Lava from the Kilauea volcano in Hawaii was approaching a geothermal plant on Sunday according to officials.
The wells at the Puna Geothermal Venture site have been capped to prevent the release of toxic gas that can result from mixing with lava.
However, authorities on the island said they believe they have done enough to avoid any danger. thin00.14 sot Hawaii Governor David Ige
"We believe that the PGV the site is safe, that the actions that we've taken to quench the wells, to plug the wells, to make sure that we can control any release of hydrogen sulphide will be contained," Hawaii Governor David Ige told reporters.
But lava has never engulfed a geothermal plant anywhere in the world and the potential threat is untested, according to the head of the state's emergency management agency. Local residents fear an explosive emission of deadly hydrogen sulfide and other gases should wells be ruptured.
Lava had previously crossed onto an older part of the property but it has since spread to parts of the plant that are operational.
Lava-filled fissures have torn apart chunks of the southeastern side of the Big Island over the past three weeks as Kilauea has become more active.