Total Maximum Daily Load for Total Dissolved Gas in the Mid-Columbia River and Lake Roosevelt Submittal Report Washington State Spokane Tribe U. S. Environmental Department of of Indians Protection Agency Ecology June 2004 Prepared jointly by the U.S. Environmental Protection Agency and the Washington State Department of Ecology in cooperation with the Spokane Tribe of Indians Publication Information U.S. EPA For a printed copy or a compact disk of this publication, contact: Helen Rueda U.S. EPA 811 SW Sixth Avenue Portland, OR 97204 Phone: (503) 326-3280 E-mail: [email protected] Washington State This report is available on the Washington State Department of Ecology Wide Web at http://www.ecy.wa.gov/biblio/0403002.html. For a printed copy of this publication, contact: Jean Witt Department of Ecology Publications Distributions PO Box 47600 Olympia WA 98504-7600 Phone: (360) 407-7472 E-mail: [email protected] Refer to Ecology Publication Number 04-03-002 The Washington State Department of Ecology and U.S. EPA are equal opportunity agencies and do not discriminate on the basis of race, creed, color, disability, age, religion, national origin, sex, marital status, disabled veteran's status, Vietnam-era veteran's status, or sexual orientation. If you have special accommodation needs or require this document in alternative format, please contact Joan LeTourneau, Ecology, at (360)-407-6764 (voice), or Helen Rueda, EPA TMDL Project Manager, at (503) 326-3280 (voice). Ecology's telecommunications device for the deaf (TTY) number is (360) 407-6006. EPA's telecommunications device for the deaf (TTY) number is (503) 229-6993. Total Maximum Daily Load for Total Dissolved Gas in the Mid-Columbia River and Lake Roosevelt Submittal Report by Paul J. Pickett1 Helen Rueda2 and Mike Herold3 1Washington State Department of Ecology Environmental Assessment Program Olympia, WA 98504-7710 2U.S. Environmental Protection Agency Oregon Operations Office Portland, OR 97204 3Washington State Department of Ecology Water Quality Program Olympia, WA 98504-7600 June 2004 Waterbody Numbers: WA-CR-1030, -1040, -1050, and -1060 Washington State Department of Ecology Publication No. 04-03-002 This page is purposely left blank for duplex printing. Table of Contents Page List of Tables and Figures.................................................................................................. iii Acronyms and Abbreviations ............................................................................................ iv Abstract................................................................................................................................v Acknowledgements............................................................................................................ vi Executive Summary.......................................................................................................... vii Description of Waterbody, Pollutant of Concern, and Pollutant Sources................... vii Description of the Applicable Water Quality Standards and Numeric Target .......... viii Loading Capacity......................................................................................................... ix Pollutant Allocations.................................................................................................... ix Margin of Safety ............................................................................................................x Seasonal Variation .........................................................................................................x Monitoring Plan .............................................................................................................x Implementation Plan ......................................................................................................x Public Participation...................................................................................................... xi Introduction..........................................................................................................................1 Geographic Extent .........................................................................................................3 Clean Water Act Requirements .....................................................................................5 Coordination with Endangered Species Act ..................................................................6 Total Dissolved Gas Water Quality Standards ....................................................................9 State of Washington Standards ......................................................................................9 Colville Tribe Standards ..............................................................................................10 Spokane Tribe Standards .............................................................................................10 TMDL Targets .............................................................................................................10 Background........................................................................................................................13 Sources of TDG ...........................................................................................................13 Spill for Fish Passage...................................................................................................14 Involuntary Spill ..........................................................................................................14 Water Quality and Resource Impairments.........................................................................17 TDG Generation from Spills........................................................................................17 TDG Impacts on Aquatic Life .....................................................................................18 Monitoring of TDG......................................................................................................20 Analysis of Current Conditions .........................................................................................23 TDG Data Sources .......................................................................................................23 Lake Roosevelt TMDL Data........................................................................................23 Mid-Columbia TMDL Data.........................................................................................25 Identification of Sources....................................................................................................29 Lake Roosevelt.............................................................................................................30 1. Grand Coulee Dam .................................................................................................47 Page i 2. Chief Joseph Dam...................................................................................................50 3. Wells Dam ..............................................................................................................51 4. Rocky Reach Dam ..................................................................................................53 5. Rock Island Dam.....................................................................................................55 6. Wanapum Dam .......................................................................................................57 7. Priest Rapids Dam...................................................................................................59 Loading Capacity...............................................................................................................63 Linkage of TDG Loading to the Criteria .....................................................................63 Load Allocations................................................................................................................65 Long-term Attainment of Water Quality Standards.....................................................67 Monitoring of Attainment............................................................................................71 Margin of Safety ................................................................................................................73 Critical Conditions.......................................................................................................73 Criteria versus Site-specific Conditions.......................................................................73 Data Quality and Quantity ...........................................................................................73 Seasonal Variations............................................................................................................75 7Q10 Flows..................................................................................................................75 Summary of Public Involvement .......................................................................................77 Public Involvement Actions.........................................................................................77 References and Bibliography.............................................................................................79 Appendices: Appendix A. Summary Implementation Strategy Appendix B. Response to Public Comments Appendix C. Technical Analysis of TDG Processes Appendix D. Data Sets Used for the Lake Roosevelt Portion of the TMDL Appendix E. Color Photograph Figures On the Web,