FLORIDA (FL) SEPTIC TANK CONTRACTOR EXAM | 2 CURRENTLY
TESTING EXAM VERSIONS WITH ACCURATE REAL EXAM QUESTIONS
AND ANSWERS WITH RATIONALES | EXPERT VERIFIED FOR
GUARANTEED PASS | LATEST UPDATE
Question 1
Which state agency is primarily responsible for the regulation, permitting, and certification of
Onsite Sewage Treatment and Disposal Systems (OSTDS) in Florida?
A) Florida Department of Environmental Protection (FDEP)
B) Florida Department of Health (FDOH)
C) Florida Department of Business and Professional Regulation (DBPR)
D) The local Water Management District
E) The U.S. Environmental Protection Agency (EPA)
Correct Answer: B) Florida Department of Health (FDOH)
Rationale: The Florida Department of Health, through its county health departments
(CHDs), is the lead agency with statutory authority under Chapter 381, Florida Statutes,
and Chapter 62-6, Florida Administrative Code, to regulate the siting, construction, and
repair of all OSTDS in the state.
Question 2
According to Florida Administrative Code (F.A.C.) Chapter 62-6, what is the minimum required
septic tank size for a new three-bedroom single-family residence?
A) 900 gallons
B) 1050 gallons
C) 1200 gallons
D) 1500 gallons
E) 750 gallons
Correct Answer: B) 1050 gallons
Rationale: F.A.C. 62-6.015 specifies septic tank capacity based on the number of bedrooms.
For a three-bedroom residence, the minimum required tank capacity is 1050 gallons. This
size is based on an estimated daily sewage flow and is designed to provide adequate
retention time for solids to settle.
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Question 3
What is the primary function of the scum layer in a septic tank?
A) To digest the solid waste that enters the tank.
B) To provide a medium for anaerobic bacteria to thrive.
C) To prevent gases from escaping the tank.
D) To trap lighter-than-water solids like grease and oils, preventing them from entering the
drainfield.
E) To filter the effluent before it leaves the tank.
Correct Answer: D) To trap lighter-than-water solids like grease and oils, preventing them
from entering the drainfield.
Rationale: A septic tank separates waste into three layers. The scum layer is composed of
materials that are less dense than water, such as grease, fats, and oils. The outlet baffle or
tee is designed to draw effluent from the clear zone below this scum layer, preventing these
materials from being discharged and clogging the drainfield.
Question 4
What is the minimum required horizontal setback distance between a new OSTDS drainfield and
a private potable well?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
E) 200 feet
Correct Answer: B) 75 feet
Rationale: F.A.C. 62-6.005 establishes minimum setback distances to protect public health.
The drainfield, where effluent is discharged, must be located at least 75 feet from any
private drinking water well to provide a safe buffer and prevent contamination.
Question 5
The biologically active, clogged layer that forms on the bottom and sidewalls of a drainfield
trench is known as the:
A) Sludge layer
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B) Scum layer
C) Biomat
D) Filter fabric
E) Aggregate mat
Correct Answer: C) Biomat
Rationale: The biomat is a black, gelatinous layer composed of anaerobic microorganisms
and their waste products. It forms at the infiltrative surface of the drainfield. While it
provides some additional treatment, an overly thick and impermeable biomat is the
primary cause of drainfield failure as it prevents effluent from percolating into the soil.
Question 6
What is the purpose of a distribution box (D-box) in a conventional OSTDS?
A) To store excess effluent during peak flows.
B) To provide a second stage of anaerobic treatment.
C) To equally distribute effluent from the septic tank to all lateral lines of the drainfield.
D) To serve as an access point for pumping the septic tank.
E) To filter the effluent before it enters the drainfield.
Correct Answer: C) To equally distribute effluent from the septic tank to all lateral lines of
the drainfield.
Rationale: In a system with multiple drainfield trenches, a distribution box is used to split
the effluent flow evenly. This is critical for ensuring that the entire absorption field is
utilized, which prevents the hydraulic overloading and premature failure of any single
lateral line.
Question 7
According to F.A.C. 62-6, what is the minimum required separation between the bottom of a
drainfield trench and the wet-season high water table?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
E) 36 inches
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Correct Answer: D) 24 inches
Rationale: This vertical separation is crucial for the proper treatment of effluent. At least
24 inches of unsaturated, suitable soil is required below the drainfield to ensure that the
effluent is adequately treated by soil microorganisms before it reaches the groundwater.
Question 8
What is the primary function of the aggregate (gravel or stone) in a conventional drainfield
trench?
A) To filter all pathogens from the effluent.
B) To provide structural support for the pipe and create void space for effluent storage and
distribution.
C) To absorb all of the effluent from the septic tank.
D) To prevent tree roots from entering the drainfield.
E) To serve as a growth medium for aerobic bacteria.
Correct Answer: B) To provide structural support for the pipe and create void space for
effluent storage and distribution.
Rationale: The aggregate serves two main purposes: it provides a stable bed for the
perforated pipe and prevents the trench from collapsing, and its void spaces create a large
underground reservoir that allows effluent to be stored and distributed evenly across the
entire bottom infiltrative surface of the trench.
Question 9
What is the minimum required slope for a 4-inch building sewer line connecting a house to a
septic tank?
A) It must be perfectly level.
B) 1/16 inch per foot.
C) 1/8 inch per foot.
D) 1/2 inch per foot.
E) 1 inch per foot.
Correct Answer: C) 1/8 inch per foot.
