A Preliminary Assessment of the Proposal to Reopen Idaho-Maryland Mine
Grass Valley, CA – March 11, 2020
Rise Gold Corp’s application to re-open the Idaho-Maryland Mine is not yet deemed complete by Nevada County Planning Department, but a review of currently available documents provides a glimpse into the nature of the project and how it may impact our community.
The main mine access and processing facilities will be located at the 119 acre New Brunswick site located at the corner of Brunswick and East Bennett Roads. Operations will also utilize the 56 acre Centennial site on Idaho-Maryland Road west of Centennial Drive to dispose of mine waste.[1]
Mining will take place 24 hours a day, 7 days a week. About 1500 tons of waste rock and tailings will be removed from the mine daily. Of this, 500 tons per day will be mixed with cement to form a paste backfill and re-deposited into the mine. The remaining 1000 tons per day will be deposited at the Centennial site and at a 31 acre area along Brunswick Road just south of the processing facility and bounded by neighborhoods on Cedar Ridge Drive, Elk Lane, and Mink Court.
Waste rock and tailings from the mine will be transported by trucks making up to 100 round trips per day, 16 hours per day, 7 days per week. To get to the Centennial site, they will turn left onto Brunswick Road about 0.4 miles south of East Bennett Rd, pass through the intersection of East Bennett and Brunswick and turn left onto Whispering Pines Lane to reach Centennial Drive.
At the Centennial site, an area of 44 acres will be built up with “engineered fill” to depths of up to 70 feet, eventually forming a 37 acre graded surface that may be utilized for future development. Similarly, the mine waste dumped at the Brunswick Road site will eventually cover an area of 31 acres and be built up as much as 90 feet to form a 21 acre graded area for possible future industrial uses.
The trucks will be loaded with rock with a front-end loader. Hauling will take place 6:00 AM – 10:00 PM, 7 days a week. After the rock is dumped, it will be graded and compacted 7:00 AM – 3:30 PM, 7 days a week, using bulldozers, graders, and rolling compactors. [2] This activity will take place continuously for 11 years or until both build-up areas are maximized. After that, mine waste materials will have to be hauled out via Brunswick Road to Glenbrook Basin in order to access Hwy 49 for transport to sites not yet identified.
In terms of energy use, the permit application estimates a PG&E power net load of 6000 Kilowatts (KW). Planned diesel backup power generation capacity is 6000 KW. Electricity utilization is estimated at 42,757,000 Kilowatt-Hours (KWH) per year.[3] This is equivalent to the electric use of about 5000 houses.[4]
Full operations of the mine, including fuel for equipment, electricity, and other operational uses are estimated to produce around 9,000 metric tons of greenhouse gas emissions per year.[5]
Cement, explosives, diesel, and various other chemicals will be regularly transported to the site and stored. Cement will be mixed with tailings and pumped back underground and used to backfill mining voids. By one estimate, the backfill paste will use approximately 25 tons of cement daily. Explosives will include ANFO (Ammonium Nitrate and Fuel Oil), and Ammonium Nitrate Emulsion. Up to 28,000 lbs. of explosives will be stored onsite underground.[6] Diesel fuel storage will consist of a 30,000 gallon aboveground storage tank. A number of other chemicals will be utilized for processing the gold using the sulfide flotation system and other activities.
Industrial buildings covering 122,000 square feet are proposed for the New Brunswick site. Noteworthy among these would be the gold processing plant with dimensions of 425 feet by 70 feet and 65 feet high, and the shaft headframe building with a height of 165 feet. Running between these buildings will be a 365’ long enclosed conveyor system. Tailings will be stockpiled onsite while waiting for transport.
The application to re-operate the Idaho-Maryland mine states that 312 jobs would be created by the
mine operations. Of those jobs, 242 jobs are specialized technical positions likely taken by people
recruited from outside the area. The remaining jobs, truck transport of mine waste, and mineral
processing, could provide 70 jobs for current local residents.
Content provided by Community Environmental Advocates Foundation (CEA Foundation)
*** Visit the CEA website at www.cea-nc.org *** Contact via info@cea-nc.org ***
[1] Project application documents may be viewed at https://www.mynevadacounty.com/2882/Application-Documents—Rise-Grass-Valley . Unless noted, see Idaho-Maryland Mine Project Description, Nov 2019;IMM will use equivalent to 42,757,000 / 8000 = 5344 houses.
