VERY nice. There's already a pretty big "Rooftop Garden" movement in North America, hoping to use the wasted roofspace on large office buildings, much like how some residential complexes have gardens and/or animal coops on their roof. The benefits, besides having a garden/back yard type space for inner-city dwellers, is major plusses for the environment and less heat in the area from reflecting off of man-made structures.

This kind of "Argo-Farm" would be an awesome idea, and..FINALLY...people are starting to realize that a lot of time, chemicals and energy can be saved by using nature to filter some of our waste needs instead of just building bigger and bigger sewage plants.

The fact that it makes FOOD is a nice bonus.