ZF #2018-0015: Hold a public hearing to consider a recommendation to the Board of Supervisors to certify the Subsequent Environmental Impact Report and approve the CEMEX Mining and Reclamation Plan Permit Amendment Project. The project is located on a 1,902-acre site east of Interstate 505 near the community of Madison. A Subsequent Environmental Impact Report (SCH #2021020487) has been prepared for the project. (Applicant / Property Owner: CEMEX Construction Materials Pacific, LLC and CEMEX Construction Materials South, LLC) (Planner: Heidi Tschudin, Contract Planner)

Staff recommends that the Planning Commission make the following recommendations for approval of the CEMEX Mining and Reclamation Plan Permit Amendment to the Board of Supervisors:

On October 9, 2025, the Planning Commission received a presentation from staff and the applicant on the project, accepted public comments, and directed staff to return the item for deliberation and action at a duly-noticed public hearing.  The staff report and video from the October 9, 2025 meeting are available at https://yolocountyca.new.swagit.com/videos/357835. At the October 9th meeting, comments were received from Jim Barrett, Juliette Beck, and Alan Pryor.  Written comments were received from Catherine Portman, Alan Pryor, Anuj Vaidya, Alessa Johns, and Steve Sagara.  Subsequent to the meeting, Commissioner McCormick submitted a list of requested clarifications.  Attachment H includes copies of written comments and Commissioner McCormick’s email. The materials from the October 9, 2025 meeting, and all written and oral comments are part of the administrative record for this project. The discussion below provides staff responses to various discussion items that emerged during the meeting, and the clarifications requested by Commissioner McCormick.

Mercury
The State and County have been regulating and monitoring mercury in the Cache Creek watershed for many years. Mercury conditions were known and evaluated when the gravel program was developed in the mid-1990s, and have been studied as the program has evolved in the years since.  The CCAP was designed to consider mercury, and the program regulations require active monitoring and management. The requirements of the mercury monitoring program were recently significantly expanded as part of the comprehensive 2019 Cache Creek Area Plan (CCAP) Update. 

Yolo County determined that pre-existing mercury conditions could be managed and controlled, and should not preclude the opportunity to develop the program and implement the Cache Creek Parkway.  This policy reflects a balancing of competing priorities that was rigorously debated in the 1990s, and has been repeatedly confirmed by the Board of Supervisors over time through both the 2007 and 2019 ten-year interim program reviews, and with every mining permit approval, modification, and extension. 

These competing priorities included:

When considering mercury conditions in Lower Cache Creek, the greater policy framework in which this program was developed and operates provides important perspective.  Whether methylation of mercury will occur in any given pit cannot be predicted.  Outcomes are highly dependent on the conditions at and the characteristics of each operation and lake.  Possible variables that may affect formation of methylmercury include pre-existing mercury concentrations, character of bottom sediment, bottom water oxygen levels, water clarity, water agitation, character of organic matter, sunlight, and activity of methylating bacteria.  In addition, the size, diet, species, and age of fish are also relevant.

In reliance on restricted fishing access, prohibited consumption, and analysis and opinion from qualified experts that mercury conditions are not problematic in terms of soil contamination or water quality, the County has repeatedly affirmed there are no unmitigated human health concerns associated with implementation of the CCAP, including continuation of mining as proposed at the CEMEX site.  Potential biological concerns are limited to wildlife eating fish with elevated mercury.  Under current conditions this is acceptably minimized by controls on site access and by ongoing mining activity within and near the ponds.  The potential for incrementally increased exposure to fish-eating wildlife (keeping in mind that mercury is a pre-existing condition in this watershed) is a short-term minimized risk during the period of evaluation.  At the levels being documented, the County has determined that the mercury conditions are manageable and that the positive benefits of the new aquatic and riparian habitats being created in the Cache Creek Parkway, and economic benefits of the project to the County (including employment and tax generation), outweigh the short-term downsides related to potential mercury exposure for fish-eating species that may occur during the period of mining.
 

If levels of methylated mercury in fish within a lake exceed ambient levels in the watershed for at least three out of five years of initial wet pit monitoring, the gravel operators must address it with a Lake Management Plan (LMP).  Management options include water mixing, management of water chemistry, fish removal, and filling the lake (“fix it or fill it”).  The County will not accept dedication of a lake without an acceptable monitoring history and/or a successful LMP.  Operators are required to establish a mechanism to pay for their individual LMP commitments in perpetuity.  In addition, the gravel mining Maintenance and Remediation Fee account (currently $3.35 million) is available to the County should unforeseen management issues occur in reclaimed lakes owned by the County. 

The LMP is to be adapted to the unique characteristics of a specific pit.  The wet pits have varying depths, oxygen levels, temperatures, and water quality characteristics and, as such, a one-size-fits-all approach is not consistent with best available science.   Also, the options may differ during mining, versus during idle periods, versus post-mining.  The LMP may be multi-part or phased to reflect this. 

