How Boeing created a nature preserve that may also preserve pollution

The scientists and engineers of the Santa Susana Field Laboratory saw themselves as pioneers. Their work from the 1940s through the early 2000s helped put men on the moon and build missiles used to stare down the Soviet Union during the Cold War. They helped develop the first atomic reactor launched into space and operated one of the first nuclear plants to power US homes.

Santa Susana Field Lab scientists help design a lightweight nuclear reactor in 1964 to generate electricity in space.

Scientists use mechanical arms to conduct experiments in nuclear testing chambers in 1959.

This nuclear power plant under construction in 1956 at Santa Susana Field Lab later powered homes in a neighboring town.

But the innovation came at a cost.

Decades of unsafe pollution management created a health hazard that would endanger neighbors for decades to come.

Engineers mounted engines on platforms, then burned liquid rocket fuel in thousands of tests. Workers flushed engines with solvents that flowed onto the ground, eating away asphalt and draining into unlined ponds. Chemicals eventually contaminated groundwater and a nearby creek.

To get rid of waste, workers regularly burned it in open pits. They also fired rifles at barrels full of chemicals until they exploded, sending toxic plumes into the air.

Engines were anchored to platforms like these, shown circa 1960, so engineers could test their thrust and performance.

Night-time engine testing at Santa Susana Field Lab, such as this one in 1961, lit up the valley and could be heard for miles.

Employees who worked at Santa Susana in the 1950s and 1960s say waste disposal procedures included shooting barrels full of chemicals to make them explode, like in this undated photo.

And in 1959, operators pushed one of the lab's nuclear reactors past its limits, causing a partial meltdown of the core. Scientists later estimated that the amounts of some radioactive materials released in the incident exceeded those from the notorious Three Mile Island nuclear accident, which exposed an estimated 2 million people to small doses of radiation two decades later.

Today, chemicals and radioactive materials permeate the soil, groundwater and bedrock at the 2,850-acre Santa Susana property, about 30 miles northwest of downtown Los Angeles. Some pollution has traveled beyond the site, creating health concerns for more than a quarter of a million people who live within five miles.

A 2007 federal health study – conducted in response to neighbors' concerns – documented high rates of adult thyroid cancer, a disease tied to radiation exposure, within two miles of the site.

No government health studies have been done since then, but activists have documented at least 81 children and 74 adults with cancer living within 20 miles of Santa Susana. Activists showed Reuters extensive evidence to support the tally, including medical documents, news stories, photos and links to fundraisers, as well as the obituaries or memorials for 12 children.

After a 2018 wildfire on the property, scientists conducted a peer-reviewed study in 2021 that found radioactive ash at homes and on public land as far as nine miles away. Government and independent testing found contamination from Santa Susana at a neighboring children's camp, nearby parks and residential neighborhoods. Stormwater carries chemicals off the site, exceeding government limits.

Boeing Co, the National Aeronautics and Space Administration and the US Department of Energy share responsibility for the site – and they are on the hook to clean it up. Boeing assumed liability for a large portion of the property in 1996, when it acquired the previous co-owner, Rocketdyne. In 2007, Boeing signed an agreement with California to make 1,900 acres clean enough that people could live on the land and eat vegetables from their gardens.

But most of that cleanup never happened. Now, Boeing is pursuing an unorthodox strategy that could enable it to bypass cleaning up much of the land . The company is using a legal agreement meant to preserve nature to argue that it should be allowed to leave much of the pollution untouched.

The aerospace giant donated the property's development rights to a land trust under an arrangement known as a "conservation easement." Such easements, which restrict building, are intended to preserve open space, protecting scenic vistas, wildlife habitat and cultural heritage.

Boeing has held up the donation as an example of its commitment to environmental stewardship. In its 2018 annual environmental report, it quoted Stephen Thor Johnson, then president of its partner in the easement deal, the North American Land Trust (NALT). "The value of this open space," Johnson said, "will be magnified over the coming decades and be remembered as a truly visionary act like the creation of Central Park or the conservation of the Presidio."

