AK STORM DRAIN CONTRACTOR EXAM QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS)
Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a storm drain system?
A. To transport potable water
B. To collect and convey stormwater runoff
C. To transport sanitary sewage
D. To distribute irrigation water
Correct answer: B. To collect and convey stormwater runoff.
Rationale: Storm drain systems collect runoff from surfaces and
convey it safely to an approved discharge point or stormwater
management facility.
2. Which factor most directly affects the amount of
stormwater runoff from a paved surface?
A. Surface color
B. Surface permeability
C. Pipe material
D. Manhole diameter
Correct answer: B. Surface permeability.
,Rationale: Impervious surfaces such as asphalt and concrete
produce more runoff because little water infiltrates the ground.
3. What is a catch basin primarily designed to do?
A. Store drinking water
B. Collect surface runoff and debris
C. Increase water pressure
D. Treat sanitary wastewater
Correct answer: B. Collect surface runoff and debris.
Rationale: Catch basins collect stormwater entering through a
grate and may provide a sump for sediment and debris.
4. Why is proper slope important in a storm drain pipe?
A. It prevents all groundwater infiltration
B. It allows gravity flow through the pipe
C. It eliminates the need for pipe bedding
D. It increases pipe wall thickness
Correct answer: B. It allows gravity flow through the pipe.
Rationale: Storm drains generally depend on gravity, so the
designed slope provides the required hydraulic gradient.
5. What is a manhole commonly used for in a storm drain
system?
,A. Increasing rainfall
B. Providing access for inspection and maintenance
C. Filtering drinking water
D. Supporting electrical conductors
Correct answer: B. Providing access for inspection and
maintenance.
Rationale: Manholes provide access to underground drainage
piping and are often located at changes in direction, grade, or
pipe size.
6. Which drawing normally shows the vertical elevations of a
storm drain system?
A. Finish schedule
B. Plumbing fixture schedule
C. Profile drawing
D. Door schedule
Correct answer: C. Profile drawing.
Rationale: A storm drain profile shows pipe elevations, slopes,
structures, and related vertical information.
7. What does invert elevation refer to?
A. Elevation of the top of a pipe
B. Elevation of the bottom inside of a pipe or structure
, C. Elevation of finished pavement
D. Elevation of the ground surface only
Correct answer: B. Elevation of the bottom inside of a pipe or
structure.
Rationale: The invert is the lowest inside elevation of a pipe or
drainage structure and is critical for establishing hydraulic
grade and pipe slope.
8. What is the main purpose of pipe bedding?
A. To increase rainfall
B. To provide uniform support beneath the pipe
C. To replace the pipe
D. To prevent surveying
Correct answer: B. To provide uniform support beneath the
pipe.
Rationale: Proper bedding distributes loads and helps maintain
the designed pipe alignment and grade.
9. What can happen if storm drain pipe is improperly bedded?
A. The pipe can settle or deform
B. The pipe automatically increases capacity
C. Water becomes potable
D. The pipe becomes fire-resistant
AND CORRECT ANSWERS (VERIFIED ANSWERS)
Q&A 2027 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of a storm drain system?
A. To transport potable water
B. To collect and convey stormwater runoff
C. To transport sanitary sewage
D. To distribute irrigation water
Correct answer: B. To collect and convey stormwater runoff.
Rationale: Storm drain systems collect runoff from surfaces and
convey it safely to an approved discharge point or stormwater
management facility.
2. Which factor most directly affects the amount of
stormwater runoff from a paved surface?
A. Surface color
B. Surface permeability
C. Pipe material
D. Manhole diameter
Correct answer: B. Surface permeability.
,Rationale: Impervious surfaces such as asphalt and concrete
produce more runoff because little water infiltrates the ground.
3. What is a catch basin primarily designed to do?
A. Store drinking water
B. Collect surface runoff and debris
C. Increase water pressure
D. Treat sanitary wastewater
Correct answer: B. Collect surface runoff and debris.
Rationale: Catch basins collect stormwater entering through a
grate and may provide a sump for sediment and debris.
4. Why is proper slope important in a storm drain pipe?
A. It prevents all groundwater infiltration
B. It allows gravity flow through the pipe
C. It eliminates the need for pipe bedding
D. It increases pipe wall thickness
Correct answer: B. It allows gravity flow through the pipe.
Rationale: Storm drains generally depend on gravity, so the
designed slope provides the required hydraulic gradient.
5. What is a manhole commonly used for in a storm drain
system?
,A. Increasing rainfall
B. Providing access for inspection and maintenance
C. Filtering drinking water
D. Supporting electrical conductors
Correct answer: B. Providing access for inspection and
maintenance.
Rationale: Manholes provide access to underground drainage
piping and are often located at changes in direction, grade, or
pipe size.
6. Which drawing normally shows the vertical elevations of a
storm drain system?
A. Finish schedule
B. Plumbing fixture schedule
C. Profile drawing
D. Door schedule
Correct answer: C. Profile drawing.
Rationale: A storm drain profile shows pipe elevations, slopes,
structures, and related vertical information.
7. What does invert elevation refer to?
A. Elevation of the top of a pipe
B. Elevation of the bottom inside of a pipe or structure
, C. Elevation of finished pavement
D. Elevation of the ground surface only
Correct answer: B. Elevation of the bottom inside of a pipe or
structure.
Rationale: The invert is the lowest inside elevation of a pipe or
drainage structure and is critical for establishing hydraulic
grade and pipe slope.
8. What is the main purpose of pipe bedding?
A. To increase rainfall
B. To provide uniform support beneath the pipe
C. To replace the pipe
D. To prevent surveying
Correct answer: B. To provide uniform support beneath the
pipe.
Rationale: Proper bedding distributes loads and helps maintain
the designed pipe alignment and grade.
9. What can happen if storm drain pipe is improperly bedded?
A. The pipe can settle or deform
B. The pipe automatically increases capacity
C. Water becomes potable
D. The pipe becomes fire-resistant
