The Washington area is getting a new public television station today, made possible by Northern Virginia's newest landmark, a 689-foot television tower that is taller than the Washington Monument.

WNVC-Channel 56 will begin broadcasting a wide range of news, public affairs, sports, music and entertainment on June 21. Today, it will go on the air in a three-week dress rehearsal, using programs normally broadcast on its sister public television station WNVT-Channel 53.

Channel 53 went off the air last night for the summer while its facilities are moved into a new joint Channels 53-56 headquarters on the Beltway at Rte. 50, at the base of what residents are already calling Fairfax County's Eiffel Tower. When Channel 53 returns in three months it will broadcast almost exclusively educational and children's programs.

Like WETA-Channel 26, Channel 56 is a nonprofit, public television station. But it will broadcast more news than WETA, including coverage of Congress, the Virginia legislature and local public affairs. It is not a member of the Public Broadcasting Service (PBS) and will carry none of the popular PBS programs such as Masterpiece Theater.

Weekend programming on Channel 56 will feature entertainment, including sports, concerts, country-music series, theater and movie classics.

Channel 56 is primarily a Virginia station and will aim its powerful signal at Northern Virginia residents. But WNVC officials say its 1.25-million watts will make its signal receivable in most of the Washington region and as far away as Annapolis--at least for houses on hills or with good antennas.

The tower itself was controversial, especially for the roughly 1,000 residents of the Yorktown Square condominium development, some of whom live within 600 feet of the tower's base.

"We were the only opposition at last year's hearing, and it was hard being against public television. It made us look as though we wanted to deprive the school children of Northern Virginia," said Yorktown Square spokesman Lake Lester.

He said that since completion of the tower this spring, "it's like living in the shadow of the Eiffel Tower." Lester said residents were concerned about possible health hazards from radio waves. They also worried that the huge tower, now the tallest object in the Washington region, will lower home values and lead to the construction of other towers in the largely industrial Merrifield area.

The Fairfax County Planning Commission two weeks ago delayed action for six months on the request of FM radio station WEZR to add a radio antenna to the new tower.

Channel 56 may be competing with Channel 26 in one crucial area: fund-raising. More than 30 percent of the budgets of the public TV stations comes from public support, with WETA depending somewhat more on contributions from 100,000 members for its $15 million annual budget. WNVT has about 2,500 members supporting its $1.5-million annual budget.

The Virginia General Assembly is the major supporter of the Central Virginia Educational Television Corp. of Richmond, which operates both 53 and 56. It launched Channel 53 in 1972 with live coverage of the state legislature. It also pioneered live coverage of Congress.

Channel 53 will resume broadcasting from its station and tower near Fredericksburg in September, but the station's staff will trade its present offices on the Northern Virginia Community College campus in Annandale for new quarters beside the Beltway.