Toilet and Lav Downhill of Septic Tank

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cay816

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Hello,

I have a small outbuilding downhill from my main house. Around 100 yards away from the house with around 30 feet of elevation change. I am wanting to install a toilet and sink in the outbuilding and pump it back up to our existing septic tank. From what I've been reading it looks like I should install a small holding tank at the outbuilding with a grinder pump inside it to pump up to the septic tank and connect in. Does this sound right? What are some resources I could reference to help me learn more about this system and everything involved?

Thanks!
 
Gotcha, that is good to know. What is the thought process behind deciding when a grinder is needed or not?

I was actually just looking at some of the packaged liberty pumps, love the simplicity of an all inclusive package.
 
I only use a grinder when I’m pumping into a forced sewer main.

Thats a city sewer main under constant pressure. My pump must pump against this pressure and it creates a slurry to do this and high head pressure. I use a 1.25” pipe to pump the slurry to the street.

My grinders cost 1200-1500 while a solids pump cost 4-500
 
One thing you want to make sure is that your pump can handle the 30’ elevation and the 300’ distance.

Grinders are typically more powerful, at least the ones I use are.
 
Gotcha, that makes sense. Since I'm not pumping into a pressurized system I don't need that extra pressure from the slurry.

I will for sure need to measure the elevation change more accurately and calculate that head pressure out. Should I just take the elevation change and then add 1' of head for each fitting?

If I needed lets say 30' of head total, how much higher should the pump shutoff head be above that? I'm assuming there's a factor of safety involved?
 
Gotcha, that is good to know. What is the thought process behind deciding when a grinder is needed or not?

I was actually just looking at some of the packaged liberty pumps, love the simplicity of an all inclusive package.
Grinders should not be used in septic systems, nor should macerator pumps like Sanilfo systems. They can clog the distribution lines in a septic field and cause it to fail.
 
Gotcha, that makes sense. Since I'm not pumping into a pressurized system I don't need that extra pressure from the slurry.

I will for sure need to measure the elevation change more accurately and calculate that head pressure out. Should I just take the elevation change and then add 1' of head for each fitting?

If I needed lets say 30' of head total, how much higher should the pump shutoff head be above that? I'm assuming there's a factor of safety involved?
here's how you get TDH = RUN+ 50 (TO ALLOW FOR FITTINGS) =XYZ
MOVE DECIMAL BACK 2 PLACES
MULTIPLY BY 2.06
ADD THAT TO YOUR LIFT
 
Gotcha, that makes sense. Since I'm not pumping into a pressurized system I don't need that extra pressure from the slurry.

I will for sure need to measure the elevation change more accurately and calculate that head pressure out. Should I just take the elevation change and then add 1' of head for each fitting?

If I needed lets say 30' of head total, how much higher should the pump shutoff head be above that? I'm assuming there's a factor of safety involved?

It’s usually in the pumps spec sheet. As your head goes up the pumps capacity goes down. You don’t need much capacity if it’s a “ sometimes “ bathroom.

Just refer the the pumps curve.
 

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