TEXAS ON-SITE SEWAGE FACILITY (OSSF)
INSTALLER II EXAM VERIFIED QUESTIONS
AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED.PDF
.||NEWEST EXAM!!!
Overview Coverage
The 150-question bank for the Texas On-Site Sewage Facility (OSSF) Installer
II license covers four critical domains. Mastery of these areas is essential for passing
the TCEQ computer-based examination.
1. Regulatory & Administrative Rules (25%)
TCEQ Chapter 285: Detailed knowledge of Texas state laws governing sewage
disposal.
Licensing Authority: Scope of work for Installer II vs. Installer I; apprentice supervision
rules.
Permitting & Inspections: The role of the Authorized Agent (AA) and Designated
Representative (DR), and the "Notice to Approve for Use" process.
Administrative Compliance: Maintenance contract requirements, 14-day reporting
rules, and emergency repair protocols.
2. Technical System Design & Installation (35%)
Advanced Systems: Installation of Aerobic Treatment Units (ATUs), Low-Pressure
Dosing (LPD), Drip Irrigation, and Mound systems.
Tanks & Components: Tank buoyancy, H-20 traffic loading, baffle/tee placement, and
pump tank reserve capacity.
Materials & Specs: Pipe ratings (SDR 26/Schedule 40), purple pipe for reclaimed
water, and gravel-less/chamber system credits.
Hydraulics: Total Dynamic Head (TDH), pump "short-cycling," and siphon prevention
(vacuum breakers).
3. Site Evaluation & Soil Science (25%)
Soil Classification: Identifying Class I (Sand) through Class IV (Heavy Clay) and their
respective Application Rates (Ra).
, Restrictive Horizons: Identifying "depth to bedrock" and the seasonal high-water table
through redoximorphic features (mottling).
Setback Requirements: Memorizing horizontal separation distances from wells
(50/100ft), property lines (5/20ft), and public waterways (75ft).
Soil Substitution: Technical requirements for replacing Class IV soils with suitable
media.
4. Calculations & Safety (15%)
Sizing Math: Calculating daily usage (GPD) based on bedrooms/square footage and
determining absorption area (Area = GPD / Ra).
Geometric Formulas: Solving for square footage in rectangular trenches and circular
spray patterns.
Operational Safety: Managing hazardous gases (), electrical safety (separate alarm
circuits), and mandatory safety lids for child protection.
Disinfection: Calculating chlorine residual (0.1 mg/l minimum) and understanding the
dangers of stabilized pool chlorine.
1. A homeowner wants to install a septic tank on their property. What is the
minimum required separation distance between the septic tank and a private
water well?
A) 10 feet
B) 25 feet
C) 50 feet
D) 100 feet
The tank itself requires a 50-foot setback. However, the disposal area (drainfield) must
be 100 feet away from the well to prevent groundwater contamination.
2. Which of the following activities is an OSSF Installer II authorized to perform
that an Installer I cannot?
A) Repair a broken gravity pipe
B) Install a standard 1,000-gallon septic tank
C) Install an Aerobic Treatment Unit (ATU) or pressure-dosed system
D) Perform a site evaluation for a commercial property
Installer II's are licensed to install all types of OSSF systems, including complex
aerobic and pressure-distributed systems. Installer I's are limited to "standard" systems
only.
3. According to TCEQ Chapter 285, what is the minimum liquid capacity for a
septic tank serving a 4-bedroom home that is 3,200 square feet?
,A) 750 gallons
B) 1,000 gallons
C) 1,250 gallons
D) 1,500 gallons
For a residence with 4 bedrooms (or between 3,501–4,500 sq. ft.), the minimum
capacity required is 1,250 gallons.
4. When evaluating a site for a new system, you discover the soil is a Class IV
(heavy clay). Which of the following is true?
A) It is the best soil for a standard drainfield
B) It has a high percolation rate
C) It is considered unsuitable for a standard soil substitution drainfield
D) It does not require a Professional Engineer's design
Class IV soils (clays) have poor drainage and high "shrink-swell" potential. Because
they don't absorb effluent well, they usually require non-standard systems like ATUs or
ET beds.
5. What is the maximum allowable slope for a standard OSSF disposal area
without requiring a special design by a Professional Engineer (PE)?
A) 15%
B) 20%
C) 30%
D) 45%
TCEQ rules state that a standard system cannot be installed on a slope
exceeding 30% because effluent may "break out" of the surface or flow too quickly to be
treated.
