Evaporation ponds are used throughout the world for such purposes as wastewater treatment, salt harvesting, the collection and processing of agricultural runoff, for varied mining and industrial purposes, and for remediation and cleanup of contaminated sites. The actual construction of evaporation ponds also varies, but the essential elements are the same. Evaporation ponds are typically lined basins that are designed to collect minerals in the form of precipitated salt crystals or sludge that contains unwanted or toxic particulate that can then be manually harvested and transported to an off-site location for proper disposal, or reclaimed for other varied uses. Brine ponds are used extensively at inland desalination plants, and more advanced solar ponds have the ability to generate and store electricity. The science is fascinating.
Actual effectiveness of an evaporation pond is weather dependent, and it is also affected by the terrain and the cost of the land. Generally, an evaporation pond is highly feasible in locations that have warm, dry climates and a sufficiently large area of flat terrain that can be devoted to the pond. Key factors are low humidity, low precipitation and high evaporation rates. Brine disposal ponds are only applicable in regions with average annual humidity lower than 60%. They are ineffective in regions with an annual evaporation rate of less than 1.0 m/y and annual rainfall greater than 0.3 m/y.
