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Virginia Wastewater Operator Class 4 License
Exam QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Virginia Wastewater Operator Class 4 License Exam
10 Point-Form Exam Coverage Areas
1. Activated Sludge (15–20%) – Process variations, microbiology, MCRT, sludge wasting, foaming,
troubleshooting .
2. Disinfection – Chlorination (hypochlorite/gas), dechlorination, UV disinfection, safety,
chlorinator operation .
3. Laboratory – Sampling, BOD, TSS, pH, DO, chlorine residual, fecal coliform testing .
4. Safety – Confined space entry, H₂S/explosive gas hazards, PPE, chemical handling, OSHA
regulations, emergency plans .
5. Sedimentation/Clarifiers – Primary/secondary clarifiers, troubleshooting, flotation processes,
loading rates .
6. Preliminary Treatment – Bar screens, comminutors, grit channels, flow measurement devices
(weirs, flumes, electromagnetic, ultrasonic, bubbler) .
7. Pumps & Pumping – Centrifugal/progressive cavity pumps, maintenance, troubleshooting,
controls, water hammer .
8. Solids Handling – Residual solids management, thickening, dewatering, anaerobic digestion .
9. Advanced Treatment – Nutrient removal (nitrification/denitrification), phosphorus removal,
tertiary filtration .
10. Mathematics (10–15%) – Detention time, flow rates, chemical dosing, loading rates,
conversions .
Section 1: Eligibility & Licensing Requirements
QUESTION 1
A Class 4 license applicant must have either a high school diploma and how much experience?
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A) Three months
B) Six months
C) One year
D) Two years
Answer: B – The minimum requirement is six months of experience as an operator-in-training in a Class
4 or higher facility .
QUESTION 2
If an applicant does NOT have a high school diploma or GED, how much experience is required for a
Class IV license?
A) Six months
B) One year
C) Two years
D) Four years
Answer: B – One year of experience is required for applicants without a diploma or GED .
QUESTION 3
How often must Virginia wastewater operator licenses be renewed?
A) Every year
B) Every 2 years
C) Every 3 years
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D) Every 5 years
Answer: B – Licenses must be renewed every two years .
QUESTION 4
Can an individual take the Class IV examination before completing all education and experience
requirements?
A) No, all requirements must be met first
B) Yes, but the license is not issued until requirements are verified and met
C) Yes, and the license is issued immediately
D) No, only after three years of experience
Answer: B – Applicants may take the exam before meeting requirements, provided all requirements will
be met within three months after the exam date. The license is not issued until all requirements are
verified .
QUESTION 5
What is the minimum education requirement for a Class 4 license in Virginia?
A) Bachelor's degree
B) Associate's degree
C) High school diploma or GED
D) No education requirement
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Answer: C – A high school diploma or GED is the minimum education requirement, though a Class IV
license can be obtained with no high school diploma and one year of experience .
QUESTION 6
How many re-exam attempts are allowed before a new application is required?
A) One attempt
B) Two attempts
C) Three attempts
D) Unlimited attempts
Answer: B – An applicant may retake the exam up to two times within two years. If both reexaminations
are failed, a new application with fee is required .
QUESTION 7
What is the minimum lead time to submit an application for examination or re-examination?
A) 15 days
B) 30 days
C) 45 days
D) 60 days
Answer: D – Applications must be received at least 60 days prior to a scheduled examination .
Virginia Wastewater Operator Class 4 License
Exam QUESTIONS AND VERIFIED ANSWERS WITH
RATIONALES JUST RELEASED
Virginia Wastewater Operator Class 4 License Exam
10 Point-Form Exam Coverage Areas
1. Activated Sludge (15–20%) – Process variations, microbiology, MCRT, sludge wasting, foaming,
troubleshooting .
2. Disinfection – Chlorination (hypochlorite/gas), dechlorination, UV disinfection, safety,
chlorinator operation .
3. Laboratory – Sampling, BOD, TSS, pH, DO, chlorine residual, fecal coliform testing .
4. Safety – Confined space entry, H₂S/explosive gas hazards, PPE, chemical handling, OSHA
regulations, emergency plans .
5. Sedimentation/Clarifiers – Primary/secondary clarifiers, troubleshooting, flotation processes,
loading rates .
6. Preliminary Treatment – Bar screens, comminutors, grit channels, flow measurement devices
(weirs, flumes, electromagnetic, ultrasonic, bubbler) .
7. Pumps & Pumping – Centrifugal/progressive cavity pumps, maintenance, troubleshooting,
controls, water hammer .
8. Solids Handling – Residual solids management, thickening, dewatering, anaerobic digestion .
9. Advanced Treatment – Nutrient removal (nitrification/denitrification), phosphorus removal,
tertiary filtration .
10. Mathematics (10–15%) – Detention time, flow rates, chemical dosing, loading rates,
conversions .
Section 1: Eligibility & Licensing Requirements
QUESTION 1
A Class 4 license applicant must have either a high school diploma and how much experience?
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A) Three months
B) Six months
C) One year
D) Two years
Answer: B – The minimum requirement is six months of experience as an operator-in-training in a Class
4 or higher facility .
QUESTION 2
If an applicant does NOT have a high school diploma or GED, how much experience is required for a
Class IV license?
A) Six months
B) One year
C) Two years
D) Four years
Answer: B – One year of experience is required for applicants without a diploma or GED .
QUESTION 3
How often must Virginia wastewater operator licenses be renewed?
A) Every year
B) Every 2 years
C) Every 3 years
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D) Every 5 years
Answer: B – Licenses must be renewed every two years .
QUESTION 4
Can an individual take the Class IV examination before completing all education and experience
requirements?
A) No, all requirements must be met first
B) Yes, but the license is not issued until requirements are verified and met
C) Yes, and the license is issued immediately
D) No, only after three years of experience
Answer: B – Applicants may take the exam before meeting requirements, provided all requirements will
be met within three months after the exam date. The license is not issued until all requirements are
verified .
QUESTION 5
What is the minimum education requirement for a Class 4 license in Virginia?
A) Bachelor's degree
B) Associate's degree
C) High school diploma or GED
D) No education requirement
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Answer: C – A high school diploma or GED is the minimum education requirement, though a Class IV
license can be obtained with no high school diploma and one year of experience .
QUESTION 6
How many re-exam attempts are allowed before a new application is required?
A) One attempt
B) Two attempts
C) Three attempts
D) Unlimited attempts
Answer: B – An applicant may retake the exam up to two times within two years. If both reexaminations
are failed, a new application with fee is required .
QUESTION 7
What is the minimum lead time to submit an application for examination or re-examination?
A) 15 days
B) 30 days
C) 45 days
D) 60 days
Answer: D – Applications must be received at least 60 days prior to a scheduled examination .
