I am looking at going with a below grade discharge arrangement after having my sump pump hose freeze this winter. Was specifically looking at the sump pump, but I think I may do the same for the down spouts for the gutters.
The back yard has a 1-2% slope away from the house.

The original idea was to have the sump pump exit the house below grade, take follow a ~20' run (1-2% down grade) away from the house, then exit into either a weeping tile or those plastic pipes with the pre-drilled holes.

With the gutter/downspouts, I was thinking of doing the same in a parallel system, instead of the existing arrangement of dumping all the water on the grass. (The sub pump dumps the water on the grass as well currently.)
I could have the sump pump connect to the same below grade system and simply put in a couple check valves.

I only took ownership this past December, so now I am going over everything trying to fix the shortcuts the previous owners had taken.


Thoughts?

 

Let's start from the beginning. Is the sump pump in the cellar? If so, is it there because the foundation needs to be sealed & someone decided it was easier to install a pump?

 

Pulpo,
The sump pump is in the basement. They appear to be a common thing in this town.
The sump pit is poured concrete (approximately 18" round), with what looks like a single 4" pipe (weeping tile) entering into the pit about 18" from the top of the pit.
The basement is approximately 35ft x 45ft poured concrete (unfinished) and has no sign of water anywhere. That being said, it's pretty easy to hide concrete water damage during a 75 year period.

 

It sounds like there is a high water table & that's why the sump pump is needed. I've never seen one discharge underground. I imagine it can be done but my only question would be if some type of vent, in the line, would be needed or not.

 

The water table is pretty high here, but I think the sump pump pit is being suplied by the weeping tiles on west and east side of the house. I don't understand why, but that is what I can see without fulling investigating (been busy with other higher priority things).
When I remove the lid to the pit (wood cover someone made), I can only see two 3-4" weeping tile type pipe and a completely concrete enclosed pit.
That being said, sump pumps appear to be a very common thing in this small town.

As for the below grade discharge (back on topic now), The game plan was to exit the house below the estimated frost line (24"), run within ~1-2" of the foundation to the edge of the property. Most likely I would have the pipe run from the South East corner of the house (where the pit is located), to the edge of the property near the South West corner of the house. From there, I would extend the hard pipe 15-20ft south before connecting it to a weeping tile or hard pipe with pre-drilled holes.
Ultimately I would like to run the pipe work the 100-125ft to the south edge of the property, and let it drain out there, but my money tree isn't producing and I'll be doing the digging manually.
If I backfill around the drilled pipe/weeping tile with a corse gravel, I don't think drainage would be an issue.

 

Try it. You can always vent the pipe at a later date, if it's needed.

 

I'll look into the venting once I get the basic layout designed.
The one area of concern is going from the feed line to the discharge area/line.

The original idea
At a quick look, it appears that the feed line will be 1.25" to 1.5" and the discharge area will be larger (3"-4").
I'll be using a large discharge area/pipe in order to allow the water to more gracefully discharge into the ground. This should reduce the chances of a sink hole effect. Availability of wheeping tile or pre-drilled drain pipe is also better in the larger diameter.
I'm thinking I might add a checkvalve before the discharge area, but then that will add a potential failure point. The check valve would prevent the ground water in the discharge area from feeding back into the feed line.

Potential Option
I may run the same 1.25" to 1.5" feed line into a field bed type system.
I'm starting to think that ground saturation could pose an issue with a fully below grade setup. If the ground is already saturated, there will be more load on the pump, and could displace ground around the discharge area.

Potential Option 2
Run the 1.25" -1.5" feed line below grade from the exit of the house, to the very back of the property where it drops into a step bank.
The only issues with this is the cost of the pipe work, my back pains, and a low potential of the exit being a freezing point (fairly unlikely).

Going back to the drawing board I think on this one.

 

I did a job similar to option #2. It went all the way to where there was a drop. That a good idea.

 

Pulpo,

Looking at the length it would have to travel, I am wondering if option #2 is a good idea. I'm looking at ~100-150ft run from the house to the drop off at the end of the property.
That being said, the sump pump is 3/4hp and two of the 3 downspouts are 25-30ft vertical drops, so the water would have some push behind it.

 

I did some measurements with the GPS this weekend. It's almost exactly 50M (164ft) from the house to the edge of the property where it slopes down into the river.
I think I will opt for running the sump pump the distance, but will look at an alternative for the gutter downspouts. The sump pump will have volume and pressure behind it, where the rain fall we get here... won't be enough to move the water the length.

Now the question being, do I go with 1.5" hose or run a reducer to a smaller hose?
A smaller hose would increase the pressure and move the water out better, but could increase the back on the pump.