Uranium levels in water near mines no different than from natural orebodies - USGS

 The hydrology section of the new USGS report  (http://pubs.er.usgs.gov/usgspubs/sir/sir20105025?from=home)  on uranium-bearing breccia pipes in northern Arizona describes the results of testing more than 1,000 water samples from the area.  Andrea Alpine, head of the USGS Southwest Biological Science Center in Flagstaff, and editor of the report, is quoted by the AZ Daily Sun as saying they could not discern the source of the 5% of the samples that have uranium levels above EPA drinking water standards for uranium.  The report concludes that  these springs and wells are close by or in direct contact with naturally occurring orebodies.  The uranium concentrations found naturally occurring (1 - 20.6 ppb) and those near mines (2 - 19.5 ppb) look to me to be about the same.   

The Center for Biological Diversity says the report "demonstrates unequivocally that uranium mining should not proceed in these environmentally sensitive lands," pointing in particular to high levels of uranium at old mines that have not been reclaimed.



The USGS report concludes:

Historical water-quality and water-chemistry data evaluated for 1,014 water samples from 428 sites indicate that about 70 sites have exceeded either the primary or secondary maximum contaminant levels for certain major ions and trace elements, such as arsenic, iron, lead, manganese, radium, sulfate,
and uranium. These data suggest that water recharged from the surface or from perched water-bearing zones may contain dissolved gypsum from overlying rock units or may have been in contact with sulfide-rich ore. A few springs and wells in the region contain concentrations of dissolved uranium greater than the U.S. Environmental Protection Agency maximum contaminant level of 30 μg/L. These springs and wells are close by or in direct contact with orebodies.

Samples from 15 springs and 5 wells in the region contained dissolved uranium concentrations greater than the U.S. Environmental Protection Agency maximum contaminant level for drinking water. These springs and wells are close by or in direct contact with mineralized orebodies, and those concentrations are related to natural processes, mining, or to both.