Jordan River Total Maximum Daily Load Water Quality Study - Phase 1 Prepared for: Utah Department of Environmental Quality Division of Water Quality 195 North 1950 West Salt Lake City, Utah 84116 Carl Adams- Project Supervisor Hilary Arens- Project Manager Prepared by: Cirrus Ecological Solutions, LC 965 South 100 West, Suite 200 Logan, Utah 84321 Stantec Consulting Inc. 3995 South 700 East, Suite 300 Salt Lake City, Utah 84107 EPA APPROVAL DATE JUNE 5, 2013 i Jordan River TMDL Jordan River – 1 (UT16020204-001) Waterbody ID Jordan River – 2 (UT16020204-002) Jordan River – 3 (UT16020204-003) Parameter of Concern Dissolved Oxygen Pollutant of Concern Total Organic Matter Class 3B Protected for warm water species of game fish and aquatic life, including the necessary Impaired Beneficial Use aquatic organisms in their food chain. Loading Assessment Current Load 2,225,523 kg/yr Total Organic Matter Loading Capacity 1,373,630 kg/yr or 3,763 kg/day Total Organic Matter (38% reduction) Load capacity based on OM concentrations that result in DO model endpoint of 5.5 mg/L, Margin of Safety including 1.0 mg/L implicit MOS added to the instantaneous DO water quality standard of 4.5 mg/L. Bulk Load Allocation 684,586 kg/yr Total Organic Matter (35% reduction) Bulk Waste Load 689,044 kg/yr Total Organic Matter (41% reduction) Allocation Defined Total OM load to lower Jordan River (kg/yr) <= 1,373,630 kg/yr Targets/Endpoints Dissolved Oxygen => 4.5 mg/L Nonpoint Pollutant Utah Lake, Tributaries, Diffuse Runoff, Irrigation Return Flow, Groundwater Sources Wastewater Stormwater Jordan Basin WRF (UT0025852) Phase I Permit South Valley WRF (UT0024384) Salt Lake County Central Valley WRF (UT0024392) Salt Lake City South Davis WTP (UT0021628) UDOT Regulated Point Source Phase II Permit Pollutants Bluffdale Midvale South Salt Lake Draper Murray Taylorsville Herriman Riverton West Jordan Holladay Sandy West Valley Lehi South Jordan Phased TMDL Phase II (2012–2018): Characterization of OM and WQ Response; BMP Implementation Phase III (2018–2023): BAT Design; Implementation of Stormwater Capital Improvements; Begin TMDL Strategy implementation strategy in revised TMDL. Phase IV (2023-2028): Construction upgrades for point sources to meet WLAs, meet all DO water quality standards. ii TABLE OF CONTENTS Table of Contents ............................................................................................................................ iii List of Appendices ....................................................................................................................... v List of Tables .............................................................................................................................. vi List of Figures ............................................................................................................................. vi Executive Summary ..................................................................................................................... S-1 1.0 Introduction and State of the Jordan River ................................................................................ 1 1.1 The TMDL Process ................................................................................................................ 1 1.1.1 Federal Requirements of Clean Water Act ..................................................................... 1 1.1.2 TMDL Guidelines ........................................................................................................... 2 1.1.3 Utah Water Quality Standards and Jordan River Beneficial Uses .................................. 2 1.1.4 Status of current impairments and phased approach ....................................................... 3 1.2 Watershed Description ........................................................................................................... 6 1.2.1 Topography ..................................................................................................................... 6 1.2.2 Geology/Soils .................................................................................................................. 9 1.2.3 Precipitation .................................................................................................................... 9 1.2.4 Hydrology ....................................................................................................................... 9 1.3 Stakeholders and the TMDL process ................................................................................... 10 1.3.1 Federal, State, and Municipal Authority ....................................................................... 10 1.3.2 Municipal Water Demand ............................................................................................. 12 1.3.3 Flood Control ................................................................................................................ 14 1.4 Water Quality ....................................................................................................................... 14 1.4.1 Data Collection ............................................................................................................. 14 1.4.2 Existing Water Quality Conditions ............................................................................... 16 1.5 Summary and Discussion ..................................................................................................... 18 2.0 Water Quality Linkage in the lower Jordan River ................................................................... 23 2.1 Introduction .......................................................................................................................... 23 2.2 Evidence of DO Impairment in the lower Jordan River ...................................................... 23 2.2.1 Water Quality Stations on the lower Jordan River ........................................................ 23 2.2.2 Seasonal Patterns in DO Measurements and Violations ............................................... 24 2.2.3 DO Deficits ................................................................................................................... 25 2.3 Processes Affecting DO in Streams and Rivers ................................................................... 26 2.4 Critical Condition ................................................................................................................. 28 2.4.1 Definition ...................................................................................................................... 28 2.4.2 Application to the Lower Jordan River ......................................................................... 29 2.4.2.1 Process Used to Identify Critical Condition for DO .............................................. 29 2.4.2.2 Findings Relating to Critical Condition ................................................................. 29 2.4.2.3 Critical Condition for DO in the Lower Jordan River ........................................... 32 2.5 Modeling water quality responses to pollutant loading in lower Jordan River – Application of the QUAL2Kw Water Quality Model .......................................................... 32 iii 2.5.1 Model Description......................................................................................................... 32 2.5.2 Calibration ..................................................................................................................... 33 2.6 DO Endpoint for the Lower Jordan River ............................................................................ 34 2.6.1 Definition and Use of Endpoints in the TMDL ............................................................ 34 2.6.2 Margins of Safety in Establishing an Endpoint ............................................................. 34 2.7 Pollutant of concern and permissible loads (water quality responses to pollutants from QUAL2KW Model) ............................................................................................................. 37 2.7.1 Effect of Reducing Nutrients on DO in the lower Jordan River ................................... 37 2.7.2 Effect of Reducing Organic Matter on DO in the lower Jordan River.......................... 38 2.7.3 Nature of OM in the Jordan River................................................................................. 39 2.8 Summary .............................................................................................................................. 41 3.0 Pollutant Source Analysis ........................................................................................................ 43 3.1. Jordan River Organic Matter............................................................................................... 43 3.2 Jordan River OM Pollutant Source Characteristics ............................................................. 44 3.2.1 Wastewater treatment plants ......................................................................................... 44 3.2.2 Stormwater .................................................................................................................... 46 3.2.3 Utah Lake ...................................................................................................................... 47 3.2.4 Tributaries ..................................................................................................................... 48 3.2.5 Diffuse Runoff .............................................................................................................