A Deep, Non-potable Water Supply for the Ochoa Sulphate of Potash (SOP) Mine Project, New Mexico, USA

摘要

Competing with communities, agriculture, and industry for potable-water resources can pose great challenges for mining companies seeking public and regulatory support for proposed projects. In semi-arid and arid regions of the world where freshwater resources are limited, using potable resources to supply water to mining operations often faces opposition from existing water users or is subject to lengthy regulatory reviews. Here we describe how Intercontinental Potash Corp. (USA) developed a deep, non-potable water supply from the Capitan aquifer for its Ochoa SOP Mine Project (Ochoa Project) in southeastern New Mexico (USA) that safeguards the limited freshwater resources. Through a program of exploratory well drilling, aquifer testing, and groundwater flow modeling, we find that the Capitan aquifer can sustain the proposed pumping rate of 252 L/s for a 50 year period, and that drawdown is predicted to be up to 200 m in the area of the proposed well field. We also find that depletions from the Pecos River, a connected stream subject to interstate compact agreements for water deliveries, are predicted to be at a rate of up to 1.10 L/s. We attribute the minimal impacts of the proposed pumping on the Pecos River largely to a zone of low hydraulic conductivity (1.5 x 10(-3) m/day) near the county line that separates the aquifer where pumping is proposed in Lea County, New Mexico, from the area where the aquifer is connected to the Pecos River in Eddy County, New Mexico.