Los Angeles River Watershed Bacteria Total Maximum Daily ... Jul 10, 2015 ¢  2007), Los Angeles River

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  • Los Angeles River Watershed Bacteria

    Total Maximum Daily Load

    July 15, 2010

    California Regional Water Quality Control Board Los Angeles Region

    320 West Fourth Street, Suite 200 Los Angeles, California 90013

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    Acronyms 303(d) list State of California Clean Water Act section 303(d) List of Water

    Quality Limited Segments BMPs Best Management Practices BSI Bacteria Source Identification Study Caltrans California Department of Transportation CFR Code of Federal Regulations cfs Cubic Feet per Second CMP Coordinated Monitoring Plan CREST Cleaner Rivers through Effective Stakeholder-led TMDLs CWA Clean Water Act EO Executive Officer HFS High Flow Suspension IRP Integrated Resources Plan LA Load Allocation LACDPW Los Angeles County Department of Public Works LARWQCB Los Angeles Regional Water Quality Control Board LAX Los Angeles International Airport LDC Load Duration Curve LFD Low Flow Diversion LID Low Impact Development LRS Load Reduction Strategy mgd Million Gallons per Day mL Milliliter MOS Margin of Safety MPN Most Probably Number MS4 Municipal Separate Storm Sewer System NPDES National Pollutant Discharge Elimination System OWTS Onsite Wastewater Treatment Systems O&M Operation and Maintenance SCCWRP Southern California Coastal Water Research Project SEA Significant Ecological Areas SSO Sanitary Sewer Overflows SWPPP Storm Water Pollution Prevention Plan SWRCB State Water Resources Control Board TMDL Total Maximum Daily Load UAA Use Attainability Analysis USEPA United States Environmental Protection Agency WDR Waste Discharge Requirement WLA Waste Load Allocation WRP Water Reclamation Plant

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    Table of Contents 1 INTRODUCTION...................................................................................................... 1

    1.1 Regulatory Background......................................................................................... 3 1.2 Environmental Setting ........................................................................................... 4

    1.2.1 Reach Definition ............................................................................................. 5 1.2.2 Land Use ......................................................................................................... 8 1.2.3 Climate/Rainfall............................................................................................ 10 1.2.4 Watershed Habitat......................................................................................... 10

    1.2.4.1 Special Habitat Areas ............................................................................. 10 1.2.4.2 Threatened and Endangered Species...................................................... 12

    2 Problem Identification ............................................................................................. 13 2.1 CWA Section 303(d) Listed reaches and tributaries ........................................... 13

    2.1.1 Beneficial Uses ............................................................................................. 14 2.2 Water Quality Objectives .................................................................................... 16

    2.2.1 Antidegradation............................................................................................. 18 2.3 Review of data ..................................................................................................... 19

    3 Numeric Targets....................................................................................................... 21 3.1 Alternative Targets Considered ........................................................................... 21 3.2 Recommended Alternative .................................................................................. 22 3.3 Wet Weather ........................................................................................................ 22 3.4 The Continuing Process....................................................................................... 24

    4 Source Assessment.................................................................................................... 24 4.1 Point Sources ....................................................................................................... 25

    4.1.1 Municipal Storm Water................................................................................. 25 4.1.2 Major NPDES Discharges ............................................................................ 27

    4.1.2.1 Wastewater Reclamation Plants ............................................................. 27 4.1.3 Other Storm Water Permits........................................................................... 28 4.1.4 Other General NPDES Permits, Minor Individual NPDES Permits, and Industrial Waste Water Permits.................................................................................. 29

    4.2 Nonpoint Sources ................................................................................................ 29 4.2.1 Septic Systems .............................................................................................. 29 4.2.2 Sanitary Sewer Overflows ............................................................................ 30 4.2.3 Natural Sources............................................................................................. 30 4.2.4 In-Channel Sources....................................................................................... 30

    5 Linkage Analysis ...................................................................................................... 32 6 Allocations................................................................................................................. 36

    6.1 Interim Allocations: MS4 dischargers, dry weather............................................ 36 6.2 Final Allocations.................................................................................................. 39

    6.2.1 Final Load Allocations.................................................................................. 39 6.2.2 Final Wasteload Allocations ......................................................................... 39 6.2.3 Allowable Exceedance Days......................................................................... 40 6.2.4 Calculating Dry Weather and Wet Weather Exceedance Probabilities ........ 40 6.2.5 Calculating Allowable Exceedance Days at a Targeted Location ................ 40 6.2.6 Reference System.......................................................................................... 41 6.2.7 Critical condition (reference year) ................................................................ 42

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    6.3 Translating exceedance probabilities into estimated exceedance days during the critical condition ............................................................................................................ 42

    6.3.1 High Flow Suspension .................................................................................. 43 7 Margin of Safety ....................................................................................................... 44 8 Critical Conditions ................................................................................................... 45 9 Implementation Strategy ......................................................................................... 46

    9.1 Introduction ......................................................................................................... 46 9.2 Potential Implementation Actions ....................................................................... 47

    9.2.1 Structural Implementation Actions ............................................................... 47 9.2.1.1 Dry Weather Structural BMPs ............................................................... 47 9.2.1.2 Wet Weather Structural BMPs............................................................... 48

    9.2.1.2.1 Sub-Regional Structural BMPs ......................................................... 48 9.2.1.2.2 Regional Structural BMPs................................................................. 48

    9.2.2 Non-structural Best Management Practices.................................................. 49 9.2.2.1 Administrative Controls ......................................................................... 49 9.2.2.2 Outreach and Education ......................................................................... 49

    9.3 Responsible parties .............................................................................................. 49 9.4 Implementation: Dry weather .............................................................................. 53

    9.4.1 Dry Weather Implementation for Non-point Sources................................... 53 9.4.2 Dry Weather Implementation for Point Sources........................................... 54 9.4.3 Water Reclamation Plants............................................................................. 54 9.4.4 General and Individual Industrial Stormwater NPDES Dischargers ............ 54 9.4.5 MS4 Dry Weather Implementation............................................................... 54 9.4.6 Prioritization of segments; MS4 dry weather implementation ..................... 64

    9.5 Wet Weather Implementation.............................................................................. 67 9.6 Implementation Schedule .................................................................................... 68 9.7 Monit