The Maryland Environmental Service has proposed that most of the treated waste of metropolitan Washington be shipped by barge 30 miles down the Potomac River to a 1,700-acre site in rural Charles County.

This plan is the latest in a long line of solutions to a problem that has plagued the region for nearly a decade: what to do with the some 600 tons of sludge churned out each day by the Blue Plains sewage treatment plant in Southwest Washington.

The other proposed solutions have ranged from trucking the waste to Ohio to burying it at Andrews Air Force Base to just dumping it into the Potomac. These plans proved to temporary, environmentally unsound, or unsuccessful.

Maryland environmental officials are confident the Charles County proposal will prove to be less controversial than its predecessors, which produced lawsuits, protests and headlines proclaiming "Sludge Wars."

They base this confidence primarily on the fact that the scheme involves the construction of a sludge compost facility that would transform the treated waste into a useful, uncontraminated soil additive.

The site is located in sparsely populated farm country on Cedars Point Neck along the Potomac between Nanjemoy and Port Tobacco Creeks. The nearest place name is the unincorporated village of Welcome about three miles away.

The land in question on Cedars Point Neck - 3,300 acres in all - has been owned by the Maryland Province of the Society of Jesus since the province obtained a land grant from King Charles of England in 1649.

Half the land has been leased to the U.S. Department of Army since World War II for use as a munitions testing field. The Rev. Joseph A. Panuska, S.J., said that part of the tract has been contaminated with unexploded shells.

The section of the tract the Jesuits have offered to lease to the Maryland Environmental Service for the compost facility has been used by tenant farmers for several years.

The county commissioners in Charles County, who must approve the proposal, have appointed an advisory committee to study the potential environmental and financial impact of the composting site.

Several farmers in the area attended a press conference Wednesday at which the proposal was explained. "There was more a sense of interest than fear," said one county official.

Mrs. B. B. Kemp, who lives in a farmhouse that overlooks the proposed site, said she supported the plan. "We're very pleased with it, to tell you the truth," she said. "We think it answers a lot of the environmental problems." Mrs. Kemp's husband is the chairman of the advisory committee.

According to the proposal, only 100 of the 1,700 acres would actually be used for the compost facility. The remainder would serve as an experimental farm using the sewage sludge to prepare the soil. This process known as the "biomass principle," has been refined at the Beltsville Agricultural Research Center in Prince George's County.

The Beltsville station developed a model of what the state agency hopes to do on a grander scale in Charles County. At the Beltsville research center, some 60 tons of sludge from the Blue Plains plant was composted each day and used successfully for nursery and sod farming, on vegetable and flower gardens, and for golf courses.

Thomas D. McKewen, director of the environmental service, said the plant would cost an estimated $20 million, a sum to be borne by the federal government.