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About the Field Guide

Formulas, calculators, and reference charts for wastewater operators, built to work at the plant with or without a signal.

The Field Guide is free for operators, students, trainers, utilities, and anyone else who finds it useful. There are no accounts and no ads.

You can:

  • Use it on the job, including at investor-owned and for-profit utilities.
  • Teach with it, including in certification training programs that charge tuition.
  • Print pages for your plant or classroom.
  • Copy, adapt, or host your own version, as long as you credit the Field Guide and share your changes under the same terms.

You can’t sell it, put it behind a paywall, or bundle it into a paid product or app. The formulas and facts themselves aren’t claimed by anyone, so use them however you like.

The written content is licensed under CC BY-NC-SA 4.0 and the code under the PolyForm Noncommercial License 1.0.0. The full terms are on GitHub. If you want to do something they don’t allow, just ask.

Formulas follow the conventions used on WPI operator certification formula sheets. Typical ranges, presets, and example values are general guidance, not your plant's numbers. Check results against your own plant data, permit limits, SOPs, and O&M manual, and confirm with your supervisor or engineer before changing anything.

The Field Guide comes with no warranty. You are responsible for how you use what it tells you.

Astro, Starlight, the DocKit theme, and other open-source software. See the third-party notices for credits and licenses.