SACRAMENTO — Capping a six-year legislative battle, the Assembly on Wednesday sent to Gov. Arnold Schwarzenegger a bill that would require the Boeing Co. to clean its Santa Susana Field Laboratory site to the highest environmental standards before the land can be developed.

The measure was approved on a bipartisan, 49-29 vote, and was supported by all the members whose districts surround the site. Ventura County Assemblywoman Audra Strickland, R-Moorpark, who is home expecting to give birth any day, had a statement of support read on the Assembly floor.

Assemblywoman Julia Brownley, D-Santa Monica, also supported the bill. "This will protect the community from Boeing selling the property and having it developed until it's cleaned up to the highest standards," she said. "This is a really toxic place."

The 2,849-acre property in eastern Ventura County is the home of a laboratory established in 1946 and has been the site of rocket engine tests and nuclear energy research. It housed a nuclear reactor that experienced a partial meltdown in 1959.

A cleanup program conducted by Boeing, the federal Department of Energy and NASA is under way as environmental studies continue. The work is being overseen by the state Department of Toxic Substances Control.

Boeing Co. spokesman Dan Beck said the company was disappointed in the bill's passage.

"We had been working hard to find a way to continue to clean up the site in a thorough and timely manner that was in the best interest of the state and public," Beck said. "We are going to continue to work with all of the appropriate agencies to keep moving forward with the cleanup of the site and the proper disposition of the property."

Sen. Sheila Kuehl, D-Santa Monica, has tried repeatedly to get similar legislation approved. This year, she said, supporters finally convinced a majority of lawmakers that "we're not making this up. People don't remember the cowboy days of nuclear reactors. They can't believe this is real."

Brownley said she hopes the support of seven Republicans — six who voted for the bill and Strickland — will help convince Schwarzenegger that the effort has bipartisan support and should be signed.

A spokeswoman for the governor said the administration has not yet taken a position on the measure.

Kuehl said she has requested a meeting with Schwarzenegger to discuss the issue. "I think the governor is being lobbied very, very aggressively by Boeing," she said.

Assemblyman Cameron Smyth, R-Santa Clarita, whose district includes much of Simi Valley, said he spent much of his summer recess touring the site and talking with people on both sides of the issue.

"I couldn't come up with a logical reason to oppose the bill," he said.

Local activists who have long lobbied for strict cleanup legislation said they were pleased with Wednesday's vote.

"I can't begin to tell you how happy I am," said Christina Walsh of Canoga Park. "The evidence is speaking for itself."

The measure was supported by the boards of supervisors in Ventura and Los Angeles counties and by the Simi Valley City Council, which weighed in for the first time this year.

"It falls in line with Simi Valley's position that public safety is paramount for us," said City Councilman Glen Becerra.

Daniel Hirsch, a co-founder of the nuclear watchdog group Committee to Bridge the Gap, said the bipartisan cooperation among area legislators was the key to putting the measure over the top after years of failure.

"If you're persistent, it shows that even the weak and the powerless can overcome a big corporation," he said.

Schwarzenegger will have 30 days after the Legislature adjourns to act on the bill. Lawmakers are expected to adjourn for the year sometime next week, no later than Friday.