Delon Hampton & Associates (DHA) served as the structural engineer of record for a significant portion of the Enhanced Nitrogen Removal Facilities (ENRF) project at DC Water's Blue Plains Advanced Wastewater Treatment Plant (AWWTP).This project was the result of an initiative to reduce the amount of nitrogen released into the Chesapeake Bay. Prior to the construction of ENRF, the Blue Plains plant used the same set of reactors for both the Nitrification and Denitrification processes. Working as a structural engineering subconsultant, DHA’s portion of the ENRF design added a dedicated set of Denitrification Reactors. Having overall dimensions of 300 feet by 500 feet and total capacity of 40 million gallons, key design elements of the new concrete basin included exterior and interior walls, foundations, and access bridges over the reactor tanks.