Sewage backup into Operating Room

[Dr. D]

Hi all,
Thank you for any input, and I apologize in advance for my plumbing ignorance.
I own a small animal hospital and am going through an addition/remodel. We just moved into the addition while the old building is being remodeled (old building is 10 years old, never had a plumbing issue).
In the past 2 months, we've had 3 backups of raw sewage into our new surgery suite. Upstream from the OR is a toilet, sink, and kennel drain; downstream, the 3" pipe ties into a 4" pipe via a Y joint.
First plumber blames tampon, second plumber blames an unidentified solid object, and 3rd plumber determines a back flow at the Y joint that goes upstream and downstream in the 4" pipe.
Contractor wants me to put in a toilet with a pump to pump sewage up and over a wall into the old building and avoid the new pipe all together.
I would like advice from someone that is not involved at all in the project. I have attached a very rudimentary drawing.
Thank you for any advice.
Erin

 

[Plumber69]

Camera it, find out whats wrong. 2nd guy should of... 3rd guy definitely should of

 

[Sponsor]

 

[Dr. D]

It's been camera'd twice now. This last time is where they found water going both ways at the Y joint--up toward the trench drain in the kennel and down the main line.
The other option I've been given is to replace the 3" pipe with a 4" pipe, but that is obviously the more expensive and PITA route, and I'm not even sure that would fix the problem.

 

[Sylvan]

Sounds like back pitched and undersized waste /soil lines ..

A 4" compared to a 3" is not that much of a difference in cost and in the long "run" pun untended it is easier to maintain a 4" line with proper pitch

I recently had a job someone installed a wye backwards and they backfilled with no inspection.

They refused to come back and fix it properly

 

[Dr. D]

Thank you for your replies. I've attached a real drawing of the plumbing if that helps. I just don't want sewage backing up into my OR. The
supposed problem area is circled just right of center in the pic.
ETA: if it is a backpitch problem, would you recommend blasting out the floor to fix it, or just use a macerator toilet that would go up and tie into the old plumbing line?

 

[Terry]

If it's a pitch problem, then a pressure assist toilet may work as they have very good drainline carry.
Here is a video of a 1.1 gallon flush and they have the 1.6 gallon option too which would do even better.

I shot this while I was at their factory in Michigan.

If you do decide to redo the plumbing in the ground, I would get somebody out with a "Wet Saw"
A nice clean cut with no dust.

 

[Tuttles Revenge]

Plumbing doesn't just back up for no reason. Either there is a blockage, the slope wasn't maintained properly, a belly has occured or a fitting has been installed improperly. How long ago was this work done? Is this all new work? The blueprints indicate to me that this was a professional job and I would expect it would have been done properly. Is there a recorded video of the camera work that you could post on Youtube to link here? My hunch is that there is a blockage in the line somewhere downstream of the OR which is preventing the waste to flow properly downstream. My gut tells me its a test balloon that was deflated but not removed.

I would hire a separate recorded video inspection that is independant of the contractors previously involved without telling them what problems you're having to get a completely fresh perspective.

 

[Jeff H Young]

Plumbing doesn't just back up for no reason. Either there is a blockage, the slope wasn't maintained properly, a belly has occured or a fitting has been installed improperly. How long ago was this work done? Is this all new work? The blueprints indicate to me that this was a professional job and I would expect it would have been done properly. Is there a recorded video of the camera work that you could post on Youtube to link here? My hunch is that there is a blockage in the line somewhere downstream of the OR which is preventing the waste to flow properly downstream. My gut tells me its a test balloon that was deflated but not removed.

I would hire a separate recorded video inspection that is independant of the contractors previously involved without telling them what problems you're having to get a completely fresh perspective.

I would do the same thing, I dont have the gut feeling of a test plug in there but its entirely possible . something is going on and video inspection is the best only real choice . One time I had recuring back up our company was blaming the homeowner (new house) I went out snaked and camera found a piece of 1 1/2" pipe inside of a 3 inch line. got it fixed though