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July 30, 2010 2 of 24 <br />apparently began after the Fall 2008 sampling event, indicating that data collected in 2009 was <br />affected by bentonite, a clay that would scavenge (or sorb) dissolved metals and be filtered out of <br />the sample. Therefore, the 2009 sampling results for MW11 are not valid, and MW11 has been <br />removed from water quality monitoring. <br />The background uranium concentrations in bedrock monitoring well MW 1 l range from 0.0013 <br />mg/L to 2.63 mg/L with a mean concentration of 0.244 mg/L, based on 12 valid samples collected <br />from 1999 to 2008. The representative background concentration, calculated as the mean plus two <br />standard deviations, is 1.75 mg/L. Because the well is completed above the mine, and not in the <br />ore zone, this value may underestimate the background pre-mining water quality in the ore zone. <br />It is notable that the protective intent of the 0.03 mg/l groundwater standard is linked to the <br />potential for direct domestic use of the groundwater. The 0.03 mg/L standard is a human-health <br />standard based on a 70 kg man drinking 2 liters of water per day for 30 years. DRMS arguments <br />selectively ignore this underlying premise and intent of the standard. Local groundwater in <br />bedrock in the vicinity of the mine has never been, nor will be in the foreseeable future, suitable <br />for domestic uses. <br />WATER QUALITY STANDARDS APPLY AT THE POINT OF COMPLIANCE, NOT IN THE <br />MINE POOL <br />Comparing the water quality in the mine pool to drinking water standards is inappropriate (See <br />Draft Order paragraphs 8 and 17). It conflicts with Colorado Ground Water Quality Rules (5 CCR <br />1002-41) which state that: <br />Mining activities are recognized to occur within ground water <br />bodies and that water quality within the disturbed area will <br />obviously change. The point(s) of compliance established outside the <br />area anticipated to be disturbed may protect the water body while <br />allowing the mining activity. <br />The water quality standard applied at the designated point of compliance will, by definition, take <br />into account potential exposure pathways to humans because the groundwater limit for uranium is <br />a health-based standard. Application of the standard at the point of compliance in Ralston Creek <br />is consistent with the objective of protecting human health and the environment. <br />"Point of Compliance" in the Mineral Rules and Regulations of the Colorado Mined Land <br />Reclamation Board for Hard Rock, Metal and Designated Mining Operations is defined as <br />follows: <br />"Point of Compliance" means locations down-gradient of the facility or activity at <br />which water sampling may be conducted to demonstrate compliance with <br />applicable groundwater standards established by the Water Quality Control <br />Commission, or permit conditions required by the Office or Board to measure <br />compliance with the MLRB permit.