# Inverted "J"'s coming out of the ground **URL:** \ **Category:** Factual Questions\ **Created:** [June 18, 2002, 10:52pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763 "2002-06-18T22:52:11Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 18, 2002, 10:52pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/1 "2002-06-18T22:52:11Z")
Has anybody seen these. They are made of large diameter metal pipes (probably about 12’’) coming about 2 feet out of the ground? I had always assumed they were some sort of vents for the sewer lines. But there is a field near my house that must have 50 or 100 of these. Since they are such an eyesore I figured if they were vents they would combine them and have a few large ones rather then so many smaller ones. Also on a somewhat related note. I also wondered about something that lookes like an arrow pointing up (also made out of pipes) that I usually see near railroad crossings. Any ideas?? ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [June 18, 2002, 10:57pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/2 "2002-06-18T22:57:15Z")
Was the field built over a landfill or something? Maybe they’re letting methane out. Or perhaps they’re to vent radon. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [June 18, 2002, 11:01pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/3 "2002-06-18T23:01:31Z")
Drydocked submarines, probably. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [June 18, 2002, 11:05pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/4 "2002-06-18T23:05:11Z")
They’re one-half of a giant alien velcro pad that will be used on December 12, 2012 to pluck the planet out of orbit and doom humanity. ---
**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\ **Post date:** [June 18, 2002, 11:43pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/5 "2002-06-18T23:43:09Z")
My guess is they have something to do with wells. Is there a water company office nearby? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 19, 2002, 1:36am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/6 "2002-06-19T01:36:50Z")
My guess would be part of a leaching field (waste water drainage into the ground) ---
**Author:** ![Osip](https://avatars.discourse-cdn.com/v4/letter/o/4491bb/32.png) [@Osip](https://boards.straightdope.com/u/Osip)\ **Post date:** [June 19, 2002, 2:47am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/7 "2002-06-19T02:47:42Z")
Sounds like they are growing Candy Cane trees 🙂 ---
**Author:** ![d12](https://avatars.discourse-cdn.com/v4/letter/d/71c47a/32.png) [@d12](https://boards.straightdope.com/u/d12)\ **Post date:** [June 19, 2002, 4:02am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/8 "2002-06-19T04:02:43Z")
Maybe there is a bunker underneath (and I’m serious too). ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [June 19, 2002, 4:08am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/9 "2002-06-19T04:08:30Z")
Where did my post go? 😕 Oh, well…try it again. They’re “leach field vents”, part of the private sewer system (septic field) for the nearest subdivision. [http://www.cmhhealth.org/images/Leach%20field.jpg](http://www.cmhhealth.org/images/Leach%20field.jpg) From this website. [http://www.cmhhealth.org/programs/water%20sewage%20permit%20policy.htm](http://www.cmhhealth.org/programs/water%20sewage%20permit%20policy.htm) ---
**Author:** ![Berkut](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Berkut](https://boards.straightdope.com/u/Berkut)\ **Post date:** [June 19, 2002, 4:16am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/10 "2002-06-19T04:16:08Z")
> [@](#): > > \*Originally posted by AskNott \* > \*\*Drydocked submarines, probably. \*\* Oh my God, I just spewed tea all over my monitor. ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [June 19, 2002, 4:16am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/11 "2002-06-19T04:16:10Z")
> [@](#): > > \*Originally posted by Duck Duck Goose \* > They’re “leach field vents”, part of the private sewer system (septic field) for the nearest subdivision. > > [http://www.cmhhealth.org/images/Leach%20field.jpg](http://www.cmhhealth.org/images/Leach%20field.jpg) > > From this website. > [http://www.cmhhealth.org/programs/water%20sewage%20permit%20policy.htm](http://www.cmhhealth.org/programs/water%20sewage%20permit%20policy.htm) Robin Leach lives underground? Oh, the _Lives of the Rich & Famous_ … 😃 ---
