Democratic Fairfax Supervisors Martha V. Pennino of Centreville District and Sandra L. Duckworth of Mount Vernon District have made it official: they're running for reelection to the County Board of Supervisors.

Pennino, who has served four terms as supervisor since her 1967 election, is vice chairman of the board and has been dubbed "Mother Fairfax" by fellow board members. In announcing, Pennino said: "One of my primary crusades will be getting a hospital in the Reston-Herndon area," which she represents and which currently lacks a hospital.

Duckworth, who has represented the Mount Vernon District since 1979, said she would focus on increased security at the District-run prison at Lorton and revitalization of the Rte. 1 corridor if reelected to a second term. "Rte. 1 is turning a corner towards the future. We must move forward to make it a prized and lively business asset," she said.

Republican Elaine McConnell, founder of the Accotink Academy for children with learning disabilities, announced that she is challenging Supervisor Marie Travesky, Republican of Springfield District. McConnell sees traffic, over-development, taxes, schools and crime as key problems confronting Springfield residents. She serves as an adviser to Rep. Stanford Parris on military academy appointments.

West Springfield businessman Bruce Green, in his first bid for public office, is seeking the 42nd District seat now held by retiring Del. Warren E. Barry. Green, director of training for Mount Vernon Realty, has been active in Fairfax County Republican Party activities for many years and is a member of the executive committee.

Barry has announced he will seek the GOP nomination for clerk of Fairfax Circuit Court.

Arlington Democrat Frank O'Leary said he will seek the party's nomination for county treasurer, a post that has been held the past 12 years by Republican Bennie L. Fletcher.

O'Leary, president of NOVA Research Associates, a computer development and operations firm, said he would seek to increase the use of computer technology in the treasurer's office. He also said he would focus on making the office more accessible to citizens and suggested starting a direct-payment system that would allow residents to pay taxes and water bills through Arlington banks as they now can with utility and credit card bills.

Fletcher has not yet indicated whether he will seek a fourth term.

George Dowd, a Dumfries law partner and former legislative aide to Del. Floyd C. Bagley (D-Prince William), said he will seek the Democratic nomination for the 28th Senate District seat held by John H. Chichester, a Republican.

"Right now I'm trying to sell myself to the Democratic Party, so I really don't know what the issues will be this fall," said Dowd, 53. "But I think I certainly have an advantage in representing the district as a Democrat."

Chichester, 45, a Fredericksburg insurance agent, has said he plans to run for a second four-year term.

John Bonfadini, 44, a professor of education at George Mason University, said he will run for the seat on the Prince William Board of Supervisors being vacated by retiring Vice Chairman Don L. White.

Bonfadini, a Democrat, was a candidate last year for the state House of Delegates from the 50th District but lost to Republican Harry Parrish. White represents the Gainesville magisterial district and has served two terms.

Emilie Miller, a former chairman of the Fairfax Democratic Committee, formally declared she will be a candidate to succeed retiring Democratic Sen. Adelard L. Brault in Fairfax County's 34th Senate District.

Miller, who served since 1980 as Brault's legislative aide, cited her years of community service, particularly in the field of mental health and retardation, and her experience in the General Assembly as her chief qualifications.

In a statement, Miller set education and the equitable treatment of Northern Virginia as her top priorities. A graduate of Drake University in Des Moines, Miller has been active in the state Democratic party since 1968.