what makes the blue lagoon in iceland blue
Blue Lagoon (geothermal spa) The rich mineral content is provided by the underground geological layers and pushed up to the surface by the hot water (at about 1.2 MPa (170 psi) pressure and 240 °C (464 °F) temperature) used by the plant. Because of its mineral concentration, water cannot be recycled and must be disposed of in the nearby landscape, a permeable lava field that varies in thickness from 50 cm (20 in) to 1 m (3.3 ft). The silicate minerals is the primary cause of that water's milky blue shade. After the minerals have formed a deposit, the water reinfiltrates the ground, but the deposit renders it impermeable over time, hence the necessity for the plant to continuously dig new ponds in the nearby lava field.