Lawmakers in Arizona are debating whether special high school districts for vocational education that are springing up around the state have become too much of a good thing, thanks to rising costs for taxpayers.

Pending legislation would slap a two-year moratorium on expanding or forming joint technological education districts while lawmakers study the big picture.

“It’s a budget issue,” said the bill’s sponsor, House Appropriations Chairwoman Laura Knaperek, R-Tempe.

The Legislature originally authorized the special technology districts in a 1990 law. Since then, eight districts have been established, serving a total of about 4,000 students and offering courses in such fields as digital imaging and video production.

The tech districts levy a local property tax with voter approval but also get per-student funding from the state. The state’s tab has risen from $3.8 million in 1998 to an estimated $14 million this year.

Because many students only attend tech schools part-time to take vocational courses while taking other subjects at their home high schools, there’s an overlap of enrollment, which means the state pays more for such students than regular high school students.

Knaperek said she’s questioning both that and how some of the newer tech districts funnel money to existing high schools without building a separate campus.

These districts are “getting the extra amount of money … for keeping the students right on campus and in some cases providing the same services to the child as they had originally,” Knaperek said.

The tech districts, Knaperek said, were intended to have freestanding buildings or campuses. But that’s not realistic for rural technology districts, where low population densities dictate that technology facilities and equipment be located at existing schools, said Sen. Pete Rios, D-Hayden.