The soil in Washoe Park, a public park in Anaconda, Montana, contains arsenic concentrations up to 3,800 parts per million, a level so toxic the federal government was forced to classify it under its most serious environmental emergency program, the Superfund.

How a Railroad Poisoned a Town

The Anaconda Smelter Superfund Site sits in the heart of Deer Lodge County, Montana. For generations, industrial operations by Atlantic Richfield Company (ARCO) and its subsidiary, Rarus Railway Company, deposited arsenic-laden material throughout the town’s railroad infrastructure. That material did not stay in the rail beds. It spread.

The EPA’s own findings confirm that the same arsenic-contaminated material used to construct railroad beds was scattered into adjacent commercial and industrial areas throughout the town of Anaconda. This means the poison traveled. It moved from the tracks into the ground under businesses, community corridors, and public trails.

The EPA’s 2024 amended order formally documents arsenic concentrations in historic railroad bed material ranging from under 250 to approximately 3,800 parts per million (ppm). For context: the EPA’s residential soil screening level for arsenic is typically around 0.39 ppm. The contamination found here is nearly 10,000 times that baseline threshold in the worst-affected spots.

The Sites Contaminated: Community Spaces Turned Toxic Zones

The specific sites named in the EPA order are not abstract industrial zones. They are places where people live their daily lives. The West Valley Railroad Spur, the Washoe Park Railroad beds, and the North Side Trail are explicitly identified as contaminated. Washoe Park is a public park. The North Side Trail is a walking path. These are spaces built for community use, and they sit on top of a carcinogen.

The commercial and industrial areas contaminated by arsenic spread are located near active railroad beds that run directly through the town of Anaconda, Montana. This is not a remote contamination event at an isolated industrial facility. The poison is woven into the geography of where people work and travel every day.

The EPA’s order notes that historic railroad beds are those “no longer active, do not contain ties or railways,” meaning ARCO and Rarus Railway abandoned the infrastructure, left the arsenic-laced material behind, and walked away. The cleanup obligation that remained did not disappear. It accumulated, quietly, in the soil.

The Non-Financial Ledger

Washoe Park is where families in Anaconda take their kids on weekends. It is where teenagers hang out. It is where older residents walk the trails. The EPA’s order specifically names the Washoe Park Railroad beds as one of the contaminated sites requiring remediation. Every step taken through that park has been a step through arsenic-contaminated soil. That is what ARCO left behind when it moved on.

The North Side Trail is a walking path, the kind of infrastructure a small town builds to give its residents somewhere to breathe fresh air and feel connected to their community. The EPA names it as contaminated. The people who built daily routines around that trail, the early-morning walkers, the parents pushing strollers, the kids on bikes, did so on top of a known carcinogen deposited by a corporation that no longer felt responsible for the ground it poisoned.

Arsenic is a Group 1 human carcinogen, meaning there is no scientific debate about whether it causes cancer. Long-term exposure through skin contact, ingestion of contaminated dust, or inhalation of arsenic particles in dry soil increases the risk of lung, bladder, and skin cancers, among others. The EPA found concentrations in some areas reaching 3,800 parts per million. Children playing in dirt, digging in soil, and putting their hands in their mouths represent the most direct and most tragic exposure pathway, and it was the people of Anaconda, not ARCO’s executives, who bore that risk.

The remediation plan required under the 2024 order includes removing contaminated surface soils and replacing them with clean fill, revegetating affected areas, installing engineered covers, and establishing institutional controls. In plain language: they have to dig up the poisoned dirt, haul it away as waste, and put down new ground. That process should have started decades ago. The West Valley Railroad Spur, the Washoe Park beds, the North Side Trail, and the commercial zones along the active rail corridor all exist in a town of roughly 9,000 people. There is no corner of that community that can be called untouched by what ARCO built and then abandoned.

Legal Receipts: What the Order Actually Says

“Historic railroad beds and commercial/industrial areas are contaminated with elevated concentrations of arsenic. This arsenic was contained in material used to construct both the historic and active railroad beds. Some of the material was spread to commercial/industrial areas, resulting in elevated concentrations of arsenic in those areas as well.” — EPA Findings of Fact, Section II, Paragraph 6 — Amendment to Administrative Order, 2024

“Concentrations of arsenic in historic railroad bed material range from less than 250 to approximately 3,800 parts per million. Concentrations of arsenic in commercial/industrial areas range from less than 250 to approximately 1,500 parts per million.” — EPA Findings of Fact, Section II, Paragraph 6 — Amendment to Administrative Order, 2024

“This amendment directs Respondents to perform additional remedial action within the Community Soils and the Regional Water Waste and Soils Operable Units, both within the Anaconda Smelter NPL Site, for historic railroad beds and for commercial/industrial areas within the town of Anaconda, Montana which are contaminated with arsenic.” — EPA Introduction, Section I, Paragraph 1 — Amendment to Administrative Order, 2024

“Action to reduce arsenic concentrations in commercial/industrial areas will include removal of surface soils and replacement with clean fill, revegetation, use of engineered covers, and use of institutional controls.” — EPA Introduction, Section I, Paragraph 3 — Amendment to Administrative Order, 2024

“‘Historic’ railroad beds are those beds which are no longer active, do not contain ties or railways, and are located within or near the town of Anaconda, Montana. These include the West Valley Railroad Spur, the Washoe Park Railroad beds, the North Side Trail, and other miscellaneous spurs.” — EPA Findings of Fact, Section II, Paragraph 4 — Amendment to Administrative Order, 2024

Societal Impact Mapping

Environmental Degradation: Poison Baked Into the Landscape

The contamination documented in the EPA order is not a spill or a single incident. It is the result of years of deliberate industrial construction using arsenic-laden material for railroad beds, followed by deliberate abandonment of those beds and the toxic material within them. The EPA’s order covers the Regional Water, Waste, and Soils Operable Unit, a designation that signals the contamination extends beyond soil into the broader environmental system of the region.

