The Berkeley Pit: Murders Most Fowl
May 6, 2015 | Posted in: Science
It was blizzard weather followed by a thick fog that set the stage for the death of 342 snow geese in November 1995. These worn out weather-whipped birds, traveling their yearly epic migration, sighted water below, a large lake surrounded by high walls promising protection from the elements. Down they soared in elegant order, landing in the water raucously, squawking and honking, shaking out exhausted wings, grooming messy feathers, and sipping from the surface of the lake. They had landed in the Berkeley Pit, those tired fowls, and they never left.
Butte, Montana, is today a place of little note to anyone living outside it, but back in the 1880s copper was discovered here in enormous quantities, and so the town became a metal mecca. Electricity was just lighting up the country and so the price for copper was soaring, and here in Butte there was a little hill (nicknamed “The Richest Hill on Earth” in its heyday), only four square miles, that supplied for over 50 years a third of the copper used in the U.S. and a sixth of entire world’s usage. In the 1940s, the price for copper began to drop, and it was decided that mining would be easier and cheaper if the top of the hill was simply blown off. Open pit mining began in earnest, driving down, down, down into the heart of the hill, tiered walls rising up around a center forging ever deeper. But prices kept dropping with them and finally the mining party ended, ironically enough, on Earth Day 1982: laborers, trucks, bulldozers, drills, foreman, geologists, they all packed up and left, and the pumps that had been busy pumping throughout the whole operation, preventing the perpetual slow flood of groundwater from filling their pit, were packed away too.
Water was free to seep up, trickle in, and rain down, collecting in the pit. Slowly, so slowly at first, the water accumulated, and it took ten years before a rusty puddle was visible down in the center. But water isn’t in a rush, and it kept on leaking in, growing till its edges touched wider and then higher, reaching rocky walls still laced with minerals, notably pyrite.
There’s a chemical reaction that occurs when water, air, and pyrite combine, creating sulfuric acid which further hastens the leeching of metals from rock. Pyrite, that ridiculed fool’s gold, was as common as dirt in the pit, and so a brew began, a toxic combination of gold, silver, zinc, copper, arsenic, cadmium, aluminum, iron, magnesium, and among others, turning the water into a shimmering, ill mixture (colored green, black, red, and gray) with an acidity level the equivalent of lemon juice. Today, the puddle has grown into 40 billion gallons of water that covers 700 acres, thankfully contained still by the high tiered sides of the inverted hill and renamed the Berkeley Pit.
If after reading this you wished to walk down into the pit, you would be required to pass a 40 hour Hazmat program. If you wanted to take a boat ride on its multi-colored surface, you would need to have a fiberglass vessel to ensure your ship wouldn’t be dissolved before you reached the shore again. Onto this poisonous water our poor snow geese landed, and sipped its contents into their delicate bodies. When the fog cleared from over the water two days later, the birds’ remains floated in the hundreds, and biopsies showed that the noxious water had burned holes in their esophagi. A sad fate, and an even sadder end to our tale this would be, but it isn’t the end.
The Berkeley Pit had, until a mere year before the snow geese tragedy, been thought to be antithetical to life, a death trap for any organisms in any form. But one day a stick was found in the water, covered in a slimy green. It was brought to Andrea and Don Stierle, a husband and wife research team at the local university. Lo and behold, the slime was alive, was a single-celled algae in fact. Over the following twenty years a whole host of amazing and often unique algae, bacteria, protozoa, and fungi have been discovered within the unimaginably inhospitable waters of the pit. It is, to quote a favorite misquote of an early Star Trek episode, “Life, but not as we know it.” Some of these have been tested for possible cancer-fighting properties, with promising results.
For our story however, there’s only one life form found in the poisonous pit water that brings our tale to a serendipitous conclusion, and that organism is a yeast. Not just any yeast, but an uncommon one. When the Stierle team scooped its goopy, black form up from the pit water they were firstly surprised because yeast wasn’t believed to be able to live in such acidic water, and secondly it wasn’t like any yeast they had ever come across. This yeast had a special talent, absorbing the metals right out of the pit water, and so leaving behind safer H2O for other life forms. Other organisms also have this talent, but most only absorb 10-15% of metals in water, whereas this yeast takes in 85-95%.
But where did it come from? They had to send a sample away to be identified. The results came back, and there was only one place this yeast had ever been identified before: in rectal swabs of geese.
In all the annals of tragedy, the demise of one migrating flock of snow geese may seem inconsequential, but our story exemplifies this universal truth: there is no waste, only a changing of form. Most human societies are living out of accordance with this law, so in our short time spent upon the Earth we have created many Berkeley pits and other disaster zones, home now only to plastics and pollutants that are of no use and generally destructive to all life forms. But give the Earth time, both geological time and yeast time, and the waste will be absorbed, transformed into new forms, once more participating in the cycle of eating and being eaten. The Berkeley Pit is still toxic, and the water is still rising, but in the future, whether we are there or not, it will be restored, due in no small part to the metal-eating yeast of the martyred snow geese.
I heard this story originally on the sublime podcast Radiolab, listen below:
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