For this job, the customer was saying they could smell sewage in the back corner of the house. So I cry underneath the house and found sewage right under where the toilet was and where it was going out side towards the city drain. I found a big crack, just below the toilet and saw signs of leakage around the joints and also saw 2 inch galvanized pipe rusted through. My recommendation is replacing the galvanized pipes from the toilet to the outside drain and replacing all galvanized pipe. As of right now, I was not able to fix the sewage smell.