What this site is
Operator Exam Prep publishes free study content and free practice questions for the four major operator certification disciplines: water treatment, water distribution, wastewater treatment, and collection systems. Content is organized by discipline, by certification grade, and by state, because the exam you actually sit depends on all three.
What this site is not
Operator Exam Prep is not a government website and is not affiliated with any state certifying agency, exam vendor, or trade association. We don’t administer exams, issue certifications, or grant continuing education credit. Every state page links directly to that state’s official certifying agency, and we encourage you to confirm requirements there before relying on anything here.
Why it exists
Operator certification exams are consistent in structure but scattered in documentation: the topics tested are similar nationwide, but the grade names, passing scores, renewal rules, and administering agency differ by state and are rarely collected in one place. This site exists to put that information next to the content you actually need to study, especially the applied math that trips up more operators than anything else.
How the content is put together
See Editorial Standards for how pages are researched and reviewed, and Methodology for how specific figures (pass rates, exam facts, grade-nomenclature tables) are sourced and kept current.
Found something wrong?
Certification rules change, and we would rather fix a mistake than leave it up. See Contact.