6. Which pipe material and rating is the minimum requirement for the line leading
from the house to the septic tank?
A) Thin-wall PVC
B) Schedule 20 PVC
C) 3-inch SDR 26 or Schedule 40 PVC
D) 4-inch corrugated HDPE
To prevent crushing and leaks, the "stub-out" to the tank must be at least 3 inches in
diameter and made of heavy-duty SDR 26 or Schedule 40 pipe.
7. For an Aerobic Treatment Unit (ATU) that uses surface application (spray
irrigation), what is the minimum required chlorine residual that must be
maintained in the pump tank?
A) 0.01 mg/l
, B) 0.1 mg/l
C) 1.0 mg/l
D) 5.0 mg/l
The effluent must be disinfected before surface application. TCEQ requires a minimum
chlorine residual of 0.1 mg/l to ensure pathogens are killed before the water is sprayed.
8. Which component is required to be installed in a pump tank to alert the owner
if the pump fails or the water level gets too high?
A) A secondary pump
B) A check valve
C) An audiovisual alarm on a separate circuit
D) A pressure gauge
An audiovisual alarm (light and buzzer) is mandatory. It must be on a separate
branch circuit from the pump so that if the pump trips its breaker, the alarm will still
have power to notify the owner.
9. What is the minimum required distance between a spray head (surface
application) and a property line?
A) 5 feet
B) 20 feet
C) 50 feet
D) 75 feet
To prevent "overspray" onto neighboring lots, spray heads must be set back at least 20
feet from property lines. This can be reduced to 10 feet if specific physical barriers are
present.
10. When installing a tank in an area with a high-water table, what is the primary
concern for the installer?
A) The tank will get too cold
B) Tank buoyancy (the tank "floating" out of the ground)
C) Increased bacterial growth
D) Excessive evaporation
An empty or partially empty tank in saturated soil acts like a boat. Buoyancy can cause
the tank to "pop" or float out of the ground, rupturing the pipes. Installers must use
anchors or "deadmen" to secure it.
11. Which of the following is a requirement for the "trash tank" (pretreatment
tank) located in front of an ATU?
A) It must be at least 2,000 gallons
B) It must have a mechanical aerator
INSTALLER II EXAM VERIFIED QUESTIONS
AND DETAILED SOLUTIONS LATEST
UPDATE THIS YEAR-JUST RELEASED.PDF
.||NEWEST EXAM!!!
Overview Coverage
The 150-question bank for the Texas On-Site Sewage Facility (OSSF) Installer
II license covers four critical domains. Mastery of these areas is essential for passing
the TCEQ computer-based examination.
1. Regulatory & Administrative Rules (25%)
TCEQ Chapter 285: Detailed knowledge of Texas state laws governing sewage
disposal.
Licensing Authority: Scope of work for Installer II vs. Installer I; apprentice supervision
rules.
Permitting & Inspections: The role of the Authorized Agent (AA) and Designated
Representative (DR), and the "Notice to Approve for Use" process.
Administrative Compliance: Maintenance contract requirements, 14-day reporting
rules, and emergency repair protocols.
2. Technical System Design & Installation (35%)
Advanced Systems: Installation of Aerobic Treatment Units (ATUs), Low-Pressure
Dosing (LPD), Drip Irrigation, and Mound systems.
Tanks & Components: Tank buoyancy, H-20 traffic loading, baffle/tee placement, and
pump tank reserve capacity.
Materials & Specs: Pipe ratings (SDR 26/Schedule 40), purple pipe for reclaimed
water, and gravel-less/chamber system credits.
Hydraulics: Total Dynamic Head (TDH), pump "short-cycling," and siphon prevention
(vacuum breakers).
3. Site Evaluation & Soil Science (25%)
Soil Classification: Identifying Class I (Sand) through Class IV (Heavy Clay) and their
respective Application Rates (Ra).
, Restrictive Horizons: Identifying "depth to bedrock" and the seasonal high-water table
through redoximorphic features (mottling).
Setback Requirements: Memorizing horizontal separation distances from wells
(50/100ft), property lines (5/20ft), and public waterways (75ft).
Soil Substitution: Technical requirements for replacing Class IV soils with suitable
media.
4. Calculations & Safety (15%)
Sizing Math: Calculating daily usage (GPD) based on bedrooms/square footage and
determining absorption area (Area = GPD / Ra).
Geometric Formulas: Solving for square footage in rectangular trenches and circular
spray patterns.
