TEXAS OSSF INSTALLER PRACTICE TEST
2026: ACE YOUR TCEQ EXAM
SECTION 1: REGULATORY FRAMEWORK AND TCEQ RULES (30 TAC CHAPTER 285)
1. Under Texas regulations, an OSSF is defined as a system that treats and disposes of
what type of wastewater?
A) Industrial wastewater from manufacturing plants
B) Domestic sewage from a dwelling or business with a flow rate of less than 5,000 gallons
per day
C) Agricultural runoff and stormwater
D) Any wastewater with a high concentration of heavy metals
Answer: B) Domestic sewage from a dwelling or business with a flow rate of less than
5,000 gallons per day
Rationale: TCEQ rules define an OSSF as a system designed to treat and dispose of
domestic sewage with a design flow of less than 5,000 gallons per day, distinguishing it
from larger municipal or industrial treatment facilities.
2. What is the minimum horizontal distance required between a septic tank and a
private water well in Texas?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: D) 100 feet
Rationale: To protect groundwater and drinking water sources from contamination, TCEQ
,regulations mandate a minimum setback of 100 feet between any OSSF component,
including the septic tank, and a private water supply well.
3. Which entity is designated as the Authorized Agent (AA) for enforcing OSSF rules in
most counties without a local health department?
A) The Texas Department of State Health Services (DSHS)
B) The local city council
C) The TCEQ
D) The county commissioner
Answer: C) The TCEQ
Rationale: The TCEQ serves as the Authorized Agent for enforcing OSSF regulations in
areas that do not have a local health department with a certified program. They have the
primary authority for permitting, inspection, and enforcement.
4. An Installer II license permits the holder to do which of the following?
A) Install conventional gravity systems only
B) Construct all types of OSSF, including aerobic and alternative systems
C) Perform site evaluations and soil testing without supervision
D) Design OSSF systems for any size residence
Answer: B) Construct all types of OSSF, including aerobic and alternative systems
Rationale: The Installer II license is the advanced level of installation certification in Texas,
authorizing the holder to construct all types of on-site sewage facilities, not just
conventional ones.
5. According to TCEQ rules, who is responsible for obtaining the permit before the
installation of an OSSF?
A) The installer
B) The homeowner
C) The property owner
D) The real estate agent handling the property sale
Answer: C) The property owner
Rationale: While the installer may assist in the process, the ultimate legal responsibility for
obtaining an OSSF permit from the Authorized Agent lies with the property owner.
6. What is the minimum setback required between a septic tank and a property line in
Texas?
A) 5 feet
B) 10 feet
,C) 15 feet
D) 20 feet
Answer: B) 10 feet
Rationale: Standard TCEQ regulations require a minimum 10-foot horizontal separation
distance from a septic tank to a property line to ensure adequate space for maintenance
and to prevent encroachment.
7. Cesspools and seepage pits are considered legal methods of sewage disposal in
Texas.
A) True
B) False
Answer: B) False
Rationale: TCEQ regulations explicitly prohibit the use of cesspools and seepage pits for
sewage disposal in Texas due to their high potential for groundwater contamination and
lack of adequate treatment.
8. What is the minimum horizontal distance required between a spray irrigation area
and a private water well?
A) 50 feet
B) 100 feet
C) 200 feet
D) 300 feet
Answer: B) 100 feet
Rationale: The TCEQ requires a minimum setback of 100 feet between the spray zone of an
OSSF and a private water well to minimize the risk of pathogen or contaminant intrusion
into the water supply.
9. Under TCEQ regulations, an OSSF must be designed to prevent what?
A) The creation of a nuisance
B) The contamination of groundwater
C) A threat to public health
D) All of the above
Answer: D) All of the above
Rationale: The primary regulatory objective for any OSSF is to be sited, designed, and
installed in a manner that prevents a nuisance, protects groundwater quality, and
safeguards public health.
, 10. Maintenance records for an OSSF must be kept on file and made available to the
TCEQ or Authorized Agent upon request.
A) True
B) False
Answer: A) True
Rationale: Property owners and maintenance providers are required by law to maintain
accurate service records for the life of the system, demonstrating compliance with
maintenance schedules.
SECTION 2: SITE EVALUATION AND SOIL CLASSIFICATION
11. During a site evaluation, what is the primary purpose of performing a soil textural
analysis?
A) To determine the amount of organic matter in the soil
B) To estimate the soil's ability to percolate wastewater and the depth to restrictive layers
C) To measure the pH level of the soil
D) To assess the soil's color
Answer: B) To estimate the soil's ability to percolate wastewater and the depth to
restrictive layers
Rationale: Soil texture (the percentage of sand, silt, and clay) is a primary indicator of
permeability and drainage, which are critical for selecting an appropriate disposal field and
predicting system performance.
12. A soil with a high percentage of clay is generally preferred for a drain field due to its
high permeability.
A) True
B) False
Answer: B) False
Rationale: Clay soils have small particles and tight pore spaces, resulting in low
permeability (slow percolation). Sandy soils are preferred for drain fields due to their high
permeability and ability to absorb and disperse wastewater.
