ALTERATIONS TO SMALL STREAMS FROM ACTIVITIES ASSOCIATED WITH HIGH-VOLUME HYDRAULIC FRACTURING: FAYETTEVILLE SHALE AS A CASE STUDY

Biological integrity is defined as persistent and stable community composition and ecological function that can change with alterations. An inherent challenge in identifying ecological indicators is adequate data prior to ecosystem alterations, unknown interactions among alterations, and the appropriate scale to measure indicators. Oil and gas extraction is among the most common landscape disturbance that has increased in the last decade in density and geographic expanse across the U.S. in regions without a history of extraction. Disturbances associated with extraction are land clearing for supporting infrastructure, freshwater withdrawals, and possible chemical and wastewater water spills during drilling/fracturing, reuse, transport, and treatment. The well and pipeline density along with violations in a watershed are often used as indicators of biological risk in at the reach (100 m) and small (<130 km²) watershed scale. To date, more wells placed close to stream channels, surface water withdrawal volumes that are not scaled to stream discharge seasonal and daily volumes and more frequent transport of wastewater and spills increase the risk for measurable ecological alterations. Ecological responses that may serve as endpoints associated with these changes remain largely unquantified. Ecological indicators that flag modifications in biological integrity from land use changes are needed to address rapid species loss and altered ecological functions. We will summarize the existing surface water physical, chemical, and biological responses to HVHF that are drawn from our experience in the Fayetteville Shale (FS) and associated indicators of environmental changes.