Aerial Photos of Cargill’s Solar Evaporation Salt Mine

John P.

Aerial Photo Outside of San FranciscoMonths ago when flying into San Francisco, our plane was diverted into a holding pattern a little ways outside the airport due to traffic, and as I watched from the window I noticed that we were circling some sort of massive pools of colored water. They were so vibrant in color that I was amazed, and I took a bunch of photos (and posted them).

What I didn’t know at the time was, that was the Cargill solar evaporation salt production facility. I actually just learned it by watching the TV show “Modern Marvels” that was specifically on salt production. As soon as they began describing the location of the facility I instantly knew what I had seen months ago!

Anyway, the rich colors that you can see in the ariel photography are supposedly due to the microorganisms that live in this heavy concentration of salt water called brine. The brine contains a concentration of about 25% salt, which is about the maximum amount of salt that can actually be disolved in water.

Cargill describes the salt production facility as such:

Solar Evaporation

Solar salt is produced through the natural evaporation of sea water or other naturally occurring brine. Salt water is captured in shallow ponds and allowed to evaporate by means of the sun and wind. During the process, a salt bed forms on the bottom of the pond. The salt is harvested, washed, screened and packaged. The typical solar “crop” takes from one to five years to produce.

So, what they are doing is flooding sea water into these large areas and then basically letting it evaporate away over time and leaving millions of tons of salt behind for harvesting.

This is actually similar to a naturally occurring process which is demonstrated in a few inland bodies of water such as Utah’s Great Salt Lake, the Dead Sea, and other ancient bodies of water. For example, the great salt lake used to be many times larger than it is now. But over time the water has evaporated, leaving the concentration of salt much, much higher than even the ocean. About seven times higher to be exact! In the southern portion of the lake the concentration is about 15% salt, which the northern half is closer to 25%.

You can actually see the difference in the salt concentrations from the satellite imagery in the embedded map below:

View Larger Map

And of course, the world famous Bonneville Salt Flats nearby are just another part of the evaporated ancient lake that the Great Salt Lake comes from. The Salt Flats of course being the place that most of the world’s land speed records were set.

Anyway, I know I rambled on a little there and moved from San Francisco over to Utah, but I thought the whole thing was just so cool, starting with the fact that I had actually photographed a salt plant without really knowing it. Hope you guys found it as interesting as I did.


  1. says

    OMG, those guys go FAST!!! Wow!

    The wanderings of this post were quite interesting! It’s funny when you find something like that out months later after seeing it. The colors are just amazing!

    And that’s SUCH a trip that you can actually see the difference in salt concentration in that satellite photo of the Great Salt Lake – very cool!

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