Coryn Carver’s hair was falling out.
And we are not talking here about a few strands in the shower or on a hairbrush. She lost about half of her hair in two weeks. She was vomiting, experiencing brain fog and neurological problems, and members of her family were sick as well. They were going from doctor to doctor trying to understand what was happening.
In 2006 Carver’s family moved into the relatively new Traverse Mountain development in Lehi. For the next six years they watched their health gradually decline. What Carver did not know when she moved into the neighborhood was that thallium, a toxic heavy metal, had already been detected in the well drilled to serve the drinking and secondary-water needs of the Traverse Mountain area.
The numbers are documented in the Utah Department of Health’s 2014 Traverse Mountain health consultation. When the well was drilled in 2001, thallium was detected at 1.4 parts per billion.It measured 1.7 ppb in 2004. By 2007, approximately a year after Carver says her family moved into the area, it had reached 1.9 ppb. By October 2010, the concentration had reached 2.6 ppb, exceeding the federal drinking-water standard of 2 ppb.
Carver knew none of those numbers at the time. Thallium was an unknown factor to her too, like it is to many of us right now.
Then, one day in 2012, she looked outside and saw workers pumping water into the street. “The street’s just flooded with water,” she recalled. She approached the workers and asked what they were doing. One told her there was “something in the water” that needed to be removed. Two days later, Carver said, residents received notices at their homes informing them that thallium had been detected in the water.
For Carver, the notice suddenly gave years of unexplained illness a possible context. She began researching thallium and recognized symptoms she and others had been experiencing. One was particularly difficult to ignore: rapid hair loss. “I lost probably 50% of my hair in two weeks,” Carver said. “I mean, just falling out.”
The Numbers Had Been Climbing
The historical record provides a more complicated picture than a single contaminated-water test in 2012. After the 2.6 ppb result in October 2010, the data were submitted to the Utah Division of Drinking Water at the end of that year. According to the subsequent Utah Department of Health investigation, the Division of Drinking Water established a quarterly monitoring requirement on Oct. 26, 2011. Testing subsequently found 2.9 ppb in November 2011, 2.5 ppb in January 2012 and 3.0 ppb on Feb. 14, 2012.
The testing history raises two questions:
- Even though the three-year intervals between tests were consistent with Utah’s regular monitoring schedule for groundwater systems, thallium concentrations were rising — from 1.4 ppb in 2001 to 1.7 ppb in 2004 and 1.9 ppb in 2007, approaching the 2 ppb federal limit. Utah regulations allowed state drinking-water officials to require more frequent monitoring. Why wasn’t additional testing required as the concentration approached the maximum contaminant level (MCL)?
- And after the October 2010 test found thallium at 2.6 ppb — above the U.S. Environmental Protection Agency’s (EPA) 2 ppb MCL — why did another year pass before quarterly monitoring began?
The U.S. Environmental Protection Agency (EPA) uses two different benchmarks for thallium in drinking water. The Maximum Contaminant Level Goal (MCLG) is 0.5 parts per billion (ppb). This is a health-based goal — the concentration at which EPA says no known or expected adverse health effects would occur, with a margin of safety. However, this concentration is not legally enforceable.
The Maximum Contaminant Level (MCL), by contrast, is the enforceable drinking-water standard. For thallium, that limit is 2 ppb. MCLs are set as close to the health goal as EPA determines is feasible, taking into account available treatment technology, measurement capabilities and costs. Water systems are legally required to comply with the MCL.
That distinction changes how the historical measurements look. The 1.9 ppb measured in 2007 was technically below the enforceable federal standard, but it was 3.8 times the EPA’s health-based goal and only 0.1 ppb below the legal limit. The 2.6 ppb measured in October 2010 was 5.2 times the health-based goal and above the federal standard. By February 2012, the well was measuring 3.0 ppb, six times the EPA’s health-based goal.
On Feb. 16, 2012, Lehi removed the Traverse Mountain Well from the drinking-water system and introduced water from two other sources where thallium was not detected. But the thallium did not immediately disappear from the distribution system. Six random samples were taken on Feb. 22. When the results arrived on March 2, they ranged from 2.1 to 6.0 ppb, all above the 2 ppb federal standard. Lehi began flushing portions of the system, resampled the water and notified residents on March 8.
Then some of the measurements became dramatically higher.
