# Wastewater Operator Test Prep — Certification Math Calculator > Wastewater operator's essential offline calculator for certification math. (iPhone/iPad app by Mike Watson.) - Source: https://appshunter.io/ios/app/wastewater-operator-test-prep/id6761349297 (this page in markdown: same URL + `.md`) - Developer: [Mike Watson](https://appshunter.io/developer/1848411021) - Category: Education, Utilities - Price: Free - Rating: 5.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 15.1 · 28 MB - Languages: American English - Released: 2026-03-31 - Data updated: 2026-08-25 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/wastewater-operator-test-prep/id6761349297/reviews.md ## What is Wastewater Operator Test Prep? Studying for your wastewater operator certification exam? Practice with real exam-style questions, then master the math — the section where most candidates lose points. PRACTICE MODE Hundreds of original practice questions covering Class I through Class IV, weighted across content areas the way the real certification exams are: treatment process, equipment and maintenance, laboratory, and safety and regulations. Math word problems are freshly generated every quiz with realistic plant values, and every answer comes with a worked, step-by-step solution. Pick your session — a 10-question quick quiz, a 25-question study session, or a full 100-question exam-length run — filter by certification class, and drill just math or just concepts when you want to. Wrong answers are modeled on the classic mistakes — the dropped 8.34, the inverted ratio — so the quiz teaches you what to watch for. 50 CALCULATORS The full certification exam formula sheet, Class I through Class IV. Every result shows the formula with your values substituted in, exactly the way you'd show your work on the exam. Practice until the math is automatic, then keep the app in your pocket for daily process control once you're licensed. SHOW YOUR WORK Tap any result to see your actual inputs plugged into the equation — dose, flow, and conversion factors spelled out step by step. Verify the math instead of trusting a black box. HYDRAULICS & LOADING • Pounds / Mass Loading (MGD, GPD, or GPM input) • Detention Time • Percent Removal • Surface Overflow Rate and Weir Overflow Rate • Rectangular and Circular Tank Volume • Pipe Velocity, Channel Flow (Q = A × V), Float Test Velocity • Hydraulic Loading, Total Flow from Meter Readings CHEMICAL DOSING • Chemical Dose / Feed Rate (dry and liquid with SG) • Chlorine Demand • Hypochlorite Feed Rate • Solution Strength • Alkalinity for Nitrification SOLIDS CONTROL • Sludge Volume Index (SVI) • RAS Rate, RAS Pump Rate, RAS Solids Balance • MLSS / MLVSS Inventory • WAS Flow Required • Sludge Volume Pumped, Dry Pounds Pumped, Solids Recovery PROCESS CONTROL • Sludge Age and full MCRT / SRT • F/M Ratio • Solids Loading Rate • OUR / SOUR • Volatile Solids Reduction (Van Kleeck) • Digester Loading, Trickling Filter Organic Loading PUMPING & HORSEPOWER • Water, Brake, and Motor Horsepower • Wire-to-Water Efficiency • Power Cost • Pumping Rate, Wet Well Drawdown, Total Dynamic Head LAB & SAMPLING • BOD (Dilution Method) • Total Suspended Solids • Percent Volatile Solids UNIT CONVERSIONS • Flow (MGD, GPM, GPD, cfs) • Volume (gallons, liters, cubic feet, acre-feet) • Pressure to Head, Power, Temperature BUILT FOR THE FIELD • Works 100% offline — study anywhere, calculate anywhere • Large, readable results designed for gloved hands • Copy Result pastes a formatted summary, math included, ready for texts or emails • Formula reference screen with source attribution for every equation • Calculation history saves your last 20 results • Dark mode support ACCESSIBILITY • Full VoiceOver support — every input, button, and result is labeled • High contrast dark mode with OLED-friendly true black • Large touch targets sized for field use Formulas follow the ABC formula sheet and Sacramento State OIT course materials — the same references most state certification exams draw from. Independent study tool — not affiliated with ABC, AWWA, or any certification board. Built by Product Party for wastewater professionals. ## Key