Sounds like we never found them.
Poor excuse. George Bush was surrounded by competent people who told him.
We knew they were there and chose not to do anything about that facility probably because it would be too hazardous.
There were / are more than 10,000 munition storage locations throughout Iraq. I think we found most of them but it remains unknown how many weren’t found and cleaned out. I’m sure that process took years, and perhaps was left unfinished when we left. I have always maintained that this was the reason that all stories about chemical weapons were spiked so soon after the fall of Iraq. We simply didn’t know how long it would take to search for all the places where even small stockpiles still existed— and the last thing we wanted was to be in some kind of race with terrorist groups for who could find them first. So... Early on— immediately in fact— the story is crafted that there aren’t any chemical weapons to be found.
Chemical weapons aren’t the sort of thing you’d ever want to stockpile very much of in the first place. They have a shelf life, and storage management is a nightmare. Most of the existing stock went to Syria, IMHO, as documented by Tommy Franks in his memoir. It was then likely destroyed by an Israeli air strike at a bekaa valley ammo dump.
But small amounts probably did still sit unfound in some of those thousands of sites all over Iraq. Probably artillery shells.