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3.3 CKD Leachate
<br />Quarterly composite samples of CKD solids collected from the former wet process kilns at the Holcim Portland
<br />plant are composed primarily of oxides of calcium, silica, potassium, aluminum, iron, and sulfate (Table 6a),
<br />and contain trace metals including antimony, arsenic, barium, beryllium, cadmium, chromium, copper, lead,
<br />mercury, nickel, selenium, silver, thallium, and zinc {Table 66). The quarterly composite CKD samples were
<br />evaluated using the Toxicity Characteristic Leaching Procedure, TCLP (EPA Method 1311). Antimony,
<br />arsenic, barium, beryllium, cadmium, chromium, copper, lead, manganese, mercury, nickel, selenium, silver,
<br />thallium, and zinc were detected in the TCLP leachate (Table 6c). The TCLP concentrations for Cd, Cu, Pb,
<br />Mn, Ni, Se, and Zn increased in the 4'" Qtr. 2000 and ls' Qtr. 2001 samples, especially for PO #2. Holcim
<br />suspects that these increases are an artifact of a change in laboratories and, potentially, in leaching and analytical
<br />procedures.
<br />In 1997 and 1998, leach tests were performed on CKD materials from the previous "wet kiln" cement process at
<br />the Holcim Portland plant combined with sludge from the Fremont Sanitation District to determine the likely
<br />mobility of these constituents if rainwater and/or groundwater were to contact these wastes. Combined
<br />CKD/sludge samples were submitted For TCLP and Synthetic Precipitation Leaching Procedure (SPLP) testing
<br />in 1998 (RGI, 1999). The TCLP method was modified to include the use of site-specific groundwater collected
<br />from MW-6 in place of the standard leaching fluid. The SPLP was run using "west of the Mississippi" synthetic
<br />precipitation. Aluminum was the only metal detected from the TCLP test while nickel, selenium, aluminum,
<br />iron, and manganese were detected in the SPLP leachate (Table 7). No exceedances of regulatory limits were
<br />noted.
<br />BLASLAND, BOUCK & LEE, INC.
<br />~znaroz engineers & scientists 34
<br />Geoundwettt MOnrtori~Plan ll.dot
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