These questions are also included as "Test Your Knowledge" questions in the Wastewater Treatment Fundamentals II—Solids Handling and Support Systems 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. This study guide is a perfect companion for operators preparing for their first levels of the certification examination and for trainers interested in giving their students an opportunity to practically apply what they’ve learned.