Water source The lagoon is man-made. The water is a byproduct from the nearby
Svartsengi geothermal power plant where
superheated water is vented from the ground near a lava flow and used to run
turbines that generate electricity. After going through the turbines, the steam and hot water pass through a
heat exchanger to provide heat for a municipal
water heating system. Then the water is fed into the lagoon. The rich mineral content is provided by the underground geological layers and pushed up to the surface at a pressure of about and temperature of , which is used by the powerplant. Because of its high mineral concentration, the water cannot be recycled, and must be disposed of in the nearby landscape, a permeable
lava field that varies in thickness from . After the minerals have formed a deposit, the water reinfiltrates the ground, but the deposits render the ground impermeable over time, so the plant needs to continuously dig new ponds in the nearby lava field. The water renews every two days. and the lagoon subsequently became popular. Bathing facilities opened in 1987, and in 1992 the Blue Lagoon company was established. A psoriasis clinic was opened in 1994 up from 919,000 visitors in 2015. The company had a revenue of
€102 million and a profit of €31 million in 2017.
2023–25 earthquake swarm and volcanic eruptions On 23 October 2023, the Department of Civil Protection and Emergency Management announced a level of uncertainty due to a
seismic swarm in the area. The resort faced some criticism for continuing to accept customers with some likening the situation to events leading up to the
2019 Whakaari/White Island eruption. Guests were reportedly not informed about the unfolding events in the area and the risk of using the lagoon. On 4 November 2023, Helga Árnadóttir, CEO of sales at the Blue Lagoon said that closing the resort was not in the picture. Árnadóttir criticized , professor of geology at the University of Iceland, for predicting an eruption in the area, saying that there were no
harmonic tremors reported. On 7 November, the tour company Reykjavik Excursions cancelled all trips to the lagoon for three days due to concern about their staff and customers' well-being. The resort remained open until 9 November 2023, when about 40 guests at the Silica hotel were reported fleeing in panic due to a seismic swarm in the area and the resort announced a temporary one week closure. The management of the Blue Lagoon announced the site's closure to visitors from 9–16 November as a precaution following the earthquakes. The closure period was later extended to 30 November 2023, and then further to 7 December. Though briefly reopened, the Blue Lagoon was again closed until 6 January due to a volcanic eruption at
Sundhnúkur, all facilities were reopened by 10 January. Another eruption caused a further closure on 14 January, reopening again by 20 January. A third eruption on 8 February forced the resort to close again but reopened once more on 16 February. A fourth eruption on 16 March caused the lagoon to, once again, close. It reopened on 7 April 2024. After another eruption, the lava reached the Blue Lagoon on 22 November 2024, destroying the car park. ==See also==