Cheryl Shadden doesn’t see herself as an activist. But when a controversy over cryptocurrency landed on her front doorstep, Shadden said, she became a “redneck warrior.” 

The 61-year-old works at a hospital in Granbury, the town 40 miles southwest of Fort Worth where Shadden has lived for a majority of her life. There, she found contentment in raising her animals — eight dogs, six cats, six horses and one parrot. Her closest neighbor is just shy of a mile away, and Shadden hasn’t often found the need to interact with them.

However, that changed when a new neighbor came into town.

In 2022, a large Bitcoin mining operation was established at Constellation Energy’s Wolf Hollow power plant, a quarter-mile from where Shadden lives. The mine runs day and night. Nearly 23,000 fan-cooled computers are trying to crack the right algorithm and solve complex math problems to get just one Bitcoin, the globe’s most well-known cryptocurrency. 

Shadden and other Hood County residents didn’t know the mining operation was moving in. That is, until the noise started.

Residents blame the ongoing noise pollution for health issues that have popped up since the plant opened. Shadden said her ears started ringing and buzzing in March whenever she was home, but would stop when she went to work. After the ringing became worse, she went to an audiologist, where she was diagnosed with permanent conductive hearing loss. 

It’s not just Shadden. She said her neighbors are experiencing hearing loss, dizziness and vertigo, along with a mother and teenage son who received cochlear implants. They link the complications to the Bitcoin mine’s arrival. 

“We’re really hoping for change,” Shadden said. “People here are so sick, I mean they’re so sick. It’s not random, it’s everybody in this area.”

Geraldine Lathers has lived in Granbury for 30 years and is almost a mile away from the mine. She said she has been suffering from vertigo and hearing problems in her left ear. At first, she didn’t know what the cause could be. But, as she kept hearing the constant humming of the mines, she started to link the issues with the noise. 

“I’m all for progress and all of that, but not at the expense of people,” Lathers said. “I don’t think it’s right. Right’s right and wrong is wrong.” 

Marathon Digital Holdings acquired and started operating the Granbury Bitcoin mine in January. Amid the controversy and backlash, Marathon released a sound survey in July conducted by an independent third party. 

The company said the report showed noise levels declined from 78 decibels to 63 decibels, representing an “over 50% reduction in the perceived loudness” of the facility. Marathon, also known as MARA, did not respond to questions about health concerns. 

“These reductions are the result of several steps MARA has taken to enhance operations at the site, including deactivating a total of 95 air-cooled containers and converting 20% of the site, or 4,780 machines, to liquid immersion cooling,” a Marathon spokesperson said in a statement.

In the same survey, they included current and future noise mitigation plans, such as having a sound wall, planting trees and enhancing landscaping in November and deactivating air-cooled containers and converting to liquid immersion cooling, the Marathon spokesperson said. 

Beyond improvements to the site, the company touted its contributions to the Granbury community, including the creation of 19 jobs, $3 million in tax revenue and $100,000 in donations to schools and nonprofits. 

“We are committed to being good neighbors and continuing to take action for the betterment of the community,” the spokesperson said. 

Neighbors say the noise has not declined enough to stop them from banding together to draw national headlines and alert elected officials to concerns for their health and the environment. 

“You’re talking about a red county, this is primarily a Republican county,” Shadden said. “To get Republicans to stand up and do something about this, you’ve literally put a stick of dynamite in their drawers and blown them up off of their recliner to do something.”

Noise pollution at core of crypto controversy

Noise pollution has become a top concern for residents living near cryptocurrency operations. When they run their own unofficial sound tests, Shadden and neighbors report they are seeing decibels from 70 up to 103. Texas law states that noise exceeding a decibel level of 85 is presumed unreasonable. 

“It’s like a motor just going constantly,” Lathers said. “It sounds to me like a distant plane or boat whistle going.”

Lee Bratcher, the president and founder of the Texas Blockchain Council, a group promoting cryptocurrency growth and innovation in Texas, said Marathon has been working to continue improving the Granbury data center since taking over operational control earlier this year. Data shows that the noise levels are “substantially below” those required by the state, he said. 

“It is evident from the results of Absolute Noise Control’s sound study that MARA’s efforts are paying off as there have been significant reductions in sound levels over the past few months,” Bratcher said. “Having worked extensively with the MARA team, I know that they are committed not only to being in compliance, but to being a good neighbor and a valued member of the communities in which they operate. Regardless of the positive findings, MARA will continue to invest in the improvement of their Hood County site and in the Granbury community.” 

However, Shadden said she is skeptical of these results as she believes they should have conducted decibel readings for longer than 15 minutes, claiming she’d measured decibel levels of 88 at 10 a.m. on a Monday morning at her property.

In a June trial involving Marathon Digital Holdings, plant manager David Fischer and sound expert Barry Dickey testified that sound survey protocols require tests to be done at a minimum of three to five minutes and for a period of up to 10 minutes.

Hood County Commissioners Court voted 3-2 on July 23 to conduct their own sound survey on the Bitcoin mines. Commissioner Nannette Samuelson said the independent survey is necessary. 

“It’s kind of like somebody living in an area where there’s pollutants in the air,” Samuelson said. “You can’t see them, but you’re breathing them in. It’s killing you, but you just don’t know because you can’t see it.” 

