Laserfiche WebLink
CNAPTERFIVE Graft EIS Reuislons <br />monitoring wells. In addition, wells were also classified as "other" if the use of the well was <br />unknown or unavailable to the State Engineer's Office. The purpose for comiucting the well <br />searches was to identify types of groundwater use in the project azea and to €;eographically locate <br />these uses. <br />3.4.1.5 Snrinas <br />There are three springs within three miles of the Piceance Site. as shown on :Figure C-1 a in <br />Appendix C. The nearest is less than 1.75 miles south of the Piceance Site at the confluence of <br />Rvan Gulch and Piceance Creek. A second spring is located 1.5 miles upstn:am from the <br />confluence along Piceance Creek. These sprin sg are hydrologically unaradi~;nt of the Piceance <br />Site. The other spring is located about 2.5 miles northeast of the Piceance Site on the east bank <br />of Piceance Creek neaz Square S Ranch. <br />Limited water qualiri information from the USGS database seazch is available for the spring <br />below Rvan Gulch (Appendix K of the Final EIS1. The TDS was recorded as 2.600 mg11 in a <br />sample collected in 1973. Data aze not available for the other two springs. <br />3.4.2 Project Area Hydrogeology <br />Hydrogeologic chazacteristics of the Piceance Site, pipeline corridor and Parachute Site are <br />discussed in this section. Figure 3.4-4 shows the wells discussed in the following sections. <br />These wells aze also included on the location mans for all wells in the azea in Appendix C. . <br />Water quality information is available for five American Soda wells (Table :3.4-2). nine White <br />River Nahcolite (WRPTI wells (Table 3.4-41. and other wells in the Proiect Area identified from <br />the USGS database seazch (Tables 3.4-3 and 3.4-51. Raw analytical data for the American Soda <br />and USGS wells aze included in Appendix K. Appendix K also includes data collected during <br />drilling of the American Soda wells (grab sampled and from USGS wells for which the geologic <br />unit monitored is unlmown. <br />3.4.2.1 Piceance Site <br />Three aquifers occur within three principal geologic sequences at the Piceance Site: the neaz- <br />surface alluvial aquifer beneath the streams (Alluvial Aquifer); the Upper Aquifer, which <br />includes the saturated part of the Uinta Formation and the upper part of the ]?azachute Creek <br />Member above the Mahogany Zone; and the Lower Aquifer, which include:; the lower part of the <br />Parachute Creek Member from the Mahogany Zone down to the top of the Saline Zone <br />(Dissolution Surface). The Mahogany Zone is considered a leaky, semi-confining layer, while <br />the Saline Zone is a confining layer. Monitoring wells installed by Americam Soda aze shown on <br />Figure 2-10. A summary of the construction details for theseproposed monitoring wells is <br />provided in Table 3.4-1. Water quality information for the American Soda •wells is summarized <br />in Table 3.4-2. Raw analytical data for these wells aze provided in Appendix K. ~ . <br />e e ~.....e,:.,e ~,..a_,...e,.~ ....:.. ......a:«•,.., lessr~ed-Helew- <br />Alluvial Aquifers <br />Local alluvial aquifers neaz the Piceance Site aze restricted to the broad, low-lying Piceance <br />Creek valley and tributary drainages. These shallow aquifers are primarily confined to <br />Quaternary alluvium valley fill consisting of sand, gravel, silt, and clay weathered from the <br />5-10 <br />