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Section 6 Cross-Connection and Backflow Prevention Program 6-2 SECTION 6 - CROSS-CONNECTION and BACKFLOW PREVENTION PROGRAM Updated 01/24/17

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Section 6 Cross-Connection and Backflow Prevention Program 6-2 SECTION 6 - CROSS-CONNECTION and BACKFLOW PREVENTION PROGRAM Updated 01/24/17 Mobile Area Water and Sewer System Section 6 Cross-Connection and Backflow Prevention Program February 17, 2017 SECTION 6 - CROSS-CONNECTION AND BACKFLOW PREVENTION PROGRAM Updated 01/24/17 TABLE OF CONTENTS 6.01 Intent of Policy ................................................................................................................................... 4 6.02 Definitions ........................................................................................................................................... 4 6.03 Statement of Policy ............................................................................................................................ 7 6.04 New Service Connections .................................................................................................................. 8 General ................................................................................................................................... 8 Residential .............................................................................................................................. 8 Non-Residential ...................................................................................................................... 8 Irrigation ................................................................................................................................. 8 6.05 Existing Service Connections ........................................................................................................... 9 General ................................................................................................................................... 9 Residential .............................................................................................................................. 9 Non-Residential ...................................................................................................................... 9 Irrigation ................................................................................................................................. 9 6.06 Responsibilities of MAWSS, Customer, and Tester .................................................................... 10 MAWSS ............................................................................................................................... 10 Customer .............................................................................................................................. 10 Tester .................................................................................................................................... 10 6.07 Additional Rules for Protection of MAWSS Water Supply System .......................................... 11 6.08 Description and Causes of Backflow ............................................................................................. 11 Back-siphonage .................................................................................................................... 11 Backpressure ........................................................................................................................ 11 6.09 Approved Backflow Prevention Methods ..................................................................................... 12 Double Check Valve Assemblies ......................................................................................... 12 (a) Double Check Valve Assembly (DCVA) ............................................................... 12 (b) Double Check Valve Detector Backflow Prevention Assembly (DCDA) ............. 13 Residential Dual Check (RDC) Valve ................................................................................. 14 Reduced-pressure Principle Backflow Prevention Assembly (RPBA) ............................... 15 Reduced-pressure Principle Detector Backflow Prevention Assembly (RPDA) ................ 15 6.10 Backflow Prevention Selection Criteria ........................................................................................ 16 6.11 Facilities Requiring Backflow Prevention Assemblies ................................................................ 17 Fire Protection Systems ........................................................................................................ 18 High-Hazard Fire Systems ................................................................................................... 18 Low-Hazard Fire Systems .................................................................................................... 18 Premises Isolation ................................................................................................................ 18 Health Hazard ....................................................................................................................... 18 Non-Health Hazard .............................................................................................................. 18 6.12 Approved Backflow Prevention Assemblies ................................................................................. 19 6.13 Installation of Assemblies and Standard Details .......................................................................... 19 General ................................................................................................................................. 19 6.14 Backflow Prevention Assembly Removal ...................................................................................... 22 Removal ............................................................................................................................... 22 Relocation ............................................................................................................................. 22 Replacement ......................................................................................................................... 22 6.15 Testing and Repairs of Backflow Prevention Assemblies ........................................................... 23 Requirements of Testing Personnel ..................................................................................... 23 Testing Frequency ................................................................................................................ 24 Test Reports .......................................................................................................................... 24 Repairs .................................................................................................................................. 24 6.16 Inspection of Backflow Prevention Assemblies ............................................................................ 24 Section 6 Cross-Connection and Backflow Prevention Program 6-2 SECTION 6 - CROSS-CONNECTION AND BACKFLOW PREVENTION PROGRAM Updated 01/24/17 6.17 Reports and Records ....................................................................................................................... 26 6.18 Non-Compliance with Policy .......................................................................................................... 26 6.19 References ......................................................................................................................................... 26 Appendices Appendix A – Forms Appendix B – Customer Checklists Appendix C – Standard Details Appendix D – Thermal Expansion Protection Appendix E – Facilities Requiring Backflow Prevention Appendix F – Approved Backflow Preventers Tables Table 1. Potential Backflow Hazards ............................................................................................................. 16 Table 2. Means of Backflow Prevention ........................................................................................................ 17 Table 3. Summary of Backflow Prevention Assembly Installation and Testing ........................................... 25 Figures Figure 1. Double Check Valve Assembly (Section) ...................................................................................... 13 Figure 2. Double Check Valve with Detector Assembly (Section) ............................................................... 14 Figure 3. Residential Dual Check Valve (Section) ........................................................................................ 14 Figure 4. Reduced-pressure Principle Backflow Prevention Assembly (Section) ......................................... 15 Figure 5. Reduced-pressure Principle Detector Backflow Prevention Assembly (Photo) ............................ 16 Section 6 Cross-Connection and Backflow Prevention Program 6-3 SECTION 6 - CROSS-CONNECTION AND BACKFLOW PREVENTION PROGRAM Updated 01/24/17 6.01 INTENT OF POLICY The Board of Water and Sewer Commissioners of the City of Mobile (also known as the Mobile Area Water and Sewer System [MAWSS]) is responsible for maintaining a cross- connection control program that protects the public potable water supply against actual or potential contamination from cross-connection, backpressure, or back-siphonage. As a result, MAWSS has developed a Cross-Connection and Backflow Prevention Program (the “Program”) in compliance with the latest edition of the International Plumbing Code, International Fire Code, American Water Works Association (AWWA) Manual of Water Supply Practices M14, and Alabama Department of Environmental Management Regulation (ADEM) Admin., Code R. 335-7-9-03. The Program requires that all new and certain existing water service connections contain a backflow prevention device/assembly.
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