Distribution of boron in thermal waters of western Anatolia, Turkey, and examples of their environmental impacts

Abstract.

Boron concentrations of the CO₂-rich thermal waters in western Anatolia have a wide range of 1–63 mg/l. Cl/B molal ratios of high temperature waters (>150 °C) have low values ranging from 1 to 10. In low-temperature thermal waters (<150 °C), with the exception of samples that have some seawater, Cl/B ratios range from 2 to 88. The positive correlation between HCO₃ and B values for thermal waters means that B concentrations in thermal waters are also associated with the dissolution of carbonates. In addition to the water–rock interaction, boron in thermal waters is probably controlled by the contribution of B by degassing of magma intrusives. Sericite, illite and tourmaline minerals, which are abundant in Menderes Massif rocks, are considered to be the main reason for the high boron contents. High B concentrations of thermal waters causes environmental problems in groundwaters and surface waters in some agricultural areas of western Anatolia. Re-injection of thermal waters to the reservoir is the best way to dispose of the geothermal wastewater and prevent contamination problems.