TCEQ Wastewater Collection System
Operator – Class I Examination With
Actual Questions Verified Answers,Plus
Rationales /Expert Verified For
Guaranteed Pass (2026/2027 Study
Guide) Latest Update/Instant Download
Pdf.
1. What is the primary purpose of a wastewater collection system?
A. To produce drinking water
B. To collect and transport wastewater for treatment or disposal
C. To generate electrical power
D. To disinfect stormwater before discharge
Correct Answer: B. To collect and transport wastewater for treatment
or disposal
Rationale: A wastewater collection system is designed to collect
wastewater from homes, businesses, and industries and transport it
safely to a wastewater treatment facility or another approved point of
treatment or disposal.
, 2. Which type of wastewater collection system carries wastewater
and stormwater in the same pipe?
A. Separate sanitary sewer system
B. Force main system
C. Combined sewer system
D. Vacuum sewer system
Correct Answer: C. Combined sewer system
Rationale: A combined sewer system transports both sanitary
wastewater and stormwater runoff through the same collection pipes.
During heavy rainfall, combined systems may experience excessive flows
and potential overflows.
3. What is the main purpose of a manhole in a wastewater collection
system?
A. To treat wastewater
B. To provide access for inspection, maintenance, and cleaning
C. To disinfect wastewater
D. To measure chlorine residual
Correct Answer: B. To provide access for inspection, maintenance, and
cleaning
Rationale: Manholes provide personnel and equipment access to
underground collection system components. Operators use them for
inspection, cleaning, flow monitoring, maintenance, and connecting
sewer lines.
, 4. Which condition is most likely to cause infiltration into a sanitary
sewer?
A. A properly sealed pipe joint
B. A crack in a sewer pipe below the groundwater level
C. A functioning backflow preventer
D. A properly maintained pump station
Correct Answer: B. A crack in a sewer pipe below the groundwater
level
Rationale: Infiltration occurs when groundwater enters a collection
system through defects such as cracks, broken pipes, deteriorated joints,
or defective manholes. Groundwater pressure can force water into the
sewer.
5. What is inflow in a wastewater collection system?
A. Groundwater entering through pipe cracks
B. Wastewater entering from residential plumbing
C. Surface water entering the system through improper connections or
openings
D. Treated wastewater leaving a treatment plant
Correct Answer: C. Surface water entering the system through
improper connections or openings
Rationale: Inflow is water that enters the collection system from direct
sources such as roof drains, yard drains, stormwater connections, and
improperly sealed manholes. Unlike infiltration, inflow usually enters
directly and rapidly during rainfall.
, 6. Excessive infiltration and inflow can cause which operational
problem?
A. Reduced hydraulic loading
B. Increased treatment and pumping requirements
C. Elimination of maintenance needs
D. Decreased wastewater flow
Correct Answer: B. Increased treatment and pumping requirements
Rationale: Excessive infiltration and inflow increase the volume of water
transported through the collection system. This can overload pipes, lift
stations, and treatment facilities and increase pumping, treatment, and
maintenance costs.
7. What is the purpose of maintaining adequate velocity in a gravity
sewer?
A. To increase corrosion
B. To promote solids deposition
C. To help prevent solids from settling in the pipe
D. To reduce pipe capacity
Correct Answer: C. To help prevent solids from settling in the pipe
Rationale: Adequate flow velocity helps keep solids suspended and
moving through the collection system. Low velocities can allow solids,
grease, and debris to accumulate, increasing the risk of blockages.
Operator – Class I Examination With
Actual Questions Verified Answers,Plus
Rationales /Expert Verified For
Guaranteed Pass (2026/2027 Study
Guide) Latest Update/Instant Download
Pdf.
1. What is the primary purpose of a wastewater collection system?
A. To produce drinking water
B. To collect and transport wastewater for treatment or disposal
C. To generate electrical power
D. To disinfect stormwater before discharge
Correct Answer: B. To collect and transport wastewater for treatment
or disposal
Rationale: A wastewater collection system is designed to collect
wastewater from homes, businesses, and industries and transport it
safely to a wastewater treatment facility or another approved point of
treatment or disposal.
, 2. Which type of wastewater collection system carries wastewater
and stormwater in the same pipe?
A. Separate sanitary sewer system
B. Force main system
C. Combined sewer system
D. Vacuum sewer system
Correct Answer: C. Combined sewer system
Rationale: A combined sewer system transports both sanitary
wastewater and stormwater runoff through the same collection pipes.
During heavy rainfall, combined systems may experience excessive flows
and potential overflows.
3. What is the main purpose of a manhole in a wastewater collection
system?
A. To treat wastewater
B. To provide access for inspection, maintenance, and cleaning
C. To disinfect wastewater
D. To measure chlorine residual
Correct Answer: B. To provide access for inspection, maintenance, and
cleaning
Rationale: Manholes provide personnel and equipment access to
underground collection system components. Operators use them for
inspection, cleaning, flow monitoring, maintenance, and connecting
sewer lines.
, 4. Which condition is most likely to cause infiltration into a sanitary
sewer?
A. A properly sealed pipe joint
B. A crack in a sewer pipe below the groundwater level
C. A functioning backflow preventer
D. A properly maintained pump station
Correct Answer: B. A crack in a sewer pipe below the groundwater
level
Rationale: Infiltration occurs when groundwater enters a collection
system through defects such as cracks, broken pipes, deteriorated joints,
or defective manholes. Groundwater pressure can force water into the
sewer.
5. What is inflow in a wastewater collection system?
A. Groundwater entering through pipe cracks
B. Wastewater entering from residential plumbing
C. Surface water entering the system through improper connections or
openings
D. Treated wastewater leaving a treatment plant
Correct Answer: C. Surface water entering the system through
improper connections or openings
Rationale: Inflow is water that enters the collection system from direct
sources such as roof drains, yard drains, stormwater connections, and
improperly sealed manholes. Unlike infiltration, inflow usually enters
directly and rapidly during rainfall.
, 6. Excessive infiltration and inflow can cause which operational
problem?
A. Reduced hydraulic loading
B. Increased treatment and pumping requirements
C. Elimination of maintenance needs
D. Decreased wastewater flow
Correct Answer: B. Increased treatment and pumping requirements
Rationale: Excessive infiltration and inflow increase the volume of water
transported through the collection system. This can overload pipes, lift
stations, and treatment facilities and increase pumping, treatment, and
maintenance costs.
7. What is the purpose of maintaining adequate velocity in a gravity
sewer?
A. To increase corrosion
B. To promote solids deposition
C. To help prevent solids from settling in the pipe
D. To reduce pipe capacity
Correct Answer: C. To help prevent solids from settling in the pipe
Rationale: Adequate flow velocity helps keep solids suspended and
moving through the collection system. Low velocities can allow solids,
grease, and debris to accumulate, increasing the risk of blockages.
