Comparison

WPI Exam Prep vs Wastewater Operator Test Prep

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

WPI Exam Prep

Features
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WPI Exam Prep App The Official App from WPI for water treatment, wastewater treatment, collection, and distribution industry professionals. Prepare confidently for your water/ wastewater operator exams, using the WPI Exam Prep App, the only app that combines powerful study tools, authentic practice questions, and personalized insights from our AI learning assistant. Key Features - Hundreds of official practice questions created by industry experts, exactly like the ones you'll face on exam day. - Customizable study sessions tailored to your individual learning needs. - Instant feedback and detailed explanations for every question to enhance your understanding. - Advanced progress tracking to pinpoint your strengths and weaknesses across topics. - Interactive leaderboards and gamification elements to motivate and engage. - AI-driven analytics offering personalized insights and recommendations for optimal study effectiveness. - Dark mode for comfortable studying anytime, anywhere. Why Choose WPI Exam Prep? - Official content developed by trained industry professionals, ensuring reliability and accuracy. - Extensive practice materials that adapt and evolve with your exam preparation needs. What's Coming Next - Continuous expansion to include additional levels and certifications - Enhanced personalization tools, including study planners and targeted recommendations. - Digital flash cards and an interactive AI Math learning assistant Download WPI Exam Prep app today and navigate your path to certification with confidence!

About

Wastewater Operator Test Prep

This professional calculator provides 16 essential wastewater treatment calculations for licensed operators, covering Class I through Class IV certification math. It displays formulas and substituted values for easy verification and works completely offline, making it ideal for field use.

Highlights
  • 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
Features
Read full description

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.

Screenshots

WPI Exam Prep4 screens
Wastewater Operator Test Prep4 screens

Verdict

The call

The clearest difference is update cadence: Wastewater Operator Test Prep at monthly against WPI Exam Prep's every 3 months. On price, ads, in-app purchases and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

WPI Exam Prep ships an update every 3 months, Wastewater Operator Test Prep monthly. The most recent releases landed on October 25, 2026 and October 9, 2026 respectively.

Scorecard1 real difference · 8 level
WPI Exam Prep versus Wastewater Operator Test Prep: the parameters behind the verdict, then further details
ParameterWPI Exam PrepWastewater Operator Test Prep
PriceFreeFree
Rating—5.0 (1 ratings) — better
Number of ratings—1 — better
Update frequencyEvery 3 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.415.1 — better
Further details — not scored
Size120 MB28 MB
Age rating4+4+
DeveloperMemorangMike Watson

In-app purchases

None

WPI Exam Prep

No in-app purchases

None

Wastewater Operator Test Prep

No in-app purchases

Questions

Is WPI Exam Prep free?
WPI Exam Prep is free to download, with no in-app purchases.
Is Wastewater Operator Test Prep free?
Wastewater Operator Test Prep is free to download, with no in-app purchases.
Do WPI Exam Prep or Wastewater Operator Test Prep have ads?
Neither WPI Exam Prep nor Wastewater Operator Test Prep shows ads.
Which is updated more often, WPI Exam Prep or Wastewater Operator Test Prep?
WPI Exam Prep ships an update every 3 months, and Wastewater Operator Test Prep monthly. Most recently, WPI Exam Prep was updated on October 25, 2026 and Wastewater Operator Test Prep on October 9, 2026.

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