The Montgomery County Council sided with environmentalists instead of church leaders yesterday, voting unanimously to place development limits on federally tax-exempt institutions in the county's 93,000-acre agricultural reserve.

Council members closed a loophole in a 25-year-old policy that had exempted institutions including churches, private schools and day-care centers from a ban on public water and sewer service within the nationally known reserve in northwestern Montgomery.

The ban had forced most homes in the reserve to rely on septic systems, effectively limiting their size. It now will be extended to future construction by churches and other tax-exempt institutions.

"It's a significant restriction," said council President Tom Perez (D-Silver Spring). "The door isn't hermetically sealed . . . but it's a very difficult door to open."

Although day-care centers, private schools and other facilities will also be affected, opposition from churches became the focal point of debate. The council yesterday also denied a request from Bethel World Outreach Ministries International in Silver Spring to be the last tax-exempt institution to receive public water and sewer in the reserve.

"I feel an act of injustice has been done," said Bishop Darlingston G. Johnson, pastor of the 2,000-member church. "There's discrimination here."

Last year, Johnson said, the church bought 120 acres in the reserve for $3 million. Its leaders knew at the time that the county's policy excluded churches from the water and sewer ban. The church planned to keep 75 acres as farmland, he said.

"Now, we're forced to sell this land to a developer who will build four houses on that land," Johnson said yesterday. "It's never going to be put in agriculture."

Council members said the decision was proof of their commitment to limiting development in the reserve, which covers one-third of the county.

"I think it's about time," said council member Michael Knapp (D-Upcounty). "We had to do this. We shouldn't have deferred as long as we did."

When the county created the reserve 25 years ago, it limited development to one house per 25 acres and further discouraged building by banning public water and sewer to most facilities. It is particularly hard for large facilities to operate on traditional septic systems.

"The best way to protect the agricultural reserve is to keep sewer pipes where they belong: in areas of Montgomery County slated for development and out of farmland," said Derick P. Berlage, chairman of the county's Planning Board. "This is the first time the county has made an unequivocal statement that sewer service has no place in the agricultural reserve."

With land becoming scarce and increasingly expensive in the southern part of the county, several churches had taken advantage of the sewer loophole, buying property within the reserve to expand their congregations.

The 2,000-member Seneca Creek Community Church in Germantown waited two years for the council to decide whether to close the loophole, eventually losing its contract on a 105-acre property in the reserve. The council voted 6 to 2 yesterday, with Perez and Nancy Floreen (D-At Large) in opposition, to deny Bethel World's request to essentially be grandfathered out of the new policy.

Environmentalists have complained of an onslaught of development pressures in the reserve as the county becomes more urban. For instance, in recent years, other types of man-made sewage disposal systems have made it easier for developers to build on rural land.

Jane Evans, president of the Laytonsville-based Citizens to Preserve the Reserve, called the decision a good first step but said the council has to address other threats to the reserve.

"We would like to see the County Council continue in the thinking they used today when they said they were drawing a line between where the development stops and the agricultural reserve starts," she said after the vote.