ABC Wastewater Collection Level 3/ 77 Q&A/
2024-2025.
Turbidity in wastewater is caused by
A. color
B. dissolved calcium
C. hardness
D. finely divided suspended material - Answer: D. finely divided suspended material
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?
Page 1 of 20
,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
Page 2 of 20
, 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
C. highly desirable, since it encourages employee growth and frees the
D. supervisor for other tasks
E. passing the buck - Answer: C. highly desirable, since it encourages employee growth
Page 3 of 20
2024-2025.
Turbidity in wastewater is caused by
A. color
B. dissolved calcium
C. hardness
D. finely divided suspended material - Answer: D. finely divided suspended material
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?
Page 1 of 20
,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
Page 2 of 20
, 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
C. highly desirable, since it encourages employee growth and frees the
D. supervisor for other tasks
E. passing the buck - Answer: C. highly desirable, since it encourages employee growth
Page 3 of 20
