A thousand acres of the Santa Susana Field Laboratory may become parkland as early as 2009, Boeing Co. officials said Thursday.

The land, which sits on the southern border of the 2,850-acre facility in the hills south of Simi Valley, is a buffer zone and was not used for operations at the former nuclear and rocket engine test site.

Its use as parkland would require the determination by state regulators that the contaminated site is clean enough to be released for public use.

A week ago, Boeing announced its intention to transfer 2,400 acres of the field laboratory to the state after the property is cleaned. The land would be restricted to use as parkland, open space and recreational activities.

The announcement coincided with Gov. Arnold Schwarzenegger signing into law a bill, SB990, that prohibits the release of the field laboratory for any use unless it is cleaned to the strictest of cleanup standards.

However, the standards in the new law would be voided by an amendment carried by its author, Sen. Sheila Kuehl, D-Santa Monica, once Boeing Co. and the state strike a binding agreement on the land transfer.

The binding agreement would set standards agreed to by Boeing officials and two state regulatory agencies. The land would be cleaned to a level appropriate for residential use.

"In order for there to be a transfer to the state — a gift to the state — that condition, that standard in SB990 needs to be changed," said Steve Barker, president of Boeing Realty.

Activists have derided the agreement between the state and Boeing, and the proposed amendment, which would require the Legislature's vote.

"What they want to do is ignore the new law and do no additional cleanup whatsoever, and we won't let that happen," said Dan Hirsch of the nuclear watchdog group Committee to Bridge the Gap.

"We will deliver on what we promised," said Tom Gallacher, Boeing's director of environment, health and safety. That standard is stricter than what is required as open space.

Gallacher said it would be impossible for the company to clean the site to the level called for in Kuehl's bill, which is the level set for Environmental Protection Agency Superfund sites.

"Based on technology we cannot meet the standard for all isotopes," he said. "It makes it unachievable for us."

Environmental watchdogs disputed Boeing's assertions.

"These are EPA standards set across the country so there is no reason they couldn't meet them," said James Birkelund of the National Resources Defense Council.

Discussions about the future of the site began in earnest about 18 months ago, when it became clear that NASA would be wrapping up its operations at the field laboratory. The space agency owns 450 acres at the site, and the land transfer applies only to the acreage Boeing owns.

Conversations between Boeing and the state began earlier this year.

Additional pieces of the land would be released for park use as they are cleaned and given approval by the state.