₂nd Draft

USE OF CYANIDE IN MINING

 

 

The proposed amendment to the Colorado Constitution:

 

·        Prohibits new open pit mining operations that use cyanide in two ways to extract gold and silver, and

·        Prohibits the expansion of existing open pit mines that extract gold and silver in these two ways.

 

 

Background

 

 

                        Open pit, also known as open cut, mining is a method of removing ore from the surface of the earth. Ore is rock that contains  profitable amounts of minerals such as gold and silver. Cyanide leaching is used to extract gold and silver from low-grade ore.

 

            This measure prohibits cyanide heap and vat leaching to extract gold and silver from open pit mines.  Both heap and vat leaching use cyanide to get gold and silver from crushed ore.  Heap leaching involves piling ore on a lined pads designed to collect the cyanide solution.  In vat leaching, the ore and cyanide solution are combined in vats or tanks. The gold and silver are recovered from the cyanide solution once the leaching process is completed. The used cyanide solution is either recycled and reused or is neutralized.

 

Mines that use cyanide must comply with federal and state water quality laws and regulations. The state requires mines to have a permit to use cyanide and an environmental protection plan. The plan describes how the mine will protect wildlife and water resources from the cyanide processing operations. Each mine must have a state-approved emergency response plan to follow if an accidental release of cyanide occurs. Mines are required to set money aside to cover the cost of environmental monitoring, cleanup and mine closure.  The state is required to fully inspect the operations annually to ensure that these environmental safeguards are in place, although inspections may occur more often.

 

 

 

 

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   Arguments For

 

1) The potential for environmental damage will be reduced if open pit mines are prohibited from expanding their cyanide processing operations. Cyanide is toxic and small amounts can kill animals and humans. Within the past ten years, pipes carrying cyanide solution have ruptured. Although these ruptures have not harmed the environment, there is never any assurance that environmental safeguards are completely reliable. While mines must set money aside to clean-up any potential environmental problems, there is no requirement that mines be financially stable. A major release of cyanide solution may cost millions of dollars to remedy. If the mine cannot pay the total clean-up cost, the state may be financially responsible

 

2)             Open pit gold mining scars the earth’s surface and creates unsightly piles of waste.  Cyanide leaching is a profitable extraction process typically used at open pit gold mines.  Without this measure, two open pit gold mines could expand their cyanide leaching operations and new mines could be created.  As the number of open pit gold mines using cyanide leaching increases, the negative visual effects associated will also rise.

 

Arguments Against

 

1) The measure unfairly restricts the expansion of two active open pit gold mines when other types of mining operations use the same mineral extraction process. For example, underground mines can continue to use cyanide heap and vat leaching to extract gold and silver.  Open pit and underground mines can continue to use cyanide processing to extract lead, zinc, copper and molybdenum.  The restriction would economically impact the two open pit gold mines because cyanide processing is the least expensive and most efficient way to extract gold from low-grade ore.  The mines would not be able to expand their existing operations which may eventually cause them to shut down. One of the mines is the largest employer m Teller County and offers some of the highest paying jobs in the area.

 

2)          The measure is unnecessary because there are reliable environmental safeguards in place. In 1993, the state implemented strict new environmental standards. For example, structures that hold cyanide solution must meet specific design and construction standards. State engineers examine all construction and certify that the structures will properly hold cyanide before they may be used.  The state has not issued a violation for polluting surface or underground water with cyanide since the new standards have been in place.

 

 

                   July 14,2000            -2-