Water remains safe to drink after low levels of contaminants are detected in one O‘ahu water well

Posted on Apr 1, 2020 in Newsroom

HONOLULU – During routine sampling of drinking water systems across the state, low levels of one organic and one inorganic chemical were detected in water samples collected at the St. Stephen’s Diocesan Center water system on O‘ahu. The St. Stephen’s Diocesan Center water system is a small non-residential system which serves approximately 45 persons near Kailua. 

Atrazine and cadmium were detected in water from the SSDC-1 Well source. Drinking water from this well remains safe, as the levels detected were well below the U.S. Environmental Protection Agency (EPA) and State Maximum Contaminant Level (MCLs) for these contaminants.  

“The levels of the chemicals do not pose a public health threat, and the water from this well is safe to drink,” said Keith Kawaoka, deputy director for environmental health. “The Department of Health will continue to work together with this water system 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.”

The atrazine level confirmed at the SSDC-1 Well was 0.054 parts per billion (ppb). This trace level is less than one-fiftieth of the EPA and state MCL of 3 ppb. EPA defines the MCL as the highest level of a contaminant that is allowed in drinking water. The standards are set to avoid human health risks based on a lifetime of consuming water containing that level of contaminant. Atrazine is an herbicide used on row crops such as sugar cane.

Cadmium, an inorganic contaminant, was confirmed at 1.37 ppb, which is well below the federal and state MCL of 5 ppb. The presence of cadmium could be attributed to the corrosion of galvanized iron piping.

Water from this water system is tested as mandated by federal and state drinking water regulations. To date, the water system continues to be in full compliance with all federal and state standards for drinking water.

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