Texas On-Site Sewage Facility (OSSF) Maintenance Provider Licensing Exam
Questions and Answers |Fall 2026/2027 Update | 100% Correct Latest
QUESTION 1
An on-site sewage facility (OSSF) is primarily designed to:
A. Store domestic waste only
B. Treat and disperse wastewater on the property where it originates
C. Collect rainwater for reuse
D. Pump sewage to public mains
CORRECT ANSWER: B. Treat and disperse wastewater on the property where it originates
RATIONALE: OSSFs are decentralized systems managing wastewater treatment and disposal in
areas without centralized sewer service.
QUESTION 2
The Texas Commission on Environmental Quality (TCEQ) is responsible for:
A. Building inspections
B. Enforcing OSSF regulations and licensing standards
C. Plumbing service licenses only
D. Federal wastewater oversight
CORRECT ANSWER: B. Enforcing OSSF regulations and licensing standards
RATIONALE: TCEQ establishes design, installation, and maintenance requirements for OSSFs
under state law.
QUESTION 3
The liquid portion exiting a septic tank before soil dispersal is called:
A. Effluent
B. Sludge
C. Scum
D. Reclaimed water
CORRECT ANSWER: A. Effluent
,RATIONALE: Effluent is clarified liquid wastewater that passes through to further treatment or
disposal components.
QUESTION 4
The sludge layer in a septic tank primarily consists of:
A. Floating fats
B. Settled solids and biomass
C. Gas bubbles
D. Chemical additives
CORRECT ANSWER: B. Settled solids and biomass
RATIONALE: Heavier materials settle and decompose anaerobically, forming the sludge layer at
the tank bottom.
QUESTION 5
What is the main function of a septic tank baffle or tee?
A. Increase tank volume
B. Prevent floating scum from entering the outlet
C. Provide aeration
D. Store grease traps
CORRECT ANSWER: B. Prevent floating scum from entering the outlet
RATIONALE: Baffles or tees direct wastewater flow downward, retaining solids and scum inside
the tank.
QUESTION 6
Texas OSSF regulations are found in which administrative code?
A. 30 TAC Chapter 285
B. 26 CFR Part 301
C. 40 CFR Part 60
D. 29 TAC Chapter 10
CORRECT ANSWER: A. 30 TAC Chapter 285
,RATIONALE: This chapter defines statewide design, permitting, maintenance, and licensing
criteria for OSSFs.
QUESTION 7
The maximum daily wastewater flow used for residential OSSF design is based on:
A. Fixture count
B. Number of bedrooms
C. Lot size
D. Household income
CORRECT ANSWER: B. Number of bedrooms
RATIONALE: Bedroom count correlates with occupancy potential, forming the basis for design
flow calculations.
QUESTION 8
An aerobic treatment unit (ATU) differs from a septic tank because it:
A. Uses only anaerobic microorganisms
B. Is a sealed waste-holding unit
C. Provides aeration and aerobic microbial digestion
D. Requires no maintenance
CORRECT ANSWER: C. Provides aeration and aerobic microbial digestion
RATIONALE: Aerobes oxidize organic matter more efficiently, producing clearer effluent for
subsurface or surface disposal.
QUESTION 9
Chlorination in an ATU disinfection chamber primarily:
A. Neutralizes high pH
B. Kills pathogenic organisms before effluent discharge
C. Reduces turbidity only
D. Adds nutrients to microbes
CORRECT ANSWER: B. Kills pathogenic organisms before effluent discharge
, RATIONALE: Proper chlorine residuals ensure sanitary effluent quality where surface application
occurs.
QUESTION 10
A maintenance provider must inspect a type II or type III system at least:
A. Once every 12 months
B. Twice per year
C. Three times per year
D. Only when customer requests
CORRECT ANSWER: C. Three times per year
RATIONALE: TCEQ requires a minimum of three inspections annually for higher-treatment
aerobic systems.
QUESTION 11
Effluent filters at septic tank outlets serve to:
A. Increase oxygen supply
B. Prevent suspended solids from entering the drainfield
C. Add nutrients
D. Accelerate chemical degradation
CORRECT ANSWER: B. Prevent suspended solids from entering the drainfield
RATIONALE: Filters reduce clogging risk in downstream dispersal components.
