Class "C" Water Exam questions and
answers graded A+ updated to pass
A common chemical used in the disinfection of a small water supply is- - correct answer
✔✔Calcium Hypochlorite
A physical connection between a potable water supply and a house well would be- - correct
answer ✔✔A Cross Connection
The amount of Chlorine in mg/L that is used by reacting with iron, organics, or bacteria is
called? - correct answer ✔✔Demand
All of the following are Physical characteristics of Chlorine gas- - correct answer ✔✔Greenish
Yellow color
Heavier than air
Pungent, Penetrating odor
Corrosive
Which of the following would be considered a part of a hypo-chlorinator system? - correct
answer ✔✔Solution feed pump
According to state requirements, all public water supply wells should be provided with a raised
concrete sealing block, screened vents and- - correct answer ✔✔Flow measuring device
The drawdown of a water well is determined by- - correct answer ✔✔The difference in static
and pumping levels
,The pH of water indicates- - correct answer ✔✔If it is more acidic or base
The pH of water is expressed by a scale of numbers ranging from- - correct answer ✔✔0-14
Water that is considered neutral is expressed on the pH scale at- - correct answer ✔✔7
Which of the following is a required step in collecting a routine distribution sample for
bacteriological testing? - correct answer ✔✔Use of an approved, sterile container
Sand filtration will remove which of the following from surface water? - correct answer
✔✔Turbidity
Activated Carbon is used in a Surface Water Plant primarily for? - correct answer ✔✔Taste and
Odor control
Which of the following chemical(s) are commonly used as coagulants in surface water
treatment? - correct answer ✔✔Alum and Ferric Chloride
Ground storage tanks are required to be provided with which of the following? - correct answer
✔✔Screened Vents
An approved locking roof hatch
An overflow pipe with hinged flap device
Annual inspection and maintenance as needed
An elevated storage tank should be protected against corrosion by- - correct answer
✔✔Painting
Cathodic protection
Water stabilization
, A public water supply system should maintain residual pressure of 20 psi and a minimum
normal operating pressure of- - correct answer ✔✔35 psi
Before a new or repaired water line is placed into service, it must be properly disinfected by
providing a chlorine dosage of _____ and proper detention time. - correct answer ✔✔50 mg/L
Water bearing formations beneath the earth's surface that are used as a source of water for
public water supplies are- - correct answer ✔✔Aquifers
The purpose of an air line on a well is- - correct answer ✔✔Determine water levels in the well
The mesh size is an important feature of a well screen because property sized openings should-
- correct answer ✔✔Reduce the amount of sand pumped
When treating surface water, the process of coagulation will be most affected by the- - correct
answer ✔✔pH, alkalinity, temperature, and chemical dosage
A rapid sand filter should be backwashed when- - correct answer ✔✔When the loss of head
gauge indicated between 6 and 10 ft.
Which of the following is an acceptable disinfection residual at the far reaches of the
distribution system- - correct answer ✔✔0.2 mg/L free chlorine residual
0.5 mg/L chloramine residual for a surface water supply
0.8 mg/L chloramine residual when using chloramine treatment
0.5 mg/L free chlorine residual for a groundwater supply
One gallon of water weighs- - correct answer ✔✔8.34 lbs
answers graded A+ updated to pass
A common chemical used in the disinfection of a small water supply is- - correct answer
✔✔Calcium Hypochlorite
A physical connection between a potable water supply and a house well would be- - correct
answer ✔✔A Cross Connection
The amount of Chlorine in mg/L that is used by reacting with iron, organics, or bacteria is
called? - correct answer ✔✔Demand
All of the following are Physical characteristics of Chlorine gas- - correct answer ✔✔Greenish
Yellow color
Heavier than air
Pungent, Penetrating odor
Corrosive
Which of the following would be considered a part of a hypo-chlorinator system? - correct
answer ✔✔Solution feed pump
According to state requirements, all public water supply wells should be provided with a raised
concrete sealing block, screened vents and- - correct answer ✔✔Flow measuring device
The drawdown of a water well is determined by- - correct answer ✔✔The difference in static
and pumping levels
,The pH of water indicates- - correct answer ✔✔If it is more acidic or base
The pH of water is expressed by a scale of numbers ranging from- - correct answer ✔✔0-14
Water that is considered neutral is expressed on the pH scale at- - correct answer ✔✔7
Which of the following is a required step in collecting a routine distribution sample for
bacteriological testing? - correct answer ✔✔Use of an approved, sterile container
Sand filtration will remove which of the following from surface water? - correct answer
✔✔Turbidity
Activated Carbon is used in a Surface Water Plant primarily for? - correct answer ✔✔Taste and
Odor control
Which of the following chemical(s) are commonly used as coagulants in surface water
treatment? - correct answer ✔✔Alum and Ferric Chloride
Ground storage tanks are required to be provided with which of the following? - correct answer
✔✔Screened Vents
An approved locking roof hatch
An overflow pipe with hinged flap device
Annual inspection and maintenance as needed
An elevated storage tank should be protected against corrosion by- - correct answer
✔✔Painting
Cathodic protection
Water stabilization
, A public water supply system should maintain residual pressure of 20 psi and a minimum
normal operating pressure of- - correct answer ✔✔35 psi
Before a new or repaired water line is placed into service, it must be properly disinfected by
providing a chlorine dosage of _____ and proper detention time. - correct answer ✔✔50 mg/L
Water bearing formations beneath the earth's surface that are used as a source of water for
public water supplies are- - correct answer ✔✔Aquifers
The purpose of an air line on a well is- - correct answer ✔✔Determine water levels in the well
The mesh size is an important feature of a well screen because property sized openings should-
- correct answer ✔✔Reduce the amount of sand pumped
When treating surface water, the process of coagulation will be most affected by the- - correct
answer ✔✔pH, alkalinity, temperature, and chemical dosage
A rapid sand filter should be backwashed when- - correct answer ✔✔When the loss of head
gauge indicated between 6 and 10 ft.
Which of the following is an acceptable disinfection residual at the far reaches of the
distribution system- - correct answer ✔✔0.2 mg/L free chlorine residual
0.5 mg/L chloramine residual for a surface water supply
0.8 mg/L chloramine residual when using chloramine treatment
0.5 mg/L free chlorine residual for a groundwater supply
One gallon of water weighs- - correct answer ✔✔8.34 lbs