13. What is the minimum acceptable perc rate for a conventional drain field in Texas?
A) 1 minute per inch
B) 15 minutes per inch
C) 60 minutes per inch
D) 120 minutes per inch
2026: ACE YOUR TCEQ EXAM
SECTION 1: REGULATORY FRAMEWORK AND TCEQ RULES (30 TAC CHAPTER 285)
1. Under Texas regulations, an OSSF is defined as a system that treats and disposes of
what type of wastewater?
A) Industrial wastewater from manufacturing plants
B) Domestic sewage from a dwelling or business with a flow rate of less than 5,000 gallons
per day
C) Agricultural runoff and stormwater
D) Any wastewater with a high concentration of heavy metals
Answer: B) Domestic sewage from a dwelling or business with a flow rate of less than
5,000 gallons per day
Rationale: TCEQ rules define an OSSF as a system designed to treat and dispose of
domestic sewage with a design flow of less than 5,000 gallons per day, distinguishing it
from larger municipal or industrial treatment facilities.
2. What is the minimum horizontal distance required between a septic tank and a
private water well in Texas?
A) 25 feet
B) 50 feet
C) 75 feet
D) 100 feet
Answer: D) 100 feet
Rationale: To protect groundwater and drinking water sources from contamination, TCEQ
,regulations mandate a minimum setback of 100 feet between any OSSF component,
including the septic tank, and a private water supply well.
3. Which entity is designated as the Authorized Agent (AA) for enforcing OSSF rules in
most counties without a local health department?
A) The Texas Department of State Health Services (DSHS)
B) The local city council
C) The TCEQ
D) The county commissioner
Answer: C) The TCEQ
Rationale: The TCEQ serves as the Authorized Agent for enforcing OSSF regulations in
areas that do not have a local health department with a certified program. They have the
primary authority for permitting, inspection, and enforcement.
4. An Installer II license permits the holder to do which of the following?
A) Install conventional gravity systems only
B) Construct all types of OSSF, including aerobic and alternative systems
C) Perform site evaluations and soil testing without supervision
D) Design OSSF systems for any size residence
Answer: B) Construct all types of OSSF, including aerobic and alternative systems
Rationale: The Installer II license is the advanced level of installation certification in Texas,
authorizing the holder to construct all types of on-site sewage facilities, not just
conventional ones.
5. According to TCEQ rules, who is responsible for obtaining the permit before the
installation of an OSSF?
A) The installer
B) The homeowner
C) The property owner
D) The real estate agent handling the property sale
Answer: C) The property owner
Rationale: While the installer may assist in the process, the ultimate legal responsibility for
obtaining an OSSF permit from the Authorized Agent lies with the property owner.
6. What is the minimum setback required between a septic tank and a property line in
Texas?
A) 5 feet
B) 10 feet
,C) 15 feet
D) 20 feet
Answer: B) 10 feet
Rationale: Standard TCEQ regulations require a minimum 10-foot horizontal separation
distance from a septic tank to a property line to ensure adequate space for maintenance
and to prevent encroachment.
7. Cesspools and seepage pits are considered legal methods of sewage disposal in
Texas.
A) True
B) False
Answer: B) False
Rationale: TCEQ regulations explicitly prohibit the use of cesspools and seepage pits for
sewage disposal in Texas due to their high potential for groundwater contamination and
lack of adequate treatment.
8. What is the minimum horizontal distance required between a spray irrigation area
and a private water well?
A) 50 feet
B) 100 feet
C) 200 feet
D) 300 feet
Answer: B) 100 feet
Rationale: The TCEQ requires a minimum setback of 100 feet between the spray zone of an
OSSF and a private water well to minimize the risk of pathogen or contaminant intrusion
into the water supply.
9. Under TCEQ regulations, an OSSF must be designed to prevent what?
A) The creation of a nuisance
B) The contamination of groundwater
C) A threat to public health
D) All of the above
Answer: D) All of the above
Rationale: The primary regulatory objective for any OSSF is to be sited, designed, and
installed in a manner that prevents a nuisance, protects groundwater quality, and
safeguards public health.
, 10. Maintenance records for an OSSF must be kept on file and made available to the
TCEQ or Authorized Agent upon request.
A) True
B) False
Answer: A) True
Rationale: Property owners and maintenance providers are required by law to maintain
accurate service records for the life of the system, demonstrating compliance with
maintenance schedules.
SECTION 2: SITE EVALUATION AND SOIL CLASSIFICATION
11. During a site evaluation, what is the primary purpose of performing a soil textural
analysis?
A) To determine the amount of organic matter in the soil
B) To estimate the soil's ability to percolate wastewater and the depth to restrictive layers
C) To measure the pH level of the soil
D) To assess the soil's color
Answer: B) To estimate the soil's ability to percolate wastewater and the depth to
restrictive layers
Rationale: Soil texture (the percentage of sand, silt, and clay) is a primary indicator of
permeability and drainage, which are critical for selecting an appropriate disposal field and
predicting system performance.
12. A soil with a high percentage of clay is generally preferred for a drain field due to its
high permeability.
A) True
B) False
Answer: B) False
Rationale: Clay soils have small particles and tight pore spaces, resulting in low
permeability (slow percolation). Sandy soils are preferred for drain fields due to their high
permeability and ability to absorb and disperse wastewater.
13. What is the minimum acceptable perc rate for a conventional drain field in Texas?
A) 1 minute per inch
B) 15 minutes per inch
C) 60 minutes per inch
D) 120 minutes per inch
