Also available for salt is evaporated sea water. This technique was used for centuries in warm coastal areas:
- Pump (or flow) sea water into a shallow, sealed pool.
- Close off the pool form the sea.
- Let it sit in a good hot tropical sun and evaporate for a while until half or 3/4 or so is gone.
- Pump out the very salty water, and boil the rest; refill the pool.
Usually, in a full production cycle, you have several pools at various stages of evaporation, and enough facilities to boil off one pool at a time.
In places where it rains frequently, you can cover the ponds with a tent (depending on size).
This method was popular from Roman times until the early 20th century around the Mediterranean Sea - France, Spain, Sicily, North Africa, Greece, Israel, Egypt.
This technique was used in the Carribbean Islands, when the Europeans colonized them. And San Francisco Bay and around the Great Salt Lake in Utah.
Avery Island, Louisiana, (home of McIlleney's famous Tobasco Sauce) has a major salt mine no longer in use (but available).
Grand Saline, Texas, and Sifto Mine in Goderich, Ontario have active salt mines. Fairport, OH has an active mine 2000 ft deep.
Inagua (Bahamas) has an active solar/evaporation system - has since the 1950s. Hmmm. Need to see what drives that...
There are probably other minor sources of Salt that over the course of the 20th Century became less economically viable as a salt production location (certainly, that is what happened in central NY), but could serve again at a more localized level of production and distribution. If you live in Rochester, NY (in June 2000), it will be more possible to get salt from Syracuse, NY (up I-90 or along the Erie Canal - it's still there and still wet, mostly) than from Avery Island, LA, Grand Saline, Texas, or Detroit, MI.
Uncle Ted