1
CWEA COLLECTIONS SYSTEM MAINTENANCE GRADE
3 EXAM 2026/27 VERSION
Which of the following is the most common factor leading to the
generation of hydrogen sulfide in sewers?
a. Anaerobic conditions.
b. Constantly high velocity of flow in sewers.
c. Low concentrations of ferrous sulfide.
d. Presence of highly soluble fats and oils. - Correct Answer-a. Anaerobic
conditions.
A category 2 SSO is:
a. any SSO which does not reach surface waters.
b. not reportable.
c. preventable.
d. any SSO which is not category 1. - Correct Answer-d. any SSO which
is not category 1.
Which tool would you use for cleaning under a pipe, or hard dirt near a
pipe?
a. Miner's pick.
b. Wrench.
c. Drill.
d. Hammer. - Correct Answer-a. Miner's pick.
,2
A torque wrench is used to tighten which device?
a. Pipe clamp.
b. Drill chuck.
c. Light bulb.
d. Sheet metal screw - Correct Answer-a. Pipe clamp.
Which unit uses high water pressure and a vacuum to clean sewer
lines?
a. Jetter
b. Mechanical rodder
c. Combination unit
d. Bucket machine - Correct Answer-c. Combination unit
In sewer maintenance, what is a pig?
a. A ball forced through a sewer line.
b. A power rod.
a. Any foul smelling equipment.
b. The hydraulic rodding truck. - Correct Answer-a. A ball forced through
a sewer line.
When pouring a concrete slab, which of the following tools is used to
finish the concrete?
, 3
a. Grasshopper.
b. Tamper.
c. Trowel.
d. Vibrator. - Correct Answer-c. Trowel.
What tool is used to snare a broken section of sewer rod?
a. Square stock corkscrew.
b. Auger.
c. Pickup tool.
d. Pull out tool. - Correct Answer-c. Pickup tool.
Why is the replacement of wastewater collection systems in some
downtown streets difficult?
a. Crowding of other underground utilities.
b. Records have not been maintained properly and the collection
system is lost.
c. Some people have landscaped their backyards over the collection
system and do not want their yards dug up.
d. The streets will have to be paved again - Correct Answer-a.
Crowding of other underground utilities.
How can the velocity of water flowing in a sewer be estimated?
a. Driving between manholes and reading the speedometer.
b. Measuring the Manning's roughness coefficient for the sewer.
CWEA COLLECTIONS SYSTEM MAINTENANCE GRADE
3 EXAM 2026/27 VERSION
Which of the following is the most common factor leading to the
generation of hydrogen sulfide in sewers?
a. Anaerobic conditions.
b. Constantly high velocity of flow in sewers.
c. Low concentrations of ferrous sulfide.
d. Presence of highly soluble fats and oils. - Correct Answer-a. Anaerobic
conditions.
A category 2 SSO is:
a. any SSO which does not reach surface waters.
b. not reportable.
c. preventable.
d. any SSO which is not category 1. - Correct Answer-d. any SSO which
is not category 1.
Which tool would you use for cleaning under a pipe, or hard dirt near a
pipe?
a. Miner's pick.
b. Wrench.
c. Drill.
d. Hammer. - Correct Answer-a. Miner's pick.
,2
A torque wrench is used to tighten which device?
a. Pipe clamp.
b. Drill chuck.
c. Light bulb.
d. Sheet metal screw - Correct Answer-a. Pipe clamp.
Which unit uses high water pressure and a vacuum to clean sewer
lines?
a. Jetter
b. Mechanical rodder
c. Combination unit
d. Bucket machine - Correct Answer-c. Combination unit
In sewer maintenance, what is a pig?
a. A ball forced through a sewer line.
b. A power rod.
a. Any foul smelling equipment.
b. The hydraulic rodding truck. - Correct Answer-a. A ball forced through
a sewer line.
When pouring a concrete slab, which of the following tools is used to
finish the concrete?
, 3
a. Grasshopper.
b. Tamper.
c. Trowel.
d. Vibrator. - Correct Answer-c. Trowel.
What tool is used to snare a broken section of sewer rod?
a. Square stock corkscrew.
b. Auger.
c. Pickup tool.
d. Pull out tool. - Correct Answer-c. Pickup tool.
Why is the replacement of wastewater collection systems in some
downtown streets difficult?
a. Crowding of other underground utilities.
b. Records have not been maintained properly and the collection
system is lost.
c. Some people have landscaped their backyards over the collection
system and do not want their yards dug up.
d. The streets will have to be paved again - Correct Answer-a.
Crowding of other underground utilities.
How can the velocity of water flowing in a sewer be estimated?
a. Driving between manholes and reading the speedometer.
b. Measuring the Manning's roughness coefficient for the sewer.
