Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

AWWOA Practice Exams > Waste Water Collection > Flashcards

Waste Water Collection Flashcards

1
Q

Illegal connections:
A. Will result in settling of solids in the lines.
B. Can contribute to the surcharging problems.
C. Promotes the development of hydrogen sulfide gas.
D. Used where high structural loads or reliability is needed.

A

B. Can contribute to the surcharging problems.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Inverted siphons:
A. Are normally used if horsepower required is less than 5 hp.
B. Would result in flow velocity of 0.6 m/s in a 75 mm diameter pipe.
C. Are probably the most widely used type of level control device.
D. Are designed to maintain high flow velocities.

A

D. Are designed to maintain high flow velocities.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the minimum size and slope that residential gravity collection service lines should be set at?
A. 2.5 mm, 0.5% slope
B. 5 mm, 1% slope
C. 100 mm, 2% slope
D. 200 mm, 4% slope

A

C. 100 mm, 2% slope

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What device is commonly used to cut and shred solids in wastewater?
A. Bar screen
B. Comminutor
C. Eductor device
D. Closed impeller

A

B. Comminutor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What type of pump impeller is best suited for use in wastewater applications?
A. An open or semi-open impeller.
B. A closed multi-vane impeller.
C. A regenerative turbine impeller.
D. A gear pump.

A

A. An open or semi-open impeller.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the advantage of a wet-dry well type of lift station over a wet well only?
A. A wet well type is cheaper to construct.
B. Submersible pumps are cheaper to operate.
C. Dry wells make cleaning easier.
D. The dry well allows safer and easier access to equipment.

A

D. The dry well allows safer and easier access to equipment.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What harm can be done if lift station pumps start and stop too often?
A. Cavitation caused by vortexing.
B. Excessive lantern ring wear.
C. Pump or motor damage due to overheating.
D. Lift station overflow.

A

C. Pump or motor damage due to overheating.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What problems can arise at a wastewater lift station if the time between pump stop and pump start is too long?
A. The lift station is over capacity and requires upgrading.
B. Odours may develop due to anaerobic decomposition.
C. Plugging of the pump intake due to settling.
D. Aerobic decomposition will create odours.

A

B. Odours may develop due to anaerobic decomposition.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Stoppages in pipe flow are commonly caused by:
A. Grease blockage or tree roots.
B. Debris or high velocity.
C. Joint failure or excessive pipe slope.
D. Pipe failure or inadequate pipe leakage.

A

A. Grease blockage or tree roots.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are two common causes of surcharging?
A. Stormwater infiltration and exfiltration into the ground.
B. Lift station failure and over design of the line in question.
C. Force main collapse and inadequate flows.
D. Increased population load and groundwater infiltration.

A

D. Increased population load and groundwater infiltration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The slope of gravity collection systems is often maintained within specific limits. What problems can arise if the pipe slope is too steep?
A. Erosion of the pipe and settling of solids.
B. Backflow and grease build up.
C. High velocities which release odours and corrosion.
D. Siphoning and grease build up.

A

C. High velocities which release odours and corrosion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which inspection/testing method is most effective in determining if a sewer is leaking into a creek?
A. Sewer jacking.
B. Dye testing.
C. MPN Test.
D. A bucket machine.

A

B. Dye testing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

At what locations are lift stations normally installed?
A. Where wastewater flow direction changes significantly.
B. Where wastewater must be pumped to a higher elevation.
C. Where the elevation of the sewer drops at an excessive rate.
D. Where land is available.

