Nampa treatment center’s water shows high uranium levels. What’s the danger?
Uranium levels above EPA guidelines have been confirmed in drinking water in wells serving some buildings on the Southwest Idaho Treatment Center (SWITC) campus, a facility managed by the Idaho Department of Health and Welfare.
In a press release, Health and Welfare said it was providing bottled water to SWITC staff and residents while investigating the problem further.
“I am taking this very seriously out of an abundance of caution,” said DHW Director Juliet Charron. “Based on what we know about uranium exposure and the results of previous testing of SWITC’s well water, it is likely the risk is very low.”
Uranium is a naturally occurring mineral that can leach into well water from the surrounding bedrock. City water is routinely tested in accordance with the Idaho Department of Environmental Quality guidelines, but testing of private wells is managed individually. DHW recommends testing well water for uranium every three to five years.
In the release last week, DHW stated that the last uranium tests for the SWITC wells were conducted in 2021, and also said that the water testing policies and procedures were under review.
Nick Schofield, DEQ spokesperson, told the Idaho Statesman that SWITC “was a regulated public water system until 2022 and had tested the drinking water at the campus for uranium since 1995.” Schofield confirmed that recent samples from exceeded the EPA maximum contaminant levels for uranium, but compliance is determined based on annual exposure calculated from “a running average of four quarterly samples.”
“The wells at SWITC never violated the uranium MCL via their running annual average. Uranium levels showed a consistent fluctuation, peaking in the summer and fall months (June–October) and significantly dropping the rest of the year,” said Schofield.
“DEQ is working with the Idaho Department of Health and Welfare to test water at the SWITC facility. As required by the Safe Drinking Water Act, DEQ will require public notice if the SWITC facility violates the MCL for uranium once an annual average can be calculated.”
Health risks associated with high levels of uranium in drinking water
The uranium found in drinking water is not as radioactive as the uranium in nuclear fuel.
Naturally occurring uranium is a mixture of multiple forms, or isotopes. More than 99% of naturally occurring uranium is found in the least radioactive form: U-238. The uranium used in nuclear fuel undergoes an enrichment process to increase the levels of the more radioactive U-235 form.
The DHW lists kidney damage as the main health concern from uranium in drinking water.
Most uranium ingested from drinking water passes right through the gastrointestinal tract. According to the CDC, only 0.1 to 6% of the uranium is absorbed into the body through the bloodstream. The kidneys filter uranium out of the blood and clear it from the body in urine, but some of that uranium hangs onto kidney cells and causes damage. The kidneys are resilient organs and damage from uranium is reversible as long as exposure is not prolonged.
If your water comes from a private well, the DHW website emphasizes that you are responsible for getting the water tested to make sure it is safe to drink. DHW suggests keeping a log to help keep track of maintenance and tests.
In the event your well water tests come back with high levels of uranium or another contaminant, stop drinking the water immediately and contact Health and Welfare to discuss next steps. DHW notes that uranium can’t be removed from water by boiling it, and you shouldn’t use contaminated water in your garden either, as uranium can accumulate in root vegetables and leafy greens, among other things.
See the DHW website for more resources on testing your well water.