Exam Prep Books
Printed study guides and workbooks from Operator Master. Write in them, take them to work, and study away from a screen.
Washington Group I Exam Prep
Wastewater treatment operator study guide and workbook for the Group I exam: lessons with pictures, practice questions, math steps with units, and answers that explain every choice.
Buy on AmazonWashington Group II Exam Prep
Wastewater treatment operator study guide and workbook for the Group II exam: lessons with pictures, practice questions, math steps with units, and answers that explain every choice.
Buy on Amazon
Books are sold and shipped by Amazon. More levels and states are on the way.
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