NASHVILLE, Tenn. -- The state is planning to build two data centers in the next three years for $68 million that will serve as safe storing houses for all of Tennessee's computer operations.

The current center, located near the bicentennial mall in downtown Nashville on the site of a former landfill, is 20 years old.

For computer technology, "20 years is a lifetime," said Mark Bengel, the state's chief information officer.

The old foundation is cracking, which has required moving equipment. And it's located near a railroad, which could be a threat if a train carrying hazardous material derails.

The two planned centers, one north of downtown Nashville and another in Smyrna, will each house half of the state's technology load and back up the other half.

"That way, if the data center gets hit by fire or a tornado, or some catastrophic disaster, you only have to recover half your systems. We use the opposite data center to recover the other," Bengel said.

Other outside computer experts in Tennessee agreed with the plan.

"You can't have people not getting paychecks, and you can't have people not able to send e-mails. Oak Ridge National Labs has its own redundant data center for its business operations. All major banks do. You have to, because you never know what's going to happen," said Buddy Bland, head of Oak Ridge's computing facility.

Each new building will be 35,000 square feet, matching the total 70,000 square feet at the current center.

But the centers will still provide room for growth because data storage technology has shrunk significantly in the last 20 years and will likely continue to do so.

"We'll get a good 20 years of growth out of these buildings as the equipment becomes smaller," he said.