We've owned this home for 5+ years now, and these pipes have been bugging me. Even moreso now that I'm looking to do some landscaping right over one of them.

The house was built in the 60's in a Philadelphia PA suburb. We have city lines for natural gas, water, and sewer. The pipes wiggle a bit with a touch, but don't pull out. They're very firmly capped. 811 hasn't ever marked them when we've had them out before, and I intend to have them out before I do anything, but I want to know if anyone can ID them ahead of time so I can call a specific utility.

One of the pipes is in the front side yard, near the driveway but far away from the street. The other is in the backyard next to our patio.

woman's hand next to a capped off metal pipe capped off metal pipe, no hand visible woman's hand next to a second capped off metal pipe second capped off metal pipe, no hand visible

  • can you go to your gas meter and see if there are any lines other than the ones that go into the house? Then go into the crawlspace/basement to see if any exit in the direction of those pipes?
    – redlude97
    Commented Dec 30, 2020 at 20:29
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    Also check and see if there are any clues inside your house (crawlspace/basement area if accessible) to see if there are any similar unidentified pipes leaving the basement headed in those general areas.
    – Milwrdfan
    Commented Dec 31, 2020 at 16:39
  • 1
    Are these pipes in a line? If so - mentally extend the line and see what's in the path? I presume they run to/from your home, so what's at that point? If the line runs toward the road, what's out there to give some clues ?
    – Criggie
    Commented Dec 31, 2020 at 23:24
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    Dirty hack - get an assistant to lightly tap one with a hammer while you listen closely to another one. A sharp >TINK< sound might tell you they are piped together under the ground or a dull _..-tHUd-.._ implies separate as the impact travels through soil.
    – Criggie
    Commented Jan 1, 2021 at 3:21
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    @HagenvonEitzen It's a special short phone number for a service that will tell you all of the documented locations of buried utility pipes and conduits on your land. Very helpful for not accidentally digging into a water main ... as long as the documentation is accurate and up to date. In Pennsylvania I believe it's this outfit: pa1call.org
    – zwol
    Commented Jan 2, 2021 at 15:00

8 Answers 8


Even though 811 ignored them doesn't mean they are not a private utility. It is possible they are natural gas or waterlines, or were an electrical conduit however they are most likely just pipes driven into the ground as support for a past fence.

To rule out private utilities you can call an HVAC contractor licensed in PA to work on gas (most installers and maintenance companies have employees who are) to come out and verify it. They will likely uncap it and use a special meter to detect gas. If there is water or electrical lines they will be able to tell you and give you guidance on your next steps. They will need access to the home and it will be easier for them and you if you clean out any areas in the home where pipes or electrical lines could be concealed behind exterior walls or crawl spaces on the side of the property the pipes are on.

Absent any utilities, you can dig down to the base or use a pipewrench on the pipe and unscrew the pipe and pull the unscrewed pipe up. If it is welded to a spade or something weird, you'll have to dig down all the way or cut the pipe off below grade.

If you have never worked with natural gas I don't think it would be responsible for you to take any advice walking you through dealing with a suspected gas line other than to call a licensed and trained professional.

  • 4
    Absolutely, thank you for walking through what would happen. I have a healthy fear of mucking up anything involving pipes or electricity or gas, and these definitely feel like they'd qualify regardless. I'll call 811 about these spots specifically, and if nothing turns up I'll ask our HVAC guys to poke around with them.
    – Marisa
    Commented Dec 30, 2020 at 20:28
  • If 811 works there the way it does here in Minnesota, it is going to be each utility marking their own lines, or a contracted company acting on one or several of their behalf. They are supposed to also mark abandoned lines belonging to them but this doesn't always happen. When digging, don't throw the shovel into the ground, rather step on it using your foot to push. You will feel restrictions more easily that way. If you hit something suspicious, use a wooden spoon and wear leather or cotton gloves in case it is live electrical, you're unlikely to get shocked with dry gloves on! Commented Dec 30, 2020 at 20:53
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    Low pressure gas lines are exceedingly dangerous... I would definitely want to verify that they are absolutely not connected to anything before doing anything to them. May require some shoveling for a day or two...
    – Dúthomhas
    Commented Dec 31, 2020 at 3:38
  • It's also possible, however very unlikely, these are abandoned irrigation spigots. I only say that because of the location of the 1 next to a line of landscape dividers and the other apparently in a mass of backyard growth that could have been a past garden. Definitely getting a pro out to figure this out would be ideal. Commented Dec 31, 2020 at 17:01
  • @JackOfAllMasterOf2 It looks like PA does work that way. Other states, like Maryland, have a single contractor (such as this one) that marks all of the lines all at once.
    – Moshe Katz
    Commented Jan 6, 2021 at 19:58

It's impossible to tell as these are just generic threaded steel pipe. If this were mine and I wanted to know, I'd dig down and see what's there. That will likely answer your question.

