Comparison

Wastewater Operator Test Prep vs Wastewater Operator Prep

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

Head to head
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.

About

Wastewater Operator Prep

Prepare for your wastewater operator certification exam with extensive practice questions and detailed explanations. This app covers all treatment processes and offers personalized study plans, timed modes, and progress tracking to boost your confidence and understanding.

Highlights
  • 1,027 practice questions
  • Detailed explanations for each answer
  • Full treatment process coverage
  • Personalized daily study plans
  • Timed practice modes
  • Progress tracking and pass probability
Features
Read full description

Walk into your wastewater operator certification exam ready. Wastewater Operator Prep gives you 1,027 practice questions with a clear explanation for every single answer, so you don't just memorize the right choice - you understand the treatment science behind it. Built for candidates preparing for ABC/state wastewater treatment operator certification exams. WHY IT WORKS Passing isn't about cramming. It's about repeated, targeted practice across every area the exam tests - then reinforcing exactly what you got wrong until it sticks. - 1,027 questions written to match the real exams' style and difficulty - An explanation on every answer, so each question teaches you something - Full treatment-process coverage: Preliminary & Primary Treatment - Activated Sludge - Secondary Clarification - Disinfection - Nutrient Removal - Solids Handling & Biosolids - Laboratory & Sampling - Collection Systems - Math & Dosage Calculations - Safety & Regulations STUDY YOUR WAY - Daily Plan that sizes itself to your exam date and keeps you on pace - Quick 10 for a fast review between shifts - Timed Mode to build exam-day speed and stamina - Smart Review using spaced repetition to resurface weak spots - Full-Length Mock Exam that simulates the real thing - Missed Questions queue so nothing slips through - Custom Quiz to drill any topic on demand TRACK YOUR PROGRESS - Pass probability that updates as you practice - Accuracy broken down by topic - Streaks to keep you consistent - Exam countdown WHO IT'S FOR Wastewater treatment operators preparing for ABC or state certification exams at any grade level. START TODAY Your exam date isn't moving. Start a free trial, take your first Quick 10 today, and watch your pass probability climb. --- SUBSCRIPTION DETAILS Full access is available through an auto-renewing subscription: A free trial is available for new subscribers. Payment will be charged to your Apple ID account at confirmation of purchase. Your subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. You can manage and cancel your subscriptions by going to your App Store account settings after purchase. Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription. Terms of Use: https://hermesdigitalbr-spec.github.io/wastewater-legal/terms.html Privacy Policy: https://hermesdigitalbr-spec.github.io/wastewater-legal/privacy.html Terms of Use (EULA): https://www.apple.com/legal/itunes/appstore/dev/stdeula/

Screenshots

Wastewater Operator Test Prep4 screens
Wastewater Operator Prep3 screens

Verdict

The call

The clearest difference is rating: Wastewater Operator Test Prep at 5.0 against Wastewater Operator Prep's 4.5. Wastewater Operator Test Prep also leads on in-app purchases (none vs 3) and iOS requirement (15.1 vs 17.0). On price, ratings volume, update cadence and ads 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. Wastewater Operator Prep sells 3 in-app purchases, starting at $5.99 per 7 days. Wastewater Operator Test Prep asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Wastewater Operator Test Prep holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly monthly. The most recent releases landed on October 9, 2026 and October 29, 2026 respectively.

Scorecard4 real differences · 5 level
Wastewater Operator Test Prep versus Wastewater Operator Prep: the parameters behind the verdict, then further details
ParameterWastewater Operator Test PrepWastewater Operator Prep
PriceFreeFree
Rating5.0 (1 ratings) — better4.5 (2 ratings)
Number of ratings12 — better
Update frequencyMonthlyMonthly
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.1 — better17.0
Further details — not scored
Size28 MB9 MB
Age rating4+4+
DeveloperMike WatsonHermes Inteligencia Digital Ltda

Customer experience

Wastewater Operator Test Prep

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Wastewater Operator Prep

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Wastewater Operator Test Prep

No in-app purchases

3 purchases

Wastewater Operator Prep

Subscriptions3
  • Wastewater Prep Weekly3 Days trial$5.997 Days
  • Wastewater Prep Monthly3 Days trial$14.991 Month
  • Quarterly3 Days trial$29.993 Months

Questions

Is Wastewater Operator Test Prep free?
Wastewater Operator Test Prep is free to download, with no in-app purchases.
Is Wastewater Operator Prep free?
Wastewater Operator Prep is free to download, with in-app purchases available.
Which has better reviews, Wastewater Operator Test Prep or Wastewater Operator Prep?
Wastewater Operator Test Prep is rated higher. Wastewater Operator Test Prep averages 5.0 out of 5 from 1 ratings, while Wastewater Operator Prep averages 4.5 from 2 ratings.
Do Wastewater Operator Test Prep or Wastewater Operator Prep have ads?
Neither Wastewater Operator Test Prep nor Wastewater Operator Prep shows ads.
Which is updated more often, Wastewater Operator Test Prep or Wastewater Operator Prep?
Wastewater Operator Test Prep ships an update monthly, and Wastewater Operator Prep monthly. Most recently, Wastewater Operator Test Prep was updated on October 9, 2026 and Wastewater Operator Prep on October 29, 2026.

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