Uranium Water Test

Who should test for uranium

ATSDR describes uranium as a mildly radioactive element that is naturally present in nearly all rocks and soils, and EPA lists erosion of natural deposits as its source in drinking water. It has no smell or taste, the Connecticut Department of Public Health (CT DPH) says, so testing your well water is the only way to find out whether your well has high uranium.

If you have a private well, the test is up to you. CT DPH says private well owners are responsible for the quality of their drinking water, and that homeowners with private wells are generally not required to test it. Uranium is not part of the yearly well check CDC recommends (total coliform bacteria, nitrates, total dissolved solids and pH), so you have to ask for it by name.

Where uranium is more likely. The U.S. Geological Survey sampled domestic wells across the country and found uranium above EPA's legal limit in 1.7 percent^[4] of them. The highest concentrations turned up most often in basin-fill aquifers in the West and in crystalline-rock aquifers in the Rocky Mountains and the Northeast. USGS says uranium is particularly enriched in certain rocks, such as granites. CT DPH explains how it reaches a well: when a well is drilled into bedrock that contains uranium, the uranium can get into the well water, and the amount varies greatly from place to place. ATSDR adds that higher levels may be found where rocks and soil naturally hold more uranium, and that people living near uranium mining, processing and manufacturing facilities may be exposed to more.

When to test. CT DPH advises testing your private well at least once for uranium, and names two moments:

• When you buy a house with a well.
• When a new well is drilled. Connecticut now requires a uranium test for newly drilled wells.

ATSDR also suggests having your water tested if you suspect your drinking water might have elevated uranium.

Uranium and arsenic. USGS says that, like arsenic, uranium's presence in groundwater is affected by conditions in the aquifer such as dissolved oxygen. If you are testing a bedrock well for one, the arsenic water test covers the other. You can also build a test plan for your home, or read our well water testing guide for the yearly well check.

Certified lab or home kit

Use a state-certified lab and ask for the right test. CT DPH recommends that you contact a laboratory and ask for a uranium test using ICP-MS, which it says is quicker and less expensive than the alternatives. The Lab methods list at the end of this section includes ICP-MS (EPA Method 200.8) along with the other methods EPA approves for uranium. CDC tells well owners that local or state health departments should have a list of state-certified laboratories. In Connecticut, CT DPH tells residents to search its list of State-certified labs for those testing radiochemicals in drinking water. Our directory of certified water testing labs lists state-certified labs in the states we cover, and our guide to well water testing cost shows verified lab prices.

A measured number is the point. The question a uranium test answers is how your well compares with EPA's legal limit, which is a concentration. Only a lab analysis gives you a concentration you can compare with that limit and with your own later results.

Home kits. A uranium result you could compare with EPA's limit comes from a laboratory method like the ones in the Lab methods list below. If a product doesn't report a measured concentration from a certified lab, treat it as a screening step at most, and confirm anything that matters with a lab.

Questions to ask the lab before you order:

• Is the lab certified in your state for uranium in drinking water?
• Which method does it use, and does the report give a concentration you can compare with EPA's limit?
• Does it supply the bottle and any preservative, and how soon must the sample reach it?
• Does it offer a radium test too? CT DPH says radium is sometimes found with uranium and suggests considering a radium test if your uranium result is low.

Lab methods

• EPA 200.8 (ICP-mass spectrometry)
• EPA 908.0 (radiochemical)
• ASTM D5174 (laser phosphorimetry)

Source: ecfr.gov (source for lab methods) (opens in a new tab)

How to collect a uranium sample

Uranium reaches a well from the rock around it, so a uranium sample is about the well water itself. Always follow the instructions in your lab's kit, since they are written for that lab's bottle and method. The quick guide near the top of this page lists the sample bottle and the preservative EPA's sampling guidance names for uranium.

1. Check the timing. Read your lab's instructions for how soon the sample must reach it and which days it receives samples, and collect close to a shipping or drop-off time.
2. Decide what you want to know. If you have any treatment device, ask the lab whether to sample before it, after it, or both. Sampling before treatment tells you about the well; sampling after it tells you what you are drinking.
3. Pick the right tap. Use a cold-water tap you drink or cook from, usually the kitchen sink.
4. Remove any attachments. Take off a hose or aerator attachment, unless your kit says otherwise.
5. Run the water the way your lab says. Your kit tells you whether to let the water run before you fill the bottle, and for how long.
6. Fill the bottle without rinsing it. The quick guide shows that uranium samples are preserved with acid. If the bottle came with anything inside, don't rinse it out, and don't let it overflow. Cap it tightly.
7. Label, pack and send. Write the date, time and tap, and whether the sample was taken before or after treatment, then send it within the window your lab gives you.

Common mistakes to avoid

• Sampling only after a filter when you wanted to know about the well itself.
• Rinsing out a bottle that came with a preservative inside.
• Sampling from an outdoor spigot or a hose when you wanted to know about your drinking water.
• Ordering a general metals panel without checking that it reports uranium.

What your uranium level means

Your lab report gives a number. Here is how to read it against the federal benchmarks.

The EPA maximum contaminant level (MCL) for uranium is 30 µg/L^[1]. It is the enforceable limit for public water systems. Private wells don't have to meet it, but it is the federal benchmark you can compare a well result with. EPA lists an increased risk of cancer and kidney toxicity as potential effects of long-term exposure above it.

EPA's health goal (MCLG) for uranium is 0 µg/L^[1]. EPA defines an MCLG as the level below which there is no known or expected risk to health. It is a non-enforceable goal, not a limit.

Check the units. The MCL above is a mass of uranium per liter of water. If your report gives uranium in a different unit, ask the lab to give it to you in the same unit as the MCL before you compare.

What the risk is about. CT DPH says the chemical properties of uranium in drinking water are of greater concern than its radioactivity, that most ingested uranium leaves the body, and that drinking water with elevated uranium can affect the kidneys over time. ATSDR says the health effects of natural uranium are due to chemical effects and not to radiation. A water test can't diagnose anything. If you have health concerns, talk to a health professional and bring your lab report. Our guide to uranium in water covers the health effects, where uranium in well water comes from and what to do after a confirmed result.

Putting your result in context

• No uranium detected. No treatment needed based on this result. Keep the report as a baseline.
• Uranium detected, below the MCL. No treatment needed based on the federal limit. CT DPH says uranium levels can fluctuate, and suggests testing again every 5 years^[2] if your water has a detectable level.
• At or above the MCL. Retest with a certified lab to confirm before you decide anything. ATSDR suggests considering bottled water if elevated levels are found. CT DPH says reverse osmosis systems are the most common and very effective treatment for uranium, and that because uranium enters the body mainly by drinking it, treating the water you drink is usually enough. CT DPH adds that a refrigerator water or ice dispenser should also be considered as a place for point-of-use treatment. It advises testing treated water every year.

CT DPH says bathing and showering with water that contains uranium is usually not a health concern. Any treatment choice should start from a confirmed certified-lab result, and a retest of the treated water shows whether it worked.