Minnesota Subsurface Sewage
Treatment System Advanced Installer
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. In a subsurface sewage treatment system (SSTS), the primary purpose
of the septic tank is to:
A. Disinfect wastewater completely
B. Remove all dissolved solids
C. Settle solids and provide anaerobic treatment
D. Increase soil absorption rates
Answer: C. Settle solids and provide anaerobic treatment
,The septic tank allows solids to settle as sludge and scum while anaerobic
bacteria partially break down organic matter before effluent enters the
soil treatment system.
2. The advanced installer must evaluate soil texture primarily because it
determines:
A. Pump horsepower only
B. Wastewater temperature
C. Treatment and dispersal capability
D. Septic tank color requirements
Answer: C. Treatment and dispersal capability
Soil texture affects hydraulic conductivity, treatment performance, and the
ability of soil to properly accept and treat wastewater.
3. The limiting soil layer in an SSTS site evaluation is important because
it:
A. Determines the minimum setback distance only
B. Controls how wastewater can be treated and dispersed
C. Determines the tank manufacturer
D. Eliminates the need for design calculations
Answer: B. Controls how wastewater can be treated and dispersed
,Limiting layers such as bedrock, groundwater, or unsuitable soils restrict
treatment depth and influence system design.
4. The vertical separation distance in an advanced SSTS design refers to
the distance between:
A. Tank inlet and outlet pipes
B. Distribution pipe and property boundary
C. Bottom of dispersal media and limiting soil layer
D. Pump tank and electrical panel
Answer: C. Bottom of dispersal media and limiting soil layer
Vertical separation provides adequate unsaturated soil depth for
wastewater treatment before reaching groundwater or restrictive layers.
5. A pressure distribution system is designed to:
A. Deliver equal wastewater distribution throughout the soil
treatment area
B. Eliminate the need for septic tanks
C. Increase wastewater strength
D. Replace soil treatment entirely
Answer: A. Deliver equal wastewater distribution throughout the soil
treatment area
, Pressure distribution uses pumps and small-diameter piping to apply
effluent evenly across the treatment area.
6. The most important reason for maintaining accurate installation
records is to:
A. Reduce construction costs
B. Document compliance and future system location
C. Increase tank capacity
D. Eliminate maintenance needs
Answer: B. Document compliance and future system location
As-built records help regulators and property owners understand system
components, location, and compliance status.
7. The advanced installer must protect the soil treatment area from
compaction because compaction:
A. Improves infiltration
B. Reduces soil treatment capacity
C. Increases oxygen transfer
D. Prevents wastewater flow
Answer: B. Reduces soil treatment capacity
Heavy equipment can compress soil pores, reducing infiltration rates and
harming treatment performance.
Treatment System Advanced Installer
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. In a subsurface sewage treatment system (SSTS), the primary purpose
of the septic tank is to:
A. Disinfect wastewater completely
B. Remove all dissolved solids
C. Settle solids and provide anaerobic treatment
D. Increase soil absorption rates
Answer: C. Settle solids and provide anaerobic treatment
,The septic tank allows solids to settle as sludge and scum while anaerobic
bacteria partially break down organic matter before effluent enters the
soil treatment system.
2. The advanced installer must evaluate soil texture primarily because it
determines:
A. Pump horsepower only
B. Wastewater temperature
C. Treatment and dispersal capability
D. Septic tank color requirements
Answer: C. Treatment and dispersal capability
Soil texture affects hydraulic conductivity, treatment performance, and the
ability of soil to properly accept and treat wastewater.
3. The limiting soil layer in an SSTS site evaluation is important because
it:
A. Determines the minimum setback distance only
B. Controls how wastewater can be treated and dispersed
C. Determines the tank manufacturer
D. Eliminates the need for design calculations
Answer: B. Controls how wastewater can be treated and dispersed
,Limiting layers such as bedrock, groundwater, or unsuitable soils restrict
treatment depth and influence system design.
4. The vertical separation distance in an advanced SSTS design refers to
the distance between:
A. Tank inlet and outlet pipes
B. Distribution pipe and property boundary
C. Bottom of dispersal media and limiting soil layer
D. Pump tank and electrical panel
Answer: C. Bottom of dispersal media and limiting soil layer
Vertical separation provides adequate unsaturated soil depth for
wastewater treatment before reaching groundwater or restrictive layers.
5. A pressure distribution system is designed to:
A. Deliver equal wastewater distribution throughout the soil
treatment area
B. Eliminate the need for septic tanks
C. Increase wastewater strength
D. Replace soil treatment entirely
Answer: A. Deliver equal wastewater distribution throughout the soil
treatment area
, Pressure distribution uses pumps and small-diameter piping to apply
effluent evenly across the treatment area.
6. The most important reason for maintaining accurate installation
records is to:
A. Reduce construction costs
B. Document compliance and future system location
C. Increase tank capacity
D. Eliminate maintenance needs
Answer: B. Document compliance and future system location
As-built records help regulators and property owners understand system
components, location, and compliance status.
7. The advanced installer must protect the soil treatment area from
compaction because compaction:
A. Improves infiltration
B. Reduces soil treatment capacity
C. Increases oxygen transfer
D. Prevents wastewater flow
Answer: B. Reduces soil treatment capacity
Heavy equipment can compress soil pores, reducing infiltration rates and
harming treatment performance.
