Laserfiche WebLink
. .r b • <br /> <br />ambient concentrations. The comparisons need to use the AccuLabs data to obtain the <br />appropriate level of sensitivity, as Dr. Posey observed eazly in this process. These are the <br />comparisons that demonstrate the equivalency between the quality of the humidity cell <br />extracts and ambient ground- and surface-water quality. <br />It makes no sense for CC&V to propose, and bond for, a "cap" in addition to the soil cap <br />that is currently planned and required by the approved permit. The soil cap will certainly <br />reduce infiltration of water though the overburden material and when that soil is relatively <br />saturated at depth, the available oxygen (for deeper infiltration) will be reduced. I believe <br />this was agreed to during the introductory meeting held to discuss the submission. <br />It is not possible, nor is it appropriate, for the humidity cell data to dictate capping just <br />because acidic waters are generated. That is to say that humidity cell tests that generate <br />acidic waters are not a basis to call the tested rock acid-generating and then to require <br />mitigation. Obviously native rocks in their "ambient positions" aze often acid-generating. <br />Rather the humidity cell data must be compazed to the ambient water quality to determine <br />whether a uniquely different and unacceptable water-quality is produced. In this case, the <br />tested rock produces water of essentially the same quality as the ground water and surface <br />water. Therefore there is no basis to require capping other than the very effective "capping" <br />provided by the plant growth medium and drainage that minimizes standing water. The acid- <br />base testing has shown us that we must track the material, avoid placing some of it in Arequa <br />Gulch, and monitor water quality. The testing has not demonstrated a need for the type of <br />capping suggested by some in the OMLR. <br />CC&V has absolutely no problem in continuing to monitor water quality for telltale signs of <br />excessive acid generation and metals. We plan to so monitor. It will also be possible to <br />determine densities and permeabilities of placed materials which, in turn, will provide <br />additional information about the moisture-retention properties of the soils and overburden and <br />thus the controls on oxygen infiltration. We have proposed the monitoring and are akeady <br />conducting a good part of it. Therefore we believe we have complied with the applicable <br />statutory and regulatory requirements. <br />Thank you again for this opportunity. <br />FILE: POSEYWQ.MEM <br />23 <br />Attachment (1): a/s <br />