Washington Level II Wastewater Study Guide

Operator Master has 211 Level II practice questions and 25 Level II math practice questions. Every question has an explanation. These are the topics the practice questions cover:

• Math and Calculations62 questions
• Biological Treatment43 questions
• Plant Operations41 questions
• Pumps and Hydraulics17 questions
• Disinfection10 questions
• Laboratory10 questions
• Primary Treatment8 questions
• Secondary Clarification8 questions
• Grit Removal4 questions
• Headworks and Screening3 questions
• Solids Handling3 questions
• Regulations and Compliance2 questions

This list describes Operator Master's practice, not the official exam outline. See the official resources below for what the exam covers.

1. Practice One Topic at a Time

   Answer practice questions and read each explanation, including for the ones you get right.

   Start Level II Practice→Try Sample Questions→

2. Learn the Math

   Work through the Math Center topics step by step. The pie wheel lessons show how to set up and rearrange a formula.

   Open the Math Center→Pie Wheel Lessons→Math Formulas with Worked Examples→

3. Take a Full Practice Exam

   The timed practice exam gives a score by topic at the end, so you can see where to spend your time.

   Open the Full Practice Exam→

4. Review and Repeat

   Go back to your weakest topics, practice them again, then take another full practice exam.

• Math and Calculations62 questions
• Biological Treatment43 questions
• Plant Operations41 questions
• Pumps and Hydraulics17 questions
• Disinfection10 questions
• Laboratory10 questions
• Primary Treatment8 questions
• Secondary Clarification8 questions
• Grit Removal4 questions
• Headworks and Screening3 questions
• Solids Handling3 questions
• Regulations and Compliance2 questions

How many Level II practice questions does Operator Master have?

Operator Master has 211 free Level II practice questions and 25 Level II math practice questions. Every question has an explanation.

What topics do the Level II practice questions cover?

Math and Calculations, Biological Treatment, Plant Operations, Pumps and Hydraulics, Disinfection, Laboratory, Primary Treatment, Secondary Clarification, Grit Removal, Headworks and Screening, Solids Handling, Regulations and Compliance. This list describes Operator Master's practice, not the official exam outline.

Where can I find what the Level II exam covers?

The Washington Department of Ecology's certification information covers applying, the exam and study resources. WPI's Need-to-Know Criteria list what wastewater treatment exams cover. Check with Ecology which materials apply to your exam.

Is Operator Master part of the official exam?

Operator Master is independent. It is not affiliated with WPI, PSI, ABC or the Washington State Department of Ecology, does not reproduce live exam content and does not guarantee a passing score.

• Washington Department of Ecology: certification information covers applying, the exam, study resources and who to contact.
• Water Professionals International (WPI): Need-to-Know Criteria lists what wastewater treatment exams cover. Check with Ecology which materials apply to your exam.