2012-04-13_REVISION - C1981014 - Laserfiche WebLink

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April 13, 2012 Page 3 of 6 The Division concurs that the small size of the currently approved Portal reference area is problematic and falls below the recommended reference area size of three acres (Guidelines for compliance with Land Use and Vegetation Requirements of the Colorado Mined Land Reclamation Board for Coal Mining, October 1988, and Rule 4.015.7(3)(c)). The Division suggests that enlarging the reference area to the southeast and northeast could be a potential solution. Based upon walking the site and locating the southwest corner post of the reference area, the Division disagrees that the approved reference area extends into the previously reclaimed roadway. This reclaimed roadway appears to be associated with the historic Peacock mine. The Division agrees that using a reference area exhibiting only one slope aspect in the vegetative community, Ponderosa - Pinyon- Juniper Woodland, described as a vegetation type "characterized by dense stands of ponderosa on north facing slopes and dominant stands of one - seeded juniper on east and south facing slopes," does not thoroughly represent the pre- mining vegetation type. Based upon pre - permit aerial photos, and mine area topographic maps (Map 14) the pre - disturbance landscape tended to have ridges and valleys trending southwest to northeast. The Southfield portal area was a narrow valley between ridges. Since the portal area was disturbed prior to the State permanent program, there was no pre- disturbance baseline data for the portal area. Aerial photos would allow one to project that the portal area was a narrow valley with both southeast facing hill slopes and northwest facing hillslopes. The Division believes the currently approved Portal Reference Area (Plot B) would reasonably represent the northern facing slopes of this vegetation types. The proposed Portal Reference Area appears that it would reasonably represent southeasterly slope aspects of this community. The Division suggests that utilizing both the PPJ reference areas to represent this vegetation community may be a reasonable approach. 5. Please incorporate both PPJ reference areas in to the reclamation success reference area requirements. i) Ideally the reference areas representing both aspects would be of similar sizes to avoid bias. ii) Previously disturbed areas should be excluded from both reference areas. iii) The permittee will propose sample methodology and data compilation that meets Rule 4.15.11. The Division concurs that there is an error in Exhibit 11, Keenan 1980 Vegetation sampling data. Plot B reference area (Ponderosa - pinyon - juniper woodland) summary of vegetative cover totals 11.39% cover. It is unclear from the text discussion of the 1980 sampling why the text states the vegetative cover was 19.1 %. The supporting data (Table 4) does not support the 19.1% value. Table 5 shows the correct summation of the Portal Reference Area "total Basal Vegetation Cover" of 11.39 %. Table 3 shows that the Refuse Dump baseline vegetative cover equaled 19.1%. Summarizing Table 4, the four tree species measured during the 1980 Keenan Mine Portal Reference Area sampling found the four tree species; Juniper monosperma, Juniper scopulorum, Pinus edulis, and Pinus ponderosa, only accounted for 2.08% cover on the Mine Portal Reference Area.