CWEA COLLECTIONS SYSTEM MAINTENANCE
2026/2027 EXAM QUESTIONS WITH ANSWERS
Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause: - ANS-
odors
Flatter sewer line grades may cause added sewer maintenance expense and odor
nuisance. This is caused by what? - ANS-A decrease in velocity which allows organic
and inorganic solids to settle out. This, in turn, allows biological activity to happen which
corrodes the pipe and releases hydrogen sulfide (H2S) which smells like rotten eggs
Clear water in entering a collection system is called what? - ANS-infiltration
Infiltration can occur in a pipe when the pipe is: - ANS-cracked, broken, fractures, has
roots coming into it etc.
The main reason we add sodium hypochlorite to sewers is to control: - ANS-BOD
, Roots can enter collection systems through: - ANS-cracked pipes, broken pipes,
fractured pipes
The lowest point on the inside of a pipe is called what? - ANS-the invert
The very top of the outside of a pipe is called what? - ANS-The crown
How often must an excavation site and adjacent areas be inspected for hazardous
conditions? - ANS-Daily
protective shoring systems options include: - ANS-proper shoring or benching of the
sides of the excavation, supporting the sides of a tench with shoring using a shield in an
excavation area.
Proper operation and maintenance of wastewater collection is defined as: - ANS-
keeping wastewater flowing through pipes
What is minimum design velocity for a sewer? - ANS-a minimum of two feet per second
Vitrified clay pipe is what type of pipe? - ANS-Rigid
What is another name for a manhole? - ANS-Maintenance hole
What are the four parts of a manhole? - ANS-lid, cone, barrel and base
What are some sewer testing methods? - ANS-Air, water, mandrill, smoke, dye, lamping
What are some hydraulic cleaning methods? - ANS-Flushing, balling, kites, parachutes,
poly pigs (pigging), high velocity cleaning, jetting, skids and tiger tails.
what is the formula for the area of a square? - ANS-Length x width
The main advantage of using CCTV is what? - ANS-You can see and record the length
and severity of defective pipe
A hazard that may damage a TV camera going through a sewer is: - ANS-an offset joint
What is the formula for the volume of a cube? - ANS-Length x Width x Height
What is the formula for the area of a circle? - ANS-0.785 x Diameter x Diameter
What is the formula for the volume of a pipe? - ANS-0.785 x Diameter x Diameter x
Length
A flow of 650 pgm would be how many mgd? - ANS-0.936
2026/2027 EXAM QUESTIONS WITH ANSWERS
Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause: - ANS-
odors
Flatter sewer line grades may cause added sewer maintenance expense and odor
nuisance. This is caused by what? - ANS-A decrease in velocity which allows organic
and inorganic solids to settle out. This, in turn, allows biological activity to happen which
corrodes the pipe and releases hydrogen sulfide (H2S) which smells like rotten eggs
Clear water in entering a collection system is called what? - ANS-infiltration
Infiltration can occur in a pipe when the pipe is: - ANS-cracked, broken, fractures, has
roots coming into it etc.
The main reason we add sodium hypochlorite to sewers is to control: - ANS-BOD
, Roots can enter collection systems through: - ANS-cracked pipes, broken pipes,
fractured pipes
The lowest point on the inside of a pipe is called what? - ANS-the invert
The very top of the outside of a pipe is called what? - ANS-The crown
How often must an excavation site and adjacent areas be inspected for hazardous
conditions? - ANS-Daily
protective shoring systems options include: - ANS-proper shoring or benching of the
sides of the excavation, supporting the sides of a tench with shoring using a shield in an
excavation area.
Proper operation and maintenance of wastewater collection is defined as: - ANS-
keeping wastewater flowing through pipes
What is minimum design velocity for a sewer? - ANS-a minimum of two feet per second
Vitrified clay pipe is what type of pipe? - ANS-Rigid
What is another name for a manhole? - ANS-Maintenance hole
What are the four parts of a manhole? - ANS-lid, cone, barrel and base
What are some sewer testing methods? - ANS-Air, water, mandrill, smoke, dye, lamping
What are some hydraulic cleaning methods? - ANS-Flushing, balling, kites, parachutes,
poly pigs (pigging), high velocity cleaning, jetting, skids and tiger tails.
what is the formula for the area of a square? - ANS-Length x width
The main advantage of using CCTV is what? - ANS-You can see and record the length
and severity of defective pipe
A hazard that may damage a TV camera going through a sewer is: - ANS-an offset joint
What is the formula for the volume of a cube? - ANS-Length x Width x Height
What is the formula for the area of a circle? - ANS-0.785 x Diameter x Diameter
What is the formula for the volume of a pipe? - ANS-0.785 x Diameter x Diameter x
Length
A flow of 650 pgm would be how many mgd? - ANS-0.936
