Collection - Q&A Flashcards
In which direction would you place the nozzle in the sewer when using high velocity cleaning machines?
a) upstream in the sewer against the flow
b) downstream in the sewer with the flow
c) does not matter
d) dépense on the velocity
a) upstream in the sewer against the flow
On the following abbreviations listed, which is NOT used in computing or expressing flow rates?
a) ft/sec
b) gpm
c) MGD
d) PSI
d) PSI
Where are manholes typically placed?
a) 500 foot
b) intersections
c) change in pipe diameters
d) all of the above
d) all of the above
A pig would likely to be used in the cleaning of a:
a) gravity sewer
b) storm sewer
c) force main
d) house or building sewer
c) force main
What is the main purpose of a manhole?
a) a sampling point for wastewater
b) for water storage in case of a blockage
c) for access to inspect or clean lines
d) to trap rodents
c) for access to inspect or clean lines
How far apart typically are manholes from each other?
a) 50 - 100 ft
b) 100 - 200 ft
c) 300 - 400 ft
d) 800 - 1000 ft
c) 300 - 400 ft
Gravity sewers are designed with a slope to achieve minimum flow velocities of ____ to prevent solids from settling
a) 1 feet per second
b) 2 feet per second
c) 1 feet per minute
d) 2 feet per minute
b) 2 feet per second
As-built drawings are:
a) Preliminary drawings prior to system startup
b) Corrected construction drawings that show changes made in the field installation
c) Useless to operators
d) Safety sheets for hazardous chemicals
b) Corrected construction drawings that show changes made in the field installation
What is the purpose of an open channel flow measurement primary element?
a) to create a condition that can measure the depth of flow
b) to create flow conditions that prevents the deposition of solids and debris
c) to create flow conditions that produces a known relationship between flow and depth
d) to create laminar flow conditions at all times
c) to create flow conditions that produces a known relationship between flow and depth
What is the main reason of water seepage into a sanitary sewer line?
a) excessive depth of sewer lines
b) hydraulically overloaded sewers
c) diameter of sewer too small
d) poor construction of the collection line, mainly at pipe joint
d) poor construction of the collection line, mainly at pipe joint
What is the maximum velocity in main line?
a) 6fps
b) 7fps
c) 10fps
d) 12fps
c) 10fps
Check - main line for water?
A wet well is essentially a:
a) holding tank
b) clarifier
c) drinking water source
d) all of the above
a) holding tank
What should be considered as the scouring velocity of sanitary sewers?
a) 1ft/sec
b) 2ft/sec
c) 4ft/sec
d) 4.5ft/sec
b) 2ft/sec = 0.6m /sec
A bubbler would most likely to be found in
a) a sewer cleaning truck
b) a manhole with little flow
c) a pump station dry well
d) a pump station wet well
d) a pump station wet well
Of the following, which does NOT lead to roots entering a collection system?
a) improper pipe bedding
b) misaligned pipe joints
c) differential settling
d) manholes properly sealed
d) manholes properly sealed
End of a sewer pipe that is formed to fit into the bell of the next pipe is called:
a) clamp
b) spigot
c) invert
d) housing
b) spigot
Image: spigot end (embout “normal” on the left) to fit into a stationary bell end (litteralement en forme de cloche on the right)
What type of energy is produced when water moves through a pipe?
a) kinetic energy
b) mechanical energy
c) potential energy
d) velocity energy
a) kinetic energy
Which of the listed methods cleans sewer lines hydraulically?
a) chemical addition
b) high velocity jetting machine
c) power bucket machine
d) power rodding machine
b) high velocity jetting machine
Which type of impeller is best to use for pumping water with low volumes of solids?
a) closed
b) open
c) semi-open
d) split
SURPRIIIISE
Wastewater collection systems television inspection is used to
a) determine what joints have to be sealed
b) regulate flow
c) determine where sources of infiltration originate
d) both a and c
d) both a and c
Efforts to eliminate infiltration and inflow in a collection system are made primarily to:
a) reduce hydraulic loads
b) reduce dilution of wastewater
c) prevent debris from entering into pipes
d) provide a higher ground water table
a) reduce hydraulic loads
When nearby residents complain of objectionable odors emanating from a pump station, you should:
a) tell the residents that you have no control over odors
b) use large amounts of lime to raise the pH of the septic wastewater
c) determine the cause of the odors and take corrective action
d) use commercial masking agents
c) determine the cause of the odors and take corrective action
