APPENDIX D DAM REMOVAL SEDIMENT MANAGEMENT …...Mar 21, 2013 · Dam Removal Sediment Management Strategies APPENDIX D: DAM REMOVAL SEDIMENT MANAGEMENT STRATEGIES D.1 INTRODUCTION

APPENDIX D

DAM REMOVAL SEDIMENT MANAGEMENT STRATEGIES

Appendix D Dam Removal Sediment Management Strategies

Table of Contents APPENDIX D: DAM REMOVAL SEDIMENT MANAGEMENT STRATEGIES ........... D-1

D.1 Introduction .................................................................................................................. D-1

D.2 Matilija Dam (Proposed) .............................................................................................. D-2

D.2.1 Description ............................................................................................................ D-2

D.2.2 Summary of Sediment Data – Metals Data Only (USACE 2002) ........................ D-3

D.2.3 Potentially Applicable Sediment Quality Guidelines ........................................... D-4

D.3 J. C. Boyle, Copco 1, Copco 2, and Iron Gate Dams (Proposed) ................................ D-4

D.3.1 Description ............................................................................................................ D-4

D.3.2 Summary of Sediment Data – Metals Data Only (USACE 2006) ........................ D-6

D.3.3 Potentially Applicable Sediment Quality Guidelines ........................................... D-7

D.4 Elk Creek, Gold Ray, Gold Hill, and Savage Rapids Dams (Completed) ................... D-8

D.4.1 Description ............................................................................................................ D-8

D.4.2 Summary of Sediment Data .................................................................................. D-9

D.4.3 Potentially Applicable Sediment Quality Criteria................................................. D-9

D.5 Condit Dam (In Progress) ............................................................................................ D-9

D.5.1 Description ............................................................................................................ D-9

D.5.2 Summary of Sediment Data from Northwestern Lake, Condit Dam .................. D-10

D.5.3 Applicable Sediment Quality Criteria ................................................................. D-11

D.6 Elwha and Glines Dams (In Progress) ....................................................................... D-11

D.6.1 Description .......................................................................................................... D-11

D.6.2 Summary of Sediment Data ................................................................................ D-12

D.6.3 Applicable Sediment Quality Criteria ................................................................. D-12

D.7 Milltown Reservoir Sediments Superfund Site (Completed) ..................................... D-13

D.7.1 Description .......................................................................................................... D-13

D.7.2 Summary of Sediment Data from Area 1 (Most contaminated) of the Milltown Reservoir ........................................................................................................................... D-14

D.7.3 Applicable Water Quality Criteria ...................................................................... D-14

D.8 Englebright Dam (Under Evaluation) ........................................................................ D-15

D.8.1 Description .......................................................................................................... D-15

D.8.2 Summary of Sediment Data – Metals Data Only (USACE, 2002) ..................... D-16

D.8.3 Potentially Applicable Sediment Quality Guidelines ......................................... D-16

D.8.4 Summary ............................................................................................................. D-17

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D.9 Information Sources ................................................................................................... D-19

D.9.1 Primary Source of Sediment Criteria .................................................................. D-19

D.9.2 Primary Sources of Dam Information ................................................................. D-19

List of Tables Table D-1. Matilija Dam Sediment Quality Criteria Evaluation ............................................... D-4

Table D-2. Klamath Dams Sediment Data ................................................................................. D-6

Table D-3a. Klamath Dams Sediment Quality Criteria Evaluation ........................................... D-7

Table D-3b. Klamath Dams Sediment Quality Criteria Evaluation ........................................... D-7

Table D-3c. Klamath Dams Sediment Quality Criteria Evaluation ........................................... D-8

Table D-4. Condit Dam Sediment Data ................................................................................... D-10

Table D-5. Condit Dam Sediment Quality Criteria Evaluation ............................................... D-11

Table D-6. Elwha and Glines Dams Sediment Quality Criteria Evaluation ............................ D-12

Table D-7. Milltown Area 1 Metal Concentration ................................................................... D-14

Table D-8. Milltown Dam Water Quality Criteria Evaluation ................................................. D-14

Table D-9. Englebright Lake Dam Sediment Quality Criteria Evaluation .............................. D-16

Table D-9s. Englebright Lake Dam Sediment Quality Criteria Evaluation ............................. D-17

Table D-10b. Englebright Lake Dam Sediment Quality Criteria Evaluation .......................... D-17

Yuba Salmon Forum Technical Work Group Page D-ii March 2013 Fish Passage Infrastructure Report


Abbreviations and Acronyms µg/L micrograms per liter

a-f acre-feet

Ag Silver

Al Aluminum

ARAR applicable or relevant and appropriate standards, requirements and criteria

As Arsenic

BT Bio-accumulation Trigger

BTL Bioaccumulation Trigger Level

Cd Cadmium

CDFW California Department of Fish and Wildlife (formerly California Department of Fish and Game)

CEQA California Environmental Quality Act

Cr Chromium

Cu Copper

DMEF Dredged Material Evaluation Framework

EIR Environmental Impact Report

EIS Environmental Impact Study

EPA Environmental Protection Agency

ERL Effect Range Low

ERM Effect Range Median

ESA Endangered Species Act

Fe Iron

FWS United States Fish and Wildlife Service

Hg Mercury

kg kilogram

LARWQCB Los Angeles Regional Water Quality Control Board

LEL Low Effect Level

MCY million cubic yards

mg milligram

ML Maximum Level

MRL Method Reporting Limit

NEPA National Environmental Policy Act

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Ni Nickel

NMFS National Marine Fisheries Service

NOAA National Oceanic and Atmospheric Administration

Pb Lead

PEC Probable Effect Consensus

PEL Probable Effect Level

PNWSEF Pacific Northwest Sediment Evaluation Framework

PSDDA Puget Sound Dredged Disposal Analysis

PSDMMP Puget Sound Dredge Material Management Program

Sb Antimony

Se Selenium

SEF Sediment Evaluation Framework

SEL Severe Effect Level

SL Screening Level

SQuiRTS Screening Quick Reference Tables for Sediments

TDS Total Dissolved Solids

TEC Threshold Effect Consensus

TEL Threshold Effect Level

TRV Toxicity Reference Value

TSS Total Suspended Sediments

USACE United States Army Corps of Engineers

USBR United States Bureau of Reclamation

VCWPD Ventura County Watershed Protection District

WQS Water Quality Standards

Zn Zinc

Yuba Salmon Forum Technical Work Group Page D-iv March 2013 Fish Passage Infrastructure Report


APPENDIX D: DAM REMOVAL SEDIMENT MANAGEMENT STRATEGIES

D.1 INTRODUCTION A preliminary evaluation of sediment impounded by various dams in the western United States and sediment management strategies associated with a number of dam removal projects was conducted to identify potential approaches for minimizing impacts of impounded sediments to the Yuba River during possible breaching or removal of the Englebright Dam. The evaluation reviewed the range of metals concentrations reported for these watersheds in the sediment, upgradient sources for the metals, total volume of sediments possibly affected by disturbance or resuspension, and the total reach of downstream water bodies potentially impacted from the discharge of sediments. For this analysis 13 dams representing past, current and proposed dam removal projects located in CA, OR, WA, and MT were briefly reviewed for sediment management programs proposed or conducted, applicable state and federal sediment quality criteria evaluated or applied, and sediment quality data. The evaluation of sediment quality was limited to the review of readily available metals concentration data.

