Oahu recycling rates are above the national average and Honolulu ranks among the top cities in the country in landfill diversion. By employing both recycling and waste-to-energy, almost 78% of Oahu's Municipal Solid Waste (MSW) is being diverted from Waimanalo Gulch Sanitary Landfill (WGSL). Expansions to the H-POWER waste-to-energy plant and increases in recycling will further decrease what goes to landfill in the coming years.
Based on data collected for calendar year 2014, Oahu currently diverts 78% of Oahu’s MSW from the WGSL, and 73% of total waste from landfills when construction and demolition waste is included. See Recycling and Landfill Diversion charts and tables. Of the 22% being landfilled at WGSL, 18% is ash/residue from H-POWER and only 6% is unprocessed MSW.
By 2016 the City expects to increase landfill diversion rates to more than 80% of MSW. Recycling rates are expected to increase somewhat with greater levels of public participation, but more significant increases will be derived through waste-to-energy. Expansions to H-POWER in 2012 increased the plant’s capacity by an additional 300,000 tons per year, and the City is working to redirect additional wastes from landfill to H-POWER. (H-POWER video and Powerpoint). A new sewage sludge receiving station went into operation in May 2015 and will divert an additional 20,000 tons of sewage sludge and 20,000 tons of bulking material from the landfill. Further, the City expects to begin processing Auto Shredder Residue (ASR) by the end of 2015, which will divert 30,000 more tons from the landfill.
How we manage our island’s waste will affect generations to come. Further increasing recycling and waste-to-energy will benefit the environment and divert thousands more tons from the landfill. Oahu generated nearly 1.9 million tons of total waste in 2014, almost 1.4 million of which were diverted to beneficial use in recycling and waste-to-energy. Nearly 900,000 tons of various materials were reused and remade into new products, and another 500,000 tons were converted into electricity at the H-POWER waste-to-energy facility. We can and need to do more.
Each Hawaii county is required to submit an integrated solid waste management plan to the State Department of Health every 10 years, and to provide an interim status update report on the implementation of that plan five years after it is submitted. The City and County of Honolulu’s most recent plan was submitted in December 2008, and the interim report on implementation was submitted in December 2013. The next revised plan will be submitted in 2018. The City's 2008 solid waste management plan, the 2013 interim report and the technical studies that contributed to the development of the plan, are posted online in the Resource Library, along with previous master plan documents and studies and annual recycling rate data for 1988 to present.
The ultimate goal is to minimize the use of landfills to the absolute smallest practical level. Currently on Oahu, both recycling and waste-to-energy divert a the majority of the waste from the landfills. Recycling remanufactures waste products into new products. On Oahu, our waste-to-energy facility (H-POWER) enables us to convert garbage into energy, which contributes to our island’s energy sustainability. In order to further increase landfill diversion, we must consider how best to utilize our garbage as a resource – to remanufacture new products or generate additional power.
By 2016, the City anticipates that little more than ash will be disposed in the Waimanalo Gulch Sanitary Landfill. Of the 18% going to landfill, only about 2% represents MSW that could neither be recycled nor processed through waste-to-energy.