AK Sewage System Installer Exam
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary purpose of a sewage system?
A. Supply drinking water
B. Collect and treat wastewater
C. Irrigate crops
D. Pump oil
Rationale: A sewage system is designed to collect and treat wastewater to
prevent environmental contamination.
2. Which component of a sewage system prevents backflow?
A. Sump pump
B. Drainage pipe
C. Check valve
D. Septic tank
Rationale: A check valve allows flow in one direction and prevents
backflow of sewage.
3. What is the minimum slope recommended for a gravity sewer line?
A. 0.5%
B. 1%
C. 2%
D. 5%
,Rationale: A minimum slope of 2% ensures proper gravity flow and
prevents blockages.
4. Which material is commonly used for residential sewer piping?
A. Copper
B. PVC
C. Aluminum
D. Iron
Rationale: PVC is durable, resistant to corrosion, and commonly used for
residential sewer piping.
5. What is the main function of a septic tank?
A. Pump water to homes
B. Store drinking water
C. Separate solids from liquids in wastewater
D. Treat stormwater
Rationale: Septic tanks allow solids to settle while liquids flow to the drain
field for further treatment.
6. How often should a typical septic tank be pumped?
A. Every 6 months
B. Every 3–5 years
C. Every 10 years
D. Only when full
Rationale: Regular pumping prevents solids from overflowing into the
drain field and causing system failure.
7. What is a leach field designed to do?
A. Store wastewater
B. Filter rainwater
C. Disperse effluent into the soil
D. Collect stormwater
Rationale: Leach fields allow treated effluent to percolate into the ground,
further filtering contaminants.
, 8. Which safety equipment is essential when entering a confined sewage
tank?
A. Hard hat only
B. Gloves only
C. Respirator and gas detector
D. Earplugs
Rationale: Sewage tanks can contain toxic gases; respirators and gas
detectors prevent asphyxiation or poisoning.
9. What is the primary cause of sewage system blockages?
A. Excess water
B. Soil movement
C. Grease, roots, and foreign objects
D. High air pressure
Rationale: Grease, tree roots, and foreign objects are common causes of
clogs in sewage systems.
10. Which test ensures a newly installed sewer line is watertight?
A. pH test
B. Soil percolation test
C. Air or water pressure test
D. Temperature test
Rationale: Air or water pressure tests verify that pipes are sealed properly
and free from leaks.
11. What is the main purpose of a manhole in a sewage system?
A. Increase water pressure
B. Treat wastewater
C. Provide access for inspection and maintenance
D. Store sewage
Rationale: Manholes allow technicians to inspect, clean, and maintain
sewer lines.
12. How deep should a typical residential sewer main be buried to
avoid freezing?
Questions And Correct Answers
(Verified Answers) Plus Rationale2026
Q&A| Instant Download Pdf
1. What is the primary purpose of a sewage system?
A. Supply drinking water
B. Collect and treat wastewater
C. Irrigate crops
D. Pump oil
Rationale: A sewage system is designed to collect and treat wastewater to
prevent environmental contamination.
2. Which component of a sewage system prevents backflow?
A. Sump pump
B. Drainage pipe
C. Check valve
D. Septic tank
Rationale: A check valve allows flow in one direction and prevents
backflow of sewage.
3. What is the minimum slope recommended for a gravity sewer line?
A. 0.5%
B. 1%
C. 2%
D. 5%
,Rationale: A minimum slope of 2% ensures proper gravity flow and
prevents blockages.
4. Which material is commonly used for residential sewer piping?
A. Copper
B. PVC
C. Aluminum
D. Iron
Rationale: PVC is durable, resistant to corrosion, and commonly used for
residential sewer piping.
5. What is the main function of a septic tank?
A. Pump water to homes
B. Store drinking water
C. Separate solids from liquids in wastewater
D. Treat stormwater
Rationale: Septic tanks allow solids to settle while liquids flow to the drain
field for further treatment.
6. How often should a typical septic tank be pumped?
A. Every 6 months
B. Every 3–5 years
C. Every 10 years
D. Only when full
Rationale: Regular pumping prevents solids from overflowing into the
drain field and causing system failure.
7. What is a leach field designed to do?
A. Store wastewater
B. Filter rainwater
C. Disperse effluent into the soil
D. Collect stormwater
Rationale: Leach fields allow treated effluent to percolate into the ground,
further filtering contaminants.
, 8. Which safety equipment is essential when entering a confined sewage
tank?
A. Hard hat only
B. Gloves only
C. Respirator and gas detector
D. Earplugs
Rationale: Sewage tanks can contain toxic gases; respirators and gas
detectors prevent asphyxiation or poisoning.
9. What is the primary cause of sewage system blockages?
A. Excess water
B. Soil movement
C. Grease, roots, and foreign objects
D. High air pressure
Rationale: Grease, tree roots, and foreign objects are common causes of
clogs in sewage systems.
10. Which test ensures a newly installed sewer line is watertight?
A. pH test
B. Soil percolation test
C. Air or water pressure test
D. Temperature test
Rationale: Air or water pressure tests verify that pipes are sealed properly
and free from leaks.
11. What is the main purpose of a manhole in a sewage system?
A. Increase water pressure
B. Treat wastewater
C. Provide access for inspection and maintenance
D. Store sewage
Rationale: Manholes allow technicians to inspect, clean, and maintain
sewer lines.
12. How deep should a typical residential sewer main be buried to
avoid freezing?
