ABSTRACT

Increasing demands on water resources throughout the semi-arid south western United States have driven the exploration for groundwater to greater depths. A recently completed project to explore and develop groundwater resources from deep fractured rock aquifers at a site in New Mexico was conducted using geophysical analysis, geologic mapping, isotopic analysis, exploration well zone testing, and production well aquifer testing. The site is composed of a synclinorium bounded by two major fault zones; numerous smaller fault zones and geologic structures are also present. Two deep wells (screened from 412 to 652 m below ground surface [bgs] and 152 to 210 m bgs) were constructed and tested at the site. Aquifer testing of the most productive well indicated a highly productive aquifer of limited extent, with two discernible low-permeability boundaries. These findings are important for the prediction of long-term well yield and pumping effects on adjacent groundwater users and spring flow.