FROM THE PREFACE In the years since the first edition, I have continued to consider ways in which the texts could be improved. In this regard, I researched several topics including how people learn (learning styles, etc.), how the brain functions in storing and retrieving information, and the fundamentals of memory systems. Many of the changes incorporated in this second edition are a result of this research. The changes were field-tested during a three-year period in which I taught a water and wastewater mathematics course for Palomar Community College, San Marcos, California. All the fundamental math concepts and skills needed for daily water/wastewater treatment plant operations. This first volume, "Basic Math Concepts for Water and Wastewater Plant Operators," provides a thorough review of the necessary mathematical concepts and skills encountered in the daily operations of a water and wastewater treatment plant. Each chapter begins with a skills check to allow the student to determine whether or not a review of the topic is needed. Practice problems illustrate the concepts presented in each section.