Seepage from older tailing ponds, Chino Mines Company, New Mexico: Part II

This paper presents the rationale for and description of a relatively simple hydrologic conceptual flow model for the Chino Mines Company’s older tailing ponds and identifies factors controlling current and future seepage quantity. Representative hydrologic properties and conditions are assigned to major flow regions in this model, and Darcy’s Law for one-dimensional downward flow is used to compute volumetric flux from the base of the tailing. Based on the assumption that the underlying Gila Conglomerate does not restrict downward flow, the flux from the base of the tailing is assumed to be equivalent to the groundwater recharge rate. From use of this conceptual model and in situ monitoring of hydraulic parameters, it appears that water is slowly draining from the ponds at a rate of between 0.2 and 4 centimeters per year and that steady-state conditions are being approached. This calculated present-day flux is then compared with previously reported values.