AWWA Cross-Connection Control and Backflow Prevention

Question 1

What is a cross-connection in a water distribution system?

Accepted Answer

Any actual or potential connection between a potable water supply and a source of contamination

Answer

A cross-connection is any actual or potential connection between the potable water supply and any source of contamination or pollution that could allow backflow to occur.

Question 2

What is backflow in a water distribution context?

Accepted Answer

The undesirable reversal of flow of water or other substances into the potable water supply

Answer

Backflow is the undesirable reversal of flow of water or other substances into the potable water distribution system, potentially introducing contaminants.

Question 3

What are the two recognized types of backflow?

Accepted Answer

Backsiphonage and backpressure

Answer

The two types of backflow are backsiphonage (caused by negative pressure in the supply line) and backpressure (caused by downstream pressure exceeding supply pressure).

Question 4

Which backflow prevention device provides the highest level of protection against contamination?

Accepted Answer

Reduced pressure principle assembly (RPZ)

Answer

The reduced pressure principle (RPZ) assembly provides the highest mechanical protection because it has two independent check valves plus a relief valve that opens if either check valve fails.

Question 5

What pressure condition causes backsiphonage?

Accepted Answer

Negative or sub-atmospheric pressure developing in the supply line

Answer

Backsiphonage occurs when negative or sub-atmospheric pressure develops in the supply piping, creating a siphon effect that pulls water backward through the cross-connection.

(AWWA) American Water Works Association Practice Test

(AWWA) American Water Works Association Practice Test

AWWA Cross-Connection Control and Backflow Prevention