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 within the aquifer matrix, and leakage of poor quality water into the aquifer from adjacent units.

Groundwater Development
Approximately 97 percent of the total groundwater use in this subbasin is for agricultural, industrial, and municipal purposes. Agricultural wells in the Pathfinder to Guernsey subbasin are permitted for about 53 percent of the total amount of permitted groundwater use in this subbasin. Most of these wells obtain water from the Quaternary and/or Late Tertiary Aquifer Systems. Industrial use, including power generation, mining, and petroleum recovery, is the second largest permitted groundwater user at about 25 percent of permitted subbasin groundwater use. While some of the industrial use wells obtain water from the Quaternary Aquifer System, many industrial wells obtain water from other aquifers in the area. Municipalities and community public water systems in this area are permitted to use approximately 20 percent of total permitted subbasin groundwater use. Groundwater is used by 13 municipal and community public water systems in the Pathfinder to Guernsey subbasin. The Central Wyoming Regional Water System (Casper), the Town of Mills, and the Town of Douglas supplement their groundwater usage with surface water supplies. Domestic use is a minor groundwater use in the Pathfinder to Guernsey subbasin, and less than 3 percent of subbasin groundwater use is for recreational and environmental purposes.

Platte County Control Area
On February 1, 1982, the State Board of Control in Water Division No. 1 established the Platte County Control Area due to development in the Wheatland-Dwyer Junction area of the County. The portion of the Platte County Control Area located in the Pathfinder to Guernsey subbasin can be seen by clicking here. A Control Area Advisory Board reviews and makes recommendations to the Wyoming State EngineerÆs Office concerning any new development of high capacity wells, enlargements of existing permitted wells, or placing new lands under irrigation within the Control Area. Within the southeastern portion of this subbasin, the Platte County Control Area will play a role in the development of future high capacity wells.