This manual is intended to serve as a principal reference for contemporary practice for energy-conscious design of water resource recovery facilities (WRRFs). It discusses principles and concepts of energy sources and their uses in the transport, treatment, and recovery of water and water resources. The manual also addresses utility billing procedures and incentives as well as energy considerations for a variety of equipment and processes, such as electric motors and transformers, pumps, controls, aeration systems, blowers, energy generation, and solids processes. Energy is often a major category of cost associated with wastewater treatment—this manual provides insights that can reduce those costs by 10 to 50% or more. Revenues from resource recovery can also provide a stream of income that will support other improvement activities within a water resource recovery facility.