findings, adopt the mitigation monitoring and reporting program, approve the permit and reclamation amendments, and authorize an amended development agreement after the November public hearing.

CEMEX representatives (Robert Cutter and consultant Yasha Sabre) described operational details and why the company seeks the changes. They said the site continues concurrent reclamation and that updated geologic modeling and experience with an electric dredge informed a more efficient mining configuration that reduces the need to expand into new land. They said Phase 3 will be used as the primary settling pond for process fines and that the company intends to continue returning land to agriculture where soil resources allow. CEMEX also said it would participate in and fund a county-led, programmatic Lake Management Plan to study and pilot measures to address methylmercury in off‑channel pits.

Public comment and scientific concerns: Three public speakers and written commenters focused on mercury, reclamation outcomes and the long timeline for returning mined land to habitat or agriculture. Scientists and county staff were repeatedly cited: pits that become permanently wet must receive five consecutive years of monitoring for methylmercury in fish tissue and the water column; three exceedances of the ambient standard in a five-year set triggers expanded analysis that informs a lake management plan and possible remediation. CEMEX said it has been monitoring since 2015 at several pits, that the maximum authorized mining depth remains unchanged (75 feet maximum excavation; about 60 feet maximum pool), and that the firm will be responsible for implementing remedies if monitoring shows persistent methylmercury problems.

Next steps and limits on county action: Because the notice in a local paper did not comply with the Government Code’s timing requirement, staff advised the commission that it must treat the session as a public meeting, not a decision hearing. Staff said all presentations and comments would be part of the administrative record and the matter will be re‑noticed and heard as a public hearing on Nov. 13; at that hearing the commission may forward a recommendation to the Board of Supervisors. No motions or votes on the amendment were taken at this meeting.

Commissioners asked for additional data and clarification on monitoring schedules, recent mercury sampling results and the proposed schedule for reclamation phases. Staff and the applicant said they expect the 2023–24 mercury study material to be released before the November hearing, and CEMEX said it will continue to work with county scientists on pilot remediation techniques such as destratification, sediment sealing and sequestration materials.

Notes on what was not decided: The commission did not certify the SEIR, approve permit or reclamation amendments, or authorize execution of the amended development agreement; those actions remain pending the rescheduled public hearing and any subsequent Board of Supervisors action.