belly in sewer line

Check Hydro Physics. You will then really be confused. I just went through this, paying over $5,000 for replacement of a slightly bellied 4" pvc drain pipe running from the house to the septic tank, only now to seriously question whether I wasted over %5,000. In my case, our house was being sold, and the buyer insisted on having the system inpected and having a belly in a pipe corrected. Unfortunately I used the same plumber who said I had a belly problem to charge me over $5,000 to fix the belly problem. For me it was the same old, same old. If you ask a surgeon if you need surgery, you are going to get some surgery. I am guessing few drain pipes leading to septic tanks or public sewer lines are perfectly level, and practically all have some ups and downs or sags alias bellies. Be skeptical, get second opinions, require the plumber to qualtify in increments of .25 inches the sag, and negotiate the price.

Actually most sewer pipes do not have bellies or sags. And are graded at .25 per foot. When you run a sewer camera down the line there should be no liquid build up at all. If there is a sag than the solids will build up in that area and could eventually cause a clogged line.