Small-Scale Suction Gold Dredging

Presented by: Joseph C. Greene, Research Biologist Prepared for a Meeting with Oregon State Legislators, Oregon Small-scale Miners, and US EPA Region 10 Representatives March 9, 2006 Oregon House Of Representatives Office Building, Salem, Oregon

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Small-Scale Suction Dredging and the Environment

It is my opinion that the results from scientific investigations, presented in the Environmental Impact Reports, prepared by the State of California, Clearwater National Forest and Siskiyou National Forest, provide all the evidence required to support the determination that small-scale suction dredging is

de minimis

and impacts from these dredges are

less than significant

.

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The “Real” Problem

Many people want outdoor settings to be left in a

natural condition for quiet enjoyment. Thus suction dredging is perceived as a conflict with these activities. The noise of the suction dredge engines and exhaust fumes and the presence of the suction dredge activities may be the very things many people go outdoors to escape. However, suction dredgers

also enjoy the outdoors.

(CDFG, page V25) 3

The “Real” Problem

It should be noted that suction dredging is considered a legitimate activity on rivers and streams and suction dredge operators have a

Federally mandated right to operate. Dredgers also have the basic right, of all citizens, to enjoy and utilize streams as long as their activities are in compliance with the laws and

regulations of the State.

ORS 541.110 provides, “the use of water of lakes and running streams of Oregon for the purpose of developing the mineral resources is declared to be a public and beneficial use and a public necessity.”

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For discussion the following excerpts were taken from the

Draft Environmental Impact Report, Adoption of Amended Regulations for Suction Dredge Mining. 1997. State of California, Dept. of Fish and Game.

The Conclusions in this report concur with those found in the Clearwater and Siskiyou National Forest Environmental Impact Reports.

These documents are the culmination of literature searches for scientific evidence regarding the impacts of small-scale suction dredging on the environment and consultations with stakeholders and concerned citizens.

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Research to Support the Siskiyou National Forest DEIR

The SNF engaged Dr. Peter B. Bayley, Dept. Fisheries & Wildlife, Oregon State University, to conduct a “Cumulative Effects Analysis” on the effects of suction dredging forest-wide Dr. Bayley concluded:

"The statistical analyses did not indicate that suction dredge mining has no effect on the three responses measured, but rather any effect that may exist could not be detected at the commonly used Type I error rate of 0.05."

(In other words, if there is an effect, it's so small they can't measure it.)

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Dr. Bayley continued…

"The reader is reminded of the effect of scale. Localized, short-term effects of suction dredge mining have been documented in a qualitative sense. However, on the scales occupied by fish populations such local disturbances would need a strong cumulative intensity of many operations to have a measurable effect."

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Dr. Bayley concluded…

"Given that this analysis could not detect an effect averaged over good and bad miners and that a more powerful study would be very expensive, it would seem that public money would be better spent on encouraging compliance with current guidelines than on further study."

Now, back to the comments published in the California Department of Fish and Game “Draft Environmental Impact Report”.

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The area or length of river or streambed worked by a single suction dredger as compared to total river length is relatively small compared to the total available area.

An individual suction dredge operation small-scale suction dredge (representing 90 percent of all suction dredges) may spend a total of 4 to 8 hours per day in the water dredging an area from 1 to 10 m 2 (3-33 ft 2 ).

affects a relatively small portion of a stream or river . A The average number of hours spent is 5.6 hours per day . The remaining time is spent working on equipment and processing dredged materials.

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Current regulations on most rivers and streams, in conjunction with riparian protective measures,

results in a less than significant impact to

channel morphology.

Turbidity and sedimentation levels

generally return to background levels within 20 to 80 m

(66-263 ft) below the dredging activities. In many of the studies performed on suction dredging, potentially adverse impacts to river resources were reported.

Effects of increased turbidity levels and sedimentation, decreases in invertebrate populations and re-configuration of

the streambed were temporary and localized.

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Suction dredging can have significant short-term and localized adverse impacts invertebrate abundance and community composition. However, on local benthic

over the long-term, the

impacts appear to be less than significant.

Colonies of invertebrates generally re-colonize areas disturbed by suction dredges within a relatively short period of time ranging from one to two months. Impacts to benthic invertebrate communities, from suction dredging,

appear to

be less than significant.

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Effects to benthic and/or invertebrate communities, turbidity and water quality appear to be

less than

significant.

They are usually localized and temporary in duration!

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Impacts on Fish

Effects from elevated levels of turbidity and suspended sediment normally associated with suction dredging as regulated in the past in California

appear to be less than significant with regard to impacts to fish and other river resources

because of the level of turbidity created and the short distance downstream of a suction dredge where turbidity levels return to normal.

ADULTS: Suction dredging appears to have little direct immediate physical effect on adult fishes in terms of harm from actual entrainment by dredges.

