The Campbell Industrial Park lot once occupied by the Chem-Wood Treatment Co. is heavily contaminated with a variety of chemicals used to make lumber termite-resistant during the 15 years that the company was in business. Among the contaminants are pentachlorophenol, a wood preservative, and a dioxin that is a byproduct of penta’s manufacture. Both are extremely toxic to humans.
The Chem-Wood plant at 91-476 Komohana Street began treating lumber for protection against insect damage in 1973. Before that time, the site had been used for wood-treatment by another operator, Hawai`i Wood Preserving Co.
Chem-Wood employed two processes. One, in use from 1973 until the plant closed in October 1988, involved pressure-treating wood with chromated copper arsenate (CCA). The other, in use from 1983 until 1988, treated wood with pentachlorophenol (also known as penta or PCP). Penta as manufactured usually contains dioxins as a contaminant, in concentrations as high as the hundred part-per-million range. This is the source of the dioxin contamination.
A Decade of Woe
In June 1988, Chem-Wood and its general manager, Erle Kitagawa, were indicted by a federal grand jury on charges of storing hazardous wastes without a permit. A month later, U.S. District Judge Harold Fong fined Kitagawa $5,000 and Chem-Wood $25,000 for violating the federal Resource Conservation and Recovery Act, which governs disposal of hazardous waste.
Chem-Wood’s parent company, Herbert K. Horita Realty, then entered into an agreement with the EPA, promising to pay for all required remedial work at the site and agreeing to place $250,000 in a trust fund that could be tapped by the EPA in the event Horita failed to finish the cleanup. Already, according to newspaper reports in 1988, Horita had paid out more than $800,000 in remedial work at the site. Completing the job was estimated to cost at least $1 million more, those reports said.
According to the EPA’s San Francisco office, whose jurisdiction includes Hawai`i, the balance in the trust fund has grown to $400,000. There has been no need to draw from that account, an agency staffer said, since Horita Realty has continued to pay the engineering firm overseeing cleanup operations.
The first outward sign of trouble at the site came in September 1986, when the Environmental Protection Agency made a surprise inspection of the site. The earliest documented clean-up effort began two months later, when Unitek Environmental Services excavated arsenic- and chromium-contaminated soil to a depth of between six and nine inches. Most of the excavation was near tanks, pumps, and piping. That work, which lasted until September 1987, resulted in 96 55-gallon drums being packed with soil and shipped to a mainland disposal site. An additional 92 55-gallon drums were packed with soil taken from a site where wood had been stored. More than 5,000 empty 16-gallon drums contaminated with CCA were crushed and removed for mainland disposal.
By the time the indictments were handed up, the assistant U.S. attorney prosecuting the case, Robert Godbey, was reported by The Honolulu Advertiser to have said the site was “so soaked with arsenic and chromium that the soil itself has become a hazardous waste at depths in some places of as much as 50 inches.”
Later surveys of soil contaminants found “pentachlorophenol and metals are located primarily in the top two feet of the soil profile and decrease rapidly with depth except in a few isolated areas where the soil received repeated spills,” according to a December 1994 report by Woodward-Clyde Consultants, the firm hired to oversee site cleanup. “The soil adsorption sites in these areas may not have been able to adsorb any more of the [chemicals of concern] and leached to greater depths.” In other words, when repeated spills caused the soil to be saturated to the fullest extent possible, the contaminants were pushed to ever deeper levels in the soil.
According to a Woodward-Clyde report, arsenic, copper and chromium concentrations in the near-surface soil samples were as high as 500 milligrams per kilogram (parts per million). Concentrations in the soil of extremely toxic hexavalent chromium were as high as 100 mg/kg.
Ongoing Work
Cleanup work at the site continues. In February, the EPA and the state Department of Health published a notice of their intention to allow Woodward-Clyde Consultants to conduct “treatment studies on contaminated soil” at the site for up to a year. As part of this, Woodward-Clyde will undertake a pilot study of soil bioremediation — a method that uses microorganisms to metabolize the organic chemicals (penta and mineral spirits) — in six 30-gallon drums. In addition, they may try to “solidify” the metal contaminants in the soil — a process that would involve mixing the soil with cement in hopes that the metal contaminants would not migrate from the site.
At the same time, Woodward-Clyde will also try to recover “free product” — an oily, five-percent solution of penta in mineral spirits — that floats atop the water table in the caprock aquifer. This is to be accomplished by removing the free product from large-diameter boreholes.
