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The County should deny the Idaho-Maryland Mine and should not certify the Final EIR

The County's Final Environmental and Economic Impact Reports have been published. On May 11, 2023, the Planning Commission voted unanimously to recommend denial of the project and the environmental impact report. The final decision will be made by the Board of Supervisors on October 2 & 3, 2023.

CEA Foundation and MineWatch Coalition technical and legal experts prepared a series of strategic arguments that were delivered to the County. Read below to learn why the County has no obligation to the approve the mine. Get smart about the top six reasons why the project should be denied and the environmental report should NOT be certified.


The County has no obligation to approve the Mine.

The many environmental impacts associated with the mine, as well as its inconsistency with Grass Valley’s and the County’s land use plans provide ample justification for denying the mine project. The Final EIR (FEIR) also has serious deficiencies and should not be certified. It fails to substantiate several claims that impacts would not be “significant” and does not comply with CEQA (California Environmental Quality Act). Environmental impacts unavoidable - The FEIR lists several significant and unavoidable environmental impacts that endanger this community's health and quality of life. These include aesthetics, traffic, and noise. There are also serious deficiencies in the FEIR that put the County and its citizens at even greater risk. Key deficiencies are shown in sections 2-6 below. Inconsistent with General Plan - The Mine project is inconsistent with numerous Nevada County General Plan goals and policies. The Plan’s goal 17.1 calls for recognizing and protecting mineral resources in a manner that does not create land use conflicts. And yet, multiple conflicts exist with goals for not only land use, but also economic development, safety, climate change, noise, aesthetics, water, and coordination with cities and towns. A specific list of conflicts can be found here. Legal considerations - The County can confidently proceed with denial knowing the decision does not qualify as “taking”, which is a legal term that describes a project rejection that denies an owner their right to develop a property. Both the Brunswick and Centennial properties are currently zoned“ Light Industrial”, which provide a reasonable use of the properties. The applicant would need to secure approval of rezoning the Brunswick site to M1-M1 (Light Industrial with Mineral Extraction) in order to proceed with the project. There is ample case law to uphold the rejection of FEIR certification if a project is denied. If the current FEIR were to be certified, then the project later denied, it will be a flawed EIR in County records that could be used in future applications. Read more legal considerations here. Inadequate economic justification - The Economic Impact Report on the Mine showed a huge range of possible revenue outcomes from very low to very high, making actual revenue potential uncertain. Only the lower estimates were backed by proven gold reserves. Expert community reviewers found that even low-end figures were overly optimistic with a heavy reliance on information provided by the applicant. The assertion that property values wouldn’t decline was a big miss. It failed to recognize local realtor expertise or use acceptable home appraisal methods. Additional downside risk was not evaluated. Learn more about the community review here. Just say no! - Continuing with the EIR and project consideration will just cost the County in loss of time and energy as well as that of staff and the community. This community is overwhelmingly opposed to the Mine project, as evidenced by the over 5,500 petition signatures submitted to the County last summer and the fact that 95% of the opinion pieces published in The Union about the mine are against it. More information about opposition can be found here.


Following are six key deficiencies of the FEIR. 1 Well Owners Shafted in the Final EIR

The FEIR’s conclusion that groundwater impacts from the mine project will not be significant was not substantiated. Serious deficiencies identified by expert reviewers of the Draft EIR were not addressed, resulting in a final report that does not comply with CEQA and fails to identify the potential impacts. ● CEQA requires a current baseline to assess potential impacts and determine mitigations. The computer model used for the analysis did not use current monitoring data from any of the over 300 domestic wells in the mineral rights area. It relied only on sparse patches of data from over 15 years ago. The Final EIR acknowledges that data is needed, but the approach calls for drilling 15new monitoring wells as a basis for verifying the computer model after the EIR is certified! The questionable computer model estimates well waterdrops at 1 to 10 feet for 152 wells, then avoids declaring the impact as “significant” by creating an arbitrary threshold of significance at 10%.

● The final EIR also adds a completely inadequate supplemental domestic monitoring plan for 378 newly-identified properties. Among the many deficiencies, the new program only includes about half the wells in the mineral rights vicinity and provides neither additional NID infrastructure to speed water replacement nor a third-party liaison to negotiate issues if problems arise. Read public comments from the Wells Coalition, CEA Foundation, and San Juan Ridge Taxpayers Association here. 2 Mine Waste Management Inadequacies Risk Water Quality

The FEIR’s conclusion that water quality impacts related to mine waste will not be significant is unsupported. The Water Board made it clear in Draft EIR comments that more rock testing is needed to assess the likely concentration levels of hazardous elements in the rock to be mined. The FEIR’s plan for storing and disposing of mine waste has extensive gaps, creating a risk for long-term mine water pollution similar to what this community has seen in the past. ● Rise Gold’s project plans to deposit 1000 tons of tailings and waste rock per day on the Centennial and Brunswick sites for the first11 years. After that, the plan is to dispose of it via off-site sales. However, only waste classified as Group C can be used for engineered fill deposits or off-site sales. The more hazardous Groups A and B require special handling. The FEIR asserts that “mine materials will likely be classified as Group C”, but its conclusions rely on just 11 feet of drill core samples.

