Groundwater Quality
The best quality groundwater is usually derived closest to the geologic outcrop areas of each aquifer. Generally, the water quality of groundwater derived from each aquifer is variable and dependent upon a variety of factors including, but not necessarily limited to distance from the recharge area, aquifer transmissivity and storage, groundwater flow rates, aquifer rock type, dissolution of soluble salts and minerals within the aquifer matrix, and leakage of poor quality water into the aquifer from adjacent units.

Groundwater Development
Most of total permitted groundwater use in the South Platte River subbasin is for agricultural, industrial, and municipal purposes. Eastern Laramie County is one of the most extensively farmed cropland areas of Wyoming and uses wells as the primary source of crop irrigation water. These wells obtain water predominantly from the Late Tertiary Aquifer System. Municipal and community public water systems also use groundwater in the subbasin. While the City of Cheyenne uses both surface and groundwater for its municipal supply, the other 12 community water supply systems in the subbasin rely on groundwater only. The Late Tertiary Aquifer System is the principal aquifer that has been developed for community water supply wells in this area. Industrial use is the third largest permitted user of groundwater in the subbasin, and industrial use sectors include mining, petroleum recovery, and oil refining. Industrial wells obtain water from the Early Cretaceous and Late Tertiary Aquifer Systems. Domestic use is a minor groundwater use in the South Platte River subbasin, and less than 1 percent of permitted groundwater use is for recreational and environmental purposes.

Laramie County Control Area
On September 2, 1981, the State Board of Control in Water Division No. 1 established the Laramie County Control Area due to well interference between agricultural wells and groundwater level declines in the heavily developed eastern portion of Laramie County. The portion of the Laramie County Control Area located in the South Platte River subbasin can be seen by clicking here. The Control Area Advisory Board reviews and makes recommendations to the Wyoming State EngineerÆs Office concerning development of any new high capacity wells, enlargements of existing permitted wells, or placing new lands under irrigation within the Control Area. The Laramie County Control Area plays a large role in the utilization of existing groundwater sources and development of potential future supplies within this Control Area.