The National Park Service hopes to get $20 million in Land and Water Conservation funds during the coming fiscal year to but 4,000 acres of additional parkland in the greater Washington area including expansion of Manassas National Battlefield Park.

It would be the first significant expansion of federal parkland here in several years and the [WORD ILLEGIBLE] acquisition since the Land and Water Conservation Act was passed in 1965, according to Jack Fish, director of National Capital Region parks.

The act, which funnels revenue from leasing federal lands back into the purchase and development of parkland, will have $900 million to disburse next year. So far the program has provided $36 million for area federal parks, almost all in the 1960's. To date, state and local parks in Virginia have received $33 million, Maryland parks $30 million and District $8 million .

The Park also is proposing $12 million in restoration projects here, under the 2-year old Bicentennial Land Heritage program. Almost all the funds would be used to restore parks and park buildings, including $1 million in repairs on the C&O Canal and at Fort Washington, and $5 million in repair work on deteriorated bridges along the George Washington Memorial Parkway north of Rosslyn.

Congress must approve the allocation of both Bicentennial Land Heritage funds and Land and Water Conservation funds on the Park Service as well as any expansion of federal parks.

The largest park acquisition proposed the 1,400-acre, $8.5 million expansion of Mansassas National Battlefield Park, apparently also is the least likely to receive congressional approval because of opposition from the Prince William County Board of Supervisors.

However, the major park purchase proposed, $7.9 million to add 1,800 acres to the C&O National Historical Park, stand a much better chance of passage. It would complete the purchase of all remaining privately own land within the boundaries of the canal park created by Congress in 1971.

Other proposed parkland purchases here include the creation of Monocacy National Battlefield in Sharpsburg, Md., with the purchase of 633 acres for $3.5 million. The site of a major Confederate victory in 1864. Monocacy was declared a National Millitary Park in 1934. However, federal funds to buy the park site, still privately owned farmland, were not authorized until 1976 when it was made a national millitary park.

Farther afield in the Park Service's National Capital Region, is the proposed $950,000, 108-acre expansion of Harper's Ferry National Historical Park.The Park Service plans to build an off-site parking lot, ban traffic from the historic section and start a shuttle bus system, With an additional $1.5 million in construction funds earmarked for Harper's Ferry, the Park Service also hopes some of the many historic buildings now boarded up there.

Like the Park Service's national budget , the $12 million in proposed construction projects in the Washington area involve few new buildings, but rather stabilization or restoration of existing building and parks.

The single largest area construction job would be the $5 million resurfacing of five of the eight bridges on the George Washington Memorial Parkway north of Rosslyn. The Park Service has surfaced three of the bridges in the past three years, but instead of continuing to do a year and impeding parkway traffic for the next five years "we're proposing to do it all once and get it over with," said spokesman George Berklacy.

The resurfacing which would take about a year, would begin after the start of the 1979 fiscal year Nov. 1 if approved by Congress. The five bridges, all about 15-year-old, span Windy Run, Spout Run, Donaldson Run, Gulf Branch and Glebe Road, where it ends near Chain Bridge.

In additional Bicentennial Land Heritage funds would be used to rehabilitate the existing Mansassas battlefield visitors center ($228,000) and Wolf trap Farm's Filene Center ($393,000). Arlington House in Arlington National Centery would receive $151,000 for repair work and the largest section of George Washington's ill-fated potomack Canal at Great Falls, predeccessor to the C&O Canal, would receive $393,000 worth of stablizing work to its locks.

Fort Washington, considered by historians to be one of the nation's most magnificent forts, is slated to receive $455,000 for needed repairs to its giant masonry walls and its may boarded up 150-year-old buildings. It would be the first significant repair work done on the fort in almost two decades. The Park Service also proposes to build additional comfort stations for the one million picnickers a year who use the park grounds.

The Federicks Douglas Home in Anacostia, a federal park since 1962, is to get a $318,000 visitors center under the proposed Park Service construction budget to handle increasing numbers of visiters.

The Expansion of the Manassas National Battlefield commemorating the first battle of the Civil War in 1861 and second major battle in 1862 - where Confederate Gen. Thomas J. Jackson acquired the nickname "Stonewall" - has been proposed for several years.

A bill authorizing the addition of 1,768 acres on the property of the present 3,000-acre park, including about 300 acres in scenic easements, has been sponsored by Rep. Harbert E. Harris II(D-Va.) and passed the House each of the past two years. But it has been blocked in the Senate. It would include land around the historic Stone Bridge over Bull Run and groves of tress still pock-marked fron the battles.

Virginia's two U.S. senators, Harry F. Byrd Jr.(I) and William L. Scott (R), while not themselves opposing the park's expansion, have held up passage of the park bill because of the opposition from Prince William supervisors County officials said Prince Willian needs development and they against any federal, stage or area park expansion within the county. Park Service officials say historical and environmental groups and the majority of the landowners in the area favor the battlefield expansion.

An aid to Sen. Byrd said last week there apparently is little chance the park bill will past this year.

The Park Service's National Visitor Center at Union Station, which would receive $323,000 allocation in the proposed fiscal 1979 construction budget, for repairs in its heating system, still continues to be one of the major items in the Park Service's proposed $59.4 million operating budget. The Park Service is asking for $6.1 million to operate it next year.

The little-used visitor center was to have a giant parking garage for tourist for the Bicentennial, but its construction was late and finally was halted by Congress in the summer of 1976 because of hugh cost overruns. The garage, still incomplete, ultimately may cost $45 million.

More than $1 million of the annual operating costs go to staff the visitor center - it has a full-time staff of 28 - and another $1 million to heat, light and clean it. The major budget item is the annual $3.5 million the park Service must for 25 years under the original $26 million lease-purchase agreement to buy the station from the railroads.

Under an agreement reached last fall by the secretaries of Interior and Transportation, the original Union Station, now used solely as the visitor center, will once again be used primarily as a train station. Plans to accomplish this, and to finish the garage, are to be presented to Congress when a study of the visitor center is completed.