I have finished basement and has finished bathroom with standing shower, floor drain, laundry tub, whaher dryer and sump pump. Sum pump is pumping out to front yard it is not connected in drain.
I am planning to convert existing sewer system to overhead sewer and I called 4 plumbing contractor and all gave me different suggestion.
1) one contractor said he will pull all drain lines to pit overhead it and connect to existing sewer
2) second contractor said it is good to make pit next to washer. Pull all drains to pit, overhead the sewer bring down and connect to existing sewer.
3) third cotractor said it is good to make a pit on existing toilet and move toilet on left side. Overhead the sewer bring down, core through the wall, connect out side sewer line with 90 angle and install clean out.

Now, no one has told me regarding the hydrostatic pressure of sewer backup. While I was looking online and saw articles about to make sure it does not get pressure otherwise it can damage the underground sewer lines.
Can you please give me your expert advise on which suggestion is better? Also, if the question of pressure then what is the remedies?

Thanks
j.shah

I have worked on 3 basement lift systems. All of them drained into a pit box and pumped into an overhead line through a sanitary Y mounted up. Connect the ejector pump through a check valve and a shut off valve, 2" ball usually. I did not read any mention of a vent. Ejector pumps, at least in GA, are all connected to a dedicated vent, not a house vent line.

I agree with previous post...

Basement bathroom should drain into its own sewer ejector pit. From there, pump it up to the existing sewer system (overhead pipes ) using 2" diameter discharge pipe. Use at least 1 check valve right above the pump. That's how we do it... Back to you... Milo

I agree, and can you tell me which way is better out of below three suggestion to have overhead? (FYI: main sewer line going out is behind the toilet)
Also, how about the pressure in the sewer if there is back up?
1) one contractor said he will pull all drain lines to pit overhead it and connect to existing sewer
2) second contractor said it is good to make pit next to washer. Pull all drains to pit, overhead the sewer bring down and connect to existing sewer.
3) third cotractor said it is good to make a pit on existing toilet and move toilet on left side. Overhead the sewer bring down, core through the wall, connect out side sewer line with 90 angle and install clean out.

I am sorry but I am not sure I completely understand the enclosed suggestions... Can you post a drawing of your situation ?

Anyway...

1. If you have existing overhead sewer pipes that service rest of the house (1st and 2nd floor ) than leave them as they are. There is absolutely no reason to bring them down to the pit - and then pump sewage back up.

2. Location of sewer ejector (pit) is up to your plumber. Place it anywhere in the basement bathroom or even outside that bathroom where it makes sense. Technically, it can be placed anywhere.

3. You will install check valve(s) on your sewer ejector discharge pipe. Therefore, you should not worry about what happens if/when main sewer backs up.