[5] Ibid [3] [6] Environmental Factors of Blasting Report for the Proposed Idaho-Maryland Gold Project, Sept 27, 2019, https://www.mynevadacounty.com/DocumentCenter/View/30457/Environmental-Factors-of-Blasting-ReportJan 21, 2020 – Facing EPA Superfund Designation, RISE Gold Compelled To Cleanup Existing Idaho-Maryland Mine Tailings
While Canadian mining company RISE Gold Corp was promoting the gold mine potential and alluring prospects of gaining permits to reopen the Idaho-Maryland Mine (IM Mine) in Grass Valley, CA, federal and state regulatory agencies were focusing on the polluted tailings that cover most of the 56.4 acre site and taking steps leading towards a Superfund Designation.
There has been little public disclosure of the contaminated legacy IM Mine tailings, but correspondence from the EPA dated Sept 26, 2019 indicates that IM Mine’s potential designation as a Superfund site was conditionally deferred because RISE entered into a cleanup contract with the California Department of Toxic Substance Control (DTSC).[1] On August 13, 2019, RISE Gold CEO Ben Mossman signed agreements to cleanup the site, also known as the Centennial site.[2] According to the DTSC records, RISE has been dealing with this issue from at least as early as March 13, 2019, when the first Scoping Meetings with the DTSC took place.[3]
Tests conducted in 1993 by Vector Engineering showed elevated levels of arsenic, chromium, copper, mercury, lead, and nickel over two large areas of the legacy tailings, one area originating from the Mercury gold extraction processing that took place prior to 1926, and a second area being from the Cyanide extraction processing that took place from 1936 until the mine closed around 1956.[4] More recent reports from the DTSC determined that lead, arsenic, nickel, and mercury are present at hazardous levels.[5] Contaminated tailings cover roughly 2/3 of the 56.4 acres with depths ranging from 2 to 20 feet.
As an additional complication, RISE Gold’s recent bid to re-open the mine includes plans to use the site for disposal of 1.6 million tons of mine waste rock and tailings as “engineered fill” over the course of 5 years, covering 44 acres and creating a built-up area 30 to 70 feet above current grade. However, a recently posted geotechnical report indicates that the legacy tailings are not structurally adequate for use underneath the engineered fill, so they have to be completely excavated before the dumping can take place.[6] The full extent of the contamination within the tailings is not yet clear, but even if some of the tailings are clean they will all have to be extracted and then remixed with other aggregates before they would be stable enough to be built upon as planned.[7]
Rise Gold has not yet revealed what procedures will be used to get the legacy tailings off the bedrock and safely dealt with before the new waste rock and tailings from mine operations can be deposited. Nor is it clear whether the contaminated tailings will need to be sequestered separately on site, whether they can be integrated into the engineered fill, or whether they need to be trucked to a waste disposal facility.
According to the agreement, the entire remediation process will be overseen by the DTSC. However, Nevada County and other government agencies will be overseeing all operations with respect to the IM Mine re-opening permits, which is independent of the DTSC permitting and is a separate project with a separate time frame.
[1] US EPA Transmittal of Preliminary Assessment Report,Sept 26, 2019, https://www.envirostor.dtsc.ca.gov/public/final_documents2?global_id=29100007&enforcement_id=60472136 [2] Cleanup Agreement, Signed by RISE Aug 13, 2019, https://www.envirostor.dtsc.ca.gov/public/final_documents2?global_id=60000716&enforcement_id=60458269 [3] Ibid., Exhibit E [4] “Contaminant Assessment of the Bouma-Erickson-Toms Property”, Vector Engineering, Nov 1993. [5] Centennial Geotechnical Report, NV5, https://www.mynevadacounty.com/DocumentCenter/View/31540/Centennial-Industrial-Site-Geotechnical-Engineering-Report [6] Centennial Site History, DTSC, https://www.envirostor.dtsc.ca.gov/public/profile_report?global_id=60000716 [7] Idaho-Maryland Mine Project Description, Nov 2019, pg 16, https://www.mynevadacounty.com/DocumentCenter/View/31023/Applicants-Project-DescriptionJan 20, 2020 – Some Key Points From The Initial Application (details may change)
The operation will remove 1000 tons of ore and 500 tons of non-gold bearing rock a day with mining continuous 24 hours a day, 7 days a week.
