Texas On-Site Sewage Facility (OSSF) Installer II
Exam Recommended Questions with Verified
Answers & Detailed Rationales | 2026/2027 PDF
Study Guide
Regulations & Compliance
Q1. According to Texas Commission on Environmental Quality
(TCEQ), which of the following is required before installing an OSSF
system?
A. Verbal approval from property owner
B. Approved site evaluation and permit
C. Only a sketch of the property
D. Nothing, if the lot is under one acre
OSSF installation requires a TCEQ-approved site evaluation and permit to
ensure compliance with regulations.
Q2. What is the minimum setback distance for a septic tank from a
water well in Texas?
A. 25 feet
B. 50 feet
C. 100 feet
D. 150 feet
State regulations require septic tanks to be at least 100 feet from a water
well to protect water quality.
Q3. OSSF systems must comply with which Texas administrative
code?
A. 25 TAC §229
B. 30 TAC §285
,C. 40 TAC §101
D. 50 TAC §300
30 TAC §285 governs OSSF rules and installation standards in Texas.
Q4. Who is legally allowed to inspect an OSSF system after
installation?
A. Any contractor
B. Licensed OSSF inspector or regulatory authority
C. Property owner
D. Neighbor with experience
Inspections must be conducted by licensed inspectors or TCEQ-authorized
personnel.
Q5. Failure to comply with OSSF regulations may result in:
A. Verbal warning only
B. Fines, civil penalties, and permit revocation
C. Nothing
D. Reduced property tax
Non-compliance can lead to fines, civil penalties, or revocation of license.
System Components
Q6. Which component of an OSSF system separates solids from
liquids?
A. Drainfield
B. Aerobic treatment unit
C. Septic tank
D. Distribution box
The septic tank allows solids to settle while liquids flow to the drainfield.
, Q7. What is the primary function of a distribution box in a
conventional septic system?
A. Aerate wastewater
B. Filter solids
C. Evenly distribute effluent to the drainfield
D. Pump water to surface
The distribution box ensures effluent is evenly spread across the drainfield
trenches.
Q8. Aerobic treatment units (ATUs) are required when:
A. Soil has excellent percolation
B. Site limitations prevent standard drainfield installation
C. Property is over five acres
D. Septic tank is oversized
ATUs provide advanced treatment when site conditions limit standard soil
absorption.
Q9. The effluent from an OSSF system is considered fully treated
when:
A. It reaches the septic tank
B. It passes through all system components and meets TCEQ quality
standards
C. It enters the drainfield
D. It is odorless
Proper treatment is achieved after effluent meets quality standards at the
system’s final stage.
Q10. The typical capacity of a residential septic tank in Texas is:
A. 500 gallons
B. 1,000–1,500 gallons
C. 2,000–2,500 gallons
D. 3,000 gallons
Exam Recommended Questions with Verified
Answers & Detailed Rationales | 2026/2027 PDF
Study Guide
Regulations & Compliance
Q1. According to Texas Commission on Environmental Quality
(TCEQ), which of the following is required before installing an OSSF
system?
A. Verbal approval from property owner
B. Approved site evaluation and permit
C. Only a sketch of the property
D. Nothing, if the lot is under one acre
OSSF installation requires a TCEQ-approved site evaluation and permit to
ensure compliance with regulations.
Q2. What is the minimum setback distance for a septic tank from a
water well in Texas?
A. 25 feet
B. 50 feet
C. 100 feet
D. 150 feet
State regulations require septic tanks to be at least 100 feet from a water
well to protect water quality.
Q3. OSSF systems must comply with which Texas administrative
code?
A. 25 TAC §229
B. 30 TAC §285
,C. 40 TAC §101
D. 50 TAC §300
30 TAC §285 governs OSSF rules and installation standards in Texas.
Q4. Who is legally allowed to inspect an OSSF system after
installation?
A. Any contractor
B. Licensed OSSF inspector or regulatory authority
C. Property owner
D. Neighbor with experience
Inspections must be conducted by licensed inspectors or TCEQ-authorized
personnel.
Q5. Failure to comply with OSSF regulations may result in:
A. Verbal warning only
B. Fines, civil penalties, and permit revocation
C. Nothing
D. Reduced property tax
Non-compliance can lead to fines, civil penalties, or revocation of license.
System Components
Q6. Which component of an OSSF system separates solids from
liquids?
A. Drainfield
B. Aerobic treatment unit
C. Septic tank
D. Distribution box
The septic tank allows solids to settle while liquids flow to the drainfield.
, Q7. What is the primary function of a distribution box in a
conventional septic system?
A. Aerate wastewater
B. Filter solids
C. Evenly distribute effluent to the drainfield
D. Pump water to surface
The distribution box ensures effluent is evenly spread across the drainfield
trenches.
Q8. Aerobic treatment units (ATUs) are required when:
A. Soil has excellent percolation
B. Site limitations prevent standard drainfield installation
C. Property is over five acres
D. Septic tank is oversized
ATUs provide advanced treatment when site conditions limit standard soil
absorption.
Q9. The effluent from an OSSF system is considered fully treated
when:
A. It reaches the septic tank
B. It passes through all system components and meets TCEQ quality
standards
C. It enters the drainfield
D. It is odorless
Proper treatment is achieved after effluent meets quality standards at the
system’s final stage.
Q10. The typical capacity of a residential septic tank in Texas is:
A. 500 gallons
B. 1,000–1,500 gallons
C. 2,000–2,500 gallons
D. 3,000 gallons
