[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;

[2] Noise and Vibration Analysis, Table 9, https://www.mynevadacounty.com/DocumentCenter/View/30467/Noise-and-Vibration-Study-Report

[3]Air Quality and greenhouse Gas Emissions Analysis Technical Report for the Idaho-Maryland Mine Project, Feb 2020, pgs 73-74, https://www.mynevadacounty.com/DocumentCenter/View/33583/Air-Quality-and-GHG-Report—ADDED-392020

[4] Average energy usage per CA residence = 667 KWH / month = ~8000 KWH / year. https://www.electricchoice.com/blog/electricity-on-average-do-homes/
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-Report

Jan 21, 2020, Press Release
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] OnAugust 13, 2019, RISE Gold Corp 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 thatlead, 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 theyhave 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’s 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;

[2] Cleanup Agreement, Signed by RISE Aug 13, 2019;

[3] Ibid., Exhibit E

[4] “Contaminant Assessment of the Bouma-Erickson-Toms Property”, Vector Engineering,
Nov 1993.

[5] Centennial Geotechnical Report, NV5

[6] Centennial Site History, DTSC,

[7] Idaho-Maryland Mine Project Description, Nov 2019, pg 16;

Content provided by Community Environmental Advocates Foundation (CEA Foundation)
*** Visit the CEA website at http://www.cea-nc.org *** Contact via info@cea-nc.org ***

Community Environmental Advocates, Press Release, January 14, 2020

A Canadian company, Rise Gold Corporation, aka Rise Grass Valley, has filed an application for a permit to reopen the Idaho Maryland mine. These are some key points from the initial application:
  • 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 Bennet 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 CO2 daily. Thus, the CO2 generated in one day—just by the backfill plant—will be roughly equivalent to the CO2 generated by over 1600 cars.

The project description, noise study, and other documents related to Rise Gold’s application can be obtained at:


If you object to having an industrial-scale gold mine in our community, voice your objections to Matt Kelley, who is the Project Planner for the County, and your Nevada County District Supervisor. Mr. Kelley can be reached by phone at 530-265-1423 or by email to matt.kelley@co.nevada.ca.us. Your district supervisor can be found at:


Demand an open, public process, full disclosure of the current physical and chemical hazards on the properties in question, and the negative impacts the mine will have on our community.

CEA Foundation is committed to being fully engaged to protect our community from the impacts of this massive project. Subscribe to our newsletter for further information.

*** Visit the CEA website at www.cea-nc.org *** Contact via info@cea-nc.org ***










By Ralph Silberstein

The Idaho-Maryland Mine was recently acquired from Emgold Mining by RISE Gold Corp, a junior mining company from Canada. The prior Canadian owner, Emgold Mining, spent years trying to get the mine opened and failed. Due to immense environmental impacts, financial obstacles and public opposition, Emgold eventually abandoned the project.

Repeating the pattern of Emgold, RISE, the new owner, has recently completed some exploratory drilling and has been publishing enticing reports. In a Jan 3, 2018 press release, RISE CEO Ben Mossman stated “The presence of high-grade gold values in the walls of the quartz veins was not expected…” and “The possibility that there could be very substantial gold mineralization in the developed upper levels of the mine is astonishing…”

Except this isn’t astonishing news at all. RISE is excitedly reporting gold deposits in concentrations previously reported in multiple glowing reports by Emgold [e.g Emgold Publication March 2008].

It all sounds so promising, so easy, such a lucrative deal. Multiple alluring reports have been produced yet again. Following the pattern of Emgold, RISE has turned to funding methods that are not approved by the SEC, collecting more than $2 million via “private placements”.

Why didn’t Emgold open the mine? What is going on?

The reality is that the mine is flooded and deposits lie thousands of feet under polluted water.

The mine shut down in 1956 due to LOW PRODUCTION. In order to get to what gold is left, miles of tunnels have to be dewatered and continuously treated to meet the strict California standards. So a water purification system to handle large volume has to be designed and built. It will have to run forever.

Also, discharging this water means putting South Fork Wolf Creek at flood stage. This creek is a pristine little stream that runs down into the beautiful meadows along Bennett Street. The land is owned by Empire Mine State Park and has been undergoing habitat restoration. Extensive environmental studies will be required to assess the impacts on this habitat before anything can go forward.

There also will have to be studies and guarantees to protect local well owners. Costly water mains and service lines will have to be installed in advance throughout the area to provide a solution for the possibility that the mine would impact these wells.

