Wastewater Treatment Fundamentals I: Liquid Treatment covers all aspects of liquid treatment processes and helps operators prepare for the first three levels of certification examinations. In addition to learning the basics of liquid treatment, operators will gain a thorough understanding of critical aspects of biological treatment, nutrient removal, and disinfection. After learning from real-life examples, users can apply the material they learn to situations they encounter in their day-to-day work. Highlights of Wastewater Treatment Fundamentals include: Detailed visuals and infographics; Comprehensive math examples; Practice questions for each module with lots of variety; Accessible language for all levels of operators; Easy to read format; and Peer reviewed. This self-study manual aligns with updated Need-to-Know Criteria from the Association of Boards of Certification (ABC) and are based on WEFs extensive existing resource collection, including Operation of Water Resource Recovery Facilities, MOP 11.