The ideas presented by Stahl (2018) are intriguing. There is a wealth of information that supports that groundwater pumping has perturbed the hydrologic cycle at a global scale (Konikow 2011; Rodell et al. 2018) and perturbations to global elemental cycles would not be unexpected. However, the analysis presented by Stahl (2018) is problematic. Stahl assumes that the 45% of produced waters from oil field operations that were not used in enhanced oil recovery (EOR) are released into the more active portion of the hydrological cycle based on 2007 figures for the United States from Clark and Veil (2009). This figure is substantially lower in reality. Clark and Veil (2009) report that 38.2% of produced waters were injected into nonproducing strata. This injection occurs almost exclusively through Class II disposal wells, which are typically installed in saline aquifers (EPA 2018). Similar practices have been noted in Canada, where there has been a net gain in the amount of water in the Western Canada Sedimentary Basin (Ferguson 2015). In addition, Stahl states that 45% of Shell’s produced water is discharged at the surface based on an estimate from Khatib and Verbeek (2003). However, that study also noted that much of this discharge was to the ocean as part of offshore drilling activities. The overestimation of addition of produced water to the active portion of global elemental cycles will have a notable effect on estimates of fluxes of elements such as Li, Na, Cl, and Ca, which are found in high concentrations