In October, I bought a large home with a sump pit in the basement. The previous owners had a sump pump but left it shut off (unplugged). I bought the house three months before moving in, so the pump had been disabled for at least that long. The pit was filled with water up to the top of the three inlet pipes and there's no evidence that water ever went above that level.

I thought it odd that the pump was installed, but disabled. So I turned it on and it works. But the pit re-fills to the level of the float switch within 90 seconds! I figured I would just leave it and see if the incoming flow of water would decrease, but it has been four months now and the inflow of water has been the same regardless of weather conditions outside. See picture to get an idea of how fast it fills.

I tried to figure out where the water drains to. It flows through a pipe to the exterior of the house and then turns 90 degrees straight down into the ground. Where it leads from there... I have no idea. This elbow joint occurs underneath our patio, so without tearing the whole patio out and then digging, I don't see any way to figure out where the pipe leads. We do not have city sewer, and I am sure it does not feed into the septic tank (I checked).

Should I be concerned? Should I just disable the pump and let the pit fill up until it stops and just leave it like that? It never seems to overflow and there's no evidence of water ever flooding into the basement. Any tips for how we might figure out where the water is draining to?

Water flowing in

  • I'd contact the local government, and try to figure out how high the water table is. The solution may be to set the float switch higher.
    – Tester101
    Commented Feb 8, 2015 at 17:04
  • I do believe the water table is high. There is actually standing water (wetlands) on the property. The previous owners stated that it wasn't there when they built the house 20 years ago, but it formed after the area started seeing more development (other homes being built up on neighboring lots). Hopefully, since it wasn't there naturally, my local municipality will allow me to tamper with it if that ends up being the best course of action. Commented Feb 8, 2015 at 17:24
  • I have thought about raising the level of the float switch to be right at the top, just before the water overflows. Unfortunately, this pump has a built-in float switch that isn't adjustable, so I would need a secondary float switch that controls the main power supply to the whole unit. While possible to do, it definitely means more single points of failure. Commented Feb 8, 2015 at 17:25

1 Answer 1


To raise the float level without adding any additional points of failure, just move the whole pump up - shorten the pipe, put concrete blocks under the pump to raise it in the pit. Your power bill will thank you.

You could try putting a strong dye [food coloring or fabric dye can work, but "septic dye" is probably the most effective] in the water, though it may be hard to tell what's happening with that - I have to suspect that you may be pumping in circles (outlet insufficiently far from the house, so the "discharged' water shows up in the pit a few minutes later) but that will be tricky to trace with dye. If all the water is "new" the dye should just get progressively paler, and the water coming in the drainage pipes should be clear, not tinted. You can also look for dye coming out into places away from the house.

image of septic dye from clermonthealthdistrict.org

A more complicated approach that might work would be to mix up or buy a strong dye solution and use a tube to "inject" it very near the pump intake as the pump is pumping (trying to minimize what gets in the sump itself) and then you might see the sump get darker if it's recirculating.

It sounds like the water may be passing in from one or more of your pipes and out again from one or more of your pipes (when the pump is not powered up) - a little bit of dye squirted near each pipe in turn (with the pump off) may diagnose this and show if there is "flow-though."

  • Thank you! This is what I am going to do - move the whole pump up. Also, I'll try the dye trick once the snow has melted. Commented Feb 8, 2015 at 19:49

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