Left unsaid was how Boeing stands to benefit. Within a month of donating the easement to NALT, Boeing told the state of California it no longer intended to make the property clean enough to live on. Because the easement prohibits building on the land, the company said, Boeing instead intended to make the property safe for light recreation, such as hiking. That lesser standard would leave the vast majority of chemical pollution in the ground and shave at least tens of millions and perhaps hundreds of millions of dollars off the company's cleanup costs, according to a Reuters analysis of the proposed cleanup standards and soil sampling data. Four independent cleanup specialists vetted the analysis.

California rejected Boeing's argument that the conservation easement warranted a lesser cleanup, but to avoid a lawsuit and further delays, the state reopened negotiations with the company anyway. Boeing has won a preliminary victory in getting the state to consider new cleanup scenarios, including some that take the easement into account. All of the new options would leave more pollution behind than the cleanup the state approved years ago, according to a Reuters review of the company's latest agreement with the California Department of Toxic Substances Control (DTSC).

Boeing's strategy angers Jen Connell, who lost her husband, Mike, in April to glioblastoma, an aggressive brain cancer. He lived most of his 50 years within five miles of Santa Susana's rocket-testing platforms and blamed radioactive ash from there for his disease. Radiation is known to increase the risk of glioblastoma.

"What about preserving human life?" said the mother of two. "They got a smoke screen going on to make them look like they have a halo."

Boeing, in a statement to Reuters, said it is "misleading" to say that it is using the conservation easement to limit cleanup at Santa Susana. Boeing noted it has agreed to clean up one type of contaminant – radioactive material – to levels present before the field lab existed. Though its agreement with California expresses Boeing's preference to clean up other contaminants to the safe-for-recreation standard, the company also noted it has agreed to accept whatever cleanup the state chooses, including a stricter option that would make the site safe for homes and gardening. State officials told Reuters they intend to require this.

Still, state officials acknowledged that all the options outlined in the new Boeing agreement would clean up less soil than called for in the old one. In a written response to Reuters, they said the changes reflected the state's use of "best available science." Regulators will hold Boeing to the same health protections required previously, they wrote, and the easement will not influence their choice of a cleanup option.

'Foolish'

The idea of using a conservation easement to lobby for a lesser cleanup of polluted land rankles James Florio, the former US representative who authored the Comprehensive Environmental Response, Compensation, and Liability Act of 1980. Congress passed the act, commonly known as the Superfund law, to require companies to clean up their toxic messes. Easements shouldn't be used as an excuse to leave pollution behind, Florio said.

"Saying you're not going to clean it up because it's not going to do any harm, because it's not going to be used, is foolish," he said.

Yet dozens of companies across the United States have benefited from the strategy. And the country's top environmental watchdog, the US Environmental Protection Agency, is encouraging conservation easements on polluted land as a way to make contaminated sites useful again.

Conservation easements on contaminated sites

Because of decentralized record-keeping systems, no one knows how many conservation easements are on contaminated land. Reuters identified 40 mostly by scouring county land records and regulatory documents.

Reuters found conservation easements on at least 40 contaminated sites, including former landfills, mines, waste ponds and burn pits. Twenty-four of the locations are or have been in the federal Superfund program, which targets the nation's most toxic waste sites.

In each case Reuters uncovered, the easement contract notes the land's history of contamination. For at least 25 sites, Reuters found documents that acknowledge the safety of the cleanup relies in part on the conservation easement's promise to prevent development or other activities on the land. In at least six cases, state or federal regulators cited the easement's land restrictions as a reason to let polluters conduct lesser cleanups that left some contamination behind.

Meant to protect people from dangerous exposure to toxic substances, the easement arrangements rely on landowners, land trusts and developers to honor prohibitions on unsafe activity for as long as the danger remains. But Reuters found that these agreements and others like them are inconsistently enforced, lapses that can result in dire health consequences, legal and environmental scholars said.

Environmental monitoring reports show pollution is migrating from some of these contaminated sites and threatening neighboring communities. At others, contaminants endanger plants and animals. People have built homes, unwittingly or not, on or near properties that had restrictions similar to conservation easements, exposing them to contaminated water, toxic fumes and cancer causing chemicals.