QUESTION 12
The typical design life of a properly maintained aerobic treatment unit is:
A. 3–5 years
B. 10–15 years
C. 20+ years
D. Unlimited
CORRECT ANSWER: B. 10–15 years
Questions and Answers |Fall 2026/2027 Update | 100% Correct Latest
QUESTION 1
An on-site sewage facility (OSSF) is primarily designed to:
A. Store domestic waste only
B. Treat and disperse wastewater on the property where it originates
C. Collect rainwater for reuse
D. Pump sewage to public mains
CORRECT ANSWER: B. Treat and disperse wastewater on the property where it originates
RATIONALE: OSSFs are decentralized systems managing wastewater treatment and disposal in
areas without centralized sewer service.
QUESTION 2
The Texas Commission on Environmental Quality (TCEQ) is responsible for:
A. Building inspections
B. Enforcing OSSF regulations and licensing standards
C. Plumbing service licenses only
D. Federal wastewater oversight
CORRECT ANSWER: B. Enforcing OSSF regulations and licensing standards
RATIONALE: TCEQ establishes design, installation, and maintenance requirements for OSSFs
under state law.
QUESTION 3
The liquid portion exiting a septic tank before soil dispersal is called:
A. Effluent
B. Sludge
C. Scum
D. Reclaimed water
CORRECT ANSWER: A. Effluent
,RATIONALE: Effluent is clarified liquid wastewater that passes through to further treatment or
disposal components.
QUESTION 4
The sludge layer in a septic tank primarily consists of:
A. Floating fats
B. Settled solids and biomass
C. Gas bubbles
D. Chemical additives
CORRECT ANSWER: B. Settled solids and biomass
RATIONALE: Heavier materials settle and decompose anaerobically, forming the sludge layer at
the tank bottom.
QUESTION 5
What is the main function of a septic tank baffle or tee?
A. Increase tank volume
B. Prevent floating scum from entering the outlet
C. Provide aeration
D. Store grease traps
CORRECT ANSWER: B. Prevent floating scum from entering the outlet
RATIONALE: Baffles or tees direct wastewater flow downward, retaining solids and scum inside
the tank.
QUESTION 6
Texas OSSF regulations are found in which administrative code?
A. 30 TAC Chapter 285
B. 26 CFR Part 301
C. 40 CFR Part 60
D. 29 TAC Chapter 10
CORRECT ANSWER: A. 30 TAC Chapter 285
,RATIONALE: This chapter defines statewide design, permitting, maintenance, and licensing
criteria for OSSFs.
QUESTION 7
The maximum daily wastewater flow used for residential OSSF design is based on:
A. Fixture count
B. Number of bedrooms
C. Lot size
D. Household income
CORRECT ANSWER: B. Number of bedrooms
RATIONALE: Bedroom count correlates with occupancy potential, forming the basis for design
flow calculations.
QUESTION 8
An aerobic treatment unit (ATU) differs from a septic tank because it:
A. Uses only anaerobic microorganisms
B. Is a sealed waste-holding unit
C. Provides aeration and aerobic microbial digestion
D. Requires no maintenance
CORRECT ANSWER: C. Provides aeration and aerobic microbial digestion
RATIONALE: Aerobes oxidize organic matter more efficiently, producing clearer effluent for
subsurface or surface disposal.
QUESTION 9
Chlorination in an ATU disinfection chamber primarily:
A. Neutralizes high pH
B. Kills pathogenic organisms before effluent discharge
C. Reduces turbidity only
D. Adds nutrients to microbes
CORRECT ANSWER: B. Kills pathogenic organisms before effluent discharge
, RATIONALE: Proper chlorine residuals ensure sanitary effluent quality where surface application
occurs.
QUESTION 10
A maintenance provider must inspect a type II or type III system at least:
A. Once every 12 months
B. Twice per year
C. Three times per year
D. Only when customer requests
CORRECT ANSWER: C. Three times per year
RATIONALE: TCEQ requires a minimum of three inspections annually for higher-treatment
aerobic systems.
QUESTION 11
Effluent filters at septic tank outlets serve to:
A. Increase oxygen supply
B. Prevent suspended solids from entering the drainfield
C. Add nutrients
D. Accelerate chemical degradation
CORRECT ANSWER: B. Prevent suspended solids from entering the drainfield
RATIONALE: Filters reduce clogging risk in downstream dispersal components.
QUESTION 12
The typical design life of a properly maintained aerobic treatment unit is:
A. 3–5 years
B. 10–15 years
C. 20+ years
D. Unlimited
CORRECT ANSWER: B. 10–15 years
