|
Mine Wastes along the Carson River
|
|
The most damaging aspect of mine waste occurred along the Carson River. Poor
mining practices from the latter half of the nineteenth century are entirely
to blame. Mine tailings were disposed directly into the Carson River from
the numerous mills that were set up along its course to treat the ores from
the area. Quartz and clay sludge called tailings from the milling
operations was dumped directly into the river by these mills. For a time, the added
sediment load raised the riverbed and caused tailings sediment
to overflow onto fertile floodplains where agricultural potential is the
greatest. Further, it inundated riparian habitat along the river's course
with sediment. A simplified schematic diagram found at the
following link shows the effect the mine tailings had on the
floodplains adjacent to the river
(floodplain.JPG). Over the decades, repeated floods along the Carson River have re-established the riparian habitat and flushd the flood plain, such that today the environmental legacy of the Comstock is primarily a concern regarding mercury added during ore processing.
Natural and added toxic elements and compounds
Many toxic elements and compounds in the environment on the Comstock are naturally
occurring within the ore deposit, in the surrounding mineralized rock, and in
the waters that emanate from the area. These toxins are an assortment of
heavy metals including arsenic. Naturally occurring arsenic is an environmental concern in many parts of the world and occurs regardless of mining. However, miners added substantial mercury
to the ore during the processes of recovering the valuable metals.
An article in Nevada Geology, "Mercury Contamination of the Carson River" discusses some of the results of research into the mine wastes of the Carson River.
|
|
Mine Wastes along the Carson River
|
|
