August 17, 2020
The following scoping comments were submitted to the county in response to the Notice of Preparation (NOP) of the Draft Environmental Impact Report.
Matt Kelley, Senior Planner Nevada County
Planning Dept. 950 Maidu Ave
Nevada City, CA 95959-8617
Notice of Preparation Comments for the Idaho-Maryland Mine Project, Scoping
Dear Mr. Kelley,
Please accept these comments on behalf of CEA Foundation regarding the preparation of the Environmental Impact Report for the Idaho-Maryland Mine Permit Application.
Aesthetics An analysis of aesthetics’ impacts must be made. All visual impacts must be evaluated.
The project includes 122,000 sq. ft. of structures plainly visible from East Bennett Rd, Brunswick Rd., and from multiple surrounding rural residential neighborhoods. The proposed ore processing facility is 425 feet by 70 feet, and 65 feet high. Construction of “engineered fill” pads on both sites will create the continuous presence of operations that are synonymous to a gravel quarry, involving continuous haul trucks, graders, and compactors working on an ever increasing build up area of engineered fill.
These operations will continue for about 11 years, and ultimately result in a highly visible fill area covering 44 acres at the Centennial site with heights up to 70 feet, and a similar fill area covering 31 acres on the Brunswick site with heights of up to 90 feet. Following that, approximately 70 years of operations will entail trucking mine waste to Hwy 49 via Brunswick Rd.
The removal of woodlands and open space will starkly degrade the aesthetic nature of the area, impacting its rural residential character and diminishing property values. Increased traffic will affect the quality of life.
Noise and dust and other impacts must be evaluated on their aesthetic impacts. The project is in the City of Grass Valley Sphere of Influence.
2. The aesthetic impact must be evaluated with respect to the Grass Valley Development Code and the General Plan.
Over the last few decades the areas surrounding the Idaho Maryland Mine have become predominantly residential.
3. The EIR must evaluate how the reopening of the mine would change the character and trajectory of development in this section of Nevada County.
Agriculture and Forestry The areas of lower conifer and oak woodlands which will remain outside the direct physical constructs of the project sites will be impacted by light, air pollution, noise, temperature changes, and other impacts.
A Forest Restoration and Management Plan should be required to prevent further degradation of these woodlands and to preserve and enhance the native habitat. Ongoing biological monitoring should be conducted in these areas throughout the life of the project. Air Quality As evidenced at the Empire Mine State Park, mining and milling operations at the mine left behind a mixture of naturally occurring contaminants (arsenic, lead, cadmium, and other metals) and introduced cyanide and mercury (used in the gold extraction process). Operations produced ore rock and generated tailings and waste rock. Contamination produced by these operations was determined to pose a health hazard to people, wildlife, and area waterways.
Arsenic has been classified as a carcinogen and causes other severe health issues, including thickening skin, pain, nausea, paralysis, and blindness. A legacy of gold mining at Empire Mine and elsewhere is the contamination of mine wastes and associated soils, surface waters, and groundwaters with arsenic (As), mercury (Hg), lead (Pb), and other metals.
Disturbance of materials containing mafic and ultramafic rocks is regulated by the California Air Resources Board (CARB) and the Northern Sierra Air Quality Management District (NSAQMD).
The presence of naturally occurring contaminants (arsenic, lead, cadmium, and other metals) which are released into the air and soil when the mine rock is crushed should be independently investigated and included in the EIR and clearly explained for the public to review. Impacts to the public as well as employees of the mine should be included in the discussion. Fugitive dust from surface operations will affect air quality. Dust and air pollutants from all sources must be contained.
3. The EIR should analyze all sources of air pollutants.
4. It should specify how these sources of air pollutants will be contained and controlled. These include but are not limited to dust and emissions from truck transport, chemical emissions, equipment emissions and exhaust, odors, emissions from all mining activities on the surface and within the processing facilities and mine tunnels.
Wind, dry conditions, and other circumstances may require cessation of mining operations and surface activities.
5. The EIR must identify and set criteria for managing these conditions.
6. Air quality impacts from all aspects of construction and operations and from the production and transport of materials and equipment produced off site must be evaluated.
7. Air quality impacts from the processing of ore and mining by-products offsite must be evaluated.
8. Emissions due to the other supplemental activities including but not limited to relocation of non- residents for employment, transportation, traffic impacts, construction and operation of utilities and utility services must be evaluated.