Even without considering the dewatering issues, it is questionable whether it would be financially feasible to mine the ore that remains at such depths. In California, the Surface Mining and Reclamation Act (SMARA) requires that all mines have a reclamation plan in place before starting. Gone are the days in which a mining company could extract massive amounts of waste rock, leave tailings all over the place, pollute the area with mercury or cyanide or arsenic, and then leave it all when the gold runs out. In order for the mine to get SMARA approval, the area will need a reclamation plan and a huge guarantee bond.

This problem is even larger because the mine property already has vast areas of tailings left over from earlier days which are in need of testing and potential remediation. In a recent EPA study of California abandoned mines to determine their potentials of hazardous exposure, Idaho Maryland Mine is listed as number one! [“Prioritization of California Abandoned Mines Exposure-Based Algorithm” May 9, 2017, Hillenbrand]. RISE Gold now owns this legacy clean up problem.

And there will be other environmental impacts. The mine is situated at the City of Grass Valley. There will be noise impacts, air pollution impacts, traffic impacts, and energy consumption limitations due to California’s strict new climate change laws. The project will need to have an Environmental Impact Report which must be approved by multiple agencies. It is well known that the local environmental community will not stand for anything other than full and careful scrutiny.

The executives at RISE undoubtably know all this, but make little mention of these huge obstacles. CEO Ben Mossman recently spoke at a mining conference as if the permitting would be easy, with “only county approval needed”, failing to mention a reality that paints an entirely different picture. But, in one sense, Mossman is right. Idaho-Maryland Mine is still a very productive gold mine. Only instead of mining for gold, it is again being used to mine unwary investors: in the last year alone RISE has collected over $2 million in investment cash.

Ralph Silberstein is a member of Community Environmental Advocates


In a press release dated today (February 1, 2013) Canadian penny-stock mining company, Emgold Mining Corporation, uses language more explicitly suggestive of closing-up shop in Grass Valley than any they have used before. They suggest they may drop the Idaho-Maryland Mine project altogether to focus their resources on “other assets the Company has in its portfolio.”


Further to the Company’s October 26, 2011 and September 7, 2012 press releases, permitting activities associated with the Idaho-Maryland Project (the “Project”) remain on hold pending the resurgence of the junior mining equity markets. Emgold reiterates what it stated in its past press releases that, despite the current price of gold, financing for projects in the junior mining sector is extremely difficult. In the event that insufficient funds can be raised to move the Project forward, Emgold will continue to delay the Project until market conditions improve or, as a worst case, drop it to focus on the other assets the Company currently has in its portfolio.

The current extension of the Lease and Option to Purchase Agreement (the “BET Agreement”) expires today. The BET Agreement, signed in 2002, originally had a five year term. It has been extended three times to date, in two year increments, with the last extension taking effect on February 1, 2011. Emgold is currently in negotiations with the BET Trust to extend the agreement, which covers the lease and option to purchase of approximately 2,750 acres of mineral rights and 91 acres of surface rights associated with the Project. If negotiations to extend the BET Agreement are unsuccessful, Emgold will terminate the Project and focus on the other assets the Company currently has in its portfolio.

The City of Grass Valley cancelled Emgold’s IMM Project application after it failed to meet a city-imposed deadline of September 10, 2012 for submitting the necessary funds to the City of Grass Valley for independent consultants to begin preparation of a revised Draft Environmental Impact Report (DEIR) on the proposed mine and ceramics factory.

For more information, see CLAIM-GV.org.


Today, the Nevada County Board of Supervisors approved a contract for $179,811 with consultants PMC to prepare an Environmental Impact Report (EIR) for the proposed re-opening of the San Juan Ridge Mine. The San Juan Ridge Taxpayers Association (SJRTA) commends Nevada County’s decision to prepare a full EIR for the project in light of the possibility of significant negative impacts to the water supply, environment and local economy.

Because the applicant promised no impacts to water when the mine originally opened in 1993, the SJRTA was willing to accept the project with mitigations.  But the applicant was wrong, and the mine caused dewatering of 12 wells in the surrounding community, including the well for our local elementary school.  Some wells were contaminated with a variety of metals and minerals. To this day, the school’s water must be treated at the school district’s expense to meet drinking water quality standards.