The County’s regulations distinguish between preparation of an LMP and implementation of an LMP.  This is intended to ensure that the LMP is developed with input from the first five years of fish mercury monitoring, the additional required five years of fish mercury monitoring, the five years of expanded water column profiling, bottom sediment testing, and other relevant analysis that may be undertaken.  The LMP must be prepared by a qualified aquatic scientist or equivalent professional acceptable to the County.  Peer review of the LMP may be required at the discretion of the County.  The County has committed to a process of oversight whereby the LMP will be presented to the Cache Creek Technical Advisory Committee at a public meeting during which interested parties will have an opportunity to provide input.  Presentation to the Planning Commission and/or Board of Supervisors may be scheduled at the discretion of the County.  The LMP must be accepted by the County. Upon acceptance of the LMP, the operator must implement the plan.

Implementation should generally occur within three years of reported results from the expanded analyses undertaken pursuant to County Code Section 10-5.517(f) of the Reclamation Ordinance.  If lake management does not achieve acceptable results and/or demonstrate declining mercury levels after a maximum of three years of implementation, at the discretion of the County, the operator may be required to prepare an alternate management plan with reasonable likelihood of addressing the conditions.

After three years of implementation of an alternate management plan, at the discretion of the County, the operator must prepare and submit revisions to the reclamation plan (including appropriate applications and information for processing the permit amendment) to fill the pit lake with suitable fill material to a level no less than five feet above the average seasonal high groundwater level, and modify the end use to agriculture, habitat, or open space at the discretion of the County, subject to Article 6 of the Mining Ordinance and/or Article 8 of the Reclamation Ordinance as may be applicable.  A general summary of the County’s methyl mercury monitoring requirements during mining is provided below (other requirements apply during and after reclamation):

GENERAL SUMMARY OF METHYL MERCURY MONITORING REQUIREMENTS DURING MINING

(Yolo County Reclamation Ordinance Section 10-5.517)

1 – Applies to any pit approved for reclamation to a permanent pond or water feature §10-5.517

2 – Triggered once the pit is permanently wet and navigable by a monitoring boat §10-5.517(c)(1)

3 – Fish tissue monitoring and water column profiling required annually for 5 years §10-5.517(c)(1)

4 – Response threshold exceeded for 3 out of 5 years during initial monitoring §10-5.517(e)(2):

A – additional 5 years of monitoring required §10-5.517(e)(2)

B – expanded analysis required §10-5.517(f)(1)

· expanded lake water column profiling §10-5.517(f)(1)

· bottom sediment analysis §10-5.517(f)(1)

· other relevant analysis §10-5.517(f)(2)

C – preparation of a Lake Management Plan (LMP) required §10-5.517(g)

5 – LMP implementation upon acceptance by County, generally within 3 years of concluding expanded analysis §10-5.517(g)(1)(A)

6 – Implement LMP and monitor results for 3 years §10-5.517(g)(1)(A)

7 – If LMP not successful, prepare Alternate Management Plan and/or revise approved reclamation plan to fill the pit §10-5.517(g)(1)(A) and (B)

If monitoring after implementation of lake management activities during the post-reclamation phase demonstrates levels of fish tissue mercury at or below the ambient mercury level for any three monitoring years (i.e., the LMP is effective), the operator must continue implementation of the plan and continue monitoring, or provide adequate funding for the County to do both, in perpetuity (Section 10-5.517(g)(2)(D) of the Reclamation Ordinance).

Most mining permits provide for the dedication of land, including lakes, to the County, post-reclamation. The County will not accept dedication of any mined/reclaimed parcel without an acceptable monitoring history and/or a successful LMP.  Operators are required to establish a mechanism to pay for implementation of their individual LMP commitment in perpetuity.  As noted above, the County’s gravel mining Maintenance and Remediation Fee is available for County use should future unforeseen management issues occur in publicly owned reclaimed lakes. 

In October of 2024, CEMEX, Vulcan (formerly Syar), and Teichert (Esparto) were notified that LMPs would be required for the affected ponds at their respective operations.  To improve the quality and consistency of results from a programmatic perspective, the County chose to implement the LMP portion of the regulations collectively for all affected operators by using one expert consultant to develop one overall strategy for management of the lakes, that would subsequently guide LMP implementation at individual lakes based on lake-specific conditions and results.  This process is underway and expected to be completed in 2026.

2023 and 2024 Mercury Monitoring and Related Reports
Remaining outstanding mercury monitoring and related reports were posted to the County’s website prior to the public hearing.  Please refer to the September 11, 2025, memorandum from staff to the Planning Commission entitled “Response Regarding Inquiries Concerning Yolo County Gravel Mining Program” for more detailed information regarding the mercury monitoring program and other related matters: County Response to Sierra Club Yolano Group Correspondence Regarding the Cache Creek Area Plan Program(1).pdf. The tables in Attachment I summarize the mercury monitoring conclusions to date.

