Texas Class C Wastewater Treatment
Operator Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
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1. What is the primary purpose of wastewater treatment?
A. To increase nutrient levels
B. To produce sludge for disposal
C. To protect public health and the environment
D. To generate potable water directly
The primary goal of wastewater treatment is to remove
contaminants to protect public health and prevent environmental
damage.
2. In Texas, which agency regulates wastewater treatment plant operator
licensing?
, A. Texas Commission on Environmental Quality (TCEQ)
B. Environmental Protection Agency (EPA)
C. Texas Department of Health
D. Texas Water Development Board
TCEQ oversees the licensing and certification of wastewater
operators in Texas.
3. Which term describes the suspended solids and microorganisms in the
aeration basin?
A. Supernatant
B. Sludge blanket
C. Effluent
D. Mixed liquor
Mixed liquor is the combination of wastewater and activated sludge
in the aeration basin.
4. Which process step removes large debris such as rags and sticks?
A. Grit removal
B. Screening
C. Sedimentation
D. Disinfection
Screening is the first step in wastewater treatment to physically
remove large debris.
5. What is the primary role of the grit chamber?
A. Remove floating grease
, C. Remove heavy inorganic particles
B. Remove dissolved solids
D. Remove pathogens
Grit chambers slow the flow so sand and gravel settle out before
further treatment.
6. Which unit process relies on microorganisms to break down organic
matter?
A. Biological treatment
B. Chemical treatment
C. Screening
D. Chlorination
Biological treatment uses microorganisms to consume organic
pollutants.
7. Which is a common type of secondary clarifier?
A. Imhoff tank
B. Bar screen
C. Sand filter
D. Circular sedimentation tank
Circular secondary clarifiers are widely used to settle biological solids
after aeration.
8. The measure of oxygen consumed by microorganisms while
decomposing organic matter is:
A. Total suspended solids
, B. Biochemical oxygen demand (BOD)
C. Chemical oxygen demand (COD)
D. Dissolved oxygen
BOD measures the amount of oxygen microorganisms need to
decompose organic material in water.
9. Which parameter is most important for aeration basin performance?
A. pH
B. Turbidity
C. Dissolved oxygen
D. Chlorine residual
Maintaining adequate DO in the aeration basin ensures
microorganisms remain active.
10. Which lab test measures the concentration of solids that settle
in a graduated cylinder in 30 minutes?
A. Settleable solids
B. Volatile solids
C. TSS
D. Sludge age
Settleable solids are measured to assess clarifier performance and
sludge settling ability.
11. The activated sludge process requires returning settled biomass
to:
A. Headworks
Operator Exam Questions And Correct
Answers (Verified Answers) Plus
Rationales 2025|2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of wastewater treatment?
A. To increase nutrient levels
B. To produce sludge for disposal
C. To protect public health and the environment
D. To generate potable water directly
The primary goal of wastewater treatment is to remove
contaminants to protect public health and prevent environmental
damage.
2. In Texas, which agency regulates wastewater treatment plant operator
licensing?
, A. Texas Commission on Environmental Quality (TCEQ)
B. Environmental Protection Agency (EPA)
C. Texas Department of Health
D. Texas Water Development Board
TCEQ oversees the licensing and certification of wastewater
operators in Texas.
3. Which term describes the suspended solids and microorganisms in the
aeration basin?
A. Supernatant
B. Sludge blanket
C. Effluent
D. Mixed liquor
Mixed liquor is the combination of wastewater and activated sludge
in the aeration basin.
4. Which process step removes large debris such as rags and sticks?
A. Grit removal
B. Screening
C. Sedimentation
D. Disinfection
Screening is the first step in wastewater treatment to physically
remove large debris.
5. What is the primary role of the grit chamber?
A. Remove floating grease
, C. Remove heavy inorganic particles
B. Remove dissolved solids
D. Remove pathogens
Grit chambers slow the flow so sand and gravel settle out before
further treatment.
6. Which unit process relies on microorganisms to break down organic
matter?
A. Biological treatment
B. Chemical treatment
C. Screening
D. Chlorination
Biological treatment uses microorganisms to consume organic
pollutants.
7. Which is a common type of secondary clarifier?
A. Imhoff tank
B. Bar screen
C. Sand filter
D. Circular sedimentation tank
Circular secondary clarifiers are widely used to settle biological solids
after aeration.
8. The measure of oxygen consumed by microorganisms while
decomposing organic matter is:
A. Total suspended solids
, B. Biochemical oxygen demand (BOD)
C. Chemical oxygen demand (COD)
D. Dissolved oxygen
BOD measures the amount of oxygen microorganisms need to
decompose organic material in water.
9. Which parameter is most important for aeration basin performance?
A. pH
B. Turbidity
C. Dissolved oxygen
D. Chlorine residual
Maintaining adequate DO in the aeration basin ensures
microorganisms remain active.
10. Which lab test measures the concentration of solids that settle
in a graduated cylinder in 30 minutes?
A. Settleable solids
B. Volatile solids
C. TSS
D. Sludge age
Settleable solids are measured to assess clarifier performance and
sludge settling ability.
11. The activated sludge process requires returning settled biomass
to:
A. Headworks