Rationale: The building sewer must have a continuous downward slope to ensure that solid
waste is carried along by the wastewater and does not become stranded in the pipe. The
TESTING EXAM VERSIONS WITH ACCURATE REAL EXAM QUESTIONS
AND ANSWERS WITH RATIONALES | EXPERT VERIFIED FOR
GUARANTEED PASS | LATEST UPDATE
Question 1
Which state agency is primarily responsible for the regulation, permitting, and certification of
Onsite Sewage Treatment and Disposal Systems (OSTDS) in Florida?
A) Florida Department of Environmental Protection (FDEP)
B) Florida Department of Health (FDOH)
C) Florida Department of Business and Professional Regulation (DBPR)
D) The local Water Management District
E) The U.S. Environmental Protection Agency (EPA)
Correct Answer: B) Florida Department of Health (FDOH)
Rationale: The Florida Department of Health, through its county health departments
(CHDs), is the lead agency with statutory authority under Chapter 381, Florida Statutes,
and Chapter 62-6, Florida Administrative Code, to regulate the siting, construction, and
repair of all OSTDS in the state.
Question 2
According to Florida Administrative Code (F.A.C.) Chapter 62-6, what is the minimum required
septic tank size for a new three-bedroom single-family residence?
A) 900 gallons
B) 1050 gallons
C) 1200 gallons
D) 1500 gallons
E) 750 gallons
Correct Answer: B) 1050 gallons
Rationale: F.A.C. 62-6.015 specifies septic tank capacity based on the number of bedrooms.
For a three-bedroom residence, the minimum required tank capacity is 1050 gallons. This
size is based on an estimated daily sewage flow and is designed to provide adequate
retention time for solids to settle.
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Question 3
What is the primary function of the scum layer in a septic tank?
A) To digest the solid waste that enters the tank.
B) To provide a medium for anaerobic bacteria to thrive.
C) To prevent gases from escaping the tank.
D) To trap lighter-than-water solids like grease and oils, preventing them from entering the
drainfield.
E) To filter the effluent before it leaves the tank.
Correct Answer: D) To trap lighter-than-water solids like grease and oils, preventing them
from entering the drainfield.
Rationale: A septic tank separates waste into three layers. The scum layer is composed of
materials that are less dense than water, such as grease, fats, and oils. The outlet baffle or
tee is designed to draw effluent from the clear zone below this scum layer, preventing these
materials from being discharged and clogging the drainfield.
Question 4
What is the minimum required horizontal setback distance between a new OSTDS drainfield and
a private potable well?
A) 50 feet
B) 75 feet
C) 100 feet
D) 150 feet
E) 200 feet
Correct Answer: B) 75 feet
Rationale: F.A.C. 62-6.005 establishes minimum setback distances to protect public health.
The drainfield, where effluent is discharged, must be located at least 75 feet from any
private drinking water well to provide a safe buffer and prevent contamination.
Question 5
The biologically active, clogged layer that forms on the bottom and sidewalls of a drainfield
trench is known as the:
A) Sludge layer
,[Type here]
B) Scum layer
C) Biomat
D) Filter fabric
E) Aggregate mat
Correct Answer: C) Biomat
Rationale: The biomat is a black, gelatinous layer composed of anaerobic microorganisms
and their waste products. It forms at the infiltrative surface of the drainfield. While it
provides some additional treatment, an overly thick and impermeable biomat is the
primary cause of drainfield failure as it prevents effluent from percolating into the soil.
Question 6
What is the purpose of a distribution box (D-box) in a conventional OSTDS?
A) To store excess effluent during peak flows.
B) To provide a second stage of anaerobic treatment.
C) To equally distribute effluent from the septic tank to all lateral lines of the drainfield.
D) To serve as an access point for pumping the septic tank.
E) To filter the effluent before it enters the drainfield.
Correct Answer: C) To equally distribute effluent from the septic tank to all lateral lines of
the drainfield.
Rationale: In a system with multiple drainfield trenches, a distribution box is used to split
the effluent flow evenly. This is critical for ensuring that the entire absorption field is
utilized, which prevents the hydraulic overloading and premature failure of any single
lateral line.
Question 7
According to F.A.C. 62-6, what is the minimum required separation between the bottom of a
drainfield trench and the wet-season high water table?
A) 6 inches
B) 12 inches
C) 18 inches
D) 24 inches
E) 36 inches
, [Type here]
Correct Answer: D) 24 inches
Rationale: This vertical separation is crucial for the proper treatment of effluent. At least
24 inches of unsaturated, suitable soil is required below the drainfield to ensure that the
effluent is adequately treated by soil microorganisms before it reaches the groundwater.
Question 8
What is the primary function of the aggregate (gravel or stone) in a conventional drainfield
trench?
A) To filter all pathogens from the effluent.
B) To provide structural support for the pipe and create void space for effluent storage and
distribution.
C) To absorb all of the effluent from the septic tank.
D) To prevent tree roots from entering the drainfield.
E) To serve as a growth medium for aerobic bacteria.
Correct Answer: B) To provide structural support for the pipe and create void space for
effluent storage and distribution.
Rationale: The aggregate serves two main purposes: it provides a stable bed for the
perforated pipe and prevents the trench from collapsing, and its void spaces create a large
underground reservoir that allows effluent to be stored and distributed evenly across the
entire bottom infiltrative surface of the trench.
Question 9
What is the minimum required slope for a 4-inch building sewer line connecting a house to a
septic tank?
A) It must be perfectly level.
B) 1/16 inch per foot.
C) 1/8 inch per foot.
D) 1/2 inch per foot.
E) 1 inch per foot.
Correct Answer: C) 1/8 inch per foot.
Rationale: The building sewer must have a continuous downward slope to ensure that solid
waste is carried along by the wastewater and does not become stranded in the pipe. The