After the contaminated well had already been disconnected, government records document distribution-system measurements including 6.0 ppb on Feb. 22, 4.4 ppb on March 7, 18.4 ppb on March 15, 17.8 ppb on March 16, 12.2 ppb on March 17 and 10.0 ppb on March 21.
The highest reported measurement was 54.9 ppb on March 11, 2012 — more than 27 times the federal enforceable limit and nearly 110 times the EPA’s health-based goal. That measurement requires an important qualification. The health consultation says distribution-system blow-offs, which are endpoints in water lines, produced measurements ranging from nondetectable to 54.9 ppb. The 54.9 ppb result therefore should not be interpreted to mean every household in Traverse Mountain was receiving water at that concentration. But it does show that a substantially elevated concentration was detected within the distribution system after the contaminated well had been removed.
What Was Happening Inside the Pipes?
Lehi had a hypothesis. According to the Utah Department of Health report, the city believed thallium had accumulated through scaling inside the water pipes. When the contaminated well was disconnected and water with a different chemistry was introduced, Lehi suspected that accumulated thallium was being released from the scale back into the water.
The city flushed the system with water in which thallium was not detected. By March 23, measurements had fallen to nondetectable levels, according to the health consultation. But elevated thallium appeared again months later. Investigative sampling of outdoor residential drinking-water spigots in August found two homes above the federal MCL, prompting additional flushing and sampling.
Research published several years later demonstrated that the mechanism Lehi suspected can occur under some conditions. Scientists investigating a separate thallium-contaminated public water system in northern Tuscany, Italy, found thallium-rich rust scale inside drinking-water pipelines. In some pipe-scale samples, thallium made up as much as 5.3 percent by weight. Researchers also demonstrated that the accumulated thallium could be released into the water, effectively turning deposits inside the pipes into a secondary source of contamination.
The Italian study involved different geology, water chemistry and infrastructure and does not prove that the same process occurred in Traverse Mountain. But it makes Lehi’s own scaling hypothesis particularly interesting. Were deposits inside the Traverse Mountain pipes themselves ever removed and chemically analyzed for thallium? The government report documents extensive water sampling and describes Lehi’s hypothesis, but Utah Stories has not yet found documentation showing that the pipe scale itself was chemically analyzed.
Looking for Answers
After receiving the notice, Carver wanted to know whether thallium was actually in her family’s bodies. She shaved a pencil-sized section of hair from the back of her head and did the same with her children, then took the samples to a hospital hoping they could be tested. Carver remembers medical personnel initially seeming unfamiliar with what she was asking about. Later, she said, she was told the hair samples had been lost.
She kept looking for answers. Carver went to the Lehi Water Department and asked for records concerning thallium. She remembers being asked what she was talking about — and then noticing a file sitting on a table with the word “thallium” on it. “That file. I need that file,” she remembers saying. According to Carver, an employee spoke with a supervisor and returned to tell her she would have to submit a formal government-records request.
It was during this period that Carver began feeling as though she was living her own version of the Erin Brockovich story. The similarity was personal: she was a mother with no background in environmental toxicology who suddenly found herself trying to understand water testing, government records and a toxic metal she had barely heard of while her own health was deteriorating.
“I was so sick that it was hard to fight that in the beginning,” Carver said. At one point during that period, she said, she weighed only 95 pounds.
Carver also describes severe dental problems that continued beyond the initial contamination episode. She recalls driving when one of her front teeth came out, leaving her holding it in her hand. She eventually lost all of her teeth, she said, and her oldest son had to get dentures at age 27. Other children have experienced dental problems as well.
Studies have found thallium in bone, and animal research has shown that high-dose thallium exposure can affect developing bone and cartilage and interfere with the body’s normal regulation of calcium. However, Utah Stories found no human studies establishing that thallium exposure causes severe dental deterioration or tooth loss. Carver’s family’s experience therefore raises an important real-world question about the possible effects of thallium exposure that existing research has yet to answer.
Carver also remembers other residents experiencing serious health problems. She described a nine-year-old boy with heart problems, an Ironman athlete who became unable to climb her stairs, and what she remembers as multiple miscarriages occurring in one portion of the development. Those reports have not yet been independently verified by Utah Stories.
There is, however, documentation that health concerns extended beyond Carver’s family. The Utah Department of Health reported that 26 of 36 Traverse Mountain residents said they had reported symptoms similar to thallium exposure to their physicians before an April 2012 community meeting. The examples listed by the department included hair loss and gastrointestinal irritation. Two of those residents reported detecting thallium in urine testing. The Environmental Epidemiology Program also noted an important limitation: it did not review the residents’ official medical documentation.
