County officials hope to build Hawaii island’s first municipal composting operation — at a construction cost of $10.5 million — to divert green waste and organic materials from the island’s two landfills.

Hawaii County’s Department of Environmental Management said the proposed East Hawai‘i Organics Facility is needed, in part, because the South Hilo Sanitary Landfill is expected to reach its permitted maximum capacity within the next two years.

The county already has begun closure procedures on the South Hilo Sanitary Landfill.

County officials said the composting facility also would help extend the life of the island’s only other landfill, the West Hawai‘i Sanitary Landfill, while creating composting and mulch to support agriculture.

The East Hawai‘i Organics Facility is planned to accept compostable waste from residents, businesses and government agencies.

It would be located in Keaau in the Puna district on the north side of the W.H. Shipman Business Park. The composting facility would comprise approximately 3 acres within the approximately 40-acre parcel.

The 40-acre parcel consists of mostly mixed non-native vegetation, according to the county. The land next to the 3-acre site for the East Hawai‘i Organics Facility is currently used for commercial agriculture and papaya production.

County officials said construction is expected to take 18 months to two years.