Fill dirt is typically sourced from the subsoil that sits at least six inches below the surface, under the topsoil. It does not contain any organic or biological components that will eventually decompose, which means it’s unlikely to shift and settle over time. After the dirt has been collected, it is sifted multiple times to remove rocks and debris. This is why it’s also called clean fill.
If you need help deciding which fill material to use, please refer to our article on the difference between fill sand & fill dirt.