Analysis of selected trace metals in leachate from reference fly ash. Phase II. Supplemental leaching program. Final report

An inter-laboratory testing program was conducted to isolate and measure the primary components of variability in the American Society for Testing and Materials' (ASTM) and Environmental Protection Agency's (EPA) extraction procedures for testing the leaching potential of solid wastes. The program is a continuation of the Collaborative Test Programs undertaken jointly by ASTM Subcommittee D19.12 and the US Department of Energy (DOE). The National Bureau of Standards was retained by DOE to design the program and analyze the results. Engineering-Science provided initial program coordination, and Webster and Associates coodinated the data analysis and preparation of the report, both under contract to DOE. Thirteen laboratories participated in the program, all on a voluntary basis. In carrying out the program, specially prepared samples of a Reference Fly Ash were utilized in order to minimize sample heterogeneity. Each laboratory preformed both the ASTM and EPA extraction procedures on the Reference Fly Ash in duplicate, split the extract into two equal portions, completed duplicate analytical determinations on one portion, and shipped the other portion to a central laboratory. The central laboratory performed duplicate analytical determinations on all extracts. The main observations and conclusions from the test program are: (1) sampling may be a largemore » variable in field situations; however, with the use of the Reference Fly Ash, sample heterogeneity was controlled, allowing analysis of effects other than sampling variability; (2) the cooperating laboratories demonstrated acceptable analytical reproducibility based on analytical quality control data; (3) poor reproducibility of the trace metal results on the extracts from the Reference Fly Ash was shown to be primarily due to variability in the leaching process rather than analytical technique.« less