Geologic structure, hydrology, and water quality of the Laramie-Fox Hills aquifer in the Denver basin, Colorado

The Denver ground-water basin underlies a 6,700-square-mile area extending from Greeley in the north to Colorado Springs in the south, and from the Front Range in the west to near Limon in the east.  The four major bedrock aquifers that occur in the basin are the Laramie-Fox Hills aquifer (the deepest aquifer), the Arapahoe aquifer, the Denver aquifer, and the Dawson aquifer (the uppermost aquifer).  The Laramie-Fox Hills aquifer, which is the subject of this report, underlies the entire area of the basin in east-central Colorado (index map, fig. 1) and is an important source of water for residents in the northern Denver suburban area and in the rural areas of eastern Jefferson, Arapahoe, and Elbert Counties, Adams County, and southern Weld and El Paso Counties.  About 90 percent of the estimated 1,700 wells completed in the aquifer supply water to residents and livestock.  The remaining wells supply water for commercial and industrial use and limited irrigation of commercial crops.