Cross ConnectionControl & Backflow Basics

by: Garrett Yates Backflow Management Inc.

(800) 841-7689www.bmi-backflow.com

What is a Cross Connection?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.

Common cross connections

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

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 fromone of two different

hydraulic conditions

BACKFLOW IS CAUSED BY:

Backpressure

Backsiphonage

Backpressure

An elevation of pressure downstream of An elevation of pressure downstream of the distribution system that would the distribution system that would cause or tend to cause, water to flow cause or tend to cause, water to flow opposite of intended direction.opposite of intended direction.

Common causes: pumps, elevation, Common causes: pumps, elevation, thermal expansionthermal expansion

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

HAZARD LEVELS

•Low Hazard (Low-Health, Non-Health)

•High Hazard(High-Health, Health-

Hazard)

Public Water System Contamination Conditions:

1. Supply Piping Unprotected

2. Physical Cross-Connection Made

3. Actual Contaminant Present, and

4. A Backflow Condition Occurs

All four conditions must occursimultaneously

Probability of Occurrence?

Numerous, well documented cases where…

Drinking Water Has Been Contaminated Via Cross-Connections

PNWS-AWWA

MANUALS

4th Edition

200 Incidents

5th Edition

400 Incidents

Summary ofBACKFLOW INCIDENTS

Fifth Edition, December 1995

CROSS CONNECTION CONTROL COMMITTEEPACIFIC NORTHWEST SECTION - A.W.W.A.

BACKFLOWPREVENTERS

Air Gap Separation

BACKFLOW DEVICES

Single Checks

Dual ChecksAtmospheric Vacuum

BreakersHose Bibb Vacuum

Breakers

BACKFLOWASSEMBLIES

Spill Resistant Pressure Vacuum Breaker

Assembly

Pressure Vacuum Breaker Assembly

Double Check Valve Assembly

Reduced Pressure Backflow Assembly

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.

PREMISE ISOLATIONPREMISE ISOLATION

IN-PREMISE IN-PREMISE PROTECTIONPROTECTION

WHY SHOULD A PWS CARE ABOUT CROSS-CONNECTIONS?

Because… Under backflow conditions, contaminants

may enter the drinking water supply through unprotected cross- connections and adversely impact public health .

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.

• Reasonably Reduce the Risk of Contamination of the Public Water System , AND

• Reduce the Water Purveyor’s Exposure to Legal Liability

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

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”)

Purveyor’s LiabilitySecondary/ Subtle Sources

• Imposing Unreasonable Requirements

• Beyond Purveyor’s Jurisdiction

• Misrepresenting the Actions of the Purveyor

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

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

• 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

Recommendations continued:

• 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