CHARLESTON, W.Va.—Three weeks after a leak at a chemical storage facility left more than 300,000 West Virginians without access to potable water, many residents continue to avoid drinking from their taps. A “Do Not Use” order has been lifted since January 17. The incident took place on the morning of January 9 and resulted in the leakage of about 38,000 liters of a chemical mixture from a storage facility into the Elk River, which supplies much of the area’s tap water.

The company that operates this facility, Freedom Industries, initially claimed the only leaked substance was 4-methylcyclohexane methanol (MCHM), an organic solvent used to wash the impurities out of coal before it is burned. It has since disclosed, however, that a second, proprietary chemical, “PPH, stripped,” (a mixture primarily of propylene glycol phenyl ether and dipropylene glycol phenyl ether, according to the Centers for Disease Control) was also present in the leaked mixture. Moreover, the company’s estimate of the quantity of the leaked chemicals has steadily increased, rising from 28,000 to 38,000 liters last week.

Freedom Industries was contacted several times, starting on Friday, for comment on this story but did not respond.

The changing narrative has left many residents affected by the leak skeptical of the safety of their water. “Who is to say there isn’t a third chemical they aren’t telling us about? They haven’t been forthcoming about it, and that’s why many of us still won’t drink the water,” says Mouaz Haffar, a lifelong Charleston resident. “They’ve broken the public trust,” he adds.

This skepticism was exacerbated last week by the testimony of Marshall University environmental scientist Scott Simonton, who announced that he detected formaldehyde in samples of tap water he had obtained at a restaurant in Charleston. Simonton, who is a member of the state’s Environmental Quality Board, speculated that this formaldehyde was a by-product of degraded MCHM from the leak. “It’s frightening, it’s really frightening,” Simonton said during his testimony to West Virginia’s Joint Legislative Oversight Commission on State Water Resources. “What we know scares us, and we know there’s a lot more we don’t know.”

This announcement set off a wave of hysteria in the local media leading to a dismissive statement from the state’s Bureau for Public Health Commissioner Letitia Tierney, who called Simonton’s findings “totally unfounded.”

“Subject matter experts who have been assisting West Virginia through this entire emergency response state that the only way possible for formaldehyde to come from MCHM is if it were combusted at 500 degrees Fahrenheit,” the statement read, implying that the formaldehyde could not have come from the leaked MCHM because the MCHM was not subjected to such high temperatures.

Simonton’s tests detected formaldehyde at 32 to 33 parts per billion. The U.S. Centers for Disease Control and Prevention issued a statement in response to this issue, asserting that this level is “commonly encountered” and not cause for alarm. The Occupational Safety and Health Administration’s guidelines call for the limiting of exposure to formaldehyde to 750 ppb per work week. Formaldehyde is present in many widely used products, including building materials and cigarettes. The U.S. Environmental Protection Agency has designated formaldehyde as a “probable human carcinogen.” Its short-term physiological effects include eye, nose and throat irritation if inhaled and corrosion of the gastrointestinal tract if ingested.

Earlier this week, West Virginia American Water (WVAW), the company responsible for the water supply in the affected area, provided an update on the results of tests it has been running on the levels of MCHM and PPH in the water. The company says the level of MCHM in 85 percent of system is “nondetectable.” Even though in the remaining areas it is still above the nondetectable level, it is well below the one-ppm health-protective limit established by the CDC. The levels of PPH are even lower, barely registering when tested on the parts per billion level. “Our team expects that it will take a few more days of persistent flushing before all sample points used throughout the system reflect nondetectable levels,” says Jeff McIntyre, president of WVAW.

West Virginia has a long history of accidents related to the coal industry leading to environmental damage. Experts suggest this history could be contributing to the ongoing skepticism, despite the low levels of chemicals now detected in the water.

Michael Hendryx, a professor at the Indiana University School of Public Health who previously spent several years studying the public health effects of the coal industry in West Virginia, says he was “saddened and disappointed but not surprised” when he heard about the leak. A study by Hendryx published in the American Journal of Public Health in 2008 found that, compared with residents in the rest of the state, residents of West Virginia’s coal mining counties were 70 percent likelier to suffer from kidney disease, 60 percent likelier to have obstructive lung diseases such as emphysema and 30 percent likelier to have high blood pressure. Another of his studies, published in the Journal of Health Disparities Research and Practice in 2012, found that residents of areas surrounding mountaintop-removal coal mines “had significantly higher mortality rates, total poverty rates and child poverty rates every year compared to other…counties.” Hendryx says that pollution, including leakage of chemicals into the water supply, could be a contributor to the relatively worse health outcomes he observed in certain areas of the state.

When considering the January chemical leak in the context of West Virginia’s long, troubled history with industrial accidents and its lax regulatory environment, Hendryx says he thinks it makes sense to remain skeptical about the region’s freshwater even after it has been declared safe. “I personally would not drink it, cook with it or bathe in it,” Hendryx says. “I would not wash my clothes with it. I would not give it to my dog.”