DIY Home Improvement Forum banner

Sump Pump Pit Install Question

3K views 18 replies 5 participants last post by  AllanJ 
#1 · (Edited)
Hello,

I have a sump pump pit that seems to be getting a lot of ground water through the weep holes (at the bottom of pit) and from small gap around the PVC pipe that enters the pit. Please see picture below (red arrow shows the water coming in). This isn't actual setup in my house but just as an illustration. I have exterior drain tile setup.

I rarely see water actually coming through the PVC pipe other than during heavy rain.

I presume this is OK given that water needs to go somewhere but the gap around the PVC may be filling the pit sooner and keeping the sump pump running more often.

Is it advisable to fill this gap around the PVC to slow down the water entering the pit? If so, what could I use? I think it's about 1/2" gap but enough to force ground water into the gap... I currently have the pump being actuated at the bottom edge of this PVC pipe

Thanks

 
See less See more
1
#3 ·
Thanks for the quick reply. Gutters and grading are good however I am towards the lower end of the neighborhood but have not seen any puddling around the house. I also tested for leaking city water. I am accepting the fact that I have high water table but thinking about ways to prolong the sump pump so it doesn't turn on all the time. Luckilyi have adjustable float switch so I can let the water rise a bit but seems to stabilize around 10" below concrete floor.
 
#4 ·
First, where is the pump ejecting to?
Second, if you have perimeter perforations as shown in the illustration the water should be entering those before it gets up to the pipe.

If your foundation was dug into the ground creating a pong under the surrounding grade it could take quite awhile to lower that level. If you can't lower that level with your pump, ie water is entering to replace what you pump, then an exterior solution would be needed. Once water seeps into the soil id drains along an underground contour that we cannot see. Often it is the original grade that existed before the area was built. Major project would be to determine where that water is coming from and divert it before it enters the pond under your house.

Bud
 
#10 ·
If your foundation was dug into the ground creating a pong under the surrounding grade it could take quite awhile to lower that level. If you can't lower that level with your pump, ie water is entering to replace what you pump, then an exterior solution would be needed. Once water seeps into the soil id drains along an underground contour that we cannot see. Often it is the original grade that existed before the area was built. Major project would be to determine where that water is coming from and divert it before it enters the pond under your house.

Bud
Bud - any idea as to exterior solutions to address this? While I've lived in this home for less than a year, I don't see this water level going down other than during super dry season. How do you divert underground water away and perhaps tie to city stormwater system? I noticed one of my neighbor has a stormwater basin that is constantly flowing water (3 ft down) as if he had tied in underground water to the basin...

I am planning to do what I can to divert all gutter as far away from home as possible but as I mentioned, water level is high even though no rain/snow for weeks.
 
#5 ·
More facts on this home:

1. New construction with 10 ft basement. Previous home was a ranch with probably no basement but not sure;
2. Water from Sump pump ejects about 10ft outside which ties to the storm sewer system. I was concerned with water recycling back into pit but did a dye test and don't think that's my issue
3. Water level in the pit doesn't fluctuate much. Even after pumping, the water level quickly shoots up to about 10" -11" below the basement floor. The pit is about 22" deep.
4. Bud - only if I had xray vision that I can see what's going on below my basement foundation :) I tried running the pump more often by lowering the switch but the water level goes up after rain/snow. I am hoping someone builds a new house next to me diverting underground water elsewhere.
 
#8 ·
Yes, very clear. I had city do water test twice and they claim little to no chlorine etc. to be considered a leak. Water usage remains consistent and reasonable. I guess there could be leak from my neighbor that is trickling down to me.

Also, there is a house behind me sitting about 5 ft higher than me. I also have another home who's backyard is on my side yard (drains towards me). I think it's far away enough (about 30 ft from me) to make a huge difference in ground water.
 
#7 ·
It's very common for water to come in around the pipe entering the crock. Draintile systems aren't designed ot be a sealed system like sanitary plumbing/etc... Water flows with the path of least resistance and to the lowest point, and with the well-perculating stone around the crock and under the entire floor, the system is doing exactly what it's supposed to.

IMPO, 10-11" below the basement floor at rest is fine for the water level. When you get under 8" or so is when I'd be more concerned.

Two quick questions though:
- Is there a check valve in the discharge line?
- How long does the pump run (inn seconds) before it shuts off again?
 
#9 ·
1. Absolutely, there is quiet check valve. I have Proseries pump and a backup pump with battery which is tied to whole house generator.

2. I can adjust this with my switch. Right now, I have it running for 14 sec. Default is 10 sec.

Sadly, once the pit is clear of water, it fills up quickly up to about 10" and the last 1" would take probably an hour or more to fill before it activates the switch - hope that makes sense.

One more info that might be relevant. My pit is 18" wide and 22" deep. Would it help if I got 24" wide pit? I am wondering if that would perhaps lower the water level in the pit?
 
#11 · (Edited)
You said you are "towards the lower end of the neighborhood", that implies you may not have a good slope to help drain all water away, both above ground and below ground.

