Mayor Kirk Caldwell today announced a city contract with Covanta Projects LLC to build and operate an H-POWER facility that also treats and recycles ash so that it does not end up in Oahu’s landfill.

The contract — issued Dec. 7 — costs approximately $60 million over 11 years.

“As an island with finite natural resources and land, we understand the importance of minimizing the impact from the waste we generate,” Caldwell said in a news release. “Through our investments in the H-POWER plant, including our cutting edge sludge burning facility, we have led the way in recovering value from waste, while minimizing the amount we send to our Waimanalo Gulch Sanitary Landfill (WGSL).”

Instead of going into the landfill, the ash byproduct of H-POWER would be treated and cleaned and could then potentially be used as construction material. Metals that are recovered from the ash would be recycled as well.

Annually, H-POWER, or Honolulu Program Of Waste Energy Recovery, produces approximately 180,000 tons of ash, which currently goes to the Waimanalo Gulch landfill in Kapolei.

The contract reduces the ash by 60%, according to Lori Kahikina, director of the Department of Environmental Services, and efforts to do so have been a years-long effort.

“ENV has been working since the beginning of our term to find a viable option for the ash byproduct of H-POWER as the industry needed time to develop the appropriate technology,” Kahikina said in a release. “Honolulu will be one of the first to deploy this type of technology to ‘clean’ and reuse the ash versus disposing of it at WGSL. We are proud of the progressiveness of our H-POWER facility.”

The first phase of the contract includes the design and installation of the H-POWER Ash and Automotive Shredder Residue Processing Facility followed by 10 years of operation and maintenance, with an option to extend the contract another five years, if funds are available and permits secured.

Honolulu City Councilwoman Kym Pine, who represents Kapolei, where H-POWER and the landfill are located, released a statement today expressing support of the contract.

“One of my top priorities has been to close the landfill and the ash was the remaining trash that kept it open on a weekly basis,” said Pine in the statement. “This contract will also relieve the backlog of disposing of abandoned vehicles throughout the city. No community should ever have a landfill again. It is just unconscionable to put toxic trash into the earth on an island.”

H-POWER began operations May 1990 under an initiative started by the late Mayor Frank Fasi.

In 2012, the waste-to-energy facility added a third boiler to take in an additional 900 tons per day, and three years later, a sludge receiving facility to handle wastewater biosolids. The facility processes more than 745,000 tons of waste that would otherwise have gone to landfills.

Historically, nearly 90% of the volume of municipal solid waste received at H-POWER has been diverted from the Waimanalo Gulch landfill and converted into renewable energy, supplying up to 10% of Oahu’s electricity needs.

“We are excited to partner with our long-term client in Honolulu for an on-site solution for ash recycling and reuse,” said Christopher Baker, Covanta vice president and general manager in the release. “We look forward to finalizing the terms with the city and helping them get closer to the goal of a circular economy.”