Know Your Process.

Two processes, one goal: remove nitrogen. Learn how nitrification and denitrification work, the bacteria involved, operator controls, and exactly what the exam tests.

SVI measures how well activated sludge settles. Learn the formula, normal ranges, what a high SVI means, and how to run the settleometer test.

A clear, practical guide — what's on the exam, how to study, and what separates operators who pass from those who don't.

Understand activated sludge from the ground up — how it works, why it fails, and what exam questions you'll see.

These are not the same problem — and the exam knows it. Learn the causes, how to identify each, and what to do.

Chlorine, UV, ozone — the exam tests all of them. A clear breakdown of how each works and what you need to know.

BOD is one of the most important parameters in wastewater treatment — and one of the most tested on the operator exam. Here's what it means and why it matters.

A complete walkthrough of the wastewater treatment process — preliminary, primary, secondary, and tertiary — and what operators need to know about each stage.

BOD, MLSS, SVI, F:M, HRT — if these acronyms trip you up on the exam, this guide is for you.

Key formulas, SVI ranges, safety numbers, and the most tested concepts for Class I and II exams — all in one place.

How much do wastewater operators make? Salary by certification level, state, and experience — plus how to earn more.

What wastewater operators actually do day-to-day — duties, skills, certification requirements, and what employers look for.

Seven steps from start to certificate — experience requirements, application process, exam prep, and what happens after you pass.

From application to certificate — a complete timeline including experience requirements, exam scheduling, and study time.