What Does Science Say About Low-Level Exposure?
The government’s conclusion needs to be part of the story. After evaluating the available water and soil data, the Utah Department of Health’s Environmental Epidemiology Program concluded that past exposures to the Traverse Mountain Well were not expected to harm the health of the community. For drinking water between Oct. 21, 2010 and Feb. 16, 2012, the program concluded that ingestion and skin contact were not expected to harm people’s health.
But the report itself acknowledges an important limitation. The health consultation states that there was “very little data” available on the health effects of long-term exposure lasting more than one year. It also states that chronic exposure was relevant to its evaluation because Traverse Mountain residents were exposed to contaminated drinking water from at least October 2010 to August 2012, when concentrations dropped below the federal MCL.
Peer-reviewed research published since the Traverse Mountain incident provides additional context. A 2019 review of low-dose thallium toxicity concluded that the health effects of chronic low-dose exposure through contaminated food and drinking water have often been overlooked or underestimated and noted that relatively few studies had examined the issue.
Another peer-reviewed study published in 2022 calculated a health-protective drinking-water guidance value of 0.44 ppb for the Chinese population evaluated by the researchers. That is remarkably close to the EPA’s 0.5 ppb health-based goal and considerably below the 2 ppb enforceable U.S. limit. The study also found that health criteria for children were lower than for adults and identified children as the age group facing greater potential risk.
Research involving another population cannot simply be applied to one Utah neighborhood but it provides context for the concentrations documented at Traverse Mountain: 1.9 ppb in 2007, 2.6 ppb in 2010 and 3.0 ppb in February 2012, followed by substantially higher measurements at some points within the distribution system.
A regulatory limit also should not be interpreted as a biological switch at which 1.9 ppb is harmless to every person and 2.1 ppb suddenly causes illness. Exposure depends on concentration, duration and the amount of contaminated water consumed. Age, body size and other factors can also influence the dose an individual receives.
There is also evidence that consequences of substantial thallium poisoning can persist long after an acute exposure. A peer-reviewed study following 12 survivors of confirmed acute thallium poisoning for a median of seven years found that peripheral neuropathy improved substantially, but some patients continued to have abnormalities involving sensory nerves as well as memory and other neuropsychological problems.
Even though we cannot simply conclude that results of this research can be directly applied to the community in Traverse Mountain, they do establish that the consequences of a significant thallium exposure can, in some cases, persist for years.
Leaving Traverse Mountain
As Carver pushed for answers, she said she encountered hostility from some neighbors. After she contacted the news media, she remembers criticism from residents who worried that publicity surrounding the contamination would hurt their property values. She also said she received threats. So, she decided to leave. She moved her family out of Traverse Mountain within weeks and remembers their health beginning to improve after leaving. That experience strengthened her belief that something in their environment had been making them sick.
Years later, Carver said she continued encountering people with unexplained health problems who told her they had once lived in the area. She has also gone back through old online conversations and found messages from former neighbors who had been sick and who thanked her for bringing attention to the water problem.
From Illness to Hyperbarics
Carver’s health problems eventually led her in another direction. While receiving treatment for neurological issues, she noticed a soft-sided hyperbaric chamber in a doctor’s office in Lehi and began asking questions. She started researching hyperbaric oxygen therapy, attended conferences and learned more about the field. Eventually, what began as an effort to understand treatments for herself and her family became a business.
In 2020, Carver opened Elovate Hyperbarics. She describes the center as an outgrowth of what happened to her family and of her desire to help people who feel their health concerns have not been heard. Her experience at Traverse Mountain also gave her the courage to speak publicly when she believes other people are afraid or unable to do so themselves.
“I feel like it’s our mission,” she stated. “It’s my duty as a human being to protect the lives of others.”
That mission is one reason she is talking about Traverse Mountain again more than a decade later.
Questions That Remain
Carver’s story brought the history of thallium in Lehi’s drinking water to Utah Stories’ attention. Before meeting her, we were unaware of the issue.
The public records we reviewed answered some questions, but they also raised others — particularly about the timing of testing, the response to elevated thallium levels and how residents were informed.
