I have an old conduit going through my concrete foundation, about 1 foot underground. It's roughly 1 inch diameter, some sort of poly pipe. It used to have a couple of copper lines running to an underground oil tank. The oil tank was removed a long time ago, but the lines were just cut and bent over. Water has been leaking in through the conduit (not around it) every time we get a big rain. Today I dug down to the conduit to look into plugging it from the outside. I've removed the copper lines and now have a 1" conduit to nowhere in my foundation that I need to plug. What is the best way to plug this thing? The conduit is about 14" long going through a 12" wall. A local box hardware store guy said I need to pull out the conduit and plug the hole with "Quikrete Hydraulic Water Stop" and to even burn out the old conduit if I had to. Then I talked with another guy at the same store, and he said that I probably won't be able to get the conduit out, and that I should fill it up with an expanding foam, and seal the outside end with some sort of caulking. I thought I would just buy some sort of two part epoxy and fill it up, but I guess thats the wrong idea? I've enclosed a picture of the inside and the outside. I live in New Hampshire USA, so it does get cold here in the winter if that makes a difference... ?