ABC Wastewater Level 3 - General
1. Turbidity in wastewater is caused by
A. color
B. dissolved calcium
C. hardness
D. finely divided suspended material: D. finely divided suspended material
2. The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane: C. hydrogen sulfide
3. How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62: A. 0.44
4. 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: C. reduce corrosion
5. A wet well probe is usually used for ________ determination(s) of level.
A. approximate
B. dual point
C. continuous
D. single point: D. single point
6. 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
, ABC Wastewater Level 3 - General
B. pump not primed
C. impeller clogged
D. discharge head too low: D. discharge head too low
7. Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis: C. galvanic action
8. 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: B. opened fully
9. 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: D. shaft or shaft sleeve will be damaged
10. 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: C. loss of suction due to air being allowed to enter pump
11. 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
, ABC Wastewater Level 3 - General
D. improved by decreasing the recirculation: A. upward through the filter
12. 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: B. high oxygen uptake and slow settling rate
13. The reaction of chlorine and ammonia produces a compound which is called
A. ammonium chloride
B. chloral hydrate
C. chloramine
D. hydrazine: C. chloramine
14. 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: C. injector clogged
15. 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: B. less effective
16. The precipitate in coagulation with alum is aluminum
A. bicarbonate
B. carbonate
C. hydroxide
D. sulfate: C. hydroxide
, ABC Wastewater Level 3 - General
17. 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: C. sheared pin or disengaged clutch
18. The least amount of chemical used to remove turbidity is known as the
A. coagulation range
B. combination dosage
C. efficiency range
D. dosage: D. dosage
19. 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: C. centrifugation
20. Sodium chloride is used in the low pressure wet oxidation unit's
A. water softener
B. steam generator
C. deaerator
D. chemical feed tank: A. water softener
21. The quantity of volatile solids in the content of the sludge is an indirect measure of the
A. amount of the sample that will evaporate upon standing
1. Turbidity in wastewater is caused by
A. color
B. dissolved calcium
C. hardness
D. finely divided suspended material: D. finely divided suspended material
2. The gas most commonly associated with septic wastewater is
A. carbon dioxide
B. carbon monoxide
C. hydrogen sulfide
D. methane: C. hydrogen sulfide
3. How many cubic meters per second in 10 MGD?
A. 0.44
B. 1.44
C. 4.73
D. 24.62: A. 0.44
4. 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: C. reduce corrosion
5. A wet well probe is usually used for ________ determination(s) of level.
A. approximate
B. dual point
C. continuous
D. single point: D. single point
6. 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
, ABC Wastewater Level 3 - General
B. pump not primed
C. impeller clogged
D. discharge head too low: D. discharge head too low
7. Metal pipes often fail because of
A. back siphonage
B. browning movement
C. galvanic action
D. reverse osmosis: C. galvanic action
8. 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: B. opened fully
9. 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: D. shaft or shaft sleeve will be damaged
10. 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: C. loss of suction due to air being allowed to enter pump
11. 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
, ABC Wastewater Level 3 - General
D. improved by decreasing the recirculation: A. upward through the filter
12. 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: B. high oxygen uptake and slow settling rate
13. The reaction of chlorine and ammonia produces a compound which is called
A. ammonium chloride
B. chloral hydrate
C. chloramine
D. hydrazine: C. chloramine
14. 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: C. injector clogged
15. 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: B. less effective
16. The precipitate in coagulation with alum is aluminum
A. bicarbonate
B. carbonate
C. hydroxide
D. sulfate: C. hydroxide
, ABC Wastewater Level 3 - General
17. 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: C. sheared pin or disengaged clutch
18. The least amount of chemical used to remove turbidity is known as the
A. coagulation range
B. combination dosage
C. efficiency range
D. dosage: D. dosage
19. 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: C. centrifugation
20. Sodium chloride is used in the low pressure wet oxidation unit's
A. water softener
B. steam generator
C. deaerator
D. chemical feed tank: A. water softener
21. The quantity of volatile solids in the content of the sludge is an indirect measure of the
A. amount of the sample that will evaporate upon standing