In addition to Englebright Dam sediments, this evaluation reviewed programs conducted at Matilija (CA), San Clemente (CA), Condit (WA), Elwa (WA), Glines (WA), and Milltown Dams (MT), plus the four Klamath River Dams (Copco 1 and 2, Iron Gate, and JC Boyle) (CA and OR). The potential release of sediments from Englebright Dam were evaluated against sediment quality criteria either proposed or applied to other dam removal projects on the West Coast.

Sediment quality of the reviewed projects ranged from highly contaminated to residual background metals concentrations. The majority of the sediment management programs reviewed specified the discharge of sediments to downstream environments. A dam removal site located in Montana (Milltown) contained the most heavily contaminated sediments of all sites reviewed and in that particular case, impounded sediments were excavated and transported by railcar to an off-site disposal site. A currently proposed sediment management strategy for a dam removal site located in southern California includes as a possible option, partial excavation of fine-grained sediments with off-site disposal and the natural transport of the remaining coarser-grained sediments downstream. The dam removal sites reviewed bracket the Englebright Lake Dam site both in its environmental setting and the range of metals reported in impounded sediments.

Some of the various sediment management strategies applied at other dam sites that may be applicable to a removal of Englebright Dam include US Bureau of Reclamation (USBR, 2009):

• Natural erosion of all or a portion of reservoir sediments by river action;

• Construction of a bypass river channel around reservoir sediments;

• Excavation of sediments;

• Hydraulic or mechanical dredging of sediments;

• Stabilization of sediments, both temporary or permanent;

• Staged release of reservoir sediments;

• Partial release of reservoir sediments;

Yuba Salmon Forum Technical Work Group Page D-1 March 2013 Description of Potential Passage Scenarios


• Development of a plan that includes the capture of released reservoir sediments in downstream features such as other reservoirs, sediment traps, or in-stream structures.

• A combination of various sediment management strategies. The following sections provide a summary of each dam project evaluated. It should be noted that sediment data was difficult to obtain for most of these sites, so the brief summary of data quality should not be considered all inclusive and any comparison to the Englebright Lake sediment data is not complete. If additional analyses of sediment data are required, contact with individuals associated with these individual dam projects is recommended. Primary sources of information are listed in the final section of this document.

D.2 MATILIJA DAM (PROPOSED) D.2.1 Description

• Location: Ventura County, California. The dam is located 15.6 miles from the ocean.

• River(s): Matilija Creek (after confluence with the North Matilija Creek 0.6 miles downstream, Matilija Creek becomes the Ventura River).

• Dam Constructed: 1947

• Purpose of Dam: Water Supply and Flood Control

• Proposed Dam Action: The current preferred option is a combination of notching to the current sediment line and future dam removal.

• Reason for Action: Loss of reservoir capacity due to sedimentation and the dam's impact on the recovery of the southern steelhead trout, an endangered species.

• Owner/Operator (at time of dam action): Ventura County Watershed Protection District (VCWPD)

• Current Dam Dimensions: 168 feet high (originally constructed at 198 feet), 620 feet wide.

• Current Reservoir Capacity: Less than 500 acre-feet (a-f) (originally designed for 7,000+ acre-feet)

• Reservoir Area: Originally designed as 127 acres

• Volume of Sediments to be Managed: Approximately six million cubic yards (MCY) of sand-size and larger sediments. Most of the fine-grained sediment fraction is thought to have passed over the dam during flood events.

• Upgradient Sources of Impacted Sediments: None identified.

• Sediment Management Program: Currently, a number of options are being evaluated. One proposal is to notch the dam, drawdown the water level, and dry out impounded sediments. Then, approximately 2.1 MCY of the remaining fine-grained sediments will be excavated or transported by slurry line to an upgradient disposal site (Baldwin Road Disposal Areas) or placed in piles adjacent to the stream and revegetated. Coarser-grained sediments will be naturally transported downstream. Another option is to transport impounded sediments downstream by slurry line to a point below the Robles



Diversion, which feeds Lake Casitas, a drinking water source. A combination of several of these options is also being discussed.

• Primary State and Federal Agencies Involved in Dam Action: VCWPD and U.S. Army Corp of Engineers (USACE)

• Other Regulatory Agencies Involved: U.S. Fish and Wildlife Service (FWS), California Fish and Wildlife (CFW), Los Angeles Region Water Quality Control Board (LARWQCB), National Marine Fisheries Service (NMFS)

• Sediment Criteria Evaluated: Primarily Puget Sound Dredged Disposal Analysis (PSDDA) and NOAA sediment quality guidelines.

• Preliminary Results of the Comparison of Sediment Metals Data to Various Sediment Metals Criteria Evaluated: Based on USACE sediment sampling, none of the impounded sediments exceed PSDDA criteria. Some samples for some analytes (primarily metals) exceed the NOAA sediment quality guidelines.

• Other Regulatory Considerations: A Federal Endangered Species Action Section 7 Consultation and Biological Opinion are required. A Programmatic Streambed Alteration Agreement is also required. Instream sediment and nutrient loads as it relates to downstream water quality is a significant issue.

• Downstream Impacts: Increase in TDS, nutrients, and TSS

• Estimated Cost (2011): Approximately $145 million, including an estimated $20-$40 million for sediment management.

D.2.2 Summary of Sediment Data – Metals Data Only (USACE 2002) Metals exceeding potentially applicable sediment quality guidelines: Nickel (20 samples) > National Oceanic and Atmospheric Administration Effect Range Low (NOAA ERL), copper (3 samples) >NOAA ERL, mercury (4 samples) >NOAA ERL, and arsenic (1 sample) >NOAA ERL.



D.2.3 Potentially Applicable Sediment Quality Guidelines

Table D-1. Matilija Dam Sediment Quality Criteria Evaluation NOAA NOAA PSDDA PSDDA

Metal ERL (mg/kg) ERM (mg/kg) SL (mg/kg) ML (mg/kg) Antimony (Sb) - - 15 200 Arsenic (As) 8.2 70 57 700 Cadmium (Cd) 1.2 9.6 5.1 14 Chromium (Cr) 81 370 - - Copper (Cu) 34 270 390 1,300 Lead (Pb) 46.7 218 450 1,200 Mercury (Hg) 0.15 0.71 0.41 2.3 Nickel (Ni) 20.9 51.6 140 370 Selenium (Se) - - 0 - Silver (Ag) 1 3.7 6.1 8.4 Zinc (Zn) 150 410 410 3,800 Notes: NOAA Effects Range-Low (ERL), Medium sediment criteria (ERM), sediment criteria (ML), National Oceanic and Atmospheric Administration (NOAA), Puget Sound Dredge Disposal Analysis (PSDDA), Screening Level (SL)

D.3 J. C. BOYLE, COPCO 1, COPCO 2, AND IRON GATE DAMS (PROPOSED) D.3.1 Description

• Location: Southern Oregon and Northern California

• River(s): Klamath

• Dams Constructed: 1956-1958 (J.C. Boyle); 1918 (Copco 1); 1925 (Copco 2); 1962 (Iron Gate).

• Purpose of Dams: Water supply and power generation. Copco 2 is a reregulation dam with a small reservoir capacity.

• Proposed Dam Action: Removal of some or all dams is proposed. Possible dam action includes notching, diversion, or some other combination. The Secretary of the Interior will make a determination on the removal of the Klamath River Dams by March 2012.

• Reason for Action: Cost of required improvements including fish passage modifications, for FERC re-licensing.