The named sites span the geography of an entire town. The West Valley Railroad Spur, the Washoe Park Railroad beds, the North Side Trail, and “other miscellaneous spurs” represent a network of contamination woven throughout Anaconda’s landscape. The EPA further confirms that arsenic spread from railroad beds into adjacent commercial and industrial zones, meaning the poison migrated and is not contained in a single, manageable footprint.

Remediation actions required by the order include excavation, clean fill replacement, revegetation, and engineered covers. These are the tools governments use when the environmental damage is so pervasive that natural recovery is impossible. The land around Anaconda cannot heal itself from 3,800 parts per million of arsenic. It requires industrial-scale intervention, decades after the corporation responsible for depositing that arsenic moved on.

Public Health: A Known Carcinogen, A Captive Community

Arsenic is among the most studied and most definitively classified carcinogens in environmental health science. The EPA’s own contamination thresholds for arsenic in residential soil reflect that reality. The concentrations documented in Anaconda, reaching up to 3,800 ppm in railroad bed material and 1,500 ppm in commercial and industrial zones, represent exposures that a small, working-class Montana town had no power to avoid and no resources to remediate on their own.

The EPA’s required response actions explicitly address “direct human contact with railroad bed material,” confirming that the agency identified human exposure as an active, ongoing risk, not a theoretical future concern. People were walking on, playing in, and breathing dust from these sites. The institutional controls required as part of the remediation plan are government-imposed restrictions on land use, restrictions that become necessary only when a contamination event is severe enough to require permanent behavioral changes from an affected population.

Communities like Anaconda, Montana are disproportionately working-class and rural, with limited political capital, limited access to legal resources, and limited ability to simply leave. They are exactly the communities that corporations target, explicitly or through structural indifference, when they decide that toxic waste management is too expensive. The people of Anaconda did not choose to live next to a Superfund site. ARCO and Rarus Railway built one around them.

Economic Inequality: Who Pays, Who Profits, Who Lives With It

The Anaconda Smelter Superfund designation means the federal government determined that the contamination here requires emergency-level intervention under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). That law exists because corporations routinely created catastrophic environmental damage and then used bankruptcy, corporate restructuring, or sheer legal attrition to escape cleanup costs. The Superfund program forces liable parties to pay, but the process takes years, sometimes decades, while affected communities absorb the public health consequences.

The 2024 order amendment reflects the timeline of this failure. A Remedial Action Work Plan was completed on October 27, 2005, nearly twenty years before this amendment was signed. The contamination was known and documented. The affected sites were identified. And still, in 2024, the EPA is issuing orders directing the companies to perform “additional remedial action.” That is not a system working. That is a system managing delay.

ARCO is a subsidiary of BP, one of the largest oil and gas companies on earth. BP reported revenues of over $200 billion (enough for every single resident of Montana to receive roughly $185,000 each) in recent years. The cost of digging up poisoned soil in a small Montana town and replacing it with clean fill is, in the context of BP’s balance sheet, a rounding error. For the residents of Anaconda, the contamination represents a generational tax on their health, their property values, and their community’s identity that no corporate filing will ever fully account for.

The “Cost of a Life” Metric

What Now?

The Companies Responsible

• Atlantic Richfield Company (ARCO), subsidiary of BP plc, named Respondent in the EPA order.
• Rarus Railway Company, co-Respondent and operator of the contaminated rail infrastructure in Anaconda, Montana.

Regulatory Watchlist: Who Is Supposed to Hold Them Accountable

• U.S. Environmental Protection Agency (EPA) Region 8: The issuing authority on this order, responsible for enforcing cleanup timelines and standards at the Anaconda Smelter Superfund Site.
• Montana Department of Environmental Quality (DEQ): Named in the order as having oversight and approval authority over the Remedial Action Work Plan alongside the EPA.
• EPA Superfund Enforcement Division: Responsible for ensuring ARCO and Rarus Railway comply with the 2024 amended order and complete all required remediation actions.
• Department of Justice Environment and Natural Resources Division: Has authority to pursue civil penalties against Superfund respondents who fail to comply with EPA orders.

What You Can Do Right Now

If you live in Anaconda or Deer Lodge County, contact the Montana DEQ and demand a public timeline for completion of remediation at the West Valley Railroad Spur, Washoe Park Railroad beds, and the North Side Trail. Ask specifically which sites have already been cleaned and which remain contaminated. Demand that information in writing, and share it with your neighbors. Connect with environmental justice organizations already working in the Mountain West, including groups focused on Superfund community advocacy. Corporate accountability at Superfund sites does not happen because regulators volunteer it. It happens because communities refuse to let the story be buried under bureaucratic process. Your attention is the one thing ARCO cannot outspend.