Michael There could be a couple different issues going on here. 1) Is the exit line near a leach field? If so, the smells from the ground could be entering the exit line and transferring through the pipe into the sump pit. Does the pump have a check valve (back flow preventer)? Does your system have a freezing preventer? This is found on the outside near the pipe coming out of the house. If so, are the smells emitting from the preventer? If this issue is coming from transfer through the pipe, I would recommend having the company which installed it come back and move the exit line away from the leach field. Any reputable company should do this without additional costs to you. Another option is to have a second check valve installed. 2) A greater issue and harder and more expensive fix is a faulty leach field. If this is the case a Pumber will be needed. It is not always obvious that the problem does not originate in the tank, but in the drainfield. Puddles of water appearing on the surface of the drain field are a good indication that the soil is flooded and the drain field is failing. It is not always easy to diagnose the cause of backups. A recent issue of the EPA newsletter Pipeline lists signs of failure as "slowly draining sinks and toilets, gurgling sounds in the plumbing, plumbing backups, sewage odors in the house, or tests showing the presence of bacteria in well water." Hope this helps and good luck!

I had another company come in and install a sub floor system which has worked good except there is now an odor coming from the box. I had water tested and there is trace amounts of feces. We never had this problem before the system was installed. Any help would be appreciated.