Florida (FL) Septic Tank Contractor Practice
Exam 2026
Prepare to pass the Florida Septic Tank Contractor Exam 2026 with confidence! This 300-
question practice guide covers all essential topics including system design, installation,
maintenance, effluent management, safety, and Florida laws (Ch. 64E-6 F.A.C., Ch. 381 F.S.).
Each question includes a detailed rationale, helping you understand concepts and avoid
common mistakes.
1. In Florida, onsite sewage treatment and disposal systems (OSTDS) such as septic tanks
are primarily regulated by which agency?
A. Florida Department of Environmental Protection
B. U.S. Environmental Protection Agency
C. Florida Department of Health
D. County Public Works Department
Correct Answer: C
Rationale: The Florida Department of Health (DOH) administers the OSTDS program,
including permitting, inspections, contractor licensing, and regulatory enforcement for septic
systems.
2. The primary purpose of a septic tank is to:
A. Disinfect wastewater
B. Separate solids from wastewater before it enters the drainfield
,C. Pump sewage to municipal treatment plants
D. Add oxygen to wastewater
Correct Answer: B
Rationale: A septic tank allows heavier solids to settle as sludge while lighter materials float as
scum. The clarified liquid (effluent) then flows to the drainfield for further treatment.
3. The liquid leaving the septic tank and entering the soil absorption system is called:
A. Sludge
B. Sewage
C. Effluent
D. Leachate
Correct Answer: C
Rationale: Effluent is partially treated wastewater that exits the septic tank and flows into the
drainfield where soil treatment occurs.
4. Which component helps ensure wastewater is distributed evenly to multiple drainfield
trenches?
A. Septic riser
B. Effluent filter
C. Distribution box
D. Pump chamber
Correct Answer: C
,Rationale: A distribution box (D-box) splits the effluent flow evenly among multiple drainfield
lines to prevent overloading a single trench.
5. What is the typical minimum septic tank capacity for a standard single-family residence?
A. 500 gallons
B. 750 gallons
C. 1,000 gallons
D. 2,500 gallons
Correct Answer: C
Rationale: Most residential septic systems require a minimum 1,000-gallon tank, although
larger homes may require larger tanks based on occupancy or bedroom count.
6. The scum layer in a septic tank consists primarily of:
A. Settled sand and soil
B. Fats, oils, grease, and floating debris
C. Groundwater infiltration
D. Dissolved chemicals
Correct Answer: B
Rationale: Grease, oils, and floating organic matter rise to the top of the tank, forming the scum
layer, which must be contained within the tank.
7. The sludge layer inside a septic tank forms:
, A. At the surface of the tank
B. In the outlet pipe
C. At the bottom of the tank
D. Inside the drainfield
Correct Answer: C
Rationale: Heavier solids settle at the bottom of the septic tank forming the sludge layer, which
must be periodically removed through pumping.
8. A percolation test is performed to determine:
A. Tank capacity
B. Wastewater strength
C. Soil absorption rate
D. Pipe pressure
Correct Answer: C
Rationale: A percolation (perc) test measures how quickly water moves through soil, which
determines the suitability and design size of a septic drainfield.
9. Which soil type is generally most suitable for a conventional septic drainfield?
A. Clay soil
B. Bedrock
C. Saturated soil
D. Sandy, well-drained soil
Correct Answer: D
Exam 2026
Prepare to pass the Florida Septic Tank Contractor Exam 2026 with confidence! This 300-
question practice guide covers all essential topics including system design, installation,
maintenance, effluent management, safety, and Florida laws (Ch. 64E-6 F.A.C., Ch. 381 F.S.).
Each question includes a detailed rationale, helping you understand concepts and avoid
common mistakes.
1. In Florida, onsite sewage treatment and disposal systems (OSTDS) such as septic tanks
are primarily regulated by which agency?
A. Florida Department of Environmental Protection
B. U.S. Environmental Protection Agency
C. Florida Department of Health
D. County Public Works Department
Correct Answer: C
Rationale: The Florida Department of Health (DOH) administers the OSTDS program,
including permitting, inspections, contractor licensing, and regulatory enforcement for septic
systems.
2. The primary purpose of a septic tank is to:
A. Disinfect wastewater
B. Separate solids from wastewater before it enters the drainfield
,C. Pump sewage to municipal treatment plants
D. Add oxygen to wastewater
Correct Answer: B
Rationale: A septic tank allows heavier solids to settle as sludge while lighter materials float as
scum. The clarified liquid (effluent) then flows to the drainfield for further treatment.
3. The liquid leaving the septic tank and entering the soil absorption system is called:
A. Sludge
B. Sewage
C. Effluent
D. Leachate
Correct Answer: C
Rationale: Effluent is partially treated wastewater that exits the septic tank and flows into the
drainfield where soil treatment occurs.
4. Which component helps ensure wastewater is distributed evenly to multiple drainfield
trenches?
A. Septic riser
B. Effluent filter
C. Distribution box
D. Pump chamber
Correct Answer: C
,Rationale: A distribution box (D-box) splits the effluent flow evenly among multiple drainfield
lines to prevent overloading a single trench.
5. What is the typical minimum septic tank capacity for a standard single-family residence?
A. 500 gallons
B. 750 gallons
C. 1,000 gallons
D. 2,500 gallons
Correct Answer: C
Rationale: Most residential septic systems require a minimum 1,000-gallon tank, although
larger homes may require larger tanks based on occupancy or bedroom count.
6. The scum layer in a septic tank consists primarily of:
A. Settled sand and soil
B. Fats, oils, grease, and floating debris
C. Groundwater infiltration
D. Dissolved chemicals
Correct Answer: B
Rationale: Grease, oils, and floating organic matter rise to the top of the tank, forming the scum
layer, which must be contained within the tank.
7. The sludge layer inside a septic tank forms:
, A. At the surface of the tank
B. In the outlet pipe
C. At the bottom of the tank
D. Inside the drainfield
Correct Answer: C
Rationale: Heavier solids settle at the bottom of the septic tank forming the sludge layer, which
must be periodically removed through pumping.
8. A percolation test is performed to determine:
A. Tank capacity
B. Wastewater strength
C. Soil absorption rate
D. Pipe pressure
Correct Answer: C
Rationale: A percolation (perc) test measures how quickly water moves through soil, which
determines the suitability and design size of a septic drainfield.
9. Which soil type is generally most suitable for a conventional septic drainfield?
A. Clay soil
B. Bedrock
C. Saturated soil
D. Sandy, well-drained soil
Correct Answer: D
