Well Contamination at Del Monte: The Making of a Superfund Site

posted in: May 1996 | 2

In 1975, the Del Monte pineapple plantation on O`ahu made a fateful change in its management of soil fumigants. Until that time, the plantation had purchased the fumigants — used to control root nematodes — in metal drums, typically containing 50 or 55 gallons. In 1975, though, it began purchasing the primary fumigant it used, ethylene dibromide (EDB), in bulk shipments, which were stored in a 25,000-gallon tank hard by a drinking-water well at Kunia.

Two years later, on April 7, 1977, the danger inherent in the new approach burst into full view. The flexible hose on the bulk container of EDB broke when Del Monte began to empty the EDB into its holding tank. According to a letter dated April 12, 1977, from the plantation superintendent, N.E. Blomberg, to the Hawai`i sales representative for Dow Chemical Co., manufacturer of EDB, the break was not noticed immediately: “Since this is a closed system of transfer and takes approximately one hour to empty no one stands by during this time. About five minutes after we started the emptying process the break was noted by our shop personnel who immediately shut the valve.”

Blomberg calculated that, of the 2,648 gallons of EDB in the full container, 191 had been transferred into Del Monte’s tank and 1,962 remained in the bulk shipping container when the leak was discovered. Unaccounted for were 495 gallons, which had either soaked into the ground or evaporated, according to Blomberg.

The area of the spill “is near our domestic water well,” Blomberg informed Dow. The well, only about 50 feet away from the spill site, supplied drinking water to more than 600 residents at Kunia Camp. “From the way the well is constructed we do not believe any contamination took place,” he said — while adding that he believed Dow had taken water samples for analysis.

Blomberg’s letter concludes:

“Only one employee got the spill on his hands and after four days still reports no problem. He was the shop supervisor that closed the valve. He had worked with EDB before and knew how to wash with copious amount of water.

“It is my understanding that Dow will replace all the lost fumigant.”

History in the Making

In light of all that has transpired in the intervening years, as a direct consequence of that spill, Blomberg’s worry over the cost of the lost fumigant takes on the dimensions of legendary superficiality. Did he have a distant cousin who fussed over the arrangement of the Titanic’s deck chairs?

Last month marked the 19th anniversary of that spill, whose impact is still being felt in the loss to O`ahu of a once productive drinking water source, in the cost required to treat water systems downslope of the spill area, and in the cost to Del Monte of undertaking a cleanup of the site in accordance with federal Superfund requirements.

And those costs, running into the tens of millions of dollars, are merely the easily measured ones. The toll on human health is far more difficult to assess scientifically, although theoretically, it is more than likely that harm has been or will be done — that someone has contracted a cancer as a result of the spill, or that an infant was born with a genetic defect. For EDB is a dangerous chemical that the Environmental Protection Agency has determined to be carcinogenic (cancer-causing) and mutagenic (causing genetic defects).

Three Years Later

The outcome of the tests, if any, that Blomberg believed Dow to have made is not reported in any of the files maintained by the state Department of Health. The DOH did its own sampling of the well on April 15, 1977, but determined that EDB was not present in the water at a level above the test’s limit of detection. (At 500 parts per trillion, the limit of detection was crude by today’s standards. In fact, the present maximum contaminant level for EDB in drinking water is 40 parts per trillion, or less than a tenth of the level of EDB required to trigger a positive reading in the 1977 test.)

The well was tested again in June 1979, but only for the presence of another soil fumigant, dibromochloropropane, or DBCP. According to a “Data Summary and Evaluation Report for the Del Monte … Superfund Site” prepared for the Environmental Protection Agency by ICF Technology, Inc., in April 1995 (the ICF report), “the results indicated DBCP was present at the detection limit (0.4 micrograms per liter). A confirmatory sample collected by Del Monte on August 13, 1979, indicated the presence of DBCP at 0.3 mg/L (the detection limit had been lowered to 0.2 mg/L).”

Meanwhile, the well continued to supply drinking water to residents of the Kunia camp.

In April 1980, at the urging of the EPA, the state again undertook a systematic program of testing more than 60 wells in areas where soil fumigants had been applied on O`ahu and Maui. Test results from a sample taken on April 14 from the Kunia Camp well showed EDB present at 92 mg/liter — 2,300 times the .04 mg/L maximum EDB contaminant level that was then in effect.

(The microgram-per-liter ratio expresses parts per billion. Fractions of micrograms may also be expressed as nanograms, or parts per trillion. Thus, .04 mg/L equals 40 nanograms per liter, or ng/L. For purposes of comparison, a concentration of one part per billion is equal to one teaspoon of contaminant in a 2.5 million gallon water tank, much like many of those used by the Honolulu Board of Water Supply.)