The matchmaker

Some environmental regulators and cleanup consultants argue that easements can play an important role on polluted properties. Along with deed restrictions, zoning controls and other notices attached to land records, easements aim to ensure that people don't build on contaminated land.

Nor is it always possible to fully decontaminate polluted land. The cost can be out of reach. It also can be technically impossible or impractical.

"I wish there were endless resources to clean everything up," said Jim Kuipers, a consulting engineer who has worked on mine cleanups for decades. "The EPA's charge is to protect human health and the environment. It's not to restore to background or entirely pure conditions."

Regulators have long supported easements as a warning flag for future generations. Reuters found some dating back as far as 1991.

But that was never their intended purpose, scholars say. "Plunking a conservation easement on a property in lieu of cleaning it up is a perversion of the use of a conservation easement," said Nancy McLaughlin, a law professor at the University of Utah whose work focuses on the legal agreements.

Yet in recent years, the US Environmental Protection Agency, the regulatory body responsible for monitoring and approving cleanups of Superfund sites, has been encouraging companies to use easements to save time and reduce costs. The agency notes additional benefits: Preserving land can boost a company's image as a friend of the environment, and some can claim tax deductions for donating their polluted land.

Easements can "provide win-win-win opportunities for everyone and in many cases, also vulnerable species," the EPA told Reuters in a statement. The deals also can help companies "repair their relationship with the community."

The agency held a webinar in January 2020 called "The Brilliant and Profitable Role of Conservation Easements in Superfund Site Redevelopment."

"Never underestimate the value of a great story," Bill Denman, then EPA acting national program manager for Superfund redevelopment, told participants. "The environment wins, the community wins, the developer wins."

Denman has played matchmaker, looking to connect companies with land trusts willing to take easements on contaminated land. One ally is Kat West, a former EPA lawyer turned consultant who has called herself the "EPA whisperer."

West was a featured speaker at the January 2020 webinar. She contacted EPA regulators that month via email, saying she had spoken with NALT – the land trust that holds the easement on Boeing's Santa Susana property – about doing more work on contaminated sites. NALT was looking for new partners, she said.

"Steve Carter is the President and said we can send people directly to him," West wrote.

West arranged a call with Carter and the EPA's Denman. Soon, Denman provided Carter a new opportunity. In a February 2020 email, Denman introduced the NALT leader to a cleanup specialist from the multinational chemical company BASF to discuss a conservation easement on contaminated BASF land. The EPA told Reuters the conversation was meant to explore placing a conservation easement on the land to protect a bird habitat that had been created during a cleanup nine years earlier.

The EPA said the conservation idea never came to fruition. A BASF spokesperson said he was unaware of any ongoing discussions with NALT. West declined to comment.

Asked about the agency's promotion of conservation easements, the EPA described the deals as tools to ensure the future safety of a site, not influencers of its cleanup decisions. The EPA said it encourages adding easements after a cleanup method is chosen, not before.

An opaque system

Conservation easements gained prominence after the US Congress in 1980 created permanent tax breaks for them, to preserve "natural resources and cultural heritage."

It is impossible to know how many companies have placed conservation easements on contaminated land. Also unknowable is whether companies have sought tax breaks for such easements in the name of land conservation. That's because neither corporations nor nonprofits are required to disclose detailed information about the easements. The EPA and other regulators say they don't keep count or any central record of them. Tax deductions and land appraisals are private, and the United States keeps no comprehensive records of property conservation.

Reuters identified most of the 40 easements on contaminated land by searching for mentions in environmental regulatory documents and by reviewing land records in hundreds of US counties, where the easements are recorded along with property deeds. Beyond Boeing, major multinationals that have granted easements on polluted land directly or via subsidiaries include oil companies Chevron, BP, ExxonMobil and Citgo Petroleum, chemicals giant DuPont, aerospace contractor Lockheed Martin and drug maker AstraZeneca.

"Plunking a conservation easement on a property in lieu of cleaning it up is a perversion of the use of a conservation easement."

