Treasure Island is slated to become a mixed-use community for 20,000 residents, once the U.S. Navy can satisfy regulators that it has cleaned up the former base’s Cold War legacy of chemical and radioactive toxins.Anna Vignet/Center for Investigative Reporting

Land slated for development on Treasure Island contains elevated concentrations of cesium-137, a byproduct of nuclear fission associated with an increased risk of cancer, according to an independent analysis commissioned by the Center for Investigative Reporting.

The findings, discovered through soil samples gathered by reporters and tested by two independent certified laboratories, appear to undermine some past statements by the U.S. Navy about the land’s historic uses and the present condition of the island.

Results show cesium-137 levels up to three times that previously acknowledged by the Navy and at least 60 percent higher than the Navy’s own thresholds for environmental safety.

“The questions raised by your testing should be fully vetted by the Navy,” said Gary Butner, former chief of the radiologic health branch at the California Department of Public Health, who was a state watchdog for the Treasure Island cleanup until he retired in 2011. “I just don’t have a sense there’s a strong commitment to go and (clean) the site. They just don’t want to spend any money there.”

Exposure to cesium-137 “can result in cancer risks much higher than typical environmental exposures,” according to the federal Environmental Protection Agency.

The concentrations discovered by CIR do not necessarily confirm a health hazard, according to Jan Beyea, a prominent nuclear physicist specializing in the health effects of low-level radiation. They are no greater than common contamination worldwide from 20th-century nuclear fallout.

But, Beyea said, the unexpected finding should prompt a more thorough evaluation of the island for potentially hotter spots.

“The fact that there is a level above standards is a clear mandate for further study and assessment of the extent of contamination and its origin,” Beyea wrote in an email, adding that more systematic testing is particularly important given that public play areas are planned nearby.

“Building a playfield is not an appropriate plan at this time,” he wrote, “given the tendency for little children to put things in their mouths.”

Reporter Katharine Mieszkowski carries buckets containing carefully separated soil samples from Treasure Island, which later were tested at two independent certified radiation labs.Anna Vignet/Center for Investigative Reporting

CIR shared the test results with the Navy, City of San Francisco, and state Departments of Public Health and Toxic Substances Control, requesting interviews with experts involved in the Treasure Island cleanup. All four responded with statements.

The Navy said the test results did not warrant action.

“Such limited data taken out of context doesn’t provide much value in determining site conditions or making programmatic decisions,” wrote Keith Forman, the Navy’s Treasure Island cleanup coordinator.

Michael Tymoff, San Francisco Mayor Ed Lee’s Treasure Island development director, said CIR’s findings provide no reason for the city to take action.

“The city has no basis to comment on the validity or accuracy of the tests,” he said.

The Department of Public Health said it “does not comment on research conducted by others.”

However, the Department of Toxic Substances Control, which oversees the Navy cleanup, said in a statement that it had to review the findings and would work with the Public Health Department “to determine what it means and where we go from here.”

Butner and other state radiation specialists have for years complained in emails, reports and memos that the Navy has been reluctant to test for fission byproducts such as cesium-137 – despite a Cold War history suggesting the possibility of such contamination.

Instead, the Navy has focused on radium-226, used for glow-in-the-dark ship deck markers and gauges commonly discarded at military bases during the mid-20th century.

The distinction is significant: If Treasure Island were contaminated only with radium, that would be consistent with the former base’s public face as a way station and barracks for sailors on their way to the Pacific. Potential contamination by fission byproducts such as cesium-137, however, points to possible aftereffects of Treasure Island’s more guarded history: host to radioactive ships from Bikini Atoll atomic tests and a major education center training personnel for nuclear war.

Butner said the Navy’s didn’t look for all the waste that might have been left behind during the base’s Cold War years.

“Instead of going out and surveying the ground for everything, they said, ‘OK, this is what we’re looking for, and we’re not looking for cesium, for thorium,’ ” he said. “The federal government’s motivation is to keep moving forward and not ask many questions.”

Until the early 1990s, the U.S. Navy operated atomic warfare training academies on Treasure Island. Some radioactive materials were stored in and around a mocked-up nuclear war training ship, the USS Pandemonium.U.S. Navy photo

Cold War legacy

The CIR-commissioned findings bolster criticisms, contained in hundreds of pages of internal emails and memos from specialists at the state Public Health Department, that accuse the Navy of failing to adequately inspect Treasure Island for radioactive waste and of perhaps minimizing its Cold War legacy to more swiftly sell off the former base.

The Navy repeatedly has rebuffed health officials’ demands that Treasure Island be thoroughly vetted for radioactive contamination – a multimillion-dollar job – before it is made available for a planned high-rise development.

The Navy stands to receive more than $100 million from San Francisco for the base, provided the military performs a satisfactory cleanup of chemical and radioactive waste.

Until the early 1990s, the Navy operated atomic warfare training academies on Treasure Island, using instruction materials and devices that included radioactive plutonium, cesium, tritium, cadmium, strontium, krypton and cobalt. These supplies were stored at various locations around the former base, including supply depots, classrooms and vaults, and in and around a mocked-up atomic warfare training ship – the USS Pandemonium.

CIR’s samples were taken from under a palm tree 50 feet from a classroom building where cesium-137 was kept, according to military archives. A 1974 radiation safety audit identified cesium samples used and stored there with radioactivity several times the amount necessary to injure or kill someone who mishandled them. In 1993, shipping manifests from the same building showed even greater amounts of cesium-137 taken away from the same site that year.

Areas of concern on Treasure Island

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Minute amounts of cesium-137 can contaminate broad areas. When a Spanish steel mill in 1998 accidentally incinerated an amount less than that stored in the Treasure Island classroom building, the smoke plume deposited detectable radioactive material hundreds of miles away.

