Silver Falcon Mining Inc. (fka SFMI)

[User-65225]

Not sure if this is what he means, but this is taken from the EPA website... Sounds like water that sits in these shafts for decades becomes quite contaminated with heavy metals, acids, etc... which most likely means the EPA will want them to monitor and treat it before they can drain it into other bodies of water...

http://water.epa.gov/polwaste/nps/upload/2000_08_pdfs_amscch.pdf

Underground Mining. Underground mining has been the major method for the production of certain metals but in recent years has been increasingly less common in the United States. The mid-1990's have seen a mild resurgence of underground mining as the depths of several major open pit mines have reached their economic limit. Underground mining typically has significantly less impact on the surface environment than do surface methods. This is primarily the result of reduced surface disturbance (i.e., a smaller facility “footprint”) and the much lower quantities of non-ore materials that must be removed and disposed as waste. Large underground workings, when abandoned, have sometimes caused subsidence or caving at the surface, resulting in disturbance to structures, roads, and surface water drainages. In addition, drainage from underground mines may cause significant alteration to the quality of ground water and can affect surface water as well. Mine drainage water quality is highly dependent on the characteristics of host rock and can vary widely.

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Mine Water. Water entering a surface or underground mine is referred to as mine water. Sources of this water are groundwater seepage, surface water inflow, or direct precipitation. In the absence of a natural or manmade drainage, active mine operations below the water table must pump out mine water to access the orebody. Depending on the hydrogeology of the mine this can be accomplished as simply pumping the water from the mine to grouting the rock in depression in the ground water table, thereby reducing infiltration. At some mines enormous quantities may have to be pumped continuously from the mine during operations. Active mines may use mine water for dust control and as process water in the mill circuit; otherwise they typically discharge the flow to surface water under a National Pollutant Discharge Elimination System (NPDES) permit or similar state permit. Mine water discharge from operating mines is typically regulated and often does not have the residence time in the ore or mine needed to create highly acidic waters or waters highly-loaded with dissolved metals. However, the need to treat mine water prior to discharge is highly site specific.
When a mine closes, dewatering the mine generally ceases. Underground mines often fill; mine water may be released through openings such as adits, or through fractures and fissures that reach the surface. If present, man-made gravity drains will continue to flow. Surface mines that extend below the water table will return to that level when pumping ceases, either forming a lake in the pit or inundating and saturating fill material. Recovery of ground water to or near pre-mining levels following the cessation of pumping can take substantial amounts of time, however, and the effects resulting from ground water drawdown may continue to be felt for decades.
Water from abandoned mines may contain significant concentrations of heavy metals and total dissolved solids and may have elevated temperatures and altered pH, depending on the nature of the orebody and local geochemical conditions. These waters may become acidic over time when exposed to oxygen and, if present, pyrites or other sulfide minerals. The acidic water may also solubilize metals contained in the mine and mined materials, creating high concentrations of metals in solution. These acidic metal-laden waters may contaminate down-gradient ground-water and surface water resources. Neutral and alkaline mine waters may also contain metals in excess of water quality standards and be of significant concern to human health and the environment.