Nancy McLaughlin, a law professor at the University of Utah whose work focuses on conservation easements

Boeing and Chevron were among a handful of companies that said they did not seek tax deductions for their conservation easements. Citgo Petroleum confirmed it took a tax deduction but declined to disclose the amount. The others either declined to comment, didn't respond to inquiries or said they didn't know if they took a deduction. Reuters found 13 companies with easement contracts that refer to the section of the Internal Revenue Service code that allows for conservation-easement tax deductions, leaving the door open to claim them.

Even without claiming tax breaks, companies can realize significant financial savings by leveraging the easements in cleanup negotiations with regulators.

Companies save money because in choosing a cleanup plan, regulators consider how people might use the property in the future and what health risks the contaminants pose. The most expensive cleanups restore property to a pristine condition or make it safe enough for people to live there, drink the groundwater and eat food grown in home gardens. Less cleanup is required if the land is to be used for hiking or other recreation. Even less is necessary if a conservation easement allows little to no use of the property.

The savings can easily total tens of millions of dollars, said engineer Kuipers, who has consulted on dozens of cleanups and testified in court cases as an expert on cost estimates. For the largest and most contaminated sites, like Boeing's, he said, companies could save hundreds of millions of dollars.

EPA records show Chevron saved an estimated $45 million when the EPA approved a less costly cleanup for a Questa, New Mexico, site where Chevron once mined molybdenum, a metal used mainly in the construction and energy sectors. The agency cited a 2009 conservation easement as a reason to allow the company to make part of the site clean enough for industrial use rather than requiring it to make the land safe for housing.

The choice left 25 times more cancer-causing polychlorinated biphenyls (PCBs) in the ground than the most stringent cleanup would have allowed, EPA records show. The records also show that molybdenum, which had been found at levels 75 times higher than is safe for housing, was not required to be cleaned up at all in that section. Chevron provides bottled water to employees of a local fishery because the metal – harmful to people and wildlife in high doses – has been found in tap water there, according to a 2018 state and federal report about the site. A fishery employee confirmed that the company is still providing water today.

In an emailed response to questions, Chevron said the conservation easement supports the cleanup goals for the property. It said that the land is too steep for home construction and that the company is doing everything the EPA requires in its cleanup.

Boeing declined to answer questions about how much it stands to save if California allows it to scale back the cleanup at Santa Susana. State regulators said they have not yet estimated the costs of the various scenarios. "Based on similar cleanups, we expect the costs of cleaning up the Boeing areas of responsibility to be in the hundreds of millions of dollars," the regulators said.

A Reuters analysis of the state's various cleanup standards shows Boeing's cleanup could allow some chemicals to remain at levels tens, hundreds, and even thousands of times higher than previously promised.

Officials from the DTSC objected to the news agency's focus on the amount of pollution the cleanup would leave behind. What matters, they said, are the health standards driving the cleanup requirements. Those standards focus on minimizing the risk of cancer or other health issues.

State officials said they still intend to require Boeing to make the land safe enough to live on, even though the law requires them to consider other scenarios, some of which require less cleanup.

"DTSC has fought fervently for a clear path toward this high standard and will continue to do so until the cleanup is complete," they said in an emailed response.

Yet at Boeing's behest, the state has changed the way it calculates safety standards at Santa Susana.

A Boeing contractor urged DTSC officials to reexamine the formula that determines which parts of Santa Susana need to be cleaned up, state emails show. DTSC officials said they agreed because their previous calculations did not reflect the "best science." Under the state's revised formula, even the strictest cleanup DTSC is considering – one that allows homes on the property – would leave far more pollution behind.

Corporations and their partners who support the use of conservation easements say that even if some contaminants remain, the open land still provides viable wildlife habitat and green space for people to enjoy. If the land were fully cleaned up, some argue, those benefits would be lost because companies would sell the land to developers to recoup some of their cleanup costs.

If remaining contamination is properly managed, cleanup specialists said, sites can be used safely as parks, soccer fields, parking lots and more. Easements and other land-use restrictions can help conserve land worth preserving and protect people from the hazards that remain.