A

B. Where wastewater must be pumped to a higher elevation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How many manholes must be placed along a 914 m large diameter sewer line?
A. 7
B. 6
C. 5
D. 4

A

A. 7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Determine the total wastewater volume produced from the bathroom during one day.
A. 230 L
B. 150 L
C. 380 L
D. 610 L

A

C. 380 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following uses the most water in a given week?
A. Toilets
B. Showers
C. Dishwasher
D. Laundry

A

A. Toilets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the total wastewater production for one week?
A. 2660 L
B. 3810 L
C. 3786 L
D. 4706 L

A

D. 4706 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How long does it take for the lift station to fill from the pump stop level to the pump start level?
A. 13.50 min
B. 16.98 min
C. 22.64 min
D. 28.30 min

A

B. 16.98 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Determine the pump cycle time for this lift station.
A. 16.98 min
B. 65.85 min
C. 82.83 min
D. 99.81 min

A

C. 82.83 min

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What gases can be encountered in a sewer manhole?
A. Cryogens and hydrogen sulfide
B. Chlorates and methane
C. Hydrogen sulfide and CFC
D. Methane and hydrogen sulfide

A

D. Methane and hydrogen sulfide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which two factors significantly influence the design of a wastewater collection system?
A. Characteristics of the wastewater and treatment protocol
B. Climate and rodent control
C. Topography and wastewater flow
D. Peak flows entering the system and presence of algae

A

C. Topography and wastewater flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are two of the main situations requiring a lift station in a wastewater collection system?
A. Where wastewater must be pumped to a remote location and where “C” factors become excessive.
B. Where sewer use bylaws are enacted and where “C” factors become excessive.
C. Where service connections are improperly installed and where solids collect.
D. Where a gravity system is no longer economical to construct and where wastewater must be pumped to a remote location.

A

D. Where a gravity system is no longer economical to construct and where wastewater must be pumped to a remote location.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

In a sanitary sewer system, maximum flow occurs at about ______ p.m. Minimum flow occurs at about ______ a.m.
A. 6 to 8 pm; 2 to 4 am
B. 8 to 10 pm; 2 to 4 am
C. 6 to 8 pm; 4 to 6 am
D. 4 to 6 pm; 6 to 8 am

A

B. 8 to 10 pm; 2 to 4 am

24
Q

Which two problems would likely arise if the velocity in a sewer is too high?
A. Joint displacement or settling of debris and solid material.
B. Thermal turnover or hydraulic under loading.
C. Damage caused by scouring or release of gases resulting in corrosion and odours.
D. Hydraulic under loading or joint displacement.

A

C. Damage caused by scouring or release of gases resulting in corrosion and odours.

25
Q

In a typical sanitary sewer system, the maximum daily flow equals ______ times the average daily flow, and the minimum daily flow equals ______ times the average daily flow.
A. 1.5; 3/4
B. 2.5; 3/4
C. 1.5; 1/2
D. 2.0; 2/3

A

D. 2.0; 2/3

26
Q

List two problems that could occur if the velocity in a sewer is too low?
A. Solids will settle out and create blockages or stagnant wastewater will become septic, creating odours and corrosion.
B. Hydraulic over loading or thermal turnover.
C. Scouring of the pipe surface or joint displacement.
D. Blockage of the line caused by solids settling out or hydraulic over loading.

A

A. Solids will settle out and create blockages or stagnant wastewater will become septic, creating odours and corrosion.

27
Q

If a sewer has a grade of 0.001, it will fall 0.1 m in:
A. 1 m of length
B. 10 m of length
C. 100 m of length
D. 1000 m of length

A

C. 100 m of length

28
Q

Which of the following list the major components of a sanitary wastewater collection system?
A. Lateral sewers, storm sewers, stand pipe reservoirs.
B. Service connection, lift stations, trunk sewers.
C. Main sewers, storm sewers, elevated storage.
D. Interceptor sewers, pressure reducing stations, storm sewers.

A

B. Service connection, lift stations, trunk sewers.

29
Q

Which of the following best describes the reasons for incorporating manholes in a collection system?
A. Provide access to the sewer for inspection or provide sufficient retention time for settling to occur.
B. Allow for sewer misalignment or provide a location where algae control can be conducted.
C. Provide access to the sewer for cleaning or flow diversion.
D. Provide a location for dropping the sewer elevation or ensuring that the grader operator maintains correct elevation.

