AK Sewage System Installer Exam —
Practice Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
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1. What is the primary purpose of a septic tank in an onsite wastewater
system?
A. Disinfect wastewater
B. Store drinking water
C. Settle solids and provide anaerobic treatment
D. Pump wastewater directly into soil
Answer: C. Settle solids and provide anaerobic treatment
Rationale: A septic tank separates solids and floatable materials from
wastewater and provides limited anaerobic biological treatment before
effluent enters the soil treatment system.
, 2. Which component normally receives wastewater after it leaves a
septic tank?
A. Water meter
B. Soil absorption system
C. Backflow preventer
D. Roof drain
Answer: B. Soil absorption system
Rationale: Septic tank effluent is conveyed to a soil treatment or
absorption system where the soil provides additional treatment and
dispersal.
3. What is the main function of the soil in an onsite wastewater
treatment system?
A. Increase wastewater temperature
B. Store household chemicals
C. Filter, treat, and disperse wastewater
D. Increase wastewater flow
Answer: C. Filter, treat, and disperse wastewater
Rationale: Properly selected and constructed soil provides physical,
chemical, and biological treatment while allowing effluent to disperse.
, 4. Why is a percolation or soil evaluation important before installing a
sewage system?
A. To determine the home's electrical load
B. To determine the roof pitch
C. To determine whether the soil can adequately accept and treat
wastewater
D. To determine the septic tank color
Answer: C. To determine whether the soil can adequately accept and treat
wastewater
Rationale: Soil characteristics strongly influence the design, sizing, and
suitability of a wastewater treatment area.
5. Which soil characteristic is particularly important when evaluating a
soil absorption area?
A. Paint color
B. Permeability
C. Building height
D. Water heater size
Answer: B. Permeability
, Rationale: Soil permeability affects how rapidly effluent can move through
the treatment area and whether adequate treatment and dispersal can
occur.
6. What is the purpose of maintaining separation from groundwater
when installing a soil absorption system?
A. To increase water pressure
B. To keep groundwater warm
C. To protect groundwater and provide adequate treatment
D. To reduce septic tank capacity
Answer: C. To protect groundwater and provide adequate treatment
Rationale: Adequate separation allows the soil to provide treatment
before effluent can reach groundwater.
7. Which condition is generally undesirable for a conventional soil
absorption area?
A. Suitable unsaturated soil
B. Proper separation from limiting layers
C. Seasonally saturated soil
D. Proper drainage
Answer: C. Seasonally saturated soil
Practice Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary purpose of a septic tank in an onsite wastewater
system?
A. Disinfect wastewater
B. Store drinking water
C. Settle solids and provide anaerobic treatment
D. Pump wastewater directly into soil
Answer: C. Settle solids and provide anaerobic treatment
Rationale: A septic tank separates solids and floatable materials from
wastewater and provides limited anaerobic biological treatment before
effluent enters the soil treatment system.
, 2. Which component normally receives wastewater after it leaves a
septic tank?
A. Water meter
B. Soil absorption system
C. Backflow preventer
D. Roof drain
Answer: B. Soil absorption system
Rationale: Septic tank effluent is conveyed to a soil treatment or
absorption system where the soil provides additional treatment and
dispersal.
3. What is the main function of the soil in an onsite wastewater
treatment system?
A. Increase wastewater temperature
B. Store household chemicals
C. Filter, treat, and disperse wastewater
D. Increase wastewater flow
Answer: C. Filter, treat, and disperse wastewater
Rationale: Properly selected and constructed soil provides physical,
chemical, and biological treatment while allowing effluent to disperse.
, 4. Why is a percolation or soil evaluation important before installing a
sewage system?
A. To determine the home's electrical load
B. To determine the roof pitch
C. To determine whether the soil can adequately accept and treat
wastewater
D. To determine the septic tank color
Answer: C. To determine whether the soil can adequately accept and treat
wastewater
Rationale: Soil characteristics strongly influence the design, sizing, and
suitability of a wastewater treatment area.
5. Which soil characteristic is particularly important when evaluating a
soil absorption area?
A. Paint color
B. Permeability
C. Building height
D. Water heater size
Answer: B. Permeability
, Rationale: Soil permeability affects how rapidly effluent can move through
the treatment area and whether adequate treatment and dispersal can
occur.
6. What is the purpose of maintaining separation from groundwater
when installing a soil absorption system?
A. To increase water pressure
B. To keep groundwater warm
C. To protect groundwater and provide adequate treatment
D. To reduce septic tank capacity
Answer: C. To protect groundwater and provide adequate treatment
Rationale: Adequate separation allows the soil to provide treatment
before effluent can reach groundwater.
7. Which condition is generally undesirable for a conventional soil
absorption area?
A. Suitable unsaturated soil
B. Proper separation from limiting layers
C. Seasonally saturated soil
D. Proper drainage
Answer: C. Seasonally saturated soil
