[ Process Control Tools ]

The Operator's
Toolkit

Free calculators, reference tables, and field guides for wastewater treatment plant operators. No account required. No paywall. No ads. No vendor agenda.

Open Calculators Reference Tables
27 Tools
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12 Reference Tables
·
14 Field Guides
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Free & Open Source
[ Toolkit ]

What's in the toolkit

Every tool built from field experience. No fluff, no paywalls — just the math and reference data you need on the floor.

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Calculators
27 tools
Activated sludge, hydraulics, solids handling, and digester operations — with live results as you type.
  • SVI & Settleability
  • F/M Ratio, MCRT, RAS Rate
  • HRT, WOR, Surface Loading
  • Chemical Dosing, Mass Loading
  • VSR, VS Loading, Digester DT
  • 12 Formula Pie Wheels
Open Calculators →
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Reference
12 tables
Quick-access process data organized for field use — DO targets, pH ranges, loading benchmarks, conversions.
  • DO Operating Ranges by Zone
  • pH Targets by Process
  • Loading Rate Benchmarks
  • Temperature Effects
  • Common Unit Conversions
  • Alkalinity Targets & Consumption
  • Chemical Feed Reference
  • Oxygen Demand Factors
  • Biosolids Classification
  • Solids Production
  • Filamentous Organisms
  • Lab Methods Reference
View Reference →
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Field Guides
14 guides
Practical guidance for common operations and troubleshooting scenarios — written the way it should have been explained earlier.
  • Plant Startup
  • Upset Response
  • Seasonal Adjustments
  • Dewatering Operations
  • Digester Management
Read Guides →
[ Recently Updated ]
New Tool (Draft) Process Decision Matrix — Guided Troubleshooter New Guide Secondary Clarifier Troubleshooting New Guides Laboratory Methods Guides Updated Reference — 5 New Tables
[ About ]

Built for
operators,
not vendors

Every calculator here is one I use on shift. Every reference table is something I've had to look up enough times that I finally put it somewhere permanent.

A lot of "technical resources" in this industry are vendor documentation dressed as neutral information — everything from equipment manuals to "educational guides" is ultimately trying to sell you chemicals, equipment, or consulting. This site exists outside that model. No vendor relationships, no affiliate links, no content that exists to sell you a product.

Written by an operator, for operators. Free, open source, and built to work on a phone in the middle of a process upset.

About the builder and how to contribute → Step-by-step contributing guide →