The federal government has come up with a triple-barreled approach to a 6-year-old impasse over ownership of the Alexandria waterfront, which could mean a partial resolution of the dispute between the city and the federal government in the next 30 days, Major Charles E. Beatley Jr. has told the City Council.

Beatley, who met with federal officials last week, said the federal approach could end a dispute over three areas: the 50-acre waterfront, the Bogle tract and Cameron Mews and Founders Park, two townhouse developments.

As a first step to lifting the cloud over titles to the areas, Beatley said, the federal government is seeking a permanent agreement with the owners of the 153 townhouses in Cameron Mews and Founders Park that the structures will never exceed their current three-story heights. If that agreement is forthcoming, Beatley said, federal officials have told him the government would be willing to drop its actions in seeking title to the land where the townhouses sit.

Secondly, federal officials are negotiating with attorneys for Development Resources, Inc., a firm that is planning to build an office complex on the property once knowns as the Bogle tract, which is several blocks west of the waterfront. Beatley said a resolution to the government's formal title claim to the area, which was filed in August, may be at hand, possibly within the next few weeks.

Finally, Beatley announced a tentative timetable for talks between city and federal officials concerned with resovling the 6-year-old federal title claim to the waterfront itself.

If all goes well, and city and federal officials can agree on a development plan for the waterfront, Beatley said, then perphaps as early as next April or May the government would drop its title claim to the area, which has frozen all improvements there since 1973.

"I am as optimistic as I can possibly be," Beatley said after the two-hour meeting with federal officials. "We had good, erious, friendly talks. They weren't just playing poker. They want maximum citizen input. They care about the waterfront."

Also representing the city at the meeting were Vice Mayor Robert L. Calhoun, city manager Douglas Harman, city attorney Cyril D. Calley and planning director Engin Artremel.

The unprecedented timetable, which Beatley presented to the City Council at a public hearing last weekend, calls for city and federal officials to come up with a joint plan by late November for developing the water-front. The goal, Beatley said, would be to compare the city's own mixed-use proposal with a similar federal plan.

"They (federal officials) are concerned about the heights of buildings in the area," Beatley said, noting that it was the first time the officials had expressed those concerns directly to him.

That concern was forcefully expressed six years ago when the federal government filed its lawsuit claiming title to the waterfront. The suit was filed at the behest of environmentalists concerned about then-current plans for highrise development along the waterfront.

This week, Virginia Attorney General J. Marshall Coleman demanded that the government drop the lawsuit.

In his first public statement on the issue, Coleman told U.S. Attorney General Benjamin R. Civiletti that he knew of "no compelling need for the federal government to own this land." Coleman, a Republican, asked Civiletti to "exercise your authority" in ending the lawsuit.

Coleman was ordered Monday by Gov. John N. Dalton to "monitor" attempts by city and federal officials to end the dispute. City Council member Donald C. Casey called the offer "little more than an election-year ploy." City elections will be Nov. 6.