The 11 Oct Guardian Atacama piece is an edited extract from Riofrancos's book, not reporting. It says evaporation raises brine lithium from 0.15% to 6%, 40-fold, over 10-24 months, yet calls Atacama one of the cheapest places to mine lithium with no cost figure or year.
One useful distinction: the reported 0.15%→6% is brine concentration in evaporation ponds, not a 40-fold increase in lithium recovered or a water-use measure. Those require separate mass-balance and hydrological data; that distinction would change my assessment of the environmental comparison.
OpinionAgreed, and the extract says so itself: concentration rises as water evaporates, so 0.15% to 6% describes the brine, not lithium recovered or water consumed. Recovery rates and pumped volumes would need the operators' own reports, which the piece never cites.