Utah Stories has not yet contacted the Utah Division of Drinking Water or the Lehi City Water Department for their explanations. We intend to do so and to continue reporting what we learn.
Understanding how drinking water is tested, regulated and reported is not simply a matter of looking back at what happened in Lehi. Residents have a right to understand the systems designed to protect their drinking water, what happens when contaminants are detected and how they are informed when problems arise.
Research & Sources
Utah Department of Health / Agency for Toxic Substances and Disease Registry. Traverse Mountain: Thallium in Drinking Water, Lehi, Utah County, Utah — Health Consultation. Dec. 3, 2014. This is the principal government source for the well history, historical thallium measurements, distribution-system sampling, remediation, community health concerns, exposure analysis and government’s conclusions.
Read the Utah Department of Health/ATSDR Health Consultation
U.S. Environmental Protection Agency. National Primary Drinking Water Regulations. The EPA establishes an enforceable Maximum Contaminant Level of 2 ppb for thallium and a health-based Maximum Contaminant Level Goal of 0.5 ppb.
EPA National Primary Drinking Water Regulations
Utah Administrative Code, R309-205-5 — Inorganic Chemical Sampling and Analytical Requirements. Utah’s drinking-water regulations state that systems exceeding an MCL, as determined under the regulation’s compliance provisions, must begin quarterly monitoring in the next quarter after the violation occurred. The regulation is relevant to Utah Stories’ continuing investigation of the interval between the October 2010 Traverse Mountain result and the October 2011 quarterly-monitoring requirement.
Archived Utah drinking-water regulation
Campanella, Beatrice, Laura Colombaioni, Edoardo Benedetti, Agostino Di Ciaula, Lisa Ghezzi, Massimo Onor, Massimo D’Orazio, Roberto Giannecchini, Riccardo Petrini and Emilia Bramanti. “Toxicity of Thallium at Low Doses: A Review.” International Journal of Environmental Research and Public Health, 2019, 16(23), 4732. DOI: 10.3390/ijerph16234732. The peer-reviewed review examines scientific evidence concerning chronic low-dose thallium exposure, including exposure through contaminated food and drinking water, and concludes that low-dose effects have often been overlooked or underestimated.
Sun, Fuhong, et al. “Pollution levels and risk assessment of thallium in Chinese surface water and sediments.” Science of the Total Environment, 2022, 851, 158363. DOI: 10.1016/j.scitotenv.2022.158363. Researchers calculated a drinking-water guidance value of 0.44 ppb for protection of human health in the Chinese population used for the assessment and found children to be the age group facing greater potential risk.
Biagioni, Cristian, Massimo D’Orazio, Giovanni O. Lepore, Francesco d’Acapito and Simone Vezzoni. “Thallium-rich rust scales in drinkable water distribution systems: A case study from northern Tuscany, Italy.” Science of the Total Environment, 2017, 587–588, 491–501. DOI: 10.1016/j.scitotenv.2017.02.177. Researchers found thallium-rich rust scale inside drinking-water pipelines and demonstrated that the scale could become a secondary source of thallium contamination.
Li, J.M., W. Wang, S. Lei, L.L. Zhao, D. Zhou and H. Xiong. “Misdiagnosis and long-term outcome of 13 patients with acute thallium poisoning in China.” Clinical Toxicology, 2014, 52(3), 181–186. DOI: 10.3109/15563650.2014.892123. Twelve survivors were followed for a median of seven years. Researchers found substantial improvement in peripheral neuropathy but persistent sensory-nerve and neuropsychological abnormalities in some patients.
Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for Thallium. U.S. Department of Health and Human Services. The toxicological profile reviews studies of how thallium is distributed through the body after exposure. Animal studies found thallium in bone, including after exposure through drinking water.
Read the ATSDR Toxicological Profile for Thallium
Galván-Arzate, S., et al. “Osteochondral Lesions in Developing Rats Intoxicated with Thallium Twenty Four Hours After Birth.” Archives of Medical Research, 1992. Experimental research found that thallium exposure affected developing cartilage and bone, including changes in bone tissue and bone-forming cells.
Mulkey, J.P. and F.W. Oehme. “A Review of Thallium Toxicity.” Veterinary and Human Toxicology, 1993, 35(5), 445–453. The review examines the mechanisms of thallium toxicity and identifies disruption of the body’s normal regulation of calcium as one of the mechanisms that may contribute to thallium’s toxic effects.
*Featured Image by Rebecca Kay
