This document discusses opportunities to enhance the water-energy nexus at wastewater treatment plants. It notes that most water usage is for power supply and agriculture, while wastewater treatment only accounts for about 12% of total water withdrawals. The document outlines the typical wastewater treatment process and energy usage. It also discusses new biological treatment technologies using algae that can produce resources like fertilizer, feed, and biogas from wastewater. The document recommends broader adoption of on-site renewables, storage, biotreatment, and beneficial water reuse to improve sustainability and resilience at wastewater treatment plants.