TEXAS ENVIRONMENTAL OPERATOR
LICENSING LEVEL II QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which parameter is most critical for determining biological activity
in activated sludge?
A. Turbidity
B. pH
C. Dissolved Oxygen
D. Conductivity
Answer: C
Dissolved oxygen supports microbial metabolism in the activated sludge
process.
2. What is the primary purpose of chlorination in water treatment?
A. Hardness removal
B. Disinfection
C. Sedimentation enhancement
D. pH stabilization
Answer: B
Chlorination is mainly used to inactivate pathogens.
3. A flowmeter reading in MGD stands for:
,A. Million gallons discharged
B. Million gallons delivered
C. Million gallons per day
D. Minimum gallon demand
Answer: C
MGD is the standard unit for large-volume flow rates.
4. During sedimentation, the main mechanism removing suspended
solids is:
A. Oxidation
B. Filtration
C. Settling by gravity
D. Aeration
Answer: C
Gravity causes particles denser than water to settle.
5. Which lab value is most important in assessing organic loading to a
wastewater plant?
A. TSS
B. BOD
C. pH
D. Temperature
Answer: B
BOD indicates the oxygen demand for biodegradable organics.
6. The most common coagulant in drinking water treatment is:
,A. Sodium hypochlorite
B. Ferric chloride
C. Aluminum sulfate
D. Sodium carbonate
Answer: C
Alum is widely used for coagulation and floc formation.
7. A confined space requires monitoring for oxygen because:
A. Oxygen corrodes metal
B. High oxygen causes dizziness
C. Low oxygen can be fatal
D. It prevents microbial growth
Answer: C
Low oxygen levels pose immediate life-threatening hazards.
8. Sludge with a strong rotten egg odor typically indicates:
A. Aerobic activity
B. Anaerobic decomposition
C. Excess DO
D. Polymer overdose
Answer: B
Hydrogen sulfide odor is associated with anaerobic processes.
9. Turbidity is measured in:
A. MGD
B. NTU
C. mg/L
, D. pCi
Answer: B
NTU measures clarity and suspended particles.
10. The purpose of a grit chamber is to remove:
A. Heavy inorganic materials
B. Organic solids
C. Pathogens
D. Dissolved solids
Answer: A
Grit chambers target sand, gravel, and other heavy debris.
11. Which process increases the surface area for bacteria in
treatment?
A. Coagulation
B. Filtration
C. Trickling filters
D. Disinfection
Answer: C
Trickling filters rely on biofilm growth to decompose organics.
12. pH is a measure of:
A. Acidity/alkalinity
B. Temperature
C. Conductance
D. Oxygen saturation
LICENSING LEVEL II QUESTIONS AND
CORRECT ANSWERS (VERIFIED ANSWERS)
PLUS RATIONALES 2026 Q&A | INSTANT
DOWNLOAD PDF
1. Which parameter is most critical for determining biological activity
in activated sludge?
A. Turbidity
B. pH
C. Dissolved Oxygen
D. Conductivity
Answer: C
Dissolved oxygen supports microbial metabolism in the activated sludge
process.
2. What is the primary purpose of chlorination in water treatment?
A. Hardness removal
B. Disinfection
C. Sedimentation enhancement
D. pH stabilization
Answer: B
Chlorination is mainly used to inactivate pathogens.
3. A flowmeter reading in MGD stands for:
,A. Million gallons discharged
B. Million gallons delivered
C. Million gallons per day
D. Minimum gallon demand
Answer: C
MGD is the standard unit for large-volume flow rates.
4. During sedimentation, the main mechanism removing suspended
solids is:
A. Oxidation
B. Filtration
C. Settling by gravity
D. Aeration
Answer: C
Gravity causes particles denser than water to settle.
5. Which lab value is most important in assessing organic loading to a
wastewater plant?
A. TSS
B. BOD
C. pH
D. Temperature
Answer: B
BOD indicates the oxygen demand for biodegradable organics.
6. The most common coagulant in drinking water treatment is:
,A. Sodium hypochlorite
B. Ferric chloride
C. Aluminum sulfate
D. Sodium carbonate
Answer: C
Alum is widely used for coagulation and floc formation.
7. A confined space requires monitoring for oxygen because:
A. Oxygen corrodes metal
B. High oxygen causes dizziness
C. Low oxygen can be fatal
D. It prevents microbial growth
Answer: C
Low oxygen levels pose immediate life-threatening hazards.
8. Sludge with a strong rotten egg odor typically indicates:
A. Aerobic activity
B. Anaerobic decomposition
C. Excess DO
D. Polymer overdose
Answer: B
Hydrogen sulfide odor is associated with anaerobic processes.
9. Turbidity is measured in:
A. MGD
B. NTU
C. mg/L
, D. pCi
Answer: B
NTU measures clarity and suspended particles.
10. The purpose of a grit chamber is to remove:
A. Heavy inorganic materials
B. Organic solids
C. Pathogens
D. Dissolved solids
Answer: A
Grit chambers target sand, gravel, and other heavy debris.
11. Which process increases the surface area for bacteria in
treatment?
A. Coagulation
B. Filtration
C. Trickling filters
D. Disinfection
Answer: C
Trickling filters rely on biofilm growth to decompose organics.
12. pH is a measure of:
A. Acidity/alkalinity
B. Temperature
C. Conductance
D. Oxygen saturation
