Lift Stations

Question 1

True or False Questions: The greater the velocity of flow in pipes, the smaller the friction losses.

Answer 1

FALSE

Question 2

True or False Questions: When using pumps that are NOT self priming the wet well levelshould be drawn down below the centerline of the pump impeller

Answer 2

FALSE

Question 3

True or False Questions: Mechanical seals have stuffing boxes.

Answer 3

True

Question 4

True or False Questions: If a Communications interface is made with programmable logic controllers (PLCs) at other stations the PLC can become the front end of a simple Supervisory Control and Data Acquisition (SCADA) system

Answer 4

True

Question 5

True or False Questions: One of an operator’s jobs is to tell Engineers how to design lift stations

Answer 5

False

Question 6

True or False Questions:
If the rotation of an impeller of a centrifugal pump is in the wrong direction, the amp reading will be higher than the motor rating due to more work being done by the pump by rotating backward.

Answer 6

False

Question 7

What is the most important requirement of a lift station?1)Economics

2) Operation and maintenance 3)Reliability
4) Safety

Answer 7

Reliability

Question 8

A ground fault circuit interrupter GFCI is designed to limit electric shock to a current and time duration value below what level?

1) That which can cause ignition of clothing
2) That which can create minor pain sensations
3) That which can pass through your body
4) That which can produce serious injury.

Answer 8

That which can produce Serious injury.

Question 9

What happens when a seal fails on a submersible pump?

1) Waste water that flows into the portable water supply and contaminates the water
2) Waste Water leaks into the driveway and can cause electrical outages number
3) Waste water overflows the seal and causes adverse environmental impacts
4) Wastewater penetrates the motor compartment and burns and shorts out the motor.

Answer 9

Wastewater penetrates the motor compartment in Burns and shorts out the motor.

Question 10

Why should large horizontal centrifugal pumps have a vent valve on top of the Volute?

1) For priming purposes
2) For purpose of preventing water hammer
3) to prevent formation of vacuum
4) To release entrained air

Answer 10

For priming purposes

Question 11

What is the main purpose of gate valves in a lift station?

1) To check the pump efficiency on the pump curve 2) To function as a check valve went to check valves fail
3) To isolate the pump from the force main during pump or check valve maintenance
4) To throttle pump flows to avoid overloading the sewer system.

Answer 11

To isolate the pump from the Force main during pump or check valve maintenance.

Question 12

Why should operation and maintenance operators be given the opportunity to review the prints and specifications of a new lift station before the award of a contract for new construction?

1) to allow operators to learn how to design lift stations.
2) to be sure adequate Provisions have been made for the station to be easily and properly operate and maintained
3) to commit on the reliability of the specified equipment manufacturers
4) to promote communication between design Engineers operation and maintenance operators.

Answer 12

To be sure adequate Provisions have been made for the station to be easily and properly operated & maintained.

Question 13

What is the most significant factor in determining the frequency of lift station visits?

1) attitude of operating agency 2) compliance with regulatory permits
3) potential for nuisances
4) type of Wastewater being conveyed

Answer 13

1) attitude of operating agency

Question 14

What is the critical period of time if a lift station does fail?The length of time from when the failure occurs

1) at current pumping level until all pop start to lower water level number.
2) at high water level in the wet well to win back up flooding or overflows will occur
3) until emergency crew can arrive at lift station
4) until public notifies collection system agency

Answer 14

2) at high water level in the wet well to win back up flooding or overflows will occur

Question 15

Where should lift station operation and maintenance records be filed?

1) At the agency’s main office
2) At the cruise locker room
3) in the crews vehicle binder
4) in the lift station book

Answer 15

1) At the agency’s main office

Question 16

Multiple choice:
What can happen when a lift station or Force main fails?
1) newspaper headlines can tarnish the image of the collection system Agency 2)significant impact on environment number
3) Wastewater can back up into homes
4) Waste Water can be discharged into rivers
5) Wastewater will have to flow within the sewers

Answer 16

1) newspaper headlines can tarnish the image of the collection system Agency 2)significant impact on environment number
3) Wastewater can back up into homes
4) Waste Water can be discharged into rivers

Question 17

Multiple choice:
Why should collection system operators help Engineers design lift stations?
1) to allow Engineers time to design other lift stations
2)to gain important experience designing lift stations
3) to improve operation and maintenance of lift stations
4)to lower operating cost of lift stations
5) to minimize bypasses and backups caused by lift station failures

