I could find no official notice that this part of the aqueduct is open or closed to the public, and the entrance at Elm Street does not have any restrictive signage.  The pedestrian gate at Elm street is open.  The path crosses the sudbury river on a footbridge installed over the pipe that forms the visible part of the aqueduct's sudbury river siphon.  It is one of two such siphons crossing the sudbury river.