David Roberti, state Integrated Waste Management Board member and a former state senator from the San Fernando Valley, said he is launching an investigation to try to find out how much radioactive material has been deposited at the Bradley Landfill in Sun Valley.

Authorities recently discovered that Rocketdyne has been sending construction debris such as concrete and metal, and soil to the Los Angeles County landfill without the knowledge of local regulating authorities.

Landfill operators said they were unaware of the potentially contaminated shipments. Rocketdyne began cleanup of the nuclear and rocket research facility in the hills above Simi Valley a decade ago.

"Municipal landfills are not set up to be repositories for radioactive waste," Roberti said.

Boeing spokesman Dan Beck said the items taken to the landfill had been cleared by the Department of Energy and the Department of Health Services before they went to the site.

"There may have been some minimal radioactivity, but it was cleared for shipment," Beck said.

He said the company sends contaminated waste to approved toxic waste sites and was uncertain what other local municipal landfills might have been used.

Frank Kiesler, manager of the Simi Valley Landfill and Recycling Center, said Rocketdyne had not deposited any items there, and he had turned down requests from contractors doing work at the site.

Roberti maintains that even low levels of radioactivity or contamination are unacceptable for public landfills in populated areas, and he is concerned about migration of toxicants through ground-water and various materials.

"There is only so much radioactivity a body can take. It's cumulative," Roberti said.

Officials from the state Department of Health Services said the current regulations cap acceptable levels of radioactive waste in municipal landfills at 25 millirems. Kevin Reilly, DHS deputy director for prevention services said that standard had been adopted by 49 states.

Critics say exposure up to 25 millirems is the equivalent of an additional 300 chest X-rays in a lifetime, which can cause fatal cancer in one out of every 1,000 people. Reilly did not dispute that comparison, but said there are many factors to be considered in the mathematical equation, such as body weight and dose of radiation.

Roberti serves on the state Senate Select Committee on Urban Landfills, chaired by State Sen. Gloria Romero, D-Rosemead. Two weeks ago, Romero introduced a bill that would ban radioactive debris from local landfills. Debris from those sites, Romero fears, would be harmful to public health if recycled into neighborhood building projects or consumer goods.

The Rocketdyne controversy is now moving south to Los Angeles. Mayor Jim Hahn announced Tuesday the city would conduct a full investigation of the materials deposited at the Bradley Landfill. Expressing concern that cleanup of the Rocketdyne site is affecting Los Angeles residents, Councilman Nate Holden will conduct an environmental committee hearing regarding the issue at 3:30 p.m. Tuesday at Los Angeles City Hall.

Officials say the high cost of disposing of contaminated waste may be an incentive for illegal dumping. Fees for dumping waste in municipal landfills is $30 to $40 per ton, while fees to dispose of toxic waste are $100 to $300 per cubic foot.

To remove radioactive waste from landfills, Roberti said, the state will "err on the side of public health."

-- Roberta Freeman's e-mail address is rfreeman@insidevc.com .