Are you going for any LEED certification on this building? Also, are you going to try and cut and fill any of that 40k that you are hauling off? That looks like decent dirt. Much better than most of the gumbo crap we have down here.
If you aren't going for any LEED certification, there are some good ideas on building green on the USGBC site, especially pertaining to reusing and storing rainwater and hvac runoff. http://www.usgbc.org/DisplayPage.aspx?CMSPageID=75
You probably already know all of this stuff. Just in case. Looks like a cool project!