Uranium in Drinking Water

Uranium is a naturally occurring radioactive element found in varying concentrations in rock and soil throughout the United States. It dissolves into groundwater as water passes through uranium-bearing geological formations, making well water and groundwater-sourced systems the primary concern. While many people associate uranium with nuclear power, the health risk from uranium in drinking water is actually twofold: it is both a radioactive element (posing cancer risk from radiation) and a toxic heavy metal (causing chemical damage to the kidneys).

The kidney toxicity of uranium is actually the more immediate health concern at levels near the EPA's maximum contaminant level of 30 parts per billion. Uranium accumulates in the kidneys and can cause damage to the renal tubules, the tiny structures that filter waste from your blood. Long-term exposure increases the risk of kidney disease and impaired kidney function. The cancer risk comes from uranium's radioactive decay: as it breaks down over millennia, it emits alpha particles that can damage DNA and increase the risk of bone cancer and other malignancies.

Uranium contamination is most prevalent in the western United States, particularly in areas with granitic geology -- parts of Colorado, New Mexico, Arizona, Utah, Nevada, California, and the Dakotas. However, elevated levels have been found in every region of the country. Small community water systems and private wells in these areas may have uranium levels exceeding the EPA standard without the owners knowing, since private wells are unregulated and many small systems lack the testing resources of larger utilities.