Rise Gold attempts to reopen once lucrative Idaho-Maryland Gold Mine | TheUnion.com

Rise Gold attempts to reopen once lucrative Idaho-Maryland Gold Mine

John Orona
Staff Writer

After two years of exploratory drilling at the flooded Idaho-Maryland Mine just east of the Grass Valley city limit, Rise Gold Corporation has submitted a permit application that would allow it to reopen what was once the second largest lode gold producer in the United States.

The mine produced 129,000 ounces of gold per year before being shut down by the U.S. government in 1942 to focus resources on the war effort. Previous attempts to revive the gold mine in the 1950s, 1980s and most recently in 2010 have all failed due to varying combinations of financial distress and community pushback.

“Everything that’s been designed has been designed for the purposes of minimizing the impacts of the project,” Rise Gold President Ben Mossman said. “Because of the historic permitting of the mine we were able to understand what the most important issues are to the community and how to mitigate those at the start of the design stage.”

The 93 acres of surface land and 2,800 acres of mineral rights that comprise the Idaho-Maryland Mine project were bought by Rise Gold after its previous owner spent nearly a decade trying to get the project past the permitting stage before ultimately failing to produce an environmental impact report that satisfied the community.

The permit application was filed after the company completed more than 67,000 feet of exploration core drilling which, according to Rise Gold, demonstrated a continuation of gold mineralization in both the Idaho and Brunswick gold veins below the historic mine level about a mile below the surface.

The company was allowed to do exploratory drilling due to the M1 zoning classification of the area but will need to have the area rezoned by the county, receive approval for its clean-up plan and obtain a use permit and variance before the planned deep underground mining and above ground gold processing can begin.

That process is expected to take at least a year and doesn’t include other permits that will need to be obtained by outside agencies such as the State Water Resources Control Board and the Northern Sierra Air Quality Management District.

Grass Valley was the lead agency during the last attempt to reopen the mine. According to Nevada County Planning Director Brian Foss, Grass Valley had the option of taking the role of lead agency on the project because it is within its sphere of influence. It declined this time as it would have had to annex the project into the city,

Next steps

Once the county reviews the application it will hire a third party consultant to create a draft environmental impact report, the step the previous owner never completed following demands to address traffic, air quality, noise and water concerns.

While many technical and environmental documents were submitted along with the permit application and can be found on the county’s website, the traffic, groundwater hydrology and air quality studies will not be available until January, Mossman said.

In 2017, the Environmental Protection Agency ranked the top 50 abandoned mines in California in terms of risk to residential areas, recreation areas and the environment.

The Idaho-Maryland Mine ranked as the most outstanding mine in need of abatement overall, first in waterborne residential exposure, second in direct residential exposure and second in waterborne ecological exposure. The ranking takes into account factors like mine size and proximity to schools when determining the potential impact.

According to Sierra Fund CEO Elizabeth Martin, the greenhouse gas emissions from transporting the proposed 1,000 tons of mined rock per day away from the site and the impact on local water wells are the biggest concerns with reopening the mine.

“There’s an enormous amount of water underground and they have to move it aside to get to the gold, so that means what used to be your nice well down in this area is suddenly sucked dry because you have a pump somewhere down there literally sucking the water out,” Martin said. “One could imagine what that would be like to have huge trucks full of material many times an hour driving through downtown Grass Valley. One can imagine the transportation impacts would likely be raised.”

According to Rise Gold, it does not anticipate running into the same environmental challenges as previous owners because it won’t have the ceramic manufacturing setup previously proposed which significantly contributed to air quality emissions.

The company also plans to construct a pipeline of potable water to supply to about two dozen residents along East Bennett Road whose wells may be affected by draining water from the mine, a move it said is purely precautionary.

Water removed from the site would be treated through aeration followed by filtration through a manganese dioxide filter in a man-made pond on the site before an estimated 500-1,200 gallons per minute are discharged into Wolf Creek.

If the mine is allowed to reopen, Rise Gold would renovate the existing Brunswick Shaft that towers over the property and extends 3,400 feet below the surface to move rocks out of the mine. They also plan to construct a second shaft extending 3,280 feet below the surface as well as several buildings to house the mineral processing plants and operational facilities.

The company expects the project would create 300 direct jobs and as many as 1,200 in total based on a 3.9 workforce multiplier for the mining industry.

No cyanide or mercury would be used in the mineral processing.

“It is too early to define the implications of the proposed reopening of the mine, because we simply do not have adequate information at this point in time,” Board of Supervisors Chairman Richard Anderson said in an email. “On one hand, there may be local economic benefit. On the other, there may be significant environmental impact. The project-review process is intended to reveal these aspects so as to allow the board to make an informed decision.”

To contact Staff Writer John Orona, email jorona@theunion.com or call 530-477-4229.


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