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DUMPS Mine Waste

Rise Gold owns the toxic Centennial Site and is obligated to clean it up. That’s good for the community, but if the Mine is approved, they’ll use it to dump more mine waste.

pre-superfund site



Rise Gold owns two sites, the Centennial site near downtown Grass Valley off of Idaho-Maryland Road, and the larger Brunswick site at the intersection of East Bennett and Brunswick Roads.

The Centennial site is a historically toxic site that is facing EPA Superfund designation.

That designation has been "conditionally deferred" for the time being because Rise Gold has agreed to clean up the site under the supervision of the CA Department of Toxic Substances Control (DTSC). And now, the proposed Idaho-Maryland Mine project plans to use it as the first place they’ll put their “engineered fill” using waste rock and tailings extracted from the mine.

Environmental advocates like CEA Foundation fully support the cleanup, but are opposed to dumping mine waste on the site.

The goal is to restore the property to a healthy natural state, including reestablishing vegetation, reclaiming some wetlands, and letting existing seasonal creeks continue to flow. Per the zoning planned by the City of Grass Valley, open spaces would be developed as a mixed-use Business Park with some Medium Density Housing. Rise Gold is paying for the work.

The project was started in August 2019 and is completely independent of the Mine project, which is managed by the Nevada County Planning Department. For the Centennial Site cleanup, DTSC is the lead agency. It uses different inspectors. And there is no dependency on the mine being approved.


A Preliminary Endangerment Assessment (PEA) was published in 2020 that evaluated the contaminants and guided the planning for the Centennial Site. 


The first draft of a Remediation Action Plan (RAP)  was published in July 2021 and the public was invited to comment. Under CEQA, this is a "Mitigated Negative Declaration", which examines the impacts and proposed mitigations (such as how to mitigate the damage to wetlands that will get dug up during the cleanup.) DTSC has not published a schedule for the second draft yet.

Learn more about comments that were provided by CEA Foundation and coalition partners.  



A key issue related to the Centennial Site is the fact that the County's Final Environmental Impact Report excludes the Centennial Site from the full analysis of the impacts of the proposed Idaho-Maryland 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.

Read more about why the County should deny the Final EIR and the project

Centennial Site.PNG

Listen to Barbara Rivenes from the Sierra Club as she explains the EPA's requirements for cleaning up Centennial site and how that relates to the proposed reopening of the Idaho-Maryland Mine. 

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