Adrian Shelley, the Texas director of Public Citizen, a consumer advocacy nonprofit group who has spoken against cryptocurrency mining in Texas, said the loud noises people hear from Bitcoin mines are coming from the fans that help cool the computers. 

“Any noise in that range that you regularly endure is going to have impacts on quality of life and potentially more serious health impacts,” Shelley said. “You shouldn’t really be expected to endure open-endedness.” 

Rising anxiety over energy use, Texas power grid

Another concern cited by residents is the impact of cryptocurrency mining on energy use. Bratcher said Bitcoin mining operations in Texas collectively consume up to 3,000 megawatts of energy a day — enough to power 600,000 homes during periods of peak demand. 

Ed Hirs is a University of Houston lecturer and energy market expert. He equates cryptocurrency miners to parasites on the grid.

“It’s a new load on the overall grid and that’s just not free,” Hirs said.

During a Texas Senate committee meeting in June, ERCOT predicted that the state’s grid demand is expected to double over the next six years, with the growth coming from oil and gas operators and data centers that are powering artificial intelligence and cryptocurrency mining. 

This came as a shock for some lawmakers. In a post on X in June, Texas Lieutenant Governor Dan Patrick said crypto miners and data centers will be responsible for more than 50% of the energy use increase. 

“We need to take a close look at those two industries,” Patrick wrote. “They produce very few jobs compared to the incredible demands they place on our grid. Crypto mining may actually make more money selling electricity back to the grid than from their crypto mining operations.”

While Bitcoin mining companies are not required to register with the state, ERCOT CEO Pablo Vegas said during a June Texas Committee on State Affairs meeting that legislation would require Bitcoin mining facilities to register. The Public Utility Commission of Texas introduced potential rules in late August, with a decision coming at a later date. 

“What would be more helpful for ERCOT is to have more visibility to what these large loads are doing,” Vegas said during the meeting. “A good place to start could be making sure we can track and potentially control the loads of cryptos. Cryptos are a unique business. Their use of energy is tied directly to the cost of electricity and the cost of Bitcoin.” 

Those in the cryptocurrency industry point out how Bitcoin mines can help the grid. For example, Bitcoin mines have the option to get paid to shut down their operations when demand on the grid is at its peak. 

Hirs said that option — which he describes as demand response programs — could be extended to all Texans by allowing power companies to pay or offer credits to customers who reduce their energy consumption when demand is at a peak. 

“I’m here, I’ve been in Texas for a lot longer,” Hirs said. “I’ve had a smart meter for 15 years. Why hasn’t ERCOT offered me that opportunity? (ERCOT is) dragging their feet on demand response programs.” 

Bitcoin mining has support from Fort Worth, Texas leaders

Fort Worth has a history of cryptocurrency mining dating to 2022, when the city became the first in the country to install a cryptocurrency mining machine in its City Hall. Carlo Capua, the city’s chief of strategy and innovation, said the concerns over Bitcoin mining came up when Fort Worth was fleshing out plans for its own machine.

The conversation around Bitcoin mines reminds Capua of the early days of fracking, which took off in the Fort Worth area in the late 2000s amid the Barnett Shale boom. There are many unanswered questions, which is why the city started small with one machine in its data center, Capua said. 

“It’s about as noisy as a hairdryer on low,” he said of the city’s machine. “But I can imagine that people who live near mines, it’s probably like living near an airport or living by train tracks. Except if you move to an airport, you know it’s going to be loud. This is probably something like with natural gas wells or fracking, people didn’t realize until it started to get loud.” 

Regardless, the city’s openness to Bitcoin has been positive, Capua said. He said it allowed new waves of cryptocurrency businesses to move to Fort Worth and demonstrated why Fort Worth is innovative and forward thinking as a home for entrepreneurs. 

As for the cryptocurrency machine in City Hall, the Report found that over the span of two years, the machine ran a profit of $3,925.89. Capua said there’s no plan to expand or change the Bitcoin mining program. It would be up to City Council to move forward with any changes. 

“We’ve done our best to educate the public on why we’re doing this,” Capua said. “It’s just learning hands on with something super high tech, that’s helping brand us as a great city and a forward thinking city.”

Texas politicians, such as Sen. Ted Cruz and Gov. Greg Abbott, have continued to show support for new cryptocurrency operations in Texas. 

Meanwhile, neighbors in Granbury are trying to rally political opposition, pushing for new policies such as preventing Bitcoin mines near residential neighborhoods and lowering how much energy Bitcoin mines consume. 

Hood County commissioners supported a resolution urging the Texas Legislature to take action to “address acoustical and noise pollution, destruction of property values, and the incredible demand on the Texas energy grid caused by cryptocurrency mining.” 

After living in Fort Worth for nearly 30 years, Thomas Weeks moved to Granbury in 2009 for a quieter environment. His home sits a half-mile from the mining operation. Like his neighbors, the 64-year-old is still seeking peace from the Bitcoin mine that sends a constant droning to his front porch. 

Weeks, who has been retired for five and a half years, is waiting for his wife to join him in retirement soon. They want to sell their home in the next few years to move to a lake house farther north. 

“But at the rate this is going, I probably won’t be able to sell my home,” Weeks said. “Or if I do, I have to sell it at a much lower price and make nothing from it. I shouldn’t have to do that.” 

Kevin Vu is a recent graduate of the University of Texas at Austin and contributor to the Fort Worth Report.