Basement stairwells usually have a seperate drain to the sump as do each run of tile from the perimeter of the building. There is filter cloth which is used to line drainage systems of the type you describe. It was not always used. If the cloth was not used, silt from the backfill and years of soaking rain will infiltrate the stone surrounding the tile and eventually the tile itself. Settlement will also cause dips in the pipe itself which will cause some water to "belly UP". Some of this silt will serve to level out those bellies and allow the water to drain. So a little silt at these points is ok.

Rather than throw the most dire probelms at you and try to scare you with the more complex and worse case scenarios, I'll stick with the simplest and most affordable action. I think this would apply to your situation for a couple of reasons. One, the house is 24 years old and if it were a "really bad" problem, you would be complaining of flooding, not slow water drainage. Two, I've seen the problem you describe many times and the easy fix has always worked, with the soil composition you've described. If you had clay soil, it would have been much more complex.

In my experience, I think the drain tile from the walk out stairway to the pump has a 24 year buildup of silt in it. There are a number of ways to clear it. It will be a little time consuming (a few hours) but it is a DYI job and will be is as good as new when you're finished.

Remove the drain screen and put a garden hose without a nozzel into the cellar drain and let water run into it at a rate it will readily drain (you will increase rate as you clear the silt). At the sump end, insert another garden hose with a nozzel into the pipe where the water drains from. The nozzel should be the single cylinder type and locked into the heavy spray position. Start inserting the hose further into the pipe, the further the better, while running the water at full pressure. Silt will start washing out. As the flow increase, increase the water pressure to the outside hose. If the outside hose can easily be inserted further into the drain, do it. Keep working it this way until the watre runs clear. This method will keep you from clogging the pipe with silt.

I don't recommend you do this but, once complete, you could put a ping pong ball in one end and a shop vac at the other and the ball would pop right through. Now how did I know that?

Irisman, thank you for the advice. I tried this today, but came up empty.

Unfortunatley, the pipe that comes into the sump well makes a sharp 90 degree bend down about 25 inches out from the wall and then must turn again 90 degrees to run parellel to the ground. Even removing the nozzle from the hose, I couldn't negotiate this. At the other side, the drain in the concrete stairwell makes a 90 degree bend towards the house 10 inches down and I couldn't get a hose into this either. Is it possible that there might be a trap in the stariwell drain to prevent bugs from crawling into the house when it is dry? Unfortunately, we have no foundation diagram or "owner's manual" to assist us in figuring this out.

I did some more plunging this morning after rains last night and early today (5 inches in two days). That pulled up some more silty/sandy soil into the stairwell and seems to have cleared the clogged tile. At least when I turn the nozzle on at full blast, the water dosen't come up and out of the drain. But when I stop, the water dosen't disapper either and the level stabilizes at the top of the steel pipe which is connected at the bottom of the drain bowl.

As a side note, we do have a large multi-stemmed Viburnum shrub about about 15 feet tall next to the house. Is it possible that Viburnum roots might extend 4 feet down and into the drain tile?

At this point we are considering a company like Roto-Rooter to snake out the drain tile. I'm not sure if they do foundation drainage tiles. I may just buy a heavy duty drill type snake a give it a try myself. I will need this anyway for the ocassional clog in the bathroom pipes. My last hand crank snake broke and wasn't really long enough.

Not sure about the plant root. Be careful when using a snake since you could puncture the tile. Don't force it, let it churn at its own rate. I think perhaps the 2 90 degree bends might have some silt build up. When you plunge, it appears to clear the drainage problem for a while. That makes me think the problem is closer to the outside drain. If you have a pressure washer, you may be able to push the tubing (without the nozzel) into the opening. Otherwise, if it were mine and the water drains after plunging, I think I would run water into the drain until it starts to back up, plunge until it clears. I'd repeat this until it doesn't back up any more. It might take an hour or two worth of work but then you can be away from home when it rains and not worry.

5 inches of rain in 2 days!!! Quite substantial. The silty/sandy soil you are getting out of the drain sounds to be what has washed into it over the years. Usually when there's a real problem, you'd be pulling up mud and fine roots.

We are up to 8 inches of rain over the last 3 days! The secondary roads are flooded everywhere in the SW IN region. It was quite a storm event. Thank goodness the power didn't go out. I will be getting a backup sump pump installed sometime soon.

We have received 3 inches of rain over the last few days, I live in a brand new house. The drain tile does not drain into the sump pump, my pump well is dry. Should I try using a snake by myself or hire a professional to do so...it's weird to be in a brand new home where the drain tile does not drain, at one point it drained (when we bought the house)it's stopped since then. Please advise.