(CNN) -- The lingering smell of licorice closed several schools around Charleston, West Virginia, on Thursday, nearly a month after a chemical spill that left more than a quarter million people without water.
The unscheduled holidays underscore ongoing public concern about whether the water is safe to drink after a methanol compound leaked from a tank farm upstream from Charleston. Though state and federal officials tried to reassure residents this week, "We are still getting feedback that there is a level of worry," said Laura Jordan, a spokeswoman for West Virginia American Water, the local water company.
Jordan said the licorice odor given off by the chemical -- 4-methylcyclohexane methanol, known as MCHM -- is so strong that it can be picked up even if there is no detectable amount in the water.
The chemical, used to clean coal to reduce ash, leaked into the Elk River and from there into Charleston's water supply on January 9. The result was a do-not-use order that left about 300,000 people in the area unable to drink or bathe in their water, some for more than a week.
An elementary and high school located about 15 miles downstream from the January spill closed early Wednesday and stayed closed Thursday because of renewed complaints about the licorice smell, said Liza Cordeiro, a spokeswoman for the state Department of Education. The complaints came as the schools were trying to flush their water lines to get rid of discolored water after a main broke nearby, she said.
One high school student went to a hospital after complaining of burning eyes, and a teacher there was taken to the hospital after fainting, Cordeiro said. School administrators dismissed the students soon after 9 a.m., she said.
Meanwhile, a grade school in Charleston was closed early Thursday after the licorice smell came out of a dishwasher, the Kanawha County School District reported. Two other schools were closed as well, the district said.
Jordan said some smell and discoloration can be expected as water lines are flushed out. But she added, "It doesn't mean there is any health risk involved."
"We're pushing it out and getting rid of any trace," she said.
An independent water test conducted at CNN's request found trace levels of MCHM earlier this week, both in untreated river water and in tap water from two homes in Charleston. The amounts range from less than half a part per billion to 1.6 parts per billion -- well below the safe level of 1 part per million set by the Centers for Disease Control and Prevention. Whether that level is safe has been disputed.
Dr. Tanja Popovic, the director of the CDC's National Center for Environmental Health, told reporters Wednesday that repeated testing shows the water is safe.
"What I can say is that with all the scientific evidence that we have, with everything that numerous people have worked on so far, I can say that you can use your water however you like," Popovic said. "You can drink it, you can bathe in it, you can use it how you like."
And Gov. Earl Ray Tomblin said tests have shown levels of less than 10 parts per billion or too low to detect. Tomblin said he and his staff have been drinking the water "for the last couple of weeks." But when asked whether he could declare it "100% safe," he said, "No."
"The only thing that we can rely upon is what the experts tell us, and, you know, for all the tests done that's who we've got to depend upon," he said.
A federal grand jury is probing the spill at Freedom Industries, the storage facility at the source of leak, sources familiar with the grand jury's activities told CNN this week.
The spill was originally estimated at about 7,500 gallons, but Freedom Industries reported in late January that about 10,000 gallons of chemical had escaped. The company also told regulators that in addition to the methanol compound that escaped from a ruptured tank, a second chemical -- a mix of polyglycol ethers, known as PPH -- was part of the leak.
PPH is not believed to pose any new health hazard for the people of Charleston,but the state environmental agency said failing to accurately report the makeup of the leak is a violation of state law.
CNN's Kevin Conlon contributed to this report.