WAIMANALO GULCH SANITARY LANDFILL

The issues surrounding landfills are among some of the most difficult public discussions around the country. Everyone agrees that efforts must be made to reduce the use of landfills through increased recycling, composting, waste-to-energy and other technologies. This is a goal shared by the City and County of Honolulu which has reduced the need for landfill space by upwards of 90 percent. Although a landfill is not necessarily required every day, one is still needed to receive waste materials that cannot be processed, despite the City’s best efforts to do so. As such, planning for the next landfill location is still required.

Currently, Oahu has two landfills: the City-owned Waimanalo Gulch Sanitary Landfill (WGSL); and the privately-owned PVT landfill. WGSL is Oahu’s only municipal solid waste (MSW) landfill while PVT landfill is designated for construction and demolition waste only.

Continued Use of WGSL
Community concerns regarding the landfill are addressed by holding public meetings every three months to report on the status of the continued use of the landfill and the City's efforts to reduce or continue use of the landfill. See links to meeting notices and summaries in the side bar.

The continued use of the WGSL is being determined. The City estimates the physical capacity of the landfill would enable it to continue to receive waste materials for at least the next 20 years. However, the State Land Use Commission (LUC) limited the duration of its use by order. The November 1, 2019 LUC Order requires the City to identify an alternative landfill site that may be used upon closure of WGSL by no later than December 31, 2022 and closes the landfill by no later than March 2, 2028.

It is essential for the City to maintain a landfill to accept MSW that cannot presently be reused, recycled or is unsuitable for H-POWER. The completion of the H-POWER Third Boiler Expansion project in mid-2012 substantially reduced the amount of waste disposed at the landfill, but certain types of waste remain unsuitable for processing at H-POWER.

New Landfill
The process to evaluate the merit of proposed landfill locations was conducted in two parts.  For the first of the two evaluations, the Mayor formed a Landfill Site Advisory Committee to assist the City in identifying landfill locations and to rank the sites based on certain criteria. The committee, with support from the City’s consultant, evaluated over 300 parcels on Oahu. Using technical and regulatory restrictions and additional filters based on community concerns, the committee identified and ranked 11 potential locations. The meetings were open to the public, and public comment was accepted prior to the committee member discussions of agenda items. Meeting notices and summaries are linked in the side bar to the right. The final report (and appendices) were submitted in September 2012.

The second evaluation built upon the results of the first evaluation, ranking the 11 sites using six additional criteria: landfill lifespan, site development cost, roadway improvement cost, access road requirement, location relative to H-POWER, and acquisition. The report was finalized in November 2017.

Act 73, approved on September 15, 2020, restricts waste disposal sites from being located in a conservation district and requires a buffer zone of no less than a half-mile around residences, schools and hospitals for construction, modification or expansion of waste or disposal sites. The enactment of Act 73 has affected the City’s ability to site a new landfill using the information in the November 2017 report. The City is working with a consultant to re-evaluate potential sites based on the restrictions imposed by Act 73.