City of Albany City of Cohoes City of Rensselaer City of Troy City of Watervliet Village of Green Island June 30, 2011 Albany Pool CSO Long Term Control Plan Submitted to and NYSDEC Table of Contents Executive Summary 1.0 Introduction 1.1 Project Background ............................................................................................................................1-1 1.2 Organization of this Report ...............................................................................................................1-2 1.2.1 Introduction .............................................................................................................................1-2 1.2.2 Receiving Water Conditions and Assessment ......................................................................1-2 1.2.3 Combined Sewer System Mapping, Database & Digitizing ................................................1-2 1.2.4 Combined Sewer System Monitoring....................................................................................1-2 1.2.5 Combined Sewer System Modeling ......................................................................................1-2 1.2.6 WWTP Wet Weather Capacity Study ....................................................................................1-3 1.2.7 Development and Evaluation of CSO Control Alternatives ................................................1-3 1.2.8 Financial Capability Assessment ...........................................................................................1-3 1.2.9 Implementation Schedule.......................................................................................................1-3 1.2.10 Public Participation Program Support ..................................................................................1-3 1.3 Acknowledgements ...........................................................................................................................1-3 2.0 Receiving Waters Conditions Assessment 2.1 Introduction ........................................................................................................................................2-1 2.2 Water Quality Standards ...................................................................................................................2-1 2.3 Acknowledgements ...........................................................................................................................2-2 2.4 Summary of 2008 Sampling Program...............................................................................................2-3 2.4.1 Water Quality Sampling Locations in 2008 ...........................................................................2-3 2.4.2 Water Quality Sampling Events in 2008................................................................................2-8 2.4.3 Albany Pool Hydrodynamics ................................................................................................2-9 2.4.4 Dry Weather Conditions Observed in 2008 ........................................................................ 2-10 2.4.5 Wet Weather Conditions Observed in 2008 ........................................................................ 2-13 2.5 Summary of 2009 Sampling Program............................................................................................. 2-15 2.5.1 Water Quality Sampling Locations in 2009 ......................................................................... 2-15 2.5.2 Water Quality Sampling Events in 2009.............................................................................. 2-19 2.5.3 Dry Weather Conditions Observed in 2009 ........................................................................ 2-19 2.5.4 Wet Weather Conditions Observed in 2009 ........................................................................ 2-22 2.5.5 Dissolved Oxygen in 2009 .................................................................................................... 2-25 2.5.6 Quality Assurance and Quality Control.............................................................................. 2-25 2.6 Implications for CSO Control ......................................................................................................... 2-28 i Table of Contents 3.0 Combined Sewer Mapping, Database and Digitizing 3.1 Introduction ........................................................................................................................................3-1 3.2 Sewer System Data ............................................................................................................................3-1 3.3 Regulator/Diversion/Special Structure Data ....................................................................................3-2 3.4 Sewershed Data..................................................................................................................................3-2 3.5 Graphical Database ............................................................................................................................3-2 4.0 Combined Sewer System Monitoring 4.1 Introduction ........................................................................................................................................4-1 4.2 Acknowledgements ...........................................................................................................................4-2 4.3 Summary of 2008 Flow and Rainfall Monitoring Program ............................................................4-2 4.4 Flow Monitoring ................................................................................................................................4-4 4.4.1 Flow Monitoring for the ACSD North Plant CSS Model .....................................................4-5 4.4.2 Flow Monitoring for the ACSD South Plant CSS Model .....................................................4-7 4.4.3 Flow Monitoring for the RCSD CSS Model (City of Troy Contributory Area) ..................4-9 4.4.4 Flow Monitoring for the RCSD CSS Model (City of Rensselaer Contributory Area) ...... 4-11 4.5 Flow Metering Specifications .......................................................................................................... 4-13 4.6 Rainfall Monitoring ......................................................................................................................... 4-13 4.7 Monitoring Results .......................................................................................................................... 4-15 5.0 CSO Model Development .................................................................................................................5-1 5.1 Introduction ........................................................................................................................................5-1 5.2 Model Development ..........................................................................................................................5-1 5.3 Individual Models..............................................................................................................................5-3 5.3.1 Albany North ..........................................................................................................................5-4 5.3.2 Albany South ...........................................................................................................................5-6 5.3.3 Rensselaer ................................................................................................................................5-8 5.3.4 Troy ........................................................................................................................................ 5-10 5.4 Model Calibration ............................................................................................................................ 5-12 5.5 Calibration Parameters .................................................................................................................... 5-12 5.5.1 Dry Weather Flow ................................................................................................................. 5-12 5.5.2 Wet Weather Flow ................................................................................................................ 5-12 5.6 System-Specific Issues ..................................................................................................................... 5-13 5.6.1 Albany North ........................................................................................................................ 5-13 5.6.2 Albany South ......................................................................................................................... 5-13 ii Table of Contents 5.6.3 Rensselaer .............................................................................................................................. 5-13 5.6.4 Troy ........................................................................................................................................ 5-14 5.7 Model Definition of Existing System Performance ....................................................................... 5-14 5.8 Calibrated Model Adjustments....................................................................................................... 5-14 5.9 CSO Statistics ................................................................................................................................... 5-15 5.10 System-Specific Discussion ............................................................................................................