• Owner/Operator (at time of dam removal): PacifiCorp for all four dams

• Current Dam Dimensions: 68 feet high, 714 feet wide (J.C. Boyle); 132 feet high (Copco 1); 37 feet high (Copco 2); 188 feet high (Iron Gate).

• Current Reservoir Capacity: 3,500 a-f (JC Boyle); 46,900 a-f (Copco 1); 75 a-f (Copco 2); and 58,000 a-f (Iron gate).



• Volume of Sediments to be Managed: 7.4 MCY (Copco 1); 4.8 MCY (Iron Gate); 1 MCY (JC Boyle); Copco 2 contains only a minimal volume of sediments.

• Upgradient Sources of Impacted Sediments: None identified, but upstream non-point discharges associated with agriculture and other commercial activities may have impacted some portion of impounded sediments in the JC Boyle, Copco 1, and Iron Gate Dams and sediments located at the Klamath River estuary.

• Sediment Management Program: Based on sediment data reported, release of impounded sediments to downstream environments may be the preferred option.

• Sediment Criteria Evaluated: As part of the formal Secretarial Determination for the Klamath River Sediment Study, both freshwater and marine sediment quality screening levels are being reviewed. For the marine sediment environment, Puget Sound Dredge Material Management Program (PSDMMP) Screening Level (SL), Bio-accumulation Trigger (BT), and Maximum Level (ML) sediment quality criteria have been included. For the freshwater sediment environment, the Pacific Northwest Sediment Evaluation Framework (PNWSEF) Screening Level (SL1 and SL2) values for sediment quality criteria have been included.

• Preliminary Results of the Comparison of Sediment Metals Data to Various Sediment Metals Criteria Evaluated: Exceedances of NOAA sediment quality criteria were reported for J.C. Boyle Reservoir - chromium, copper, nickel, and zinc; Copco 1 Reservoir - chromium, copper, iron, nickel, and zinc; Irongate Reservoir - arsenic, copper, nickel; Klamath River Estuary - chromium, copper, iron, and zinc. The number of exceedances in each reservoir and the estuary and which criteria were exceeded were not specified (Chauncey et al, date unknown).

• Other Laws/Regulations/Criteria Evaluated: An Environmental Impact Statement/Environmental Impact Report (EIS/EIR) has been conducted to provide backing for the National Environmental Policy Act (NEPA) and California Environmental Quality Act (CEQA) review process.

• Downstream Impacts: Likely some impacts to the downstream environment from elevated TSS and TDS concentrations.

• Estimated Cost (2011): Approximately $290 million for all four dams including management of sediments.



D.3.2 Summary of Sediment Data – Metals Data Only (USACE 2006)

Table D-2. Klamath Dams Sediment Data Metal

(mg/kg) Klamath River

Estuary JC Boyle Reservoir

Copco 1 Reservoir

Iron Gate Reservoir

(Al) 13,000/13,0001 25,700/26,000 29,354/29,000 36,142/37,000

Antimony (Sb) <0.30/<0.27 <MRL <MRL <MRL

Arsenic (As) 3.2/2.2 10.4/11.0 8.58/8.8 8.35/7.85

Cadmium (Cd) <0.15/<0.14 <MRL <MRL <MRL

Chromium (Cr) 96/97 30.1/30.0 35.6/36.0 36.3/36.0

Copper (Cu) 26/19 26.8/28.0 28.1/28.0 29.3/28.0

(Fe) 24,000/24,000 20,329/20,500 21,118/21,000 27,215/28,500

Lead (Pb) 4.3/3.0 9.80/8.80 8.5/8.5 8.1/8.3

Mercury (Hg) <0.060/<0.054 <MRL <MRL <MRL

Nickel (Ni) 110/110 24.3/24.5 25.7/26.0 25.7/26.5

Selenium (Se) 0.36/<0.27 <MRL <MRL <MRL

Silver (Ag) <0.75/<0.68 <MRL <MRL <MRL

Zinc (Zn) 43/42 48.5/50.5 50.6/50.0 55.5/54.5

Notes: Sediment data from all sample boring locations and at all depths. 1 Average Concentration (mg/kg)/Median Concentration (mg/kg). <MRL - Analyte not detected; less than method reporting limit.




Table D-3a. Klamath Dams Sediment Quality Criteria Evaluation

PNWSEF

Freshwater (Interim)

PNWSEF Freshwater

(Interim) PSDMMP (Marine)

PSDMMP (Marine)

PSDMMP (Marine)

Metal (mg/kg) SL1 SL2 Screening Levels

Bioaccumulation Trigger Levels

Maximum Levels

Antimony (Sb) - - 15 - 200

Arsenic (As) 20 51 57 507 700

Cadmium (Cd) 1.1 1.5 5.1 11.3 14

Chromium (Cr) 95 100 - 267 -

Copper (Cu) 80 830 390 1,027 1,300

Lead (Pb) 340 430 450 975 1,200

Mercury (Hg) 0.28 0.75 0.41 1.5 2.3

Nickel (Ni) 60 70 140 370 370

Selenium (Se) - - - 3.0 -

Silver (Ag) 6.1 2.5 6.1 6.1 8.4

Zinc (Zn) 130 400 410 2,783 3,800 Notes: Pacific Northwest Sediment Evaluation framework (SEF) - Sediment Quality Guidelines Screening Levels 1 and 2 Puget Sound Dredge Material Management Program (PSDMMP) Screening Level (SL) and Maximum Level (ML) Criteria.

Table D-3b. Klamath Dams Sediment Quality Criteria Evaluation

SQuiRTS (Freshwater Sediment)[Buchman, 2008] Metal (mg/kg) TEC TEL LEL PEC PEL SEL

Antimony (Sb)

0.63

2.4

Arsenic (As) 9.79 5.90 6.00 33.0 17.0 33.0

Cadmium (Cd) 0.99 0.60 0.60 4.98 3.53 10.0

Chromium (Cr) 43.4 37.3 26.0 111 90.0 110

Copper (Cu) 31.6 35.7 16.0 149 197 110

Lead (Pb) 35.8 35.0 31.0 128 91.3 250

Mercury (Hg) 0.18 0.17 0.20 1.06 0.486 2.00

Nickel (Ni) 22.7 18.0 16.0 48.6 36.0 75.0

Selenium (Se) - - - - - -

Silver (Ag) - - 0.50+ - - -

Zinc (Zn) 121 123 120 459 315 820 Source: Buchman, M.F., 2008. NOAA Screening Quick Reference Table for Inorganics in Sediment. Notes: EPA TEC - Threshold Effect Consensus, EPA TEL - Threshold Effect level, EPA LEL - Low Effect Level, EPA PEC - Probable Effect Consensus, EPA PEL - Probable Effect Level, EPA SEL - Severe Effect Level



Table D-3c. Klamath Dams Sediment Quality Criteria Evaluation

SQuiRTS (Marine Sediment) Metal (mg/kg) ERL ERM T20 TEL T50 PEL

Antimony (Sb)

0.63

2.4

Arsenic (As) 8.2 70 7.4 7.24 20 41.6

Cadmium (Cd) 1.2 9.6 0.38 0.68 1.4 4.21

Chromium (Cr) 81 370 49 52.3 141 160

Copper (Cu) 34 270 32 18.7 94 108

Lead (Pb) 46.7 218 30 30.24 94 112

Mercury (Hg) 0.15 0.71 0.14 0.13 0.48 0.7

Nickel (Ni) 20.9 51.6 15 15.9 47 42.8


Silver (Ag) 1.0 3.7 0.23 0.73 1.1 1.77

Zinc (Zn) 150 410 94 124 245 271 Source: Buchman, M.F., 2008. NOAA Screening Quick Reference Table for Inorganics in Sediment. NOAA ERL - Effect Range Low, NOAA ERM - Effect Range Median, EPA T20 - 20% probability of observing sediment toxicity, T50 - 50% probability of observing sediment toxicity, EPA TEL - Threshold Effect Level, EPA PEL – Probable Effect Level

D.4 ELK CREEK, GOLD RAY, GOLD HILL, AND SAVAGE RAPIDS DAMS (COMPLETED)

D.4.1 Description • Location: Oregon

• River(s): Rogue

• Dams Constructed: 1904 (Gold Ray Dam); 1921 (Savage Rapids Dam); Not described for the other two dams in documents reviewed.

