Tennessee Septic System Installer Licensing
Exam Practice Questions And Correct Answers
(Verified Answers) Plus Rationales
1. What is the primary purpose of a septic tank?
a) To treat drinking water
b) To store stormwater
c) To separate solids from wastewater and begin treatment
d) To aerate wastewater
Rationale: Septic tanks separate solids from liquids, allowing
partial treatment before effuent moves to the drainfield.
2. Which soil property is most important for a drainfield to function
properly?
a) Color
b) Permeability
c) Depth
d) Temperature
Rationale: Proper soil permeability ensures effuent percolates at a
rate suitable for treatment.
3. What is the minimum distance a septic tank must be from a
private well in Tennessee?
a) 10 feet
, b) 25 feet
c) 50 feet
d) 100 feet
Rationale: Regulations require a 50-foot separation to prevent
contamination of the water supply.
4. How often should a typical septic tank be pumped?
a) Every year
b) Every 2 years
c) Every 3–5 years
d) Every 10 years
Rationale: Pumping frequency depends on usage, but 3–5 years is
standard for average households.
5. What type of bacteria primarily breaks down solids in a septic
tank?
a) Aerobic bacteria
b) Anaerobic bacteria
c) Photosynthetic bacteria
d) Nitrogen-fixing bacteria
Rationale: Anaerobic bacteria decompose organic solids in the
oxygen-limited environment of a septic tank.
6. What is the main function of the distribution box in a septic
system?
a) To treat wastewater
b) To evenly distribute effluent to the drainfield trenches
c) To remove solids
d) To store efluent
, Rationale: The distribution box ensures effuent is evenly dispersed
across all drainfield lines.
7. What can cause a drainfield to fail?
a) Proper soil type
b) Correct system sizing
c) Excessive water use or poor maintenance
d) Regular pumping
Rationale: Overloading or neglect can saturate the soil, preventing
proper effuent absorption.
8. Which type of soil is least suitable for a conventional septic
drainfield?
a) Sandy soil
b) Clay soil
c) Loamy soil
d) Gravelly soil
Rationale: Clay soils drain poorly, which can cause system failure.
9. What is the primary regulatory agency for septic systems in
Tennessee?
a) Environmental Protection Agency
b) Department of Health
c) Tennessee Department of Environment & Conservation (TDEC)
d) U.S. Department of Agriculture
Rationale: TDEC sets rules and enforces regulations for septic
system installation and maintenance.
10. What is the purpose of a septic tank efluent filter?
a) To increase water flow
b) To aerate wastewater
Exam Practice Questions And Correct Answers
(Verified Answers) Plus Rationales
1. What is the primary purpose of a septic tank?
a) To treat drinking water
b) To store stormwater
c) To separate solids from wastewater and begin treatment
d) To aerate wastewater
Rationale: Septic tanks separate solids from liquids, allowing
partial treatment before effuent moves to the drainfield.
2. Which soil property is most important for a drainfield to function
properly?
a) Color
b) Permeability
c) Depth
d) Temperature
Rationale: Proper soil permeability ensures effuent percolates at a
rate suitable for treatment.
3. What is the minimum distance a septic tank must be from a
private well in Tennessee?
a) 10 feet
, b) 25 feet
c) 50 feet
d) 100 feet
Rationale: Regulations require a 50-foot separation to prevent
contamination of the water supply.
4. How often should a typical septic tank be pumped?
a) Every year
b) Every 2 years
c) Every 3–5 years
d) Every 10 years
Rationale: Pumping frequency depends on usage, but 3–5 years is
standard for average households.
5. What type of bacteria primarily breaks down solids in a septic
tank?
a) Aerobic bacteria
b) Anaerobic bacteria
c) Photosynthetic bacteria
d) Nitrogen-fixing bacteria
Rationale: Anaerobic bacteria decompose organic solids in the
oxygen-limited environment of a septic tank.
6. What is the main function of the distribution box in a septic
system?
a) To treat wastewater
b) To evenly distribute effluent to the drainfield trenches
c) To remove solids
d) To store efluent
, Rationale: The distribution box ensures effuent is evenly dispersed
across all drainfield lines.
7. What can cause a drainfield to fail?
a) Proper soil type
b) Correct system sizing
c) Excessive water use or poor maintenance
d) Regular pumping
Rationale: Overloading or neglect can saturate the soil, preventing
proper effuent absorption.
8. Which type of soil is least suitable for a conventional septic
drainfield?
a) Sandy soil
b) Clay soil
c) Loamy soil
d) Gravelly soil
Rationale: Clay soils drain poorly, which can cause system failure.
9. What is the primary regulatory agency for septic systems in
Tennessee?
a) Environmental Protection Agency
b) Department of Health
c) Tennessee Department of Environment & Conservation (TDEC)
d) U.S. Department of Agriculture
Rationale: TDEC sets rules and enforces regulations for septic
system installation and maintenance.
10. What is the purpose of a septic tank efluent filter?
a) To increase water flow
b) To aerate wastewater