CEMEX Project Mercury Outcomes
As reflected in the monitoring reports and summary above, fish in the CEMEX Phase 1 Pond have reflected acceptable mercury levels and the Phase 1 pond has been used as a “control” pond for analytical purposes for almost a decade.  The Phases 3 and 4 ponds were previously combined.   In 2020 they were separated into two ponds, with the western Phase 3 pond remaining isolated and undisturbed, and active mining continuing in the eastern Phase 4 pond.  Prior to separation, fish from the combined Phases 3 and 4 pond generally exhibited elevated mercury levels.  After separation, results for each pond varied, with some acceptable and some inconclusive results in specific years as shown in Attachment I.

For the Phase 1 control pond, this outcome may be related to changes in activity at this pond as well as a changed source of fill material.  Between 2015 and 2024, Phase 1 activities evolved from active mining with slurry inputs, to slurry only, to no mining or slurry, back to slurry inputs and, recently, changes in source material for the slurry.  Through and including the 2023 monitoring, the slurry flow for this pond was generated from the wet mining activities in Phase 4.  In 2024, CEMEX commenced initial dry mining on a portion of Phase 5 resulting in a changed source of fill material (2022 Minor Modification approved May 10, 2022.)  The 2024 report indicates that previously dry soil mercury may be more available for methylation than after that same soil has been submerged for several years, suggesting a likelihood of reduced level over time as Phase 5 transitions from dry to wet material.  This outcome is identified in the report as the “New Reservoir Effect” and has been experienced under similar conditions in other environments.         

As noted above, in October 2024, CEMEX was notified that an LMP would be required for the Phases 3 and 4 ponds.  Also as noted above, the County is presently undergoing a process to prepare a programmatic lake management strategy for site-specific implementation, which would apply to the CEMEX Phases 3 and 4 ponds under current mining and reclamation approvals.  Identification and preliminary design of appropriate mercury management controls for the Phases 3 and 4 ponds are currently actively being developed by a County-retained qualified scientist as a component of the programmatic LMP process.  Notably, as a part of the subject application, CEMEX is proposing to fill the Phases 3 and 4 lakes, with final reclamation to agriculture.  Filling of the lakes is an allowed option for compliance with Section 10.5-517 of the Reclamation Ordinance and would fully satisfy CEMEX’s responsibilities under the mercury regulations.  Subsequent to approval of the proposed revised reclamation plan, the operator would no longer be required to monitor Phases 3 or 4 ponds.  However, it could be useful for the mercury analysis to nevertheless carry out pilot mercury controls on the Phase 3 pond and continue to monitor both ponds until monitoring is no longer feasible under the revised reclamation plans, which the Applicant is agreeable to do.  In light of this, staff recommends a new condition of approval as follows:

28.16.  The operator shall prepare and implement, in coordination with the County and its scientific expert, a short-term LMP (consistent with the requirements of Reclamation Ordinance Sections 10-5.517(g)(1) and 10-5.517(g)(1)(a) but with no obligation to prepare an alternate management plan) consisting of pilot mercury reduction controls in the Phase 3 pond, and continue mercury testing (consistent with the requirements of Reclamation Ordinance Section 10-5.517(c)(1) and 10-5.517(f)) in both the Phase 3 and 4 ponds until such time as it is no longer feasible to undertake monitoring under the new approved reclamation (e.g. the ponds are no longer navigable by the monitoring vessel).

The SEIR investigated whether proposed changes to increase the size and shape of the Phases 5 and 6 lakes would have the potential to result in worsened mercury outcomes as compared to currently approved reclamation plans, and concluded that the proposed changes would be less-than-significant.  The following excerpt (SEIR, Draft Volume, Chapter 4.6, Hydrology and Water Quality, page 4.6-31 thru 4.6-32) is relevant:

… The proposed project would modify approved lake reclamation reducing the total number of lakes from 4 to 2, increasing their size by approximately 51 acres total, and reducing the linear connectivity of the reclaimed lake habitat to the existing creek corridor by about 2,340 feet (see Table 4.3-2 and Figure 3-21).    Under the proposed project, the Phase 3-4 wet pit would be backfilled to reclaimed agriculture rather than to an open lake.  Therefore if the project is approved, an LMP would not be required for the Phase 3-4 wet pit.

From a general wildlife perspective, the approved reclamation plan offers more habitat connectivity for wildlife because it borders a longer stretch of the existing creek corridor (see Impact 4.3-6).  However, the proposed changes should not adversely affect potential mercury hazards.  With regard to potential mercury hazards, the two proposed larger lakes can  be expected to function very similarly to the originally proposed design.  The proposed lakes remain in the same general location and will contain the same general base concentrations of historic mercury.  They will be in the same general orientation to prevailing winds.  Most importantly, the maximum depth of 70 feet would not change.  Lake depth is important is influencing the natural biogeochemical cycles in the lakes, including the methylmercury cycle (Memorandum from Dr. Darell Slotton to County dated August 13, 2021¹).  Depth and mixing forces (mainly surface winds) determine how and if  a lake will stratify into layers during the warm season.  The extent of seasonal stratification affects the natural cycles.  The changed design will allow for greater mixing from surface winds (“wind fetch”) due to larger surface area, leading to potentially deeper mixing of water columns.  This would be beneficial and could result in a reduction for methylmercury production and accumulation in fish.  Fish mercury is being monitored closely through the requirements of Section 10-5.517 of the Reclamation Ordinance, and will continue under any design, together with mandatory remediation measures as needed. 