• Purpose of Dams: Irrigation diversion (Savage Rapids Dam) and power generation.

• Dam Action Implemented: Elk Creek Dam notched in 2008, Gold Ray Dam removed in 2010; Gold Hill Dam removed in 2008; and Savage Rapids Dam removed in 2009. In all cases, impounded sediments were discharged downstream as dams were removed or notched.

• Owner/Operator (at time of dam removal): Grants Pass Irrigation District (Savage Rapids Dam); Jackson County (Gold Ray Dam); City of Gold Hill (Gold Hill Dam); USACE (Elk Creek Dam).

• Dam Dimensions: 39 feet high x 500 feet wide (Savage Rapids Dam); 35 feet high x approximately 500 feet wide (Gold Ray Dam); 8 feet high x 900 feet wide (Gold Hill Dam); Unknown (Elk Creek Dam).

• Reservoir Capacities: Not described in documents reviewed.

• Volume of Sediments to be Managed: Not described in documents reviewed.



• Upgradient Sources of Impacted Sediments: Not described in documents reviewed. However, limited sediment data for the Gold Ray Dam suggests potential upstream sources of metals.

• Sediment Management Program: Impounded sediments discharged.

• Sediment Criteria Evaluated: PNWSEF and NOAA sediment quality criteria. The assumption is that PSDMMP, EPA, and State of Oregon water and sediment quality criteria were also evaluated.

• Other Criteria Evaluated: Not described in documents reviewed.

• Downstream Impacts: Intermittent increases in TDS and TSS concentrations downstream of the four dams were likely during removal and notching.

D.4.2 Summary of Sediment Data All sediment data for the Savage Rapids and Gold Hill Dams were reported as less than PNWSEF sediment quality criteria. Gold Ray Dam sediment data: Copper ranged from 163 to 594 mg/kg; nickel ranged from 101 to 235 mg/kg; lead ranged from 10.6 to 123 mg/kg; and zinc ranged from 355 to 879 mg/kg. Arsenic and cadmium ranged from less than method detection limits to 17.7 and 33.3 mg/kg, respectively. The reported metals concentrations for sediments impounded behind the Gold Ray Dam were below EPA limits for contaminated sediments. Many sediment samples exceeded NOAA ERL and ERM sediment quality criteria (Jackson County Gold Ray Sediment Assessment Report, HDR October 2009).

D.4.3 Potentially Applicable Sediment Quality Criteria Not described in documents reviewed.

D.5 CONDIT DAM (IN PROGRESS) D.5.1 Description

• Location: Southern Washington

• River(s): White Salmon


• Purpose of Dam: Power generation

• Impounded Water Body: 92-acre Northwestern lake

• Dam Action Implemented: Dam removal began October 2011. Dam was breached by drilling an 18 foot x 13 foot x 100 foot tunnel in the base of the dam and applying 700 pounds of explosives for final breaching on October 26, 2011. Remaining dam structure will be removed after reservoir drawdown has been completed. Residual impounded sediments will be stabilized.

• Owner/Operator (at time of dam removal): PacifiCorp

• Dam Dimensions: 125 feet in height.

• Reservoir Capacity: 2,025 acre-feet



• Volume of Sediments to be Managed: 2.3 million cubic yards. Estimated percent of impounded sediments released downstream to the White Salmon and Columbia Rivers during dam breaching, 70-95%.

• Upgradient Sources of Impacted Sediments: None identified. However, mercury was reported consistently at concentrations exceeding PNWSEF SL1 and SL2 sediment quality criteria. Based on sediment data, source of mercury was thought to be naturally occurring.

• Sediment Management Program: Sediments were released during dam breaching. Because the Condit Dam was located approximately 3.3 miles from the Columbia River, it was determined any exceedances of water quality criteria in the White Salmon River from TDS, TSS, and mercury would be temporary and have minimal impact on downstream aquatic resources.

• Sediment Criteria Evaluated: USACE Dredged Material Evaluation Framework (DMEF) and PNWSEF sediment quality criteria.

• Other Criteria Evaluated: Because mercury exceeded both PNWSEF SL1 and SL2 sediment quality criteria, a sediment elutriation test was conducted. The results were compared to various EPA and State of Washington water quality criteria. The results exceeded Washing Department of Ecology Ambient Water Quality Criteria for Chronic Exposures. State of Washington turbidity criteria were also applicable to the project.

• Downstream Impacts: Temporary exceedances of sediment quality criteria due to elevated levels of TDS, TSS and mercury.

D.5.2 Summary of Sediment Data from Northwestern Lake, Condit Dam

Table D-4. Condit Dam Sediment Data Metals (mg/kg) Average Metals (mg/kg) Average Antimony 0.10 Arsenic 1.5 Cadmium 0.1 Chromium 9.2 Copper 17.6 Lead 4.4 Mercury 0.80 Nickel 10.4 Silver 0.10 Zinc 33.0



D.5.3 Applicable Sediment Quality Criteria

Table D-5. Condit Dam Sediment Quality Criteria Evaluation

DMEF

(Marine) DMEF

(Marine) DMEF

(Marine) SEF


SEF Freshwater

(Interim)

Metal (mg/kg) Screening levels Bioaccumulation Trigger Levels Maximum Levels SL1 SL2

Antimony (Sb) 150 - 200 - -

Arsenic (As) 57 507 700 20 51

Cadmium (Cd) 5.1 11.3 14 1.1 1.5

Chromium (Cr) - 267 - 95 100

Copper (Cu) 390 1,027 1,300 80 830

Lead (Pb) 450 975 1,200 340 430

Mercury (Hg) 0.41 1.5 2.3 0.28 0.75

Nickel (Ni) 140 370 370 60 70

Silver (Ag) 6.1 6.1 8.4 2.0 2.5

Zinc (Zn) 410 2,783 3,800 130 400 Sources: USACE et al - Dredged Material Evaluation Framework - Lower Columbia River Management Area, November 1998 Pacific Northwest Sediment Evaluation framework (PNWSEF) - Interim Sediment Quality Guidelines

D.6 ELWHA AND GLINES DAMS (IN PROGRESS) D.6.1 Description

• Location: Five miles from Puget Sound in Clallam County, Washington (Elwha Dam); 13 miles from Puget Sound in Olympic National Park, Clallam County, Washington (Glines Dam)

• River(s): Elwha

• Dam Constructed: 1910-1913 (Elwha Dam), 1926-1927 (Glines Dam)

• Purpose: Power generation

• Impounded Water Bodies: Lake Aldwell (Elwha Dam), Lake Miles (Glines Dam).

