Forecasting Selenium Discharges to the San Francisco Bay-Delta Estuary: Ecological Effects of a Proposed San Luis Drain Extension Professional Paper 1646 U.S. Department of the Interior U.S. Geological Survey COVER PHOTOGRAPHS Sources California Coast Ranges adjacent to the western San Joaquin Valley Irrigated farm fields in the western San Joaquin Valley A section of the San Luis Drain presently being used Oil refinery adjacent to San Francisco Bay Environment Satellite view of San Francisco Bay-Delta Estuary with close-up of wetland environment Physiology/Bioaccumulation Mysid Clam Amphipod Effects Lesser scaup in flight Forecasting Selenium Discharges to the San Francisco Bay-Delta Estuary: Ecological Effects of a Proposed San Luis Drain Extension Theresa S. Presser and Samuel N. Luoma Professional Paper 1646 This work was performed with the support of a U.S. Environmental Protection Agency interagency funding agreement (EPA/IAG DW 14955347-01-0, Region 9) and cooperative funding agreements with Contra Costa County and Contra Costa Water District. This is a revision of and supersedes U.S. Geological Survey Open-File Report 00-416 (Luoma, S.N. and Presser, T.S., 2000, Forecasting Selenium Discharges to the San Fran- cisco Bay-Delta Estuary: Ecological Effects of a Proposed San Luis Drain Extension, 358 p.). U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Dirk Kempthorne, Secretary U.S. Geological Survey P. Patrick Leahy, Acting Director U.S. Geological Survey, Reston, Virginia: 2006 For sale by U.S. Geological Survey Information Services Box 25286, Denver Federal Center Denver, CO 80225 For product and ordering information: World Wide Web: http://www.usgs.gov/pubprod Telephone: 1-888-ASK-USGS For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment: World Wide Web: http://www.usgs.gov Telephone: 1-888-ASK-USGS Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement of the U.S. Government. Cataloging-in-publication data are on file with the Library of Congress (URL http://www.loc.gov/). iii Contents Abstract ...........................................................................................................................................................1 Introduction.....................................................................................................................................................2 Generic Selenium Issues .....................................................................................................................6 Selenium Issues in the Bay-Delta ......................................................................................................7 Changing Selenium Issues .........................................................................................................................15 Approach to Understanding Changing Issues ........................................................................................18 Sources of Selenium in the Bay-Delta .....................................................................................................19 Selenium from the Western San Joaquin Valley ...........................................................................19 Selenium from Oil Refineries ............................................................................................................35 Selenium from the Sacramento River .............................................................................................36 Summary...............................................................................................................................................36 Hydraulic Connections and Conveyance of Selenium to the Bay-Delta ............................................36 Concentrations of Selenium in the Bay-Delta .........................................................................................38 Effects of Source Water Selenium Loads on Receiving Water Selenium Concentrations ....38 Existing Concentrations in the Bay-Delta .......................................................................................39 Chemical Forms of Selenium (Speciation) ...............................................................................................40 Particulate and Sediment-Associated Selenium ...................................................................................41 Processes Affecting Particulate Selenium ....................................................................................41 Sources of Particulate Selenium in the Bay-Delta .........................................................................43 Bioaccumulation of Selenium by Invertebrates .....................................................................................46 Processes ............................................................................................................................................46 Selenium in Invertebrates from the Bay-Delta ..............................................................................47 Summary of Exposure ........................................................................................................................48 Modeling Selenium Bioaccumulation in the Bay-Delta: Dynamic Multi-Pathway Bioaccumulation (DYMBAM) Model .................................................................................49 Bioaccumulation of Selenium by Predators ............................................................................................50 Dietary Exposure .................................................................................................................................50 Existing Selenium Concentrations in Tissues of Birds and Fish in the Bay-Delta ...................51 Effects of Selenium on Predators .............................................................................................................54 Relating Selenium Concentrations in Food (Prey) to Effects in Predators ................................55 Relating Selenium Concentrations in Tissue to Effects in Predators .........................................57 Selenium Hazard Rating ....................................................................................................................59 Scenarios and Forecasts ............................................................................................................................63 Scenarios of Composite Loads and Volumes to the Bay-Delta ..................................................63 Forecasts of Speciation and Transformation ................................................................................75 Forecasts of Particulate Selenium Concentrations ......................................................................77 Forecasts of Bioaccumulation in Consumer Organisms ..............................................................82 Forecast of Selenium Concentrations in Tissues of Predators ...................................................87 Ecological Risk .............................................................................................................................................90 Cumulative Effects on the Bay-Delta ...............................................................................................90 Implications for Water Quality Criteria for the Protection of Aquatic Life ................................94 iv Conclusions...................................................................................................................................................94 Extent and Sustainability of Agricultural Discharge from the San Joaquin Valley ..................94 Water Management Implications ....................................................................................................95 Indicators of Ecological Risk and Monitoring Needs ...................................................................95 Concluding Perspective .....................................................................................................................97 Appendix A. Export Drain Planning History and Geologic Inventory ................................................100 Envisioned Drainage Discharges and Salt Loads .......................................................................101 Geologic Inventory and Reservoir of Selenium in the San Joaquin Valley .............................107 Characteristics and Timing of Selenium Source Water Release as Drainage .......................110 Appendix B. San Joaquin Valley Agricultural Drainage Projections ................................................114 Projected Selenium Loads from Historic Data and Evidentiary Testimony .............................116 Projections from Drainage Program Management Options ......................................................124 Projections from Currently Available Data ...................................................................................124 Estimates of Capacity of Drainage Conveyance (proposed San Luis Drain extension) .......135 Total flux from Agricultural Drainage Discharge (lbs Selenium per day) ................................135 Appendix C. Agricultural Drainage Discharge to the San Joaquin River .........................................137 Models of Discharge to the San Joaquin River ..........................................................................138 Appendix D. Temporal