dredge pump vs trash pump

Getting sewage uphill... sort of

Crosby Dog

I am installing a full bathroom with a standard bottom outlet toilet on the second floor of my garage that is 137 feet and slightly downhill from my main house's septic tank. The first floor of the garage is approximately 6' below the inlet of my septic tank, the second floor is approximately 4' above it. The utility ditch I am digging which will house the waste line needs to be 4' deep to be below the frost line here in the mountains of upstate New York.

I'm trying to find the best setup to get the second floor garage bathroom waste over to the septic tank.

The Sanigrind system from Saniflow seems a good match as it can be paired with a regular bottom outlet toilet, and with its 25' vertical / 150' horizontal pumping ability, it should have no issue reaching my septic tank, right? The thing that worries me is that the horizontal run is going to be long and a bit uphill all the way. Should I be looking at pit-based macerator pumping systems instead?

Any advice or input is greatly appreciated. Excavation is set to begin on my garage this week, so trying to figure out whether I should build a pit, etc. Would love to hear what folks have done in similar situations.

BukitCase

Dunno if the unit you're looking at can do that, but it might be less hassle (depending on whether you need a shower, dozen users, etc) to consider one of these

Crosby Dog

Thanks, Steve. I have considered composting toilets. I even actually considered 100% off grid power, a rain catchment system, etc, but I'm leaning towards making the garage apartment as "normal" as possible as our parents will be staying in it and they are not at all savvy or comfortable with these alternative options.

I'd love to hear suggestions for tieing into the main septic.

BukitCase

I'm pretty good at sniffing out "yean, buts", and this upward to 25 feet and/or 150 feet horizontally (with gravity fall). It sounds to me like you may have close to the correct SLOPE, but unfortunately it's in the WRONG DIRECTION.

In a "normal" waste system, if the slope (usually spec'd at 1/4" per foot) isn't correct, the accepted method is to "step" the drain - so sub-sections of pipe are either at the correct slope, or VERTICAL - otherwise the solids are "marooned" in place as the liquid drains away. This usually ends up with clogs, and NOT the Irish dancing kind.

Sorry I couldn't tell you how it WOULD work, but I think I would keep looking...

u3b3rg33k

a possible solution to avoid that issue would be to make sure your basin/sump is large enough so you're pumping at least the volume of the pipe every run. that would help prevent solid stacking in the pipe. minimizing pipe diameter and keeping flow rates high should help too, within reason.

I'm pretty sure you have to size to match your supply capacity, so if someone leaves all the faucets running you don't flood your building. with that in mind the only way to avoid short cycling/increase run times is to make your sump bigger.

someone out there probably has real numbers for this, since boring deep into hillsides isn't always practical.

walta

Since it is not my money I say dig your trench deep enough for gravity to do the work and put a pit with a lift station near the current tank.

Before you dig make sure you understand your local rules and who enforces them. I have to believe there is no legal way to do what you are talking about without a permits and inspections anywhere in New York State.

It is very very unlikely when the old system was installed anyone would spend thousands of dollars more to build enough excess capacity to support this large of an addition based on someday we might build an addition.

My guess is when the planning commission looks at your garage plans complete with 2 full baths they will declare it to be two or three bedrooms dwelling unit and requiring total replacement of the old system with a much larger system or a separate system for the new building.

TTMotorsports

I have looked into a very similar thing in the past and basically with permit allowing I would have to install a smaller sewage tank for the below septic stuff and a sewage grinder pump to pump the ****, literally, up hill to septic

TTMotorsports

Something like this.

larry4406

Some of the homes I built were on county forced sewer mains due to adverse grade/rock.

We installed Environmental-One (E-1) grinder pumps. Whole house (including basement) gravity flows to the pump basin, then the pump blows it thru a 2" lateral to a common force main. Each home has a check valve in its discharge so pumped effluent from the other homes cannot back flow into the basin. The basin has corrugations on the outside and you pour a couple yards of concrete around it to provide ballast so the chamber can't float out of the ground due to groundwater. My first house was on one of these and worked great.

I have also installed E-1 pumps that discharge to a septic system. About 30' prior to the septic tank, the 2" pressure discharge line connects to a 3" pipe which then is set on 1/4" per foot pitch to gravity flow to the septic tank. This is done to depressurize and slow down the forced effluent and to not swirl and disrupt the settling within the tank.

My current home has its septic field higher than the solids and pump chambers. It has twin Zoeller 161-0004 pumps with a controller that alternates the pump usage. In this case, it is only pumping the liquids from the pump chamber (solids settle in the first tank and liquid flows to the pump chamber).

Crosby Dog

Thanks so much for all the replies. Larry, below are you saying that the 2" pipe running from the E-1 pump is not with gravity fall? Can that run of pipe be slightly uphill, or no?

"I have also installed E-1 pumps that discharge to a septic system. About 30' prior to the septic tank, the 2" pressure discharge line connects to a 3" pipe which then is set on 1/4" per foot pitch to gravity flow to the septic tank. This is done to depressurize and slow down the forced effluent and to not swirl and disrupt the settling within the tank."

Crosby Dog

And thanks Bukitcase, I read the same thing re gravity fall soon after I posted.

Regarding number of bathrooms - we are only looking to add one bath in the garage. Additionally, septic capacity is based on the number of bedrooms, not bathrooms. We have a 3 bed house on a 1200 gal septic tank, and so 1 additional bedroom would put us at the max of 4 bedrooms on the tank.

larry4406

The E-1 pump is a positive displacement pump so yes the 2” discharge runs uphill against grade.

The systems that I have been involved with the 2” line ultimately crests the hill and then flows via gravity in a larger pipe network. One subdivision of ours had 5 homes that pumped to a single force main that rose in elevation 25-35’ if I recall. At the top of the hill it connected to a sewer manhole which connected to a conventional gravity sewer.

The force main remains full. As the pump runs a slug of effluent enters and the same amount out falls at the top.

My pumped septic system at current house has a force main up to the top of the grade where it enlarges to 3” pipe for a run of about 45’ where it then enters the distribution box and then to the drain field. My house gravity flows to the tanks but the septic field is higher than the tanks.

jives

Ours is like Larry's. I suggest gravity flow to a separate pump station/basin, then a grinder/jet pump to push it to a distribution box and leach field. Trying to use the uphill septic system 150' away seems a challenge, but I'm sure there must be some sort of solution.