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If you're new to Superfund — or if you've lived here your whole life and still feel unsure about what it all means — you're in the right place.
The Butte–Silver Bow cleanup is one of the largest and most complex Superfund sites in the country. That complexity can make it hard to find clear answers. This page gives you the essentials, without technical language or assumptions about what you already know.
You don't need to read everything. Start with what matters to you.
What is Superfund?
Superfund is a federal program created to clean up hazardous contamination and protect human health and the environment. It was established in 1980, after decades of industrial activity across the country left communities with contaminated soil, water, and air.
At Superfund sites, responsible parties are required to investigate contamination, clean it up, and monitor conditions over time. The work is overseen by the Environmental Protection Agency (EPA), often in partnership with state agencies.
Superfund cleanups are not quick. They are designed to be protective over the long term — sometimes for generations.
Learn more about what Superfund is — and what it is not →
Why is this site different?
The Butte–Silver Bow Superfund site is different from many others because of its scale, its history, and its location within a living community.
This site includes:
- The Berkeley Pit
- More than 10,000 miles of underground mine workings beneath Butte
- Silver Bow Creek and its floodplain
- Warm Springs Ponds at the headwaters of the Clark Fork River
Mining, ore processing, and smelting occurred here for more than a century, long before modern environmental protections existed. Contamination affected soils, groundwater, surface water, vegetation, and ecosystems — and it occurred in places where people lived, worked, and raised families.
Because of this, cleanup happens in many places at once, and at different stages.
How is the cleanup organized?
Because the site is so large, it is divided into areas called Operable Units, often shortened to "OUs."
Each Operable Unit focuses on a specific part of the site, such as:
- mine flooding
- residential soils
- stream corridors
- tailings ponds
- waste rock areas
Each area moves through investigation, design, cleanup, and long-term monitoring at its own pace.
You do not need to understand Operable Units to use this site — but they are useful for organizing information.
Quick answers to common questions
Yes. Butte's public drinking water comes from multiple sources and is treated at modern water treatment plants. Water quality is tested frequently and meets or exceeds all standards for drinking, cooking, and bathing.
No. The water level in the Berkeley Pit is actively managed. Water is pumped, treated, and released to keep the level well below a protective limit established to prevent uncontrolled release.
This system is designed to operate indefinitely.
Think of Superfund as an orchestra.
The EPA is the conductor, overseeing the process. The State of Montana, Atlantic Richfield, contractors, and others carry out different parts of the work under EPA supervision.
The short answer is that this site is enormous and the problems are complex.
Each part of the cleanup involves: investigation, design, public review, construction, and long-term monitoring.
Some work has been completed. Some is ongoing. Some is still being studied to make sure the right decisions are made.
What should I do if I'm concerned?
If you have questions about your home, your yard, or your health, there are programs in place to help.
You can:
- Learn about free soil and attic testing
- Schedule blood lead testing, especially for children
- Speak with professionals who work directly with residents
You don't need to figure this out on your own.
How to use the rest of this site
There is no right way to explore this site.
Some people start with history. Some go straight to health information. Some want to know what's coming next.
Every page includes links to related topics, so you can follow your curiosity — or stop when you've had enough for the day.
If you ever feel lost, you can always return here or use the menu at the top of the page.