2012-01-23_APPLICATION CORRESPONDENCE - C2010088 (3)

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The Mount Garfield Formation and Sego Sandstone contain buff to yellowish -brown sandstone bedded with soft gray shale that contains one or more beds of bituminous coal and underlying thick beds of sandstone that rest upon the marine Mancos shale. Overlying the Mount Garfield and Sego Sandstone are the Hunter Canyon, Wasatch, Green River and Uinta Formations, which successively rise to the lava- capped deposits on Grand Mesa. The western escarpment of Grand Mesa, elevation 10,000 feet, overlooks the Grand Valley from the east. This lava- capped formation and others farther up the Colorado River consist of igneous, sandstone, and shale formations and are the source of the older alluvial deposits on Orchard Mesa and of the younger alluvium on the Colorado River flood plain. The mountainous terrain with deep canyons that flanks Grand Valley to the southwest and west of Grand Junction is more complex geologically than other parts adjoining the Grand Junction Area. This complexity results from the Uncompahgre uplift, as is evidenced by the sharply tilted landscape and varicolored rocks to the west of the Redlands. This uplift, after ages of severe geologic erosion, has caused the exposure of several of the upheaved geologic formations that before the uplift normally were situated far below the thick, 4,000 foot, Mancos shale bed. From the top downward, in respect to their former position below the Mancos shale, the formations include Dakota, Morrison, Summerville, Entrada, Kayenta, Chinle, and the lower pre - Cambrian. These give rise to the sandy soils of the Redlands. Surface Water The permit and adjacent area lies west of the Fruita refinery on areas of relatively level ground with an overall gradient to the southwest. The area is drained by two drainage areas, Reed Wash in the central portion of the permit area and Loma Drain to the west. Reed Wash and Loma Drain flow generally southwest to the Colorado River, a distance of only about 0.25 miles. A discussion of the surface water aspects of the proposed permit area and adjacent area can be found in Sections 2.04.5 and 2.04.7 of the permit application. Map 08, "Hydrologic Monitoring Locations ", shows the locations of the surface water monitoring sites used in the gathering of the baseline surface water data that is presented in Appendix 3 of the PAP. The proposed Fruita Loadout permit area is located in the Colorado River Basin. The southwest corner of the permit area is about 6 feet higher in elevation and 800 feet to the northeast of the 100 year flood plain of the Colorado River. Map 08 shows the upstream and downstream monitoring sites for the Colorado River, designated as US -CR and DS -CR respectively. The baseline surface water data for the Colorado River show that a high flow rate of 15,100 cfs occurred in the second quarter of 2010 while the low flow rate of 2,910 cfs occurred in the fourth quarter of 2010. The flow rates during the first, third and fourth quarters of 2010 are very close in magnitude while the flow rate for the second quarter of 2010 was far higher due to the influence of snowmelt. As explained in Subsection III G of Section B of these Findings, the Colorado River will not be sampled during loadout operations except for the four quarters preceding bond release, in order to verify the PHC conclusions concerning impacts to the Colorado River. 11