Cold weather sump pump discharge questions

[oldtinsmith]

Sump pump pit: 28"dia. x 22" deep (to stone bottom)
Wayne SPV500 pedestal sump pump (1/3 HP & 3100GPH)
Discharge pipe is 1 1/2
Discharge length (proposed) 115' to 120' to storm sewer (clean out / man hole cover). My neighbors sump discharge runs into it. My drop is 36".
The discharge pipe will be running 35' to a gravel drive (to my post frame shop) and at an angle under the drive (total length run under the drive is 24').
Questions:
Should I run 3" or 4" DWV or PVC under ground? Should/how do I reinforce the pipe that runs under the gravel drive (if need be)?

The frost line here is 42". In the 20 years I've lived here, I've never seen the water in the storm sewer freeze (even when the water is only 36" below the surface!).

When we bought this house, the PVC that was installed to the waste sewer system (no longer a septic system) has an inspection "sticker" on it dated 5-8-82. The PVC system looks like it has never been altered, but, the sump pump discharge is tied into it. Could it have been legal to do that in 1982? Could that install be grandfathered in?

I wrote this post (book) so I'll have some idea what I'll have to do if I need to change the sump pump discharge. What would you people do?

Doug

 

[kbs2244]

First, go big.
You want the pipe to drain completely dry and you need air space above the water to get this.

Second, can you go alongside the driveway?
You are asking for problems if you are going to be driving on the pipe.
Even if you do not break it, when the thaw comes, you will be pushing it deeper in places and losing your slope.

The sewer isn’t freezing because it is drawing heat from below it.
Your pipe doesn’t go that deep.

If you now have a seprate storm sewer system I would doubt it is OK any longer to put sump pump water in the waste system.

 

[oldtinsmith]

kbs2244, thanks for answering my post and for your input. I appreciate it! I was hoping for a few more replies, but, it is what it is.

Doug

 

[blazentrout]

I was told that 3" pipe 'may' freeze if the slope did not let it dry out and to run 4" as a min.
Now some some qualifiers for what i will be getting into for my sump/foor drain- 150aprox run, 3' drop, 30' under only 12" of soil(at the 2/3rd point of my run).

The big thing is how often does your sump pump run?

 

[oldtinsmith]

blazentrout, thanks for also answering my post! Heavy rainfall/snowmelt, the pump runs about once every 6 to 8 minutes. Right now it's running once every 25 minutes. Our usual July/August dry spell, it very seldom runs if at all.

Doug

 

[Architorture]

If it is running that often it doesn't seem like it should freeze. I have one that runs perhaps 30 or 40 feet at a rental property that is probably only 12" below grade. It runs quite often in the winter and actually warms the sidewalk over it enough to melt the snow.

 

[oldtinsmith]

Architorture, thanks for your input. I found your statement about the discharge warming the sidewalk interesting to say the least! Do you know what diameter your discharge pipe is?

Doug

 

[Architorture]

it isn't a dramatic amount of melting...perhaps a 12-15" wide swath directly over the pipe. The pipe itself is 4" PVC that is also tied into the downspouts.

I have it set up so the 2" discharge from the pump passes through the wall and then drains into the 4" line.

 

[oldtinsmith]

it isn't a dramatic amount of melting...perhaps a 12-15" wide swath directly over the pipe. The pipe itself is 4" PVC that is also tied into the downspouts.

I have it set up so the 2" discharge from the pump passes through the wall and then drains into the 4" line.

What schedule PCV do you have (40?).

Doug

 

[Architorture]

I can't say for sure what makes up the main run as I did not install it, the portions that poke up above grade at the downspouts appear to be of the thin walled variety.

the portion under the sidewalk basically receives no load as the sidewalk is only 4' wide and most likely just spans over the drain pipe.

For your situation, considering vehicle traffic and loading you are going to want the pipe down deep enough for the driveway base to carry the load around it. A 3 or 4" pipe should not be difficult to do. I'd imagine it would take a substantial load to crush sch40 pipe buried 12" below a properly constructed driveway.

I have a 4" asphalt drive with a reasonably deep base that has probably (4) 4" PVC storm drains going under it at a few different elevations and I've had several loaded tri-axles over the drive without problems. Just make sure you start off deep enough to get plenty of gravel over top....preferably gravel that can be compacted and won't shift under load placing stress on the pipe

 

[oldtinsmith]

Architorture, thanks again, my friend. I should have mentioned that the vehicle traffic back to my shop is minimal. I might drive the Lumina van back there twice a month, and once or twice a year my son comes up with his 1/2 ton pickup pulling his lawn care double axle trailer. When the drive was put in, the top soil (8 inches deep!) was removed and 8 inches of sand base was compacted in its place. Then, 4 inches of crushed stone was laid on top of the sand. That was over 10 years ago. Do you know anything about 4 inch plastic double wall [corrugated smooth inside/soil sealed N 12 (?)] pipe?

