A year ago our septic backed-up into our ground level bathroom. We ended up having the septic replaced and everything seemed fine (there was no odor). 2-3 months later we redid that bathroom. Soon after the corner shower base was removed we started smelling the "eggy" odor. This odor was very strong and could be smelled throughout the house. Walking in the front door, felt like getting punched in the face. There was and is no odor outside the house. We then did the bleach thing and eventually the smell subsided. However, once in a while the smell comes back. The last time it did, at the same time, the toilet was bubbling (kind of like it was burping). My concern originally was that the piping was somehow damaged when the corner shower base was removed, but I would then have expected the smell to still be there. Any thoughts would be appreciated.

" The last time it did, at the same time, the toilet was bubbling (kind of like it was burping)."
You have just told me what's causing your b ad smell. You have a partial blockage downstream from the toilet and every time byou flush or discharge a washer the discharge hits the clog and bounces back sending a bubble of sewer gas ahead of it. That's what you smell. The solution would be to snake the line from the lavatory roof vent. Put out enough cable to reach the base and 20 feet more. Let m,e know if the smell continues. Good luck, Tom

Sorry for the long delay in giving an update, but only just now have one. Okay, so we had a 3" black on a 45 degree angle from the house (near the downstairs bathroom) and going into the ground. Had no idea what this was for but assumed it needed to be connected to the drywell when I replaced the septic. BAD IDEA! It turns out while the pipe may have been active in the past, it had since been disconnected. The smell in the garage was a direct result of this pipe being connected to the drywell. The connection was just feeding the septic gases into my home. At least it was an easy fix, too bad we found out about it after more than a year. Fixed that issue last week, but we now have a smell when we do wash that appears in the basement. Haven't seen/heard the bubbling in the toilet and now not sure what deal is. The smell is coming from inside the washer. Also, our clothes now have a mildew smell. We thought this might be unrelated and due to an aging dryer. Could there be a problem with the water supply? We have village water.