Free practice
Water & Wastewater Operator Practice Tests
Pick your discipline and grade. Every question comes with the correct answer and a full explanation — no signup required.
- 8+
- Practice questions
- 4
- Disciplines
- 16
- Practice sets
Choose your discipline and certification grade below to start a free practice set. Every question includes the correct answer and a full explanation, so you can see exactly why an answer is right before you move on.
These questions are independent study material, not official exam questions, and are meant to supplement, not replace, your state certifying agency’s own exam content outline. Exact topics, grade names, and requirements vary by state — each discipline overview below links to the states we cover.
Water Treatment
Exam overview →Certification for operators who treat drinking water at surface or groundwater plants.
Water Distribution
Exam overview →Certification for operators who maintain the pipes, pumps, and storage that deliver drinking water.
Wastewater Treatment
Exam overview →Certification for operators who treat municipal and industrial wastewater before discharge.
Collection Systems
Exam overview →Certification for operators who maintain sewers and lift stations that convey wastewater.