Doug

 

[Architorture]

the flexible black corrugated stuff? I've certainly used it. It's a little different than PVC because it won't fail by cracking when overloaded...it will just flatten instead because it is flexible instead of being brittle like pvc

The ability to get long lengths that can be curved is beneficial when trying to go a long distance in a straight line...nothing is worse than discovering a big root or rock at the end of a long trench

 

[oldtinsmith]

No, it is a double walled rigid pipe. It has a corrugated outer wall and a smooth inner wall. Male and female ends with a seal for a slip type fit. HDPE N12 is a high density type of plastic.

Doug

 

[REPO]

On my friends shop up here in Canada he was only able to run his sewer line from his shop at about 2-3' underground. His system uses a pump to pump waste out to his sewer line from his house to the lagoon. The line is ran in a sand bed with a heat trace line with 2" rigid foam insulation layer over it, then treated 2x8 lumber over that, then filled in with dirt.

It has been in service for about 10 years now without a problem.

Whenever you burry a water line that will be driven over, the frost will easily be pushed down twice as far as normal. Simply laying lumber over top will prevent a great deal of this, as well as stop the line from being compressed.


Sent from my iPad using Tapatalk

 

[CasesCustoms]

Should I run 3" or 4" DWV or PVC under ground? Should/how do I reinforce the pipe that runs under the gravel drive (if need be)?

When I ran my gutter drains (similar situation) my plumber recommended that I use 4" PVC (Schedule 40 minimum) in case I ever needed to drive over the lines to get the well in the future. With you planning to drive over the line routinely, I would definitely go with PVC instead of DWV .

 

[oldtinsmith]

REPO, great to hear from a neighbor to my north! I like what you've added to this post too! ... CasesCustoms, Your point about 4" PVC instead of DWV is a good one!

Thanks guys!
Doug

 

[lametec]

I have 2" PVC about 4" under ground. Doesn't freeze.

I put a check valve inside the house the allows air in (but not water out) to make sure the pipe drains.

 

[oldtinsmith]

lametec, the check valve is a good idea! Thanks.

Doug

 

[LifeLongWNYer]

I had to do a little digging around here about 3 weeks ago. The spot had about 6-7" inches of snow ( works as insulation ) and the frost still ended at 38" below grade.

Now, for sure, EVERY winter isn't like this one was, but if I'd have buried my line at 36" there is a good chance that it would freeze sometime in the next 5 to 7 years.



.

 

[oldtinsmith]

LifeLongWNYer, Thank you for replying. We have to dig our footings to 42" here. Some water supply pipes were bursting this winter down over 50"!

Doug

 

[Architorture]

No, it is a double walled rigid pipe. It has a corrugated outer wall and a smooth inner wall. Male and female ends with a seal for a slip type fit. HDPE N12 is a high density type of plastic.

Doug

Gotcha...only ever used the big culvert size in that stuff...seems like overkill for the application as I imagine the minimum coverage would still be in the range that would work well for pvc

 

[mr overdunne]

good info in here. im getting ready to start this project on my own house.

 

[oldtinsmith]

I found this while searching Bay County sites [in the second post (by kbs2244) he mentioned running the discharge along the drive):
" Individual sump pump & lot drainage leads must be connected to the storm sewer system at a manhole or catch basin, or connected to a header pipe paralleling the roadway & tapped into a manhole or catch basin. "
" Sump pump or lot drainage leads will be private and will be the responsibility of individual lot owners to maintain".
So,,,,,if I've read this right, I should be able to bury the discharge pipe along side the driveway and tie into the buried pipe (12"dia.) in front of my house and not under my driveway to the manhole in the corner of my lot!... I may need an approved "tap in" fitting at the header pipe. ... So,,,, 1) I'll need to see the county drain commission for approval/permit and ask about a tap in fitting, if I can tap in a 4" discharge pipe into the 12" header pipe and if I need a physical "break" in the discharge pipe at the house. ... Right now I have ALOT of family situations that must be taken care of, so none of the above questions will be answered for a number of weeks. ... Thanks to all responders to this post for posing and answering my questions! Let's keep this going because it WILL help other people!!!

Doug