2020 Review Water Quality Standards for Salinity Colorado River System October 2020 Colorado River Basin Salinity Control Forum 2020 Review WATER QUALITY STANDARDS FOR SALINITY COLORADO RIVER SYSTEM October 2020 Prepared by Colorado River Basin Salinity Control Forum COLORADO RIVER BASIN SALINITY CONTROL FORUM MEMBERS ARIZONA Clint Chandler, Assistant Director Department of Water Resources Patrick Dent, Director of Water Policy Central Arizona Water Conservation District Krista Osterberg, Surface Water Section Manager, Water Quality Division Department of Environmental Quality CALIFORNIA Bill Hasencamp, Manager, Colorado River Resources Metropolitan Water District of Southern California Tanya Trujillo COLORADO Rebecca Mitchell, Director Colorado Water Conservation Board Patrick Pfaltzgraff, Director, Water Quality Control Division Department of Public Health and Environment David W. Robbins, Attorney at Law NEVADA Andrew Burns, Manager, Water Resources Division Southern Nevada Water Authority Sara Price, Senior Assistant Director Colorado River Commission of Nevada NEW MEXICO John R. D’Antonio, Jr., New Mexico State Engineer Rolf Schmidt-Petersen, Director Interstate Stream Commission UTAH Todd Adams, Director, Division of Water Resources Department of Natural Resources James Harris, Water Quality Division Department of Environmental Quality Gawain Snow WYOMING Chad Espenscheid, Engineer/Rancher Patrick T. Tyrrell David Waterstreet, Program Manager, Water Quality Division Department of Environmental Quality FORUM Don A. Barnett, Executive Director Colorado River Basin Salinity Control Forum i The Colorado River Basin ii TRANSMITTAL LETTERS The Federal Water Pollution Control Act requires that at least once every three years the Basin States review water quality standards relating to the salinity of the Colorado River. The states collectively initiated this review under direction of the Forum. The Forum prepared a draft review and, after providing an opportunity for public comment, prepared this final 2020 Review. With the adoption of this final review, copies are being sent to the Colorado River Basin State Governors listed below for inclusion within their individual state water quality standards. Honorable Douglas A. Ducey Honorable Michelle Lujan Grisham Governor of Arizona Governor of New Mexico State Capitol State Capitol Phoenix, AZ 85007 Santa Fe, NM 87503 Honorable Gavin Newsom Honorable Gary R. Herbert Governor of California Governor of Utah State Capitol State Capitol Sacramento, CA 95814 Salt Lake City, UT 84114 Honorable Jared Polis Honorable Mark Gordon Governor of Colorado Governor of Wyoming State Capitol State Capitol Denver, CO 80203 Cheyenne, WY 82002 Honorable Steve Sisolak Governor of Nevada State Capitol Carson City, NV 89701 iii LIST OF ABBREVIATIONS 208 Plan Section 208 of the Clean Water Act amendments of 1972 and 1977 requiring integrated area-wide plans and programs for dealing with water pollution problems Act The Colorado River Basin Salinity Control Act (P.L. 93-320) (1974), as amended by P.L. 98-569 (1984), P.L. 104-20 (1995), P.L. 104-127 (1996), P.L. 106-459 (2000), P.L. 107-171 (2002) and P.L. 110-246 (2008) Basin Colorado River Basin Basin Funds Lower Colorado River Basin Development Fund and Upper Colorado River Basin Fund Basin States Arizona, California, Colorado, Nevada, New Mexico, Utah, Wyoming BSP Basin States Program Basinwide Program Basinwide Salinity Control Program BLM United States Bureau of Land Management Clean Water Act P.L. 92-500 Congress United States Congress CRSS Colorado River Simulation System EQIP Environmental Quality Incentives Program EPA United States Environmental Protection Agency Forum Colorado River Basin Salinity Control Forum kaf thousand acre-feet Ktons thousand tons (of salt) maf million acre-feet mgd million gallons per day mg/L milligrams per liter Mtons million tons (of salt) NPDES National Pollutant Discharge Elimination System NRCS Natural Resources Conservation Service Program Colorado River Basin Salinity Control Program Reclamation United States Bureau of Reclamation Review Triennial Review, Water Quality Standards for Salinity, Colorado River System TDS Total Dissolved Solids TMDL Total Maximum Daily Load USDA United States Department of Agriculture USGS United States Geological Survey WWTP Wastewater Treatment Plant iv TABLE OF CONTENTS COLORADO RIVER BASIN SALINITY CONTROL FORUM MEMBERS............................................. i COLORADO RIVER BASIN MAP ............................................................................................................. ii TRANSMITTAL LETTERS ....................................................................................................................... iii LIST OF ABBREVIATIONS ...................................................................................................................... iv TABLE OF CONTENTS ............................................................................................................................ v TABLES …………………………………………………………………………………………………...v FIGURES ..