Florida Class C Water Treatment Operator Exam
2025 Prep Test Bank with 600 Most Recent Questions
and Correct Verified Answers/ FL Class C Water
Operator Test Latest 2026-2026 (Brand New!)
to obtain a "C" water license, an operator must have ________ hours of on the job
training. - ANSWER-2,080
the chief operator for a class "B" WTP needs what level of license? - ANSWER-B
a "B" class WTP must have a "C" operator or higher on duty for ______. -
ANSWER-16 hrs a day / 7 days a week
E-coli broth is used when testing for____. - ANSWER-fecal coliform
chlorine should never be fed ahead of ___? - ANSWER-polyphosphates
the distribution system has complaints of pink water. The WTP has a greensand
filter. What is most likely the cause? - ANSWER-overdose of potassium
permanganate
the addition of chlorine to water until the demand is satisfied and every drop of
water after that is free residual is called? - ANSWER-break point chlorination
adding alum to water _____ the PH level. - ANSWER-lowers
pg. 1
,a common membrane used in reverse osmosis water treatment is____. -
ANSWER-cellulose acetate
all surface water and ground water under the influence of surface water must be
_______. - ANSWER-disinfected and filtered.
what is the action level for lead? - ANSWER- 0.015 mg/l
what is the maximum chlorine residual level allowed in the distribution system? -
ANSWER-4.0 mg/l
for water systems using chlorine dioxide, what is the MCL for chlorite? -
ANSWER-1.0 mg/l
what is the MCL for color? - ANSWER-15
the MCL for turbidity is not more than ____ NTU as a monthly average -
ANSWER-0.5
the WTP uses 360 gallons of 10% NaOCl a day. how many pounds of CL2 do they
use? - ANSWER-300
when chlorine is added to water, it is a more efficient disinfectant when the PH is
lower and a greater percentage of ______ is present. - ANSWER-HOCL
the term flash mix is associated with which of the following processes? -
ANSWER-coagulation
pg. 2
,the storage tank is 10 feet wide and 20 feet deep. the operator ran a pump for 15
minutes to lower the water level 5 feet. how many gallons were removed? -
ANSWER-2936
the utilities dept. budgeted $9,000 for annual chemical purchases. they used 200
pounds of chlorine a day for the first 60 days of the budget year. the chlorine cost
$0.19 per pound. how much money did they spend on chlorine? - ANSWER-
$2,280
when analyzing a 100 ml sample of water for alkalinity, it took 5ml of .02 N
sulfuric acid to reach a PH of 8.3 and 5 more ml of titrant to reach a ph of 4.5. what
is the P alkalinity? - ANSWER-50
when installing a pipe fitting that will change direction of flow. what is the proper
installation method? - ANSWER-thrust block
the pressure gauge on the chlorine feed reads 90s and the injector gauge reads 10s.
The chlorine residual keeps dropping. what is most likely the cause? - ANSWER-
restriction in supply line
how long must water plant operation records be kept on site? - ANSWER-10 years
what is usually indicated when at sample point "A" in a water main a high DO
reading is obtained, and at sample point "B" downstream, the DO reading is
substantially lower? - ANSWER-corrosion
What is an Ampere? - ANSWER-a unit of measurement for current
Which of the following is a type of pump that is commonly used in a water
treatment plant? - ANSWER-Centrifugal
pg. 3
, What is a multi-staged pump? - ANSWER-has more than one impeller
if the pump impeller is running backwards, what action must be taken to correct
the rotation? - ANSWER-switch any two electrical leads
When should the packing of a pump be adjusted? - ANSWER-when the pump is
running
when a pump fails to deliver at its rated capacity, what is most likely the cause? -
ANSWER-air leak
what is a common cause for vibrations in a motor? - ANSWER-misalignment of
the couplings
What is the purpose of the wear rings in a pump? - ANSWER-Plug internal
leakage
what should the seal water pressure be for a pump? - ANSWER-5 psi higher than
the pumps discharge pressure
what is the purpose of the seal water? - ANSWER-block out air intake and
lubricate the packing
what is the recommended maximum suction lift? - ANSWER-15 ft.
