Drinking Water Operator Certification
Exam Study Materials

The Water Supply System Operator Examinations are comprised of five levels, Class A-E, with A being the highest level. The exams are closed book, time allowed is three (3) hours, each exam has 100 multiple-choice questions, and math formula sheets will be provided. There are some recommended reference sources listed below. In addition we also have lists available on subjects that each operator classification needs to know. If you would like a copy please Noel Hansen at 651-201-4690. The training materials available to you, along with your operating experience and common sense, should help you pass the certification exam.

Recommended reference sources

The study guides from the Minnesota Department of Health and Minnesota Rural Water Association provide information that is helpful in obtaining a license and preparing for certification exams.

• Minnesota Class E Study Guide (PDF)
• Minnesota Class D Study Guide (PDF)
• Minnesota Water Works Operations Manual

The Association of Boards of Certification also has a useful list of exam references, including the Class A and B conversion tables.

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