………………………………………………………………………………………………. vi APPENDICES …………………………………………………………………………………………... vi SUMMARY .................................................................................................................................................. 1 PURPOSE OF THE REVIEW ...................................................................................................................... 3 HISTORY AND BACKGROUND .............................................................................................................. 4 UNDERSTANDING THE SALINITY OF THE COLORADO RIVER ..................................................... 6 PROVISION FOR REVIEWING AND REVISING THE STANDARD .................................................... 9 NUMERIC CRITERIA ................................................................................................................................. 9 PLAN OF IMPLEMENTATION ............................................................................................................... 10 General .............................................................................................................................. 10 Constructed Measures ...................................................................................................... 11 Accomplishments and Future Control ............................................................................. 12 Forum Policies and NPDES Permits ................................................................................. 18 State Water Quality Management Plans ........................................................................... 18 CONCLUSION AND ADOPTION OF THE STANDARDS .................................................................... 27 FUTURE PROGRAM ............................................................................................................................... 28 TABLES Table 1 Control Measures in Place in 2020 ................................................................................... 15 Table 2 Additional Controls – Plan of Implementation 2023 ....................................................... 17 Table 3 Remaining Potential Salinity Control (2021-2040) ......................................................... 17 Table 4 Plan of Implementation Levels Modeled by CRSS ......................................................... 29 Table 5 Annual Damages and Damage Reductions ....................................................................... 32 v FIGURES Figure 1 2014-2018 Average Generalized Flow and Salinity Concentrations Across the Colorado River Basin .................................................................................................... 7 Figure 2 Flow Weighted Average Annual Salt Concentrations at Numeric Criteria Stations ......... 8 Figure 3 Salinity Control Program Impact below Hoover Dam ..................................................... 13 Figure 4 Salinity Control Program Impact below Parker Dam ....................................................... 14 Figure 5 Salinity Control Program Impact at Imperial Dam ........................................................... 14 Figure 6 Colorado River Basin Salinity Control Areas ................................................................... 16 Figure 7 Projected Annual Average Salinity Concentration below Hoover Dam ........................... 30 Figure 8 Projected Annual Average Salinity Concentration below Parker Dam ............................ 30 Figure 9 Projected Annual Average Salinity Concentration at Imperial Dam ................................ 31 APPENDICES Appendix A Observed Flow-Weighted Average Salinity at the Numeric Criteria Stations .............. A-1 Appendix B Forum Policies Policy for Implementation of Colorado River Salinity Standards Through the NPDES Permit Program .......................................................................................... B-1 NPDES Permit Program Policy for Implementation of Colorado River Salinity Standards .................................................................................................... B-5 Attachment 1 - Guidance on New Construction Determination .......................... B-15 Policy for Use of Brackish and/or Saline Waters for Industrial Purposes .................. B-16 Policy for Implementation of Colorado River Salinity Standards Through the NPDES Permit Program for Intercepted Groundwater ........................................