The proposed project would increase the acreage of reclaimed wet pit lakes (relative to the reclamation plan considered in the 1996 EIR) and these lakes may be found to contain elevated levels of methylmercury in the future. However, Section 10-5.517 of the Reclamation Ordinance requires specific monitoring activities and lake management efforts (including remediation if necessary) if elevated levels are identified. Therefore, potential impacts related to violation of water quality standards or waste discharge requirements would remain less than significant.
1 Document 34 in the SEIR Draft volume reference documents.

Under the requirements of the program, CEMEX will be subsequently required to implement the mercury monitoring protocols in the Phases 5 and 6 pits.  Results will be identified in future reports and will determine future lake management requirements, if any.

CCAP and Climate Change
Consistency between the proposed project and County climate change policy and regulations is addressed in the SEIR.  The 2019 CCAP Update EIR determined that the CCAP was consistent with County climate adaptation goals, policies, and actions as identified in the 2011 Climate Action Plan (see 2019 CCAP Update EIR, Impact GHG-2, pages 4.7-13 to 4.7-14, Draft Volume).  The subject CEMEX project has also been determined to be consistent (SEIR, Draft volume, Impact 4.2-6 on pages 4.2-36 through 4.2-37).

The SEIR documents aspects of the CCAP and the CEMEX operation that achieve the climate action goals of the County.  The CCAP ensures a local source of aggregate (thus reducing emissions associated with transportation of material to nearby projects), minimizes the area of allowed mining, minimizes the footprint of allowed mining, and requires reclamation to land uses that sequester carbon and minimize GHG emissions (particularly as compared to urban uses).   With regard specifically to the CEMEX operation, this operator utilizes an electric dredge for mining, an electric conveyor system for onsite material transport, and relies on a wind turbine energy system which supplies renewable energy for approximately 30 percent of the energy demand at the plant facilities. 

The SEIR identifies that the project would result in increased GHG emissions relative to the baseline conditions (Impact 4.2-5, Draft volume, pages 4.2-33 through 4.3-35).  Mitigation Measure 4.2-5 (new proposed Condition of Approval No. 65.2) requires development and implementation of a project level greenhouse gas reduction plan to mitigate this impact.  This condition requires the applicant to reduce annual GHG emissions to baseline levels and provides a menu of possible strategies.  Other relevant project conditions include Conditions of Approval Nos. 28.13 and 65.1 related to increased use of clean energy.  These conditions are excerpted below:
 

 

 

On January 24, 2023, the Yolo County General Plan was amended to address the topic of Environmental Justice including general consideration of unique health risks of disadvantaged communities (as defined in State law), promoting civic engagement in public decision-making, and prioritizing actions to address the needs of disadvantaged communities.  Policy language related to climate adaptation was added to the General Plan as a component of this amendment. A review of project consistency with relevant new and/or substantially amended goals, policies, and actions from this General Plan amendment is provided on pages 3-82 through 3-88 of the Final volume of the SEIR.

 

In December 2024, the County adopted the 2030 Climate Action and Adaptation Plan (2030 CAAP). The 2030 CAAP provides updated information relevant to reduction of greenhouse gas emissions and management of climate change risks, and contains updated inventories of community-wide greenhouse gas emissions, County owned vehicles and facilities, and locally relevant life-cycle emissions.  The baseline inventory and emissions forecasts in both the 2011 CAP and the 2030 CAAP captured emissions associated with existing and planned land uses in the County, including mining operations allowed under the CCAP.  The 2030 CAAP will help inform future modifications to the requirements of the General Plan, and did not change the validity or conclusions of the climate change and greenhouse gas emission analysis of the project in the SEIR.

 

Of potential relevance to the project, the 2030 CAAP included Measure DT 3 (Encourage Transition to Electric Vehicles) which states:

Action DT 3e: Develop EV truck incentive pilot program for large-scale mining and gravel operations within Yolo County. 

Although such a program is not currently in existence, implementation could be accomplished in coordination with the County mining industry and, upon adoption, relevant future changes in the CCAP and operator conditions of approval could be initiated through the required ten-year interim review process authorized by the CCAP.

Timing of Reclamation and the Parkway Plan
Among the significant benefits of the County’s mining program are:

Related to the first bullet, the limited off-channel mining allowed under the CCAP was found to be substantially more sustainable in line with the values and policies of the Yolo County than previous mining practices within the channel of Cache Creek. 

Related to the second bullet, the original Off-Channel Mining Plan (OCMP) and Cache Creek Resources Management Plan (CCRMP) both identified six geographic areas for recreational use generally at or near the current locations of the Capay Open Space Park, Granite Esparto site, Vulcan (Syar) site, CEMEX, Cache Creek Nature Preserve, and Granite Woodland Reiff property. These sites, located at approximately two-mile intervals, were identified to function as trailheads or staging areas for a future integrated system of trails and recreation areas similar to resources and facilities along the San Joaquin and American Rivers, although at a less intensive scale of development. Frontage on County roads and proximity to State highways were identified as important considerations to ensure adequate public access.  A range of recreational uses were anticipated from passive activities such as hiking, bird-watching, horseback riding, and educational exhibits to open space, to more intensive open space activities such as non-motorized boating, catch and release fishing, bicycle riding, and picnicking.

