Uranium

At a glance: Uranium is a naturally occurring metal found in some bedrock, and wells drilled into that rock can pick it up. It has no taste, color or smell. Over time, drinking water above EPA’s 30 µg/L limit can harm the kidneys, and uranium’s radioactivity adds cancer risk. Test a well at least once. If yours is high, a reverse osmosis unit for drinking and cooking water is usually enough, because uranium matters when you swallow it, not when you shower.

Public water systems must meet the 30 µg/L limit. This is mainly a private well issue.

What it is and where it comes from

Uranium is an element that has been in rocks since the earth formed. Connecticut’s Department of Public Health explains that when a well is drilled into bedrock containing uranium, the uranium can get into the water, that deeper bedrock wells are the most susceptible, and that levels vary greatly from place to place. EPA’s health table lists erosion of natural deposits as the source.

Uranium often travels with other natural radionuclides. EPA notes that uranium decays over time and forms radium, and Connecticut’s health department says radium and radon may be found in association with uranium.

It is less common than arsenic or nitrate but not rare. A USGS study of more than 2,000 domestic wells found uranium above a health benchmark in about 1 to 2 percent of wells. Your health department will know whether it shows up in your area.

Health and household effects

Uranium is a health issue only. It causes no stains, taste or smell.

The main concern is chemical, not radioactive. Connecticut’s health department says the chemical properties of uranium in drinking water are of greater concern than its radioactivity, and that studies show drinking water with elevated uranium can affect the kidneys over time. EPA’s health table lists kidney toxicity and increased risk of cancer. The Water Quality Association’s fact sheet adds that uranium can decay into other radioactive substances, such as radium, that can cause cancer with extensive exposure over a long time.

Most swallowed uranium leaves the body, according to Connecticut’s health department, and only a small amount is absorbed. Skin contact and breathing are not significant routes, which is why bathing and showering are not a concern unless levels are extremely high.

Limits and what they mean

Standard	Level	What it means
EPA MCL	30 µg/L	Enforceable for public systems since December 2003
EPA health goal (MCLG)	Zero	No level is considered risk-free
WHO guideline	30 µg/L	Provisional international guideline
Connecticut advice	Above 900 µg/L	Contact health officials about a safe water supply

The Water Quality Association notes EPA set 30 µg/L based on kidney toxicity, and that it is equivalent to about 27 picocuries per liter of radioactivity, so it also limits cancer risk. Private wells are not covered by the rule.

How to test

Connecticut’s health department recommends asking a certified lab for a uranium test by ICP-MS, which it says is quicker and less expensive than alternatives. Vermont’s state lab includes uranium in its $100 inorganic chemicals kit and offers a $45 gross alpha radiation test that screens for radioactivity from uranium and radium.

When to test, per Connecticut: when you buy a house with a well or drill a new one, then every 5 years because levels can fluctuate, and every year if you have treatment, to confirm it works. EPA suggests testing wells for radionuclides every three years. If uranium is high, ask about radium too, unless your treatment will remove both. Our well testing guide covers labs and sampling.

Treatment options

Method	How well it works	Certification to look for	Cost range
Reverse osmosis, point of use	High	No NSF/ANSI uranium protocol; ask for test data	$300 to $1,500
Anion exchange resin (specialty media), whole house	High	None	$1,500 to $2,500
Activated alumina, point of use	High	None	$300 to $700, plus $300 to $500 every 6 to 12 months
Distillation, point of use	High	NSF/ANSI 62	$300 to $1,200
Standard water softener	Not effective	Not applicable	Not a uranium fix

Cost ranges are Minnesota Department of Health estimates based on 2017 and 2018 quotes, low end self-installed and high end professionally installed.

No certification exists. The Water Quality Association says there are no protocols in any NSF/ANSI standard for uranium reduction, so no product can be certified for it. Choose a system based on competent performance data for uranium specifically, and test the treated water after installation.

Point of use is usually enough. Because uranium enters the body mainly through drinking, Connecticut’s health department says it is not usually necessary to treat all the water in the home, only the water you drink. Compare approaches in whole-house filter vs reverse osmosis, and use the filter finder to compare RO systems.

Plan for disposal. EPA warns that point-of-use filters and media used for radionuclides often collect too much radiation to go out with ordinary trash. Ask the installer or your state radiation program how to dispose of spent cartridges and resin.

When to call a professional

Call your state or local health department if uranium is above 30 µg/L. Connecticut advises contacting health officials about options for a safe water supply if uranium exceeds 900 µg/L, 30 times the EPA standard.

Use a water treatment professional for whole-house anion exchange, and ask about radium and radon at the same time, since they can occur with uranium and are best considered in the same treatment plan. MDH notes that anion exchange can make water more corrosive, so test lead and copper after installation.