Landscape impacts of infrastructure associated with Utica shale oil and gas extraction in eastern Ohio
Extraction of gas and oil from the Utica shale of eastern Ohio has increased rapidly since it began in 2011. Extraction requires the construction of well pads, pipelines and associated infrastructure. This infrastructure is widely dispersed and necessarily connected throughout the region and has the potential to further fragment the already patchy landscape. This study examined the extent of these landscape disturbances with the goal of developing tools to predict the scale and nature of future disturbances in relation to topography and land use. High resolution (20 cm) aerial photography of an 1169 km2 area was done on April 18-20, 2014. The study area included the most active area of Utica shale drilling in eastern Ohio and covered 517 km2 that were glaciated in the Wisconsinian glaciation and 652 km2 that were unglaciated. The two areas had similar elevations but the glaciated area had 19% of the area in forest and 80% in agriculture. The unglaciated area was 30% forested and 68% agricultural land use. The unglaciated area had significantly steeper slopes with 20% of the area having slopes >13%. Well pads, limits of disturbance, buried pipeline areas, presumed bored pipeline lengths and other areas of disturbance directly attributable to oil and gas infrastructure were digitized from the aerial images.
At the time of collecting the images, 122 well pads had been constructed, accommodating 394 wells: 206 producing, 188 drilled and drilling, and an additional 86 permitted. Well pad area was remarkably consistent at 1.35 ha per pad with no difference between glaciated (n=43) and unglaciated (n=79) areas. Mean areas for limits of disturbance, including the well pad area, were significantly greater in the unglaciated area (2.45 ha vs. 2.98 ha). Area disturbed directly by pipeline burial totaled 873 ha with mean pipeline area per well pad of 6.6 ha in glaciated areas and 7.4 ha in unglaciated areas. Disturbance of sensitive areas was avoided by directionally boring pipelines to avoid surface disturbance. Total bored pipeline length was 26.1 km, crossing beneath 207 roads, 160 streams, 62 wetlands and 35 floodplains. Fragmentation of landscape patches occurred along 31% of the buried pipeline length with the remainder located along patch edges. In general, the area disturbed by gas production infrastructure was greater where slopes are steeper and fragmentation is somewhat more likely in forests than expected relative to overall mean forested area.