• Dam Action: Elwha Dam removal began with notching on September 27, 2011, scheduled for completion in 2012; Glines Dam removal began September 2011, scheduled for completion 2013-2014

• Owner/Operator (at time of dam removal): PacifiCorp

• Dam Dimensions: 108 feet high (Elwha Dam), 210 feet high (Glines Dam)

• Reservoir Capacities: 8,108 acre-feet (Elwha Dam); 39,725 acre-feet (Glines Dam).



• Volume of Sediments to be Managed: 3.9 million cubic yards (Elwha Dam), 17 million cubic yards (Glines Dam). Estimated percent of impounded sediments to be released in stages downstream to the Elwha River and Puget Sound during dam removals are approximately 65% for the Elwha Dam and approximately 40% for the Glines Dam.

• Upgradient Sources of Impacted Sediments: None identified

• Sediment Management Program: Release sediments in stages downstream to the Elwha River and Puget Sound

• Sediment Criteria Evaluated: USACE PSDDA, EPA, and PNWSEF sediment quality criteria.

• Other Criteria Evaluated: None identified.

• Downstream Impacts: Primarily temporary increase in TDS and TSS. Impacts to downstream aquatic resources are to be minimized by timed releases of sediment during different times of the year.

D.6.2 Summary of Sediment Data A brief summary of sediment data (USBR, 2006) stated that only iron and manganese in reservoir sediments exceed background metals concentrations. It is unknown what the background concentrations are for metals in fresh water sediments.

D.6.3 Applicable Sediment Quality Criteria

Table D-6. Elwha and Glines Dams Sediment Quality Criteria Evaluation

PNWSEF


PNWSEF Freshwater

(Interim) EPA EPA PSDDA

(Marine) PSDDA (Marine)

PSDDA (Marine)

Metal (mg/kg) SL1 SL2 PEC TEC Screening Levels


Maximum Levels

Antimony (Sb) - - - - 15 - 200

Arsenic (As) 20 51 9.79 33 57 507 700

Cadmium (Cd) 1.1 1.5 - - 5.1 11.3 14

Chromium (Cr) 95 100 43.4 111 - 267 -

Copper (Cu) 80 830 - - 390 1,027 1,300

Lead (Pb) 340 430 35.8 128 450 975 1,200

Mercury (Hg) 0.28 0.75 0.18 1.06 0.41 1.5 2.3

Nickel (Ni) 60 70 22.7 48.6 140 370 370

Selenium (Se) - - - - - 3 -

Silver (Ag) 6.1 2.5 - - 6.1 6.1 8.4

Zinc (Zn) 130 400 - - 410 2,783 3,800 Sources: Pacific Northwest Sediment Evaluation framework (PNWSEF) – Sediment Quality Guidelines USEPA (2000) Freshwater Sediment Quality Guidelines – Probable Effect Concentrations (PEC) and Threshold Effect Concentrations (TEC) Puget Sound Dredge Disposal Analysis (PSDDA) Screening Level (SL) and Maximum Level (ML) Criteria.



D.7 MILLTOWN RESERVOIR SEDIMENTS SUPERFUND SITE (COMPLETED) D.7.1 Description

• Location: Five miles east of Missoula, Montana

• River(s): Confluence of Clark Fork and Blackfoot Rivers


• Purpose: Power generation

• Dam Action Implemented: Dam removal began in 2008 and was completed in 2010.

• Owner/Operator (at time of dam removal): Northwestern Energy Corporation. Because the contaminated sediments impounded behind the Milltown Dam were originally generated upstream by historic Anaconda mining/smelting operations at Butte and Anaconda, Montana, ARCO Environmental LLC (BP subsidiary), purchaser of Anaconda assets in 1979, was responsible for the excavation of contaminated sediments and other specified remediation /mitigation activities at the Milltown Reservoir Superfund site.

• Dam Dimensions: Approximately 28 feet high x 800 feet wide.

• Reservoir Capacity: Unknown

• Estimated Volume of Sediments to be Managed: 6.6 million cubic yards of contaminated sediments.

• Upgradient Sources of Impacted Sediments: Historic mining operations in the Butte-Anaconda-Deer Valley area. A flood shortly after the Milltown dam was constructed transported heavily contaminated sediments to the confluence of the Clark Fork and Blackfoot Rivers where it became impounded behind the Milltown Dam.

• Sediment Management Program: Prior to dam removal, a cofferdam was built around the most contaminated sediments. Dam was breached in 2008 and the reservoir water level lowered. Between 2007 and 2009, approximately 2.5 million cubic yards of highly contaminated sediments were excavated, dewatered, loaded on railcars, and shipped 95 miles to the Anaconda Superfund site for disposal. Another 250,000 cubic yards of contaminated sediments have been excavated, dewatered, and disposed of on-site in a repository located away from the Clark Fork River.

• Sediment Criteria Evaluated: Because the primary impacts identified were to local groundwater drinking sources and downstream surface water bodies, water quality criteria were the drivers for cleanup of contaminated sediments impounded behind the Milltown reservoir. No specific sediment criteria were located.

• Other Criteria Evaluated: Federal water quality criteria (acute, chronic, and primary drinking water) and Montana acute and chronic toxicity standards were evaluated. Based on human health and ecological risk assessments for the site, arsenic and copper were identified as the two primary contaminants of concern. Federal drinking water criteria for arsenic (10 ug/L) and a site specific trout toxicity reference value for copper (37 ug/L) were the cleanup criteria selected for remediation of the Milltown Reservoir Superfund site.



• Additional Federal and State Acts/Laws/Regulations Evaluated: Because the Milltown Reservoir Sediment site was addressed under federal Superfund Authority, cleanup of the site complied with all federal and State of Montana applicable or relevant and appropriate standards, requirements and criteria (ARARs). As a result, in addition to the 22 federal acts and orders found to be relevant and appropriate or applicable, 13 State of Montana regulations were determined to be applicable in identifying appropriate remediation goals of sediments, surface water, and groundwater at the site. Although some of the federal orders and acts are specific to Superfund sites, other orders, acts, or regulations required evaluation if federal funds are to be used.

• Downstream Impacts: Modeling studies showed that elevated concentrations of TSS, arsenic, copper, cadmium, lead, and zinc would occur during dam removal and excavation of sediments from the Milltown Reservoir. Elevated concentrations of TDS, TSS, and some metals have been documented as far as 170 miles downstream on the Clark Fork River. Recent data suggest the modeling studies may have underestimated downstream impacts from the release of contaminated sediments during site remediation. Studies of downstream surface water bodies, sediments, and aquatic populations are on-going.

• Estimated Cost for Sediment Management Program: $100 million dollars.

