(TMDL) Assessment for the Neshaminy Creek Watershed in Southeast Pennsylvania Table of Contents
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Total Maximum Daily Load (TMDL) Assessment for the Neshaminy Creek Watershed in Southeast Pennsylvania Table of Contents Page A1.0 OVERVIEW………………………………………………………………………… 1 A2.0 HYDROLOGIC /WATER QUALITY MODELING………………………………. 8 A2.1 Data Compilation and Model Overview………………………………………… 8 A2.2 GIS-Based Derivation of Input Data……………………………………………. 10 A2.3 Watershed Model Calibration…………………………………………………… 10 A2.4 Relationship Between Dissolved Oxygen Levels, Nutrient Loads and Organic Enrichment…………………………………………………………….. 16 B. POINT SOURCE TMDLs FOR THE ENTIRE NESHAMINY CREEK WATERSHED (Executive Summary)……….……….………………………. 18 B1.0 INTRODUCTION.…………………………………………………………………. 19 B2.0 EVALUATION OF POINT SOURCE LOADS……………………………………. 20 B3.0 REACH BY REACH ASSESSMENT……………………………………………… 27 B3.1 Cooks Run (482A)………………………………………………………………. 27 B3.2 Little Neshaminy Creek (980629-1342-GLW)………………..………………… 27 B3.3 Mill Creek (20010417-1342-GLW)…………………………………………….. 29 B3.4 Neshaminy Creek (467)………………………………………….……………… 30 B3.5 Neshaminy Creek (980515-1347-GLW)..…………………….………….……… 32 B3.6 Neshaminy Creek (980609-1259-GLW)………………………..………………. 32 B3.7 Park Creek (980622-1146-GLW)………………………………..……………… 34 B3.8 Park Creek (980622-1147-GLW)……………………………..………………… 35 B3.9 West Branch Neshaminy Creek (492)……………………………..……………. 35 B3.10 West Branch Neshaminy Creek (980202-1043-GLW)…………..……………. 36 B3.11 West Branch Neshaminy Creek (980205-1330-GLW)………………………… 37 B3.12 West Branch Neshaminy Creek (980205-1333-GLW)………………………… 38 C. LITTLE NESHAMINY CREEK……………………………………………………… 40 D. LAKE GALENA……………………………………………………………………… 58 E. PINE RUN…………………………………………………………………………….. 78 i Table of Contents (cont.) Page F. SUB-BASIN #1 OF WEST BRANCH NESHAMINY CREEK……………………… 94 G. SUB-BASIN #2 OF WEST BRANCH NESHAMINY CREEK……………………… 107 H. SUB-BASIN #3 OF WEST BRANCH NESHAMINY CREEK…………………….. 121 I. SUB-BASIN #4 OF WEST BRANCH NESHAMINY CREEK……………………… 138 J. COOKS RUN………………………………………………………………………….. 155 K. NESHAMINY CREEK TRIBUTARY #1…………………………………………….. 168 L. NESHAMINY CREEK TRIBUTARY #2…………………………………………….. 182 M. NESHAMINY CREEK TRIBUTARY #3……………………………………………. 196 N. NESHAMINY CREEK TRIBUTARY #4……………………………………………. 211 O. MILL CREEK SUB-BASIN #1………………………………………………………. 213 P. MILL CREEK SUB-BASIN #2……………………………………………………….. 227 Q. CORE CREEK………………………………………………………………………… 241 R. NESHAMINY CREEK SOUTH #1…………………………………………………… 255 S. NESHAMINY CREEK SOUTH #2…………………………………………………… 269 T. NESHAMINY CREEK SOUTH #3…………………………………………………… 271 Appendix A. GWLF Users Manual Appendix B. Streambank Erosion Calculations within AVGWLF Appendix C. TMDL Information Sheet Appendix D. TMDL Methodology Used in Pennsylvania Appendix E. Proposed Comprehensive Stormwater Management Policy Appendix F. AVGWLF Modeling Output for Sub-watersheds Appendix G. EMPR Results for Selected Watersheds ii A1.0 OVERVIEW This comprehensive document has been prepared to address all of the impaired stream segments contained within the Neshaminy Creek watershed located in Bucks and Montgomery Counties, Pennsylvania (see Figure A1). This urbanized watershed, which comprises about 148,679 acres, is located primarily in the Piedmont physiographic province to the north of Philadelphia. In terms of land use/cover, it is approximately 24% developed, 38% agriculture, 36% wooded, and 2% other (primarily wetland and disturbed), and has approximately 418.3 miles of streams. Since 1996, 203.3 miles of these streams (about 48.6%) have been included on Pennsylvania’s 303(d) list of streams having aquatic life use impairments. A complete listing of the segments impacted, along with their respective sources and causes of impairment, is given in Table A1. Within this document, the different sections have been organized to address impairments by geographic unit (i.e., sub-watershed) and by sources and causes of impairment. The first section addresses municipal point source impairments within the entire Neshaminy Creek watershed. Subsequent sections address the different sub-watersheds listed in Table A1 (which are also depicted in Figure A2). To be consistent with other TMDL documents prepared by the Pennsylvania Department of Environmental Protection (PaDEP), an Executive Summary has also been prepared for each section. Figure A1. Location of Neshaminy Creek watershed. 