On April 24, the Kunia well was retested. This time, the concentration of EDB stood at 300 mg/L, or 7,500 times the maximum contaminant level at the time.

In both samples, DBCP was found to be present at 11 mg/L, or 275 times the state maximum contaminant level set for that chemical.

The day following results from the second tests, the state Department of Health ordered Del Monte to stop using the well as a source of potable water for Kunia Camp.

Swift March

For years, pesticide users and producers had claimed that the risk of chemicals such as EDB migrating to the water table was minimal. Most of the chemicals were thought to volatilize when exposed to sunlight. What remained was thought to bind tightly to the soil and degrade over time.

When tests of well water in California and Florida began to show evidence of EDB contamination, that belief began to be challenged. Locally, evidence of EDB’s relatively swift march to the groundwater was provided by John Mink, a hydrologist retained in 1980 by Del Monte to assess the extent of contamination resulting from the 1977 spill.

Shortly after beginning his work, Mink discovered a second “focus” of contaminants. A site inspection report prepared in 1990 for the Environmental Protection Agency by Ecology and Environment (the E&E report) summarizes Mink’s findings: “From the 1940s to 1975, drums of both EDB and DBCP were stored on bare ground on the slope of a small gully located approximately 50 to 150 feet north of the Kunia Camp well. It is likely that the release of contaminants from the storage area in the gully was systematic, resulting from poor housekeeping practices during the mixing, handling, and dispensing of soil fumigants stored in drums; this release may have occurred throughout the duration of the gully’s use as a storage location.”

The E&E report states: “Based on drilling techniques employed in 1947, it is believed that the annular space [the space between the well casing and drilled borehole] of the Kunia Camp well was left open, and that it may provide for the movement of contaminants from the perched aquifer zone to the deeper drinking water aquifer,” also known as the basal lens. “The most likely scenario,” the report continues, “based on the behavior of the ratio of contaminants in samples from the Kunia Camp well plotted against time, is that both the storage-area plume and the spill-area plume are drawn into the well as it is pumped.”

The ICF report in 1995 noted that when a down-hole video was made of the well in 1980, “groundwater seepage through the perforated casing above the water table was observed, and was interpreted as coming from the overlying saprolite aquifer. Due to the absence of grout in the well annulus, the well’s proximity to confirmed soils contamination, and the seepage observed in the video logs, the well is considered a potential conduit for contaminants to the basal aquifer.”

In other words, the presence of saturated soil at relatively shallow levels allowed the EDB plume to expand rapidly to the deep-water well shaft. From there, it had a straight shot into the basal aquifer. And the more the well was pumped, the more the EDB was injected into the primary source of drinking water on O`ahu — the Pearl Harbor aquifer.

Pumping Pesticides

Three shallow wells drilled as part of Mink’s study revealed another surprise: the existence of a high-level perched aquifer that began 20 to 30 feet below the surface of the ground and extended downward to about 150 feet below the surface. As part of his analysis of the extent of contamination, Mink began testing the water in the perched aquifer. At one well near the pesticide storage and mixing area, the initial concentration of EDB was about 200,000 parts per billion in February 1981, while DBCP was pegged at 500 ppb. At a nearby well, EDB concentrations were slightly lower (50,000 ppb), but levels of DBCP were higher — initially, 15,000 ppb, with a peak reading of nearly 3 million ppb DBCP (2,964,000 ppb, for a concentration of almost 3 tenths of a percent).

At a shallow well just 25 feet away from the deep (and contaminated) Kunia Camp basal well, EDB concentrations were far less — around 300 ppb, on average. Mink speculated that “most of the spill evaporated or was bio-degraded near the ground surface, but a small quantity reached the perched water.” An equally plausible explanation for the relatively low levels of EDB in the perched aquifer, however — and one supported by the high levels of EDB in the basal well — is that the EDB had long since gone to deeper levels.

In any event, in 1981, Del Monte fitted the three perched-aquifer wells with 10-gallon-per-minute pumps, which it ran several hours each day in an effort to remove contaminated water. By 1984, Mink reported significant drops in EDB levels: in one of the two wells near the mixing and storage area, EDB concentrations were down 86 percent (to 7,000 ppb) by the end of 1983, while in the other they fell 93 percent (to 15,000 ppb). In the area of the EDB spill, the perched water contamination went from 300 ppb to less than 50 ppb. According to reports made to the EPA, the pumped water was sprayed onto an unplanted field or was used for dust control.

