These are only two examples. Tree roots can grow and spread to split or crack fittings/pipe.
The other example is something customers or even the other companies would not think of. This pool deck was slab jacked to level out the concrete. After the deck is core drilled, liquid concrete is used to float the concrete level. The problem is that the liquid concrete used around a pool can cause major damage to the underground plumbing and equipment. It will find every open crevice and will fill with the material. This picture shows the concrete was pressurized and cracked the fitting along with the pipe going to the swimming pool skimmer.
