Just in the nick of time? Hawaii engineers finally plug poisonous gas wells at geothermal plant as lava creeps just 1,000 feet away

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Production wells at a geothermal plant under threat by lava flowing from Hawaii's Kilauea volcano have been plugged to prevent toxic gases from seeping out.

Lava from a nearby, new volcanic vent entered, then stalled, on the 815-acre property where the Puna Geothermal Venture wells occupy about 40 acres. Residents have been concerned about hazards if the lava flowed over the plant's facilities, or if heat generated would interact with various chemicals used on-site.

Ten wells were 'quenched' by cooling them with enough cold water to counter the pressure of volcanic steam coming from below, said Hawaii Gov. David Ige. The last well was plugged with mud, because it had remained hot despite the infusion of water. Metal plugs in the wells, which run as deep as 8,000 feet underground, are an additional stopgap measure.

As of Tuesday, the lava was flowing less than 1,000 feet away from the wells.  

 The wells at the Puna Geothermal Venture plant were plugged overnight as lava from Hawaii's Kilauea volcano inched closer to the site. The plant is pictured above on Tuesday 

Ten well were 'quenched' with water which countered the pressure of the volcanic steam below, to prevent the emission of toxic gases. An eleventh well was plugged with mud because water wouldn't cool it down. The plan on Tuesday

 Lava has already crossed onto the plant's land and destroyed one building, was still about 1,000 feet from the wells on Tuesday

'All wells are stable at this point,' said Ige. County officials are also monitoring various gases that may leak into the atmosphere.

A spike in gas levels could prompt a mass evacuation, said Hawaii County Civil Defense Administrator Talmadge Magno. Officials, however, have not discussed specific scenarios that would lead to such an emergency.

Puna Geothermal, owned by Nevada's Ormat Technologies, was shut down shortly after Kilauea began spewing lava on May 3. The plant harnesses heat and steam from the earth's core to spin turbines to generate power. A flammable gas called pentane is used as part of the process, though officials earlier this month removed 50,000 gallons of it from the plant to reduce the chance of explosions.

The plant has capacity to produce 38 megawatts of electricity, providing roughly one-quarter of the Big Island's daily energy demand.

Lava destroyed a building near the plant late Monday, bringing the total number of structures overtaken in the past several weeks to nearly 50, including dozens of homes. The latest was a warehouse adjacent to the Puna plant, Hawaii County spokeswoman Janet Snyder told the Honolulu Star-Advertiser. The building was owned by the state and was used in geothermal research projects in the early days of the site.

 County officials say they are closely monitoring emissions, and will issue an evacuation if toxic fumes spike. Above, lava flows near the plant on Monday

 The plant harnesses heat and steam from the earth's core which spin turbines to generate power. The plant pictured above on Monday

 The Nevada-owned plant provides about a quarter of the Big Island's power. the plane is pictured above on May 16 

Native Hawaiians have long expressed frustration with the plant since it came online in 1989; they say it is built on sacred land. Goddess of fire, Pele, is believed to live on Kilauea volcano, and the plant itself is thought to desecrate her name.

Other residents have voiced concerns over health and safety.

Scientists, however, say the conditions on Kilauea make it a good site for harnessing the earth for renewable energy.

'There's heat beneath the ground if you dig deep enough everywhere,' said Laura Wisland, a senior analyst at the Union of Concerned Scientists. But in some places in the U.S. 'it's just hotter, and you can access the geothermal energy more easily.'

Lava flows have already reached the ocean. When lava hits the cold ocean water, it creates a steam called laze which is toxic. Hawaiian and mariners are being warned to avoid this toxic steam. Above, a lava flow entering the ocean on Tuesday 

This image released by the USGS shows a lava fissure on Tuesday. Lava has been spouting on the island for the past three weeks 

Kilauea's summit is now belching 15,000 tons of the gas each day up from 6,000 tons daily prior to the May 3 eruption

Geothermal energy is also considered a clean resource as it doesn't generate greenhouse gas emissions, said Bridget Ayling, the director of Nevada's Great Basin Center for Geothermal Energy.

Ormat said in a May 15 statement that there was a low risk of surface lava making its way to the facility. The company also said there was no damage to the facilities above-ground and that it was continuing to assess the impact. The plant is expected to begin operating 'as soon as it is safe to do so,' according to the statement.

Puna Geothermal represents about 4.5 percent of Ormat's worldwide generating capacity. Last year, the Hawaii plant generated about $11 million of net income for the company. Ormat is traded on the New York Stock Exchange, and shares have fallen nearly 10 percent since Kilauea began erupting.

Kaleikini said the gases that could potentially leak from the Puna plant are no different from those coming from active fissures.

The U.S. Geological Survey said sulfur dioxide emissions from the volcano have more than doubled since the current eruption began. Kilauea's summit is now belching 15,000 tons of the gas each day up from 6,000 tons  daily prior to the May 3 eruption.

Scientists say lava from Kilauea is causing explosions as it enters the ocean, which can look like fireworks. Above, lava producing laze on Monday

Joe Kekedi takes pictures as lava enters the ocean on May 20 off the Big Island of Hawaii

Scientists say lava from Kilauea is causing explosions as it enters the ocean, which can look like fireworks. When lava hits the sea and cools, it breaks apart and sends fragments flying into the air, which could land on boats in the water, said U.S. Geological Survey scientist Wendy Stovall.

Underscoring the eruption's dangers, a Hawaii man was hit by a flying piece of lava over the weekend said the molten rock nearly sheared his leg in half.

Darryl Clinton told the Honolulu television station KHON that he was on the roof of a home helping to put out fires from flying rocks when an explosion several hundred yards away launched a 'lava bomb' that him above the ankle.

Clinton said doctors saved his leg, but he must avoid putting weight on it for six weeks.

Clinton was the first person to suffer a major injury because of the eruption.

And there appears to be no end in sight, as the USGS announced a new lava flow Wednesday morning.

'Note a new lava flow that was observed during this morning's overflight west of the active channels,' the agency wrote on Facebook.

On the bright side, it appears that the flows aren't growing larger.

The USGS said that the flow field 'has not expanded significantly during the past day'.