|
<br />Section - 2.04.7
<br />Analysis values indicate a neutral to slightly alkaline pH and elevated EC, IDS, hardness, and
<br />dissolved iron and manganese, as summarized by Tables 2.04.7-T3B, B Coal Seam Water Quality
<br />Summary and 2.04.7-T3C, D Coal Seam Water Quality Summary. Characteristic of deeper perched
<br />ground water, the stored mine water is somewhat isolated from and less subject to seasonal
<br />fluctuation in water level and water quality. Generally, the quality of stored mine water is consistent
<br />iw tl, dnFh n<rehe.t ..d. ..ter J_;__ F u a` -1 a mr?crss > >-
<br />.. "'r r "grOL•.. - 6 . at c etiatcu S, i , an"' uissolveu
<br />metals. For active mine areas, the only treatment typically required for mine water discharge to meet
<br />applicable effluent standards is temporary retention to allow settling of suspended solids.
<br />Ground Water Rights and Use - Due to quality and yield considerations, surface water and
<br />associated alluvial/colluvial units are the primary water supply sources in the area. Of the three
<br />identified ground water units previously discussed, the only unit which provides adequate quantities of
<br />water of suitable quality to support beneficial use is the alluvial/coUuvial aquifer system.
<br />Existing water rights documentation, as updated by the Colorado Division of Water Resources in
<br />October, 2002 and summarized in Table 2.04.7-T4, Water Rights Summary - Mine and Adjacent
<br />Areas, indicates a total of fifteen ground water rights in the mine and adjacent areas. Of the identified
<br />ground water rights, as shown on the Surface Water Hydrology Map, (Map 2.04-M6), all are
<br />associated with the North Fork or tributary alluvial/colluvial deposits except Hotchkiss Spring No. 1,
<br />Tony Bear Yuma Spring, Mt. Gunnison Mine, and several water rights associated with shallow ground
<br />water in the Hubbard Creek drainage to the west (Blue Ribbon Well, J&M Spring, and Pipeline Nos. 1
<br />and 2).
<br />As indicated by Table 2.04.7-T4, allocations for the identified ground water rights are relatively small,
<br />ranging from 0.004 to 1.002 cfs. Ground water use in the area is limited to individual domestic water
<br />supply (Kanzler Well, Norris Well No. 1, Tony Bear Yuma Spring, New Majnik House Well, Sell No.
<br />1 Well); small stock watering and irrigation (Hotchkiss Spring No. 1, J&M Spring and Pipeline Nos. 1
<br />and 2); small municipal water supply (Somerset Water Supply System, Somerset P/A); and mine use
<br />(Somerset Mine Well, Bear Well No. 1, Hawk's Nest Well, Mount Gunnison Mine, Blue Ribbon
<br />Well).
<br />Surface Water Information
<br />In the mine permit and adjacent areas, beneficial use of surface water is generally limited to ditch
<br />withdrawals from the larger surface drainages for small-scale local or downstream irrigation use.
<br />Because of the rugged terrain in the mine vicinity, most irrigation use occurs at least five miles
<br />downstream, near the Town of Paonia, where the North Fork Valley opens out into a broad alluvial
<br />plain. Because of limited flows and significant seasonal fluctuations in the smaller drainages, the
<br />North Fork, Thompson Creek, and Hubbard Creek are the only drainages in the mine vicinity which
<br />are subject to surface withdrawals. Given these considerations, the significance of surface water
<br />resources relative to ongoing and proposed mining operations involves potential mining-related
<br />impacts on surface runoff characteristics, perennial drainages, and disturbed area or mine water
<br />discharge to surface drainages. The following sections characterize surface water occurrence,
<br />environment and conditions as a basis for evaluation of these potential impacts.
<br />Mine Area Watersheds, Surface Water Occurrence, and Relationship to Mining Disturbance -
<br />The regional surface watershed area, which includes the tine permit and adjacent areas, is the
<br />watershed of the North Fork of the Gunnison River as shown by Figure 2.04.7-F8, Surface
<br />Watershed Area. The regional watershed is defined by the crest of Grand Mesa to the north, the crest
<br />of the Elk Mountains to the east and south, and the Colorado River Valley to the west. Within the
<br />regional surface watershed area, the terrain is generally mountainous with Englemann spruce/blue
<br />PR-05
<br />2.04-50 Revised October 2002
|