1|Page
CSWO Exam 2025 / Certified Storm Water Operator
Exam Prep with 100 Questions and Correct Answers
from the CSWO and SESC Comprehensive Training
Manual
Ammonia mixed with chlorine gas creates a -
...ANSWER...✓✓ white smoke
The most difficult part of a water distribution operator's
job. - ...ANSWER...✓✓ furnish a continuous supply
Physical connection between a safe and potentially
unsafe water source. - ...ANSWER...✓✓ cross connection
A distribution system is a - ...ANSWER...✓✓ looped
system
Dead end mains should be flushed - ...ANSWER...✓✓
every month
Excess nitrate causes a condition called - ...ANSWER...✓✓
blue baby syndrome
,2|Page
Water hardness is caused by - ...ANSWER...✓✓ calcium
and magnesium
Sewer mains should be __ft away from water mains. -
...ANSWER...✓✓ 9
Water with a pH less than 7 is considered to be -
...ANSWER...✓✓ acidic
Bacti records are kept for ____yrs and chemical records
are kept for ___yrs. - ...ANSWER...✓✓ 5, 10
Bacti samples have to be returned to the lab within ___hrs
of the collection time. - ...ANSWER...✓✓ 30
Color in the water supply should be less than _____ units.
- ...ANSWER...✓✓ 15
Chlorine is ______ times heavier than air. - ...ANSWER...✓✓
2.5
, 3|Page
90% of underground pipe failures are related to improper
- ...ANSWER...✓✓ backfill and bedding
The spoil bank should be located at least ___ft away from
the ditch. - ...ANSWER...✓✓ 2
The following minimum residuals is ______mg/L for free
chlorine and ____mg/L for total chlorine. - ...ANSWER...✓✓
.2, .5
Public opinion of the water utility is _______ at a standstill.
- ...ANSWER...✓✓ never
A bacti sample should be taken every ____ft of pipe. -
...ANSWER...✓✓ 1000
The most common collection point for a bacti sample is
the water tap _______. - ...ANSWER...✓✓ outside the house
A standpipe is considered ground storage unless it
exceeds _____ft above the highest ________. -
...ANSWER...✓✓ 80, service connection
CSWO Exam 2025 / Certified Storm Water Operator
Exam Prep with 100 Questions and Correct Answers
from the CSWO and SESC Comprehensive Training
Manual
Ammonia mixed with chlorine gas creates a -
...ANSWER...✓✓ white smoke
The most difficult part of a water distribution operator's
job. - ...ANSWER...✓✓ furnish a continuous supply
Physical connection between a safe and potentially
unsafe water source. - ...ANSWER...✓✓ cross connection
A distribution system is a - ...ANSWER...✓✓ looped
system
Dead end mains should be flushed - ...ANSWER...✓✓
every month
Excess nitrate causes a condition called - ...ANSWER...✓✓
blue baby syndrome
,2|Page
Water hardness is caused by - ...ANSWER...✓✓ calcium
and magnesium
Sewer mains should be __ft away from water mains. -
...ANSWER...✓✓ 9
Water with a pH less than 7 is considered to be -
...ANSWER...✓✓ acidic
Bacti records are kept for ____yrs and chemical records
are kept for ___yrs. - ...ANSWER...✓✓ 5, 10
Bacti samples have to be returned to the lab within ___hrs
of the collection time. - ...ANSWER...✓✓ 30
Color in the water supply should be less than _____ units.
- ...ANSWER...✓✓ 15
Chlorine is ______ times heavier than air. - ...ANSWER...✓✓
2.5
, 3|Page
90% of underground pipe failures are related to improper
- ...ANSWER...✓✓ backfill and bedding
The spoil bank should be located at least ___ft away from
the ditch. - ...ANSWER...✓✓ 2
The following minimum residuals is ______mg/L for free
chlorine and ____mg/L for total chlorine. - ...ANSWER...✓✓
.2, .5
Public opinion of the water utility is _______ at a standstill.
- ...ANSWER...✓✓ never
A bacti sample should be taken every ____ft of pipe. -
...ANSWER...✓✓ 1000
The most common collection point for a bacti sample is
the water tap _______. - ...ANSWER...✓✓ outside the house
A standpipe is considered ground storage unless it
exceeds _____ft above the highest ________. -
...ANSWER...✓✓ 80, service connection
