The dust_grassdirt_a.zip file you have requested: Skins / Objects / CS: Source: Custom Dirt and Grass Textures - 2.76mb is not available. Perhaps try browsing all files for the game Counter-Strike: Source and upload any files you want to share or are missing. This is the only information we could locate:
These are custom grass and dirt textures for de_dust and de_dust2 taken from real pictures from the author's yard. They are normal mapped also.