Mining Contamination in the Rocky Mountains

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Mining Contamination in the Rocky Mountains

• By Kaley Williams

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Mining

• AMD (Acid Mine Drainage) Definition and
  Importance
• Case Study- Summitville CO

Ouray Colorado, A small mining community since
the 1800s.
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Importance of Mining Contamination

• Mining contaminating watersheds has become one
  of the largest pollutants of water in the West
• Pollution can continue to flow into bodies of
  water long after the mining ends
• The metals have severe environmental effects
  degrading water quality and aquatic habitat

Yellow Boy Precipitation in a mountain stream,
San Juan Mountains, Colorado.
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Pollution

• Acid Mine Drainage (AMD) is metal-rich water that
  is formed from the oxidation of pyrite (FeS2)
  with air and water.
• Mineral pollutants in the water of iron, zinc,
  aluminum, manganese, cobalt, nickel, copper,
  arsenic, cadmium, and lead. 
• AMD makes water highly acidic and ends up having
  a high concentration of dissolved heavy metals.
  The precipitate from the iron forms red, orange,
  and yellow sediments in the surrounding areas.
• The United States Environmental Protection Agency
  (EPA) has singled out AMD as the number one
  quality problem

This precipitate is also called "yellow boy".  
It is an unsightly, slimy, yellow or orange
colored solid that coats the stream bed and
discolors the water.  "Yellow boy" also has a
negative impact on all living organisms in the
stream.
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Summitville and its History

• Gold was first discovered in Summitville in 1870.
  The Summitville mine went into production in
  1980s using a new technique for extracting low
  grade ores.
• Cyanide heap leaching is a process used to
  extract gold by crushing the rock and sprinkling
  it with cyanide to leach out the precious metals.
• Located at 11,500 ft in the San Juan Mountains in
  the Southwest part of Colorado, the site covered
  1,400 acres of federally owned land.
• This process accounts for 35 of domestic gold
  production and has made the US the second ranked
  producer in the world.

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Summitvilles Timeline
The Alamosa River begins showing signs of life.
Already, tax payers have spent over 128 million
on cleaning up the area, and the total long term
clean up is determined to go on for at least
another decade spending 3 million a year
December, SCMCI declared bankruptcy and abandoned
the mine site leaving a mess of more than 120
million to clean up for the EPA
Emergency pumpback system was installed to
recycle contaminated solution back to leach pad
1992
2000
1986
1989
1994
A process solution treatment was installed to
clear up the discharge
The EPA had placed the Summitville mine site on
the National Priorities List as a Superfund toxic
cleanup site. The EPA was spending 53,000 a day
to clean up the worst parts of the contamination
Terrace Reservoir
Headwaters of the Alamosa River. A natural
acidic iron spring.
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Tying It All Together

• Mining can drastically impact its environment and
  the surrounding ecosystems. AMD contaminates
  water sources degrading the quality of water that
  affects both humans and plant and animal
  habitats.
• Summitville, CO is one example out of thousands
  that exemplify the affects of mining and the
  forms of pollution that are dealt with on a daily
  basses.
• There are many different techniques to cleaning
  up mining pollution, but they are expensive and
  become long term projects. With recent
  developments in the government and public
  awareness of the problems associated with mining,
  technology is improving for cleaning up the water
  systems as well as preventing future
  contamination.