We are getting ready to install a new shower in our basement. When we had our house built about 8 yrs ago we asked to have a shower & toilet drains roughed in. I cut off the plastic cover for the floor drain to gain access to the drain pipe. After digging about 13inches I found the pipe. We have been having some fairly heavy rains the last week & this weekend that has been keeping our sump-pump running. But off & on iv'e noticed that there is water that is filling up the hole I had dug. (The water doesn't stink. So I don't think it's water that somehow leaked out/over of the toilet drain.) I'm guessing it's from the rain. We live in a area that has quite a bit of clay in the ground. The water doesn't seem to be reabsorbing into the ground.
What does anyone recommend to fill around the drain pipes when we get it all installed?