KENTUCKY CERTIFIED SEPTIC SYSTEM
INSTALLER PRACTICE EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which of the following is the primary purpose of a septic system?
A. Increase soil fertility
B. Treat and dispose of household wastewater **
C. Store rainwater
D. Provide irrigation water
Rationale: A septic system is designed to treat and safely dispose of
household wastewater onsite.
2. What is the minimum recommended distance between a septic
tank and a water well?
A. 25 feet
B. 50 feet
C. 100 feet **
D. 200 feet
Rationale: Kentucky regulations generally require a minimum of 100
feet between a septic tank and any potable water source to prevent
contamination.
,3. Which soil type is least suitable for a conventional septic system?
A. Sandy soil
B. Loamy soil
C. Clay soil **
D. Gravel
Rationale: Clay soil has poor permeability, which can prevent proper
drainage and treatment in a septic system.
4. What is the typical lifespan of a properly maintained septic tank?
A. 5-10 years
B. 15-20 years
C. 20-30 years **
D. 40-50 years
Rationale: With proper maintenance, septic tanks can last 20-30 years
before replacement is needed.
5. What is the main function of the distribution box in a septic
system?
A. Treat wastewater
B. Evenly distribute effluent to drainfield lines **
C. Filter solids from wastewater
D. Store wastewater temporarily
Rationale: The distribution box ensures effluent is evenly spread to the
leach field trenches.
6. How often should a typical septic tank be pumped?
A. Every 1 year
,B. Every 3-5 years **
C. Every 10 years
D. Only when it overflows
Rationale: Pumping every 3-5 years prevents solids from entering the
drainfield, prolonging system life.
7. Which component prevents solids from leaving the septic tank and
entering the drainfield?
A. Effluent filter **
B. Baffle
C. Lid
D. Vent pipe
Rationale: An effluent filter traps solids and prevents clogging of the
drainfield.
8. Which of the following is NOT recommended for disposal into a
septic system?
A. Laundry wastewater
B. Cooking oils and grease **
C. Toilet wastewater
D. Bathroom sink wastewater
Rationale: Cooking oils and grease can clog the system and should not
be disposed of in a septic system.
9. What is the typical slope required for septic tank inlet and outlet
pipes?
A. 1/8 inch per foot
, B. 1/4 inch per foot **
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: A slope of 1/4 inch per foot allows proper flow of wastewater
without causing backups.
10. Which of the following inspections is required before backfilling a
septic tank?
A. Soil test
B. Tank volume verification **
C. Water test
D. Landscaping approval
Rationale: Inspectors verify the tank is properly sized and installed
before backfilling.
11. What type of septic system is recommended for soils with poor
drainage?
A. Conventional gravity system
B. Mound system **
C. Sand filter system
D. Lagoon system
Rationale: Mound systems elevate the drainfield to allow adequate
treatment in poorly draining soils.
12. Which of the following is a sign that a septic system may be
failing?
A. Lush green grass over the drainfield
INSTALLER PRACTICE EXAM QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which of the following is the primary purpose of a septic system?
A. Increase soil fertility
B. Treat and dispose of household wastewater **
C. Store rainwater
D. Provide irrigation water
Rationale: A septic system is designed to treat and safely dispose of
household wastewater onsite.
2. What is the minimum recommended distance between a septic
tank and a water well?
A. 25 feet
B. 50 feet
C. 100 feet **
D. 200 feet
Rationale: Kentucky regulations generally require a minimum of 100
feet between a septic tank and any potable water source to prevent
contamination.
,3. Which soil type is least suitable for a conventional septic system?
A. Sandy soil
B. Loamy soil
C. Clay soil **
D. Gravel
Rationale: Clay soil has poor permeability, which can prevent proper
drainage and treatment in a septic system.
4. What is the typical lifespan of a properly maintained septic tank?
A. 5-10 years
B. 15-20 years
C. 20-30 years **
D. 40-50 years
Rationale: With proper maintenance, septic tanks can last 20-30 years
before replacement is needed.
5. What is the main function of the distribution box in a septic
system?
A. Treat wastewater
B. Evenly distribute effluent to drainfield lines **
C. Filter solids from wastewater
D. Store wastewater temporarily
Rationale: The distribution box ensures effluent is evenly spread to the
leach field trenches.
6. How often should a typical septic tank be pumped?
A. Every 1 year
,B. Every 3-5 years **
C. Every 10 years
D. Only when it overflows
Rationale: Pumping every 3-5 years prevents solids from entering the
drainfield, prolonging system life.
7. Which component prevents solids from leaving the septic tank and
entering the drainfield?
A. Effluent filter **
B. Baffle
C. Lid
D. Vent pipe
Rationale: An effluent filter traps solids and prevents clogging of the
drainfield.
8. Which of the following is NOT recommended for disposal into a
septic system?
A. Laundry wastewater
B. Cooking oils and grease **
C. Toilet wastewater
D. Bathroom sink wastewater
Rationale: Cooking oils and grease can clog the system and should not
be disposed of in a septic system.
9. What is the typical slope required for septic tank inlet and outlet
pipes?
A. 1/8 inch per foot
, B. 1/4 inch per foot **
C. 1/2 inch per foot
D. 1 inch per foot
Rationale: A slope of 1/4 inch per foot allows proper flow of wastewater
without causing backups.
10. Which of the following inspections is required before backfilling a
septic tank?
A. Soil test
B. Tank volume verification **
C. Water test
D. Landscaping approval
Rationale: Inspectors verify the tank is properly sized and installed
before backfilling.
11. What type of septic system is recommended for soils with poor
drainage?
A. Conventional gravity system
B. Mound system **
C. Sand filter system
D. Lagoon system
Rationale: Mound systems elevate the drainfield to allow adequate
treatment in poorly draining soils.
12. Which of the following is a sign that a septic system may be
failing?
A. Lush green grass over the drainfield
