Salty water also known as Saline water is a general term for water that contains a significant concentration of dissolved salts (mainly NaCl). The salt concentration is usually expressed in parts per thousand (permillle, ‰) or parts per million (ppm). The United States Geological Survey classifies saline water in three salinity categories. Salt concentration in slightly saline water is around 1,000 to 3,000 ppm (0.1-0.3%), in moderately saline water 3,000 to 10,000 ppm (0.3-1%) and in highly saline water 10,000 to 35,000 ppm (1-3.5%). Seawater has a salinity of roughly 35,000 ppm, equivalent to 35 grams of salt per one liter (or kilogram) of water. 


The saturation level is dependent on the temperature of the water. At freezing one mililiter of water can dissolve about 357 milligrams of salt; a concentration of 35.7%. At boiling the amount that can be dissolved in a mililiter of water increases to about 390 milligrams or 39% saline solution.