Barbara Williams of Alexandria is 17, pregnant and single, but she is optimistic about her future..

Williams is one of 275 local youths working in the city's summer jobs program. She is spending three months as a clerk with the Alexandria Code Enforcement office and will return this fall for her senior year at T.C. Williams High School.

Her hope is that she can continue the job part time, as her boss has offered, so that she'll be that much closer to a career as a secretary.

"There's a real opportunity here. This is a learning experience," said Williams, who lives in a foster home. "It gives you a chance to decide what you want and to see that things aren't as easy as you thought."

If it weren't for the program, Williams said, she would probably be ringing sales behind a cash register rather than learning word processing on a computer.

The federally sponsored summer jobs program is in its 12th year in Alexandria, and positions are still available to eligible participants through Aug. 15, said Dail Moore, director of the city's Office of Employment Training.

Applicants between the ages of 14 and 21 who are living below the federally established poverty level are placed in entry-level positions with public or private nonprofit firms. Foster children or those in families receiving public assistance are automatically eligible.

Moore said that about half of the approximately 100 work sites are in local government agencies, such as the city recreation program. The jobs pay $3.50 an hour, just above the minimum wage of $3.35.

"We provide an exposure to the world of work, to employers' expectations, and the encouragement and means to return to school," Moore said of the seasonal effort. "For some youths, this is the only source of income they have for buying new clothes for the school year."

Moore said officials of the Alexandria program are particularly proud of its in-school component, through which 139 of the participants each spend 15 hours a week taking classes in "vocational exploration" and remedial language and math. The classes are taught at the Secondary Schools Occupational Center at the school administration office, 3801 Braddock Rd.

Eric McKenzie, who started this spring as the city's first year-round employment and training coordinator, directs the summer program. He supervises seven counselors who work with young people and their employers to match interests and needs and to iron out any problems.

McKenzie knows the potential for success in the program: He got his start at age 14 in the summer of 1964 with the Neighborhood Youth Corps, and worked his way up to director of the program in Joliet, Ill. The federal summer jobs program has since had several different names, and most recently was part of the Comprehensive Employment Training Act (CETA), but it has maintained the same mission of providing employment for underprivileged youths.

McKenzie said that while the program operates only during the summer, the goal is to follow through and help young people prepare for careers, whether that involves study for civil service or General Education Diploma (GED) exams, examining job options, or simply deterring teen-agers from quitting school.

More information about the jobs program and eligibility can be obtained by calling the Department of Employment Training at 838-0940.