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Water Distribution Exam 1 Questions and Answers with
100% Complete Solutions UPDATED!!!
Back siphonage - ANSWER backflow due to negative or reduced
pressure in water system. occurs during low pressure events
such as a line leak
Reverse flow caused by a loss of supply pressure
Back Pressure - ANSWER Is caused when a potable water
system is connected to a non potable supply operating under a
higher pressure that pushes contaminated liquid back into the
public water system
Back Pressure - ANSWER Occurs when the pressure of the
connected system exceeds the pressure of the drinking water
system
Backflow - ANSWER Occurs when the pressure of the non-
potable system. Exceeds the positive pressure in the water
distribution lines.
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Diseases attributed to cross-connections: - ANSWER Dysentery•
Gastroenteritis• Hepatitis• Salmonellas
Direct Cross-Connection - ANSWER A direct cross-connection is
subject to backpressure or backsiphonage.
Undesirable material being pushed into the system.
Indirect Cross-Connection - ANSWER Undesirable material
being pulled into the system.
An indirect cross-connection is subject to back-siphonage only.
Air Gap - ANSWER Air Gap: physical separation of the potable
and non-potable system by an air space.
The simplest, most reliable way to provide backflow prevention
Reduced Pressure (RP) Zone Backflow Preventer - ANSWER
Provides the greatest protection against backflow caused by
back-pressure and back-siphonage.
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The RPZ should be used where continuous pressure or high
hazard conditions exist,
Reduced Pressure (RP) Zone Backflow Preventer - ANSWER
Must be tested annually and internal parts replaced every five
years.
Pressure Vacuum Breakers (PVB) - ANSWER Must be used under
continuous pressure.
They must be installed at least 12 inches above the usage point
to prevent back-siphonage.
Atmospheric Vacuum Breakers (AVB) - ANSWER Intended to
protect against back-siphonage but not back pressure. Check
valve and vent open to atmosphere.
Corrosion is the result? - ANSWER Corrosion is the result of an
electrochemical reaction
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Lead and Copper Rule - ANSWER Protect public health by
minimizing the amount of lead and/or copper dissolving into
tap water.
Anode (Galvanic Corrosion) - ANSWER where electrons are lost
through the metal.
Cathode.(Galvanic Corrosion) - ANSWER : where electrons are
gained and then leave the metal
Calcium Carbonate - ANSWER Water is considered stable when
it is just saturated with calcium carbonate.
Used for corrosion protection of pipe by a thin film of CaCo3 on
the interior of pipes.
Langelier Saturation Index (LSI) - ANSWER LSI values >zero
indicate scaling potential (i.e., precipitating).
The ideal range for balanced water is -0.3 to +0.3
Water Distribution Exam 1 Questions and Answers with
100% Complete Solutions UPDATED!!!
Back siphonage - ANSWER backflow due to negative or reduced
pressure in water system. occurs during low pressure events
such as a line leak
Reverse flow caused by a loss of supply pressure
Back Pressure - ANSWER Is caused when a potable water
system is connected to a non potable supply operating under a
higher pressure that pushes contaminated liquid back into the
public water system
Back Pressure - ANSWER Occurs when the pressure of the
connected system exceeds the pressure of the drinking water
system
Backflow - ANSWER Occurs when the pressure of the non-
potable system. Exceeds the positive pressure in the water
distribution lines.
,2|Page
Diseases attributed to cross-connections: - ANSWER Dysentery•
Gastroenteritis• Hepatitis• Salmonellas
Direct Cross-Connection - ANSWER A direct cross-connection is
subject to backpressure or backsiphonage.
Undesirable material being pushed into the system.
Indirect Cross-Connection - ANSWER Undesirable material
being pulled into the system.
An indirect cross-connection is subject to back-siphonage only.
Air Gap - ANSWER Air Gap: physical separation of the potable
and non-potable system by an air space.
The simplest, most reliable way to provide backflow prevention
Reduced Pressure (RP) Zone Backflow Preventer - ANSWER
Provides the greatest protection against backflow caused by
back-pressure and back-siphonage.
,3|Page
The RPZ should be used where continuous pressure or high
hazard conditions exist,
Reduced Pressure (RP) Zone Backflow Preventer - ANSWER
Must be tested annually and internal parts replaced every five
years.
Pressure Vacuum Breakers (PVB) - ANSWER Must be used under
continuous pressure.
They must be installed at least 12 inches above the usage point
to prevent back-siphonage.
Atmospheric Vacuum Breakers (AVB) - ANSWER Intended to
protect against back-siphonage but not back pressure. Check
valve and vent open to atmosphere.
Corrosion is the result? - ANSWER Corrosion is the result of an
electrochemical reaction
, 4|Page
Lead and Copper Rule - ANSWER Protect public health by
minimizing the amount of lead and/or copper dissolving into
tap water.
Anode (Galvanic Corrosion) - ANSWER where electrons are lost
through the metal.
Cathode.(Galvanic Corrosion) - ANSWER : where electrons are
gained and then leave the metal
Calcium Carbonate - ANSWER Water is considered stable when
it is just saturated with calcium carbonate.
Used for corrosion protection of pipe by a thin film of CaCo3 on
the interior of pipes.
Langelier Saturation Index (LSI) - ANSWER LSI values >zero
indicate scaling potential (i.e., precipitating).
The ideal range for balanced water is -0.3 to +0.3