● The FEIR does not provide adequate provisions for the storage of Group A or Group B mine waste, which will be required by the Water Board. Since any waste that is not Group C cannot be used for engineered fill or off-site sales, viable alternative strategies must be defined. The FEIR introduced a new suggestion that if not Group C “...the waste rock would be placed underground”, but CEQA requires storage of Group A or B mine waste underground to be reviewed in a Draft EIR.

● This extensive set of gaps in mine waste management also introduces uncertainties about Rise Gold’s ability to operate by disposing of mine waste from off-site sales. Read public comments from CEA Foundation here.

3 Mine Waste Management Inadequacies Put Air Quality at Risk

The FEIR’s conclusion that air quality impacts related to mine waste will be effectively mitigated is unsupported. Asbestos is found in all rock types in the Idaho-Maryland Mine in varying concentrations. The FEIR’s plan for managing concentration levels to ensure that mine waste meets safety requirements before being shipped out of the facility is inadequate. ● Management of asbestos emissions is a complicated task. If the rolling average over a 3-month period of asbestos concentration in mine waste exceeds 0.01% by weight, it cannot be shipped out of the mine facility. Rise Gold’s primary approach – as described in the Asbestos, Serpentinite, and Ultramafic Rock (ASUR) management plan – simply proposes that cores would be sampled before excavation and that if asbestos levels are too high, the rock won’t be mined. There is not enough evidence, however, to establish that they can feasibly stay below the limits using this plan.

● The test data in the FEIR for determining the potential impacts from Asbestos is inadequate for CEQA compliance. Of the testing that was provided, which came from just 3 drill cores, 40% of the samples exceeded the 0.01% threshold. Thus, for assessing the impacts of asbestos air pollution, spot sampling has been done on less than 1/1000th of the mine rock that will be excavated over the 80 year life of the Use Permit.

Read public comments from CEA Foundation here.

4 FEIR Fails to Assess Impacts of Centennial Site

The FEIR excludes the Centennial Site from the full analysis of the impacts of the mine project. This prevents the County from understanding the full environmental impacts and is a clear violation of CEQA, which requires that impact assessments be based on current conditions, not a speculative future condition. ● The 56-acre Centennial site is the location of hazardous waste left over from past Idaho-Maryland Mine operations. The California Department of Toxic Substances Control (DTSC) is managing the cleanup, but their Remedial Action Plan (RAP) is only in draft form. It is unclear when the plan will be finalized or when DTSC might approve the clean up.

● Per CEQA, the EIR must provide an environmental assessment of the current conditions of a project site to establish a baseline in order to determine impacts. This was not done. The FEIR assumes the site will be cleaned up before it gets used to deposit new mine waste. The plan calls for placing 1.6 million tons of mine waste (assuming it qualifies as Group C) over the course of 5 years, covering about 44 acres to a height of up to 55 feet. And yet, the significant work needed to accomplish this clean-up is not disclosed or evaluated in the FEIR. Numerous aspects of this RAP draft have been questioned in public comments and the final project details are unknown. Read public comments from CEA Foundation here. 5 Greenhouse Gas Emission Impacts dismissed in FEIR.

The FEIR concludes that the mine’s greenhouse gas (GHG) emission impacts will be “less than significant”, but it uses an unsupportable, obsolete threshold measure to justify its position. The only correct threshold – given current climate studies, CA SB-32, and today’s state goals – is net zero. The County has not formally adopted its own threshold of significance, but it has set ambitious goals to reduce GHG through energy reduction in its Energy Action Plan. The Mine’s sizable energy footprint would be a serious setback. ● The FEIR sets the significance impact threshold of 10,000 Metric Tons (MT) of GHG emissions per year. Mine operations are projected to produce approximately 9,000 MT per year, which is just under the set limit. This does not, however, include the over 4000 MT of additional emissions that will be generated by cement manufacturers to provide the massive amount of cement that will be used to produce cemented paste backfill for 500 tons/day of mine tailings.

● The outdated 10,000 MT/year threshold is one that was used by other air districts such as the Bay Area in the past. More recent projects, however, such as the Sargent Ranch Quarry project managed by the Bay Area Air Quality Management District in 2022, use net zero for the significance threshold.

● The mine’s electricity usage is approximately equivalent to the annual use of 5000 homes. The Mine’s energy use would be so sizable that it would completely offset the amount of residential reductions the County wants to achieve each year in its Energy Action Plan.

Read public comments from CEA Foundation here.

6 No Viable Plan for Disposing of Mine Waste.

The FEIR does not provide adequate information regarding the viability of the plan to dispose of mine waste through off-site sales and does not have provisions for adequate on-site temporary storage or permanent disposal of mine waste, leading to potentially significant impacts.

  • The project documents call for approximately 11 years of operations in which the mine waste will be disposed of on the Centennial and Brunswick sites as “Engineered Fill,” but the FEIR fails to resolve uncertainties affecting the viability of that plan. Due to inadequate testing information in the FEIR, the mine waste could not be classified as Group C mine waste by the Regional Water Quality Control Board as needed to allow dumping onto these two sites. In addition, due to inadequate testing of mine drill cores for asbestos to establish a reasonable assessment of the potential hazards due to airborne asbestos, numerous management issues regarding the safe handling and placement of asbestos-bearing rock as “Restricted Materials” remain unresolved.

  • Worse still, for the remaining 65 or more years of operations, even if the issues of potential water and asbestos impacts are resolved, significant issues remain as to how and where the mine waste will be disposed.

Read public comments from CEA Foundation here.


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