Laserfiche WebLink
Visual observations of the reclaimed areas by the Division during the combined Phase II/Phase III <br />bond release and prior inspections indicate that the proposed release area does not exhibit excessive <br />rills or gullies that would be indicative of excessive erosion and resultant sediment transport. The <br />Division finds that revegetation efforts on the bond release areas are adequate to control erosion and <br />that the reclaimed areas are not contributing suspended solids to streamflow or run off outside the <br />permit area in excess of levels determined on adjacent non mined areas. The sampling methods used <br />for the various criteria below meet the rigors outlined in Rule 4.15.11(1) and the permit application. <br />Phase III Revegetation Standards and Success <br />All areas requested for combined Phase II and III (39.4 acres), bond release per SL7 have previously <br />received Phase I release and meet the minimum liability period as required by Rule 3.02.3(2)(b). The <br />applicant is requesting Phase III bond release on 315 acres that have achieved Phase I and 11 release <br />previously. Given this, the total proposed Phase III bond release area for SL7 is 354.4 acres. <br />Transect data tables, sample adequacy, production and diversity calculations are presented in <br />Attachment D of the SL7 application and seed mixes are documented in the Annual Reclamation <br />Reports. For a thorough discussion of standards, mandatory and alternative tests, and calculations <br />please refer to the PAP, the SL7 bond release request and the associated Appendix D. <br />Cover success was discussed in the Phase II portion of this document. The bond release block was <br />also evaluated for Phase III release. The success standard for cover was achieved for both year 2015 <br />and 2016. <br />Production <br />Production sampling comprises harvesting of biomass produced during the current year within a 0.5 <br />square meter sample plot. Lichens, mosses, noxious weeds and shrub production are not clipped. <br />Following clipping, the material is oven dried and weighed to determine average production for <br />the bond release blocks (BRB). Units comprise grams per square meter (gm/0.5 sq m), and <br />pounds per acre (lbs/ac). The allowable herbaceous production values for the four vegetation types <br />in the reference area are used in the weight averaged calculations to determine the production <br />standard. <br />Thirty production transects were sampled in 2015 and 35 in year 2016 and 32 transects in each <br />reference area in both years. Reclamation productivity success will be considered successful <br />when annual herbaceous production on the bond release area is 90 percent or greater than the <br />annual herbaceous production weighted average based on the four primary pre mine vegetation <br />type contributions to total acreage. <br />Sample adequacy was not demonstrated with 30 samples in either the reclaimed or the reference <br />areas for years 2015 and 2016. Therefore, reclamation success for Phase III is demonstrated by <br />passing a one sample t-test of the "reverse null" hypothesis (CDMG 2005 revised rule, 4.15.11 (2)(c)) <br />and following a square root transformation of the data, the test was passed. <br />The 2015 BR132 reclaimed area mean allowable herbaceous production of 1,709.2 pounds per acre <br />far exceeded 90 percent of the production performance standard of 736.4 pounds per acre. The <br />average herbaceous production by annuals and biennials sampled in the BRB-2 was less than 10% of <br />total herbaceous production. <br />Permit Number C-1994-082 Page 14 of 23 <br />