Water from the deep basal well was also pumped out “every three or four days, from four to eight hours” a day, according to Mink, but the results were not nearly as dramatic. “At the start of pumping, the concentration of EDB has a median value of 2.3 ppb,” Mink wrote. “Four hours later the median falls to 0.7 ppb and remains at this value for the following four hours…. At the start of pumping the median value of DBCP is 2.6 ppb … After four hours, the median is 2.0 ppb, and it remains at this level another four hours later.”

According to E&E, the failure of the Kunia Camp well to show a “marked decrease of contaminant concentration over time … indicates that contamination of the deeper aquifer has occurred.”

Pumping of the perched wells was for the most part discontinued in 1983, but the Kunia deep-water well continued to be pumped until September 6, 1994, when the EPA informed Calvin Oda of Del Monte Fresh Produce (Hawai`i), Inc., that the practice amounted to an unapproved treatment technology and constituted “an unlawful disposal of hazardous substances.” On receiving the notice, Oda replied, Del Monte immediately disconnected the Kunia Well from the “non-crop irrigation system and terminated all clean-up activities at the Kunia Well site until alternative treatment technologies can be developed and implemented.”

Rather than the shallow wells aiding in the site clean-up, the ICF report suggests that their drilling and pumping may have actually contributed to contamination of the basal aquifer. “The perched wells were located in the areas containing the highest concentrations of soil fumigants … [and] may have potentially contributed to the vertical migration of EDB and 1,2-dibromo-3-chloropropane (DBCP).”

In describing contamination of one of the perched-water wells, in fact, ICF suggests it acted as a drain for water accumulating in the excavated pit. “Due to the location of Well 9X at the bottom of the excavation,” ICF states, “groundwater infiltrating into the pit and rainwater accumulating in the pit will likely migrate down the well casing.” The shallow wells were finally capped in late 1994 or early 1995.

Digging Out

In addition to the pumping program, Del Monte tried to decontaminate the pesticide storage and mixing area by excavating massive amounts of the surface soil as well as the underlying weathered rock, known as saprolite. Del Monte had hoped to remove all soil containing EDB at levels greater than 10,000 ppb of EDB, but, according to the ICF report, “excavation activities were terminated when perched groundwater infiltrated the excavation and soils could no longer be removed.”

More than 18,000 tons of soil and rock were excavated, in some places to a depth of 60 feet below the ground surface, and then spread over 20 acres of nearby agricultural fields. In addition, about 100 tons of soil were excavated around the spill area. The hope was that much of the contamination in the excavated soil as well as in the newly exposed subsurface areas would volatilize when it came into contact with air and sunlight.

Immediately after the last excavation, in September 1983, soil samples from the sidewalls of the excavation found EDB concentrations ranging from 17.5 to 482 ppb, while DBCP was found at levels between 7.5 and 421 ppb. Soil samples from the same area made six months later found much lower concentrations of both chemicals. EDB was present at levels ranging from 18.6 to 27.8 ppb, while DBCP ranged from non-detectable levels to 67.2 ppb.

More than a decade later, three soil samples were taken from the excavation pit. DBCP remained at a concentration of 67.2 ppb in one sample, while it was undetectable in the remaining two. EDB was detected in each of the samples, with concentrations ranging from 18.6 to 27.9 ppb.

The EPA has established what it calls preliminary remediation goals for EDB and DBCP, both of which are suspected cancer-causing agents. For residential soil, the preliminary remediation goal for EDB is 5.1 parts per billion; for DBCP, the figure is 320 ppb.

* * *
Enter the EPA

A year following closure of the Kunia Camp well, Del Monte notified the Environmental Protection Agency of the spill and the discovery of what it described as “suspected chronic low-level spills of DBCP and EDB in the storage area … during mixing operations or transfer of these chemicals from storage drums to the supply truck.”

By 1984, the Kunia well was one of several O`ahu wells that the state of Hawai`i had proposed to the EPA for consideration as possible Superfund sites, under the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, better known as the Superfund law). The other wells had become contaminated through the routine and legal use of pesticides. Under the interpretation of Reagan administration officials, this source of contamination made the wells ineligible for cleanup under the Superfund protocols. Only the Kunia well could be shown to have been contaminated by a spill; for this reason, it alone among the contaminated O`ahu wells became the subject of further investigation by the EPA.

For the next 10 years, the EPA’s investigation continued. Among other things, Del Monte disclosed to the EPA that in 1980, it buried 43.5 pounds of methyl bromide in a field adjoining the plantation’s northern boundary with the Army’s Schofield Barracks installation. It disclosed also that before 1980, it had buried empty drums used for fumigant storage at 22 different sites, of which 17 could be located.

