CDPH Water Distribution Grade 2 Exam WITH
Questions and Complete Solutions/Verified
Answers |Latest Update 2-24-2025
What chlorine concentration should be produced when disinfecting a well or well pump?
a.) 25 mg/L
b.) 50 mg/L
c.) 75 mg/L
d.) 100 mg/L - ANSWER b.) 50 mg/L
When disinfecting a new or repaired main, what is the minimum chlorine residual at
the extreme end of the main after standing for 24 hours?
a.) 15 mg/L
b.) 20 mg/L
c.) 25 mg/L
d.) 30 mg/L - ANSWER c.) 25 mg/L
Chlorine will destroy bacteria most rapidly at what pH?
a.) 7.5
,b.) 8.5
c.) 9.5
d.) 10.5 - ANSWER a.) 7.5
Which of the following pH ranges would deposit a thin film of calcium carbonate on the
inside surface of a pipe?
a.) 2.0-3.0
b.) 4.0-5.0
c.) 6.0-7.0
d.) 8.0-9.0 - ANSWER d.) 8.0-9.0
Where should sodium hypochlorite (liquid bleach) be stored?
a.) Away from flammable objects, as it is a fire hazard
b.) Away from equipment that is susceptible to corrosion
c.) In closed containers at room temperature for no longer than 6 months
d.) Near the chemical feed pump day tank, to lessen operator handling risks - ANSWER b.)
Away from equipment that is susceptible to corrosion
The space between the inner or protective casing and the outer casing or drill hole should
be filled with cement grout to a minimum of how many feet?
a.) 10 feet
b.) 15 feet
c.) 20 feet
d.) 35 feet - ANSWER a.) 10 feet
, Clearwells are used for:
a.) Treated water
b.) Pumps and supplies
c.) High pH water
d.) Untreated well water - ANSWER a.) Treated water
The four components of a fire hydrant are:
a.) The inlet pipe connection from water supply, main valve, barrel, and the arm
b.) The inlet pipe connection from water supply, main valve, barrel, and the head
c.) The outlet pipe connectionto water supply, main valve, barrel, and the head
d.) the inlet pipe connection from water supply, the trigger, barrel, and the head - ANSWER
b.) The inlet pipe connection from water supply, main valve, barrel, and the head
Electrical demand in a wiring system is determined by the amount of:
a.) Ohms in the entire system
b.) Voltage a system draws
c.) Watts consumed
d.) Water pressure in the system - ANSWER c.) Watts consumed
Chlorine may be added to water in a continuous, slug, and/or the ______ method to initially
disinfect a pipeline?
a.) Segmented
b.) Tablet
c.) Low dose
Questions and Complete Solutions/Verified
Answers |Latest Update 2-24-2025
What chlorine concentration should be produced when disinfecting a well or well pump?
a.) 25 mg/L
b.) 50 mg/L
c.) 75 mg/L
d.) 100 mg/L - ANSWER b.) 50 mg/L
When disinfecting a new or repaired main, what is the minimum chlorine residual at
the extreme end of the main after standing for 24 hours?
a.) 15 mg/L
b.) 20 mg/L
c.) 25 mg/L
d.) 30 mg/L - ANSWER c.) 25 mg/L
Chlorine will destroy bacteria most rapidly at what pH?
a.) 7.5
,b.) 8.5
c.) 9.5
d.) 10.5 - ANSWER a.) 7.5
Which of the following pH ranges would deposit a thin film of calcium carbonate on the
inside surface of a pipe?
a.) 2.0-3.0
b.) 4.0-5.0
c.) 6.0-7.0
d.) 8.0-9.0 - ANSWER d.) 8.0-9.0
Where should sodium hypochlorite (liquid bleach) be stored?
a.) Away from flammable objects, as it is a fire hazard
b.) Away from equipment that is susceptible to corrosion
c.) In closed containers at room temperature for no longer than 6 months
d.) Near the chemical feed pump day tank, to lessen operator handling risks - ANSWER b.)
Away from equipment that is susceptible to corrosion
The space between the inner or protective casing and the outer casing or drill hole should
be filled with cement grout to a minimum of how many feet?
a.) 10 feet
b.) 15 feet
c.) 20 feet
d.) 35 feet - ANSWER a.) 10 feet
, Clearwells are used for:
a.) Treated water
b.) Pumps and supplies
c.) High pH water
d.) Untreated well water - ANSWER a.) Treated water
The four components of a fire hydrant are:
a.) The inlet pipe connection from water supply, main valve, barrel, and the arm
b.) The inlet pipe connection from water supply, main valve, barrel, and the head
c.) The outlet pipe connectionto water supply, main valve, barrel, and the head
d.) the inlet pipe connection from water supply, the trigger, barrel, and the head - ANSWER
b.) The inlet pipe connection from water supply, main valve, barrel, and the head
Electrical demand in a wiring system is determined by the amount of:
a.) Ohms in the entire system
b.) Voltage a system draws
c.) Watts consumed
d.) Water pressure in the system - ANSWER c.) Watts consumed
Chlorine may be added to water in a continuous, slug, and/or the ______ method to initially
disinfect a pipeline?
a.) Segmented
b.) Tablet
c.) Low dose
