STRATEGIES TO CONTROL MERCURY POLLUTION IN THE CACHE CREEK BASIN, NORTHERN CALIFORNIA 2011 Group Project Prepared by: Melissa Riley, Amibeth Sheridan, Bethany Taylor, Kristiana Teige, Toshiyuki Yamasaki, and Nick Zigler Faculty Advisor: Arturo A. Keller, Ph.D. Client: U.S. Department of Interior, Bureau of Land Management – California State Office Strategies to Control Mercury Pollution in the Cache Creek Basin, Northern California As authors of this Group Project report, we are proud to archive this report on the Bren School’s website such that the results of our research are available for all to read. Our signatures on the document signify our joint responsibility to fulfill the archiving standards set by the Bren School of Environmental Science & Management. _________________________________ _________________________________ Melissa Riley Amibeth Sheridan _________________________________ _________________________________ Bethany Taylor Kristiana Teige _________________________________ _________________________________ Toshiyuki Yamasaki Nick Zigler The mission of the Bren School of Environmental Science & Management is to produce professionals with unrivaled training in environmental science and management who will devote their unique skills to the diagnosis, assessment, mitigation, prevention, and remedy of the environmental problems of today and the future. A guiding principle of the School is that the analysis of environmental problems requires quantitative training in more than one discipline and an awareness of the physical, biological, social, political, and economic consequences that arise from scientific or technological decisions. The Group Project is required of all students in the Master’s of Environmental Science and Management (MESM) Program. It is a three-quarter activity in which small groups of students conduct focused, interdisciplinary research on the scientific, management, and policy dimensions of a specific environmental issue. This Final Group Project Report is authored by MESM students and has been reviewed and approved by: _________________________________ Arturo A. Keller March 2011 TABLE OF CONTENTS TABLE OF CONTENTS ............................................................................................ i LIST OF FIGURES ................................................................................................... iii LIST OF TABLES ..................................................................................................... vi ACKNOWLEDGEMENTS ...................................................................................... ix ABSTRACT ................................................................................................................. x EXECUTIVE SUMMARY ....................................................................................... xi PROJECT OBJECTIVES....................................................................................... xvi PROJECT SIGNIFICANCE ................................................................................. xvii BACKGROUND ......................................................................................................... 1 Cache Creek ............................................................................................................. 1 Mercury Chemistry ................................................................................................. 9 Ecological Effects of Mercury Contamination ................................................... 12 Mercury Sources ................................................................................................... 15 Harley Gulch ........................................................................................................ 21 Bear Creek and Sulphur Creek ............................................................................ 23 Davis Creek ......................................................................................................... 26 Clear Lake ............................................................................................................ 27 Summary .............................................................................................................. 27 Regulatory Framework......................................................................................... 28 BLM Management, Water Board, and Basin Plan Background .......................... 28 Applicable Regulations, Policies, and Laws ....................................................... 33 Remediation/ Restoration Technologies & Management Options ................... 42 Containment Technologies .................................................................................. 45 Erosion Controls and Stream Bank Stabilization ................................................ 47 Removal ............................................................................................................... 49 Phytoremediation ................................................................................................. 51 Physical and Chemical Treatment (Soil) ............................................................. 54 Chemical Treatment (Water) ............................................................................... 56 Emerging Technologies ....................................................................................... 58 Additional Management Options......................................................................... 63 Summary of Remediation Technologies ............................................................. 64 Current Remediation in the Cache Creek Basin ................................................ 67 Sulphur Bank Mercury Mine ............................................................................... 67 Abbott and Turkey Run Mines ............................................................................ 67 Knoxville Mining District ................................................................................... 68 METHODOLOGY ................................................................................................... 69 i Decision Trees & Matrices ................................................................................... 69 Assessment Criteria............................................................................................... 70 Ranking System & Case Studies .......................................................................... 71 Harley Gulch Wetlands ....................................................................................... 73 Harley Gulch Delta .............................................................................................. 87 Sulphur Creek Stream Banks, Cherry Hill to Manzanita .................................... 93 West End Mine Waste Rock Pile ...................................................................... 101 Clyde Mine ........................................................................................................ 106 Turkey Run Spring ............................................................................................ 111 Summary of Case Studies .................................................................................. 116 Watershed Modeling ........................................................................................... 118 Watershed Model Setup and Calibration Process .............................................. 119 Erosivity............................................................................................................. 121 Soil Mercury Concentrations ............................................................................. 123 Watershed Modeling Results.............................................................................. 126 Water Budget ..................................................................................................... 126 Sediment Budget................................................................................................ 129 Mercury Budget ................................................................................................. 132 Prior Mercury Load Calculations from the Cache Creek Basin ........................ 137 Methylmercury Budget ...................................................................................... 142 Evaluation of Remediation Actions in the Cache Creek Basin ......................... 145 Evaluation of Remediation Actions in the Harley Gulch Watershed ................ 147 Evaluation of Remediation Actions in the Sulphur Creek Watershed .............. 150 Evaluation of Remediation Actions in the Bear Creek Watershed ................... 151 Discussion of Cache Creek Canyon ................................................................... 152 Summary of Watershed Model .......................................................................... 156 RECOMMENDATIONS ........................................................................................ 157 Actions to take ..................................................................................................... 158 Additional Data Collection and Monitoring Plan ............................................ 160 Further Research................................................................................................. 164 Partnerships ......................................................................................................... 166 CONCLUSION ......................................................................................................