Gauge: Water Operator Prep

Independent wastewater-operator study aid, not affiliated with WPI/ABC or any certifying authority. Its Class III practice form follows an older WPI/ABC outline, not WPI's revised 2025 outline. Check which exam your state or province administers. THE CALCULATORS ARE FREE Forty-nine interactive calculators and one geometric-mean reference cover flow and volume, detention and loading, process control, solids, chemical feed, pumping, power, and laboratory math. Each card shows a relationship, a practical note, and a common mistake. The geometric-mean card does not calculate; use your permit's specified method and zero-count rule. No account or advertising. FORMULA SELECTION PRACTICE WPI/ABC standardized wastewater exams provide a Formula/Conversion Table; other exams may differ. Two-stage questions let you choose a relationship, then compute a value while carrying units through. WORKED SOLUTIONS Calculation items show worked steps with units. The app can flag some common unit and magnitude slips, such as omitting 8.34 pounds per gallon, as study feedback rather than an official grading judgment. OLDER CLASS III PRACTICE MODEL The timed form uses five areas and 15 scored calculation items from WPI/ABC's previous Class III outline. WPI's revised 2025 outline has four areas and 14 percent calculation items; your certifying authority determines which exam you actually take. This app's form always adds ten unscored practice items, while WPI says a real exam may contain up to ten. The separate math score is personal feedback, not a certification prediction. SOURCES AND LIMITS The app includes authored explanations and cites regulations where relevant. Use current permits, plant procedures, approved methods, and your certifying authority's materials for real-world work. Report suspected errors through the Support link. WORKS WITH NO SIGNAL Study content and calculators are bundled on the device. Purchases, restores, and links to outside resources may need a connection. FREE, AND WHAT THE UNLOCK ADDS Free: 49 interactive calculators, the geometric-mean reference, and 88 practice questions drawn from five study areas. The one-time unlock opens the complete question bank, worked solutions, timed forms, formula-selection drills, spaced repetition, and area-by-area results feedback. One payment, no subscription, no account.