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Sample <br />Location <br />Geomorphic <br />Setting <br />Elevation <br />(ft amsl) <br />Sample <br />Date <br />Flow <br />Rate <br />Temperature <br />(°C) <br />pH <br />Specific <br />conductance <br />(US /cm) <br />Dissolved <br />Oxygen <br />(mg/I) <br />Upper <br />Incised <br />6,875 <br />12/05/04 <br />_Winn) <br />10 -15 <br />3.0 <br />1,670 <br />Straight <br />stream <br />1/24/05 <br />20 <br />2.6 <br />1,750 <br />Gulch <br />channel in <br />2/16/05 <br />110 <br />3.9 <br />00 <br />1,490 <br />I <br />narrow valley <br />3/14/05 <br />90 <br />1.7 <br />1,800 <br />4/19/05 <br />225 <br />8.4 <br />1,080 <br />Lower <br />Incised <br />6,665 <br />12/05/04 <br />5-10 <br />3.7 <br />CO CO OD CO OD <br />1,647 <br />7.26 <br />Straight <br />stream <br />1/24/05 <br />30 -35 <br />4.7 <br />1,742 <br />7.91 <br />Gulch <br />channel in <br />2/16/05 <br />225 <br />4.7 <br />1,640 <br />1.38 <br />valley <br />3/14/05 <br />110 <br />2.8 <br />1,820 <br />1.38 <br />4/19/05 <br />225 <br />8.3 <br />1.140 <br />1.41 <br />Upper <br />Incised <br />7,155 <br />12/08/04 <br />Dry <br />- <br />- <br />- <br />- <br />Co llom <br />stream <br />1/27/05 <br />Dry <br />- <br />- <br />- <br />- <br />Gulch <br />channel in <br />2/16/05 <br />Dry <br />- <br />- <br />- <br />- <br />narrow valley <br />3/14/05 <br />50 <br />1.1 <br />8.5 <br />710 <br />1.06 <br />4/19/05 <br />340 <br />9.2 <br />8.4 <br />530 <br />1.36 <br />Stream Descriptions <br />i <br />1 <br />=Walsh <br />Environmental Scientists and Engineers. LI.0 <br />Many reaches of the incised channels have unstable cut banks and recently- slumped <br />surfaces. The sides and bottoms of the stream channels are vegetated with a mixture of <br />big sagebrush, willows, and box - elder. There is little sinuosity developed in the channels. <br />Closer to the axis of the syncline, the stream valleys are wider with moderate side slopes. <br />On the north limb of the syncline, Morgan and Collom Gulches and Jubb Creek have <br />eroded through the steeply south - dipping rocks of the Williams Fork and Iles Formations <br />and into the top of the Mancos Shale. Stream gradients in this area are approximately <br />0.02 percent. <br />The type of water flow in a stream is important, as it affects such factors as riparian <br />vegetation, wildlife habitat, and human use. The type of water flow also affects frequency <br />of sampling and interpretation of the water quality samples. Streams can be classified as <br />ephemeral, intermittent, or perennial (American Geological Institute 1972). An <br />ephemeral stream (or reach) flows briefly only in direct response to precipitation in the <br />immediate locality, and its channel is at all times above the water table. An intermittent <br />stream (or reach) flows only at certain times of the year, as when it receives water from <br />springs or from surface water sources. A perennial stream (or reach) flows continuously <br />throughout the year (American Geological Institute 1972). <br />Within the proposed lease area, streams are ephemeral or intermittent (WMC 2005). <br />Wilson and Milk Creeks to the east of the project area are the nearest perennial streams. <br />In general, flow in the upper reaches of streams in the vicinity of the Collom Mine is <br />intermittent or ephemeral. A portion of stream flow in the upper reaches infiltrates into <br />the valley fill and recharges the groundwater system. Stream flow in the lower reaches is <br />intermittent during the summer months and appears to be maintained by groundwater <br />discharge from the valley fill and bedrock. Table 3 presents stream flow and water <br />quality data. <br />V PKOJLl n1 01 .PPS heal 11L \1 -, -rA (on.m ."fi <br />Table 3 Stream Attributes' <br />26 <br />