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This is Part III of a series on geothermal energy development in Chaffee County.

This news story will address some of the concerns put forth by concerned residents with BV Community for a Pristine Mt. Princeton including groundwater contamination, noise, viewsheds, and potential for earthquakes.

For a more in-depth discussion on the impacts and technical details of geothermal energy than this article can offer, Mt. Princeton Geothermal is planning to put together community outreach informational sessions sometime over the coming months. These sessions will include an impartial moderator as well as scientists and experts in the field of geothermal. When there are more solidified details on that front we will let you know.

To read the earlier parts of this series on geothermal energy:

Part I: Getting Up to Speed

Part II: The Path to Power

A map indicating the section of land on which Mt. Princeton Geothermal has been granted a geothermal resource exploration lease. Image courtesy of Mt. Princeton Geothermal.

It is easy to decry the variety of complaints raised by those with BV Community for a Pristine Mt. Princeton (PMP) as a standard case of NIMBY-ism. As Tom McCracken, high school math teacher and willing spokesman for PMP noted when the phrase came up, “Is that such a bad thing?”

For many people, their home and surrounding property is the largest investment of their lifetime, so being mindful of its surrounding environment is vital.

“I hear a lot of ‘I think that’…” said McCracken, “but I don’t hear the ‘we know that’…”

This type of distrust is what brought about the formation of PMP and their attempts to illuminate the dangers inherent to a geothermal power plant.

But, in their protests, PMP has used what Chaffee County Commissioner Keith Baker and Sangre De Cristo Electric Association (SDCEA) Director Dan Daly both separately described as misinformation. Baker was careful to add to his statement of misinformation at the August 8 Board of County Commissioners’ (BoCC) meeting that there is a difference between misinformation and disinformation (a difference of malicious intent which should not be imposed upon PMP and their opposition to the construction of a geothermal facility).

That is, there has been no intent to deceive.

But, many of the arguments put forth by PMP come attached to the exculpatory phrase “We’re just asking questions,” a tactic often used to discount relevant facts and expertise.

As stated in Part II, it is not possible to take answers from the realm of thinking into the realm of knowing until resource testing has been done at the site of interest. In addressing a range of worries over the course of this article, it would be irresponsible to speak with full certainty as to what a geothermal plant would look like at the proposed location.

A simple diagram of a binary geothermal plant, with additional usage of extracted resources for the heating of nearby residences, as proposed by MPG. Image courtesy of MPG.

In order to operate from a consistent baseline, this article will assume that, if a plant were to be constructed, it would be a somewhat small, 10 Megawatt (MW) binary facility, as described by Hank Held, CEO of MPG, in a letter to the Lost Creek Homeowners Association. (Refer to the accompanying image.) Binary plants use both water and a low-boiling point medium to generate steam that runs a turbine.

Trout Creek Solar, for the sake of comparison, is a 2 MW facility and fills out approximately 4.5 percent of SDCEA’s energy profile.* At 10 MW, a geothermal facility could provide electricity to the equivalent of up to 6,000 homes.

Quality of Environment

Groundwater Contamination

Perhaps the primary environmental concern is the potential for groundwater contamination.

PMP cites, as one example, the reported discovery of a geyser some miles away from New Mexico’s Lightning Dock geothermal facility. That New Mexico facility operates as a sort of boogeyman for the PMP, given its multiple transfers of ownership and the host of environmental horror stories left in its operational wake.

Unfortunately, the New Mexican government did not actually investigate the contamination claim, so its validity is still in question. The currently available Lightning Dock fact sheet says it operates without pollutants. The CEO of Cyrq Energy, the company that runs Lightning Dock, flatly denied responsibility in the Las Cruces Sun-News, saying, “absolutely none of that is true and there is no evidence whatsoever that it is.” Of course, given that Cyrq’s CEO has an obvious conflict of interest, that claim comes with a salt shaker attached.

According to geologist and Key Account Specialist at SDCEA Mike Allen, at the time of Lightning Dock’s original proposal and construction, New Mexico’s regulations on geothermal production and exploration were less stringent than those in Colorado today.

The BoCC has latitude to impose environmentally protective regulations by way of the 1041 review process, which is covered in Part II of this series (or, read the geothermal 1041 regulations document itself, specifically Article 4, Section 10-404). Part II also touches on some of the regulatory aspects behind permitting from state bodies as well.

