The state Department of Health is seeking public comment on a draft permit for closure of the Hilo landfill.
The permit calls for covering the 40-acre landfill with artificial liners and a layer of topsoil.
Bill Kucharski, Hawaii County Environmental Management director, said the landfill is expected to be full in late summer or early fall, though that remains a moving target. Afterward, the closure process will begin, and waste from East Hawaii transfer stations will be hauled to the West Hawaii landfill.
Closure could take a year, and the project is estimated to cost $20 million.
Monitoring for groundwater contamination and methane will be ongoing.
Kucharski said the actual cost will be known as early as next week when bids are opened. He said six companies expressed interest in bidding on the project.
Typically, closed landfills are covered with a clay layer. Kucharski said artificial liners are being used in part because they are cheaper to ship and would prevent trees from growing on the surface.
“We believe that’s really the best way to move forward,” he said.
Closure of the landfill, built without a liner, has been talked about for decades.
Kucharski said the permit requires the closure process to begin within 30 days of the landfill no longer receiving waste.
He said the county has the vehicles it needs to haul waste across the island. The trucks are expected to return with green waste from West Hawaii to be used at a composting facility planned for the W.H. Shipman Business Park.
Kucharski said the county finalized its environmental assessment for that project, allowing for the design work to proceed.
Comments on the landfill closure permit will be taken until March 19.
Copies are available at http://health.hawaii.gov/shwb/solid-waste/ and at DOH’s Hilo office at 1582 Kamehameha Ave.
Email Tom Callis at tcallis@hawaiitribune-herald.com.