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Our comments to California Fish and Game for initial scoping process for the new suction dredging EIR

December 3, 2009

December 3, 2009
Mark Stopher
California Department of Fish and Game
601 Locust St
Redding, CA 96001

Mr. Stopher,

Thank you for the opportunity to provide comments on the initial scoping study for the suction dredge permitting program for California.

I have been the editor, publisher and owner of ICMJ’s Prospecting and Mining Journal for ten years. The magazine was originally established in 1931 as the California Mining Journal and has been based in California since its inception. I also worked for the magazine prior to purchasing it, beginning in 1982. I began suction gold dredging in 1983, and have used suction gold dredges in both California and Oregon waterways. I believe my personal and professional experience provides valuable expertise in the area of suction gold dredging.

I have spent a considerable amount of time examining the initial study document and summary of available studies recently released for comments. Nowhere in those documents are the overriding laws listed or discussed, including the grants afforded miners by the mining laws from 1866 to present. While I’m sure you are aware that no regulations can be changed or implemented without considering the laws pertaining to mining, I am also aware that the various mining laws and grants are covered in comments submitted by Public Lands for the People and others, so I will not duplicate their efforts here.

The majority of the material cited in the Notice of Preparation was published prior to the original EIR in 1994 and subsequent attempt at a new EIR in 1997. The research material listed after that date is inadequate to support a change from insignificant to deleterious. In fact, I was unable to locate any definitive studies that make this conclusion; rather, the literature cited is ripe with speculation, often using words such as “may” cause or “could” cause harm to fish or their spawning areas.

I attended the public scoping meeting in Sacramento. At the meeting, Mark Stopher stated that materials submitted to the State Water Resources Control Board in their recent (2007) scoping process were included and do not need to be resubmitted. However, this does not seem to be the case.

Joseph C. Greene, a retired U.S. EPA research biologist, provided a peer review of available studies on suction gold dredging to the State Water Resources Control Board (2007).  He concluded, “The issue against suction dredge operations in the streams of the United States appears to be less an issue of environmental protection and more of an issue of certain organized individuals and groups being unwilling to share the outdoors with others without like interests.”

Claudia Wise is a retired U.S. EPA physical scientist/chemist. She provided a peer review of available studies to Governor Schwarzenegger prior to the passage of SB 670 (2009). She stated, “Dozens of peer-reviewed journal articles some commissioned by the USEPA, USGS, CDFG, Corp of Engineers, and many more from universities support suction dredging as having de minimis effects or no significant effect on the environment they are used in.  Nothing has changed in peer-reviewed literature since that time to change this fact.”

Page 41 of the scoping literature states that mercury is discharged into our waterways by suction dredges. This is dishonest at best. Mercury is a heavy metal that settles at or near the bedrock due to its high specific gravity so it often gets vacuumed up and entrained in the dredge’s riffles along with other heavy metals and minerals. One study cited in the scoping document claimed that approximately 98% of the mercury was recovered during a test. The study went on to claim that the remaining 2% could cause problems through fish contamination and methylation. Claudia Wise addresses this concern in her peer review:

          The mining community of today is, in my opinion, the only group that is in a position with the technology to help with the removal of lead and mercury at a very economical price to the public.  Any residual mercury remaining after dredging is that much less to worry about residing in our Nations waterways.

In reviewing Humphrey's (2005) comments regarding possible problems associated with collecting mercury via suction dredging methods, it is right to look to the suction dredge community for help locating hotspots and removing mercury from the river systems.  In my opinion the data provided in the report by Humphrey's (2005) did not demonstrate any clear conclusions that would prohibit the State from allowing this activity.  On the contrary, in the discussion of results it was stated that a suction dredge in the American River was able to collect 98 percent of the measured mercury processed through the dredge.  The amount of mercury collected may have been higher if the investigators had been using a dredge with the modern jet flare design. Even 98 percent is a huge plus for the environment and it would be irresponsible to not allow mercury to be removed from the rivers and streams whenever it is found.

In Humphreys report (2005), the author expressed concern for the loss of a small portion (2%) of the mercury from the back end of the sluice box.  In the conclusions it was stated that the amount lost constituted a concentration more than ten times higher than that needed to classify it as hazardous waste.  Yet 98 percent of the mercury was now secured and the process did not add any mercury to the system that was not already present.  The small fraction lost, because of its density, would relocate back onto the river floor buried in the sediment close to where it was removed while dredging.
Mercury is continuously moved every winter in high storm events.  Since the cessation of hydraulic mining, accumulated sediment from hydraulic placer mining has been transported to the Sacramento–San Joaquin Delta and San Francisco Bay by sustained remobilization (James, 1991).  Providing a program to collect mercury from miners would aid the Water Board’s mission of reducing mercury contamination in the deltas and bays where mercury methylation is a large concern.

In the test described by Humphreys (2005) a small portion of floured mercury was collected in the sediments as it escaped the sluice box.  This mercury whether floured before it entered the sluice box, or not, would still be in elemental form.  Regardless of surface area it would be no more toxic then the other 98 percent that was suggested to be left in place. 