(Earlier plans to collect the free product by digging a trench and skimming off the oily product from water that collected in it have been abandoned, according to Nicole Moutoux of the regional EPA office in San Francisco. Among other things, Moutoux said the difficulty of digging a trench in the coral substrate, the possibility of worker exposure to dangerous chemicals in the soil while digging, and the simple fact that people could fall into the trench contributed to the decision to abandon this decision.)
According to Woodward-Clyde, after the site is cleaned up, “future land use plans are for paving the entire site and locating portable office trailers for construction company offices. In addition, a warehouse will be built and the paved areas will be used for equipment storage and parking.”
Owner of the site now is a Japanese-based company, Soga Hawai`i, which purchased the land from Chem-Wood on March 11, 1991, for $1.2 million. Soga Hawai`i owns the Ewa Beach International Golf Club.
Chemicals of Concern
Both pentachlorophenol and chromated copper arsenate are hazardous to human health. One of the components in CCA, hexavalent chromium, is especially toxic and can lead to increased cases of lung cancer among exposed populations.
Hexavalent chromium has been found at elevated levels in samples of groundwater taken from monitoring wells to the north and west of the wood-treatment area. Despite the statements in Woodward-Clyde documents that water contamination is expected to occur only downgradient of the site (and therefore not pose a risk to the upgradient freshwater sources), hexavalent chromium seems to be spreading to groundwater north of the Chem-Wood site and is found at elevated concentrations in monitoring wells on the lot to the north occupied by Morrow Crane. Of the groundwater samples taken in January 1995, two wells showed even higher concentrations than samples taken in November 1993, 12 were the same, and just three concentrations were lower. One well tested in January 1995 had a hexavalent chromium concentration of 2.78 milligrams per liter (parts per million). The EPA’s maximum contaminant level for total chromium (including the much less toxic trivalent chromium) is 0.1 mg/L.
Elevated levels of copper and arsenic also have been detected in samples from monitoring wells upgradient of the process site.
Extremely high levels of pentachlorophenol continue to be present in groundwater samples. Unlike the metal contaminants, the plume of penta contamination has trended downslope of the site. Wells on the Precision Wood lot (to the south of Chem-Wood) exhibited some of the highest concentrations of penta contamination in the January 1995 testing. One well showed pentachlorophenol at 170 mg/L in 1995, when testing of the same well in 1993 found concentrations of 15.9 mg/L.
In summarizing the well tests, Woodward-Clyde writes: “The lateral extent of contamination measured in January 1995 appears to be somewhat smaller than the extent detected in November 1993, although this may be partially an artifact of the fewer number of localities sampled in January 1995. Overall, the concentrations of copper and pentachlorophenol measured in January 1995 were lower than levels measured in November 1993, while the measured concentrations of arsenic, chromium, and hexavalent chromium were, on average, roughly similar.”
Penta
Workers at the Chem-Wood site today wear moon suits and masks if they are doing tasks that may expose them to penta. The precautions are in keeping with the toxic nature of the chemical.
On the basis of animal studies, scientists believe that a 150-pound person would die following oral ingestion of 1.09 ounces of a 10-percent penta solution or dermal absorption of 4.4 ounces. In 1956, a tank-truck driver who splashed a mixture of diesel oil and penta on his hand died within 24 hours. A detergent whose formulation included penta was found to be the cause of death of a newborn in 1966.
Sublethal doses have been linked to acute leukemia, Hodgkin’s and non-Hodgkins lymphomas, and other soft-tissue cancers. Sublethal exposures are suspected of suppressing the body’s immune system and can severely irritate the skin and lungs.
Byproduct contaminants that result from the manufacture of penta, and which are usually found in commercial grade product, include hexachlorobenzene (HCB) and various dioxins and furans, including hexa dioxin. Animal tests show HCB can cause liver cancer and thyroid damage. While hexa dioxin is not the most lethal dioxin (that distinction falls to 2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD), it still has been labeled by the EPA as a potent carcinogen.
According to Moutoux of the EPA, that agency has no plans to conduct any health studies on former Chem-Wood workers. The EPA does not involve itself in such matters, she said, which more properly fall to the Occupational Safety and Health Administration.
For Further Reading On Pentachlorophenol
Racquel Skolnick, “Persistent and Poisonous.” Greenpeace, 13:1, pp. 16-19.
Volume 6, Number 10 April 1996