TACOMA — The state superintendent’s office estimates that the cost of administering the Washington Assessment of Student Learning could jump by $15 million to $25 million in 2009.

That’s on top of the $22 million originally budgeted.

The increase is being driven mainly by a higher demand for testing because of the federal No Child Left Behind education law, said Joe Willhoft, an assistant state superintendent of public instruction in Olympia.

Sen. Rosemary McAuliffe, D-Bothell, chairwoman of the Senate Education Committee, said paying $47 million for one year of testing is not an option.

Instead, state leaders are pressing for changes they say would shave millions off the cost and cut the amount of time spent testing without diminishing the accuracy of the WASL.

The savings would come primarily from chopping the number of open-ended, thought-provoking questions and delaying some extra features. And even then, the tests would still cost an extra $15 million or so.

State Superintendent Terry Bergeson’s office had already considered reducing the number of questions that require students to write out their answers or show their work on math problems.

Those so-called “open-ended” questions are time-consuming and costly to grade but are designed to determine how well students understand the material.

Gov. Chris Gregoire had staff check to make sure reductions in open-ended questions wouldn’t diminish the results, said Judy Hartmann, an education policy analyst in the governor’s office.

Sen. McAuliffe said she supports the cuts.

“One of my goals was to create what I would call a mini-WASL,” McAuliffe said, and reducing the number of open-ended questions meets that goal in her mind.

“It’s not just about the cost savings, it’s really about trying not to over-test,” she said.

Even with the savings, the state school superintendent would need up to $17 million more from the state Legislature for additional testing costs and a few add-ons. The amount will be negotiated in the next two weeks as the legislative session wraps up.

The Senate budget sets the low mark with an $11.3 million increase, while the House budgeted $14 million and the governor proposed $17 million.

Other states are grappling with higher testing costs, too.

The federal No Child Left Behind law’s requirements for standardized tests have driven up demand in the past few years, and there are only a handful of major testing companies.

Administrators evaluate the cost of testing on a per-booklet basis.

This year’s cost is $17 per booklet. That’s expected to jump to $28 per booklet next year, then drop to $23 per booklet in 2010 after a balloon payment is made to the current contractor, Willhoft said.

The $23 tests are comparable to those under the previous contract, which ended in 2005, Willhoft said.

Mary Lindquist, president of the Washington Education Association, said the teachers union is concerned about the cost of the WASL and questions what the state is getting out of it.

“We certainly embrace the concept of having high standards for our students, we just question whether or not the WASL is the right tool,” she said.

The union has opposed the test, arguing that, among other things, the results don’t arrive in time for teachers to help students learn material. The tests also don’t indicate specific weaknesses, meaning teachers can’t target their lesson plans.

To address those concerns, two add-ons that likely will make the cut are quicker test returns and diagnostics that would help teachers and parents understand where students need improvement.