Arsenic, Mercury, and Selenium in Fish Tissue and Water from Idaho’s Major Rivers: A Statewide Assessment Prepared by Don A. Essig March 2010 This page intentionally left blank. Assessment of Arsenic, Mercury, and Selenium in Fish and Water from Rivers Acknowledgements This document is the product of a cooperative effort between the Idaho Department of Environmental Quality (DEQ) and the U.S. Environmental Protection Agency (EPA). EPA provided supplemental monitoring funds that enabled this work to take place, and Tony Olsen of EPA’s Corvallis laboratory generated the random selection of rivers for this project. Jason Pappani of DEQ hired, trained, and supervised a seasonal crew that performed the field work. The staff of Brooks Rand, LLC, particularly Misty Kennard-Mayer and Bryan Setzer, was responsive to our analytical needs and questions. Xin Dai of DEQ’s Technical Services Division performed the quality assurance/quality control review. Mary Anne Kosterman of DEQ handled data management and prepared the maps. Finally, I thank the reviewers: Mary Anne Kosterman, Carl Brown, Jeanna Burrup, Lisa Hansen, and Michael McIntyre. Without their help, the imperfections would be more numerous and obvious. Thank you all for your kind help. Cover Photo: Selway River just above Selway Falls, taken by Don Essig i Assessment of Arsenic, Mercury, and Selenium in Fish and Water from Rivers This page intentionally left blank. ii Assessment of Arsenic, Mercury, and Selenium in Fish and Water from Rivers Contents This report covers the entire project from design through implementation to results, some recent related data on mercury in fish in Idaho, and discussion. These elements are presented in that order and have been arranged into six general parts. List of Acronyms, Abbreviations, and Symbols....................................................................... vii Executive Summary..................................................................................................................... xi Part A. Project Management, Background, and Design ........................................................... 1 Project Organization.................................................................................................................................1 Background and Objectives......................................................................................................................1 Study Design ............................................................................................................................................4 Quality Assurance and Quality Control....................................................................................................9 Part B. Sample Collection, Preparation, and Handling, and Data Management ................. 11 Sample Collection ..................................................................................................................................11 Sample Handling ....................................................................................................................................12 Composite Tissue Samples.....................................................................................................................13 Data Management...................................................................................................................................13 Part C. Quality Control Results ................................................................................................ 15 Field QC Samples...................................................................................................................................15 Laboratory QC Samples .........................................................................................................................16 Part D. Analytical Results for Water and Fish Tissue from Rivers....................................... 23 Sites Sampled .........................................................................................................................................23 Mercury, Arsenic, and Selenium Levels in Fish Tissue .........................................................................27 Levels of Mercury, Arsenic, and Selenium in River Water ...................................................................33 Part E. Analytical Results for Off-Project Monitoring ........................................................... 41 Hatchery Chinook Salmon .....................................................................................................................41 USGS Water Samples.............................................................................................................................42 Part F. Discussion........................................................................................................................ 43 Limitations of the Assessment................................................................................................................43 Summary of Comparison to Criteria ......................................................................................................44 Bioaccumulation Factors (BAFs) ...........................................................................................................46 Arsenic Forms and Bioaccumulation .....................................................................................................48 Selenium-Mercury Interactions ..............................................................................................................48 Fish Tissue vs. Water Criteria and Protection of Aquatic Life...............................................................50 Fish Consumption Advisories ................................................................................................................51 Source and Control of Mercury in Fish..................................................................................................52 References.................................................................................................................................... 55 Glossary ....................................................................................................................................... 63 iii Assessment of Arsenic, Mercury, and Selenium in Fish and Water from Rivers Appendix A. River Site Selection............................................................................................. A-1 Appendix B. River Sites Actually Sampled ............................................................................ B-1 Appendix C. Fish Species Code List........................................................................................ C-1 Appendix D. Summary of Fish Lengths and Weights ........................................................... D-1 Appendix E. Analytical Results ............................................................................................... E-1 Appendix F. Quality Control Sample Results .........................................................................F-1 Appendix G. QA/QC Evaluation.............................................................................................G-1 Appendix H. Cumulative Distribution Plots ..........................................................................H-1 List of Figures Figure 1. Idaho Fish Consumption Advisories as of November 2009............................................ 3 Figure 2. Electrofishing Raft......................................................................................................... 11 Figure 3. River Sites Sampled in 2006 and 2008.......................................................................... 24 Figure 4. Example of Differences in Tissue Mercury Content by Species and Size of Fish, for Snake River at Lewiston, generated using USGS EMMMA...................................... 26 Figure 5. Mercury Concentrations in Fish Tissue, 2006 and 2008 Combined ............................. 30 Figure 6. Map of Total Mercury in Water Concentrations ........................................................... 34 Figure 7. Fraction of Water Total Mercury that is Methylmercury.............................................. 36 Figure 8. Map of Methylmercury in Water Concentrations ......................................................... 37 Figure 9. Total and Inorganic Arsenic (As) in Water ................................................................... 38 Figure 10. Total Selenium (Se) in Water...................................................................................... 39 Figure 11. Relation of Fish Tissue Total Mercury to Water Total Mercury................................. 45 Figure 12. Relation of Fish Tissue Total Mercury to Water Methylmercury............................... 46 Figure 13. 2007 Regional Air Emissions of Mercury................................................................... 53 Figure H-1. Cumulative Distribution Plot of Arsenic in Fish Tissue ......................................... H-1 Figure H-2. Cumulative Distribution Plot of Mercury in Fish Tissue........................................ H-2 Figure H-3. Cumulative Distribution Plot of Selenium in Fish Tissue....................................... H-3 Figure H-4. Cumulative Distribution Plot of Inorganic Arsenic in Water ................................. H-4 Figure H-5. Cumulative Distribution Plot of Total Arsenic in Water ........................................ H-5 Figure H-6. Cumulative Distribution Plot of Mercury