A NEW PARADIGM IN THE ENERGY-WATER QUALITY NEXUS: QUANTIFICATION OF THE WATER LOSS FROM ENERGY-RELATED CONTAMINATION (Invited Presentation)

The water withdrawal and consumption needed for the different cycles of fossil fuels recovery and processing is large and can affect water availability and quality, particularly in water-scarce areas. Based upon updated water intensity and energy utilization data, we evaluated the global water withdrawal for the different stages of fossil fuels extraction and production as 642x10⁹ m³, while global water consumption increased to 57.8x10⁹ m³ in 2019 [1]. These estimates far exceed previous models, reflecting the rapid rise of global energy consumption, specifically the increasing intensity of unconventional oil and gas exploration. Parallel to water use, we estimate that the global wastewater from fossil fuels in 2019 was 43 x10⁹ m³, in which coal and crude oil wastewaters consisted of 52% and 46%, respectively. Given the high levels of contaminants in wastewater associated with fossil fuels, the release of even small volume of the wastewater through spills, leaks or inadequate management to the environment severely affects the water quality of the receiving water and thus induces a large impaired-water intensity, which commonly is not evaluated in the energy-water nexus paradigm. Reevaluation of energy-water nexus, considering water quality degradation indicates that the actual water intensity of fossil fuels is even larger than the estimated water footprint based on water quantity alone. We highlight the negative cycle in which decades of increasing water and energy consumption have resulted in over-exploitation and depletion of water resources, which is further exacerbated by large water utilization for energy development, water quality degradation from energy-derived contaminants. The environmental legacy of fossil fuels through abandoned oil and gas wells, leaching of contaminants from oil and wastewater spills sites, discharge of acid mine drainage, and disposal of coal combustion residuals will continue to impact the quality of water resources for decades to come, even in scenarios where fossil fuels utilization is declining.

[1] Vengosh, A. and Weinthal, E. (2022) Water Quality Impacts of the Energy-Water Nexus, Cambridge University Press.