A Look Inside the Largest Desalination Plant in the Western Hemisphere

The largest ocean desalination plant in the Western Hemisphere is expected to begin operation within days, heralding what may be a new era in U.S. water use. The Carlsbad, California, plant will serve San Diego County with the capacity to produce 50 million gallons of fresh water daily, about one-tenth of the county's total water use.

Construction of the plant by Poseidon Water of Boston lasted nearly 14 years, and totaled about $1 billion. The project—and the concept of “desal” in general—has received much criticism from the environmental community in particular, who say desalination harms marine ecosystems and costs significantly more than water from sources like conservation, recycling, and stormwater collection.