2009-09-25_PERMIT FILE - M2009076 (43)

Home Browse Search

Reclamation Feasibility Report - Virginia Canyon • The solid samples were screened through a % inch stainless steel sieve, then placed in pre- cleaned 125 ml glass jars. The solid samples were analyzed for total metals following method SW 6010B. Arsenic, Cadmium, Copper, Lead, Iron and Zinc were measured in each sample. The deionized water leachate was collected by the following method: 150 ml of sample was removed and placed in a 1-liter plastic beaker along with 300 ml of deionized water. The wetted sample was then vigorously mixed for 15 seconds; plastic wrap was placed over the top, then left to settle for 90 minutes. Ninety minutes was the amount of time it took for the clay fraction to settle to the bottom of the beaker. After 90 minutes, the liquid was filtered through very fine grade soil filters (approximately 2 micron). A portion of the liquid was then used to measure the total acidity, pH, and specific conductance. The remaining liquid was acidified with nitric acid for lab analysis. Total acidity was determined using a Hach digital titrator to reach a phenolthalein end-point. The results from the solid sample and leachate analysis are presented in Appendix 6. The 2:1 deionized water method provides information on the amount of leachable metals in the waste sample. The solid sample total metals analysis provides information on the total amount of metal in the waste sample. In general, there was a poor correlation between the results of the two testing methods. The total metals analysis of the solid samples resulted in a much smaller relative range in concentrations than the 2:1 deionized water leachate analysis. This probably indicates that the metals in some samples are in a different crystalline form than others. The crystalline form of the mineral is partially responsible for the rate of weathering. At all the sampling sites, measurements and observations were recorded, including: • 1. Latitude/Longitude (uncorrected) 2. Major mineralogy and abundance of major sulfides 3. Approximate distance from a defined drainage channel 4. Degree of erosion (0-4) (0=no erosion, 4=Gullies over 12" deep) 5. Volumetric measurements 6. Presence and approximate size of a vegetation kill zone 7. Presence of vegetation on waste pile 8. Texture (fine = <2mm, medium = mostly gravel size, coarse = mostly cobble size) 9. Equipment access description 10. Feasibility of reclamation measures A synopsis of the measurements and observations is presented in Appendix 7. Visual observations were made of 126 other mine sites (Figure 4). These mine sites were viewed from a distance. Observations included approximate volume of mine waste, degree of erosion, presence of a vegetation kill zone, equipment access, and distance from a defined drainage. A synopsis of the observations is presented in Appendix 8. STREAM SEDIMENT SAMPLING Stream sediments were sampled at 28 locations during the summer of 1999 (Figure 5). The data from sediment sampling is presented in Appendix 9. Sediment samples were collected at the same sampling locations as the water quality samples collected by CSM and transported to the Colorado School of Mines for analysis (1). The sediment samples were analyzed by five different procedures ranging from mild dissolution to aggressive digestion as follows: 9