The Fort Union aquifer in north-central Wyoming is the sole source of
water for over small 75 public water systems and several industrial and
commercial operations in the Gillette area. The Fort Union is also a
key element in the water supply for the City of Gillette.
Under a memorandum of agreement between WWDC and the Ground Water
Division of the Wyoming State Engineer's Office, a long-range monitoring
program to evaluate the condition of the Fort Union aquifer was conducted.
The goal of this continuing study is to develop a management plan to
insure the long-term, responsible use of this important water resource.
The parameters of the study area approximately correspond to the Gillette
Planning District, although some monitoring will occur outside the
district boundary to establish baseline data, provide control points and
sample water quality. Ultimately, the monitoring plan will define the
long-term yield of the groundwater resource and determine optimal well
spacing. An accurate analysis of the effects of present usage on the
condition of the Fort Union Aquifer is essential to proper management of
the resource. The results of the analysis will provide information which
may be used to develop well spacing requirements, completion standards
and other factors to foster efficient use of the aquifer. The
information will be used by the WWDC in its funding decisions, by the
City of Gillette in its planning efforts, and by the State Engineer in
In 1994, eight Fort Union monitoring wells were completed in the
Gillette area under the supervision of the State Engineer's Office. The
wells were logged and equipped with long-term monitoring equipment. A
schedule for water quality monitoring was established. In 1995, the
State Engineer continued the project with the conversion of several
existing wells to monitor wells, the collection of baseline data, and
preparation of the project report. The State Engineer has submitted a
final report on the activities related to well construction,
installation of monitoring equipment, and preliminary data collection.
The report was submitted in a format that will allow updating as
additional information is retrieved from the ongoing monitoring program.
A Task Force consisting of representatives from the SEO, WWDC, Campbell
County and the City of Gillette will continue to review monitoring
activities, evaluate the results and make recommendations to the
RECOMMENDED LEGISLATIVE ACTION:
No legislative action is required on this project