Berkeley PitBerkeley Pit

The Deadly Mine ofThe Deadly Mine of

Butte, MontanaButte, Montana

Butte, MontanaButte, MontanaThe Pit

The Town

•County Seat of Silver Bow County, Montana

•One of the largest and most notorious copper boomtowns.

•The advent of electricity was the reason Butte was hit so hard for the supply of copper.

•City attracted many workers.

Berkeley Pit…the beginningBerkeley Pit…the beginning

•Began in July, 1955

•Located on a prominent vein extending from the main Anaconda vein system.

•Open-pit mining was more economical and less dangerous.

•Low-grade ore could be recovered with simple tools.

Beginning…continuedBeginning…continued

• Within 1st year of operation, pit extracted more than 17,000 tons of ore/day.

• About 127 tons of copper was produced from the ore.

• 1 billion tons of material was mined from the pit.

Taking Over the LandTaking Over the Land• Two communities and much of

Butte’s crowded east side was purchased for mining. – Two Cities:

• Meaderville• McQueen

Meaderville

McQueen

The PitThe Pit

• Mile and a half wide

• 1780 feet deep

• Contains 900 feet of water that is HIGHLY acidic

• Aquifers filled the pit, allowing pyrite and sulphide minerals in the ore and rock walls to decay, releasing acid.

• Has many dangerous chemicals– Arsenic– Cadmium– Zinc– Sulfur Acid

Arsenic stained hands

Hundreds Die Hundreds Die

Hundreds DieHundreds Die

• In 1995, a large flock of snow geese, landed on the water and perished.

• 342 carcasses were recovered. • ARCO, custodians of the pit, denied

allegations that the toxic water caused the death of the geese.

• Thought the cause of death was acute aspergillosis

• Colorado State University tested the corpses and came up with this theory.

• State of Montana disputed the results, as in their own labs the cause was different.

The Geese

The FogThe Fog

• Residents were concerned the fog that was given off by the pit was a health hazard.

• Most recent development in the “clean-up” process was a treatment plant on Horseshoe Bend.– Facility intended to treat and divert water

coming from the Horseshow Bend Flow.

– Would treat water in the Berkeley Pit in 2018, or whenever the critical water level point.

Other LifeOther Life

• New fungal and bacterial species have been found to be able to adapt to the harsh environment of the pit.

• Have been able to evolve because of intense competition for the limited resources in the pond.

• Natural products have been isolated from these organisms and show signs of the ability to cure cancer.

The End of the HazardThe End of the Hazard

• Pit was closed in 1982, under the direction of Atlantic Richfield Company (ARCO).

• Water pumps at the bottom of the pit were removed.

• In 1990, plans were devised for solving the underwater ground problem.

• Berkeley Pit has now become one of the largest sights for the Superfund sites.