Class C Water Operator License Exam
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Ammonia mixed with chlorine gas creates a - Correct
Answers ✅white smoke
The most difficult part of a water distribution operator's job. -
Correct Answers ✅furnish a continuous supply
Physical connection between a safe and potentially unsafe
water source. - Correct Answers ✅cross connection
A distribution system is a - Correct Answers ✅looped
system
Dead end mains should be flushed - Correct Answers
✅every month
Excess nitrate causes a condition called - Correct Answers
✅blue baby syndrome
Water hardness is caused by - Correct Answers ✅calcium
and magnesium
Sewer mains should be __ft away from water mains. -
Correct Answers ✅9
,Class C Water Operator License Exam
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Water with a pH less than 7 is considered to be - Correct
Answers ✅acidic
Bacti records are kept for ____yrs and chemical records are
kept for ___yrs. - Correct Answers ✅5, 10
Bacti samples have to be returned to the lab within ___hrs of
the collection time. - Correct Answers ✅30
Color in the water supply should be less than _____ units. -
Correct Answers ✅15
Chlorine is ______ times heavier than air. - Correct Answers
✅2.5
90% of underground pipe failures are related to improper -
Correct Answers ✅backfill and bedding
The spoil bank should be located at least ___ft away from the
ditch. - Correct Answers ✅2
The following minimum residuals is ______mg/L for free
chlorine and ____mg/L for total chlorine. - Correct Answers
✅.2, .5
, Class C Water Operator License Exam
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Public opinion of the water utility is _______ at a standstill. -
Correct Answers ✅never
A bacti sample should be taken every ____ft of pipe. - Correct
Answers ✅1000
The most common collection point for a bacti sample is the
water tap _______. - Correct Answers ✅outside the house
A standpipe is considered ground storage unless it exceeds
_____ft above the highest ________. - Correct Answers ✅80,
service connection
________ protection is the electrochemical method for
preventing ________ of metal tanks. - Correct Answers
✅cathodic, corrosion
The _____ is the only cross connection control method
approved by _______. - Correct Answers ✅air gap, tceq
_______ on a pipeline depend on the _____ or coefficient of
pipe roughness. - Correct Answers ✅friction loss, c factor
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Ammonia mixed with chlorine gas creates a - Correct
Answers ✅white smoke
The most difficult part of a water distribution operator's job. -
Correct Answers ✅furnish a continuous supply
Physical connection between a safe and potentially unsafe
water source. - Correct Answers ✅cross connection
A distribution system is a - Correct Answers ✅looped
system
Dead end mains should be flushed - Correct Answers
✅every month
Excess nitrate causes a condition called - Correct Answers
✅blue baby syndrome
Water hardness is caused by - Correct Answers ✅calcium
and magnesium
Sewer mains should be __ft away from water mains. -
Correct Answers ✅9
,Class C Water Operator License Exam
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Water with a pH less than 7 is considered to be - Correct
Answers ✅acidic
Bacti records are kept for ____yrs and chemical records are
kept for ___yrs. - Correct Answers ✅5, 10
Bacti samples have to be returned to the lab within ___hrs of
the collection time. - Correct Answers ✅30
Color in the water supply should be less than _____ units. -
Correct Answers ✅15
Chlorine is ______ times heavier than air. - Correct Answers
✅2.5
90% of underground pipe failures are related to improper -
Correct Answers ✅backfill and bedding
The spoil bank should be located at least ___ft away from the
ditch. - Correct Answers ✅2
The following minimum residuals is ______mg/L for free
chlorine and ____mg/L for total chlorine. - Correct Answers
✅.2, .5
, Class C Water Operator License Exam
Past Exam QUESTIONS AND ANSWERS
100% score (reupdated 2025)
Public opinion of the water utility is _______ at a standstill. -
Correct Answers ✅never
A bacti sample should be taken every ____ft of pipe. - Correct
Answers ✅1000
The most common collection point for a bacti sample is the
water tap _______. - Correct Answers ✅outside the house
A standpipe is considered ground storage unless it exceeds
_____ft above the highest ________. - Correct Answers ✅80,
service connection
________ protection is the electrochemical method for
preventing ________ of metal tanks. - Correct Answers
✅cathodic, corrosion
The _____ is the only cross connection control method
approved by _______. - Correct Answers ✅air gap, tceq
_______ on a pipeline depend on the _____ or coefficient of
pipe roughness. - Correct Answers ✅friction loss, c factor
