Vaca Muerta is the major region in South America where horizontal drilling and hydraulic fracturing techniques are used to extract unconventional shale oil and gas. Despite the growing interest in the Vaca Muerta resources, there is only a limited understanding of the impacts that their extraction could have on local water resources. This study uses a water balance model to investigate the hydrological implication of unconventional oil and gas extraction in this region. We find that, with current rates of extraction, water scarcity is observed for four months a year. We also find that water consumption per fractured well increased 2.5 times in the period 2012–2016 and produced water from unconventional shale formation sharply increased from roughly zero to 1.15 × 10⁶ m³ y⁻¹ in the 2009–2017 period. Our projections estimate that in this region future water consumption for unconventional oil and gas extraction will increase 2.2 times in the 2017–2024 period reaching 7.40 × 10⁶ m³ y⁻¹. The consequent exacerbation of current water scarcity will likely lead to competition with irrigated agriculture, the greatest water consumer in this semiarid region. Produced water recycling, domestic wastewater reuse, brackish groundwater use, and waterless unconventional oil and gas extraction technologies are some of the strategies that could be adopted to meet future additional water demand. Our results estimate the likely range of water consumption and production from hydraulic fracturing operations in the Vaca Muerta region under current and future conditions. These results could be used to make informed decisions for the sustainable water management in this semiarid region of Argentina.

High volumes of flowback and produced water are generated everyday as a byproduct of hydraulic fracturing operations and shale gas developments across the United States. Since most shale gas developments are located in semi-arid to arid U.S. regions close to agricultural production, there are many opportunities for reusing these waters as potential alternatives or supplements to fresh water resources for irrigation activities. However, the impacts of high salinity and total organic content of these types of water on crop physiological parameters and plant growth needs to be investigated to determine their utility and feasibility. The aim of the present study was to evaluate the response of switchgrass and rapeseed to treated produced water as an irrigation water source. In this greenhouse study, the influence of produced water at four total organic carbon (TOC) concentrations [1.22, 38.3, 232.2 and 1352.4mg/l] and three total dissolved solids (TDS) levels [400,3,500, and 21,000mg/l] on rapeseed (Brassica napus L.) and switchgrass (Panicum virgatum L.), two relatively salt-tolerant, non-food, biofuel crops, was studied. Seedling emergence, biomass yield, plant height, leaf electrolyte leakage, and plant uptake were evaluated. Irrigation water with the highest salinity and TOC concentration resulted in significantly lower growth health and physiological characteristics of both crop species. The organic content of the produced water had a negative impact on biomass yield and physiological parameters of both species. The results of this study could be valuable for regulators and stakeholders in development of treatment standards in which organic matter should be removed to less than 50mg/l to keep leaf EL (cell damage) to less than 50% and a TOC concentration of less than 5mg/l required to keep a sustainable biomass production rate.