I'm a public advocate promoting the global shift toward energy independence through upgrades in community-driven energy efficiency and renewable energy production. http://www.linkedin.com/in/aaroncampbell
Huge roofs with huge cisterns makes for lots of runoff collection. Walmart says they are going solar so why stop there? They could treat their own water inside and Culliganize it for sale if they want. Providing their roofs are clean enough I guess.