Uranium in well water
If you're here, a lab report probably just handed you a number next to an element you associate with something other than drinking water, and you're trying to work out how bad it is and what to do.
Here's the direct version.
The standard
The federal maximum contaminant level for uranium in drinking water is 30 micrograms per liter (µg/L), the same thing as 0.030 mg/L. It was set under the EPA Radionuclides Rule of 2000.
That standard applies to public water systems. Private wells aren't covered by it, Idaho doesn't require private well testing, and no agency will ever check yours. The number still matters, because it's the benchmark every treatment decision and every future real-estate transaction is going to reference.
Before you react to your result, check the units on the report. Uranium is usually reported in µg/L; a report printed in mg/L moves the decimal three places, and misreading that line changes everything about the conversation. Some labs also report uranium as radiological activity, picocuries per liter, which is a different scale entirely; the drinking-water standard is mass-based. If the units on your report don't match the standard's, that's the first thing to sort out, and it's a two-minute phone conversation.
We're not going to tell you what uranium does to people. Same policy as every page on this site: that's the lane of the EPA, the Agency for Toxic Substances and Disease Registry, and your own physician, and a water treatment company that leads with health effects is doing something other than water treatment. What we can tell you is what the standard is, where uranium comes from, and what actually removes it.
Why it's in the water here
The inland Northwest sits on a lot of granite. Uranium occurs naturally in granitic rock, and groundwater moving through granite-derived formations picks it up, which is why it turns up in private wells across North Idaho and eastern Washington with no industry, no spill, and no event behind it. It was in the rock before the well was drilled.
Depth, fracturing, and which formation your well draws from decide the number, which is why a neighbor's clean result tells you very little about yours. Regional health agencies on both sides of the state line recommend testing private wells for uranium for exactly this reason.
It has no taste, no smell, and no color at any concentration a well produces. No stain, no odor, no signal your plumbing will ever give you. A certified lab test is the only way anyone finds it, which is usually exactly how the number you're holding got found.
What removes uranium
Two approaches carry the residential category:
Anion exchange, in most well water, dissolved uranium travels as carbonate complexes that carry a negative charge, and a properly specified anion-exchange system captures them. This is the whole-house answer. It's chemistry-dependent, pH and the rest of your report set the specification, which is why the system gets designed from the lab work, not from a catalog page.
Reverse osmosis at the tap, a drinking-water stage at the kitchen sink, covering the water you drink and cook with. For many households at moderate numbers, treating the water you actually ingest is the proportionate answer, and it costs a fraction of a whole-house build.
Which one your house calls for is a function of your number and your report. We make one recommendation, and when the less expensive one is the right one, that's the recommendation.
What is not a uranium treatment
A water softener is not a uranium treatment. This needs saying carefully, because it's half-true in a way that gets misused. A standard cation softener can incidentally pick up some uranium under some water chemistries. But it isn't designed for it, its performance can't be predicted or verified, nothing about its regeneration cycle was engineered with uranium in mind, and a resin bed quietly accumulating a radionuclide raises handling questions that nobody selling it as a fix has answered. If a softener is being offered to you as the answer to a uranium number, the offer is wrong. It's a hardness appliance.
A carbon filter, no. Taste-and-odor tool.
Boiling, worse than doing nothing. Boiling removes water and leaves the uranium behind, so the concentration goes up.
A pitcher filter, not unless it carries a specific certification for uranium, which almost none do. The certification is the thing to check, not the front of the box.
While we're here: radon is a different conversation
Same geology, different element, different rules. Radon comes up in granite country, and it is not something we treat or sell equipment for, we refer it out rather than improvising in someone else's specialty, and the referral usually starts with testing the air in the house, which is where the radon question generally gets answered. If a water-system quote you're comparing bundles in a radon fix, ask exactly what it is and who stands behind it.
Whole house or just the tap?
The same honest answer as arsenic, because the logic is the same.
Point-of-use, the kitchen RO, covers drinking and cooking at a fraction of the cost, and for a dissolved metal you ingest, that's the route that matters. For many households at moderate numbers it's a reasonable answer, and when it is, it's the one we give.
Whole-house anion exchange earns its price where the number is higher, or where the rest of the report needs whole-house treatment anyway, and uranium rarely arrives in an otherwise clean report, because the geology that carries it tends to carry company. Your report decides. That's the prescription model, and it's why we don't quote a system until the lab work exists.
What we'd do
A free consult first, twenty minutes on the phone, your report in front of you. We'll read the number with you against the standard, check the units line, and tell you what your result would actually take, including when the honest answer is the tap-level system.
If you don't have a report yet, or yours didn't include uranium, plenty of basic panels don't, the Water Assessment is a paid certified panel, credited in full toward a system if you move forward, and yours to keep if you don't. It covers uranium alongside the rest of what a well in this region can carry.
And uranium is precisely the case the 30-Day Verification exists for: you cannot see, taste, or smell whether the equipment worked. Thirty days after installation, a certified lab tells you, same collection method, same lab, your number next to your target, on their letterhead.