By: R. E. Blackett, H. P. Ross, and C. B. Forster
Discovered in 1975 by local farmers, the Newcastle geothermal resource has developed slowly. Pumping of geothermal water from the unconfined aquifer for space heating, mainly for commercial greenhouses, began in the early 1980s, and by 1988 three greenhouse complexes were producing tropical plants and vegetables for sale. One of the early operators went out of business, and in 1993 a California-based company purchased land, drilled new wells, and began construction of the first stage of a large-scale, geothermally heated greenhouse development.
Investigations by various organizations to characterize the geological and geophysical aspects of the system did not address the long-term, geohydrologic effects of large-scale withdrawal from the geothermal reservoir. Because future demands on the geothermal aquifer could stress the long-term productivity of the resource, we examined changes in the thermal regime of the system for the period 1976 through 1995. We present results of detailed, periodic temperature-gradient monitoring of available monitor wells during the past three years and compare them to readings made in 1976 and 1988.
Pages: 31 p.
Location: Iron County
Media Type: Paper Publication