Cross Connection

Question 1

Cross Connection

Answer 1

actual or potential connections between a potable and nonpotable water supply
• Whenever the pressure of the polluted source exceeds the
pressure of the potable source the potential for backflow and
contamination exists

Question 2

• Backflow

Answer 2

Any unwanted flow of non-potable water or

substance into the potable water distribution system

Question 3

Pressure effect

Answer 3

water flows from high pressure to low

pressure

Question 4

Backpressure

Answer 4

Occurs when the user system is at a higher pressure than the
supply water system, allowing undesirable substances to be
“pushed” back into the potable water system

Question 5

Backsiphonage

Answer 5

Caused when there is a negative or reduced pressure in the
supply piping, undesirable substances are ‘sucked’ back into the
potable water

Question 6

Degree of Hazard

Answer 6

is a function of both the degree of
potential resultant hazard and the probability of the
occurrence
Minor Hazard - Exists when the connection has a low probability
of becoming a moderate hazard.
• Moderate hazard - Exists when the contaminant has a low
probability of becoming severe
• would be objectionable
• Severe hazard - Exists when a sufficient concentration of the
the contaminant could cause death
• spread disease or illness.

Question 7

Cross Connection Control Devices

Air Gap

Answer 7

Provides physical separation between the
supply and the system.
• The most effective method
• The separation must be at least two pipe diameters.
• Never less than one inch.

Question 8

Cross Connection Control Devices

• Atmospheric Vacuum Breaker

Answer 8

minor or moderate hazards
• The Vacuum Breaker has a body with a check valve that will seat in
both directions
• Works on gravity.
• Must be installed at least 6 inches above all downstream outlets.
• Not for continuous use – 12 of 24 hour.
• Protects against backsiphonage only, not backpressure

Question 9

Cross Connection Control Devices

Pressure Vacuum Breaker – PVB

Answer 9

• Similar to the Atmospheric Vacuum Breaker, the internal check
valves are spring loaded
• Can be tested
• Can protect against minor to severe hazards.
• Protects against backsiphonage only, not backpressure
• Can be used under continuous service.

Question 10

Cross Connection Control Devices

Double Check Valve Assembly – DCVA/DCVAF

Answer 10

two single check valves coupled within one body and furnished with
test cocks and two tightly closing valves
• Most common on sprinkler systems
• Suitable for protection against backsiphonage or backpressure.
• Used to protect against minor to moderate hazards only.

Question 11

Cross Connection Control Devices

Reduced Pressure Principle Backflow Prevention Assembly

Answer 11

• RPBA
• two internally loaded independent check valves.
• Plus one mechanically independent, hydraulically dependent relief
valve located between the two check valves
• Suitable for protection against backsiphonage or backpressure
• Suitable for continuous service
• Suitable for all fire protection systems

Question 12

Cross Connection Control Devices

Single Check Valve for Fire Service – SCVAF

Answer 12

for Fire Protection Systems that are entirely constructed of
acceptable potable water materials.
• Can be tested
• Continuous service

Question 13

Responsible Parties

Answer 13

• Water Purveyor – Supplies the water, eg., City of Red Deer.
• Maintains a Cross Connection Control program
• Maintain a record of backflow devices
• Owner – responsible for the water once it enters the property,
• The water within the property
• And to ensure the water does not contaminate the public water
• Responsible to maintain the CCC devices within the property
• AWWA – American Waterworks Association
• An educational and scientific association
• Develop programs and qualifications for cross connection control
specialists
• National Plumbing Code – determines when and what type of CCC
is required
• Refers to the CSA B64.10 to determine the devices to be used

Question 14

Selection

Answer 14

Plumbing code and CSA
• Depends on degree of hazard minor, moderate or severe
• Two locations
• Premises Isolation – isolates entire premise
• Internal Protection – isolates systems within and at the source

Question 15

Installation

Answer 15

• As per manufacturers specs
• Serviceable
• Tested upon installation and documentation submitted
• An RP assembly shall not have the potential to be
submerged
• Flush lines prior to installation
• Consideration of pressure losses
• Record make, model, serial #, size, date and location
• Piping to the backflow shall be approved for potable
water

Question 16

Maintenance

Answer 16

• The responsibility of the owner
• The device must be readily accessible
• Inspect the isolation valves weekly
• Observe the relief port on the RP device is not discharging
weekly

Question 17

Testing

Answer 17

• Annually - OS&Y operated and lubricated
• Tested by an AWWA certified tester to ensure performance
• After repair, maintenance or relocation
• Report shall be supplied to the owner and the AHJ