Three-dimensional digital-computer model of the Ferron sandstone aquifer near Emery, Utah

A three-dimensional finite-difference computer model of the Ferron sand-stone aquifer was used to simulate ground-water flow in the Emery coal field in east-central Utah. The model also was used to predict the effects of pro-posed surface mining and the resulting mine dewatering on potentiometric sur-faces of the aquifer. The model was calibrated in a steady-state simulation using water levels and manmade discharges from the aquifer that were measured during 1979. Too few data were available to verify the calibrated model in a transient-state simulation with historical aquifer response to manmade dis-charges. Predictions made with the model are considered to be semiquantitative. Discharge from the proposed surface mine was predicted to average 0.3 cubic foot per second during the 15 years of operation. Drawdowns of 5 feet in the potentiometric surface of the aquifer were predicted to extend as much as 3 miles from the proposed mine after 15 years of operation.