As an outcome of subsequently permitted aggregate mining within the Lower Cache Creek planning area, and other activities, there are over 2,000 acres of land that have, or will, transfer into public ownership and/or control over time, including several of the reclaimed lakes.  Both the OCMP and CCRMP contain numerous references to, and descriptions of, an anticipated second phase of planning involving development of a Cache Creek Parkway Plan (Parkway Plan) to provide policy, regulation, and strategy for management of dedicated lands and easements transferred to public ownership as a result of implementation of the CCAP.

On February 28, 2012, the Yolo County Board of Supervisors authorized County staff to proceed with development of the Cache Creek Parkway Plan.  Work commenced at that time documenting existing conditions and exploring possible future conditions based on opportunities presented through the CCAP and on an assessment of recreational demand.

In June of 2016, the Board adopted the “Yolo County Sustainable Parks Study.” This study identified water-based recreation as a primary driver of parks use, and documented that nearly 40 percent of all observed and reported recreational activities in the County were water-based uses, including boating, swimming, kayaking, and fishing. Camping and picnicking were also identified as under-met recreational needs in strong demand in the County. 

The open space properties coming into County ownership/control through the CCAP provide Yolo County’s first opportunity to provide water-based recreation beyond that available along Putah and Cache Creeks.  Yolo County has no natural lakes.  The lakes and ponds resulting from reclaimed mining, combined with the additional habitat, open space, and trail opportunities negotiated through the gravel program provide a unique opportunity that was recognized and embraced by the County.

The Cache Creek Parkway Plan is comprised of the following components published as separate documents:

Baseline Inventory (2019) -- The Parkway Baseline Inventory provides an integrated management plan for the open space and habitat properties Yolo County already owns, or will receive, as a result of the CCAP.  It provides a map and profile, in catalog style, for each of the properties and bridge structures that will become a part of the CCAP open space system based on executed development agreements with aggregate operators.  It provides descriptive information about each property, parcel history, details relating to access and dedication terms, citations for relevant legal documents and technical studies, existing or approved improvements, and known opportunities and constraints related to existing site conditions or approved future reclaimed conditions.  The maps and graphics communicate how the entire parkway can function as an invaluable resource connecting all the communities of Yolo County to Cache Creek. It elevates the parkway properties from many individual properties to one fully integrated open space system.

Baseline Inventory Feasibility Study -- The Parkway Baseline Inventory was accompanied by a Financial Feasibility Study that confirmed the adequacy of the dedicated private funding source (per-ton fees paid by the aggregate operators). 

Master Plan (Draft 2020) -- The draft Master Plan and Parkway Vision looks beyond the baseline condition at how to improve and expand the Cache Creek Parkway to increase open space and recreational potential.  Further work to finalize and adopt this plan remains.

Master Plan Feasibility Study -- The Draft Master Plan was also accompanied by a Financial Feasibility Analysis.

Incorporated into the Parkway Plan documents are assumptions regarding the order and dates that the various components of the future parkway may be received by the County.  For some aspects of the operations there are precise dates and/or triggers for dedications to occur.  However, many of the phased reclamation and dedication requirements are dependent on the pace of mining which in turn is dependent on market conditions.  As a result, exact pace and buildout of the Parkway Plan is necessarily fluid over the 50-year horizon, and are anticipated to change as permits are amended and/or extended. 

Relationship Between CCAP Program and Individual Mining Permits
The CCAP is both a policy and regulatory program.  It was originally developed in 1996, and reaffirmed by the Board of Supervisors through CCAP Updates in both 2007 and 2019.  The mining reclamation plans for each operator have been developed and refined to be fully compliant with the policy and regulatory components of the CCAP.  The permits under which mining occurs are strictly regulated by State mining requirements, the County Mining and Reclamation Ordinances, and the extensive conditions of approval for each permit.  Each operation is subject to the ten-year interim review process which allows for, among other things, consideration of applicable new environmental regulations and statutory changes (Section 10-4.605 of the Mining Ordinance). 

From its inception, the CCAP has had a 50-year horizon, assuming an initial maximum mining permit term of 30-years and a maximum permit extension term of 20-years for a maximum total permit term of 50-years.  Originally, the anticipated horizon for the plan was approximately 2046.  With the 2019 CCAP Update, the outside horizon of the program was set at 2068, reflecting its evolving long-term outlook and to be consistent with the HCP/NCCP which was approved in significant reliance on the CCAP Parkway Plan and properties.

Each mining operator has a Development Agreement with the County which, among other things, documents the applicability of the ten-year interim review process to each operation (Section 7.2, Interim Review), and also specifies vested protection for maximum tonnage, specific acreage, maximum depth, ability to process at specified plant facilities, so long as the operation is in full compliance with the regulatory requirements and conditions of approval, there is no threat to public health or safety, and the operation does not pose a public hazard or public nuisance.

