U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12,1999--Volume 1 of 3--Contamination From Hard-Rock Mining, Water-Resources Investigation Report 99-4018A

Preliminary Model Development of the Ground- and Surface-Water System in Pinal Creek Basin, Arizona

By Cory E. Angeroth, S. A. Leake, and Brian J. Wagner

This report is available in pdf format: Angeroth.pdf 227KB

ABSTRACT

Ongoing studies of surface water and ground water contaminated by acidic-mine wastes in the Pinal Creek Basin near Globe, Arizona, include the development of a ground-water flow model. The flow system is being simulated with the U.S. Geological Survey's updated three-dimensional, finite-difference, ground-water flow model, MODFLOW-96. The model has been vertically discretized into five layers and horizontally discretized into 62.5-meter by 125-meter cells. Simulation of the hydrologic processes in the basin will provide information on the effects of streamflow infiltration, ground-water discharge to a perennial stream reach, ground-water pumping, and an unlined surface-water impoundment. The model also will be used to test the value of various types of data for calibrating ground-water flow models. The aquifer is bounded by impermeable crystalline rocks and is composed of a thick conglomerate and, near major drainages, unconsolidated alluvium where the bulk of the contamination is present.