Cross Connection Control

Question 1

Minimum test frequency for back flow prevention assemblies.

Answer 1

At least yearly

Question 2

More frequent than annual testing of back flow assemblies may be indicated under these conditions.

Answer 2

• Extremely high hazard condition- History of annual test failure

Question 3

This should be required if a facility has an auxiliary water system that is or could be connected to the public water system.

Answer 3

An approved back flow prevention assembly installed at the water service to the facility

Question 4

This method of cross connection control is typically required on the service to a sewage treatment plant.

Answer 4

Approved air gap separation

Question 5

Approved cross connection control methods when chemicals or other high hazard materials may enter the potable water system.

Answer 5

• Reduced back flow assembly (RPBA)- Air gap (AG)

Question 6

Air gap.

Answer 6

Vertical separation between a potable water supply pipe and the flood rim of a receiving vessel at least 2x the supply pipe diameter, but never less than one inch.

Question 7

Facilities that may have high hazard cross connections.

Answer 7

• Hospital- Mortuary- Chemical plant- Metal plating plant- Sewage treatment plant

Question 8

Contamination.

Answer 8

Introduction of materials into water such as disease producing micro-organisms or toxic substances that pose a health risk

Question 9

Pollution.

Answer 9

Introduction of materials into water that are objectionable, and will render the water unfit for its intended use

Question 10

Cross connection.

Answer 10

Any actual or potential physical connection between a potable water line and any pipe, vessel, or machine containing a non-potable fluid so that it is possible for the non-potable fluid to enter the potable line by backflow

Question 11

Hydraulic conditions that can cause backflow.

Answer 11

• Back pressure- Back siphonage

Question 12

Key installation requirement for reduced pressure backflow assemblies.

Answer 12

Insure that relief valve cannot be submerged

Question 13

Hazard compatible with double check valve assembly.

Answer 13

Low hazard only

Question 14

Selection of a backflow prevention assembly is based on this.

Answer 14

• Degree of hazard- Hydraulic condition (back pressure or back siphonage)

Question 15

Cross connection control where there are toxic chemicals such as pesticides or fertilizers require this type of protection.

Answer 15

RPBA or air gap protection

Question 16

Use of these types of chemicals may pose a backflow contamination threat.

Answer 16

• Pesticides- Fertilizers- Boiler and heat exchanger chemicals- Antifreeze chemicals- Cleaning agents such as soaps and detergents

Question 17

These backflow prevention devices should only be used in a back siphonage condition, never back pressure.

Answer 17

Vacum breakers:

• Atmospheric vacum breaker
• Pressure vacum breaker

Question 18

This backflow assembly includes a spring loaded air inlet valve and a check valve.

Answer 18

Pressure vacuum breaker

Question 19

These backflow prevention methods protect against back pressure, and back siphonage.

Answer 19

• Air gap
• Reduced pressure backflow assembly
• Double check valve assembly

Question 20

An improperly operated fire truck pumper can create this distribution system hazard.

Answer 20

Back siphonage due to low pressure in the main

Question 21

Implement a cross connection control program.

Answer 21

• Local ordinance that empowers a water supplier to implement a program
• Water use inspection of facilities supplied by the water system
• Installation of backflow devices at facilities where the cross connection hazards are identified
• Backflow assembly testing program, to provide annual test

Question 22

This backflow assembly includes two independently operating check valves and a differential pressure relief valve.

Answer 22

Reduced pressure backflow assembly (RPBA)

Question 23

Reasons a relief port must never be plugged or extended.

Answer 23

• It would interfere with the operation of the relief valve.

- It would interfere with the testing of the backflow assembly.