Laserfiche WebLink
III I II I II I II I'll III Doc Date:1211112001 <br />~~~ sss <br />~r SECTION 4.0 Regraded Spoil Laboratory Results <br />• <br />Trapper's approved Mining and Reclamation Permit Application (C-81-010), specifies recontoured spoil will <br />be sampled annually for various chemical and physical properties to ensure suitability as a plant growth <br />medium. Section 2.7.2 addresses the parameters to be sampled, sampling intensity and suitability ranges for <br />those spoil parameters. TR-48, approved in August, 1990, reduced the annual reporting requirements to <br />regraded Ashmore pit and problematic areas only. Additionalty, PR-3 currently in public comment, will <br />require annual reporting of regraded spoils in F pit Trapper will sample and maintain all outer spoil records <br />on site. Those records will be readily available to COMLR. <br />4.1 Methods <br />Composite spoil samples (for all pits) were taken on approximately 50-ft to 100-ft centers for each mapping <br />unit The 1992 mapping units were determined by visual and textural difference of the surface spoils. A soil <br />sampling density of approximatety one sample per 4.9 acres of A pit reclaim area was accomplished. Each <br />sample was a composite from at least one foot of spoil material The samples were analyzed for pH, EG <br />CaC03, O.M., N03-N, P, K, 2n, Fe, Mn, Gtr, Se, Ca, Mg, Na, K, SAR, % Saturation, texture, Total Hg, F, % <br />Total S, and the acid-base potential If a large negative acid-base potential would have been found, then <br />additional analysis including pyritic Sulfw and SOgS would be run for that sample. No samples exhibited a <br />significant negative acid-base potential All 1992 spoil mapping units are presented on the annual spoil <br />history map (M4-1). Each unit is identified by the year sampled, texture, and lab analysis number. <br />• 4.2 Results <br />All 1992 spoil laboratory analyses were conducted by the Colorado State University Soil Testing Laboratory. <br />Ashmore pit spoil analysis is provided in Table 41. Comparisons between the 1992 A pit laboratory results <br />and the approved suitability ranges (Permit Table 2.7-2a) indicate 1992 samples were all within allowable <br />suitability ranges. Table 42 shows the suitability ratings for the 1992 Ashmore pit spoils. <br />4.3 Discussion and Recommendations <br />As previously stated, the purpose for annual spoil sampling and analysis is to demonstrate that the regmded <br />surface spoil layer has acceptable physical and chemical properties to promote plant growth and successful <br />reclamation. The 1992 data sVOngly indicates Trapper Mine has accomplished [his goal With the <br />replacement of suitable topsoil, all spoils should provide an excellent medium for plant growth for any <br />desirable postmine land use. <br />Collation of historical spoil analyses (1985-1989) first presented in Appendic W (1989) shows all 1992 <br />parameters are within the suitability ranges (Table 4.2 and 4.3). Table 4.3 also compares 1992 A pit spoil data <br />analysis to replaced topsoil values (1985-1990). <br />[COMLA\92RBPT4] <br />• <br />