Trace levels of contaminants found in drinking wells on Maui and Big Island

The state Health Department said this morning that trace levels of organic chemicals were detected in water samples collected at two sites during routine sampling in the Hawaiian isles — one at Haiku, Maui and one on Hawaii island.

Drinking water from these wells, however, remains safe, according to the department, as the trace levels detected were below the U.S. Environmental Protection Agency and state Maximum Contaminant Level (MCL) threshholds.

In samples collected at the Haiku Town Water Association’s HT-1 Well on Maui, the department’s safe water drinking branch detected 1,2-Dibromochloropropane (DBCP) and 1,2,3-Trichloropropane (TCP). The small, residential system serves approximately 65 residents in Haiku, Maui.

In samples collected from the Kapulena Well of the Kukuihaele water system, the branch detected atrazine. The system serves approximately 450 residents on Hawaii island.

“These trace levels of the chemicals do not pose a public health threat, and the waters from these wells are safe to drink,” said Keith Kawaoka, deputy director for environmental health, in a news release. “The Department of Health will continue to work together with these water systems to ensure tests for these chemicals continue. Such testing is part of scheduled monitoring regularly conducted to ensure that everyone’s water is safe to drink and public health is not compromised.”

DBCP was a soil fumigant and nematicide used during pineapple cultivation. TCP is a man-made chemical that has been found as an impurity resulting from the production of soil fumigants. Atrazine is a widely used herbicide typically applied on row crops such as sugar cane.

The DBCP level confirmed at the HT-1 Well was 0.02 parts per billion, according to the health department — which is one‑tenth of the EPA maximum contaminant level of 0.200 ppb. It was also below the state of Hawaii’s more stringent MCL of 0.04 ppb.

The 1,2,3-Trichloropropane level confirmed at the well as 0.11 ppb, which is below the state MCL of 0.6 ppb. There is no federal standard for TCP.

Health officials said the presence of DBCP and TCP in the sample is attributed to the use of soil fumugants during former cultivation of pineapple on the site. The use of the soil fumigants ended in the mid-1980s, and the detected levels are not expected to increase in the future.

At the Kapulena Well on Hawaii island, officials confirmed 0.054 ppb of atrazine, which it said is well below the federal and state standard of 3 ppb. In 2011, atrazine had been previously reported in the Kukuihaele water system at a level of 0.27 ppb.

The state Health Department said both water systems remain in full compliance with all federal and state standards for drinking water.