Maui County water department staff take more than 16,000 samples annually to test where the water meets Safe Drinking Water Act standards, Administrative Assistant Jacky Takakura told The Maui News.

The reports sent to consumers last month indicate some contamination by agricultural chemicals in two systems, and contamination by a number of naturally occurring substances – barium, chromium and nitrates. But testing of water at sources and in the distribution systems found none of the chemicals exceeded or even approached the allowable maximum contaminant levels established by the Environmental Protection Agency or the state Department of Health.

Deputy Water Director Eric Yamashige said water leaving county treatment plants is in compliance with all standards for harmful substances or bacteria. What happens when water arrives in a consumer's plumbing is a different issue.

In cases where contaminants are found in water delivered to consumers, the contamination has been the result of problems at the consumer's faucets. That was clearly the case with findings of low levels of lead and copper detected in every system, with high readings occurring on three systems.

The samples for lead and copper are taken from consumer's faucets.

Lead contamination was over the EPA action level of 15 parts per billion in one sample on the Lower Kula system, four samples on the Upper Kula system, one on the Makawao system and two samples on the Lahaina system.

In all cases, the department said the lead appeared to have leached from fixtures in the home plumbing. Yamashige said there is no lead detected in the water coming from the county distribution system.

The samplings also recorded contamination by E. coli bacteria in the Wailuku, Makawao and Lahaina systems.

But water microbiologist Cari Sumabat said the sampling protocol requires the department follow up on any findings of E. coli in water in the distribution system by testing samples from an entire line. In all of the cases recorded in 2006, Sumabat said the testing established that the bacterial contamination occurred at the site of the original positive sample – generally taken from a fire hydrant or a faucet in a public facility.

"Usually it's geckos," she said. "Geckos have droppings, they get into everything. That's not good."

In two systems, the Water Quality Monitoring reports also showed two agricultural chemicals were detected in water sources, the Haiku well serving the Makawao system and the Napili A well serving the Lahaina system.

Both wells have low levels of DBCP and TCP, fumigants that were used on fields in the past, but are no longer used. Yamashige said chemical residues remain in the soil where the fumigants were used and are slowly percolating through the soil into the groundwater.

At Haiku, the levels were 17 parts per trillion of DBCP and 120 ppt of TCP; at Napili A, the levels were 170 ppt DBCP and 375 ppt TCP. While the levels were well below the maximum contaminant levels of 40 for DBCP and 800 for TCP, the county is treating the Napili well with granulated activated charcoal filters that eliminate all detectable traces of the chemicals, Yamashige said.

The Haiku well is not subject to similar treatment, but it is a low demand source that is diluted with water from other sources to reduce the contamination to undetectable levels.

With the high levels of treatment provided on all systems, Yamashige said water provided by the county more than meets the standards of the Safe Drinking Water Act. But there is a continuing problem of consumer systems that allow contamination of the water.

Corroded galvanized iron pipes are a particular concern, particularly on lines that are not used frequently. Complaints about discolored water at the Kula Elementary School are one example.

"As far as I know, it's not in our system," Yamashige said. "It's in older lines where the water may be sitting for long periods that the problem occurs.

"That's why we have a flushing program on sections where there is low usage. But that's kind of a hardship now Upcountry."

All of the Upcountry water systems are under drought restrictions requiring consumers to cut use by 10 percent under their average use last year.