Basic Wastewater Operator Practice
Exam Questions and Answers | Latest
Version | 2025/2026 | Correct & Verified
What is the main purpose of screening in a wastewater treatment plant?
✔✔A. Remove large debris
B. Disinfect the water
C. Add oxygen
D. Adjust pH
What does TSS stand for in wastewater testing?
A. Total System Solids
B. Total Surface Solids
✔✔C. Total Suspended Solids
D. Total Sludge Solids
Which process is mainly responsible for reducing organic matter in wastewater?
A. Screening
B. Chlorination
1
,✔✔C. Biological treatment
D. Grit removal
What is the normal range of pH for treated wastewater effluent?
A. 2–3
B. 4–5
✔✔C. 6.5–8.5
D. 10–12
What is the purpose of a flow meter in wastewater systems?
A. Measure pressure
✔✔B. Measure flow rate
C. Measure chlorine
D. Measure solids
Which of the following is a secondary treatment method?
A. Grit removal
✔✔B. Activated sludge
2
,C. Screening
D. Bar racks
What is the main purpose of disinfection in wastewater treatment?
A. Reduce BOD
✔✔B. Destroy pathogens
C. Increase DO
D. Remove grit
Which gas is dangerous and smells like rotten eggs in sewers?
A. Methane
✔✔B. Hydrogen sulfide
C. Oxygen
D. Nitrogen
Which part of a treatment plant removes sand and gravel?
A. Bar screen
✔✔B. Grit chamber
3
, C. Trickling filter
D. Chlorine contact tank
Which instrument is used to measure dissolved oxygen?
A. Turbidimeter
✔✔B. DO meter
C. pH probe
D. Flow gauge
What does FOG in wastewater refer to?
A. Flow Operation Gauge
B. Fine Organic Grit
✔✔C. Fats, Oils, and Grease
D. Final Outgoing Gas
What is the primary purpose of a primary clarifier?
A. Kill pathogens
✔✔B. Settle solids
4
Exam Questions and Answers | Latest
Version | 2025/2026 | Correct & Verified
What is the main purpose of screening in a wastewater treatment plant?
✔✔A. Remove large debris
B. Disinfect the water
C. Add oxygen
D. Adjust pH
What does TSS stand for in wastewater testing?
A. Total System Solids
B. Total Surface Solids
✔✔C. Total Suspended Solids
D. Total Sludge Solids
Which process is mainly responsible for reducing organic matter in wastewater?
A. Screening
B. Chlorination
1
,✔✔C. Biological treatment
D. Grit removal
What is the normal range of pH for treated wastewater effluent?
A. 2–3
B. 4–5
✔✔C. 6.5–8.5
D. 10–12
What is the purpose of a flow meter in wastewater systems?
A. Measure pressure
✔✔B. Measure flow rate
C. Measure chlorine
D. Measure solids
Which of the following is a secondary treatment method?
A. Grit removal
✔✔B. Activated sludge
2
,C. Screening
D. Bar racks
What is the main purpose of disinfection in wastewater treatment?
A. Reduce BOD
✔✔B. Destroy pathogens
C. Increase DO
D. Remove grit
Which gas is dangerous and smells like rotten eggs in sewers?
A. Methane
✔✔B. Hydrogen sulfide
C. Oxygen
D. Nitrogen
Which part of a treatment plant removes sand and gravel?
A. Bar screen
✔✔B. Grit chamber
3
, C. Trickling filter
D. Chlorine contact tank
Which instrument is used to measure dissolved oxygen?
A. Turbidimeter
✔✔B. DO meter
C. pH probe
D. Flow gauge
What does FOG in wastewater refer to?
A. Flow Operation Gauge
B. Fine Organic Grit
✔✔C. Fats, Oils, and Grease
D. Final Outgoing Gas
What is the primary purpose of a primary clarifier?
A. Kill pathogens
✔✔B. Settle solids
4
