New York City Department of Combined Sewer Overfl ow Environmental Protection Long Term Control Plan for Capital Project No. WP-169 Westchester Creek Long Term Control Plan II June 2014 CSO Long Term Control Plan II Long Term Control Plan Westchester Creek TABLE OF CONTENTS EXECUTIVE SUMMARY ........................................................................................................................ ES-1 1.0 INTRODUCTION ..........................................................................................................1-1 1.1 Goal Statement ................................................................................................................ 1-1 1.2 Regulatory Requirements (Federal, State, Local) ........................................................... 1-2 1.3 LTCP Planning Approach ................................................................................................ 1-4 2.0 WATERSHED/WATERBODY CHARACTERISTICS ...................................................2-1 2.1 Watershed Characteristics ............................................................................................... 2-1 2.2 Waterbody Characteristics ............................................................................................. 2-22 3.0 CSO BEST MANAGEMENT PRACTICES ...................................................................3-1 3.1 Collection System Maintenance and Inspection Program ............................................... 3-2 3.2 Maximizing Use of Collection System for Storage ........................................................... 3-3 3.3 Maximizing Wet Weather Flows to WWTPs .................................................................... 3-3 3.4 Wet Weather Operating Plan ........................................................................................... 3-3 3.5 Prohibition of Dry Weather Overflows .............................................................................. 3-4 3.6 Industrial Pretreatment Program ...................................................................................... 3-4 3.7 Control of Floatables and Settleable Solids ..................................................................... 3-5 3.8 Combined Sewer Replacement ....................................................................................... 3-5 3.9 Combined Sewer Extension ............................................................................................. 3-5 3.10 Sewer Connection and Extension Prohibitions ................................................................ 3-6 3.11 Septage and Hauled Waste ............................................................................................. 3-6 3.12 Control of Runoff .............................................................................................................. 3-6 3.13 Public Notification ............................................................................................................. 3-6 3.14 Characterization and Monitoring ...................................................................................... 3-7 3.15 CSO BMP Report Summaries ......................................................................................... 3-7 4.0 GREY INFRASTRUCTURE .........................................................................................4-1 4.1 Status of Grey Infrastructure Projects Recommended in Facility Plans .......................... 4-1 4.2 Other Water Quality Improvement Measures Recommended in Facility Plans (dredging, floatables, aeration) ........................................................................................ 4-4 4.3 Post-Construction Monitoring ........................................................................................... 4-4 5.0 GREEN INFRASTRUCTURE .......................................................................................5-1 5.1 NYC Green Infrastructure Plan (GI Plan)......................................................................... 5-1 5.2 City-wide Coordination and Implementation .................................................................... 5-2 5.3 Completed Green Infrastructure to Reduce CSOs (Citywide and Watershed) ............... 5-4 5.4 Future Green Infrastructure in the Watershed ................................................................. 5-9 6.0 BASELINE CONDITIONS AND PERFORMANCE GAP ..............................................6-1 6.1 Define Baseline Conditions .............................................................................................. 6-1 6.2 Baseline Conditions – Projected CSO Volumes and Loadings after the Facility Plan and GI Plan ...................................................................................................................... 6-4 6.3 Performance Gap ............................................................................................................. 6-6 Submittal: June 30, 2014 i CSO Long Term Control Plan II Long Term Control Plan Westchester Creek 7.0 PUBLIC PARTICIPATION AND AGENCY COORDINATION ......................................7-1 7.1 Local Stakeholder Team .................................................................................................. 7-1 7.2 Summaries of Stakeholder Meetings ............................................................................... 7-1 7.3 Coordination with Highest Attainable Use ....................................................................... 7-4 7.4 Internet Accessible Information Outreach and Inquiries .................................................. 7-4 8.0 EVALUATION OF ALTERNATIVES ............................................................................8-1 8.1 Considerations for LTCP Alternatives Under the Federal CSO Policy ............................ 8-1 8.2 Matrix of Potential CSO Reduction Alternatives to Close Performance Gap from Baseline ........................................................................................................................... 8-5 8.3 CSO Reductions and Water Quality Impact of Retained Alternatives ........................... 8-17 8.4 Cost Estimates for Retained Alternatives ...................................................................... 8-19 8.5 Cost-Attainment Curves for Retained Alternatives ........................................................ 8-20 8.6 Use Attainability Analysis ............................................................................................... 8-28 8.7 Water Quality Goals ....................................................................................................... 8-32 8.8 Recommended LTCP Elements to Meet Water Quality Goals ...................................... 8-35 9.0 LONG-TERM CSO CONTROL PLAN IMPLEMENTATION .........................................9-1 9.1 Adaptive Management (Phased Implementation) ............................................................ 9-1 9.2 Implementation Schedule ................................................................................................ 9-1 9.3 Operation Plan/O&M ........................................................................................................ 9-2 9.4 Projected Water Quality Improvements ........................................................................... 9-2 9.5 Post Construction Monitoring Plan and Program Reassessment .................................... 9-2 9.6 Consistency with Federal CSO Control Policy ................................................................. 9-2 9.7 Compliance with Water Quality Goals ........................................................................... 9-33 10.0 REFERENCES ...........................................................................................................10 -1 11.0 GLOSSARY ...............................................................................................................11 -1 APPENDICES Appendix A: Supplemental Tables Appendix B: Long Term Control Plan (LTCP) Alley Creek Kickoff Meeting - Summary of Meeting and Public Comments Received Appendix C: Long Term Control Plan (LTCP) Alley Creek Public Meeting #2 - Summary of Meeting and Public Comments Received Appendix D: Westchester Creek Use Attainability Analysis LIST OF TABLES Table ES-1. Classifications and Standards Applied .............................................................................. ES-2 Table ES-2. Baseline Compliance with Bacteria Water Quality Criteria ................................................ ES-8 Table ES-3. Summary of Retained Alternatives .................................................................................... ES-9 Table ES-4. Calculated 10-year Bacteria Attainment for Recommended Plan (Baseline Conditions) – Recreational Season (May 1st – October 31st) ............................................................... ES-12 Table ES-5. Summary of Recommended Recreational Season Bacteria Water Quality Targets ....... ES-13 Table ES-6. Time to Recover at Station E13 ....................................................................................... ES-14 Table 1-1. 2012 DEC 303(d) Impaired Waters Listed and Delisted (with Source of Impairment) ......... 1-3 Table 2-1. Westchester Creek Land Use Summary by Category(1) ....................................................... 2-4 Table 2-2. Comparison of Rainfall Years to Support Evaluation of Alternatives.................................. 2-12 Submittal: June 30, 2014 ii CSO Long Term Control Plan II Long Term Control Plan Westchester Creek Table 2-3. Hunts