Water System Operations (WSO) Water Treatment, Grades III & IV

This book was instrumental in helping me become certified

Very helpful information for your exams.

Very informative. Would recommend for anyone testing in water industry.

Being a Water Treatment Plant Operator this is a must have.

Doesn't contain everything you need you know for equivalent tests in Waterworks. Not very well organized and often confusing wording. The Sacramento books are much better.That being said, of all the books in this series, this one is the best.