No state monitor for mine: Water quality board to rely on Rise Gold for regular reports, environmental assurances |

No state monitor for mine: Water quality board to rely on Rise Gold for regular reports, environmental assurances

The Central Valley Regional Water Quality Control Board that may issue limited threat discharge permit would rely on RiseGold for regular environmental reports

The next stage of the possible reopening of the Idaho-Maryland Mine hinges on the release of a draft environmental impact report, started last year by Raney Planning & Management.

If that report states the Rise Gold Corp. project poses no “significant” risk to taxpayers, the company will move one step closer to receiving the limited threat general discharge permit from the Central Valley Regional Water Quality Control Board — a requirement to operate the mine.

The specific permit Rise Gold hopes to acquire would allow for 3.619 million gallons (5.6 cubic feet per second) of water to enter Wolf Creek every day.

According to the project’s hydrology report, Rise Gold Corp. anticipates 1.224 million gallons (1.9 cubic feet per second) will be pumped to the surface from inside the mine in a settling pond on a daily basis. The report estimates the mine will consume 123,000 gallons of groundwater daily through water vapor used in ventilation, cemented paste backfill, dust control and due to gold concentrates being transferred off site. The rest — 1.101 million gallons of “underground mining service water” — will go to Wolf Creek.

Although mining requires blasting rock, which contains various elements, to extract precious metals and minerals, Rise Gold has promised to return the water to Nevada County residents in better condition than it entered.

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.

The company behind the mine’s tentative reopening, and its CEO Ben Mossman, have committed to removing the arsenic in the sand tailings at the mine’s Centennial site. According to Mossman, the state’s Department of Toxic Substances will oversee the company’s “voluntary” clean up, left over from older mining practices that ended in 1956.

Mossman said he trusts his hydrologists, but that the state’s water control board takes measures to keep corporations like Rise Gold Corp. accountable.


John Baum, an assistant executive officer at the Central Valley Regional Water Quality Control Board, called his employer a regulatory agency that enforces the water quality laws of California. The water control board works with the identified dischargers at a site to ensure compliance with those laws.

Baum said the permits establish expectations for the company’s self-monitoring and testing of those discharges to protect California at large.

“The permitting process requires that the discharger understand their site, the associated hydrology, and constituents within the water proposed or being discharged,” Baum said. “The frequency, locations, and constituents to be sampled are tailored for each site.”

Baum said the discharger may hire consultants to prepare documents for the permit application and to meet the requirements once the permit is issued. Those consultants must meet substantial qualifications expectations.

Ultimately, Baum said there is no state-paid hydrologist that will be monitor the mine on a regular basis.

“The discharger — and their contractor — developed documents that are then submitted to our technical staff for review to ensure compliance,” Baum said. “If a discharger is out of compliance with the regulatory requirements, we start with warnings, but there are increasingly punitive actions we utilize to persuade them to obey.”

Baum said his organization prefers to “cooperate” with dischargers, but will issue financial penalties “when the situation dictates doing so.”

Baum said the water quality control board breaks mine sites into three categories: active, inactive/closed, and inactive/abandoned mines.

“There are likely hundreds of old, inactive and abandoned historical mine sites of all shapes and sizes in the region that aren’t documented,” Baum said when asked how many mines the Central Valley Water Quality Control Board oversees.

His staff knows of three active mines in Nevada County under permit: Hansen Brothers Enterprises Greenhorn Creek operation (sand and gravel), RidgeRock Quarry (crushed stone and aggregate), and the French Corral Mine (gold).

Baum said there are a number of other mines which are either inactive or legacy clean-up sites where the water board has a regulatory oversight role.

“Inactive sites may also be a cleanup site if water quality issues have been identified,” Baum said.

The legacy clean-up sites are: Empire Mine State Historic Park, Idaho-Maryland Mine project, Lava Cap Mine, Malakoff Diggins State Historic Park, North Star Water Treatment Facility (for both the North Star Mine and the Drew Tunnel), Spanish Mine and the Spenceville Mine.

Rebecca O’Neil is a staff writer with The Union. She can be reached at

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