WSP07728 - Laserfiche WebLink

Home Browse Search

CHAPTER II NEED FOR ACnON . w "'" CD ....... Several geologic formations in the area of the sprinRs are known to be water bearing. The major formations are Eagle Valley Evaporite ano Leaoville Limestone. The Eagle Valley Evaporite is predominantly inter- bedded gypsum, anhydrite, and siltstone. The evaporite rang;es in thick- ness up to 1,600 feet, and halite beds are also present at depth in the format-ion, The Leadville Limestone ranges from 180 to 250 feet thick. The upper part of the formation consists of coarse limestone, while the lower part is composed of interbedded dolomite and lirnestonp, Recharge to aquifers within these two water-bearing formations probably occurs along deep faults or outcrops, Downwarrl migrating water contacts halite and gypsum deposits of the Eagle Valley Evaporite aoO the Leadvi1 Ie Format ion, and acqui res high concent rat ions of sodiu1"l, chloride, calcium, and sulfate, The saline water is then heated at depth and subsequently enters the underlying; permeable Leadvi lle Lil'le- stone. The saline water probably mixes with other water within the limestone and then migrates toward the surface. At the surface, the saline water issues as the thermal springs at Dotsero ancl Glenwood Springs where the Colorado River has cut into the highly permei\hle Lei'lo- ville Limestone. The relative consistency of the flow, temperatnre, and salinity of the Dotsero and Glenwood sprin~s indiCAtes either a very large underground reservoir of heated water and/or a lon~ flow path through a heat source from the recharge source. . Problem quantification Results indicate that, of the 429,000 tons of salt which enter the Colorado River annually from the Glenwood-Ootsero Sprin~s Unit area, approximately 126.000 tons enter between Dotsero and Shoshone Dam ano the remaining 103,000 tons enter between the dam and just downstream of Glenwood Springs. Associated with the salt pickup in the Dotsero and Glenwood Springs areas is a saline water inflow to the Coloraoo River of approximately 30.2 ds. About 11.3 cfs of this inflow are from the Dot- sera area and the remaining 16,9 cfs are from the Glenwood Sprin~s area. The inflows and attendant salt loading are shown in Table ), Table 3 Saline water inflows and salt loadin~ Source . Ground Identified water springs inflow Total Sallnp water inflows (ds) ootsero area 5.7 7.6 13. '3 Glenwood Springs area ..7 7.2 16.. Total 15.4 14,8 30,2 Salt loading (tons per year) Dotsero area 52.000 74,000 120,000 Glenwood Springs area 174,000 129.000 303.000 Total 226,000 203,000 429,noo 13