Municipal wastewater treatment systems in the U.S. consume approximately 30 billion kWh annually, and their operations are typically the largest energy users in a community. This toolkit enables water resource recovery facilities to improve their energy efficiency, providing best practices and innovative approaches successfully used by wastewater facilities to establish and implement energy management plans. It is based on the work of DOE's Better Buildings Sustainable Wastewater Infrastructure of the Future (SWIFt) Accelerator.