Design Criteria for Sewers and Watermains - Toronto

1 1of 4 Design Criteria for Sewers and Watermains First Edition November 2009 Insert Blank Page This Text Will Not Print Design Criteria for Sewers and Watermains Contact us: Standards, Policies and Quality Assurance Tel: 416-392-8388 District Engineering Services Fax: 416-392-8241 Technical Services Metro Hall, Stn. 1180, 19th Floor 55 John Street Toronto , ON M5V 3C6 City of Toronto sewer and watermain Design Criteria Manual: This publication is available in both print and online formats. First Edition, 1st Printing November 2009 November 2009 iii Table of Contents Table of Contents Introduction.

2 Xi What This Manual Contains ..xi Chapter 1 Engineering Development Engineering Applications ..1 Engineering Drawing 2 Engineering Drawings Utility Site Plans ..4 Subsurface Underground Engineering ..6 Test Pits for Locating Utilities .. 6 Engineering Drawings Plan of Subdivision .. 7 Title Sheet .. 7 General General Plan of Services ..8 Drainage Area Plans ..9 Subdivision Grading and Building Siting Control Plan and Profile Drawings ..10 Erosion and Sedimentation Control Plan ..12 Composite Utilities Plan ..12 Storm and Sanitary Design Sheets ..12 Geotechnical Investigation and Soils Report .. 13 Site Investigation Requirements .. 13 Geotechnical Investigation Report and Delivery ..18 Pavement Structure Report Ministry of the Environment What the City is authorized to review?

3 22 What the City is not authorized to review?..23 Expanded Transfer of Review 23 Easement Types of Easements .. 26 Minimum Easement Widths ..27 As-built Drawing Submission Development Engineering Capital Improvement Other Drawings as Required .. 30 Chapter 2 Sanitary Sewers ..31 Level of Hydraulic Grade Line Requirements ..31 Types of sewer Systems ..31 iv November 2009 Design Criteria for Sewers and Watermains 31 Partially Separated ..31 Combined ..32 New Sanitary Sewers .. 32 Sanitary Trunk sewer .. 33 Combined Trunk sewer ..33 Population Densities ..34 Population Equivalents Based on Land Population Equivalents Based on Type of 35 Rezoning Site Plan Design Flows .. 36 Calculation of Peak Design Flows ..36 Residential Developments.

4 38 Commercial and Institutional Flows ..38 Industrial Flows .. 39 Extraneous Flows New Areas ..39 Extraneous Flows Existing Areas ..39 Analysis of Existing System Flows ..40 Monitored Flows .. 40 Sanitary sewer Design .. 41 Pipe 41 Roughness Coefficients ..41 Pipe 41 Minimum Maximum Velocity ..42 Minimum Grades ..42 Pipe Material .. 43 Bedding Pipe 44 Minimum Depth of Maximum Depth of Cover ..45 Location and Alignment ..45 Pipe Crossing Minimum Distance between High Water Table Conditions ..46 Gaskets in Contaminated Soil Conditions ..47 Deflection Maintenance 48 Spacing of Maintenance Holes ..48 Maintenance Hole Sizing .. 48 Maintenance Hole Frame and 49 Watertight Maintenance Hole Lids/Covers ..49 Lockable Maintenance Hole Covers.

5 49 Maintenance Hole Steps ..50 Drop 50 November 2009 v Table of Contents Maintenance Hole Safety Landings .. 50 Benching .. 51 Steps in Benching .. 51 Hydraulic Losses at Maintenance Alignment of Pipe in Maintenance Holes ..52 Pipe Connections to Maintenance Holes ..52 Pipe Connections to Existing Sanitary 53 Municipal Sanitary Service Location ..54 Minimum Size and Pipe Class of 55 Depth of 55 Sanitary Service Connections to Connections to Existing Mainline New Residential Service Connections ..55 Residential Service Connections in Connections to Existing Sewers for Lot Infill Situations ..56 Multi-family, Commercial, Institutional and Control Maintenance Hole ..56 Sanitary Service Connection Residential Sanitary Service Connection Service Connections in Easements.

