How deep should the sump be


Our home (with basement, built in 1999) has a sump pump that was installed by the previous owner. In our area, runoff from melting snow in the spring or when the neighbors leave for a weekend with their sprinklers on usually when we see water there.
The sump is about two feet deep, and the float is adjusted such that there can be 18" or so of standing water in the sump before the pump turns on. It isn't uncommon for there to be 12" of water in the sump for a week at a time, without the pump running. I don't know if the depth of this sump was determined by calculation or solely by what was in stock at Home Depot that weekend.

Is this a situation where making the sump deeper would have a benefit?

Part of me wants to dig that sucker much deeper, so that the water level is as far below the basement slab as possible. If I'm seeing water so close to the bottom of the slab in this one spot, that means it's very close to the bottom of the slab in most of the basement, right?

On the other hand digging the sump deeper, aside from the work, means that the pump might be running more than required, and perhaps cycling more often than needed.

What would you do?

Best Answer

I would not want to see 12 inches of standing water close to the slab grade in a sump pit. My first thought would be to see if you could adjust the float of the pump to turn on much sooner and keep the level down to maybe 4 to 6 inches. There should be an upper and lower level set on the pump. it would be helpful to know the make and model of the pump so we could check the specs and see if it can be easily adjusted. Keeping water standing so close to your slab can saturate your floor and cause weeping through spider cracks. I'd prefer to see the level at or below the level of the drain tile where it enters the pit.