IMPERIAL - About 50 businesses at Pittsburgh International Airport's Airmall owe Allegheny County more than $126,000 in back property taxes, a controller's audit said.

The county usually collects debt by filing liens against the debtor's property.

But in the case of the businesses at the airport, the county has just filed a lien against itself because the debtors occupy county property. Public property isn't tax exempt if it's being used for private purposes, said Pittsburgh attorney Ira Weiss said.

Those self-inflicted liens weren't really a mistake on the county's part, said Deputy County Treasurer Tom Bradley.

"For the lien process, we just see the lot and block number," said the county's deputy treasurer Tom Bradley said. "If it's listed as taxable and it's over $1 (in debt), we file a lien. That's the law."

HOMESTEAD - An engineering and design firm will move into a three-story office building that was intended to house the Dick Corp.'s headquarters.GAI Consultants Inc., now of Monroeville, bought the building in The Waterfront, a retail and entertainment complex, for $6.75 million. The firm will move its 220 employees to the building and create another 50 jobs when it moves in with help from the state's Department of Community and Economic Development, company officials said.Dick Corp., a construction firm, worked on the building for a year but decided to not relocate its headquarters to the space because of financial issues.By The Associated Press