Land use in an island state is of premium concern, and a number of Civil Beat readers sent us questions about the future of landfills in Hawaii.

Episode 9 of “Are We Doomed? And Other Burning Environmental Questions” poses these questions from Oahu, Kauai and the Big Island to experts.

Claire Caulfield/Civil Beat

Oahu

The first question came from Damien Mar Chong, who after listening to Episode 4 of “Are We Doomed?” wanted to know what happens to ash left over from burning 700,000 tons of Oahu’s trash every year.

“I imagine there’s a lot of leftover ash from burning but there’s not a lot of room … on Oahu so where does it all go?” Mar Chong asked.

Every year more than 100,000 tons of ash from H-Power are buried at the Waimanalo Gulch Sanitary Landfill in Kapolei. Other H-Power residue from things that didn’t burn completely or fell on the floor at some point in the process are also disposed of at the landfill in Kapolei.

But H-Power waste isn’t the only thing being dumped in the lined pits.

“You never know what’s going to come in,” said Tina Alder, the district manager of the landfill. On a single day the landfill could see treated medical waste, auto parts, fuel waste sludge, fish parts and trash from cruise ships. Alder’s favorite was a truckload of discarded Mickey Mouse merchandise from the nearby Disney resort at Ko Olina.

The landfill has capacity for another decade’s worth of miscellaneous waste and can continue to accept H-Power ash for the next 30 years.

The City and County of Honolulu wants to extend the timeline, and has plans to use the ash in new construction projects and even mine for gold and other precious metals in the H-Power ash to reduce the amount being sent to the landfill.

There are two other landfills on Oahu. One in Nanakuli only accepts construction and demolition waste. The U.S. Marine Corps operates a landfill near Kailua that is at 67% capacity.

Kauai

The Garden Island’s only landfill will be full in about eight years, which worries Kapaa resident Lonnie Sykos.

“If we have another big disaster on the island, our current dump would fill up way in advance of the roughly 10 years that we have left with it and so what are we going to do?” he asked.

Brittany Lyte/ Civil Beat

Lyle Tabata, the county’s deputy engineer, oversees the Kekaha landfill and says he has a plan in case of emergency.

“When we had Hurricane Iniki, we utilized temporary landfill sites around the island and we have agreements in place with various land owners to temporarily house the refuse at those locations,” he said.

But the daily barrage of household waste from island residents and visitors filling up the landfill is a slow-moving emergency. It’s taken years to agree on a potential location for a new landfill and efforts to implement a curbside recycling program and increase the landfill diversion rate have stalled.

While Tabata hopes to have a new landfill in Hanamaulu open as soon as possible, the county needs to assume land ownership and pave an access road before it can even start construction.

“I don’t like to compare it to the rail project on Oahu, but it would be considered something in that scale for us,” he said, noting that the bill could be hundreds of millions of dollars.

Sykos said he shares the fears of other Kauai residents that if the county runs into financial or technical problems with the landfills, Kauai will have to ship its trash off-island.

“While we have looked into that, it’s extremely costly,” Tabata responded, adding that the plan was abandoned not only due to the high price, but because it would require the City and County of Honolulu to change laws that bar Oahu from accepting refuse from neighbor islands.

“The plan is to meet the deadline for the landfills,” he said. “There’s not really any other option.”

The Big Island

Late last year Hawaii County closed the South Hilo Sanitary Landfill after 50 years. Now all the island’s trash is trucked to the west side of the island.

Hilo resident Doug Arnott is concerned about the cost and carbon impact of transporting trash from the most populous city to the Puuanahulu landfill, more than 70 miles away.

When brainstorming possible solutions, a nearby rock quarry caught his eye and he thought it would be a great place for a landfill.

“We have a number of very large hole-in-the-ground quarries in Hilo and we’re going to spend millions of dollars in fuel, which is not ecological these days, when we have these massive holes in the ground?” he said.

William Kucharski, director of the county Department Of Environmental Management, thought Arnott’s idea was interesting but had concerns about transferring land ownership, the quarries’ proximity to neighborhoods and if dump trucks would be able to access the quarry.

And while a number of other states have converted quarries into landfills, none on Hawaii Island are quite big enough, said University of Hawaii Geology professor Scott Rowland via email.

With a planned expansion, the Puuanahulu landfill isn’t expected to close for another 188 years.

Joe Miller, who lives in Hawaiian Acres, wants the landfill to last even longer. He told the “Are We Doomed?” podcast he’s specifically concerned that bulky construction and debris, or C&D, waste is taking up too much room.

Kucharski would love to see new landfills on the west and east side of the island dedicated solely to asphalt, rebar, concrete and other demolition debris.

But there are no plans to build construction debris landfills on the Big Island for the same reason more of this refuse isn’t recycled into new building projects: money.

“It costs more to reuse it than it does to use new material, at least at this point,” he said. “And I know that’s not an answer that is particularly attractive but I believe in many instances that’s the reason for it.”

Maui, Lanai and Molokai

The “Are We Doomed?” podcast didn’t receive any questions about landfills on Maui, Lanai or Molokai. All four landfills are expected to reach capacity in the next 20 years, according to Maui County, setting up similar concerns about land management and landfill diversion in these communities.

“Are We Doomed? And Other Burning Environmental Questions” is funded in part by grants from the Environmental Funders Group of the Hawaii Community Foundation and the Frost Family Foundation.