The Big Island of Hawaii is still under threat from the Kilauea volcano. Authorities are especially concerned about how flowing lava could affect Puna Geothermal Venture (PGV), a plant that provides at least one-quarter of the Big Island's daily energy needs via geothermal wells.

Gov. David Ige said Tuesday that authorities are monitoring the flow of lava and the threat to the plant.

He said that ten wells have been cooled with cold water to counter the pressure from rising volcanic steam. One other well was plugged with mud.

"We do believe that all 11 wells are stable and the risk to the uncontrollable release of hydrogen sulfide has been mitigated," he said.

Since the eruption began May 3, sulfur dioxide emissions have more than doubled. The air, especially in the southern part of the island, is increasingly dangerous.

Authorities have already forced more than 2,000 people to evacuate.

A spike in the level of gases in the air could lead to a mass evacuation as could a problem at the plant.

"If we really felt that the plant was at risk of being overrun and could trigger a well being exposed, then that's when we would order the evacuation," said Ige.

Lava has already destroyed nearly 50 buildings including dozens of homes.