The gooey, grayish-black sludge that spread across Roane County on a bitterly cold December morning is gone, but the fallout from the nation’s worst coal-ash spill enters a new phase on Monday when the federal government begins regulating the storage and disposal of ash from coal-fired power plants.

Effective immediately, utilities will be required to put in place a plan to control “fugitive” dust, or ash that blows away while it’s being transported or stored and could end up in streams. Within 30 days, those dust-control plans must be posted online so they are available for review by the public.

Utilities must immediately begin inspections of coal-ash storage ponds and landfills and post the results of those inspections online as well. Storage sites under construction will have to meet new design standards that require safeguards such as liners and restrict how close they can be to groundwater tables, seismic zones, flood plains and unstable areas such as sinkholes.

A year from now, utilities will have to determine whether existing storage ponds meet mandatory safety standards. Within two years, a groundwater monitoring system must be installed at coal-ash sites, and other measures will have to be taken to protect nearby water resources.

Read more from our news partners at the Knoxville News Sentinel.