A highly radioactive object has been discovered at the former Hunters Point Naval Shipyard next to a housing area that has been declared safe and free of radioactive contamination for more than a decade, The Chronicle has learned.
The finding is the latest problem at San Francisco’s most ambitious redevelopment project in a century — an effort to transform a 500-acre Superfund waste site into a bustling waterfront neighborhood of 12,000 homes.
The object — a radium deck marker about the size of a silver dollar, 1½ inches across — was unearthed Tuesday on a grassy slope beneath a stretch of newly built condos, less than a foot below ground. The state health department revealed the information Thursday in a “Progress Update” letter sent to the shipyard homeowners’ association and obtained by The Chronicle.
The housing area is known as Parcel A. The California Department of Public Health is scanning it for radioactivity after revelations that employees of the Navy’s main cleanup contractor, Tetra Tech, faked radiation measurements in other parts of the shipyard. Parcel A residents and city officials demanded a test after whistle-blowers and media reports raised the possibility that some of those problems may have extended to Parcel A, where 300 housing units have been completed and an additional 150 are under construction.
The discovery of the radium device sparked an intense debate over its significance. Several government agencies argued that the object doesn’t pose any danger because it was found behind a fence, under 10 inches of soil, and quickly removed. Residents and activists disagreed, saying the device is meaningful because there is a long history of public officials saying it shouldn’t even exist.
The Navy posted a brief statement on its website, calling the deck marker “an anomalous reading.” The federal Environmental Protection Agency said that “due to its location and level of radiation, the object was not causing harm to residents or workers.”
The state Department of Public Health did not immediately respond to requests for comment. In the letter to homeowners, Mark Starr, the deputy director of environmental health, said that no further contamination was found in the surrounding soil. San Francisco Health Officer Dr. Tomás Aragón said in a statement that the city Department of Public Health has hired an independent expert to analyze the object.
“We are confident that the Parcel A site is safe and that the object that was found poses no risks to the residents or workers there,” he said.
Radium deck markers contain glow-in-the-dark paint made of radium 226, a poisonous radioactive substance that causes bone cancer. The Navy once used large quantities of radium paint to illuminate the base at night and to light up the dials of instruments. Because radium 226 is so long-lived, with a half-life of 1,600 years, radium devices from the 1940s will still be radioactive thousands of years from now.
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