Sewage pump inside or outside?

[Innovate1]

My plans show a sewage pump in the basement of the house. The main floor can go directly into the sewer but we are very close on elevation for the basement and half bath in the detached garage. Rather than risk backup we are planning a pump. Putting it outside would eliminate any slope issues as the slope between garage (the higher floor) and basement is not quite enough so would have to go a little deeper with it in the basement. It's on the far side of the house from the garage. Putting it outside would mean for any work on it the mess would be outside. What would the top of the pit look like? What are the trade offs?

 

[Stuart in MN]

This is a picture of a typical grinder pump station, this one is a Zoeller. It's 18" in diameter and 30 inches tall, and the top basically looks like a trash can lid that is flush to the ground.

 

[meboatermike]

Depending on its mounting depth of the outside top in relation to the exterior ground level -- you may have to move some snow and or soil to access it depending on the time of year. But I would definitely put it outside -- any mess replacing or repairing it stays outside.

 

[tarmy]

Those things can stink...and the methane can potentially be ignited if near a flame.

You want that outside...

 

[HoosierMark]

I have the exact same situation. My upper floor is gravity. My basement is via sewage pump. My plumber tied a vent line for the pit into the existing sewer vents. I do not have the system hooked up yet but I do have the same type of set up as the picture. I guess if the pump quits and the pit is full the liquid will come out when I take the lid off. I have grinder pumps on a pressure sewer system at some rentals, they have alarms. I think I will ask my plumber about some type of alarm system if the pump gets too full. I have dealt with the rental pumps going out in all kinds of weather and it is not fun. Rain, snow, wind and cold plus wet ground from.... But since I have 4 of them for the last 20 plus years I am not a normal single house example. If I only had one then it would only be an issue about every 5 plus years. I would rather have my personal one in my basement.

 

[bad_idea]

How about a small lean-to pump house built onto the back face of the garage? Could build some shelves into it for storage of other stinky things.

 

[larry4406]

New construction guy here -

You have what we call a "hung" sewer meaning that your home's sewer is hung from the basement ceiling to enable gravity flow. In this case the basement (and apparently also your detached garage) can't gravity flow as they are lower than the sewer invert.

When we have hung sewers, we put an ejector crock with pump in the basement mechanical room and it serves the basement bathroom group. The detail is similar to what is posted above and it is cast into the concrete floor. It pumps vertically to the basement ceiling and connects into the hung sewer which then takes it away via gravity.

Sounds like your plans are having the detached garage gravity flow to the basement bathroom group which are then both served by the ejector crock. I would say this is a rational and economical approach.

The lid is level to slightly above the concrete floor. The lid is gasketed and provided with a vent and as such we do not experience odor issues. Use a quality brand such as Zoeller.

I have one in my house.

 

[matt_i]

I really feel like you want it inside. mainly due to having to then create several sidewall/foundation penetrations for the sewer line, the vent pipe and the electrical.

I don't think you can just vent it to the sky outside on a short stub because I've never ever seen one like that....so my WAG is the code prohibits that. Must tie back into the main stink pipe which exits the roof.

Which if you think of the geometry is going to be a pain to have a pipe entering the side and the top of the tank. Inside the basement the side version is hidden below the slab, you just deal with the vertical run to reconnect the vent. Now you have zero foundation penetrations.

 

[readhead]

I have had two and getting ready to install another in a new project. All three will be inside. Makes the hookup much easier. Also you can hear it run. If you don't hear it after a few flushes it might be time to check it. Never had an odor problem. Putting it outside may be a problem with freezing since the ejection line is always full.

 

[spudley]

I have one as pictured in the basement at a lake house. Worked fine for twenty years til last week when I was doing laundry. The float switch failed and laundry water backed up in the utility room.

I've never used the toilet for #2 as I feared failure would happen one day and I have two other toilets upstairs.

I second putting in an alarm although in my recent mishap it would need to be real loud as I was in the garage.

Hmmm...Maybe I'll should run a secondary alarm out to the garage.

 

[Slowgsr]

My high level alarm is very loud.

If I'm not home and it goes off it has an aux contact which will shut down my well pump. Stopping any water supply.

Mine is a liberty pump unit. They have high level alarms that can also alert your phone.

 

[yeldogt]

Typically for a bathroom -- the unit goes in the basement. They only have one pump and they are big enough to take enough flow should the high limit alarm go off and you flush.

The larger ones go outside (whole house) -- they have two pumps with a cycle controller.

They do make some noise -- so place them accordingly.

They provide a pump replacement cycle --- it's over 10 years. Make sure the unit is installed correctly -- so pump replacement is easy.

 

[LS6 Tommy]

Those things can stink...and the methane can potentially be ignited if near a flame.

You want that outside...

That is why they are sealed & vented to the exterior. Outside is a no-go in cold climates...

Tommy

 

[johnnyradiant]

Just place it with thought and consideration for servicing it, and doing so in less than ideal times either because of the backup, or if outside, the weather too.

Room to work so you don't have to wear any of it because you have to contort to get at it won't win you any friends or you may only hate your past self if your the one servicing it.

 

[ford33]

I have an inside sewer well and pump. It work wells and is vented by connecting to plumbing vent line. No issues in 20 years but I do open the cover and look at the pit yearly.

Three suggestions:
1. Get a high water level alarm and if possible connect it to your phone. Set it so you have time to respond before the water level overflows the well.

2. Install a battery backup with a second pump just as you would with a sump pump. Cheap insurance considering the mess created by a failed pump or float.

3. Put a reminder on your calendar to replace the float switches every 3 years whether it needs it or not. The float switches are the weakest link in the system in my opinion.

 

[flat350]

Do your plans show a floor drain in the basement,if it does the pit needs to be inside in the basement as the floor drain feeds into it also.

 

[scottydosnntkno]

Do your plans show a floor drain in the basement,if it does the pit needs to be inside in the basement as the floor drain feeds into it also.

Not in michigan. Floor drains feed into the sump, as they are considered storm water (flooding, leak,sump backup etc) sewage feeds into the sanItaly system.

At most of our new houses we put the sump and ejector pit right next to each other but they are completely separate systems.

 

[Mattlt]

I have a similar situation in my house. There was never a question of where to put the pump - it went in the basement. The lid of the pit is about the same level as the basement floor. It is vented into the rest of the plumbing system so never an issue of smell. It has a high-level alarm if it ever gets too full. I have my own well, so if the power fails, so does the well.

I have had to take the lid off once. Somehow a rag got into the basement drainage pipes and got sucked into the pump. It would have been a real PITA to have to take it apart in the middle of winter had it been outside.

In my case, any water in the basement drains to it. This includes bathroom, water softener regeneration output, AC condensate, etc. You may hear your pump run from time to time even without a flush.