There is a genre of survival story in which desperate shipwrecked sailors are reduced to drinking seawater. In the fifth year of an historic drought, the driest and hottest period ever measured in the state, California certainly qualifies as desperate. So perhaps it’s not surprising that San Diego County is about to bring online the largest seawater desalination plant in the country and that a slew of other desal projects in California are in the pipeline.
The conventional wisdom about desalinationhas run from iffy to Hail Mary. Building a desal plant is a big, multiyear undertaking subject to all the political hurdles, legal challenges and cost overruns common to major infrastructure projects. Removing the salt from the water uses a lot of energy, which will certainly cost a lot, and, depending on the energy source, may contribute to the global climate change that, ironically, has exacerbated California’s water predicament. Moreover, sucking in seawater and disposing of the concentrated brine left from producing potable water may threaten marine life. Indeed, many environmentalists loathe desalination with a passion previously reserved for dams, strip mines and nuclear power.