Drinking Water Operator Certification
Exam Specifications
To successfully take a Minnesota Department of Health exam, an operator must demonstrate knowledge of the core competencies in this document. Because certificates may be used to work in various treatment plants and distribution systems, the exams may not include technologies that are not used in each water supply but are commonly used in most.
The specifications list the percentage of questions on the exam that fall under each job duty. For example: 10% of the questions on the Class D exam relate to the job duty “Install Equipment,” and 65% of the Class D questions are based on proper distribution system operation rather than treatment plant operation.
| Job Duty | Percent of Exam Level | |||
| Class D | Class C | Class B | Class A | |
| Comply with Drinking Water Regulations | 10 | 10 | 10 | 10 |
| Evaluate and Maintain Equipment | 12 | 10 | 9 | 6 |
| Install Equipment | 10 | 8 | 5 | 5 |
| Laboratory Analysis-Collect Samples, Perform Analysis, and Interpret Results | 8 | 10 | 12 | 15 |
| Monitor, Evaluate, and Adjust Treatment Processes | 8 | 14 | 18 | 21 |
| Operate Equipment | 14 | 11 | 7 | 5 |
| Perform Safety Procedures | 10 | 8 | 7 | 5 |
| Perform Security and Administrative Duties | 8 | 9 | 12 | 13 |
| Source Water - Monitor and Evaluate Characteristics | 5 | 5 | 5 | 5 |
| System Design | 5 | 5 | 5 | 5 |
| Math Questions | 10 | 10 | 10 | 10 |
| Total | 100 | 100 | 100 | 100 |
| Treatment Plant Operation | 35% | 60% | 75% | 85% |
| Distribution System Operation | 65% | 40% | 25% | 15% |
| Class E | |
| Operate System | 22% |
| Water Quality Parameters and Sampling | 15% |
| Operate Equipment | 19% |
| Install, Maintain and Evaluate Equipment | 15% |
| Perform Safety Duties | 11% |
| Perform Administrative, Compliance, and Security Duties | 18% |
