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• The propensity for the rock to release metals to infiltrating water
<br />(leaching). To evaluate this factor meteoric water mobility procedure
<br />MWMP analyses were conducted on development rock and ore
<br />samples.... and
<br />• The volume of percolation through the rock piles. Percolation was
<br />estimated using two methods: 1) a water balance approach that considers
<br />precipitation evaporation and available water holding capacity and 2)
<br />computer modeling using a software program called UNSAT -H, which
<br />provides a more rigorous evaluation through simulation of the processes of
<br />precipitation infiltration evaporation and percolation. Estimation of the
<br />volume of percolation through the rock piles addresses uncertainties
<br />associated with the rock to soil ratio used in the MWMP tests as compared
<br />to actual field conditions; and
<br />A ... number of constituents were detected at concentrations ... greater than the
<br />Colorado groundwater standards. Below is a list of constituents detected in ... the
<br />development rock and ore stockpiles:
<br />• Topaz Mine Development Rock: arsenic, chloride, molybdenum, nitrate,
<br />nitrite, pH, selenium, sulfate, uranium, vanadium.
<br />• Sunday Mine Development Rock: antimony, arsenic, molybdenum,
<br />nitrate, nitrite, selenium, sulfate and vanadium.
<br />• St Jude Mine Development Rock: arsenic, fluoride, molybdenum, nitrate,
<br />pH, selenium, sulfate, uranium and vanadium.
<br />• West Sunday Mine Development Rock: arsenic, cadmium, chloride,`
<br />molybdenum, nitrate, nitrite, pH, selenium, sulfate, uranium and
<br />vanadium.
<br />• Composite Ore Stockpiles: antimony, arsenic, copper, lead, molybdenum,
<br />nitrate, selenium, sulfate, uranium and vanadium.
<br />• Sunday Mine Low Grade Ore: antimony, arsenic, molybdenum, selenium,
<br />sulfate and vanadium" (Denison EPP Section 13 pages 13-4 to 13 -5).
<br />Upon completion of the meteoric water mobility procedure (MWPM), Denison concludes
<br />that further testing need only focus on arsenic. Since all these heavy metals are
<br />carcinogenic in humans and selenium is know to devastating effects on fish reproduction
<br />(see Draft Environmental Impact Statement Aspinall Unit Operations- Colorado River
<br />Storage Project Gunnison River DES 09 -02) and all are present in Sunday Mine complex
<br />development rock, ore stockpiles and waste rock areas, the Division for Reclamation,
<br />Mining and Safety (DRMS) should require additional testing and future monitoring for
<br />all the above named metals. Additionally, all discharges into ephemeral streams or any
<br />drainages that flow (by any route) into Big Gypsum Creek- and thus, into the Dolores
<br />River should be monitored and negative effects mitigated.
<br />Second, on the subject of the leachate testing - the Denison EPP states,
<br />"The Top Rim sandstone is the dominant rock type present in the development
<br />rock and ore stockpiles. It is commonly medium grained well rounded gray
<br />sandstone with calcite cement. The grain size of the rock particles ranges from
<br />2
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