While the oil and gas refined by CVR Energy will someday run out, the company generates a seemingly inexhaustible supply of data: 3 to 5 TB of information in 2008 alone, says CIO and senior VP Mike Brooks. He expects that load to double every year for the foreseeable future.

Though disk may still be cheap, Brooks says, it just doesn't make financial sense for CVR to store every bit of electronic information indefinitely. Besides raising hardware, software, and utilities costs, outsized data stores make backups and enterprise search less efficient, and legal e-discovery more burdensome. When you're paying lawyers hundreds of dollars an hour to review e-mail and documents, a smaller pile means a smaller bill.

That's why CVR, a $3 billion-a-year refinery based in Sugar Land, Texas, is undertaking a massive data disposition project, hammering out policies that will govern how long the company stores its information and when it can be disposed. Between deletions based on the new rules and other technology approaches, such as deduplication, Brooks hopes to cut CVR Energy's disk use in half.

He isn't alone. More organizations are evaluating--if not yet implementing--data disposition strategies. By 2013, half of all Global 2000 companies will have formal records management systems to shepherd data through its life cycle, Gartner estimates.

But this is one area CIOs must approach with caution. There are significant technological, regulatory, and organizational hurdles to clear before organizations can eliminate data with confidence. At the top of the list are compliance and legal. Every industry has government-mandated retention requirements. On the legal side, general counsel and human resources may worry that critical pieces of information that could support their positions--in case of employment discrimination or harassment claims, for example--may be destroyed.

Technological and organizational challenges are just as daunting. Before you can dispose of information, you must identify it and know every place it resides--not a simple task. And users aren't quick to give up the mail and documents they produce. As with NRA members, you may have to pry PST files and PowerPoint decks from their cold, dead hands.