The MBTA Blue Line Extension project is a significant transportation infrastructure project aimed at enhancing the public transportation system in Boston. The project involves the construction of two new subway station platforms in different locations. The project's primary objective is to provide commuters with more convenient access to the city's downtown area, while at the same time minimizing the impact of the construction on the surrounding environment. The first station, Dartmouth St Station, is situated at the intersection of Dartmouth and Newbury Street, in the heart of an urban setting. The project's design and construction were done with utmost attention to minimizing disturbance to the surrounding area. The construction of the station utilized the Cut and Cover method, which allowed the reopening of the street as soon as possible. Additionally, the project team transported soil spills and materials through the existing tunnels underground. The proposed design of the station includes three street access points with an emergency exit to ensure accessibility and safety. All utilities were relocated except for the 72-inch combined sewer, which was supported using the pipe hanger standard detail. The station features elevators and bathrooms, meeting ADA standards and design constraints. Slurry walls were used for Support of Excavation (SOE) and groundwater management, making them cost-effective and easy to install. The station will have one staircase from the mezzanine, an additional fire-proof emergency exit with direct access to street level, and a single central platform. The second station, Park St Station, is located in the Boston Commons along Park Street. The station is built directly beneath the existing Red Line Station, and the project's design and construction were done to ensure minimal disturbance to Red Line operations. The support of excavation includes slurry walls along the length of the station, ground freezing at the intersection of the Re