I would say some municipalities have very well-defined lead service line identification programs, while others don't. Again, some of the records from the 1940s—or the records from the 1920s, for that matter—may no longer exist.
The issue we face particularly in Ontario is that we—and when I say “we”, I mean the lawyers for the province—among the different ministries have not agreed to a definition of property. Where does the municipality's property end and where does the homeowner's property begin? What rights does the municipality have on the homeowner's property?