A

C. Provide access to the sewer for cleaning or flow diversion.

30
Q

How do inverted siphons differ from gravity sewer systems?
A. The lower part of an inverted siphon actually operates under a full pipe pressure condition.
B. The siphon does not require a lift station to function.
C. Inverted siphons are used to go over obstacles that would otherwise require major construction.
D. The use of an inverted siphon is often required to lift wastewater to a higher elevation.

A

A. The lower part of an inverted siphon actually operates under a full pipe pressure condition.

31
Q

Which of the following are factors-which must be considered when selecting sewer pipe?
A. Abrasion resistance, compatibility with potable water, location of supplier.
B. Ease of construction, NPSH requirement, compatibility with material used previously.
C. Cost, hydraulic capacity, chemical resistance.
D. Structural strength effect on potability of the water, pipe quality control

A

C. Cost, hydraulic capacity, chemical resistance.

32
Q

Three materials commonly used for sewer pipe are:
A. Asbestos cement, polyvinyl chloride, steel.
B. Corrugated metal, vinyl acetate, polybutylene.
C. Vinyl chloride, wood stave, steel.
D. Vitrified clay, vinyl acetate, and fibreglass reinforced plastic.

A

A. Asbestos cement, polyvinyl chloride, steel.

33
Q

Which two problems can occur if a sewer system has excessive leakage?
A. Exfiltration, air binding
B. Surcharging, cavitation
C. Infiltration, inadequate NPSH
D. Root intrusion, exfiltration

A

D. Root intrusion, exfiltration

34
Q

What is meant by “surcharging” of a sewer system?
A. An extra charge on a service connection to the system to pay for future upgrading.
B. A flow condition in which a gravity system is over capacity, under a pressure condition.
C. A charge assessed to a customer for treatment of domestic wastewater.
D. occurs when the sewer is flowing below the normal design specs causing settling of solids.

A

B. A flow condition in which a gravity system is over capacity, under a pressure condition.

35
Q

Which two things can be determined by smoke testing?
A. Buildings connected to the sewer system, sources of surface inflow
B. Smoke toxicity, location of “lost” manholes
C. Illegal connections, sewer slope
D. Location of breaks, system hydraulic gradient

A

A. Buildings connected to the sewer system, sources of surface inflow

36
Q

Which two things can be determined by dye testing?
A. Flow patterns, surcharge frequency
B. Illegal connections, exfiltration
C. Presence of heavy metals, combined sewer outfall locations
D. Strength of wastewater, industrial discharge sources

A

B. Illegal connections, exfiltration

37
Q

Which of the following are methods of cleaning sewers?
A. Balling or epoxy coating
B. Buckets or insitu relining
C. Rodding or power flushing
D. Scooters or ultrasonic

A

C. Rodding or power flushing

38
Q

What is meant by lamping?
A. Shining a light down a manhole to observe the flow characteristics during low flow periods.
B. Ensuring that adequate illumination is present in a lift station.
C. Changing all of the bulbs in a light fixture, even when only one no longer works.
D. Directing a light source from one manhole to the next to observe sewer grade or obstructions.

A

D. Directing a light source from one manhole to the next to observe sewer grade or obstructions.

39
Q

How does a “scooter” move from one manhole to the next?
A. Cable and winch
B. Wastewater flow
C. Radio control
D. PLC control

A

B. Wastewater flow

40
Q

Why would chemical root control usually be more effective than power rodding alone?
A. Chemical treatment is much cheaper and easier.
B. A combination of rodding and chemical control is safer for the operator.
C. Rodding usually cut the roots, promoting further growth.
D. Chemicals are more environmentally friendly.

A

C. Rodding usually cut the roots, promoting further growth.

41
Q

Which two things must be known before using a chemical for root control?
A. Type of pipe used in the collection system.
B. Climatic conditions, the location of all distribution system valves.
C. Concentration required, local topography.
D. Safety precautions and hazards.

A

D. Safety precautions and hazards.

42
Q

Choose the two places in a sewer system where grease is most likely to accumulate.
A. At pipe irregularities such as misalignments, where the sewer line changes to a steep slope.
B. At service connections, at locations where wastewater flow is high velocity.
C. Where the sewer line changes direction, near external heat sources.
D. Where the sewer lines changes to shallow grade, at pipe intersections.

