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February 4, 2009 <br />Pg. 2 <br />the ground water from various depths. Considering the seasonal variation observed in the <br />data, the wells should be monitored for five quarters before any definitive decisions are <br />made regarding the data. Upgradient alluvial and bedrock monitoring wells will be needed <br />anyway to establish background ground water quality before commencing operations. <br />3) It is difficult to accept that the existence of the seep at the toe of the waste rock is merely <br />coincidence with the geologic contact, and that all of the seep discharge that is emerging <br />from the contact is unaffected geochemically by loading from the waste rock. The more <br />plausible explanation is that the contact is controlling the location of the discharge of the <br />water without regard to the water's origin, and it seems improbable that the waste rock is <br />not contributing some metal loading to the seeps. Discrete end-member ground water <br />samples would help discriminate this contribution, as well as the contributions from the <br />other hypothesized sources. <br />4) The use of trace metals as chemical tracers /indicators is highly problematic between water <br />sources that show variation in pH and Eh,_as most trace metals are strongly dependent on <br />these two variables. The Division places little validity in comparison of trace metal <br />concentrations as indicators of source in this setting where pH, and likely redox <br />potential, varies so significantly across the system. <br />Following are comments and questions that pertain to specific passages in the report: <br />Exec. Summary p. III: The conclusion that a dry waste pile indicates that the pile is not <br />"lending to acid or mineralized load in the seeps" seems to be an unsupported extrapolation of <br />conditions that existed when the piezometers were installed. Is it the opinion of the applicant <br />that the lack of moisture in the waste rock at the time of well installation rules out the, <br />possibility of episodic-events that could allow infiltration through the waste rock and delivery of <br />metal loads to the underlying material? What is the possibility that the porosity of the waste <br />rock is too high for the material to retain moisture, and infiltration passes through at a relatively <br />rapid rate?. <br />• Pg. 1: In reference to the statement "There has never been any significant impact to the Lake <br />Fork..." Is there no discharge from Deadman Gulch to the Lake Fork, is the discharge diluted <br />when it enters Lake Fork, is the discharge very small in relation to the Lake Fork, or something <br />else? Please explain. <br />• Please explain the difference between an anionic colloid and an anionic complex, or if they are <br />regarded as the same thing. <br />The report refers to consumption of anionic colloids and consumption of anionic complexes. 1) <br />To what specific anions, anionic complexes, and anionic colloids does this refer? 2) Does <br />`consumption' refer to attenuation processes such as mineral precipitation, sorption, and anion <br />exchange, or other processes such as complexation that only change the speciation of the anion <br />without actually removing it from solution?