Perched high in the Simi Hills, right between the San Fernando Valley and Simi Valley, sits a 2,850-acre patch of land that looks, at first glance, like a beautiful California nature preserve. It isn't. Not exactly. It’s the Santa Susana Field Lab, and it’s arguably one of the most contaminated sites in the United States. If you live in Southern California, you’ve probably heard the name whispered in local news or seen the protest signs, but the sheer scale of what happened there—and what is still happening—is hard to wrap your head around. Honestly, it's a mess. A radioactive, chemical, decades-long mess.
Nuclear meltdowns don't just happen in places like Chernobyl or Three Mile Island. One happened right here in 1959.
Back in the Cold War era, the Santa Susana Field Lab was the Wild West of rocket science and nuclear energy. It was a place where NASA, Boeing, and the Department of Energy pushed the limits of what was possible. They tested the engines for the Apollo moon missions. They ran experimental nuclear reactors. It was cutting-edge. It was also, by modern standards, incredibly reckless.
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What Really Happened in 1959?
The big one was the Sodium Reactor Experiment (SRE). In July 1959, the reactor experienced a partial meltdown. This wasn't some minor glitch. A cooling blockage caused fuel elements to overheat and melt. For weeks, workers reportedly vented radioactive gases into the atmosphere to keep the pressure from blowing the whole thing apart.
The crazy part? The public didn't really know about the severity of it for years.
It wasn’t just one accident, either. Throughout its history, the site saw thousands of rocket engine tests. These tests used perchlorate, trichloroethylene (TCE), and a cocktail of other nasty chemicals. When they were done, they often just burned the leftover waste in open pits. It sounds insane now. Back then, it was just "disposal."
The Toxic Legacy Left Behind
So, what’s actually in the dirt? It’s a mix of radionuclides like Cesium-137 and Strontium-90, along with heavy metals and those forever chemicals we’re all worried about now. You’ve got plumes of TCE in the groundwater that are migrating. That’s the real fear for the people living in communities like Bell Canyon, Box Canyon, and the surrounding suburbs.
They worry about the dust. When the Woolsey Fire ripped through the site in 2018, the community went into a collective panic. State agencies like the Department of Toxic Substances Control (DTSC) insisted that no harmful radiation was released in the smoke. But local activists and some independent scientists weren't so sure. They pointed to the fact that plants absorb contaminants from the soil, and when those plants burn, the chemicals go airborne.
It's a classic case of "who do you trust?"
On one side, you have government agencies with their sensors and data sets. On the other, you have families who have lived near the Santa Susana Field Lab for generations and see what they believe are "cancer clusters" in their neighborhoods. Organizations like Rocketdyne Cleanup Coalition and Parents Against SSFL have been screaming for a full cleanup for decades. They want the soil scrubbed to "background levels"—meaning it should be as clean as if the lab never existed.
The Never-Ending Cleanup Battle
Why is this taking so long? Money and bureaucracy. Always.
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In 2010, the state of California and the federal government signed agreements (AOCs) that basically promised a gold-standard cleanup. Boeing, which owns the majority of the land, didn't sign those same strict agreements. They’ve argued for a "risk-based" cleanup. Essentially, Boeing wants to clean the site to a standard that is safe for "recreational use"—think hikers and park rangers—rather than "residential use."
The difference between those two standards is billions of dollars and millions of cubic yards of soil.
If you clean it to a residential standard, you have to dig up almost everything. If you clean it to a recreational standard, you leave a lot of the contamination in place and cap it. Environmentalists argue that leaving it there is a ticking time bomb for the groundwater. Boeing argues that hauling away that much soil would require a never-ending line of trucks driving through residential streets, creating a whole different kind of environmental nightmare.
The 2022 Settlement Agreement
Things got even more complicated recently. In 2022, the DTSC and Boeing reached a settlement that was supposed to "fast-track" the cleanup. The state touted it as a major win. Activists, however, felt betrayed. They claimed the new deal significantly weakened the cleanup standards compared to what was promised years ago.
It's a dense legal thicket.
The reality is that while some buildings have been torn down and some soil has been hauled away, the bulk of the heavy lifting is still in the future. We're looking at a timeline that stretches well into the 2030s, if we're lucky.
Health Concerns and the "Cancer Cluster" Debate
This is where things get really emotional. There have been several studies over the years trying to link the Santa Susana Field Lab to health issues in the surrounding area. A famous 1997 UCLA study found that workers at the site had increased rates of certain cancers. Another study by Dr. Hal Morgenstern suggested that people living within two miles of the site had a higher risk of certain types of cancers compared to those living further away.
But—and there’s always a "but" with science—other state-funded reports have been more ambiguous. They often conclude that while there is contamination, the "pathway" for it to reach the public isn't clear enough to definitively blame the site for specific illnesses.
If you’re a parent in Simi Valley whose child has a rare form of leukemia, those "ambiguous" reports don’t mean much. To them, the link is obvious.
What Most People Get Wrong About SSFL
One big misconception is that the whole place is a glowing radioactive wasteland. It’s not. Most of the site is actually stunningly beautiful, filled with rare plants and wildlife. It’s an important corridor for mountain lions and other animals moving between mountain ranges.
This creates a weird irony.
Because the site was closed off to the public for so long, it became an accidental nature preserve. Now, some groups are concerned that a "scorched earth" cleanup—digging up every inch of soil—will destroy the very ecosystem that survived the Cold War. It’s a delicate balance: do you destroy the mountain to save the people living at the bottom of it? Or do you leave the mountain alone and risk the chemicals seeping out?
Practical Steps for Concerned Residents
If you live near the Santa Susana Field Lab, or are thinking about moving to the area, you shouldn't just panic, but you should be informed. Here is the reality of how to handle it:
- Check the DTSC EnviroStor Database. This is the official state record. You can see maps of where the contamination is highest and read the actual technical reports. It’s dense, but it’s the primary source.
- Understand Your Water Source. Most of the water in Simi Valley and the San Fernando Valley comes from the Metropolitan Water District (imported water), not from local groundwater wells. Knowing where your tap water actually comes from can alleviate a lot of immediate fear about groundwater plumes.
- Dust Mitigation. If you live in the immediate vicinity, especially during fire season or high wind events, high-quality HEPA filters in your home are a smart move. This isn't just because of SSFL; it's good practice for anyone living in Southern California's "fire belt."
- Get Involved in Public Comment. The cleanup is still in the planning stages for many areas. The DTSC is legally required to hold public meetings. Go to them. Ask the hard questions. The only reason any progress has been made at all is because of relentless public pressure.
- Look into Independent Testing. If you are truly worried about your property, you can hire private firms to test your soil or air. Be warned: it’s expensive, and interpreting the results requires an expert who isn't trying to sell you a remediation service.
The story of the Santa Susana Field Lab is a cautionary tale about what happens when scientific progress outpaces environmental ethics. It's a reminder that once you let the genie out of the bottle—whether that genie is radiation or industrial solvents—it's incredibly hard to put it back in. The hills are quiet now, the rocket engines are silent, but the legacy of what happened there is still very much alive in the soil and the local memory.
Keep an eye on the DTSC’s "SSFL Cleanup" portal for the latest updates on the 2025-2026 soil removal schedules. Staying informed is the only way to cut through the noise of both corporate PR and some of the more extreme internet rumors. The truth of Santa Susana is somewhere in the middle: a beautiful landscape burdened by a very ugly history that we are still trying to scrub away.