There are an estimated 1,100 pits that are left behind from burning coal across the country, and these pits hold a toxic mixture of arsenic, lead, mercury, and other chemicals. Despite the hazards that these waste products pose, these pits have surprisingly little oversight. North Carolina, however, has passed a regulatory coal ash law legislators called the most sweeping in the country. The bill—which legislators approved in late August and Governor Pat McCrory said Wednesday he will not be vetoing—followed a coal ash spill from Duke Energy six months ago that contaminated a 70-mile stretch of the Dan River.

Duke's response to the spill has been heavily criticized. As with any spill, it's better to prevent it in the first place than to clean it up afterward—but this is especially true for coal ash, which is next to impossible to effectively clean up once it leaches into the riverbed and surrounding soil. The toxic material left from burning coal is mixed with water to become a gray sludge that's sent into a pit or hole in the ground. The coal ash can then sink and mix with the soil.

Despite the complicated nature of the cleanup, Duke and the EPA said it was done dredging up the spill in July, having accounted for about 3,000 tons of ash out of a 39,000-ton spill. Environmentalists were not thrilled. "Their excavation could only account for 5 percent of the coal ash in the river. 95 percent is still out there," SELC Director of the Chapel Hill Office Derb Carter said in an interview in late August. "It’s going to be turned up and churned up for years.

Whatever the effect of the new law, some say that North Carolina still faces serious trouble. The North Carolina solution doesn't really address the environmental problems of the 14 highest-risk coal ash ponds across the state, which the Southern Environmental Law Center (SELC) says are leaching toxins into groundwater. (The law will require four of the ponds to be closed down by the end of 2019, but for the rest, a new commission will decide what to do.)

And the rest of the country is in trouble, too, given that the Environmental Protection Agency still hasn't finalized a rule related to coal ash and won't do sountil December. Across different states, companies take a haphazard approach. In Ohio, American Electric Power is now fighting a lawsuit that alleges workers were exposed to hazardous coal ash landfills—landfills they they were told were "safe enough to eat" from. Two utility companies in South Carolina entered into an agreement with SELC, and they will be removing their high-risk unlined pits away from waterways, in stark contrast to Duke Energy's response.