In a water treatment plant, what type of pump is commonly used to deliver
chemical solutions? - ANSWER-Positive displacement
pg. 4
2025 Prep Test Bank with 600 Most Recent Questions
and Correct Verified Answers/ FL Class C Water
Operator Test Latest 2026-2026 (Brand New!)
to obtain a "C" water license, an operator must have ________ hours of on the job
training. - ANSWER-2,080
the chief operator for a class "B" WTP needs what level of license? - ANSWER-B
a "B" class WTP must have a "C" operator or higher on duty for ______. -
ANSWER-16 hrs a day / 7 days a week
E-coli broth is used when testing for____. - ANSWER-fecal coliform
chlorine should never be fed ahead of ___? - ANSWER-polyphosphates
the distribution system has complaints of pink water. The WTP has a greensand
filter. What is most likely the cause? - ANSWER-overdose of potassium
permanganate
the addition of chlorine to water until the demand is satisfied and every drop of
water after that is free residual is called? - ANSWER-break point chlorination
adding alum to water _____ the PH level. - ANSWER-lowers
pg. 1
,a common membrane used in reverse osmosis water treatment is____. -
ANSWER-cellulose acetate
all surface water and ground water under the influence of surface water must be
_______. - ANSWER-disinfected and filtered.
what is the action level for lead? - ANSWER- 0.015 mg/l
what is the maximum chlorine residual level allowed in the distribution system? -
ANSWER-4.0 mg/l
for water systems using chlorine dioxide, what is the MCL for chlorite? -
ANSWER-1.0 mg/l
what is the MCL for color? - ANSWER-15
the MCL for turbidity is not more than ____ NTU as a monthly average -
ANSWER-0.5
the WTP uses 360 gallons of 10% NaOCl a day. how many pounds of CL2 do they
use? - ANSWER-300
when chlorine is added to water, it is a more efficient disinfectant when the PH is
lower and a greater percentage of ______ is present. - ANSWER-HOCL
the term flash mix is associated with which of the following processes? -
ANSWER-coagulation
pg. 2
,the storage tank is 10 feet wide and 20 feet deep. the operator ran a pump for 15
minutes to lower the water level 5 feet. how many gallons were removed? -
ANSWER-2936
the utilities dept. budgeted $9,000 for annual chemical purchases. they used 200
pounds of chlorine a day for the first 60 days of the budget year. the chlorine cost
$0.19 per pound. how much money did they spend on chlorine? - ANSWER-
$2,280
when analyzing a 100 ml sample of water for alkalinity, it took 5ml of .02 N
sulfuric acid to reach a PH of 8.3 and 5 more ml of titrant to reach a ph of 4.5. what
is the P alkalinity? - ANSWER-50
when installing a pipe fitting that will change direction of flow. what is the proper
installation method? - ANSWER-thrust block
the pressure gauge on the chlorine feed reads 90s and the injector gauge reads 10s.
The chlorine residual keeps dropping. what is most likely the cause? - ANSWER-
restriction in supply line
how long must water plant operation records be kept on site? - ANSWER-10 years
what is usually indicated when at sample point "A" in a water main a high DO
reading is obtained, and at sample point "B" downstream, the DO reading is
substantially lower? - ANSWER-corrosion
What is an Ampere? - ANSWER-a unit of measurement for current
Which of the following is a type of pump that is commonly used in a water
treatment plant? - ANSWER-Centrifugal
pg. 3
, What is a multi-staged pump? - ANSWER-has more than one impeller
if the pump impeller is running backwards, what action must be taken to correct
the rotation? - ANSWER-switch any two electrical leads
When should the packing of a pump be adjusted? - ANSWER-when the pump is
running
when a pump fails to deliver at its rated capacity, what is most likely the cause? -
ANSWER-air leak
what is a common cause for vibrations in a motor? - ANSWER-misalignment of
the couplings
What is the purpose of the wear rings in a pump? - ANSWER-Plug internal
leakage
what should the seal water pressure be for a pump? - ANSWER-5 psi higher than
the pumps discharge pressure
what is the purpose of the seal water? - ANSWER-block out air intake and
lubricate the packing
what is the recommended maximum suction lift? - ANSWER-15 ft.
In a water treatment plant, what type of pump is commonly used to deliver
chemical solutions? - ANSWER-Positive displacement
pg. 4
