Each aquifer has a very large areal extent within the basin, and except for the D and N aquifers, there is little vertical hydrologic connection between them. They are the main source of water supply for municipal and industrial uses. The primary industrial uses include three electrical generating stations and a pulp mill. The D-aquifer is made up of the Dakota, Cow Springs, and the Entrada Sandstones. Recharge to the D-aquifer is from local precipitation and runoff from the Defiance Uplift to the east.
Some water is lost from the aquifer by downward leakage into the underlying N-aquifer.
Water-level declines have occurred in this confined area as a result of groundwater withdrawals for the Black Mesa Coal Mine slurry pipeline operated by Peabody Coal. Water levels in the confined area are much more sensitive to pumping than those in the unconfined area. Precipitation falling on the exposed aquifer units is the main source of recharge for the N-aquifer. Groundwater in the N-aquifer moves southward and southeastward under Black Mesa. Water in the N-aquifer is of good quality and suitable for most uses.