Our house was built in 1929. It's in town (a little separated from "Main Street", but still in town; we're on a little dead-end street with just 6 houses, but it's off of a main road with plenty of development close on 2 sides).
We are on city water and swer, but our main sewer pipe leaves the house through the basement wall only 1 1/2 or 2' below ground level. Everyonre else seems to have pipes exiting either through their basement floor or much lower down the basement wall. Our main exiting pipe is a big cast iron or fired clay number; all the toilets, bathwater, sink drains, etc. connect up to this at some point, some of them very close to the exit, but the big MAIN exit (about 8" in diameter, I think) exits through the cinderblock foundation just 1 1/2 feet below ground level.
Should I be worried? This seems to have confused several of the handymen-types I know, and I can't find stores of similar situations anywhere. Is it that the house used to have its own septic tank, but then got tied to city water/sewer later? if so, where's the tie? Is there some resurce I have for finding out exactly where my sewer pipe drains into the city's? Should I worry about freezing, or if I ever drive a truck over the lawn at that point? I've been told we need to replace all this big ancient pipe anyway, but if I do that, should I address what happens outside the foundation as well? I don't want to update all the internal plumbing just to have everything go to the dogs right outside the foundation.
We're in Michigan. Granted, nothing bad's happened yet, I'm just concerned because of the apparent abnormalcy of the situation.
Anyone seen this before, or have guesses as to what led up to this, or opinions on whether it's a concern?
Thanks for reading, I would appreciate any feedback/advice.