Northern Virginia's newest regional park -- about 200 acres of playing fields along the Occoquan River adjacent to but screened from the Washington area's largest refuse landfill--was dedicated Friday with a barbecue for local officials.

Soccer, softball and baseball leagues couldn't wait for the dedication of the new Occoquan Regional Park and began using its five new playing fields overlooking the river last month when landscaping and concession and restroom buildings were completed.

Two additional soccer fields and a large boat launching ramp and boat storage area are expected to open later this summer.

The $825,000 first phase of the park is being paid for by the 25 cents-a-ton fee levied on trash trucks using the dump since 1973.

Ultimately, perhaps in the year 2072 when a 99-year-lease to use the dump expires, the park will consist of 800 acres along the Occoquan and I-95, including a landscaped, earth-covered mountain of trash. The more than $100,000 a year generated by the trash trucks will be used to support and expand the park.

The Occoquan park is on a remote edge of the District's Lorton Reformatory complex. It is being operated by the Northern Virginia Regional Park Authority and the Fairfax County Park Authority, the latter handling the busy scheduling of teams using the fields.

The lush, grassy playing fields, on riverfront farmland and an abandoned brickyard, are open to teams from Fairfax, Arlington, Alexandria and the District, which are members of the I-95 Policy Committee and which produce the trash going to the dump.

Area officials praised the new park and the benefits that refuse can produce and also took the occasion to honor environmentalist Elizabeth Hartwell, a former regional park authority board member who has fought for more than a decade to create the parks and wildlife preserve on Mason Neck and for parkland throughout Northern Virginia.

John Herrity, chairman of the Fairfax County Board of Supervisors, said "few people may appreciate today what people like Liz Hartwell have done. Only 25 years from now will they fully understand the foresight of those who have helped preserve" the open space in Northern Virginia, even the open river banks beside a dump.

Hartwell was presented with a plaque citing her leadership in helping establish more than a dozen park areas, including the new Occoquan park.

Park Authority Chairman Walter Mess of Falls Church unveiled a second plaque in honor of Calvin Baber, the first full-time staff employe hired by the park authority in 1963, four years after its creation. Baber, 56, was in charge of the then soon-to-be-opened Occoquan park when he died Feb. 12.