Exam Prep Guides
Featured · All Topics · No Math
Complete Exam Guide
200 conceptual questions across 12 major exam topics. The essential starting point for any operator preparing for Class I or Class II certification.
Deep Dive · Includes Math
Activated Sludge: Bugs, Basins & Beyond
150 questions across 11 subtopics — microbiology, SRT & F/M calculations, RAS/WAS control, secondary clarifiers, and troubleshooting. Class I & II tagged.
Water & Wastewater · Review + Exam
Introduction to Laboratory Methods
13 sections of lab content review plus 100 practice questions — safety, glassware, pipets, solutions, sampling, pH, alkalinity, QA/QC, chlorine, and DO.
Free Resources
Free Practice Questions
10 exam-style questions with full explanations. No purchase required.
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Wastewater Glossary
Plain-English definitions of 50+ essential treatment terms.
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Exam FAQ
Answers to the most common exam prep questions.
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Certification Guide
How operator certification works — grades, requirements, state programs.
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