HONOLULU – The U.S. Environmental Protection Agency and the City and County of Honolulu recently signed an agreement to begin work on the second phase of cleanup at the Waipahu Ash Landfill site on Oahu.
“Honolulu’s latest agreement will allow the ongoing cleanup at the old ash landfill to proceed to the next stage,” said Jared Blumenfeld, EPA’s Regional Administrator for the Pacific Southwest. “The work by the city to evaluate the site for remaining health and environmental risks is set to begin this month and will be completed over the next few years.”
The landfill cleanup included excavation and relocation of ash refuse, grading and erosion control, installation of a liner and soil cover, and installation of a passive gas well system and groundwater monitoring wells. The City spent approximately $16 million on this initial phase that was completed in September 2011. The main cleanup concerns at the landfill are dioxins and heavy metals in the landfill sediments and the risks posed to wetland areas near Pearl Harbor.
The second phase of the work will include characterizing residual contamination at or from the site, determining any human health and ecological risks, and evaluating potential cleanup alternatives. The City will also define the extent of ash material remaining in the soil and sediment and, if necessary, install additional monitoring wells to sample groundwater to evaluate any impact from the landfill.
The landfill is located on the Waipio Peninsula on Oahu and was an ash landfill for the City’s Waipahu Incinerator that burned municipal solid waste from 1972 until the incinerator was closed in 1991. The site encompasses about 54 acres on U.S. Navy, State of Hawaii and City and County of Honolulu property adjacent to the West Loch of Pearl Harbor.
This settlement was reached under the authority of the federal Superfund law as part of the site lies within the Pearl Harbor Superfund site, and came after a public comment period. In the last fiscal year, EPA reached agreements with responsible parties to commit an estimated $1.2 billion toward Superfund site studies and cleanups nationwide.