Coal mines no longer need to filter all runoff before it leaves the site

Federal regulators removed rules that required all surface water from coal mining sites to pass through a siltation structure. A court found the agency did not sufficiently explain why these structures were the best available technology.

For years, coal mining operations had to filter all runoff water through siltation structures, which are essentially ponds designed to let sediment settle out. This rule change means they no longer have that blanket requirement. It could make it cheaper and faster to operate some mines, as they might use other, less costly methods to manage water.