Effects of natural gas drilling on headwater streams in Arkansas

The number of active natural gas wells in the US is increasing, and Arkansas currently has ~1300 new, active wells concentrated in the Fayetteville-Shale region, with many permits pending.  All wells are in close proximity to streams, but few studies have examined drilling effects on stream sedimentation and biota. We predict installation and implementation of gas wells increases sedimentation via increased road density, vegetation clearing, reservoir creation, and pipeline construction and decreases algae and invertebrate diversity and biomass. We delineated upstream catchments from sampling points in 12, 2^nd or 3^rd order stream sites, 6 with high densities of wells and 6 with low densities in 2 major river drainage systems.  Well densities within the catchments ranged from 22 to 78 in high density catchments and 3 to 9 in low density catchments.  Land cover within catchments ranged from 39% to 81% forested and 14% to 46% pasture.   We are quantifying benthic and suspended sediments, algae, and invertebrate communities in these catchments.  Our paired catchment, broad-scale sampling approach will document the influence of drilling activities on sedimentation and biological community composition, informing the placement and permitting of future wells to minimize any potential effects to nearby headwater streams.