The Guardian reports that the US Navy withheld critical information about dangerous plutonium levels at San Francisco's Hunters Point Naval Shipyard for nearly a year before notifying city officials, raising serious questions about transparency and public safety.

The Navy conducted air quality tests in November 2023 that detected airborne plutonium exceeding federal safety thresholds at the 866-acre contaminated site. However, city officials and residents weren't alerted until late October 2024, an 11-month delay that has prompted accusations of a cover-up.

The contaminated area sits adjacent to residential neighborhoods with condominiums and a public park. The city has ambitious plans to redevelop Hunters Point with up to 10,000 housing units and commercial waterfront districts, making the contamination discovery particularly concerning for future residents.

Hunters Point served as a staging ground for nuclear weapons testing during the 1950s, when the Navy used the facility to decontaminate 79 ships irradiated during Pacific Ocean nuclear tests. This activity spread radioactive waste throughout the shipyard, leading the Environmental Protection Agency to designate it as a "superfund" site in 1989, a classification reserved for the nation's most polluted areas.

Nuclear experts estimate that approximately 2,000 grams of plutonium-239 remain at Hunters Point. This highly radioactive substance is among the most lethal materials on Earth, with inhalation of even one-millionth of an ounce causing cancer with virtually 100% certainty.

Navy's response under scrutiny

Michael Pound, the Navy's environmental coordinator overseeing the cleanup, apologized at a recent community meeting for the delayed disclosure. "On this issue we did not do a good job," Pound acknowledged.

However, the Navy has suggested the elevated plutonium reading may be erroneous. Navy officials claim a retest showed non-detectable levels and maintain that exposure levels remain safe. Yet public health advocates and attorneys remain skeptical, particularly given the site's troubled history.

Pattern of problems

This incident represents the latest in a series of controversies at Hunters Point. In 2023, the Navy and a contractor faced accusations of falsifying test results for strontium-90, another radioactive substance. The site also housed a secret Navy research laboratory where animals were injected with radioactive materials.

Jeff Ruch, senior counsel with Public Employees for Environmental Responsibility, told The Guardian that the Navy is attempting to avoid spending billions on proper cleanup. "It's been one thing after another," Ruch said, questioning what other contamination issues remain hidden.

EPA's role questioned

The EPA is overseeing the cleanup but faces criticism for inadequate oversight. The Navy claims 90% of the site saw no nuclear work, and the EPA isn't requiring radiation testing in those areas, despite radioactive material regularly appearing across the yard.

Steve Castleman, supervising attorney of Berkeley Law's Environmental Law Clinic, told the Guardian that litigation is underway, and claiming the government fails to meet strengthened cleanup standards. The EPA has requested all Navy data to independently verify findings.

Ongoing health risks

Residents already living in one developed parcel report cancer clusters and health problems they attribute to unremediated contamination. Proposed solutions include capping the property with just four inches of clean dirt, a measure critics say is insufficient.

Thousands of tons of radioactive sandblasting grit used during the 1950s cleanup operations were buried on site but never properly accounted for. "Where was it buried? The navy doesn't know and it doesn't want to look," Ruch said.

City health officials acknowledged the gravity of the situation in their October bulletin, stating that "full transparency with our communities and the department of public health is critical," while expressing deep concerns about the Navy's 11-month communication delay.