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5 <br /> Varra <br /> May 3, 1999 <br /> Page 2 <br /> 4. The TCLP method was conducted on all waste forms, but the extraction fluid (#1 or# 2) <br /> actually employed was not provided. This ought to be determined in the preliminary evaluations <br /> conducted for each waste form. The pH of the final extract was not provided as specified in <br /> method 1311 - TCLP, section 7.2.14. These data are useful in evaluating the leaching <br /> characteristics of waste form using TCLP, and response to the particular fluid. <br /> 5. Of the leach procedures employed for this project, only TCLP is a consensus methodology <br /> with information and documentation readily available for consultation. As such the particular <br /> reagents, controls, Quality Control features, and related performance data for these, or other <br /> wastes forms are not intimately known for the SELP, SGLP, and SCGLP procedures. For <br /> example, the pH of the leachate fluid for SELP is provided (5, 7, and 8.5), but the preparation of <br /> these fluids is not discussed. It is not known if buffered solutions were employed, or ratios of <br /> common mineral acids/bases. It is not known what the specification for water was for these <br /> solutions (ASTM Type II ?). The submittal included citations to possibly answer these <br /> questions, and others, but the time allotted for this evaluation, these reference materials could not <br /> be secured. For non-consensus methodologies utilized, provide the actual methods and <br /> deviations for the regulatory reviewer, and the public in general. <br /> 6. The first extraction of the SELP test was used to determine the suite of elements for the <br /> SGCLP test. Those not detected, or detected at very low concentrations were eliminated from <br /> further testing. The SGCLP table of elemental parameters indicate that Titanium and Mercury <br /> were actually eliminated from further consideration. There were no detections of Titanium <br /> reported using the SELP procedure for any waste form, or pH. However, not all of the second <br /> SELP extracts were actually analyzed for Titanium. Titanium is present in fly ash ranging Rom <br /> a high of 0.9 % (9000 ug/g) to a low of 0.15 % (1500 ug/g) as demonstrated by the compositional <br /> data for different fly, and bottom ash. (See comment 91 relating to the inability to reconcile <br /> compositional data with materials used in the leach tests). There were positive detections of Hg <br /> in the first SELP extraction volume of two fly ashes, and one positive detection of Mercury in <br /> the second SELP extraction volume at the detection limit. The Mercury detections in the first <br /> SELP extraction volume were, indeed, small, but significantly above the detection limit. <br /> 7. As a summary, Table 6 accounts for failures of the groundwater protections standards by the <br /> various ash samples tested by the SELP and SGLP leach tests. Several elemental primary <br /> groundwater standards appear to be exceeded in one, or the other extractions representing the <br /> different fly ashes. None of the fly ash samples exceeded primary standards for Sb, Ag, Ti, As, <br />