The Wastewater Operator's Guide to Preparing for the Certification Examination was prepared jointly by the Water Environment Federation, the Association of Boards of Certification (ABC), and the Certification Commission for Environmental Professionals (C2EP). It outlines what you can expect from the exam, provides key formulas, and lets you test your skills with sample questions. Updated job tasks and types of knowledge are addressed in four levels of competency. The approximately 200 questions included in this guide have been chosen to sample as many different aspects of a wastewater operator's job responsibilities as possible. Questions in the study guide are intended to provide an example of style and possible topics for certification exam questions. This guide includes C2EP 's education and experience requirements, tips for taking a certification examination, and sample formulas and conversions. Detailed answers to mathematical problems and references are provided The Water Environment Federation is a not-for-profit technical and educational organization of 33,000 individual members and 75 affiliated Member Associations representing water quality professionals around the world. Since 1928, WEF and its members have protected public health and the environment. As a global water sector leader, our mission is to connect water professionals; enrich the expertise of water professionals; increase the awareness of the impact and value of water; and provide a platform for water sector innovation.