A

D. Where the sewer lines changes to shallow grade, at pipe intersections.

43
Q

Which of the following chemicals cannot be used to control hydrogen sulfide?
A. Chlorine
B. Potassium iodide
C. Hydrogen peroxide
D. Lime

A

B. Potassium iodide

44
Q

What are the two basic types of wastewater lift stations?
A. Dry well and cribbed well.
B. Dry well and wet well.
C. Cribbed well and drilled.
D. Clear well and wet well.

A

B. Dry well and wet well.

45
Q

Which of the following is false?
A. Lift stations must be capable of handling peak flows.
B. If stored too long in the wet well, wastewater may turn septic and cause odor problems.
C. The time between pumping cycles should normally be longer than 20 minutes.
D. Pumps should not be started and stopped more than 6 to 8 times an hour, or overheating may damage the motor.

A

C. The time between pumping cycles should normally be longer than 20 minutes.

46
Q

Which of the following lists three major components of a wastewater lift station?
A. Pumps, electrical systems, controls.
B. Wet wells, disinfection facilities, ventilation systems.
C. Screens, wet well view ports, sludge thickeners.
D. Blowers, pressure reducing valves, backflow preventers.

A

A. Pumps, electrical systems, controls.

47
Q

Why are screens, comminutors or barminutors commonly used in wastewater lift stations?
A. They permit a significantly higher maximum flow using the same facilities..
B. Because they remove algae and thereby reduce the potential for odor problems.
C. Most of the organic material can then be removed, prior to biological treatment.
D. To remove or shred large debris which may cause pump or equipment damage.

A

D. To remove or shred large debris which may cause pump or equipment damage.

48
Q

What is the purpose of a wet well?
A. To provide a wet environment for the motors to operate.
B. To provide short term storage for wastewater so that pumps do not start and stop too frequently.
C. To ensure that pressure is supplied to all customers in the service area.
D. To “freshen” the wastewater prior to discharge to the receiving stream.

A

B. To provide short term storage for wastewater so that pumps do not start and stop too frequently.

49
Q

Which one of the following lists three types of level control systems commonly used in wastewater lift stations?
A. Bulbs, secchi discs, electrodes
B. Mercury tilt switches, rodders, infrared
C. Floats, electrodes, sonic systems
D. Bubblers, mechanical switches, solenoid switches

A

C. Floats, electrodes, sonic systems

50
Q

A long sewer force main must:
A. Have air release valves at high points.
B. Not have a downward slope.
C. Have manholes every 300 feet.
D. Have no bends.

A

A. Have air release valves at high points.

51
Q

A low-pressure collection system is used in conditions where:
A. Trunk sewers are not accessible.
B. High groundwater or difficult terrain makes gravity sewer construction prohibitive.
C. A lift station cannot be installed.
D. Backflow may pose a hazard to the homeowner.

A

B. High groundwater or difficult terrain makes gravity sewer construction prohibitive.

52
Q

One advantage of manhole lift station design is:
A. Ease of maintenance and repair.
B. Good for small load applications.
C. Able to handle high flow applications better.
D. Good for large residential areas.

A

B. Good for small load applications.

53
Q

Grease deposition in commercial collection lines can best be prevented by:
A. Addition of emulsifiers.
B. Pipe replacement.
C. An annual flushing programs.
D. Limiting grease disposal in sewers.

A

D. Limiting grease disposal in sewers.

54
Q

______ and ______ are effective methods used for root control.
A. High velocity jetting; Balling
B. Power rodding; Bucket machine
C. Balling; Scooter
D. Power rodding; Chemical addition

A

D. Power rodding; Chemical addition

55
Q

Trenchless techniques are becoming more popular as rehabilitation methods due to:
A. Less disruption to the public
B. Shorter turnaround time
C. Lower capital costs
D. All of the above

A

D. All of the above

AWWOA Practice Exams (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions