On the ground, today this is a fenced off empty field with some signage about how it's controlled by the Water System of New York and a some leftover construction signage referencing the contract in the source link.   You can see the specifics about this field if you look link from the source on pages 17 and 36-39. 

Based on the signage that's there, and the info in the source link, it appears that the shaft is underground underneath this field, and the field itself is reserved for access to the shaft.

The source refers to this area as the shaft, so I went with that. Certainly open to other naming suggestions, perhaps "WSNY City Tunnel 3 Shaft 23B Site"?
            ---
            
            Published using OSMCha: https://osmcha.org/changesets/134388448
            