Simpson Springs – City of Laramie
WESTON was selected by the City of Laramie to evaluate the Simpson Springs located on the Monolith Ranch to determine whether development of the groundwater at Simpson Springs can potentially be a viable drinking water source for the City of Laramie. The project included conducting a hydrogeolgic evaluation of the Simpson Springs area and conducting a well siting study to determine the optimal location for siting three test wells and two monitoring wells. The project also included development of bid documents and technical specifications to retain a drilling contractor to drilling contractor, providing drilling supervision and oversight, and conducting pump testing on the wells. WESTON also installed surface monitoring equipment in the spring outlets in order to evaluate the response of surface water in the area to pumping of the test wells.
HYDROGEOLOGIC EVALUATION AND WELL SITING STUDY
WESTON conducted several field reconnaissance studies at Simpson Springs in order to verify the mapped geology of the area and to evaluate the potential mechanisms that control the flow of the springs in the area. Based on the results of the field investigation and data obtained from nearby private wells completed in the Casper Aquifer, WESTON sited two test wells and two monitoring wells near the springs. One of the test wells was designed to penetrate the entire thickness of the Casper Aquifer in order provide information on the water bearing potential of the lower portion of the aquifer for which little information exists in the Laramie area.
TEST WELL DRILLING AND AQUIFER TESTING
As part of this project, WESTON provided assistance to the City of Laramie by developing plans and specifications for the test well drilling program and aiding the City in the bidding and Contractor selection process. The drilling program, which began in August of 2013, initially included two test wells to be completed in the Casper Aquifer. However, because information obtained during drilling indicated that much of the flow from the springs was supplied by a channel deposit in the lower Satanka Formation, a third test well completed in the channel deposit was added to the drilling program. Following installation of three test wells and two monitoring wells in November, 2013, aquifer testing was conducted on each of the test wells. A five-day combined aquifer test was also conducted.on two of the test wells.
GROUNDWATER AND SURFACE WATER MONITORING
A total of seven monitoring locations were selected to monitor surface water and groundwater during the testing program for fluctuations in water levels before, during, and after pump testing to determine if and how groundwater and surface water were influenced by the testing program.
DATA INTERPRETATION
WESTON’s evaluation of the pump test and aquifer monitoring data allowed for interpretation of a complex integrated two-aquifer system. A well-developed aquifer monitoring plan and recognition of subsurface hydrogeologic conditions allowed the entire program to be efficiently modified to test the most productive aquifer intervals while keeping the project within budget.
