Four Northern Virginia delegates and a former legislator have filed for election to the House of Delegates, assuring that all 19 incumbents in the area will seek to retain their seats. Nearly 60 political hopefuls had announced their candidacies by last week's filing deadline.

The final list of candidates includes incumbent delegates David G. Brickley and Floyd C. Bagley, both Democrats from Prince William County who announced they will seek a seat in the newly created 23rd District. The new district, which includes three delegate seats, covers Prince William County and Mannassas. In northwest Fairfax County, incumbent delegates John S. Buckley and John H. Rust Jr.,both Fairfax Republicans, said they will make bids in the three-member 50th District. Kenneth R. Plum, a Democrat and former Fairfax County delegate, also has filed for the 50th District race.

This week, the Virginia General Assembly approved a revised redistricting plan, designed to satisfy Justice Department objections that the original plan discriminated against black voters in the City of Petersburg and five nearby counties. The compromise plan still faces eight court challenges, which are to be heard by a federal court in Richmond today.

The new plan does not affect Northern Virginia House districts. 23rd District

Brickley, seeking his fourth term, said one of his major goals will be a repeal of the tax on nonprescription drugs. The measure, which passed the House and was spearheaded by Brickley, failed to gain Senate approval during the past legislative session.

Another issue high on Brickley's list will be the allocation of federal funds under the congressionally mandated block grant program. A member of the House Finance Committee, Brickley said he would work to ensure that the state's criminal rehabilitative programs are not diminished under the new budget process. In particular, Brickley advocated the retention and strengthening of prison drug abuse programs.

Joining Brickley in his concern over allocation of block grant funds, four-term delegate Bagley said the state should create a clearing-house mechanism that would ensure fair redistribution of federal funds both to localities and to agencies.

In addition to financial concerns, Bagley reiterated his tough-on-crime stance. "We have to make absolutely certain that people know we're not gong to tolerate head shops," he said, referring to businesses that sell drug paraphernalia. A member of the House Courts of Justice Committee, Bagley said he hoped the state's recently passed anti-drug paraphernalia law would not be modified by court interpretation. He also advocated legislation that would enable jury members to receive background information about a defendant before determining a sentence.

Both Brickley and Bagley support ratification of the Equal Rights Amendment and the proposed extension of the federal Voting Rights Act. 50th District

Buckley, who is completing his first term in the House, said he opposed both the ERA and extension of the Voting Rights Act. Although he said he voted for every "women's bill" during the past session, Buckley maintained the amendment is too "absolute" and, as written, would result in enforcement comparable to the civil rights laws.

"There are enough laws on the books," he said, "and the (amendment's) simple language could be warped by court interpretation." Buckley added that he sponsored legislation during the past legislative session removing questions about marital and employment status from voter registration forms.

On an economic plane, Buckley said he would like to expand tax reform. Buckley authored a "truth in taxation" law that forces localities to give the public more information about proposed property tax increases. Along this line, he said, the state should make available a comprehensive list of public services costs which might make people less staunch in their opposition to the reduction in some services.

Democrat Plum, whom Buckley defeated in 1979, said he decided to test the election waters again so he could carry on the work he began during his one 1978-80 term. In particular, he said, he would reintroduce a bill requiring parents and children to pay restitution to victims of vandalism.

Plum, who is director of adult education in Fairfax County, announced in a press release that education would continue to be one of his major concerns. As a legislator, Plum was a strong advocate of program improvements for handicapped and gifted and talented students.

Republican Rust, meanwhile, is seeking his second term. A co-patron last session of an unsuccessful bid to revamp the state's corporation commission, Rust said he would again introduce legislation to create a public utilities department that would investigate utility rate increases. The agency, which would fall under the executive branch, "would mean a real give and take in utility rate setting," he said. Now, Rust said, there is no agency specifically mandated to analyze utility rate increases.

Explaining that he has changed his mind about the Equal Rights Amendment, Rust said he now supports ratification of the amendment. During his last campaign, he opposed it.

Party primaries have been set for Sept. 8, with the general election set for Nov. 3.