What do I do about this hole in my yard?

April 25, 2014 9:35 AM

I discovered a hole, roughly 10 inches across, in my yard (at a house I just moved into). It's basically a pipe going far far down, and had a stone top resting over the hole, loosely covering it. It reminds me of the Baby Jessica well, which makes me want to get rid of it, fill it in, cover it up. But I don't know what it is. Who might I call to figure out what it is, what it's for, if I can just remove the whole thing, or if it's necessary to keep it as-is?
posted by davebug to Home & Garden (28 answers total)

If it turns out that you have to keep the hole, you could try digging a little space around it, covering it with a board that is bigger than the hole, and burying that with dirt/rocks. That way if anyone actually needs it for something it would be trivial to dig it back up but no one is accidentally going to step into it.

As far as finding out who it belongs to, I would try calling all the utilities in your area and the city.

Is it possible that it used to be the pipe to an old septic tank?
posted by Jacqueline at 9:40 AM on April 25, 2014 [4 favorites]

How big around is it? Where do you live? Is there a lining or casing to the hole? Any other description? Can you hear anything (like water or a bottom) if you drop a rock down in it and listen?

Incidentally Baby Jessica's "well" was just an 8" pipe.
posted by The 10th Regiment of Foot at 9:41 AM on April 25, 2014

You may have an 811 "call before you dig" line in your town, but if not 311 can probably organize someone to come look at it.

Your recourse may vary depending on whether you rent or own.
posted by Lyn Never at 9:42 AM on April 25, 2014 [2 favorites]

Check in with your town's Building, Engineering, Public Works, Board of Health, etc. (The exact offices will vary by jurisdiction, but basically, in most parts of the US there should be someone overseeing building construction, utility lines, and septic systems/wells. Find those people.) They may plan plans of your house that will show what this is used for. If they don't have plans, they may still have ideas. Bring a photo of the hole, if you can.

Digsafe (the call before you dig people) will mark out the utilities at your curb and sometimes where they go onto your property, but they generally won't have plans showing things on your property. However, you could also give them a try if the city or town can't help.
posted by pie ninja at 9:46 AM on April 25, 2014

If it turns out that you have to keep the hole, you could try digging a little space around it, covering it with a board that is bigger than the hole, and burying that with dirt/rocks.

That’s what I’d do, except that if it’s a board it will eventually rot out and become a hidden trap. After you’ve forgotten all about it or moved of course.
posted by bongo_x at 9:48 AM on April 25, 2014 [9 favorites]

Look up any permits that have been applied for at your address. In your area that is through the city. The permit could tell you what the thing is and who installed it.
posted by munchingzombie at 9:48 AM on April 25, 2014

Assuming you own the house, ask your realtor to get in touch with the previous owners. They may know.

Next step would probably be to check in with the local planning/permit office to see if you can figure out what it might be. Barring that, call a contractor to come and take a look at the thing and tell you what you're dealing with.
posted by valkyryn at 9:50 AM on April 25, 2014 [1 favorite]

Do you own ?

In addition to what others have said, it could also be a sinkhole. There was one near my house in WI that was 8-9 inches across and 22 feet deep. You may want to talk to a geolgist about handling it - in that case I mentioned the resolution was filling it with gravel and concrete.
posted by Pogo_Fuzzybutt at 9:51 AM on April 25, 2014

I had something like this in an older house I used to own. Turns out it was a cleanout for the main sewer line, and the fact that it wasn't properly covered and a rock had fallen down there caused some problems. The previous owners probably didn't know what it was either, considering they surrounded it with rock and put a bird bath on top of it.

There wasn't a cleanout installed on the main line in the basement like you see in newer homes, so that might be a clue. But definitely check with a plumber before you fill it in. That is, unless you want your toilet flushing directly into your basement.
posted by thejanna at 9:55 AM on April 25, 2014

Plummers have cameras they can use to put into pipes to do an inspection. Maybe try them first?

I would also put a small weight on a string and drop it down the pipe, just to see how deep it is before proceeding with any other steps.

It will help if you know how deep it is, how far from your house, etc., so you can accurately describe it to anyone you call about this.
posted by jbenben at 10:02 AM on April 25, 2014 [1 favorite]

"...if it’s a board it will eventually rot out and become a hidden trap..."

Good point. Please revise my suggestion to a more durable material, like a metal plate, thick concrete block, etc.
posted by Jacqueline at 10:03 AM on April 25, 2014

Is your house on city water? The hole might be a well from an earlier time when there was no city water there. Either way, it definitely needs to be sealed-off.
posted by Thorzdad at 10:19 AM on April 25, 2014

Response by poster: Yep, I own the place. Oh, also, the house is over 100 years old, but we're in a fairly urban area.

