Wastewater Field Guide
Practical, easy-to-scan references for wastewater and water-treatment operators.
OPERATOR MATH
Start with one simple diagram.
Find the relationship between chemical feed rate, dose, and flow—then use it in any direction. Everything below is the same pie chart, pushed a little further.
QUICK REFERENCEDavidson Pie ChartThree worked examples · Feed rate, dose, and flow- DECODERThree Names, One FormulaFeed rate, loading rate and mass — how to tell which one you were handed.
- ADJUSTMENTSDemand, Strength and PurityWhen to subtract before the chart, and when to divide after it.
- PLANNINGCost and Days of SupplyTurning pounds per day into dollars and reorder dates.
OPERATOR REFERENCE
Look it up, don't memorize it.
The full formula set, the conversions that feed it, and the twelve pie wheels worth keeping in your head — all readable on a phone in the field.
- FORMULASFormulasEvery exam formula in US and metric form, grouped by what you're working on and filterable by name.
- DIAGRAMSPie WheelsTwelve formulas drawn as wheels — cover the piece you want and read off the arithmetic.
- UNITSConversion FactorsGet every term into matching units before you run the numbers.
- GLOSSARYAbbreviationsMLVSS, SSV30, SOUR — what the letters on the page actually mean.
CALCULATORS
Plug in your numbers.
Calculators that show their work, so the answer comes with the steps you'd write on paper.
- CHEMICAL FEEDChemical DosageDose and flow in; lb/day, gal/day and a pump setting in mL/min out.
- LAB RESULTSLoading & RemovalPounds per day, removal by stage, organic loading and population equivalent.
- ACTIVATED SLUDGEProcess ControlF/M, MCRT, SVI and the WAS rate for a target sludge age.
- CLARIFIERSClarifier & Tank LoadingDetention time, surface and weir overflow and solids loading, checked against typical ranges.
- COLLECTIONPipe FlowFull-pipe velocity, partly full sewers with Manning, and force main head loss.
- JUST FOR FUNStank IndexPounds of stank per day, nose-blind time and break room clearance. Totally made up.