APPROVED CLASS A WATER OPERATOR
LICENSE EXAM Complete Study Guide
2026/2027 - 300 Practice Questions with
Verified Answers & Detailed Rationales
1. How many training hours and years of experience are required for a Class A
Water Operator certification?
• A. 100 hours training and 3 years experience
• B. 200 hours training and 5 years experience
• C. 150 hours training and 4 years experience
• D. 250 hours training and 6 years experience
Answer: B (200 hours training and 5 years experience)
Rationale: Class A Water Operator certification requires 200 hours of training and 5
years of experience, which must include 2 years of hands-on experience .
2. What training and experience is required for a Class B Water Operator?
• A. 36 hours training and 1 year experience
• B. 100 hours training and 3 years experience
• C. 200 hours training and 5 years experience
• D. 16 hours training and no experience
Answer: B (100 hours training and 3 years experience)
Rationale: Class B Water Operator requires 100 hours of training and 3 years of
experience, including 1 year of hands-on experience .
,3. How many training hours and experience are required for a Class C Water
Operator?
• A. 16 hours training and no experience
• B. 36 hours training and 1 year experience
• C. 100 hours training and 3 years experience
• D. 200 hours training and 5 years experience
Answer: B (36 hours training and 1 year experience)
Rationale: Class C Water Operator requires 36 hours of training and 1 year of
experience .
4. What are the training requirements for a Class D Water Operator?
• A. 16 hours training and no experience
• B. 36 hours training and 1 year experience
• C. 100 hours training and 3 years experience
• D. 200 hours training and 5 years experience
Answer: A (16 hours training and no experience)
Rationale: Class D Water Operator requires 16 hours of training and no prior
experience .
5. What is the definition of a Community Water System?
• A. Any public water supply that serves at least 10 service connections
• B. A public water supply that has at least 15 service connections or serves 25 or
more persons on a regular basis
• C. Any water system that serves a population over 1,000
• D. A private well serving a single household
,Answer: B
Rationale: A Community Water System is a public water supply that has at least 15
service connections or serves 25 or more persons on a regular basis .
6. What is the definition of Primary Contaminants?
• A. Contaminants that affect the taste and odor of water
• B. Contaminants identified by the EPA as harmful to human health
• C. Contaminants that cause aesthetic issues only
• D. Contaminants found naturally in all water sources
Answer: B
Rationale: Primary Contaminants are contaminants identified by the EPA as harmful to
human health. They have enforceable Maximum Contaminant Levels (MCLs) .
7. What is the Maximum Contaminant Level (MCL)?
• A. The level at which contaminants become noticeable by taste
• B. The level in which contaminants must not exceed, or public notification is
required
• C. The level at which water becomes unsafe to drink
• D. The level recommended for optimal water quality
Answer: B
Rationale: The MCL is the level in which contaminants must not exceed, or public
notification is required. These are enforceable standards set by the EPA .
8. When must an operator be certified?
• A. Within 30 days of employment
• B. Within 10 days of employment or appointment as an operator
, • C. Within 60 days of employment
• D. Within 90 days of employment
Answer: B
Rationale: An operator must be certified within 10 days of employment or appointment
as an operator .
9. How long must records at water systems be kept?
• A. 3 years
• B. 5 years
• C. 10 years
• D. Permanently
Answer: C (10 years)
Rationale: Records at water systems must be kept for 10 years .
10. What is the consequence of falsification of records?
• A. Loss of certification only
• B. A warning and retraining
• C. Loss of certification, fine of up to $25,000 per violation, and 1 year in jail
• D. Suspension of certification for 6 months
Answer: C
Rationale: Falsification of records is punishable by loss of certification, fine of up to
$25,000 per violation, and 1 year in jail .
11. What is the Monthly Operations Report (MOR)?
• A. A report submitted only when there is a violation
LICENSE EXAM Complete Study Guide
2026/2027 - 300 Practice Questions with
Verified Answers & Detailed Rationales
1. How many training hours and years of experience are required for a Class A
Water Operator certification?
• A. 100 hours training and 3 years experience
• B. 200 hours training and 5 years experience
• C. 150 hours training and 4 years experience
• D. 250 hours training and 6 years experience
Answer: B (200 hours training and 5 years experience)
Rationale: Class A Water Operator certification requires 200 hours of training and 5
years of experience, which must include 2 years of hands-on experience .
2. What training and experience is required for a Class B Water Operator?
• A. 36 hours training and 1 year experience
• B. 100 hours training and 3 years experience
• C. 200 hours training and 5 years experience
• D. 16 hours training and no experience
Answer: B (100 hours training and 3 years experience)
Rationale: Class B Water Operator requires 100 hours of training and 3 years of
experience, including 1 year of hands-on experience .
,3. How many training hours and experience are required for a Class C Water
Operator?
• A. 16 hours training and no experience
• B. 36 hours training and 1 year experience
• C. 100 hours training and 3 years experience
• D. 200 hours training and 5 years experience
Answer: B (36 hours training and 1 year experience)
Rationale: Class C Water Operator requires 36 hours of training and 1 year of
experience .
4. What are the training requirements for a Class D Water Operator?
• A. 16 hours training and no experience
• B. 36 hours training and 1 year experience
• C. 100 hours training and 3 years experience
• D. 200 hours training and 5 years experience
Answer: A (16 hours training and no experience)
Rationale: Class D Water Operator requires 16 hours of training and no prior
experience .
5. What is the definition of a Community Water System?
• A. Any public water supply that serves at least 10 service connections
• B. A public water supply that has at least 15 service connections or serves 25 or
more persons on a regular basis
• C. Any water system that serves a population over 1,000
• D. A private well serving a single household
,Answer: B
Rationale: A Community Water System is a public water supply that has at least 15
service connections or serves 25 or more persons on a regular basis .
6. What is the definition of Primary Contaminants?
• A. Contaminants that affect the taste and odor of water
• B. Contaminants identified by the EPA as harmful to human health
• C. Contaminants that cause aesthetic issues only
• D. Contaminants found naturally in all water sources
Answer: B
Rationale: Primary Contaminants are contaminants identified by the EPA as harmful to
human health. They have enforceable Maximum Contaminant Levels (MCLs) .
7. What is the Maximum Contaminant Level (MCL)?
• A. The level at which contaminants become noticeable by taste
• B. The level in which contaminants must not exceed, or public notification is
required
• C. The level at which water becomes unsafe to drink
• D. The level recommended for optimal water quality
Answer: B
Rationale: The MCL is the level in which contaminants must not exceed, or public
notification is required. These are enforceable standards set by the EPA .
8. When must an operator be certified?
• A. Within 30 days of employment
• B. Within 10 days of employment or appointment as an operator
, • C. Within 60 days of employment
• D. Within 90 days of employment
Answer: B
Rationale: An operator must be certified within 10 days of employment or appointment
as an operator .
9. How long must records at water systems be kept?
• A. 3 years
• B. 5 years
• C. 10 years
• D. Permanently
Answer: C (10 years)
Rationale: Records at water systems must be kept for 10 years .
10. What is the consequence of falsification of records?
• A. Loss of certification only
• B. A warning and retraining
• C. Loss of certification, fine of up to $25,000 per violation, and 1 year in jail
• D. Suspension of certification for 6 months
Answer: C
Rationale: Falsification of records is punishable by loss of certification, fine of up to
$25,000 per violation, and 1 year in jail .
11. What is the Monthly Operations Report (MOR)?
• A. A report submitted only when there is a violation
