ABC Wastewater Collection Level 3 Updated Study Guide
Questions and Answers 2027 | Focused Revision Pack | A+
Verified
Question 1.
The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane
Correct Answer: C. hydrogen sulfide
Question 2.
How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62
Correct Answer: A. 0.44
Question 3.
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
Correct Answer: C. reduce corrosion
Question 4.
A wet well probe is usually used for ________ determination(s) of level.
A. approximate
B. dual point
C. continuous
D. single point
Correct Answer: D. single point
Question 5.
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
Correct Answer: D. discharge head too low
Question 6.
Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis
Correct Answer: C. galvanic action
Question 7.
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
Correct Answer: B. opened fully
Question 8.
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
Correct Answer: D. shaft or shaft sleeve will be damaged
Question 9.
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
Correct Answer: C. loss of suction due to air being allowed to enter pump
Question 10.
Air flow through a trickling filter when the influent is warmer than the air temperature is
A. upward through the filter
,B. downward through the filter
C. inadequate and may require forced air ventilation
D. improved by decreasing the recirculation
Correct Answer: A. upward through the filter
Question 11.
An active sludge in the aeration tank with an abundant available food supply will have a
relatively
A. high oxygen uptake and fast settling rate
B. high oxygen uptake and slow settling rate
C. low oxygen uptake and fast settling rate
D. low oxygen uptake and slow settling rate
Correct Answer: B. high oxygen uptake and slow settling rate The reaction of
chlorine and ammonia produces a compound which is called
A. ammonium chloride
B. chloral hydrate
C. chloramine
D. hydrazine -✓✓C. chloramine
Question 12.
A malfunctioning gas chlorination system has normal gas pressure, no feed rate
indicated on rotometer, and no injector vacuum. What is the most likely cause of the
problem?
A. air leak upstream of rotameter
B. gas line plugged
C. injector clogged
D. pressure reducing valve diaphragm ruptured
Correct Answer: C. injector clogged
Question 13.
What is the impact of increased viscosity on the effectiveness of mixed media filters?
Mixed media filters are
A. affected only if temperature also changes
B. less effective
C. more effective
D. not affected
Correct Answer: B. less effective
Question 14.
The precipitate in coagulation with alum is aluminum
A. bicarbonate
, B. carbonate
C. hydroxide
D. sulfate
Correct Answer: C. hydroxide
Question 15.
Given the following data, what is the most likely cause of the mechanically cleaned bar
screen problem? DATA: Above normal water differential across bar screen Drive motor
shaft turning Drive sprocket, chain, rake not moving Less than normal flow on bar
screen downstream side Bar screen mode selector in automatic position Normal
seasonal flow (influent) coming into bar screen Alarm systems operating normally
A. low influent (incoming) level
B. raw wastewater pumping units out of service
C. sheared pin or disengaged clutch
D. none of the above
Correct Answer: C. sheared pin or disengaged clutch
Question 16.
The least amount of chemical used to remove turbidity is known as the
A. coagulation range
B. combination dosage
C. efficiency range
D. dosage
Correct Answer: D. dosage
Question 17.
The method of sludge handling resulting in a supernatant with the highest BOD is
A. aerobic digestion
B. anaerobic digestion
C. centrifugation
D. vacuum filtration
Correct Answer: C. centrifugation
Question 18.
Sodium chloride is used in the low pressure wet oxidation unit's
A. water softener
B. steam generator
C. deaerator
D. chemical feed tank
Correct Answer: A. water softener
Questions and Answers 2027 | Focused Revision Pack | A+
Verified
Question 1.
The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane
Correct Answer: C. hydrogen sulfide
Question 2.
How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62
Correct Answer: A. 0.44
Question 3.
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
Correct Answer: C. reduce corrosion
Question 4.
A wet well probe is usually used for ________ determination(s) of level.
A. approximate
B. dual point
C. continuous
D. single point
Correct Answer: D. single point
Question 5.
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
Correct Answer: D. discharge head too low
Question 6.
Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis
Correct Answer: C. galvanic action
Question 7.
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
Correct Answer: B. opened fully
Question 8.
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
Correct Answer: D. shaft or shaft sleeve will be damaged
Question 9.
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
Correct Answer: C. loss of suction due to air being allowed to enter pump
Question 10.
Air flow through a trickling filter when the influent is warmer than the air temperature is
A. upward through the filter
,B. downward through the filter
C. inadequate and may require forced air ventilation
D. improved by decreasing the recirculation
Correct Answer: A. upward through the filter
Question 11.
An active sludge in the aeration tank with an abundant available food supply will have a
relatively
A. high oxygen uptake and fast settling rate
B. high oxygen uptake and slow settling rate
C. low oxygen uptake and fast settling rate
D. low oxygen uptake and slow settling rate
Correct Answer: B. high oxygen uptake and slow settling rate The reaction of
chlorine and ammonia produces a compound which is called
A. ammonium chloride
B. chloral hydrate
C. chloramine
D. hydrazine -✓✓C. chloramine
Question 12.
A malfunctioning gas chlorination system has normal gas pressure, no feed rate
indicated on rotometer, and no injector vacuum. What is the most likely cause of the
problem?
A. air leak upstream of rotameter
B. gas line plugged
C. injector clogged
D. pressure reducing valve diaphragm ruptured
Correct Answer: C. injector clogged
Question 13.
What is the impact of increased viscosity on the effectiveness of mixed media filters?
Mixed media filters are
A. affected only if temperature also changes
B. less effective
C. more effective
D. not affected
Correct Answer: B. less effective
Question 14.
The precipitate in coagulation with alum is aluminum
A. bicarbonate
, B. carbonate
C. hydroxide
D. sulfate
Correct Answer: C. hydroxide
Question 15.
Given the following data, what is the most likely cause of the mechanically cleaned bar
screen problem? DATA: Above normal water differential across bar screen Drive motor
shaft turning Drive sprocket, chain, rake not moving Less than normal flow on bar
screen downstream side Bar screen mode selector in automatic position Normal
seasonal flow (influent) coming into bar screen Alarm systems operating normally
A. low influent (incoming) level
B. raw wastewater pumping units out of service
C. sheared pin or disengaged clutch
D. none of the above
Correct Answer: C. sheared pin or disengaged clutch
Question 16.
The least amount of chemical used to remove turbidity is known as the
A. coagulation range
B. combination dosage
C. efficiency range
D. dosage
Correct Answer: D. dosage
Question 17.
The method of sludge handling resulting in a supernatant with the highest BOD is
A. aerobic digestion
B. anaerobic digestion
C. centrifugation
D. vacuum filtration
Correct Answer: C. centrifugation
Question 18.
Sodium chloride is used in the low pressure wet oxidation unit's
A. water softener
B. steam generator
C. deaerator
D. chemical feed tank
Correct Answer: A. water softener
