The majority of mining ventures do not make it past the
stage of discovery. There is, however, no detail in the literature on the
impacts on natural waters of mineral exploration drilling. A
copper-goldmolybdenum mining deposit in Alaska was extensively investigated and
partially reclaimed until 2012; however, in 2016, full reclaim of drill sites
remained incomplete. Copper, a highly valued resource in this region, is
sub-lethally toxic to salmon. Nine sites had reported impacts from 109
inspected sites due to un-reclaimed drill-holes or drill waste disposal
activities. Artesian waters at the drill stem at seven sites resulted in
surface water or sediment elevated at neutral pH in aluminium , iron, copper,
or zinc. The concentrations of copper at artesian sites were < 0.4, 0.7, 2,
7, 15, 76, and 215 μg / L; the latter four in the state of Alaska surpassed the
requirements for water quality. It is understood that drilling waste is
disposed of in ponds and unlined sumps. Copper declined from 511 at one of five
sampled ponds, However, in the only sump region with historical evidence,
copper increased over five years from 0.3 to 1.8 μg / L at a downgradient
wetland spring to 8 μg / L over nine years. This study describes forms and
origins of pollutants and can be used to direct potential studies of
ecotoxicity and strengthen regulatory oversight. The findings of this research
provide guidance on the causes and forms of pollution. Future research should
sample pond soil, where drill waste pollutants can be sequestered, and analyse
drill waste sumps for leaching proof. It will be in the public interest for
state regulators, during inspections, to perform water , soil, or sediment
monitoring to track improvements in the ecosystem where drill holes are not
completely and permanently reclaimed.
Author (s) Details
Dr. Kendra Zamzow
Center for Science in Public Participation, Chickaloon, AK 99674, USA.
David M. Chambers
Center for Science in Public Participation, Bozeman, MT 59715, USA.
View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/279
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