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DWS finds trace contaminant in South Kona backup wells

Updated: 
December 5, 2017 - 12:05am

KAILUA-KONA — The Hawaii County Department of Water Supply has detected trace amounts of dalapon — a commonly used herbicide — in two South Kona water sources, the department announced in a press release Monday.

DWS discovered the contamination during routine water quality monitoring conducted in November. The U.S. Environmental Protection Agency maximum contaminant level is 200 micrograms per liter. According to the release, the amount of Dalapon registered in South Kona was between 1-2.5 micrograms, far below the EPA standard. It therefore poses no risk to public health, DWS said.

The release quoted the EPA and the state Department of Health indicating that minor health problems in humans are only observed after several years of consuming drinking water contaminated by dalapon.

While the DWS has said the water is safe to drink, it may not be consumed anytime soon. The two contaminated sources are Ke‘ei Well A and Ke‘ei Well B, which serve as backup wells in the South Kona system.

“These wells are not utilized unless the primary wells for this area fail,” Kaiulani Matsumoto, DWS interim information and education specialist, wrote Monday in an email to West Hawaii Today. “Under normal conditions, the primary wells for this area are the Haleki‘i Deep Well and Ke‘ei Well D, which are able to meet the daily water demands of the system.”

She added that Dalapon has never been detected in DWS wells or water sources prior to November.

Margaret Wille, former Hawaii County Council member who represented North and South Kohala, said it’s the first time she’s ever heard of any Big Island water sources being contaminated.

When asked if contaminants had ever been detected in any well or water source prior to November, Matsumoto wrote, “DWS conducts routine water quality testing for approximately 80 regulated contaminants in each of its 23 regulated water systems, all of which continue to be in compliance with federal and state standards for drinking water.”

DWS hasn’t identified the source of the contamination or how it made its way into the South Kona water supply. Matsumoto said there’s nothing about the two backup wells that make them more susceptible to potential contamination than any others.

“Any contaminant that is placed on the ground could travel downward into the ground and eventually enter the underground aquifer,” she explained. “Subsurface geology and rainfall can affect the rate at which a contaminant may move from the surface downwards. Because of this, (DWS) is required to continually conduct water quality testing to identify any changes in our water quality.”

The EPA classifies Dalapon as a general use herbicide commonly used for control of annual and perennial grasses, according to the Cornell University website. South Kona is known for its agricultural production and weed control on farms is one possible source of the contamination.

“Weeds just grow like they’re on steroids here in Hawaii,” said Suzanne Shriner, president of the Kona Coffee Farmers Association. “Pretty much most crops, except our organic farmers, are going to use some sort of herbicide.”

She added there are both regulated and nonregulated herbicides, but most farmers choose the nonregulated options that pose low health concerns, don’t require a special license to purchase and can be procured by anyone.

Wille, who now serves as chairperson of the Hawaii County Democrats Committee and co-chairperson of the Legislative Committee for the Democratic Party of Hawaii, said a top party priority this coming legislative session will be to initiate buffers and create restrictions on pesticides to protect sensitive environmental regions and social areas.

The biggest obstacle to such legislation, she said, is the powerful lobby behind the chemical production industry.

“This legislation is to prevent this kind of thing from happening,” she said.

The state Department of Health also released information Monday that it detected polychlorinated biphenyls, an organic chemical contaminant, in a reservoir tank utilized by the Kauai Department of Water Kekaha-Waimea Drinking Water System that serves approximately 5,800 people.

In a release, the DOH said none of those customers consumed contaminated water based on tests of samples from the water distribution system.

Deep well updates

The Keopu Deep Well in North Kona, which can serve accounts both north and south of the Keopu and Waiaha areas, is on track to return to service by the DWS target date of Dec. 20.

If all goes well, Matsumoto said DWS will reduce the mandatory 25 percent usage restriction to a 10 percent voluntary conservation. If that happens, it will be the first time since January there hasn’t been at least a 25 percent restriction on water use in North Kona.

The department will then turn its sites to the Hualalai Deep Well and Keahuolu Deep Well repairs. Both have failed multiple times in recent months. The equipment at the bottom of the deep well at Waiaha must still be recovered after a cable snapped during a removal effort earlier this year.

There is no timetable in place for any of those three North Kona wells to return to service.

The HOVE Deep Well site in Ka‘u, the only county water source serving Hawaiian Ocean View Estates and the Ranchos Area, remains down.

Matsumoto said the contractor has removed both the pump and motor, determining that an inoperable motor was the cause of the failure. A spare motor is on its way to the site, DWS said in a release Monday.

“The pump has been sent back to the manufacturer for refurbishing and is expected to be back on site by early January 2018,” Matsumoto said.

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