Texas On-Site Sewage Facility (OSSF) Installer II
Exam 2026 – 200 Questions with Answers &
Rationales | Complete PDF
1. What is the primary purpose of an OSSF system?
A) Provide drinking water
B) Treat and dispose of household wastewater on-site
C) Irrigate crops
D) Store stormwater
Rationale: 👀*** OSSF systems safely manage wastewater where municipal systems are
not available.
2. Which regulatory agency oversees OSSF systems in Texas?
A) EPA
B) Texas Commission on Environmental Quality (TCEQ)
C) USDA
D) Texas Health Department
Rationale: 👀*** TCEQ enforces OSSF rules and standards in Texas.
3. What is the standard minimum separation distance between a septic tank and a
drinking water well?
A) 50 feet
B) 75 feet
,C) 100 feet
D) 150 feet
Rationale: 👀*** Ensures groundwater is protected from contamination.
4. Which component of a conventional OSSF system collects solids from
wastewater?
A) Absorption field
B) Septic tank
C) Distribution box
D) Effluent filter
Rationale: 👀*** Septic tanks separate solids and scum from effluent before dispersal.
5. What is the purpose of a distribution box?
A) Treat wastewater
B) Evenly distribute effluent to the absorption field
C) Remove sludge
D) Aerate wastewater
Rationale: 👀*** Prevents overloading of any part of the drain field.
6. Which soil type has the fastest percolation rate?
A) Clay
B) Loam
,C) Sandy soil
D) Silt
Rationale: 👀*** Sandy soil allows water to drain quickly, affecting system design.
7. Which soil texture is most likely to cause effluent backup?
A) Sand
B) Clay
C) Gravel
D) Loam
Rationale: 👀*** Slow percolation can lead to system failure if not properly designed.
8. What is the minimum septic tank liquid capacity for a standard 3-bedroom home in
Texas?
A) 500 gallons
B) 750 gallons
C) 1,000 gallons
D) 1,500 gallons
Rationale: 👀*** Texas regulations require 1,000 gallons for a 3-bedroom home.
9. How often should a septic tank be pumped under normal conditions?
A) Every year
B) Every 3–5 years
, C) Every 10 years
D) Only when it fails
Rationale: 👀*** Regular pumping prevents solids from entering the drain field.
10. Which of the following is a common sign of a failing OSSF system?
A) Strong plant growth above the tank
B) Pooling effluent on the ground surface
C) Clear water in toilets
D) No odor in the yard
Rationale: 👀*** Indicates the drain field is saturated or clogged.
11. What is the minimum separation distance between an absorption trench and the
property line?
A) 5 feet
B) 10 feet
C) 5 feet minimum
D) 20 feet
Rationale: 👀*** Prevents wastewater from encroaching on neighboring properties.
12. Which of the following affects percolation rate in a soil?
A) Soil texture
B) Moisture content
Exam 2026 – 200 Questions with Answers &
Rationales | Complete PDF
1. What is the primary purpose of an OSSF system?
A) Provide drinking water
B) Treat and dispose of household wastewater on-site
C) Irrigate crops
D) Store stormwater
Rationale: 👀*** OSSF systems safely manage wastewater where municipal systems are
not available.
2. Which regulatory agency oversees OSSF systems in Texas?
A) EPA
B) Texas Commission on Environmental Quality (TCEQ)
C) USDA
D) Texas Health Department
Rationale: 👀*** TCEQ enforces OSSF rules and standards in Texas.
3. What is the standard minimum separation distance between a septic tank and a
drinking water well?
A) 50 feet
B) 75 feet
,C) 100 feet
D) 150 feet
Rationale: 👀*** Ensures groundwater is protected from contamination.
4. Which component of a conventional OSSF system collects solids from
wastewater?
A) Absorption field
B) Septic tank
C) Distribution box
D) Effluent filter
Rationale: 👀*** Septic tanks separate solids and scum from effluent before dispersal.
5. What is the purpose of a distribution box?
A) Treat wastewater
B) Evenly distribute effluent to the absorption field
C) Remove sludge
D) Aerate wastewater
Rationale: 👀*** Prevents overloading of any part of the drain field.
6. Which soil type has the fastest percolation rate?
A) Clay
B) Loam
,C) Sandy soil
D) Silt
Rationale: 👀*** Sandy soil allows water to drain quickly, affecting system design.
7. Which soil texture is most likely to cause effluent backup?
A) Sand
B) Clay
C) Gravel
D) Loam
Rationale: 👀*** Slow percolation can lead to system failure if not properly designed.
8. What is the minimum septic tank liquid capacity for a standard 3-bedroom home in
Texas?
A) 500 gallons
B) 750 gallons
C) 1,000 gallons
D) 1,500 gallons
Rationale: 👀*** Texas regulations require 1,000 gallons for a 3-bedroom home.
9. How often should a septic tank be pumped under normal conditions?
A) Every year
B) Every 3–5 years
, C) Every 10 years
D) Only when it fails
Rationale: 👀*** Regular pumping prevents solids from entering the drain field.
10. Which of the following is a common sign of a failing OSSF system?
A) Strong plant growth above the tank
B) Pooling effluent on the ground surface
C) Clear water in toilets
D) No odor in the yard
Rationale: 👀*** Indicates the drain field is saturated or clogged.
11. What is the minimum separation distance between an absorption trench and the
property line?
A) 5 feet
B) 10 feet
C) 5 feet minimum
D) 20 feet
Rationale: 👀*** Prevents wastewater from encroaching on neighboring properties.
12. Which of the following affects percolation rate in a soil?
A) Soil texture
B) Moisture content
