Anglers and other stream and river conservationists, already at odds with hydraulic fracturing, open pit mining and other fossil fuel extraction operations; are placing an increased focus on longwall mining after the state of Pennsylvania released information indicating that longwall mining operations by Consol Energy have severely depleted or entirely eliminated streamflow for six streams in the southwestern portion of the state.

Longwall mining is a more efficient mining practice than traditional room and pillar mining. In longwall mining, massive hydraulic equipment is used to shear and slice large segments of coal from mines. Unlike room and pillar mining, in which blocks of coal and other supports are left behind to support the earth, longwall mining leaves open caverns behind. These open caverns often cause surface subsidence above the mines, disrupting ecosystems and diverting water flows. In some locations, surface subsidence of more than 15 feet has resulted from longwall mining.

This latest incident isn't the first time longwall mining has been scrutinized for its effects on streams. Over a decade ago, the US Fish and Wildlife service warned that longwall mining was ruining trout streams. Citing Pennsylvania's Enlow Fork as an example, a report in the Pittsburgh Post-Gazette in 2000 noted that "longwall mining subsidence has caused an eight-mile stretch of Enlow Fork, once a pretty, babbling trout stream with a natural assortment of riffles and runs, to become little more than a series of slack-water pools filled with muddy sediment and few fish."

In the Post-Gazette report, wildlife biologist Jennifer Kagel noted that the subsidence caused by longwall mining "can mean water loss, pooling, reduced water velocity, and eventually the replacement of riffle species with slow- or standing-water species and the loss of diversity." Kagel continued, "that changes the existing uses of the stream that are protected by the state and federal Clean Water Act."

According to the above cited report from the Center for Public Integrity, Consol Energy is currently applying for a permit that would expand its largest mine in Pennsylvania, Bailey Mine, by over 3,000 acres. The expansion is expected to cause damage to a dozen additional area streams.