Washington Level I Wastewater Study Guide

Operator Master has 148 Level I practice questions and 25 Level I math practice questions. Every question has an explanation. These are the topics the practice questions cover:

• Plant Operations54 questions
• Math and Calculations50 questions
• Pumps and Hydraulics8 questions
• Primary Treatment6 questions
• Laboratory5 questions
• Secondary Clarification5 questions
• Biological Treatment4 questions
• Disinfection4 questions
• Grit Removal4 questions
• Headworks and Screening4 questions
• Regulations and Compliance2 questions
• Solids Handling2 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 I 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.

• Plant Operations54 questions
• Math and Calculations50 questions
• Pumps and Hydraulics8 questions
• Primary Treatment6 questions
• Laboratory5 questions
• Secondary Clarification5 questions
• Biological Treatment4 questions
• Disinfection4 questions
• Grit Removal4 questions
• Headworks and Screening4 questions
• Regulations and Compliance2 questions
• Solids Handling2 questions

How many Level I practice questions does Operator Master have?

Operator Master has 148 free Level I practice questions and 25 Level I math practice questions. Every question has an explanation.

What topics do the Level I practice questions cover?

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

Where can I find what the Level I 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.