Opponents of the controversial Laytonsville landfill, a temporary trash dump for Montgomery County that requires moving a 180-year-old farmhouse and moving or demolishing its dozen barns and farm buildings, go back to court Friday.

Last week a county judge issued a 10-day injunction halting construction workers from moving the handsome farmhouse and three small outbuildings so the farm site could be razed to create a sanitary landfill.

A longer injunction will be sought in Montgomery Circuit Court tomorrow by the Greater Laytonsville Civic Association and Mount Zion Citizens Associations, which have fought against the landfill and the breaking up of what is considered one of Maryland's oldest working farms. County publications have called the farmhouse "one of the most notable buildings in the entire county."

The planned landfill site is also the center of two other court cases. The site is illegal under the 1978 charter amendment, approved by county voters, that bars landfills in residential areas. But county officials have contended that the amendment is unconstitutional. The issue is expected to go trial July 25.

Laytonsville civic groups also have contested the state health permit that allows the landfill operation, a court case soon to be heard in Baltimore.

The 550-acre Oaks II farm, at Rt. 108 and Riggs Road, was bought by the county for $3.3 million in 1978. Only 110 acres will be used as a landfill, however, because most of the farm has a high-water table, making the land unsuitable for burying refuse. t

The landfill is considered a temporary site until the county finds a more Permanent place to dispose of trase, which is now buried at an industrial area near Rockville. That dump is expected to be full by early 1982.

A $500,000 feasibility study is being done on using a rock quarry near. Potomac as a dump. Also in progress is a $1 million study of a resource recovery process that would eliminate the need to bury up to 80 percent of the 1,600 tons of refuse now buried daily by the county.

The oaks farm as built between 1797 and 1805 by the Riggs family, founders of Riggs National Bank, and is said to have been where Confederate troops under Gen. J.E.B. Stuart stopped en route to the battle of Gettysburg. Graves of Civil War soldiers, slaves and some Riggs family members remain on the site, according to Priscilla Benner, one of several citizens fighting the landfill project.

The farm was bought in the 1930s by John C. Letts, founder of Sanitary Stores, predecessor of Safeway. Although tenant farmers work the land, the house has been vacant in recent years. The county will raze most of the farm buildings, and has no plans for the house and three outbuildings it proposes to move.