The Prince George's County Council approved a bill last week that would force more developers to pay thousands of dollars in fees to ease crowding in the county's public schools, where nearly 70 percent of elementary schools and many middle and high schools are crowded.

The bill, which passed 8 to 0, would tighten loopholes in a year-old law that had allowed some developers to escape paying fees to help build more classrooms. That law had exempted 32,000 of the 40,300 houses and apartments that had been approved for development.

County Executive Wayne K. Curry (D) has until June 29 to sign or veto the legislation.

Reginald A. Parks, a spokesman for Curry, did not return telephone calls seeking comment.

The legislation passed last week would reduce the number of exempted units to 17,290. It also would change the formula for deciding whether a school is over capacity, a key part of the law that requires developers to pay fees when a new subdivision sends additional students to schools that already have 5 percent more students than they are designed to hold.

The law also would place a moratorium on development near schools that are more than 30 percent over capacity. That would affect 28 elementary schools, two middle schools and two high schools.

The developers' fees range from $9,000 to $12,000 a student, depending on the type of home that is built.

By changing the formula to the same one that the state uses to determine school capacity, the council would expand the list of schools that are considered crowded. That, in turn, should increase the number of developers who would have to pay the fees.

"This bill has a more far-reaching effect than anything we've done so far," said County Council Chairman M.H. Jim Estepp (D-Upper Marlboro), who sponsored the measure. "I know this will do something, judged by the opposition from the development community."

Thomas Haller, president of the Chamber of Commerce, which opposed the legislation, said the development industry is concerned that the council keeps changing the process.

"This is the fourth time in five years that the rules have changed," Haller said. "I don't care what numbers they used. They need to pick something and stick with it."

Using the new calculations for capacity, 88 of 123 elementary schools would have enrollment more than 5 percent over capacity. Under the old formula, 51 elementary schools were considered to be more than 5 percent over capacity. The number of elementary schools operating at more than 30 percent over capacity also would increase with the new formula, from eight to 28.

The number of middle schools operating at more than 30 percent over capacity would decrease from four to two under the new formula. The number of high schools 30 percent over capacity would increase from zero to two.

Donna Beck, an Upper Marlboro resident and parent activist, pushed the council to change the formula to provide more accurate enrollment figures. She offered Frederick Douglass High School as an example of the problem that had occurred. Under the current system, Douglass was considered to be 24 percent over capacity, enough to force developers to pay fees but not enough to stop development near the school. The new formula puts enrollment at the school at almost 40 percent over capacity.

The old system "allowed developers to proceed without a pesky moratorium to stall their projects," she said. "We knew the only option was a legislative mandate" for the new formula.

Council member Audrey E. Scott (R-Bowie) said she voted for the legislation because she "supported the concept of closing the loophole."

She said that she believes the council should do more to make developers shoulder the costs of growth and that she does not believe the restrictions go far enough.

"It's a little better, but it still doesn't address the whole problem," she said. "There is still a loophole."

Council member Isaac J. Gourdine (D-Fort Washington) agreed.

"Nobody should get a break," he said. "You are still going to have a situation where people can build and are building in areas where schools are over capacity."