I have an established play area for my kids. When I created the area, I cut the grass down, capped and covered the sprinkler outlets in the area, laid down landscape/weed fabric (I forget the ply, it was the generic gray/silverish) one from Home Depot. I then layered over it to a depth of 3" with rubberized play impact surface.
Now I am getting weeds in the area, as shown in the below photo. How can I safely spray/remove the weeds without having to tear up the entire area? (The total area space is approximately 15' wide by 30' long).