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Ground Water Monitoring The ground water monitoring plan, as proposed by the applicant, is presented in Section 4.8.5.2 of the permit application. Wells to be monitored are shown on Map M52 and listed on Table 4.8-13 of the permit application. The list of water quality parameters to he monitored is found in Table 4.8-17a. The operation is in compliance with the requirements of this section. VII. Alluvial Ya11ey Floors (Rules 2.06.8 and 4.24) The Division has reviewed Sections 2.7, 4.8 and Appendix N for compliance with the requirements of this section. Description of Existing Environment The applicant has identified several areas near the Trapper Mine which meet the geomorphic criteria of an alluvial valley floor (AVF). They are No Name, Johnson, Pyeatt, and Flume Gulches and the Yampa and Williams Fork Rivers (see Map M35A of the permit application). These are discussed individually below. No Name Gulch occurs in the western portion of the mine. Unconsolidated streamlaid deposits do not exist within the portions of No Name Gulch to be disturbed at the Trapper Mine. Alluvial deposits do occur in the valley about one-half mile downstream of the mine. Portions of No Name Gulch will be mined-through and reconstructed during reclamation. These are all located upstream of the alluvial deposits. Land use along No Name Gulch is undeveloped rangeland. Portions (375 acres) of the lower reaches are used for unirrigated wheat production. These wheat fields will not be physically disturbed by mining. No irrigated crops are or have historically been grown along No Name Gulch. The average water yield for plo Name Gulch was determined by the applicant to be 117 acre-feet per year. This is an insufficient amount of water to economically support flood irrigation activities. This is substantiated through a conversation between the Division and a local Soil Conservation Service official in Craig, Colorado. Based on the limited presence of unconsolidated streamlaid deposits and the lack of sufficient quantities of water to support irrigated agricultural activity, No Name C~lch is determined not to be an AVF. Unconsolidated streamlaid deposits exist in Johnson Gulch within the permit area. These valley fill areas are all located outside the proposed mining-disturbance area. Land use along Johnson Gulch is undeveloped rangeland and cropland. The cropland consists of 725 acres of unirrigated wheat (see Map M35-b ). None of the cropland is located within the area of mining disturbance. The upper reaches of the Johnson Gulch will he mined-through and reconstructed during reclamation. No identified alluvial deposits will be mined through. The average annual water yield of Johnson Gulch is 114 acre-feet. The applicant states that this would irrigate about 20 to 38 acres for average years after evaporation losses. It would be uneconomical to construct a flood irrigation system to irrigate this small an acreage. This is confirmed through a discussion between the Division and a Soil Conservation Service official in Craig, Colorado. Therefore, based on the lack of irrigation potential and currently irrigated crop land, Johnson Gulch is determined not to be an AYF. _7 7_