Texas Wastewater Class D Final Review
Practice Exam Newest With Complete
Questions And Correct Detailed Answers|
Brand New Version!2026 2027
1. What is the primary purpose of wastewater treatment?
A. To create drinking water
B. To remove pollutants and protect public health
C. To increase water pressure
D. To disinfect stormwater only
Rationale: Wastewater treatment removes
contaminants to protect human health and the
environment.
2. Which agency regulates wastewater treatment plants in
Texas?
A. EPA
B. TCEQ
C. OSHA
D. CDC
Rationale: The Texas Commission on Environmental
Quality (TCEQ) regulates wastewater operations in
Texas.
3. What does BOD stand for?
A. Biological Oxygen Demand
B. Biochemical Oxygen Demand
, C. Bacterial Oxygen Depletion
D. Biological Organic Discharge
Rationale: BOD measures the amount of oxygen
microorganisms need to break down organic matter.
4. High BOD in effluent indicates:
A. Clean water
B. Excess organic pollution
C. High chlorine levels
D. Low turbidity
Rationale: High BOD means more oxygen is required,
showing organic pollution.
5. What is the normal pH range for wastewater?
A. 1–3
B. 3–5
C. 6.5–8.5
D. 9–12
Rationale: Most wastewater falls within a near-neutral
pH range.
6. Which process removes large solids first?
A. Screening
B. Sedimentation
C. Aeration
D. Disinfection
Rationale: Screens remove rags, sticks, and debris at
the headworks.
, 7. Grit chambers remove:
A. Organic matter
B. Sand and gravel
C. Oils
D. Bacteria
Rationale: Grit chambers protect equipment by
removing heavy inorganic solids.
8. Primary treatment mainly removes:
A. Dissolved solids
B. Settleable solids
C. Nutrients
D. Pathogens
Rationale: Primary clarification allows solids to settle
by gravity.
9. What is sludge?
A. Treated effluent
B. Settled solids removed from wastewater
C. Chlorinated water
D. Industrial waste only
Rationale: Sludge is the solid material removed during
treatment.
10. Secondary treatment primarily removes:
A. Trash
B. Grit
C. Dissolved and suspended organic matter
D. Chlorine
Practice Exam Newest With Complete
Questions And Correct Detailed Answers|
Brand New Version!2026 2027
1. What is the primary purpose of wastewater treatment?
A. To create drinking water
B. To remove pollutants and protect public health
C. To increase water pressure
D. To disinfect stormwater only
Rationale: Wastewater treatment removes
contaminants to protect human health and the
environment.
2. Which agency regulates wastewater treatment plants in
Texas?
A. EPA
B. TCEQ
C. OSHA
D. CDC
Rationale: The Texas Commission on Environmental
Quality (TCEQ) regulates wastewater operations in
Texas.
3. What does BOD stand for?
A. Biological Oxygen Demand
B. Biochemical Oxygen Demand
, C. Bacterial Oxygen Depletion
D. Biological Organic Discharge
Rationale: BOD measures the amount of oxygen
microorganisms need to break down organic matter.
4. High BOD in effluent indicates:
A. Clean water
B. Excess organic pollution
C. High chlorine levels
D. Low turbidity
Rationale: High BOD means more oxygen is required,
showing organic pollution.
5. What is the normal pH range for wastewater?
A. 1–3
B. 3–5
C. 6.5–8.5
D. 9–12
Rationale: Most wastewater falls within a near-neutral
pH range.
6. Which process removes large solids first?
A. Screening
B. Sedimentation
C. Aeration
D. Disinfection
Rationale: Screens remove rags, sticks, and debris at
the headworks.
, 7. Grit chambers remove:
A. Organic matter
B. Sand and gravel
C. Oils
D. Bacteria
Rationale: Grit chambers protect equipment by
removing heavy inorganic solids.
8. Primary treatment mainly removes:
A. Dissolved solids
B. Settleable solids
C. Nutrients
D. Pathogens
Rationale: Primary clarification allows solids to settle
by gravity.
9. What is sludge?
A. Treated effluent
B. Settled solids removed from wastewater
C. Chlorinated water
D. Industrial waste only
Rationale: Sludge is the solid material removed during
treatment.
10. Secondary treatment primarily removes:
A. Trash
B. Grit
C. Dissolved and suspended organic matter
D. Chlorine
