Laserfiche WebLink
<br /> <br />allowing interaction between the ash and the ground <br />water. The study goes on to say, on page 1-5, that the <br />contamination resulted from soluble ash components, <br />rather than heavy metals. After analyses of the Phase 2 <br />data, the study concludes that contamination from the use <br />of ash in roadway subsoil can be avoided by careful <br />planning, on a site-specific basis. <br />It would appear that no direct conclusion can be drawn <br />from this study, as to how it pertains to the Trapper <br />Mine, since the results would depend upon site-specific <br />conditions. Further study would be required at the actual <br />site, as it pertains to ground water hydrology and near <br />surface soil permeability, before the Division can <br />approve such a plan. <br />3. This study presented data from five sites, located in <br />Georgia, Arkansas, Pennsylvania, Kansas and Arizona. Zt <br />would seem logical that the data from Arizona and Kansas <br />would be more relevant to Colorado than would the other <br />sites. It would appear that the data at these two sites <br />have some problems. On page 6-15 of the study it is <br />stated that there is no downgradient well at the Arizona <br />site. Also, the statistical conclusions from the Arizona <br />site were described, on page 6-17 of the report, as <br />"tentative because of the scarcity of the data." At the <br />Kansas site, the study was somewhat hampered by local <br />variations in native chemical constituents, as reported <br />on pages 5-15 and 5-16. However, the study found, as <br />stated on page 5-16, that limited leaching of ash <br />constituents is occurring down to a depth of about three <br />feet. This was after six years of fly ash use. <br />I believe that the Division should not base its decision, <br />for this kind of a project, on data from just two sites, <br />when one of the two sites, in Arizona, has inconclusive <br />evidence. The other site, in Kansas, did show some <br />leaching of fly ash constituents, but levels were below <br />regulatory standards (see No. 3 below), except for <br />sulfate, which the study concludes is due to native <br />sulfates, not fly ash (see page 5-19). <br />4. I could not find any reference in this report as to how <br />EPA classifies fly ash. Also, there does not seem to be <br />a clear explanation of which regulatory standards are <br />being used in the analyses. Each analyses section for <br />each of the five sites in this report contains a table <br />which lists the regulatory levels for eight chemical <br />ions. There are two regulatory levels listed. One is TCLP <br />(toxicity characteristic leaching procedure) and the <br />2 <br />