The concentrations found in the CIR-commissioned tests represented mere trillionths of the quantities once stored nearby. It’s exposure to low-level radioactive contamination, however, that researchers have linked to cancer risk.

Classroom materials aren’t the only potential source of the Treasure Island cesium-137 contamination, either. Treasure Island ran a salvage and repair operation during the Cold War years when the West Coast was crowded with ships crippled and made radioactive from atomic tests, according to documents in military archives.

The base was opened for civilian use in 1996, including the leasing of former military housing to 2,000 civilians. Then in 2011, San Francisco approved plans for a 20,000-resident redevelopment project, estimated to cost $1.5 billion.

Lee, the city’s mayor, traveled to China last week to try to consummate a deal for China to loan $1.7 billion to Lennar Corp. for development at Treasure Island and the former Hunters Point Naval Shipyard. News reports Thursday said the deal fell through after the Chinese government insisted on greater control over the project.

At Hunters Point, the Navy long denied the presence of significant radioactive contamination. But in 2001, journalist Lisa Davis of SF Weekly reported that radioactive material had been mishandled during 1940s and 1950s decontamination operations and during experiments at the former base’s Naval Radiological Defense Laboratory. Congressional leaders eventually pressed for a full cleanup, delaying development plans there.

Reporter Matt Smith extracts soil near what was once the radiation exposure room at Treasure Island’s former RADIAC Instrument Maintenance School, closed by the U.S. Navy in 1993.Anna Vignet/Center for Investigative Reporting

Testing the soil

Critics maintain that Treasure Island’s radioactive cleanup would have been completed long ago had the Navy fully acknowledged potential contamination when testing began in 2007.

As recently as March, state public health workers were unearthing new radiological contamination on Treasure Island. A crew spent about 5½ days checking for radioactivity in publically accessible areas, backyards and front yards in a section of the island where residents live.

They found five locations with elevated radiation levels, according to Gonzalo Perez, chief of the department’s radiologic health branch.

One of the buildings on the parcel surveyed by CIR was identified in a 2012 Navy historical study as potentially contaminated with cesium. But the Navy argued in internal reports to state regulators that there was no cause for concern.

The Navy told state regulators in a June memo that “not one soil sample collected from Treasure Island” had worrisome concentrations of cesium-137. 

CIR’s new findings, based on surveys with sensitive radiation detection equipment followed up with soil sample tests at two radiation laboratories, throw into question those assertions.

Soil tests by Eberline Services showed cesium-137 contamination of 0.180 picocuries per gram. Tests of the same samples by New World Environmental, a former Treasure Island cleanup subcontractor, showed higher levels: up to 0.315 picocuries per gram. A picocurie, or one-trillionth of a curie, is a standard measure of the intensity of radioactivity in a sample of material. The differences between the two labs’ results are within the statistical uncertainty inherent in testing low-level radiation.

Last April, the Navy reported that it had conducted 200 soil tests and that the greatest concentration of cesium-137 it had found on Treasure Island was 0.104 picocuries per gram.

Both of the CIR-commissioned lab results also exceeded the Navy’s threshold for releasing land for development at Treasure Island: 0.113 picocuries per gram.

The Navy first established that threshold while cleaning up its property at Hunters Point. That level is at the low end of average global fallout contamination, meaning that Hunters Point, cleaned up to those established levels, actually is less radioactive than much of the San Francisco Bay Area.

The site of the cesium-137 contamination found by CIR is now a grassy lot frequently traversed by teenagers. Development plans call for construction of an apartment complex called Eastside Commons, wetlands, ballfields, tennis courts and grassy play areas on the surrounding land. Five years ago, the Navy and state regulators declared the classroom buildings there to be noncontaminated, clearing them for future development.

Concerns about the Navy’s work detecting and cleaning up radioactive waste on the island have been festering since 2006. A Navy historical analysis that year suggested there was little to indicate the former base contained significant radioactive waste.

The next year, New World Environmental was hired as a subcontractor to survey the island and found significant radioactive contamination in areas where it shouldn’t have been. One worker received such a high dose of radiation that he was removed from the job. That worker, Robert McLean, was not surprised by CIR’s findings.

“Until you find it, they don’t admit that it is there,” he said. 

This story was edited by Amy Pyle and copy edited by Nikki Frick and Christine Lee.

Matt Smith is a reporter for Reveal, covering religion. Smith's two-decade career in journalism began at The Sacramento Union in California. He went on to positions at newspapers in Albuquerque, New Mexico; Twin Falls, Idaho; Fairfield, California; and Newport News, Virginia. Between 1994 and 1997, Smith covered Latin America as a reporter in Dow Jones & Co.'s Mexico City bureau. For 14 years, he was a lead columnist at Village Voice Media in San Francisco. He came to Reveal from The Bay Citizen. Smith holds a master's degree from the Columbia University Graduate School of Journalism and a bachelor’s degree in political science from Reed College in Portland, Oregon. Before his career in journalism, Smith was a professional bicycle racer. He is based in Reveal's Emeryville, California, office.

Katharine Mieszkowski

Katharine Mieszkowski is a senior reporter and producer for Reveal. She's also been a senior writer for Salon and Fast Company. Her work has appeared in The New York Times, Rolling Stone, Mother Jones, Slate and on NPR's "All Things Considered."

Her coverage has won national awards, including the Alfred I. duPont-Columbia University Award two years in a row, an Online News Association Award, a Webby Award and a Society of Environmental Journalists Award. Mieszkowski has a bachelor's degree from Yale University. She is based in Reveal's Emeryville, California, office.