06-096DEPARTMENT OF ENVIRONMENTAL PROTECTION
("SW-846") includes the laboratory procedures for performing Method 1311, the Toxicity Characteristic Leaching Procedure (TCLP) on a waste to determine if it contains hazardous levels of any leachable TCLP constituents. 40 CFR Part 261, Appendix II, Section 1.2 states:
If a total analysis of the waste demonstrates that individual analytes are not present in the waste, or that they are present but at such low concentrations that the appropriate regulatory levels could not possibly be exceeded, the TCLP need not be run.
This provision allows flexibility in choosing the appropriate analysis for determining whether a waste is or may be hazardous by reason of the Toxicity Characteristic. If certain conditions are met, it may be possible to show by analysis for total parameters that a waste is not hazardous by characteristic without performing the TCLP analysis. This is done by determining the percent (per EPA SW-846, Method 1311, Section 7.1), calculating the "dilution" factor (DF), and dividing the total results for each constituent by the DF. If any totalDF is less than the TCLP regulatory limit for that constituent, then the waste is not TC-hazardous, and TCLP analysis is not needed. If totalDF is equal to or greater than the TCLP regulatory limit for any constituent, then the waste may be, but is not necessarily, a hazardous waste. In this case, full TCLP testing for the constituent(s) in question is required to make that determination.
TCLP analysis is done by extracting the waste with a mild aqueous acid. The fraction of the waste recovered as solid upon filtration of a sample of the waste (i.e. % wet solids - see SW-846, Method 1311, Section 7.1) determines the volume of extractant to be used (see SW-846, Sections 7.2 and 7.3). To the extent that filterable liquid is present in the waste, the extractant volume to be used is lessened.
Each unit (e.g. gram) of non-liquid waste requires the addition of twenty times its mass of extractant. Thus each gram of liquid filterable from the waste (and eventually added back to the final extract) lessens the volume of the extract by approximately nineteen grams (20 grams-1 gram=19 grams). As a result, the final volume in which all the extractable constituents are dissolved varies with the liquid content of the waste, and the "dilution" of the constituents from the waste varies. At one extreme, in the case of a waste with no filterable liquid, the mass of final extract is twenty times the mass of the original sample, resulting in a twenty-fold "dilution". At the other extreme, when the entire sample is a filterable liquid, the dilution factor is one-fold; the "extract" (the liquid) is not diluted. Such a dilution factor may be applied to the results of a totals analysis to estimate the maximum possible TCLP extract constituent concentrations for that specific waste. For this purpose, the percent filterable solids in a separate sample must be determined, and the appropriate dilution factor then determined. The TCLP Method 1311 should be consulted for details.
Chapter 405: Water Quality Monitoring, Leachate Monitoring, and Waste Characterization
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