D.7.2 Summary of Sediment Data from Area 1 (Most contaminated) of the Milltown Reservoir

Table D-7. Milltown Area 1 Metal Concentration Metal (mg/kg) Mean Range

Arsenic 510 8 – 1,540 Cadmium 14.0 0.87 – 30.5 Copper 3,704 20.0 – 10,600 Lead 335 12.0 - 794 Zinc 3,837 27.0 – 9,520

D.7.3 Applicable Water Quality Criteria

Table D-8. Milltown Dam Water Quality Criteria Evaluation

Metal (µg/L) Federal Acute

Criteria

Federal Chronic Criteria

Federal Drinking

WQS

Site Specific

Trout TRV

Montana Acute

Toxicity Standards

Montana Chronic Toxicity

Standards

Arsenic (As) 340 150 10 - 360 190

Cadmium (Cd) 4.3 2.2 - - 3.9 1.1

Copper (Cu) 13 9 - 37 18 12

Lead (Pb) 65 2.5 - - 82 3.2

Zinc (Zn) 120 120 - - 120 110



D.8 ENGLEBRIGHT DAM (UNDER EVALUATION) D.8.1 Description

• Location: Yuba and Nevada Counties, California

• River(s): Yuba


• Purpose of Dam: The Englebright lake Dam was originally intended to trap sediment from upstream hydraulic mining activities. A tremendous amount of sediment was dislodged during hydraulic mining activities from approximately the last quarter of the nineteenth and first quarter of the twentieth centuries, which continues to move downstream and accumulate in this reservoir, reducing the original storage capacity from approximately 70,000 ac-ft down to an estimated 50,000 ac-ft in 2003 (see Reservoir Capacity below).Currently, the reservoir is used primarily for recreational purposes with some water releases to benefit aquatic populations downstream, plus supplement regional domestic, agricultural, and power generation requirements.

• Dam Action Proposed: Options being discussed may include dam removal or notching with other modifications.

• Owner/Operator (at time of dam action): USACE

• Dam Dimensions: 280 feet high, 1,142 feet wide

• Reservoir Capacity: Englebright Reservoir when first constructed had a gross storage capacity of 70,000 ac-ft; however, due to sediment capture, the gross storage capacity today is approximately 50,000 ac-ft (USGS 2003).Surface Area: 815 acres

• Volume of Sediments to be Potentially Managed: Estimated total volume of sediments in Englebright lake is 28.6 MCY with an estimated 3.2 MCY in the area nearest the dam. Any reduction in dam height would cause erosion of sediment currently stored in the upstream portion of the reservoir, moving it down closer to the dam.

• Upgradient Sources of Impacted Sediments: Historical hydraulic mining operations have released sediments containing a variety of trace metals, especially mercury, which was extensively used in historic gold recovery activities.

• Sediment Management Program: Currently no identified preferred option. Most likely choices are discharge of sediments downstream, excavation and disposal off-site, encapsulation on-site, or some combination of all these options.

• Sediment Criteria Evaluated: Currently, no specific sediment criteria proposed. Potentially applicable sediment criteria include USACE PSDDP (SL, BTL, ML), NOAA (ERL, ERM), PNW SEF (SL1, SL2, SL), or State of California sediment quality criteria. The State of California is currently developing sediment quality objectives for enclosed bays and estuaries. The potential for sediment released from Englebright Lake to eventually migrate to waters of the Sacramento Delta, an area that will be included in the State's sediment quality objectives program, may require inclusion of state marine sediment quality criteria. Fresh water sediment quality criteria may be required by the local state regional water quality control board.



• Other Laws/Regulations Evaluated: None. However, the selection of a preferred option for dam action and management of sediments will require evaluation of any applicable local, county, State of California, and federal laws, regulations, acts, or orders similar to other dam sites in the western United States. The Milltown Reservoir ARAR evaluation is an example of the process that may be required for evaluating sediment management options.

• Downstream Impacts: Sediment impacts to downstream aquatic populations and stream morphology may include increased TSS, TDS, metals and other chemicals present in impounded sediments.

D.8.2 Summary of Sediment Data – Metals Data Only (USACE, 2002) Calculated means at various sample boring locations.

Metal (mg/kg): As– 37, 65-94 Cr– 151, 142, 123, 127 Pb– 23, 35-44 Hg– 0.1-0.5, 0.002-0.1 Ni– 77, 72, 99, 101


Table D-9. Englebright Lake Dam Sediment Quality Criteria Evaluation

SEF


SEF Freshwater

(Interim) PSDDP (Marine)

PSDDP (Marine)

PSDDP (Marine)

Metal (mg/kg) SL1 SL2 Screening Levels


Maximum Levels

Antimony (Sb) - - 15 - 200

Arsenic (As) 20 51 57 507 700

Cadmium (Cd) 1.1 1.5 5.1 11.3 14

Chromium (Cr) 95 100 - 267 -

Copper (Cu) 80 830 390 1,027 1,300

Lead (Pb) 340 430 450 975 1,200

Mercury (Hg) 0.28 0.75 0.41 1.5 2.3

Nickel (Ni) 60 70 140 370 370

Selenium (Se) - - - 3.0 -

Silver (Ag) 6.1 2.5 6.1 6.1 8.4

Zinc (Zn) 130 400 410 2,783 3,800



Table D-9s. Englebright Lake Dam Sediment Quality Criteria Evaluation

SQuiRTS (Freshwater Sediment) [Bachman, 2008]

Metal (mg/kg) TEC TEL LEL PEC PEL SEL

Antimony (Sb)

0.63

2.4

Arsenic (As) 9.79 5.90 6.00 33.0 17.0 33.0

Cadmium (Cd) 0.99 0.60 0.60 4.98 3.53 10.0

Chromium (Cr) 43.4 37.3 26.0 111 90.0 110

Copper (Cu) 31.6 35.7 16.0 149 197 110

Lead (Pb) 35.8 35.0 31.0 128 91.3 250

Mercury (Hg) 0.18 0.17 0.20 1.06 0.486 2.00

Nickel (Ni) 22.7 18.0 16.0 48.6 36.0 75.0


Silver (Ag) - - 0.50+ - - -

Zinc (Zn) 121 123 120 459 315 820 Source: Buchman, M.F., 2008. NOAA Screening Quick Reference Table for Inorganics in Sediment.

Notes: EPA TEC – Threshold Effect Consensus, EPA TEL – Threshold Effect level, EPA LEL – Low Effect Level, EPA PEC – Probable Effect Consensus, EPA PEL – Probable Effect Level, EPA SEL – Severe Effect Level

Table D-10b. Englebright Lake Dam Sediment Quality Criteria Evaluation SQuiRTS (Marine Sediment)

Metal (mg/kg) ERL ERM T20 TEL T50 PEL

Antimony (Sb)

0.63

2.4

Arsenic (As) 8.2 70 7.4 7.24 20 41.6

Cadmium (Cd) 1.2 9.6 0.38 0.68 1.4 4.21

Chromium (Cr) 81 370 49 52.3 141 160

Copper (Cu) 34 270 32 18.7 94 108

Lead (Pb) 46.7 218 30 30.24 94 112

Mercury (Hg) 0.15 0.71 0.14 0.13 0.48 0.7

Nickel (Ni) 20.9 51.6 15 15.9 47 42.8


Silver (Ag) 1.0 3.7 0.23 0.73 1.1 1.77

Zinc (Zn) 150 410 94 124 245 271 Source: Buchman, M.F., 2008. NOAA Screening Quick Reference Table for Inorganics in Sediment.

NOAA ERL – Effect Range Low, NOAA ERM – Effect Range Median, EPA T20 – 20% probability of observing sediment toxicity, T50 - 50% probability of observing sediment toxicity, EPA TEL – Threshold Effect Level, EPA PEL – Probable Effect Level

D.8.4 Summary Excluding the Milltown Reservoir Dam on the Clark Fork River near Missoula, Montana, an EPA Superfund site, the evaluation showed the sediments impounded by the Englebright Lake contains some of the highest concentrations of trace metals of all dams surveyed on the West



Coast. Similar to the Milltown Reservoir Dam, the Englebright Lake Dam is downgradient of historical mining districts and received metals impacted sediments from these upgradient sources for many years. Although the removal of the Milltown Reservoir Dam included the complete containment, excavation, and offsite disposal of metals impacted sediments, discharges of fine sediment fractions containing trace metals did occur during the remediation phase.