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Impacts on Fish

Juveniles: Entrained through a suction dredge does not appear to have a significant adverse effect on juvenile fish either.

Yolk Sac Fry: Entrainment can have a significant adverse effect on the more delicate stages of fish such as the yolk sac fry. During this stage the yolk sac can be easily ruptured or torn from the fish.

Eggs: Developing eggs of salmonids are significantly adversely affected by entrainment through suction dredges. The degree of harm may vary depending on species.

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Impacts on Fish

Fish eggs and yolk sac fry are protected by seasonal regulations that keep small-scale suction dredgers out of the rivers and streams during this season.

Current law requires that dredging operations must stop or move if redds are present during a permitted “In Water Work Period”.

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Impacts on Spawning Gravel

Most of the effects related to turbidity and sedimentation, and the disturbance of spawning gravels reported were temporary and localized, and therefore, represented impacts considered less than significant .

Dredge piles do not appear to occupy a significant portion of the available spawning habitat so that dredge pile impacts are expected to be less than significant

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Impacts on Spawning Gravel

Approximately 60 salmonid redds were observed in a study on Canyon Creek, CA. None of the redds were found within dredge tailing piles.

Once tailing piles are dispersed by high stream flows they do make up a component of the suitable spawning substrate.

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Salmonids do not spawn in this type of coarse overburden

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Turbidity

It has been asserted that salmon were not affected by elevated turbidity but studies have stated that salmonid growth was reduced at 25 NTU but not below.

Turbidity caused by suction dredging is highly variable. Suction dredging bedrock pockets containing only sand and gravel causes virtually no change in turbidity whereas suction dredging clay deposits causes very noticeable turbidity.

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Flood Stage, Klamath River above Portuguese Creek, 2006

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Klamath River water: The left vial was allowed to settled for 24-hours, the right vial was shaken to re-suspend the particulates. The sample was measured at 656 NTU.

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People with agendas often don’t put facts in perspective and blur the difference between facts and speculation

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Turbidity plumes, usually, do not cover wide areas of the stream and they are not continuous or consistent in sediment content

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Turbidity

Effects of the levels of turbidity and suspended sediment normally associated with suction dredging appear less than significant with regard to the health or physiology of adult and juvenile salmonids, particularly when one considers that turbidity levels return to normal levels on an average of 20-80 m (66-263 ft.) below the suction dredge. Also, natural levels of turbidity may be higher than levels of turbidity caused by suction dredging during certain times of the year.

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Notice the switch in plume turbidity density. Now the distant dredge plume is lower in suspend material concentration

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United States Department of Agriculture Forest Service Siskiyou National Forest, 200 NE Greenfield Road, Grants Pass, OR 97526-0242 Reply to: 2800 Date: October 16, 1995 Subject: rates A comparison of stream materials moved by mining suction dredge operations to the natural sediment yield To: The Record …”There are 1,092,302 acres on the Siskiyou National Forest. Using a factor of 0.33 cubic yards per acre per year times 1,092,302 acres will produce a very conservative estimate that 331,000 cubic yards of material move each year from natural causes compared to the 2413 cubic yards that was moved by suction dredge mining operations in 1995 on the Siskiyou. equals about 0.7% of natural rates .” This would be a movement rate by suction dredge mining that MICHAEL F. COOLEY, Recreation, Lands and Minerals Staff Officer, Siskiyou National Forest

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Constructing a nice deep hole for fish habitat while producing an almost imperceptible turbidity plume

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Fish Feeding

Fish have been observed feeding in turbid plumes created by suction dredging. Stern (1988) observed young steelhead feeding on dislodged invertebrates in turbid dredge plumes, even though clear water was available nearby. Cutthroat and rainbow trout have also been observed feeding.

The effects of suction dredging on the feeding of fish appears to be less than significant.

by suction dredging, and short-term.

Although invertebrate populations are negatively affected the impacts are localized

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Fish feeding below outfall from a small-scale suction gold dredge sluice box

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Behavior and Distribution

Studies in Canyon Creek, Butte Creek, and the North Fork American River, CA did not indicate a difference in fish distribution or density below or above suction dredging sites.

Stern (1988) reported that suction dredging did not appear to influence the behavior of adult spring-run salmonids in their summer holding areas.

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Behavior and Distribution

Abandoned dredge holes can provide holding and resting areas for fish. Stern (1988) observed young steelhead in active and abandoned dredge holes in Canyon Creek.

Suction dredge operators report adult salmon and steelhead moving into dredge holes overnight. Dredge holes often provide thermal and deeper water habitat for fish and some dredge holes in the Scott River, CA have held more juvenile salmonids than adjacent habitats.

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Benefits to the Environment

Small-scale suction dredge miners remove lead shot, fishing sinkers, bullets and other metals and fragments from streams and rivers. Removal of these materials by suction dredgers is considered a benefit to the environment.

