A proposed plan to clean up contaminated soil at a former Kohala Sugar Co. pesticide mixing site in Hawi calls for on-island landfill disposal.
This preferred action “provides the least restrictions on future use and redevelopment at the property” and “would alleviate the potential for community stigma related to having a contaminated site located in a residential community for perpetuity.” It was also deemed “the best balance of human health and environmental protectiveness at a reasonable cost,” according to the draft removal action report.
The cleanup is being proposed by the landowner, Hawaii Island Community Development Corp., a nonprofit focused on affordable housing. The corporation has plans for residential development on the property, the report stated.
On-island landfill disposal is among the four alternatives being considered to remedy the half-acre site, now surrounded by fallow, highly vegetated pasture land. Residential housing on the corporation’s land is within 500 feet of the site to the southwest and the Kohala Mission School is to the east within several hundred feet. There’s a fence around the area to prevent trespassers from having direct contact with site soils.
Arsenic — a common soil contaminant in Hawaii used as a herbicide in sugar cane cultivation — and dioxin — a byproduct of other historically used pesticides and herbicides — are the principle chemicals of concern and soil environmental hazards.
The public has until Jan. 8 to offer input on the report, available on the state Department of Health’s Hazard Evaluation and Emergency Response Office website, hawaii.gov/doh/heer.
Comments will also be accepted during a public meeting from 6 to 8 p.m. Thursday at the North Kohala Senior Center in Kapaau. During the meeting, there will be an overview of the site investigations and discussion about the report, including the remediation options considered and proposed. Information about the site or possible concerns about the cleanup are being sought.
The Hazard Evaluation and Emergency Response Office is providing oversight for this project and will make the final decision in regard to what action, if any, should be taken. That decision could be made as soon as early next year, said John Peard, project manager with the Hazard Evaluation and Emergency Response Office in Hilo.
However, implementation will be the responsibility of Hawaii Island Community Development Corp. and funding will need to be secured. The on-island landfill disposal is estimated to cost $484,000, Peard said.
With this preferred action, there would be site preparation, soil excavating and loading, transporting and disposal of soil at a landfill, and site restoration. “Some 2,000 tons would require excavation and disposal.” The only solid waste landfill on the island permitted to accept contaminated soil is the West Hawaii Sanitary Landfill in Puuanahulu. That facility is managed by Waste Management Solutions Inc. and located about 30 miles from the site, the report stated.
The corporation is planning to apply for a U.S. Environmental Protection Agency grant and could receive up to $200,000 to assist in cleanup efforts, Peard said.
That draft grant application is available for public review and comment. Those interested in providing testimony for the application can email Brian Nishimura, planning consultant, at btnishi@hawaiiantel.net.
The Department of Health has a site discovery and response group that identifies, investigates and remediates sites contaminated with hazardous substances. The contaminated soil at the former Kohala Sugar Co. pesticide mixing site was discovered by the department in 2009, with help from the public and by reviewing historical records, Peard said. Site investigations then conducted by the Department of Health and two environmental consultant firms confirmed soil arsenic and dioxin contamination on parts of the property, he added.
The Kohala Sugar Co. used the property for sugar cane cultivation between 1862 and 1973. Former employees said a pesticide mixing and loading area was located near the southeastern corner of the property, which is now undeveloped.
“The department does not know the exact dates that the pesticide mixing site was operated, but the presence of significant levels of arsenic indicate the mixing area was used long in the past, and presence of significant levels of dioxin indicate the mixing site continued to be used after 1950,” Peard said. “Some in the community we talked to indicated the pesticide mixing operation was going up until the Kohala Sugar Co. ceased operation in the early 1970s.”
Following the closure of the sugar company, the property has been used intermittently for cattle pasturage.
Fifteen acres of the property was rezoned from agriculture to single-family residential in 2006. The corporation subdivided the area into 43 single-family parcels and built 31 dwellings. The balance of the original parcel was also rezoned for single-family residential use in 2009, but remains a bulk parcel awaiting future subdivision.
Written comments on the proposed soil cleanup should be mailed to John Peard, Project Manager, Hawaii Department of Health, HEER Office, 1582 Kamehameha Ave., Hilo, HI 96720-4623. Or, email input to john.peard@doh.hawaii.gov.