Practice Questions
Answer exam-style questions one at a time, with explanations to learn from. Pick your track and level in Get Started above. Wastewater treatment practice covers Levels I through IV.
Operator Master
Free practice questions with explanations, a full practice exam, worked wastewater math, short courses and topic guides. Every question and course is checked against operator-training sources before it goes live.
New here? Watch a 1-minute tourA few quick choices so level names and practice match your exam. We remember them on this device, and in your account when you sign in, so you only choose once.
Choose a location above to unlock the levels
Levels go from easiest to hardest. Choose your state or province to see your own level names.
Free exam practice and operator training, explained by a working wastewater operator.
Answer exam-style questions one at a time, with explanations to learn from. Pick your track and level in Get Started above. Wastewater treatment practice covers Levels I through IV.
Operator Master is an independent study site for water and wastewater operators. It is built by a working wastewater operator who holds a Washington Group III certificate and has worked in wastewater treatment for about 13 years. Every question and course is checked against operator-training sources before it goes live, and anything we can't source stays out.
Practice questions, the practice exam, the Math Center and the learning pages are free and need no account. There are no ads. Courses ask you to sign in so your time and certificate can be recorded.
Two short videos, about a minute each.
Operator Master is independent. It is not an official examination, licensing authority, regulator, or guarantee of a passing score.