Three years ago I had my house's septic tank replaced, and the guys put in new cleanouts because they couldn't find the original ones. Well, by chance I just found them: buried under about 6" of dirt and rocks about two feet away from the house.

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What should I do with them? Abandon them because there are now new cleanouts? Or add some PVC risers to make them accessible at grade level? And if so, how should I make the connection between the old cast iron pipe to a new 3" PVC pipe? A no-hub coupler wouldn't work since the exposed cast iron pipe is flanged.

2 Answers 2


My personal style is to leave them 6" deep with carefully positioned annual flower beds on top of them - give those beds rock walls, if you like, and document the heck out of it. But if you'd rather extend them to surface:

Those plugs have pipe threads, so a PVC to MPT adapter in the correct size seems the obvious solution to connecting PVC to them.

I guess annual flower beds may not work so well in the desert - idea being to have a surface feature that maps to the subsurface feature of interest. You need a gazing ball right there, say. This method is subject to loss of documentation and/or memory.

A "hand-hole" would be another approach. Leave the plugs in place and extend access to the surface. You might know them as sprinkler-valve-boxes - a bottomless box with sides and a lid, in plastic or concrete.

  • 1
    I like the hand hole idea! I can do that without buying any materials at all, in fact.
    – iLikeDirt
    Feb 28, 2017 at 1:59
  • You don't really need "bio-organic markers" :-) -- just keep a copy of those photos so you can locate the buried cleanouts at some time in the future. Feb 28, 2017 at 17:05
  • My flowerbed technique ("bio-organic markers" ooh, la, la!) was developed after a few times (different houses) of carefully measuring from foundation corners to the correct distance where the (actually extant, for a wonder) drawings said the manhole for the septic tank was, digging, and not finding it there - then digging around trying to find the darn thing. I'd hate to try and find these from that picture - "hmm, right by the crack in that concrete - now, then, which crack was that? Which concrete was that, for that matter?"
    – Ecnerwal
    Feb 28, 2017 at 17:13
  • 1
    The hand hole idea worked perfectly for $0. Doesn't get much better than that.
    – iLikeDirt
    Mar 1, 2017 at 23:40

I would bring them to grade you never know when those will become a life saver in a plumbing emergency.

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