WEF/ABC Wastewater Treatment Fundamentals III--Advanced Treatment Operator Certification Study Questions is the latest in Water Environment Federation's operator training series and is a companion of the manual. Approximately 950 study questions and answers in this study resource represent all aspects of advanced treatment and help operators prepare for the levels three and four of the certification examinations. These questions are also included as "Test Your Knowledge" questions in the Wastewater Treatment Fundamentals III--Advanced Treatment training manual and online course developed in collaboration with the Association of Boards of Certification (ABC). This separate study guide is intended for those operators who do not have the opportunity to use the training manual or online course for study. The peer-reviewed resources in the Wastewater Treatment Fundamentals series represent the expertise of hundreds of water quality professionals. They align with updated Need-to-Know Criteria from the Association of Boards of Certification and are based on WEF's extensive existing resource collection, including Operation of Water Resource Recovery Facilities, MOP 11.