I have two conduits that bring in the water and mains electricity cable, they come up through slab in the plant cupboard. The builder has used soil pipe to bring them up so there's a reasonable gap. They also seem to be quite deep so I'm not sure hosing in expanding foam will work.

 

Any thoughts?

The water pipe should be lagged as it comes up through the drain bend. I shoved a load of wire wool down it and finished it off with expanding foam, capping the bend with a 32mm drain connector (link) (as our supply was 32mm MDPE)

Climaflex round the pipe and then foam that in place. Adding a few stainless pan scouters to the mix does deter the small furry beasts. 
 

One of these also finishes it off nicely.