Lava erupting from the Kilauea volcano has reached the property of a geothermal power plant where toxic gas lurks in underground wells, the head of the state emergency management agency said Monday.

So far, a berm has halted the advance of the lava at about 200 to 300 meters from the wells of Puna Geothermal Venture.

But if the lava interacts with the wells of the Puna Geothermal Venture, it could trigger an uncontrolled release of deadly hydrogen sulfide, Thomas Travis, administrator of the Hawaii Emergency Management Agency said during a press conference Monday.

When the Puna Geothermal Venture is operating normally, the wells feed steam into a turbine that produces 25 percent of the Big Island’s electricity.

Ormat Technologies Inc.

“If you put tremendous heat on any metal, it changes how much pressure and stress that metal can hold,” said Travis. “That’s why having lava flow across the well causes some uncertainties that have to be dealt with.”

The wells were shut down weeks ago when the eruption started.

Over the past two weeks, 10 wells have been quenched, and capped with a heavy steel plate. The work required removing the massive wellhead valves tested to resist 3,000 pounds per square inch of pressure, something that will now be accomplished by a column of water more than a mile high to resist lava entry into the well underground.

That’s the working theory anyway, and company and government emergency management officials consulted experts worldwide from New Zealand to California to Iceland on the best response to imminent lava inundation.

The trouble is, “to our knowledge, no one’s faced this before,” Travis said.

The last wellhead – Well 14 – stymied all efforts Monday to quench and cap the well. More than a mile of cold water was not enough. Ditto more than a mile of denser salt water.

“Something has happened down there in the last two weeks that won’t let it (quench),” Travis said.

Drilling mud, a highly complex and heavyweight chemical compound used extensively in oilfield drilling, is the next line of attack. Travis was confident the mud would work because it hardens and thickens under heat and pressure, he said.

That work is supposed to be complete by Tuesday, Travis said.

Wells already quenched are then sealed with a heavy steel plate at the bottom of a 30-foot hole, then backfilled with insulating cinder, said Talmadge Magno, Hawaii County’s Director of Civil Defense and a member of the four-person oversight committee appointed by Hawaii County Mayor Harry Kim and Hawaii Gov. David Ige to handle the PGV emergency.

The lava, which crossed onto the southern edge of the PGV property early Monday, is 100 to 200 meters from the plant’s 11 wells, Travis said at a Monday afternoon news conference.

Although a naturally occurring berm has so far halted the lava’s advance, officials are preparing for the worst.

The natural swale in the land is holding so far. But when it fails, only then will everyone know if the emergency response has worked.

In daily power-generation operations, deep underground fluids under pressure and heated to 350 degrees centigrade, are tapped by PGV’s production wells. The super-heated fluids rise to the surface to exchange heat with pentane, whose boiling point is lower than that of liquid propane, the gaseous pentane then powers the turbines to spin electricity from a magnetic field.

Contacted last Friday before the nearby rifts erupted into high volume lava emissions, PGV’s Mike Kaleikini was already worried about the destructive possiblities of the East Rift eruption of 2018.

The plant is owned by Ormat Technologies and sells power to the Hawaiian Electric Light Co., the Big Island’s electric utility that is part of the Hawaiian Electric Cos.

The plant made some $11 million in profit in 2017 for Ormat and and a smaller consortium of investors, CEO Isaac Angel said earlier this month in a conference call with investors.

Employing about 30 full-time staff, Puna Geothermal is a major force in the island’s power generation grid.

If the Puna Geothermal plant is damaged or destroyed, PGV has a $100 million insurance policy, Angel told investors in the conference call.

“It’s not easy to predict where it’s going to go and when it’s going to get there,” Travis said, “so it’s important we get what we can get done now.”

Civil Beat correspondent Andrew Perala contributed to this story from the Big Island.

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