The headframe, rock conveyors, ore crushers/grinders, water treatment plant, paste backfill plant, and truck loading area will all be located at the Brunswick Industrial Site at the corner of East Bennett and Brunswick Road. 122,000 square feet of industrial buildings will be constructed at this site.
Haul trucks—50 to 100 round trips per day, running from 6 AM to 10 PM, 7 days a week—will dump a mixture of barren rock and processed tailing sand at two sites: the southern end of the Brunswick site, near to and behind homes on Mink Court, Elk Lane, Brunswick Drive, and Cedar Ridge Drive; and at the Centennial site, off Idaho Maryland Rd, along the edge of Wolf Creek.
The trucks will be loaded with rock with a front-end loader from 7 AM until 7 PM, 7 days a week. After the rock is dumped, it will be compacted beginning at 7 AM using bulldozers, graders, and rolling compactors. This operation will create a large amount of noise and dust. Dust from these operations is likely to contain asbestos as well as lead and arsenic from massive tailings that must be remediated first.
In addition to four industrial-size backup diesel generators, the exhaust from the daily use of diesel trucks, bulldozers, graders, and compactors, will greatly increase greenhouse gas emissions. The paste backfill plant will create 500 tons of backfill every day, 7 days a week. The production of the cement used to make the backfill paste will release an estimated 55,000 pounds of CO 2 daily. Thus, the CO 2 generated just by the backfill plant will be roughly equivalent to the CO 2 generated by 1200 cars.
Dec 22, 2019 -RISE has submitted an application to Nevada County to open the mine. The county staff are currently reviewing the application and preparing to start the CEQA process. The application overview can be viewed at https://www.mynevadacounty.com/2881/Idaho-Maryland-Mine—Rise-Grass-Valley . The project details per the applicant’s documents can be viewed at https://www.mynevadacounty.com/2882/Application-Documents.
CEA Foundation (aka formerly CLAIM-GV) was among the agencies and groups that were contacted and invited to submit preliminary comments to provide additional information at this early stage. A comment letter was produced by the collective efforts of CEA Mining Committee and submitted on Dec16. The Mining Committee drew heavily upon experience from prior mining projects to produce this document. See:
IdahoMarylandMine_App_CEA_comments_13Dec2019 DownloadThis is the start of the permitting process which will probably take more than a year. Once the application is deemed complete and a CEQA Notice of Preparation (NOP) is recorded, public scoping meetings will follow in which possible impacts are identified for study for the Draft Environmental Impact Report (DEIR).
At this preliminary phase, CEA has identified many areas of great concern. Most notable:
–Possible misguidance to investors – The obstacles to permitting and high costs of development and operations are not adequately delineated.
-Significant GHG emissions – Initial electric usage will be at least 50 GWH/yr, or about 20% of Nevada County’s total usage. Significant fossil fuels will also be used. It needs to be net zero.
–Impacts of dewatering – Among other things, plans to dewater into S.Fork Wolf Creek were rejected in prior DEIR process due to impacts of permanent flood stage downstream.
–Ground water risks – Potential pollution risks from operations, tailings, explosives, gold processing and threat to local wells beyond the area currently identified.
–Truck traffic – Up to 16 trips/hour for up to 80 years.
–Noise – 24/7 Operations, high velocity fans, aggregate trucks loading, etc.
–Subterrainian reclamation – Risks of toxic leaching over time from 500 tons/day of slurry backfills
–Economic impacts – Negative impacts on local housing, tourism, high tech businesses
–Regulatory challenges – Constant monitoring will needed on numerous operations.
–Habitat loss -Replacing large areas of forested woodlands with barren gravel fill, including “engineered fill” covering 75 acres to depths of 30-70 feet.
Sept 29, 2019 – RISE Gold has obtained over $3.5M in funding and is preparing to apply for a mining permit. As in the previous case with Emgold Mining Co, this junior mining company from Canada is spinning a fantastic story about the prospects of the Idaho-Maryland Mine and finding speculators willing to throw their money at the project. (See risegoldcorp.com)
June 1, 2019 – The noise stopped. RISE Gold apparently completed their exploratory drilling operations. This is a great relief to the area residents who have been suffering from the noise.
