Barbara Donnellan, the new Arlington County manager that stepped in after former manager Michael Brown was asked to leave earlier this month, has hired Mark Schwartz for her old deputy's position.

Schwartz, who served as acting deputy county manager while Donnellan was acting county manager earlier this year, has been serving as director of the Department of Management and Finance for Arlington.

Donnellan also appointed William F. O'Connor III as the new head of the Department of Environmental Services.

DES is the county department that handles everything from transportation to public works and general services. O'Connell replaces acting DES chief Greg Emanuel, who took over after Robert Griffin left the county early this summer.

O'Connor comes to DES from Arlington Public Schools, where he has been serving as director of design and construction since 2008. He will take on his new role effective Nov. 8.

Schwartz will assume the role of deputy county manager immediately, and the county will be on the hunt for a new director of management and finance. The position includes overseeing the county's budget and bond sales, according to the county.