2020-07-06_REVISION - C1994082 - Laserfiche WebLink

Home Browse Search

For SU, SPL submitted results from 172 depth samples taken over 818 acres. The samples were evenly distributed throughout the reclaimed area. The results indicate that an average of 1. 8 feet of topsoil had been replaced on the sample area. The Division finds that topsoil on the partial Phase II/111 release areas has been replaced in accordance with the approved permit requirements. Phase II Vegetation Standards and Sampling Methods for partial Phase II/III areas Map 1B, SL7 Area Delineation Map submitted with the SL7 application shows the chronological order of parcel seeding as does Exhibit B, Chronological Revegetation, submitted with this application. Most areas were drill seeded with the appropriate seed mix while steep slopes were broadcast seeded at twice the drill rate. Revege- Photo 2: Rosa woodsii are plentifultation success criteria and success demonstration throughout the site. methods are presented in Tab 22 of the approved permit. For Phase II bond release, cover is the only criteria required. Transect data tables, sample adequacy calculations, diversity calculations and species lists are presented in Attachment D of the SL7 application. However for Phase III bond release the applicant must meet all vegetation success standards: herbaceous cover, herbaceous production and species diversity which is discussed later in this document. Vegetation Cover Success The revegetation success standard for cover is dependent on comparisons, based on statistically valid sampling of the reclaimed areas and extended reference areas located in undisturbed areas within the permit boundary. Within the extended reference areas SPL maintains a minimum acreage of each community type. Four major pre mining community types (Aspen, Mountain Brush, Sagebrush and Steep Mountain Brush) disturbed during the life of the mine are represented. Weighted averages for cover and production comparisons are derived from the percentage that each community type was present in the pre -mining surface area affected by mining. Success is demonstrated if statistically adequate sampling and testing pursuant to Rule 4.15.11 demonstrate that the revegetated area cover is not less than 90% of the extended reference area cover at 90% statistical confidence. Refer to pages 32-45 of Tab 22 in the permit application package for a narrative describing the extended reference area approach for measuring revegetation success and for additional details associated measuring success standards. DRMS concluded that vegetation sampling occurred according to methods prescribed in the permit as per permit Tab 22 and, that sample adequacy was achieved by methods described in rule 4.15.11(2)(a) for some criteria but not all. Where sample adequacy was not achieved the reverse null was performed as per the above rule, and adequacy requirements met. For 2015 the allowable all hit herbaceous vegetation cover sampled in the BRB2 area was 69.8% and for the year 2016, 71.3%. The 2015 standard to be met was calculated to be 48.7%, and the Permit Number C-1994-082 Page 11 of 23