Aquifer contamination is a risk inherent to geothermal resource tapping. It is with any subterranean resource, geothermal or otherwise. It falls to conscientious citizens and elected officials to make sure that any project in Colorado adheres to and properly satisfies the environmental provisions of a permitted activity. But at this time, objections and worries cannot be properly tailored to the inevitable peculiarities of a potential geothermal plant in Chaffee County.

Engineer Jody C. Robins, of the National Renewable Energy Laboratory (NREL) in Golden, Colorado, published a paper in 2021 titled, “The Impacts of Geothermal Operations on Groundwater.” In it, he found, “To date, there is no recorded instance of geothermal development contaminating shallow groundwater in the United States.”

Even at geothermal outfits that had “worst-case scenario” wellbore failures, such as at the Raft River geothermal facility in Idaho, Robins found that, “despite both wellbore failures being significant, no indication of groundwater contamination has been observed in any of the surrounding monitoring wells.”

Robins did note that some wells seem to have a limiting effect on surface geothermal expressions such as hot springs and geysers. This potentially address PMP’s worry that a geothermal plant would negatively impact Mt. Princeton Hot Springs and Resort.

He writes, “It appears likely that geothermal operations are affecting surface geothermal expressions in some fields. However, the extent of these effects is difficult to quantify because these areas have also been subject to increases in domestic consumption of groundwater and periods of drought.”

“Further geophysical testing and resource drilling would need to be performed to determine if the plumbing systems of Mt. Princeton Hot Springs and MPG are connected,” said Mike Allen.

Earthquakes 

Seismic concerns were also raised by PMP, using as evidence a disastrous 2017 earthquake in Pohang, South Korea caused by geothermal energy production. The above-linked science.org article indicates the quake was caused in part because of the geothermal facility’s impact on an “unknown fault.”

What’s more, the facility was using a technique called “enhanced geothermal” in which water is pumped into the ground to fracture the rock and make the movement of heat more efficient. If the resource MPG identifies is naturally productive of enough heat, enhanced geothermal would likely not be necessary. MPG has not indicated any plans to employ enhanced techniques.

According to Stanford geophysicist William Ellsworth, the Pohang earthquake was caused when: “Small earthquakes lingered for weeks after the operators turned the pumps off or backed off the pressure. And the earthquakes kept getting bigger as time went by… That should have been recognized as a sign… This was a particularly dangerous place.”

Chaffee County sits atop the Rio Grande Rift, which has been studied by geologists for years, though the Upper Arkansas Basin is, according to the United State Geological Survey (USGS) the least understood segment of it.

“Least understood” is, of course, a relative term and does not indicate in any way a total lack of understanding. Scientists, as a species, tend to err on the side of uncertainty.

The Rio Grande Rift is an extensional tectonic environment; a fault caused by stretching of the earth’s crust. The Yangsan Fault, on which Pohang sits, is a strike-slip fault line (wherein two tectonic boundaries grind horizontally against each other). Strike-slip faults have a far greater potential for the buildup of energy—and the catastrophic release of said energy—than an extensional fault does.

Even so, residents are within their rights to demand that MPG would not be so rash as to drill into a location where unknown or unmapped features exist. But given the extensive geological research and mapping that is required for drilling permits to be granted, it is unlikely such a feature would be found at the worst possible moment. Residents could also point out that if warning signs like the ones in Pohang exist, they should not go unaddressed.

Enhanced Geothermal Techniques

As one of the pieces of evidence backing their concern over enhanced geothermal, PMP cites an article by Stanford PhD Mark McClure titled “Why Deep Closed-Loop Geothermal Is Guaranteed To Fail.” In it, not only does McClure state that “[he is] a believer in the potential of Enhanced Geothermal Systems”, but he explains that his reservations are primarily economic. Certain types of geothermal production may be economically prohibitive, not environmentally prohibitive, given the ceiling on energy productivity at a depth of many thousands of feet.

There are any number of facilities the world over that operate well within the realm of financial sustainability and at energy output levels far higher than MPG’s proposed 10 MW facility.

The type of system McClure describes and decries involves not only deep vertical wells, but extremely long lateral well structures, structures it seems unlikely MPG would even consider building. Certainly, if these systems are as economically prohibitive as McClure says they are, MPG would not be able to run such a system.

