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 primarily provides initial treatment of domestic
wastewater in a subsurface sewage treatment system?
A. Distribution box
B. Septic tank
C. Soil absorption trench
D. Effluent pump chamber
The septic tank provides primary treatment by allowing solids to
settle, fats to float, and anaerobic digestion to begin reducing
organic matter before effluent moves to secondary treatment.
,2. The main purpose of a soil absorption system is to:
A. Store raw sewage
B. Treat effluent through soil filtration and microbial activity
C. Pump wastewater to a higher elevation
D. Separate grease from wastewater
Soil absorption systems disperse effluent into soil where natural
biological, chemical, and physical processes further treat
wastewater.
3. Which soil characteristic is MOST critical when evaluating a site for an
SSTS?
A. Soil color only
B. Surface vegetation type
C. Percolation rate and texture
D. Air temperature
Percolation rate and soil texture determine how quickly effluent can
be absorbed and treated safely in the soil.
4. A distribution box is used to:
A. Treat wastewater biologically
B. Store sludge
C. Evenly distribute effluent to multiple trenches
D. Aerate sewage
A distribution box ensures uniform flow to all soil absorption
components to prevent overloading one section.
, 5. Which of the following indicates a failing septic system?
A. Clear effluent discharge
B. Proper vegetation growth
C. Sewage surfacing in the yard
D. Low water usage
Surfacing sewage indicates system overload or soil failure, posing
health and environmental risks.
6. The minimum separation distance between a septic system and a
private well is primarily to:
A. Improve drainage
B. Reduce installation cost
C. Prevent contamination of drinking water
D. Increase oxygen levels in soil
Separation distances prevent pathogens and nitrates from
contaminating groundwater sources.
7. Effluent leaving a properly functioning septic tank is typically:
A. Sterile
B. Drinking water quality
C. Partially clarified but still containing pathogens
D. Completely solid-free and safe
Septic tank effluent still contains microorganisms and requires soil
treatment.
Treatment System Intermediate
Installer Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which component primarily provides initial treatment of domestic
wastewater in a subsurface sewage treatment system?
A. Distribution box
B. Septic tank
C. Soil absorption trench
D. Effluent pump chamber
The septic tank provides primary treatment by allowing solids to
settle, fats to float, and anaerobic digestion to begin reducing
organic matter before effluent moves to secondary treatment.
,2. The main purpose of a soil absorption system is to:
A. Store raw sewage
B. Treat effluent through soil filtration and microbial activity
C. Pump wastewater to a higher elevation
D. Separate grease from wastewater
Soil absorption systems disperse effluent into soil where natural
biological, chemical, and physical processes further treat
wastewater.
3. Which soil characteristic is MOST critical when evaluating a site for an
SSTS?
A. Soil color only
B. Surface vegetation type
C. Percolation rate and texture
D. Air temperature
Percolation rate and soil texture determine how quickly effluent can
be absorbed and treated safely in the soil.
4. A distribution box is used to:
A. Treat wastewater biologically
B. Store sludge
C. Evenly distribute effluent to multiple trenches
D. Aerate sewage
A distribution box ensures uniform flow to all soil absorption
components to prevent overloading one section.
, 5. Which of the following indicates a failing septic system?
A. Clear effluent discharge
B. Proper vegetation growth
C. Sewage surfacing in the yard
D. Low water usage
Surfacing sewage indicates system overload or soil failure, posing
health and environmental risks.
6. The minimum separation distance between a septic system and a
private well is primarily to:
A. Improve drainage
B. Reduce installation cost
C. Prevent contamination of drinking water
D. Increase oxygen levels in soil
Separation distances prevent pathogens and nitrates from
contaminating groundwater sources.
7. Effluent leaving a properly functioning septic tank is typically:
A. Sterile
B. Drinking water quality
C. Partially clarified but still containing pathogens
D. Completely solid-free and safe
Septic tank effluent still contains microorganisms and requires soil
treatment.