Answer 17

3) to improve operation and maintenance of lift stations
4) to lower operating cost of lift stations
5) to minimize bypasses and backups caused by lift station failures

Question 18

Mutiple choice:
What stations are installed at low points in the collection system and at the end of gravity sewers where what kinds of conditions exist?
1) Community concerns regarding potential power outages
2) Excavation cost to maintain gravity flow and sufficient velocity become excessive
3) groundwater today was too high for installing deep sewers 4) homeowners are requesting an aesthetically pleasing lift station structure
5) Soil stability is unstable for trenching

Answer 18

2) Excavation cost to maintain gravity flow and sufficient velocity become excessive
3) groundwater today was too high for installing deep sewers
5) Soil stability is unstable for trenching

Question 19

Multiple choice:
What must operators control at a lift station to prevent the lift station from being a nuisance to nearby neighbor?
1) appearances 
2) health hazards 
3) noise 
4) odors 
5) safety hazards

Answer 19

1) appearances
2) health hazards
3) noise
4) odors
5) safety hazards

Question 20

Multiple choice:
Why do Force Mains need air and vacuum release valves?  to avoid 
1) decrease in friction losses 
2) deposition of solids 
3) flows reversing direction 
4) increase in pumping cost 
5) reduction and pipe capacity

Answer 20

4) increase in pumping cost

5) reduction and pipe capacity

Question 21

Multiple choice:
If lift station piping and pumps or improperly designed what types of problems can develop?
1) bearing failures 
2) cavitation 
3) excessive maintenance 
4) insufficient pumping capacity 
5) vibrations

Answer 21

2) cavitation
3) excessive maintenance
4) insufficient pumping capacity
5) vibrations

Question 22

Multiple choice:
What types of float controllers are used to start and to stop pumps?
1) bottle floats 
2) cable attach floats 
3) cork floats 
4) mercury switch float controls 
5) Rod attached floats

Answer 22

2) cable attach floats
4) mercury switch float controls
5) Rod attached floats

Question 23

Multiple choice:
What are the advantages of mechanical seals over packing seals?
1) initial cost is sufficiently lower than conventional packing
2) leakage of raw sewage is eliminated
3) less power consumption than with packing
4) less wear on the pump Shaft or shaft sleeve than with packing
5) virtually maintenance-free

Answer 23

2) leakage of raw sewage is eliminated
3) less power consumption than with packing
4) less wear on the pump Shaft or shaft sleeve than with packing
5) virtually maintenance-free

Question 24

Multiple choice:
Which factors influence head loss in a pipe?
1) cavitation 
2)corrosion 
3) sediment
4) slime growths
5) total dynamic head

Answer 24

2) corrosion
3) sediment
4) slime growths
5) total dynamic head

Question 25

Multiple choice:
What safety hazards can be encountered in a lift station ?
1) dangerous electrical gear
2) explosive or toxic gases
3) inadequate drainage
4) insufficient oxygen
5) poor footing caused by grease or slimes

Answer 25

1) dangerous electrical gear
2) explosive or toxic gases
3) inadequate drainage
4) insufficient oxygen
5) poor footing caused by grease or slimes

Question 26

Multiple choice:
Frequency of lift station visits depends on what factors?
1) Adequacy of preventive maintenance and overhaul program
2) condition of the equipment 3) design of facility and Equipment installed
4) potential damage resulting from storms flooding stations
5) type of adequacy and
reliability, of the telemetry system.

Answer 26

1) Adequacy of preventive maintenance and overhaul program
2) condition of the equipment 3) design of facility and Equipment installed
4) potential damage resulting from storms flooding stations
5) type of adequacy and
reliability, of the telemetry system.

Question 27

Multiple choice:
What types of lift station failures may be found during a lift station visit?
1) Air-bound pump
2) Blocked check valve
3) Failure of water level sensing equipment
4) Plugged pump impeller
5) Tripped-out motor thermal

Answer 27

1) Air-bound pump
2) Blocked check valve
3) Failure of water level sensing equipment
4) Plugged pump impeller
5) Tripped-out motor thermal

Question 28

Multiple Choice:
Preparation of a lift station maintenance program requires consideration of what important factors?
1) Budgetary considerations
2) knowledge gained from experience
3) recommendations of equipment manufacturers
4) regulatory regulations
5) requirements of lift station

Answer 28

2) knowledge gained from experience
3) recommendations of equipment manufacturers
5) requirements of lift station