On-going Clark Fork River sediment tracking studies by the University of Montana have documented water quality impacts from trace metals up to 80 kilometers downstream (Moore et al, 2008). Post-breach copper and arsenic concentrations in the Clark Fork River have shown increases 3-5 times over pre-breach conditions. Increases in lead, cadmium, and zinc concentrations in the Clark Fork River have also been reported. The transport of metals from the Milltown Reservoir to downgradient locations was primarily associated with the clay and silt sediment fractions, suspended and dissolved organic matter, and the desorption of metals from sediments to the water column. It should be expected that the removal or modification of the Englebright Dam would result in similar metals transport scenarios.

In regard to potential sediment quality criteria that have been or may be applied to various dam modification or removal programs in California, Oregon, and Washington, federal and state (e.g. NOAA SQuiRTS, Consensus-based, Pacific Northwest Sediment Evaluation Framework (PNWSEF), or States of Washington, Oregon, and California, etc.) sediment criteria have been used or recommended. Some of the sediment data reported by the USGS for Englebright Dam show exceedances of several different freshwater sediment quality criteria for arsenic, chromium, copper, lead, mercury, nickel and zinc. It should be noted the sediment data reported represent sampling of only a portion of the total sediments impounded behind this structure.

However, neither report evaluated the potential for these heavy metals to desorb from the organic matter, clay, and silt fractions during disturbance or resuspension, a condition that could result in elevated concentrations of metals in the water column and potential exceedances of stricter water quality criteria that may be applied to future water discharges from these sites.

In summary, the removal or substantial modification to the Englebright Dam will result in the discharge of some portion of impounded sediments. The sediment discharge will likely generate physical and chemical impacts to downstream habitats and biological resources. Although the physical impacts caused by the discharge of sediments may be beneficial in the long-term if the sediment discharge is carefully controlled, the potential for detrimental impacts due to increased mercury and trace metals loading is much more of a concern. The ability to control the release of mercury and trace metals associated with the impounded sediments will be difficult due to the association of these metals with the highly mobile organic matter, clay, and silt fractions. Considering various trace metals in these impounded sediments already exceed commonly applied freshwater sediment quality criteria, there is a potential for metals concentrations in the water column to exceed the stricter water quality criteria that may be applied to any future water releases. A detailed fate and transport assessment should be conducted to better define the metals composition of the sediments impounded behind the Englebright Dam and the potential for those toxic metals to transfer to the water column during disturbance and resuspension.



D.9 INFORMATION SOURCES D.9.1 Primary Source of Sediment Criteria Buchman, M.F., 2008. NOAA Screening Quick Reference Tables. NOAA OR&R Report 08-1,

Office of Response and Restoration Division, National Oceanic and Atmospheric Administration, Seattle WA, 34 p. http://response.restoration.noaa.gov/book shelf/122 NEW-SQuiRTs.pdf

D.9.2 Primary Sources of Dam Information

San Clemente Dam ENTRIX. 2008. Final Environmental Impact report/Environmental Impact Statement San

Clemente Dam Seismic Safety Project Volumes 1-4. January.

Matilija Dam Study Group Sponsors and Center for Collaborative Policy. 2011. Matilija Dam Ecosystem

Restoration Project, Fine Sediment Study group, Final Report. Sacramento, California. August.

United States Army Corps of Engineers (USACE). 2002. Impounded Sediment Characterization, Matilija Dam, Matilija Creek Watershed, Ventura County, California. Los Angeles District, Los Angeles, CA. April.

USACE Los Angeles District. 2004. Draft Environmental Impact Statement/Environmental Impact Report (EIS/EIR) F-5 Milestone for the Matilija Dam Ecosystem Restoration Project. Los Angeles, California. July.

USACE Los Angeles District. 2004. Final EIS/EIR (F-8 milestone) for the Matilija Dam Ecosystem Restoration Project. Los Angeles, CA. September.

United States Department of Interior Bureau of Reclamation (USBR) Mid-Pacific Regional Office. 2002. Matilija Dam Ecosystem Restoration Feasibility Study, Final Geotechnical Field Investigations, Ventura County, California. Sacramento, CA. July.

USBR Technical Services Center. 2004. Hydrology, Hydraulics and Sediment Studies of Alternatives for the Matilija Dam Ecosystem Restoration Project, Ventura, CA – Final Report. Denver, Colorado. September.

USBR. 2009. Sediment Considerations for Potential Dam Removal Projects. Technical Report No. SRH-2009-39. Denver, Colorado. October.

Ventura County Watershed Protection District. 2005. Matilija Dam Water Quality Monitoring Project. Department of Justice Grant 2001-0297-007. December.

Condit Dam GEC. 2009. Condit Dam Removal Supplementary Mercury Sediment Analysis Final Report.

January 6. Seattle, WA.

Kleinfelder. 2007. Sediment Sampling and Analysis Report Northwestern Lake Condit Hydroelectric Project FERC Project No. 2342. White Salmon, Washington. Kleinfelder Project No. 53886/4. March 21.



Kleinfelder. 2007. Supplemental Evaluation for Mercury in Sediments Report Northwestern Lake Condit Hydroelectric Project FERC No. 2342. White Salmon, Washington. Kleinfelder, Project No. 53886/5.

Susewind, K. 2010. Letter to Mr. Todd Olson, PacifiCorp Energy Re: Condit Dam Decommissioning Project 401 Water Quality Certification Order No. 8049. October 12.

Washington State Department of Ecology. 2007. Condit Dam Removal Final SEPA Supplemental Environmental Impact Statement (FSEIS). Ecology Publication #07-06-012. March 23.

Washington State Department of Ecology. 2010. Condit Dam Removal Final Second Supplemental Environmental Impact Statement. Ecology Publication #09-12-017. January 21.

Klamath River Dams (JC Boyle, Copco 1, Copco 2, Iron Gate) CDM. 2011. Screening-Level Evaluation of Contaminants in Sediments from Three Reservoirs

and the Estuary of the Klamath River, 2009-2011. Sacramento, California. September.

Gathard Engineering Consulting (GEC). 2006. Letter to Michael Bowen, California State Coastal Conservancy Re: Klamath River Sediment Study. Seattle, Washington. September.

GEC. 2006. Klamath River Dam and Sediment Investigation. Seattle, Washington. November.

Keir Associates and Aquatic Ecosystem Sciences LLC. 2005. 2002 Nutrient and Hydrologic Loading to Iron Gate and COPCO Reservoirs, California. October. Mill Valley and Arcata, California and Ashland, Oregon.

Shannon & Wilson, Inc. 2006. Preliminary Review of 2006 Analytical Testing Data from Sediment Sampling Conducted at Iron Gate, Copco 1, and JC Boyle Reservoirs Klamath River, Oregon and California. Seattle Washington. September.

Stillwater Sciences, 2009. Dam Removal and Klamath River Water Quality: A Synthesis of the Current Conceptual Understanding and an Assessment of Data Gaps. Technical report. Prepared for State Coastal Conservancy, 1330 Broadway, 13th Floor, Oakland, CA 94612, 86 p.

United States Department of the Interior (USDI) Bureau of Reclamation Technical Service Center. 2009. Klamath River Dam Removals – Team Review of A/E Study Klamath Hydroelectric Project FERC License No. 2082 Oregon-California. Denver, Colorado. February.