While being open to concerns of individuals who have expressed opposition to the mining program is important, consideration of the CCAP is not before the Planning Commission.  The County has continued active implementation of the CCAP for almost three decades, including a substantive review as recently as 2019.  The policy of the program is not presently before the Commission for review or modification.  The role of the Commission for the subject application is to advise the Board regarding the request to extend the term of the CEMEX mining permits and make other operational modifications that have been described.   

Public Engagement Opportunities
The public engagement opportunities for this program and all mining permits are robust.  Starting with development of the program in the 1990s, stakeholders, including the public, property owners, Tribal interests, State and federal agencies, mining operators, and environmentalists participated in an extensive process to determine the best balance and resolution of these competing priorities and concerns.  The entire program was placed by the Board before the voters on the November 1996 ballot against an opposing citizen’s initiative. Over 60 percent of the voters supported the CCAP and that same proportion voted against the citizen’s initiative.  The CCAP carried in every supervisorial district.  Implementation of the plan began in 1997.

Significant opportunity for stakeholder involvement has continued since that time, with the subsequent process for ten-year interim review of each mining permit,  the process for each ten-year interim review and update of the program, and input on various annual reports and at various committee meetings.  Every permit application and amendment under the program has included public engagement opportunities, including community outreach, workshops, meetings, hearings, and, in some instances, field visits. 

In addition to opportunities to participate in permit application review, there was extensive outreach to all stakeholders for the first ten-year interim review process which occurred between January 2005 through March 2007, and with the second ten-year interim review process which occurred between June 2015 and December 2019. 

The third ten-year interim review is anticipated to occur in 2029, ten years following the 2019 process.  The workplan and schedule for the process will be developed by staff with input from the Planning Commission and approval by the Board of Supervisors.  The Commission and public will have an opportunity to weigh in on the process at that time.  Although this future work endeavor is not an item before the Commission as a component of the subject application, the Planning Commission could direct staff to return to a future noticed meeting to discuss the workplan and schedule for the CCAP 2029 Interim Ten-Year Review.  Should the Commission wish to take such an action, direction should be given by the Commission to staff separately from deliberations of and action on the subject CEMEX application, as it is an unrelated item. Staff recommends the Planning Commission consider this option under ‘Future Agenda Items’ on the Regular Agenda. 

There are also annual reports to the Planning Commission regarding the program and Cache Creek off-channel mining operator compliance, regular meetings of the CCRMP Technical Advisory Committee, and the annual multi-day creek walk, all of which are open for public involvement and occur on a regular schedule for anyone with interest. 

Depth of Mining/Reclaimed Lakes
During the October 9th Planning Commission meeting, conflicting information was provided regarding allowed depth of mining and reclamation activity under the CEMEX approvals.  To clarify, the maximum allowed depth is 70 feet as reported by staff, confirmed by the applicant, and reflected in the current CEMEX conditions of approval.

Characterization of the Mining Program
The County’s CCAP has been under active implementation for almost 30 years.  It is a detailed, science-based program that relies on feedback from extensive monitoring requirements, which allows for improvements over time.  It has been recognized repeatedly at regional and State levels for its innovative approach and successes.  It is long-term, self-funded, and public-benefit focused.  Constructive oversight and critique from outside observers is healthy for a program of this nature, and should always be welcomed.  Delays in implementation of some specific components of the process have occurred which is undesirable.  There have been instances where changes in staff, changes in organizational structure, other priorities for staff time, site conditions (e.g. drought, accessibility, etc.), and/or inattention to detail have affected the seamless administration of the program.  However, reporting and monitoring continue to demonstrate that the program framework is sound, and no unanticipated and/or adverse outcomes have emerged.  For a program of the size, magnitude, and term of the CCAP implementation is complicated.  Nonetheless, program successes have included improved conditions in- and off-channel, successful economic development, minimized impacts to agricultural lands, continued access to local sources of aggregate, successful restoration of habitat, and development of dedicated open space sites, among other benefits of the program.  

Supplemental Comments from Commissioner McCormick (submitted to Planning staff on 10-10-2025)
The following excerpts in italics are verbatim from the Commissioner’s email (Attachment H):

1. At the Nov PC meeting, and in context to Mr. Pryor's verbal public comments, I would like to hear more about the original 1986 commitment in the Cache Creek Area Plan to have trails and active recreation ponds in context to the application for a 20 year extension and how the application furthers or amends the original commitment in the Cache Creek Area Plan for recreational opportunities being available in a specific timeframe.
 

