PROTOCOLS FOR IDENTIFYING SANITARY SEWER OVERFLOWS American Society of Civil Engineers EPA Cooperative Agreement #CX 826097-01-0 June 2000 Protocols for Identifying Sanitary Sewer Overflows Prepared by Black & Veatch Corporation for American Society of Civil Engineers Under Cooperative Agreement with U.S. Environmental Protection Agency Office of Wastewater Management Washington, DC EPA Cooperative Agreement #CX 826097-01-0 June 2000 NOTICE The material in this document has been subject to U.S. Environmental Protection Agency technical and policy review and approved for publication. The views expressed by individual authors, however, are their own and do not necessarily reflect those of the U.S. Environmental Protection Agency. Protocols for Identifying Sanitary Sewer Overflows (SSOs) ASCE/EPA Cooperative Agreement # CX 826097-01-0 Table of Contents Table of Contents Page No. Acknowledgements..............................................................................................................vii Executive Summary............................................................................................................... 1 Phase 1...................................................................................................................... 1 Phase 2...................................................................................................................... 2 Abbreviations ............................................................................................................. 6 1.0 Introduction.............................................................................................................1-1 1.1 Objective .......................................................................................................1-1 1.2 Results or Benefits Expected...........................................................................1-1 1.3 Background....................................................................................................1-1 1.4 Approach.......................................................................................................1-3 1.4.1 Phase 1..............................................................................................1-3 1.1.1.1 Task 1: Literature Search....................................................1-3 1.1.1.2 Task 2: Information Collection............................................1-6 1.1.1.3 Task 3: Develop Comprehensive Set of Protocols ...............1-6 1.1.1.4 Task 4: Development of Guidance Manual..........................1-6 1.1.1.5 Task 5: Development of Web Page.....................................1-6 1.1.2 Phase 2..............................................................................................1-7 1.1.2.1 Task 6: Development of Informational Brochures.................1-7 1.1.2.2 Task 7: Dissemination of Informational Material...................1-7 2.0 Data Collection........................................................................................................2-1 2.1 Introduction....................................................................................................2-1 2.2 Literature Research.........................................................................................2-1 2.3 Agency Questionnaires ...................................................................................2-2 2.4 Data Processing..............................................................................................2-3 3.0 Data Analysis ..........................................................................................................3-1 3.1 Introduction....................................................................................................3-1 3.2 General Information........................................................................................3-1 3.3 Flow Information............................................................................................3-4 3.4 System Characteristics Information..................................................................3-5 3.5 Reported Wet Weather SSOs........................................................................3-5 3.6 Reported Dry Weather SSOs.........................................................................3-6 3.7 Routine Maintenance Data..............................................................................3-7 3.8 Inspection Methods and Status .......................................................................3-7 3.9 Ranking of Methods Used to Identify SSOs....................................................3-8 3.10 Status of Agency Protocols.............................................................................3-9 Final.doc i DRAFT 06/20/00 Protocols for Identifying Sanitary Sewer Overflows (SSOs) ASCE/EPA Cooperative Agreement # CX 826097-01-0 Table of Contents Table of Contents Page No. 3.11 Agency Narrative Response Evaluation.........................................................3-10 3.11.1 Response to SSOs...........................................................................3-13 3.11.2 Maintenance Problems......................................................................3-13 Final.doc ii DRAFT 06/20/00 Protocols for Identifying Sanitary Sewer Overflows (SSOs) ASCE/EPA Cooperative Agreement # CX 826097-01-0 Table of Contents Table of Contents Page No. 3.11.3 Activities to Prevent SSOs................................................................3-13 3.11.4 Limitations of SSO Findings Methods ...............................................3-14 3.11.5 Existing Protocols .............................................................................3-14 3.11.6 Methods of Identifying Locations of SSOs........................................3-14 3.11.7 Design Deficiencies...........................................................................3-15 3.12 Graphs of Agency Data ................................................................................3-15 4.0 Hydraulic Protocols .................................................................................................4-1 4.1 Objective .......................................................................................................4-1 4.2 Hydraulic Capacity Related Problems .............................................................4-1 4.3 Available Techniques......................................................................................4-2 4.3.1 Hydraulic Modeling ............................................................................4-2 1.4.2 Scattergraphs/Flow Monitoring...........................................................4-3 4.4 Methodology for Hydraulic Modeling..............................................................4-3 1.4.3 Review of Documents/Development of Inventory.................................4-4 1.4.4 Flow Analysis/Flow Monitoring...........................................................4-5 1.4.5 Building the Model..............................................................................4-8 1.4.6 Calibrating the Model.........................................................................4-8 1.4.7 Running the Model..............................................................................4-8 1.4.8 Evaluation of Model Output ................................................................4-8 4.4.1 Reporting of Findings..........................................................................4-8 4.5 Scattergraphs .................................................................................................4-9 5.0 Maintenance and Inspection Protocols .....................................................................5-1 5.1 Objective .......................................................................................................5-1 5.2 Maintenance Related Problems .......................................................................5-1 5.3 Available Techniques......................................................................................5-1 5.3.1 Customer and/or Public Complaint......................................................5-2 5.3.2 Visual Inspections after Overflows ......................................................5-2 5.3.3 Scheduled Maintenance Inspection......................................................5-3 5.3.4 GIS-Based Analysis of Past SSOs.....................................................5-3 5.3.5 Sanitary Sewer Management Systems .................................................5-4 5.3.6 Flow Monitoring.................................................................................5-6 5.3.7 Monitoring of Receiving Streams Sewage Indicators............................5-8 5.3.8 Event Notification Systems..................................................................5-8 5.3.9 Closed Circuit Television (CCTV) Inspection......................................5-8 5.3.10 Sewer Scanner and Evaluation Technology Surveys (SSET)................5-9 5.3.11 Surcharge Level Alarms/Remote Monitoring........................................5-9 5.3.12 Dye Tracing........................................................................................5-9 Final.doc iii DRAFT 06/20/00 Protocols for Identifying Sanitary Sewer Overflows (SSOs) ASCE/EPA Cooperative Agreement # CX 826097-01-0 Table of Contents Table of Contents Page No. 5.3.13 Smoke Testing..................................................................................5-10 5.3.14 Aerial Monitoring..............................................................................5-10