Source of Selenium in Water: Selenium (Se) is a natural metal found in soils and rocks. In soils, selenium often occurs in soluble forms such as selenate, which are leached into rivers through runoff, increasing the amount of selenium in groundwater. Its compounds are often used in glass, petroleum, metal, and textile production. High levels of selenium in water systems may be from agricultural runoff in normally dry, undeveloped lands. High levels of selenium in groundwater or wells may also be a sign of industrial pollution. The US EPA has established the MCL for selenium in water at 0.05 mg/L.
Symptoms of Selenium: People exposed to high levels of selenium can have problems with circulation including numbness in their extremities and loss of hair and fingernails. Toxic levels can also cause skin discoloration and tooth decay.
Filtration Solutions for Selenium: Anion exchange can reduce the amount of selenium in drinking water by 60-95%. Reverse osmosis systems and water distillation machines are also an excellent way to greatly reduce selenium in drinking water.