United States Region 9 & Office of Water EPA-xxx-x-xx-xxx Environmental Protection November 2018 Agency DRAFT Aquatic Life and Aquatic-Dependent Wildlife Selenium Water Quality Criterion for Freshwaters of California (xx November 2018) U.S. Environmental Protection Agency Region 9 Water Division San Francisco, CA U.S. Environmental Protection Agency Office of Water Office of Science and Technology Washington, D.C. TABLE OF CONTENTS TABLE OF CONTENTS ....................................................................................................................... II LIST OF TABLES .............................................................................................................................. IV LIST OF FIGURES .............................................................................................................................. V EXECUTIVE SUMMARY .................................................................................................................... IX PART 1 INTRODUCTION AND BACKGROUND ................................................................................. 1 1.1 Early Selenium Efforts .................................................................................................... 1 1.2 California Toxics Rule .................................................................................................... 4 PART 2 PROBLEM FORMULATION ................................................................................................. 6 2.1 Overview of Selenium Sources and Occurrence in California ....................................... 6 2.2 Selenium Speciation in Aquatic Systems ..................................................................... 12 2.3 Bioaccumulation of Selenium in Aquatic Systems ....................................................... 15 2.4 Effects and Biota ........................................................................................................... 17 2.4.1 Mode of Action and Toxicity of Selenium ............................................................... 17 2.4.2 Narrow Margin between Sufficiency and Toxicity of Selenium .............................. 18 2.4.3 Adverse Effects of Selenium in Fish and Birds ........................................................ 19 2.5 Assessment Endpoints .................................................................................................. 22 2.6 Measures of Ecological Effect ...................................................................................... 22 2.7 Selenium Effects Concentrations in Fish Tissues and Bird Eggs ................................. 23 2.7.1 Water ......................................................................................................................... 25 2.7.2 Summary of Assessment Endpoints and Measures of Effect ................................... 26 2.7.3 Conceptual Model of Selenium Effects on Aquatic Life and Aquatic-Dependent Wildlife .................................................................................................................................. 27 PART 3 EFFECTS ANALYSIS FOR FRESHWATER AQUATIC ORGANISMS ....................................... 29 3.1 Purpose .......................................................................................................................... 29 3.2 Overview of Effects Analysis for Freshwater Aquatic Organisms ............................... 29 3.2.1 Fish Egg-Ovary Criterion Element Concentration ................................................... 33 3.2.2 Fish Whole Body Criterion Element Concentration ................................................. 33 3.2.3 Fish Muscle Criterion Element Concentration ......................................................... 34 PART 4 EFFECTS ANALYSIS FOR AQUATIC-DEPENDENT WILDLIFE ............................................ 35 4.1 Purpose .......................................................................................................................... 35 4.2 Chronic Toxicity to Aquatic-Dependent Wildlife ........................................................ 35 4.2.1 Summary of Selenium Reproductive Toxicity Studies Used to Derive the Aquatic- Dependent Wildlife Criterion ................................................................................................ 37 4.3 Derivation of Bird Egg Criterion Element .................................................................... 42 4.4 Previously Calculated Selenium Thresholds (as EC10) for Mallard Hatchability ......... 44 4.5 Chronic Egg Selenium Criterion Element Concentration ............................................. 52 4.6 Summary of Selenium Toxicology Studies Used Qualitatively in the Criterion Derivation ................................................................................................................................. 53 4.6.1 Reproductive Studies Used Qualitatively in the Criterion Derivation ...................... 53 4.6.2 Non-Reproductive Studies Used Qualitatively in the Criterion Derivation ............. 62 ii PART 5 TRANSLATING BIRD EGG AND FISH TISSUE CRITERION ELEMENTS TO A WATER-COLUMN ELEMENT USING THE PERFORMANCE-BASED APPROACH ................................................................ 66 5.1 Purpose .......................................................................................................................... 66 5.2 Translation from Tissue Concentration to Water Column Concentration Using the Mechanistic Model ................................................................................................................... 66 5.3 Equation Parameters ..................................................................................................... 68 5.3.1 Derivation of Trophic Transfer Factor (TTF) Values ............................................... 69 5.3.2 Derivation of Egg-Ovary to Whole Body Conversion Factor (CF) Values for Aquatic Life ........................................................................................................................... 77 5.3.3 Calculation of Site-Specific Enrichment Factor (EF) Values ................................... 79 5.4 Food Web Models ......................................................................................................... 80 5.4.1 Aquatic Life .............................................................................................................. 80 5.4.2 Aquatic-Dependent Wildlife ..................................................................................... 81 5.5 Deriving National Protective Water Column Concentrations for Lentic and Lotic Systems ................................................................................................................................... 84 5.5.1 Aquatic Life .............................................................................................................. 84 5.5.2 Aquatic-Dependent Wildlife ..................................................................................... 91 5.6 Derivation of Averaging Period for Chronic Water Criterion Element and Intermittent- Exposure Water Criterion Element .......................................................................................... 99 PART 6 AQUATIC AND AQUATIC-DEPENDENT WILDLIFE CRITERIA FOR SELENIUM IN CALIFORNIA’S FRESH WATERS.................................................................................................... 101 6.1 Protection of Downstream Waters .............................................................................. 104 6.2 Site-specific Criteria ................................................................................................... 105 PART 7 SUMMARY OF U.S. FISH AND WILDLIFE SERVICE AQUATIC-DEPENDENT WILDLIFE SELENIUM REPORT ....................................................................................................................... 107 REFERENCES ................................................................................................................................ 109 APPENDIX A SUMMARY INFORMATION FOR QUANTITATIVE AND QUALITATIVE BIRD STUDIES.. 130 APPENDIX B CALCULATION OF TROPHIC TRANSFER FACTORS ................................................. 138 APPENDIX C TOTAL SELENIUM AND DISSOLVED SELENIUM CONCENTRATIONS IN CALIFORNIA WATER BODIES ............................................................................................................................ 197 iii LIST OF TABLES Table 1-1. Summary of the Proposed California Selenium Ambient Chronic Water Quality Criteria for Protection of Aquatic Life and Aquatic-Dependent Wildlife. ....................... xi Table 2-1. Predominant Chemical Forms of Selenium in Discharges Associated with Different Activities and Industries. ............................................................................................... 14 Table 2-2. Summary of Assessment Endpoints and Measures of Effect Used in Criteria Derivation for Selenium. ............................................................................................................... 27 Table 3-1. Maternal Transfer Reproductive Toxicity Studies. ......................................... 31 Table 3-2. Four Lowest Genus Mean Chronic Values for Fish Reproductive Effects (U.S. EPA 2016a). .................................................................................................................................. 33 Table 3-3. The Lowest Four Reproductive-Effect Whole Body GMCVs. ....................... 34 Table 3-4. The Lowest Four Reproductive-Effect