Water, Water Everywhere

A new desalination plant in Carlsbad, California, is bordered by Interstate 5 on one side and the Pacific Ocean on the other.

After 14 years of construction the Poseidon water desalination plant in Carlsbad, California, is starting operation. It is the largest reverse osmosis plant in the USA. It makes drinking water from sea water. I seem to recall hearing about a zillion years ago how 'we' (Americans? Scientists?) were working on reverse osmosis techniques. Seems it has finally reached the point where it is practical, or maybe we have finally gotten desperate enough to pay for it. The price Poseidon is getting for their water is about twice what San Diego pays the Metropolitan Water District of Southern California for water. I ran some numbers to see how it pencils out.


Poseidon should make money on this project, but it's a pretty thin deal. The 9.6% return they should be getting on their investment doesn't include operating costs. Those cost should be minimal, but they are not going to be zero. They have to produce the water to get paid, so breakdowns could impact their revenue stream. Their capacity is about 15% greater than what they are contracted to produce, so they have a little margin for error. Reverse osmosis depends on special filters to work. I don't know how long those filters / membranes last, but it's not forever, and replacing them is going to cost money. I wish them luck.

From a story by  Bradley J. Fikes in The San Diego Union-Tribune.