Staff Response – The question is understood to concern the 1996 program.  The CEMEX commitments for trails and recreation under approved and proposed conditions are summarized in Attachment H to the October 9, 2025 staff report: Att. H. Draft SEIR Table 3-10.  As a result of the proposed 20-year extension of permits, final reclamation would be pushed out 20 years as well.  Under the current approved CEMEX permits, 2032 was the previously assumed date for dedication of the two larger lakes and perimeter habitat, the eastern road easement, the creek frontage to centerline, and other specified riparian restoration adjoining the lakes.  Under the proposed project, those dedications would occur in 2052.  Recognition of that delay was one factor in the negotiations with the applicant that lead to the additional net gains commitments included as a part of the subject project.   The new net gains commitments are: dedication of the Millsap connector property, the new western road easement, the new creekside trail, and the identified monetary contributions.  The Board of Supervisors must ultimately determine the acceptability of the overall net gains commitments in light of the requested changes in the project.

2. I appreciate the greater set aside of habitat in this proposed plan however reflecting on the public speaker's comment regarding the value of wetlands and woodland habitat as more aligned with the natural history of Cache Creek, some additional narrative on how the ponds are appropriate vs a restoration of similar habitat types as existed prior to mining. I understand this is in the Cache Creek Area Plan however publicly framing these points would be helpful in context to this extension request.
 

Staff Response: Prior to mining, the subject property was in agricultural use.  The CCAP identifies reclamation to agriculture generally as the highest priority end use.  The CCAP directs the following priority for reclamation after mining is concluded (OCMP Action 5.4-7):  1. Agricultural uses; 2. Habitat; 3. Recreation and Open Space; and 4. Other Uses.  This is consistent with the County’s long-term focus on preservation of agriculture as integrated into the policy requirements of the General Plan.  

Degraded conditions along Lower Cache Creek during the late 1800’s and throughout the 1900’s were analyzed extensively in the early 1990’s in a seminal report referred to as the 1995 Technical Studies.  This report concluded that channel response is extremely complex, and it is not possible to isolate the morphological effects of a single variable (page 2-6) nor appropriate to assign “blame” to a single human activity for certain conditions along the creek.  Documented major historic influences on the creek have included stock grazing, clearing of land for agriculture, water diversions for irrigation, gravel extraction, farming practices, groundwater pumping, and flood control.

Over the years there has been discussion of more extensive restoration to broad floodplains and riparian forests along the banks of Cache Creek.  In developing the CCAP, the County recognized that while this may be desirable, this was not feasibly attainable in light of land ownership patterns that would require land purchase and/or condemnation to impose open space land uses, public infrastructure such as roads and bridges that impede the creek and would require removal or reconstruction, flood control requirements that protect downstream improvements and development (such as the City of Woodland), and other modern realities. In addition, the 1995 Technical Studies documented that conditions along Cache Creek have always reflected varying biological conditions due to varying groundwater elevations and conditions along different segments.  These differing creek reaches, often described as “gaining” and “losing” reaches, reflect natural conditions.  A “gaining” reach is a segment of the creek where the groundwater table is higher than the surrounding ground elevation so the water flows from the aquifer to the creek meaning the creek “gains” water.  These areas typically have consistently lush riparian vegetation.  A “losing” reach is a segment where the groundwater table is lower than the surrounding ground elevation, so the water flows from the creek to the aquifer, meaning the creek “loses” water.  These areas are typically more barren with little to no vegetation.  The interplay of groundwater levels and the episodic “flashy” nature of food flow along Cache Creek result in some areas that are lush and others that are naturally barren.

It is also notable to mention that the Applicant’s proposed Habitat Restoration Plan includes habitat restoration along the frontage of Cache Creek and perimeter habitat around the Phase 5 and 6 mining ponds, including oak savanna, riparian woodland, and perennial marsh. Islands and peninsulas are also incorporated into project design that will provide additional habitat value.

3. Regarding contractor fleets serving the various mines in the region. Diesel trucks are a significant source of ghg emissions for the CEMEX site and although an electric dredge and conveyor systems reduce onsite emissions, transportation emissions continue to be an issue that could have a few intervention points in line with existing and pending County programs. funding opportunities, and priorities.

3A. Although staff vehicle charging is good, commercial and industrial fast charging options onsite or at truck contractor facilities could potentially incentivize fleet transitions to no emissions vehicles. This would require the County and CEMEX to work with fleet contractors and may require incentivizing lower emission transport options. This may be able to serve as a model for the agricultural fleet transitions required to reduce GHG emissions in line with County goals.

3B. With a climate emergency declaration by the BOS with a goal of carbon negative by 2030, the all of County approach to reducing GHG emissions is important. The applicant and the County may consider partnering to show what's possible in mining operations. Leveraging significant State funding opportunities Yolo could well be positioned to be a beacon of innovation for mining across the State and nation, while also, as mentioned in 3A, allowing for a case study to start supporting ag fleet retrofits and transitions.
 

Staff Response: Staff believes the tools to support future collaboration on fleet improvements already exist and are built into the program and conditions.  The SEIR notes that General Plan Policy CO-8.4 encourages the County and users of fleet vehicles in all sectors of the local and regional economy to seek fleet emissions reductions:
 

Policy CO-8.4:   Encourage all businesses to take the following actions, where feasible: replace high mileage fleet vehicles with hybrid and/or alternative fuel vehicles; increase the energy efficiency of facilities; transition toward the use of renewable energy instead of non-renewable energy sources; adopt purchasing practices that promote emissions reductions and reusable materials; and increase recycling.
 