6 57 Slope Anchors .. 58 Inverted Syphons .. 58 Chapter 3 Storm Sewers ..61 Calculation Methods ..61 Rational Dynamic Computer Models .. 61 Receiving System Capacity ..63 Infill Development ..63 Rezoning Site Plan Residential Areas ..64 Commercial and Industrial Areas ..64 Greenfield Development ..64 Storm and Combined sewer Design ..65 Dual Drainage Considerations ..65 Hydraulic Grade Line Calculations ..65 Levels of Protection in Existing Separated Levels of Protection in Greenfield Levels of Protection in Combined sewer Areas ..72 Design Flow and Hydrology .. 74 Run-off Calculation ..74 Combined sewer Design Flow ..74 Storm Design Requirements ..75 vi November 2009 Design Criteria for Sewers and Watermains IDF Curves and Equations.

7 75 Storm (Minor System) ..76 Storm (Major System)..76 Runoff 77 Pre-Development Runoff .. 77 Controlling Runoff from Developments ..78 Storm Trunk Sewers ..78 Storm sewer Design ..79 Pipe 79 Roughness Coefficient .. 79 Pipe 79 Minimum Maximum Velocity ..79 Minimum Grades ..80 Pipe Material .. 80 Bedding Pipe 81 Minimum Depth of Maximum Depth of Cover ..81 Location and Alignment ..81 Pipe Crossing Minimum Distance between Radius Pipe .. 83 Roof Drains .. 83 Reverse Driveway Drainage .. 83 Storm Backwater Prevention Valves ..84 sewer Inlet Controls ..84 Gaskets in Contaminated Soil Conditions ..84 Maintenance 85 Spacing of Maintenance Holes ..85 Maintenance Hole Sizing .. 85 Manufactured Maintenance Hole Tees .. 86 Maintenance Hole Frame and 86 Lockable Maintenance Hole Covers.

8 86 Maintenance Hole Steps ..86 Drop Structures ..86 Maintenance Hole Safety Landings .. 87 Benching .. 87 Steps in Benching .. 87 Hydraulic Losses at Maintenance Changes in Pipe Alignment ..88 Municipal Storm Service Connections ..89 New Private sewer Roof Water Drains or Foundation Minimum Size and November 2009 vii Table of Contents Depth of 91 Storm Service Connections to Sewers ..91 Pipe Connections to Maintenance Holes ..91 Control Maintenance Hole ..92 Service Connections in Easements ..92 Catchbasins .. 93 Location ..93 Minimum Lead Diameter and Grade ..94 94 Types of Catchbasins .. 95 Depth of 96 Allowable Catchbasin Frame and Grates ..96 Catchbasin Lead Culverts ..97 Outlet Structures ..98 Hydraulic Requirements.

9 98 Clay 98 Safety and Aesthetics ..99 Chapter 4 Water Demand ..101 Per Capita Demand ..102 Hydraulic Model ..102 Peaking Factors .. 102 Friction Factors .. 103 Fire Protection 103 Fire Flow Testing ..106 Maximum Velocity ..107 Pressure 107 Minimum Pressure ..107 Maximum Pressure ..108 watermain Design ..109 Sizing .. 109 Location ..109 Crossings and Parallel Trench Shallow Cover Crossing Sewers and Utilities ..111 Bedding Minimum Slopes ..112 Thrust Blocks and Mechanical Depth of 113 Removal and Line Valves ..115 Sizing of Valves ..115 Number of Valves ..115 Location of Valves ..115 viii November 2009 Design Criteria for Sewers and Watermains Spacing of Valves .. 115 Valve 116 Direction to Open Valve Box and Chambers.

10 117 Air Valves and Drain Valves ..117 Zone Boundary Valves ..118 Fire Hydrants .. 119 Hydrant Spacing in Right-of-Way ..119 Location of Hydrant from Above Ground Clearances .. 121 Protection from Damage .. 121 Markings ..121 Dead-Ended Watermains ..122 Municipal Water Service Connections ..122 Fire Line and Domestic Service 123 Water Service Valving ..123 Service Connections to Transmission Mains ..124 Service Connections inside Easements ..124 Backflow Temporary Connections to Existing Watermains ..124 Fire Protection Systems .. 125 Corrosion Protection ..125 Cathodic Electrical Continuity ..125 Soil Resistivity and 125 Tracer Electrical Grounding ..126 PVC Pipe in Contaminated Toronto Transit Commission ..127 Ductile Iron near TTC Street Car Stray Current 127 Suspended Watermains .