In an excellent article from ISP-Planet, WSTA Data Center Seminar: Data Center Real Estate, Alex Goldman recites what the EVP at Tishman describes as the important factors when looking for a site for a data center:
Choosing a data center site, Bowman said, requires juggling a massive number of variables. You want access to power and fiber. If you're using water cooling, you want access to water and space for a reservoir. You want to know whether the land you're looking at it subject to flooding or other hazards. There are legal and regulatory issues. You want to know the state sales tax. He urged financial companies to think outside the box, which is the local area. "You may need to back up critical apps in Connecticut, New Jersey, or Pennsylvania, but non-critical apps can be backed up in states where there's no sales tax, such as Oregon, Georgia, or New Hampshire."
The rest of the article explains about the Wall Street data issue coupled with business continuity planning.