Excavation could begin soon at 151 Bay Street, the site of a 33-story mixed-use tower that will make up the third phase of Jersey City’s Provost Square complex. Designed by SLCE Architects and developed by Toll Brothers, the project will integrate part of the façade of the former A&P Annex Building, which has been stripped down to its concrete frame. The new structure will rise at the corner of Provost Street and Bay Street and yield 259 residential units, 6,289 square feet of retail space, and a parking garage with 218 spaces. Twelve units are to be designated as live-work units, with one for an artist in residence.