A new regional park will open next spring along the Occoquan River. The park will be located on part of the District's 3,500-acre Lorton Reformatory and sanitary landfill complex.

Under an agreement with District officials, the Northern Virginia Regional Park Authority will develop the park, which will eventually include 800 acres.

It will be financed by a surchange levied on refuse now trucked to the Lorton landfill. Park officials expect to raise about $100,000 a year from the surcharge.

The first section of the park to open will be 400 acres along the Occoquan River between I-95 and Rte. 123.

That section, to open next spring, is in Prince William County opposite the town of Occoquan and near the Occoquan Reservoir dam. The Park Authority already owns 25 miles of park land along on the northern shore of the Occoquan.

The first phase of development, already under way, includes four playing fields, a parking lot and restrooms. The fields -- two for soccer and two for softball -- will be open to the public on weekends on a first-come, first-served basis, but may be reserved during the week by league teams working through local recreation departments.

The second phase of development, not expected to be completed before 1990, will include picnic areas, boating facilities and restoration of several turn-of-the-century brick kilns.

The park is being developed at the request of Fairfax County and other jurisdictions that are part of the Metropolitan Waste Management Agency.

A master plan for the park was developed in 1976 after a series of public hearings in Northern Virginia. The park site includes 400 acres of woodland along the Occoquan River, 280 acres of sanitary landfill and 113 scres of buffer zone.