Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States.
Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States.
Sci Total Environ. 2022 Sep 20;840:156651. doi: 10.1016/j.scitotenv.2022.156651. Epub 2022 Jun 11.
The oil and gas (O&G) exploitation via hydraulic fracturing (HF) has augmented both energy production and water demand in the United States. Despite the geographical coincidence of U.S. shale plays with water-scarce areas, the water footprint of HF under drought conditions, as well as its impacts on local water allocation, have not been well understood. In this study, we investigated the water consumption by HF activities under different hydroclimate conditions in eleven O&G-producing states in the central and western U.S. from 2011 to 2020. Our results show that the water consumption under abnormally dry or drought climates accounted for 49.7 % (475.3 billion gallons or 1.8 billion m) of total water usage of HF, with 9 % (86.1 billion gallons or 325.9 million m) of water usage occurring under extreme or exceptional drought conditions. The water usage of HF under arid conditions can translate to high densities of water footprint at the local scale, equivalent to >10 % and 50 % of the annual water usage by the irrigation and domestic sectors in 6-29 irrigation-active counties and 11-51 counties (depending on the specific year), respectively. Such water stress imposed by O&G production, however, can be effectively mitigated by the reuse of flowback and produced water. Our findings, for the first time, quantify the water footprint of HF as a function of hydroclimate condition, providing evidence that the water consumption by HF intensifies local water competition and alters water supply threatened by climate variability. This renders wastewater reuse necessary to maintain water sustainability of O&G-producing regions in the context of both a rising O&G industry and a changing climate.
水力压裂（HF）开采石油和天然气（O&G）在美国既增加了能源产量，也增加了用水需求。尽管美国页岩气田与水资源匮乏地区在地理位置上重合，但在干旱条件下 HF 的水足迹以及对当地水资源分配的影响尚未得到充分了解。在这项研究中，我们调查了美国中部和西部地区 11 个 O&G 生产州在不同水文气候条件下 HF 活动的用水量，时间跨度为 2011 年至 2020 年。我们的研究结果表明，在异常干燥或干旱气候条件下，HF 的用水量占 HF 总用水量的 49.7%（4753 亿加仑或 18 亿立方米），其中 9%（861 亿加仑或 3259 万立方米）的用水量发生在极端或特殊干旱条件下。干旱条件下 HF 的用水量会导致当地水足迹密度很高，相当于 6-29 个灌溉活跃县和 11-51 个县（具体取决于特定年份）中灌溉和家庭部门年度用水量的 10%以上和 50%以上。然而，O&G 生产造成的这种用水压力可以通过回注水和产出水的再利用得到有效缓解。我们的研究结果首次量化了 HF 作为水文气候条件的函数的水足迹，为 HF 用水量加剧当地水资源竞争和改变气候变化威胁下的水资源供应提供了证据。这使得废水再利用成为 O&G 生产地区在 O&G 行业不断增长和气候变化的背景下保持水资源可持续性的必要条件。
