A massive public works project that will impact Lower Mills for the rest of the year  will start on Monday, according to officials with the Massachusetts Water Resources Authority (MWRA). Crews will begin by digging a ventilation shaft near the intersection of Morton and Sanford streets. A larger access pit will be excavated at Washington and Morton streets as well. Contractors hired by the MWRA will spend the next several months cleaning and lining water pipes along Washington Street, prompting lane closures and detours in that area through November. More details can be found online at mwra.com .