Iowa Wastewater Collection Technician Level II
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
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1. What is the primary purpose of a wastewater collection system?
A. Provide drinking water
B. Transport sewage to treatment
C. Store stormwater
D. Disinfect efluent
B
Its main function is to convey wastewater from sources to a
treatment facility.
2. A lift station is used when:
A. Wastewater must be aerated
B. Gravity flow is insufficient
C. Treatment is complete
D. Stormwater levels decrease
B
Lift stations pump wastewater where gravity alone cannot move
it.
3. The term “I/I” refers to:
A. Inflow and infiltration
B. Industrial influent
C. Internal inspection
, D. Intake intensity
A
Inflow and infiltration describe unwanted water entering the
system.
4. Excessive I/I commonly results in:
A. Lower energy use
B. Hydraulic overloading
C. Reduced flow
D. Higher sludge production
B
Too much I/I overwhelms collection and treatment capacity.
5. The purpose of a manhole drop connection is to:
A. Reduce odor
B. Reduce velocity in deep manholes
C. Prevent turbulence in deeper inlets
D. Reduce free-fall of wastewater
D
Drop connections eliminate long vertical drops that cause
turbulence.
6. The recommended minimum velocity in sewer pipes for self-
cleaning is:
A. 0.5 ft/s
B. 1.0 ft/s
C. 2.0 ft/s
D. 3.0 ft/s
C
A velocity of about 2 ft/s prevents solids deposition.
, 7. A sewer gas that poses an immediate danger to life is:
A. Oxygen
B. Nitrogen
C. Hydrogen sulfide
D. Carbon dioxide
C
H₂S can be lethal at high concentrations.
8. What is the primary cause of corrosion in collection systems?
A. UV radiation
B. Chemical feed
C. Hydrogen sulfide
D. Low temperatures
C
H₂S oxidizes to sulfuric acid, causing corrosion.
9. A confined space must have:
A. Limited entry/exit
B. Natural ventilation
C. High oxygen levels
D. Two exits
A
Manholes qualify because they have limited openings.
10. Normal atmospheric oxygen content is:
A. 10%
B. 14%
C. 21%
D. 35%
Exam Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a wastewater collection system?
A. Provide drinking water
B. Transport sewage to treatment
C. Store stormwater
D. Disinfect efluent
B
Its main function is to convey wastewater from sources to a
treatment facility.
2. A lift station is used when:
A. Wastewater must be aerated
B. Gravity flow is insufficient
C. Treatment is complete
D. Stormwater levels decrease
B
Lift stations pump wastewater where gravity alone cannot move
it.
3. The term “I/I” refers to:
A. Inflow and infiltration
B. Industrial influent
C. Internal inspection
, D. Intake intensity
A
Inflow and infiltration describe unwanted water entering the
system.
4. Excessive I/I commonly results in:
A. Lower energy use
B. Hydraulic overloading
C. Reduced flow
D. Higher sludge production
B
Too much I/I overwhelms collection and treatment capacity.
5. The purpose of a manhole drop connection is to:
A. Reduce odor
B. Reduce velocity in deep manholes
C. Prevent turbulence in deeper inlets
D. Reduce free-fall of wastewater
D
Drop connections eliminate long vertical drops that cause
turbulence.
6. The recommended minimum velocity in sewer pipes for self-
cleaning is:
A. 0.5 ft/s
B. 1.0 ft/s
C. 2.0 ft/s
D. 3.0 ft/s
C
A velocity of about 2 ft/s prevents solids deposition.
, 7. A sewer gas that poses an immediate danger to life is:
A. Oxygen
B. Nitrogen
C. Hydrogen sulfide
D. Carbon dioxide
C
H₂S can be lethal at high concentrations.
8. What is the primary cause of corrosion in collection systems?
A. UV radiation
B. Chemical feed
C. Hydrogen sulfide
D. Low temperatures
C
H₂S oxidizes to sulfuric acid, causing corrosion.
9. A confined space must have:
A. Limited entry/exit
B. Natural ventilation
C. High oxygen levels
D. Two exits
A
Manholes qualify because they have limited openings.
10. Normal atmospheric oxygen content is:
A. 10%
B. 14%
C. 21%
D. 35%
