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Cross Connection Control & Backflow Basics

Cross Connection Control & Backflow Basics. by: Garrett Yates Backflow Management Inc. (800) 841-7689 www.bmi-backflow.com. What is a Cross Connection?. A cross connection is any actual or potential link between potable water and a system or fixture that carries a non-potable substance.

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Cross Connection Control & Backflow Basics

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  1. Cross Connection Control & Backflow Basics by: Garrett Yates Backflow Management Inc. (800) 841-7689 www.bmi-backflow.com

  2. What is a Cross Connection? A cross connection is any actual or potential link between potable water and a system or fixture that carries a non-potable substance.

  3. Common cross connections

  4. Commercial, Industrial examples: • Fire protection systems • Auxiliary water supplies • Make up lines for water using equipment • Post carbonated beverage dispensers • Medical equipment i.e. x-ray developers • Film development • Chemical dispensers for commercial kitchens

  5. Cross connections pose a public health threat when water in a piping system reverses its normal direction of flow. This is referred to as Backflow. Backflow occurs from one of two different hydraulic conditions

  6. BACKFLOW IS CAUSED BY: Backpressure Backsiphonage

  7. Backpressure An elevation of pressure downstream of the distribution system that would cause or tend to cause, water to flow opposite of intended direction. Common causes: pumps, elevation, thermal expansion

  8. Backsiphonage A drop in distribution system pressure below atmospheric (partial vacuum), that would cause or tend to cause water to flow opposite of its intended direction. Common causes: Main line breaks, heavy use i.e. fire hydrant use, pump failure

  9. HAZARD LEVELS • Low Hazard • (Low-Health, Non-Health) • High Hazard • (High-Health, Health-Hazard)

  10. Public Water System Contamination Conditions: • Supply Piping Unprotected • Physical Cross-Connection Made • Actual Contaminant Present, and • A Backflow Condition Occurs All four conditions must occur simultaneously

  11. Probability of Occurrence? Numerous, well documented cases where… Drinking Water Has Been Contaminated Via Cross-Connections

  12. CROSS CONNECTION CONTROL COMMITTEE PACIFIC NORTHWEST SECTION - A.W.W.A. PNWS-AWWA MANUALS 4th Edition 200 Incidents 5th Edition 400 Incidents Summary of BACKFLOW INCIDENTS Fifth Edition, December 1995

  13. BACKFLOW PREVENTERS

  14. Air Gap Separation

  15. BACKFLOW DEVICES Single Checks Dual Checks Atmospheric Vacuum Breakers Hose Bibb Vacuum Breakers

  16. BACKFLOW ASSEMBLIES

  17. Spill Resistant Pressure Vacuum Breaker Assembly

  18. Pressure Vacuum Breaker Assembly

  19. Double Check Valve Assembly

  20. Reduced Pressure Backflow Assembly

  21. Chapter 6 of the Uniform Plumbing Code governs the control of cross connections on private property. Backflow protection is provided for customers through compliance with current plumbing codes. Water suppliers are required by regulatory agencies to protect the public water supply from contamination due to cross connections. Water suppliers and plumbing officials share the responsibility for protecting public health.

  22. PREMISE ISOLATION IN-PREMISE PROTECTION

  23. WHY SHOULD A PWS CARE ABOUT CROSS-CONNECTIONS? Because… Under backflow conditions, contaminants may enter the drinking watersupply through unprotected cross- connections and adversely impact public health .

  24. Why Do Regulatory Agencies Require CCC Programs? To Protect the Public Health by Assuring the Delivery of Safe Drinking Water to Consumers Served by Public Water Systems.

  25. Reasonably Reduce the Risk of Contamination of the Public Water System , AND • Reduce the Water Purveyor’s Exposure to Legal Liability

  26. Legal Aspects – Backflow Incident • Whenever There Is a Backflow Incident, Assume Litigation Will Follow • Litigation May Be Based On: • Violation of Regulations • Tort Action (Sued for Negligence) and/or

  27. Purveyor’s LiabilityPrimary/Obvious Sources • Breach of the Law • Failing to Develop a “Reasonable” CCC Program (Negligence Issues) • Supply Customer With Contaminated Water (“Absolute Liability”)

  28. Purveyor’s LiabilitySecondary/ Subtle Sources • Imposing Unreasonable Requirements • Beyond Purveyor’s Jurisdiction • Misrepresenting the Actions of the Purveyor

  29. Reduce Your Exposure to Liability by • Comply With Regulations • Follow Industry Standards (Defense Against Negligence) • Have Procedures to Investigate Incidents • Isolate Premises (avoid “absolute liability) • Have Service Agreements

  30. Recommended Steps for Program Implementation • Get appropriate staff training • Make major program decisions • Adopt enforcement document • Establish relationship with local administrative authority • Provide public education • Conduct hazard evaluations of all customers

  31. Recommendations continued: • Inventory existing backflow assemblies in hazard evaluation process • Make recommendations and requirements based on hazard evaluation findings • Set up process for tracking initial and annual testing of backflow assemblies (i.e. software program) • Conduct periodic re-evaluations

  32. • Keep staff training up to date because the industry is always changing • Keep the public aware of City’s program approach and customers responsibility to maintain safe plumbing • Create a standard operating procedure manual for the management of the program

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