Drilling Noise —Residents in the area have been very impacted by the 24/7 drilling noise.
Numerous complaints were made to Nevada County officials for noise violations. However, since a previous sound study by an independent acoustical consultant showed that the sound levels were marginally within legal limits, County officials were not responsive.
Residents then challenged the validity of the sound study due to the placement of the metering and due to the fact that the drilling operators had full knowledge that the metering was taking place. Measurements of the noise by residents showed noise levels in excess of the legal limits during the hours of 10:00 PM – 7:00 AM. Supervisor Dan Miller made a site visit and agreed that the noise level in a neighboring house was unacceptably loud.
As no action was being taken by the County, in May 2019 a number of people made public comments to the Board of Supervisors requesting that the drilling at least be shut down during the night. Unfortunately, no code violations were issued and no initiatives were undertaken by the BOS. Apparently, in order to compel action with the county, the residents would have to pay for a costly sound study to show that noise levels are in violation.
10/1/18 RISE violations continue — CEA Foundation continues to monitor the activities of RISE Gold Corp, the new owner of the Idaho Maryland Mine. RISE has now acquired most of the land that was previously owned or lease-optioned by Emgold, in addition to some other parcels. Since Fall 2017 they have been doing extensive drilling at the “New Brunswick” site located near the intersection of East Bennett and Brunswick Rd, adjacent to the old SPI site. (Millsite Rd).
– In mid-September 2018, RISE moved their drilling operations from near the old SPI site to the newly constructed pad at the west side of their holdings (12603 East Bennett Rd). In setting up their equipment, RISE again violated the 100’ setback from the creek! This was in spite of having been required to hire a biologist to prepare a Biological Management Plan as a consequence of prior violations last winter (see below). Also, there has been some controversy regarding their method of measurement for establishing the 100’ setback. County ordinance requires that the setback be measured from the high water mark or the top of bank, which is apparently not the case here. The County is now requiring the biologist to reflag the correct setbacks and possibly restore a larger area in the riparian zone.
– Local residents have filed complaints about noise from the drilling operations. To mitigate that, RISE has constructed a sound wall.
In March, 2018, RISE was cited for failing to obtain a Timberland Conversion Permit (as per CCR 1103.1 Conversion of Timberland). Two citations were issued: Violation of Section 4581 (PRC) – to the landowner Violation of Section 4571 (PRC) – to the logger, who was not a licensed timber operator
2/16/18 More Violations — In addition to the County grading violations, Idaho-Maryland Mine owner RISE Gold Corp failed to submit the required timber harvest plan and timberland conversion document, as per the local CalFire (CDF) Forester in charge of permits.
1/30/18 Update of RISE Grading Violations — The grading work that was done was reportedly not in conformance with the submitted plans, resulting in failed inspections failing in December/January. In addition to failing to protect against storm runoff into South Fork Wolf Creek, grading work was done in violation of the 100′ setback from the creek and a large number of trees had been logged and staged within the setback. Because of these violations and encroachment into the setback zone, a comprehensive Management Plan, to be prepared by a qualified biologist, was requested. (as per Nevada County Land Use and Development Code Section L-II 4..3.17.) County reported back that RISE must submit revised plans showing accurate depiction of work completed, erosion control measures, 100ft setback, and site survey. This submission and a biologist recommendations will be reviewed by county.
11/27/17 Idaho-Maryland Mine Grading Protections Inadequate — Local advocates from Wolf Creek Community Alliance (WCCA) and CEA noticed grading work to create a road and pad on a parcel between Bennett St and South Fork Wolf Creek. The work was done clearly without adequate storm water management protections. Complaints were lodged with Nevada County Building Dept. This property is on the western portion of the Idaho-Maryland Mine (IMM) New Brunswick site. A county permit had been taken out to build a pad. Unfortunately, the new owner of IMM, RISE Gold Corp, failed to comply with the county grading guidelines.
11/5/17 A New Mine Owner — The Idaho-Maryland Mine was acquired from Emgold Mining by Rise Gold Corp, another junior mining company from Canada. The new owner has recently completed exploratory drilling at the New Brunswick site. This site is situated at the headwaters of the pristine South Fork Wolf Creek near where Bennett Street intersects Brunswick Road.