[Z-man]

While those pipes seem a little small for it, they may be pipes atatched to an old oil tank buried in your back yard. You can get a tank sweep done to see if that is the case.

If you do have an old tank, depending on your state laws, you may have to have it removed before you can sell your house. If that is the case, you beter hope and pray it was cleaned out and filled with sand before it was decomissioned. If not, and it has holes in it - the EPA needs to do all sorts of testing on your soil. If it is contaminated, you have a lot of costly remediation ahead of you.

If you still have a tank there - get it taken out sooner than later!

-Z-man.