Texas Septic Installer Licensing Exam
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. What is the minimum setback distance from a private water well to a
standard septic tank in Texas?
a) 25 feet
b) 50 feet
c) 100 feet
d) 150 feet
Rationale: Texas regulations require a 100-foot minimum distance
between a private water well and any component of an OSSF system
to prevent contamination.
2. Who is responsible for obtaining a permit for the installation of an
OSSF system?
a) Homeowner
b) Installer
c) Property developer
d) Environmental health officer
, Rationale: The licensed installer is responsible for obtaining the
proper permits before installation.
3. Which of the following components is part of a conventional OSSF
system?
a) Aerobic treatment unit
b) Septic tank
c) Sand filter
d) Chlorinator
Rationale: A conventional system includes a septic tank and a soil
absorption system.
4. The trench bottom of a drain field must be level to within:
a) 3 inches per 100 feet
b) 2 inches per 100 feet
c) 6 inches per 100 feet
d) 4 inches per 100 feet
Rationale: To ensure even distribution of effluent, the trench bottom
must be level within 2 inches per 100 feet.
5. What is the purpose of a distribution box in a septic system?
a) Remove solids
b) Distribute effluent evenly
c) Treat sewage
d) Store effluent
Rationale: A distribution box ensures effluent is evenly distributed to
the drain field laterals.
6. Soil with what texture is generally unsuitable for a conventional drain
field?
a) Sandy loam
b) Silt loam
c) Clay
, d) Loamy sand
Rationale: Clay soils drain poorly and are generally unsuitable for
conventional systems without modifications.
7. What is the maximum daily flow allowed for a standard OSSF in Texas
without special approval?
a) 300 gallons
b) 360 gallons
c) 500 gallons
d) 600 gallons
Rationale: Systems handling more than 500 gallons/day typically
require engineering or advanced approval.
8. Which type of system is most appropriate in an area with high
groundwater?
a) Aerobic treatment unit with spray distribution
b) Conventional trench system
c) Gravel-less pipe system
d) Leaching pit
Rationale: High groundwater limits soil treatment; aerobic units
treat wastewater before dispersal.
9. In Texas, how long is an OSSF installer license valid before renewal is
required?
a) 1 year
b) 2 years
c) 3 years
d) 5 years
Rationale: Texas OSSF Installer licenses must be renewed every 2
years.
10. What agency regulates OSSF Installer licensing in Texas?
a) EPA
Practice Test Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the minimum setback distance from a private water well to a
standard septic tank in Texas?
a) 25 feet
b) 50 feet
c) 100 feet
d) 150 feet
Rationale: Texas regulations require a 100-foot minimum distance
between a private water well and any component of an OSSF system
to prevent contamination.
2. Who is responsible for obtaining a permit for the installation of an
OSSF system?
a) Homeowner
b) Installer
c) Property developer
d) Environmental health officer
, Rationale: The licensed installer is responsible for obtaining the
proper permits before installation.
3. Which of the following components is part of a conventional OSSF
system?
a) Aerobic treatment unit
b) Septic tank
c) Sand filter
d) Chlorinator
Rationale: A conventional system includes a septic tank and a soil
absorption system.
4. The trench bottom of a drain field must be level to within:
a) 3 inches per 100 feet
b) 2 inches per 100 feet
c) 6 inches per 100 feet
d) 4 inches per 100 feet
Rationale: To ensure even distribution of effluent, the trench bottom
must be level within 2 inches per 100 feet.
5. What is the purpose of a distribution box in a septic system?
a) Remove solids
b) Distribute effluent evenly
c) Treat sewage
d) Store effluent
Rationale: A distribution box ensures effluent is evenly distributed to
the drain field laterals.
6. Soil with what texture is generally unsuitable for a conventional drain
field?
a) Sandy loam
b) Silt loam
c) Clay
, d) Loamy sand
Rationale: Clay soils drain poorly and are generally unsuitable for
conventional systems without modifications.
7. What is the maximum daily flow allowed for a standard OSSF in Texas
without special approval?
a) 300 gallons
b) 360 gallons
c) 500 gallons
d) 600 gallons
Rationale: Systems handling more than 500 gallons/day typically
require engineering or advanced approval.
8. Which type of system is most appropriate in an area with high
groundwater?
a) Aerobic treatment unit with spray distribution
b) Conventional trench system
c) Gravel-less pipe system
d) Leaching pit
Rationale: High groundwater limits soil treatment; aerobic units
treat wastewater before dispersal.
9. In Texas, how long is an OSSF installer license valid before renewal is
required?
a) 1 year
b) 2 years
c) 3 years
d) 5 years
Rationale: Texas OSSF Installer licenses must be renewed every 2
years.
10. What agency regulates OSSF Installer licensing in Texas?
a) EPA
