TSF testifies to SWRCB on impacts of suction dredging

Sacramento, January 6, 2009 – Elizabeth Martin, CEO of The Sierra Fund, spoke to the State Water Resources Control Board at their January Board meeting in Sacramento, in support of a resolution to allocate $500,000 from the Board’s cleanup and abatement account to the Department of Fish and Game (DFG) in order to augment court-ordered environmental review of suction dredge mining activities. Martin pointed out that the Water Board has lead authority over protecting California’s water, stating that “we believe that you are right to be concerned about the impact of suction dredging on the State’s water quality.”

The Sierra Fund supported the Water Board’s action to fund research to better understand the impacts of suction dredging, especially in mercury laden streambeds, in response to a California court order that an environmental impact review of the suction dredging program be conducted. DFG is planning to conduct a comprehensive environmental review of suction dredging in response to a court order that required such a review in light of new information about the impacts of suction dredging.  This review was supposed to have been completed by July 2008, six months ago. 

Data generated by scientists at the SWRCB indicate that suction dredge activities disturb and mobilize the mercury left behind from gold mine operations. Martin pointed out, “There is really no credible scientific doubt about the impact of suction dredging in ‘flouring’ mercury, nor the increased potential for methylation that can result.”  Methylmercury has been a regulatory concern of the SWRCB for several years due its known serious effect on human health.

The Sierra Fund joined the Karuk Tribe, Friends of the North Fork American River, and several environmental groups in speaking to the Water Board. These groups share a concern that the well-documented impacts of suction dredging on water quality and endangered species will continue while this long-delayed environmental review is underway, despite evidence of the harm of suction dredging.

While supporting the resolution authorizing $500,000 from the Cleanup and Abatement Account to DFG for the EIR on suction dredging, The Sierra Fund asked that the SWRCB approval of the funds be contingent on the following:

  1. The SWRCB should write a letter in support of the petition by the Karuk Tribe and CalTrout to the California Department of Fish and Game to immediately suspend the permitting of suction dredging in identified water bodies until the EIR is complete and satisfactory mitigation measures are established to protect water quality and fish.
  2. The Board should participate in the environmental review to ensure that the environmental review of suction dredging takes a critical look at methylmercury issues.
  3. The SWRCB should consider regulatory actions to implement provisions of the Clean Water Act applicable to suction dredge mining, including requiring a non-point discharge permit for this activity.

After a lengthy public hearing, the State Water Resources Control Board members voted 4 – 1 to pass the resolution.  Board member Gary Wolfe voted against the resolution, stating that he wanted to see more specific language in the contract with DFG to ensure careful review of the mercury issues.  He also expressed some concern about the regulatory authority of the Board and asked for a legal opinion on whether suction dredging requires a non-point discharge permit. 

The Sierra Fund has worked with the State’s leading scientists as part of our Mining Toxins Initiative to assess and address the long term impact of gold mining on the state. Our report, Mining’s Toxic Legacy includes research developed by the US Geological Survey as well as SWRCB’s own scientists. The following “Briefing Memo” summarizes some of our concerns about the impact of suction dredging in the headwaters of the State Water Project, especially as it pertains to mercury disturbance as part of suction dredge mining for gold.



January 21, 2009 News Flash: 

Today the California Department of Fish and Game issued their Request for Qualifications (RFQ) (number P0810009) entitled “Suction Dredge Permitting Program.” 

The California Department of Fish and Game (Department) seeks Statements of Qualifications (SOQs) from interested businesses and individuals to prepare a Subsequent Environmental Impact Report (SEIR) related to the Department’s permitting program for suction dredge mining in California. The Department administers the suction dredge permitting program. The SEIR and related review under CEQA will analyze new significant and substantially more severe environmental impacts that may be occurring under the existing permitting program that were not addressed by the Department during prior environmental review completed in 1994.

The Request for Qualifications is available at: 
https://www.cscr.dgs.ca.gov/bidpkg_dl/090116105146667.doc


Gold Mining, Mercury and Suction Dredging
Excerpts from “Minings Toxic Legacy” by
The Sierra Fund, 2008

An estimated 26 million pounds of mercury were used to extract gold from ore in California, most of it in the Sierra Nevada Gold Country(1).  Of this, an estimated 10 million pounds were lost to the environment in placer mining operations and another 3 million pounds were lost from hard rock mining(2).

Elemental mercury or “quick-silver” is still commonly encountered in Sierra watersheds. Recent studies by the Delta Tributary Mercury Council indicate that runoff and erosion from gold mines in the Sierra are a significant source of mercury to the Sacramento Delta(3).

In the suction dredging process, miners remove gravels from the riverbed with a suction hose powered by an engine, and then use pans or other methods to retrieve the gold. Suction dredgers often encounter mercury and gold-mercury amalgam, which tend to fall into the cracks of the riverbed like gold.  Suction dredges re-suspend and “flour” mercury, increasing the surface area and making it more readily available for bacteria to methylate(4).

Dredgers collect the mercury and amalgam, and retort it or treat it with nitric acid to release any gold that may have amalgamated with the mercury.  They then recover the mercury and usually store it, though some miners dispose of it in an unauthorized manner, such as pouring it back into the river, onto the ground, or into municipal sewer systems.

The full text of “Mining’s Toxic Legacy” can be downloaded from The Sierra Fund’s website:  www.sierrafund.org/campaigns/mining


(1)Alpers, C., P.  R Hunerlach, J. T.May, and  R. Hothem. (2005a). Mercury Contamination from Historical Gold Mining in California. U.S. Geological Survey Fact Sheet 2005-3014

(2) Churchill, R. K. (2000). Contributions of Mercury to California’s Environment from Mercury and Gold Mining Activities–Insights from the Historical Record. Extended abstracts forthe U.S. EPA-sponsored meeting, Assessing and Managing Mercury from Historic and Current Mining

(3) Delta Tributary Mercury Council. (2002). Strategic Plan for the Reduction of Mercury-Related Risk in the Sacramento River Watershed. DeltaTributary Mercury Council.

(4) Humphreys,  R. (2005). Mercury Losses and Recovery during a Suction Dredge Test in the South Fork of the American River. California State Water Board Staff Report. Sacramento, CA.

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