1 Table A1. Aquatic Life Use 303(d) List of Streams and Sources of Impairments Year Targeted Data Source Source Cause Priority Listed for TMDL ------------------------------------------------------------------------------------------------------------------------------------------------- State Water Plan:02F Named Streams: 02F - Cooks Run Segment ID: 482 Miles Assessed: 1.4 Surface Water Monitoring Program Urban Runoff/Storm Sewers Cause Unknown Low 1996 Surface Water Monitoring Program Urban Runoff/Storm Sewers Nutrients Medium 1996 Segment ID: 482A Miles Assessed: 3.2 Surface Water Monitoring Program Municipal Point Source Nutrients Medium 1996 2003 Surface Water Monitoring Program Urban Runoff/Storm Sewers Cause Unknown Low 1996 2003 Surface Water Monitoring Program Urban Runoff/Storm Sewers Nutrients Medium 1996 2003 Named Streams: 02F - Core Creek Segment ID: 980602-0954-GLW Miles Assessed: 15.8 Surface Water Assessment Program Agriculture Siltation Medium 2002 Named Streams: 02F - Little Neshaminy Creek Segment ID: 980616-1108-GLW Miles Assessed: 5.5 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 1998 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 1998 Segment ID: 980616-1316-GLW Miles Assessed: 6.2 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 2002 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 2002 Segment ID: 980629-1341-GLW Miles Assessed: 10.5 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 1996 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 1996 Segment ID: 980629-1342-GLW Miles Assessed: 15.7 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 1996 2003 Surface Water Assessment Program Municipal Point Source Nutrients Medium 1996 2003 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 1996 2003 Named Streams: 02F - Mill Creek Segment ID: 20000525-1017-GLW Miles Assessed: 0.8 Surface Water Assessment Program Surface Mining Siltation Medium 2002 Surface Water Assessment Program Surface Mining Flow Alterations Low 2002 Segment ID: 20010417-1342-GLW Miles Assessed: 1.8 Surface Water Assessment Program Municipal Point Source Nutrients Medium 2002 Segment ID: 20010426-1512-GLW Miles Assessed: 2.2 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 2002 Segment ID: 980609-1425-GLW Miles Assessed: 3.9 Surface Water Assessment Program Small Residential Runoff Flow Alterations Low 2002 Surface Water Assessment Program Small Residential Runoff Siltation Medium 2002 Named Streams: 02F - Park Creek Segment ID: 20010510-1303-GLW Miles Assessed: 0.2 Surface Water Assessment Program Other Oil and Grease Medium 1996 Segment ID: 20010511-1045-GLW Miles Assessed: 1.7 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 2002 Segment ID: 980622-1146-GLW Miles Assessed: 6.2 Surface Water Assessment Program Municipal Point Source Nutrients Medium 1996 2003 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 1996 2003 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 1996 2003 Segment ID: 980622-1147-GLW Miles Assessed: 1.2 Surface Water Assessment Program Municipal Point Source Nutrients Medium 1996 2003 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 1996 2003 Surface Water Assessment Program Urban Runoff/Storm Sewers Water/Flow Variability Low 1996 2003 2 Table A1. (cont.) Aquatic Life Use 303(d) List of Streams and Sources of Impairments Year Targeted Data Source Source Cause Priority Listed for TMDL ------------------------------------------------------------------------------------------------------------------------------------------------- Named Streams: 02F - Neshaminy Creek Segment ID: 20010426-1235-GLW Miles Assessed: 5.2 Surface Water Assessment Program Land Development Siltation Medium 2002 Surface Water Assessment Program Agriculture Siltation Medium 2002 Segment ID: 20010525-1250-GLW Miles Assessed: 7.6 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 2002 Segment ID: 20010525-1330-GLW Miles Assessed: 5.4 Surface Water Assessment Program Urban Runoff/Storm Sewers Siltation Medium 2002 Segment ID: 467 Miles Assessed: 36.5 Surface Water Assessment Program Municipal Point Source Nutrients Medium 1996 2003 Surface Water Assessment Program Other Cause Unknown Low 1996 2003 Surface Water Assessment Program Municipal Point Source Organic Enrichment/Low D.O. Medium 1996 2003 Surface Water Assessment Program Municipal Point Source pH Medium 1996 2003 Segment ID: 980202-1313-GLW Miles Assessed: 3.3 Surface Water Assessment Program Agriculture Excessive Algal Growth Medium 1996 2003 Surface Water Assessment Program Agriculture Siltation Medium 1996 2003 Surface Water Assessment Program Construction Siltation Medium 1996 2003 Segment ID: 980205-1211-GLW Miles Assessed: 1.5 Surface Water Assessment Program Land Development Water/Flow Variability Low 2002 Surface Water Assessment Program Urban Runoff/Storm Sewers Flow Alterations Low 2002 Segment ID: 980427-0945-GLW Miles Assessed: 4.6 Surface Water