TEXAS WASTEWATER OPERATOR LICENSING
LEVEL I QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF.
1. What is the primary purpose of wastewater treatment?
A. Produce drinking water
B. Reduce pollutants before discharge
C. Remove all microorganisms
D. Increase water alkalinity
Answer: B
The goal is to reduce pollutants to protect public health and the
environment.
2. What does TCEQ stand for?
A. Texas Commission on Environmental Quality
B. Texas Clean Environment Quality
C. Technical Commission for Environmental Questions
D. Texas Certified Environmental Quality
Answer: A
TCEQ regulates wastewater operator licensing and facility compliance.
3. What is the typical unit for measuring flow in wastewater systems?
,A. Gallons per hour
B. Cubic yards
C. Gallons per minute
D. Million gallons per day
Answer: D
MGD (million gallons per day) is the standard measurement.
4. What is influent?
A. Treated wastewater leaving the plant
B. Solids removed after treatment
C. Raw wastewater entering the plant
D. Recycled activated sludge
Answer: C
Influent is the wastewater that flows into a treatment facility.
5. What is effluent?
A. Wastewater entering the plant
B. Sludge after digestion
C. Treated water leaving the plant
D. Untreated industrial discharge
Answer: C
Effluent is water discharged after treatment.
6. Which process removes settleable solids?
A. Disinfection
B. Primary clarification
C. Aeration
,D. Filtration
Answer: B
Primary clarifiers remove solids by settling.
7. What is BOD?
A. Biological Oxygen Demand
B. Basic Oxygen Dilution
C. Bacteria Oxidation Degree
D. Biogas Output Demand
Answer: A
BOD measures the amount of oxygen needed for microorganisms to
break down organic matter.
8. Which lab test measures suspended particles?
A. BOD
B. TSS
C. pH
D. DO
Answer: B
TSS = Total Suspended Solids.
9. What is the optimal pH range for biological treatment?
A. 3–4
B. 5–6
C. 6.5–8.5
D. 9–10
, Answer: C
Microorganisms function best at near-neutral pH.
10. What is the purpose of aeration in activated sludge?
A. Remove solids
B. Add oxygen for microorganisms
C. Reduce flow rate
D. Kill pathogens
Answer: B
Oxygen supports microbial activity.
11. DO stands for:
A. Dissolved Organics
B. Direct Oxidation
C. Dissolved Oxygen
D. Diluted Oxygen
Answer: C
DO is the amount of oxygen dissolved in water.
12. What is sludge?
A. Treated drinking water
B. Settled solids from wastewater
C. Stormwater runoff
D. Recycled effluent
Answer: B
Sludge consists of solids removed during treatment.
LEVEL I QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF.
1. What is the primary purpose of wastewater treatment?
A. Produce drinking water
B. Reduce pollutants before discharge
C. Remove all microorganisms
D. Increase water alkalinity
Answer: B
The goal is to reduce pollutants to protect public health and the
environment.
2. What does TCEQ stand for?
A. Texas Commission on Environmental Quality
B. Texas Clean Environment Quality
C. Technical Commission for Environmental Questions
D. Texas Certified Environmental Quality
Answer: A
TCEQ regulates wastewater operator licensing and facility compliance.
3. What is the typical unit for measuring flow in wastewater systems?
,A. Gallons per hour
B. Cubic yards
C. Gallons per minute
D. Million gallons per day
Answer: D
MGD (million gallons per day) is the standard measurement.
4. What is influent?
A. Treated wastewater leaving the plant
B. Solids removed after treatment
C. Raw wastewater entering the plant
D. Recycled activated sludge
Answer: C
Influent is the wastewater that flows into a treatment facility.
5. What is effluent?
A. Wastewater entering the plant
B. Sludge after digestion
C. Treated water leaving the plant
D. Untreated industrial discharge
Answer: C
Effluent is water discharged after treatment.
6. Which process removes settleable solids?
A. Disinfection
B. Primary clarification
C. Aeration
,D. Filtration
Answer: B
Primary clarifiers remove solids by settling.
7. What is BOD?
A. Biological Oxygen Demand
B. Basic Oxygen Dilution
C. Bacteria Oxidation Degree
D. Biogas Output Demand
Answer: A
BOD measures the amount of oxygen needed for microorganisms to
break down organic matter.
8. Which lab test measures suspended particles?
A. BOD
B. TSS
C. pH
D. DO
Answer: B
TSS = Total Suspended Solids.
9. What is the optimal pH range for biological treatment?
A. 3–4
B. 5–6
C. 6.5–8.5
D. 9–10
, Answer: C
Microorganisms function best at near-neutral pH.
10. What is the purpose of aeration in activated sludge?
A. Remove solids
B. Add oxygen for microorganisms
C. Reduce flow rate
D. Kill pathogens
Answer: B
Oxygen supports microbial activity.
11. DO stands for:
A. Dissolved Organics
B. Direct Oxidation
C. Dissolved Oxygen
D. Diluted Oxygen
Answer: C
DO is the amount of oxygen dissolved in water.
12. What is sludge?
A. Treated drinking water
B. Settled solids from wastewater
C. Stormwater runoff
D. Recycled effluent
Answer: B
Sludge consists of solids removed during treatment.
