A proposal to ban the extension of public water and sewer service to allow megachurches to be built in Montgomery County's agricultural reserve has cleared its first major hurdle.

In a unanimous decision Thursday night, the county's Planning Board recommended that utility limits be placed on churches, day-care centers and other "private institutional facilities" proposed for the 93,000-acre reserve. The board also recommended size restrictions on the facilities.

County Council members will begin considering the recommendations next week, starting with a public hearing Tuesday.

Environmentalists and church leaders have been at odds over what development, if any, should be allowed in the agricultural reserve, a swath in northern Montgomery that covers one-third of the county. Council members have found themselves trying to balance the concerns of a politically powerful religious community with a desire to promote the county's nationally recognized land preservation program.

At issue is whether churches and other federally tax-exempt organizations should continue to be the only facilities that can get public sewer hookups in the reserve.

Without the sewer hookups, churches would have to use less reliable septic tanks, which would effectively deter them from the reserve.

The Planning Board's recommended size restrictions would affect all properties in rural areas. If adopted by the County Council, the rules would forbid landowners to build on more than 15 percent of their total acreage in the reserve and 20 percent in other low-density rural zones.

Nearly 30 people testified before the vote was taken shortly before 11 p.m. Thursday, delivering passionate pleas to the Planning Board members.

"What's before you tonight is a door slammer," said Devin Doolan, an attorney representing the Archdiocese of Washington. "It's a concept that says churches need not apply in a third of the county."

Planning Board Chairman Derick Berlage called Doolan's statement a "grotesque oversimplification."

"The issue is not whether houses of worship should be regulated," Berlage said. "The issue is how they should be regulated."

Environmentalists argued that lax rules undermine the intent of the reserve.

"If you want to continue to have agriculture in the agricultural reserve, you need to have contiguous land," Carol Franconi, a Laytonsville resident, told the board. "The farmer can't work around the church facility."

Land in southern Montgomery is scarce and expensive, forcing churches to the north. Bethel World Outreach Church in Silver Spring, for example, has been waiting for more than a year for approval to build a larger facility in the agricultural reserve. Barbara A. Sears, an attorney representing the church, testified that environmentalists were exaggerating the problem.

The Planning Board made some concessions by adding grandfather clauses. Owners of private facilities who applied for public sewer service before Thursday night would not be automatically rejected. If approved, they could build on up to 30 percent of their land. County officials said 11 applications are pending.

"We can be fair to those who bought land and let a few fish in the net but close the net afterward," Berlage said. "The goal is to protect the land for farming over the long haul."

The debate over what to do with the megachurches has dragged on for about two years. The Planning Board supported a similar proposal last year, but the council put it on hold for further examination.

"I think all of us are anxious to resolve the issue, which has been around the past couple of years," said council member Steven A. Silverman (D-At Large). "But we need to understand what we're voting on. There are a lot of questions which haven't been answered."

Planning Board members seemed eager to move on after Thursday's vote. When asked why he supported the restrictions, Commissioner John M. Robinson gave a terse reply before walking away. "I think it's a fair proposal. That's all," he said.