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Intention of Congress

"The development of information which describes the relationship of pollutants to water quality is essential for carrying out the objective of the Clean Water Act. This information, known as criteria, is required under Section 304(a) to be developed and published by the Administrator and issued to the states and public. Criteria to be developed in this section should draw upon the best scientific knowledge on the subject, including information, if any, from the National Academy of Sciences, the U.S Geological Survey in the Department of Interior, scholarly literature, academic experts, and other sources.”

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Establishing Effects of Pollutants

“Criteria establish the effects of pollutants on health or welfare, receiving water ecosystems and man, and identify the natural chemical, physical and biological integrity of the Nation's waters.” “The concentration and dispersal of pollutants and their by products through biological, physical and chemical processes and any related changes in the diversity, productivity, or stability of receiving water ecosystems would be part of the information provided ”.

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Natural Integrity of Waters …may be determined:



Partially by consultation of historical records on species composition;



Partially from ecological studies or comparable habitats; and, of the area



Partially from modeling studies which make estimations of the balanced natural ecosystem based on available information.

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USEPA Fact Sheet

January 14, 2000 On Nov. 18, 1996, EPA and the two environmental groups entered into a settlement agreement into waters of the United States.

to resolve the challenge to the general permit. The proposed permit sets conditions on the discharge - or release – of pollutants from the operation The settlement agreement placer mining mining.

required EPA to complete two studies related to the impact of on the natural environment in Alaska. One was to address the discharge of metals by placer mining operations and the other was to address the impact of suction dredge

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Impact of Suction Dredging on Water Quality, Benthic Habitat, and Biota in the Fortymile River, Resurrection Creek, and Chatanika River, Alaska

FINAL REPORT Submitted June 1999

Prepared For:

US Environmental Protection Agency Region 10 Seattle, Washington

Prepared By:

Aaron M. Prussian, Todd V. Royer, and G. Wayne Minshall Department of Biological Sciences Idaho State University Pocatello, Idaho 37

Alaska Study Summary

The report described the results of research into the effects of commercial and small-scale suction dredging on the water quality, habitat, and biota of Fortymile River, Resurrection Creek and the Chatanika River, Alaska. Focus of the work on Fortymile River was on an 8-inch suction dredge located on the main stem and a 10-inch suction dredge South Fork. located on the

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Alaska Study Summary

Water chemistry measured on Fortymile River showed the primary effects of suction dredging were increased turbidity, total filterable solids, and Cu and Zn concentrations downstream of the dredge. The results from this sampling revealed a relatively intense, but localized, decline in water clarity during the time the dredge was operating.

These variables returned to upstream levels within 80-160 m (263-524 ft.) downstream of the dredge.

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Alaska Study Summary

Cross-sectional profiles indicate that the of the dredge piles relative to the width of the Fortymile River was small.

impact Macroinvertebrate abundance and diversity were greatly reduced in the first 10 m (33 ft.) below the dredge but returned to values seen at the reference site by 80 to 160 m (263-524 ft.) downstream of the dredge.

One year after dredging on the main stem and South Fork of Fortymile River, recovery of macro invertebrate diversity appeared to be substantial.

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Alaska Study Summary

The second component of this project is to examine the effects of small-scale suction dredging on smaller streams in Alaska. Sampling was conducted on Resurrection Creek and on the Chatanika River, Alaska.

The results from Resurrection Creek showed that there was no difference in the macro invertebrate communities area and the locations downstream of the mining area , between the mining in terms of macroinvertebrate density, taxa richness, EPT richness, or food resources.

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Alaska Study Summary

Results from the Chatanika River showed slight downstream decreases in macroinvertebrate density, but all other measures remained similar to those of the reference area.

In general, the results are in agreement with other studies that have found only localized reductions in macroinvertebrate abundance in relation to small-scale suction dredging.

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USEPA Fact Sheet

January 14, 2000 The U.S. Environmental Protection Agency (EPA) Plans To Issue A Wastewater Discharge Permit To: Alaska Mechanical Placer Miners

This will also serve as a notice of a

FINDING OF NO SIGNIFICANT IMPACT

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USEPA Fact Sheet

January 14, 2000 The environmental groups believed that the suction dredge report (40-mile River, Resurrection Creek, and Chatanika River) did not address all of the required elements as set out in the 1996 settlement agreement.

To avoid further litigation permits, over the general EPA and the environmental groups entered into another settlement agreement.

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The EPA had chosen to flex its legal muscle where scientific data does not justify their actions. Other Federal Agencies have stated the following: “. . . For decades, suction dredging has been essentially unmanaged. Its effects were considered

insignificant and its consequences immeasurable.

” (

Siskiyou National Forest Draft Environmental Impact Statement).

And, the U.S. Army Corps of Engineers stated, “

To regulate against a potential for harm, where none has been shown to exist, is unjustifiable and must be challenged."

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Presented by Joseph C. Greene, Research Biologist (March 9, 2006 in Salem, Oregon)