I'm fighting to stop myself from doing the totally idiotic thing and lowering my iPhone on a rope into the hole with the LED and FaceTime on.
posted by davebug at 10:20 AM on April 25, 2014 [15 favorites]

How close to the house is the hole? It could be a coal hole. I have one in between my house and my driveway, but it has a lid and my upstairs neighbors have put a decorative stone turtle on top of it.
posted by mskyle at 10:38 AM on April 25, 2014

I phone on string sounds like an amazing idea, as long as there isn't water on the bottom. Maybe a waterproof iPhone case first. Then the string.
posted by slateyness at 10:46 AM on April 25, 2014 [1 favorite]

Facetime would be problematic, I think (rf transmission out of a steel casing is a problem), but a video from an i-thing would definitely do the job. Get a clear plastic jar and punch some holes in the top so you can get something like a clothesline tied securely through them, because it's hard to tie stuff to an i-thing. Tape a flashlight into the jar, pointing down. Start i-thing camera, put it in the jar, and lower away.

You know if you hit water because the cord will go slack. When you hit bottom or water, tie a knot in the cord so you can measure how deep it went. Please post a link to the resulting video!

Is there any concrete around it, at all? Dig down a foot or two.
Modern wells require that the top of the well casing have a sanitary seal of concrete around the outside of steel casing, to prevent surface water from contaminating the well. If you are going to abandon a well, there is a procedure that also prevents groundwater contamination.

I would not contact a government agency about your well. It could cause you trouble in the future.

If you don't want to abandon it, you can get a well head to seal it, and allow use later.
posted by the Real Dan at 10:52 AM on April 25, 2014 [5 favorites]

FYI, this sounds almost exactly like the sewer cleanout line we were forced to have installed a little over a year ago -- except without the cap. Is it within, say, 10 feet of the house? Ours is secured at the top with sturdy mesh grate that is held on by something that looks like a giant muffler clamp, then there is a cap over the top. There is soil around the lip, but it doesn't cover the cap. This picture I found with Google is what ours looks like. (We have a 9" diameter pipe.) Here's another one. (Interestingly, both these pages are focused on how to replace a missing cap.
posted by anastasiav at 11:10 AM on April 25, 2014 [1 favorite]

It probably is worth making a quick call to 811 (that is the correct number in your area). April is National Safe Digging Month, so I'm sure they'll be extra pleased to tell you whether there's anything utility-related there.
posted by aubilenon at 11:22 AM on April 25, 2014

Seriously. Time for photos. And a video.
posted by shew at 11:28 AM on April 25, 2014 [1 favorite]

There wasn't a cleanout installed on the main line in the basement like you see in newer homes

We have a cleanout in the garage and another cleanout in the yard where the external sewer trap is.
posted by ROU_Xenophobe at 11:38 AM on April 25, 2014

I vote sewer cleanout as well. We have one of these that's the access for a line serving this house as well as the one next door (a duplex that we later purchased). We had a concrete ring and concrete cap installed [vaguely similar to the well cap here], and you really can't move it unless you're an athletic adult, so it's pretty safe. We have it augered (Roto Rooted) out every 2-3 years.
posted by dhartung at 11:54 AM on April 25, 2014 [1 favorite]

Response by poster: Here's a photo, with part of my foot in there for scale. It's right about 6 inches in diameter.
posted by davebug at 12:57 PM on April 25, 2014

If you're in the city of Seattle, but in a formerly unincorporated area -- say north of 85th St -- maybe an old septic system cleanout? Wild guess.
posted by zvs at 1:25 PM on April 25, 2014

This sounds weird, but try this: get somebody in the house to flush the toilet closest to where the hole is. While he/she is doing that, get your head down near the hole and listen to see if you hear running water in the pipe. If you do, it's certainly a sewer cleanout.
posted by nushustu at 1:48 PM on April 25, 2014 [1 favorite]

It doesn't look like iron to me: there's a chip out of it in the lower left quadrant of the picture.
Test it with a magnet. I don't think it's a well. Leach field vent?
posted by the Real Dan at 2:42 PM on April 25, 2014

My guess based on the photo is terra cotta sewer pipe, which I've dealt with in several older houses. Common to switch from cast iron pipe inside the building to terra cotta for the run through the yard to the sewer main.
posted by rudd135 at 7:51 PM on April 25, 2014 [1 favorite]

If you have to leave the hole, cover it with a slate approx 2ft square and an inch thick. Prepare the ground so it lies flat. It will be too heavy for kids to move.
posted by SemiSalt at 5:50 AM on April 26, 2014

I'd bet a hundred dollars that's a vent trap. (not a sewer cleanout.) On older sewer systems, especially ones where the storm and soil run together, the vent trap keeps sewer gases (from the main sewer) from getting into your house.

As for covering it, a floor drain cover (with holes) sized for the larger ring, should do the trick.
posted by notsnot at 8:27 PM on April 27, 2014