Aside from grossly polluted environments, mercury is normally a problem only where the rate of natural formation of methyl mercury from inorganic mercury is greater than the reverse reaction. Methyl mercury is the only form of mercury that accumulates appreciably in macroinvertebrates and fish. Environments that are known to favor the production of methyl mercury include certain types of wetlands, dilute low-pH lakes in the Northeast and North central United States, parts of the Florida Everglades, newly flooded reservoirs, and coastal wetlands, particularly along the Gulf of Mexico, Atlantic Ocean, and San Francisco Bay (USGS 2000). 

If not collected the mercury is guaranteed to end up farther downstream, and eventually in the delta or the bay, where methylation is a real environmental problem. In my opinion it would be a highly irresponsible management practice to leave a large portion of mercury in the rivers and streams because of unrealistic concerns for the lesser amount moving only a short distance away from an operating dredge.  Most likely if floured the movement of fine mercury would extend no farther than 50-feet off the end of the sluice box.  That would relate to the distance a turbidity plume might extend downstream from a small-scale suction dredge. 

However, if the mercury was left in place the next storm event would surely move it downstream closer to, and eventually into, the bay and delta. In fact, according to Humphrey's study in 2005 mercury was seen moving down stream and re-deposited on bedrock already dredge cleaned.  The important fact here is mercury was flowing down stream in a suction dredge free zone during lower river flows than what take place under high winter river conditions.

It is most important to reduce the total amount of mercury in the streams and rivers and its transport downstream into the bays and deltas.  This is defined as a part of Total Maximum Daily Load (“TMDL”) goals.
We know for certain that mercury is transported downstream throughout the winter season during high water events. Therefore, anytime there is the possibility for the removal of mercury by miners it should be undertaken and supported. (Emphasis added.)

Mr. Josiah H. Cornell III is retired from the USDA Forest Service in Oregon. Cornell addressed many of the issues related to spawning of salmon in his own study of suction gold dredging. Cornell stated:

          Salmonids spawned in the vicinity of the previous season's dredging, but, in one study, salmonids redds were not located in tailing piles. The gravels dispersed by the high stream flows, which included dredge tailings, certainly composed a portion of the suitable spawning gravels each year. Dredge tailings have been observed to provide good salmonid spawning ground due to the loose condition of the sand and gravel. In some places, mining debris may provide the best or only habitat.

A five-inch dredge could improve the intergravel environment for both fish eggs and benthos. Weighing all factors, dredging can improve the gravel environment for both fish eggs and aquatic insects. (Emphasis added.)

Mr. Greene, Ms. Wise and Mr. Cornell have extensive experience relevant to the upcoming EIR on suction gold dredging, including water quality, temperature, turbidity, fish, biota, and related topics. As we have recently learned from the release of emails indicating fraud involving the IPCC’s climate change reports, some scientists have a desire to skew results whether it be motivated by continued monetary grants, personal or political agendas. Mr. Greene, Ms. Wise and Mr. Cornell are now retired from their respective government agencies. They are no longer dependant on grant money, nor are they required to adapt to an agency agenda to maintain employment. For these reasons, their opinions should carry a much stronger weight in this process.

I have included copies of the peer reviews of Joseph C. Greene and Claudia Wise so their peer reviews can be included in this scoping process.

Based upon my personal and professional experience, which includes operation of a four-inch dredge over many years, I can state unequivocally that your data in “Table 1: Characteristics of Various Suction Dredges” is grossly exaggerated. The data suggests that suction dredges move large amounts of material. For example, a six-inch dredge may be capable of moving 6 to 17 cubic yards of material in one hour, but no miner is going to move that much material because much of the gold will be missed.

Table 1 states a miner utilizing a 4-inch dredge will move 1 to 5 cubic yards per hour. In my experience, I moved approximately 2 cubic yards of material per day with a 4-inch dredge averaging 6 hours with the dredge in operation, or 0.333 cubic yards per hour. Based on my personal and professional experience, I believe 0.333 cubic yards per hour is a realistic amount for any miner using a 4-inch dredge. Each miner is looking to recover as much gold as possible, not to just move material. While a dredge can surely move more material, the miner’s goal is to clean out the cracks and crevices to recover the gold, which is a time-consuming process. Much of the miner’s time is spent cleaning out those cracks and crevices, hence the lower volume of material processed.

I understand that the economic impact may not be considered until later in the process. However, I’m including a recent study I completed with the assistance of Pat Keene of Keene Engineering, a major suction dredge manufacturer, and Rachel Dunn of Gold Pan California, a retail mining store. Based on the results of that study, we found that suction dredging has a minimum economic impact in California of $65.46 million, not including several major categories like payroll and property taxes, commercial retail rents, trade magazines, and more. The study was conducted when the gold price was $871.86 per troy ounce. With the current gold price at $1,215 per troy ounce, and many unemployed citizens looking toward gold mining as a way to make ends meet, the current economic impact should easily exceed $100 million in my professional opinion.

This concludes my comments.


Scott M. Harn
ICMJ’s Prospecting and Mining Journal
831 479-1500


A.    Joseph C. Greene; Peer review submitted to State Water Quality Control Board, 2007.
B.    Claudia Wise; Peer review submitted to Governor Schwarzenegger’s office regarding SB 670, 2009.
C.    Harn, Scott; Dunn, Rachel; Keene, Pat; “The Economic Impact of Suction Dredging in California,” ICMJ’s Prospecting and Mining Journal, Vol. 79 No. 2, pgs 37-38, Sept. 2009.

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