TOTAL MAXIMUM DAILY LOAD STUDY FOR BACTERIA MOUNT HOPE BAY AND THE KICKEMUIT RIVER ESTUARY 303(d) listings addressed in this study: Kickemuit River (RI0007033E-01A) Kickemuit River (RI0007033E-01B) Kickemuit River (RI0007033E-01C) Mount Hope Bay (RI0007032E-01A) Mount Hope Bay (RI0007032E-01B) Mount Hope Bay (RI0007032E-01C) Mount Hope Bay (RI0007032E-01D) State of Rhode Island Department of Environmental Management Office of Water Resources Surface Water Protection Section Final January 2010 1 TABLE OF CONTENTS List of FIGURES ..........................................................................................................................................4 LIST OF TABLES........................................................................................................................................5 Abstract.........................................................................................................................................................6 1.0 Introduction........................................................................................................................................7 1.1 Study Area.......................................................................................................................................... 7 Waterbody Descriptions ......................................................................................................................... 9 Waterbody Segment Impairments .......................................................................................................... 9 1.2 Pollutant of Concern ........................................................................................................................ 12 1.3 Priority Ranking............................................................................................................................... 12 1.4 Applicable Water Quality Standards................................................................................................ 12 Water Use Classification ...................................................................................................................... 12 Applicable Water Quality Criteria........................................................................................................ 13 Numeric Water Quality Targets ........................................................................................................... 13 Other Applicable Standards in Shellfish Growing Areas..................................................................... 13 Antidegradation Policy......................................................................................................................... 13 2.0 Background ......................................................................................................................................14 2.1 Description of Study Area................................................................................................................ 14 Taunton River....................................................................................................................................... 14 Mount Hope Bay .................................................................................................................................. 16 Kickemuit River ................................................................................................................................... 16 2.2 Environmental Setting...................................................................................................................... 17 Mount Hope Bay .................................................................................................................................. 17 Kickemuit River ................................................................................................................................... 18 2.3 Shellfish Growing Area Management.............................................................................................. 18 3.0 Water Quality Characterization........................................................................................................23 3.1 Overview/Summary ......................................................................................................................... 23 US FDA Microbiological Survey of Mount Hope Bay (1986-1987)................................................... 23 ASA Water Quality Surveys in Mount Hope Bay (1990).................................................................... 24 RIDEM wet weather monitoring (2006) .............................................................................................. 24 3.2 Shellfish Program Annual Review of Bacteriological Data............................................................. 29 3.3 Water Quality Summary and Resource Impairments....................................................................... 30 4.0 Pollutant Source Assessment ...........................................................................................................31 4.1 Combined Sewer Overflows ............................................................................................................ 32 4.2 Stormwater Discharges from MS4s ................................................................................................. 34 Prioritized Sources in the Town of Warren.......................................................................................... 36 Prioritized Sources in the Town of Bristol ........................................................................................... 38 Prioritized Sources in the Town of Tiverton ........................................................................................ 39 4.3 Stormwater from Industrial Activities ............................................................................................. 42 4.4 Streams and Wetlands draining to Mount Hope Bay and the Kickemuit River............................... 42 4.5 Localized Estuarine Areas Characterized By High Fecal Coliform Levels..................................... 43 Mount Hope Bay .................................................................................................................................. 43 Kickemuit River ................................................................................................................................... 43 4.6 Other Potential Sources.................................................................................................................... 44 Sanitary Waste...................................................................................................................................... 44 Marine Vessel Discharges .................................................................................................................... 48 Wildlife/Waterfowl .............................................................................................................................. 48 Non-Migratory Geese and Swans......................................................................................................... 48 Kickemuit Reservoir and Upper Kickemuit River ............................................................................... 49 5.0 TMDL Analysis...............................................................................................................................50 2 5.1 Applicable Water Quality Criteria ................................................................................................... 50 5.2 Numeric Water Quality Targets....................................................................................................... 50 5.3 Water Quality and Resource Impairments ....................................................................................... 50 5.4 Critical Conditions and Seasonal Variation- Analysis..................................................................... 50 Consideration of Critical Conditions.................................................................................................... 51 Weather ................................................................................................................................................ 51 River Flow............................................................................................................................................ 51 Tide....................................................................................................................................................... 53 Consideration of Seasonal Variation.................................................................................................... 53 Critical Condition and Seasonal Variation-Summary .......................................................................... 54 5.5 Margin of Safety .............................................................................................................................. 55 5.6 Technical Analysis........................................................................................................................... 55 5.7 Establishing the Allowable Loading ................................................................................................ 55 5.8 Required Reductions........................................................................................................................ 56 5.9 Load and Waste load Allocations ...................................................................................................