Rainwater- or snowmelt-induced leaching of major elements, trace elements, and acid from mine wastes or naturally mineralized areas and the effects of the resulting runoff on adjacent streams are common environmental concerns. Another concern is the direct or indirect uptake of potentially toxic metals from these leachates into the food chain.
Many other geogenic materials (for example, soils, mineralized rocks, dusts, volcanic ash, and forest-fire ash) may also react chemically with water to produce leachates with increased concentrations of major and trace elements and altered pH. Because of this potential, it is important to have a tool that will aid the environmental scientist in quantifying and understanding the leachability of geologically derived material and the chemical reactions that can occur when the material comes into contact with water.
Traditionally, laboratory leach studies have been a useful way to assess the potential effects from the leaching of materials. However, the leach tests most commonly used are complicated and time consuming and require specialized equipment. In light of these factors, the U.S. Geological Survey (USGS) has developed a fast (5-minute), relatively simple and cost-effective leach test. The USGS Field Leach Test (FLT) can easily be performed in the laboratory or onsite to effectively simulate the chemical reactions that occur when geologic materials are leached by water.
Version 1.0
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| Posted September 2005 |
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