Fleet emissions are controlled by State and federal regulations such as the 2007 In-Use Off-Road Diesel Vehicle Regulation implemented by the State, which requires off-road equipment fleets to meet specific retrofit requirements and idling limits.  The fleet of off-road equipment operated within the project site is subject to these regulations (SEIR, Draft volume, Chapter 4.2, Air Quality Greenhouse Gases, and Energy, page 4.2-41). Other examples include the California Air Resources Board’s Advanced Clean Fleets Regulation and Truck and Bus Regulation. The Truck and Bus Regulation, in effect since 2008, requires that as of January 1, 2023, all diesel-powered vehicles operating in California with a gross vehicle weight rating over 14,000 pounds must have a 2010 or newer engine and emission system, with few exceptions. This regulation applies to commercial on-road aggregate transport trucks.

As identified earlier in this report, the 2030 CAAP included Measure DT 3 (Encourage Transition to Electric Vehicles) which supports the development of an EV truck pilot program gravel operations. As noted, implementation could be accomplished in coordination with the County mining industry through the CCAP program interim review process.    

Condition of Approval No. 65.1 imposed by the Board of Supervisors in 2000 encourages the operators to use cleaner vehicles and equipment, and to retrofit existing vehicles and equipment.  Condition of Approval No. 65.2(a) identifies equipment retrofit as an option for GHG emissions reductions required of the operator.  The Commission could consider modification of Condition 65.2 as shown below to add a new option “f” that would emphasize the County’s interest in further reducing carbon emissions from the haul fleet, which the Applicant is agreeable to add.  The option related to purchase of carbon credits would be reordered to item “g”:
 

65.2.  Prior to the August 11, 2027 (the original date of expiration of the 1996 entitlements), the operator shall submit for review and approval, a Greenhouse Gas Reduction Plan (GHGRP) to the Yolo County Department of Community Services. In order to demonstrate that implementation of the proposed project would not result in a net increase in GHG emissions from baseline conditions, the GHGRP shall demonstrate how annual operational emissions of the proposed project would be reduced to or below the annual baseline emissions of 5,668 MTCO2e. Strategies to achieve emissions reductions may include, but are not limited to, the following:  …
 

f. Commercial haul truck retrofit, or permanent replacement with one or more zero-emissions haul truck(s);
 

4. Although this one project site is important, the work on this 20 year extension has the potential to inform any other mines that want to extend their operations, and inform the next 10 year review of the Cache Creek Area Plan to support solutions that are facing all of the mines (methyl mercury management being one). In line with Ms. Beck's public comments, this seems like a great time to align the CEMEX extension request, now, and the Cache Creek Area Plan, at the next ten year review, with the general plan and climate action and adaptation plan. Additional context on how this permit extension request aligns (or could be conditioned to align) with the GP and CAAP, particularly in regard to decarbonization and resilience goals, would be helpful.
 

Staff Response: Regarding the term of the mining permit, permit extensions (of up to 20 years) are explicitly contemplated under the CCAP (Section 10-4.426 of the Mining Ordinance) and in the existing conditions of approval for the approved CEMEX operation (Condition of Approval No. 6).  The adaptive aspect of the program is relevant to the comment.  The CCAP has built-in mechanisms and requirements for consideration of monitoring, analysis, and reporting outcomes from each operation, from interim reviews, including annual review of compliance with conditions of approval, and other relevant studies and analysis in adapting the program over time.

Regarding methyl mercury, please see discussion presented earlier in this report.   

Regarding plan and project consistency, as the General Plan is amended and/or updated over time, other County planning and regulatory documents including community and specific plans (such as the CCAP) and regulations in the County Code must be similarly modified to ensure policy and regulatory alignment.   This is true for State and federal regulations that change over time as well.  Importantly, the CCAP is fully consistent with the General Plan and all adopted polices and regulations of the County, including those related to environmental justice, climate change, and GHG.  Moreover, the SEIR demonstrates that the proposed project, as recommended for approval, is also fully consistent with the policies and actions of the General Plan and adopted Climate Action Plan (CAP) (see for example Response to Comment 9-5 in Attachment A).  The FEIR documents that the 2030 CAAP does not supersede the County’s adopted 2011 CAP, though the gravel program and the Cemex project are both generally consistent with the 2030 CAAP. In other words, the analysis demonstrates that there is alignment and consistency between all of the relevant plans and policies of the County, and this specific project request.

This application was reviewed by the Planning and Natural Resources Divisions, with support from County Counsel and a contract land use planner.

Any person who is dissatisfied with the decisions of this Planning Commission may appeal to the Board of Supervisors by filing a notice of appeal with the Clerk of the Board within fifteen (15) days from the date of the action. A Planning Commission Appeal Form and appeal fee immediately payable to “County of Yolo” must be submitted at the time of filing. The Board of Supervisors may sustain, modify or overrule this decision. The Planning Commission Appeal Form can be accessed at the following link: https://www.yolocounty.org/government/board-of-supervisors/clerk-of-the-board/planning-commission-appeal