CHARLESTON, W.Va. (AP) — The number of customers given the green light to use tap water continues to inch up after a chemical spill in West Virginia.

As of 7:30 a.m. Tuesday, West Virginia American Water said about 35 percent of affected customers had been cleared to turn their water back on. Thursday's spill affected 100,000 customers in the state, or about 300,000 people in all.

It could still be days before everyone in the Charleston metropolitan area gets the same good news.

The water company encourages customers to check a map on its website for their status. On Tuesday morning, a large swatch across the nine affected counties remained in the "do not use" red zone. Those in the blue zone should have safe washing and drinking water, as long as people flush out their systems. Officials say the water may still have a slight licorice odor.

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