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What does CC&V attribute the gradual rise in sulfate concentrations in these <br />compliance wells? Please explain. <br />V. The statement that the water quality will be similar to Carlton Tunnel water is of concern <br />on two levels: <br />a) First, these are two significantly different environments, one being an <br />underground flow system that has been flowing for decades and has established <br />some level of equilibrium as evidenced by the relatively consistent water quality <br />of the tunnel discharge, the other a pile of fresh, crushed rock that will be exposed <br />to a new environment of weathering and oxidizing conditions. It is unlikely the <br />two systems will weather and leach similarly. <br />b) The Carlton Tunnel has been there for over 60 years, and if an assumption is made <br />that the ground water flow system feeding it has established some kind of stasis or <br />equilibrium, then DBMS, wonders about the existence of preferential flow paths <br />causing selective dissolution and depletion of available minerals along those flow <br />paths. The overburden that will be crushed and piled will be fresh material and <br />has not undergone that level of selective dissolution and depletion. <br />W. Under Volume 5 Executive summary the operator states "The pregnant solution from the <br />Cresson project VLF will be fully contained within the existing Phase I, II & Phase IV PSSAS <br />or the 20 million gallon Phases I, II &III external pond. Unless the External pond is <br />connected to the valley leach facility as the rest of the pregnant ponds located in Phase <br />I, II, & IV yonds this pond is approved to only be used on an emergency basis The <br />solution to be stored in this pond can not exceed 20 ppm WAD cyanide after it is treated <br />with hydrogen peroxide, and as such it is not considered by the DRMS to be part of the <br />valley leach facility. Even though the design was similar to the existing pregnant ponds <br />in the valley leach facility, as requested by the Division with its own GW monitoring <br />well, it was never intended to store solution for extended periods with similar <br />concentration of cyanide as the pregnant ponds At present CC&V is utilizing the pond <br />to store fresh water to be used as makeup water in the valley leach facility. If CC&V <br />wants to utilize this pond as a pregnant pond, the same infrastructures that are utilized in <br />the existing pregnant ponds have to be in place and a Technical Revision to the permit <br />addressing these changes must be submitted. <br />X. CC&V proposes to change the water balance from the current static model to a dynamic <br />model utilizing the Golder and Associates created modeling program called Gold Sim. <br />Even though the Division does not object in principle about the change, we do have some <br />concerns about the proposed change. First DRMS would like to see the module, for the <br />program as stated above, so we can understand the input parameters. <br />Y. According to the model, it is supposed to predict when a solution applied onto the pad will <br />report to the pregnant solution collection ponds. At present the DRMS has in place <br />hydrostatic head measuring transducers in the pregnant solution collection ponds. Based <br />on the total water balance for the Valley Leach Facility, each pond level cannot exceed 80% <br />of total capacity during normal operation as measured in feet of hydrostatic head. That is <br />not expected to change under the current proposed dynamic water balance proposal. <br />Under the current amendment, CC&V is proposing to increase the total pumping rate in the <br />valley leach facility from the current 14,900 gpm, to 29,000 gpm, which is double the current <br />13