What is Brine and Where Does it Come From?
Brine is the salty water trapped in rock formations associated with oil and gas deposits. It consists mostly of sodium chloride but can also contain other things such as organics, bromide, some heavy metals and boron. Its source as a pollutant is usually oil stripper wells which produce less than 10 barrels of oil per day with typically a 10:1 ratio of brine to oil. Such wells are distributed throughout Kentucky and are often located on farmland. In some cases, brine rises to the land surface even where no oil wells are present.
Evangelou, V. P.; Marsi, M.; and Wells, Kenneth L., "The Effect of Oil Well Brines on Agricultural Fields and Water" (1990). Agronomy Notes. 147.