Having the right tools can mean the difference between a quick project and a complete mess. Fortunately, you won't need too much to handle the projects here and what you will need is pretty inexpensive (certainly less expensive than hiring a plumber). You can get everything on this list for about $100, and you won't need it all unless you're doing all the projects. Where I live, that's about the cost of hiring a plumber for an hour.
I had 207 Plumbing come to fix a leak in my ceiling. It's a terrible, terrible company to do business with. He came and fixed a broken pipe in the ceiling, and I asked him to check the rest of the pipe to make sure that nothing else was broken, he said everything was OK and charged me $219.00 for 45 minutes and left. Never cleaned up his mess. I went to clean up the mess after he left and found there was more damage to the pipe. I called him to come back, which he did. He looked at the water coming down from the ceiling, into a light fixture and said he had another job to go to and couldn't come back until next week. He also wanted to charge me $350.00 to come back. I told him that was too much and he said he would make an exception and only charge me $219.00. Now I have major damage done to the ceiling, the light fixture and the floor. All of this could have been prevented if he had stayed and fixed the problem. I will NOT hire him again.
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?
When a person has a blockage in their sewage system they often try to fix it themselves by adding an acid or a base such as Drano in an attempt to dissolve or dislodge the problem. These chemicals can get into the plumbers eyes when the sewage is splashed during the repair. The plumbers skin during the repair does come into contact with the sewage water. The owner of the toilet might not report to the plumber they have already tried Drano a highly caustic base .