"If it passes as a law with tough conditions, it could harm not only the operation of current projects but also future projects," said Juan Carlos Guajardo, head of the Chilean mining think tank CESCO. "Depending on the conditions, the scenarios would make mining activity very difficult in high mountain areas."
Environmentalists point to the crucial role played by glaciers in protecting Chile's water as reason enough to implement the wider definition.
A glacier is snow that has compacted into ice and that survives the warm summer months. Glaciers are important because they act as natural dams, storing water for use throughout the year after the winter snow has melted. Even small glaciers can hold gigantic amounts of water that become critical during warm months and especially in long dry spells.
Argentina, across the Andes mountains from Chile, adopted a law in 2010 that broadly defines glaciers — theoretically protecting not only the icy masses most people think of, but also "rock glaciers" and frozen groundwater on mountaintops where glaciers have melted away from the surface. The Argentine National Glacier Institute, which had a heavy hand in drafting Argentina's law, pushed the definition because it's believed most glacial water actually comes from such reserves.
The Argentine law remains largely unenforced, but mining has still to develop in a big way there.
In Chile, however, such a move could have a much bigger impact on the world's copper and gold supplies. For now, the bill doesn't include protections on peri-glacial or permafrost areas and is far less punitive than Argentina's law, but it could be amended to broaden the definition of glaciers. No matter what, it would be Chile's first law specifically protecting glaciers.
Mining offers Chile's poor their best shot at a middle-class life, especially in the rugged desert areas in the north, where most mines are. Copper accounts for about a third of government revenue, and the state has a policy of shoring up national reserves during periods of high prices.
The country has some of Latin America's most stable ground rules for mining. But the narrow nation that stretches 2,650 miles (4,270 kilometers) along the Pacific also has the largest number of glaciers, from icy southern Patagonia to its most northern latitudes.
A broader definition could severely hamper the Chilean industry's hopes to mine gold and copper from places where icy masses have retreated on the surface, exposing rich ore veins that share mountaintops with other forms of glacier water.
Already, environmentalists have demanded tougher protections for nearby populations and natural resources, and mining projects have faced costly delays.
Jorge Daniel Taillant, director of the Center for Human Rights and the Environment, called glaciers a vulnerable resource that's in jeopardy because of mining.
Taillant tracks environmental compliance by mining companies and has focused on the impact of dozens of mining projects in Argentina and in Chile on glaciers.
"A broad definition of glaciers in the law helps capture the large variety of glaciers that exist in the Andes," Taillant said. "Protecting only the most well-known uncovered white glaciers is not enough. Melting glaciers are one of the telltale signs of climate change, and as such we need laws to protect climate-vulnerable glaciers."
If passed, the bill could halt mining operations such as Barrick's $8 billion Pascua-Lama or state mining company Codelco's $6.8 billion Andina 244 expansion project, which are both surrounded by glaciers and permafrost areas. To move forward, the projects would need further environmental safeguards to ensure they're not hurting ice.
The resurfacing of the bill comes at a time when the Andina project is being widely questioned. Codelco wants to turn Andina into its star mine to produce more than 600,000 metric tons of copper a year, up from 250,000 now.