Texas Wastewater Class B | Questions with 100% Correct
Answers | Verified | Latest Update 2025
Texas Wastewater Class B Practice Questions – Verified 2025
1. What is the primary purpose of an activated sludge process?
A. Chlorination
B. Removal of organic matter
C. Sand filtration
D. pH adjustment
Activated sludge promotes biological degradation of organic material in
wastewater.
2. What is the minimum chlorine contact time required by TCEQ rules when
disinfecting wastewater effluent?
A. 10 minutes
B. 15 minutes
C. 30 minutes
D. 60 minutes
TCEQ requires a minimum of 30 minutes contact time at peak flow for effective
disinfection.
3. Which lab test best indicates the strength of wastewater?
A. pH
B. BOD
C. TSS
D. DO
,Biochemical Oxygen Demand (BOD) reflects the amount of organic material
present.
4. What is the typical range of pH for treated wastewater discharge?
A. 5.0 - 6.0
B. 6.0 - 9.0
C. 7.5 - 10.0
D. 4.0 - 6.0
TCEQ requires pH of treated effluent to be within 6.0 to 9.0.
5. What type of bacteria thrives in the activated sludge process?
A. Anaerobic
B. Facultative
C. Aerobic
D. Pathogenic
Aerobic bacteria dominate in the activated sludge system, using oxygen to
break down waste.
6. What is the main cause of filamentous bulking in an aeration basin?
A. High chlorine levels
B. Low dissolved oxygen levels
C. High alkalinity
D. Excessive pH
Low DO promotes filamentous bacteria growth, leading to poor settling sludge.
7. What is the typical MLSS concentration range for extended aeration systems?
A. 500–1,000 mg/L
B. 2,000–3,000 mg/L
, C. 3,000–5,000 mg/L
D. 5,000–8,000 mg/L
Extended aeration systems operate at higher MLSS due to longer detention
times.
8. What is the purpose of a clarifier in wastewater treatment?
A. Add chlorine
B. Settle suspended solids
C. Increase oxygen
D. Remove grease
Clarifiers separate solids from liquids, allowing sludge to settle.
9. What is the F:M ratio a comparison of?
A. Flow to mass
B. Food to microorganisms
C. Filter media to influent
D. Final effluent to mean cell residence time
The F:M ratio helps operators control the biological activity in the aeration
basin.
10. What test measures the amount of oxygen consumed by microorganisms
over a five-day period?
A. DO
B. COD
C. BOD
D. TSS
BOD5 is the standard measure for organic pollution in wastewater.
Answers | Verified | Latest Update 2025
Texas Wastewater Class B Practice Questions – Verified 2025
1. What is the primary purpose of an activated sludge process?
A. Chlorination
B. Removal of organic matter
C. Sand filtration
D. pH adjustment
Activated sludge promotes biological degradation of organic material in
wastewater.
2. What is the minimum chlorine contact time required by TCEQ rules when
disinfecting wastewater effluent?
A. 10 minutes
B. 15 minutes
C. 30 minutes
D. 60 minutes
TCEQ requires a minimum of 30 minutes contact time at peak flow for effective
disinfection.
3. Which lab test best indicates the strength of wastewater?
A. pH
B. BOD
C. TSS
D. DO
,Biochemical Oxygen Demand (BOD) reflects the amount of organic material
present.
4. What is the typical range of pH for treated wastewater discharge?
A. 5.0 - 6.0
B. 6.0 - 9.0
C. 7.5 - 10.0
D. 4.0 - 6.0
TCEQ requires pH of treated effluent to be within 6.0 to 9.0.
5. What type of bacteria thrives in the activated sludge process?
A. Anaerobic
B. Facultative
C. Aerobic
D. Pathogenic
Aerobic bacteria dominate in the activated sludge system, using oxygen to
break down waste.
6. What is the main cause of filamentous bulking in an aeration basin?
A. High chlorine levels
B. Low dissolved oxygen levels
C. High alkalinity
D. Excessive pH
Low DO promotes filamentous bacteria growth, leading to poor settling sludge.
7. What is the typical MLSS concentration range for extended aeration systems?
A. 500–1,000 mg/L
B. 2,000–3,000 mg/L
, C. 3,000–5,000 mg/L
D. 5,000–8,000 mg/L
Extended aeration systems operate at higher MLSS due to longer detention
times.
8. What is the purpose of a clarifier in wastewater treatment?
A. Add chlorine
B. Settle suspended solids
C. Increase oxygen
D. Remove grease
Clarifiers separate solids from liquids, allowing sludge to settle.
9. What is the F:M ratio a comparison of?
A. Flow to mass
B. Food to microorganisms
C. Filter media to influent
D. Final effluent to mean cell residence time
The F:M ratio helps operators control the biological activity in the aeration
basin.
10. What test measures the amount of oxygen consumed by microorganisms
over a five-day period?
A. DO
B. COD
C. BOD
D. TSS
BOD5 is the standard measure for organic pollution in wastewater.
