Collection - Q&A

Question 1

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

Answer 1

a) upstream in the sewer against the flow

Question 2

On the following abbreviations listed, which is NOT used in computing or expressing flow rates?

a) ft/sec
b) gpm
c) MGD
d) PSI

Answer 2

d) PSI

Question 3

Where are manholes typically placed?

a) 500 foot
b) intersections
c) change in pipe diameters
d) all of the above

Answer 3

d) all of the above

Question 4

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

Answer 4

c) force main

Question 5

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

Answer 5

c) for access to inspect or clean lines

Question 6

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

Answer 6

c) 300 - 400 ft

Question 7

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

Answer 7

b) 2 feet per second

Question 8

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

Answer 8

b) Corrected construction drawings that show changes made in the field installation

Question 9

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

Answer 9

c) to create flow conditions that produces a known relationship between flow and depth

Question 10

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

Answer 10

d) poor construction of the collection line, mainly at pipe joint

Question 11

What is the maximum velocity in main line?

a) 6fps
b) 7fps
c) 10fps
d) 12fps

Answer 11

c) 10fps

Check - main line for water?

Question 12

A wet well is essentially a:

a) holding tank
b) clarifier
c) drinking water source
d) all of the above

Answer 12

a) holding tank

Question 13

What should be considered as the scouring velocity of sanitary sewers?

a) 1ft/sec
b) 2ft/sec
c) 4ft/sec
d) 4.5ft/sec

Answer 13

b) 2ft/sec = 0.6m /sec

Question 14

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

Answer 14

d) a pump station wet well

Question 15

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

Answer 15

d) manholes properly sealed

Question 16

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

Answer 16

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)

Question 17

What type of energy is produced when water moves through a pipe?

a) kinetic energy
b) mechanical energy
c) potential energy
d) velocity energy

Answer 17

a) kinetic energy

Question 18

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

Answer 18

b) high velocity jetting machine

Question 19

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

Answer 19

SURPRIIIISE

Question 20

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

Answer 20

d) both a and c

Question 21

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

Answer 21

a) reduce hydraulic loads

Question 22

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

Answer 22

c) determine the cause of the odors and take corrective action