Without that xray vision it is difficult to see the water moving below your property, but it always is, just depends upon how far down the impervious layer is. When the dig a foundation they can sometimes dig out a depression in that layer which becomes a below grade pond that your basement is sitting in. Trying to pump that dry while the surrounding area is replenishing ir is nearly impossible.

The perimeter drain system installed when the house was built should be draining somewhere and that is possible what is controlling the limit to which the water table is rising.

if you have access to a lower drainage area then more and lower drains could be installed. Otherwise it would seem the current limit will remain. As long as the water level stops 10" below the floor level you are ok.

IMO I would have a couple more sump pits as back ups.

Bud
https://water.usgs.gov/edu/watercycleinfiltration.html
 
  • Like
Reactions: sbkim
#12 ·
Hi Bud - sorry to resurrect again but a couple quick questions:

1. After heavy rain, I notice puddling of water in my neighbors yard which is about 20-25 ft away from my foundation. Not much I can do about it given it's their property but could that eventually make its way to my pit? I live in Chicago so it's clay based soil mostly

2. When I raised the float switch, pump ran once every 8 hours. Eventually, water level catches up and now running once every 1 hour despite no rain in days. Does this mean, water table is lowered artificially but in the end it will keep going up? I am tempted to raise the switch again about 1/2" which seems to buy me hours before pump turning on. However, I read you shouldn't raise the water level past bottom of pvc inlet pipe? Regardless, I have about 10" space between floor and pit water level.

Thanks
 
#13 ·
If it isn't raining then the water you are getting is probably due to the surrounding water level or water flow. Your neighbors pond would be contributing to that but not the primary cause of what is happening underground. If you had an old fashioned hand dug well you would see that natural water level. If you tried to pump it dry it would be difficult and if you stopped pumping it would probably recover to exactly where you started.

Long term I would consider an outside pump deeper than what you now have to lower the level below your drainage system. That would eliminate any silting issues and most of the cycling. Modern pumps are much more efficient so not all that bad energy wise and you could switch it off during the dryer seasons.

Bud
 
  • Like
Reactions: sbkim
#15 ·
If you are in a frost free climate you have a lot of flexibility as to how and where that water surfaces. In my climate it just means where you want your skating rink.

Well guys and soil engineers have a massive amount of information relating to what is below the surface all over the entire country. I would bet a lot of that is available over the internet if you can understand it, they do speak a different language. But well drillers have details from way back to prepare them for any new work. Even though wells may not be in use where city water has been established, the records still exist. I'm fortunate to have a couple of very friendly well guys who are happy to share their knowledge. Doesn't hurt to knock on a few doors and ask what they know about the surface water in your area.

Bud
 
#17 · (Edited)
It is not necessary or desirable to plug little holes in the pit liner unless lots of dirt comes in.

The properly installed and working sump pump, pit, and drain tile system creates an artificial water table lower than the surrounding natural water table thus sparing your basement from flooding.

If you turn off the sump pump and leave it off, the artificial water table under your house gradually rises to more or less match the natural water table again.

The natural water table may vary with rainfall. There may be some weeks when the natural water table will also be below your basement floor and the water will rise in the pit and stop before the fat drain pipes (from the perimeter drain tiles) dumping into the pit are submerged. The pump can be adjusted so it does not continually run during these times.

If the water level stops with the pit partly filled and there is no basement flooding then things can stay that way indefinitely without pumping. But when the pump does start, it should keep going until the pit is nearly empty.

The water table can vary even in a horizontal span of a few feet. f you adjust the pump start water level upwares and a little too high and then the far side of the basement floods, then adjust it back down and let the pump run normally for about a week to see if you lowered the artifical water table again far enough.

When the pit fills rapidly after being emptied and then slows down this could mean that the pump finishes when lots of water is still queued up in the drain tiles and dumping into the pit. This can be improved by having a larger or deeper pit.
 
#18 · (Edited)
Thank you AllaJ - very helpful ans easy to understand for a dummie like me.

Changing out to a bigger pit or adding another pit sounds like a lot of work and $. My pump currently runs once an hour (even without rain) all throughout the day with the switch set at the middle of the pit (water sitting right at the bottom of pvc). Is this too often? I have a backup pump and willing to change out primary after 2-3 years to prevent issues.

If I raise this an inch, I think it would go 4-5 hours before next run. I have a feeling that water level eventually goes up to that higher mark...Is it OK to cover up the PVC inlet pipe with water but still have the water level around 8 to 9" from the basement floor?
 
#19 · (Edited)
You can usually get away with the water covering the PVC drain tiles halfway. It is risky to cover the PVC completely because, if the drain tiles get completely full of water anywhere along the perimeter of the basement, you can get basement floor flooding at the far side of the basement.

If you raise the switch an inch, how long it eventually takes for the water to rise to that higher mark depends on the natural water table and climate and rain conditions that week. Adjusting the switch is trial and error. Allow a week between trials for the artificial water table to respond to the switch level change.
 
  • Like
Reactions: sbkim
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top