Total Maximum Daily Loads for the Twelvepole Creek Watershed, West Virginia Draft Report November 2020- REVISED 12/8/2020 Revisions and additions are noted in Table of Contents and italicized in documented On the cover: Photos provided by WVDEP Division of Water and Waste Management Twelvepole Creek Watershed: TMDL Report CONTENTS Acronyms, Abbreviations, and Definitions ..................................................................................v Executive Summary ................................................................................................................... viii 1.0 Report Format ....................................................................................................................1 2.0 Introduction ........................................................................................................................1 2.1 Total Maximum Daily Loads ...................................................................................1 2.2 Water Quality Standards ..........................................................................................4 3.0 Watershed Description and Data Inventory....................................................................6 3.1 Watershed Description .............................................................................................6 3.2 Data Inventory .........................................................................................................8 3.3 Impaired Waterbodies ............................................................................................10 4.0 Biological Impairment and Stressor Identification ......................................................21 4.1 Introduction ............................................................................................................21 4.2 Data Review ...........................................................................................................22 4.3 Candidate Causes/Pathways...................................................................................22 4.4 Stressor Identification Results ...............................................................................25 5.0 Metals and Selenium Source Assessment ......................................................................32 5.1 Metals and Selenium Point Sources .......................................................................32 5.1.1 Mining Point Sources .................................................................................34 5.1.2 Non-mining Point Sources .........................................................................35 5.1.3 Construction Stormwater Permits ..............................................................36 5.1.4 Municipal Separate Storm Sewer Systems (MS4)- ADDED .....................38 5.2 Metals Nonpoint Sources .......................................................................................40 5.2.1 Abandoned Mine Lands .............................................................................40 5.2.2 Sediment Sources .......................................................................................40 5.3 Beryllium Source Assessment ...............................................................................46 5.4 Selenium Source Assessment ................................................................................47 6.0 pH Source Assessment .....................................................................................................50 6.1 Abandoned Mine Land Seeps ......................................................................................50 6.2 Acid Deposition ...........................................................................................................50 6.3 pH – Natural Alkalinity Sources ..................................................................................51 i Twelvepole Creek Watershed: TMDL Report 7.0 Fecal Coliform Source Assessment.................................................................................51 7.1 Fecal Coliform Point Sources ................................................................................51 7.1.1 Individual NPDES Permits ........................................................................51 7.1.2 Overflows ...................................................................................................52 7.1.3 Municipal Separate Storm Sewer Systems (MS4)- ADDED .....................52 7.1.4 General Sewage Permits ............................................................................52 7.2 Fecal Coliform Nonpoint Sources .........................................................................54 7.2.1 On-site Treatment Systems ........................................................................54 7.2.2 Urban/Residential Runoff ..........................................................................56 7.2.3 Agriculture .................................................................................................56 7.2.4 Natural Background (Wildlife) ..................................................................56 8.0 DISSOLVED OXYGEN SOURCE ASSESSMENT .....................................................57 9.0 Modeling Process .............................................................................................................57 9.1 Model Selection .....................................................................................................58 9.2 Model Setup ...........................................................................................................59 9.2.1 General MDAS Configuration ...................................................................59 9.2.2 Metals and Sediment Configuration ..........................................................60 9.2.3 Aluminum and pH Configuration- ADDED ..............................................61 9.2.4 Selenium Configuration .............................................................................63 9.2.5 Fecal Coliform Configuration ....................................................................63 9.3 Hydrology Calibration ...........................................................................................63 9.4 Water Quality Calibration ......................................................................................64 9.5 Modeling Technique for Biological Impacts with Sedimentation Stressors .........65 9.6 Allocation Strategy ................................................................................................66 9.6.1 TMDL Endpoints .......................................................................................66 9.6.2 Baseline Conditions and Source Loading Alternatives- REVISED ...........67 9.7 TMDLs and Source Allocations ............................................................................70 9.7.1 Total Iron TMDLs - REVISED ..................................................................70 9.7.2 Dissolved Aluminum and pH TMDLs- REVISED ....................................74 9.7.3 Total Selenium TMDLs .............................................................................76 9.7.4 Fecal Coliform Bacteria TMDLs - REVISED ............................................77 9.7.5 Seasonal Variation .....................................................................................79 9.7.6 Critical Conditions .....................................................................................79 9.7.7 TMDL Presentation- REVISED .................................................................79 10.0 TMDL Results ..................................................................................................................81 11.0 Future Growth- REVISED ..............................................................................................97 11.1 Iron .........................................................................................................................97 11.2 Fecal Coliform Bacteria .........................................................................................98 ii Twelvepole Creek Watershed: TMDL Report 12.0 Public Participation .........................................................................................................99 12.1 Public Meetings .....................................................................................................99 12.2 Public Notice and Public Comment Period ...........................................................99 12.3 Response Summary ................................................................................................99 13.0 Reasonable Assurance - REVISED ..............................................................................100 13.1 NPDES Permitting ...............................................................................................100 13.2 Watershed Improvement Branch- Nonpoint Source Program .............................101 13.3 Public Sewer Projects ..........................................................................................101 14.0 Monitoring Plan .............................................................................................................101 14.1 NPDES Compliance.............................................................................................102 14.2 Nonpoint Source Project Monitoring ...................................................................102 14.3 TMDL Effectiveness Monitoring ........................................................................102 15.0 References .......................................................................................................................103