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Section 2 <br />Methodology <br />each development rock sample (DM-TPWR, DM-SVWR, DM-SJWR, DM-WRSWR, • <br />DM-V4WR) was created in an effort to generate similar leachate results (metals <br />concentrations) as those observed during the MWWP test performed previously by <br />Energy Laboratory. The generated leachates were created using the western rain <br />water formula identified in SW-846 method 1312 (SPLP). A 1:1 ratio (weight to <br />weight)of extraction fluid #2 (reagent water adjusted to pH 5.0 standard units [su] <br />using 60/40 weight percent mixture of H2SO4 and HN03 as described in EPA's SW <br />846 Method 1312) and development rock was added to a clean 5-gallon bucket. Fluid <br />#2 is a synthetic rainwater appropriate for sites in the Western U.S., and was chosen <br />to simulate percolation of precipitation through the vadose zone. The materials were <br />tumbled at approximately 20 rotations per minute (rpm) for 48 hours to achieve <br />equilibrium between the solids and the solution. After the 48-hour tumbling time, the <br />solution was separated from the solids via pressure filtration through a 0.45 <br />micrometer (gm) pressure filter. A sample of the leachate was submitted to Energy <br />Laboratories in Casper Wyoming and analyzed for total metals (EPA 200.8) and gross <br />alpha/ gross beta (EPA 900.0). <br />2.2.2 Batch Attenuation Preparation Methods <br />The batch/attenuation adsorption test generally followed ASTM D4646-03 (Standard <br />Test Method for 24-hour Batch-Type Measurement of Contaminant Sorption by Soils <br />and Sediments) and Batch -Type Adsorption Procedures for Estimation Attenuation <br />of Chemicals (EPA Publication 530-SW-87-006). A total of five solution:soil ratios were <br />used in the batches for each of the soils. The ratios ranged from approximately 60:1 to • <br />approximately 4:1 (mL:g) as shown in Table 2-1. The soil (associate with each <br />development rock) was placed in 1L nalgene bottles and filled with the leachate that <br />was generated as described above. Table 2-1 presents the mass of sample and volume <br />of leachate solution used. The samples were tumbled at approximately 20 rpm for 48 <br />hours to achieve equilibrium between the solids and the solution. Previous testing by <br />CDM on numerous projects has indicated that equilibrium is usually reached within <br />24 to 48 hours. <br />The aqueous samples were decanted at the CDM laboratory to separate the bulk <br />solids from the water. The sample was then sent via overnight carrier to Energy <br />Laboratories in Casper, Wyoming at a temperature of 40DC (on ice) where the solution <br />was separated from the remaining solids and filtered through a 0.45 um membrane. <br />Analyses for metals (method EPA 200.8) and gross alpha/beta (EPA 900.0) were <br />performed by Energy Laboratory. <br />• <br />cm 2-2 <br />7:\84986-Denison Mines\Task Order 3 - DMO Sampling and Analysis Plan\Task 3.12 - Soil, Ore, Rock Data Assessment ReporflSanday Rock ReportWttachmentsMeneation Report_w rking draft 040309.doc