WASTEWATER COLLECTIONS III
COMPREHENSIVE EXAM 2026
◉ The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane. Answer: C. hydrogen sulfide
◉ How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62. Answer: A. 0.44
◉ Mechanical ventilation of a lift station is required to
A. lower temperatures to reduce proportion of hydrogen sulfide
B. reduce chlorine demand
C. reduce corrosion
D. increase DO in raw wastewater. Answer: C. reduce corrosion
,◉ A wet well probe is usually used for ________ determination(s) of
level.
A. approximate
B. dual point
C. continuous
D. single point. Answer: D. single point
◉ A pump is delivering at less than the expected rate of discharge.
Which of the causes listed below is incorrect?
A. speed of motor too low
B. pump not primed
C. impeller clogged
D. discharge head too low. Answer: D. discharge head too low
◉ Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis. Answer: C. galvanic action
◉ When a fire hydrant is operated, it should be
A. just opened enough to have a flow
, B. opened fully
C. opened halfway
D. regulated to flow required. Answer: B. opened fully
◉ If the pump bearings on horizontal centrifugal pumps are over
lubricated, the most important effect is that the extra lubricant
A. will result in smoother and more efficient operation of the pump
B. will not make any difference in the operation of the pump
C. will be wasted
D. shaft or shaft sleeve will be damaged. Answer: D. shaft or shaft
sleeve will be damaged
◉ If packing is not maintained properly,
A. cavitation damage will result
B. impeller will corrode
C. loss of suction due to air being allowed to enter pump
D. shaft or shaft sleeve will be damaged. Answer: C. loss of suction
due to air being allowed to enter pump
◉ In certain situations, a supervisor encourages the employees to
make their own decisions. This is considered to be
A. against the rules to follow past experiences in decision-making
B. bad form since the supervisor eventually loses control
COMPREHENSIVE EXAM 2026
◉ The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane. Answer: C. hydrogen sulfide
◉ How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62. Answer: A. 0.44
◉ Mechanical ventilation of a lift station is required to
A. lower temperatures to reduce proportion of hydrogen sulfide
B. reduce chlorine demand
C. reduce corrosion
D. increase DO in raw wastewater. Answer: C. reduce corrosion
,◉ A wet well probe is usually used for ________ determination(s) of
level.
A. approximate
B. dual point
C. continuous
D. single point. Answer: D. single point
◉ A pump is delivering at less than the expected rate of discharge.
Which of the causes listed below is incorrect?
A. speed of motor too low
B. pump not primed
C. impeller clogged
D. discharge head too low. Answer: D. discharge head too low
◉ Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis. Answer: C. galvanic action
◉ When a fire hydrant is operated, it should be
A. just opened enough to have a flow
, B. opened fully
C. opened halfway
D. regulated to flow required. Answer: B. opened fully
◉ If the pump bearings on horizontal centrifugal pumps are over
lubricated, the most important effect is that the extra lubricant
A. will result in smoother and more efficient operation of the pump
B. will not make any difference in the operation of the pump
C. will be wasted
D. shaft or shaft sleeve will be damaged. Answer: D. shaft or shaft
sleeve will be damaged
◉ If packing is not maintained properly,
A. cavitation damage will result
B. impeller will corrode
C. loss of suction due to air being allowed to enter pump
D. shaft or shaft sleeve will be damaged. Answer: C. loss of suction
due to air being allowed to enter pump
◉ In certain situations, a supervisor encourages the employees to
make their own decisions. This is considered to be
A. against the rules to follow past experiences in decision-making
B. bad form since the supervisor eventually loses control