Some environmental scientists say the benefits to wildlife and the environment are often overstated.

Take Santa Susana. Boeing has said that the land preservation plan has "secured Santa Susana's bright future as open space habitat." The site is home to endangered plants and more than 150 types of animals.

Some of the cleanup options the state is considering would leave wildlife vulnerable to cancers and reproductive issues for decades, if not centuries, to come, said Frank von Hippel, a professor of environmental health sciences at the University of Arizona who reviewed the primary Santa Susana cleanup scenarios. Studies have linked many of the site's contaminants to animal tumors, cancers, and reproductive and immune dysfunction.

"If the property is not safe for people, then it certainly is not safe for much of the wildlife," von Hippel said.

State regulators said they would use Boeing's ecological risk assessments in evaluating the impacts on wildlife.

"The assertion that the cleanup will 'leave wildlife vulnerable' is incorrect," the regulators said in their response.

The use of conservation easements as protection for people isn't foolproof, either. The limits recorded in conservation easements, deed restrictions and other controls linked to property records can get lost with the passage of time. And history shows that can have devastating health consequences.

It was this very kind of public health disaster that spurred Congress to create the Superfund program in 1980 to require cleanup of the nation's most polluted lands. Congress was responding to a national outcry over children and adults sickened by pollution in the Love Canal neighborhood of Niagara Falls, New York.

The owner of a former chemical plant had sold to the Niagara Falls Board of Education – for a cost of $1 – land that the company had used as a dumping ground for more than 21,000 tons of toxic waste. Attached to the 1953 sale documents – and publicly filed at the Niagara County clerk's office – was a warning that the land contained dangerous chemicals and that the buyers assumed all liability, including risk of death. Though different from a conservation easement, the notice had the same intent: to warn people about the property's limitations.

Just a year later, the Board of Education, needing classrooms for a growing community, built an elementary school on the property. For more than 20 years, children splashed in contaminated puddles and played over leaking waste drums buried just beneath the surface. Several children required medical treatment for chemical burns on their faces.

After chemicals seeped into neighboring homes, the state declared a public health emergency in 1978. Pregnant women and children under age 2 were told to evacuate. The school was closed, at least 80 chemicals were identified at the site, and residents of the Love Canal neighborhood were instructed to stay out of their basements. More than 700 homes would eventually be razed.

Reuters found other examples of failed protections.

They included an abandoned battery recycling plant in Hamburg, Pennsylvania, where the EPA found chickens and cows grazing on contaminated land and drinking lead-contaminated water in 2012 in violation of a conservation easement. Lead contamination can transfer from cows and chickens to people who consume their dairy products. Reuters was unable to determine whether that occurred here.

In Newark, New Jersey, Ronson Metals Corp closed a decades-old factory that had made cigarette lighters. The company, with state permission, left hazardous chemicals – including trichloroethylene, which can cause neurological damage and has been linked to cancer – in the soil, covering the site with clay and crushed stone. It filed a deed restriction in 2002, limiting the land's use to non-residential purposes such as parking. Despite this, developers built 19 homes and five businesses on the land in the 2000s. After the state learned of the situation in 2012, it installed pumps to vent toxic fumes from residents' basements.

Conservation easements, in theory, carry more protection than the simple notice filed in the case of Love Canal. They require some entity – such as a government agency or a land trust – to accept responsibility for enforcement.

"Put quite simply, our goal is to leave places better than we found them."

Boeing, in a 2017 white paper on corporate conservation

The Land Trust Alliance, the primary association of land trusts, publishes best practices for land trusts overseeing conservation easements. They call for visiting the land at least once every five years. In intervening years, annual checks can be done from the air. In the event a land trust disbands, it should take "reasonable steps" to transfer conservation easements to other stewards.

NALT, the land trust that accepted Boeing's controversial easement, left the voluntary alliance because it disagreed with a 2019 policy change requiring member land trusts to review donors' tax appraisals, said Carter, NALT's president. NALT believed that policy conflicted with IRS guidance, he said.

