The Montgomery County Council decided yesterday to go ahead with plans for a $246 million incinerator that proponents say would safely handle the county's trash and garbage disposal problems for at least 20 years.

The facility, which would be in operation in 1987, would burn up to 1,400 tons of refuse daily and generate the energy equivalent of 400,000 barrels of oil annually, enough power for 18,000 homes, according to county officials.

The council unanimously endorsed the facility, the Solid Waste Energy Recovery Project, at a site at Rte. 355 and Shady Grove Road.

Neighbors of the site have objected vigorously, claiming that toxic emissions would endanger lives. Detractors also said the incinerator should be in a less populated area.

The council's resolution said the council "believes that this facility will not pose a health problem to the communities adjacent to the site."

The council's action authorizes solicitation of construction proposals from contractors. The council also asked the executive branch of the county government to present a financing plan for the project.

Although the council's action apparently clears the way for the incinerator, Council President Neal Potter asked County Executive Charles W. Gilchrist for further information on the possibility of shipping the county's trash by rail for dumping in other jurisdictions.