features - 16 essential wastewater calculations - Supports Class I-IV certification math - Shows formulas and substituted values - Works 100% offline - Large, readable results for field use - Copy result for sharing - Calculation history ## Frequently asked questions about Wastewater Operator Test Prep ### What calculations does Wastewater Operator Calculator include? Wastewater Operator Calculator includes 16 essential calculations covering hydraulics, loading, solids control, and process control. These range from basic Pounds formulas to MCRT, F/M Ratio, and Volatile Solids Reduction, all relevant for Class I through Class IV certification math. ### Can I use Wastewater Operator Calculator offline? Yes, Wastewater Operator Calculator works 100% offline. This feature is crucial for use in areas with limited or no internet connectivity, such as concrete bunkers, underground pump stations, or remote facilities. ### How does Wastewater Operator Calculator help with showing my work for exams? Every result in Wastewater Operator Calculator displays the formula used and allows you to tap 'Show Your Work' to see your exact input values substituted into the equation. This mirrors the process required for certification exams. ### What devices is Wastewater Operator Calculator available on? Wastewater Operator Calculator is available on devices running Android, as indicated by its release and update information. Specific device compatibility would depend on the Android version supported by the app. ### How often is Wastewater Operator Calculator updated? Wastewater Operator Calculator was last updated on April 2, 2026, with version 1.1.0. This indicates a recent update, suggesting ongoing support and potential for future improvements. ### What is the age rating for Wastewater Operator Calculator? Wastewater Operator Calculator has an age rating of 4+. This means it is considered suitable for all ages and does not contain content that would be inappropriate for children. ### Does Wastewater Operator Calculator have ads? The provided data does not indicate the presence of advertisements for Wastewater Operator Calculator. It is listed as free and does not mention any ad-supported features. ### What is the user sentiment for Wastewater Operator Calculator? Wastewater Operator Calculator has received a perfect rating of 5.0 stars from 1 rating. This single rating suggests highly positive user sentiment among its early users. ## Version history (last 4 releases) ### 2.0.0 — 2026-08-19 Big update for exam season: • NEW Practice tab — hundreds of exam-style questions across treatment process, equipment, lab, and safety, Class I–IV, weighted like the real certification exams. Freshly generated math problems every quiz, worked step-by-step solutions, and a score summary with review of what you missed. • Pick your session: 10-question quick quiz, 25-question study session, or a full 100-question exam-length run • 34 new calculators, bringing the total to 50: pumping & horsepower, chemical dosing, lab math, more hydraulics, and unit conversions • Mass loading now accepts GPD and GPM flow directly • Rate-the-app support, an analytics opt-out in Settings, and polish throughout ### 1.2.0 — 2026-07-17 -Updated UI across all screens/calculators ### 1.1.0 — 2026-04-02 -Integrated anonymous signals for issue resolution ### 1.0.0 (2) — 2026-03-31 No release notes. ## More apps by Mike Watson - [Leafed - Private Book Tracker](https://appshunter.io/ios/app/leafed-private-book-tracker/id6754466418) - [HVAC Load Calculator Manual J](https://appshunter.io/ios/app/hvac-load-calculator-manual-j/id6758120488) - [Water Damage Report Photo Docs](https://appshunter.io/ios/app/water-damage-report-photo-docs/id6758919407) - [Spray Mix & Tank Calculator](https://appshunter.io/ios/app/spray-mix-and-tank-calculator/id6759580852) - [A2L Safe Charge - Superheat](https://appshunter.io/ios/app/a2l-safe-charge-superheat/id6760899340) - [Attentionly: ADHD Time Audit](https://appshunter.io/ios/app/attentionly-adhd-time-audit/id6761147386) All apps by Mike Watson: https://appshunter.io/developer/1848411021 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-25.*