CHARLESTON, W.Va. — For the fifth straight day, hundreds of thousands of people in West Virginia had to wash, cook and brush their teeth with bottled water, but officials promised the ban on tap water that was tainted by a chemical spill would soon be lifted.

Over the weekend, tests showed that levels of the licorice-smelling chemical used in coal processing were consistently below a toxic threshold, and in some samples, there was no trace of the chemical at all. As the tests were expected to continue Monday, there were still questions about how and why the leak occurred and whether the company, Freedom Industries, took too long to let state officials know about the problem.