Regional
Wolf Creek, Toxics, and Public Services Key Topics at Idaho-Maryland Mine Meeting
Author: Susan Lauer, YubaNet
Published on Jan 25, 2008 - 4:08:03 PM

While a rainy evening may have kept some residents away from a city-sponsored meeting about the proposed Idaho-Maryland Mine, the 50 or so that gathered heard about how mine operations might impact Wolf Creek and public services, while importing hazardous materials to the area.

The meeting on Jan. 23 was the second of four to keep the community updated about work being done for the draft Environmental Impact Report (EIR) on a proposal by Emgold to reopen the abandoned Idaho-Maryland gold mine, shuttered since 1956. The draft EIR is scheduled to be released in spring 2008.

"Because this issue is so complex, we want to keep the community engaged and informed," said Tom Last, planning director in Grass Valley.

Mine Dewatering and Water Quality in Wolf Creek

During the first six to nine months, 532 million gallons of water from 72 miles of flooded mine shafts (to a depth of 3,300 feet) would be dewatered, treated and pumped into Wolf Creek and South Fork Wolf Creek so gold mining exploration could begin. The flow into the creek is estimated at 2,700 gallons per minute or 6 cubic feet per second. After that, dewatering would continue at a rate of 500-1200 gallons per minute, until the mine closes.

The water would be pumped from the mine tunnels and contained in a settling pond to be treated at an onsite treatment plant. The water then would be conveyed to a storage detention pond and ultimately discharged into Wolf Creek.

The treatment process would include water aeration and reduction of turbidity (cloudiness due to disturbed sediment), as well as reduction of contaminants, including iron, arsenic, and magnesium.

"Before it goes into the creek, the water will be treated according to regulations," said Pete Hudson, senior hydrologist at Environmental Science Associates (ESA), the city's consultant preparing the EIR. "We are analyzing what will be the effect of adding water during the dewatering process."

Wolf Creek and South Fork Wolf Creek are tributaries to the Bear River, which feeds the Sacramento River. NID imports water into both Wolf Creek and Bear River. The Wolf Creek watershed covers 2,738 acres and South Fork Wolf Creek 1,487 acres.

Water Quality Issues

Surface water testing was done by Emgold in 1991 and 1996, and in 2003 to the present. Currently, water is collected at 45 locations quarterly to establish a baseline or "screening level" of water quality upstream.

Specifically, ESA consultants are analyzing how mine dewatering might affect both branches of Wolf Creek, including changes to stream water quality, increased flow, erosion and flooding, and how it could impact sensitive riparian habitat and species accustomed to low-flows in the dry season.

Hazardous Materials

Hazardous materials such as cyanide, explosives, fuels and lubricants will be used for mining operations.

"Hazardous materials are heavily regulated on both the state and federal levels," noted Hudson, citing the Federal Mine Safety and Health Act (MSHA) among others.

Emgold proposes to truck in sodium cyanide (NaCN) in one- to two ton nylon "super sacks" in granular or powder form and perhaps in liquid form in 4,000 gallon double-walled container trucks. The "super sacks" would be delivered about once every three weeks.

Emgold will be using a closed-looped cyanide leach system, to separate the gold from the ore. From there, the cyanide goes into a destruction chamber.

Hudson also noted that explosives would be stored on the surface, with long-term storage underground, in accordance with state and federal regulations.

Public Services

ESA consultant Jennifer Johnson discussed how the proposed mine could affect public services in the area.

The mine would have a security plan, including 24/7 security, a border fence topped with razor or barbed wire, guards posted at the main gate and Bennett Street gate, and security cameras.

As far as impact to local services, such as police and fire departments, Johnson said that an estimated 627 new residents would move into the community - up to 200 workers in the mine operations plus their families.

Given this flux in population, the Grass Valley Police Department would need four more officers and two support staff, additional equipment and more unpaid volunteers in order to maintain service level.

One problematic area is the fact that the police department is already at capacity, so there could be a need for new facilities.

The Fire Department would also need additional staff, due to the increased population. Another issue is that several of the mine buildings would be taller than the current reach of the city's aerial ladder truck, which is 45 feet.

In the draft EIR, consultants will note potential impacts and propose mitigation measures, which can include fees or other solutions to offset those impacts.

Emergency Response Plan at the Mine

Emgold would develop a plan and take precautionary measures in the event of an emergency, including keeping 42,000 gallons of stored water onsite that would be available for fire suppression.

In terms of mine rescue, if there are fewer than 35 people underground, the mine would train one rescue person for every 10 people underground. An additional two rescue teams in Northern California (in Tuolumne and Lassen) would be available. They could be onsite in two hours by helicopter.

If the mine has more than 35 people underground, the mine would need to train its own onsite rescue teams with five members on two teams available at all times.

Emgold, a junior mining company from Canada, wants to explore for gold starting in 2010 or 2011.

The Draft EIR is slated to be ready in spring 2008, with details about the environmental impacts of proposed mine operations and also mitigation plans to offset any impacts. Before dewatering and mining, Emgold will need approval by the City of Grass Valley as well as state and federal agencies.

