The News & Observer reports Wake County officials think one in five private wells in the area could have unhealthy levels of naturally-occurring radon and uranium.
A groundwater protection official said one local household had 20 times the safe amount But the official says there's no need to panic as long as residents get their water tested.
The county is sending warnings to 19,000 property owners. Those who don't use private wells are not affected.
It was not immediately clear from news reports what kind of illnesses the two people had. Their doctors asked that their water be tested.
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