NALT's holdings of more than 500 easements include others that have stirred controversy, including one on property owned by former President Donald Trump. That property is the subject of a tax fraud investigation by the New York attorney general. Trump denies wrongdoing and calls the probe a politically motivated witch hunt.

Since 2006, at least nine IRS disputes over NALT easements have ended up in US Tax Court.  The cases include some on golf courses with conditions that the IRS says run counter to conservation, such as strong chemicals used to maintain the greens and a border collie trained to chase away wildlife. The IRS also opened an audit of an investment group's 2018 tax return that included a $220 million deduction facilitated by NALT. The deduction relied on a practice lawmakers have labeled an "abusive tax shelter" that uses overinflated land valuations. Asked about the status of the case, the IRS said it could not comment on "pending litigation." NALT declined to comment.

Carter said the trust does not shy away from "messy" projects that fit its conservation mission.

NALT and Boeing declined to disclose the full terms of their deal. Carter said Boeing paid NALT a "pretty hefty" sum to monitor the Santa Susana site in perpetuity. Neither he nor Boeing would reveal the amount.

Asked what the monitoring would entail, Carter said NALT intends to visit the property at least once a year and will use drones and satellite imagery to help enforce the easement. Carter emphasized that NALT is not responsible for monitoring any remaining pollution and assumed no liability for the contamination.

Since granting the easement to NALT, Boeing has been promoting the deal on its website and in company reports as an example of its commitment to environmental stewardship.

In 2021, at a ceremony sponsored by Boeing, the Wildlife Habitat Council gave the company an award for its efforts to preserve the Santa Susana site. The nonprofit council, created by industry to promote corporate conservation, also listed Boeing as the sponsor of a 2017 white paper on corporate conservation, in which the company's director of environment, health and safety wrote: "In our pursuit of global environmental leadership, we champion the value of going above and beyond compliance. Our robust remediation and restoration program exemplifies this approach. Put quite simply, our goal is to leave places better than we found them."

Margaret O'Gorman, president of the Wildlife Habitat Council, declined to comment on the dispute over the Santa Susana cleanup, but called the site "an incredible asset for nature as one of the last open spaces in the Simi Valley." A spokesman for the council said its awards are based on scores determined by third-party reviewers.

Melissa Bumstead has been speaking out against such claims since learning about the Santa Susana pollution seven years ago.

The mother of two says she still regrets moving her family in 2012 to West Hills, less than five miles southeast of the Boeing site. Two years after they settled there, her daughter, Grace, was diagnosed with a rare form of leukemia at age 4.

Grace has spent much of her childhood in hospitals. With a weakened immune system, playgrounds, dance classes and even eating fresh strawberries proved too dangerous for her to enjoy. Two girls she befriended in treatment have since died.

After a relapse and bone marrow transplant in 2017, Grace, now 12, is in remission but must take growth hormone shots daily until she's 16 to counter side effects of treatments she's endured.

"I struggle with this now even though I know it's not my fault," Bumstead said. Grace's cancer is considered "one in a million," but there has been at least one other child diagnosed with the same rare cancer less than five miles from Santa Susana since Grace got sick, Bumstead said.

In 2005, Boeing paid $30 million to settle neighbors' claims that contamination from Santa Susana caused cancers and other illnesses, according to a plaintiff in the case. Boeing declined to comment on the settlement.

The 1959 nuclear reactor accident at the site may have caused hundreds, if not thousands, of cancer cases in neighboring communities, an advisory panel of scientists and other stakeholders concluded in a 2006 government-commissioned report.

A separate 2007 government-funded study found the area had an unusually high rate of thyroid cancers, and noted evidence that thyroid-disrupting contaminants from the lab had leaked into off-site groundwater. The scientists said there were too few cases to draw any conclusions about childhood cancers.

No government-sponsored research has been done since 2007, but activists say they have documented at least 81 children with cancer within 20 miles of the Boeing site. The cases include leukemia, rhabdomyosarcoma, Ewing sarcoma and aggressive and fatal brain cancers.

