a mixture of water and a soluble salt. Most common brines are sodium chloride NaCl, potassium chloride KCl and calcium chloride CaCl₂. Brine densities may range from 8.33 to > 19 lb/gal (1 to >2.28 g/cc). The USGS definition of a brine is a salinity of more than 35,000 mg/L (after USGS, 1984).