Life Cycle Water Consumption and Wastewater Generation Impacts of a Marcellus Shale Gas Well

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• 作者：Mohan Jiang ; Chris T. Hendrickson ; Jeanne M. VanBriesen
• 刊名：Environmental Science & Technology
• 出版年：2014
• 出版时间：February 4, 2014
• 年：2014
• 卷：48
• 期：3
• 页码：1911-1920
• 全文大小：492K
• ISSN：1520-5851

文摘

This study estimates the life cycle water consumption and wastewater generation impacts of a Marcellus shale gas well from its construction to end of life. Direct water consumption at the well site was assessed by analysis of data from approximately 500 individual well completion reports collected in 2010 by the Pennsylvania Department of Conservation and Natural Resources. Indirect water consumption for supply chain production at each life cycle stage of the well was estimated using the economic input鈥搊utput life cycle assessment (EIO-LCA) method. Life cycle direct and indirect water quality pollution impacts were assessed and compared using the tool for the reduction and assessment of chemical and other environmental impacts (TRACI). Wastewater treatment cost was proposed as an additional indicator for water quality pollution impacts from shale gas well wastewater. Four water management scenarios for Marcellus shale well wastewater were assessed: current conditions in Pennsylvania; complete discharge; direct reuse and desalination; and complete desalination. The results show that under the current conditions, an average Marcellus shale gas well consumes 20鈥?00 m³ (with a range from 6700 to 33鈥?00 m³) of freshwater per well over its life cycle excluding final gas utilization, with 65% direct water consumption at the well site and 35% indirect water consumption across the supply chain production. If all flowback and produced water is released into the environment without treatment, direct wastewater from a Marcellus shale gas well is estimated to have 300鈥?000 kg N-eq eutrophication potential, 900鈥?3鈥?00 kg 2,4D-eq freshwater ecotoxicity potential, 0鈥?70 kg benzene-eq carcinogenic potential, and 2800鈥?1鈥?00 MT toluene-eq noncarcinogenic potential. The potential toxicity of the chemicals in the wastewater from the well site exceeds those associated with supply chain production, except for carcinogenic effects. If all the Marcellus shale well wastewater is treated to surface discharge standards by desalination, $59鈥?00鈥?70鈥?00 per well would be required. The life cycle study results indicate that when gas end use is not considered hydraulic fracturing is the largest contributor to the life cycle water impacts of a Marcellus shale gas well.