**Author:** ![ratatoskK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ratatoskk/32/2987_2.png) [@ratatoskK](https://boards.straightdope.com/u/ratatoskK)\ **Post date:** [June 19, 2002, 11:52am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/12 "2002-06-19T11:52:06Z")
But leaching field vents are not 12 inches in diameter. The ones I’ve seen are white PVC and are just a couple of inches in diameter. ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [June 19, 2002, 11:13pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/13 "2002-06-19T23:13:51Z")
Right. I know exactly what you’re talking about, and this is it. On the diagram of the entire field, the leach field vent is at the very bottom left, indicated by the circled dot. There’s an arrow pointing from the picture of the vent over to the right, to where it goes in the field. Then there’s another arrow pointing diagonally down to the right, to the pix of either the 180 elbow or slotted cap. Neither of these looks like they are 12" in diameter–they look like they’re only a few inches in diameter, just like the ones you’re describing. On the diagram on the left, the thing that is 12" is part of the trench for the pipes. The trench itself is 8" wide, so the vent has to be narrower than 8". I hope this is making sense. 🙂 ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [June 20, 2002, 5:04am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/14 "2002-06-20T05:04:50Z")
Two questions then, why is it that sometimes I’ll see a single one on the side of a very busy intersection, and sometimes I’ll see a field with 50 to 100 of them (honestly it loooks like a plumbers graveyard). ---
**Author:** ![Duck\_Duck\_Goose](https://avatars.discourse-cdn.com/v4/letter/d/50afbb/32.png) [@Duck\_Duck\_Goose](https://boards.straightdope.com/u/Duck_Duck_Goose)\ **Post date:** [June 20, 2002, 5:27am UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/15 "2002-06-20T05:27:32Z")
Well, the field full of them is probably the private sewer system (septic field) for the nearest subdivision or apartment complex. I’m guessing that the single one (I’ve seen them, too) is just some kind of gas venting for the regular sewer system. ---
**Author:** ![rriggstx](https://avatars.discourse-cdn.com/v4/letter/r/fbc32d/32.png) [@rriggstx](https://boards.straightdope.com/u/rriggstx)\ **Post date:** [August 5, 2002, 1:46pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/16 "2002-08-05T13:46:44Z")
Oh, oh, OH! Mr. Kotter! Mr. KotTER! I know, I know! The ones at intersections are casing vents. When pipelines go under roadways (auto or rail), they are wrapped in a casing so that the weight of the roadway does not rest on the pipe. The space between the pipeline and the casing is vented. Now, if I just remember _why_ the casing is vented… :rolleyes: ---
**Author:** ![TwoBuyFour](https://avatars.discourse-cdn.com/v4/letter/t/76d3ee/32.png) [@TwoBuyFour](https://boards.straightdope.com/u/TwoBuyFour)\ **Post date:** [August 5, 2002, 2:00pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/17 "2002-08-05T14:00:23Z")
Go Rriggstx! Two postings since 1999! I love when a doper gets excited about a post. ---
**Author:** ![Homebrew](https://avatars.discourse-cdn.com/v4/letter/h/c89c15/32.png) [@Homebrew](https://boards.straightdope.com/u/Homebrew)\ **Post date:** [August 5, 2002, 4:19pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/18 "2002-08-05T16:19:12Z")
_Time for Teletubbies. Time for Teletubbies_ ---
**Author:** ![Null\_Racer](https://avatars.discourse-cdn.com/v4/letter/n/278dde/32.png) [@Null\_Racer](https://boards.straightdope.com/u/Null_Racer)\ **Post date:** [August 5, 2002, 9:02pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/19 "2002-08-05T21:02:26Z")
I hope you haven’t ruled out Fraggle Chimineys? ---
**Author:** ![alex\_arg](https://avatars.discourse-cdn.com/v4/letter/a/ebca7d/32.png) [@alex\_arg](https://boards.straightdope.com/u/alex_arg)\ **Post date:** [August 5, 2002, 9:11pm UTC](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763/20 "2002-08-05T21:11:33Z")
Seriosly now. If they’re all methane vents, wouldn’t Joey P’s place have a nice fart fragance all day? [Next page](https://boards.straightdope.com/t/inverted-j-s-coming-out-of-the-ground/114763.md?page=2)