Wednesday's public workshop was the second of four. The next meeting is scheduled for Feb. 13 and will present information about the project's reclamation plan and financial assurances. The final meeting is scheduled for March 2 and will address traffic and other cumulative impacts, including air quality. Check the City of Grass Valley's website for updated information.

Here are some of the questions and comments by the public with answers from the consultants and additional information provided by YubaNet.

Q: "There have been tests that confirm the mercury from past mining exists in streambeds around Nevada County. It stays in place because there's no additional water or disturbance. Have you done tests of the streambed and bank in Wolf Creek and South Fork Wolf Creek or downstream to determine if mercury could be disturbed?"

A: Water quality tests are being done. "Mercury is a tricky beast..." noted geochemist Bill Walker, adding that consultants will look into all water quality issues.

Q: "There will be dangerous and toxic materials used at the mine. How much will be stored onsite?"

A: That amount will be disclosed in the draft EIR, according to Tom Last.

Q: It's been found that toxics are still in the Empire Mine - they are still there after so many years. Any guarantees that this won't happen here? Is there a dollar value to cover damage if it occurs?

A: "There is a process and procedure that is addressed in the reclamation plan. We'll talk about it during the next (February) meeting," said Tom Last.

Q: There's 72 miles of tunnels. Do you know what's down there?

A: City mining consultant Ray Krauss said, "We will comprehensively look at everything. There will be uncertainty. That's why we take the 'belt and suspenders' approach with redundancies. So if you can't tell what might happen, you have contingencies if something does happen. The idea is to identify what can go wrong and build into the plan ways to deal with it."

Q: "I wonder if that mine is in the wrong place? There are a lot of regulations ... but the law means nothing if it's not enforced. I would feel better if the hazardous material is not near me."

A: Tom Last noted that the regulations for hazardous materials are stringent, and the material will be handled with care.

Q: A resident commented about a recent study of other recent mining operations, noting there was a "75% failure rate to comply with clean water standards. How will we know that our EIR will be accurate?"

A: "The key is to work collectively so if the project is approved by the city, everything is addressed," said Ray Krauss.

Additional information: The research to which the questioner referred is "Comparison of Predicted and Actual Water Quality at Hardrock Mines," and "Predicting Water Quality Problems at Hardrock Mines: Methods and Models, Uncertainties, and State-of-the-Art," by Jim Kuipers, P.E., and geochemist Ann Maest, Ph.D., who analyzed water quality predictions and outcomes at 25 representative metal mines permitted in the U.S. during the last 25 years. It was published in Dec. 2006. It found that "faulty water quality predictions, mitigation measures and regulatory failures result in the approval of mines that create significant water pollution problems. Despite assurances from government regulators and mine proponents that mines would not pollute clean water, researchers found that 76 percent of studied mines exceeded water quality standards, polluting rivers, and groundwater with toxic contaminants, such as lead, mercury, arsenic and cyanide, and exposing taxpayers to huge cleanup liabilities." In the 25 mines studied, other findings include:

-- 93 percent of mines that are near groundwater and have elevated potential for acid drainage or contaminant leaching exceeded water quality standards
--85 percent of mines that are near surface water and have elevated potential for acid drainage or contaminant leaching exceeded water quality standards
-- Water quality standards for toxic heavy metals, such as lead, mercury, cadmium, copper, and zinc, were exceeded at 63 percent of mines.
-- Mitigation measures predicted to protect clean water failed at 64 percent of the mines.

To read the entire study, go to http://mineralpolicy.org/PR_KuipersMaest.cfm

Q: "There aren't a lot of gold miners here, and we are trying to attract clean tech from the Bay Area. Why even begin thinking about attracting mine operations that could be so detrimental to the community. What's the value?"

A: "We have an applicant on property designated as a mineral resource zone by the state. They have a right as a landowner to apply."

Additional information: The California Surface Mining and Reclamation Act (SMARA) of 1975 requires the state to classify land into mineral resources zones, based on either known or inferred mineral potential. The Idaho-Maryland mine, which operated from 1862 to 1956 is a mineral resource zone (MRZ). According to the state, "the primary goal of the mineral land classification is to ensure that the mineral potential of the land is recognized by local government decision makers and considered before making land use decisions that could preclude mining." While local governments are required to note MRZs in their General Plans, there is no state requirement that property designated as a mineral resource zone be set aside for actual mining. Local governments can zone it for other kinds of development, including residential housing, business park, etc.

Q: "Current flows will be replaced by treated water. What will be the effect of that?"

A: Water quality studies will monitor the treated water to ensure that it will be clean enough to go into the creeks.

Q: In reference to the fact that Emgold plans to backfill the mine shafts with tailings and waste rock, "What will happen 100 years from now? Will we still be treating the polluted water from the mine? The mine runs for 20-30 years. What about after that? What provisions?"

A: "The best we can do is the make calculations that will show what the water quality will be. It will be different. That will be studied in great detail. We are concerned about water quality," said Bill Walker.

Much of the information presented at the meeting is published in the Notice of Preparation/Initial Study, available on the city's website: http://www.cityofgrassvalley.com/services/departments/cdd/IDMDMINE.php

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