Wastewater Collection Technician Level I
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. To treat wastewater before use
B. To transport wastewater from homes and businesses to
treatment facilities
C. To produce potable water
D. To recycle stormwater
Rationale: The collection system’s main function is to safely convey
wastewater to treatment plants, not treat it on-site.
2. Which type of pipe is most commonly used in gravity sewer
systems?
A. Copper
B. PVC (Polyvinyl Chloride)
C. Steel
D. Asbestos
Rationale: PVC is durable, corrosion-resistant, and cost-effective for
gravity sewers.
3. What is the minimum slope typically required for a 6-inch
diameter sewer pipe?
A. 0.25%
, B. 0.5%
C. 1%
D. 2%
Rationale: A 1% slope ensures adequate flow velocity to prevent solids
from settling in a 6-inch sewer pipe.
4. What is the function of a manhole in a sewer system?
A. To treat wastewater
B. To increase flow velocity
C. To provide access for inspection, cleaning, and maintenance
D. To separate solids from liquids
Rationale: Manholes allow personnel to access pipelines for
maintenance and inspection.
5. What type of wastewater is typically handled by a collection
system?
A. Stormwater only
B. Industrial wastewater only
C. Domestic and commercial wastewater
D. Potable water
Rationale: Wastewater collection systems primarily handle sewage from
homes, businesses, and some industrial sources.
6. Which of the following is a common cause of sewer blockages?
A. High water flow
B. Excess slope
C. Grease, roots, and debris
D. Proper maintenance
, Rationale: Blockages often occur due to foreign materials entering the
system.
7. What is the purpose of a lift station in a wastewater collection
system?
A. To filter wastewater
B. To pump wastewater from lower elevations to higher
elevations
C. To remove solids
D. To chlorinate effluent
Rationale: Lift stations move wastewater where gravity flow is
insufficient.
8. What is a typical sign of a sewer backup in a residential area?
A. Slow drain only
B. Water rising in toilets or drains
C. Clear water in pipes
D. Strong airflow in vents
Rationale: Rising water indicates wastewater cannot flow freely,
signaling a blockage.
9. Which type of valve is commonly used in sewer force mains?
A. Check valve
B. Gate valve
C. Butterfly valve
D. Globe valve
Rationale: Gate valves are durable and provide full open or close,
suitable for force mains.
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. To treat wastewater before use
B. To transport wastewater from homes and businesses to
treatment facilities
C. To produce potable water
D. To recycle stormwater
Rationale: The collection system’s main function is to safely convey
wastewater to treatment plants, not treat it on-site.
2. Which type of pipe is most commonly used in gravity sewer
systems?
A. Copper
B. PVC (Polyvinyl Chloride)
C. Steel
D. Asbestos
Rationale: PVC is durable, corrosion-resistant, and cost-effective for
gravity sewers.
3. What is the minimum slope typically required for a 6-inch
diameter sewer pipe?
A. 0.25%
, B. 0.5%
C. 1%
D. 2%
Rationale: A 1% slope ensures adequate flow velocity to prevent solids
from settling in a 6-inch sewer pipe.
4. What is the function of a manhole in a sewer system?
A. To treat wastewater
B. To increase flow velocity
C. To provide access for inspection, cleaning, and maintenance
D. To separate solids from liquids
Rationale: Manholes allow personnel to access pipelines for
maintenance and inspection.
5. What type of wastewater is typically handled by a collection
system?
A. Stormwater only
B. Industrial wastewater only
C. Domestic and commercial wastewater
D. Potable water
Rationale: Wastewater collection systems primarily handle sewage from
homes, businesses, and some industrial sources.
6. Which of the following is a common cause of sewer blockages?
A. High water flow
B. Excess slope
C. Grease, roots, and debris
D. Proper maintenance
, Rationale: Blockages often occur due to foreign materials entering the
system.
7. What is the purpose of a lift station in a wastewater collection
system?
A. To filter wastewater
B. To pump wastewater from lower elevations to higher
elevations
C. To remove solids
D. To chlorinate effluent
Rationale: Lift stations move wastewater where gravity flow is
insufficient.
8. What is a typical sign of a sewer backup in a residential area?
A. Slow drain only
B. Water rising in toilets or drains
C. Clear water in pipes
D. Strong airflow in vents
Rationale: Rising water indicates wastewater cannot flow freely,
signaling a blockage.
9. Which type of valve is commonly used in sewer force mains?
A. Check valve
B. Gate valve
C. Butterfly valve
D. Globe valve
Rationale: Gate valves are durable and provide full open or close,
suitable for force mains.
