Prison taps geothermal aquifer

UTAH STATE PRISON — A vast underground aquifer of near-boiling water is saving Utah taxpayers hundreds of thousands of dollars.

The geothermal reservoir — located roughly 1,000 feet beneath the Utah State Prison — has been tapped as an alternative energy source to provide heat and hot water to hundreds of inmates.

By the time the second phase of the project is completed in 2005, savings in natural gas costs alone will amount to $190,000 annually, said Bruce Munson, account executive for Milwaukee-based Johnson Controls Inc., the company responsible for building the project.

"It's a guaranteed contract," Munson said. "In the event we don't save them $190,000 a year, we will write them a check for the difference."

In fact, during the first phase of construction — from July 2003 to July 2004 — roughly $238,000 in savings in electrical, natural gas and water costs were realized.

And since the pump became operational in January, the underground reservoir has been responsible for providing hot water and heating to the four Oquirrh medium security buildings, which house 576 inmates.

By next year the project's benefits will extend to a special service dorm, a furniture and sewing shop and the Wasatch facility, which has 846 inmates.

The $11.5 million project will be paid back over 16 years from savings in utility costs.

"All of this heat is basically free from Mother Earth," said Michael Glenn, program specialist for the Utah Energy Office, which oversees energy efficiency programs for state buildings. "This is the best investment for the Utah taxpayer."

Back in 1951, when the first 600 inmates were transferred from Sugar House Prison to the new facility, the thought of a geothermal energy source at the prison was as remote a concept as the prison itself.

"They decided this would be the best place to build the prison because nobody was around here," said Jack Ford, a spokesman for the Utah Department of Corrections. "It wasn't a built-up community, which it now is 50 years later."

Yet had the prison been situated about a quarter mile to the south or to the north, said Bob Blackett, a senior geologist with the Utah Geological Survey, the benefits of the geothermal reservoir could have been lost.

"They are pretty much point sources," Blackett said. "They're not very laterally extensive."

The underground water travels through faults and fractures in deep circulation patterns where it is heated by the Earth's normal geothermal gradient.