William Roche, who served 17 years on the Somerville Board of Aldermen as the representative for Ward 1, has been hired as the city's full-time personnel director.

The Somerville Board of Aldermen approved their former colleague's hire at a meeting on Feb. 28.

Roche stepped down from the Somerville Board of Aldermen on Dec. 13, 2012, citing a desire to spend more time with his family.

Almost immediately—the morning after, in fact—Somerville Mayor Joseph Curtatone's office announced Roche had been tapped to serve as part-time, interim personnel director for the city. In that role, Roche was tasked, among other things, with helping to find a full-time replacement for Sarah Kloos, the previous personnel director, who stepped down on Nov. 30, 2012 when she had her second child.

In talking about hiring Roche on a full-time basis, Curtatone said Monday that "I asked him to come on full-time" back in December.

"His background and qualifications are impeccable," the mayor said.

Roche holds a master's degree in human resources from Boston University, and he spent over a decade working as a human resources manager at NSTAR, where he also served as a safety compliance manager, according to an announcement sent by the city in December.

Curtatone said, "We went through an extensive search" to find a new personnel director, and Roche fit the bill.

The former alderman recently retired from NSTAR, which allowed him to take on his new role on a full-time basis, the mayor said.