If nothing inside the home was altered you should not be getting a smell. Personally I'm confused as to why the repair person would have left the original line there and ran another one through a new hole. I would have pulled the old line up, ran the new line (in PVC) and used the same hole in the septic tank instead of creating a new one. Did he seal up the hole in the tank from the old line?
Jump up ^ "II. The Plumbers". The Atlantic. Retrieved 17 September 2013. In the early evening of June 17, 1971, Henry Kissinger held forth in the Oval Office, telling his President, and John Ehrlichman and Bob Haldeman, all about Daniel Ellsberg. Kissinger's comments were recorded, of course, on the hidden White House taping system, and four years later, a portion of that tape was listened to by the Watergate Special Prosecution Force, which was then investigating the internal White House police unit known as the Plumbers.