Area B

The Ogallala and White River Formations dip gently downward from Area A (on the west) toward Area B (on the east), resulting in the water-table/potentiometric surface moving from within the White River Formation in Area A to within the overlying Ogallala Formation in Area B. The western edge of Area B marks the approximate line where the Ogallala Formation becomes saturated. Within Area B the uppermost water-bearing units include the lowermost units of the Ogallala Formation and uppermost layers of the White River Formation.

Map of Area B at missile site 4

There are numerous wells of various types located in Area B, as described below:

  • Seven Test Hole wells (TH-2 through TH-6, TH-9, and TH-10; TH-1 typically has very little water or is dry)
  • Eleven USACE monitoring well locations, most with multiple screened intervals
  • Six municipal water supply wells; two additional wells (Belvoir No. 5 and Belvoir No. 6) have been drilled but not yet brought on line
  • Several stock wells operated by either submersible pumps or windmills
  • Eleven industrial wells owned by Dyno Nobel
  • A new two-well monitoring cluster installed by the USGS near TH-5 (BRO-1A and BRO-2)
  • Several irrigation wells that discharge water to Lone Tree Creek
  • Two deeper test wells (WR-2 and WR-3) installed as part of a study of the White River Formation
  • Nine domestic (residential) wells
  • A few miscellaneous/industrial wells

Most of the wells in this area are screened in the Ogallala Aquifer, except for a few wells completed deeper than 250 feet that penetrate the White River Formation (Saler No. 4 and Cow Camp #1 stock wells and the three domestic wells located near the west end of Otto Road: Cande’s#888, Coulson #1, and the “7H” well). All of these wells are all located close to the west edge of Area B.

Man conducting water testing

Trichloroethylene (TCE) contamination ranging from non-detect to just over 50 milligrams per liter (mg/L) is present in the Ogallala Formation and upper White River Formation groundwater in Area B. Well locations in Area B and the outline of the TCE plume are shown in Figure 4. The yellow outline on the figure represents groundwater with 5 mg/L of TCE, which is the EPA’s drinking-water action level for TCE. The area within the yellow outline is the TCE contaminant plume. Unsaturated soils in Area B are not contaminated.