After years of disputes, Montgomery County's democratic council and its Republican county executive have agreed that the county should build new sewage treatment facilities that would make it possible for developers to construct almost twice as many houses each year as they have in any of the past four.

Montgomery officials agreed that when new sewage facilities are completed in the mid-1980s they should accommodate the construction of 5,500 new homes a year. County officials said most of the growth should occur in the area along Rte. I-270.

County officials will present alternate plans for various kinds of sewage treatment facilities to officials of the Environmental Protection Agency today at a meeting in Philadelphia. The county needs EPA approval of any proposed plants largely because it hopes the federal government will pay for them.

Montgomery Developers greeted the county decision with some skepticism yesterday. The building industry will be "a whole lot more comfortable with the decision to accelerate growth rates "when we see those sewer taps," said Joseph Rodgers, a land development consultant.

"We've been through this before," Rodgers said. "Everybody will say, 'this is great,' and then they'll hold a hearing, and four people will complain about the rock strata and the snail darter and everything else, and it'll all go back to the drawing boards."

After eight years of countrywide sewer moratoriums that crippled development and a nationwide recession that further slowed growth, "we can see the light in being able to resume a 'normal' growth pattern for the county," said Council member John Menke, who drafted the latest proposal.

The moratoriums, imposed in 1970 and lifted for most of the county in May, decreased the number of house constructed annually to a low of 1,200 to 1,500 in the early 1970s. In the late 1960s as many as 8,000 houses were built in Montgomery each year.

In reaction to the population explosion of the 1960s, Montgomery voters elected officials pledged to restricting the construction of homes unless there were schools, roads and other public facilities to serve them.

Builders and developers soon charged that the county had been taken over by the advocates of "no-growth," a charge that has fueled political campaigns ever since. This week, however, the council and county executive decided they would try to solve the county's unresolved sewer problems before they leave office at the end of the year.

In April, U.S. District Judge John L. Smith Jr. upheld the EPA's veto of the proposed major regional sewage treatment plant at Dickerson in upper Montgomery County. The $400 million plant would have handled Montgomery County's sewage treatment needs into the 21st century and also would have provided extra treatment capacity for the District of Columbia, which is approaching the limits of its allocation at the Blue Plant regional plant.

With that death knell, the divided Montgomery County Council confessed to considering choices involving one or more conventional or Other forms of sewage treatment plants to serve the county.

County Executive James P. Gleason wanted the county to build largest treatment facilities to accommodate more growth and to provide treatment capacity for use by other jurisdictions in the region. The council, however, sought to restrict the amount of growth and to build a facility that primarily would serve the county's needs. Once the Dickerson plant was vetoed, Gleason agreed to compromise with the council on the lower figure to present a united front in Philadelphia.

The county officials want to learn "definitively" from EPA Administrator Jack Schramm today whether the federal government will finance the new treatment facilities, estimated to cost $60 to $80 million: whether discharges will be allowed above intake points for county drinking water and whether the county must construct facilities that will serve the entire region.

"We have caught up on the policies of the '60s," said Menke. "Now we need to intelligently deal with the needs of the '80s - or well have another sewer moratorium on our hands" when existing sewer capacity runs out in about six years.