  • Could be anything ; from age and location - lines to buried heating oil storage tanks that are no longer used. It was not unusual to just forget them when nat gas became available. Commented Dec 30, 2020 at 21:08
  • Agreed - a little bit of spade work could provide a lot more info. If they end in a lump of concrete then it could be a fence, vs if they end in a T junction into another pipe.
    – Criggie
    Commented Dec 31, 2020 at 23:22

If no underground utilities can identify them then it is very likely they were installed without a permit and so no service has record of their location or for what use. Do as jwh20 suggests and dig down. Their placement suggests they are auxillary water taps.

I had similar pipes all around my 50's era home. It turned out they were taps into water service (between meter and house) placing locations for spigots on all sides of house where there was originally just one located on the wall.

  • 1
    This feels like the most likely answer, but there is a spigot off the side of the house fairly close to the one by the patio. I'm getting a professional either way to tell me for sure!
    – Marisa
    Commented Dec 30, 2020 at 20:29
  • 2
    Best idea yet. Please be sure to update your post with what you did. And what the outcome was.
    – user113627
    Commented Dec 30, 2020 at 20:37

You could get lucky checking if these unknown pipes connect to known water or gas system using the continuity function on a multimeter.

If no continuity, then no useful information (as there could be several reasons for this). The 9 volt battery in the meter should be safe.

You will need to attach a long wire to the pipe, then take other end of wire to near water/gas pipes/faucets/spigot and use meter.

For a long wire you could use a normal extension cord.

You get an assistant to hold the earth pin on an extension cord on the pipe while you play with the other end.

Can also check if the two pipes are connected to each other this way.

If this is not clear, ask questions and helpful people will reply.

  • 6
    For any great length of metal pipe buried in damp earth, I would expect to see significant continuity even from entirely separate pipes.
    – MikeB
    Commented Dec 31, 2020 at 12:10
  • 1
    A continuity test would be inconclusive since soil becomes conductive below ground at some point depending on soil conditions. Usually within 6 feet of the surface. There is circuit tracing equipment available that can transmit a radio signal through the pipe and be detected if connected to an interior pipe or with special equipment through the soil. It is expensive and usually only used by utility contractors. Commented Dec 31, 2020 at 20:02
  • At 9v DC (multimeter level), the difference between a metallic connection and earth leakage should be clear. On the other hand, if you have all metallic connections to your furnace or water heater, you'll probably see a very low resistance between gas and water lines even if the safety earth bonding between them is missing.
    – grahamj42
    Commented Jan 1, 2021 at 10:46

They may be property corners. If so, please do not remove them! :-) We surveyors need them to protect your property rights.

  • 2
    Yes, this was my thought too. Could be an “EIP” (Existing Iron Pipe) used for boundary marking, though all the ones on my property are all at/below the soil level so the mower doesn’t bite it. Commented Jan 9 at 13:34

That end cap looks very similar to this.

enter image description here

1-1/4" Galvanized Malleable Iron Pipe End Cap Threaded Ends, 300 Liquid & Gas psi, 150 Steam psi https://www.mscdirect.com/product/details/36990166

This sort of cap is designed to resist high pressures. Whatever is in there, you don't want to risk it coming out in case you can't get the cap back on again.

  • 2
    That is an excellent point, but does not mean that the contents is under pressure now, or ever was. I can imagine someone selecting a solid product over a flimsier one, and these are decades old by now so have lasted, proving their robustness.
    – Criggie
    Commented Jan 1, 2021 at 3:19
  • 1
    @Criggie - I agree but best to be cautious. Commented Jan 1, 2021 at 10:16

As others have said, it's impossible to tell without following the line, so be careful. I've seen unused sprinklers capped like this, and it could also be capped electrical lines for yard lights.


they may not belong to official utilities and i suspect they do not. They may be places where electrical lines were ran from the house to support lighting. Perhaps they were never actually carried forward to completion of actually installing the lights but had the idea that perhaps someday and in preperation burried the pipe either with or without wiring inside ready to go. You can pick that kind of pipe and endcap up at any hardware store and all you would have to do is run a wire retriever down the pipe, they come on spools of different lengths, and attach the wires and then pull the tape back with the connected wires if there isnt wires already there. scope cameras are pretty cheap these days as well 12$ for one that hooks to your phone . make sure the power is off maybe before putting anything down there though if your worried about getting shocked but I dont see how that would happen.



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