HILO — Gov. David Ige and the state’s Civil Defense chief expressed confidence Tuesday that the risk of a hydrogen sulfide release at Puna Geothermal Venture has been mitigated as lava creeps onto its property.
While mechanical plugs aren’t installed yet, Hawaii Emergency Management Agency Administrator Tom Travis said 10 of the 11 wells have been “quenched,” and pressure was declining at the last well of concern. If lava from the ongoing Kilauea eruption in lower Puna covered a wellhead, it’s expected that its integrity will hold and an uncontrolled gas release won’t occur.
“We do feel at this point that the facility is stable and the highest risks have been mitigated,” Ige told reporters.
Travis, who led a task force to ensure the safety of PGV during the eruption crisis, said a “mud plug” was installed at KS-14, the last well to be addressed, but noted that installing mechanical plugs would require opening two safety valves, which creates some risk. He said the additional plugs will be installed if workers can complete the work without being interrupted by molten rock or sulfur dioxide emissions from nearby fissures.
Nonetheless, Travis said he thinks the measures taken so far will be sufficient.
“The well field at PGV is essentially safe,” Travis told reporters.
“The status is stable, predictable and understandable,” he added. “And, there’s no reason as a result of the status of the wells to feel any undue concern.”
Mike Kaleikini, senior director of Hawaii affairs for PGV’s parent company, Ormat, agreed with that assessment.
“I have full confidence that everything is in a very safe state right now,” he said.
On Tuesday, lava continued to enter the ocean between Isaac Hale and MacKenzie beach parks with vigorous fountaining at the lava fissures in Leilani Estates and in and around Lanipuna Gardens.
Fissure activity was concentrated in the central area of the eruption, said Jim Kauahikaua, Hawaiian Volcano Observatory geophysicist.
Some “backflow” had entered PGV’s property, which is slightly uphill. Kaleikini said the lava was several hundred yards from the nearest wells.
Meanwhile, eruptions of ash continue at Kilauea’s summit inside Hawaii Volcanoes National Park, which remains closed because of the increased volcanic hazards.
Geologists say the ongoing explosive eruptions are widening the vent inside Halema‘uma‘u Crater and causing part of the crater wall to subside.
Jessica Ferracane, park spokeswoman, said preparations are ongoing to reopen Chain of Craters Road as an emergency evacuation route through the park, should lava make Highway 130 impassable. She said an agreement between federal and state agencies was being reviewed.
Reopening the route would involve chiseling through about 0.7 mile of lava rock that covered the road during the “61g” flow from Pu‘u ‘O‘o, which has ceased.
Ferracane said thermal imaging has identified at least one “hot spot” from the former flow.
Talmadge Magno, Hawaii County Civil Defense administrator, said use of that road remains an option but noted officials will keep Highway 130, which experienced cracking because of magma intrusion along the East Rift Zone, open as long as possible.
“As a last resort to get folks out, it will be an option but it’s not our first option,” he said.
When asked about other options, Magno said, “We’re looking at alternate routes, but everything has got to cross that east rift, so we’re pretty limited on alternatives.
“Part of the message has been to let people know that this is coming down, that possibly they are going to get isolated. So, they need to make that decision that if you need to be in Hilo or other places for work, you need to consider moving out.”
While hydrogen sulfide from PGV was a concern, geologists note that sulfur dioxide emissions from the lower Puna eruption remain high.
Wendy Stovall, a U.S. Geological Survey volcanologist, said the emission rate was 15,000 tons a day a few days ago at the eruption site. At the summit, that rate is 3,000 to 6,000 tons a day.
State and federal officials installed additional air monitors around the eruption site. The eruption started May 3 in Leilani Estates and has displaced about 2,000 people.
Email Tom Callis at tcallis@hawaiitribune-herald.com.