Precious Metals Recovery LLC RCRA Permit Application Dry Hills ...

None of the parameters had a significant effect on the results of
the ruggedness test.
9.2 Precision. Many TCLP precision (reproducibility) studies have been
performed, and have shown that, in general, the precision of the TCLP is
comparable to or exceeds that of the EP toxicity test and that method precision
is adequate. One of the more significant contributions to poor precision appears
to be related to sample homogeneity and inter-laboratory variation (due to the
nature of waste materials).
9.2.1 Metals - The results of a multi-laboratory study are shown
in Table 6, and indicate that a single analysis of a waste may not be
adequate for waste characterization and identification requirements.
9.2.2 Semi-Volatile Organic Compounds - The results of two
studies are shown in Tables 7 and 8. Single laboratory precision was
excellent with greater than 90 percent of the results exhibiting an RSD
less than 25 percent. Over 85 percent of all individual compounds in the
multi-laboratory study fell in the RSD range of 20 - 120 percent. Both
studies concluded that the TCLP provides adequate precision. It was also
determined that the high acetate content of the extraction fluid did not
present problems (i.e., column degradation of the gas chromatograph) for
the analytical conditions used.
9.2.3 Volatile Organic Compounds - Eleven laboratories
participated in a collaborative study of the use of the ZHE with two waste
types which were fortified with a mixture of VOCs. The results of the
collaborative study are shown in Table 9. Precision results for VOCs tend
to occur over a considerable range. However, the range and mean RSD
compared very closely to the same collaborative study metals results in
Table 6. Blackburn and Show concluded that at the 95% level of significance:
1) recoveries among laboratories were statistically similar, 2)
recoveries did not vary significantly between the two sample types, and 3)
each laboratory showed the same pattern of recovery for each of the two
samples.
10.0 REFERENCES
1. Blackburn, W.B. and Show, I. "Collaborative Study of the Toxicity
Characteristics Leaching Procedure (TCLP)." Draft Final Report, Contract No. 68-
03-1958, S-Cubed, November 1986.
2. Newcomer, L.R., Blackburn, W.B., Kimmell, T.A. "Performance of the
Toxicity Characteristic Leaching Procedure." Wilson Laboratories, S-Cubed, U.S.
EPA, December 1986.
3. Williams, L.R., Francis, C.W.; Maskarinec, M.P., Taylor D.R., and Rothman,
N. "Single-Laboratory Evaluation of Mobility Procedure for Solid Waste." EMSL,
ORNL, S-Cubed, ENSECO.
CD-ROM 1311- 23 Revision 0
July 1992