In response to questions, Boeing sent Reuters links to studies, reports, memos and a professor's slideshow that had mixed conclusions. Some did not find unusual cancer rates, while others found elevated rates only in some types of cancers.

Bumstead, who founded Parents Against Santa Susana Field Lab in 2017, said she sees Boeing's conservation easement as the latest in a long line of greenwashing tactics to avoid cleanup. Though none of the cleanup scenarios the state is considering would require a complete cleanup of the site, her grassroots group is determined to keep pressing for that outcome.

Jen Connell joined Bumstead's efforts and began tracking brain cancers in the area after her husband, Mike, was diagnosed in September 2020 at age 48 with glioblastoma, a rare and aggressive brain cancer linked to radiation exposure. Activists have documented at least 20 cases of the cancer within 20 miles of the former field lab. Half were diagnosed after the 2018 Woolsey fire that started at Santa Susana. Reuters reviewed fundraising posts, statements from relatives, and obituaries for some of the cases.

The couple was married for 20 years with two teenage sons. Mike lived all but two years of his life less than five miles downhill from the Santa Susana Field Lab. The other two were spent living near another toxic waste site.

Mike believed the 2018 wildfire stirred up radiation that caused his cancer. In his last Facebook post, five months before his death, he reflected on living in the shadow of Santa Susana and recalled playing near the field lab as a kid.

"We used to hear the rocket test motors daily," he said. "Those Rocketdyne hills have always been a hot spot over the years and now … the 2018 fires have spread all this existing mess across Simi Valley."

He passed away in his wife's arms on April 6th, after 19 months and three surgeries fighting cancer.

Companies are not alone in reducing their cleanup costs by declaring polluted land a conservation area and calling it a win for plants, animals and people. The US government does it, too.

Congress and the US military have shaved hundreds of millions of dollars off costly cleanups over the past three decades by declaring polluted government sites or land around them wildlife refuges.

The tactic is similar to that of corporations and other landowners, who use a different tool – a so-called "conservation easement" – to reduce cleanup costs on polluted land. Reuters found such easements on at least 40 contaminated sites, including former landfills, mines, waste ponds and burn pits.

One example of the government's use of this strategy: the Rocky Flats National Wildlife Refuge, near Denver, Colorado.

The refuge, home to elk, prairie falcons and hundreds of other plant and animal species, surrounds land targeted in a 1989 FBI raid that led to $18.5 million in environmental fines against Rockwell International Corp. The now-defunct contractor managed the federally owned nuclear weapons parts plant for the US Department of Energy.

Decades of poor safety practices tainted the area with plutonium, americium, uranium, and other contaminants. Plutonium, a radioactive element that can spontaneously combust, caused repeated fires and spread toxic smoke. Thousands of drums corroded, leaking radioactive waste into the soil. Winds scattered contaminated dust, and storms carried polluted runoff into creeks.

The federal government was responsible for a cleanup in the 1990s and early 2000s that included removing tons of weapons-grade nuclear material and solid waste and treating more than 16 million gallons of wastewater. That cost federal taxpayers $7 billion.

More contamination remained, much of it at the former plant. The Department of Energy was considering removing the plant's most toxic topsoil and sending it to radioactive disposal facilities. That option would have cost about $266 million, according to state and federal documents about the cleanup.

Congress helped cut the cleanup's cost. In 2001, lawmakers passed the Rocky Flats National Wildlife Refuge Act, establishing a wildlife refuge on about eight square miles surrounding the former plant. The US Fish and Wildlife Service now manages the site.

Congress excluded the most contaminated land around the plant from the refuge. Still, the act creating the refuge helped the federal government save more than $200 million on the cleanup of the adjoining property. Rather than removing most of the polluted topsoil, the DOE chose a cheaper $43 million option that left behind most of the contaminated dirt.

Key to the plan was the assumption that the only people near the former plant would be refuge visitors and workers, the government cleanup documents show. No one would live on the land, open businesses or drink the water.

In response to questions about the cleanup and remaining pollution, the DOE and the Fish and Wildlife Service referred to the government's cleanup decision, which found that it was safe to allow people to visit the refuge area without restrictions.

