Anyone who is having an in ground pool installed in their yard will very soon into the process will literally have a mountain of excavated dirt piled up nice and high for any and all to see. When it comes time to backfill the pool, level the ground or anything that requires support, common sense quickly suggests that you should start with the mountain of dirt and use that first.

I mean, why wouldn’t you re-purpose something as basic as all that available dirt rather that truck it all away and then bring in something new?

Unfortunately common sense in this case is wrong. While in some cases pool companies will re-use this excavated dirt for things such as backfill or to level ground and so on the reality is the dirt that was excavated should never be used as backfill or levelling of anything near an in ground pool. 

There are several reasons for this.

First, it comes down to the consistency of the medium.

Simply put, consistency matters.

When backfilling or even levelling, the actual consistency of the dirt you have excavated when digging the hole for your pool is unknown and most likely to be of poor consistency. If the dirt or fill you use has is of low to poor consistency, it will over time compact, compress or even erode which is a prescription to create all kinds of expensive problems to fix. What kind of expensive problems? There are many possibilities. You could run into wall bulges or shallows, or even pool walls that could completely collapse. Beyond that you can end up with leaks, torn liners, cracked pipes and more. There is almost no end to the grief it can create. 

Even cement pads can crack as support medium shifts, settles and erodes over time. Unfortunately as many homeowners have no idea the danger that exists by re-using excavated dirt, they can be easily convinced that the “common sense re-purposing” is the smart move, only to start having various problems down the road (long after your pool installation company has left).

So what should be used for fill when building a pool? 

Either crushed stone compacted to ninety five percent or pea stone. Yes it is more expensive, but at the end of the day it is the right way to do the job and if you don’t do this part right, the headaches that can come from this as mentioned are many. The excavated dirt itself should be removed from the property. And one more thing, never use any fill that is organic in nature.