DRAFT Total Maximum Daily Load Shoreline Segments in Lake County, Illinois Nine Segments from North Point Marina Beach to Highland Park Rosewood Beach Pathogen Indicators (Escherichia coli) Illinois Environmental Protection Agency February 13, 2013 Total Maximum Daily Load Lake County, Illinois – Nine Segments Table of Contents List of Acronyms .......................................................................................................................................... v 1. Introduction ............................................................................................................................................ 1 1.1 Priority Ranking .......................................................................................................................... 1 1.2 Framework for Illinois Shoreline Segments TMDL Development ............................................. 2 2. Overview of Impaired Segments ............................................................................................................ 5 2.1 Watershed Characterization ........................................................................................................ 8 2.1.1 North Point Marina Beach ............................................................................................ 8 2.1.2 Illinois Beach State Park – North Beach .................................................................... 12 2.1.3 Illinois Beach State Park – South Beach .................................................................... 15 2.1.4 Waukegan Beaches..................................................................................................... 18 2.1.5 Lake Bluff Sunrise Beach........................................................................................... 22 2.1.6 Lake Forest Park Beach .............................................................................................. 25 2.1.7 Highland Park Beaches .............................................................................................. 28 2.2 Current E. coli Conditions ........................................................................................................ 32 3. Problem Statement ............................................................................................................................... 35 3.1 WQS and TMDL Targets ......................................................................................................... 36 3.2 Linkage Analysis ...................................................................................................................... 39 3.2.1 GLCFS ....................................................................................................................... 43 3.2.2 Precipitation ............................................................................................................... 44 3.2.3 Land Use .................................................................................................................... 45 3.2.4 Substrate ..................................................................................................................... 46 3.2.5 Shoreline Physical Characteristics ............................................................................. 47 3.2.6 Ravines ....................................................................................................................... 48 3.3 Loading Capacity and Existing Load ....................................................................................... 49 4. Total Maximum Daily Loads ............................................................................................................... 50 4.1 Pollutant Source Assessment ..................................................................................................... 51 4.1.1 Sewage Treatment Plants ........................................................................................... 51 4.1.2 Stormwater ................................................................................................................. 52 4.1.3 Gulls and Other Sources ............................................................................................. 54 4.2 Pollutant Allocations ................................................................................................................. 54 4.2.1 Wasteload Allocations ............................................................................................... 54 4.2.2 Load Allocations ....................................................................................................... 56 4.3 Margin of Safety ........................................................................................................................ 56 4.4 Seasonal Variation ..................................................................................................................... 56 4.5 Critical Conditions ..................................................................................................................... 57 4.6 Reserve Capacity ....................................................................................................................... 58 4.7 TMDLs ...................................................................................................................................... 58 4.8 Load Reduction Calculation Methods ....................................................................................... 58 4.8.1 Step 1: Data Collection and Initial Analysis .............................................................. 59 4.8.2 Step 2: Initial Model Fitting ....................................................................................... 59 4.8.3 Step 3: Simulation ...................................................................................................... 59 4.9 Final Reductions ........................................................................................................................ 59 4.9.1 Distributional Groups ................................................................................................. 60 4.9.2 Analysis ...................................................................................................................... 62 5. Implementation and Monitoring Recommendations ............................................................................ 64 5.1 Implementation Plan ................................................................................................................. 64 5.1.1 Descriptions of BMPs ................................................................................................ 65 ii Total Maximum Daily Load Lake County, Illinois – Nine Segments 5.1.2 Management Strategy ................................................................................................. 71 5.1.3 Implementation ........................................................................................................... 76 5.1.4 Funding Sources ......................................................................................................... 76 5.2 Reasonable Assurance .............................................................................................................. 77 5.3 Monitoring Recommendations to Track TMDL Effectiveness ................................................ 82 6. Public Participation .............................................................................................................................. 82 References ................................................................................................................................................... 83 Appendix I: Lake County NPDES Discharges Not Expected to Contribute E. coli ................................... 88 Appendix II: Load Reduction Calculation Methods ................................................................................... 89 A.1 Step 1: Exploratory Data Analysis – Response Variable .......................................................... 89 A.2 Step 2: Exploratory Data Analysis – Predictor Variables ......................................................... 89 A.3 Step 3: Initial Model Fitting ...................................................................................................... 90 A.4 Step 4: Simulation for Load Reduction ..................................................................................... 91 References ............................................................................................................................................ 92 List of Figures 2-1. Drainage Areas for Impaired Beaches in Lake County, Illinois ...................................................... 7 2-2. North Point Marina Beach and Drainage Catchment within Illinois ............................................... 9 2-3. IBSP North Beach and Drainage Catchment ................................................................................. 13 2-4. IBSP South Beach and Drainage Catchment ................................................................................. 15 2-5. Waukegan Beaches and Drainage Catchments .............................................................................. 19 2-6. Lake Bluff Sunrise Beach and Drainage Catchment ..................................................................... 22 2-7. Lake Forest Park Beach and Drainage Catchment ......................................................................... 25 2-8. Highland Park Beaches and Drainage Catchments .......................................................................