Water at Kunia still polluted after 21 years

By Jan TenBruggencate
Advertiser Science Writer

Twenty-one years after toxic chemicals were found in groundwater under the Del Monte pineapple village of Kunia in Central O'ahu, the water is still not safe to drink.

Millions of dollars have been spent on studies, cleanup and decontamination trials, and millions more will be spent before the Kunia water will be pesticide-free.

The U.S. Environmental Protection Agency considers Kunia one of the most serious chemically polluted areas in the state, and added it to the National Priorities List in 1994. That brought the resources of the federal Superfund program to bear, although Del Monte, whose pesticide spills caused the problem, is responsible for paying for the cleanup.

The EPA will present its plan for a cleanup in public meetings this fall, seven years after Superfund designation, and it may be a year or more longer before a final cleanup plan is actually enacted.

"Superfund sites do take a long time. That's normal," said Amy Playdon, remedial project manager with the state Health Department's Hazard Evaluation and Emergency Response office.

Janet Rosati, EPA site manager for the Del Monte Superfund cleanup, agreed that it's an extended, complex process.

"It is not unusual for the environmental sampling, data analysis, risk assessment, analysis of treatment technologies and community involvement activities associated with a Federal Superfund site to take years," Rosati said.

If there's good news out of all the time this has taken, it's that Del Monte Fresh Produce, with financial help from the U.S. Department of Agriculture, may have developed an effective, low-tech cleanup method for the pesticides, using a common Hawai'i weedy shrub.

Green solution

Del Monte has installed some 60 shallow extraction wells in the roughly four acres of the contaminated zone, and has been using them to pump pesticide-laden shallow groundwater. The water is delivered to a groundbreaking detoxification system developed by the company with federal assistance. The technique is called phytoremediation, or more plainly, fixing things using plants. The U.S. Department of Agriculture contributed $800,000 toward this pilot project through the nonprofit Pacific International Center for High Technology Research.

The water is pumped into two lined planting areas measuring 50 by 150 feet, which are filled with the weedy legume commonly called haole koa. This plant is common in dry areas around the islands, but the phytoremediation project uses a special fast-growing variety, and rather than scraggly shrubs, they are growing into dense, green trees 25 feet high.

"Those plants are beautiful, not like any haole koa you've ever seen," said Paula Helfrich, the project coordinator for the Pacific International Center for High Technology Research.

While the water used to irrigate the haole koa is severely contaminated with pesticides, the leachate pumped from the bottom of the planting areas is pesticide-free, said Keith Matsumoto, president of the research center.

Helfrich said most of the removal of the pesticides is done through bioremediation, meaning soil organisms like bacteria break them down. But phytoremediation via the haole koa plants finishes the job, she said.

When the plants are pruned, they are chipped and composted, then reintroduced to the test cells, but tests on the pruned material indicates it contains no pesticide residue. Soil tests show the pesticides have also been removed from the dirt.

Cheaper than charcoal filter

Matsumoto said the phytoremediation process is cleaning up the soil and water far more cheaply than it can be done through charcoal filtration or any other known system.

The process is effective enough that it may be the final solution for cleaning up the polluted groundwater under Kunia, but that decision won't be made for at least another year.

Decades ago, Del Monte stored agricultural chemicals in drums in Kunia alongside a site where agricultural chemicals for its pineapple fields were mixed. In April 1977, a few feet from both locations, there was a spill of 495 gallons of the pesticide EDB, which also contained some of the pesticide DBCP.

Much of the chemical mix from leaking storage barrels and the spill site soaked into the soil and seeped deeper underground with each rainfall.

The Health Department sampled wells near pineapple fields in 1980 and found high levels of pesticides in the drinking water under Kunia. The potable water well was ordered disconnected from the Kunia Village water system, which was then served by an uncontaminated well in the region.

A study by the federal Agency for Toxic Substances and Disease Registry found that the Health Department caught the tainted well before it could cause health problems for the fewer than 1,000 residents of the plantation town. It concluded that "the people of Kunia were not exposed to significant levels" of the chemicals in drinking water.

Del Monte began a remediation program, initially under the guidance of the state Health Department and now under the EPA.

Cost to be near $20 million

The cost of cleaning up a few hundred gallons of spilled pesticide could near $20 million, not including the money spent so far. Del Monte is paying for the cleanup, and reimbursing the EPA for its work on the site.

Del Monte Fresh Produce general manager Calvin Oda said he was unable to respond to Advertiser questions about costs or other issues without prior approval of his company's president, who was traveling abroad. The EPA's Rosati said that while she is not privy to Del Monte's costs so far, there are estimates for the upcoming cleanup.

"Costs for treatment of the shallow groundwater range from $1.9 million to $2.5 million. Costs for treatment of the deep aquifer range from $3.3 million to $17 million," Rosati said.

While some cleanup work has been under way, the large-scale effort to detoxify the site is at least a year off. A plan for the work is being prepared, and a public hearing on it is tentatively scheduled for later this year. A decision on which alternatives to use could be concluded by next spring, and then the EPA must negotiate a consent decree with Del Monte.

Finally, the company will develop plans for how to accomplish the selected alternative, and get the approval of the EPA before beginning work.

Two-level problem

The spill area covers an area of about 400 feet by 400 feet, Rosati said, and spreads in a plume downward to the basal groundwater 830 feet below the surface.

There are two areas of groundwater under Kunia. One is a shallow "perched" aquifer that runs from as shallow as 25 feet below the surface to as deep as 100 feet down. A second is the basal groundwater, roughly 830 feet down. Between these sources is a hard lava rock area that is not saturated with water.

An investigation of the site found high levels of pesticides in the perched water, and much lower but still troublesome levels in the basal groundwater. The perched water, which in some instances has pesticide levels thousands of times the maximum allowable for human consumption, had not been used for drinking.

In one of the first parts of the cleanup, Del Monte removed 18,000 tons of contaminated soil and spread it on a nearby field. The fumigants are volatile, meaning they evaporate when exposed to air. For a time, Del Monte pumped contaminated water and used it to irrigate noncrop fields, allowing the chemicals to evaporate in contact with the air. The EPA stopped that practice.

Later, the phytoremediation project was developed.

The ultimate remediation process approved by the agency may well be phytoremediation. It could be used to treat the worst of Kunia's contaminated basal groundwater just as it is for the perched water, Rosati said.

But perhaps not all of the polluted water would be treated. As the groundwater moves seaward, it is diluted, and some of it could end up dropping below federal warning standards without treatment, Rosati said.