Rocky Flats was not the first contaminated government site Congress turned into a wildlife preserve. In 1992, lawmakers established the Rocky Mountain Arsenal, a former chemical weapons plant, as a national wildlife refuge. Federal cleanup documents describe the designation as an "integral component" in choosing the site's cleanup.

Eight years later, the Fish and Wildlife Service agreed to oversee Big Oaks National Wildlife Refuge, formed on most of Jefferson Proving Ground, a former munitions and weapons testing site in Indiana where the Army left behind about 1.5 million rounds of unexploded ordnance. The refuge includes the highest concentration of this ordnance, as well as 154,000 pounds of depleted uranium.

Although federal cleanup documents note the danger posed by the ordnance and high levels of heavy metals in the water and soil, the Army recommended no further scrubbing of the area because of its intended use as a preserve with restricted access. Most of the area remains closed to the public.

"Creating the refuge helped save hundreds of millions of dollars of taxpayer money, while ensuring the safety of personnel that would have been responsible for attempting to remove the high concentration and volatility of explosive munitions on site," the Army told Reuters in a statement. While cost is a factor in choosing a cleanup, it is not the only factor, the Army added. The Army has deferred studying further cleanup options because of physical dangers and continues to monitor the site to ensure human health and the environment are protected, it said.

Converting contaminated sites for conservation has pluses and minuses, said David Havlick, a professor at the University of Colorado, Colorado Springs, who researches the repurposing of former military sites. Areas that might have festered can be recycled to provide true ecological benefits and protections for wildlife, he said.

But declaring a refuge can also be the government "shirking their cleanup obligations," he said.

"There's an ambiguity to many of these sites, where it's hard to find the perfect solution," said Havlick.

The Rocky Flats refuge, 16 miles northwest of densely populated Denver, has been open to the public since 2018 along restricted paths. Today, the Fish and Wildlife Service website invites visitors to "take a nature escape!" and go hiking, biking and horseback riding.

Not everyone is convinced of its safety. Several school districts will not bring children there on field trips. And five local groups sued government agencies to block public access. A judge ruled in favor of the agencies last year, and the local groups have appealed.

The Colorado Hazardous Materials and Waste Management Division's website says that inhaling radioactive dust at the Rocky Flats refuge could cause cancer in rare cases but the risk is below one in a million.

A single unlucky breath can have enormous consequences, argues Marco Kaltofen, a civil engineer who conducts nuclear forensic investigations. Plutonium is rarely harmful outside the body, but poses danger if a particle lodges in the lungs, he said. Radiation can remain in lung tissue for decades, disrupting cell structures and causing cancers.

"In my view, the state is saying, 'Good news, only a few people will get cancer,'" Kaltofen said.

The US Fish and Wildlife Service told Reuters in an emailed statement that it is "confident in the results of the cleanup at Rocky Flats National Wildlife Refuge" and in federal and state public health findings that the refuge is safe and not considered polluted.

In response to neighbors' concerns, the Colorado Department of Public Health and Environment conducted studies in 1998, 2016 and an update in 2017. These studies did not find notably elevated cancer rates near the plant. Critics point to a 1981 report by the Jefferson County health director that focused more directly on downwind areas and found cancer rates 16% higher for those living closest to the plant.

"We know, and understand, people become concerned when they hear about new activities in the Rocky Flats area, which was once highly contaminated and does contain residual contamination; although within federal health standards," the Colorado Department of Public Health and Environment said in an emailed statement to Reuters. "Recent environmental testing has shown very low levels of plutonium in the area, and the risk from any potential exposure to that dirt and dust is well below health-based limits."

A 2021 wildfire that came within two miles of Rocky Flats highlights the potential risk that more contaminants could spread through smoke, said Michael Ketterer, a Northern Arizona University professor emeritus of chemistry and biochemistry who has studied the area at activists' request.

"Is this really a health risk? I can think of more serious ones," Ketterer said. "But in my mind it wouldn't be a good idea to be downwind of Rocky Flats when there's a lot of dust in the air or a wildfire with a plume of dusk and smoke."