In September 1990, Ecology and Environment, Inc., submitted to the EPA its preliminary site inspection report. In 1992, the EPA completed a hazard ranking process, and on May 7, 1993, the EPA announced it was proposing to add the Del Monte plantation to the roster of sites on its National Priorities List (Superfund). Following a comment period (during which time objections to the listing were made to the EPA by Hawai`i’s senior senator, Daniel K. Inouye), the site was formally added to the Superfund list on December 16, 1994.

The first step in the Superfund cleanup process is the remedial investigation/feasibility (RI/FS) study, which provides a detailed look at the extent and nature of contamination. Following that is an engineering evaluation/cost analysis study. Separately, a feasibility study is to be done to evaluate various ways of removing contaminants from the groundwater.

Once these studies are completed, the public will have an opportunity to comment on the cleanup options. Afterward, the EPA will write an action memorandum, setting forth the required cleanup elements, or develop a record of decision, or both, and the cleanup will begin.

Costs associated with the preparation of these studies and the cleanup are to be paid by the responsible parties, and so far, Del Monte has borne the brunt of them. Initially, Dow Chemical Co. was approached as a potentially responsible party (it manufactured the EDB that spilled back in 1977). Its attorneys responded by saying they would pay no more than 20 percent of the cost of developing an RI/FS for the Kunia Camp well. Since then, however, Dow has notified the EPA that, on the basis of an affidavit from a shipping clerk, Dow did not own either the hose or the tank involved in the 1977 spill of EDB; its participation in the RI/FS, it announced, would be limited to “voluntary consulting activity.”

Public Involvement

For the moment, Del Monte alone is paying for the consultant studies required as part of the Superfund cleanup process. Doing the on-site work for Del Monte is Woodward-Clyde Consultants.

In coming months, the EPA will hold a number of meetings with the public, intended to keep citizens informed about the cleanup process. A technical assistance grant (TAG) is available to a selected community group. Under the TAG program, the EPA will provide a grant of up to $50,000 to be used for hiring a technical advisory to review site conditions and other data associated with the cleanup process.

For more information on eligibility for the TAG program or to be notified of future meetings, the person to call is EPA community relations coordinator David Cooper. He may be reached at the EPA Region IX office in San Francisco at 415 744-2182 (voice); 415 744-1796 (facsimile); or by writing him at US EPA, Attn: David Cooper (H-1-1-), 75 Hawthorne Street, San Francisco California 94105.

* * *
Future Use?

The entire Del Monte plantation, including lands south and north of Schofield Barracks on the O`ahu Central Plain, have been included in the area subject to Superfund cleanup. This has put on hold state plans to acquire part of the northern plantation lands, owned by the Galbraith Trust, and now threatens to delay or disrupt designs of the City and County of Honolulu to develop part of the area for purposes of recreation and sewage treatment by means of artificial wetlands.
In 1995, the state Legislature voted to acquire 2,100 acres of the Galbraith land in exchange for 500 acres of state-owned land in Kapolei. The action was vetoed by Governor Cayetano, who cited the presence of contaminated sites on the Galbraith land. Among the sites of concern are areas used for disposal of pesticide rinseate, pesticide drums, and two underground storage tanks (whose removal was not done according to the stringent state requirements). “The value of the Galbraith Estate land is unquestionably lessened because of its new status as a Superfund site,” Cayetano said in his veto message. “[T]he exchange would expose the state to enormous liability.”

Hardly was the ink dry on the veto message when the City and County of Honolulu Department of Wastewater Management expressed its interest in acquiring 512 acres of Galbraith land. About 150 acres would be used to build a wetland, where effluent from the (to be upgraded) Wahiawa sewage treatment plant would undergo final cleansing. The remainder, according to the city’s initial plans, would be used for a “wildlife park.” The land would be acquired through eminent domain. The city has provided no cost breakdown for the land acquisition part of the project, but overall costs are set at $26.8 million for land, planning, engineering, and construction.

Del Monte has indicated it is opposed to the city’s proposal, since it intends to keep using the Galbraith land for pineapple cultivation.

Volume 6, Number 11 May 1996

2 Responses

  1. Linda davis

    Wanted to find a contact number for cancers relating to servicemen and
    Women stationed at fs kunia in the early
    80s. Many family’s have multiple cancers that are not family history related.

    • Aloha, Linda. I’m not sure what you’re looking for, but perhaps the state Department of Health Safe Drinking Water Branch can be of assistance: (808) 586-4258

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