Narrator: Imagine living in a town
where the dust is so toxic
that the city will vacuum your attic for free.
Attic crew worker: The things we test for are arsenic and lead.
Narrator: Welcome to Butte,
where for 150 years,
the mining industry dumped waste in all kinds of places.
The biggest thing is the dust.
You know, this is what, when I was saying dust —
a day, two days later, it's back to what it is right now.
Narrator: At one point, this city produced
so much copper, it was nicknamed "the richest hill on Earth."
Now, the industry has to pay billions of dollars
for one of America's largest environmental cleanups.
And this toxic lake filled with acid and heavy metals
is at the center of it all.
So how did the richest hill get stuck with a deadly pit?
And can this old mining city clean up
more than a century's worth of waste?
Like generations before him in Butte,
Larry Hoffman spent most of his life
in the mines.
Larry: I've been underground
basically since I was 8 years old.
Narrator: He operates the city's last underground mine.
It's called the Orphan Boy,
and it opened over a century ago.
At the peak of the copper boom,
there were over 100 shafts like this one.
Imagine thousands of men working as far as a mile down
in extreme heat and near complete darkness.
And then you turn off the light,
and then there's one candle burning
that the men work by.
Narrator: Underground mining was the norm for decades.
But when the richest veins of copper started running dry,
Butte switched to open-pit mining,
which was cheaper and safer.
The Berkeley Pit opened in the 1950s.
Pumps would work 24-7 to keep it dry.
As the pit grew,
it swallowed up entire neighborhoods.
Anaconda, the company that monopolized mining
for most of Butte's history,
owned the earth under everyone's house.
An estimated 3,500 homes were relocated
to make way for the pit in the 1960s and '70s.
But no one was prepared for the industry's looming collapse.
By the 1980s, the mine was under new management.
The oil company Atlantic Richfield —
what most people call ARCO —
had been closing mines around Butte
as copper prices crashed.
That's when the Berkeley Pit started turning
into a toxic lake.
The miners' union went on strike after the company failed
to make a deal.
ARCO closed the pit and shut down the water pumps.
Nearly 10,000 miles of underground tunnels
beneath the Berkeley Pit began flooding.
Air and water mixed with iron pyrite, or fool's gold,
to complete the chemical formula for sulfuric acid.
When that mixture hit the walls of the flooded mines,
heavy metal started to leach from the rock.
Every year for the next three decades,
the level of the toxic water rose.
Larry: No, it was a huge mistake to shut down the pumps,
and it was something that was eminently foreseeable.
Where's the water going to go if you quit pumping?
It's just going to keep rising.
Narrator: The pit water has leveled off for now.
If it goes up another 50 feet
it could threaten the\rgroundwaters around Butte.
And it's so toxic
it can cook birds from the inside out.
But around the same time the pit started to flood,
something else happened
thousands of miles away
that would mean big changes in Butte.
Congress passed a new law that forced corporate polluters
to pay huge sums for the messes they make.
The government called it Superfund.
Host: Years ago, people didn't understand
how certain chemical wastes would affect people's health
and the environment.
Many wastes were dumped on the ground,
into rivers, or left out in the open.
Narrator: Today, about 73 million Americans live
within 3 miles of a Superfund cleanup site.
And the rest can drive
to one without refilling their gas tank.
In 1987, ARCO committed hundreds of millions of dollars
to Butte's Superfund.
But with so much waste, where does a cleanup even start?
Experts have looked into all kinds of solutions,
but the Berkeley Pit is too big to cover
or fill in with earth.
To keep birds off the water,
the plastic shade balls
that are used elsewhere wouldn't work.
It would take up to four years and cost $80 million
to produce enough balls to cover the 435-acre lake.
So for now, a team keeps birds out with guns,
drones,
and noise machines.
All of these tools are paid for by ARCO
and Montana Resources, the company that continues mining
in Butte today.
The two companies also fund one
of Butte's most expensive Superfund projects,
the $19 million treatment facility
that filters water from the Berkeley Pit.
So far, it's helped to keep the water from rising
and spilling over into the aquifer.
And the Berkeley Pit water
is 100 times less acidic than it was in 2013.
The plant releases up to 6 million gallons
of treated pit water into a nearby creek every day.
Butte's soil is also contaminated with a by-product
of mining called waste rock.
That's material that miners pulled out of the ground,
but didn't contain enough metals to process.
Waste rock usually contains enough acid
to kill most plant life.
That's why huge patches of the Butte Hill remain bare.
In Butte, the most common solution is to bury them.
Robert: Everybody understands that there is waste below us.
So we have a cap material here that is 18 inches.
Robert: Do you guys see this?
This is tailings, waste material
that we don't want to really have our plants dealing with.
Happy Earth Day.
Narrator: Exactly 39 years to the day since the pumps
at the Berkeley Pit shut down,
a group of students and educators gathered
on the Butte Hill to return native plants to the landscape.
Robert Pal is the professor
who oversees the native plant program.
Robert: Here we are at the Montana Tech greenhouse.
And the native plant project
is approximately growing 5,000 containerized plants yearly
for the Butte restoration out on the hill.
Morgan: So these are all lupine seeds,
and we like to give them a head start in the greenhouse.
So basically, we successfully germinated them,
we prepared the soil trays, and now transplanting them.
Narrator: The hope is that the plants will do some
of the cleanup work on their own.
Robert: So some of them are really adapted to contamination,
and we have been conducting our experiments,
and we are finding
that they are good at taking up different metals.
And it doesn't kill them. It accumulates in their bodies.
Narrator: Thanks to the Superfund money,
Butte now has skate parks and baseball diamonds
on what used to be waste dumps.
And public health seems to be improving as well.
A 2019 study found that overall mortality decreased
in the communities around Butte every year
since the Superfund cleanup started.
And the Berkeley Pit?
Well, it's become a pretty popular tourist attraction.
Helen: "Not your average death metal."
This is a top-down view of the pit.
Not everyone loves "More acid than Woodstock,"
but I think it's funny, so.
Narrator: Every year, tens of thousands
of visitors pay $3 to see it.
Justin: I think it's gorgeous.
I've been thoroughly surprised.
Anna: I mean, it may be toxic and lethal,
but it's really pretty.
Justin: Yeah, if I didn't know about the toxicity
of it, I would probably want to jump in,
but now I don't want to.
Narrator: The viewing platform raises enough money
to pay the staff,
so nobody's getting rich off the Berkeley Pit anymore.
But with Superfund, Butte is on a path
to clean up the mistakes of the past.
If you liked this story,
be sure to check out our other episode
about why Butte spent millions of dollars
to keep birds off the Berkeley Pit.
To see more episodes of Worldwide Waste,
click on our series playlist.