The proposed San Juan Ridge Mine would operate in close proximity to our public elementary school, our only medical clinic, our community cultural center, and businesses that employ more than 200 people.  Says SJRTA president Gary Parsons, “The mine could devastate our water supply and our community, further poison the water that we provide for our school children, and damage our economy and our natural environment.”

While we commend the County for requiring an EIR for the project, the SJRTA has concerns that the EIR be fully funded.  Given the broad range of potential environmental impacts and magnitude of potential effects, and the difficulty of understanding underground water supplies, there is a need for special analytical tools that may be costly.  Costs for the recently proposed Idaho-Maryland Mine’s Environmental Impact Report were estimated to be $440,000.  Impacts at the San Juan Ridge Mine site would also include potential dumping into sensitive creeks and habitat for rare wildlife species, as well as a more complex hydrologic system, and thus EIR costs may be higher.

The San Juan Ridge Taxpayers Association will provide more information as to our concerns when a formal Notice of Preparation of an Environmental Impact Statement is made available by Nevada County in the coming weeks.

The San Juan Ridge Taxpayers Association (SJRTA) is a membership organization representing taxpayer interests on the San Juan Ridge of Nevada County, CA since 1974. The SJRTA membership includes taxpaying residents and non-resident landowners of the San Juan Ridge and other local concerned citizens.

By Don Pelton

Jeff Pelline, in his Sierra Foothils Report a few days ago, wrote about  City Council candidate Howard Levine’s position on various local issues, including his support for re-opening the Idaho-Maryland Mine. I’ve spent enough years, in an effort with others, to research all aspects of this issue, including its inadequacy as a business proposition, that I’m inclined now to the view that anyone who supports re-opening the mine must not be acquainted with all the facts.

Here are the comments I appended to Jeff’s posting, encouraging current council members as well as candidate hopefuls to study the issue more fully:

I hope that if Howard Levine is elected to the council, he will reconsider his support for re-opening the Idaho Maryland Mine.

Now that Emgold’s application has fortunately expired, the council should critique its own role in allowing such a poorly-crafted business proposal to drag out for nearly a decade, not only wasting valuable community resources, but preventing a more viable project for that site to be considered in its stead.

We expect the council, at the very least, to recognize a viable business proposal when it sees one, but its handling of the Emgold fiasco suggests that it still has some important lessons to learn in this regard.

It’s tempting to say that the council should be able to evaluate a proposal on its business merits altogether aside from its environmental impacts. But in truth the environmental impacts of a proposal are integral to its economic viability. It’s not clear to me that this fundamental aspect of doing business in the Sierras is well-understood by the current council, much less by hopefuls like Howard Levine.(See the work of Steve Frisch’s Sierra Business Council for a good understanding of this issue).

Among the council’s biggest mistakes with Emgold was its failure to obtain a competent economic viability study of the project proposal contained in Emgold’s application. The 2005 study conducted by the SF Bay Area consulting group Bay Area Economics, an organization that had no experience with evaluating a mining project, was not adequate.

The council should immediately establish, with community feedback, some ground rules and guidelines for a minimally-acceptable application for mining within city limits, since the impacts of such a development will profoundly affect Grass Valley’s character and business climate.

There are good arguments for prohibiting mining altogether within city limits. The council should be willing to hear and consider these arguments.

After some years working with others to critique Emgold’s application, I have come to the conclusion that the biggest overlooked fact about the idea of re-opening the IMM is its monstrously huge scale. Few really grasp this.

The underground extent of the IMM is about the same as the city of Grass valley itself (~3200 acres). It runs under the Sierra Nevada Memorial Hospital, under the Basin, and out to the Y juncture of 174 and Brunswick.

This geographical extent, as huge as it is, is exceeded by its potential sphere of harm (including hydrologic uncertainty about well failures, etc). This is all copiously documented in the work of CLAIM-GV (Citizens Looking At Impacts of Mining in Grass Valley).

A common misunderstanding is that the mine — if reopened in the heart of downtown Grass Valley — would have limited impact, potentially affecting only those who live in close proximity to it.

Because of its scale, every resident in Western Nevada County effectively lives in close proximity to IMM.

My suggestion to Howard Levine and all other council hopefuls, as well as to the current council members, is to start this self-critique by reading Tom Grundy’s excellent and widely published article on the weaknesses of Emgold’s application. It was published in the Union, in Yubanet and in my own Sierra Voices, which I shamelessly plug here:

Will Grass Valley Learn From Its Mistakes With Emgold?