Hi, I'm Greg — your personal water operator instructor!
I'm here to walk you through every chapter, explain tough concepts, and make sure you feel confident before exam day. This site is 100% free because everyone deserves a great education.
🛠️ Your Learning Tools
📖 Class D — Study Lessons
Click Study to read the full guide. Mark each lesson complete as you go. Greg will update his tip after every completion!
🧠 Practice Quiz — Class D
Each round draws 10–15 random questions from a pool of 150 per chapter — you'll never see the exact same quiz twice!
🔢 Math Practice — 20 Questions Per Round
Water operator math: flow rates, chemical dosing, tank volumes, and more. A fresh set every time!
🗂️ Flash Cards
Click any card to flip it. Add your own cards, then print them all out to study anywhere!
💡 Tip: Use your browser's Print function (Ctrl+P / ⌘+P) — only the cards will print.
▶️ YouTube Video Library
Search for any water operator topic or browse curated videos for your class. Greg picks the best ones!