The “X” is a historic – and busy! – intersection of Sumner Avenue, Belmont Avenue and Dickinson Street in Springfield, MA the most populous city in the Connecticut River watershed. Through the use of green infrastructure, “Greening the X” attempts to increase the ecological performance of the “X” streetscape while also improving the human experience of a dense, urban neighborhood. By considering community needs gathered during two participatory design workshops and incorporating the recent proposed renovations of the intersection, this project offers ecological design possibilities that infiltrate water and reduce the likelihood of a combined sewer overflow (CSO) event. Complete with a toolbox of useful Green Street design components, this project is intended to serve as a case study for the viability of Green Streets across the City of Springfield.