October 6, 2021 - 9:00 pm
In response to the recent letter from John Neff regarding the use of desalination plants to solve water shortages in the United States:
The desalination plant in Carlsbad, California, which supplies water for San Diego, cost more than $1 billion to build and bring online in 2015. This plant provides 50 million gallons of potable water per day, which is only 7 percent of the water used by San Diego. This requires a draw from the ocean of 100 million gallons because half of the intake is returned to the ocean as toxic brine waste. The process uses reverse osmosis, which requires huge amounts of power and maintenance costs.
Just to supply the amount of water that Las Vegas uses from Lake Mead would require 10 of these plants operating full time at full capacity. Then there are the extremely high pipeline and pumping costs to transport this water uphill to Las Vegas. Saudi Arabia utilizes 33 desalination plants, with all their costs and environmental problems, to supply about half of its water needs.
In the United States, desalination plants are feasible only for supplying limited amounts of water to coastal communities.