CALDWELL — Groundwater throughout southwestern Idaho are contaminated with trace amounts of arsenic, nitrates and fluoride, according to Southwest District Health officials.

There’s no need for alarm, Environmental Health Services director David Loper said — these contaminants occur naturally and usually don’t pose a significant health risk. Nonetheless, he continued, it’s important for residents to be informed about groundwater issues.

“It’s just an opportunity to make sure private well owners aware that they need to sample their wells,” Loper said. “They’re not regulated, and there are naturally occurring and human-caused concerns in groundwater that they need to be aware of.”

It’s important, he said, because while municipal water supplies are regulated and carefully monitored, privately-owned wells are not. It’s up to each well owner to make sure their water is safe. The health district will provide resources and technical support, but beyond that, the responsibility falls upon each well’s owner.

Health district officials recommend scheduling a test each year with a state-certified lab to check for contaminants. In addition, well water should be tested every time there’s a change in taste, odor or appearance, and whenever the well system is serviced.

“You’d be surprised how many people don’t understand, when they turn on the faucet, where that’s coming from,” Loper said. “People are surprised that nobody samples those wells.”

For more information, or for help locating a testing lab, visit Southwest District Health’s web site at swdh.org