Weeks after health authorities had told West Virginians that their water was safe to drink again following a toxic spill, schools in Charleston sent students home abruptly last week when students and staff members detected the telltale licorice odor of the leaked chemical.

Officials have repeatedly backtracked since lifting a tap-water ban about a week after the Jan. 9 spill, first advising pregnant women not to drink the water and then resuming the distribution of bottled water.

Around Charleston, the capital, restaurants advertise that they cook only with bottled water.

What began as a public health emergency after chemicals contaminated the drinking water of 300,000 people has spiraled into a crisis of confidence in state and federal authorities, as residents complain of confusing messages and say they do not trust experts. The spill continues to arouse fear and outrage, and it threatens a political crisis in a state where lawmakers have long supported the coal and chemical industries.

Joe Merchant, a meteorologist at the National Weather Service who moved to the area two years ago, said Gov. Earl Ray Tomblin’s administration and federal health officials had “refused to communicate uncertainty, and completely lost credibility with the people here.”