I recently put an outdoor kitchen in my yard and the plumber drilled a hole in my foundation aprox. 1 1/2" X 4" to run the water lines and the gas line now months later after covering up the walls in my finished basement we realized that water is coming in thru this hole that was never fixed by the plumber. What would be the best way to repair this hole being there are copper water lines and black gas pipe in this hole.
It would be best to have had some sort of sleave over the copper line to protect it from direct contact with the foundation, PVC pipe would work.
You did not post a picture so where going to have to guess.
Most often Hydrolic cement is used to fill any holes over about 1/2".
Any smaller then that and silicone caulking should work.