State sampling has detected trace amounts of volatile organic chemicals in two Maui water systems.

The routine sampling by the state Department of Health revealed ethylbenzene and toluene, both solvents, at the Kamole Weir clear well of the Maui Department of Water Supply's Makawao water system, the health department said in a press release.

At another location trace amounts of the herbicide atrazine has been detected in the Consolidated Baseyards water system in Wailuku.

The Makawao system serves a population of about 27,000 people and the baseyard serves about 25 people.

"These findings do not represent a health threat, but the law requires us and we want to keep the public informed," said Laurence Lau, deputy director for environmental health. "The Department of Health will continue to monitor these systems to ensure that public health is not compromised."

Ethylbenzene was detected at 3 parts per billion (ppb) where as the accepted maximum contaminant level (MCL) is 700 ppb.

Toluene was detected at 4.6 ppb and the MCL for toluene is 1,000 ppb.

Other chemicals found were m-Xylene and p-Xylene (combined) at 11.0 ppb, and o-Xylene was detected at 2.8 ppb. The federal and state MCL for total Xylenes is 10,000 ppb.

These volatile organic chemicals are believed to originate in an epoxy coating that was used in the new clear well, the press release said.

Water tested prior to the clear well did not contain these contaminants.

The concentrations found are well below the MCL for all the contaminants. Also, the concentration of ethylbenzene, toluene, and m-Xylene/p-Xylene decreased by about 50 percent between January and February 2009.