You are using the "old" (now undocumented) syntax for FusionTableLayer constructors. Use the new syntax and it works.
//Fusion Table (Sewer Lines)
var _ftId = "140ge-x0HKkzrlZYOdrCxYBNlu4ta15vpHetZh_s";
var _ft = new google.maps.FusionTablesLayer({
query: {
select: "Shape",
from: _ftId,
where: ""
},
options: {
styleId: 6,
templateId: 2
}
});
_ft.setMap(map);