USDI Bureau of Reclamation Mid-Pacific Region. 2011. Sediment Chemistry Investigation: Sampling, Analysis, and Quality Assurance Findings for Klamath River Reservoirs and Estuary, October 2009 – January 2010. May.

United States Geological Survey (USGS). 2011. Klamath Dam Removal Draft EIS/EIR Hearing. Presentation. Portland, Oregon. September.

USGS, United States Environmental Protection Agency, United States Fish and Wildlife Service, and Stillwater Services. 2010. Sediment Contaminant Study: Summary of Findings and Next Steps. Presentation. October



Elwha and Glines Dams Czuba et al. 2011. Anticipated Sediment Delivery to the Lower Elwha River During and

Following Dam Removal. Chapter 2. Coastal Habitats of the Elwha River, Washington – Biological and Physical Patterns and Processes Prior to Dam Removal.

Duda et al. 2008. Baseline Studies in the Elwha River Ecosystem Prior to Dam Removal: Introduction to the Special Issue. Northwest Science, Vol. 82, Special Issues.

Entrix, Inc. No Date. Chapter 2.4 Elwha River and Tributaries. WRIA 18 Watershed Plan

Magril et al. 2011. Baseline Hydrologic Studies in the Lower Elwha River Prior to Dam Removal. Chapter 4. Coastal Habitats of the Elwha River, Washington – Biological and Physical Patterns and Processes Prior to Dam Removal.

State of Washington Department of Ecology. 2007. Letter Re: Water Quality Certification Order #3959 (Corps No. 200600334) Elwha River Ecosystem Project, Clallam County, Washington. Olympia, Washington. February 16.

USDI National Park Service. 2004. Elwha River Ecosystem Restoration Implementation. Draft Supplement to the Final Environmental Impact Statement. Olympic National Park, Washington. December.

USDI National Park Service. 2005. Elwha River Ecosystem Restoration Implementation. Final Supplement to the Final Environmental Impact Statement. Olympic National Park, Washington. July.

USDI National Park Service. 2009. Record of Decision Elwha River Ecosystem Restoration Implementation Final Supplemental Environmental Impact Statement. Olympic National Park, Washington.

USDI Bureau of Reclamation. 1995. Elwha River Restoration, Elwha Dam Removal. Value Engineering Presentation Report. Denver. December 15.

USDI Bureau of Reclamation. 2006. Numerical Hydraulic Modeling and Assessment in Support of Elwha Surface Diversion Project. Technical Service Center, Denver, Colorado. September.

USDI Bureau of Reclamation. 2009. Sediment considerations for Potential Dam removal Projects. Technical Report No. SRH-2009-39. Technical Service Center. Denver, Colorado. October.

USDI Bureau of Reclamation. 2011. Elwha River Restoration through the Removal of Elwha and Glines Canyon Dams. Presentation. Technical Services center, Denver, Colorado.

USGS. 2000. An Assessment of Available Data and Information and Possible Methods of Analysis of the Water Resources of the Elwha-Morse Watershed, Washington. Water Resources Division. Tacoma, Washington. March.

Milltown Axtmann, E. and S. Louma. 1991. Large-scale Distribution of Metal Contamination in the Fine-

grained Sediments of the Clark Fork River, Montana, U.S.A. Applied Geochemistry, Vol. 6, pp. 75-88.



Axtmann, E., D. Cain, and S. Louma. 1997. Effect of Tributary Inflows on the Distribution of Trace Metals in the Fine-grained Bed Sediments and Benthic Insects of the Clark Fork River, Montana. Environ. Sci. Technol. 31, 750-758.

Envirocon. 2006. Final Remedial Action Monitoring Plan Milltown Reservoir Sediments Operable Unit. May 18.

Envirocon, EMC2, Land & Water Consulting, West Consultants, Inc., and ENSR International. 2004. Final Technical memorandum Milltown Reservoir Dry Removal Scour Evaluation. May.

Johnsen, James. 2011. Sampling and Modeling of Sediment Transport and Reservoir erosion Following Dam Removal: Milltown Dam, Montana. MS Thesis, university of Montana, Missoula, MT. Spring.

Moore, J., K. Garcia, and H. Langer. 2008. Milltown Dam Sediment Release Tracking Study. In-Progress. University of Montana, Missoula, MT.

Sando, S. and J. Lambing. 2010. Loads of Suspended Sediment and Selected Trace Elements in the Clark Fork Basin, Montana, Before and After the Removal of Milltown Dam. Presentation. 2nd Joint Federal Interagency Conference. Las Vegas, Nevada. June 27 – July 1.

USGS. 2008. Estimated Loads of Suspended Sediment and Selected Trace Elements Transported through Milltown reservoir in the Upper Clark Fork Basin, Montana, Water Years 2004-07. Scientific Investigations Report 2008-5080.

USGS. 2011. Estimated Loads of Suspended Sediment and Selected Trace Elements Transported through the Clark Fork Basin, Montana, in Selected Periods Before and After the Breach of Milltown Dam (water Years 1985-2009). Scientific investigations Report 2011-5030.

USEPA. 2004. EPA Superfund Record of Decision Milltown Reservoir Sediments EPA ID: MTD980717565 OU 03 Milltown, MT. April 29.

Gold Ray and Marmot Dams Bierly, K. 2010. Agenda item Q: Gold Ray Dam January 20-21, 2010 OWEB Board Meeting.

Memorandum. Oregon Watershed Enhancement Board. Salem, Oregon. January 5.

HDR. 2009. Jackson county Gold Ray Sediment Assessment Report.

Major, J, K. SPICER, and A. RHODE. 2008. Initial fluvial response to the Removal of Oregon’s Marmot Dam. EOS, Vol. 89, No. 27, Pages 241-252. July.

Englebright Dam Snyder, N. et al. 2004. Estimating Accumulation Rates and Physical Properties of Sediment

Behind a Dam: Englebright Lake, Yuba River, northern California. WATER RESOURCES RESEARCH, VOL. 40.

Synder, N. et al. 2004. Sediment Grain-size and Loss-on-ignition Analyses from 2002 Englebright Lake Coring and Sampling Campaigns. USGS Open-File Report 2004-1080.

Synder, N. et al. 2004. Report on the May-June 2002 Englebright Lake Deep Coring Campaign. USGS Open-File Report 2004-1061



Synder, N. and M. Hampton. 2003. Preliminary Cross Section of Englebright Lake Sediments. USGS Open-File Report 03-397. Pacific Science Center, Santa Cruz, CA 95060

James, L. Allan. 2005. Sediment from Hydraulic Mining Detained by Englebright and Small Dams in the Yuba Basin. Geomorphology 71 (2005) 202– 226.

Alpers, C. et al. 2004. Geochemical Data for Mercury, Methylmercury, and Other Constituents in Sediments from Englebright Lake, California, 2002. Prepared in cooperation with the CALFED Ecosystem Restoration Program, the California Bay–Delta Authority, and the California Resources Agency. USGS Data Series 151

Hunerlach, M. et al. 1999. Mercury Contamination from Hydraulic Placer-Gold Mining in the Dutch Flat Mining. District, California. Report 99-4018B, p.179-189



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APPENDIX D DAM REMOVAL SEDIMENT MANAGEMENT …...Mar 21, 2013 · Dam Removal Sediment Management Strategies APPENDIX D: DAM REMOVAL SEDIMENT MANAGEMENT STRATEGIES D.1 INTRODUCTION