9. The effect on air quality of extended activities such as reclamation activities and water treatment operations, must be assessed for their entire lifespan, beyond 80 years.
10. Rise Gold must show how the cumulative effect of small drips and spills during transfer and fueling activities will be prevented from entering into the environment (as happens at gas stations), and contaminating Wolf Creek.
11. All of the above mentioned conditions should be assessed in terms of the range of predicted changes in weather patterns due to global warming.
Biological Resources The project has potentially significant impacts on biological resources. The majority of the 175 acres being utilized will be disrupted due to construction, grading, engineered fill, and other actions, followed by prolonged ongoing operations, eliminating forested habitat and impacting riparian zones. Noise, air pollution, temperature changes, traffic, light spillage and other impacts will affect wildlife far beyond the project boundaries.
Short term and long term impacts on biological resourced must be assessed. Baselines of flora and fauna on both sites and in surrounding areas must be established. In particular, biological impacts in the riparian zone of South Fork Wolf Creek downstream must be established due to significant changes in flow, seasonality impacts, temperature, pH, dissolved solids, and other water quality criteria relevant to aquatic life. For example, what will be the effect of removing 18 acres of forest habitat? What effect will the constant noise, traffic, nighttime lighting, and depositing of engineered fill have on the wildlife that inhabit the area around the mine site? Will there be an increase in animal-vehicle accidents? What effect will the mine have on seeps and natural springs used as a water source. Will wildlife be forced into neighboring residential areas, creating hazards?
4. Wetlands on both sites must be delineated and project impacts on wildlife assessed.
5. Perennial and seasonal seeps, springs, and creeks must be delineated and project impacts on wildlife assessed.
6. The spring fed pond designated as “clay-lined pond” on the Brunswick site and the marsh and meadow lands below that pond must be evaluated for impacts to the aquatic and avian species.
The South Fork Wolf Creek is a perennial stream that originates on the East side of Brunswick Rd. It is incorrectly classified in the current project descriptions.
7. The riparian habitat along this stream in the reach to the West of Brunswick Rd before it flows into a grated culvert on the Brunswick site must be evaluated.
8. The culverted portion of the stream should be daylighted across the project and afforded 100’ setback protections.9. The EIR also must include reviews and approvals from CA Dept of Fish and Wildlife, US Fish and Wildlife Service, the Regional Water Quality Control Board, California State Parks (Regarding impacts to Empire Mine State Park Restoration Areas downstream on South Fork Wolf Creek ), and other oversight agencies.
Tribal Cultural Resources The mine project sites are both located in areas that were probably inhabited by native Nisenan people prior to the arrival of miners and settlers. Despite the fact that the sites are extremely impacted by mining and other activities, it is highly likely that there are undisturbed soils that have remained in place under the overburden of tailings, waste rock, pavement, and fill. These may contain tribal cultural resources from generations of occupancy.
An archeological analysis of the area must be conducted in order to determine the degree to which this is a cultural heritage site of the Nisenan people. Careful monitoring of construction and mining related activities must be conducted, especially when excavating native soils. Geology Soils and Mineral Resources The project includes dumping of waste rock and tailings into two major, engineered fill pads. Landfills settle as buried materials realign, decompose, and are transported by surface and subsurface flows. Cover integrity is compromised by vegetation, burrowing animals, and depressions that allow surface pooling, etc.
The impacts of these must be evaluated. Monitoring of the integrity of the landfill cover must be established. Funding for routine maintenance must be explained. Approval for the landfill at the Centennial M-1 site requires that Nevada County allow entitlements for development in a Seismic Hazard Zone, and along an Earthquake Fault line. In addition, construction in areas with slopes that exceed 30%, and are comprised of highly erodible soils, is in planning.
4. A full analysis of how the landfill will be designed to prevent seismically induced slope failure must be made.
The applicant has asked for waivers on multiple entitlements.
5. The EIR must respond to each of these waivers and explain on what grounds these waivers will be granted.
6. The EIR must contain options other than these waivers. For example, a reduced slope, or a reduced size of the mine waste piles must be considered. Elimination of onsite dumping must also be considered.
Energy What happens when there is a power outage?
