Page 1 of 147
Virginia Wastewater Operator Class 1 License
Exam QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Virginia Wastewater Operator Class 1 License Exam
QUESTION 1
Which preliminary treatment process removes large objects such as rags, sticks, and plastics from
wastewater?
| ○ A. Grit removal |
| ● B. Screening |
| ○ C. Sedimentation |
| ○ D. Chlorination |
Correct Answer: B
Rationale: Screening is used to remove large debris that could damage equipment or hinder
downstream processes . Bar screens are the first line of defense in wastewater treatment plants.
QUESTION 2
What is the main purpose of comminution in wastewater treatment?
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| ○ A. To remove grit |
| ● B. To grind and shred solids |
| ○ C. To disinfect wastewater |
| ○ D. To settle out suspended solids |
Correct Answer: B
Rationale: Comminutors grind and shred solids to prevent clogging and improve downstream treatment
efficiency . This process reduces particle size for easier handling.
QUESTION 3
In grit removal systems, which characteristic is most important for effective separation?
| ○ A. Color of particles |
| ● B. Particle density |
| ○ C. Particle stickiness |
| ○ D. Particle odor |
Correct Answer: B
Rationale: Grit removal relies on the higher density of grit compared to organic matter, allowing it to
settle . This is the fundamental principle of gravity separation.
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QUESTION 4
What device is commonly used to measure the flow of wastewater entering a plant?
| ○ A. Bar screen |
| ● B. Flow meter |
| ○ C. Chlorinator |
| ○ D. Diffuser |
Correct Answer: B
Rationale: Flow meters are designed to accurately measure wastewater flow rates . This data is essential
for process control and regulatory reporting.
QUESTION 5
Flow equalization primarily helps to:
| ○ A. Remove pathogens |
| ○ B. Prevent equipment wear |
| ● C. Balance variations in flow and load |
| ○ D. Increase sludge production |
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Correct Answer: C
Rationale: Flow equalization basins smooth out fluctuations in flow and pollutant load to optimize
downstream treatment . This stabilizes the treatment process.
QUESTION 6
Which of the following is NOT a typical component of primary treatment?
| ○ A. Sedimentation |
| ○ B. Flotation |
| ● C. Activated sludge |
| ○ D. Clarifier operation |
Correct Answer: C
Rationale: Activated sludge is a secondary treatment process, not primary . Primary treatment involves
physical separation processes.
QUESTION 7
What is the primary function of a primary clarifier?
Virginia Wastewater Operator Class 1 License
Exam QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Virginia Wastewater Operator Class 1 License Exam
QUESTION 1
Which preliminary treatment process removes large objects such as rags, sticks, and plastics from
wastewater?
| ○ A. Grit removal |
| ● B. Screening |
| ○ C. Sedimentation |
| ○ D. Chlorination |
Correct Answer: B
Rationale: Screening is used to remove large debris that could damage equipment or hinder
downstream processes . Bar screens are the first line of defense in wastewater treatment plants.
QUESTION 2
What is the main purpose of comminution in wastewater treatment?
, Page 2 of 147
| ○ A. To remove grit |
| ● B. To grind and shred solids |
| ○ C. To disinfect wastewater |
| ○ D. To settle out suspended solids |
Correct Answer: B
Rationale: Comminutors grind and shred solids to prevent clogging and improve downstream treatment
efficiency . This process reduces particle size for easier handling.
QUESTION 3
In grit removal systems, which characteristic is most important for effective separation?
| ○ A. Color of particles |
| ● B. Particle density |
| ○ C. Particle stickiness |
| ○ D. Particle odor |
Correct Answer: B
Rationale: Grit removal relies on the higher density of grit compared to organic matter, allowing it to
settle . This is the fundamental principle of gravity separation.
, Page 3 of 147
QUESTION 4
What device is commonly used to measure the flow of wastewater entering a plant?
| ○ A. Bar screen |
| ● B. Flow meter |
| ○ C. Chlorinator |
| ○ D. Diffuser |
Correct Answer: B
Rationale: Flow meters are designed to accurately measure wastewater flow rates . This data is essential
for process control and regulatory reporting.
QUESTION 5
Flow equalization primarily helps to:
| ○ A. Remove pathogens |
| ○ B. Prevent equipment wear |
| ● C. Balance variations in flow and load |
| ○ D. Increase sludge production |
, Page 4 of 147
Correct Answer: C
Rationale: Flow equalization basins smooth out fluctuations in flow and pollutant load to optimize
downstream treatment . This stabilizes the treatment process.
QUESTION 6
Which of the following is NOT a typical component of primary treatment?
| ○ A. Sedimentation |
| ○ B. Flotation |
| ● C. Activated sludge |
| ○ D. Clarifier operation |
Correct Answer: C
Rationale: Activated sludge is a secondary treatment process, not primary . Primary treatment involves
physical separation processes.
QUESTION 7
What is the primary function of a primary clarifier?
