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Mr. Juston Smithers Waste Characterization of Ash n February 11, 2015 The DPFs physically trap and collect diesel soot fr el contains trace concentrations of metals that accumulate in the a aterials may also potentially be present in the ash. Based on preliminary in ormation eveloped previously, ENVIRON anticipated that the ash would exhibit a California hazardous waste characteristic of toxicity because of total metals content, and thus analysis of total metals was recommended for confirmation. In addition, analysis of leachable metals and leachable organics using the federal Toxicity Characteristic Leaching Procedure (TCLP) was recommended in order to assess whether the ash would exhibit a RCRA hazardous waste characteristic. Four samples of ash were collected by 44 Energy Tech and submitted to McCampbell Analytical, Inc. The laboratory reports of the results are attached. All four samples were analyzed for total metals and for TCLP lead and chromium, as discussed below. One sample was analyzed for TCLP organics. Total Metals. Metals that were detected in the total metals analysis are summarized on Table 1, along with the corresponding Total Threshold Limit Concentration (TTLC). Wastes that contain metals in concentrations that meet or exceed the TTLC thresholds exhibit a characteristic of toxicity under California hazardous waste regulations (22 CCR 66261.24(a)(2)). As indicated on Table 1, all four samples contained zinc in excess of the TTLC threshold of 5,000 milligrams per kilogram (mg/kg), indicating a characteristic of toxicity. The samples also contained total chromium in excess of the TTLC for chromium VI, but not in excess of the TTLC for chromium and chromium III compounds. Additional testing for chromium VI would be necessary to confirm whether or not the ash is hazardous by the TTLC for chromium, although such testing is not warranted given that the ash has already been confirmed to exhibit a characteristic of toxicity for zinc. Similarly, other additional tests that would indicate a California toxicity characteristic (i.e., soluble organics and aquatic toxicity) are not warranted. Leachable Metals. Wastes that contain leachable metals in concentrations that meet or exceed TCLP thresholds exhibit a characteristic of toxicity under both California and RCRA hazardous waste regulations. Because RCRA wastes are regulated differently than California - only wastes (i.e., non-RCRA wastes), particularly when shipped out of state, additional testing was conducted to determine if the ash samples fail the TCLP. The TCLP involves an extraction step in which the waste sample is mixed with an extraction fluid in a weight proportion of 1:20, effectively resulting in a 20 -fold dilution. As a result, only metals for which the total metals concentration is at least 20 times the respective TCLP have sufficient metal content to potentially fail the TCLP. As indicated on Table 1, all samples contained total lead and total chromium at concentrations at least 20 times the TCLP thresholds. Consequently, all four samples were analyzed for lead and chromium using the TCLP. As indicated on Table 2, neither lead nor chromium were detected above the TCLP, and hence the ash does not exhibit a RCRA characteristic for toxicity due to metals. Leachable Organics. Wastes that contain certain leachable organic constituents in concentrations that meet or exceed TCLP thresholds exhibit a characteristic of toxicity under both California and RCRA hazardous waste regulations. One ash sample was analyzed for TCLP constituents; the laboratory report includes results for concentration of the entire suite of volatile and semivolatile organic constituents that are typically reported using standard USEPA test methods, although only a limited number of constituents have TCLP thresholds.