where is my drywell?

[George]

We have an older house (c 1920?). The cellar drain (only) goes to a drywell, which has gotten quite slow lately. The drain is in the center for the floor. It goes through a trap, with a clean-out access on the other side. After that, it runs off more-or-less horizontally. A snake has some difficulty about 6' in, but runs free after passing that.

So, my question: in those days, would there have been a rule-of-thumb as to where they put the drywell - under the house, or out past the foundation? ISTM, it would be easier to put it under, since the cellar was already dug out.

Any thoughts appreciated. Thanks, G

[trader4]

What's the water table level? I've only seen drywells used for water sources at or near ground level. Gutter drains or washing machines for example. With a basement floor drain, unless the water table level is really low, I would think a drywell would be problematic. It would have to be like 12ft below grade. A heavy rain and you could have water coming in, instead of out.

But assuming there is one, I doubt it's under the floor. I have never heard of a drywell being put under a basement floor. Also, does just the one drain go to it? If so, you would think if the drywell is there, it would then be directly below it, no? If you're gonna have it below the floor, then why not right there?

What purpose exactly does the floor drain serve?

[dpb]

Sounds like either

a) you've got tree roots or,

b) the line has finally begun failing.

I'd suggest getting a plumber/drain service w/ a camera they can send down to see what the state of affairs is.

As trader4 says, it's highly unlikely it terminates under the slab but I'd suspect it's probably time that the slab's going to have to be cut to repair, unfortunately. But, if you get the camera you're going to find out.

You could always try the roto-rooter route first and see if they can cut some roots out and solve your problem for a while...

[trader4]

Key question here is what the importance of the floor drain is? I've never lived in a house that had a floor drain in the basement. I know they exist and I guess if I could have one, with guarantee of zero problems, it would be nice. On the other hand, in the house I'm living in now, it has a basement. When I bought it, I painted the basement floor. I use the basement mostly for storage. Haven't had a single instance in 20 years where I would have used a drain like the OP has.

Or a lot of people finish their basements. In which case I don't see the compelling need for the drain either. You don't have a drain in the kitchen floor, typically, right? And if for some reason, like a torrential rain, the basement has 6" of water, what good is a drywell, below that level going to do you?

[George]

Further info,

- the drain mostly just serves the washing machine. The (separate) 'stack' drain runs out to a 'septic system' (we've never looked at it in

20 yrs). This line runs about 3' _above_ the cellar floor.

- Plan B is to connect to the city sewer. We've been told that would run ~$10K, which is kind of a lot just so we can do laundry. Plus, it would still be 3' off the floor, so we'd have to run the washing machine discharge into a sump, and then pump it through a check valve into the (new) sewer line.

- We've never had a problem with water coming up the drain, despite a moderately wet climate.

- I have no doubt that roots are into the drywell, and, from the way the snake feels, I'm pretty sure that the pipe has failed. The question is, where? If the drywell is outside, it would need a backhoe, and there's the foundation, ... $$$. If it's inside, I can at least break through the floor and look at it. Again, it's not clear it would be worth it, just to be able to do laundry.

Good point. Probably, it's outside. Not what I wanted.

G

[hrhofmann]

Camera, camera, camera!!!

[trader4]

Why isn't plan B to connect the washing machine to the existing septic system? In new construction, that's exactly what's done. For an old system, like you have it wouldn't be my first choice, but it beats spending $10K. Or if you don't give a damn about code, make a new drywell and route the washing machine into it.

[dpb]

On 10/5/2013 1:01 PM, [e-mail] wrote: ...

Seems pretty much immaterial to OP's question to me...if he were routinely flooding the basement I suspect his question would have a far different tenor than that asked...since the house is nearly 100 yr old, needing to worry about what it was/is seems a little late in the game to me. :)

[David L. Martel]

George,

I'm guessing here but If you run a metal snalke into the drywell, try finding the snake with a metal detector.

Dave M.

[willshak]

Call a septic/drywell cleaning service. They will usually find your tanks, either by probing with a rod, or using a metal detector, or ground scanning radar. They can also clean out the drainpipe. Once you find it, take measurements from the tank lid to specific points on the house where all meet at the tank. Write down all the measurements and where the reference points are and save them in a safe place. That's how I locate my drywell. My septic tank lid is buried right under a small removable sculpture in the flower bed.

[bob haller]

if tree roots are the suspect, mix rock salt with very hot water and send it down the line. the salt will kill the roots but leave the trees unhurt...

i have been doing this for over 15 years to keep my bad sewer line open. Its cheap, non hazardous, and has worked well for me...

its highly likely that lint has clogged the sums drain field. in the old days cotton would of just rotted away, but the synthetics may never decompose

[George]

As far as using the existing septic, we'd have to put in a sump for the wash water, and pump it up to the sewer line. (as noted, the septic line is 3' above the cellar floor.)

... and other possibilities. For now, the laundramat is probably the cheapest. Before we sell, we'll probably connect to the city sewer. I kind of doubt this septic (whatever is down there) would score well in an inspection.

G

[George]

Thanks for all the replies. I think the answer is, as suggested above, 'If they put the drywell under the cellar, they'd put it right under the drain, not run it off somewhere.' Seems obvious, now that I hear it.

G

[trader4]

What I was getting at was that if it's rarely used and since most basements don't have them to begin with, then if a snake doesn't work, it's probably not worth fixing.

He's now reported back that it's used for a washing machine drain. So, if a snake doesn't work, I don't think there is much point in calling a plumber to do a camera inspection, etc. I guess he could do that, but that money could go towards connecting the washing machine to the sewer and sealing off the floor drain.

[krw]

The floor drain in my brother's house is connected to the sanitary sewer. I found that out one morning when I was taking a shower in the downstairs bathroom. Apparently the sewer froze occasionally. What a mess!

[krw]

Sometimes these go to the sump, where you pump it out, or to daylight. In this case, I see the use. To just dump into the ground, not so much. It seems to be an unwanted source for ground water.

[trader4]

Remarkable, we agree on something. I wonder where the location is? It must be somewhere with a low ground water level, ie far below the basement floor.

[hrhofmann]

They dump soap-laden washwater out on the ground?? I can see the rinse water, but not the wash water.

[krw]

That's not an unusual setup. Mine doesn't have a "tub" now but I'll get there. The laundry in the other house is on a slab so any water will end up in the garage (a step down), anyway.

[krw]

Not necessarily. I've seen more than one geyser installed in basements.