CO Wastewater Systems Contractor
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which component of a wastewater collection system is primarily
intended to provide access for inspection, cleaning, maintenance,
and changes in pipeline direction or elevation?
A. Cleanout plug
B. Manhole
C. Backwater valve
D. Grease interceptor
A manhole provides personnel and equipment access to a wastewater
collection system and is commonly installed at junctions, changes in
direction or grade, and other locations requiring maintenance access.
2. When installing a gravity sanitary sewer, why is maintaining the
specified pipe slope particularly important?
A. It eliminates the need for bedding material
B. It prevents all corrosion of the pipe
C. It helps maintain adequate self-cleansing velocity while preserving
,the designed hydraulic capacity
D. It allows the pipe to operate under continuous pressure
Proper slope establishes the hydraulic gradient needed for wastewater
to flow by gravity and helps prevent excessive solids deposition caused
by inadequate flow velocity.
3. Before excavating for a wastewater pipeline in Colorado, what is the
contractor's most important initial utility-related responsibility?
A. Begin excavation at the lowest elevation
B. Remove all surface vegetation
C. Determine the location of existing underground utilities through the
required locating process
D. Install the sewer pipe before contacting utility owners
Existing underground utilities must be located before excavation so that
the work can be planned safely and damage to buried infrastructure can
be avoided.
4. What is the primary purpose of granular bedding beneath a
wastewater sewer pipe?
A. Increase wastewater temperature
B. Prevent the pipe from carrying any structural load
C. Provide uniform support and help maintain the designed pipe
alignment and grade
D. Eliminate the need for trench backfill
,Proper bedding supports the pipe uniformly, reduces point loading, and
helps maintain the required line and grade during and after installation.
5. A sewer pipe has been installed with a localized high point between
two manholes. What is the most likely hydraulic consequence?
A. Increased pressure throughout the entire system
B. Reduced flow capacity and possible accumulation of air or
wastewater at the high point
C. Increased pipe wall thickness
D. Elimination of infiltration
A high point can interfere with gravity flow and create hydraulic
restrictions, particularly when the pipeline was designed for a
continuous grade.
6. What is the principal difference between a gravity sanitary sewer
and a force main?
A. Gravity sewers always use metallic pipe
B. Force mains do not convey wastewater
C. Gravity sewers rely primarily on elevation and gravity, while force
mains convey wastewater under pressure
D. Gravity sewers require a pump at every manhole
Gravity systems use an elevation difference to transport wastewater,
whereas force mains depend on pumps or other pressure-producing
equipment to move wastewater.
7. What is the primary function of a sewage lift station?
, A. Remove all dissolved solids from wastewater
B. Increase the diameter of a sewer main
C. Raise wastewater to a higher elevation when gravity flow cannot
provide the required conveyance
D. Disinfect drinking water
A lift station pumps wastewater from a lower elevation to a higher
elevation so that it can continue through the collection or treatment
system.
8. Why should wastewater lift-station pumps be selected based on
both flow and total dynamic head?
A. Pump color depends on head requirements
B. The pump must deliver the required flow against the resistance and
elevation difference of the discharge system
C. Head determines the chemical dosage only
D. Flow is unrelated to pump performance
Pump performance depends on the relationship between required flow
and total dynamic head, which includes static elevation and friction or
other system losses.
9. What is a major concern when a wastewater force main is
improperly designed for rapid pump shutdown?
A. Increased potable-water pressure
B. Water hammer and transient pressure conditions
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2027 Q&A| Instant
Download Pdf.
1. Which component of a wastewater collection system is primarily
intended to provide access for inspection, cleaning, maintenance,
and changes in pipeline direction or elevation?
A. Cleanout plug
B. Manhole
C. Backwater valve
D. Grease interceptor
A manhole provides personnel and equipment access to a wastewater
collection system and is commonly installed at junctions, changes in
direction or grade, and other locations requiring maintenance access.
2. When installing a gravity sanitary sewer, why is maintaining the
specified pipe slope particularly important?
A. It eliminates the need for bedding material
B. It prevents all corrosion of the pipe
C. It helps maintain adequate self-cleansing velocity while preserving
,the designed hydraulic capacity
D. It allows the pipe to operate under continuous pressure
Proper slope establishes the hydraulic gradient needed for wastewater
to flow by gravity and helps prevent excessive solids deposition caused
by inadequate flow velocity.
3. Before excavating for a wastewater pipeline in Colorado, what is the
contractor's most important initial utility-related responsibility?
A. Begin excavation at the lowest elevation
B. Remove all surface vegetation
C. Determine the location of existing underground utilities through the
required locating process
D. Install the sewer pipe before contacting utility owners
Existing underground utilities must be located before excavation so that
the work can be planned safely and damage to buried infrastructure can
be avoided.
4. What is the primary purpose of granular bedding beneath a
wastewater sewer pipe?
A. Increase wastewater temperature
B. Prevent the pipe from carrying any structural load
C. Provide uniform support and help maintain the designed pipe
alignment and grade
D. Eliminate the need for trench backfill
,Proper bedding supports the pipe uniformly, reduces point loading, and
helps maintain the required line and grade during and after installation.
5. A sewer pipe has been installed with a localized high point between
two manholes. What is the most likely hydraulic consequence?
A. Increased pressure throughout the entire system
B. Reduced flow capacity and possible accumulation of air or
wastewater at the high point
C. Increased pipe wall thickness
D. Elimination of infiltration
A high point can interfere with gravity flow and create hydraulic
restrictions, particularly when the pipeline was designed for a
continuous grade.
6. What is the principal difference between a gravity sanitary sewer
and a force main?
A. Gravity sewers always use metallic pipe
B. Force mains do not convey wastewater
C. Gravity sewers rely primarily on elevation and gravity, while force
mains convey wastewater under pressure
D. Gravity sewers require a pump at every manhole
Gravity systems use an elevation difference to transport wastewater,
whereas force mains depend on pumps or other pressure-producing
equipment to move wastewater.
7. What is the primary function of a sewage lift station?
, A. Remove all dissolved solids from wastewater
B. Increase the diameter of a sewer main
C. Raise wastewater to a higher elevation when gravity flow cannot
provide the required conveyance
D. Disinfect drinking water
A lift station pumps wastewater from a lower elevation to a higher
elevation so that it can continue through the collection or treatment
system.
8. Why should wastewater lift-station pumps be selected based on
both flow and total dynamic head?
A. Pump color depends on head requirements
B. The pump must deliver the required flow against the resistance and
elevation difference of the discharge system
C. Head determines the chemical dosage only
D. Flow is unrelated to pump performance
Pump performance depends on the relationship between required flow
and total dynamic head, which includes static elevation and friction or
other system losses.
9. What is a major concern when a wastewater force main is
improperly designed for rapid pump shutdown?
A. Increased potable-water pressure
B. Water hammer and transient pressure conditions
