West Virginia Gov. Earl Ray Tomblin on Tuesday announced a plan to test the water in homes in the state capital of Charleston and nine surrounding counties amid safety concerns following a chemical spill last month.

On Jan. 9, an estimated 10,000 gallons of a coal-processing chemical blend called Crude MCHM leaked into the Elk River and left 300,000 people without tap water for at least five days.

Several state health officials at a congressional hearing Monday declined to say that the water was safe to drink, even though tests have shown quantities of MCHM to be well below a limit set by the U.S. Centers for Disease Control and Prevention.

"It is time for the political officials to step aside and let the scientists do what they do," Mr. Tomblin said Tuesday.

He announced $650,000 in initial funding and named two drinking-water experts to spearhead the program, Andrew Whelton, an environmental and civil engineer at the University of South Alabama, and Jeffrey Rosen, president of Corona Environmental Consulting LLC.