- Overview.
- Species of special concern.
- Fishing pressure.
- Cyanide toxicity.
- Stream dewatering.
- Oxygen depletion.
- Sedimentation.
- Heavy metal contamination.
- Cumulative impacts.

Overview:

• The mine will be located at the confluence of the Blackfoot River and the Landers Fork of the Blackfoot – less than a quarter mile from the river's banks.
• The Blackfoot River is one of the most popular recreational rivers in Montana. During the 1995 fishing season, the Montana DFWP estimated that fishing use topped 36,000 angler days. The annual value of recreational fishing on the Blackfoot River by both resident and nonresident anglers is about $7.2 million.
• The Blackfoot River is considered a Class I trout stream. It supports wild populations of five trout species including bull, brown, rainbow, brook and westslope cutthroat trout.
• Mining activities have already impaired the Blackfoot River. The most severe impact occurred in 1975 when the Mike Horse mine tailings dam was breached by a flood and its toxic contents were spilled into the river's headwaters. Many cutthroat, brown and brook trout died as a result, and river sediments were contaminated by heavy metals. Thirteen years after the spill, the abundance of cutthroat trout, age one and older, were less than 25% the level before the spill. A 1991 study found significant cadmium contamination in stone flies and brown trout more than 46 miles downstream. The Mike Horse Mine area is now a state superfund site.
• Over the last five years, Trout Unlimited, the MTDFWP, the USFWS and other groups have spent over a million dollars on stream restoration efforts along the Blackfoot River – the largest restoration project of its kind in the U.S. The Blackfoot fishery is now showing signs of improvement from this investment.

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Species of special concern:

• Westslope cutthroat and bull trout are both listed as "Class A" species of special concern – meaning that the species have limited numbers and/or limited habitats in Montana and elsewhere in North America. Bull trout and westslope cutthroat are present in only 42% and 19% of their native Montana range, respectively. In addition, the USFWS has determined that bull trout warrant protection under the Endangered Species Act.
• In 1994, Gov. Marc Racicot established a bull trout restoration team to develop a restoration plan for Montana. The team identified Copper Creek and the Landers Fork as core areas for bull trout recovery, and recommended that these areas be provided with the most stringent protection. Core areas are drainages that currently contain the strongest remaining populations of bull trout, and are relatively undisturbed.
• Landers Fork provides a migratory pathway to Copper Creek – which supports the 2nd largest bull trout population in the Blackfoot drainage. Landers Fork and Copper Creek are critical to bull trout recovery because they are two of only three drainages in the entire Blackfoot River system where brook trout have not been found. Hybridization between brook and bull trout result in sterile offspring.
• The upper Blackfoot is also important for westslope cutthroat. It represents the largest unfragmented population of westslope cutthroat in the entire Blackfoot system. Furthermore, the westslope cutthroat populations in this area are genetically pure. Hybridization with rainbow trout often result in offspring with low reproductive and survival rates.
• Migratory westslope cutthroat and bull trout spawn in small tributary streams, and migrate to large rivers or lakes. There, they mature, eventually returning once again to the small headwater streams to spawn. Impaired conditions anywhere along the journey reduce their chance of survival.
  

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Fishing pressure:

• The proposed mine will drastically increase the number of people in the upper Blackfoot basin around Lincoln with consequent increases in fishing pressure.

Cyanide Toxicity:

• Cyanide heap-leaching is a gold extraction method that has resulted in significant spills, leaks and unpermitted discharges at every gold mine in Montana. By using this technology, the mine is likely to contaminate the Blackfoot and Landers Fork with cyanide. This could kill fish and aquatic insects throughout the upper River because cyanide is highly toxic and can persist in groundwater indefinitely.

Stream Dewatering:

• To keep the pit dry for mine operations, the mine will pump an average of 2.5 million gallons of groundwater a day and discharge it into gravel ditches adjacent to the Landers Fork and Blackfoot River. The mine will also consume 2 million gallons a day for dust control and ore processing.
• The manipulation and use of such massive volumes of water is likely to disrupt delicate ground and surface water connections and dewater sections of the rivers. This could dry up stream edges, elevate water temperatures, destroy spawning and rearing areas, and strand migrating fish.

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Oxygen Depletion:

• Nitrates, originating from the 27 million pounds of ammonium nitrate to be used to blast the pit, will enter the Blackfoot and Landers Fork in stormwater run-off and in seepage from the leach pads or waste rock piles. Nitrates are one of the major fertilizers or nutrients that encourage algae growth. Elevated nitrate levels often cause large mats of algae to grow, depleting the oxygen supply, interfering with spawning and choking out fish.
• This is particularly critical for westslope cutthroat because they spawn in the spring. Their eggs are present in the gravel when high water temperatures and low summer-time flows may reduce oxygen concentrations to critical levels. Eggs are particularly sensitive to low oxygen levels beause they take up oxygen by diffusion through the skin rather than through more efficient gills.

Sedimentation:

• Sedimentation in the Blackfoot River is likely to increase substantially since four square miles of land will be disturbed and three miles of Highway 200 will be relocated closer to the river. When fine sediment settles to the streambed, it prevents oxygenated water from reaching eggs in their spawning gravels and may actually form a barrier that prevents newly hatched fish from emerging.
• Bull trout are particularly vulnerable to increases in fine sediments because bull trout eggs and newly hatched fish stay in the streambed for more than 200 days.

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Heavy metal contamination:

• By piling 450 million tons of waste rock at the edge of the Blackfoot's floodplain, the mine could expose area groundwater to acidic materials and toxic heavy metals that will drain from the waste heaps. This could harm aquatic life, hinder trout production and even sterilize streams.
• Zinc, iron and manganese will be discharged into groundwater at levels greater than state water quality standards. The mine plans to use an 8-mile mixing zone (4 miles each of the Landers Fork and Blackfoot River ) to dilute the discharge water containing these heavy metals. Heavy metals, however are not biodegradable. They simply settle to the streambed where they contaminate aquatic insects which live and feed there. The insects, in turn, contaminate the fish that depend on them for food. Heavy metal contamination from past mining activities has completely eliminated trout from Silver Bow Creek and severely reduced trout populations in the upper Clark Fork River.
  

Cumulative Impacts:

• Although each individual impact may have only a small effect on aquatic life, the cumulative effects of these impacts may push an already stressed population over the edge. A 1990 study conducted by the Department of Environmental Quality reports that the Blackfoot fishery has "declined from its former status" and "it is possible that a combination of nearly undetectable chronic stresses are taking their toll on the Blackfoot River."

IMPACT ON WATER QUALITY
FACTS ABOUT THE MINE

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