It appears the Pasco School District will do everything possible to avoid switching some of its schools to a multi-track year-round calendar.

The school board Tuesday unanimously approved the recommendations of a task force convened to address overcrowding: Pasco elementaries should switch to the new calendar to free up space and sixth grade would be moved from the middle to the elementary schools.

But after hearing from parents and staff during dozens of meetings held in the past weeks, district staff asked that the new schedule be delayed as long as possible. The board adopted that amendment to the original recommendation.

The move to a year-round calendar will not happen until at least the 2013-14 school year.

And the change won't automatically be districtwide. Rather, schools will move to the new schedule as they cross certain enrollment thresholds.

Tuesday's vote directed staff to move ahead in preparing for the drastic switch. But district officials were unable to say how much time parents would be given to prepare for the new calendar, should their children's schools switch to year-round.

Several Pasco schools are only a few dozen students away from the threshold to trigger the switch to year-round, a chart displayed during the meeting showed.

While these schools are the most overcrowded, almost all Pasco schools house more students than they were designed for.

Pasco's September student count almost was 15,500 -- about 500 more than last year. And that is good news by the standards of the fastest-growing district in the state. The district has been growing by about 700 to 800 students in recent years.

It convened a task force early this year to come up with solutions for its overcrowded schools. The group last month recommended that the district create K-6 elementary schools, with only seventh and eighth grade remaining in middle schools.

The K-6 elementaries should shift to a 60/20 schedule a year after they pass a certain enrollment threshold, the task force said.

Going to a 60/20 schedule means a school's students are split up in four groups. Students go to school for 60 days, stay home for 20, go to school for 60, and so on. The state-mandated 180-day school year remains intact, but is broken up differently. There is no more long, shared summer break.

The trick is that the four groups go to school on staggered schedules, so that only three-fourths of all students are in class at the same time. This creates 33 percent more school capacity.

Parents and teachers have voiced their concerns in the many meetings held since the task force made public its recommendation last month. The new calendar might disrupt family vacations, because kids in secondary schools would remain on the traditional school calendar. Pasco teachers whose children go to school in another district also would be affected.

Many attending the meetings asked if the money to run the more-expensive calendar would be well-spent.

District officials for the first time announced cost estimates for the plan Tuesday. It would cost up to $260,000 more per year to run an elementary on a year-round schedule, said John Morgan, director of operations.

In addition, additional annual costs of close to $1 million for buses, food and other support services would arise districtwide if most of the elementaries were on the new schedule.

There is money in the operating fund now to pay for costs associated with overcrowding, Morgan said. That money would cover the extra costs caused by switching calendars.

The district has surveyed parents in recent weeks. A vast majority of those who responded to the poll wanted the district to run another bond levy as soon as possible. Voters in April rejected a property tax increase to build new schools in Pasco.

Some 80 percent of respondents said that impact fees should be paid by new housing developments in the district.

And three-fourths of those who took the survey said they want more portable classrooms set up in the district to delay the switch to the new calendar, Morgan said.

That's exactly what the district is doing now. Staff recommended that multi-track year-round be delayed as long as possible, by using as many portables as schools possibly can, having students eat lunch in their classrooms, sharing gym space between elementaries and middle schools, and overall trying to squeeze as much use out of existing space as possible.

The new schedule couldn't be put in place by next school year, Morgan said. "It takes nine months to one year to pull this off," he told the Herald after the meeting. "Everybody we talked to said, 'Don't do this unless you absolutely have to.' "

Tuesday's vote authorizes Morgan's staff to develop the plan to switch over, he said. But to actually switch a school to the new schedule would require another vote by the board, Morgan said.

And it's unclear when such a vote could come, or how much lead time parents would get once a school's enrollment is high enough to switch schedules.

For example, James McGee Elementary is 23 students away from its year-round threshold, Morgan said. It has room for one more portable on its grounds.

District staff will keep the board constantly updated on enrollment figures, but it will be up to board members to decide when the first school in Pasco would switch calendars, Morgan said.

He declined to say when the cut-off for such a decision might be, given that staff and parents need up to one year before the beginning of the school year to adjust to an upcoming switch.

"Our goal is let parents know as soon as we possibly can," he said.

Also Tuesday: The board voted against a petition from a group of families in rural Franklin County for their properties to be permanently transferred into the Pasco School District from the North Franklin School District.