I’m tapping into what was a 4″ floor drain in my basement to move my laundry area and ran into something interesting below the floor.  The floor drain I removed had a groundwater check valve that had rusted shut about ten years ago when the house was then equipped with a sump pump.  In the photo, the two clay lines tied into that floor drain (the stub of the cast iron can be seen in the center of the photo).  About three inches below the level of the cast iron line (at the very top of the photo) is a 4″ cast iron pipe that I presume brought groundwater runoff from below the middle level (slab on grade) of the split level home.  The pipe is about 34″ below the finished floor.

Since this pipe is so low, it obviously would rely on the groundwater level rising high enough to reach the clay tiles and leach into the original trap.  It had a lot of water coming from it when first uncovered, but has since dried out over the three days or so that I have been pumping the trench dry.  Since I have the floor opened, I’m moving the sump pit to a more suitable location and using a deeper basin.

Should I try to extend this pipe toward the new basin, or, as my original plan entailed, backfill with crushed stone and allow the water to percolate into the new sump pit (essentially how it had been originally, but only into the clay tiles, and eventually the floor drain).  What type of crushed stone should I look at using if I go this route?

Thanks so much in advance for the help!