Northern Virginia voters are being asked to approve several bond issues on the Nov. 6 ballot on such diverse projects as the construction of schools, Metrorail, community conservation programs, park acquisitions and road improvements.

In Arlington, the four proposed bond issues, totaling just under $30 million, have won the unanimous approval of the County Board and were overwhelmingly endorsed by the Arlington Civic Federation, a coalition of the county's neighborhood civic associations. They are being opposed by the Arlington Taxpayers Association.

The bond referenda cover routine projects that voters have approved in past years, and mark the beginning of a new county policy to place such issues on ballots only in even-numbered years when there is a larger voter turnout because of national political races.

Mark Jinks, the county's budget director, said passage of the proposed bond issues is not expected to affect adversely the county's generally excellent bond ratings of Aaa from Moody's, a perfect rating, and AA+ from Standard and Poor's, a near-perfect rating.

Robert E. Harrington, president of the taxpayers' association, said the group's members oppose the referenda because they believe such annually recurring projects should be financed on a pay-as-you-go basis. By the time the bonds are paid off, the association argues, some of the project costs could double.

The largest proposed issue on the Arlington ballot is $13 million for Metrorail. The funds would be used to help finance the county's share of building and purchasing land for the 101-mile regional subway system for about two years. The county paid a disproportionately high share of the system's costs in the early construction years because the system was operating in close-in Arlington. Its share now is decreasing annually.

Another proposed bond issue calls for $6.8 million in community conservation funds. Under this program, the county and a residential neighborhood or local business group can plan and jointly pay for capital improvements to public areas in their neighborhoods. The improvements, to upgrade and conserve the area, can include road and sidewalk construction, local park development, installation of underground utilities and lighting or drainage projects.

The funds have been used for dozens of neighborhood conservation projects and to spruce up local shopping centers, such as those in Westover and Lee Heights.

A third referendum seeks a little over $4 million for the purchase and development of regional and local parks, open space or recreational facilities. Locally, the funds would be used to continue the county's program to provide more open space and parkland in the more highly developed areas around Metro stations. Funds would also be used for the county's contributions to the Northern Virginia Regional Park Authority's acquisition and improvement programs.

A fourth bond question seeks $6.14 million for street and highway projects. Monies can be used to purchase and improve the existing transportation network, including pedestrian and bike paths; for the installation of underground utilities; and for improvements to storm drainage systems.

In Fairfax County, voters are being asked to approve three bond issues totaling $109.8 million for new schools, neighborhood improvements and storm sewer projects.

The largest and most controversial proposed bond issue is $74.8 million for five new schools in the county's rapidly developing western sector, and refurbishments to several other schools throughout the county.

Other questions include $20 million for the county's neighborhood improvement program and $15 million for storm drainage projects. Under the neighborhood improvement program, residents of a particular area and the county share the costs of building and improving streets, sidewalks and street lighting, for example. The sewer funds would be used for storm drainage projects to prevent flooding and soil erosion problems.

In Prince William County, the only bond referendum seeks $20 million for road improvement projects countywide, including funds to design and purchase rights-of-way for the planned Rte. 234 bypass around Manassas.

In Loudoun County, two bond questions seek $6.4 million for improvements to the county's solid-waste landfill system and almost $6.6 million for renovation and construction of libraries countywide.

The county has to improve its landfill to meet state environmental standards for groundwater runoff. The point of the referendum, a county official said, is to ask residents whether the project should be funded through $6.4 million in general obligation bonds or on a pay-as-you-go basis through annual budget appropriations.

Alexandria and Fairfax City have no referenda on the ballot, officials said.