The first known use of evaporation ponds was to extract salt from seawater, and the methods have changed little throughout history. The Phoenicians, Romans and Chinese obtained salt in this way. Large flats filled with seawater evaporated naturally in the sun, leaving behind dry salt to be collected. Today, similar salt collection occurs in many countries surrounding the Mediterranean, and in other warmer climates around the globe, including Hawaii. Large salt producers, including Morton Salt that operates an underground mine in Grand Saline, Texas, still occasionally use surface drying fields to isolate salt crystals for various uses.
Other methods, including boiling water evaporators, can be traced to the Onondaga Indians from the area around Syracuse, New York, in 1654. The same technology is still in use today, but it is problematic due to corrosion, and it is not an effective method for large-scale evaporative needs. Natural outdoor evaporation ponds are considered highly effective for a wide variety of applications, and great strides have been made over the past several centuries in understanding how to utilize them to even greater advantage. Although the basic science is essentially unchanged since they were first used to harvest essential salts, modern evaporation ponds are highly scientific and closely monitored.
