Minnesota Subsurface Sewage
Treatment System Intermediate
Installer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which component of a Subsurface Sewage Treatment System (SSTS) is
primarily responsible for separating solids from liquid wastewater
before treatment occurs in the soil?
A. Distribution box
B. Septic tank
C. Soil dispersal trench
D. Pump tank
Answer: B. Septic tank
,The septic tank allows solids to settle as sludge and fats/oils to float as
scum while partially clarified effluent moves to the treatment area.
2. The main purpose of a soil treatment area in an SSTS is to:
A. Store wastewater permanently
B. Remove all solids mechanically
C. Provide biological treatment and dispersal
D. Increase wastewater temperature
Answer: C. Provide biological treatment and dispersal
The soil treatment area uses microorganisms and soil filtration processes
to treat effluent while allowing controlled absorption into the ground.
3. In Minnesota SSTS installation, a designer must evaluate the soil
primarily to determine:
A. Property value
B. Treatment capability and hydraulic loading
C. Landscape appearance
D. Pipe color requirements
Answer: B. Treatment capability and hydraulic loading
Soil characteristics determine whether wastewater can be adequately
treated and dispersed without causing failures.
, 4. Which soil characteristic has the greatest effect on wastewater
movement through soil?
A. Soil color only
B. Texture and structure
C. Rock size only
D. Surface vegetation
Answer: B. Texture and structure
Soil texture and structure control permeability, treatment capacity, and
the movement of effluent through the soil profile.
5. A septic tank outlet filter is designed to:
A. Increase tank volume
B. Prevent solids from leaving the tank
C. Add chlorine to wastewater
D. Pump wastewater faster
Answer: B. Prevent solids from leaving the tank
Outlet filters protect the soil treatment area by reducing the amount of
suspended solids discharged from the tank.
6. The liquid depth of a typical septic tank is important because it:
, A. Controls settling and retention time
B. Determines soil texture
C. Eliminates groundwater
D. Increases pipe slope
Answer: A. Controls settling and retention time
Adequate liquid depth provides enough time for solids separation and
biological processes.
7. The purpose of a distribution box is to:
A. Collect sludge
B. Evenly distribute effluent to trenches
C. Treat sewage chemically
D. Vent the plumbing system
Answer: B. Evenly distribute effluent to trenches
A distribution box directs effluent equally among multiple soil treatment
trenches.
8. Pressure distribution systems are used primarily to:
A. Eliminate septic tanks
B. Apply effluent evenly throughout the soil treatment area
Treatment System Intermediate
Installer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which component of a Subsurface Sewage Treatment System (SSTS) is
primarily responsible for separating solids from liquid wastewater
before treatment occurs in the soil?
A. Distribution box
B. Septic tank
C. Soil dispersal trench
D. Pump tank
Answer: B. Septic tank
,The septic tank allows solids to settle as sludge and fats/oils to float as
scum while partially clarified effluent moves to the treatment area.
2. The main purpose of a soil treatment area in an SSTS is to:
A. Store wastewater permanently
B. Remove all solids mechanically
C. Provide biological treatment and dispersal
D. Increase wastewater temperature
Answer: C. Provide biological treatment and dispersal
The soil treatment area uses microorganisms and soil filtration processes
to treat effluent while allowing controlled absorption into the ground.
3. In Minnesota SSTS installation, a designer must evaluate the soil
primarily to determine:
A. Property value
B. Treatment capability and hydraulic loading
C. Landscape appearance
D. Pipe color requirements
Answer: B. Treatment capability and hydraulic loading
Soil characteristics determine whether wastewater can be adequately
treated and dispersed without causing failures.
, 4. Which soil characteristic has the greatest effect on wastewater
movement through soil?
A. Soil color only
B. Texture and structure
C. Rock size only
D. Surface vegetation
Answer: B. Texture and structure
Soil texture and structure control permeability, treatment capacity, and
the movement of effluent through the soil profile.
5. A septic tank outlet filter is designed to:
A. Increase tank volume
B. Prevent solids from leaving the tank
C. Add chlorine to wastewater
D. Pump wastewater faster
Answer: B. Prevent solids from leaving the tank
Outlet filters protect the soil treatment area by reducing the amount of
suspended solids discharged from the tank.
6. The liquid depth of a typical septic tank is important because it:
, A. Controls settling and retention time
B. Determines soil texture
C. Eliminates groundwater
D. Increases pipe slope
Answer: A. Controls settling and retention time
Adequate liquid depth provides enough time for solids separation and
biological processes.
7. The purpose of a distribution box is to:
A. Collect sludge
B. Evenly distribute effluent to trenches
C. Treat sewage chemically
D. Vent the plumbing system
Answer: B. Evenly distribute effluent to trenches
A distribution box directs effluent equally among multiple soil treatment
trenches.
8. Pressure distribution systems are used primarily to:
A. Eliminate septic tanks
B. Apply effluent evenly throughout the soil treatment area