The Yellowstone Example

PMP often brings up, as part of their geologic considerations, Yellowstone National Park. PMP reminds audiences that geothermal energy production is prohibited at Yellowstone due to the desired preservation of features like the Old Faithful geyser and, “there is quite a lot we [the United States Geological Survey] don’t understand about how water moves beneath the surface in the Yellowstone area.”

The fact is, Chaffee County does not sit atop the type of magma reservoirs that lie below the surface of Yellowstone, and, interestingly, Mt. Princeton and Mt. Antero are the very remnants of ancient magma chambers. What’s more, geologic experts have told Ark Valley Voice that geologists have a very comprehensive picture of water movement under Yellowstone, given the extreme amount of monitoring that takes place there on a daily basis. Again, scientists grade on a very different curve of understanding than that of an average person.

Quality of Life

Noise Pollution

At the July 21 PMP meeting, several speakers raised concerns of excessive noise produced by geothermal plant turbines. Their worries were backed by stories and anecdotal evidence of one speaker’s brother who had reportedly been to a geothermal plant and been forced to wear not only earplugs, but further hearing protection on top of those.

“You’ll be able to hear this thing in town,” said one attendee, without any facts to back up the comment.

The site at which  MPG proposes to put their initial test well location. Image courtesy of MPG.

There is evidence that suggests otherwise. In 1982 study for Consultants in Engineering Acoustics, engineer Thomas Norris found that at a range of 1,000 feet, with “full use of demonstrated noise control technology, noise can be reduced to levels acceptable to most quiet rural communities.”

As you may expect, noise mitigation technology has evolved considerably since Norris’ study in 1982. MPG plans to work with a noise mitigation specialist to keep noise pollution to an absolute minimum, said Held.

Measurements taken at four geothermal facilities run by Landsvirkjun, Iceland’s national power company, between 2014 and 2018 indicated that noise levels, save for four often-explainable outliers, were consistently in the range of 25 to 50 dBA (dBA indicates decibels adjusted for the peculiar range of human hearing capabilities).

These are remote facilitates with less of an imperative for noise control, and already the captured volume range is quite low. According to Yale Health and Safety, the range between 25 dBA and 55 dBA is the difference between a whisper and a household refrigerator.

Held says the currently proposed location for a power production facility would be 6,000 linear feet away from the Lost Creek subdivision’s boundaries. Per MPG’s current estimates, noise levels at a distance of just half a mile (2,640 ft) would be 17.9 dBA. That is around 2 dBA lower than a ticking watch, according to the Hearing Health Foundation.

Visual Obstruction

As for visual disturbance, that is harder to discuss quantitatively, since beauty and its inverse are both in the eye of the beholder. Chaffee County regulations would not allow any part of the facility to exceed a height of 35 ft, which Held believes is doable, given that multiple manufacturers of cooling towers meet that standard.

An architect’s rendering of the view from Rodeo Road, looking onto the hypothetical 10 MW plant, concealed partially by trees. Photo Courtesy of MPG.

MPG has proposed their facility is ultimately placed such that it is surrounded by trees, minimizing visual impact. At the relatively small productive capacity of 10 MW, Held posited the land footprint of their facility would be only 8.5 acres, far off from the protested acreage figures of 50 to 60 that came up at the July 21 meeting and the Fourth of July parade.

If years of research and testing lined up, MPG would build a closed-loop, air-cooled binary production facility. In these types of geothermal facilities, there is no cloud of water vapor produced, and all water used in the generation of electricity is reinjected into the ground.

Per the U.S. Department of Energy, “​​Geothermal energy has the smallest land footprint of any comparable energy source in the world. They are compact and use less land per gigawatt hours (404 m2) than coal (3642 m2), wind (1335 m2), or solar photovoltaic plants (3237 m2).”

Final Thoughts

The energy course our world has charted thus far is revealing itself, in new and uniquely distressing ways each day, to have been hilariously misguided.

Solutions must be provided and the solutions themselves must be vetted. God (or whoever else) forbid, a proposed solution not only fails to address a given problem, but exacerbates it.

We must therefore move forward not only as conscientious creators, but conscientious sentries as well; each group demanding good faith from the other and being equally generous in their return. Places like Chaffee County historically excel in this venue, and Ark Valley Voice urges them to continue in that vein as geothermal energy in Colorado steps out of its early stages.

*This article was edited on August 19 to add a comparison between existing energy production facilities in Buena Vista and the potential geothermal plant.