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I'm replacing the sump basin/liner in my home which is currently a perforated 5 gallon bucket surrounded by gravel. I have an interior drain system that has two pipes terminating into the gravel pit area (but not into the basin itself - the water dumps into the gravel and through the holes in the bucket). We have a high water table and the sump runs every few minutes on normal days.

My question is: should I replace the bucket with a solid liner, with openings for the drain pipe to go directly into the basin to be pumped out.... or should I use a perforated liner that allows water to come in in addition to the drain pipes? It seems counter-intuitive to me to have the drain pipes empty into a basin with holes in it... but maybe I'm missing something and water needs to be allowed in in addition to the drains?

I really appreciate any advice you can give. Thanks!

Oh my - two very different responses! My thought was that if it the liner is sealed any additional water pressure would result in the perforated drain tile doing it's job "better" and bringing the water to the pit. However, the response from Ed was exactly what I'm concerned about (the ground water causing the floor to leak).

If I use a perforated bucket it would surely always have water at the bottom because of the high water table. Would it be okay to elevate the sump in the pit (using something like pavers) so that it's only emptying to a depth around 6" below the slab? The problem now is it's constantly cycling to remove ground water that is over a foot below the slab. I'm using a Zoeller without an adjustable float, so raising the pump itself is the only thing I can think of.

Thanks again for the responses.

Edited to add photo of current setup. The current bucket top sits a couple of inches below the top of the slab... when I install the new basin I will make it level with the slab and fill with concrete.Current Setup

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    Commented Jan 30, 2019 at 23:53

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I've installed many drain tile systems in Minnesota, and none of them used perforated pails. Really, you don't want to be collecting water from that far below your slab (and typically don't need to). All drainage should occur in the drainage medium via the tile.

If the drain tile (pipe) is perforated, there's no reason to have holes in your bucket unless you have a particular need to drain that deep. You're more likely to get sediment if you collect from down there as well.

Response to your answer/comment:

Your drainage medium (the clean rock I assume is below your slab) acts as the drainage path to the drain tile, which is simply a collector. If they're doing their respective jobs, no significant amount of water is present at the slab underside, and the question is rather moot. You don't need perforation unless you don't have drainage media under the slab, and if you don't, a perforated bucket only serves to allow drainage in the immediate vicinity of the bucket anyway. It won't keep your basement dry throughout.

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  • Thanks again for the reply. Apologies for posting my follow-up as an answer, I see how it works now. There does appear to be clean rock as a drainage medium under the entire slab. I guess I'll go with the solid bucket and see how things perform. Are you able to address my follow-up regarding pump height?
    – Glen
    Commented Jan 30, 2019 at 16:41
  • There's no need to raise the pump since the pail will only collect from the level of the bottom of the inlet anyway, which is maybe 10-14 inches below the top of the pail/slab surface. That's the weir of the system.
    – isherwood
    Commented Jan 30, 2019 at 16:43
  • We disagree on this one, I have done this exact sump system on several homes in Oregon. Closing off the ability to keep the ground water away from the slab may at least cause damp floors and at worst cause puddling. The depth of the sump in this area needs to be at least 6-8 inches below the bottom of the slab. If some blocks were installed in the bottom of the bucket and there were no problems maybe the pump could be raised some more. I would tape some plastic on the floor and test for moisture in the slab now furthest away from the sump. Make the change and repeat the test.
    – Ed Beal
    Commented Jan 30, 2019 at 17:36
  • Ed, the inlet to the pail in my scenario is 8-10 inches below the underside of the slab. If that isn't enough, I don't know how much would be.
    – isherwood
    Commented Jan 30, 2019 at 17:40
  • Ed - Can you clarify on your point about "closing off the ability to keep ground water away from the slab...". Isn't that exactly what the drain tile/pipe is intended to do? Are you saying that in addition to what enters the drain tile, there would be more ground water that needs to enter the perforations in the basin to avoid seeping through the slab?
    – Glen
    Commented Jan 30, 2019 at 18:17
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The perforations are to allow ground water into the pit. If you seal this up your floor and walls will have more water pressure on them and may start leaking. Make sure to use a perforated liner.

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You're in a high water table area so I'll have to defer to the design of the system as is, as I picture it in my head (because I am not in one. See the old answer at the end, and the comments).

Assuming they'd reach into the new sump, cut holes for the drains but do not perforate it. If they aren't going to make it, either extend them or do perforate it.

Get a separate switch and put the pump as far down as it will go and the switch as high as possible, for less cycling. But put it on some bricks to prevent it sucking in sediment.

Should my sump pail be perforated? That depends on where your water table is.

Mine's low and my soil is clay, so I would perforate it.

Your water table is exceptionally high, so I wouldn't.

The thing you're complaining about is it cycling. It's cycling because it's in a 5 gal bucket, with an integral float.

A larger and sealed cistern, with a pump with a separate switch, wouldn't cycle so much.

A five gallon bucket for a sump in an area with a high water table... seriously? There's your problem right there.

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  • You've said what you would do, but not why. What's the point of perforating in clay? You'll get very limited drainage and a lot of sediment.
    – isherwood
    Commented Jan 30, 2019 at 21:15
  • @isherwood - For the foundation to be stable and the ground under it to not be subject to liquefaction. If your water table is 6" below your slab, that's a battle you can't win anyway - and shouldn't try to fight.
    – Mazura
    Commented Jan 30, 2019 at 21:19
  • My point is that you cannot effectively drain a foundation with only clay under the slab. Perforated or not, the other side of the house will see no benefit.
    – isherwood
    Commented Jan 30, 2019 at 21:21
  • @isherwood - My entire foundation is a cistern because it's clay; that's why I want holes. Basement's entirely below grade and I probably drain the entire block. But it takes a while to fill, again because it clay, so there's no cycle issues, also because it's in a hole much wider in diameter than a 5g bucket. If you're worried about hydo pressure, gah call somebody (!). But where I live it's just the difference between a somewhat wet floor or not. - Fourth opinion needed. Ideally from someone who lives even less then 500' above sea level.
    – Mazura
    Commented Jan 30, 2019 at 21:33
  • I KNOW I need to upgrade from the 5 gallon bucket, which is why I asked the question about the new basin. I'd say the water table is currently ~10" below the top of the slab. I don't know the soil make up, but from what I can tell there is at least several inches of gravel under the slab. The drain tile has some water running through it almost constantly. I will be routing those pipes into the basin. If the basin is perforated it seems to me that the water will end up seeping OUT of the holes, back into the water table and then through the pipes again, resulting in unnecessary cycling.
    – Glen
    Commented Jan 30, 2019 at 21:58

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