Bought a house last week, which -- Canadian winter -- had been mightily surrounded by snow, including in the driveway. Today, with the snow melting, I saw this in front of the garage door. It extends about 2" up past the driveway surface.

Cap relative to garage door

The cap on the pipe is black and has some sort of little handle on it.

Pipe cap

It comes off very easily, and underneath there's about 8' to 10' of pipe (I think? I'm lousy at eyeballing things), rimed with frost, leading to what looks like standing water.

Frosty Pipe

The fact that there's a big ol' PVC (or something) pipe jutting several inches out of the driveway in front of the garage is kind of annoying, but not having any idea what's going on here (sewer vent? In my driveway?) is more annoying. What's this pipe doing here? What's it for? Can I chop it down, fill it in, seal it shut?

5 Answers 5


It's a cleanout for the sewer line. You can shorten it to grade level, but you cannot remove or pave over it.

You'll probably never need it, but if you do, you'll want quick access to it.

  • 1
    That would make sense if it's an attached garage. I'm gonna have to go with RV poo pipe otherwise.
    – Mazura
    Mar 18, 2015 at 1:44
  • 1
    The garage is unattached; the house is 100+ years old and the garage is pretty old too. There's a lot of weirdness around the property, but it's really not the sort of place that would have RV voiding capabilities. Mar 18, 2015 at 12:58
  • @mattshepherd Is it possible that the garage was built after the house? Where is this pipe in relation to the house?
    – Tester101
    Mar 18, 2015 at 13:36
  • All things are possible; the garage is probably more recent than the 100+ year old house (it has a garage door, and IIRC cars were not standard issue in the 1920s). The pipe is 10' from the back door. It's not "close" to the house, and there are no obvious pipe out points in the basement going in that general direction. Mar 19, 2015 at 15:55
  • Do you have sewer or septic? If sewer, do you have any idea where the sewer line is?
    – Tester101
    Mar 19, 2015 at 16:19

Another option in addition to the other answers is a cleanout/inspection line for the weeping system. If you're far enough north that there's still ice in mid-March, weeping systems are a must-have to prevent foundation damage from frost heaves. Quick test; if it smells like sewer gas, it's a sanitary sewer cleanout. If it smells like earth, mildew or just stagnant water, it's probably the weeping system which feeds to the storm sewer.


Closing the loop on this, years later -- it was kind of a cleanout. Our neighbour two doors down started having sewer backups in her basement, and it was determined that three houses were all on the same outflow pipe, coming under my driveway, with a crushed pipe more or less where this cleanout was.

We split the cost for the fix (all three houses) since we shared the pipe. After they dug up my driveway this was clearly a system created by some sort of lunatic cheapskate former house owner: it was a bunch of PVC pipe held together with clothes hangers and duct tape underneath the whole system. The entire "cleanout" pipe was pointless and unnecessary. It's gone now.


I wouldn't go any further than shortening it slightly without first actually figuring out what it is - where local inspection is going to have significant advantages over the ponderings of the internet. Filling it in and sealing it shut (more than the removable cap) would be foolish without positive identification. It has probably heaved itself up from a formerly level with the surface installation.

Try asking the seller, first.

The color is commonly sewer pipe, but that's no guarantee.

If you can shine a light down and see the water, you could flush some dye and see if you see color.


If it's a sewer cleanout you should be able to detect noxious gasses emanating from the pipe once the cap is removed. To double check; have a helper flush a toilet while you listen for running water with the cap removed. My first thought when I viewed the photo was that it was a field drain with the grate removed and someone used a test cap to cover the opening.

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