All aspects of operations during a power outage and a power restart must be assessed in terms of emergency power capacity, safety, emergency services, impact on the environment and other impacts. An assessment of these energy impact conditions should be done for short term and long term scenarios. An analysis of how the proposed energy use of the mine impacts the Nevada County Energy Action Plan. The EIR must assess the availability of gas and electric utilities and other utility providers, and their capacity to serve the project. Greenhouse Gas Emissions (GHG)
Due to global warming and the 80 year scope of the proposed project, the full range of predicted changes in weather patterns and precipitation must be considered in estimating the surface water runoff and storm water management systems, as well as water usage and shortages, fire risks, temperature impacts on water resources and habitat, and all other impacts from climate change.
The following analyses must be included in the EIR with respect to GHG impacts:
Air quality and GHG emissions from transportation of materials and equipment. Embedded energy costs, costs due to the production of materials and equipment. All project related activities of employees, non-resident and resident. Emissions due to the relocation of non-residents into the area to fill jobs Impacts from traffic due to mining operations. Activities following closure (beyond 80 years) should be assessed, including but not limited to:
6. Emissions from continuing operation of water treatment facilities following mine closure
7. Maintenance and testing of stockpiled materials, monitoring wells, reclamation, etc.
All initial and ongoing supplemental activities should be assessed in terms of energy costs and GHG emissions such as:
8. The provision of new water lines, additional energy costs of water transport, road improvements off site.
9. Emissions from reclamation
10. Emissions of GHG gases other than CO2
11. Cumulative impacts must be considered in all GHG sources.
12. California targets for GHG emissions reductions for 2030 and 2050 must be addressed with viable solutions for meeting reductions
13. Project alternatives in scale, scope, and configuration must be considered as options for addressing GHG emissions over the course of the project lifespan.
Hazards and Hazardous Materials The EIR must fully evaluate the potential impacts of accidental release or harm from transport, storage, and utilization of explosives and other hazardous materials. Provisions for general employee health and safety must be considered in all work environments. In particular, risk to health, safety, and lifespan due to mining hazards must be assessed, including the effects of long term exposures, chemicals, fugitive dust, exhaust and other health risks. Wildfire impacts must be assessed. The EIR must evaluate the wildfire risks of facilities and materials, such as fuel storage tanks and chemicals, and how they will be kept from contributing to the existing fire danger at this location. Wildfire evacuation issues must be addressed, as well as emergency response. Safety issues with haul trucks and other mine related traffic must be assessed. Earthquake hazards must be analyzed. Potential hazards from subsidence or collapse of mining tunnels over the 2585 acres of mineral rights must be addressed. Hydrology and Water Quality The Geotechnical Report prepared by NV5, submitted by the applicant states that: Index testing of the near-surface soils were performed as part of our soil evaluation in an effort to evaluate corrosion potential. The measured minimum resistivity values indicate that the on-site soil conditions exhibit a “moderate“ risk for corrosion of ferrous metals in contact with the soil or rock. The presence of high acidity, pH of 5.5 or less, in the soil samples is considered corrosive to concrete. Soil with a pH of 5.5 or less can react with the lime in concrete to form soluble reaction products that can easily leach out of the concrete. The result is a more porous, weaker concrete.
All soils issues must be investigated as part of the EIR and clearly explained to the public. California Health and Safety Code Division 20, Section 6.5 defines disposal as:
The abandonment of any waste which may be emitted into the air or discharged into or on any land or waters including groundwaters, or may otherwise enter into the environment creates a disposal site at the mining site. Using sand generated from blasting to refill the tunnels left from previous mining may contaminate groundwater and should be investigated and included in the EIR. Waste rock and tailings that are deposited below the surface in any form (e.g. cemented slurry, crushed rock, etc.) must be investigated and included in the EIR. Underground refilling of past mining tunnels should include continuous quality assurance inspections during placement of backfill, testing of mineral composition to verify conformance with pH ranges deemed acceptable.
The flooded Idaho-Maryland Mine must be dewatered and then a maintenance level of water discharge must be maintained. The initial dewatering will require discharge of 2500 acre-feet of mine water. After about 6 months of operation, the discharge rate will drop to about 1.9 cfs. continuing throughout the lifespan of the 80 year project and beyond that indefinitely. All of this water must be treated to remove contaminants.