Operational Safety: Managing hazardous gases (), electrical safety (separate alarm
circuits), and mandatory safety lids for child protection.
Disinfection: Calculating chlorine residual (0.1 mg/l minimum) and understanding the
dangers of stabilized pool chlorine.
1. A homeowner wants to install a septic tank on their property. What is the
minimum required separation distance between the septic tank and a private
water well?
A) 10 feet
B) 25 feet
C) 50 feet
D) 100 feet
The tank itself requires a 50-foot setback. However, the disposal area (drainfield) must
be 100 feet away from the well to prevent groundwater contamination.
2. Which of the following activities is an OSSF Installer II authorized to perform
that an Installer I cannot?
A) Repair a broken gravity pipe
B) Install a standard 1,000-gallon septic tank
C) Install an Aerobic Treatment Unit (ATU) or pressure-dosed system
D) Perform a site evaluation for a commercial property
Installer II's are licensed to install all types of OSSF systems, including complex
aerobic and pressure-distributed systems. Installer I's are limited to "standard" systems
only.
3. According to TCEQ Chapter 285, what is the minimum liquid capacity for a
septic tank serving a 4-bedroom home that is 3,200 square feet?
,A) 750 gallons
B) 1,000 gallons
C) 1,250 gallons
D) 1,500 gallons
For a residence with 4 bedrooms (or between 3,501–4,500 sq. ft.), the minimum
capacity required is 1,250 gallons.
4. When evaluating a site for a new system, you discover the soil is a Class IV
(heavy clay). Which of the following is true?
A) It is the best soil for a standard drainfield
B) It has a high percolation rate
C) It is considered unsuitable for a standard soil substitution drainfield
D) It does not require a Professional Engineer's design
Class IV soils (clays) have poor drainage and high "shrink-swell" potential. Because
they don't absorb effluent well, they usually require non-standard systems like ATUs or
ET beds.
5. What is the maximum allowable slope for a standard OSSF disposal area
without requiring a special design by a Professional Engineer (PE)?
A) 15%
B) 20%
C) 30%
D) 45%
TCEQ rules state that a standard system cannot be installed on a slope
exceeding 30% because effluent may "break out" of the surface or flow too quickly to be
treated.
6. Which pipe material and rating is the minimum requirement for the line leading
from the house to the septic tank?
A) Thin-wall PVC
B) Schedule 20 PVC
C) 3-inch SDR 26 or Schedule 40 PVC
D) 4-inch corrugated HDPE
To prevent crushing and leaks, the "stub-out" to the tank must be at least 3 inches in
diameter and made of heavy-duty SDR 26 or Schedule 40 pipe.
7. For an Aerobic Treatment Unit (ATU) that uses surface application (spray
irrigation), what is the minimum required chlorine residual that must be
maintained in the pump tank?
A) 0.01 mg/l
, B) 0.1 mg/l
C) 1.0 mg/l
D) 5.0 mg/l
The effluent must be disinfected before surface application. TCEQ requires a minimum
chlorine residual of 0.1 mg/l to ensure pathogens are killed before the water is sprayed.
8. Which component is required to be installed in a pump tank to alert the owner
if the pump fails or the water level gets too high?
A) A secondary pump
B) A check valve
C) An audiovisual alarm on a separate circuit
D) A pressure gauge
An audiovisual alarm (light and buzzer) is mandatory. It must be on a separate
branch circuit from the pump so that if the pump trips its breaker, the alarm will still
have power to notify the owner.
9. What is the minimum required distance between a spray head (surface
application) and a property line?
A) 5 feet
B) 20 feet
C) 50 feet
D) 75 feet
To prevent "overspray" onto neighboring lots, spray heads must be set back at least 20
feet from property lines. This can be reduced to 10 feet if specific physical barriers are
present.
10. When installing a tank in an area with a high-water table, what is the primary
concern for the installer?
A) The tank will get too cold
B) Tank buoyancy (the tank "floating" out of the ground)
C) Increased bacterial growth
D) Excessive evaporation
An empty or partially empty tank in saturated soil acts like a boat. Buoyancy can cause
the tank to "pop" or float out of the ground, rupturing the pipes. Installers must use
anchors or "deadmen" to secure it.
11. Which of the following is a requirement for the "trash tank" (pretreatment
tank) located in front of an ATU?
A) It must be at least 2,000 gallons
B) It must have a mechanical aerator
