I am asking to be better informed when I speak to my prospective plumbers on doing this job.
I have a septic tank that has already been sized for the additional bathroom I want to install in my Garage, I thought of this when i replaced it two years ago.
Where it is located was the only place I could install it in relation to the leach field
What I want to do is add a bathroom in my garage, my issues are that the septic tank sits 5 feet higher than the grade of the garage which means about 8 feet total when you put in the basin tank in the ground at the garage and the closest I can get it to the tank is 50 feet away.
Now , the drain from the basin can horizontally go natural gravity for 38 feet of the 50 feet because the shortest distance to my septic is through my stone driveway so technically I only have to pump up a distance of 10 feet maximum allowing for 1/4 " drop every foot and a running distance of 12 feet.
So my questions are;
1-can a pump up system be installed at the actual point of vertical discharge in the driveway? ( i can easily camouflage it)
(It would be below frost line and the discharge pipe would be running vertically and horizontally to reach tank and i would run a dedicated electric line to it)
2-if not...then is there a problem running discharge horizontally for that distance before pushing that waste up?
(if so, i can go around the driveway to keep a constant up pitch but the length will increase from 50' to 70')
3- what pumps are the best to use in this situation (brand, horsepower or however you calculate this)
I am looking for the best professional advice to do this job and that it will not only work, but last.
Normally the waste would flow by gravity to the septic tank. The heavy solids sink to the bottom and grease and oils form a layer on top of the liquid in the septic tank. The baffle and tee allow only the effluent to flow by gravity out the end of the septic tank. The effluent usually flows by gravity into a pump tank. Then you would have an effulent pump that pumps the liquid to a distribution box (d-box) or pressure manifold etc. and then to the drain field. In your case you could pump to the existing septic tank. There are other ways to do it but I would do it this way.