Formula8 min read
Hydraulic Loading Rate Formula for Trickling Filters
Master the hydraulic loading rate formula for trickling filters with worked examples, HLR ranges, and tips to avoid exam traps.
Wastewater Math Formulas
Reference guides and worked examples for the math formulas you need to pass your wastewater operator certification exam.
Math is one of the biggest hurdles on wastewater operator certification exams. Whether you're calculating Sludge Volume Index (SVI), Food-to-Microorganism (F/M) ratio, or detention time, you need to know the formulas and how to apply them under exam conditions.
Each guide below breaks down a formula with a clear definition, the equation, units, a worked example, and common exam traps to watch out for.
Formula7 min read
Weir Overflow Rate Formula: Clarifier Calculation
Master the weir overflow rate formula with step-by-step worked examples and exam tips to avoid confusing it with surface overflow rate.
Formula11 min read
Pump Head Calculation: Total Dynamic Head Formula
Learn how to calculate total dynamic head (TDH) for wastewater pumps. Step-by-step formula, worked example, and common exam traps.
Formula9 min read
SRT Formula: How to Calculate Mean Cell Residence Time
Master the SRT formula for wastewater with step-by-step MCRT calculation examples. Same concept, three names - clear it up before exam day.
Formula8 min read
BOD Removal Efficiency Formula: Calculate Percent Removal
Master the BOD removal efficiency formula with step-by-step examples, common exam traps, and tips to nail percent removal calculations.
Formula8 min read
Sludge Volume Index Formula: How to Calculate and Interpret SVI
Master the sludge volume index formula with step-by-step examples. Learn SVI calculation, interpretation ranges, and common exam traps.
Formula9 min read
Pounds Formula Wastewater: Math You Must Know for the Exam
Master the pounds formula (lbs = concentration × flow × 8.34) with worked examples, unit tips, and common exam traps.
Formula8 min read
Chlorine Dosage Formula: Dose, Demand, and Residual
Master the chlorine dosage formula (Dose = Demand + Residual) with worked examples and exam tips for wastewater operator certification.
Formula9 min read
Detention Time Calculation for Wastewater Operators
Master the detention time calculation with worked examples, unit conversions, and exam tips. HRT formula made simple for your certification exam.
Formula7 min read
Surface Overflow Rate Formula: Clarifier Design Calculation
Master the surface overflow rate formula for clarifier design. Step-by-step SOR calculation with unit conversions and exam tips.
Formula9 min read
F:M Ratio Formula: How to Calculate It Step by Step
Learn the F:M ratio formula with worked examples, unit conversions, and exam tips. Master food-to-microorganism ratio calculations for your certification exam.