so we asked scott simonton for help. an environmental engineer and scientist, he's studied mining and its impact on water for decades. he's also a pilot. >> a lot of these mining sites are restricted so we can't get to them on the ground down here, so today we're going to take to the skies to see what they look like from above. coal from west virginia is facing competition from other states and from natural gas. and after extracting the most easily accessible coal over the past few decades, companies have turned to a faster - and more aggressive - process to get what's left: - mountain top removal. the top of a mountain is blasted off to expose the seams of coal. heavy metals that have been locked in rock for millennia are exposed to air and water. >> pretty much anywhere you see cleared areas up here on mountain tops, those are surface mining sites. chemicals like the one that leaked into elk river are used to wash the coal at prep plants like this - to separate the coal from rock and clay. the waste that is left over -