Concentrated brines and salt deposits can accumulate as a result of irrigation on saline soils and/or using water with relatively high amounts of dissolved salts. Continuation of productive land use may require disposal of excess saline residues. Commonly proposed is dumping into local salt lakes or pumping into saline aquifers, or even freshwater watercourses. These methods, together with continuation of the original irrigation practices, degrade the land and can carry other serious environmental impacts which are rarely considered.
Brine waste includes toxic concentrations of magnesium sulfate, potassium chloride,bromine, iodine and boron.
The Mexican Environment protection agency observed a fish kill caused by a spill of over four million gallons of brine waste from a plant in Laguna Ojo de Liebre in may 1998.